JP6297518B2 - Tractor - Google Patents

Description

The present invention relates to a tractor for agricultural.

  In recent years, due to the application of high-level exhaust gas regulations related to diesel engines, exhaust gas purification devices that purify air pollutants in exhaust gases on agricultural machinery, construction machines, ships, etc. equipped with diesel engines There is a growing demand for mounting post-processing devices. Therefore, some conventional work vehicles such as tractors have an exhaust gas purification device disposed in the engine room under the hood together with the diesel engine when the exhaust gas purification device is mounted (see Patent Document 1).

JP 2013-116692 A

  By the way, when the diesel engine having the above-described exhaust gas countermeasure device is applied to a work vehicle such as a tractor, not only the diesel engine and the exhaust gas countermeasure device but also a radiator or Various parts such as batteries and electronic parts related to exhaust gas countermeasure devices must be packed.

  However, in the installation space of the work vehicle, not only the diesel engine itself but also the exhaust gas purification device becomes considerably hot due to the heat generated by the driving diesel engine. Therefore, it is necessary to adjust the temperature in the engine room so as not to be adversely affected by heat generation from the diesel engine or the exhaust gas countermeasure device, and it is necessary to examine an appropriate arrangement structure and cooling structure. Moreover, if the heating to the driver's seat arranged behind the engine room is not reduced, the comfortability of the operator is deteriorated.

  Therefore, the present invention seeks to provide a work vehicle that has been improved by examining these current conditions.

The tractor according to the present invention includes an engine mounted on a front portion of a traveling machine body, a cooling fan for the engine, and a bonnet that covers the engine. The cooling fan is disposed on a front side of the engine, and the cooling fan In the tractor configured to take cooling air into the bonnet from the front grill formed on the front surface of the bonnet by driving the upper and lower opening holes on the left and right sides of the bonnet. provided, said pair of air volume adjustment plate covering a portion of the opening hole is provided inside the hood, each pair of the air volume adjusting plate is installed at the rear edge side of each of the opening holes of the left and right, of one The air volume adjusting plate covers the entire rear edge of the corresponding upper opening hole and the lower opening hole, while the other air volume adjusting plate corresponds to Is intended to cover a portion of the lower opening hole of said upper opening hole and the lower opening hole that.

In the tractor , the front edge of one of the air volume adjusting plates is positioned behind the front edge of the other air volume adjusting plate, and a plurality of opening holes are provided in the other air volume adjusting plate. Good.

In the tractor , the cooling fan may be rotated in a direction from one air volume adjusting plate to the other air volume adjusting plate.

The working vehicle of the reference example includes an engine mounted on a front portion of a traveling machine body, a cooling fan for engine air cooling, a fan shroud surrounding the cooling fan, and a hood that covers the engine, the cooling fan, and the fan shroud. In the working vehicle, the cooling fan is disposed on the front side of the engine, and the cooling air taken from the front of the bonnet by driving the cooling fan is guided to the engine behind the fan shroud. A side guide plate that is more upright is disposed on one side of the fan shroud, and the space between the fan shroud and the engine is covered with the side guide plate, thereby being supplied from the fan shroud. Cooling air is prevented from being exhausted to the outside of the hood immediately after the fan shroud. Or as capable of inducing efficient cooling air loud behind the engine.

  In the work vehicle, a lower guide plate that extends outward from the upper end of one side of the traveling machine body is disposed at a position from the rear side of the fan shroud to the front side of the one side of the engine, and the upper surface of the lower guide plate The side guide plate is erected and the lower guide plate is extended from the upper side of the traveling machine body to cover the space between the traveling machine body and the bonnet. Exhaust to the lower side of the traveling machine body immediately after the shroud can be suppressed, and cooling air can be efficiently guided to the engine behind the fan shroud.

  In the above work vehicle, a starter is installed below the exhaust manifold arranged on one side of the engine, the lower guide plate is arranged in front of the starter, and the lower guide plate extends to the front of the starter. As a result, the cooling air can be guided to the starter, which is an electrical device, together with the side guide plate, thereby reducing the influence on the starter due to heat dissipation from the exhaust manifold that becomes hot, and the failure of the starter, which is an electrical device. It is good also as what can prevent.

  In the work vehicle, an aftertreatment device for purifying exhaust gas from the exhaust manifold is provided above the engine, and a shielding plate is disposed on one side of the engine so that a part from the lower side of the aftertreatment device is provided. A heat shield member that covers the upper part of the starter with the shield plate and projects from the cylinder block of the engine toward the engine side is connected to the lower edge of the shield plate, By covering the engine side with the heat shield member, the heat shield against the engine can be improved, and at the same time, heat retention can be prevented on the engine side. At this time, it is possible to optimize the thermal efficiency in the engine room inside the hood, thereby preventing abnormal operation of the engine and improving the driving efficiency. In addition, by providing a heat shield member above the starter that is an electrical device, it is possible to reduce the influence on the starter due to heat radiation from the exhaust manifold that becomes high temperature, and to prevent a failure of the starter that is an electrical device.

  In the work vehicle, if the cooling fan rotates in a direction from the other side of the engine toward one side, a side guide plate can be arranged in accordance with the exhaust direction of the cooling air from the fan shroud. It is possible to prevent a decrease in the amount of cooling air that is guided from the fan shroud to the engine, and to improve the cooling efficiency in the engine room.

  In the work vehicle, an inner shielding plate projects from a position corresponding to the vicinity of the left and right sides of the fan shroud on the inner wall of the bonnet, and the inner side provided on the bonnet when the bonnet is closed. A shielding plate may be brought into contact with the left and right side portions of the fan shroud.

  In the work vehicle, the fan shroud includes an upper shielding portion that extends in the left-right direction on the upper surface and a pair of left and right side shielding portions that extend in the vertical direction on the left and right side surfaces, and closes the bonnet. At this time, the upper shielding portion may be brought into contact with the sealing member on the back surface of the bonnet ceiling portion, and the side shielding portion may be brought into contact with the inner shielding plate of the bonnet.

  In the work vehicle, a heat insulating material is attached to an inner wall of the bonnet and corresponding to both sides of the engine to prevent the bonnet from being heated due to exhaust heat of the engine, and an engine room It is good also as what can heat the inside from outside air and can operate the above-mentioned post-processing apparatus in a high temperature environment.

  The work vehicle includes an engine cover formed of a perforated plate on the lower left and right rear sides of the bonnet, and an upper end position of the engine cover is positioned below the post-processing device. While releasing the air heated by the processing apparatus to the outside, the heat retention effect of the post-processing apparatus by the bonnet may be enhanced to enable the regeneration operation at a high temperature.

  According to the present invention, by providing an air volume adjusting plate that covers a part of the opening holes in the left and right sides of the bonnet, the flow rate of the cooling air sucked from the left and right opening holes is adjusted, and the rectified cooling air is cooled. Can be guided to fans. Therefore, the flow of the cooling air that has passed through the cooling fan can be stabilized on the left and right, and the deviation in the flow of the cooling air based on the rotation direction of the cooling fan can be suppressed. Thereby, cooling air can be efficiently supplied to the engine arranged at the rear, the thermal efficiency in the engine room inside the hood can be optimized, and abnormal operation of the engine can be prevented and at the same time the driving efficiency can be improved.

  According to the present invention, by providing the air volume adjusting plate on the rear edge side of the opening hole, it is possible to prevent the cooling air from staying on the side of the fan shroud covering the cooling fan, and the cooling air is efficiently supplied to the suction portion of the fan shroud. Can be guided. Further, by providing one air volume adjusting plate that increases the amount of suction in front of the fan shroud so as to extend along the entire rear edge of the opening hole, the cooling air can be easily taken into the fan shroud. Furthermore, the other air volume adjustment plate is provided so as to cover part of the opening hole, and by forming resistance to the cooling air flow, the air flow rate taken in from the left and right opening holes is adjusted, and the cooling air suction direction by the fan shroud The flow of cooling air can be rectified according to

  According to the present invention, the air flow adjustment plate has a different length from that of the other air flow adjustment plate, and the air taken in from the left and right opening holes is provided by providing a plurality of opening holes in the other air flow adjustment plate. By adjusting the flow rate, the flow of the cooling air can be rectified according to the cooling air suction direction by the fan shroud.

It is a left view of the work vehicle of this invention. It is a right view of the work vehicle. It is a top view of the work vehicle. It is a bottom view of the work vehicle. It is a top view of the traveling body in the work vehicle. It is a front perspective view of the work vehicle. It is a back perspective view of the work vehicle. It is the back perspective view which looked at the run body from the left side. It is the rear perspective view which looked at the traveling body from the right side. It is the front perspective view which looked at the traveling body from the right side. It is a back perspective view of a diesel engine carried in a work vehicle of the present invention. It is a front perspective view of the diesel engine. It is sectional drawing seen from the front which shows the structure in the engine room in the work vehicle. It is sectional drawing seen from the back which shows the structure in the engine room in the work vehicle. It is a partially expanded view which shows the relationship between the traveling body of the work vehicle, and a flywheel housing. It is a front perspective view which shows the structure of the front part inside the bonnet of the work vehicle. It is a left perspective view which shows the structure inside the bonnet of the work vehicle. It is a right view which shows the structure of the front part inside the bonnet of the work vehicle. It is a left view which shows the structure of the front part inside the bonnet of the work vehicle. It is a plane enlarged view which shows the structure inside the bonnet of the work vehicle. It is a left side enlarged view showing the composition in the engine room of the work vehicle. It is a left expansion perspective view showing composition in an engine room of the work vehicle. It is a front perspective view which shows the flame | frame structure in the engine room of the work vehicle. It is an expansion perspective view of the frame composition in the engine room. It is a perspective view which shows the structure of the front position in the engine compartment of the work vehicle. It is a perspective view which shows the movement state of the capacitor | condenser and oil cooler which were provided in the work vehicle. It is an enlarged plan view which shows the structure of a bonnet shield board in the engine room.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. First, the structure of the tractor 1 as a work vehicle in the embodiment will be described with reference to FIGS. The traveling machine body 2 of the tractor 1 in the embodiment is supported by a pair of left and right rear wheels 4 as well as a pair of left and right front wheels 3 as a traveling unit. The tractor 1 is configured to travel forward and backward by driving the rear wheels 4 and the front wheels 3 with a common rail type diesel engine 5 (hereinafter simply referred to as an engine) as a power source mounted on the front portion of the traveling machine body 2. Has been. The engine 5 is covered with a bonnet 6. A cabin 7 is installed on the upper surface of the traveling machine body 2. Inside the cabin 7, a steering seat 8 and a steering handle (round handle) that moves the steering direction of the front wheel 3 to the left and right by steering. 9 are arranged. A step 10 on which the operator gets on and off is provided at the outer lower portion of the cabin 7. A fuel tank 11 that supplies fuel to the engine 5 is provided below the bottom of the cabin 7.

  The traveling machine body 2 includes an engine frame (front frame) 14 having a front bumper (frame connecting member) 12 and a front axle case 13, and left and right machine body frames (rear frame) 15 detachably fixed to the rear part of the engine frame 14. It is comprised by. A front axle 16 is rotatably protruded outward from the left and right ends of the front axle case 13. The front wheels 3 are attached to the left and right ends of the front axle case 13 via the front axle 16. A transmission case 17 is connected to the rear part of the body frame 15 for appropriately changing the rotational power from the engine 5 and transmitting it to the front and rear four wheels 3, 3, 4, 4.

  A tank frame 18 having a rectangular frame plate shape in a bottom view projecting outward in the left and right directions is bolted to the lower surface sides of the left and right body frames 15 and the mission case 17. The fuel tank 11 of the embodiment is divided into left and right two parts. The left and right fuel tanks 11 are distributed and mounted on the upper surface side of the left and right projecting portions of the tank frame 18. The tank frame 18 is extended to the right side, and a battery 272 is mounted on an extension part on the right side of the tank frame 18. In addition, one of the steps 10 is fixed to the extended portion on the right side of the tank frame 18. The left and right rear axle cases 19 are mounted on the left and right outer surfaces of the mission case 17 so as to protrude outward. Left and right rear axle cases 20 are rotatably inserted in the left and right rear axle cases 19. The rear wheel 4 is attached to the mission case 17 via the rear axle 20. Upper portions of the left and right rear wheels 4 are covered with left and right rear fenders 21.

  A hydraulic lifting mechanism 22 that lifts and lowers a working machine such as a rotary tiller is detachably attached to the rear upper surface of the mission case 17. A working machine such as a rotary tiller is connected to the rear portion of the transmission case 17 via a three-point link mechanism including a pair of left and right lower links 23 and a top link 24. On the rear side surface of the mission case 17, a PTO shaft 25 for transmitting a PTO driving force to a working machine such as a rotary tiller is provided to project rearward.

  A flywheel 61 is attached to an engine output shaft 53 protruding rearward from the rear side of the engine 5 so as to be directly connected. A main shaft 27 projecting rearward from the flywheel 61 and a main transmission input shaft 28 projecting forward from the front side of the transmission case 17 are connected via a power transmission shaft 29 having universal shaft joints at both ends. In the transmission case 17, a hydraulic continuously variable transmission, a forward / reverse switching mechanism, a traveling auxiliary transmission gear mechanism, and a differential gear mechanism for rear wheels are arranged. The rotational power of the engine 5 is transmitted to the main transmission input shaft 28 of the transmission case 17 via the main driving shaft 27 and the power transmission shaft 29, and is appropriately shifted by the hydraulic continuously variable transmission and the traveling auxiliary transmission gear mechanism. Then, the transmission power is transmitted to the left and right rear wheels 4 through the rear wheel differential gear mechanism.

  The front wheel output shaft 30 projecting forward from the lower front portion of the transmission case 17 projects rearward from the front axle case 13 containing a front wheel differential gear mechanism (not shown) via a front wheel drive shaft 31. A front wheel transmission shaft (not shown) is connected. Transmission power by the hydraulic continuously variable transmission and the traveling auxiliary transmission gear mechanism in the transmission case 17 is transmitted from the front wheel output shaft 30, the front wheel drive shaft 31, and the front wheel transmission shaft to the front wheel differential gear mechanism in the front axle case 13. Is transmitted to the left and right front wheels 3 via.

  The transmission case 17 includes a front transmission case 112 having a main transmission input shaft 28 and the like, a rear transmission case 113 having a rear axle case 19 and the like, and a front side of the rear transmission case 113 connected to the rear side of the front transmission case 112. An intermediate case 114 is provided. The rear ends of the left and right machine body frames 15 are connected to the left and right side surfaces of the intermediate case 114 via the left and right upper and lower machine body connecting shafts 115 and 116. That is, the rear end portions of the left and right airframe frames 15 are connected to the left and right side surfaces of the intermediate case 114 by the two upper airframe connecting shaft bodies 115 and the two lower airframe connecting shaft bodies 116. The mission case 17 is integrally connected to form the rear part of the traveling machine body 2. Further, the front transmission case 112 or the power transmission shaft 29 is disposed between the left and right body frames 15 to configure the traveling machine body 2 so as to protect the front transmission case 112 and the like.

  Furthermore, left and right front support bases 96 that support the front side of the cabin 7 and left and right rear support bases 97 that support the rear part of the cabin 7 are provided. A front support 96 is bolted to the front end of the left and right machine frame 15 and the front bottom of the cabin 7 is supported on the upper surface of the front support 96 via a vibration isolating rubber member 98. doing. A rear support 97 is fastened to the middle of the left and right widths of the upper surface of the left and right rear axle cases 19 extending horizontally in the left-right direction, and the cabin 7 is connected to the upper surface of the rear support 97 via a vibration isolating rubber body 99. Anti-vibration support is provided at the rear bottom. Accordingly, the traveling machine body 2 supports the cabin 7 in a vibration-proof manner via the plurality of vibration-proof rubber bodies 98 and 99.

  Further, a rear support 97 is disposed on the upper surface side of the rear axle case 19 and an anti-sway bracket 101 is disposed on the lower surface side of the rear axle case 19 so that the end face of the cross section sandwiches the rear axle case 19 having a substantially rectangular tube shape. The rear support 97 and the steady bracket 101 are fastened with bolts 102. Both ends of a steady-state rod body 103 with turnbuckles that can be expanded and contracted are connected to an intermediate portion of the lower link 23 that extends in the front-rear direction and the steady-rest bracket 101 to prevent left-right vibration of the lower link 23. doing.

  The cabin 7 that covers the control seat 8 on the traveling machine body 2 includes a cabin frame 300 that forms a framework. The cabin frame 300 includes a pair of left and right front columns 301 positioned in front of the control seat 8, a pair of left and right rear columns 302 positioned behind the control seat 8, and a front beam that connects between the upper ends of the front columns 301. A member 303, a rear beam member 304 for connecting the upper ends of the rear columns 302, and a left and right side beam member 305 for connecting the upper ends of the front columns 301 and the rear columns 302 arranged in the front-rear direction. It is a box frame. A roof body 306 is detachably attached to the upper end side of the cabin frame 301, that is, on a rectangular frame constituted by the front beam member 303, the rear beam member 304, and the left and right side beam members 305.

  Note that the longitudinal ends of the left and right bottom frames 311 extending in the front-rear direction are connected to the lower ends of the front strut 301 and the rear strut 302. The floor plate 40 is stretched on the upper surface side of the left and right bottom frames 311, the dashboard 33 is erected on the front end side of the floor plate 40, and the steering handle 9 is installed on the rear surface side of the dashboard 33 via the steering column 32. . A brake pedal 35 and the like are disposed on the front upper surface side of the floor board 40, and the control seat 8 is attached to the rear upper surface side of the floor board 40.

  An air conditioner 364 that manages the air conditioning in the cabin 7 is accommodated in the rear portion of the roof body 306 attached to the upper end side of the cabin frame 301. The air conditioner 364 adjusts the air conditioning (indoor temperature) in the cabin 7 by heating using the cooling water of the engine 5 or cooling using the compressor 211, the condenser 275, and the evaporator driven by the engine. . A refrigerant hose 280 connected to the air conditioner 364 is piped to the front lower side along the cabin frame 301.

  As is apparent from the arrangement structure of the front windshield 321, the rear windshield 322, and the left and right side doors 323, the columns 301 and 302 and the beam members 303, 304, and 305 are arranged on the sides of the cabin 7 (cabin frame 300). Located in the department. That is, it is possible to widen windows on the front, rear, left and right sides of the cabin frame 300. In the embodiment, a front window glass 321, a rear window glass 322, and left and right side doors 323 made of transparent glass are disposed on the front, rear, left and right side surfaces of the cabin frame 300. As a result, the rigidity of the cabin frame 300 can be ensured while ensuring a wide field of view of the operator in the front-rear and left-right directions.

  As shown in FIGS. 11 to 14, the diesel engine 5 has a cylinder head 55 mounted on a cylinder block 54 containing an engine output shaft 53 and a piston, and an intake manifold 56 is disposed on the right side surface of the cylinder head 55. On the other hand, an exhaust manifold 57 is disposed on the left side of the cylinder head 55. That is, in the engine 5, the intake manifold 56 and the exhaust manifold 57 are distributed and arranged on both side surfaces along the engine output shaft 53. A cooling fan 59 is disposed on the front surface of the cylinder block 54 in the diesel engine 5, while a flywheel 61 is disposed on the rear surface of the cylinder block 54. That is, the flywheel 59 and the cooling fan 61 are distributed and arranged on both side surfaces intersecting the engine output shaft 53 in the engine 5.

  The flywheel 61 is disposed in the flywheel housing 60. A flywheel 61 is pivotally supported on the rear end side of the output shaft 53. The power of the diesel engine 5 is taken out via the output shaft 53 to the working part of the work vehicle. An engine starter 69 is provided in the flywheel housing 60. The pinion gear of the starter 69 for starting the engine meshes with the ring gear of the flywheel 61. When the diesel engine 5 is started, the output shaft 53 starts to rotate (so-called cranking is executed) by rotating the ring gear of the flywheel 61 with the rotational force of the starter 69. An engine leg mounting portion 60 a is provided on the upper surface of the flywheel housing 60. A rear engine leg (engine mount) 240 having anti-vibration rubber can be bolted to the engine leg mounting part 60a.

  In the diesel engine 5, an oil pan 62 is disposed on the lower surface of the cylinder block 54. Lubricating oil in the oil pan 62 is supplied to each lubricating portion of the diesel engine 5 through an oil filter 63 disposed on the right side surface of the cylinder block 54. The oil filter 63 is attached to the right side surface of the cylinder block 54 via an oil filter support member 88. One side surface (left side surface) of the oil filter support member 88 is connected to a connection port (oil filter mounting position) with the oil passage provided in the cylinder block 54, and the other side surface (right side surface) of the oil filter support member 88 is upper side. Attach the oil filter 63 to the.

  The diesel engine 5 includes a fuel supply pump 64 for supplying fuel, a cylindrical common rail 66 for pumping fuel to the injector, a fuel filter 67 for removing foreign matter from the fuel from the fuel tank 11, an intake manifold 56, A connected EGR device 75 is provided on the right side surface thereof. The fuel in the fuel tank 11 is supplied to the fuel supply pump 64 via the fuel filter 67, and is then pumped from the fuel supply pump 64 to the common rail 66. Accordingly, since the high-pressure fuel is stored in the common rail 66, the high-pressure fuel in the common rail 66 is injected into each cylinder of the engine 5 from each injector by controlling the opening and closing of the fuel injection valve of each injector.

  On the front side of the cylinder head 55 (on the cooling fan 59 side), a cooling water pump 71 for lubricating lubricating water is disposed coaxially with the fan shaft of the cooling fan 59. The cooling water pump 71 is configured to be driven together with the cooling fan 59 by the rotation of the engine output shaft 53. The cooling water in the radiator 235 mounted on the work vehicle is supplied to the cooling water pump 71 via a thermostat case 70 provided on the upper part of the cooling water pump 71. Then, by driving the cooling water pump 71, cooling water is supplied to a water cooling jacket (not shown) formed in the cylinder head 55 and the cylinder block 56 to cool the diesel engine 5. Cooling water that has contributed to cooling the diesel engine 5 is returned to the radiator 235. Further, the cooling water pump 71 faces the cooling fan 59 in the positional relationship, and the cooling air from the cooling fan 59 strikes the cooling water pump 71. The cooling water in the radiator 235 is supplied to the cylinder block 54 and the cylinder head 55 by driving the cooling water pump 71 to cool the diesel engine 5.

  Engine leg mounting portions 74 are provided on the left and right side surfaces of the cylinder block 54, respectively. A front engine leg (engine mount) 238 having anti-vibration rubber can be bolted to each engine leg mounting portion 74. In the embodiment, the engine leg mounting portions 74 on the cylinder block 54 side are bolted to the engine frames 14 via the engine legs 238 so that the cylinder blocks 54 are sandwiched between the pair of left and right engine frames 14 in the work vehicle. Thereby, both engine frames 14 of the work vehicle support the diesel engine 5 front side.

  An intake communication pipe 76 to which fresh air (external air) is supplied is connected to the right side inlet of the intake manifold 56, and an intake throttle member 77 is provided on the intake inlet side (upstream side) of the intake communication pipe 76. ing. Further, a recirculation exhaust gas pipe 78 to which a part of exhaust gas (EGR gas) of the diesel engine 5 is supplied is connected to an upper surface inlet portion of the intake manifold 56 through an EGR valve member 79. In the intake manifold 56, the intake outlet side (downstream side) of the intake communication pipe 76 and the connection part (rear part) with the EGR valve member 79 are configured as a main body case of the EGR device (exhaust gas recirculation device) 75. Yes. In other words, the intake intake side of the intake manifold 56 constitutes an EGR main body case.

  The EGR device (exhaust gas recirculation device) 75 is mainly located on the right side of the diesel engine 5, specifically, on the right side of the cylinder head 55, and a part of the exhaust gas (EGR gas) of the diesel engine 5 and new The air is mixed and supplied to the intake manifold 56. The device (exhaust gas recirculation device) 75 includes an EGR main body case constituted by a part of the intake manifold 56, an intake communication pipe 76 communicating with the intake manifold 56, an intake throttle member 77 provided in the intake communication pipe 76, A recirculation exhaust gas pipe 78 connected to the exhaust manifold 57 via the EGR cooler 80 and an EGR valve member 79 for communicating the intake manifold 56 with the recirculation exhaust gas pipe 80 are provided. The engine 5 connects the EGR cooler 80 and the EGR device 75 that are arranged on both side surfaces by a recirculation exhaust gas pipe 78 that bypasses the rear surface of the engine 5 (the flywheel 61 side) as a reflux line.

  An intake throttle member 77 is connected to the intake intake side of the intake manifold 56 via an intake communication pipe 76. The outlet side of the recirculated exhaust gas pipe 78 is also connected to the intake intake side of the intake manifold 56 via an EGR valve member 79. The inlet side of the recirculation exhaust gas pipe 78 is connected to the exhaust manifold 57 via the EGR cooler 80. By adjusting the opening degree of the EGR valve in the EGR valve member 79, the supply amount of EGR gas to the intake intake side of the intake manifold 56 is adjusted.

  In the above configuration, fresh air is supplied to the intake intake side of the intake manifold 56 via the intake communication pipe 76 and the intake throttle member 77, while EGR gas is supplied from the exhaust manifold 57 to the intake intake side of the intake manifold 56. To do. Fresh air from the outside and EGR gas from the exhaust manifold 57 are mixed on the intake intake side of the intake manifold 56. By recirculating a part of the exhaust gas discharged from the diesel engine 5 to the exhaust manifold 57 from the intake manifold 56 to the diesel engine 5, the maximum combustion temperature at the time of high load operation is lowered, and NOx (nitrogen from the diesel engine 5 is reduced. Oxide emissions are reduced.

  The engine 5 includes a turbocharger 81 that compresses air with the exhaust gas from the exhaust manifold 57. The turbocharger 81 includes a compressor case 83 with a built-in blower wheel. The intake side of the compressor case 83 is connected to the intake / exhaust side of the air cleaner 221 via an air supply pipe 222, while the intake air of the compressor case 83 is connected. The discharge side is connected to the upstream relay pipe 223. The turbocharger 81 includes a turbine case 82 with a built-in turbine wheel. The turbocharger 81 connects the exhaust intake side of the turbine case 82 to the exhaust gas outlet of the exhaust manifold 57, while the intake discharge side of the turbine case 82 is connected to the rear side. It connects with the exhaust-gas inlet_port | entrance of the exhaust-gas purification apparatus 52 which is a processing apparatus. The air supply pipe 222 is connected to a breather chamber (not shown) in the head cover 8 through a blow-by gas return pipe 222a. The blow-by gas from which the lubricating oil is separated and removed in the breather chamber (not shown) is returned to the intake pipe 222 through the blow-by gas return pipe 222a, is returned to the intake manifold 56, and is re-supplied to each cylinder of the engine 5.

  The diesel engine 5 includes a continuous regeneration type exhaust gas purification device (DPF) 52. The exhaust gas purification device 52 is provided with an exhaust gas inlet pipe 161 on the outer peripheral surface of the case on one end side (rear side) in the longitudinal direction, and the exhaust gas inlet pipe 161 is connected to the exhaust gas of the turbine case 82 in the turbocharger 81. The exhaust side communicates with the exhaust side through an exhaust communication pipe 84. In the exhaust gas purification device 52, the exhaust gas inlet pipe 161 is opened toward the lower left side, while the exhaust gas outlet pipe 162 is opened upward on the right side.

  The exhaust gas purification device 52 is connected to an exhaust communication pipe 84 that communicates with the turbocharger 81, and the exhaust communication pipe 84 is bolted to the exhaust manifold 204 at the lower end side thereof so that the exhaust gas is exhausted. It is configured as a support (DPF support) for the purification device 52. The exhaust communication pipe 85 is fastened to the exhaust discharge side of the turbine case 82 in the turbocharger 81 by a bolt, and the exhaust discharge side is fastened to the exhaust gas inlet 161 of the exhaust gas purification device 52. Therefore, the exhaust manifold 57 and the exhaust gas purification device 52 communicate with each other via the turbine case 82 and the exhaust communication pipe 84 in the turbocharger 81.

  The engine 5 includes an outlet side bracket body 176 and an inlet side bracket body 177 as a housing support body that supports and fixes the exhaust gas purification device 52. The outlet side bracket body 176 and the inlet side bracket body 177 are erected on the front side and the rear side that intersect the engine output shaft 53 in the cylinder head 55 of the engine 5. The inlet side bracket body 177 is located on the rear surface side of the engine 5 and supports the exhaust intake side of the exhaust gas purification device 52 together with the exhaust communication pipe 84. The outlet side bracket body 176 is located on the front side of the engine 5 and supports the exhaust discharge side of the exhaust gas purification device 52.

  The inlet side bracket body 176 is located on the rear side of the cylinder head 55 (above the flywheel housing 60). The inlet side bracket body 176 has a lower end side of the fixed bracket (first bracket) 178 fastened to the rear surface of the cylinder head 5 with a bolt. A relay bracket 179 is bolted to the upper end side of the fixed bracket 178. The proximal end side of the extension bracket (third bracket) 180 is bolted to the middle portion of the relay bracket (second bracket) 179, and the distal end side of the extension bracket 180 is the inlet of the gas purification housing 168 via the bolt and nut. Fastened to the side lid (upstream lid) 169.

  The outlet side bracket body 177 is located on the front surface side (cooling fan 59 side) of the cylinder head 55. The outlet side bracket body 177 of the embodiment is configured to be divided into an outlet side first bracket (fourth bracket) 181 and an outlet side second bracket (fifth bracket) 182. The outlet-side first bracket 181 is formed of a substantially L-shaped member that extends upward from the right side of the cylinder head 55 and is bent leftward above the cylinder head 55. On the other hand, the outlet-side second bracket 182 is configured by a substantially L-shaped member that extends upward from the left side of the cylinder head 55 and is bent rightward above the cylinder head 55. Therefore, the outlet side bracket body 177 has a substantially portal shape on the front surface side of the cylinder head 55 and is fixed so as to straddle the cylinder head 55 at the rear position of the thermostat case 70.

  As is clear from the above description, the exhaust gas purifying device 52 of the embodiment is disposed above the diesel engine 4 via the exhaust communication pipe 84, the inlet side bracket body 176, and the outlet side bracket body 177, which are housing supports. The cylinder head 55, the intake manifold 56 and the exhaust manifold 57 of the engine 1 are detachably connected. Further, the inlet side bracket body 176 and the exhaust communication pipe 84 on the upstream side (exhaust intake side) in the exhaust gas movement direction are distributed to the cylinder head 55 and the exhaust manifold 57, and downstream in the exhaust gas movement direction (exhaust exhaust side). By distributing the outlet side bracket body 177 (the outlet side first bracket 181 and the outlet side second bracket 182) to the cylinder head 55 and the intake manifold 56, the exhaust gas purification device 52 is supported at four points.

  As shown in FIG. 13 and FIG. 14, the bonnet 6 of the tractor 1 is formed in a U-shaped cross section downward. Then, the left and right corners of the bonnet 6 are chamfered so as to be inclined obliquely downward to the left and right outside in a front view, so that the front view of the operator seated on the control seat 8, particularly the left and right sides of the bonnet 6, Good visibility. The exhaust gas purification device (DPF) 52 and the exhaust communication pipe 84 are opposed to the left inner wall surface of the bonnet 6, while the intake communication pipe 76 is opposed to the right inner wall surface of the bonnet 6. Further, the exhaust communication pipe 84 is disposed at a position facing the left engine cover 232, while the exhaust communication pipe 84 is disposed at a position facing the right engine cover 23.

  An intake communication pipe 76 having a hollow portion for supplying fresh air to the intake manifold 56 is inclined upward toward the cylinder head 55 and extends upward from the intake manifold 56. That is, in the intake communication pipe 76, the fresh air intake port on the upper end side is offset toward the output shaft 53 (engine 5 center position) of the engine 5 with respect to the fresh air discharge port on the lower end side. The intake communication pipe 76 is arranged along the shape narrowed upward in the bonnet 6, and the intake throttle member 77 is disposed between the upper part of the engine 5 and the inner surface of the bonnet 6 than the intake communication pipe 76. Can be placed closer to the center position. Therefore, the downstream relay pipe 225 that allows the fresh air discharge side of the intercooler 224 and the intake throttle member 77 to communicate with each other can be designed to be short, and can be compactly accommodated in the hood 6 that has a narrower left and right width.

  The exhaust communication pipe 84 having a hollow portion for supplying the exhaust gas from the exhaust manifold 57 to the exhaust gas purification device 52 is structured to be inclined upward toward the cylinder head 55, and the exhaust gas of the exhaust gas purification device 52. The exhaust gas purification device 52 is supported by being connected to the inlet pipe 161. That is, the exhaust communication pipe 84 is connected to the lower end side connection support portion 84a connected to the lower end side exhaust manifold 57, and the upper end side exhaust gas discharge port is connected to the output shaft 53 (engine 5 center position) of the engine 5. It is offset closer. Further, the exhaust gas purification device 52 is configured to incline the exhaust gas inlet pipe 161 toward the lower side (inlet flange body side) toward the outer side of the engine 5 (bonnet 6 inner wall side).

  The exhaust gas purification device 52 and the exhaust communication pipe 84 are arranged along a shape narrowed upward in the bonnet 6, and the exhaust gas purification device 52 is disposed between the upper portion of the engine 5 and the inner surface of the bonnet 6. It can be supported near the center position. Therefore, the exhaust gas purifying device 52 can be accommodated in a compact manner in the bonnet 6 whose lateral width becomes narrower upward. In addition, the exhaust gas purifying device 52, which is a heavy object, can be supported close to the center of gravity of the engine 5, and an increase in vibration, noise, and the like of the engine 5 accompanying the mounting of the exhaust gas purifying device 52 can be suppressed. Further, the influence on the shape of the hood 6 due to the exhaust gas purification device 52 being assembled to the engine 5 can be reduced, and the shape of the hood 6 need not be complicated.

  As shown in FIGS. 14 and 15, a flywheel housing 60 that covers a flywheel 61 disposed on an end surface that intersects the core line of the engine output shaft 53 is configured to have a width W1 narrower than a height H1. By making the shape of the flywheel housing 60 narrower, the engine 5 can be mounted without causing the flywheel housing 60 to interfere with the traveling machine body 2 having a narrow left and right width. Further, in the traveling machine body 2, since the machine engine frame 15 is provided outside the engine frame 14 via the spacer 293, the width between the left and right machine engine frames 15 is wider than the width between the left and right engine frames 14. On the other hand, in the engine 5, the flywheel housing 61 is disposed rearward, and the main transmission input shaft 28 of the transmission case 17 connected to the body frame 15 and the flywheel 61 are connected. Accordingly, the flywheel housing 61 having the widest left-right width in the engine 5 can be sufficiently disposed between the body frames 15 and the flywheel housing 61 can be prevented from colliding with the traveling body 2 having a different vibration system. Damage can be prevented.

  The flywheel housing 61 has an outer shape in which a left and right sides of a circle are cut out and at the same time an pedestal engine leg mounting portion 60a is protruded on the upper portion, and the upper engine leg mounting portion 60a is interposed via a rear engine leg body 240. And connected to the traveling machine body 2. The flywheel housing 61 not only can be mounted on the traveling machine body 2 having a narrow width, but also forms a pedestal-shaped engine leg mounting portion 60 a that can be connected to the traveling machine body 2. Therefore, the rigidity by the support structure of the engine 5 can be compensated by connecting to the traveling machine body 2 by the flywheel housing 61 having high rigidity.

  More specifically, a portal-type engine support frame 237 is installed above the support beam frame 236 that bridges the pair of left and right aircraft frames 15, and the flywheel housing 61 and the engine support beam frame 237 are arranged side by side. Arrange. Then, the rear surface of the engine leg 238 is connected to the upper surface of the engine support frame 237 via the anti-vibration rubber 239 while being connected to the upper surface of the engine leg mounting portion 60a on the flywheel housing 61 in front of the engine leg 238.

  As shown in FIGS. 4 to 10, the upstream relay pipe 223 and the downstream relay pipe 225 are arranged separately on both sides of the engine 5, and the intercooler 224 installed on the frame frame 226 in front of the engine 5. Is extended toward the upper front side of the engine 5. Further, the air cleaner 221 is arranged on the upper front side of the frame frame 226, and an air supply pipe 222 connected to the air cleaner 221 extends over the frame frame 226 and extends behind the left side of the engine 5. The fresh air intake side of the intake communication pipe 76 of the engine 5 communicates with the downstream relay pipe 225 via the intake throttle member 77. Further, the turbine supercharger 81 of the engine 5 has the fresh air intake side of the compressor case 83 in communication with the air supply pipe 222, while the fresh air discharge side of the compressor case 83 is in communication with the downstream relay pipe 225. Yes.

  With the above configuration, fresh air (external air) sucked into the air cleaner 221 is removed by the air cleaner 221 and purified, and then sucked into the compressor case 83 of the turbocharger 81 through the air supply pipe 222. . The pressurized fresh air compressed in the compressor case 83 of the turbocharger 81 is supplied to the EGR main body case of the EGR device 75 via the relay pipes 223 and 225 and the intercooler 224. On the other hand, a part of the exhaust gas (EGR gas) from the exhaust manifold 57 is cooled by the EGR cooler 80 and then supplied to the EGR main body case of the EGR device 85 via the recirculation exhaust gas pipe 78.

  Further, in the engine room under the bonnet 6, the air supply pipe 222, the upstream relay pipe 223, and the downstream relay pipe 225 are arranged in the left and right directions, so that the turbocharger 81 and the intake manifold 56 are left and right. The piping can be efficiently performed with respect to the engine 5 that is distributed and arranged. Therefore, by arranging the pipes 222, 223, and 225 for the air flow path to the outside of the engine 5 without difficulty, the heating based on the exhaust heat of the engine 5 and the exhaust gas purification device 52 is suppressed, and the inside of the pipe is The thermal influence on the passing air can be reduced. The intercooler 224 arranged in front of the engine room can be arranged by distributing the fresh air outlet side and the fresh air inlet side to the left and right. Accordingly, not only can the upstream relay pipe 223 and the downstream relay pipe 225 communicated with the engine 5 be shortened, but the intercooler 224 can be accommodated compactly in front of the engine room.

  As shown in FIGS. 13 to 15 and the like, the front end sides of the left and right airframe frames 15 are connected to the rear end sides of the left and right engine frames 14 via spacers 297, and the left and right airframe frames 15 are connected to the left and right engine frames. It arrange | positions so that the flame | frame 14 may be pinched. The connection surface (outer surface) of the support beam frame 236 with the body frame 15 is the same surface as the connection surface (outer surface) of the spacer 297 with the body frame 15. The support beam frame 236 is bolted to the left and right airframe frames 15 to mount the left and right airframe frames 15, and the engine support frame 237 is mounted on the upper surface thereof. The engine support frame 237 has a shape that surrounds the flywheel 61 of the diesel engine 5 together with the support beam frame 236 by fastening the lower end surface of the engine support frame 237 with the upper surface of the support beam frame 236.

  The diesel engine 5 includes an engine support bracket 298 provided at a middle portion of the pair of left and right engine frames 14 with an engine leg mounting portion 74 provided on the lower side of the left and right side surfaces thereof via an engine leg 238 having a vibration isolation rubber 239. It is connected. In the diesel engine 5, an engine leg mounting portion 60 a provided on the rear flywheel housing 60 is connected to the upper surface of the engine support frame 237 via an engine leg (engine mount) 240 having a vibration isolation rubber 241. .

  The engine legs 238 are bolted to the upper part of the engine support bracket 298 connected to the outside of the midway part of the pair of left and right engine frames 14 with the anti-vibration rubber 239 on the lower side. The diesel engine 5 is sandwiched between the engine frames 14 by a pair of left and right engine legs 238 to support the front side of the diesel engine 5. The rear surface of the diesel engine 5 is connected to the front end sides of the pair of left and right body frames 15 via the support beam frame 236, the engine support frame 237, and the engine legs 240, and the diesel engine 5 is rearward at the front end of the body frame 15 The side is supported. The diesel engine 5 is supported on the traveling machine body 2 by the left and right front vibration isolation rubber 239 and the left and right rear vibration isolation rubber 241.

  As shown in FIGS. 13 to 17 and the like, the bonnet 6 forms a front grille 231 on the front lower side to cover the front of the engine room. An engine cover 232 formed of a perforated plate is disposed on the left and right rear lower sides of the bonnet 6 to cover the left and right sides of the engine room. That is, the hood 6 and the engine cover 232 cover the front, upper, and left and right sides of the diesel engine 5. As shown in FIGS. 21 and 22, the upper end position of the engine cover 232 is positioned below the exhaust gas purification device 224, and the air heated by the engine 5 and the exhaust gas purification device 224 is released to the outside. The heat retention effect of the exhaust gas purification device 224 by the bonnet 6 is enhanced, and the regeneration operation at a high temperature is enabled.

  As shown in FIGS. 13, 14, and 17, the bonnet 6 has a plate-like heat insulating material 287 pasted on the inner side walls of the left and right side surface portions 265 and in regions corresponding to the both side surfaces of the engine 5. The heat insulating material 237 is located above the engine cover 232 and covers the inner wall of the bonnet 6 from the rear edge of the side surface portion 265 of the bonnet 6 toward the front. By installing the heat insulating material 287, it is possible to prevent the bonnet 6 from being heated due to exhaust heat of the engine 5 and the exhaust gas purification device 224, and to insulate the engine room from outside air to operate the exhaust gas purification device 224 in a high temperature environment. .

  As shown in FIGS. 16 to 20, the bonnet 6 includes a front grille 231 at the center of the front surface, and the ceiling portion 264 on the upper side of the bonnet 6 has a shape inclined obliquely upward from the front to the rear. Yes. The front grill 231 includes a pair of left and right dustproof nets 231b fixed by a central frame 231a. In the bonnet 6, the space below the ceiling portion 264 is widened, and a space for accommodating the exhaust gas purification device 52 can be formed in the engine room inside the bonnet 6. The bonnet 6 has opening holes 268 (268a, 268b) in front of the left and right side surface portions 265, and takes in cooling air from the left and right sides of the bonnet 6 through a pair of left and right opening holes 268. Further, the bonnet 6 is provided with a pair of left and right opening holes 270 in front of the ceiling portion 264, and the cooling air is taken in from the upper front side of the bonnet 6 through the pair of left and right opening holes 270. The opening holes 268 and 270 are covered with a net-like dustproof net.

  As shown in FIG. 16, the bonnet 6 has a shielding projection (inner shielding plate) 266 that is projected from the inner surface of the left and right side surfaces 265 extending in the vertical direction, and the tip of the shielding projection 266 is sealed with a sealing member (elastic resin material). Etc.) It is covered with 266a. The shielding protrusion 266 is disposed at a position corresponding to the vicinity of the left and right sides of the radiator 235. More specifically, the shielding projection 266 is provided so as to extend vertically along the rear edge of the opening 268 at a position behind the opening 268 of the bonnet 6. Therefore, when the bonnet 6 is closed, the shielding protrusion 266 contacts the side shielding part 234b of the fan shroud 234 located on the back surface of the radiator 235.

  As shown in FIG. 17, the bonnet 6 has a sealing member (urethane material or the like) 267 pasted on a portion of the back surface (inner peripheral surface) of the ceiling portion 264 facing the upper shielding portion 234 a of the fan shroud 234. When the bonnet 6 is closed, the seal member 267 abuts so as to press the upper shielding portion 234a of the fan shroud 234, and the gap between the upper surface of the fan shroud 234 and the inner peripheral surface of the bonnet 6 is made as much as possible. fill in. Further, as shown in FIGS. 16 and 17, the bonnet 6 is fitted with a seal member (such as an elastic resin material) 269 at the lower edge in front of the shielding protrusion 266. When the bonnet 6 is closed, the seal member 269 at the lower edge of the bonnet 6 abuts against the upper surface on the outer edge side of the frame bottom plate 233.

  As shown in FIGS. 16 and 17, when the bonnet 6 is closed, the sealing member 267 of the ceiling portion 265 is brought into contact with the upper shielding portion 234 a of the fan shroud 234, and the shielding protrusions 266 of the side surface portions 269 are brought into contact with the fan shroud 234. It is made to contact | abut to the side shielding part 234b. Thereby, when the bonnet 6 is closed, a space separated by the front and rear of the fan shroud 234 is formed. Further, when the hood 6 is closed, the contact portion between the hood 6 and the frame bottom plate 233 in front of the fan shroud 234 is sealed in order to bring the seal member 269 at the lower edge of the bonnet 6 into contact with the frame bottom plate 233. Therefore, the outside air outside the hood 6 is introduced from the opening holes 268 and 270 of the bonnet 6 and the opening holes 233z of the frame bottom plate 233.

  As shown in FIGS. 16 to 20, the bonnet 6 has opening holes 268 (268 a, 268 b) formed in the left and right side surface portions 265, and a pair of left and right air volume adjusting plates 285, 286 that covers a part of the left and right side surface portions 265. Is provided inside the bonnet 6. By providing air volume adjusting plates 285 and 286 that cover a part of the opening hole 268 in the left and right side surface portions 265 of the bonnet 6, the flow rate of the cooling air sucked from the left and right opening holes 266 is adjusted, and the rectified cooling air is supplied. Can be directed to the fan shroud 234.

  Therefore, the unevenness of the cooling effect in the heat exchanger such as the radiator 235 disposed in front of the fan shroud 234 can be reduced. In addition, the flow of the cooling air that has passed through the fan shroud 234 can be stabilized on the left and right, and deviation in the flow of the cooling air based on the rotation direction of the cooling fan 59 can be suppressed. Thereby, the cooling air can be efficiently supplied to the engine 5 disposed behind the fan shroud 234, the thermal efficiency in the engine room inside the bonnet 6 can be optimized, and abnormal operation of the engine 6 can be prevented at the same time. Drive efficiency can be improved.

  The bonnet 6 includes left and right opening holes 268 at positions in front of the fan shroud 234, and a pair of left and right air volume adjusting plates 285 and 286 are installed on the rear edge sides of the left and right opening holes 268, respectively. By providing the air volume adjusting plates 285 and 286 on the rear edge side of the opening hole 268, the cooling air can be prevented from staying on the side of the fan shroud 234, and the cooling air can be efficiently guided to the suction portion of the fan shroud 234. The cooling fan 59 rotates in a direction (in the direction of the arrow in FIGS. 18 to 20) in which the upper blade is moved from the right side to the left side. That is, the cooling fan 9 rotates clockwise in front view.

  As shown in FIGS. 16 to 19, the right air volume adjusting plate 285 covers the entire rear edge of the corresponding opening hole 268, while the left air volume adjusting plate 286 covers the lower side of the corresponding opening hole 268. . That is, by providing the right air volume adjusting plate 285 that increases the suction amount in front of the fan shroud 234 along the rear edges of both the upper and lower opening holes 268a and 268b, the cooling air can be easily taken into the fan shroud 234. . On the other hand, the left air volume adjusting plate 286 is provided so as to cover only the lower opening hole 268b, thereby forming a resistance to the cooling air flow. As a result, the flow rate of the cooling air can be rectified in accordance with the cooling air suction direction by the fan shroud 234 by adjusting the air flow rate taken in from the left and right opening holes 268.

  The bonnet 6 includes opening holes 268a and 268b that are vertically adjacent to the left and right side surfaces 265, respectively, and a pair of left and right opening holes 268a and 268b are covered with an affirmative dust-proof net on the inner walls of the left and right side surfaces 265. The right air volume adjusting plate 285 is fixed to the inner wall of the right side surface portion 265 via a dust-proof net along the rear edges of the upper and lower opening holes 268a and 268b in the right side surface portion 265. The left air volume adjusting plate 286 is fixed to the inner wall of the left side surface portion 265 via a dust net along the rear edge of the lower opening hole 268b in the left side surface portion 265.

  As shown in FIGS. 16 to 20, the front edge of the right air volume adjusting plate 285 is positioned behind the front edge of the left air volume adjusting plate 286, and a plurality of opening holes 286 a are formed in the left air volume adjusting plate 286. Is provided. The right air volume adjusting plate 285 and the left air volume adjusting plate 286 have different lengths, and the left air volume adjusting plate 286 is provided with a plurality of opening holes 286a, so that the air taken in from the left and right opening holes 268 is provided. The flow rate of the cooling air can be rectified in accordance with the cooling air suction direction by the fan shroud 234 by adjusting the flow rate.

  As shown in FIGS. 16 and 18, the right air volume adjusting plate 285 has a shape that covers a part of the rear edge side of both the upper and lower openings 268 a and 268 b of the right side surface 265. On the other hand, as shown in FIGS. 17 and 19, the left air volume adjusting plate 286 is disposed below the upper opening 268a on the left side surface 266 and covers only the lower opening 268b. Further, the left air volume adjusting plate 286 has a shape that covers a portion other than a part of the front edge side of the lower opening 268b in the left side surface portion 266, and opens a plurality of opening holes 286a.

  As shown in FIGS. 16 to 20, the inner wall of the bonnet 6 is provided with a shielding projection (inner shielding plate) 266 at a position corresponding to the vicinity of the left and right sides of the fan shroud 234, and the hood 6 is closed. When this occurs, the shielding projections 266 provided on the bonnet 6 are brought into contact with the left and right sides of the fan shroud. The air volume adjusting plates 285 and 286 have rear edges positioned in front of the shielding projection 266 and behind the opening 268, respectively.

  The right air volume adjusting plate 285 covers the rear edge side of the opening 268 of the right side surface portion 266, while the left air volume adjusting plate 286 includes an opening hole 286a and covers most of the opening portions 268 of the right side surface portion 266. That is, the area of the left air volume adjusting plate 286 covering the opening 268 is larger than that of the right air volume adjusting plate 285, and the resistance to the intake of outside air by the left opening 268 is larger than that of the right opening 268. doing. Therefore, the flow velocity of the cooling air can be made uniform inside the bonnet 6 by adjusting the suction air velocity from the openings 231b, 268, 270 of each part of the bonnet 6. As a result, it is possible to prevent clogging from occurring in an opening having a large amount of suction due to dust or the like due to a bias in the amount of suction in any of the openings 231b, 268, and 270.

  As shown in FIGS. 21, 22, and the like, the paired left and right engine frames (front frame) 14 have their front end side inner surfaces connected to the left and right outer surfaces of the frame connecting member 12. The frame connecting member 12 is made of a rectangular metal casting, and the diesel engine 5 is supported on the engine frame 14 installed by the frame connecting member 12. A frame bottom plate 233 is installed on the upper edges of the left and right engine frames 14 and the upper surface of the front bumper 12 so as to cover the upper front side of the engine frame 14. An under cover 296 that covers the lower front side of the engine 5 is disposed at the rear end of the frame bottom plate 233. The under cover 296 has a front end connected to the frame bottom plate 233 and a rear left and right side edge connected to the left and right engine frames 14. The under cover 296 includes a front part that extends from the rear end of the frame bottom plate 233 toward the lower end of the engine frame 14, and a rear part that extends forward and below the engine 5.

  The lower surface of the frame bottom plate 233 is connected to the side surfaces of the left and right engine frames 14 via connecting brackets 233a and 233b arranged on the front and rear sides. Further, the frame bottom plate 233 is constituted by a front bottom plate 233x and a rear bottom plate 233y which are divided into front and rear parts. The left and right edge sides of the lower surface of the front bottom plate 233x are connected to the front of the other end of the connection bracket 233a that connects one end to the side of the pair of left and right engine frames 14, and the front side of the front bottom plate 233x is fastened to the frame connecting member 12. Has been. The rear bottom plate 233y connects the left and right edge sides of the front lower surface with the other end rear of the pair of left and right connection brackets 233a, and connects the left and right edge sides of the front lower surface to the other ends of the pair of left and right connection brackets 233b.

  The frame bottom plate 233 includes an opening hole 233z in the left and right center region. The opening hole 233z is provided in the front bottom plate 233x of the frame bottom plate 233 and is covered with a net-like dustproof net. That is, each of the bonnet 6 and the frame bottom plate 233 has openings 231b, 233a, 268, 270 at positions ahead of the cooling fan 59 of the engine 5, and the bonnet 6 and the frame bottom plate are driven by the cooling fan 59. Cooling air is taken into the engine room in the bonnet 5 from the openings 231 b, 233 z, 268, and 270 of the 233.

  By opening the bonnet 6 and the frame bottom plate 233, the opening area can be made larger than the air flow rate through which the cooling fan 59 passes in a limited configuration in front of the cooling fan 59. Thereby, the flow velocity of the cooling air passing through the cooling fan 59 can be suppressed, the cooling air in the engine room can be optimally controlled, and not only the back flow in the engine room is prevented, but also the cooling air is effective on the engine 5 side. Can be guided. Further, by making the opening 233z of the frame bottom plate 233 into a net shape, it is possible to prevent dust from entering the engine room, and it is possible to drop the dust by its own weight after the engine 5 is stopped.

  Further, the opening 233z of the frame bottom plate 233 is disposed at a position above the frame connecting member 12. Since the frame connecting member 12 of the traveling machine body 2 is disposed below the opening 233z of the frame bottom plate 233, when the outside air flows into the engine room through the opening 233z, the frame connecting member 12 prevents dust and mud from entering. Can do. Moreover, the support structure of the engine 5 can be strengthened by fixing the engine frame 14 that supports the engine 5 with the frame connecting member 12 that is a metal casting.

  As shown in FIG. 23 and the like, the left engine cover frame 257 has a shape inclined upward from the front end toward the rear end. The left engine cover frame 257 has a rear end coupled to the left edge of the left side shield surface 246 of the bonnet shield plate 244 and a front end coupled to a coupling bracket 259 connected to the side of the left engine frame 14. The connection bracket 259 is fixed to the engine frame 14 at a position between the frame bottom plate 233 and the front engine leg 238. The left engine cover 232 is connected to the front and rear end portions and the middle portion of the left engine cover frame, and is connected to the left side surface of the engine support frame 237 and is fixed to the lower side of the left side surface of the bonnet 6.

  The right engine cover frame 258 has a front end coupled to a coupling bracket 259 (see FIG. 24) connected to the side of the left engine frame 14, and has a shape that is inclined upward and then bent downward. I have. The right engine cover frame 258 has a rear end at the same height as the front end, and both ends of the right engine cover frame 258 are connected to a lower plate 258 a fixed to the engine cover frame 258. The engine cover frame 259 connects one end of the upper plate 258b to the bent portion.

  The right engine cover 232 is connected to the front and rear ends of the left engine cover frame and the other end of the upper plate 258b, and is fixed to the lower side of the right side surface of the bonnet 6. The right engine cover 232 has a shape in which a part of the lower edge is cut out, and is configured so that the oil filter 63 of the engine 5 can protrude outward. The length in the front-rear direction of the right engine cover 232 is shorter than that of the left engine cover 233, and the exhaust pipe 227 and the tail pipe 229 are connected to the rear of the right engine cover 232.

  As shown in FIGS. 17 and 21 to 24, the connection bracket 259 connected to the side of the left engine frame 14 has an upper end on the frame outer cover 216 that is a surface (horizontal plane) perpendicular to the connection portion with the engine frame 14. It is comprised by the L-shape which it had. The frame outer cover 216 extends from the upper end of the engine frame 14 toward the lower end of the engine cover 232 and covers the lower side of the engine cover 232. Similarly, the connection bracket 259 connected to the side surface of the right engine frame 14 is also formed in an L shape having a frame outer cover 219 that is a surface perpendicular to the connection portion with the engine frame 14. The left and right connecting brackets 259 are configured such that the left frame outer cover 216 is longer in the front-rear direction than the right frame outer cover 216 and reaches the front edge of the rear front engine leg 238.

  As shown in FIGS. 17 and 21 to 24, the frame outer cover 216 has a shape extending in the front-rear direction from the rear of the fan shroud 234 to the front edge of the front engine leg 238. On the upper surface of the frame outer cover 216, a side guide plate 217 formed in a plane parallel to the engine frame 14 is erected upward. On the upper surface of the frame outer cover 216, the side guide plate 217 is extended from the rear side of the side shroud 234a of the fan shroud 234 to the front of the engine 5, so that the rear side of the fan shroud 234 and the lower side portion of the cooling fan 59 are sideways. Cover with a guide plate 217.

  That is, the side guide plate 217 erected from the traveling machine body 2 (engine frame 14) is disposed on one side (left side) of the fan shroud 234, and a part between the fan shroud 234 and the engine 5 is disposed. Cover with side guide plate 217. By disposing the side guide plate 217 below the fan shroud 234, it is possible to prevent the cooling air supplied from the fan shroud 234 from being exhausted to the outside of the hood 6 and the engine cover 232 immediately after the fan shroud 234. The cooling air can be efficiently guided to the engine 5 behind the fan shroud 234. Further, since the side guide plate 217 can be arranged in accordance with the exhaust direction of the cooling air from the fan shroud 234, it is possible to prevent the amount of cooling air guided from the fan shroud 234 to the engine 5 from decreasing, Cooling efficiency can be improved.

  Also, as shown in FIGS. 17 and 21 to 24, a plate-like frame outer cover 218 extends toward the engine starter 69 at the rear edge of the front engine leg 238. The frame outer cover 218 has a lateral width equivalent to the lateral width of the upper surface of the front engine leg 238, and is constructed from the upper end of the engine frame 14 toward the lower end of the engine cover 232. The frame outer cover 216 and the frame outer cover 218 arranged in front of and behind the front engine leg 238 have a horizontal plane with a horizontal width equivalent to the upper surface of the front engine leg 238, so that the space between the engine frame 14 and the engine cover 232 is Can be blocked.

  By disposing the frame outer cover 216, the upper surface of the front engine leg 238, and the frame outer cover 218 continuously in the front-rear direction, the frame outer cover 216 extends from the upper end of one side of the traveling machine body 2 (engine frame 14) to the outer side of the machine. Constitutes a lower guide plate. Then, the frame outer cover 216, the upper surface of the front engine leg 238, and the lower guide plate by the frame outer cover 218 are arranged in a position from the rear side of the fan shroud 234 to the front side of one side of the engine 5, and the lower side of the engine cover 232 is cover. That is, the lower guide plate (frame outer cover 216, front engine leg 238 upper surface, and frame outer cover 218) is extended from the upper side of the traveling machine body 2 (engine frame 14) to cover the space between the traveling machine body 2 and the engine cover 232. The configuration.

  Thereby, it is possible to prevent the cooling air supplied from the fan shroud 234 from coming out to the outside lower side of the traveling machine body 2 immediately after the fan shroud 234, and the cooling air can be efficiently guided to the engine 5 behind the fan shroud 234. More specifically, the lower guide plates (the frame outer cover 216, the front engine leg 238 upper surface, and the frame outer cover 218) are extended from the rear side of the fan shroud 234 to the front side of the starter 69 for starting the engine, so that side guidance is provided. Together with the plate, the cooling air can be guided to the engine starter 69 which is an electric device. Accordingly, it is possible to reduce the influence on the engine starter starter 69 due to the heat radiation from the exhaust manifold 57 that becomes high temperature, and to prevent a failure of the engine starter starter 69 that is an electrical device.

  As shown in FIGS. 17, 21, and 22, a shielding plate 205 that covers the left side surface of the engine 5 is disposed below the exhaust gas purification device (DPF) 52. Since the shielding plate 205 is configured to cover the exhaust manifold 57, the EGR cooler 80, the turbocharger 81, and the exhaust communication pipe 84, the high heat source component in the engine 5 is covered with the shielding plate 205. Therefore, the exhaust gas supplied to the DPF 52 can be maintained at a high temperature, and a decrease in the regeneration capability of the DPF 52 can be prevented.

  The shield plate 205 is bolted to the exhaust gas intake port side of the exhaust communication pipe 84 (on the connection portion side with the turbine case 82 of the turbocharger 81), and is connected to the second outlet side via the shield plate fixing bracket 207. It is connected to the rear part connecting portion 182 d of the bracket 182 and supported by the engine 5. The shielding plate fixing bracket 207 is also connected to an upstream relay pipe 223 that communicates the fresh air intake port of the intercooler 224 and the compressor case 83 of the turbocharger 81, and the upstream relay pipe 223 is also connected to the engine 5. Is supported by the second bracket 182 on the outlet side.

  As shown in FIGS. 17, 21, and 22, a heat shield member 206 connected to one side of the engine 5 is provided below the exhaust manifold 57, and an engine starter 69 is disposed below the heat shield member 206. I am letting. The heat shield member 206 connected to the left side surface of the cylinder block 54 protrudes toward the engine cover 232 at a position between the engine starter 69 and the EGR cooler 80. Accordingly, by covering the starter 69, which is an electrical device, with the heat shield member 206, the thermal influence on the starter 69 due to heat radiation from the exhaust manifold 57 or the like that becomes high is reduced, and the starter, which is an electrical device, is started. The failure of the starter 69 can be prevented.

  As shown in FIGS. 21 and 22, the shield plate 205 has a lower edge connected to the right edge of the heat shield member 206, and the connected shield plate 205 and heat shield member 206 and the exhaust gas purification device 52 are connected to the left side of the engine. , A closed space having front and rear openings is formed. That is, the exhaust manifold 57, the EGR cooler 80, the turbocharger 81, and the exhaust communication pipe 84 are surrounded by the shielding plate 205, the heat shielding member 206, and the exhaust gas purification device 52. Since the closed space is formed by the shielding plate 205 and the heat shielding member 206 in this way, the flow rate of the cooling air passing through the exhaust manifold 57, the EGR cooler 80, the turbocharger 81, and the exhaust communication pipe 84 can be limited. In addition, high-temperature exhaust gas can be supplied to the exhaust gas purification device 52, and a reduction in its regeneration processing capacity can be prevented.

  A notch is provided on the lower front side of the shielding plate 205, and the front side of the heat shielding member 206 is bent toward the upper turbocharger 81. Accordingly, the front side of the EGR cooler 80 can be covered with the bent portion on the front side of the heat shield member 206, and the upstream relay pipe 223 can be passed between the notch portion on the lower front side of the shield plate 205 and the heat shield member 206. Further, when the shielding plate 205 and the heat shielding member 206 are connected, an opening is formed on the lower front side, so that a part of the cooling air can be supplied to the EGR cooler 80. Therefore, the shape of the shielding plate 205 and the heat shielding member 206 can be controlled so as to flow the cooling air optimal for the cooling action in the EGR cooler 80.

  Further, the shielding plate 205 is provided with a notch at a position on the upper rear side and facing the exhaust gas inlet pipe 161 of the exhaust gas purification device 52. Thereby, the cooling air heated inside the shielding plate 205 and the heat shielding member 206 can flow behind the shielding plate 205 without staying inside the shielding plate 205 and the heat shielding member 206. Therefore, the cooling air heated by passing through the left side of the engine 5 can be exhausted to the outside through the opening hole of the left engine cover 232, etc., and the heat retention on the left side of the engine 5 that becomes relatively high is retained. Can be prevented.

  In the engine room, a shielding plate 205 is arranged on the left side of the engine 5 so as to cover the lower part of the exhaust gas purifying device 52 and above the starting starter 69 with the shielding plate 205, and from the cylinder block 54 of the engine 5. A heat shield member 206 projecting toward the left side of the engine 5 is connected to the lower edge of the shield plate 205, and the starter 69 for starting is covered with the heat shield member 206. By covering the side of the engine 5 with the shielding plate 205, the heat shielding property to the engine 5 can be improved and at the same time, heat retention on the side of the engine 5 can be prevented. And the thermal efficiency in an engine room can be optimized, the abnormal operation of the engine 5 etc. can be prevented and drive efficiency can be improved simultaneously. In addition, by providing the heat shield member 206 above the starter 69 that is an electric device, the influence on the starter 69 due to heat radiation from the exhaust manifold 57 that becomes high temperature is reduced, and the starter that is an electric device is started. The failure of the starter 69 can be prevented.

  As shown in FIGS. 18 to 26 and the like, the engine control device (engine ECU) 271 is disposed in front of a heat exchanger such as a radiator 235 described later. The engine ECU 271 receives sensor signals from the sensors of the engine 5 and controls driving of the engine 5. The engine control device 271 is erected on the frame bottom plate 235 along the longitudinal direction of the traveling machine body 2 (longitudinal direction of the engine frame 14). That is, the engine ECU 271 stands on the front bottom plate 233x of the frame bottom plate 233, and is disposed at a position on the back side of the front surface of the bonnet 6 so that the lateral width thereof is narrowed.

  By disposing the engine ECU 271 with the longitudinal direction as the front-rear direction, the installation direction of the engine ECU 271 can be aligned with the cooling air flowing in the front-rear direction in the engine room by the cooling fan 59. Thereby, since engine ECU271 can reduce the shielding area with respect to the flow of cooling air, the fall of the cooling air flow rate to engine 5 can be controlled, and the inside of an engine room can be maintained at a proper temperature.

  The frame bottom plate 233x has a harness conduction hole 233w in the vicinity of the standing position of the engine ECU 271 and at a position behind the opening 233z. A harness (not shown) connected to the engine ECU 271 is guided to the bottom side of the traveling machine body 2 through the harness conduction hole 233w, and is connected to the rear engine 5, the battery 272, and the like. By arranging the engine ECU 271 on the front bottom plate 233x and providing the harness conduction hole 233x on the front bottom plate 271, the engine ECU 233x can be configured as a single unit by the front bottom plate 233x, and assemblability can be improved.

  Further, the engine ECU 271 is disposed at a position between the dust net (opening) 231 b provided symmetrically on the front surface of the bonnet 6 and above the opening 233 z of the frame bottom plate 233. That is, the engine ECU 271 is disposed on the back side of the frame pair 231a of the front grill 231, and stands on the front bottom plate 233x so as to straddle the left and right centers of the opening 233z of the frame bottom plate 233. Since the engine ECU 271 can be disposed at a position that does not overlap the opening 231b of the bonnet 6, the engine ECU 271 does not reduce the opening area for inflow of cooling air. Further, by arranging the engine ECU 271 above the opening 233z of the frame bottom plate 233, the cooling effect of the engine ECU 271 can be obtained.

  As shown in FIGS. 18 to 26 and the like, a radiator 235 having a fan shroud 234 attached to the back side is erected on the rear bottom plate 233y of the frame bottom plate 233 so as to be positioned on the front side of the engine 5. The fan shroud 234 surrounds the outer peripheral side of the cooling fan 59 and allows the radiator 235 and the cooling fan 59 to communicate with each other. The radiator 235 is supported inside a rectangular radiator frame 260 fixed to the frame bottom plate 233 in an upright state. The radiator frame 260 is provided with a dust-proof net 260a on the front surface, so that intrusion of dust and the like into the frame-shaped radiator frame 260 is prevented. The radiator frame 260 is fixed on the frame bottom plate 233 so as to surround the inner radiator 235 and is also connected to the fan shroud 234.

  A radiator 235 having a fan shroud 234 attached to the back side is erected on the frame bottom plate 233 so as to be positioned on the front side of the engine 5. The fan shroud 234 surrounds the outer peripheral side of the cooling fan 206 and allows the radiator 235 and the cooling fan 206 to communicate with each other. The fan shroud 234 has an upper shielding part 234a whose upper end has a T-shaped cross section, and a side shielding part 234b that protrudes from the left and right side surfaces. The upper shielding portion 234a is disposed so as to extend in the left-right direction over the entire upper surface of the fan shroud 234, and has a configuration in which the upper end thereof is brought close to the lower surface of the ceiling portion 259 of the bonnet 6 when the bonnet 6 is closed. The pair of left and right side shielding portions 234b are arranged so as to extend in the vertical direction over the entire left and right side surfaces of the fan shroud 234, and when the bonnet 6 is closed, the left and right ends thereof are side portions 273 of the bonnet 6. It has the structure made to adjoin with an inner surface.

  A rectangular frame-shaped frame 226 is erected on the frame plate 233 on the front side of the radiator 235. A frame frame 226, a radiator 235, and a fan shroud 234 are arranged in this order from the front above the axle case connecting portion 295 that bridges the left and right engine frames 14. The frame frame 226 is formed so that the rear surface is covered with the radiator 235, and the front surface and the left and right side surfaces thereof are covered with a mesh plate. In the frame frame 226, an oil cooler, a fuel cooler, and the like are installed in addition to the above intercooler. An air cleaner 221 is disposed above the front surface of the frame frame 226. As a result, the cooling air sucked from the front grille 231 flows toward the frame frame 226 behind the front grille 231, thereby cooling the air cleaner 221 and cooling the intercooler, oil cooler, and fuel cooler in the frame frame 226. To do. In addition, the cooling air from the front reaches the radiator 235 provided on the rear surface of the frame frame 226, thereby enhancing the cooling effect on the cooling water supplied to the diesel engine 5.

  On the front side of the radiator 235, the frame frame 226 is erected on the rear bottom plate 233y of the frame bottom plate 233. The frame frame 226 includes an air cleaner support frame 261 that supports the air cleaner 221. The air cleaner support frame 261 is a bent rod-shaped frame, and one end is connected to the rear bottom plate 233y and the other end is connected to the radiator frame 260. An air cleaner 221 is fixed above the air cleaner support frame 261, and a fuel cooler 273 for cooling the fuel is fixed to the air cleaner support frame 261 at a position below the air cleaner 221.

  The frame frame 226 includes a portal frame 262 that is bent into a portal shape and has both ends fixed on the frame bottom plate 233y. The portal frame 262 is erected between the radiator frame 260 and the air cleaner support frame 261 with both left and right ends (lower ends) coupled to the frame bottom plate 233y. The left and right central portions of the upper frame of the portal frame 262 are connected to the upper and lower middle portions of the air cleaner support frame 261. The air cleaner support frame 261 supports the air cleaner 221 above the connection portion with the portal frame 262 and supports the fuel cooler 273 below the connection portion with the portal frame 262.

  The portal frame 262 supports an oil cooler 274 for cooling the lubricating oil on the rear side (the radiator 235 side), and supports a condenser 275 for cooling the refrigerant on the front side (the fuel cooler 273 side). In addition, the intercooler 224 is vertically clamped by the intercooler connection bracket 263 fixed to the upper end side of the air cleaner support frame 261 and the upper frame of the portal frame 262, and the intercooler 224 is supported above the oil cooler 274. doing. In addition, a dustproof net 263a is sandwiched and supported in front of the intercooler 224 by an upper frame of the portal frame 262 and an intercooler connection bracket 263.

  The capacitor 275 is configured as a case-integrated type, and a receiver dryer 276 that separates refrigerant into gas and liquid is connected and fixed to the side surface of the case, and a dust-proof net 27a is provided on the front surface of the case. The air cleaner support frame 261 erected from the bottom plate frame 233 is bent obliquely rearward above the condenser 275 and further bent rearward above the intercooler 224. Accordingly, the air cleaner 221 is supported by the air cleaner support frame 261 so as to be positioned above the capacitor 275 at a position partially overlapping with the capacitor 275 in the front-rear direction.

  As shown in FIGS. 18 to 26 and the like, a plurality of heat exchangers including the intercooler 224 are arranged on the front surface of the radiator 235 so that the pressure loss of the offset portion with the cooling fan 59 is reduced. . Thereby, the flow velocity distribution of the cooling air flowing in the fan shroud 234 is leveled, and the generation of the differential pressure in the fan shroud 234 can be suppressed. Therefore, the backflow of the cooling air in the radiator 235 can be prevented, and the cooling efficiency in the radiator 235 can be increased.

  More specifically, the intercooler 224 is disposed on the upper front side of the radiator 235, the oil cooler 274 for cooling the lubricating oil is disposed on the lower front side of the radiator 235, and the condenser 275 is disposed on the front side of the oil cooler 274. With this arrangement, the pressure loss in the offset region between the cooling fan 59 and the radiator 235 is reduced, so that the cooling air can be taken in cheaply and the load applied to the cooling fan 59 can be reduced.

  Further, the air cleaner 221 is fixed at a position separated from the intercooler 224 in front of the intercooler 224. By arranging the air cleaner 221 and the intercooler 224 apart from each other, a space can be provided above the radiator 235 so that the cooling air can easily flow into the radiator 235. Thereby, the flow velocity distribution of the cooling air in the engine room under the hood 6 can be leveled in the height direction, and the backflow of the cooling air can be suppressed.

  As shown in FIG. 25, FIG. 26, etc., the air cleaner 221 and the capacitor 275 are arranged in front of the radiator 235 so that the capacitor 275 can be pulled out in the left-right direction. In other words, the rail 262 a is provided on the front side of the upper frame of the portal frame 262, while the rail 262 b is installed at a position directly below the rail 262 a of the frame bottom plate 233. Then, the upper and lower edges of the capacitor 275 are engaged with the upper and lower rails 262a and 262b, so that the capacitor 275 is sandwiched between the portal frame 262 and the rear bottom plate 233y so as to be slidable in the left-right direction.

  The condenser 275 is configured integrally with a receiver dryer 276 in which refrigerant hoses 277 and 278 connected to the air conditioning compressor 211 and the air conditioner 364 are coupled. The refrigerant hoses 277 and 278 are gripped so as to be hooked by the fan shroud 235 and the intercooler connection bracket 263. The capacitor 275 can be pulled out only by removing the hooks of the refrigerant hoses 277 and 278, and there is no need to remove the refrigerant hoses 277 and 278 from the receiver dryer 276. In this way, in the engine room, the space behind the air cleaner 221 is used to pull out the capacitor 275, thereby making it easy to access the space behind the capacitor 275. Therefore, the complexity of maintenance work such as dust removal work behind the capacitor 275 can be eliminated.

  On the front surface of the radiator 235, an intercooler 224 and an oil cooler 274 are arranged one above the other, and the oil cooler 274 is rotated around the vertical axis in a portal frame (fixed frame) 262 that fixes the upper intercooler 274. It is fixed so that it can move. That is, a shaft support member 262 c is provided on either one of the left and right frames of the portal frame 262, one of the left and right side surfaces of the oil cooler 274 is pivotally supported around the vertical axis, and the oil cooler 274 is attached to the portal frame 262. It can be opened and closed. In the present embodiment, the condenser 275 is pulled out to the right together with the receiver dryer 276 installed on the right side surface, so that the oil cooler 274 is pivotally supported on the right frame of the portal frame 262. Since the oil cooler 274 is installed behind the pullable condenser 275 so as to be rotatable around the vertical axis, the operator can easily access the lower part of the front surface of the radiator 235 where dust tends to accumulate due to the flow of cooling air, and the maintenance work is complicated. Can be eliminated.

  As shown in FIGS. 23 and 24, etc., a pair of left and right support frames 242 and 243 are erected on the upper surface of the engine support frame 237 so as to sandwich the engine leg 240 from the left and right. A bonnet shield plate (shield plate) 244 covering the rear of the bonnet 6 is connected to the pair of left and right support frames 242 and 243 so that the lower edge thereof is separated from the upper surface of the engine leg 240. The beam frame 248 is installed over the fan shroud 234 and the bonnet shield plate 244, respectively. Since the fan shroud 234 and the bonnet shield plate 244 that are stably supported by the traveling machine body 2 are installed by being connected by a pair of beam frames 248, these members are integrated to form a robust engine room frame body as a whole. it can.

  The left and right sides of the bonnet shield plate 244 are bent to cover the left and right rear sides of the engine room, while a space is formed between the front surface of the cabin 7 and the noise generated from the engine 5 in the engine room is generated by the cabin 7 ( Propagation to the control seat 8) can be prevented. Further, since the bonnet shield plate 244 has a shape in which both the left and right sides are inclined forward in a plan view, the left and right regions of the space surrounded by the engine room and the cabin 7 under the bonnet 6 are widened. Therefore, as shown in FIG. 7 and the like, a plurality of refrigerant hoses 277 and 279 on the engine room side connected to the receiver dryer 276 and the air conditioning compressor compressor 211 are connected to the air conditioner 364 of the cabin 7. When connecting to the refrigerant hose 280, the connection work behind the bonnet shield plate 244 is facilitated.

  The bonnet shield plate 244 includes a rear shield surface (first shield surface) 245 that has a front surface fixed to a pair of left and right column frames 242 and 243 and extends substantially parallel to the front windshield 321 front surface of the cabin 7, and the rear shield surface 245. It is composed of a pair of left and right side shield surfaces (second and third shield surfaces) 246 and 247 inclined forward from the left and right edges. Further, the left and right side shield surfaces 246 and 247 are connected to the middle portions of the support frames 242 and 243 and are supported more firmly.

  The bonnet shield plate 244 is disposed at a position separated from the front surface of the windshield 321 by the support frames 242 and 243. The left and right side shield surfaces 246 and 247 are inclined so that the left and right edges of the bonnet shield plate 244 are further separated from the front windshield 321 forward, and the cabin 7 is located at the left and right positions behind the bonnet shield plate 244. And can expand the space.

  As described above, the bonnet shield plate 244 has a bent shape in plan view. That is, both the left and right sides of the bonnet shield plate 244 are bent forward so that the left and right edges of the bonnet shield plate 244 are arranged in front of the center portion. Since the heat in the engine room under the hood 6 is shielded by the hood shield plate 244, it is possible to prevent the cabin 7 (control seat 8) behind the engine room from being heated by exhaust heat from the engine room. Therefore, the operator in the cabin 7 can comfortably operate without being affected by the exhaust heat of the engine 5 and the exhaust gas purification device 52.

  Inside the bonnet 6, a bonnet shield plate 244 is disposed on the back side of the bonnet 6 to cover at least the back surfaces of the exhaust gas purification device 52 and the exhaust pipe 227. The bonnet shield plate 244 covers at least the back surface of the diesel engine 5 by having a shape projecting left and right from the pair of left and right column frames 242 and 243. And the area | region of the bonnet shield board 244 right side is open | released in the engine room back side, and the exhaust pipe 227 and the tail pipe 229 are connected in the said area | region. By cutting out the lower right side of the right shield surface 247, a pleasant region for connecting the exhaust pipe 227 and the tail pipe 229 is provided.

  By covering the back of the hood 6 with the hood shield plate 244, heat in the engine room under the hood 6 is shielded by the hood shield plate 244, and the cabin 7 side is heated by exhaust heat from the engine room. Can be prevented. Therefore, the operator in the cabin 7 can comfortably operate without being affected by the exhaust heat of the diesel engine 5 and the exhaust gas purification device 52. By disposing the bonnet shield plate 244 away from the front surface of the cabin 7, a heat insulating layer is formed between the cabin 7 disposed behind the bonnet 6 and the bonnet shield plate 244.

  As shown in FIGS. 23, 24, and 28, a pair of left and right support frames 242 and 243 are connected to a central region (rear shield surface 245) sandwiched between bent portions of the bonnet shield plate 244. 242 and 243 and a fan shroud 235 are installed by a beam frame 248. Since the fan shroud 235 and the support frames 242 and 243 that are stably supported by the traveling machine body 2 are erected and connected by the beam frame 248, these members are integrated to form a robust engine room frame body as a whole. .

  A bonnet support bracket 255 is installed on the upper ends of the support frames 242 and 243. The bonnet support bracket 255 is connected to the hinge member 253 provided at the rear part of the bonnet 6 so that the rear part of the bonnet 6 is pivotally supported on the upper ends of the support frames 242 and 243. The bonnet support bracket 255 has a shape in which both right and left edges are bent, and is fixed to the front sides of the support frames 242 and 243. The bonnet support bracket 255 is configured in a U shape (U shape) in which both left and right edges are bent rearward, and both ends are connected to the column frames 242 and 243 and the front surface of the beam frame 248 is connected to the bonnet support bracket 255. Connect to the rear end. That is, the beam frame 248 is connected to the support frames 242 and 243 via the bonnet support bracket 255.

  The beam frame 248 extends in the front-rear direction so that the right edge of the beam frame 248 is positioned on the right side of the center position of the bonnet 6. The exhaust gas purification device 52 is disposed along the beam frame 248 so that the exhaust gas purification device 52 is positioned between the beam frame 248 and the inner side surface of the bonnet 6 above the engine 5. Since the exhaust gas purification device 52 is positioned between the beam frame 248 and the inner side surface of the bonnet 6, the space around the exhaust gas purification device 52 is widened, and the complexity of component assembly and maintenance above the engine 6 can be eliminated.

  A heat shield plate 250 is provided above the engine 5 so as to cover the rear side from the middle part of the beam frame 248 under the hood 6. Crosspiece frames 251 and 252 are extended on both the left and right sides in the middle part and the rear end of the beam frame 248, respectively. That is, the front crosspiece frame 251 is fixed on the upper halfway part of the beam frame 248 and extends to the left and right of the beam frame 248. A rear crosspiece frame 252 is fixed on the upper rear end of the beam frame 248 and extends to the left and right of the beam frame 248. Then, both front and rear edges of the heat shield plate 250 are fixed to a pair of front and rear crosspiece frames 251 and 252. The heat shield plate 250 is disposed so as to cover the upper part of the exhaust gas purification device 52 and the exhaust pipe 227 on the upper side of the engine 5. By disposing the heat shield plate 250 between the exhaust gas purifying device 52 and the exhaust pipe 227 and the bonnet 6, it is possible to prevent the bonnet 6 from being heated by exhaust heat from the engine room.

  An exhaust gas purification device 52 mounted on the upper part of the engine 5 is positioned behind the bonnet 6, and a heat shield plate 250 is disposed between the bonnet 6 and the exhaust gas purification device 52. By disposing the heat shield plate 250 on the exhaust gas purification device 52, it is possible to prevent the bonnet 6 from being heated by the exhaust heat of the exhaust gas purification device 52 and the diesel engine 5. Further, a space can be formed between the hood 6 and the heat shield plate 250 to insulate the engine room below the heat shield plate 250 from the outside air, and the exhaust gas purification device 52 can be operated in a high temperature environment. .

  Further, in addition to the heat shield plate 250, a bonnet shield plate 244 that is disposed on the back side of the bonnet 6 and covers at least the exhaust gas purification device 52 from the back side is provided. Since the heat in the engine room under the hood 6 is shielded by the hood shield plate 244 together with the heat shield plate 250, the cabin 7 can be prevented from being heated by exhaust heat from the engine room. Further, by providing a gap between the bonnet shield plate 244 and the heat shield plate 250, it is difficult to trap hot air in the engine room below the bonnet 6, and heat damage to the exhaust gas purifying device 52 itself, the bonnet 6 and the like is prevented. Generation can be suppressed.

  Stretchable gas springs (bonnet dampers) 256 and 256 are disposed on the left and right sides of the heat shield plate 250 below the bonnet 6. One end (rear end) of each of the left and right gas springs 256, 256 is pivotally attached to the engine room frame body, and the other end (front end) of each of the gas springs 256, 256 is pivotally attached to the upper inner surface of the bonnet 6. doing. The extension frame 249 has a shape extending left and right with the rear end of the beam frame 248 as the center, and is connected to the left and right ends of the rear frame 252.

  That is, the extension frame 249 is integrated with the beam frame 248 and the rear beam frame 252 on the rear end side of the beam frame 248. Then, one end (rear end) of each of the pair of left and right gas springs 256 and 256 is pivotally attached to the left and right ends of the extension frame 249 at a position ahead of the left and right ends of the rear frame 252.

  Further, the bonnet 6 is held in the open position by the thrust action of the gas spring 256. Therefore, by lifting the front part of the bonnet 6 and opening the bonnet 6 with the upper end position of the bonnet shield plate 244 as an axis fulcrum, the bonnet 6 can be held open by the gas spring 256, so that the diesel engine 5 Maintenance work can be performed.

  In addition, the structure of each part in this invention is not limited to embodiment of illustration, A various change is possible in the range which does not deviate from the meaning of this invention.

DESCRIPTION OF SYMBOLS 1 Tractor 2 Traveling machine body 5 Diesel engine 6 Bonnet 7 Cabin 10 Step 10x Front right step 10y Back right step 11 Fuel tank 14 Engine frame 15 Body frame 18 Tank frame 52 Exhaust gas purification device (DPF)
54 Cylinder block 55 Cylinder head 56 Intake manifold 57 Exhaust manifold 59 Cooling fan 60 Flywheel housing 216 Frame outer cover (downward guide plate)
217 Side guide plate 218 Frame outer cover (downward guide plate)
219 Frame outer cover (downward guide plate)
232 Side engine cover 233 Frame bottom plate 234 Fan shroud 234a Upper shielding portion 234b Side shielding portion 238 Front engine leg 264 Ceiling portion 265 Side surface portion 266 Shielding protrusion (shielding plate)
266a Seal member (elastic member)
267 Seal member (elastic member)
268 Opening hole 268a Upper opening hole 268b Lower opening hole 269 Sealing member 270 Opening hole 285 Air volume adjusting plate (right)
286 Airflow adjustment plate (left)
287 Insulation

Claims (3)

An engine mounted on a front portion of the traveling machine body, a cooling fan for the engine, and a bonnet that covers the engine; the cooling fan is disposed on a front side of the engine; and the hood is driven by driving the cooling fan. In the tractor configured to take cooling air from the front grill formed on the front surface into the bonnet,
On each of the left and right sides of the bonnet, an upper opening hole and a lower opening hole are provided above and below ,
The pair of left and right air volume adjustment plate covering a portion of the opening hole is provided within the bonnet,
Each of the pair of left and right air volume adjusting plates is installed on the rear edge side of each of the left and right opening holes,
One of the air volume adjusting plates covers the entire rear edge of the corresponding upper opening hole and the lower opening hole, while the other air volume adjusting plate includes the corresponding upper opening hole and the lower opening hole. A tractor characterized by covering a part of the lower opening hole . The front edge of one of the air volume adjusting plates is located behind the front edge of the other air volume adjusting plate, and the other air volume adjusting plate is provided with a plurality of opening holes. The tractor according to 1 . 3. The tractor according to claim 1, wherein the cooling fan rotates in a direction from one air volume adjusting plate to the other air volume adjusting plate. 4.

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