JP2015151999A - Control device of multi-cylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure combustion stability of an engine by making a lamp height low, and prevent deterioration of fuel consumption in a multi-cylinder engine provided with a valve stop device having a lock mechanism in a pivot type HLA.SOLUTION: In light load operation of whole cylinder operation of an engine, when an oil temperature exceeds a predetermined threshold, an engine rotational frequency is increased, and target torque of the engine is reduced.

Description

  The present invention relates to a control device for a multi-cylinder engine.

  Patent Document 1 describes that in a valve operating device including a swing arm type valve variable mechanism, a pivot type HLA, and a swing arm, the engine speed is increased when the oil temperature exceeds a set temperature. A technology that increases the oil amount and hydraulic pressure by increasing the engine speed, thereby reducing the amount of HLA hydraulic oil leak-down in each cylinder and reducing engine vibration by suppressing variations in lift characteristics between cylinders. is there.

  There is also known a cylinder number control engine that switches between all-cylinder operation for operating all of a plurality of cylinders of the engine and reduced-cylinder operation for stopping the operation of a specific cylinder that is a part of all cylinders. While all cylinders are operated during high load, some cylinders are deactivated during low load operation to reduce fuel consumption.

  In such a cylinder number control engine, for example, a valve stop device for closing the intake / exhaust valves in a part of the cylinders is provided in a valve operating device provided with the pivot type HLA. The valve stop device has, for example, a lock mechanism that prevents the HLA from moving downward. By releasing the lock, the valve stop device moves downward when the HLA is pushed by the swing arm, and the intake / exhaust valve does not open. Configured as follows.

JP 2010-059945 A

  By the way, the cam profile of the intake and exhaust cams of a specific cylinder (stop cylinder) equipped with the valve stop device is designed to increase the lamp height in consideration of the clearance of the lock mechanism, its variation and wear, and other cylinders (non-cylinder) The stop cylinder) must also be designed with a high lamp height to match the specific cylinder. Therefore, the overlap of the intake and exhaust valves increases (internal EGR increases), engine combustion becomes unstable during idle operation of all cylinders of the engine, and the valve overlap amount between the cylinders due to the variation in the clearance. There is a concern that engine fluctuations may occur due to torque fluctuations due to variations.

  In order to solve this problem, it is conceivable to reduce the valve overlap amount by shifting the opening / closing timing of the intake / exhaust valve. However, if the timing is largely shifted, fuel consumption and output are deteriorated.

  Therefore, the present invention provides a multi-cylinder engine provided with a valve stop device having a lock mechanism in a pivot type HLA, so that the lamp height can be designed to be low so as to ensure combustion stability of the engine and to improve fuel efficiency. The problem is to suppress the deterioration.

  In order to solve the above-described problems, the present invention is designed to increase the engine speed and decrease the target torque of the engine when the oil temperature is high during the light load operation of the engine.

The control device for a multi-cylinder engine presented here has a plurality of cylinders, each of which supports a swing arm with a pivot type HLA and operates the swing arm with a camshaft cam so that an intake valve or an exhaust valve Equipped with a valve gear that opens and closes
At least one of the intake valve and the exhaust valve of the specific cylinder among the plurality of cylinders has a lock mechanism that prevents the HLA from moving downward so that the valve is opened and closed by the swing arm. Is provided with a valve stop device that releases the HLA and allows the HLA to move downward and closes the valve.
A hydraulic actuator including the HLA of the engine and an oil pump for supplying oil to the lubrication part;
When the oil temperature exceeds a predetermined threshold during all-cylinder operation in which the HLA of the specific cylinder is prevented from descending, the engine speed is increased and the engine target torque is decreased. Control means is provided.

  When a valve stop device having a lock mechanism is provided in the pivot type HLA, the lamp height is designed in consideration of the clearance of the lock mechanism, its variation and wear as described above. On the other hand, according to the present invention, when the oil temperature exceeds a predetermined threshold during the light load operation of the all cylinder operation, the engine speed is increased, so that the amount of oil leakage of HLA is reduced. The amount of HLA subsidence is reduced by the reduction in the amount of oil leak, so that the lamp height can be lowered, which is advantageous in ensuring combustion stability during light load operation. Thus, when the oil temperature exceeds a predetermined threshold, the engine speed is increased and the target torque of the engine is decreased, so that deterioration of fuel consumption can be suppressed.

In a preferred aspect of the present invention, the apparatus includes an angular velocity fluctuation amount detection device that detects an angular velocity fluctuation amount of the crankshaft of the engine,
When the angular velocity fluctuation amount detected by the angular velocity fluctuation amount detection device is larger than a predetermined threshold value during the light load operation of the all-cylinder operation, the control means is configured so that the angular velocity fluctuation amount becomes equal to or less than the predetermined threshold value. Furthermore, the engine driving load is increased by increasing the discharge amount of the oil pump.

  That is, although a reduction in the target torque of the engine is advantageous in terms of fuel consumption, it is necessary to avoid an increase in the engine torque fluctuation due to an increase in the angular speed fluctuation amount of the crankshaft. Therefore, when the angular velocity fluctuation amount is larger than the predetermined threshold value, the discharge amount of the oil pump is increased so that the angular velocity fluctuation amount is not more than the predetermined threshold value. Thereby, the driving load of the engine increases. As a result, the intake air amount increases, the amount of fresh air with respect to the internal EGR amount in each cylinder increases, and the fuel injection amount also increases, so that the combustion stability in each cylinder is improved.

In a preferred aspect of the present invention, the apparatus further comprises a hydraulic pressure detection device that detects the hydraulic pressure of the hydraulic pressure supply device and the hydraulic path for supplying oil to the lubrication unit,
The oil pump is a variable displacement type that can adjust the oil discharge amount,
The control means controls the discharge amount of the oil pump so that the oil pressure detected by the oil pressure detection device becomes a target oil pressure set in advance in the hydraulic operation device in accordance with the operating state of the engine. It is characterized by.

  By adopting the variable displacement oil pump, it is possible to improve the fuel consumption by appropriately adjusting the driving load of the oil pump while securing the hydraulic pressure of the hydraulic actuator that changes according to the operating state of the engine.

  According to the present invention, each cylinder is provided with a valve operating device that supports a swing arm by a pivot type HLA, and the specific cylinder is provided with a valve stop device having a lock mechanism that prevents the HLA from moving downward, so that all cylinders can be operated. During light load operation, when the oil temperature exceeds a predetermined threshold, the engine speed is increased and the target torque of the engine is decreased, so that the oil temperature is predetermined during light load operation in all cylinder operation. The amount of oil leakage of HLA when the threshold value is exceeded is reduced, so that the sinking of HLA is reduced, so that the lamp height can be lowered, which is advantageous for ensuring combustion stability during light load operation. . In addition, when the oil temperature exceeds a predetermined threshold, the engine speed is increased and the target torque of the engine is decreased, so that deterioration of fuel consumption can be suppressed.

1 is a cross-sectional view showing a schematic configuration of a multi-cylinder engine according to an embodiment of the present invention. It is sectional drawing which shows the structure and action | operation of a hydraulically operated valve stop apparatus. (A) is sectional drawing which shows schematic structure of a variable valve timing mechanism, (b) is a graph which shows typically the valve characteristics (relationship between a phase and lift amount) of an intake valve and an exhaust valve. It is a figure which shows schematic structure of an oil supply apparatus. It is a figure which shows the characteristic of a variable displacement type oil pump. It is a figure which shows the reduced-cylinder operation area | region of an engine. It is a figure for demonstrating the setting of the target hydraulic pressure of a pump. It is a hydraulic control map which shows the target oil pressure with respect to the operating state of an engine. It is a duty ratio map which shows the duty ratio with respect to the driving | running state of an engine. It is a figure which shows the flow of the flow volume (discharge amount) control of an oil pump. It is a figure which shows the flow of cylinder number control of an engine. It is a time chart which shows the driving | running state of an engine at the time of switching from all cylinder operation to reduced cylinder operation. It is a figure explaining the lamp height of the cam profile of an intake / exhaust valve. It is a figure explaining the valve overlap of an intake / exhaust valve. It is explanatory drawing about the lever ratio of a swing arm. It is explanatory drawing which shows the relationship between the increase change amount (DELTA) H of the sinking of HLA, and the lift decrease change amount (DELTA) L of an intake / exhaust valve. It is explanatory drawing about the setting of the lamp height in the case which is not provided with a valve stop apparatus. It is explanatory drawing about the setting of the lamp height in a case provided with a valve stop apparatus. It is a figure which shows the difference in the valve overlap amount by the presence or absence of a valve stop apparatus. It is a graph which shows the relationship between oil temperature, an engine speed, and a sinkdown amount. It is a figure which shows the cam profile on each design of idle speed 550rpm and 850rpm when oil temperature is 140 degreeC. It is a flowchart of idle operation control.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its use.

  A multi-cylinder engine 2 (hereinafter simply referred to as “engine 2”) shown in FIG. 1 is an in-line four-cylinder gasoline engine in which first to fourth cylinders are arranged in series in a direction perpendicular to the plane of FIG. Therefore, it is mounted on a vehicle such as an automobile. In the engine 2, a cam cover 3, a cylinder head 4, a cylinder block 5, and an oil pan 6 (see FIG. 4) are connected vertically. A piston 8 provided on a cylinder (cylinder bore) 7 of the cylinder block 5 and a crankshaft 9 are connected by a connecting rod 10, and a combustion chamber 11 is formed by the cylinder 7, the piston 8 and the cylinder head 4 of the cylinder block 5. Yes.

  The cylinder head 4 is provided with an intake valve 14 and an exhaust valve 15 that open and close the intake port 12 and the exhaust port 13. The intake valve 14 and the exhaust valve 15 are urged in the closing direction (upward in FIG. 1) by return springs 16 and 17. A valve operating device for the intake valve 14 and the exhaust valve 15 supports the swing arms 20 and 21 by a pivot type HLA (a well-known hydraulic lash adjuster that automatically adjusts the valve clearance to zero by hydraulic pressure) 24. The swing arms 20 and 21 are operated by the cams 18a and 19a of the cam shafts 18 and 19, respectively. That is, the rotatable cam followers 20a and 21a at the substantially central portions of the swing arms 20 and 21 are pushed downward by the cams 18a and 19a, and the swing arms 20 and 21 swing around the pivot 23 of the HLA 24 that supports one end thereof. The other end of the swing arms 20 and 21 pushes the intake valve 14 and the exhaust valve 15 downward against the urging force of the return springs 16 and 17 to open them.

  In the first and fourth cylinders (specific cylinders) located at both ends in the cylinder row direction of the engine 2, a hydraulically operated valve stop device 25 having a lock mechanism that prevents the HLA 24 from moving downward is provided. The valve stop device 25 releases the lock of the HLA 24 during the reduced-cylinder operation of the engine and allows its downward movement, thereby bringing the intake and exhaust valves 14 and 15 into a closed valve stop state. Thereby, the operation (combustion operation) of the first and fourth cylinders is stopped. The second and third cylinders near the center in the cylinder row direction are not provided with a valve stop device, and operate even during the reduced cylinder operation. The engine 2 is switched between an all-cylinder operation in which all cylinders are operated and a reduced-cylinder operation in which the first and fourth cylinders are deactivated and the second and third cylinders are activated according to the operation state.

  Mounting holes 26 and 27 for inserting and mounting the lower end portion of the valve stop device 25 are provided in portions on the intake side and the exhaust side corresponding to the first and fourth cylinders in the cylinder head 4. Two oil passages 61, 63 and 62, 64 communicate with the mounting holes 26, 27, respectively. The oil passages 61 and 62 supply hydraulic pressure (operating pressure) to the valve stop device 25, and the oil passages 63 and 64 supply hydraulic pressure to the HLA 24. A mounting hole for inserting and mounting the lower end portion of the HLA 24 is provided in portions on the intake side and the exhaust side corresponding to the second and third cylinders in the cylinder head 4. Only the oil passages 63 and 64 communicate with the mounting hole.

  The cylinder block 5 is provided with a main gallery 54 extending in the cylinder row direction in the side wall on the exhaust side of the cylinder 7. An oil jet (oil injection valve) 28 for cooling the piston communicating with the main gallery 54 is provided for each piston 8 in the vicinity of the lower side of the main gallery 54. The oil jet 28 has a nozzle portion 28 a disposed on the lower side of the piston 8, and injects oil toward the back surface of the top portion of the piston 8.

  Oil showers 29 and 30 formed of pipes are provided above the camshafts 18 and 19, respectively. Lubricating oil is dripped from the oil showers 29 and 30 to the cams 18a and 19a of the cam shafts 18 and 19 and the contact portions between the swing arms 20 and 21 and the cam followers 20a and 21a.

  Next, the valve stop device 25 which is one of the hydraulic actuators will be described with reference to FIG. The valve stop device 25 is provided between a bottomed outer cylinder 251 that slidably houses the HLA 24 in the axial direction, a pair of opposing lock pins 252 provided on the lower side of the HLA 24, and both lock pins 252. And a lost motion spring 254 provided between the bottom of the outer cylinder 251 and the HLA 24.

  The outer cylinder 251 is formed with two through-holes 251a that face each other in the diameter direction of the outer cylinder 251. The pair of lock pins 252 are provided so as to be able to enter and exit the two through holes 251 a from the inside of the outer cylinder 251. As shown in FIG. 2A, a state in which the pair of lock pins 252 are fitted in the through holes 251a is a locked state in which the lock pins 252 prevent the HLA 24 from moving downward. As shown in FIGS. 2 (b) and 2 (c), the state in which the pair of lock pins 252 has been removed from the through hole 251a to the inside of the outer cylinder 251 is an unlocked state that allows the HLA 24 to move down together with the lock pin 252. is there. A lock mechanism is configured by the through hole 251 a of the outer cylinder 251 and the lock pin 252.

  The pair of lock pins 252 is urged by a lock spring 253 in a direction (lock direction) in which the lock pin 252 is fitted into the through hole 251a. When receiving a hydraulic pressure against the urging force of the lock spring from the oil passages 61 and 62, the pair of lock pins 252 comes out from the through hole 251a to the inside of the outer cylinder 251 as shown in FIG. ). The lost motion spring 254 biases the pair of lock pins 252 together with the HLA 24 in the upward movement direction. When the HLA 24 is pushed by the swing arms 20 and 21 in the unlocked state, the lost motion spring 254 is compressed as shown in FIG. 2C, and the HLA 24 moves down in the outer cylinder 251 together with the lock pin 252. (Valve stopped state).

  The return springs 16 and 17 that bias the intake and exhaust valves 14 and 15 upward are configured to have a stronger biasing force than the lost motion spring 254 that biases the pivot mechanism 25a upward. Therefore, when the cams 18a and 19a push the swing arms 20 and 21 downward in the unlocked state, the tops of the intake and exhaust valves 14 and 15 become fulcrums for swinging the swing arms 20 and 21, and the HLA 24 The intake / exhaust valves 14 and 15 are not opened by being pushed downward against the urging force of the lost motion spring 254.

  Next, referring to FIG. 3, variable valve timing as a hydraulic actuator that changes the valve characteristics of at least one (both in the present embodiment) of the intake and exhaust valves 14 and 15 of all cylinders of the engine 2 by hydraulic operation. The mechanisms 32 and 33 (hereinafter simply referred to as “VVT”) will be described. VVT32 is an intake-side VVT, and VVT33 is an exhaust-side VVT.

  The VVTs 32 and 33 include substantially annular housings 321 and 331 and rotors 322 and 332 accommodated inside the housings 321 and 331. The housings 321 and 331 are coupled to cam pulleys 323 and 333 that rotate in synchronization with the crankshaft 9 so as to be integrally rotatable. The rotors 322 and 332 are connected to camshafts 18 and 19 that open and close the intake and exhaust valves 14 and 15 so as to be integrally rotatable. Inside the housings 321 and 331, there are retarded hydraulic chambers 325 and 335 and advanced hydraulic chambers 326 and 336 defined by inner peripheral surfaces of the housings 321 and 331 and vanes 324 and 334 provided in the rotors 322 and 332. A plurality of and are formed. These retarded hydraulic chambers 325 and 335 and the advanced hydraulic chambers 326 and 336 are supplied with variable displacement oil pumps 36 (see FIG. 4), which supply oil via first direction switching valves 34 and 35 (see FIG. 4). 4) is connected. When the oil is guided to the retarded hydraulic chambers 325 and 335 by the control of the first direction switching valves 34 and 35, the rotation direction of the cam shafts 18 and 19 (the direction of the arrow in FIG. 3A) is determined by the hydraulic pressure. Since it moves in the opposite direction, the opening timing of the intake and exhaust valves 14 and 15 is delayed. On the other hand, when the oil is guided to the advance hydraulic chambers 326 and 336, the camshafts 18 and 19 are moved in the rotation direction by the hydraulic pressure, The opening timing of the intake / exhaust valves 14, 15 is advanced.

  FIG. 3B shows the opening phases of the intake valve 14 and the exhaust valve 15. As can be seen from the figure, the valve opening phase of the intake valve 14 is changed to the advance direction (see the arrow in FIG. 3B) by the VVT 32 (and / or 33) (and / or the exhaust valve 15). The valve opening phase of the exhaust valve 15 and the valve opening period of the intake valve 14 (see the alternate long and short dash line) overlap. By overlapping the opening periods of the intake valve 14 and the exhaust valve 15 in this way, the amount of internal EGR during engine combustion can be increased, and pumping loss can be reduced to improve fuel efficiency. Further, since the combustion temperature can be suppressed, NOx generation can be suppressed and exhaust purification can be achieved. On the other hand, when the valve opening phase of the intake valve 14 is changed in the retard direction (and / or the valve opening phase of the exhaust valve 15 is changed in the advance direction) by the VVT 32 (and / or 33), the intake valve 14 The valve overlap amount between the valve opening period (see the solid line) and the valve opening period of the exhaust valve 15 is reduced, so that stable combustibility is achieved when the engine load is lighter than a predetermined threshold, such as during idling. It can be secured. In the present embodiment, in order to increase the valve overlap amount as much as possible when the load is high, the valve opening periods of the intake valve 14 and the exhaust valve 15 are overlapped even when the load is light.

  Next, the oil supply apparatus 1 that supplies oil to the engine 2 will be described with reference to FIG. The oil supply device 1 includes a variable displacement oil pump 36 that is driven by rotation of the crankshaft 9 and a hydraulic path 50 that guides the oil boosted by the oil pump 36 to the lubricating portion of the engine 2 and the hydraulic actuator. ing. The oil pump 36 is an auxiliary machine driven by the engine 2, and the auxiliary machine includes an alternator 81 as a generator that is driven by the engine 2 and generates electric power.

  The hydraulic path 50 includes a pipe, a path drilled in the cylinder head 4, the cylinder block 5, and the like. The hydraulic path 50 includes a first communication path 51 extending from the discharge port 361b of the oil pump 36 to the branch point 54a in the cylinder block 5, the main gallery 54 extending in the cylinder row direction in the cylinder block 5, and the main gallery 54. A second communication path 52 extending from the upper branching point 54 b to the cylinder head 4, a third communication path 53 extending in the horizontal direction between the intake side and the exhaust side in the cylinder head 4, and a second communication path in the cylinder head 4. A plurality of oil passages 61 to 69 branched from the three-way passage 53 are provided.

  The oil pump 36 includes a housing 361 that includes a pump body having a pump housing chamber and a cover member that closes one side opening of the pump body, and is rotatably supported by the housing 361. A drive shaft 362 that passes through and is rotationally driven by the crankshaft 9, a rotor 363 coupled to the drive shaft 362, and a vane accommodated in a retractable manner in each of a plurality of radially extending slits formed in the rotor 363. And a pump chamber 365 that is a plurality of hydraulic oil chambers together with the rotor 363 and the adjacent vanes 364. The cam ring 366 that is defined, and the cam ring 366 that is housed in the pump body and is offset from the rotation center of the rotor 363 A spring 367 that biases the cam ring 366 toward the amount increasing side, and a pair of ring members 368 having a smaller diameter than the rotor 363 are slidably disposed on both inner peripheral sides of the rotor 363. .

  The housing 361 includes a suction port 361 a that supplies oil to the pump chamber 365 and a discharge port 361 b that discharges oil from the pump chamber 365. A pressure chamber 369 is formed by the inner peripheral surface of the housing 361 and the outer peripheral surface of the cam ring 366, and an introduction hole 369 a is opened in the pressure chamber 369. By introducing oil into the pressure chamber 369 from the introduction hole 369a, the cam ring 366 swings around the fulcrum 361c, and as a result, the rotor 363 is eccentric relative to the cam ring 366, and the oil pump 36 discharges. The capacity changes.

  An oil strainer 39 facing the oil pan 6 is connected to the suction port 361 a of the oil pump 36. In the first communication passage 51 communicating with the discharge port 361b of the oil pump 36, an oil filter 37 and an oil cooler 38 are arranged in order from the upstream side to the downstream side. The oil in the oil pan 6 is pumped up by the oil pump 36 through the oil strainer 39, filtered by the oil filter 37, cooled by the oil cooler 38, and introduced into the main gallery 54 in the cylinder block 5.

  The main gallery 54 supplies oil to metal bearings arranged in the oil jet 28 for injecting cooling oil to the back side of the four pistons 8 and five main journals for rotatably supporting the crankshaft 9. It is connected to the oil supply part 42 of the metal bearing arrange | positioned at the crankpin of the crankshaft 9 which connects the part 41 and the four connecting rods 10 rotatably. Oil is constantly supplied to the main gallery 54.

  On the downstream side of the branch point 54 c on the main gallery 54, oil is supplied from the introduction hole 369 a to the oil supply portion 43 that supplies oil to the hydraulic chain tensioner and the pressure chamber 369 of the oil pump 36 via the linear solenoid valve 49. An oil passage 40 to be supplied is connected.

  The oil passage 68 branched from the branch point 53a of the third communication passage 53 is connected to the advance hydraulic chamber 336 of the exhaust side VVT 33 for changing the opening / closing timing of the exhaust valve 15 via the exhaust side first direction switching valve 35, and It is connected to the retarded hydraulic chamber 335 and is configured to supply oil by controlling the first direction switching valve 35. The oil passage 64 branched from the branch point 53a includes a metal bearing oil supply unit 45 (see the white triangle Δ in FIG. 4) disposed in the cam journal of the exhaust-side cam shaft 19 and the HLA 24 (black in FIG. 4). It is connected to a valve stop device 25 (see the white oval in FIG. 4). An oil passage 66 that branches from a branch point 64 a of the oil passage 64 is connected to an oil shower 30 that supplies lubricating oil to the swing arm 21 on the exhaust side. Oil is always supplied to the oil passage 64 and the oil passage 66.

  The intake side is the same as the exhaust side, and the oil passage 67 branched from the branch point 53c of the third communication passage 53 changes the opening / closing timing of the intake valve 14 via the intake side first direction switching valve 34. The VVT 32 is connected to the advance hydraulic chamber 326 and the retard hydraulic chamber 325. The oil path 63 branched from the branch point 53d includes a metal bearing oil supply unit 44 (see a white triangle Δ in FIG. 4) disposed in the cam journal of the intake-side cam shaft 18 and an HLA 24 (black in FIG. 4). It is connected to a valve stop device 25 (see the white oval in FIG. 4). The oil passage 65 branched from the branch point 63a of the oil passage 63 is connected to an oil shower 29 that supplies lubricating oil to the swing arm 20 on the intake side.

  The oil passage 69 branched from the branch point 53c of the third communication path 53 has a check valve 48 that restricts the direction of oil flow in only one direction from the upstream side to the downstream side, and the check valve 48 and the branch point 53c. And a hydraulic pressure sensor 70 that detects the hydraulic pressure in the hydraulic path 50 (upstream of the check valve 48 in the oil path 69). The hydraulic pressure sensor 70 constitutes a hydraulic pressure detection device that detects the hydraulic pressure of the hydraulic pressure path 50 for supplying oil to the lubrication part of the engine 2 and the hydraulic operation device by the oil pump 36.

  The oil passage 69 branches at the branch point 69 a downstream of the check valve 48 into the two oil passages 61 and 62 communicating with the mounting holes 26 and 27 for the valve stop device 25. The oil passages 61 and 62 are connected to the intake-side and exhaust-side valve stop devices 25 via the intake-side and exhaust-side second direction switching valves 46 and 47, respectively. Oil is supplied to each valve stop device 25 by controlling the second direction switching valves 46 and 47.

  The metal bearing for rotatably supporting the crankshaft 9 and the camshafts 18 and 19 and the lubricating and cooling oil supplied to the piston 8 and the camshafts 18 and 19 are shown after being cooled and lubricated. Return to the oil pan 6 through the drain oil passage.

  The operation of the engine 2 is controlled by a controller (control means) 100. The controller 100 receives detection information from various sensors (hydraulic sensor 70, crank angle sensor 71, throttle position sensor 72, oil temperature sensor 73, cam angle sensor 74, water temperature sensor 75, etc.) that detect the operating state of the engine 2. Entered. The crank angle sensor 71 detects the rotation angle of the crankshaft 9, and the engine speed is detected based on this detection signal. The throttle position sensor 72 detects the amount of depression of the accelerator pedal (accelerator opening) by the occupant of the vehicle on which the engine 2 is mounted, and the engine load is detected based on this. The oil temperature sensor 73 and the oil pressure sensor 70 detect the oil temperature and pressure in the oil pressure path. The oil temperature sensor 73 is disposed in the third communication path 53 of the hydraulic path 50. A cam angle sensor 74 provided in the vicinity of the cam shafts 18 and 19 detects the rotational phase of the cam shafts 18 and 19, and the operating angles of the VVTs 32 and 33 are detected based on the cam angles. Further, the water temperature sensor 75 detects the temperature of the cooling water of the engine 2 (hereinafter referred to as water temperature).

  The controller 100 is a control device based on a well-known microcomputer, and includes a signal input unit that inputs detection signals from the various sensors, a calculation unit that performs calculation processing related to control, and a device to be controlled ( A signal output unit that outputs a control signal to the first direction switching valves 34 and 35, the second direction switching valves 46 and 47, the linear solenoid valve 49, the alternator 81, and the like, and a program and data required for control (hydraulic control described later) A storage unit for storing a map, a duty ratio map, and the like.

  The linear solenoid valve 49 is a flow rate (discharge amount) control valve for controlling the discharge amount from the oil pump 36 in accordance with the operating state of the engine 2. Oil is supplied to the pressure chamber 369 of the oil pump 36 when the linear solenoid valve 49 is opened. Since the configuration of the linear solenoid valve 49 itself is well known, a description thereof will be omitted. The flow rate (discharge amount) control valve is not limited to the linear solenoid valve 49, and for example, an electromagnetic control valve may be used.

  The controller 100 transmits a control signal having a duty ratio according to the operating state of the engine 2 to the linear solenoid valve 49 to control the hydraulic pressure supplied to the pressure chamber 369 of the oil pump 36 via the linear solenoid valve 49. To do. The flow rate (discharge amount) of the oil pump 36 is controlled by controlling the amount of eccentricity of the cam ring 366 and the amount of change in the internal volume of the pump chamber 365 by the hydraulic pressure of the pressure chamber 369. That is, the capacity of the oil pump 36 is controlled by the duty ratio. Here, since the oil pump 36 is driven by the crankshaft 9 of the engine 2, the flow rate (discharge amount) of the oil pump 36 is proportional to the engine speed, as shown in FIG. When the duty ratio represents the ratio of the energization time to the linear solenoid valve 49 with respect to the time of one cycle, as shown in the figure, the greater the duty ratio, the greater the hydraulic pressure to the pressure chamber 369 of the oil pump 36. The inclination of the flow rate of the oil pump 36 with respect to the pressure becomes small. As the discharge amount of the oil pump 36 increases, the drive load of the oil pump 36 driven by the engine 2 increases, and the discharge amount of the oil pump 36 is controlled by the control of the drive load of the oil pump 36. But there is.

  In this way, the controller 100 constitutes a pump control device that controls the discharge amount of the oil pump 36 by changing the capacity of the oil pump 36, and an auxiliary device control device that controls the driving load of the oil pump 36 as an auxiliary device. Will be configured. The controller 100 also controls the driving load of the alternator 81 as an auxiliary machine.

  Next, the reduced cylinder operation of the engine 2 will be described with reference to FIG. The reduced-cylinder operation or all-cylinder operation of the engine 2 is switched according to the operating state of the engine 2. That is, when the operating state of the engine 2 that is grasped from the engine speed, the engine load, and the engine water temperature is in the illustrated reduced cylinder operating region, the reduced cylinder operation is executed. A reduced cylinder operation preparation area is provided adjacent to the reduced cylinder operation area, and when the engine is in the reduced cylinder operation preparation area, the hydraulic pressure is stopped as a preparation for executing the reduced cylinder operation. The pressure is raised in advance toward the required oil pressure of the device 25. When the operating state of the engine 2 is outside the reduced cylinder operation region and the reduced cylinder operation preparation region, the all cylinder operation is executed.

  Referring to FIG. 6 (a), when the engine speed is increased by accelerating at a predetermined engine load (L0 or less), all cylinder operation is performed at an engine speed less than a predetermined speed V1, and the engine speed is increased. When V becomes greater than or equal to V1 and less than V2 (> V1), preparation for reduced cylinder operation starts, and when the engine speed becomes equal to or greater than V2, reduced cylinder operation is performed. Further, for example, when the engine speed is decreased by decelerating at a predetermined engine load (L0 or less), all cylinder operation is performed when the engine speed is V4 or more, and the engine speed is V3 (<V4) or more. When it is less than V4, preparation for reduced cylinder operation is performed, and when the engine speed becomes V3 or less, reduced cylinder operation is performed.

  Referring to FIG. 6B, when the vehicle runs at a predetermined engine speed (V2 to V3) and a predetermined engine load (L0 or less) and the engine 2 warms up and the water temperature rises, the water temperature is less than T0. Then, all-cylinder operation is performed, and when the water temperature is equal to or higher than T0 and lower than T1, preparation for reduced-cylinder operation is performed, and when the water temperature is equal to or higher than T1, reduced-cylinder operation is performed.

  If the reduced-cylinder operation preparation region is not provided, when switching from all-cylinder operation to reduced-cylinder operation, the hydraulic pressure is increased to the required hydraulic pressure of the valve stop device 25 after the operating state of the engine 2 enters the reduced-cylinder operation region. However, since the time for performing the reduced cylinder operation is shortened by the time until the hydraulic pressure reaches the required oil pressure, the fuel efficiency of the engine 2 is reduced by the amount of time for performing the reduced cylinder operation.

  Therefore, in the present embodiment, in order to maximize the fuel efficiency of the engine 2, a reduced cylinder operation preparation region is provided adjacent to the reduced cylinder operation region, and the hydraulic pressure is increased in advance in the reduced cylinder operation preparation region, The target hydraulic pressure (see FIG. 7A) is set so as to eliminate the loss of time until the hydraulic pressure reaches the required hydraulic pressure.

  In addition, as shown to Fig.6 (a), it is good also considering the area | region shown with the dashed-dotted line adjacent to the high engine load side of a reduced cylinder operation area | region as a reduced cylinder operation preparation area | region. Thereby, for example, when the engine load decreases at a predetermined engine speed (V2 or more and V3 or less), all cylinder operation is performed when the engine load is L1 (> L0) or more, and the engine load is more than L0 and less than L1. Then, the reduced cylinder operation may be started, and when the engine load becomes L0 or less, the reduced cylinder operation may be performed.

  Next, referring to FIG. 7, each hydraulic actuator (here, in addition to the valve stop device 25 and the VVTs 32 and 33, a metal bearing such as an oil jet 28 and a journal of the crankshaft 9 is included in the hydraulic actuator. The required oil pressure and the target oil pressure of the oil pump 36 will be described. The oil supply device 1 in the present embodiment supplies oil to a plurality of hydraulic actuators by one oil pump 36, and the required hydraulic pressure required by each hydraulic actuator changes according to the operating state of the engine 2. To do. Therefore, in order to obtain a hydraulic pressure that is required for all hydraulic operating devices in all operating states of the engine 2, the oil pump 36 has the highest required hydraulic pressure of each hydraulic operating device for each operating state of the engine 2. It is necessary to set a hydraulic pressure higher than the required hydraulic pressure to a target hydraulic pressure corresponding to the operating state of the engine 2. For this purpose, in the present embodiment, the required hydraulic pressures of the valve stop device 25, the oil jet 28, the journal of the crankshaft 9 and the VVTs 32 and 33, which have a relatively high required hydraulic pressure among all the hydraulic actuators, are used. What is necessary is just to set target oil pressure so that it may satisfy | fill. This is because, if the target oil pressure is set in this way, other hydraulic actuators having a relatively low required oil pressure naturally satisfy the required oil pressure.

  Referring to FIG. 7A, the hydraulic actuators having a relatively high required oil pressure during the low load operation of the engine 2 are the VVTs 32 and 33, the metal bearings, and the valve stop device 25. The required oil pressure of each of these hydraulic actuators changes according to the operating state of the engine 2. For example, the required oil pressure of VVTs 32 and 33 (described as “VVT required oil pressure” in FIG. 7) is substantially constant when the engine speed is equal to or higher than V0 (<V1). The required oil pressure of the metal bearing (described as “metal required oil pressure” in FIG. 7) increases as the engine speed increases. The required hydraulic pressure of the valve stop device 25 (described as “valve stop required hydraulic pressure” in FIG. 7) is substantially constant at a predetermined range of engine speed (V2 to V3). Then, comparing these required oil pressures for each engine speed, when the engine speed is lower than V0, there is only the metal required oil pressure, and when the engine speed is V0 to V2, the VVT required oil pressure is the highest, and the engine speed When the number is V2 to V3, the valve stop required oil pressure is the highest, when the engine speed is V3 to V6, the VVT required oil pressure is the highest, and when the engine speed is V6 or more, the metal required oil pressure is the highest. Therefore, it is necessary to set the above-mentioned highest required oil pressure as the reference target oil pressure to the target oil pressure of the oil pump 36 for each engine speed.

  Here, at the engine speeds (V1 to V2, V3 to V4) before and after the engine speed (V2 to V3) at which the reduced cylinder operation is performed, the target hydraulic pressure becomes the valve stop request hydraulic pressure in preparation for the reduced cylinder operation. It is set by correcting from the reference target hydraulic pressure so as to increase the pressure in advance. According to this, as described with reference to FIG. 6, when the engine speed reaches the engine speed at which the reduced cylinder operation is performed, the loss of time until the hydraulic pressure reaches the valve stop required hydraulic pressure is eliminated, and the fuel consumption of the engine is reduced. Efficiency can be improved. An example of the target oil pressure of the oil pump 36 set by this correction (described as “oil pump target oil pressure” in FIG. 7) is indicated by the bold lines (V1 to V2, V3 to V4) in FIG. Yes.

  Further, considering the response delay of the oil pump 36, the overload of the oil pump 36, etc., the required oil pressure changes rapidly with respect to the engine speed with respect to the reference target oil pressure after the correction of the above-mentioned reduction cylinder operation preparation. The target oil pressure is set by correcting so that the change in the oil pressure at the engine speed (for example, V0, V1, V4) to be reduced is gradually increased or decreased according to the engine speed at a hydraulic pressure higher than the required oil pressure. It is good. An example of the target oil pressure of the oil pump 36 set by performing this correction is shown by a thick line (V0 or less, V0 to V1, V4 to V5) in FIG.

  Referring to FIG. 7 (b), the hydraulic actuators having a relatively high required oil pressure during the high load operation of the engine 2 are the VVTs 32 and 33, the metal bearings, and the oil jets 28. As in the case of low load operation, the required oil pressure of each of these hydraulic actuators changes according to the operating state of the engine 2. For example, the VVT required oil pressure is substantially constant when the engine speed is equal to or higher than V0 '. The required oil pressure increases as the engine speed increases. Further, the required oil pressure of the oil jet 28 is 0 when the engine speed is less than V2 ′, and increases from that to a certain rotational speed according to the engine speed, and is constant above the rotational speed.

  In the case of high load operation as well as in the case of low load operation, the target target oil pressure is corrected by correcting the reference target oil pressure at the engine speed (for example, V0 ′, V2 ′) at which the required oil pressure changes rapidly with respect to the engine speed. An example of the target oil pressure of the oil pump 36 that is set by performing appropriate correction (particularly V0 ′ or less, correction by V1 ′ to V2 ′) is shown by a thick line in FIG. 7B. ing.

  The target oil pressure of the oil pump 36 shown in the figure changes in a polygonal line, but may change smoothly in a curved line. In the present embodiment, the target hydraulic pressure is set based on the required hydraulic pressures of the valve stop device 25, the oil jet 28, the metal bearing, and the VVTs 32 and 33, which have a relatively high required hydraulic pressure. However, the hydraulic actuator is not limited to these. What is necessary is just to set the target hydraulic pressure in consideration of the required hydraulic pressure, whatever the hydraulic actuator having a relatively high required hydraulic pressure.

  Next, the hydraulic control map will be described with reference to FIG. The target oil pressure of the oil pump 36 shown in FIG. 7 is obtained by using the engine speed as a parameter. Further, FIG. 8 shows the target oil pressure in a three-dimensional graph using the engine load and the oil temperature as parameters. It is the shown hydraulic control map. That is, this hydraulic pressure control map is based on the highest required hydraulic pressure among the required hydraulic pressures of each hydraulic actuator for each operating state of the engine 2 (here, the oil temperature is included in addition to the engine speed and the engine load). Thus, the target hydraulic pressure corresponding to the operating state is set in advance.

  FIGS. 8A, 8B, and 8C show hydraulic control maps when the engine 2 (oil temperature) is hot, warm, and cold, respectively. The controller 100 uses these hydraulic control maps properly according to the oil temperature. That is, when the engine 2 is started and the engine 2 is in a cold state (oil temperature is lower than T1), the controller 100 determines the engine 2 based on the cold hydraulic control map shown in FIG. Read the target oil pressure according to the operating condition (engine speed, engine load). When the engine 2 warms up and the oil reaches a predetermined oil temperature T1 or higher, the target hydraulic pressure is read based on the warm hydraulic control map shown in FIG. Is equal to or higher than a predetermined oil temperature T2 (> T1), the target oil pressure is read based on the oil pressure control map at the time of high temperature shown in FIG.

  In the present embodiment, the target oil pressure is read using a hydraulic control map set in advance for each temperature range by dividing the oil temperature into three temperature ranges of high temperature, warm time, and cold time. The target hydraulic pressure may be read using only one hydraulic control map without considering the oil temperature. Conversely, more hydraulic control maps may be prepared by dividing the temperature range more finely. Furthermore, the oil pressure t within the temperature range (T1 ≦ t <T2) targeted by one oil pressure control map (for example, the oil pressure control map at the time of warming) has read the target oil pressure P1 having the same value. In consideration of the target oil pressure (P2) within the temperature range before and after (T2 ≦ t), the target oil pressure p is proportionally converted according to the oil temperature t (p = (t−T1) × (P2−P1) / ( It may be calculated according to T2-T1)). As described above, the target hydraulic pressure corresponding to the temperature can be read and calculated with higher accuracy, so that the pump displacement can be controlled with higher accuracy.

  Next, the duty ratio map will be described with reference to FIG. The duty ratio map here reads the target oil pressure for each operation state (engine speed, engine load, and oil temperature) of the engine 2 from the above-described oil pressure control map, and based on the read target oil pressure, the flow path of the oil passage A target discharge amount of oil supplied from the oil pump 36 is set in consideration of resistance and the like, and the operation calculated in consideration of the engine speed (oil pump speed) and the like based on the set target discharge amount A target duty ratio corresponding to the state is set in advance.

  FIGS. 9A, 9B and 9C show duty ratio maps when the engine 2 (oil temperature) is hot, warm and cold, respectively. The controller 100 uses these duty ratio maps depending on the oil temperature. That is, since the engine is in a cold state when the engine 2 is started, the controller 100 determines the operation state of the engine 2 (the engine speed, the engine speed based on the cold duty ratio map shown in FIG. 9C). Read the duty ratio according to the engine load. When the engine 2 warms up and the oil reaches a predetermined oil temperature T1 or higher, the target duty ratio is read based on the duty ratio map during warming shown in FIG. 9B, and the engine 2 is completely warmed up. When the engine reaches a predetermined oil temperature T2 (> T1) or higher, the target duty ratio is read based on the high-temperature duty ratio map shown in FIG.

  In this embodiment, the oil temperature is divided into three temperature ranges of high temperature, warm time, and cold time, and the duty ratio is read using a duty ratio map set in advance for each temperature range. As with the hydraulic control map described above, only one duty ratio map is prepared, more temperature range is divided into more duty ratio maps, or the target duty ratio is proportionally converted according to the oil temperature. It may be calculated.

  Next, the flow rate (discharge amount) control operation of the oil pump 36 by the controller 100 will be described according to the flowchart of FIG.

  First, in step S1, in order to grasp the operating state of the engine 2 after starting, detection information is read from various sensors, and engine load, engine speed, oil temperature, and the like are detected.

  Subsequently, in step S2, a duty ratio map stored in advance in the controller 100 is read, and a target duty ratio corresponding to the engine load, engine speed, and oil temperature read in step S1 is read.

  In the next step S3, it is determined whether or not the current duty ratio matches the target duty ratio read in step S2. When the determination in step S3 is YES, the process proceeds to step S5. On the other hand, when the determination in step S3 is NO, the process proceeds to step S4 to output a signal indicating the target duty ratio to the linear solenoid valve 49 (described as “flow rate control valve” in the flowchart of FIG. 10), and then step Proceed to S5.

  In step S5, the current oil pressure is read from the oil pressure sensor 70. In the next step S6, a pre-stored oil pressure control map is read, and the target oil pressure corresponding to the current engine operating state is read from the oil pressure control map.

  In the next step S7, it is determined whether or not the current oil pressure matches the target oil pressure read in step S6. When the determination in step S7 is NO, the process proceeds to step S8 to output an output signal in which the target duty ratio is changed by a predetermined ratio to the linear solenoid valve 49, and then returns to step S5. That is, the discharge amount of the oil pump 36 is controlled so that the oil pressure detected by the oil pressure sensor 70 becomes the target oil pressure.

  On the other hand, when the determination in step S7 is YES, the process proceeds to step S9 to detect the engine load, the engine speed and the oil temperature, and whether or not the engine load, the engine speed and the oil temperature have changed in the next step S10. Determine whether.

  When the determination in step S10 is YES, the process returns to step S2, while when the determination in step S10 is NO, the process returns to step S5. The above flow rate control is continued until the engine 2 is stopped.

  The flow rate control of the oil pump 36 described above is a combination of the feedforward control of the duty ratio and the feedback control of the hydraulic pressure. According to this flow rate control, the responsiveness is improved by the feedforward control and the accuracy by the feedback control is improved. Improvement and realization.

  Subsequently, an operation of controlling the number of cylinders by the controller 100 will be described according to the flowchart of FIG.

  First, in step S11, in order to grasp the operating state of the engine 2 after starting, detection information is read from various sensors, and an engine load, an engine speed, a water temperature, and the like are detected. In the next step S12, based on the read engine load, engine speed, and water temperature, it is determined whether or not the current engine operating condition satisfies the valve stop operating condition (is in the reduced cylinder operating range). To do. When this determination is NO, the process proceeds to step S13 to perform a four-cylinder operation (all-cylinder operation).

  On the other hand, when the determination in step S12 is YES, the process proceeds to step S14 to operate the first direction switching valves 34 and 35 connected to the VVTs 32 and 33, and in the next step S15, the current cam angle is detected from the cam angle sensor 74. Is read. In the next step S16, it is determined whether or not the current operating angle of the VVTs 32 and 33 corresponding to the read current cam angle is a target operating angle.

  If the determination in step S16 is no, the process returns to step S15. That is, the operation of the second direction switching valves 46 and 47 is prohibited until the current operating angle reaches the target operating angle. When the determination in step S16 is YES, the process proceeds to step S17 to operate the second direction switching valves 46 and 47 to perform the two-cylinder operation (reduced cylinder operation).

  Next, referring to FIG. 12, when the VVT 32 is operating at the time of the reduced cylinder operation request immediately after the operation state of the engine 2 enters the reduced cylinder operation region (here, only the VVT 32 of the VVTs 32 and 33 is operated). A specific example in which the cylinder number control operation shown in FIG. 11 is executed will be described.

  At time t1, the first direction switching valve 34 for the VVT 32 is operated. Thereby, the supply of oil to the advance hydraulic chamber 326 of the VVT 32 is started, and the operating angle of the VVT 32 changes from θ2 toward θ1. As a result, the hydraulic pressure is lower than the valve stop request hydraulic pressure P1.

  Here, when the current operation state of the engine 2 enters the reduced cylinder operation region and satisfies the valve stop operation condition, the operation of the VVT 32 is continued until the operation angle of the VVT 32 reaches the target operation angle θ1, that is, While the oil pressure is lower than the valve stop request oil pressure P1, the valve stop device 25 is not operated.

  At time t2, the operating angle of the VVT 32 reaches the target operating angle θ1, and when the operation of the VVT 32 is completed, the supply of oil to the advance hydraulic chamber 326 of the VVT 32 is completed, so that the hydraulic pressure returns to the valve stop request hydraulic pressure P1. .

  At time t3 after time t2 when the hydraulic pressure returns to the valve stop requesting hydraulic pressure P1, the second direction switching valves 46 and 47 are operated to supply the hydraulic pressure to the valve stop device 25, and the engine is switched from the four-cylinder operation to the two-cylinder operation. Switch. As described above, after the advance angle control of the VVT 32, the shift to the reduced cylinder (2 cylinder) operation is performed, so the intake charge amount is increased by the advance angle control of the intake and exhaust valves 14 and 15, and the load is handled by the 2 cylinders. The rotational fluctuation of the engine 2 can be suppressed.

  The check valve 48 is energized by a spring so as to open when the hydraulic pressure in the third communication passage 53 becomes equal to or higher than the required hydraulic pressure of the valve stop device 25, and allows oil flow only in one direction from the upstream side to the downstream side. regulate. The check valve 48 opens with a hydraulic pressure larger than the required hydraulic pressure of the VVTs 32 and 33.

  When the VVTs 32 and 33 are activated during the reduced cylinder operation for actuating the valve stop device 25, the hydraulic pressure in the third communication passage 53 decreases, but from the valve stop device 25 to the third communication passage 53 upstream of the check valve 48. Since the oil flow is blocked by the check valve 48, the required hydraulic pressure in the valve stop device 25 on the downstream side of the check valve 48 is ensured. Therefore, malfunction of the valve stop device 25 due to a decrease in the hydraulic pressure in the third communication passage 53 can be prevented.

  As described above, when the engine load is a light load that is equal to or less than a predetermined threshold, such as during idling, the valve opening periods of the intake valve 14 and the exhaust valve 15 are overlapped as in the case of a high load. Further, at the time of the light load (in the present embodiment, at the time of the light load when the engine speed is less than the predetermined rotation speed V1), all cylinder operation is performed. Note that, regardless of the engine speed, all-cylinder operation may be performed at the time of the light load.

  When the valve overlap amount at the light load is increased, the internal EGR amount is relatively larger than the amount of fresh air in each cylinder of the engine 2 and the combustion stability is lowered. The valve overlap amount is set as large as possible within the range that can ensure the combustion stability. If the valve overlap amount at the light load is larger than the set value, the combustion stability is deteriorated. there is a possibility.

<Lamp height design concept>
In the present embodiment, a valve stop device 25 that stops the intake and exhaust valves 14 and 15 of the first and fourth cylinders according to the operating state of the engine 2 is provided. In the valve stop device 25, a predetermined clearance is required between the inner peripheral surface of the through hole 251a of the outer cylinder 251 and the outer peripheral surface of the lock pin 252 in order to facilitate the operation of the lock mechanism. The clearance of the lock mechanism varies depending on manufacturing errors, and the inner peripheral surface of the through hole 251 a of the outer cylinder 251 and the outer peripheral surface of the lock pin 252 are worn with the operation of the lock pin 252.

  Therefore, it is necessary to design the ramp height of the cam profile related to the intake / exhaust valves 14 and 15 in consideration of the clearance variation and wear. The concept of designing the lamp height will be described below.

(common belief)
In the cam profile shown in FIG. 13A, the valve-opening side required ramp height Ho is determined by the lift loss at the time of valve opening at the assumed maximum oil temperature (for example, 145 ° C.). This lift loss occurs when the plunger 24a of the HLA 24 shown in FIG. 2 is pushed by the cam and the oil in the high pressure chamber below the check valve 24b is elastically compressed until it becomes a substantially rigid body. The required valve height Hc on the valve closing side is a height obtained by combining the lift loss with the sink down (sinking) amount of the plunger 24a during the valve opening period at the assumed maximum oil temperature (for example, 145 ° C.) during idle operation. . The sink-down occurs when oil in the high-pressure chamber is pressurized through the plunger 24a and leaks from the sliding surface between the plunger 24a and the HLA body.

  As shown in FIG. 13B, when the oil temperature is normal (for example, 90 ° C.), the lift loss at the time of valve opening and the sink down during the valve opening period are smaller than those at the maximum oil temperature. As a result, the remaining lamp height on the valve opening side is Hor, and the remaining lamp height on the valve closing side is Hcr. Accordingly, the actual valve lift characteristic at the normal oil temperature is as shown in FIG. 14A, and the valve opening overlap of the intake and exhaust valves 14 and 15 is as shown in FIG. 14B.

(Swing arm lever ratio and lift loss and sink down)
As shown in FIG. 15, the lever ratio of the swing arms 20 and 21 is generally 1.5 to 1.7. If the lever ratio is 1.6, and the lift amount of the intake and exhaust valves 14 and 15 is 10 mm, the downward movement amount of the cam followers 20a and 21a by the cams 18a and 19a is (10 / 1.6) mm. . In order to stop the valve, the amount of lost motion of the HLA 24 by the valve stop device 25 needs to be (10 / 0.6) mm or more. If the amount of lost motion is large, the overall height of the valve stop device 25 increases and the engine 2 increases accordingly. Therefore, in order to reduce the lost motion, it is preferable to increase the lever ratio, for example, 2.2.

  Therefore, the load L applied to the HLA 24 when the lever ratio is increased is calculated. Assuming that the return spring load of the intake and exhaust valves 14 and 15 is Fvs, when the lever ratio is 1.6, “load L = (1.6-1) × Fvs = 0.6 Fvs”. In order to reduce the lost motion, for example, when the lever ratio is 2.2, if the return spring load Fvs is the same, “load L = (2.2-1) × Fvs = 1.2 Fvs”. That is, when the lever ratio is 2.2, the load L applied to the HLA 24 is double that when the lever ratio is 1.6. Therefore, assuming that the sinking amount (lift loss amount and sinkdown amount) of the HLA 24 is proportional to the load L, the increase change amount ΔH of the sinking is 1.6 when the lever ratio is 2.2. Will be double that of.

  FIG. 16 is an explanatory diagram showing the relationship between the increase change amount ΔH of the sinking of the HLA 24 and the lift decrease change amount ΔL of the intake and exhaust valves 14 and 15. This relationship is “ΔL = (1.6−1) × ΔH = 0.6ΔH” when the lever ratio is 1.6, and “ΔL = (2.2−1) × ΔH when the lever ratio is 2.2. = 1.2ΔH ”. In other words, the lift amount decreases and changes with double the sensitivity with respect to the increase in the sinking amount of the HLA 24.

  As described above, when the lever ratio is changed from 1.6 to 2.2 in order to reduce the lost motion, the sinking amount of the HLA 24 is doubled, and the sensitivity of the change in the lift amount with respect to the sinking is doubled. Therefore, the lift decrease change ΔL of the intake / exhaust valves 14 and 15 is eventually quadrupled.

(Considering clearance of lock mechanism)
FIG. 17 is an explanatory diagram for setting the lamp height when there is no valve stop device. In this case, the valve-opening side required lamp height Ho is set based on the lift loss amount of the HLA 24, and the valve-closing side required lamp height Hc is a sum of the lift loss amount and the sink down amount of the HLA 24.

  FIG. 18 is an explanatory diagram of ramp height setting in an HLA with a valve stop device (first and fourth cylinders of the embodiment). In this case, the required valve height Ho on the valve opening side is set in addition to the design clearance of the lock mechanism, the amount of clearance variation due to manufacturing errors (plus side), and the expected wear amount of the lock mechanism in addition to the lift loss amount of the HLA 24. It will be. For the required lamp height Hc on the valve closing side, the lock mechanism design clearance, clearance variation due to manufacturing errors (plus side) and the lock mechanism assumed wear amount are combined with the HLA 24 lift loss amount and sink down amount. It will be set in addition to the value.

  Here, the design clearance of the lock mechanism at each of the valve-opening side required lamp height Ho and the valve-closing side required lamp height Hc is the height at which the HLA 24 is necessarily sunk, and therefore the lift of the intake / exhaust valves 14, 15 Does not appear.

  Even in the HLA without valve stop device (second and third cylinders), it is necessary to adjust the lamp height to the HLA with valve stop device (first and fourth cylinders). The additional lamp height required for this is the sum of the amount of clearance variation due to manufacturing errors (plus side) and the estimated wear amount of the lock mechanism.

(Summary)
After all, when the valve stop device 25 having the lock mechanism is provided in the pivot type HLA 24, the increase in the lift decrease change ΔL of the intake and exhaust valves 14 and 15 with the increase in the lever ratio described above, the variation in the clearance of the lock mechanism, and It is necessary to design the cam profile in consideration of the assumed wear amount, which greatly increases the lamp height.

  FIG. 19 schematically shows a difference in valve overlap amount between the intake and exhaust valves 14 and 15 depending on the presence or absence of the valve stop device 25. With the valve stop device, the valve opening period of the intake / exhaust valves 14 and 15 increases as the lamp height increases, and as a result, the valve overlap amount becomes larger than that without the valve stop device. This means that the internal EGR is increased and the combustion stability is deteriorated in the idling operation of the engine.

<Measures for increasing lamp height (idle operation control)>
The controller 100 determines that the oil temperature (oil temperature) is equal to or less than a predetermined threshold value during light load operation (idle operation) of all cylinder operation in which the valve stop devices 25 of the first and fourth cylinders prevent the HLA 24 from moving downward. In some cases, the idle speed is set to a predetermined value within a range of 500 to 600 rpm, for example. Then, when the oil temperature exceeds a predetermined threshold, the idle speed is increased according to the oil temperature, and the target torque (target indicated torque) of the engine is decreased according to the idle speed.

  FIG. 20 shows the relationship between the oil temperature, the engine speed, and the sink down amount. As the oil temperature increases, the viscosity of the oil decreases and the amount of oil leak in the HLA 24 increases, so that the sink down amount increases. On the other hand, as the engine speed increases, the time during which the plunger 24a of the HLA 24 is pushed by the cam and the oil in the high pressure chamber is at a high pressure is shortened, so the amount of oil leak is reduced and the amount of sink down is reduced.

  Therefore, for example, when the oil temperature threshold is set to a predetermined value within the range of 100 to 120 ° C. and the oil temperature exceeds the predetermined threshold, the idle rotation speed is increased according to the oil temperature, and the oil leak amount To prevent an increase in the amount of sync down. For example, when the predetermined value of the idle speed is 550 rpm, the predetermined threshold value of the oil temperature is 110 ° C., and the oil temperature exceeds 110 ° C., the sink down amount is at the idle speed 550 rpm and the oil temperature 110 ° C. As the oil temperature rises, the degree of increase in the idling speed is increased so as not to exceed the sinkdown amount.

  FIG. 21 shows respective cam profiles when the idle temperature is 550 rpm and 850 rpm when the oil temperature is 140 ° C. (dashed line is 550 rpm, solid line is 850 rpm). By reducing the lift loss amount and the sink down amount as the idle speed increases, the valve-opening side required lamp height can be lowered by ΔHo, and the valve-closing side required lamp height can be lowered by ΔHc. it can.

  In addition, the controller 100 makes the vehicle occupant uncomfortable due to a predetermined threshold value (maximum value-minimum value of the angular velocity of the crankshaft 9) of the crankshaft 9 during the light load operation of the all cylinder operation. Is larger than the predetermined threshold value, the angular velocity fluctuation amount is larger than the predetermined threshold value so that the angular velocity fluctuation amount is less than or equal to the predetermined threshold value. The current driving load is increased by a predetermined amount.

  In the present embodiment, it is determined whether or not all cylinders are operated based on the engine operating state (engine load, engine speed, and engine water temperature), and whether or not the engine is idle (accelerator opening is substantially fully closed) based on the accelerator opening. It is determined whether or not. The crank angle sensor 71 and the controller 100 constitute an angular velocity variation detection device that detects the angular velocity variation of the crankshaft 9. A pressure sensor for detecting the pressure in each cylinder (pressure in the combustion chamber 11) is provided for each cylinder, and the controller 100 determines the crankshaft 9 from the combustion pressure in each cylinder by the pressure sensor. It is also possible to detect the angular velocity fluctuation amount. In this case, the pressure sensor and the controller 100 constitute the angular velocity variation detection device.

  In the auxiliary drive load increase control, the increase amount of the auxiliary drive load (that is, the predetermined amount) is an amount that provides an engine load that can suppress the angular velocity fluctuation amount to be equal to or less than the predetermined threshold value. This is an amount corresponding to the angular velocity fluctuation amount. It should be noted that a constant amount can be used regardless of the angular velocity fluctuation amount.

  That is, when the driving load of the auxiliary machine increases, the engine load increases, thereby increasing the intake air amount, increasing the amount of fresh air with respect to the internal EGR amount in each cylinder, and increasing the fuel injection amount. Therefore, the combustion stability is improved in all cylinders including the first and fourth cylinders. As a result, engine torque fluctuation (the angular velocity fluctuation amount) is suppressed.

  In the increase control of the auxiliary machine drive load, when the drive load of the oil pump 36 is increased, the discharge amount of the oil pump 36 is increased. In other words, when the angular velocity fluctuation amount is larger than the predetermined threshold during the idle operation of the all cylinder operation, the target hydraulic pressure is increased with respect to the current target hydraulic pressure, thereby reducing the discharge amount of the oil pump 36 at the current time. Increase with respect to the discharge amount. When the angular velocity fluctuation amount is equal to or less than the predetermined threshold value, the target hydraulic pressure becomes the target hydraulic pressure based on the hydraulic pressure control map. When the angular velocity fluctuation amount is larger than the predetermined threshold value, the target hydraulic pressure becomes larger than the target hydraulic pressure based on the hydraulic pressure control map.

  The increase amount of the target hydraulic pressure is set based on the oil temperature. That is, as the oil temperature is lowered, the viscosity of the oil is increased and the driving load of the oil pump 36 is increased. Therefore, the amount of increase in the discharge amount can be reduced accordingly, and as a result, the amount of increase in the target oil pressure is increased. Will be less.

  In this embodiment, the controller 100 increases the drive load of the alternator 81 when the drive load of the alternator 81 can be increased when the drive load of the auxiliary machine is increased with respect to the current drive load. The increase amount of the discharge amount of the oil pump 36 (the increase amount of the target hydraulic pressure) is adjusted by the increase amount of the drive load 81. That is, when the drive load of the alternator 81 can be increased, the drive load of the alternator 81 is preferentially increased (when the alternator 81 is not in the power generation state, the power generation state is set, the generated power is increased from 0, and the alternator 81 is increased. When the generator is in a power generation state, the generated power is increased.) If the predetermined amount can be covered by the increased amount of the drive load of the alternator 81, the discharge amount of the oil pump 36 is not increased (discharge). Set the amount of increase to 0).

  Further, when the increase amount of the drive load of the alternator 81 is insufficient with respect to the predetermined amount, the discharge amount of the oil pump 36 is increased, and the increase amount of the drive load accompanying the increase in the discharge amount is set as described above. The amount obtained by subtracting the amount of increase in the drive load of the alternator 81 from the fixed amount (the amount of increase in the target hydraulic pressure corresponding to the amount) is obtained. When the drive load of the alternator 81 can be increased, the generated power can be increased with the increase of the drive load, and the increased generated power is charged to the battery mounted on the vehicle. Or when it can be used with electrical components mounted on the vehicle. When the state of charge (SOC) of the battery is in a fully charged state or a state close thereto, and the electric component cannot be used, the driving load of the alternator 81 cannot be increased. At this time, the discharge amount of the oil pump 36 (drive load of the oil pump 36) is increased without increasing the drive load of the alternator 81 (the increase amount of the drive load of the alternator 81 is set to 0).

  Hereinafter, the flow of idle operation control by the controller 100 will be described based on the flowchart of FIG.

  In step S50, detection information is read from various sensors, and engine load (accelerator opening), engine speed, angular velocity fluctuation amount of the crankshaft 9, water temperature, oil temperature, and the like are detected. In the next step S51, it is determined whether or not the engine 2 is in an all-cylinder operation and idle operation state. When it is the all cylinder / idle operation, the process proceeds to step S52, and it is determined whether or not the oil temperature exceeds a predetermined threshold value.

  When the oil temperature is equal to or lower than the predetermined threshold value, the process proceeds to step S53, and the idle speed is set to a predetermined value. When the oil temperature exceeds the predetermined threshold value, the process proceeds to step S54, and the idle speed is increased from a predetermined value according to the oil temperature. In step S55 following steps S53 and S54, a target torque (target indicated torque) of the engine is calculated in accordance with the idle speed. That is, when the idle speed is increased from a predetermined value according to the oil temperature, the target torque of the engine is decreased according to the increase amount.

  In the next step S56, the air amount control by the throttle valve or VVT 32, 33 and the fuel injection amount control by the fuel injection valve are performed corresponding to the target torque, and the ignition timing control by the spark plug is performed in the next step S57. .

  In the next step S58, it is determined whether or not the angular velocity fluctuation amount of the crankshaft 9 is equal to or less than a predetermined threshold value. If the determination in step S58 is YES, the process returns to step S52. If the determination in step S58 is NO, the process proceeds to step S59.

  In step S59, the target torque is corrected. That is, the target torque is increased from the current target torque. Specifically, the target torque is increased according to the angular velocity fluctuation amount to a torque that allows the angular velocity fluctuation amount to be suppressed below the predetermined threshold. Note that the target torque may be increased by adding a constant torque to the current target torque regardless of the angular velocity fluctuation amount.

  In the next step S60, a load increase amount (corresponding to the predetermined amount) necessary for obtaining the corrected target torque is calculated, and in the next step S61, it is determined whether or not the drive load of the alternator 81 can be increased. To do. When the determination in step S61 is YES, the process proceeds to step S62, while when the determination in step S61 is NO, the process proceeds to step S64.

  In step S62, the drive load of the alternator 81 is increased. At this time, if there is a limit on the amount of increase in the generated power by the alternator 81 from the viewpoint of the SOC of the battery or the usage state of the electrical component, the drive load increase amount corresponding to the limited generated power increase amount is necessary. When the load increase amount is smaller than the load increase amount, the drive load increase amount corresponding to the limited generated power increase amount is set, and the drive corresponding to the limited generated power increase amount is not limited or is limited. When the load increase amount is equal to or greater than the required load increase amount, the drive load increase amount corresponding to the required load increase amount is set.

  In the next step S63, it is determined whether or not the increase amount of the drive load of the alternator 81 is sufficient with respect to the required load increase amount (whether or not it is not less than the required load increase amount). When the determination in step S63 is YES, the process returns without increasing the driving load of the oil pump 36. If the determination in step S63 is no, the process proceeds to step S64.

  In step S64 that proceeds when the determination in step S62 is NO or when the determination in step S63 is NO, the drive load (discharge amount) of the oil pump 36 is increased. That is, when the drive load of the alternator 81 cannot be increased (when the determination in step S61 is NO), the increase amount of the drive load of the oil pump 36 is set to the required load increase amount, and the drive load of the alternator 81 is increased. However, when the increase amount of the drive load of the alternator 81 is not sufficient for the required load increase amount (when the determination in step S63 is NO), the increase amount of the drive load of the alternator 81 is set to the required load. A value obtained by subtracting the increase amount of the drive load of the alternator 81 from the increase amount.

  In the next step S65, whether or not the increase amount of the drive load of the oil pump 36 is sufficient with respect to the value obtained by subtracting the increase amount of the drive load of the alternator 81 from the required load increase amount (is equal to or greater than this value). Whether or not). If the determination in step S65 is yes, the process returns. If the determination in step S65 is no, the process returns to step S64. The above-mentioned auxiliary machine drive load increase control ends when the operating state of the engine 2 enters the reduced cylinder operation region or when the engine load becomes larger than the predetermined threshold.

  As described above, when the valve stop device 25 having the lock mechanism is provided in the pivot type HLA 24, the lift decrease change ΔL of the intake and exhaust valves 14 and 15 with the increase in the lever ratio, the variation in the clearance of the lock mechanism, It is necessary to design the cam profile in consideration of the assumed wear amount, which greatly increases the lamp height.

  On the other hand, according to the idling operation control, the idling speed is increased when the oil temperature exceeds a predetermined threshold during idling operation of all cylinders, so the amount of oil leak of the HLA 24 is reduced. Since the sinking of the HLA 24 is reduced by the reduction of the oil leak amount, the lamp height can be designed to be low. Therefore, it is easy to suppress the increase in the amount of valve overlap during idling and to ensure combustion stability. Thus, when the oil temperature exceeds a predetermined threshold, the idle speed is increased and the target torque of the engine is decreased, so that deterioration of fuel consumption can be suppressed.

  Further, when the angular velocity fluctuation amount of the crankshaft 9 is larger than a predetermined threshold value, the driving load of the auxiliary machine (alternator, oil pump) is increased with respect to the current driving load so that the angular velocity fluctuation amount is less than the predetermined threshold value. Therefore, even if the valve overlap amount during idling operation is increased by providing the valve stop device 25, combustion stability can be improved in all cylinders including the specific cylinder. In addition, during the idling operation, fluctuations in engine torque can be suppressed, and engine vibration due to the fluctuations can be reduced.

  The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above embodiment, when the drive load of the alternator 81 can be increased in the auxiliary drive drive load increase control, the drive load of the alternator 81 is increased. However, only the drive load of the oil pump 36 is always increased. You may make it make it. Or you may make it increase the drive load of auxiliary machines other than the oil pump 36 and the alternator 81 independently or in combination with these.

  In the above embodiment, the engine 2 is an in-line four-cylinder gasoline engine. However, any engine may be used as long as it is a multi-cylinder engine, for example, a diesel engine.

2 Multi-cylinder engine 14 Intake valve 15 Exhaust valve 18 Cam shaft 19 Cam shaft 18a Cam 19a Cam 20 Swing arm 21 Swing arm 24 Pivot type HLA
25 Valve stop device (hydraulic actuator)
32 Intake side variable valve timing mechanism (hydraulic actuator)
33 Exhaust variable valve timing mechanism (hydraulic actuator)
36 Variable displacement oil pump (auxiliary machine)
71 Crank angle sensor (angular velocity fluctuation detection device)
73 Oil temperature sensor (oil temperature detector)
81 Alternator (auxiliary machine)
100 controller (control means)
252 Lock pin (lock mechanism)

Claims (3)

It has a plurality of cylinders, each of which includes a valve operating device that supports a swing arm with a pivot type HLA and operates the swing arm with a camshaft cam to open and close an intake valve or an exhaust valve,
At least one of the intake valve and the exhaust valve of the specific cylinder among the plurality of cylinders has a lock mechanism that prevents the HLA from moving downward so that the valve is opened and closed by the swing arm. Is provided with a valve stop device that releases the HLA and allows the HLA to move downward and closes the valve.
A control device for a multi-cylinder engine comprising a hydraulic actuator including the HLA of the engine and an oil pump for supplying oil to a lubricating part,
When the oil temperature exceeds a predetermined threshold during all-cylinder operation in which the HLA of the specific cylinder is prevented from descending, the engine speed is increased and the engine target torque is decreased. A control device for a multi-cylinder engine, comprising control means. In claim 1,
An angular velocity fluctuation amount detecting device for detecting an angular velocity fluctuation amount of the crankshaft of the engine,
When the angular velocity fluctuation amount detected by the angular velocity fluctuation amount detection device is larger than a predetermined threshold value during the light load operation of the all-cylinder operation, the control means is configured so that the angular velocity fluctuation amount becomes equal to or less than the predetermined threshold value. In addition, the controller for a multi-cylinder engine increases the driving load of the engine by increasing the discharge amount of the oil pump. In claim 1 or claim 2,
A hydraulic pressure detecting device for detecting the hydraulic pressure of the hydraulic pressure supply path for supplying oil to the hydraulic operating device and the lubricating part;
The oil pump is a variable displacement type that can adjust the oil discharge amount,
The control means controls the discharge amount of the oil pump so that the oil pressure detected by the oil pressure detection device becomes a target oil pressure set in advance in the hydraulic operation device in accordance with the operating state of the engine. A control device for a multi-cylinder engine.

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