JP4573482B2 - Lubricator for engine with balancer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to crankcase fixedly an axis and flat line guide axis of the cylinder, fitted balance weight guide hole slidably in the guide shaft, the interlocking means the balance weight on the crankshaft The present invention relates to a lubrication device in an engine with a balancer that is connected to the balance weight and reciprocates a balance weight in a direction opposite to a piston sliding in a cylinder.
[0002]
[Prior art]
Such a conventional engine with a balancer is already known as disclosed in, for example, Japanese Utility Model Publication No. 63-39465.
[0003]
[Problems to be solved by the invention]
Generally, lubricating oil is supplied by an oil pump and forcedly lubricated around the crankshaft is widely performed. However, it is desirable to reduce the capacity of the oil pump as much as possible in terms of weight reduction and cost reduction.
[0004]
The present invention has been made in view of such circumstances, and provides a lubricating device for an engine with a balancer that allows the balancer of the engine to exhibit an oil pump function and enables a reduction in the capacity of the oil pump to be used. For the purpose.
[0005]
[Means for Solving the Problems]
To achieve the above object, the present invention is the crankcase fixedly an axis and flat line guide axis of the cylinder, fitted balance weight guide hole slidably in the guide shaft, the balance weights linked via the interlocking means to the crankshaft, a balancer with engine in which the balance weight to the piston in the opposite direction of sliding in a cylinder to reciprocate, the guide hole of the balance weight, the balance weight In what defines a pump oil chamber that expands and contracts with the reciprocating motion of
To the pump oil chamber, with connecting the discharge side of the oil pump that pumps driven by the lubricating oil to the crank shaft, the pump oil chamber by communicating the lubrication of the crank shaft, when volume shrinkage of the pump oil chamber The discharge pressure of the oil pump becomes a resistance, and the back flow of oil from the pump oil chamber is prevented without using a one-way valve .
[0006]
According to this feature, the pump oil chamber in the guide hole repeats the expansion and contraction of the volume by the reciprocating movement of the balance weight, and exhibits the pump action. At the time of the volume contraction, the discharge pressure of the oil pump is the resistance. Since the oil backflow is prevented, the oil pumped from the oil pump is effectively boosted and supplied to the lubrication part of the crankshaft, and the lubrication can be performed effectively. A pump can be used, and a special one-way valve that prevents backflow of oil is unnecessary, which can contribute to weight reduction and cost reduction.
[0007]
The interlocking means corresponds to the eccentric shaft portion 42, the link 43 and the pivot 44 in the embodiment of the present invention described later.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below based on embodiments of the present invention shown in the accompanying drawings.
[0009]
1 is a longitudinal sectional side view of an essential part of an engine with a balancer according to the present invention, FIG. 2 is a view taken along the arrow 2 in FIG. 1, FIG. 3 is a view taken along the arrow 3 in FIG. 5 is a sectional view taken along line 5-5 in FIG. 1, FIG. 6 is a sectional view taken along line 6-6 in FIG. 2, FIG. 7 is a sectional view taken along arrow 7 in FIG. 9 is a sectional view taken along line 9-9 of FIG. 6, FIG. 10 is a longitudinal sectional view (A), left side view (B) and right side view (C) showing the camshaft, and FIG. 11 is a modification of the engine of the present invention. It is a vertical section top view which shows an example.
[0010]
First, the overall configuration of the engine with a balancer will be described.
[0011]
1, FIG. 4 and FIG. 5, an engine body 1 of an engine E with a balancer includes a crankcase 2, a cylinder block 3 that protrudes obliquely upward from one side of the crankcase 2, and the cylinder block. 3 and a cylinder head 4 joined to the head. The crankcase 2 is installed on the engine bed of various work equipment on the installation surface 5 on the lower surface thereof.
[0012]
The crankcase 2 is composed of a case main body 1a cast integrally with the cylinder block 3 and having one end surface opened, and a side cover 2b coupled to the open end. The crankshaft is connected to the case main body 1a and the side cover 2b. Both ends of 6 are rotatably supported via ball bearings 7, 7 'and oil seals 8, 8'. The crankshaft 6 protrudes out of the crankcase 2 with an output shaft portion 6o at one end and an accessory mounting shaft portion 6a at the other end, and the flywheel 10 is key-coupled to the accessory mounting shaft portion 6a. In addition, the cooling fan 12 that supplies cooling air to each part of the engine body 1 and a carburetor 30 described later is fixed to the outer end surface of the flywheel 10 with the bolt 13. A recoil-type engine starter 14 is disposed outside the cooling fan 12.
[0013]
A stator 15a of a generator 15 is attached to the outer end surface of the crankcase 2 facing the flywheel 10, and the flywheel 10 includes a plurality of magnets 15b arranged on the outer periphery of the stator 15a, Also serves as a roller for the machine 15.
[0014]
The crankshaft 6 includes a pair of crankpins 6p and 6p having a phase difference of 360 ° in the crankcase 2. A pair of pistons 17 and 17 are connected to the crank pins 6p and 6p via connecting rods 16 and 16, and a pair of cylinders 18 and 18 into which the pistons 17 and 17 are slidably fitted are parallel to the cylinder block 3. Formed.
[0015]
In the cylinder head 4, combustion chambers 20, 20, intake ports 21, 21 and exhaust ports 22, 22 are formed corresponding to the cylinders 18, 18, and the intake ports 21, 21 and exhaust ports 22, 22 are opened and closed. Intake valves 23 and 23 and exhaust valves 24 and 24 are mounted. At that time, the intake ports 21 and 21 and the exhaust ports 22 and 22 are arranged vertically, the upstream ends of the intake ports 21 and 21 open to the upper surface of the cylinder head 4, and the downstream ends of the exhaust ports 22 and 22 are the cylinder head. 4 opens on the lower surface.
[0016]
The spark plugs 25, 25 that cause the electrodes to face the combustion chambers 20, 20 are screwed to the cylinder head 4 from both the left and right sides.
[0017]
As shown in FIGS. 1, 2, 6 and 7, an intake manifold 27 is fixed to the upper surface of the cylinder head 4 with bolts 28. The intake manifold 27 includes a pair of intake passages 29, 29 that individually communicate with the intake ports 21, 21 and extend horizontally, and the upstream ends of the intake passages 29, 29 are arranged on the cooling side of the cylinder head 4. It opens toward one side on the same side as the fan 12, and a double carburetor 30 is connected to these openings. Thus, the vaporizer 30 is disposed adjacent to the cooling fan 12 in the radial direction.
[0018]
An air cleaner 32 is connected to the upstream end of the carburetor 30 via an intake duct 31 with the upstream end facing upward. The air cleaner 32 is disposed above the cylinder block 3 and the cylinder head 4.
[0019]
The carburetor 30 and the intake duct 31 are coupled to the intake manifold 27 by a plurality of through bolts 33. The air cleaner 32 is attached to the intake duct 31 by a single mounting bolt 34 planted in the intake duct 31.
[0020]
An exhaust manifold 35 is fixed to the lower surface of the cylinder head 4 with bolts 39. The exhaust manifold 35 includes a single exhaust passage 36 that communicates with the exhaust ports 22 and 22 and extends horizontally, and opens toward the other side of the cylinder head 4 of the exhaust passage 36. An exhaust pipe 37 disposed on the other side of the cylinder head 4 opposite to the carburetor 30 is connected to the downstream end of the exhaust manifold 35, and a muffler 38 is connected to the upper end of the exhaust pipe 37. Thus, the air cleaner 32 and the muffler 38 are disposed adjacent to and along the axis of the crankshaft 6 above the cylinder block 3 and the cylinder head 4 as shown in FIGS.
[0021]
A fuel tank 41 adjacent to the air cleaner 32 and the muffler 38 is disposed above the crankcase 2 and supported by a bracket 40 protruding from the upper surface thereof (see FIGS. 1 and 3).
[0022]
4 and 8, an eccentric shaft portion 42 is formed at the center portion of the crankshaft 6, and the large end portion of the link 43 is rotatably fitted to the eccentric shaft portion 42, and the small end portion thereof is fitted to the small end portion. Is connected to a balance weight 45 via a pivot 44 parallel to the crankshaft 6. The balance weight 45 is fixed to the inner wall of the crankcase 2 and extends parallel to the axis of the cylinders 18, 18. In addition, the guide hole 47 of the weight 45 is slidably fitted. The balance weight 45 reciprocates in the opposite direction to the pistons 17, 17 that slide in the cylinders 18, 18 during operation of the engine E. At this time, the balance weight 45 substantially balances the inertial force of both pistons 17, 17. It is designed to exert inertial force.
[0023]
Incidentally, the crank shaft 6, auxiliary mounting shaft portion 6a, the driving timing pulley 57 (to be described later) and a crankshaft half 6A having an eccentric shaft portion 42, divided into a crankshaft half 6B having an output shaft portion 6o Then, after assembling the link 43 to the eccentric shaft portion 42, the opposite end portions 6Aa and 6Ba of both crankshaft halves 6A and 6B are press-fitted together.
[0024]
Thus, the engine E is configured as a parallel two-cylinder engine with equidistant explosion by giving a phase difference of 360 ° to the pair of crankpins 6p, 6p of the crankshaft 6. Therefore, even if the displacement is increased, the vibration can be reduced by the dispersion of the explosion vibration, and the vibration of the engine E can be further reduced by the balance action of the inertia force between the balance weight 45 and the pistons 17 and 17. be able to. In addition, the intake and exhaust manifolds 27 and 35 are disposed horizontally above and below the inclined cylinder head 4, and the carburetor 30 and the exhaust pipe are disposed on opposite sides of the cylinder head 4. When the periphery of the cylinder head 4 is configured compactly, a large installation space for the air cleaner 32 and the muffler 38 can be secured above the cylinder block 3 and the cylinder head 4, which can contribute to the compactness of the engine E. Moreover, heating of the intake system by the exhaust system can be avoided without using a special heat shield, which can contribute to simplification of the structure.
[0025]
Further, since the carburetor 30 is arranged so as to be adjacent to the cooling fan 12 connected to one end of the crankshaft 6 in the radial direction, the space around the outer periphery of the cooling fan 12 can be effectively used as the installation space for the carburetor. Can contribute to further downsizing the engine E.
[0026]
Further, an air cleaner 32 and a muffler 38 are disposed adjacent to each other along the axial direction of the crankshaft 6 above the cylinder block 3 and the cylinder head 4, and a fuel tank 41 adjacent to the air cleaner 32 and the muffler 38 is disposed above the crankcase 2. Therefore, the space above the cylinder block 3, the cylinder head 4 and the crankcase 2 can be effectively used as a space for installing the air cleaner 32, the muffler 38 and the fuel tank 41, and the engine E can be made more compact. Can be achieved.
[0027]
Next, the lubrication system of the engine E will be described.
[0028]
4 and 8, the guide shaft 46, the balance weight 45, the pivot 44, the link 43, and the crank shaft 6 are formed with a series of lubricating oil passages 50 for supplying oil to the outer peripheral surfaces of the pair of crank pins 6p, 6p. In addition, a pump oil chamber 48 is provided in the middle of the lubricating oil passage 50. The pump oil chamber 48 is defined in the guide hole 47 of the balance weight 45 by the tip end of the guide shaft 46, and expands and contracts as the balance weight 45 reciprocates.
[0029]
On the other hand, an oil pump 53 that is driven from the crankshaft 6 and driven by driven gears 51 and 52 is attached to the inner wall of the side cover 2b. A discharge port of the oil pump 53 and a guide shaft 46 are formed. The oil pipe 54 is connected to the inlet of the lubricating oil passage 50.
[0030]
Thus, during operation of the engine E, the oil pump 53 sucks the lubricating oil 56 stored in the bottom of the crankcase 2 through the strainer 55 and passes it through the oil pipe 54 and the lubricating oil passage 50 to the crank pins 6p and 6p. Supply and lubricate the rotating sliding surface between the connecting rods 16 and 16.
[0031]
At that time, the pump oil chamber 48 in the guide hole 47 repeats the expansion and contraction of the volume by the reciprocating movement of the balance weight 45 and exhibits the pump action. At the time of the volume contraction, the discharge pressure of the oil pump 53 is reduced. Since the oil becomes a resistance and the reverse flow of the oil is prevented, the oil pumped from the oil pump 53 can be effectively boosted and supplied to the crankpins 6p, 6p side, and the lubrication can be effectively performed. it can. Therefore, it is possible to use a small-capacity oil pump 53, and a special one-way valve that prevents backflow of oil is not required, so that weight reduction and cost reduction can be achieved.
[0032]
Further, in the middle of the lubricating oil passage 50, the sliding surface between the eccentric shaft portion 42 and the pivot 44 and the sliding surface between the guide shaft 46 and the balance weight 45 can be lubricated by the oil passing therethrough.
[0033]
Next, the valve train of the engine E will be described.
[0034]
4, 5, 9, and 10, a drive timing pulley 57 adjacent to the eccentric shaft portion 42 is formed at the center portion of the crankshaft 6. On the other hand, a cam support shaft 61 parallel to the crankshaft 6 is attached to the cylinder head 4, and the driven timing pulley 58 at the center of the cam shaft 62 that is rotatably supported by the cam support shaft 61 and the above drive. A timing belt 59 is stretched between the timing pulley 57. The drive and driven timing pulleys 57 and 58 and the belt 59 constitute a timing transmission device 60 that drives the camshaft 62 from the crankshaft 6 with a reduction ratio of 1/2.
[0035]
The cam shaft 62 is formed with a pair of exhaust cams 66, 66 arranged with the driven timing pulley 58 interposed therebetween, and intake cams 65, 65 adjacent to the outer ends of the exhaust cams 66, 66. 66 has a larger diameter than the outer intake cams 65, 65. The cam shaft 62 is restricted from moving in the axial direction by a pair of support walls 67 and 67 formed on the cylinder head 4 to support both ends of the cam support shaft 61. A pair of small support walls 68, 68 are integrally connected to the support walls 67, 67, and both ends of the rocker shaft 69 parallel to the cam support shaft 61 are supported by them. An intake rocker arm 70 and an exhaust rocker arm 71 are individually swingably supported on each rocker shaft 69. The intake rocker arm 70 includes a first arm 70a having a U-shaped cross section whose base end is supported by the rocker shaft 69 and whose tip is in contact with the head of the intake valve 23 via an adjustment bolt 72, and the first arm 70a. The second arm 70b extends from one side wall and slidably contacts the outer peripheral surface of the intake cam 65.
[0036]
Further, the exhaust rocker arm 71 is supported by a rocker shaft 69 while covering the proximal end portion of the first arm 70a, and the distal end portion abuts against the head portion of the exhaust valve 24 via an adjusting bolt 73. And a second arm 71b extending from one side wall of the first arm 71a and in sliding contact with the outer peripheral surface of the exhaust cam 66.
[0037]
The intake and exhaust valves 23 and 24 are equipped with valve springs 74 and 75 that urge them in the valve closing direction.
[0038]
Each rocker shaft 69 has an enormous head 69a at the outer end facing the outer side of the cylinder head 4, and the head 69a is connected to the cylinder head 4 so as to cover the valve train. It arrange | positions so that it may contact | abut on the inner surface. Therefore, when the head cover 76 is detached, the rocker shafts 69 and 69 can be inserted into and removed from the small support walls 68 and 68. When the head cover 76 is attached, the rocker shafts 69 and 69 are supported by the inner walls. Separation from the walls 68, 68 is prevented.
[0039]
A locking pin 77 is attached to the rocker shaft 69 between the small support walls 68, 68, and the locking pin 77 is inserted into the lateral hole 78 of the cam support shaft 61, and is removed from the support wall 67 of the cam support shaft 61. The withdrawal is prevented.
[0040]
FIG. 11 shows a modification of the engine of the present invention. The timing transmission device 60 is disposed adjacent to the inner wall of the side cover 2b, and the driven timing pulley 58 of the timing transmission device 60 is a cam spindle. 61 except that the cam shaft 62 is key-coupled to the cam support shaft 61 and the driven timing pulley 58 drives the cam shaft 62 via the cam support shaft 61. The configuration is the same as that of the embodiment, and in FIG. 11, the same reference numerals are assigned to the portions corresponding to those of the embodiment, and the description thereof is omitted.
[0041]
The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the gist of the present invention. For example, in the cam shaft 62, the intake cam 65 can be disposed on the large diameter side, the exhaust cam 66 can be disposed on the small diameter side, and the exhaust rocker arm 71 can be disposed inside the intake rocker arm 70.
[0042]
【The invention's effect】
According to the present invention as described above, the crankcase fixedly an axis and flat line guide axis of the cylinder, fitted balance weight guide hole slidably in the guide shaft, the balance weight In an engine with a balancer that is connected to the crankshaft via interlocking means so that the balance weight reciprocates in the direction opposite to the piston sliding in the cylinder , the pump oil chamber in the guide hole of the balance weight is the balance weight. The pump action is exhibited by repeating the expansion and contraction of the volume by the reciprocating movement of the oil , but when the volume contracts, the oil pump discharge pressure becomes a resistance and the back flow of the oil is prevented, so it is pumped from the oil pump. The oil can be effectively boosted and supplied to the lubrication part of the crankshaft for effective lubrication. Use of the pump enables, also not required even special one-way valve to prevent back flow of oil, lighter, it can contribute to cost reduction.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional side view of a main part of an engine with a balancer according to the present invention.
FIG. 2 is a view taken in the direction of arrow 2 in FIG.
3 is a view taken in the direction of arrow 3 in FIG.
4 is a cross-sectional view taken along line 4-4 of FIG.
5 is a cross-sectional view taken along line 5-5 in FIG.
6 is a cross-sectional view taken along line 6-6 of FIG.
7 is a view taken in the direction of arrow 7 in FIG. 2;
8 is a cross-sectional view taken along line 8-8 in FIG.
9 is a cross-sectional view taken along line 9-9 in FIG.
FIG. 10 is a longitudinal sectional view (A), a left side view (B), and a right side view (C) showing a camshaft.
FIG. 11 is a longitudinal plan view showing a modification of the engine of the present invention.
[Explanation of symbols]
E ... Engine 2 ... Crankcase 6 ... Crankshaft 17 ... Piston 18 ... Cylinder 42 ... One of interlocking means Eccentric shaft part 43 constituting the part .... Link 44 constituting part of the interlocking means ... Pivot 45 constituting part of the interlocking means ... Balance weight 46 ...・ Guide shaft 47 ... Guide hole 48 ... Pump oil chamber

Claims (1)

The crankcase (2), a cylinder (18) axis and a flat line guide shaft (46) fixedly mounted in the guide holes of the balance weight (45) to (47) slidably on the guide shaft (46) The balance weight (45) is connected to the crankshaft (6) via the interlocking means (42, 43, 44), and in the opposite direction to the piston (17) sliding in the cylinder (18). An engine with a balancer that reciprocates the balance weight (45) ,
The guide hole (47) of the balance weight (45) defines a pump oil chamber (48) that expands and contracts as the balance weight (45) reciprocates .
The pump oil chamber (48) is connected to the discharge side of an oil pump (53) that is driven by the crankshaft (6) to pump the lubricating oil (56), and the pump oil chamber (48) is connected to the crankshaft (48). 6) by communicating the lubrication of, at the time of the volume shrinkage of the pump oil chamber (48) is the discharge pressure of the oil pump (53) is a resistor, the backflow of oil from the pump oil chamber (48) is one A lubrication device for an engine with a balancer, characterized in that it is blocked without being caused by a directional valve .

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