JPH0530407U - Splash lubrication system for engines with balancer system - Google Patents

Abstract

(57) [Summary] [Structure] In an engine with a balancer device, the splash lubrication device is configured as follows. The balancer shaft 3 is mounted below the crank shaft 2, and the center of rotation 4 of the balancer shaft 3 is mounted.
The balancer weight shoulder surface 8 extending in the circumferential direction from the side allows the lubricating oil 6 to be splashed up into the crank chamber 1. A splash shielding plate 11 is provided in the crank chamber 1 at a position facing the crank chamber side opening 10 of the breather communication passage 9. [Effect] The width of the crank chamber 1 can be narrowed, and the engine can be downsized. Wide balancer weight shoulders 8
Since the lubricating oil 6 can be flipped up by, the lubricating performance is high. Of the splashes of the lubricating oil 6 splashed up in the crank chamber 1, the splashes of the lubricating oil 6 toward the cylinder side opening 10 of the breather communication passage 9 collide with the splash shielding plate 11 and come into contact with the breather communication passage 9.
Since the oil does not flow directly into the bladder chamber 73, the lubricating oil is prevented from spouting from the blazer chamber 73.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a splash lubrication device for an engine with a balancer device.

[0002]

[Prior art]

 The balancer device used in the engine balances the reciprocating inertial force of the piston with the centrifugal force of the balancer weight to reduce engine vibration. This device is useful when vibration cannot be reduced by balancing the reciprocating inertial forces between the pistons, such as in a single cylinder engine. For this reason, this device is widely used in single cylinder engines and the like. On the other hand, the splash lubrication device is a device that splashes the lubricating oil accumulated in the lower part of the crank chamber into the crank chamber with a splashing device, sprays the lubricating oil and supplies it to the crankshaft and the like. This device does not require a lubricating oil pump or a lubricating oil supply passage unlike the pressure feeding lubricating device, and can be simply configured. For this reason, this device has been widely used in general-purpose engines that are required to be low in cost.

As a conventional technology of an engine with a balancer device, there is one shown in FIG. The balancer shaft 103 is installed in parallel with the crank shaft 102 installed in the crank chamber 101, and the balancer shaft 103 is provided with a balancer weight 105 which is eccentric from the rotation center 104 of the balancer shaft 103. It is configured to be rotationally interlocked with the crankshaft 102 via a device. The balancer shaft 103 is mounted on the lateral side of the crankshaft 102, and the balancer weight 105 is configured to rotate above a specified oil surface 107 of the lubricating oil 106.

In the above prior art, the following droplet lubrication device is provided. That is, an oil spoon 109 is projected downward from the connecting rod cap 108, and the tip of this oil spoon 109 is rotated along the rotation locus 110 above and below the specified oil surface 107 of the lubricating oil 106. The lubricating oil 106 is splashed up into the crank chamber 101 at the tip of the oil spawn 109. In the figure, 111 is a connecting rod bolt.

[0005]

[Problems to be solved by the device]

 The above conventional technique has the following problems. Since the balancer shaft 103 is mounted on the lateral side of the crank shaft 102, it is necessary to widen the lateral width of the crank chamber 101 in order to avoid interference with the balancer weight 105, and the engine becomes large.

When the rotation speed of the crankshaft 102 is increased, the rotation speed of the oil spoon 109 is also increased, and the amount of the splash of the lubricating oil 106 is increased to an appropriate amount or more, which is transmitted from the crank chamber 101 through the breather communication passage to the blazer chamber (see FIG. A large amount of oil flows into the outside), the lubricating oil separation capacity of the blazer chamber does not reach this, and lubricating oil may blow out from the blazer chamber.

An object of the present invention is to provide a splash lubrication device for an engine with a balancer device, which can reduce the lateral width of the crank chamber and prevent the lubricating oil from being blown out from the blazer chamber.

[0008]

[Means for Solving the Problems]

 In the present invention, as illustrated in FIG. 1, a balancer shaft 3 is installed in parallel with a crank shaft 2 installed in a crank chamber 1, and a balancer weight 5 eccentric from a rotation center 4 is formed on the balancer shaft 3. In the engine with the balancer device in which the balancer shaft 3 is rotationally interlocked with the crankshaft 2 via the timing transmission device, the splash lubrication device is configured as follows. To do.

That is, the balancer shaft 3 is mounted below the crank shaft 2, and the rotation center 4 of the balancer shaft 3 has a prescribed oil level 7 of the lubricating oil 6 stored in the lower portion of the crank chamber 1. The balancer weights 5 are arranged in the vicinity of the balancer weights 5 so that the balancer weights 5 rotate above and below the specified oil surface 7 of the lubricating oil 6, and the balancer weight shoulder surface 8 extends in the circumferential direction from the rotation center 4 side of the balancer shaft 3. The lubricating oil 6 is configured to be splashed up into the crank chamber 1, and a splash shielding plate 11 is provided in the crank chamber 1 at a position facing the crank chamber side opening 10 of the breather communication passage 9. It is characterized by

[0010]

[Action]

 When the crankshaft 2 rotates, the balancer shaft 3 is rotationally interlocked via the timing transmission, and the balancer weight 5 formed on the balancer shaft 3 generates a centrifugal force, which is generated by the piston 29. Reduces engine vibration in balance with reciprocating inertial force.

Further, when the balancer weight 5 rotates, the lubricating oil 6 is splashed and splashed up in the crank chamber 1 by the balancer weight shoulder surface 8, and the lubricating oil 6 is splashed on the crankshaft 2 and the like and lubricated. Is done. Since the surface area of the balancer weight shoulder surface 8 can be formed to be relatively large, the amount of the lubricating oil 6 splashed in the crank chamber 1 is large and the lubrication performance is high. Further, the amount of the lubricating oil 6 splashed is large, but of these, the one toward the crank chamber side opening 10 of the breather communication passage 9 collides with the splash shield plate 11, so the lubricating oil 6 splashes in the breather communication passage 9. Will never flow in directly.

Since the balancer shaft 3 is pivotally supported below the crankshaft 2, the lateral width of the crank chamber 1 is narrower than that in the case where the balancer shaft 3 is pivotally supported on the lateral side of the crankshaft 2. can do. Moreover, since the balancer weight 5 is adapted to rotate above and below the specified oil surface 7 of the lubricating oil 6, it is not necessary to vertically expand the space inside the crank chamber 1.

[0013]

[Effect of the device]

 Since the balancer shaft is pivotally supported below the crank shaft, the lateral width of the crank chamber can be narrowed and the engine can be downsized. .

The balancer weight is configured to rotate above and below the specified oil level of the lubricating oil, and the balancer weight shoulder surface extending in the circumferential direction from the rotation center side of the balancer shaft allows the lubricating oil to be splashed up into the crank chamber. Although the balancer weight shoulder surface can be formed relatively large, the amount of lubricating oil splashing increases and the lubrication performance improves.

Since the splash shielding plate is provided in the crank chamber at a position facing the cylinder side opening of the breather communication passage, among the splashes of the lubricating oil splashed into the crank chamber, the cylinder of the breather communication passage is provided. Those that go to the side opening collide with the splash shield and do not flow directly into the breather communication passage. Therefore, the lubricating oil is prevented from being blown out from the breather chamber.

[0016]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a vertical sectional front view of a splash lubrication type air-cooled single cylinder gasoline engine equipped with a balancer device according to an embodiment of the present invention. 2 is a vertical sectional front view of the lower portion of the engine of FIG. FIG. 3 is a cross-sectional plan view of the engine of FIG. FIG. 4 is a cross-sectional plan view of the centrifugal governor device used in the engine of FIG. FIG. 5 is a perspective view of the splash lubrication device, the splash shield, and the blazer communication passage used in the engine of FIG.

The engine shown in FIG. 1 is configured as follows. The crank chamber 1 is integrally formed on the lower side of the cylinder body 80 to form a cylinder block 81. A crank chamber cover 12 (see FIG. 3) is attached to the front side of the crank chamber 1. The cylinder head 13 and the head cover 14 are sequentially assembled on the upper side of the cylinder body 80. A fuel tank 15 is arranged on the head cover 14. Lubricating oil 6 is stored in the lower part of the crank chamber 1.

The cylinder liner 16 is fitted in the cylinder body 80, and the piston 29 is fitted in the cylinder liner 16 so as to be slidable up and down. A recess is provided in each of the bottom surface of the cylinder head 13 and the piston head 18, and the recess forms the combustion chamber 20. The crankshaft 2 is linked to the piston 29 via the connecting rod 21. As shown in FIG. 3, in the crankshaft 2, a crank pin 24 is installed between a pair of front and rear crank arms 22 and 23, and front and rear crank journals 25 and 26 are protruded from the front and rear crank arms 22 and 23 in the front and rear direction. Is configured. The front and rear crank journals 25 and 26 are borne by the crank chamber cover 11 and the rear wall 27 of the crank chamber 1 via bearing bearings, respectively, whereby the crankshaft 2 is mounted in the crank chamber 1 in the front-rear direction. .. As shown in FIG. 1, the crank pin 24 is internally fitted to the connecting rod large end portion 57, and the connecting rod cap 17 is fixed to the connecting rod large end portion 57 by a connecting rod bolt 19.

Further, as shown in FIG. 1, the combustion chamber 20 faces an ignition plug 30, an intake valve 31, and an exhaust valve (not shown). The intake port 32 provided with the intake valve 31 communicates with the carburetor 33. The intake valve 31 is operated by a valve cam 34 via a valve mechanism. The carburetor 33 is adapted to be adjusted by a speed control mechanism.

The structure of the valve mechanism is as follows. A rocker arm 35 is provided in the head cover 14, the output end of the rocker arm 35 is in contact with the valve shaft head of the intake valve 31, and the input end is in contact with the head of the push rod 36. The lower end of the push rod 36 is placed on the tappet 37, and the lower end of the tappet 37 is placed on the cam surface of the valve operating cam 34. As shown in FIG. 3, the front and rear ends of the valve operating cam shaft 38 provided with the valve operating cam 34 are borne by the wall of the crank chamber cover 12 and the rear wall 27 of the crank chamber 1, respectively. A valve cam shaft 38 is mounted in the crank chamber 1 in the front-rear direction. The valve operating camshaft 38 is adapted to be interlocked with the crankshaft 2 via a timing transmission device described later.

The structure of the speed control mechanism is as follows. As shown in FIG. 1, a governor lever 41 is interlockingly connected to a speed control lever 39 via a governor spring 40, and a throttle valve arm 43 of a carburetor 33 is interlockingly connected to the governor lever 41 via an interlocking rod 42. The lower end portion of the governor lever 41 is attached to the base end portion of the governor lever shaft 44, and the governor lever shaft 44 is rotatably inserted in the lateral wall 45 of the crank chamber 1 so that the governor lever 41 can swing. The front end of the governor lever shaft 44 is associated with the centrifugal governor 46.

The configuration of the centrifugal governor 46 is as follows. As shown in FIG. 4, a bowl-shaped governor case 48 is rotatably supported by the governor shaft 47. A base end portion of a flyweight 49 is pivotally supported on the inner bottom portion of the governor case 48, and the tip end portion of the flyweight 49 is pivoted outward by rotation. A claw 50 is provided at the base end of the flyweight 49 so as to project toward the governor shaft 47. The slide cap 51 is slidably fitted to the tip of the governor shaft 47, and the tip 52 of the governor lever shaft 44 is abutted to the tip of the slide cap 51. A flange portion 53 is provided at the base end of the slide cap 51, and the claw 50 of the flyweight 49 is brought into contact with the flange portion 53. The base end of the governor shaft 47 is supported by the wall of the crank chamber cover 12 in a cantilever manner, whereby the centrifugal governor 46 projects rearward from the crank chamber cover 12.

According to the centrifugal governor 46, when the rotational speed of the flyweight 49 increases, the tip of the flyweight 49 swings as shown by the arrow 54, the pawl 50 is raised, and the slide cap 51 slides. Then, the tip end portion 52 of the governor lever shaft is pushed as indicated by an arrow 55 to swing the governor lever 41 shown in FIG. 1, and the throttle valve opening of the carburetor 33 is adjusted to be small. Further, as shown in FIG. 2, a stopper bolt 82 is screwed through the lateral wall of the crank chamber 1 in a penetrating manner. As shown in FIG. 4, the stopper bolt 82 is projected between the governor lever shaft and a locus 83 of the oil spoon 28, which will be described later, so that the oil spoon 28 does not interfere with the tip end portion 52 of the swinging governor lever shaft. ing. The crank chamber centrifugal type governor 46 is adapted to be interlocked with the crankshaft 2 via a timing transmission device described later.

This engine is equipped with a balancer device, which is as follows. As shown in FIG. 3, a balancer shaft 3 is installed in the crank chamber 1 in parallel with the crankshaft 2, and a balancer weight 5 eccentric from the center of rotation is formed on the balancer shaft 3. The balancer weight 5 is formed as a semi-cylindrical block 56, 56 distributed in the front and rear, and as shown in FIG. 5, the balancer weight shoulder surface 8 extending in the circumferential direction from the rotation center 4 side of the balancer shaft 3 is formed on the upper surface thereof. Are formed. As shown in FIG. 3, both blocks 56, 56 constituting the balancer weight 5 are connected to each other by the small diameter portion 59 facing the connecting rod large end portion 57, and interference between the balancer weight 5 and the connecting rod large end portion 57 is avoided. It is like this. Both ends of the balancer shaft 3 are borne by the rear wall 27 of the crank chamber 1 and the wall of the crank chamber cover 12, respectively, so that the balancer shaft 3 is mounted in the crank chamber 1 in the front-rear direction.

According to this balancer device, the centrifugal force of the balancer weight 5 generated by the rotation is balanced with the reciprocating inertial force of the piston 9 (see FIG. 1), and the vibration of the engine is reduced. The balancer shaft 3 is adapted to be driven by the crankshaft 2 via a timing transmission device.

The timing transmission device is configured as follows. As shown in FIG. 3, a large-diameter crank gear 59 and a small-diameter crank gear 60 are fitted on the crankshaft 2. A balancer gear 61 is fitted on the balancer shaft 3. A valve gear 62 is fitted on the valve cam shaft 38. As shown in FIG. 4, a governor gear 63 is formed around the governor case 48. As shown in FIG. 3, the large-diameter crank gear 59 and the balancer gear 61 mesh with each other, and the small-diameter crank gear 60 and the valve gear 62 mesh with each other. Further, as shown in FIG. 2, the valve gear 62 and the governor gear 63 are meshed with each other.

In this timing transmission, as shown in FIG. 2, when the large-diameter crank gear 59 and the small-diameter crank gear 60 rotate together with the crankshaft 2 in the clockwise direction as indicated by the arrow 64, the balancer gear 61 moves in the direction of the arrow 65. As described above, the valve gear 62 is rotationally interlocked in the counterclockwise direction, the valve gear 62 is rotationally interlocked in the counterclockwise direction as indicated by the arrow 66, and the governor gear 63 is rotationally interlocked in the clockwise direction as indicated by the arrow 67. Therefore, when the crankshaft 2 rotates, the balancer shaft 3 rotates counterclockwise, the valve cam shaft 38 rotates counterclockwise, and the centrifugal governor 46 rotates clockwise.

The splash lubrication device for this engine is configured as follows. As shown in FIG. 2, an oil spoon 28 is fixed to the connecting rod cap 17 with connecting rod bolts 19. Further, the balancer shaft 3 is pivotally supported below the crankshaft 2, the rotation center 4 of the balancer shaft 3 is arranged near the specified oil level 7 of the lubricating oil 6, and the balancer weight 5 is set to the specified oil level 7 of the lubricating oil 6. Is configured to rotate above and below. As a result, the lubricating oil 6 is splashed into the crank chamber 1 by the balancer weight shoulder surface 8 extending in the circumferential direction from the rotation center 4 side of the balancer shaft 3. The lower half of the balancer gear 61 and the lower half of the centrifugal governor 46 are dipped in the lubricating oil 6.

In this splash lubrication device, as shown in FIG. 2, the lubricating oil 6 is splashed up as follows. The lubricating oil 6 is splashed up by the rotating oil spoon 28, and the lubricating oil 6 is splashed up by the balancer shoulder surface 8 of the balancer weight 5 which rotates counterclockwise as indicated by arrow 68 as indicated by arrow 69. Further, the lubricating oil 6 is splashed up as shown by the arrow 70 by the balancer gear 61 rotating counterclockwise as shown by the arrow 65. In addition, the lubricating oil 6 is splashed up as indicated by the arrow 71 by the governor gear 63 that rotates clockwise as indicated by the arrow 67. The state where the lubricating oil 6 is flipped up is also shown in FIG.

According to this splash lubrication device, as shown in FIG. 2, the splashed splash of the lubricating oil 6 is splashed on the crankshaft 2 and the valve operating camshaft 38, and the connecting rod large end portion 57 is formed. And the crank pin 24 and the valve cam 34 and the tappet 37 are lubricated. Further, a part of the splashes is splashed on the inner peripheral surface of the cylinder liner 16, and the piston 29 (see FIG. 1) and the cylinder liner 16 are lubricated. In addition, a part of the droplets is splashed inside the piston 29, and the piston 29 is cooled.

This engine is equipped with a blazer device, which is configured as follows. As shown in FIG. 1, the crank chamber 1 is communicated with the blazer chamber 73 via the blazer communication passage 9. A reed valve 74 is provided in the blazer chamber 73. The blazer chamber 73 is open to the atmosphere via an atmosphere communication pipe 75 on the lower side of the flow path of the reed valve 74. The blazer chamber 73 is formed across the cylinder head 13 and the head cover 14, and the reed valve 74 is fixed by being sandwiched between the cylinder head 13 and the head cover 14. As shown in FIG. 5, the breather communication passage 9 includes a push rod chamber 72, two communication holes 77 downwardly guided from the inner bottom of the push rod chamber 72, and a lower side of the push rod chamber 72. The horizontal hole 78 is opened, and the two crank chamber-side openings 10 are drawn out downward from the horizontal hole 78. The blazer communication passage 9 also serves as a return passage for the lubricating oil from the blazer chamber 73 and the rocker arm chamber 76. Each of the communication hole 7 and the crank chamber side opening 10 is formed in a long hole shape that is long in the front-rear direction, the passage area thereof is widened, and clogging by lubricating oil is prevented. By preventing the clogging of the lubricating oil, the blazer device operates normally and the crank chamber is maintained at a negative pressure. A splash shielding plate 11 having an L-shaped cross section is provided in the crank chamber 1 below the crank chamber side opening 10. The splash shielding plate 11 is projected from the rear wall of the crank chamber 1 to the front side and is integrally formed with the crank chamber 1. As shown in FIG. 1, the breather communication passage 9 also communicates with the rocker arm chamber 76.

According to this blazer device, the blow-by gas leaked from the combustion chamber 20 of FIG. 1 into the crank chamber 1 entrains the droplets of the lubricating oil 6 to make the droplets mist-like, and with this, It flows into the blazer chamber 73 through the blazer communication passage 9 of 5. Lubricating oil is separated from the blow-by gas by the reed valve 74 in the blazer chamber 73 shown in FIG. 1, and the blow-by gas from which the lubricating oil has been removed is released into the atmosphere through the atmosphere communication pipe 75. Further, the blow-by gas accompanied with mist-like lubricating oil also flows into the rocker arm chamber 76 from the push rod chamber 72, the lubricating oil is supplied to the rocker arm 35, and the rocker arm 35 is lubricated. Further, as shown in FIG. 5, a part of the lubricating oil splashes splashed up by the balancer weight shoulder surface 8 and the balancer gear 61 collides with the splash shield plate 10 and the opening portion of the breather communication passage 9 on the crank chamber side. 10 does not directly enter, and a large amount of lubricating oil does not flow into the blazer chamber 73 shown in FIG.

[Brief description of drawings]

FIG. 1 is a front view in vertical section of a splash lubrication type air-cooled single cylinder gasoline engine equipped with a balancer device according to an embodiment of the present invention.

2 is a vertical cross-sectional front view of the lower portion of the engine of FIG. 1. FIG.

3 is a cross-sectional plan view of the engine of FIG.

4 is a cross-sectional plan view of a centrifugal governor device used in the engine of FIG.

5 is a perspective view of a splash lubrication device, a splash shield, and a breather communication path used in the engine of FIG.

FIG. 6 is a vertical cross-sectional front view of a droplet lubricated engine including a balancer device according to a conventional technique.

[Explanation of symbols]

1 ... Crank chamber, 2 ... Crank shaft, 3 ... Balancer shaft, 4
... 3 rotation center, 5 ... balancer weight, 6 ... lubricating oil,
7 ... 6 regulated oil level, 8 ... balancer weight shoulder surface, 9 ... blazer communication passage, 10 ... 9 crank chamber side opening, 11 ... splash shield plate.

Claims (1)

[Scope of utility model registration request] 1. A balancer shaft (3) is installed parallel to a crank shaft (2) installed in a crank chamber (1), and the balancer shaft (3) is eccentric from its rotation center (4). (5) is formed, and the balancer shaft (3) is configured to be rotationally interlocked with the crankshaft (2) via a timing transmission device. In the engine with a balancer device, the balancer shaft (3) is The balancer shaft (3) is mounted below the crankshaft (2), and the rotation center (4) of the balancer shaft (3) is the prescribed oil level of the lubricating oil (6) stored in the lower part of the crank chamber (1).
The balancer weight (5) is arranged in the vicinity of (7) and is configured to rotate above and below the specified oil surface (7) of the lubricating oil (6), and the balance center (4) of the balancer shaft (3). The balancer weight shoulder surface (8) extending in the circumferential direction from the side is configured so that the lubricating oil (6) is splashed up into the crank chamber (1), and the crank chamber side opening of the breather communication passageway (9) is formed. Department
A splash lubrication device for an engine with a balancer device, characterized in that a splash shield plate (11) is provided in the crank chamber (1) at a position opposed to (10).