JPH0586825A - Splashing lubricator for engine with balancer device - Google Patents

Abstract

PURPOSE:To miniaturize the engine and reduce the cost of a connecting rod cap by journaling a balancer shaft below a crankshaft, and turning a balancer weight above and below the specified oil level of lubricating oil. CONSTITUTION:A balancer shaft 3 is journaled below a crankshaft 2. The rotational center 4 of the blanacer shaft 3 is disposed around the specified oil level 7 of lubricating oil 6 which is stored in the lower part of a crank chamber 1. A balancer weight 5 is constituted so as to turn above and below the specified oil level 7 of the lubricating oil 6 in a vertical direction, and splash the lubricating oil 6 into the crank chamber 1 with the shoulder surface 8 of the balancer weight which extends in a peripheral direction from the rotational center 4 side of the balancer shaft 3. It is thus possible to decrease the lateral width of the crank chamber miniaturize the engine. It is also possible to commonly use a connecting rod cap and a force feed lubricating type engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a splash lubrication device for an engine with a balancer device.

[0002]

2. Description of the Related Art A balancer device used for an engine is a device for reducing the vibration of the engine by balancing the reciprocating inertial force of a piston with the centrifugal force of a balancer weight. This device is useful when vibration cannot be reduced by balancing the reciprocating inertial forces between the pistons, 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 portion of the crank chamber into the crank chamber by a splash device to spray the lubricating oil and supply it to the crankshaft and the like. This device does not require a lubrication oil pump or a lubrication oil supply passage unlike the pressure-feed lubrication device,
It can be easily configured. Therefore, this device
It is widely used in general-purpose engines that require cost reduction.

As a conventional technology of an engine with a balancer device, there is one shown in FIG. This is the crank chamber 101
The balancer shaft 1 is parallel to the crank shaft 102 installed inside.
The balancer shaft 103 is provided with a balancer weight 105 that is eccentric from the rotation center 104 of the balancer shaft 103, and the balancer shaft 103 is rotatably interlocked with the crankshaft 102 via a timing transmission device. The balancer shaft 103 is mounted on the lateral side of the crank shaft 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 splash lubrication device is provided. That is, the connecting rod cap 1
08, an oil spoon 109 is provided so as to project downward, and a tip end portion of the oil spoon 109 is configured to rotate along a rotation locus 110 above and below a prescribed oil surface 107 of the lubricating oil 106. Is to be flipped up into the crank chamber 101 at the tip of the oil spoon 109. The oil spoon 109 is integrally formed with the connecting rod cap 108. In addition, there is also one in which the oil spoon 109 is formed of a metal plate and is fixed to the connecting rod cap 108 with the connecting rod bolt 111.

[0005]

The above-mentioned prior art 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.

Since the oil spoon 109 is integrally formed with the connecting rod cap 108, the connecting rod cap 108 cannot be used in common with the pressure-feed lubricated engine. When this connecting rod cap 108 is used in the pressure-feed lubrication engine, the pressure-feed lubrication engine is restricted because the arrangement and selection of other parts (for example, the oil strainer at the oil suction port) is limited in order to avoid interference with the oil spoon 109. This is because there is a great disadvantage in designing. As described above, when the oil spoon 109 is integrally formed with the connecting rod cap 108, the connecting rod cap 108 is used only as a dedicated component of the splash lubrication engine, resulting in high cost.

In the case where the oil spoon 109 is made of sheet metal, the oil spoon 109 and the connecting rod cap 108 are separate parts, and therefore, compared with the case where the oil spoon 109 is integrally cast with the connecting rod cap 108. The score increases. Also, when fixing the connecting rod cap 108, an oil spoon 109
Must be fixed at the same time with the connecting rod bolt 111, the work of fixing the connecting rod cap 108 becomes complicated, and the manufacturing efficiency of the engine decreases.

According to the present invention, the width of the crank chamber can be reduced,
It is an object of the present invention to provide a splash lubrication device for an engine with a balancer device, which can be commonly used for a pressure-feed lubrication engine and can be efficiently manufactured with a small number of parts.

[0009]

According to 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 the balancer shaft 3 has its rotation center. In the engine with the balancer device in which the balancer weight 5 which is eccentric from 4 is formed and the balancer shaft 3 is rotationally interlocked with the crankshaft 2 through the timing transmission device, the splash lubrication device is as follows. It is characterized in that it is configured.

That is, the balancer shaft 3 is mounted below the crankshaft 2, and the center of rotation 4 of the balancer shaft 3 is near the prescribed oil level 7 of the lubricating oil 6 stored in the lower portion of the crank chamber 1. The balancer weight 5 is configured to 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 so as to be splashed up into the crank chamber 1.

[0011]

When the crankshaft 2 is rotated, the balancer shaft 3 is rotatably interlocked with each other via the timing transmission device, and the balancer weight 5 formed on the balancer shaft 3 is rotated to generate a centrifugal force. The engine vibration is reduced in balance with the reciprocating inertial force of.

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 for lubrication.

Further, since the balancer shaft 3 is pivotally supported below the crankshaft 2, the lateral width of the crank chamber 1 is made narrower than in the case where the balancer shaft 3 is pivotally supported on the lateral side of the crankshaft 2. be able to. Moreover, the balancer weight 5
Is rotated over the specified oil surface 7 of the lubricating oil 6, it is not necessary to expand the space in the crank chamber 1 in the vertical direction.

Further, the balancer weight shoulder 8 is provided with lubricating oil 6
No need for an oil spoon as it bounces up.

[0015]

Since the balancer shaft is 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 causes the lubricating oil to be splashed up into the crank chamber. The oil spoon is not necessary because it is configured as. Therefore, the connecting rod cap can be shared with the pressure-feed lubrication engine, and the cost of the connecting rod cap can be reduced.

Since the oil spoon is unnecessary, the number of parts is reduced. Further, since the work of installing the oil spoon is not required, the work efficiency of the engine is increased.

[0018]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a vertical cross-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. Figure 4
FIG. 2 is a cross-sectional plan view of a centrifugal governor device used in the engine of FIG. FIG. 5 is a perspective view of a splash lubrication device used in the engine of FIG.

The engine shown in FIG. 1 is constructed as follows. The crank chamber 1 is integrally molded below the cylinder body 10 to form a cylinder block 11. A crank chamber cover 12 is provided on the front side of the crank chamber 1 (see FIG. 3).
Is assembled. A cylinder head 13 and a head cover 14 are sequentially assembled on the upper side of the cylinder body 10. A fuel tank 15 is arranged on the head cover 14. Lubricating oil 6 is stored in the lower portion of the crank chamber 1.

A cylinder liner 16 is fitted in the cylinder body 10, and a piston 9 is fitted in the cylinder liner 16 so as to be vertically slidable. 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 9 via a 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 projected 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 crankpin 24 is internally fitted to the connecting rod large end portion 57, and as shown in FIG. 1, the connecting rod cap 17 is fixed to the connecting rod large end portion 57 with connecting rod bolts 19.

As shown in FIG. 1, the combustion chamber 20 faces a spark 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 operating 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 the tappet 3
7, the tappet 37 has a lower end portion which is operated by the valve cam 34.
Is mounted on the cam surface of. As shown in FIG. 3, the valve cam shaft 38 to which the valve cam 34 is attached has front and rear ends thereof on the wall of the crank chamber cover 12 and the rear wall 27 of the crank chamber 1.
The valve operating cam shaft 38 is axially mounted in the crank chamber 1 in the front-rear direction. The valve operating camshaft 38 is connected to the crankshaft 2 via a timing transmission device described later.
It is supposed to be linked from.

The structure of the speed control mechanism is as follows. As shown in FIG. 1, a governor lever 41 is interlockingly connected to the speed control lever 39 via a governor spring 40, and a throttle valve arm 43 of the 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 tip of the governor lever shaft 44 is linked to the centrifugal governor 46.

The structure 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. Governor case 4
The base end of the flyweight 49 is pivotally supported on the inner bottom of 8.
The tip end portion of the flyweight 49 is configured to swing outward due to the rotation. A claw 50 is provided on 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 has a crank chamber cover 12
Is supported by a cantilever on the wall of the crankcase, and a centrifugal governor 46 projects rearward from the crankcase cover 12.

According to the centrifugal governor 46, when the rotation speed of the flyweight 49 increases, the flyweight 4
The tip of 9 swings as shown by the arrow 54, and the claw 50 rises,
The slide cap 51 is slid, the tip end portion 52 of the governor lever shaft is pushed as shown by an arrow 55, and the governor lever 41 shown in FIG. 1 is swung, so that the opening degree of the throttle valve of the carburetor 33 is adjusted to be small. become. The centrifugal 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.
A balancer shaft 3 is installed in the crank chamber 1 in parallel with the crank shaft 2, and a balancer weight 5 eccentric from the center of rotation is formed on the balancer shaft 3. The balancer weight 5 is a semi-cylindrical block 56.5 distributed in the front and rear.
As shown in FIG. 5, a 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. As shown in FIG.
Both blocks 56 forming the balancer weight 5
Is connected by a small diameter portion 59 facing the connecting rod large end portion 57 so that interference between the balancer weight 5 and the connecting rod large end portion 57 can be avoided. Both ends of the balancer shaft 3 have a rear wall 27 and a crank chamber cover 12 of the crank chamber 1.
Of 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 interlocked with the crank shaft 2 via a timing transmission device.

The timing transmission is constructed 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. In addition, FIG.
As shown in, 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 shown by the arrow 64, the balancer gear 61 shows 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 constructed as follows. As shown in FIG. 2, the balancer shaft 3 is rotatably supported below the crankshaft 2, the rotation center 4 of the balancer shaft 3 is disposed near the specified oil surface 7 of the lubricating oil 6, and the balancer weight 5 is the lubricating oil 6 It is configured to rotate above and below the prescribed oil level 7. 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. In addition, the lower half of the balancer gear 61 and the centrifugal governor 4
The lower half of 6 is soaked in 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 as indicated by an arrow 69 on the balancer shoulder surface 8 of the balancer weight 5 which rotates counterclockwise as indicated by an arrow 68. 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 apparatus, as shown in FIG.
The valve rod cam shaft 38 is struck by the valve rod cam 38 to lubricate the connecting rod large end portion 57 and the crank pin 24, and the valve valve cam 34 and the tappet 37 are lubricated. Further, a part of the droplets is splashed on the inner peripheral surface of the cylinder liner 16, and lubrication between the piston 9 (see FIG. 1) and the cylinder liner 16 is performed. In addition, a part of the droplets is splashed inside the piston 9 to cool the piston 9.

This engine is equipped with a blazer device,
It is structured as follows. As shown in Figure 1,
The crank chamber 1 is connected to the blazer chamber 73 via the push rod chamber 72. The reed valve 7 is installed in the breather chamber 73.
4 are provided. The breather 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 sandwiched and fixed between the cylinder head 13 and the head cover 14. The push rod chamber 72 is also in communication with the rocker arm chamber 76.

According to this blazer device, the blow-by gas leaking from the combustion chamber 20 into the crank chamber 1 entrains the droplets of the lubricating oil 6 and makes the droplets mist-like, and the push-rod chamber 72 is formed along with this. It flows into the blazer chamber 73 via. Then, the reed valve 74 in the breather chamber 73 separates the lubricating oil from the blow-by gas, 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 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.

[Brief description of drawings]

FIG. 1 is a vertical cross-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 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 used in the engine of FIG. 1. 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 prescribed oil level, 8 ... balancer weight shoulder surface.

Claims (1)

[Claims] 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).
It is arranged in the vicinity of (7), and the balancer weight (5) is configured to rotate above and below the specified oil surface (7) of the lubricating oil (6), and the center of rotation (4) of the balancer shaft (3). A balancer weight shoulder surface (8) extending in the circumferential direction from the side, the lubricating oil (6) is configured to be splashed into the crank chamber (1). Splash lubrication device.