JPH0627494B2 - Lubricating device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for an internal combustion engine, and more particularly to an internal combustion engine in which a main shaft having a lubrication passage and a drive shaft communicate with each other at symmetrical positions of their shaft ends. The present invention relates to a lubrication device.

[Prior Art] As is well known, a main shaft of a transmission and a drive shaft are rotatably supported by a crankcase of an internal combustion engine. The lubrication is performed by lubricating oil that circulates in a lubricating passage that is provided so as to communicate with the main shaft and the tribe shaft from the crankcase.

Lubrication of this type of internal combustion engine is conducted by pumping oil from an oil pan below the internal combustion engine by means of an oil pump to the lubricating passage of the crankcase and guiding it to the lubricating passage of the main shaft. Then, the lubrication passage of the drive shaft is guided from the main shaft through the lubrication passage of the crankcase, and the circulation gear lubricates the transmission gear portion and the bearing portion.

By the way, the introduction positions of the main shaft and the drive shaft from the oil pump side to the lubrication passages are limited by various devices arranged near the oil pump and the internal combustion engine. In addition, since the transmission gears of the main shaft and the drive shaft are lubricated by injecting lubricating oil from the outside, the lubrication passage that connects the main shaft and the drive shaft is provided in the crankcase from the shaft end portion of the main shaft. It is guided to the opposite shaft end of the drive shaft via a bypass passage and communicates at symmetrical positions.

[Problems to be Solved by the Invention] By the way, in order to downsize an internal combustion engine or mount engine-related equipment such as a starter motor compactly, the shape of the crankcase is changed, and an installation space for the equipment related to these engines is changed. Has been secured.

For this reason, in the case where a bypass passage is formed in the crankcase and the lubrication passage between the main shaft of the transmission and the drive shaft is communicated, the crankcase is formed in a complicated shape such as a step.

Therefore, in order to form the bypass passage in the crankcase, there are problems that the number of drilling steps is increased, labor is required, and manufacturing cost is increased.

The present invention has been made in view of the above circumstances, and it is possible to easily form a bypass passage that connects the main shaft and the drive shaft separately from the crankcase, and to easily dispose the bypass passage in the crankcase with a simple structure. It is an object of the present invention to provide a lubricating device for an internal combustion engine.

[Means for Solving the Problems] In order to solve the above problems, a lubricating device for an internal combustion engine according to the present invention axially supports a main shaft having a lubricating passage of a transmission and a drive shaft in a crankcase, and A lubricating device for an internal combustion engine, comprising a shift fork of the transmission on one side with a line connecting a shaft and a drive shaft as a boundary, and communicating a lubricating passage between the main shaft and the drive shaft at a symmetrical position of a shaft end. A bypass pipe that connects the lubrication passage of the main shaft and the lubrication passage of the drive shaft is arranged on the opposite side of the shift fork centering on a line connecting the main shaft and the tribe shaft.

[Operation] According to the present invention, the bypass pipe that is guided from the lubrication passage of the crankcase to the lubrication passage of the main shaft and is installed on the crankcase is used to lubricate the shaft end portion of the drive shaft opposite to the shaft end portion of the main shaft. Circulate. In this way, by connecting the lubrication passages of the main shaft and the drive shaft with the bypass pipe, the bypass passages can be easily arranged even if the crankcase has a complicated shape.

Moreover, the bypass pipe is arranged on the opposite side of the shift fork centering on the line connecting the main shaft and the drive shaft,
Since the shift fork does not get in the way, the bypass pipe can be placed close to the main shaft and the drive shaft.

[Embodiment] An embodiment of a lubricating device for an internal combustion engine according to the present invention will be described below in detail with reference to the accompanying drawings. 1 is a side view of an internal combustion engine to which the present invention is applied, FIG. 2 is a II-II sectional view of FIG. 1, and FIG. 3 is a III-III sectional view of FIG.

In the figure, reference numeral 1 is a crankcase of an internal combustion engine mounted on a motorcycle, and the crankcase 1 is formed by joining an upper case 2 and a lower case 3. A cylinder 4 is mounted on the crankcase 1, and the cylinder 4
A piston 5 is arranged so as to be movable up and down, and a rotational force is applied to a crankshaft 6 which is pivotally supported by the crankcase 1.

A starter motor 7 is arranged above the crankcase 1, and a gear 7a of the starter motor 7 meshes with a large-diameter gear 8a of a starter gear 8. Starter gear 8
Is rotatably provided on a support shaft 9 provided on the upper portion of the crankcase 1, and a small diameter gear 8b of the starter gear 8 meshes with a large diameter gear 10a provided on the generator shaft 10 and is provided on the generator shaft 10. Small diameter gear 10b is chain 1
It is connected to the gear 12 of the crankshaft 6 via 1.
Since the starter motor 7 is arranged in the vicinity of the upper part of the crankcase 1 and the starter gear 8 is arranged in the upper case 2, the installation space is increased by increasing the starter gear 8 in a stepwise manner, and the starter gear 8 is arranged. It is formed in a supporting structure.

The main shaft 13 and the drive shaft 14 of the transmission are bearings 15,
It is rotatably supported by the crank race 1 via 16. An input gear 17 is fixed to a shaft end portion 13a of the main shaft 13, and the input gear 17 meshes with a crank gear 18 fixed to the crank shaft 6 to transmit the rotational force of the crank shaft 6 to the main shaft 13. It is supposed to do.

Between the bearings 15, 15 of the main shaft 13, a six-speed transmission gear group 19 is arranged. This main shaft 1
Similarly to the drive shaft 14 facing the bearing 3,
A transmission gear group 20 that meshes with the transmission gear group 19 of the main shaft 13 is disposed between the six shafts 6.

Transmission gear groups 19 and 2 of the main shaft 13 and the drive shaft 14
The claws of the shift forks 21 and 22 arranged below are fitted into the annular groove formed at 0. Thus, the shift fork 2 of the transmission is provided on one side with the line L connecting the main shaft 13 and the drive shaft 14 as a boundary.
1, 22 are provided.

The shift forks 21 and 22 engage with grooves formed in a shift drum (not shown), and each time the pedal is depressed or pulled up, the shift drum rotates by one step to move the respective shift forks 21 and 22. Moving.
By the movement of the shift forks 21 and 22, the transmission gear group 20 of the drive shaft 14 and the transmission gear group 1 of the main shaft 13 are
A predetermined transmission gear is selected from 9. A drive sprocket 23 is fixed to the shaft end portion 14a of the drive shaft 14, and the rear wheel is driven via a chain.

Lubricating passages 24 and 25 are formed in the main shaft 13 and the drive shaft 14 in the axial direction, and branches for lubricating the bearings 26 and 27 and the groove portions 28 and 29 of the transmission gear groups 19 and 20 from the lubricating passages 24 and 25, respectively. Holes 30 and 31 are formed. The lubrication passage 24 of the main shaft 13 is the shaft end portion 13b on the side opposite to the input gear side, and communicates with the lubrication passage 24 of the main shaft 13 from the lubrication passage 32 formed in the crankcase 1 through the introduction passage 33 and the opposite side. Flows in the direction of the shaft end portion 13a. The introduction passage 33 communicates with a connection passage 34 formed in the crankcase 1.

On the other hand, the lubrication passage 25 of the drive shaft 14 is provided at the shaft end portion 14b opposite to the drive sprocket 23 at the crankcase 1
Communicating with the introduction passage 35 formed in
Lead in the a direction.

The connecting passage 34 on the side of the main shaft 13 and the drive shaft 14
A bypass pipe 36, which communicates the both with the side introduction passage 35, is disposed above the main shaft 13 and the drive shaft 14 in close proximity thereto.

That is, the bypass pipe 36 is arranged on the opposite side of the shift forks 21 and 22 with the line L connecting the main shaft 13 and the drive shaft 14 as the center, and the shift forks 21 and 22 do not get in the way. The internal combustion engine as a whole can be made small in size because it can be arranged close to the shaft 13 and the drive shaft 14, and the loss due to the flow resistance of the lubricating oil can be reduced without making the lubricating passage longer.

The bypass pipe 36 is composed of an injection pipe portion 36a and a connecting pipe portion 36b, and both ends of the injection pipe portion 36a have support portions 37a,
It is supported by the crankcase 1 via 37b and arranged so as to be parallel to the main shaft 13. Around the injection pipe portion 36a, an appropriate number of injection ports 38 are provided toward the main shaft 13, the drive shaft 14, and the shift forks 21, 22. Lubricating oil is injected from the injection ports 38 to The sliding portions of the transmission gear groups 19 and 20 and the shift mechanism are lubricated. The connecting pipe portion 36b of the bypass pipe 36 is arranged along the outside of the side wall of the crankcase 1, one end thereof is connected to the support portion 37b of the injection pipe portion 36a, and the other end thereof is connected to the crankcase via the support portion 37c. Supported by 1.

An L-shaped support lever 39 is connected to the support portion 37b of the injection pipe portion 36a and the support portion 37c of the connection pipe portion 36b, and the bent portion at the center of the support lever 39 is fixed to the crankcase 1 with a tightening bolt 40. The connecting pipe portion 36b is fixed and held in the crankcase 1.

Next, the operation of this embodiment will be described. Lubricating oil is supplied to the lubricating passage 24 of the main shaft 13 from the lubricating passage 32 formed in the crankcase 1 through the introduction passage 33 by the operation of an oil pump (not shown). The lubrication passage 24 is supplied to the bearing 26 and the groove portion 28 of the transmission gear 19 through the branch hole 30 to lubricate the respective sliding portions.

The lubricating oil passing through the introduction passage 33 formed in the crankcase 1 passes from the connection passage 34 of the crankcase 1 to the injection pipe portion 36a and the connection pipe portion 36b of the bypass pipe 36,
It is supplied to the introduction passage 35 arranged in the crankcase 1. When the lubricating oil passes through the injection pipe portion 36 a of the bypass pipe 36, the lubricating oil is injected from the injection port 38 and the transmission gear group 1
9. Lubricate 9, 20 and the sliding part of the shift mechanism. Further, the lubricating oil passing through the lubricating passage 25 of the drive shaft 14 passes through the branch hole 31 and the bearing 27 and the groove 29 of the transmission gear group 19.
Is supplied to.

Since the bypass pipe 36 is disposed close to and above the main shaft 13 and the drive shaft 14, the crank chamber can be narrowed by that amount, and a space for disposing the starter motor 7 and the like can be easily secured. . In addition, the transmission gear groups 19 and 20, the shift forks 21 and 22, and the groove portion 2 with which the claws thereof are engaged by the lubricating oil injected from the bypass pipe 36.
8 and 29 are reliably lubricated. Further, because of the structure of injecting from the bypass pipe 36 as described above, when the crankcase 1 is cast-molded as in the conventional case, the crankcase 1 is easily molded as compared with the case where the bypass passage is formed by casting.
In addition, there is no risk of leakage of lubrication due to porosity. Further, it has an advantage that the injection port for injecting the lubricating oil can be easily formed and can be easily formed in multiple directions.

[Advantages of the Invention] As described above, according to the present invention, since the lubrication passage of the main shaft and the lubrication passage of the drive shaft are connected via the bypass pipe,
Even in a crankcase having a complicated shape, the lubricating passage that connects the main shaft and the drive shaft can be easily arranged with a simple structure.

Also, since the bypass pipe is placed on the opposite side of the shift fork centering on the line connecting the main shaft and the drive shaft, the shift fork does not get in the way, so the bypass pipe is placed close to the main shaft and the drive shaft. Therefore, the internal combustion engine as a whole can be made compact, and the loss due to the flow resistance of the lubricating oil can be reduced without making the lubricating passage longer.

[Brief description of drawings]

1 is a side view of an internal combustion engine to which the present invention is applied, FIG. 2 is a II-II sectional view of FIG. 1, and FIG. 3 is a III-III sectional view of FIG. DESCRIPTION OF SYMBOLS 1 ... Crank case, 2 ... Upper case 3 ... Lower case, 6 ... Crank shaft 7 ... Starter motor, 8 ... Starter gear 13 ... Main shaft, 14 ... Drive shaft 19, 20 ... Shift gear group 21, 22 ... Shift fork 24 , 25 ... Lubrication passage, 36 ... Bypass pipe 36a ... Injection pipe part, 36b ... Connection pipe part

Claims (1)

[Claims] 1. A main shaft having a transmission lubrication passage and a drive shaft are pivotally supported by a crankcase, and a shift fork of the transmission is provided on one side with a line connecting the main shaft and the drive shaft as a boundary. In a lubricating device for an internal combustion engine, wherein a lubricating passage for the main shaft and the drive shaft communicates with each other at a symmetrical position of a shaft end, on the opposite side of the shift fork centering on a line connecting the main shaft and the drive shaft, A lubricating device for an internal combustion engine, wherein a bypass pipe that connects the lubricating passage of the main shaft and the lubricating passage of the drive shaft is arranged.