JPS6270612A - Oiling circuit of internal combustion engine - Google Patents

Abstract

PURPOSE:To simplify the oiling passage for reducing the working manhour and number of parts by forming, in a crank case, an oiling passage branched from a discharge oil passage which is led out from an oil pump, and making the oil passage open at the end surface of a hollow countershaft. CONSTITUTION:When a main shaft 5 is driven to be rotated by a crank shaft 3 via a clutch mechanism, the rotation is transmitted to a pump shaft via transmitting means 20, 23, 22 to drive an oil pump. Then, the oil pump takes in the oil gathered at the bottom of a crank case 4 through an oil strainer 25 and a suction pipe 24, and discharges it in the oiling passage 26 formed inside the crank case 4. Further, the oil is introduced into an oil reservoir via an oiling passage 30, and then is injected into the hollow part of a countershaft 8 from the central opening part of a nozzle plate. Thus, since the oiling passage 26, 30 to the countershaft 8 are formed only in the crank case 4, the expected purpose can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention particularly relates to a refueling circuit for an internal combustion engine that improves the refueling of a countershaft and simplifies the circuit structure.

(Prior Art) Fig. 4 shows a conventional example of an oil supply circuit for the countershaft of an internal combustion engine. Oil pressurized by an oil pump 01 driven by the engine is pumped from the crankcase 03 to the side gear case as shown in the figure. 03 side, and was guided to a nozzle 05 press-fitted into the opening end of the inner wall of an oil passage 04 formed in the side gear case 03. And this nozzle 0
5 has two injection holes 05a and 05b,
The oil injected from the injection hole 05a passes through the hollow part 06a of the countershaft 06, and passes through the hollow part 06a of the countershaft 06.
A plurality of oil supply holes 07a radially bored in the peripheral wall of...
, 07b to each gear mechanism, and lubricates them.
The oil injected from the injection hole 05b is supplied to the meshing portion between the bevel gear 08 provided at the end of the counter shaft 06 and the bevel gear 010 provided at the end of the output shaft 09, and lubricates the meshing portion.

(Problems to be Solved by the Invention) However, in the conventional circuit configuration described above, it is necessary to transfer the oil from the crankcase side to the side gear case side, which requires a large number of parts and the oil passage becomes complicated. The problem is that the number of machining steps increases, oil flow loss also increases, and sufficient lubrication cannot be achieved.

The present invention has been made in view of the above-mentioned problems, and its purpose is to simplify the oil supply circuit to the countershaft, reduce the number of parts and processing man-hours, and reduce oil flow loss. An object of the present invention is to provide a refueling circuit for an internal combustion engine that is capable of providing sufficient lubrication.

(Means for Solving the Problems) In order to achieve the above object, the present invention forms an oil supply passage branching from a discharge oil passage led out from an oil pump in the crankcase, and connects the oil supply passage to the end surface of a hollow countershaft. It was opened to the public.

(Operation) The oil discharged from the oil pump is directly supplied to the countershaft through the oil supply path formed in the crankcase without passing through the side gear case, so the oil supply circuit to the countershaft is significantly simplified. Along with this, the flow loss of oil is also reduced, and its pressure drop is suppressed.

(Example) An example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a side view of an internal combustion engine equipped with a refueling circuit according to the present invention, FIG. 2 is an enlarged sectional view taken along the line n-tr in FIG. 1, and FIG. 3 is an enlarged sectional view taken along the line m-m in FIG. 1. It is.

The internal combustion engine 1 shown in FIG.
It is equipped with A piston (not shown) is slidably fitted into each cylinder 2, 2°, and the reciprocating motion of these pistons is converted into rotational motion of the crankshaft 3 via a connecting rod.

This crankshaft 3 is rotatably supported by a crankcase 4 via a ball bearing (not shown), and a main shaft 5 is rotatably supported at the rear of the crankcase 4 (to the left in FIG. 1) in parallel with the crankshaft 3. Supported. Power transmission from the crankshaft 3 side to the main shaft 5 is selectively interrupted or interrupted by a clutch mechanism 6 provided at an end of the main shaft 5. Incidentally, on the outer periphery of the intermediate portion of the main shaft 5, a group of transmission gears 7 having different numbers of teeth are provided.

Furthermore, at the rear of the main shaft 5, a hollow countershaft 8 is mounted parallel to the main shaft 5 and has a ball bearing 9.1.
The main shaft 5 is rotatably supported at the center of the main shaft 5, and a transmission gear group 11 that selectively meshes with the transmission gear group 7 provided on the outer periphery of the main shaft 5 is provided on the outer periphery of the intermediate portion thereof. Further, a bevel gear 12 is formed at the end of this countershaft 8. In addition, the countershaft 8 has
Oil supply hole 8a for supplying oil to the transmission gear group 11...
is pierced.

On the other hand, a side gear case 1 is attached to the side end of the crankcase 4.
3 is attached to the side gear case 13, and an output shaft 14 is perpendicular to the counter shaft 8 and rotatably supported via ball bearings 15 and 16. A bevel gear 17 that meshes with the bevel gear is formed at one end of the output shaft 14.

By the way, a rotary type oil pump 18 is disposed diagonally below the main shaft 5, and a sprocket 20 is connected to the end of the pump shaft 19, and the sprocket 20 and the main shaft are connected to each other. A chain 23 is wound between sprockets 22 tied to the ends of the sprockets 5. A suction pipe 24 is connected to the suction side of the oil pump 18, and an oil strainer 25 provided at the lower part of the crankcase 4 is connected to the end of the suction pipe 24. Further, as shown in FIG. 2, an oil passage 26 formed in the crankcase 4 communicates with the discharge side of the oil pump 18, and this oil passage 26 opens into a lower hole 28 of a screw seat 27. . And this pilot hole 28
One end of an oblique oil passage 30 formed in the rib portion 29 of the crankcase 4 is open, and the other end of the core oil passage 30 is connected to a ball bearing 10 that supports one end of the countershaft 8.
It opens into a circular oil reservoir 31 (see FIG. 3) formed between the engine and the crankcase 4. Note that a nozzle plate 32 whose central portion opens toward the hollow portion of the countershaft 8 is held in this oil reservoir portion 31 .

When the main shaft 5 is rotationally driven by the crankshaft 3 via the clutch mechanism 6, this rotation is caused by the sprocket 20, the chain 23, and the sprocket 2.
2 to the pump shaft 19, and the oil pump 18
is driven. This oil pump 18 sucks oil accumulated in the lower part of the crankcase 4 through an oil strainer 25 and a suction pipe 24, increases the pressure to a predetermined pressure, and then discharges it into an oil passage 26 formed in the crankcase 4. This oil is further led to an oil reservoir 31 via an oil passage 30 and is injected into the hollow portion of the countershaft 8 from the central opening of the nozzle plate 32.

By the way, the countershaft 8 rotates at a predetermined speed by selective meshing between the transmission gear group 11 provided thereon and the transmission gear group 7 provided on the main shaft 5, and this rotation is caused by the rotation of both bevel gears 12.17. Output shaft 14 by meshing
, and the output shaft 14 is rotationally driven. During the rotation of the countershaft 8, a part of the oil injected into the hollow part of the countershaft 8 is scattered in the radial direction from the oil supply holes 8a due to the centrifugal force acting on the countershaft 8, and is transmitted to the transmission gear group 11.
Lubricate.

Further, another part of the oil flows axially through the hollow portion of the countershaft 8 and lubricates the meshing portions of both bevel gears 12 and 17. In this case, the oil also flows in the axial direction due to the negative pressure generated around the bevel gear 12 as it rotates. The oil that has lubricated each part falls under its own weight, collects in an oil reservoir at the bottom of the crankcase 4, and is sucked and pressurized again by the oil pump 18, lubricating each part in the same manner as above.

In the above, since the oil passages 26 and 30, which are the oil supply passages to the countershaft 8, are formed only in the crankcase 4, the oil passage is simplified and its machining is easy, and the number of component parts is reduced. It is possible to shorten the length, reduce oil flow loss, and enhance the lubrication effect.

(Effects of the Invention) As is clear from the above description, according to the present invention, the oil supply path to the countershaft is formed only in the crankcase to simplify it, thereby reducing the number of machining steps and the number of component parts. At the same time, it is possible to reduce flow loss of oil and suppress pressure loss, and a sufficient lubrication effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side view of an internal combustion engine equipped with a refueling circuit according to the present invention, FIG. 2 is an enlarged sectional view taken along line n and n in FIG. 1, and FIG. 3 is a sectional view taken along line mm in FIG. FIG. 4 is a diagram showing a conventional oil supply circuit. ■...Internal combustion engine, 3...Crankshaft, 4...
・Crankcase, 5...Main shaft, 8...
Counter shaft, 18...Oil pump, 26.3
0... Oil path, 31... Oil reservoir, 32... Nozzle plate. Applicant Honda Motor Co., Ltd. Agent Patent Attorney Toshihiko Watanabe Second Decoy

Claims (1)

[Claims] 1. An oil supply circuit for an internal combustion engine, characterized in that an oil supply passage branching from a discharge oil passage led out from an oil pump is formed in the crankcase, and the oil supply passage is opened at the end face of a hollow countershaft.