JP3185625B2 - Lubrication system for 4-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for a four-stroke engine.

[0002]

2. Description of the Related Art Since an engine has many sliding parts and rotating parts inside, lubricating oil is supplied to each part using a lubricating device, and the function of the lubricating oil reduces the frictional resistance of each part, thereby improving the function of the engine. It is designed to fully demonstrate.

[0003] For example, a method using a wet sump method 4
In a general lubricating oil path of a lubricating device for a cycle engine, first, lubricating oil stored in an oil pan provided at a lower portion of a crankcase of the engine is sucked up by an oil pump. The sucked lubricating oil is filtered by an oil filter and sent to each lubricating portion in the engine via an oil passage and an external pipe formed in the crankcase.

The lubricating oil that has lubricated each lubricating portion in the engine falls naturally or returns to the oil pan via an oil passage or the like again.

[0005] Some motorcycles equipped with a high-performance engine such as a racer are provided with an oil cooler for cooling lubricating oil having a reduced lubricating ability due to a high temperature. Further, a motorcycle provided with an oil-cooled engine that cools a part of an engine, for example, a valve train, with lubricating oil also has an oil cooler for cooling lubricating oil.

[0006] As shown in, for example, Japanese Patent Application Laid-Open No. 61-207808, an oil cooler is disposed between an oil pump and an oil filter.

[0007]

However, the lubricating oil cooled by the oil cooler receives heat in the oil passage on the way before reaching the final lubrication section, and the oil temperature rises by the time it reaches the final lubrication section. Lubrication and cooling effects decrease.
As a result, the durability of the engine decreases.

Further, when an oil passage is formed in the crankcase, the structure of the crankcase becomes complicated.
It becomes large.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a lubricating device for a four-stroke engine that can directly supply cooled lubricating oil to each lubricating part.

[0010]

According to a first aspect of the present invention, there is provided a lubricating apparatus for a four-stroke engine, comprising: an oil filter and an inlet of an oil cooler; And an oil cooler is connected by a second oil pipe to an outlet of the oil cooler and a branch passage provided in a cylinder head of the engine, and the branch passage is connected to a camshaft in the cylinder head and a valve train. The lubricating oil cooled by the oil cooler is directly guided to the mechanism, and a third oil pipe is connected to the branch passage to connect the lubricating oil cooled by the oil cooler to the crankshaft of the engine. In the lubricating device for a four-stroke engine configured to directly lead the oil to the fourth oil pipe, The pipe is branched by the fourth oil pipe is obtained by configured to guide direct the lubricating oil cooled by the oil cooler to the transmission mechanism.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a left side view showing an example of a motorcycle to which the present invention is applied. As shown in FIG. 1, the motorcycle 1 has a body frame 2, and an engine 3 is mounted on a lower front portion of the body frame 2. A fuel tank 4 is provided above the engine 3, and an operation seat 5 is provided behind the fuel tank 4.

A head pipe 6 is provided in front of the body frame 2.
The head pipe 6 is provided with a steering mechanism 7.
Is provided. The steering mechanism 7 is provided with a front fork 9 and a handlebar 10 for rotatably supporting the front wheel 8, and the handlebar 10 steers the front wheel 8 to be able to turn left and right.

On the other hand, a swing arm 12 is pivotally mounted on a pivot shaft 11 erected at the center lower portion of the body frame 2 so as to freely swing around the pivot shaft 11, and a rear wheel 13 is pivoted at the rear end of the swing arm 12. Freely supported.

FIG. 2 is an enlarged left side view of the engine 3.
FIG. 3 is a front view of the engine 3. And FIG.
Is a schematic diagram showing a lubrication system of an engine lubrication device 14 described later.

As shown in FIGS. 2 to 4, the engine 3 includes:
Mainly the engine case 15, the cylinder block 16,
An outer shape is constituted by the cylinder head 17. The engine 3 is an air-cooled 4-cycle single-cylinder engine,
A single overhead camshaft (SOH) that opens and closes the valves 18 and 19 by providing a camshaft 20 for opening and closing the intake and exhaust valves 18 and 19 above the cylinder head 17.
A C type valve train 21 is provided.

An intake passage 22 and an exhaust passage 23 are provided in the cylinder head 17, and a carburetor 24 as an engine intake system 24 is provided in the intake passage 22 as shown in FIG.
a and the air cleaner 24b are connected. On the other hand, an exhaust pipe 25a and a muffler 25b as an engine exhaust system 25 are connected to the exhaust passage 23.

As shown in FIG. 4, a front side of the engine case 15 is a crankcase 15a, and a rear side is a transmission case 15b in which a transmission mechanism 26 is provided. A crankshaft 27 is provided in the crankcase 15a.
Are arranged at right angles to the traveling direction of the vehicle.

The connecting rod 2 is connected to the crankshaft 27.
Eight large ends 28a are connected. Also, connecting rod 28
The piston 29 is connected to a small end (not shown). Then, the piston 29 reciprocates in the cylinder block 16 in, for example, the vertical direction in the drawing. The reciprocating stroke of the piston 29 is converted into rotational motion by the crankshaft 27, and is transmitted from a primary drive gear (not shown) provided at one end of the crankshaft 27 to a countershaft 3 of the transmission mechanism 26 via a clutch mechanism (not shown).
0 and the drive shaft 31. A plurality of transmission gears 32 and 33 having different diameters and different numbers of teeth are provided on the countershaft 30 and the drive shaft 31, and the primary reduction is performed by changing the combination of these transmission gears 32 and 33.

The engine 3 includes an engine lubrication device 14
Is provided. The engine lubrication device 14 mainly includes an oil pan 34 provided at a lower portion of the crankcase 15a, an oil pump 36 for pumping lubricating oil 35 stored in the oil pan 34, and an oil filter for filtering the lubricating oil 35. 37, a plurality of oil passages 38 and 39 for guiding the lubricating oil 35 to various parts in the engine 3, and oil pipes 40 to 43. The engine 3 has an oil cooler 4 that cools a lubricating oil 35 that becomes hot.
4 is provided in front of the engine 3. Reference numeral 45 denotes an oil strainer disposed in the oil pan 34, which removes relatively large foreign matter in the lubricating oil 35 pumped by the oil pump 36. Note that the oil pump 36 and the oil filter 37 are disposed in the crankcase 15a.

The lubricating oil 35 in the oil pan 34 is pumped up by an oil pump 36 and the first oil passage 3
After being filtered by an oil filter 37 provided in the middle of 8, it is guided out of the crankcase 15 a. After that, the lubricating oil 35 is guided to the inlet 44 a of the oil cooler 44 by the first oil pipe 40.

The lubricating oil 35 is cooled by an oil cooler 44, and the second oil pipe 41
Through the cylinder head 17. Oil cooler 4
The lubricating oil 35 cooled by the cylinder head 4 and guided to the cylinder head 17 is branched by a second oil passage 39 which is a branch passage, and a part of the lubricating oil 35 is
Guided to zero, lubricating this. Further, a part of the lubricating oil 35 is injected from the jet 46 toward the valve train 21 to cool it. Further, the remaining lubricating oil 35 is guided to the crankshaft 27 via the third oil pipe 42, and lubricates it. Furthermore, a fourth oil pipe 43 branches off from the middle of the third oil pipe 42 and guides the lubricating oil 35 to the counter shaft 30 and the drive shaft 31 of the transmission mechanism 26 to lubricate them. Then, the lubricating oil 35 that has lubricated and cooled each part falls naturally and returns to the oil pan 34.

As shown in FIG. 5, a small hole 47 is formed at the branch point of the fourth oil pipe 43 in the middle of the third oil pipe 42, and the small hole 47 supplies the lubricating oil supplied to the transmission mechanism 26. 35 is controlled.

In the middle of each of the oil pipes 40 to 43, a joint pipe 48 made of an elastic material such as a rubber pipe is provided.
Are arranged to absorb vibrations of the entire oil pipes 40 to 43 and distortion during assembly.

As described above, according to the present invention, the oil cooler 44
The lubricating oil 35 cooled by the above is directly supplied to each lubricating part such as the camshaft 20, the valve mechanism 21, the crankshaft 27, and the transmission mechanism 26, so that the lubricating oil 35 does not receive heat on the way and exhibits a high lubrication and cooling effect. I do. As a result, the durability of the engine 3 is improved.

Further, since the lubricating oil 35 is supplied to the respective lubricating parts by the oil pipes 40 to 43, the degree of freedom of the piping layout is increased, so that the engine lubricating device 14 can be made lightweight and compact, and the lubricating oil 35 is distributed. Adjustment becomes easy.

Further, by interposing a joint pipe 48 made of an elastic material in the middle of each of the oil pipes 40 to 43, vibration is absorbed and the durability of the entire oil pipes 40 to 43 is improved. Is also absorbed, so that maintainability such as disassembly and assembly is improved.

[0028]

As described above, according to the four-stroke engine lubrication system of the present invention, the oil filter and the inlet of the oil cooler are connected by the first oil pipe,
An outlet of the oil cooler and a branch passage provided in a cylinder head of the engine are connected by a second oil pipe, and the branch passage is connected to a camshaft and a valve mechanism in the cylinder head by the oil cooler. A third oil pipe is connected to the branch passage to directly guide the lubricating oil cooled by the oil cooler to the crankshaft of the engine, while the lubricating oil is configured to directly guide the cooled lubricating oil. In the lubricating device for a four-stroke engine, a fourth oil pipe is branched from the middle of the third oil pipe, and the lubricating oil cooled by the oil cooler is directly guided to the transmission mechanism by the fourth oil pipe. The lubricating oil cooled by the oil cooler does not receive heat Is directly supplied to the lubricated parts, high lubricity,
It exerts a cooling effect and improves engine durability.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a lubrication device for a four-cycle engine according to the present invention.

FIG. 2 is an enlarged left side view of the engine.

FIG. 3 is a front view of the engine.

FIG. 4 is a schematic diagram showing a lubrication system of the engine lubrication device.

FIG. 5 is an enlarged sectional view of a branch point in the middle of the oil pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 3 Engine 14 Engine lubrication device 17 Cylinder head 20 Camshaft 21 Valve train 26 Transmission mechanism 27 Crankshaft 35 Lubricating oil 36 Oil pump 37 Oil filter 38 First oil passage 39 Second oil passage (branch passage) 40 first oil pipe 41 second oil pipe 42 third oil pipe 43 fourth oil pipe 44 oil cooler 44a oil cooler inlet 44b oil cooler outlet 48 joint pipe

Claims (1)

(57) [Claims] 1. An oil filter and an inlet of an oil cooler are connected by a first oil pipe, and an outlet of the oil cooler and a branch passage provided in a cylinder head of the engine are connected by a second oil pipe. The branch passage is configured to directly guide the lubricating oil cooled by the oil cooler to the camshaft and the valve mechanism in the cylinder head, while a third oil pipe is connected to the branch passage. In a lubricating device for a four-stroke engine configured to directly guide the lubricating oil cooled by the oil cooler to a crankshaft of the engine, a fourth oil pipe is branched from the middle of the third oil pipe. The lubricating oil cooled by the oil cooler by the fourth oil pipe is directly sent to the transmission mechanism. A lubricating device for a four-stroke engine, wherein the lubricating device is configured to be guided.