JP2002104270A - Oil cooler of 4 cycle engine for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To intend cutting down a weight and a cost and enhancing oil cooling performance. SOLUTION: An outlet 29 and a return inlet 30 for lubricating oil are formed in the vicinity of an oil filter 24. On the other hand, an exhaust part 27 is provided in the upper part of an oil cooler 25. A supply part 28 of the lubricating oil is provided in the lower part of the oil cooler positioned diagonally opposite to the exhaust part. The exhaust part of the lubricating oil for the oil cooler is connected to the return outlet of the lubricating oil for an engine 3 through the oil returning passage 32, and the supply part of the lubricating oil for the oil cooler is connected to the outlet of the lubricating oil for the engine through an oil supply passage 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oil cooler for a four-stroke engine for a motorcycle.

[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] Some motorcycles equipped with a high-performance engine are provided with an oil cooler for cooling lubricating oil whose lubricating ability has decreased due to high temperature. The engine and the oil cooler are usually connected by an oil supply passage and an oil return passage.

[0004] For example, when the engine is large and the oil cooler is also large, air is hardly accumulated in the oil cooler.
Both oil passages are connected to the upper part of the oil cooler.
In the case of a small oil cooler for a small engine,
Since the flow velocity of the lubricating oil flowing through the inside is high and air does not easily accumulate, both oil passages are connected to the lower part of the oil cooler in consideration of layout characteristics.

[0005]

However, connecting both oil passages to the upper part of the oil cooler is not preferable because the length of the passage is increased, the weight is increased, and the cost is increased.

When both oil passages are connected to the lower portion of the oil cooler, air tends to enter the oil cooler when the oil passage is replaced, and when the air enters the oil cooler, the oil cooling performance of the oil cooler decreases. Not preferred.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an oil cooler for a four-stroke engine for a motorcycle, in which weight and cost are reduced and oil cooling performance is improved. And

[0008]

According to the present invention, there is provided an oil cooler for a four-stroke engine for a motorcycle according to the present invention. An engine is mounted on a body frame provided with a pair of down tubes, an oil filter is provided at a lower front portion of the engine, an oil pan is provided at a lower portion of the engine, and an exhaust pipe extending from the engine is provided at a side of the oil pan. On the other hand, in a motorcycle four-cycle engine having an oil cooler elongated in the vehicle width direction above the exhaust pipe and in front of the down tube, a lubricating oil outlet and a return port are provided near the oil filter. On the other hand, a discharge part for lubricating oil is provided on the upper part of the oil cooler. A lubricating oil supply section is provided at a lower portion of the oil cooler at a diagonal position of the section, and a lubricating oil discharge section of the oil cooler and a return port of the lubricating oil of the engine are connected via an oil return passage. The lubricating oil supply section of the oil cooler and the engine lubricating oil outlet are connected via a supply passage.

In order to solve the above-mentioned problem, as described in claim 2, in the cylinder axis direction of the engine, the oil cooler rearward above the camshaft provided on the cylinder head of the engine, Further, a cooling fan is provided between the left and right down tubes.

Further, in order to solve the above-mentioned problems,
According to a third aspect of the present invention, the oil supply passage and the oil return passage are respectively arranged along the exhaust pipe extending from a cylinder head of the engine to a collecting portion.

Furthermore, in order to solve the above-mentioned problem, the oil pan is offsetly disposed on one side of the vehicle body, and the oil pan is disposed on the opposite side of the oil pan with respect to the center of the vehicle body. And a discharge portion for the lubricating oil is provided above the oil cooler on the side where the collective portion for the exhaust pipe is disposed.

[0012]

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 center 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.

A pair of left and right down tubes 11 extend rearward and downward from a lower portion of the head pipe 6 and extend upward after passing through a lower portion of the engine 3.
On the other hand, a swing arm 13 is pivotally mounted on a pivot shaft 12 erected at the center lower portion of the body frame 2 so as to freely swing around the pivot shaft 12, and a rear wheel 14 is rotatably supported at the rear end of the swing arm 13. Is done.

FIG. 2 is an enlarged left side view of the engine 3.
FIG. 3 is a front view of the engine 3. As shown in FIGS. 2 and 3, the engine 3 mainly includes an engine case 1.
5, an engine case 15, a cylinder block 16 tilted forward, and a cylinder head 17 mounted on the cylinder block 16 form an outer shape.
The engine 3 is an air-cooled four-cycle four-cylinder engine, which is a parallel engine in which each cylinder is arranged side by side in the width direction of the vehicle body, and has a camshaft 18 for opening and closing intake and exhaust valves (not shown) above the cylinder head 17. Is provided on each valve, and a double overhead cam (DOHC) type valve operating mechanism for opening and closing each valve is provided.

At the rear of the cylinder head 17, a carburetor 19 and an air cleaner 20 constituting an engine intake system are provided.
On the other hand, an exhaust pipe 21 serving as an engine exhaust system is connected to each cylinder at the front of the cylinder head 17, and they are assembled together at the lower part of the engine 3 and extend rearward, and a muffler 22 is provided at a downstream end thereof. Connected.

The engine 3 is provided with an engine lubrication device. The engine lubrication system mainly consists of the engine case 1
5, an oil pan 23 provided at a lower part of the oil pan 23, an oil pump (not shown) for pumping lubricating oil stored in the oil pan 23, and an oil filter 24 provided at a lower front part of the engine case 15. The engine 3 is provided with an oil cooler 25 that cools lubricating oil that becomes hot.

As shown in FIG. 3, the oil pan 23 is offsetly arranged on one side of the vehicle body, and the collecting portion 26 of the exhaust pipe 21 is arranged on the opposite side of the oil pan 23 with respect to the center of the vehicle body. The oil cooler 25 that is long in the vehicle width direction is disposed above the exhaust pipe 21 and in front of the down tube 11, as shown in FIG.

In the upper part of the oil cooler 25, the side where the collecting portion 26 of the exhaust pipe 21 is arranged, that is, in FIG.
Is provided with a lubricating oil discharge portion 27 on the upper left side. In addition, the diagonal position of the discharge portion 27, that is, FIG.
A lubricating oil supply unit 28 is provided at the lower right side of the above.

On the other hand, a lubricating oil outlet 29 and a return port 30 are formed near the oil filter 24 in the lower front part of the engine case 15, and the lubricating oil outlet 29 and the lubricating oil supply unit 28 are connected by an oil supply passage 31. At the same time, the lubricating oil return port 30 and the lubricating oil discharge portion 27 are connected by an oil return passage 32.

Each of the oil supply passage 31 and the oil return passage 32 is constituted by a pair of metallic pipes 33 and a rubber hose 34 which is a vibration absorber connecting these pipes 33, for example. The transmission to the oil cooler 25 through the oil return passage 32 and the oil return passage 32 is prevented.

The oil supply passage 31 and the oil return passage 32 are respectively arranged along the exhaust pipe 21 extending from the cylinder head 17 to the collecting portion 26. The periphery of the oil cooler 25-side pipe 33 of the oil return passage 32 is covered with a protector 35 to prevent the transfer of heat from the oil cooler 25.

The oil cooler 25 is provided with a cooling fan 36 for supplementing the cooling ability of the lubricating oil. As shown in FIG. 2, the cooling fan 36 is disposed behind the oil cooler 25 above the camshaft 18 provided in the cylinder head 17 as viewed in the cylinder axis direction, and, as shown in FIG. It is arranged between the down tubes 11.

Next, the operation of the present embodiment will be described.

A lubricating oil discharge portion 27 is provided above the oil cooler 25, and a lubricating oil supply portion 28 is provided below the oil cooler 25 at a diagonal position of the discharge portion 27, and an oil return passage 32 and an oil supply passage By connecting the oil cooler 25 and the engine 3 via the 31, the oil supply passage 31 can be shortened, the weight and cost are reduced, and the flow of the lubricating oil in the oil cooler 25 is made uniform. When the flow rate of the lubricating oil is low, the entire oil cooler 25 can be effectively used, and the cooling performance of the oil cooler 25 is improved.

Further, even if air enters the oil cooler 25 when the flow velocity of the lubricating oil is low, the oil return passage 32
Air can be extracted from the oil cooler 2
5 can be prevented from accumulating in the air 5 and the cooling performance of the oil cooler 25 can be prevented from lowering.

On the other hand, the cooling fan 36 of the oil cooler 25
Is disposed between the left and right down tubes 11, the cooling fan 36 can be stored compactly. The cooling fan 3
6, a fan drive motor 37 protrudes from the rear of the engine 3. If the cooling fan 36 is disposed above the camshaft 18 provided on the cylinder head 17 when viewed in the cylinder axis direction, the motor 37 Interference can be avoided and the gap between the engine 3 and the down tube 11 can be reduced.

Further, if the oil supply passage 31 and the oil return passage 32 are respectively arranged along the exhaust pipe 21 extending from the cylinder head 17 to the collecting portion 26, both the oil passages 31 and 32 can be connected to the exhaust pipe 21.
Does not interfere with

Further, the oil pan 23 is offset to one side of the vehicle body, and the collecting portion 26 of the exhaust pipe 21 is arranged on the opposite side of the oil pan 23 with the center of the vehicle body interposed therebetween. Can be secured sufficiently.

The oil return passage 32 is long in order to connect the oil cooler 25 to the lower part of the engine 3. The oil return passage 32 is provided with lubricating oil in the upper part of the oil cooler 25 on the side where the collecting part 26 of the exhaust pipe 21 is arranged. If the discharge portion 27 is provided, since the exhaust pipe 21 on this side is substantially vertical when viewed from the front, the oil return passage 32 can be formed substantially linearly, and a large bending process is not required.

[0032]

As described above, according to the oil cooler of the four-stroke engine for a motorcycle according to the present invention,
An engine is mounted on a body frame provided with a pair of left and right down tubes extending rearward and downward from a head pipe, an oil filter is provided at a lower front part of the engine, an oil pan is provided at a lower part of the engine, and an exhaust pipe extending from the engine is provided. In the four-stroke engine for motorcycles having a long oil cooler in the vehicle width direction above the exhaust pipe and in front of the down tube, the oil filter is located near the oil filter. While forming the lubricating oil outlet and return port, a lubricating oil discharge section is provided above the oil cooler, and a lubricating oil supply section is provided below the oil cooler at a diagonal position of the discharge section, and an oil return is provided. A discharge portion of the lubricating oil of the oil cooler and the engine through a passage; A lubricating oil return port is connected, and a lubricating oil supply section of the oil cooler and an lubricating oil outlet of the engine are connected via an oil supply passage, so that weight and cost can be reduced, The cooling performance of the oil cooler can be improved.

Further, in the cylinder axis direction of the engine, a cooling fan is provided behind the oil cooler above a camshaft provided on a cylinder head of the engine, and between the left and right down tubes. And interference between the cooling fan and the engine can be avoided.

Further, since the oil supply passage and the oil return passage are respectively disposed along the exhaust pipe extending from the cylinder head of the engine to a collecting portion, interference between the oil passages and the exhaust pipe is prevented.

Further, the oil pan is offsetly arranged on one side of the vehicle body, and the collecting section of the exhaust pipe is disposed on the opposite side of the oil pan with respect to the center of the vehicle body, and the collecting section of the exhaust pipe is arranged. Since the lubricating oil discharge section is provided above the oil cooler on the side where is disposed, the minimum ground clearance of the vehicle can be sufficiently secured,
Further, the oil return passage can be formed substantially linearly.

[Brief description of the drawings]

FIG. 1 is a left side view of a motorcycle showing an embodiment of an oil cooler of a four-stroke engine for a motorcycle 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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Body frame 3 Engine 6 Head pipe 11 Down tube 17 Cylinder head 18 Cam shaft 21 Exhaust pipe 23 Oil pan 24 Oil filter 25 Oil cooler 26 Exhaust pipe collecting part 27 Lubricating oil discharge part 28 Lubricating oil supply part 29 Lubricating oil outlet 30 Lubricating oil return port 31 Oil supply passage 32 Oil return passage 36 Cooling fan

Claims (4)

[Claims] 1. An engine is mounted on a body frame having a pair of left and right down tubes extending rearward and downward from a head pipe, an oil filter is provided at a lower front part of the engine, and an oil pan is provided at a lower part of the engine. An exhaust pipe extending from an engine is gathered on the side of the oil pan, while a four-stroke engine for a motorcycle including a long oil cooler in a vehicle width direction above the exhaust pipe and in front of the down tube, A lubricating oil outlet and a return port are formed in the vicinity of the oil filter, and a lubricating oil discharge unit is provided at the upper part of the oil cooler. And a lubricating oil discharge part of the oil cooler through an oil return passage. A four-cycle for a motorcycle, wherein a return port of the lubricating oil of the engine is connected, and a supply part of the lubricating oil of the oil cooler and an outlet of the lubricating oil of the engine are connected via an oil supply passage. Engine oil cooler. 2. The cooling fan according to claim 1, wherein a cooling fan is provided between the left and right down tubes behind the oil cooler above a camshaft provided on a cylinder head of the engine in the cylinder axis direction of the engine. Oil cooler for motorcycle 4-cycle engine. 3. The oil cooler according to claim 1, wherein the oil supply passage and the oil return passage are respectively arranged along the exhaust pipe extending from a cylinder head of the engine to a collecting portion. . 4. The oil pan is offset to one side of the vehicle body, and a collection portion of the exhaust pipe is disposed on the opposite side of the oil pan with respect to a center of the vehicle body, and the collection portion of the exhaust pipe is 4. The oil cooler for a four-stroke engine for a motorcycle according to claim 3, wherein a discharge portion for the lubricating oil is provided above the oil cooler on the side where the oil cooler is disposed.