JPH0481516A - Cooling pipe passage arranging structure for engine - Google Patents

Abstract

PURPOSE:To prevent width of a car body from widening, and shorten the length of a cooling pipe passage, by arranging a cooling pipe passage on a space generated on the way of the return part of each exhaust pipe extending from each cylinder of an engine. CONSTITUTION:Each left/light exhaust pipe 29 extending from each of cylinders 24 is firstly projected front-downward from the cylinders 24, and returned backward, then extended backward. Each exhaust port of the left/light cylinder 24 is apart from a prescribed distance so as to generate excess space 65 on the way of the return part 64 of each exhaust pipe 29 front end. In the space 65, a thermostat 44 served as a cooling pipe passage, a second pipe 47, and a bypass pipe 52 of a pipe 2 are respectively arranged. It is thus possible to shorten the cooling pipe passage connecting an engine with a radiator.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cooling pipe arrangement structure for an engine in a motorcycle.

(Prior Art) Some motorcycles have a radiator disposed above and in front of the engine, and a cooling pipe line connected to the engine from the bottom of the radiator (for example, in Japanese Utility Model Publication No. 62-1.818).
．． 518 Publication).

There are also engines in which the engine is a parallel multi-cylinder engine and has a folded portion where the exhaust pipe force S extending from each cylinder is once projected forward and then folded back toward the rear.

(Problem to be solved by the invention) By the way, in the above configuration↓, if the radiator is simply disposed above the front of the engine, there is a risk that the cooling pipe line and the folded part of the exhaust pipe will interfere with each other. Sign.

Therefore, in an attempt to avoid this interference, it is conceivable to arrange the cooling pipe line so as to bypass the outside of the folded part of the exhaust pipe, but in this case, firstly, the width dimension of the vehicle body is It's getting bigger and I don't like it. Also, secondly,
There is also the problem that the cooling pipe path becomes long.

(Object of the Invention) This invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to prevent the width of a vehicle body from increasing when a radiator is disposed above the front of a parallel multi-cylinder engine. It is an object of the present invention to shorten the cooling pipe connecting the engine and the radiator.

(Structure of the Invention) A feature of the present invention for achieving the above object is that a cooling pipe connecting the engine and the radiator is provided in the space created between the folded parts of the exhaust pipe extending from each cylinder of the engine. It is at the point where it is placed.

(for production) The effects of the above configuration are as follows.

Exhaust pipes 29 project forward from each cylinder 24 of the parallel multi-cylinder engine 20, and then are folded back. In this case, since the exhaust ports of the left and right cylinders 24.24 are separated to some extent, there is an extra space 6 between the folded portions 64.64 of each of the exhaust pipes 29.29.
5 will be born.

This invention has been made with attention to this point, and a cooling pipe path is arranged in the space 65, and the folded part of the exhaust pipe 29 is
4 and the cooling pipe line to avoid interference with each other.

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

In the figure, 1 is an off-road motorcycle. Reference numeral 2 denotes a vehicle body frame, and the vehicle body frame 2 has a head vibrator 3 at its front part, and a main frame 4 having a box-shaped cross section extends rearward from the head vibrator 3, which is a lever in plan view. . Further, a rear arm bracket 5 extends downward from the rear end of the main frame 4.

6 is a down tube, and this down tube 6 connects the front end of the main frame 4 and the lower end of the rear arm bracket 5. The front upper portions of the left and right down tubes 6.6 are reinforced by a cross member 7. Further, a stay 11 is removably installed on each town tube 6 and the ball frame 4, and these members are mutually reinforced.

A front head [2] is supported on the head vibrator 3 so as to be freely steerable. A front wheel 13 is supported at the lower end of the front fork 2, and a handle 14 is supported at the upper end of the front fork.
is installed. On the other hand, a rear arm 16 is pivotally supported on the rear arm bracket 5 by a pivot shaft 15 so as to be able to freely swing up and down, and the swinging end of this rear arm 16 is connected to the rear wheel 17.
is supported. Further, the rear arm 16 is connected to the shock absorber 1.
It is supported by the main frame 4 via 8.

A four-stroke parallel two-cylinder engine 20 is supported at the lower part of the vehicle body frame 2, and a power transmission device 21 is connected to the engine 20. The rear wheel 17 is interlocked with this power transmission device 21 by a chain winding means 22,
Power from the engine 20 is transmitted to the rear wheels 17 via the power transmission device 21 and chain winding means 22.

Each cylinder 24 of the engine 20 has a crankcase 2
5, and an intake pipe 26 is connected to each rear surface thereof. Each of the intake pipes 26 extends upward almost vertically, and a carburetor 27 and an air cleaner 28 are connected to each upper end of the intake pipes 26. In this case, the intake pipes 26,
Since the carburetor 27 and the air cleaner 28 are arranged in the vertical direction, a downdraft effect is obtained in the engine 20. 29 is an exhaust pipe, and this exhaust pipe 29 extends from each cylinder 24 to the rear of the vehicle body.

A pair of left and right front fuel tanks 32 that supply fuel to the carburetor 27 and a rear fuel tank 33 are provided, and the front fuel tank 32 is supported by the vehicle body frame 2 above the engine 20.

On the other hand, the rear fuel tank 33 is supported by the rear end of the main frame 4 and a bracket 34 protruding from the rear arm bracket 5, and a seat 35 is attached to the rear fuel tank 33.

A radiator 36 for cooling the engine 20 with water is provided, and the radiator 36 is attached to the front surface of the down tube 6 above and in front of the engine 20. In addition, 37 is a cowling.

In FIG. 2, a pair of front and rear pivot means 38.38 are provided on the left and right sides of the vehicle body frame 2, respectively, and the lower part of the front fuel tank 32 is detachably connected to the pivot means 38.38. It is locked and pivoted so as to be rotatable left and right around the locking part. Furthermore, an engaging means 39 is provided for removably engaging the upper rotational end of the front fuel tank 32 with the vehicle body frame 2 when the front fuel tank 32 is rotated toward the vehicle body frame 2. It is being Further, a buckle-type connecting means 40 is provided for connecting the front fuel tanks 32 to each other when the front fuel tanks 32 are engaged in this manner. Each front fuel tank 32 can be detachably attached to the vehicle body frame 2 by means of the pivot means 38, engagement means 39, and connection means 40. 32a is a cap.

In all sections, a pair of left and right radiators 36 are provided, and each radiator 36 is connected to the cylinder 24 and the carburetor 2.
7 are disposed close to each other in the front-rear direction. The upper part of each radiator 36 is screwed onto the front upper part of each down tube 6 via a lower cushioning material 41, and the lower part is screwed onto the front lower part of each down tube 6 by a pair of left and right lower cushioning materials 42. It is stopped and thereby supported by the vehicle body frame 2.

A water inlet 43 is provided on the upper surface of each of the radiators 36, and each radiator 3
6 can be injected independently. A thermostat 44 is installed between the lower ends of the left and right radiators 36 and 36.
The lower part of each radiator 36 is connected to the inlet of the thermostat 44 by a flexible first vibe 45, respectively.

The outlet of the thermostat 44 is connected to a flexible second water pump 46 attached to the front of the crankcase 25.
The left and right cylinders 24.2 are connected by a vibrator 47.
A vibrator joint 48 is screwed onto the rear surface between the four spaces. The discharge port of the water pump 46 is located in the crank case 25.
It also communicates with the vibration joint 48 through a water jacket (not shown) formed in each cylinder 24 .

Furthermore, flexible third pipes 49 and 49 are provided that extend outward from the pipe joint 48, and the extending ends of the third pipes 49 are connected to the upper part of the corresponding radiator 36. There is.

A first bypass vibe 51 that bypasses the left side of the cylinder 24, 24 and extends upwardly in a plan view.
is provided, and this first bypass vibe 51 is connected to the cylinder 2
It is fixed on the 4th side. And the above thermostat 4
The other outlet portion of No. 4 communicates with the front end of the first bypass vibe 51 through a flexible second bypass pipe 52, and
The rear end of the first bypass vibe 51 communicates with the pipe joint 48 through a flexible third bypass pipe 53.

In the above case, the flexible first pipe 45, second vibe 47, third vibe 49, second bypass vibe 52, and third bypass pipe 53 are made of vinyl hoses or rubber hoses, and the corresponding pipes Both are detachably connected to the connecting portion 54. Further, each of these vibrators, together with the lower cushioning material 41 and the lower cushioning material 42, absorb vibrations that try to be transmitted from the vehicle body frame 2 and engine 20 side to the radiator 36 side, and suppress the transmission.

In FIGS. 1 and 2, fan units 55 are provided to send cooling air to each of the radiators 36, respectively. When viewed from the side of the vehicle, this fan unit 55 is connected to the front fork 12, front wheel 13, and radiator 36.
This space 56 is effectively utilized.

In FIG. 1, the fan unit 55 has a sheet metal shroud 58 which is circular in front view and is screwed onto the front surface of the radiator 36 by a port 57.
Three sheet metal stays 59 extend from the front edge. A transmission motor 61 for driving a fan 60 is fitted between each of the projecting ends 59a of these stays 59.
A is bent along the outer peripheral surface of the motor 61. The motor 61 is connected to each of the protruding ends 59 a by a rubber band 62 fitted over each of the protruding ends 59 a.
It is elastically clamped in a removable manner.

The shroud 58, fan 60, and motor 61 are coaxially located, and the fan 60 is disposed within the shroud 58. Note that a commercially available hose band may be used as is for the band 62.

When the fan 60 is rotated by driving the motor 61, the cooling air generated thereby passes through the radiator 36 from the front to the rear, thereby cooling the cooling water passing through the radiator 36.

Further, while the motorcycle 1 is running, the running wind at that time also has the same effect as described above.

When the engine 20 is running, it is connected to a water pump 46.
As shown by the solid line arrow in FIG. The cooling water is discharged into the cooling water chamber inside the case 25 to cool them. Next, this cooling water is returned to the radiator 36 through the third vibrator 49 and is cooled again.

Note that when the engine 20 is started, the cooling water is not at a high temperature, so the thermostat 44 operates, and the second vibe 47 and the second bypass vibe 52 on the water pump 46 side are supplied from the first pipe 45 in the radiator 36. Close the conduit that communicates with the Therefore, the cooling water discharged from the water pump 46 and passing through the cooling water chamber and reaching the vibe joint 48 is transferred to the third bypass vibe 53, the Ml bypass pipe 51, as shown by the imaginary line in FIG. The water is returned to the water pump 46 through the second bypass vibe 52, thermostat 44, and second vibe 47. In other words,
The cooling water will circulate without passing through the radiator 36.

In all sections, the left and right exhaust pipes 29, 29 extending from each cylinder 24 once protrude forward and downward from each cylinder 24, and then are folded back and extended rearward. In this case, the exhaust ports of the left and right cylinders 24.24 are separated to some extent, and an extra space 65 is created between the folded portions 64.64 at the front ends of the exhaust pipes 29.29. The thermostat 44, the second vibe 47, and the second bypass vibe 52, which are cooling pipes, are arranged in this space 65, and this space 65 is effectively utilized.

Furthermore, each cylinder 24 and the lower part of the radiator 36 are brought closer to each other by the amount that the space 65 is effectively utilized.
For this reason, the second vibe 47 and the second bypass vibe 5
A short dimension of 2 is sufficient.

Note that although the above is based on the illustrated example, the number of cylinders may be a plurality of cylinders other than two.

(Effects of the Invention) According to the present invention, since the cooling pipe is arranged in the space created between the folded parts of each exhaust pipe, interference between the folded part of the exhaust pipe and the cooling pipe can be avoided. can be arranged compactly, thereby preventing the width dimension of the vehicle body from increasing.

Furthermore, there is an advantage that the size of the cooling pipe can be shortened by not bypassing the outside of the folded portion.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, FIG. 1 is an enlarged partial sectional view of FIG. 2, FIG. 2 is an overall left side view of the motorcycle, and FIG. ! It is an arrow view. 1. Motorcycle, 20. Engine, 29. Exhaust pipe, 36. Radiator, 44. Thermostat (cooling pipe), 47. 2nd vibe (cooling pipe), 52. 2nd bypass. Pipe (cooling pipe line), 64... folded part,
65...Space.

Claims (1)

[Claims] 1. Equipped with a parallel multi-cylinder engine, the exhaust pipes extending from each cylinder of the engine are once projected forward and then folded back toward the rear.Meanwhile, a radiator is disposed above the front of the engine, A cooling pipe arrangement structure for an engine, in which a cooling pipe is arranged in a space created between the folded portions of each of the exhaust pipes, in a motorcycle provided with a cooling pipe that continues from the bottom to the engine.