JP2994057B2 - Air-cooling system for motorcycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cooling system for an engine mounted on, for example, a scooter type motorcycle, and more particularly to an improvement in an arrangement position of a tension adjusting mechanism for absorbing expansion of a V-belt for driving a blower fan.

[0002]

2. Description of the Related Art In an engine mounted in a space covered by a body cover such as a scooter type motorcycle,
Generally, the engine is cooled using an air cooling device having a blower fan. Conventionally, as such an air cooling device, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-181017, an axial-flow-type blower is disposed on a side of a cylinder body, and the blower is connected to a V-belt and a pulley. There is one that is driven by a driving force transmitting means to cool the cylinder body.

[0003]

However, in the above-mentioned conventional air cooling device for an engine, the driving method of the blower fan is as follows.
The pulley mounted on the crankshaft and the pulley mounted on the blower fan are connected by a V-belt, thereby driving the blower fan. There is a concern that the vehicle may slip and hinder the rotation of the blower fan. In order to prevent the slip, it is effective to provide a tension adjusting mechanism for absorbing the elongation of the V-belt. However, depending on the design of the tension adjusting mechanism, there is a concern that the mechanism protrudes in the vehicle width direction and the vehicle width increases. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional situation, and provides an air cooling device for a motorcycle engine that does not hinder the rotation of a blower fan by absorbing the elongation of a V-belt without increasing the vehicle width. It is intended to provide.

[0004]

According to the present invention, a shroud surrounds the periphery of a cylinder body, a blower fan for blowing air into the shroud is disposed on a side of the cylinder body, and an impeller of the blower fan is driven. In an air-cooling system for a motorcycle engine, which is driven by a fan pulley and a crankshaft extending in a vehicle width direction and connected to a crank pulley provided outside a generator by a V-belt, a cylinder laminated on the cylinder body A cam chain wound around a cam sprocket fixed to a cam shaft provided on the head and a crank sprocket fixed to the crank shaft are provided on the opposite side of the blower fan with the cylinder body interposed therebetween. A rotary cylinder integrated with the impeller by a support portion integrally formed on the side wall of the case so as to extend to the side of the cylinder body; The fan pulley is rotatably supported, and the fan pulley is fixedly mounted on the rotary cylinder outside the impeller. The fixed pulley half is inserted into the rotary cylinder so as to be slidable in the axial direction and capable of transmitting torque. A movable pulley half fixed to the outwardly protruding end of the sliding shaft and disposed outside the fixed pulley half, wherein an inwardly protruding end of the sliding shaft and an inner end of the rotary cylinder are formed. An urging mechanism for urging the sliding shaft inward by a spring interposed therebetween to change the diameter of the fan pulley and absorb the elongation of the V-belt is disposed between the impeller and the cylinder body. It is characterized by doing.

[0005]

According to the air cooling system for a motorcycle engine of the present invention, when the V-belt is stretched and the tension is reduced, the movable pulley half of the fan pulley disposed on the blower fan side is biased by the biasing mechanism. It moves to the fixed pulley half side, thereby narrowing the interval between the two pulley halves and increasing the effective diameter of the fan pulley. As a result, the elongation of the V-belt is absorbed, and slip of the V-belt is avoided. In the present invention, an urging mechanism is provided with one half of the crank pulley and the fan pulley on the fan pulley side as a movable pulley, and the urging mechanism of the movable pulley half is a space between the impeller and the cylinder body. The vehicle width does not increase because it is located in the area. That is, in the case of this type of air cooling device, a space for disposing an impeller of a blower fan is provided between a cylinder body and a fan pulley connected to a crank pulley disposed outside a generator by a V-belt. And a certain distance is also provided between the impeller and the cylinder body. As a result, a relatively large space is created between the fan pulley and the cylinder body. In the present invention, since the urging mechanism is disposed by utilizing the space,
There is no need to secure a separate space for the biasing mechanism,
Therefore, the vehicle width does not increase. Further, in the present invention, since the cam chain that rotates the camshaft by the crankshaft is disposed on the opposite side of the blower fan with the cylinder body interposed therebetween, the chain chamber for disposing the cam chain may impair the cooling performance of the cylinder body. In addition, since the impeller is pivotally supported by a support portion integrally formed on the side wall of the crankcase, the cooling performance of the cylinder body can be improved as compared with a case where the support portion is formed on the cylinder body. Is disposed outside the impeller and the biasing mechanism is disposed between the impeller and the cylinder body, so that the fan pulley does not interfere with the cooling air sent from the blower fan, and from these points. Coolability can be maintained.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 5 are views for explaining an air cooling system for an engine according to an embodiment of the present invention. FIG. 1 and FIG. 2 are cross-sectional plan views, FIG. 3 is a plan view thereof, and FIGS. FIG. 2 is a left side view of the motorcycle.

In FIG. 1, reference numeral 1 denotes a scooter-type motorcycle. A body frame 2 of the motorcycle 1 has a head pipe 3 connected to an upper end of a vertical side 4a of a main frame 4 having a substantially L shape in a side view, and a horizontal side 4b. The front ends of a pair of left and right side frames 5a, 5a are connected near the center.
This is a so-called underbone type in which a and 5a are raised upward and extended rearward. A front fork 7 that supports the front wheel 6 at its lower end is supported by the head pipe 3 so as to be steerable left and right. A steering handle 8 is fixed to the upper end of a steering shaft 7 a of the front fork 7. ing. A fuel tank 14 is provided above the front portions of the left and right side frames 5a, 5a, and a storage box 15 is provided above the rear portions thereof. A tandem seat 16 is provided so as to cover the upper side. Furthermore, the periphery of the front fork 7, the periphery of the footrest portion, and the lower peripheral portion of the tandem seat 16 of the motorcycle 1 are surrounded by a vehicle body cover 17. The left and right side frames 5a, 5
The unit swing type engine unit 1 is connected to the rear bent portion 5b of FIG.
0 is suspended and supported.

The engine unit 10 is formed by integrating an engine body 12 and a transmission 11.
In the engine body 12, an air-cooled cylinder body 22 and a water-cooled cylinder head 23 are stacked and fastened substantially horizontally to the front wall of a left and right split crankcase 18b, and a piston 24 inserted into the cylinder body 22 is connected to a connecting rod. 2
5 is connected to the crankshaft 26.

At the right end of the crankshaft 26,
Rotating body 27a of flywheel magnet type generator 27
Is fixed, and a generator coil 27b fixed to the right side wall of the crankcase 18b is accommodated in the rotating body 27a. A crank pulley 27d is formed integrally with the boss 27c of the rotating body 27a.

A cam sprocket 29a is fixed to one end of a camshaft 28 provided in the cylinder head 23, and a cam sprocket 29a is fixed between the cam sprocket 29a and the crank sprocket 29b fixed to the crankshaft 26. Is wound with a cam chain 29c.

The transmission 11 is provided with the crankcase 1.
Power transmission case main body 18a integrally formed on the left side of 8b
A continuously variable transmission mechanism 20, a centrifugal clutch 30, and a speed reduction mechanism 21 are arranged in a transmission case 19 composed of a case cover 19a and bolts.

The continuously variable transmission mechanism 20 is formed by connecting a drive pulley 31 mounted on the left end of the crankshaft 26 and a driven pulley 32 disposed at the rear of the transmission case 19 with a V-belt 33. The driven pulley 32 is connected via a centrifugal clutch 30 to a clutch shaft 34 supported by the transmission case main body 18a.

The drive pulley 31 is connected to the crankshaft 26.
And a movable pulley half 31b fitted to the crankshaft 26 slidably in the axial direction. A roller weight 36 is disposed between the outer surface of the movable pulley half 31b and a guide plate 35 fitted and fixed to the crankshaft 26. A seal plate 37 is provided outside the guide plate 35. It is arranged. The seal plate 37 is a resin-made annular member whose outer peripheral portion is fixed to the outer peripheral portion of the movable pulley main body 31b, and whose inner peripheral portion is in contact with a one-way clutch 38 fixed to the crankshaft 26. This prevents the grease filled in the roller weight 36 from flowing out. In addition, 31c
Are blower blades integrally formed on the outer surface of the fixed pulley half 31a.

The driven pulley 32 is a fixed pulley half 32
a and a movable pulley half 32b, and the fixed pulley half 32a is a cylindrical body 39 of the centrifugal clutch 30.
It is fixed to. The movable pulley half 32b is supported by the cylindrical body 39 so as to be movable in the axial direction.
This urges the space between the fixed pulley half 32a and the fixed pulley half 32a.

The centrifugal clutch 30 has a clutch weight 42 disposed between the cylindrical body 39 supported by the clutch shaft 34 and a clutch case 41 fixed to the clutch shaft 34. When the rotation speed of the clutch 32 increases, the clutch weight 42
1 is pressed into contact with the inner surface of the clutch shaft 1, whereby power is transmitted to the clutch shaft 34.

The speed reduction mechanism 21 includes the clutch shaft 34
Is engaged with a large gear 44 of a rear wheel shaft 43 via an intermediate gear (not shown). The rear wheel axle 43 is rotatably supported via a bearing by the transmission case main body 18a and the inner case 18c bolted and fixed thereto via a bearing, and the rear wheel 13 is fixed to the rear wheel axle 43.

An outside air inlet 19d is formed at the front end of the transmission case 19, and a rear outlet 19e is formed at the rear end. Further, a front outlet 18e formed at the front end of the transmission case body 19a is formed. Is connected to a discharge duct 52b via a discharge pipe 52a. This discharge duct 52
b is inserted into a shroud 51 described later, is bent downward, and opens toward the road surface through the hole 51b.

A cooling water pump 46 is mounted on the left side wall of the cylinder head 23. The pump 46
Has a structure in which an impeller 48 is disposed in a blade chamber 47e of a pump case 47 including a case main body 47a and a case cover 47b. The blade chamber 47e is connected to the radiator 54 by a cooling water hose 49b.
A blade shaft 48a of the impeller 48 is arranged coaxially with the cam shaft 28, and is detachably connected to the cam shaft 28. A breather chamber 47c is formed in the case main body 47a so as to surround the blade shaft 48a, and a right opening of the breather chamber 47c is closed by an end face plate 50. A hose joint 47d is formed in the case body 47a so as to communicate with the breather chamber 47c. The joint 47d has a breather tube 49a.
Is connected. The breather pipe 49a is connected to a crankcase.

The cylinder body 22 is surrounded by a shroud 51 forming a cooling air passage. A generator cover 51g surrounding the generator 27 is integrally formed on the right side of the cylinder body 22 of the shroud 51, and a bulging portion 51a is formed on the left side of the cylinder body 22. An exhaust hole is formed below the bulging portion 51a, and the discharge duct 52b is inserted into the bulging portion 51a. A maintenance opening 51c is formed in a portion of the generator cover 51g facing the crankshaft 26, and is closed by a cap 53. An exhaust hole 51d is formed behind the opening 51c of the shroud 51,
Further, a positioning projection 51e for adjusting the mounting angle of the rotating body 27a of the generator 27 with respect to the crankshaft 26 is formed integrally with the inside of the exhaust hole 51d. Further, an air introduction opening 51f is formed in a right portion of the shroud 51 on the cylinder body 22. A radiator 54 is provided to cover the opening 51f, and a blower fan 55 is provided inside the radiator 54.

The blower fan 55 includes an impeller 56 and a fan pulley 57 disposed outside the impeller 56 in the vehicle width direction. The fan pulley 57 is mounted on the right end of the crankshaft 26. The V-belt 62 is connected to the crank pulley 27d. The impeller 56 is a support portion 18 integrally formed on the right side wall of the crankcase 18b.
By d, it is fixed to a rotating cylinder 59 that is supported via a bearing 58. The fan pulley 57 includes a fixed pulley half 57 a fixed to the rotary cylinder 59, and a sliding shaft 60 slidably inserted in the axial direction into the rotary cylinder 59 and spline-fitted. And a movable pulley half 57b fixed to the right end.

An urging mechanism 61 is provided between the impeller 56 and the cylinder body 22. The biasing mechanism 61 has a structure in which a spring 63c is interposed between a spring seat 63a attached to the tip of the sliding shaft 60 and a spring seat 63b inserted into the inner end of the rotary cylinder 59. is there. Accordingly, the diameter of the fan pulley 57 is changed by urging the movable pulley half 57b toward the fixed pulley half 57a by the urging mechanism 61, thereby changing the V-belt 62.
A tension adjusting mechanism 64 that absorbs the elongation of the head is configured.

Next, the operation and effect of this embodiment will be described. In the air cooling device according to the present embodiment, the rotation of the crankshaft 26 is transmitted from the crank pulley 27d to the fan pulley 57 via the V-belt 62, whereby the impeller 56 of the blower fan 55 rotates. After being introduced into the shroud 51 from the opening 51f through the opening 54, the cylinder body 22 is cooled and then discharged from the exhaust hole of the bulging portion 51a. Note that a part of the outside air introduced into the shroud 51 passes through the generator 27 and exhaust holes 5
It is discharged outward from 1d, and at this time, the portion of the generator 27 and the driving V-belt 62 are cooled. When the V-belt 62 expands and the belt tension decreases, the movable pulley half 57b of the fan pulley 57 moves to the fixed pulley half 57a side by the urging mechanism 61, whereby the effective diameter of the fan pulley 57 decreases. The V-belt 62
Is absorbed, the belt tension is properly maintained, and the impeller 56 continues to rotate without any trouble.

In this embodiment, the fan pulley 5
Since the urging mechanism 61 for moving the movable pulley half 57b of FIG. 7 is disposed between the cylinder body 22 and the impeller 56, the vehicle width is increased by disposing the urging mechanism 61. Never. That is, the cylinder body 22
It is necessary to provide a relatively large space between the impeller 56 and the impeller 56 due to its structure.
1 is disposed by utilizing this relatively large space, so that an increase in vehicle width can be avoided.

In this embodiment, since the radiator 54 is disposed in the outside air introduction opening 51f of the shroud 51, the cooling of the cylinder body 22 and the cooling of the radiator 54 can be performed by one blower fan 55.

[0025]

As described above, according to the air-cooling system for a motorcycle engine according to the present invention, the fan pulley of the blower fan disposed on the side of the cylinder body is fixed to the rotating cylinder body. It is composed of a fixed pulley half and a movable pulley half movable in the direction of the rotation axis, and the movable pulley half is urged toward the fixed pulley half by an urging mechanism. The pulley half can move and absorb the elongation of the V-belt, which has the effect of avoiding slip. Also, a cam chain is disposed on the opposite side of the blower fan, the impeller is supported by a support unit integrally formed on a side wall of the crankcase, and a fan pulley is disposed outside the impeller. Is disposed between the impeller and the cylinder body, so that the size in the vehicle width direction can be reduced while maintaining the cooling performance.

[Brief description of the drawings]

FIG. 1 is a sectional development view of an air cooling device for an engine according to an embodiment of the present invention.

FIG. 2 is a sectional development view of the engine of the embodiment.

FIG. 3 is a plan view of the engine of the embodiment.

FIG. 4 is a side view of a motorcycle equipped with the engine of the embodiment.

FIG. 5 is a side view of a motorcycle equipped with the engine of the embodiment.

[Explanation of symbols]

 Reference Signs List 10 engine unit (engine) 22 cylinder body (engine body) 26 crankshaft 27d crank pulley 55 blower fan 57 fan pulley 57a fixed pulley half 57b movable pulley half 59 cylinder (rotary shaft) 61 biasing mechanism 62 V belt 64 Tension adjustment device

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 7/12 F02B 67/06

Claims (1)

(57) [Claims] 1. A cylinder body is surrounded by a shroud.
The blower fan that blows air into the shroud
Disposed on the side of Di, is driven by a crank shaft extending in the fan pulley and the vehicle width direction to drive the impeller of the air blowing fan, and a crank pulley that is provided on the outside of the generator and connected by V-belt In the air cooling system for a motorcycle engine, a cylinder head laminated on the cylinder body is provided.
Cam sprocket fixed to the cam shaft
To the crank sprocket fixed to the above crankshaft
Place the wound cam chain on the cylinder body
Installed on the opposite side of the blower fan,
Integrally formed so as to extend to the side of the cylinder body
The rotating cylinder that is integral with the impeller is supported by the
And pulling the fan pulley from the impeller of the rotary cylinder
The fixed pulley half fixed to the outside and the rotating cylinder inside
Inserted and slidable in the axial direction and capable of transmitting rotational force
Of the fixed pulley half
And a movable pulley half disposed outside.
Interposed between the inwardly projecting end of the drive shaft and the inner end of the rotary cylinder
The sliding shaft is urged inward by the spring to change the diameter of the fan pulley to absorb the elongation of the V-belt.
An air cooling device for a motorcycle engine, wherein a biasing mechanism is disposed between the impeller and a cylinder body .