JPH05240319A - V-belt transmission device - Google Patents

Abstract

PURPOSE:To improve the kickdown performance in the speed-change and improve the feeling and the fuel consumption due to reduction of the mechanical losses by keeping the sliding resistance to change the speed of the driven pulley zero or minimum. CONSTITUTION:A V-belt transmission device implements the speed change of the rotation of the engine 2 and transmits the rotation to the drive side of the rear wheels 14 through a drive pulley 8, a V-belt 10 and a driven pulley 9. A torque cam pin 25 is implanted from the outside on a boss 15 to support one pulley piece 9a of the driven pulley 9, and this torque cam pin 25 is engaged with the cam surface of a boss 16 of the other pulley piece 9b. On the other hand, the outer end of the torque cam pin 25 is brought in the non-contact condition with the inner surface of an annular body 22 to be mounted on the other pulley piece 9b or brought into contact with the inner surface of the annular body through a ball 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-belt transmission used in a motorcycle or the like.

[0002]

2. Description of the Related Art In a motorcycle, a V-belt transmission is used as a transmission mechanism for transmitting engine rotation to rear wheels. This V-belt transmission has a crankshaft 4 supported by bearings 3 and 3 which is rotated by rotation of an engine 2 in a power unit 1 which is an engine unit case, and bearings 5 and 5 arranged rearward, as shown in the cross section of FIG. Drive shaft 7 of the mission mechanism 6 supported by
A variable speed drive pulley 8 and a driven pulley 9 are provided on the and, and the V belt 1 is provided between the pulleys 8 and 9.
0 is applied to transmit the rotation of the crankshaft 4 to the drive shaft 7 via the centrifugal clutch mechanism 11, and the gears 6 of the transmission mechanism 6 are transmitted from the drive shaft 7.
Rotation is transmitted to the rear wheel shaft 13 through a, 6b, 6c, 6d to drive the rear wheel 14.

Drive pulley 8 of crankshaft 4
One of the pulley pieces 8a is fixed to the crankshaft 4, and the other pulley piece 8b is movable in the axial direction.
Has one pulley piece 9a fixed to the boss 15 supported by the drive shaft 7, and the other pulley piece 9a.
b is fixed to a boss 16 fitted onto the boss 15, and the bosses 15 and 16 are fixed to the clutch housing 18 of the centrifugal clutch 11 and the base plate 20 of the shoe 19, respectively, so that the driven pulley 9 is rotated by the centrifugal clutch. 11
Is transmitted to the drive shaft 7 through. The effective diameter of the driven pulley 9 is changed by sliding the boss 16 of the pulley piece 9b in the axial direction.

In the V-belt transmission as described above, FIG.
One pulley piece 9 of the driven pulley 9 as shown in
The torque cam pin 21 for moving b is inserted into the hole formed in the boss 15 in the radial direction of the boss 15, and the axial movement of the torque cam pin 21 is restricted by the inner surface of the ring body 22 fixed to the outer surface of the boss 16. It is designed to prevent jumping out due to centrifugal force. And this torque cam pin 2
1, the boss 16 as an outer cylinder slides along the cam shape provided on the boss 16 along the outer periphery of the boss 15 as a cylinder in the axial direction by the action of the spring 23, and one pulley piece 9b becomes the other pulley piece. The distance is changed with respect to 9a so that the effective diameter of the pulley is changed, and the gear is changed by the change of the effective diameter of the pulley.

[0005]

However, the boss 15 as an inner cylinder is integral with one pulley piece 9a of the driven pulley 9, and the bosses 15 and 16 and the torque cam pin 21 of the engine 2 are integrated with each other when the belt gear ratio is small. It is rotated at a higher speed than the number of rotations. In this case, the annular cam 22 holds down the force of the torque cam pin 21 that pops out by centrifugal force. However, when the torque cam pin 21 is rotated at a high speed and its centrifugal force overcomes the sliding resistance between the cam groove of the boss 16 and the inner surface of the ring body 22, the torque cam pin 21 slides outward in the axial direction. The torque cam pin 21 slides outward in the axial direction, and the pin head of the torque cam pin 21 moves toward the ring body 2.
When sliding along the inner surface while being in contact with the inner surface of 2, the frictional resistance increases. When the friction coefficient at that time is μ, the sliding resistance F is F = n · m · r · μ · ω ² .
Here, n ... number of torque cam pins 21, m ... mass of torque cam pins 21, r ... radius of center of gravity of torque cam pins 21,
ω is the rotation speed of the driven pulley 19.

Therefore, when the rotational speed ω of the driven pulley 9 is large, the sliding resistance F increases, which significantly hinders the operation and deteriorates the kickdown performance.

The present invention provides a V-belt transmission capable of improving the kick-down performance at the time of shifting by reducing the sliding resistance by the torque cam pin and improving the feeling and fuel consumption by reducing the mechanical loss. The purpose is to

[0008]

In order to achieve the above-mentioned object, in the present invention, the rotation of the engine is controlled by the drive pulley, V
In a V-belt transmission that shifts and transmits to a drive side of a rear wheel via a belt and a driven pulley, a torque cam pin is planted from the outside on a boss that supports one pulley piece of the driven pulley, and the torque cam pin is attached to the boss. While engaging the cam surface of the boss of the other pulley piece,
The outer end of the torque cam pin and the inner surface of the ring body attached to the other pulley piece are brought into non-contact with each other or through a ball.

[0009]

Since the outer end of the torque cam pin is not in contact with the inner surface of the ring body or through the ball, the friction with the ring body is zero or minimum even when the driven pulley is rotating at high speed. Smooth shift operation is performed.

[0010]

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

FIG. 2 shows a first embodiment of the present invention. One pulley piece 9a is attached to a boss 15 as an inner cylinder which is rotatably supported via a bearing 24 on a drive shaft 6 of a mission mechanism 6. Is fixed to the boss 15 and supports the shoe 19 of the centrifugal clutch 11 on the boss 15.
0 is fixed.

Further, the other pulley piece 9b is fixed to a boss 16 as an outer cylinder which is fitted onto the boss 15 and the ring body 2 as a guide sleeve is provided on the outer surface of the boss 16.
2 is fixed, and a spring 23 is interposed between the pulley piece 9b of the boss 16 and the base plate 20 of the clutch 17.

A torque cam pin 25 is inserted and implanted in the boss 15 in the radial direction thereof. A steel ball 27 is fitted together with grease into the hole of the head 26 of the torque cam pin 25, and the ball 27 rollably hits the inner surface of the ring body 22 in the direction in which the torque cam pin 25 is removed by centrifugal force. It has been stopped.

Therefore, even when the drive shaft 6 rotates at a high speed and the torque cam pin 25 hits the inner surface of the annular body 22, the torque cam pin 25 hits through the ball 27 so that smooth sliding is performed.

FIG. 3 shows a second embodiment of the present invention. The torque cam pin 28 of this embodiment has a screw shaft structure and is screwed into the prepared hole of the boss 15 as an inner cylinder.
It will be planted. A space S is provided between the head portion 29 of the torque cam pin 28 and the inner surface of the ring body 22. The head 29 is provided with a hole 30 for screwing. The hole 30 is preferably a hexagonal hole because the torque cam pin 28 is small.

Therefore, in the second embodiment, the torque cam pin 2 is used.
Since 8 is screwed even when the driven pulley 9 rotates at high speed, it does not come off in the radial direction, and the distance S between the head 29 of the torque cam pin 28 and the inner surface of the ring 22 is S.
Can be kept in a non-contact state, F can be set to 0, and the cause of sliding resistance can be eliminated.

[0017]

As described above, according to the present invention, the sliding resistance between the torque cam pin and the ring can be made zero or minimum, so that the kickdown performance at high speed can be improved and the running feeling can be improved. It is possible to improve fuel efficiency by improving rings and reducing mechanical loss.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a V-belt transmission device to which the present invention is applied.

FIG. 2 is a sectional view of a main part showing a first embodiment of the present invention.

FIG. 3 is a sectional view of a main portion showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional technique.

[Explanation of symbols]

 1 Engine Unit Case 2 Engine 4 Crank Shaft 6 Mission Mechanism 7 Drive Shaft 8 Drive Pulley 8a Pulley Piece 8b Pulley Piece 9 Driven Pulley 9a Pulley Piece 9b Pulley Piece 13 Rear Wheel Shaft 14 Rear Wheel 15 Boss (Inner Tube) 16 Boss (Outer Tube) ) 21 torque cam pin 22 annular body 25 torque cam pin 27 ball 28 torque cam pin

Claims (1)

[Claims] 1. A drive pulley, V for rotating an engine.
In a V-belt transmission that shifts and transmits to a drive side of a rear wheel via a belt and a driven pulley, a torque cam pin is planted from the outside on a boss that supports one pulley piece of the driven pulley, and the torque cam pin is attached to the boss. While engaging the cam surface of the boss of the other pulley piece,
A V-belt transmission, wherein an outer end of the torque cam pin and an inner surface of an annulus attached to the other pulley piece are brought into non-contact with each other or via a ball.