JPH08233048A - Torque cam mechanism of continuously variable transmission - Google Patents

Abstract

PURPOSE: To provide a torque cam which can ensure durability by reducing the shearing breakage of the block fixed to the cam face of itself. CONSTITUTION: At the cam face 5a of a torque cam 5 is a block 7 consisting of polyimide resin (PI) material or carbon carbon (C/C) composite material fixed in the shape of a projection to the side of the cam face 6a of a hub 6. The end face 7a of projection of the block 7 is made into a face parallel with the cam face 5a, being projected by 0.4-0.6mm for optimum value and 1mm or under for maximum value from the cam face 5a of the torque cam 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque cam mechanism for a continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, a continuously variable transmission has a pair of input side pulleys mounted on an input shaft and capable of being connected / disconnected.
By a belt mounted between a pair of output side pulleys that can be attached / detached to / from the output shaft, the rotation of the input shaft can be steplessly changed and transmitted to the output shaft. A torque cam mechanism is attached to the movable pulley of the output side pulley in order to apply tension to the belt when shifting. That is, as shown in FIG. 3, a fixed pulley 2 is integrally provided on the output shaft 1, and a movable pulley 3 is provided facing the fixed pulley 2 so as to be movable along the output shaft 1. A belt 4 is hung between the fixed pulley 2 and the movable pulley 3, and a torque cam 5 is fixed to the back side of the movable pulley 3 in order to apply tension to the belt 4, and the cam surface at the right end of the torque cam 5 is fixed. The cam surface 6a of the hub 6 fixed to the output shaft 1 is brought into contact with the shaft 5a, and the hub 6 rotates as the output shaft 1 rotates, so that the cam surface 6a of the hub 6 becomes the cam surface of the torque cam 5. The torque cam 5 and the movable pulley 3 are pressed against the fixed pulley 2 by slidingly contacting the belt 5a, whereby tension is applied to the belt 4.

However, the cam surface 5a of the torque cam 5 and the cam surface 6a of the hub 6 have a large frictional resistance because they are in contact with each other, and a large thrust force is exerted when the movable pulley 3 is moved to the side opposite to the fixed pulley 2. Since it is necessary,
As shown in FIG. 4, from the cam surface 5a of the torque cam 5 to the polyimide resin (PI) material or carbon carbon (C / C)
A block 7 made of a composite material is projected, and the projecting end surface 7a of the block 7 is brought into contact with the cam surface 6a of the hub 6 to reduce the frictional resistance, and the thrust of the movable pulley 3 at the time of shifting is proposed to be reduced. However, if a shearing force F as shown in FIG. 4 is applied during gear shifting or the like, the block 7 may be chipped K, which causes the durability to be impaired.

[0004]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned problems of the prior art, and is of a continuously variable transmission capable of reducing the shear fracture of the block projected on the cam surface and ensuring the durability. The purpose of the present invention is not to provide a torque cam mechanism, and the gist thereof is between a pair of separable input side pulleys mounted on the input shaft and a pair of separable output side pulleys mounted on the output shaft. A cam surface is provided on the outer side surface of the movable pulley of the output side pulley in order to transmit the rotation of the input shaft to the output shaft by steplessly shifting the rotation of the input belt and to apply tension to the belt. A continuously variable torque cam mechanism in which the formed torque cam is concentrically fixed to the output shaft, and a hub having a cam surface that abuts the cam surface so as to face the torque cam is attached to the output shaft. transmission A block made of a polyimide resin (PI) material or a carbon-carbon (C / C) composite material is fixed to the cam surface of the torque cam or the cam surface of the hub in a protruding shape, and the block is projected. The end surface is formed so as to be projected within 1 mm from the cam surface of the torque cam or the hub and parallel to the cam surface of the torque cam or the hub.

[0005]

[Function] Since the protruding length of the block from the cam surface, that is, the protrusion margin is set within the range of 1 mm, the shear fracture of the block can be reduced, the block is prevented from being chipped, and the durability of the torque cam mechanism is improved. You can

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the configuration of a torque cam and a hub constituting a torque cam mechanism. In the torque cam 5, a flange portion 5b formed on the outer periphery of the left end of the torque cam mechanism is attached to the back side of the movable pulley 3 via a bolt. , This collar 5b
A cam surface 5a is formed at the right end on the opposite side of the above, and the cam surface 5a is formed by dividing the entire circumference into three equal parts.
On the other hand, the hub 6 has a cam surface 5a facing the cam surface 5a.
Is formed with a cam surface 6a that abuts against.

In this example, as shown in the enlarged view of FIG. 2, a recess 5c is provided on the cam surface 5a of the torque cam 5, and ethylene tetrafluoride (PTFE) and molybdenum disulfide (MoS ₂ ) are provided in the recess 5c. Block 7 made of polyimide (PI) resin containing carbon, or carbon carbon (C /
C) A block 7 made of a composite material is attached by press fitting. The block 7 may be adhered by using an adhesive, or may be pinned or embedded.

The block 7 is formed in such a shape that the projecting end surface 7a (cam surface) on the projecting end side is parallel to the cam surface 5a of the torque cam 5, and between the projecting end surface 7a and the cam surface 5a. The optimum value t is set to 0.4 to 0.6 mm and the maximum value is set to 1 mm. The value t, that is, the protruding length of the protruding end surface 7a of the block 7 from the cam surface 5a is a polyimide resin (PI). Material or carbon Carbon (C /
C) In consideration of the amount of wear of the composite material and the processing accuracy, a value of 0.4 to 0.6 mm was determined as a value at which shear fracture is least likely to occur by a strength experiment or the like.
With a protrusion t of 0.6 mm, the conventional chipping K does not occur, the shear fracture of the block 7 is reduced, and the durability is secured. If the protrusion length is within 1 mm, there is no problem in practical use.

As described above, in this embodiment, the protruding amount t of the block 7 is set within the range of 0.4 to 0.6 mm at the optimum value and 1 mm at the maximum value, and the protruding end surface 7a of the block 7 is set to the cam surface 5.
Since the protruding end surface 7a of the protruding end is slidably brought into contact with the cam surface 6a of the hub 6, the durability is improved, and the block 7 reduces the frictional resistance during sliding contact, which allows the movable portion to move. The thrust when moving the pulley 3 is favorably reduced. The same effect can be obtained by projecting the projecting end surface 7a of the block 7 from the cam surface 6a side of the hub 6 toward the cam surface 5a of the torque cam 5 with a similar margin t.

[0010]

According to the present invention, a belt mounted between a pair of separable input side pulleys mounted on an input shaft and a pair of separable output side pulleys mounted on an output shaft. In order to continuously change the rotation of the input shaft to transmit the rotation to the output shaft and to apply tension to the belt, a torque cam having a cam surface is formed on the outer surface of the movable pulley of the output pulley. A continuously variable transmission including a torque cam mechanism, comprising a hub fixed to the output shaft, the hub having a cam surface that abuts the cam surface so as to face the torque cam, and the hub is attached to the output shaft. A block made of a polyimide resin (PI) material or a carbon carbon (C / C) composite material is fixed to the cam surface of the torque cam or the cam surface of the hub in a protruding manner, and Since the protruding end surface of the lock is projected within 1 mm from the cam surface of the torque cam or the hub and is formed in a surface parallel to the cam surface of the torque cam or the hub, chipping does not occur and block The effect of reducing the shear fracture and ensuring the durability, and reducing the frictional resistance at the time of sliding contact by the block to favorably reduce the thrust when moving the movable pulley.

[Brief description of drawings]

FIG. 1 is a perspective configuration diagram of a torque cam and a hub that form a torque cam mechanism.

FIG. 2 is an enlarged view of an essential part showing a sliding contact state between a protruding end surface of a block fixed to a cam surface of a torque cam and a cam surface of a hub.

FIG. 3 is a cross-sectional configuration diagram showing a mounted state of a conventional torque cam mechanism.

FIG. 4 is an enlarged view of an essential part showing a sliding contact state between a protruding end surface of a block fixed to a cam surface of a conventional torque cam and a cam surface of a hub.

[Explanation of symbols]

 1 output shaft 2 fixed pulley 3 movable pulley 5 torque cam 5a cam surface 6 hub 6a cam surface 7 block 7a protruding end surface (cam surface) t protrusion

Claims (1)

[Claims] 1. An input shaft comprising a pair of separable input-side pulleys attached to an input shaft and a pair of separable output-side pulleys attached to an output shaft. Of the rotation of the stepless speed change and transmitted to the output shaft,
Further, in order to apply tension to the belt, a torque cam having a cam surface is fixed to the outer surface of the movable pulley of the output side pulley so as to be concentric with the output shaft and face the torque cam. In a continuously variable transmission including a torque cam mechanism in which a hub having a cam surface that abuts on the cam surface is attached to an output shaft, a camshaft surface of the torque cam or a cam surface of the hub has a polyimide resin (PI) material or A block made of carbon-carbon (C / C) composite material is fixed in a protruding shape, and the protruding end surface of the block is made to protrude within 1 mm from the cam surface of the torque cam or the hub. A torque cam mechanism for a continuously variable transmission, which is formed on a surface parallel to the cam surface of the.