JPS6126674Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a speed change pulley used in drive devices for automobiles, motorcycles, agricultural machinery, and other general industries. The present invention relates to a speed change pulley of a type in which a moving sliding sheave is provided with a spring inserted between a stopper fixed to the side of the sheave, and in which the fixing location of the spring is improved.

In a conventional speed change pulley, a V-belt is sandwiched between a pair of sheaves, and one or both sheaves prevent idling in the rotational direction of the shaft due to the pressing force of a spring on the side of the belt, and prevent it from idling in the thrust direction of the shaft. Splines or key grooves are formed so that one or both sheaves can move, but forming such splines and key grooves poses problems such as high material and processing costs.

Therefore, pulleys to improve this point have been studied from various viewpoints, and some of them have already been developed.
was suggested.

As a typical example of this variable speed pulley, as shown in FIG. A spring 6 is inserted between the sliding sheave 3 and a stopper 5 fixed to the side of the sheave, and both ends of the spring are movable in the sliding direction. It has a structure in which it is fixed to the sheave 3 and stopper 5, respectively.

However, although the variable speed pulley with this structure is effective against the above-mentioned problem,
On the other hand, if more torque than necessary is applied to the sliding sheave 3 and the torsion angle of the spring exceeds a certain value, the spring 6 or the stopper 5 may be damaged, and improving this problem has become a new issue. Ta.

The present invention focuses on such problems and aims to improve the above-mentioned drawbacks, and aims to provide a speed change pulley having a structure that does not damage the spring or other parts even if a large torque is applied to the sheave. The feature is that at least one of the opposing sheaves attached to the shaft is a sliding sheave 3 that is movable in the axial direction, and that the sliding sheave 3 is fixed to the side of this sheave. In the speed change pulley having a spring inserted between the stopper and the stopper, a protruding pin is inserted into at least one of the stopper or the boss portion of the sliding sheave 3, and the end surface of the spring is brought into contact engagement with the pin, The point is that the pin is broken by the torsional stress of the spring.

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

FIG. 2 is a partial sectional view showing an example of the speed change pulley 10 according to the present invention, and FIG. 3 is an enlarged view of the spring-fixed portion thereof. In these figures, 11 is a sheave shaft, and the fixed sheave 12 is the shaft. 11 bolts 1
3, and a sliding sheave 14 is mounted opposite thereto.

As is clear from the figure, the sliding sheave 14 is slidable in the direction of the shaft 11 and is installed on the shaft so as to be movable in the axial direction. A rotatable bush 15 is attached thereto, and a stepped boss portion 16 is formed on the outer surface of the bush 15.

Note that the member installed between the sliding sheave 14 and the sheave shaft 11 is not limited to the bush 15, and for example, a bearing or a spiral key may be used.

A flange stopper 17 is attached to the sheave shaft 11 on the right side of the sliding sheave 14, and is fixed to the sheave shaft 11 with bolts 18, and between the stopper 18 and the sliding sheave 14. A spring 19 having rebound resilience is attached so as to always press the sliding sheave 14 toward the fixed sheave 12.

In the above structure, the spring 19 has one end surface inserted into the stopper 17 to prevent the sliding sheave 14 from rotating unrestrictedly, and comes into contact with the protruding pin 20, which is a feature of the present invention. The end face is free and does not come into contact with anything.

The details of the pin 20 used here are shown in FIG. 3, and in the illustrated example, a notch 21 is provided at the base of the protrusion to cause damage due to stress concentration. . However, this may be any material or pin length that is easily damaged by appropriate stress, and it is not necessarily necessary to provide a notch. By doing so, the pin 20 will be damaged by the torsional stress of the spring when a torque exceeding an allowable value is applied to the sliding sheave 14, but other parts will be spared from damage.

In the example shown above, the pin 20 is inserted into the boss part on the stopper 17 side, but the pin 20 is not limited to the stopper 17 side, but can be inserted and protruded in the boss part on the sliding sheave side. Furthermore, the boss portions on both the stopper side and the sliding sheave side may be provided protrudingly.

FIG. 4 is a modified embodiment of FIG. 2, and shows an upper half sectional view in which the end surface of the spring is brought into contact engagement with the boss portion 16 of the sliding sheave and the stopper 17, and the boss portion 16 of the sliding pulley is also shown. A protruding pin 20 with a notch is inserted in the sheave axis direction, and the stopper 17 is also connected to the sheave axis 1 by the protruding pin 20.
It is fixed at 1. A spring 19 is inserted between the sliding sheave 14 and the stopper 17.
Both end surfaces of are in contact engagement with the two pins 20, 20, respectively. This thus allows the stopper 17 to be fixed without the use of separate bolts.

In the above case, the torsional stress tolerance values of both pins 20, 20 are not necessarily required to be the same, but it is preferable to match them as much as possible by considering the positions of the pins.

Also, the sheave opposite the sliding sheave shown in each illustrated example of the present invention is a fixed sheave, but in the case of FIG. 2, this can rotate integrally with the sheave instead of the fixed sheave. It is also possible to use a rotating sheave fitted with a bearing.

As described above, the speed change pulley of the present invention locks the spring by inserting a pin that can come into contact with the end surface of the spring into one or both of the stopper and the boss of the sliding sheave. In the unlikely event that more torque than necessary is applied to the sliding sheave and a torsional stress that exceeds the allowable value is applied to the spring, this stress will be released by breaking the pin, and parts other than the pin will be removed. It has the remarkable effect of being able to be reused by simply replacing the inexpensive pin without any damage, and it corrects the shortcomings of conventional pulleys as a speed change pulley, making it more practical and durable. This greatly improves sexual performance.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of the configuration of a conventional speed change pulley, Fig. 2 is a schematic view of an example of the speed change pulley of the present invention, showing the upper half as a sectional view, and Fig. 3 is the main part of the same Fig. 2. FIG. 4 is a partial sectional view showing a modification of the present invention. 11... Sheave shaft, 12... Sheave, 14...
Sliding sheave, 16...Sliding sheave boss part, 17
...Stopper, 19...Spring, 20...
Projecting pin, 21...notch.

Claims (1)

[Claims for Utility Model Registration] 1. At least one of a pair of opposing sheaves attached to a sheave shaft is a sliding sheave that moves in the axial direction, and the sliding sheave and the sheave are located to the side of the sheave. In a speed change pulley having a spring inserted between the stopper and the boss portion of the sliding sheave, a protruding pin that can be broken by the torsional stress of the spring is inserted into one or both of the stopper and the boss portion of the sliding sheave, A speed change pulley characterized in that the spring is brought into contact engagement with the pin at its end surface. 2. The speed change pulley according to claim 1, wherein the pin inserted into the stopper also serves as a bolt for fixing the stopper to the shaft. 3. The speed change pulley according to claim 1 or 2, wherein the pin has a notch in a part thereof.