JPH0118923Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to damper pulleys, particularly damper pulleys used in automobile engines.

Since an automobile engine has an extremely wide rotation range, a damper is attached to the output rotating shaft (crankshaft) in order to smooth rotational fluctuations. This damper is integrally connected to a pulley for driving an engine cooling fan, a generator, etc. to form a damper pulley.

Such a damper pulley generally has a structure in which an outer ring portion with a belt groove is fixed to the outer periphery of the pulley with a hub portion having a shaft hole into which a rotating shaft is inserted through a damper rubber. A V-belt that transmits the rotation of the rotating shaft to the engine cooling fan and generator is wound around the belt groove in the outer ring. The outer ring has a natural frequency that absorbs vibrations of the rotating shaft and functions as a damper mass (inertial body). That is, the outer ring portion also serves as a damper mass. However, with this type of damper pulley, not only does its radial dimension become large, but if it is used for a long time, the damper rubber and the outer periphery or outer ring of the pulley may peel, causing the damper rubber or outer ring to come off the pulley. There is a danger that this will happen.

Separately from this, a method is also known in which the hub portion with the shaft hole and the outer ring portion with the belt groove are integrated, and the damper mass is separately fixed to the outer ring portion via damper rubber. That is, in this case, a belt groove is formed on the outer periphery of the pulley, and the damper mass is fixed to this outer periphery via a damper rubber. Therefore, the damper mass has only its original purpose as an independent inertial body separate from the belt groove support part (i.e., the pulley outer circumferential part), compared to the former type in which the belt grooved outer ring part also serves as the damper mass. , no load is applied to the damper mass, and the possibility of separation is therefore reduced. However, the damper mass fixed to the side surface of the pulley periphery exists as a protrusion or protrusion, which requires extra space, which makes the engine smaller. This has hindered efforts to reduce the size or weight of the product. Furthermore, the work of assembling the damper mass and damper rubber is relatively troublesome, and improvements have been desired.

The present invention proposes a structure for the latter type of damper pulley, that is, a type in which the damper mass is provided separately from the pulley, which allows the damper mass to be easily attached without requiring any extra space.

Description will be given below with reference to the accompanying drawings.

The pulley 1 has a hub portion 5 having a shaft hole 3 into which a rotating shaft (not shown) such as a crankshaft is fitted.
and a rim portion 9 having outer circumferential belt grooves 7a and 7b. For example, a V-belt (not shown) that drives an engine cooling fan (not shown) is placed in the belt groove 7a, and a V-belt (not shown) that drives a generator (not shown) is placed in the belt groove 7b. They are wound around each other. The intermediate wall portion 12 between the hub portion 5 and the rim portion 9 is generally made thinner from the viewpoint of weight reduction, etc. Therefore, an annular recess 11 is formed between the hub portion 5 and the rim portion 9. A major feature of the present invention is that the damper mass 13 and the damper rubber 15 are disposed in the recess 11. Recess 1
For pulleys that are not provided with a recess 11
All you have to do is set it up.

In the illustrated embodiment, an annular damper mass 13 is fixed within the recess 11 by an annular damper rubber 15 surrounding the outer peripheral surface of the annular damper mass 13. The damper rubber 15 is preferably fixed to the damper mass 13 by vulcanization. The size (mass) of the damper mass 13 is appropriately designed depending on the mass of the pulley 1.

According to the present invention, the ring plate 21 is fixed in advance to the outer periphery of the damper rubber 15, and the ring plate 21 is fixed to the outer periphery of the damper rubber 15.
It is designed to be press-fitted into 1. Similar to the fixing between the damper mass 13 and the damper rubber 15, the fixing between the damper rubber 15 and the ring plate 21 is performed by vulcanization. In the embodiment shown in FIG. 1, only the ring plate 21 is press-fitted, so if the damper rubber 15 is damaged, the damper mass and damper rubber can be replaced.

Preferably, the inner peripheral surface of the damper mass 13 and the recess 11
A cavity 20 is formed between the inner circumferential wall surface and the inner circumferential wall surface.

As shown in FIG. 1, according to the present invention, the damper mass is enclosed within the pulley, so no extra space is required in the axial or radial direction.Moreover, the damper mass 13 is fixed to the damper rubber 15 on its outer peripheral surface. Sufficient peeling resistance is ensured and durability is improved. Further, even if the damper rubber is damaged for some reason, the damper mass remains within the recess 11, so that no fatal engine trouble will occur.

Furthermore, the presence of the void space 20 allows the damper mass to be freely designed to have various sizes. That is, the increase in the damper rubber can be absorbed by the space 20, and there is no need to change the design of other parts at all.
Furthermore, the presence of the void 20 facilitates press-fitting the damper mass into the damper rubber.

This cavity 20 also serves to absorb the tensile residual stress after the damper mass is installed. That is, if the damper rubber is fixed (by vulcanization) to the inner and outer peripheries of the damper mass, that is, if there is no void 20,
Since there is no place to escape to absorb deformation due to internal tensile residual stress of the damper mass or damper rubber, this residual stress may deteriorate the durability of the damper mass. Recess 20 helps reduce this possibility.

Furthermore, if the damper rubber is also fixed to the inner periphery of the damper mass, the torsion angle will be different between the inner and outer peripheries due to the difference in circumferential length between the inner and outer peripheries, which will also have an adverse effect on the durability of the damper rubber. Place 20 is useful. Generally, the damper rubber is assembled in a compressed state, but if the recess 20 exists, escape or deformation of the damper mass 13 toward the inner circumference can be absorbed, so that the amount of compression of the damper rubber can be increased.

Being able to compress the damper rubber to a large extent not only increases the durability of the rubber body, but also increases the damping effect against torsional vibrations of the crankshaft and the like.

Although the damper pulley according to the present invention is most suitable for use in automobile engines, it is not limited thereto.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a damper pulley according to the present invention, and FIG. 2 is a side view of the upper half of FIG. 1...Pulley, 3...Shaft hole, 5...Hub part, 7
a, 7b...Belt groove, 9...Rim part, 11...
Recessed portion, 13... damper mass, 15... damper rubber, 21... ring plate.

Claims (1)

[Scope of utility model registration request] A thin wall portion is formed between the hub portion having a shaft hole into which the rotating shaft is fitted and the rim portion having a belt groove on a part of the outer periphery for winding the rotation transmission belt. A damper pulley having an annular recess formed between the ring and the rim portion and located on the radially inner side of the outer circumferential belt groove, the ring having an annular damper rubber with a damper mass fixed on the inner periphery and fixed on the outer periphery of the damper rubber. A damper pulley, characterized in that the damper pulley is press-fitted into the annular recess through a plate.