JPS5838180Y2 - Cylindrical torsional damper - Google Patents

Description

[Detailed description of the invention] This invention is installed on a rotating shaft such as the crankshaft of an internal combustion engine.
The present invention relates to a cylindrical torsional damper that suppresses torsional vibration of the rotating shaft.

This type of torsional damper is manufactured by vulcanizing and adhering the inner circumferential surface of a cylindrical rubber member 2 having a trapezoidal cross section to the outer circumferential surface of an inner cylindrical member 1 made of metal, as shown in FIG. As shown in FIG. It has a structure in which an inner cylindrical member is press-fitted and fixed inside one member.

In the above configuration, the cylindrical rubber member 2 is made to have a Poisson's ratio close to 1 in order to enhance the damper function, so even if it is compressed by press-fitting, almost no volume change occurs.

That is, the rubber member 2 is maintained at a substantially constant volume because the volume corresponding to the amount of compression in the radial direction is offset by the volume expanded toward both open ends.

However, in the conventional structure in which the rubber member 2 is allowed to expand only in the direction of both opening ends, the rubber member 2
If the amount of volume movement during compression is large, the outer peripheral surface of the rubber member 2, which is the press-fit fixed side, can change its form to some extent by elongating in the axial direction, but the inner peripheral surface, which is the vulcanized adhesive side, cannot change its form. In particular, protrusion occurs at the peripheral edges of both ends, generating extremely large tensile stress.

For this reason, when the torsional vibration of the rotating shaft to be attached, for example, the crankshaft, is absorbed by the elastic deformation of the rubber member 2, cracks occur from the protruding portion.

As a result, the rubber member has disadvantages in that its torsional vibration prevention function is impaired and its durability is significantly shortened.

Therefore, in view of the above-mentioned conventional circumstances, the present invention has been developed by embedding an annular elastic member having elasticity softer than that of the cylindrical member in the end edge of at least one of the inner and outer peripheral surfaces of the elastic cylindrical member. It prevents extrusion and relieves stress concentration on the adhesive surfaces at both ends, eliminating the above drawbacks.
The object of the present invention is to provide a cylindrical torsional damper that has a stable torsional vibration prevention function and a greatly extended durability life.

Hereinafter, one embodiment of the present invention will be described based on FIGS. 4 to 6.

In the embodiment shown in FIG. 4, circumferential grooves 6 are formed at both edges of the inner circumferential surface of the cylindrical rubber member 5 that is adhered to the outer circumferential surface of the inner cylindrical member 4, and each circumferential groove 6 has an annular hollow. The elastic member 7 is fitted and fixed by a method such as gluing.

As explained based on FIG. 1, this cylindrical rubber member 5 is fitted onto the outer periphery of the metal inner cylindrical member 4 and bonded by vulcanization, and as shown in FIG. An integral torsional damper is constructed by press-fitting and fixing an outer cylindrical member 8 made of aluminum.

In this way, in a state where the outer cylindrical member 8 is press-fitted and fixed on the outer periphery of the cylindrical rubber member 5, the rubber member 5 is compressed in the radial direction, and at this time, the hollow elastic member 7 is compressed in the same manner as shown in FIG. It gets compressed and collapses.

According to the above configuration, since the elastic member 7 interposed between both side edges of the inner peripheral surface of the cylindrical rubber member 5 and the outer peripheral surface of the inner cylindrical member 4 is hollow, the rubber member 5 Since it has more flexible elasticity, it easily collapses and changes its shape when compressed, so that the tensile stress applied to the elastic member 7 due to extrusion becomes small.

Further, since the elastic member 7 is formed to have a circular cross-section and is rounded in the collapsed state, stress concentration on the adhesive surfaces at both ends can be avoided.

Therefore, the hollow elastic member 7 does not suffer from damage such as cracks, and the rubber member 5 is in close contact with the outer circumferential surface of the inner cylindrical member 4, thereby exhibiting a stable torsional vibration prevention function and excellent durability. This means that it can be used for a long period of time.

Furthermore, as mentioned above, conventionally the rubber member is allowed to expand only in the direction of both opening ends, but as in this embodiment, the elastic member 7, which is more flexible than the rubber member 5, is interposed. Since the peripheral edges of both ends of the rubber member 50 are allowed to expand not only in the axial direction but also in the radial direction, the pressing force, that is, the frictional force with the inner circumferential surface of the outer cylindrical member 8 is reduced.

Therefore, it is possible to suppress the wear of the rubber member 5 and the heat generated thereby, and there is also the advantage that stable torsional vibration function can be maintained for a long period of time.

In the above embodiment, a torsional damper in which a rubber member 5 is vulcanized and bonded to an inner cylindrical member 4, and an annular elastic member 7 is applied to the adhesive side circumferential surface of the rubber member 5 is described. However, it may also be applied to the press-fit side peripheral surface of the rubber member 5.

In this case as well, the tensile stress is reduced on both side edges of the adhesive side peripheral surface of the rubber member 5, and the same effect as described above can be obtained.

Further, an annular elastic member may be provided on both the adhesion side and the press-fit side of the rubber member 5, and even in the case where the rubber member 5 is adhered to the outer cylindrical member 8, the same procedure as above can be applied. An annular elastic member may be attached.

Furthermore, the annular elastic member 7 is not limited to a hollow one as in this embodiment, but may be a solid one (in short,
Any material may be used as long as it has sufficiently flexible elasticity compared to the rubber member serving as the main body.

As explained above, the present invention provides an annular elastic member having elasticity softer than that of the elastic cylindrical member at the edge of at least one peripheral surface of the elastic cylindrical member interposed between the two inner and outer rigid cylindrical members. The tensile stress concentrated on the edge of the adhesive side circumferential surface of the elastic cylindrical member is significantly reduced by a simple improvement by fitting the member, so that the rubber is not damaged due to cracks or other damage to the edge. This prevents deterioration of one member, and also reduces the compressive force on the edge of the circumferential surface on the press-fit side of the elastic cylindrical member, suppressing wear and heat generation caused by friction on the edge. Not only can torsional vibration be obtained, but the durable strength of the rubber member is significantly increased, and the life of the torsional damper can be greatly extended.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams explaining the structure and assembly method of a conventional cylindrical torsional damper, where A is a vertical cross section,
B is a side view, FIG. 3 is an enlarged view of the rubber member in the same torsional damper, and FIGS. 4 to 6 are longitudinal sectional views showing other embodiments of the cylindrical torsion damper according to the present invention. be. 4... Inner cylindrical member, 5... Cylindrical rubber member, 6... Annular groove, 7... Annular hollow elastic member, 8... ...Outer cylindrical member.

Claims (2)

[Scope of utility model registration request] (1) In a cylindrical torsional damper in which an elastic cylindrical member is interposed between two mutually polymerized rigid cylindrical members, one of the inner and outer peripheral surfaces of which is glued and the other is press-fitted and fixed, the elastic cylindrical member is A cylindrical torsion damper characterized in that a circumferential groove is provided in at least one end circumferential edge of the inner and outer circumferential surfaces, and an annular elastic member having elasticity more flexible than the elastic cylindrical member is fitted and integrated into the circumferential groove. . (2) A cylindrical torsional damper according to claim 1, in which the annular elastic member is formed in a hollow shape.