JPS62118120A - Resilient coupling - Google Patents

Abstract

PURPOSE:To obtain a random torsional spring characteristic reliably by regulating the torsional spring characteristic at the coupling section and the gap section. CONSTITUTION:Upon deformation of a resilient coupling 10, a resilient rubber member 20A burried in a gap section 20 will influence a force in the recovering direction onto an arm member 14B and regulate the torsional spring characteristic. On the basis of the dispersion of stress, concentration of stress onto the circumferential wall at the gap section is relieved. Consequently, when the torsional torque from the coupling 10 is removed, recovery of the coupling section 14B into the original form is assisted and the collapse of the coupling section 14B is prevented sufficiently resulting in a random torsional spring characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a flat plate-like structure that has a drive shaft and a driven shaft connected to both sides in the axial direction, and that effectively absorbs vibrations and shocks when transmitting rotational torque from the drive shaft to the driven shaft. This relates to elastic couplings.

Conventional elastic couplings of this type consist of a rubber elastic body in which a plurality of shaft mounting holes (usually four) are drilled at equal intervals around the center line, and a shaft mounting hole is formed around the shaft mounting holes adjacent to each other. ,
There is a type of elastic coupling that is constructed by embedding four thread rings in which 840d/2 x 30 thread material is wound 30 times in an annular shape. The twisting action of the thread ring provides low rigidity, and after the twisting action ends, the tensile strength of the thread ring provides high rigidity, thereby making it possible to exhibit the desired torsional spring characteristics. Note that here, the rubber elastic body mainly functions as a restraining material for the thread ring.

Such an elastic coupling is applied, for example, between a steering shaft and a gearbox of an automobile to block the transmission of vibration from the tire side to the steering wheel side based on rubber elastic force, and also to block the transmission of vibration from the steering wheel to the tire. The steering torque can be smoothly transmitted mainly under the action of the thread ring.

However, in such conventional technology, the dimensional accuracy of the thread rings is low, and in order to embed the four thread rings into the rubber elastic body, the threads are inserted between two sheets of unvulcanized rubber. When the unvulcanized rubber is heated and pressurized in the vulcanization mold with the ring in place, the thread ring is deformed by the rubber flow, making it extremely difficult to obtain the desired torsional spring characteristics. There was a problem.

In addition, normally the shaft mounting portion is reinforced by inserting cylindrical collars into each of the shaft mounting holes, but according to the prior art, part of the thread ring is inserted into the shaft mounting hole. Therefore, when inserting the collar into the shaft mounting hole, there was often a problem that the collar interfered with the exposed thread, causing the thread ring to fray.

The present invention has been made in consideration of the above-mentioned facts, and in particular, consists of an elastic coupling mainly made of a hard elastic plate made of synthetic resin with a plurality of shaft mounting holes provided around the center line. This provides an elastic coupling that can easily and reliably achieve desired torsion spring characteristics without fear of fraying of the reinforcing thread ring.

The elastic coupling according to the present invention is mainly composed of a synthetic resin hard elastic plate with a plurality of shaft mounting holes around the center line,
A gap is provided between mutually adjacent shaft mounting holes to facilitate initial deformation of the hard elastic plate in response to twisting torque acting around the center line, and a rubber elastic body is filled in the gap. It becomes.

Note that the rubber elastic body herein includes not only rubber but also rubber-like elastic bodies.

In this elastic coupling, when torsional torque is transmitted to the coupling, the gap facilitates the initial deformation of the hard elastic plate and thus the coupling. , which results in very effective absorption of vibrations and shocks. On the other hand, after the cavity reaches the limit where it can contribute to the deformation of the coupling, it deforms with a smaller amount of deformation than the initial deformation under the elastic deformation inherent to the material of the hard elastic plate. Smooth torque transmission to the driven shaft is achieved.

Here, the rubber elastic body in the cavity whose shape and dimensions are appropriately selected functions to adjust the torsional spring characteristics of the coupling by its deformation reaction force, as well as to restore the hard elastic plate to its original shape. to assist and prevent it from sagging,
Moreover, by dispersing stress to the rubber elastic body, stress concentration on the peripheral wall of the cavity can be effectively avoided.

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

1 to 3 show an elastic coupling 10 according to a first embodiment. The elastic coupling IO of this example is constructed by embedding a thin disk-shaped hard elastic plate 14 made of synthetic resin inside a protective member 12 made of rubber.
The synthetic resin hard elastic plate 14 here can be made of a hard plastic such as nylon or polyester that has a predetermined rigidity.

Here, two pairs of shaft mounting holes 16 and 18 are respectively bored in the protection member 12 and the hard elastic plate 14, separated from their centers, and these shaft mounting holes are used for coupling 1.
They are equally spaced around the zero axis.

Of these mounting holes, a drive shaft is mounted to the shaft mounting hole 16 from one side in the axial direction of the elastic coupling 10, and a driven shaft is mounted to the other shaft mounting hole 18 from the other side in the axial direction.

The hard elastic plate 14 has a peripheral portion 14A and a connecting portion 14B. The peripheral portion 14A has each shaft mounting hole 16.18.
The connecting portion 14B interconnects the adjacent peripheral portions 14A.

Here, the connecting portions 14B are arranged on a circumference centered on the axis of the coupling 10, and each of these connecting portions 14B
The inner circumferential surface of is located at the center of the hard elastic plate 14 and is defined by a cavity 20 that protrudes radially outward from a straight line connecting the centers of adjacent shaft mounting holes 16 and 18. Therefore,
Adjacent peripheral portions 148 are interconnected by curved connecting portions 14B, and each connecting portion 14A is connected to the void portion 20.
As a result, the rigidity of the hard elastic plate 14 between the shaft mounting holes 16 and 18 is effectively reduced, since relatively free deformation in the radial direction inwards and outwards is allowed.

Further, here, a rubber elastic body 2OA is embedded and fixed in the cavity 20 that partitions the connecting portion 14B as described above, and this rubber elastic body 2OA exerts a restoring reaction force on the connecting portion 14B during its deformation. At the same time, stress acting on the connecting portion 14B is dispersed.

Note that a small hole 22 used for positioning and the like is bored in the center of the rubber elastic body 20a.

The elastic coupling 10 according to the present embodiment configured as described above is constructed by inserting a cylindrical collar into the shaft mounting hole 16.18, and then inserting a pin protruding from the drive shaft and the driven shaft into the cylindrical collar. The drive shaft and driven shaft are connected by tightening nuts on these pins.

Here, in the elastic coupling 10 according to this embodiment,
Unlike conventional elastic couplings, no thread links are used and the thread rings are not exposed in the shaft mounting holes 16, 18, making insertion of the cylindrical collar into these holes extremely smooth. I can do it.

In addition, the torsion spring characteristics during use are ideal, with low rigidity at the initial stage of twisting and then high rigidity, as shown in Figure 4, making it the ideal torsion spring characteristic for automotive steering couplings. . This means that
When torsional torque is transmitted from the drive shaft to the elastic coupling 10 of this example, especially in the tension side portion, at the initial stage of twisting, each curved connecting portion 14B becomes approximately straight at a radius. Since the inward deformation is performed, low rigidity can be provided to the coupling 10. However, after that, the coupling portion 14B is elastically deformed under a spring constant specific to its material, so that the coupling 10 is deformed inwardly. The rigidity of 10 is due to the high 1st shift as expected.

Here, such torsional spring characteristics of the elastic camp ring 10 are mainly brought about based on the torsional spring characteristics of the synthetic resin hard elastic plate 14 which has a much higher spring constant than the protective member 12. Therefore, this torsion spring characteristic depends on the size of the gap 20 between the shaft mounting holes 16 and 18 and the connecting portion 1.
It can be changed arbitrarily by changing the dimensions of 4B. However, the shaft mounting hole 1 is not provided with the cavity 20.
6. If a gap-free connection = -ts 14 B is provided between 6.18 and 18, the torsion spring characteristics become highly rigid from the initial twisting stage, and the desired torsion spring characteristics cannot be obtained.

On the other hand, when the elastic coupling 10 is deformed as described above, the rubber elastic body 2OA embedded in the cavity 20 applies a force in the direction of restoring the arm member 14B to adjust the torsional spring characteristics. In addition, based on the stress distribution thereon, stress concentration on the cavity wall is alleviated, and furthermore, when the torsional torque from the coupling 10 is removed, the return of the connecting portion 14B to its original shape is prevented and the This sufficiently prevents the connecting portion 14B from becoming sagging.

Next, FIGS. 5 and 6 show a second embodiment of the present invention, in which a connecting portion 14C having a shape different from that of the previous embodiment is used. This connecting portion 14C is connected to the adjacent shaft mounting hole 16.18.
It is bifurcated into two by a gap 24 located across a straight line connecting the two, and a rubber elastic body 24A
has been embedded and fixed.

Therefore, also in this embodiment, the hard elastic plate 1
4 can be appropriately reduced by the void portion 24 to obtain desired torsion spring characteristics.

Also, the comb elastic body 24A here is also
In the same way as described above, the torsion spring characteristics of the coupling 10 are adjusted, and the rigid elastic plate 1 is adjusted by the rotational torque etc. during use.
The stress concentration on the hard elastic plate 14 is alleviated, and restoring force is imparted to the hard elastic plate 14 to improve its durability.

Next, FIG. 7.8 shows a third embodiment of the present invention.

In this embodiment, a plurality of small holes 26 are provided in the connecting portion 140 of the hard elastic plate 14 to form a cavity, and each small hole 2
A rubber elastic body is embedded in 6. Here, each small hole 26 is bored parallel to the axis of the coupling body 12 between adjacent shaft mounting holes 16, 18, and some of these small holes 26 (see FIG. In this case, three small holes among the small holes between adjacent shaft mounting holes 16.18 are arranged on a straight line connecting the axes of adjacent shaft mounting holes 16.18.

Also in the elastic coupling configured in this manner, as in each of the embodiments described above, the rigidity of the hard elastic plate 14 at the initial stage of whirring can be appropriately reduced by the small holes 26 to obtain desired torsional spring characteristics. , and the rubber elastic body 26A filled into the small hole 26 can bring about the same effect as in the previous embodiment.

In addition, in this third embodiment, since the contact area between the connecting portion 14[1 and the protective member 12 is large, the adhesive strength between the two can be increased.

Next, FIG. 9.10 shows a fourth embodiment of the present invention, and the hard elastic plate 14 in this embodiment has a planar shape that is almost the same as that of the second embodiment shown in FIG. However, as shown in FIG. 9, a through hole 28 is further bored in the connecting portion 14E. This through hole 28 passes through the connecting portion 148 in the radial direction of the coupling 10, and the connecting portion 14B
This further reduces the rigidity of the

Therefore, in this embodiment, it is possible to obtain torsion spring characteristics with a greater degree of twist than the spring characteristics of the second embodiment.

The elastic couplings 10 described in each of the above embodiments are all vulcanized and molded in the same manner as described in the prior art, that is, with the hard elastic plate 14 made of synthetic resin sandwiched between two sheets of unvulcanized rubber. Of course, it can be manufactured by pressurizing and heating with a vulcanization mold, but when both the protective member 12 and the rubber elastic body in the cavity are made of the same kind of soft plastic, injection molding Since it can be molded extremely easily using a machine, processing is significantly simpler and costs can be reduced.Also, compared to vulcanization molding, no burr is generated around the periphery, so burr removal work can be omitted. is possible.

In addition, in the above explanation, the peripheral portion L4A does not necessarily correspond to the shaft mounting hole 16.
．． It is not necessary to surround the entire circumference of the shaft 18, and it is also possible to provide a notch or the like in the middle as long as it is large enough to ensure the strength of the mounting portion of the drive shaft or driven shaft.

In addition, according to the illustrated example, each elastic coupling is constructed by embedding a hard elastic plate made of synthetic resin in the protective member, but when using it, both the drive shaft and the driven shaft must be , it will be connected to a hard elastic plate made of synthetic resin that has a spring constant much higher than the spring constant of the protective member, and the torsional spring characteristics of the coupling will be directly related to the torsional spring characteristics of the hard elastic plate made of synthetic resin. Therefore, if the rigid elastic plate made of synthetic resin can be sufficiently protected, even if the protective member is omitted from the example coupling shown in the figure, the torsional spring characteristics will be almost the same as that of the elastic coupling. Of course, it is possible to provide the desired torsional spring characteristics.

As explained above, the elastic coupling according to the present invention is significantly easier to manufacture and more convenient to handle than conventional ones, and the torsion spring characteristics can be adjusted between the connecting part and the gap part. , arbitrary torsion spring characteristics can be reliably obtained, and the work of inserting the collar into the shaft mounting hole becomes extremely smooth.

Also, here, since the void is filled with rubber elastic material,
It is possible to set the torsional spring characteristics of the coupling to a desired value, relieve stress concentration on the hard elastic plate, provide resilience against fatigue, and improve durability.

[Brief explanation of drawings]

FIG. 1 is an axis-perpendicular cross-sectional view showing a first embodiment of the elastic coupling according to the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG.
4 is a diagram showing the torsion spring characteristics of the first embodiment; FIG. 5 is a sectional view taken at right angles to the axis of the second embodiment of the present invention; FIG. 5 is a sectional view taken along the line VI-VI, FIG. 7 is an axis-perpendicular sectional view showing the third embodiment of the present invention, FIG. 8 is a sectional view taken along the line ■-■ in FIG. 7, and FIG. This figure is an axis-perpendicular sectional view showing a fourth embodiment of the present invention, and FIG. 10 is a sectional view taken along the line X--X in FIG. 9. 10 Elastic coupling 12 Protective member 14
Synthetic resin hard elastic board

Claims (1)

[Claims] 1. In an elastic coupling mainly composed of a synthetic resin hard elastic plate having a plurality of shaft mounting holes around a center line, the center line An elastic coupling in which a gap is provided to facilitate initial deformation of a hard elastic plate made of synthetic resin in response to torsional torque acting around the plate, and a rubber elastic body is embedded in the gap.