JPH0768979B2 - Coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coupling. This coupling can be applied to, for example, a flat plate-shaped coupling interposed between a steering shaft of an automobile and a gear box.

[Conventional technology]

As the coupling, as shown in FIGS. 6 and 5, there is known a coupling constituted by a board 100 having a central axis P1 and a fixture group 200 held by the board 100. Fixture group 2
00 is the first that is arranged at intervals in the circumferential direction of the central axis P1.
It consists of a fixture 210 and a second fixture 220. Board 100
Is a reinforcing band 110 in which a reinforcing thread is wound in a loop shape and connected to adjacent fittings 210 and 220, a reinforcing band 110, and a fitting 21.
It is formed of a rubber body 120 that embeds and holds 0 and 220. When using the coupling, the first fixture 210 is attached to one shaft with bolts, etc., and the second fixture 220 is attached to the other shaft with bolts, etc., so that the coupling is interposed between both shafts. Let Then, torque transmission between both shafts is performed via a coupling.

[Problems to be Solved by the Invention]

The above-mentioned coupling has an advantage that the vibration is damped by the rubber body 120 when the vibration is transmitted between the shafts. However, due to the low dimensional stability of the reinforcing thread forming the reinforcing band 110 wound around the fixtures 210 and 220, the deformation of the reinforcing thread during vulcanization of the rubber body, etc., the spring characteristics of the coupling may be reduced. It may vary.

Therefore, in recent years, the present applicant is developing a rigid body type coupling formed of a material having rigidity such as resin or metal as a method that does not use a reinforcing band that causes variations. This coupling, as shown in FIG.
An even number of through holes 310 are arranged at intervals in the circumferential direction of P2.
A rigid body (300), a first fitting (410) arranged in every other through hole (310) of the rigid body (300), a second fitting (420) arranged in every other through hole (310), and each through hole (310). And an elastic sleeve 500 bonded to each of the fixtures 410 and 420. The elastic sleeve 500 has an inner diameter of the same size along its axial length, and an outer diameter of the same size along its axial length.

In this coupling, in order to improve the vibration damping property in the axial direction, it is preferable to form the elastic sleeve 500 with a soft rubber material to reduce the spring constant in the axial direction. In this case, the spring in the rotational direction of the coupling is used. The constant also becomes small, the followability in the rotational direction of the coupling deteriorates, and there arises a problem that good torque transmissibility cannot be obtained.

The present invention has been made in view of the above circumstances, and an object thereof is a cup having a small spring constant in the axial direction and a high vibration damping property while maintaining a high followability in the rotation direction and thus a torque transmissibility. To provide a ring.

[Means for Solving the Problems]

The coupling of the present invention is interposed between one shaft and the other shaft, and an even number of penetrating in a direction substantially parallel to the central axis arranged at intervals in the circumferential direction of the central axis. A rigid resin-based rigid body having through-holes; a first fixture arranged in every other through-hole of the rigid body and having a cylindrical outer peripheral surface attached to one of the shafts; A fixture group consisting of a second fixture that is arranged in the through hole and is attached to the other side and has a cylindrical outer peripheral surface, and is interposed between the inner peripheral surface that defines each through hole of the rigid body and each fixture. , The inner peripheral surface and the elastic portion attached to the fixture, the through-hole of the rigid body has a short diameter in the rotation direction around the center axis of the rigid body, and the normal direction passing through the center axis. Has an elliptical shape with the longest diameter in, and the elastic part is located in the direction of rotation about the center axis of the rigid body. The spring constant is larger than the spring constant in the normal direction passing through the center axis.

A rigid body has a central axis. The rigid body is made of hard resin. The resin can be appropriately selected from thermoplastic resins and thermosetting resins according to the type of coupling, for example, nylon resin, epoxy resin, etc. can be adopted, and those containing a reinforcing material such as glass fiber can also be adopted. The through hole of the rigid body has an elliptical shape with a short diameter in the rotation direction around the center axis of the rigid body and a long diameter in the normal direction (radial direction) passing through the center axis. The oval shape also includes an elliptical shape.

The first fixture and the second fixture that make up the fixture group are
For example, it may have a tubular shape into which the bolt can be inserted.

The elastic portion is interposed between the inner peripheral surface that defines each through hole of the rigid body and each mounting member, is bonded to the inner peripheral surface and the mounting member, and can be formed into a sleeve shape. The elastic portion is elastically deformable. The thickness, material, hardness, etc. of the elastic portion can be appropriately selected according to the type of coupling.

In the coupling of the present invention, when the spring constant in the rotation direction around the center axis of the rigid body is k1 and the spring constant in the normal direction passing through the center axis is k2, (k1
The value of / k2) is set to be larger than 1.

[Action]

The operation of the coupling of the present invention will be described along with its method of use. At the time of use, the first attachment is attached to one shaft and the second attachment is attached to the other shaft as in the conventional case.
This places the coupling between one shaft and the other. When the driving side of one shaft and the other shaft is rotationally driven, the torque is transmitted to the driven side via the coupling. During torque transmission, the shaft and each fixture may be displaced relative to each other in the circumferential direction of the coupling, the axial direction, the normal line (radial) direction, or the direction in which these are combined. Allowed by elastic deformation of. Further, when the vibration is transmitted between the shafts, the vibration is damped by the elastic portion.

In addition, in the coupling of the present invention, the value of {(spring constant in the rotating direction) / (spring constant in the normal direction)} is 1
It is a larger structure. Therefore, the coupling is soft in the normal direction and has a rigid spring characteristic in the rotational direction. Further, the shear spring constant in the axial direction becomes smaller as the spring constant in the normal direction becomes smaller. Therefore, it has a rigid spring characteristic in the rotation direction and a soft spring characteristic in the axial direction.

〔Example〕

The coupling of the present invention will be described below with reference to the first embodiment shown in FIGS. 1 and 2. A plan view in which a part of the coupling of this embodiment is shown in section is shown in FIG. 1, and a sectional view is shown in FIG. This coupling includes a rigid body 1 having a central axis P3, a fixture group 2, and an elastic sleeve 3 as an elastic portion.
It consists of and.

The rigid body 1 is made of hard nylon resin reinforced with glass fibers and is formed into a disc shape. In the circumferential direction of the central axis P3 of the rigid body 1, a total of four through holes 1a are formed at 90 degree intervals.
The through hole 1a penetrates in a direction substantially parallel to the central axis P3. The through hole 1a has an elliptical shape in plan view having a major axis and a minor axis, and the major axis is a normal line (radius) of the coupling.
It matches the direction.

The fixture group 2 includes a metal first fixture 20 arranged in every other through hole 1a of the rigid body 1, and another every other through hole 1a.
And a second metal fixture 21 disposed on the. The first fixture 20 has a tubular shape having an insertion hole 20a. The second fixture 21 has a tubular shape having an insertion hole 21a.

The elastic sleeve 3 is interposed between the inner peripheral surface that defines the through holes 1a of the rigid body 1 and the respective mounting tools 20 and 21, and is bonded to the inner peripheral surface and the mounting tools 20 and 21. Since the elastic sleeve 3 is loaded in the elliptical through hole 1a, its planar shape is an elliptical shape having a major axis and a minor axis, the major axis of which is aligned in the radial direction of the coupling, and the minor axis of which is Aligned in the circumferential direction of the coupling.

Therefore, if the thickness of the elastic sleeve 3 in the direction of the circle S centering on the central axis P3 of the rigid body 1 is t1 and the thickness of the elastic sleeve 3 in the radial direction of the coupling is t2, then t1
It is set to <t2.

In order to manufacture the above coupling, the elastic sleeve 3 is vulcanized and adhered to the outer peripheral surfaces of the fixtures 20 and 21, and then the fixtures 20 and 21.
21. With the adhesive applied to the elastic sleeve 3, the fixtures 20 and 21 having the elastic sleeve 3 are placed in a predetermined portion of the cavity of the molding die, and in that state, the melted nylon resin containing glass fiber is placed. An injection molding machine injects into the cavity at an injection pressure of 300 to 1000 kg / cm ² , wraps the elastic sleeve 3 and the fixtures 20 and 21 with a melt of nylon resin, and solidifies the melt while maintaining pressure. Since the elastic sleeve 3 is pre-compressed by the injection pressure and the shrinkage of the nylon resin due to the solidification, it is advantageous for improving the durability and extending the life of the elastic sleeve 3.

When using the coupling of this embodiment, the second
As shown in the figure, one shaft 7 having a bifurcated connecting portion 70,
And the other shaft 8 having a bifurcated connection 80, and
The hole of the continuous part of one shaft 7, the insertion hole 20a of the first fixture 20
Tighten the nut 74 to the bolt 73 that passed through the
While connecting the fixture 20, the nut 84 is fastened to the bolt 83 passing through the hole of the connecting portion of the other shaft 8 and the communication hole 21a of the second fixture 21 to connect the second fixture 21 to the other shaft 8. Then
This connects the coupling to both shafts.

In this state, when either one of the shafts 7 and 8 is rotationally driven as the drive side shaft, the torque is transmitted to the driven side shaft via the coupling. At this time, in this embodiment,
The fixtures 20 and 21 rotate. Therefore, the elastic sleeve 3 receives a compressive / tensile load in its circumferential direction. Therefore, the spring constant k1 in the rotation direction of the coupling is basically determined by the spring constant in the compression / pulling direction in the circumferential direction (shorter diameter direction) of the elastic sleeve 3. Further, the shafts 7 and 8 may be displaced relative to each other in the direction perpendicular to the axis during torque transmission. At this time, the elastic sleeve 3 receives a compressive / tensile load in the normal direction. Therefore, the spring constant in the normal direction of the coupling
k2 is basically the normal direction of the elastic sleeve 3 (longitudinal direction)
It is determined by the spring constant at. When the thickness of the rubber material forming the elastic sleeve changes, the spring constant in the compression / tension direction changes greatly. In this embodiment, since the elastic sleeve 3 has an elliptical shape and is set to satisfy the relationship of t1 <t2, the spring constant k1 becomes large and the rigidity required as a coupling is increased in the direction in which the rotational torque is directly transmitted by pulling / compressing. It has spring characteristics. Therefore, the value of (k1 / k2) becomes larger than 1.

Further, the shear spring constant in the axial direction becomes smaller as the spring constant in the normal direction becomes smaller. Therefore, it has a rigid spring characteristic in the rotation direction and a soft spring characteristic in the axial direction.

In this way, because of the rigid spring characteristic in the rotation direction, the shaft 7,
When torque is transmitted between the gears 8, the coupling, and thus the driven shaft, follows well, and good torque transmission is obtained. Further, although the coupling of this embodiment has a rigid spring characteristic in the rotation direction, the spring characteristics in the normal direction and the axial direction are soft, so that the vibration input to the coupling in the axial direction can be effectively reduced. .

When transmitting torque, the shafts 7 and 8 and the fixtures 20 and 21
May be relatively displaced, but this relative displacement is allowed by elastic deformation of the elastic sleeve 3. Therefore the axes 7, 8,
It is possible to secure the degree of freedom of displacement of the fixtures 20 and 21.

[Other Examples]

In the first embodiment described above, when the coupling is manufactured, the rigid bodies 1 are formed by wrapping the resin around the fittings 20 and 21 having the elastic sleeve 3 as described above. Not limited to this, for example, after forming the rigid body 1 made of resin, the rigid body 1 and the fixtures 20 and 21 are arranged at predetermined positions in the cavity of the molding die, and the elastic sleeve 3
It is also possible to load unvulcanized rubber into the cavity portion corresponding to and solidify it, thereby forming the elastic sleeve 3 and thus integrally binding.

A second embodiment of the coupling of the present invention is shown in FIG. The coupling according to the second embodiment is basically the same as that of the first embodiment, and the value of (k1 / k2) is set to be larger than 1. However, in the second embodiment, the space portions 33 are formed on both sides of the fixtures 20 and 21 in the major axis direction of each elastic sleeve 3. Therefore, the value of the spring constant k2 can be further reduced while keeping the value of the spring constant k1 large, so that the value of (k1 / k2) can be set larger than that of the first embodiment. Therefore, the spring characteristics can be softened in the normal direction and the axial direction while ensuring the rigid spring characteristics in the rotation direction of the coupling, which is advantageous in reducing the vibration input in the normal direction. Further, the shear spring constant in the axial direction becomes smaller as the spring constant in the normal direction becomes smaller. Therefore, it has a rigid spring characteristic in the rotation direction and a soft spring characteristic in the axial direction. Further fixture 2
Since the space portions 33 are formed on both sides of 0 and 21, the allowance for the fixtures 20 and 21 to move in the radial direction of the coupling increases.

[Application example]

An example of applying the above-mentioned coupling is shown in FIG. In this example, the coupling is applied to a steering system of an automobile. 90 is a steering wheel, 91 is a steering column, 92 is a steering shaft, 93 is an intermediate shaft, 94 is a steering gear box, and the rigid body 1 of this coupling is interposed between the shafts 92 and 93. And the steering wheel 90
When is operated, the torque is changed to steering shaft 92.
Is transmitted to the driven side from the rigid body 1 of the coupling. At this time, since the coupling has a rigid spring characteristic in the rotational direction, good torque transmission and steering stability can be obtained. Further, since the coupling has a soft spring characteristic in the axial direction, it is possible to damp vibrations input in the axial direction.

〔The invention's effect〕

According to the coupling of the present invention, the elastic portion has {(spring constant in the rotating direction) / (spring constant in the normal direction)}.
Since the value of is larger than 1, the coupling has a soft spring characteristic in the normal direction and a rigid spring characteristic in the rotation direction. Since it has a rigid spring characteristic in the rotation direction, when the torque is transmitted from the drive side of one shaft and the other shaft to the driven side, it has good followability of the driven side shaft and good torque transmission. Is obtained.

Further, since the coupling of the present invention has a soft spring characteristic in the normal direction and the axial direction, it is advantageous for damping the vibration input in the axis-perpendicular direction and the axial direction.

[Brief description of drawings]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a plan view showing a part in section, and FIG. 2 is a longitudinal sectional view in a state of being interposed between shafts. is there. FIG. 3 shows the second aspect of the present invention.
It is a top view which shows an Example and shows a part in section. FIG. 4 is a perspective view showing an application example, FIGS. 5 and 6 show a prior art, FIG. 5 is a sectional view, and FIG. 6 is a plan view. FIG. 7 is a plan view of a coupling as a prior art. In the figure, 1 is a rigid body, 1a is a through hole, 2 is a fixture group, and 3 is an elastic sleeve.

Claims (1)

[Claims] 1. An even number of penetratings which are interposed between one shaft and the other shaft and which are arranged at intervals in the circumferential direction of the central shaft core and which penetrate in a direction substantially parallel to the central shaft core. A rigid body having a hole as a base material made of a hard resin; a first fixture arranged in every other through hole of the rigid body and attached to one shaft and having a cylindrical outer peripheral surface;
A fixture group including a second fixture having a cylindrical outer peripheral surface which is attached to the other side and is disposed in every other through hole, an inner peripheral surface defining each of the through holes of the rigid body, and each of the fixtures. Is formed between the inner peripheral surface and an elastic portion bonded to the fixture, and the through hole of the rigid body has a short diameter in the rotation direction about the central axis of the rigid body. And has an elliptical shape having a major axis in a direction normal to the central axis, and the elastic portion passes through the central axis with a spring constant in a rotation direction around the central axis of the rigid body. A coupling characterized in that it has a larger spring constant in the normal direction.