JPH0711292B2 - 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 7, there is known a coupling which is composed of a board 100 having a central axis P1 and a fixture group 200 held by the board 100. Fixture group 2
00 is a first mounting tool 210 and a second mounting tool 2 which are arranged alternately.
It consists of 20 and. The board 100 has two adjacent fixtures 210 and 220.
And a reinforcing band 110 in which a reinforcing thread is wound and connected in a loop shape,
It is formed of a reinforcing band 110 and a rubber body 120 that embeds and holds the fixtures 210 and 220. When using the coupling, the first fixture 210 is attached to one shaft with bolts or the like, and the second fixture 220 is attached to the other shaft with bolts or the like, whereby the coupling is interposed between the shafts. . Torque is transmitted between the shafts via a coupling.

[Problems to be Solved by the Invention]

In the above coupling, the vibration is damped by the rubber body 120 when the vibration is transmitted between the shafts. But fixture 2
Variation in spring characteristics of the coupling due to low dimensional stability of the reinforcing thread forming the reinforcing band 110 wound around 10, 220, deformation of the reinforcing thread during vulcanization of the rubber body 120, etc. There is.

Therefore, in recent years, the present applicant has found that a reinforcing belt that causes variations
As a method that does not use 110, we are proceeding with the development of a rigid coupling that is made of a rigid material such as resin or metal. As shown in FIG. 8, this coupling includes a resin rigid body 300 having through holes 310 arranged at intervals in the circumferential direction of the central axis P4, and every other through hole 31 of the rigid body 300.
A first mounting member 410 arranged at 0, a second mounting member 420 arranged at every other through hole 310, an inner peripheral surface defining each through hole 310, and each mounting member 410, 420. And an elastic sleeve 500 made of rubber attached to the. As shown in FIG. 8, the elastic sleeve 500 has a right cylindrical shape, and the inner diameter and the outer diameter are the same over the axial length.

The present invention has been made as a part of the above-described development, and its object is to prevent the elastic sleeve from coming off from a rigid body, and further to provide a value of {(spring constant in rotational direction) / (spring constant in axial direction)}. To provide a coupling which is advantageous for making the value greater than 1.

[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 body having through holes, a first attachment arranged in every other through hole of the rigid body and attached to one shaft, and a second attachment arranged in every other through hole and attached to the other shaft And an elastic sleeve that is interposed between the inner peripheral surface that defines each through-hole of the rigid body and each mounting tool and that is bonded to the inner peripheral surface and the mounting tool. The inner peripheral surface defining each through hole is formed such that the inner diameter of the central portion in the axial direction is different from the inner diameters of both end portions, and the outer peripheral surface of the elastic sleeve is shaped symmetrically with the inner peripheral surface of the through hole. It is what

A rigid body has a central axis. The rigid body can be made of hard resin or metal. 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 metal can be steel or aluminum alloy.

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 sleeve is interposed between the inner peripheral surface that defines each through hole of the rigid body and each mounting member, and is bonded to the inner peripheral surface and the mounting member. The elastic sleeve is elastically deformable,
Generally made of rubber. The thickness and hardness of the elastic sleeve can be appropriately selected depending on the type of coupling.

In the coupling of the present invention, the inner peripheral surface that defines each through-hole of the rigid body is formed in a shape in which the inner diameter of the central portion in the axial direction is different from the inner diameter of both end portions (for example, a barrel shape or a wrapping shape). The value of (inner diameter of central portion in axial direction / inner diameter of both end portions) on the inner peripheral surface of the through hole can be appropriately selected. The outer peripheral surface of the elastic sleeve is symmetric with the inner peripheral surface of the through hole. Therefore, if the axial center part of the inner peripheral surface of the through hole is concave, the outer peripheral surface of the elastic sleeve has a convex shape symmetrical, and if the central part of the inner peripheral surface of the through hole is convex in the axial direction, it is elastic. The outer peripheral surface of the sleeve has a concave shape symmetrical to the mold.

[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 the two shafts. Here, 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 radial direction, or a combination of these.This relative displacement is caused by elastic deformation of the elastic sleeve. Permissible.

When the vibration is transmitted between the shafts, the elastic sleeve damps the vibration.

Further, in the coupling of the present invention, the inner peripheral surface defining each of the through holes of the rigid body is formed in the shape of a barrel or in the shape of a bundle, and the outer peripheral surface of the elastic sleeve is symmetric with the inner peripheral surface of the through hole. Therefore, the engaging force between the elastic sleeve and the rigid body in the axial direction increases. Further, when torque is transmitted from one shaft to the other shaft, the elastic sleeve is pulled and compressed in the direction perpendicular to the shaft. The thickness of the elastic sleeve in the direction perpendicular to the axis has a thick portion and a thin portion, and the spring constant becomes high in the thin portion.
Therefore, the spring constant in the circumferential direction of the coupling of the present invention is high. On the other hand, the axial spring constant of the coupling is generally small because it is determined by the spring constant during the shear deformation of the sleeve. Therefore, in the coupling of the present invention, the ratio of (spring constant in rotational direction) / (spring constant in axial direction) becomes larger than 1.

〔Example〕

Hereinafter, the coupling of the present invention will be described according to the first embodiment shown in FIGS. A longitudinal sectional view of the coupling of this embodiment is shown in FIG. 1, and a plan view thereof is shown in FIG.
This coupling is composed of a rigid body 1 having a central axis P2, a fixture group 2 and an elastic sleeve 3.

The rigid body 1 is made of hard nylon resin reinforced with glass fibers and is formed into a disc shape. A total of four through holes 1a are formed at 90-degree intervals in the circumferential direction of the central axis P2 of the rigid body 1. The through hole 1a penetrates in a direction substantially parallel to the central axis P2.
Here, the inner peripheral surface that defines each through-hole 1a has a cross section that is close to the central axis P2, and is formed in a shape in which the inner diameter of the central portion in the axial direction is larger than the inner diameters of both end portions, that is, a beer barrel shape. Therefore, both ends in the axial direction are projecting parts that project inward of the through hole 1a.
It is said to be 1c.

The fixture group 2 includes a first metal fixture 20 arranged in every other through hole 1a and a second metal fixture 21 arranged in every other through hole 1a. Become. As shown in FIG. 2, the axis of the first fixture 20 and the axis of the second fixture 21 are arranged along a circle S centered on the central axis P2.
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 formed of rubber substantially coaxially with the fixtures 20 and 21. The elastic sleeve 3 has the through holes of the rigid body 1.
It is interposed between the inner peripheral surface defining 1a and the outer peripheral surfaces of the respective mounting tools 20, 21 and is bonded to the inner peripheral surface and the mounting tools 20, 21. The outer peripheral surface of the elastic sleeve 3 is symmetrical with the inner peripheral surface of the through hole 1a. Therefore, as is apparent from FIG. 1, both end portions of the elastic sleeve 3 in the axial direction are thin wall portions.

In order to manufacture the above coupling, the elastic sleeve 3 is vulcanized and adhered to the outer peripheral surfaces of the respective fittings 20 and 21, and the outer surface of the elastic sleeve 3 is further coated with an adhesive.
The fixture 20 and the fixture 21 having are arranged in a predetermined portion of the cavity of the molding die, and in that state, a molten nylon resin containing glass fiber is injected into the cavity by an injection molding machine at an injection pressure of 300 to 1000 kg / cm ² . After injection, the elastic sleeve 3 is wrapped in a nylon resin melt, and the melt is solidified while maintaining the pressure to form the rigid body 1. 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 third
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 connecting portion 70 of the one shaft 7 and the insertion hole 20 of the first fixture 20
The nut 74 of the bolt 73 passed through a is tightened to connect the first fixture 20 to the shaft 7, and the bolt 83 passed through the hole of the connecting portion 80 of the other shaft 8 and the insertion hole 21a of the second fixture 21. The nut 84 is fastened to the shaft 8 to connect the second fixture 21 to the shaft 8, thereby connecting the coupling to both shafts. In this state, when one of the shafts 7 and 8 is rotationally driven as the drive side shaft, the coupling also rotates and the torque is transmitted to the driven side shaft via the coupling. At this time, a large force may act in the direction of pulling out the elastic sleeve 3 from the through hole 1a. In this regard, in this embodiment, as described above, the inner peripheral surface that defines each through hole 1a of the rigid body 1 is formed in a barrel shape, and the outer peripheral surface of the elastic sleeve 3 is symmetrical with the inner peripheral surface of the through hole 1a. . Therefore, the engaging force between the elastic sleeve 3 and the rigid body 1 in the axial direction increases, and the elastic sleeve 3 is prevented from coming out of the rigid body 1. Therefore, when the force acting in the axial direction is within a predetermined range, it is possible to omit the adhesive layer between the outer peripheral surface of the elastic sleeve 3 and the inner peripheral surface of the through hole 1a of the rigid body 1. Of course, interposing an adhesive layer is more advantageous for preventing the elastic sleeve 3 from coming off.

As the coupling rotates, the fixture 20 and the fixture 21 rotate in the circumferential direction. At this time, the elastic sleeve 3 receives a compression / tensile load in its thickness direction. Therefore, the spring constant k1 of the coupling in the rotation direction is basically determined by the spring constant of the elastic sleeve 3 in the compression / tension direction. When the shafts 7 and 8 are displaced relative to each other in the axial direction, the elastic sleeve 3 receives a shear load. Therefore, the spring constant k2 of the coupling in the axial direction is determined by the spring constant of the elastic sleeve 3 in the shearing direction. Further, in this embodiment, when the coupling rotates, the protrusions formed at both ends of the inner peripheral surface of the through hole 1a.
Since 1c functions as a stopper in the rotation direction,
The spring constant k1 in the rotational direction can be increased while keeping the spring constant k2 in the axial direction small. Therefore, the value of (k1 / k2) is a coupling having a structure in which the elastic sleeve 500 has a right cylindrical shape as shown in FIG. Big compared to.

In this way, the spring constant k1 in the rotation direction can be increased and the spring characteristic is rigid in the rotation direction, so that the coupling, and thus the driven shaft, can follow well during torque transmission.

Further, the coupling of the present embodiment can increase the spring constant k1 in the rotational direction while reducing the spring constant k2 in the axial direction, 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 undergo relative displacement in the circumferential direction of the coupling, the axial direction, the radial direction, or a combination thereof, but this relative displacement is allowed by elastic deformation of the elastic sleeve 3. Therefore, the degree of freedom of relative displacement of the shafts 7, 8 and the fixtures 20, 21 can be secured.

A second embodiment of the coupling of the present invention is shown in FIG. The coupling according to the second embodiment has basically the same configuration as that of the first embodiment. However, in the second embodiment, the inner peripheral surface that defines the through hole 1a of the rigid body 1 in such a cross section as to the central axis P2 of the rigid body 1 has a shape in which the inner diameter of the central portion in the axial direction is smaller than the inner diameters of both ends, That is, it is formed in a wrapping shape, and therefore, the central portion in the axial direction on the inner peripheral surface defining the through hole 1a has a protruding portion.
It is said to be 1e. The outer peripheral surface of the elastic sleeve 3 is symmetric with respect to it. Therefore, in this embodiment, the slip-out resistance of the elastic sleeve 3 can be improved. Further, since the protruding portion 1e functions as a stopper in the rotation direction when the coupling rotates, the value of the spring constant k1 in the rotation direction can be increased as in the case of the first embodiment, and thus (k1 / k2) Value is 1
Get bigger. Further, as shown in FIG. 4, the protrusion 1e is formed at the axial center of the through hole 1a, so
It is advantageous to increase the swingability of 20 and 21.

By the way, the spring characteristics of the couplings having the structures shown in the first and second embodiments are schematically shown in FIG. In FIG. 9, the horizontal axis represents the spring constant k1 in the rotational direction, and the vertical axis represents the spring constant k2 in the axial direction. Here, the characteristic line A is a characteristic diagram of the coupling having the structure shown in the first embodiment, and the characteristic line B is
Shows the characteristic line of the coupling having the structure shown in the second embodiment, and characteristic line C shows the characteristic line of the coupling having the structure shown in FIG.

In the coupling having the structure shown in the first embodiment, as shown by the characteristic line A in FIG. 9, even if the spring constant k1 in the rotational direction is increased, the rate of increase of the spring constant k2 in the axial direction can be lowered. The same applies to the coupling having the structure shown in the second embodiment as shown by the characteristic line B in FIG. On the other hand, in the coupling having the structure shown in FIG. 8, when the spring constant k1 in the rotational direction is increased, the rate of increase of the spring constant k2 in the axial direction is high, as indicated by the characteristic line C in FIG.

In the above-described first embodiment, when manufacturing the coupling, the rigid bodies 1 are formed by wrapping around the fittings 20 and 21 having the elastic sleeve 3 with resin as described above. However, for example, after the rigid body 1 made of resin is formed, the rigid body 1 and the fixtures 20 and 21 are arranged at predetermined positions in the cavity of the molding die, and the cavity portion corresponding to the elastic sleeve 3 is not yet applied. Alternatively, the rubber sleeve may be loaded and solidified to form the elastic sleeve 3, and the elastic sleeve 3 may be integrally bonded.

[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 connected to the steering shaft 92 and the intermediate shaft 93. It is intervening. When the steering wheel 90 is operated, the torque is transmitted from the steering shaft 92 to the driven intermediate shaft 93 via 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 constant in its 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 inner peripheral surface that defines each through hole of the rigid body is formed in a shape in which the inner diameter of the central portion in the axial direction is different from the inner diameters of both end portions, and the outer peripheral surface of the elastic sleeve is formed of the through hole. Form-symmetric with the inner surface. Therefore, the engaging force between the elastic sleeve and the rigid body is increased, which is advantageous in suppressing the elastic sleeve from coming out of the rigid body.

Also, if the above-mentioned structure is adopted, the spring constant in the rotational direction can be increased while the spring constant in the axial direction of the coupling is kept small, so good followability and good torque when torque is transmitted between the shafts. It is advantageous to obtain transmissibility and to damp vibration input in the axial direction.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention, FIG. 1 is a sectional view, FIG. 2 is a plan view, and FIG. 3 is a state in which a coupling is interposed between shafts. FIG. FIG. 4 is a sectional view showing a second embodiment of the present invention. FIG. 5 is a perspective view showing an application example. 6 and 7 show the prior art, FIG. 6 is a sectional view, and FIG. 7 is a plan view. FIG. 8 is a plan view of a coupling as a prior art. 9th
The figure is a graph schematically showing the spring characteristics. 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, a first attachment arranged in every other through hole of the rigid body and attached to one shaft, and a second attachment arranged in another every other through hole and attached to the other shaft And an elastic sleeve that is interposed between the inner peripheral surface that defines each through hole of the rigid body and each of the mounting tools and that is bonded to the inner peripheral surface and the mounting tool. The inner peripheral surface defining each through hole of the rigid body is formed in a shape in which the inner diameter of the central portion in the axial direction is different from the inner diameters of both end portions, and the outer peripheral surface of the elastic sleeve is the inner peripheral surface of the through hole. Coupling characterized by having a type symmetry.