JPH04160227A - Coupling - Google Patents

Abstract

PURPOSE:To obtain good follow ability and torque transmit ability to reduce vibration in the axial direction by forming the inner peripheral surfaces for dividing respective penetration holes of a rigid body into forms different in their diameters in the center parts in comparison with those on both end parts and forming the outer peripheral surfaces of elastic sleeves into mold symmetry with the inner peripheral surfaces of the penetration holes. CONSTITUTION:A rigid body 1 is formed of hard nylon resin reinforced with glass fiber in like a circular plate, the sum total four penetration holes 1a are formed in peripheral direction of the center axial line P2 thereof at 90 deg. intervals, and the penetration holes 1a are guided in nearly parallel direction with the center axial line P2. Here, the inner peripheral surfaces for dividing respective penetration holes 1a are formed into forms larger in the inner diameter at the central part in the axial direction, namely into like a beer barrel, in a section along the center axial line P2. Therefore, both end parts in the axial line are made to be projecting parts 1c projecting inward the diameter of the penetration hole 1a. Moreover, the outer peripheral surface of an elastic sleeve 3 is placed in a mold symmetry with the inner peripheral surface of the penetration hole 1a. Therefore, both end parts in the axial direction of the elastic sleeve 3 are made in small thickness parts.

Description

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

[Conventional technology]

As a coupling, as shown in FIGS. 6 and 7, a coupling is known that is composed of a disc body 100 having a central axis P1 and a group of fixtures 200 held by the disc body 100.

The fixture group 200 has first fixtures 21 arranged alternately.
0 and the second attachment consists of a fixture 220. The disk body 100 includes a reinforcing band 110 formed by winding a reinforcing thread in a loop around adjacent fittings 210 and 220, and a rubber body 120 that embeds and holds the reinforcing band 110 and the fitting fittings 210 and 22σ. It is formed of. When using the coupling, the first installation involves attaching the fixture 210 to one shaft with bolts, etc., and the second
For attachment, the tool 220 is attached to the other shaft with bolts or the like, thereby interposing the coupling between the shafts. Torque transmission between the shafts takes place via couplings.

[Problem to be solved by the invention]

In the above-described coupling, when vibration is transmitted between the shafts, the rubber body 120 damps the vibration.

However, the installation is done with the reinforcing band 11 wrapped around the fittings 210 and 220.
Low dimensional stability of reinforcing thread forming 0, rubber body 120
Due to deformation of the reinforcing yarn during vulcanization, etc., the spring characteristics of the rolling tube ring may vary.

Therefore, in recent years, the present applicant has been developing a rigid coupling made of a rigid material such as resin or metal as a method that does not use the reinforcing band 110 that causes variations. As shown in FIG. 8, this coupling has through holes 3 arranged at intervals in the circumferential direction of the central axis P4.
10, a first mounting member 410 disposed in every other through hole 310 of the rigid body 300,
The second attachments arranged in every other through-hole 310 are made of rubber elastic sleeves that are connected to the inner circumferential surface that partitions each through-hole 310 and the attachments 410 and 420. 500.

As shown in FIG. 8, the elastic sleeve 500 has a right cylindrical shape, and its inner and outer diameters are the same over its axial length.

The present invention was made as part of the above-mentioned development, and its purpose is to prevent the elastic sleeve from coming off from the rigid body,
A further object of the present invention is to provide a coupling that is advantageous in making the value of ((spring constant in the rotational direction)/(spring constant in the axial direction)) greater than 1.

[Means to solve the problem]

The coupling of the present invention has an even number of penetrating shafts that are interposed between one shaft and the other shaft and that penetrate in a direction substantially parallel to the central axis and are spaced apart in the circumferential direction of the central axis. a rigid body having through holes; a first mounting device disposed in every other through hole of the rigid body and attached to one shaft; and a second mounting device disposed in every other through hole of the rigid body and attached to the other shaft. The mounting consists of a group of fittings consisting of a fitting, an inner circumferential surface that partitions each through hole of the rigid body, and an elastic sleeve that is interposed between the fitting and the inner circumferential surface and the fitting are tied to the fitting. The inner circumferential surface that partitions each through-hole of the rigid body is formed so that the inner diameter of the central portion in the axial direction is different from the inner diameter of both ends, and the outer circumferential surface of the elastic sleeve is symmetrical in shape with the inner circumferential surface of the through-hole. It is characterized by what it does.

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 depending on the type of coupling. For example, nylon resin, epoxy resin, etc. can be used, and resins containing reinforcing materials such as glass fiber can also be used. As for the metal, steel or aluminum alloy can be used.

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

The elastic sleeve has an inner circumferential surface that defines each through hole of the rigid body and each attachment is interposed between the tool, and the inner circumferential surface and the attachment are connected to the tool. The elastic sleeve is elastically deformable,
Generally made of rubber. Note that the thickness, hardness, etc. of the elastic sleeve can be appropriately selected depending on the type of coupling.

Now, in the coupling of the present invention, each penetration of the rigid body.

The inner circumferential surface that partitions the hole has a shape in which the inner diameter of the central part in the axial direction is different from the inner diameter of both ends (for example, beer barrel shape or pouch shape).
is formed. The value of (inner diameter at the center in the axial direction/inner diameter at both ends) on the inner circumferential surface of the through hole can be selected as appropriate.

Further, the outer circumferential surface of the elastic sleeve is symmetrical with the inner circumferential surface of the through hole. Therefore, if the axial center of the inner circumferential surface of the through hole is concave, the outer circumferential surface of the elastic sleeve will have a convex shape symmetrical to the shape, and if the axial center of the inner circumferential surface of the through hole is convex, the elastic sleeve will have a convex shape. The outer peripheral surface of the sleeve has a concave shape symmetrical to the mold.

[Function] The function of the coupling of the present invention will be explained together with its usage method. When in use, as in the past, the first attachment attaches the tool to one shaft, the second attachment attaches the tool to the other shaft,
This allows the coupling to be placed between the two wheels. Here, when the driving sides of one shaft and the other shaft are rotationally driven, the torque is transmitted to the driven side via the coupling. During torque transmission, the shaft and each attachment may be displaced relative to each other in the circumferential direction, axial direction, radial direction, or a combination of these directions of the coupling, but this relative displacement is due to the elastic deformation of the elastic sleeve. permissible.

Furthermore, when vibrations are transmitted between the shafts, the vibrations are damped by the elastic sleeve.

Further, in the coupling of the present invention, the inner circumferential surface of the rigid body defining each through-hole is formed in the shape of a beer barrel or a barrel, and the outer circumferential surface of the elastic sleeve is symmetrical in shape with the inner circumferential surface of the through-hole. Therefore, the engagement force between the elastic sleeve and the rigid body in the axial direction increases. Also, when torque is transmitted from one shaft to another, the elastic sleeve is pulled and compressed in a direction perpendicular to the shaft.

The thickness of the elastic sleeve in the direction perpendicular to the axis has a thicker part and a thinner part, and the spring constant is higher in the thinner part. Therefore, the spring constant of the coupling of the present invention in the circumferential direction becomes high. On the other hand, the spring constant in the axial direction of the force ring is determined by the spring constant during shear deformation of the sleeve, and is therefore generally small. Therefore, in the coupling of the present invention, the ratio (spring constant in the rotational direction)/(spring constant in the axial direction) is thicker than 1.

〔Example〕

Hereinafter, the coupling of the present invention will be explained according to a first embodiment shown in FIGS. 11 to 8. A vertical sectional view of the coupling of this embodiment is shown in FIG. 1, and a plan view is shown in FIG. 2.

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 formed into a disk shape of hard nylon resin reinforced with glass fibers. 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 l. The through hole 1a penetrates in a direction substantially parallel to the central axis P2. Here, the inner circumferential surface that partitions each through hole 1a is
When viewed in cross-section along the central axis P2, the inner diameter of the central portion in the axial direction is larger than the inner diameter of both ends, that is, it is shaped like a beer barrel. Therefore, both ends in the axial direction form protruding parts 1c that protrude radially inward of the through hole 1a.

The fixture group 2 includes first metal fixtures 20 arranged in every other through hole 1a, and metal first fixtures 20 arranged in every other through hole 1a.
A second metal fitting, located at , consists of a fitting 21 . As shown in FIG. 2, the axis of the tool 20 for the first attachment and the axis of the tool 21 for the second attachment are arranged along a circle S centered on the central axis P2.

In the first attachment, the tool 20 has a cylindrical shape with an insertion hole 20a. For the second attachment, the tool 21 has a cylindrical shape with an insertion hole 21a.

The elastic sleeve S is mounted approximately coaxially with the fitting 20.21 and is made of rubber. The elastic sleeve 3 is interposed between the inner circumferential surface that partitions each through hole 1a of the rigid body 1 and the outer circumferential surface of each attachment fitting 20, 21, and the inner circumferential surface and the attachment fitting are connected to the fittings 20, 21. has been done. The outer peripheral surface of the elastic sleeve 3 has a through hole 1a.
It is symmetrical with the inner circumferential surface of. Therefore, as is clear from FIG. 1, both ends of the elastic sleeve 3 in the axial direction have a small thickness.

To manufacture the above coupling, each installation must be performed using tool 20.2.
The elastic sleeve 3 is vulcanized and adhered to the outer circumferential surface of the elastic sleeve 3, and adhesive is applied to the outer surface of the elastic sleeve 3.The elastic sleeve 3 is attached using a tool 20 and a tool 21 in a predetermined position in the cavity of the mold. In this state, a molten nylon resin containing glass fibers is injected into the cavity by an injection molding machine at an injection pressure of 300 to 1000 kg/aI, and the elastic sleeve 3 is wrapped in the molten nylon resin and kept under pressure. At the same time, the molten body is solidified to form a rigid body 1.

Note that the elastic sleeve 3 is pre-compressed by the injection pressure and by the contraction of the nylon resin as it solidifies.
This is advantageous in improving the durability and extending the life of the elastic sleeve 3.

Now, when using the coupling of this embodiment, the eighth
As shown in the figure, one shaft 7 having a bifurcated connecting portion 70 and the other shaft 8 having a bifurcated connecting portion 80 are used, and the hole in the connecting portion 70 of one shaft 7 is For the first installation, tighten the nut 74 on the bolt 73 passed through the insertion hole 20a of the tool 20, and connect the tool 20 to the shaft 7. 21 insertion hole 21a
A nut 84 is tightened on a bolt 83 passed through the shaft 8 to connect the second mounting member 21 to the shaft 8, thereby connecting the coupling to both wheels. In this state, when one of the shafts 7.8 is driven to rotate as a 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 a direction to pull out the elastic sleeve 8 from the through hole 1a. In this regard, in this embodiment, as described above, the inner circumferential surface of the rigid body 1 that partitions each through hole 1a is formed in a beer barrel shape, and the outer circumferential surface of the elastic sleeve 3 is symmetrical in shape with the inner circumferential surface of the through hole 1a. . Therefore, the engagement force between the elastic sleeve 8 and the rigid body 1 in the axial direction increases,
The elastic sleeve 3 is prevented from being pulled out from the rigid body 1. Therefore, if the force acting in the axial direction is within a specified range,
It is also 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,
If an adhesive layer is interposed, it is more advantageous to prevent the elastic sleeve 3 from coming off.

As the coupling rotates, the installation is done by tool 20, and the installation is done by tool 2.
1 rotates in the circumferential direction. At this time, the elastic sleeve 3 receives compressive and tensile loads in its thickness direction. Therefore, the spring constant kl of the coupling in the rotational direction is basically determined by the spring constant of the elastic sleeve 3 in the compression and tension directions.

In the case of a relative displacement of the shaft 7.8 in the axial direction, the elastic sleeve 3 is also subjected to shear loads. Therefore, the spring constant 2 of the coupling in the axial direction is determined by the spring constant of the elastic sleeve 3 in the shear direction. In addition, in this embodiment, when the coupling rotates, the protrusions IC formed at both ends of the inner circumferential surface of the through hole 1a function as stoppers in the rotation direction, so the spring constant in the axial direction is reduced by 2. (The spring constant in the rotational direction can be increased by 1 while maintaining (kl
The value of /N is larger than that of a coupling in which the elastic sleeve 500 has a right cylindrical shape as shown in FIG.

In this way, the spring constant kl in the rotational direction can be increased, and since the spring has stiff spring characteristics in the rotational direction, the coupling and, in turn, the driven shaft can follow it well when transmitting torque.

Furthermore, the coupling of this embodiment has a spring constant kl in the rotational direction.
Since the spring constant in the axial direction can be made smaller by 2 while increasing the spring constant, the vibrations input to the coupling in the axial direction can be effectively reduced.

In addition, when transmitting torque, the shaft 7.8, and the mounting tool 20.
21 may be relatively displaced in the circumferential direction, axial direction, radial direction, or a combination thereof of the coupling, but this relative displacement is allowed by the elastic deformation of the elastic sleeve 3. Therefore, the shaft 7.8 and the attachment can ensure a degree of freedom in the relative displacement of the fixture 20.21.

゛ Second embodiment of the coupling of the present invention! Shown in Figure 1!4. The coupling according to the second embodiment has basically the same structure as the first embodiment. However, in the second embodiment, when viewed in cross section along the central axis P2 of the rigid body 1, the inner circumferential surface of the rigid body 1 that defines the through hole 1a has a shape in which the inner diameter of the central portion in the axial direction is smaller than the inner diameter of both ends; In other words, it is formed in a tufted shape,
Therefore, the central portion in the axial direction of the inner circumferential surface that partitions the through hole 1a is a protruding portion 1e. Also elastic sleeve 3
The outer circumferential surface of is symmetrical to it. Therefore, in this embodiment, the wave resistance of the elastic sleeve 3 can be improved. Furthermore, when the coupling rotates, the protrusion 1e functions as a stopper in the rotation direction, so as in the first embodiment,
The value of the spring constant kl in the direction of rotation can be increased, so that the value of (kl/2) is greater than 1. Further, as shown in FIG. 4, since the protrusion 1e is formed in the axial center of the through hole 1a, the mounting is advantageous in increasing the swingability of the tool 20.21.

Incidentally, 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 shows the spring constant kl in the rotational direction, and the vertical axis shows the spring constant 2 in the axial direction. Here characteristic line A
is a characteristic line of the coupling having the structure shown in the first example, characteristic line B is a characteristic line of the coupling having the structure shown in the second example,
Characteristic line C shows the characteristic line of the coupling of the structure shown in FIG.

In the coupling having the structure shown in the first embodiment, even if the spring constant kl in the rotational direction is increased, the rate of increase of 2 in the spring constant in the axial direction can be kept low, as shown by the characteristic line A in FIG. . The same applies to the coupling of the structure shown in the second embodiment, as shown by characteristic line B in FIG. On the other hand, in the coupling having the structure shown in FIG. 8, as shown by the characteristic line C in FIG. 9, when the spring constant kl in the rotational direction is increased, the spring constant in the axial direction increases by 2 at a high rate.

In the above-described first embodiment, when manufacturing the coupling, as described above, when mounting the elastic sleeve 3, the parts 20 and 21 are wrapped with resin to form the rigid body 1. For example, after forming the rigid body 1 made of resin, the rigid body 1 is attached to the fixture 20.21.
is placed in a predetermined part of the cavity of the mold, and unvulcanized rubber is loaded into the cavity portion corresponding to the elastic sleeve 8 and solidified, thereby forming the elastic sleeve 3 and binding it together. You can decide.

[Application example]

FIG. 5 shows an example in which the above-mentioned coupling is applied. In this example, the coupling is applied to an automobile steering system. 90 is a steering wheel, 91 is a steering column, 92 is a steering shaft, 93
is an intermittent shaft, 94 is a steering gear box, and the rigid body 1 of this coupling is a steering shaft 92 and an intermittent shaft 93.
It is interposed and connected to. When the steering wheel 90 is operated, the torque is transmitted from the steering shaft 92 to the driven-side intermittent shaft 93 via the rigid body 1 of the coupling. At this time, since the coupling has stiff spring characteristics in the direction of rotation, good torque transmission performance and steering stability can be obtained. Furthermore, since the coupling has a softer spring constant in the axial direction, it is possible to attenuate vibrations input in the axial direction.

〔Effect of the invention〕

According to the coupling of the present invention, the inner circumferential surface of the rigid body that partitions each through-hole is formed such that the inner diameter of the central portion in the axial direction is different from the inner diameter of both ends, and the outer circumferential surface of the elastic sleeve is It forms symmetry with the inner peripheral surface.

This increases the engagement force between the elastic sleeve and the rigid body, which is advantageous in preventing the elastic sleeve from coming off the rigid body.

In addition, by adopting the above structure, the spring constant in the rotational direction can be increased while keeping the spring constant in the axial direction of the coupling small, resulting in good followability and good control when torque is transmitted between the shafts. This is advantageous in providing torque transmittance and attenuating vibrations input in the axial direction.

[Brief explanation 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 shows a state in which the coupling is interposed between the shafts. FIG. FIG. 4 is a sectional view showing a second embodiment of the present invention. FIG. 5 is a perspective view showing an example of application. 6 and 7 show the prior art, FIG. 6 being a sectional view and FIG. 7 being a plan view. FIG. 8 is a plan view of a prior art coupling. 9th
The figure is a graph schematically showing spring characteristics. In the figure, 1 is a rigid body, 1a is a through hole, 2 is a group of fixtures, and 3 is an elastic sleeve. Patent applicant: Tokai Rubber Industries Co., Ltd.

Claims (1)

[Claims] (1) An even number of through holes are interposed between one shaft and the other shaft, and are arranged at intervals in the circumferential direction of the central axis and penetrate in a direction substantially parallel to the central axis. a first fixture arranged in every other through hole of the rigid body and attached to one shaft; and a second fixture arranged in every other through hole and attached to the other shaft. an elastic sleeve interposed between an inner circumferential surface defining each through hole of the rigid body and each of the fittings and connected to the inner circumferential surface and the fitting; The inner circumferential surface that partitions each through-hole of the rigid body is formed in such a shape that the inner diameter at the center in the axial direction is different from the inner diameter at both ends, and the outer circumferential surface of the elastic sleeve is symmetrical in shape with the inner circumferential surface of the through-hole. A coupling characterized by: