JPH09196077A - Shaft coupling and manufacturing method thereof - Google Patents

Abstract

(57) Abstract: In a shaft coupling such as a steering coupling for vibration-proof connecting a predetermined shaft to be connected, relative displacement in the axial direction between the shafts to be connected while ensuring vibration-proof characteristics around the central axis. Increase the ability to regulate. SOLUTION: A first elastic body 54 is interposed between circumferentially opposed surfaces 34, 36 formed between a cylindrical member 12 and a shaft member 16 and made to approach each other by relative rotation around a central axis, In the shaft coupling 10 in which the rotational force is transmitted via the first elastic body 54, the axially perpendicular facing surfaces 38, 40 located between the tubular member 12 and the axial member 16 in a direction orthogonal to the axial direction. And the surfaces 38, 4 facing each other in the direction perpendicular to the axis are formed.
The second elastic body 56 was interposed between 0, and the pre-compression larger than that of the first elastic body 54 was applied to the second elastic body 56.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft coupling such as a steering coupling and a method for manufacturing the shaft coupling, and in particular, to enhance the ability to regulate relative displacement in the axial direction while ensuring vibration damping performance in the twisting direction around the central axis. The present invention relates to a shaft coupling having a novel structure and a manufacturing method thereof.

[0002]

BACKGROUND ART Generally, in a vehicle steering system including a plurality of shafts or the like for transmitting a steering force (rotational operation force) input from a steering wheel to a steering gear, a steering system from a road surface, a steering gear, or a suspension system is used. In order to suppress the transmission of the input vibration to the steering wheel side, a steering coupling, which is a kind of shaft coupling that is a vibration isolation device, is provided on the transmission path of the steering force.

As a kind of shaft coupling such as the steering coupling, it has been heretofore known as the actual open shaft shovel 62-10.
As disclosed in Japanese Laid-Open Patent Publication No. 0267, etc., the inner peripheral surface of the cylindrical member and the outer peripheral surface of the shaft member inserted in the inner hole of the cylindrical member in a non-contact manner with a predetermined gap are rotated about the central axis. Forming a circumferential facing surface that is brought closer to each other by the relative rotation of the rubber elastic body, and interposing a rubber elastic body between the circumferential facing surfaces so that the rotational force about the central axis is transmitted between the two members. It is known that the structure is designed to be done through.

Further, in such a shaft coupling, in general, the other of the tubular member and the shaft member is press-fitted into the rubber elastic body bonded to the one of the tubular member and the shaft member,
It has a structure in which the tubular member and the shaft member are elastically connected by applying a predetermined precompression or tightening margin to the rubber elastic body. By adjusting the precompression or tightening margin for the rubber elastic body, By adjusting the spring characteristics of the rubber elastic body, the characteristics of the shaft coupling can be tuned.

However, in order to obtain excellent anti-vibration performance,
If the soft spring characteristic is set by reducing the pre-compression or tightening margin for the rubber elastic body, the relative axial restraining force between the tubular member and the shaft member via the rubber elastic body is reduced, and the tubular member is reduced. And the shaft member is relatively displaced in the axial direction,
The workability of assembling to the vehicle is adversely affected, and the relative displacement of the tubular member and the shaft member in the axial direction makes it difficult to stably obtain the desired spring characteristics. . On the other hand, if the pre-compression or tightening margin for the rubber elastic body is set to a large value in order to obtain sufficient relative axial restraining force between the tubular member and the shaft member, the spring characteristic of the rubber elastic body becomes hard and the vibration proof is achieved. It is unavoidable that the performance deteriorates. Therefore, it has been extremely difficult in the past to achieve both the vibration isolation performance and the axial restraint force.

[0006]

The present invention has been made in view of the circumstances as described above, and a problem to be solved by the present invention is to secure good vibration damping performance and
A shaft coupling having a novel structure and a manufacturing method thereof, which can advantageously set a restriction force of relative displacement in the axial direction of a tubular member and a shaft member without adding a special member or complicating the structure. To provide.

[0007]

In order to solve such a problem, a feature of the present invention resides in that an inner peripheral surface of a cylindrical member and an outer peripheral surface of a shaft member inserted into an inner hole of the cylindrical member with a predetermined gap. And a circumferentially opposed surface that is made to approach each other by relative rotation around the central axis, and a first elastic body is interposed between the circumferentially opposed surfaces to form a central axis between the two members. In a shaft joint in which the rotational force is transmitted via the first elastic body, the shaft joint is located between the inner peripheral surface of the tubular member and the outer peripheral surface of the shaft member in a direction orthogonal to the axis. An axially-opposed surface was formed, and a second elastic body was interposed between the axially-opposed surfaces, and a precompression greater than that of the first elastic body was applied to the second elastic body. Especially.

In the shaft coupling having such a structure, the second elastic body is pressed against the axially opposed surfaces of the cylindrical member and the shaft member based on its elastic force, so that the second elastic body is A relative restraining force is exerted on the tubular member and the shaft member via the elastic body. Here, the second elastic body is interposed between the axially opposed surfaces of the cylindrical member and the shaft member, and the elastic force in the second elastic body is a torsion spring about the central axes of the cylindrical member and the shaft member. There is almost no direct influence on the characteristics, and the compressive stress in the second elastic body is directly applied to the first elastic body interposed between the circumferentially opposed surfaces of the tubular member and the shaft member. Therefore, it is possible to obtain a desired spring characteristic in the relative rotation direction in the first elastic body and also obtain a restraining force in the axial direction in the second elastic body.

Therefore, while the connecting characteristic of the tubular member and the shaft member that realizes good vibration damping performance is ensured by the first rubber elastic body, the second rubber elastic body serves to connect the tubular member and the shaft member. The restraint force against relative displacement in the axial direction can be easily and advantageously obtained.

In the shaft joint having the structure according to the present invention, the circumferentially facing surface may be formed at a portion substantially different from the axially facing surface in the axial direction of the tubular member and the axial member. Although possible, preferably, the circumferentially facing surface and the axially perpendicularly facing surface are formed so as to be located substantially at different portions in the circumferential direction. With this structure,
The circumferential facing surface and the axially facing surface can be positioned with excellent space efficiency, and the axial length of the shaft coupling can be set short.

Further, in the shaft coupling having the structure according to the present invention, the specific shapes, structures and numbers of the circumferentially opposed surfaces and the axially perpendicularly opposed surfaces are not limited at all, and the required vibration isolation is provided. It can be appropriately set according to the characteristics, the torque transmission characteristics, and the like.

For example, according to the present invention, by providing a projecting portion projecting in a direction perpendicular to the axis and a recess into which the projecting portion is inserted, at respective corresponding positions of the shaft member and the cylindrical member, the circumferential side surface of the projecting portion and the recessed portion A structure or the like in which the inner surface of the outer peripheral surface forms the opposing surface in the circumferential direction is preferably used. By adopting such a structure, it is possible to advantageously form a plurality of circumferentially facing surfaces with a simple structure, and between the facing surfaces of the tip surface of the protrusion and the bottom surface of the recess, and between the protrusion and the recess. It is also possible to easily form a plurality of axially-opposed faces between the opposed faces of the portion in which the is not formed.

Further, in the present invention, it is desirable that the axially-opposing faces be formed in a pair or in two or more pairs so as to be positioned so as to sandwich the shaft member in the direction perpendicular to the axis, whereby the tubular member and the shaft are formed. A large precompression can be exerted on the second elastic body while preventing eccentricity of the member.

Further, in the shaft coupling having the structure according to the present invention, the structure for pre-compressing the second elastic body is not limited at all, and the second elastic body is provided between the tubular member and the shaft member. It is also possible to adopt a structure in which the second elastic body is pre-compressed by reducing the diameter of the tubular member or expanding the diameter of the shaft member after the insertion, but in the present invention, While adhering the second elastic body to either one of the tubular member and the shaft member on the surface facing in the direction perpendicular to the axis, press-fitting and fixing the other one of the tubular member and the shaft member to the second elastic body. Therefore, a structure in which the second elastic body is pre-compressed is preferably adopted.

If such a structure is adopted, pre-compression can be applied to the second elastic body at the same time as assembling the tubular member and the shaft member without requiring special processing.
Further, since the second elastic body is adhered to either the tubular member or the shaft member, the second elastic body of the other of the tubular member and the shaft member can be easily press-fitted.

Further, in the shaft joint having the structure according to the present invention, the first elastic body and the second elastic body may be separate structures independent of each other, but in the present invention, The first elastic body and the second elastic body are integrally formed by a cylindrical body continuous in the circumferential direction, and the cylindrical body is surrounded by an inner peripheral surface of the cylindrical member and an outer peripheral surface of the shaft member. A structure in which they are continuously interposed in the direction is preferably adopted. If such a structure is adopted, the first elastic body and the second elastic body are integrated, so that the number of parts can be reduced and the assemblability can be improved.

Further, in the shaft coupling having the structure according to the present invention, the lightening portion extending in the axial direction is provided between the circumferentially opposed surfaces on which the first elastic body is arranged, and the lightening portion is provided in the lightening portion.
It is also possible to dispose a synthetic resin inner member formed with the inner peripheral surface of the lightening portion as a molding surface. When such an inner member is provided, thermal contraction of the resin material during molding of the inner member absorbs and reduces or eliminates internal stress in the first elastic body interposed between the circumferentially opposed surfaces. Therefore, adverse effects on the torsional characteristics of the shaft coupling due to the transmission of the pre-compression of the second elastic body to the first elastic body are more effectively prevented, and the torsional characteristics of the shaft coupling are improved. It is possible to more easily secure the pre-compression of the second elastic body while avoiding the adverse effect on the second elastic body, and the spring characteristic is soft and the relative rotation angle is large while the relative rotation angle between the tubular member and the shaft member is small. It is also possible to easily impart a non-linear spring characteristic in which the spring characteristic is rapidly hardened by the inner member when it becomes low.

Further, according to the present invention, (a) circumferentially opposed surfaces which are brought into and out of each other by being relatively inserted around each other by a relative rotation about the central axis by being inserted into and out of each other with a predetermined gap,
A step of preparing a cylindrical member and a shaft member that respectively form axially-opposite-opposing surfaces that are opposed to each other in a direction orthogonal to the axis at substantially different portions; and (b) first elasticity interposed between the circumferentially-opposing surfaces. A step of providing a body and a second elastic body interposed between the surfaces facing each other in the direction perpendicular to the axis on either one of the tubular member and the shaft member; and (c) for one of the tubular member and the shaft member. , The other of the tubular member and the shaft member is axially inserted in and out, and the circumferentially opposed surface and the axially perpendicularly opposed surface are positioned so as to be opposed to each other with the first elastic body and the second elastic body interposed therebetween. And press-fitting the other of the tubular member and the shaft member into the second elastic body so that a greater precompression is applied to the second elastic body than the first elastic body. The manufacturing method of the shaft coupling is also characterized.

According to such a manufacturing method, as described above, the restraining force against the relative displacement between the tubular member and the shaft member in the axial direction is advantageously exerted without adversely affecting the spring characteristics in the torsional direction about the central axis. The shaft coupling that can be obtained can be easily manufactured.

Further, in such a method of the present invention,
After providing a lightening portion extending in the axial direction between the circumferentially opposed surfaces in which the first elastic body is interposed, the tubular member and the shaft member are press-fitted and pre-compression is applied to the second elastic body. It is also possible to form the inner member housed and arranged in the lightening portion by resin-molding the inner peripheral surface of the lightening portion as a molding surface, whereby the first member by press fitting the tubular member and the shaft member. Since the thinned portion absorbs the compression of the elastic body of and the resin is filled after that, the variation of the spring characteristics mainly in the torsional direction of the tubular member and the shaft member by the first elastic body is different from that of the resin. Only the heat shrinkage and the first elastic body itself have, and it can be made very small.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 4 show a steering coupling 10 as a first embodiment of the present invention. The steering coupling 10 has a tubular metal member 12 as a tubular member, and a shaft metallic member 16 as a shaft member that is loosely inserted in the tubular metal member 12 and is interposed between them. The rubber elastic cylinder 18 has a structure in which they are elastically connected. In the steering coupling 10 of this embodiment, a tubular yoke fitting 22 is press-fitted and fixed to the tubular fitting 12, and the yoke fitting 22 is connected to the shaft on the steering gear side via a universal joint. On the other hand, shaft fitting 16
However, by being connected to the main shaft on the side of the steering wheel, a steering intermediate shaft that is interposed between the steering main shaft and the steering gear and transmits the steering force is configured.

More specifically, the tubular fitting 12 has a substantially bottomed cylindrical shape as a whole. Further, the tubular wall portion of the tubular metal member 12 is recessed radially inward at four locations on the circumference, thereby opening the outer peripheral surface and extending in the axial direction.
The book groove 24 and the four recesses 26 that open in the inner peripheral surface and extend in the axial direction are formed alternately in the circumferential direction. Further, a yoke metal fitting 22 having a thick cylindrical shape and integrally formed with a joint mounting portion 25 extending in the axial direction from one opening end edge portion in the axial direction is press-fitted and fixed to the cylindrical metal fitting 12, The tubular fitting 12 is attached to the shaft on the steering gear side via the yoke fitting 22. A pair of fitting projections 27, 27 projecting inward in the radial direction are formed on the cylindrical wall portion of the yoke fitting 22 at positions facing each other in the radial direction, and these fitting projections 27, 27 are formed.
Is fitted into the groove portions 24, 24 of the tubular fitting 12 to prevent relative rotation of the yoke fitting 22 with respect to the tubular fitting 12.

On the other hand, the shaft fitting 16 has a rod shape with a solid circular cross section, and one end portion in the axial direction has a cylindrical fitting 12.
On the other hand, the other end portion in the axial direction is a connecting portion 30 which is serrated and is connected to a main shaft (not shown). In addition, the insertion portion 28 has an axially protruding portion 4 which projects radially outward.
Book protrusions 32 are provided at equal intervals on the circumference.

Then, the insertion portion 28 of the shaft fitting 16 is inserted into the tubular fitting 12, and the protrusions 32 of the insertion portion 28 are positioned at substantially the central portions of the recesses 26 of the tubular fitting 12. Further, there is a predetermined amount of clearance between the axial end surface of the insertion portion 28 and the bottom surface of the tubular fitting 12, so that the insertion portion 28 and the tubular fitting 12 do not contact each other. In addition, the protruding portion 32 of the shaft metal fitting 16 is configured so that the protruding tip end surface thereof does not contact the bottom surface of the concave portion 26 of the tubular metal fitting 12.
The protruding height is set.

As described above, since the insertion portion 28 of the shaft fitting 16 and the tubular fitting 12 are relatively positioned, the shaft fitting 1
6, both side surfaces 34, 34 in the circumferential direction of each protruding portion 32,
The inner wall surfaces 36, 36 of the recess 26 of the tubular fitting 12 are positioned to face each other with a predetermined distance in the circumferential direction. Further, the outer peripheral surface 38 of the shaft metal fitting 16 where the protruding portion 32 is not formed is positioned so as to face the bottom inner surface 40 of the groove 24 of the tubular metal fitting 12 at a predetermined distance in the axis-perpendicular direction. Has been. That is, in the present embodiment, the circumferential side surface 34 of the protrusion 32 and the side wall inner surface 36 of the recess 26 constitute a total of eight pairs of circumferential facing surfaces, and the outer periphery of the portion where the protrusion 32 is not formed. The surface 38 and the inner surface 40 of the groove 24 form a total of four pairs of axially opposed surfaces.

Further, a rubber elastic tubular body 18 is interposed between the insertion portion 28 of the shaft metal fitting 16 and the tubular metal fitting 12, and by the rubber elastic tubular body 18, the shaft metal fitting 16 and the tubular metal fitting 12 are provided.
Are elastically connected. This rubber elastic cylinder 18
Has a shape substantially corresponding to the shape of the gap formed between the insertion portion 28 of the shaft fitting 16 and the tubular fitting 12, and is arranged in a substantially filled state between the insertion portion 28 and the tubular fitting 12. ing.

Here, the rubber elastic cylinder 18 is shown in FIG.
As shown in the vulcanization molding diagram, the outer peripheral surface is vulcanized and adhered to the inner peripheral surface of the tubular metal fitting 12, and the inner peripheral hole 44 of the shaft metal fitting 16 is attached to the inner hole 44 as shown in FIG. Insertion part 28
Are assembled by being press-fitted. Also,
The rubber elastic body 18 is provided between the circumferential facing surfaces 34, 36 located between the respective projecting portions 32, 32 and the axially perpendicular facing surfaces 38, 4.
It is thick between 0, but thin between the end surfaces of the protruding portions 32 and the bottom surface of the recessed portion 26 of the tubular fitting 12 and is thin. Is substantially divided into four in the circumferential direction, so that transmission of stress or deformation between the divided portions A, B, C, D can be suppressed.

Further, as shown in FIG. 5, of the four divided portions A, B, C and D of the rubber elastic tubular body 18 which are substantially divided by the thin portion 46, are opposed to each other in the radial direction. The pair of divided parts A and B located in the circumferential direction facing surfaces 34 and 36 of the tubular fitting 12 and the shaft fitting 16, respectively.
A slit 48 is formed as a lightening portion that extends in the circumferential direction and extends in the axial direction straddling the space 38 and the axially-opposing surfaces 38, 40. As shown in FIG. 6, the slit 48 is formed to have a size that does not collapse even after the insertion portion 28 of the shaft fitting 16 is press-fitted into the inner hole 44 of the rubber elastic tubular body 18 and assembled. After assembling the shaft fitting 16 in the inner hole 44, the assembly is set in a predetermined molding die, the slit 48 is filled with the resin material, and the resin material is cooled and solidified. Three
As shown in FIG. 3, a resin inner member 50 is formed with the inner peripheral surface of the slit 48 as a molding surface, and is disposed in the slit 48.

In the inner member 50 thus formed with the inner peripheral surface of the slit 48 as the molding surface,
Since the outer shape is faithful to the shape of the slit 48, and the outer dimension of the inner member 50 is slightly reduced due to heat shrinkage during cooling and solidification of the resin material,
The abutting force on the inner peripheral surface of the slit 48 is reduced or eliminated, and the abutting force is hardly exerted on the rubber elastic tubular body 18, or the contact force with the inner peripheral surface of the slit 48 is very small. It is assembled with a gap. As a result, the pre-compression of the insertion portion 28 of the first elastic body portion 54, which is interposed between the circumferentially facing surfaces 34 and 36 in the divided portions A and B of the rubber elastic tubular body 18 at the time of press-fitting, is slit 48. Is absorbed by the deformation of the first elastic body portion 54 in the divided portions A and B.
The variation in the spring characteristics is only that of the heat shrinkage of the resin material and that of the first elastic body portion 54 itself, which is extremely small.

When forming the inner member 50,
After injecting and filling the resin material into the slit 48, the resin material is released to release the filling pressure, and the resin material is cooled and solidified under the condition that the holding pressure against the resin material is minimized. For example, inner member 5
The abutting force of 0 on the inner surface of the slit 48 can be reduced more advantageously. In addition, the inner member 50 is formed by the tubular fitting 12
On the other hand, it is more desirable to perform after the yoke fitting 22 is press-fitted and fixed, whereby the characteristic change due to the deformation of the tubular fitting 12 due to the press fitting of the yoke fitting 22 can be effectively prevented.

On the other hand, as shown in FIG. 5, among the four divided portions A, B, C and D which are substantially divided by the thin portion 46, the other pair of radially opposed portions is arranged. Each of the divided portions C and D is provided with a pressure contact protrusion 52 that protrudes at a predetermined height on the inner peripheral surface, and the insertion portion 28 of the shaft fitting 16 is press-fitted into the inner hole 44 of the rubber elastic tubular body 18. At this time, the press contact projections 52 are pressed against the outer peripheral surface 38 of the shaft fitting 16 so as to be interposed between the axially opposed surfaces 38 and 40 in the divided portions C and D of the rubber elastic tubular body 18. An effective precompression is applied to the second elastic body portion 56.

That is, in the steering coupling 10 having such a structure, when a rotational force is applied between the tubular metal fitting 12 and the shaft metal fitting 16, the circumferentially opposed surfaces 34, 36 forming each pair are mutually opposed. When the inner member 5 is moved toward and away from each other, the rotational force is transmitted between the circumferentially facing surfaces 34 and 36 via the rubber elastic tubular body 18.
Circumferentially facing surface 3 in divided portions A and B in which 0 is interposed
Between 4 and 36, the deformation of the rubber elastic tubular body 18 is limited by the inner member 50, so that the spring characteristic rises sharply. Therefore, the circumference of the divided portions C and D in which the inner member 50 is not interposed is increased. Direction facing surfaces 34, 3
A spring rigidity sufficiently larger than that of the rubber elastic cylinder 18 between 6 is exerted. Therefore, in this embodiment, the transmission of the rotational force about the central axis between the tubular metal fitting 12 and the shaft metal fitting 16 is mainly due to the circumferential facing surfaces 34, 36 of the divided portions A, B of the rubber elastic tubular body 18. This is done by the first elastic body portions 54, 54 interposed therebetween.

The first elastic body portion 54 includes
Since the inner member 50 is assembled in a state where it exerts almost no abutting force, it has an extremely soft spring characteristic while the relative rotation angle of the tubular fitting 12 and the shaft fitting 16 is small, and is hard when the relative rotation angle becomes large. The spring characteristics have little variation, and the desired vibration isolation performance and direct operation feeling can be obtained.

Further, in the steering coupling 10 having the above-mentioned structure, the second elastic body portion 56 is used.
On the basis of the precompression applied to the second elastic body part 5
6 is an axially opposed surface 3 of the tubular metal fitting 12 and the shaft metal fitting 16.
Since they are pressed against the second elastic body portion 56, the force of the relative movement of the shaft metal fitting 16 with respect to the second elastic body portion 56 is prevented based on the pressure contact force of the second elastic body portion 56. The blocking force of the relative movement of the steering wheel in the axial direction with respect to the tubular metal fitting 12 can be effectively exerted, and thereby, the pull-out resistance at the time of assembling the steering coupling 10 to the vehicle can be sufficiently obtained and good assembling can be achieved. Workability is secured, and characteristic changes and the like due to relative displacement of the tubular fitting 12 and the shaft fitting 16 in the axial direction are advantageously prevented.

Moreover, since the second elastic body portion 56 to which the pre-compression is applied is interposed between the axially opposed surfaces 38 and 40 of the tubular fitting 12 and the axial fitting 16, the second elastic portion 56 is provided. Even if pre-compression is applied to the body portion 56, the spring characteristics around the central axis of the rubber elastic tubular body 18 are not significantly affected, and therefore, the rotational force transmission characteristics around the central axis and the prevention of the rotation are prevented. It is possible to set a large axial relative displacement regulation force between the tubular metal fitting 12 and the shaft metal fitting 16 while sufficiently securing the vibration characteristic.

Further, in particular, in this embodiment, the first elastic body portions 54, 54 which mainly provide the spring characteristic and the vibration damping characteristic about the central axis, and the shafts of the tubular fitting 12 and the axial fitting 16 by precompression. Since the second elastic body portions 56, 56 that mainly provide the relative displacement regulation force in the direction are positioned substantially in the circumferential direction by the thin-walled portion 46, the first elastic portions thereof are divided. Body part 54 and second elastic body part 5
The transmission of stress or deformation between 6 is more effectively suppressed, and the rotational force transmission characteristics and vibration isolation characteristics around the central axis, and the relative displacement regulating force in the axial direction of the tubular metal fitting 12 and the axial metal fitting 16 are suppressed. Compatibility is achieved to a higher degree.

Furthermore, in this embodiment, since the inner member 50 disposed in the first elastic body portion 54 is formed with the inner peripheral surface of the slit 48 as the molding surface, the dimensional error of each member. And the like are absorbed during the molding of the inner member 50, the tolerances of the parts are relaxed, the manufacturability is improved, and the product characteristics are stabilized.

Next, FIGS. 7 to 8 show a steering coupling 60 as a second embodiment of the present invention. The present embodiment shows another specific structural example of the circumferentially facing surface and the axially perpendicularly facing surface, as compared with the first embodiment, and has the same structure as that of the first embodiment. The members and the parts described as above are denoted by the same reference numerals as those in the first embodiment in the drawings, and detailed description thereof will be omitted.

First, in the tubular fitting 12 of the steering coupling 60 of the present embodiment, in the tubular wall portion, a groove portion 24 which is open to the outer peripheral surface and extends in the axial direction, and an axially open groove portion 24 which is open to the inner peripheral surface. Two recesses 26 are formed alternately in the circumferential direction. On the other hand, the insertion portion 28 of the shaft fitting 16 is provided with two protruding portions 32 that protrude radially outward and extend in the axial direction. Then, the insertion portion 28 of the shaft metal fitting 16 is inserted into the tubular metal fitting 12, and the respective projecting portions 32 of the insertion portion 28 are positioned at substantially the central portions in the respective recesses 26 of the tubular metal fitting 12.

As a result, in this embodiment, the protrusion 32
By the circumferential side surface 34 and the side wall inner surface 36 of the recess 26,
A total of four pairs of circumferentially opposed surfaces are formed, and the outer peripheral surface 38 and the groove 24 of the portion where the protrusion 32 is not formed are formed.
A total of two pairs of the axially-opposing surfaces are formed by the inner surface 40.

Further, the rubber elastic tubular body 18 which elastically connects the shaft metal fitting 16 and the tubular metal fitting 12 has an outer peripheral surface of the inner peripheral surface of the tubular metal fitting 12 as shown in the vulcanization molding diagram. As shown in FIG. 8, the insertion portion 28 of the shaft fitting 16 is press-fitted into the inner hole 44 of the shaft fitting 16 so as to be substantially filled between the insertion portion 28 and the tubular fitting 12. It is installed in.

In the steering coupling 60 having such a structure, when a rotational force is exerted between the tubular metal fitting 12 and the shaft metal fitting 16, the circumferentially opposed surfaces 3 forming each pair.
4, 36 are made to approach and separate from each other, and the rotational force is transmitted between the circumferentially facing surfaces 34, 36 via the rubber elastic tubular body 18, and the tubular fitting 12 and the shaft fitting 16 are also provided. When a vibration accompanied by a relative rotation of a small angle is input between the two, the vibration damping effect is exerted based on the elastic deformation of the rubber elastic tubular body 18 interposed between the circumferentially facing surfaces 34 and 36. It will be. That is, in the present embodiment, the first elastic body portion 54 is constituted by the portion of the rubber elastic tubular body 18 that is interposed between the circumferentially facing surfaces 34 and 36 forming each pair.

On the other hand, in the rubber elastic tubular body 18, the portions of the tubular metal fitting 12 and the axial metal fitting 16 that are interposed between the axially-opposite facing surfaces 38 and 40, respectively, are formed on the inner peripheral surface. A protruding press contact projection 52 is provided, and when the insertion portion 28 of the shaft fitting 16 is press-fitted into the inner hole 44 of the rubber elastic tubular body 18, the press contact projection 52 is pressed and deformed, whereby the rubber elastic tubular body 18 is pressed. By being pre-compressed and pressed against the axially-opposed surfaces 38 and 40, a force for preventing relative movement in the axial direction of the shaft fitting 16 with respect to the tubular fitting 12 is exerted. That is, in the present embodiment, the axially-opposing faces 38, 4 forming each pair of the rubber elastic tubular body 18 are formed.
The second elastic body portion 56 is constituted by the portion interposed between the zeros.

The second elastic body portion 56 to which the pre-compression is applied is interposed between the axially opposed surfaces 38 and 40 of the tubular fitting 12 and the axial fitting 16, and the tubular fitting 12 and the axial fitting 1 are provided.
Since the second elastic body portion 56 is disposed at a portion different from the first elastic body portion 54 interposed between the circumferentially facing surfaces 34 and 36 in the circumferential direction, the second elastic body portion 56 is precompressed. Even if added, the spring characteristics around the central axis of the rubber elastic tubular body 18 are not significantly affected.

Therefore, also in the steering coupling 60 of this embodiment, based on the elastic connection structure of the tubular metal fitting 12 and the shaft metal fitting 16 by the first elastic body portion 54, the rotational force transmission characteristic around the central axis and Based on the pressure contact structure of the second elastic body portion 56, it is possible to set a large amount of relative displacement regulation force in the axial direction between the tubular metal fitting 12 and the shaft metal fitting 16 while sufficiently securing the vibration damping characteristics.

In the second embodiment, the tubular fitting 12
On the inner peripheral surface of the rubber elastic tubular body 18 vulcanized and bonded to the shaft metal fitting 1
By press-fitting and fixing 6
It was supposed to be a structure that pre-compressed against, but on the contrary,
It is also possible to apply precompression to the second elastic body portion 56 by press-fitting and fixing the tubular metal fitting 12 onto the outer peripheral surface of the rubber elastic tubular body 18 vulcanized and bonded to the shaft metal fitting 16, and a specific example thereof. Is shown in FIGS. 10-12 as a third embodiment. In addition, in the present embodiment, the members and parts having the same structure as the second embodiment are denoted by the same reference numerals as those in the second embodiment in the drawings, respectively, and their details will be described. Description is omitted.

That is, in the steering coupling 62 of the present embodiment, as shown in the vulcanization molding diagram in FIG. 12, the rubber elastic tubular body 18 is vulcanized and adhered to the outer peripheral surface of the shaft fitting 16. And, as shown in FIG.
The cylindrical metal fitting 12 is press-fitted onto the outer peripheral surface thereof, so that the cylindrical metal fitting 12 is disposed in a substantially filled state between the insertion portion 28 of the shaft metal fitting 16 and the cylindrical metal fitting 12. Here, in the rubber elastic tubular body 18, the portions (second elastic body portion 56) interposed between the axially-opposite facing surfaces 38 and 40 forming each pair in the tubular metal fitting 12 and the shaft metal fitting 16, respectively, are respectively provided. A press-contact projection 52 is provided which projects onto the outer peripheral surface. When the tubular metal fitting 12 is press-fitted onto the outer peripheral surface of the rubber elastic cylinder 18, the press-contact projection 52 is provided.
As a result of being pressed and deformed, the pre-compression is applied to the second elastic body portion 56, similarly to the steering coupling 60 in the second embodiment, so that the axially opposed surfaces 38,
It is designed to be pressed against 40.

Further, in this embodiment, the tubular metal fitting 12 is made thick and is integrally formed with the yoke metal fitting, so that the member strength is improved and the rubber elastic tubular body 18 of the tubular metal fitting 12 is improved. The press-fitting work is easy, and the number of parts is reduced to improve the manufacturability.

Next, FIGS. 13 to 14 show a steering coupling 64 as a fourth embodiment of the present invention. In addition, in the present embodiment, the members and parts having the same structure as the first embodiment are denoted by the same reference numerals as those in the first embodiment in the drawings, respectively. The description is omitted.

That is, in the steering coupling 64 of the present embodiment, the tubular metal fitting 12 has a substantially hollow drum-shaped or oval frame-shaped cross section, and is opposed to each other in two directions orthogonal to each other at right angles to the axis. The peripheral wall portion is a flat portion 66, 66 and a curved portion 68, 6 having a central axis as a center of curvature.
It is supposed to be 8. Further, the shaft metal fitting 16 has a drum-shaped or oval cross section having an outer peripheral surface shape slightly smaller than that of the tubular metal fitting 12, and the outer peripheral surface portions facing each other in two directions orthogonal to the axis are orthogonal to each other. , Flat surface 70, 70
And curved surfaces 72, 72 having the central axis as the center of curvature.

As in the first embodiment, the yoke member (not shown) is externally fitted and fixed to the tubular metal member 12, while the shaft metal member 16 is mounted so as to extend through the central axis thereof. A rod member (not shown) is press-fitted and fixed into the hole 74, so that the shaft member has a structure similar to that of the shaft fitting in the first embodiment.

Then, the shaft fitting 16 is inserted into the tubular fitting 12, and the inner peripheral surface of the flat portion 66 of the tubular fitting 12 and the flat surface 70 of the shaft fitting 16 and the inner peripheral surface of the curved portion 68 of the tubular fitting 12 are inserted. The tube fitting 12 and the shaft fitting 16 are positioned so that the curved surfaces 72 of the shaft fitting 16 and the curved surface 72 of the shaft fitting 16 face each other with a predetermined distance therebetween. As a result, when the tubular fitting 12 and the shaft fitting 16 are relatively rotated about the central axis, the inner peripheral surface of the flat portion 66 of the tubular fitting 12 and the flat surface 70 of the shaft fitting 16 move toward and away from each other. While being relatively displaced, the inner peripheral surface of the curved portion 68 of the tubular metal fitting 12 and the shaft metal fitting 16 are arranged.
The curved surface 72 of FIG. 6 is relatively displaced in the circumferential direction even when the tubular metal fitting 12 and the shaft metal fitting 16 are relatively rotated about the central axis, so that the distance between the facing surfaces is kept substantially constant. Has become.

Further, as shown in FIG. 15, a rubber elastic tubular body 18 is vulcanized and adhered to the inner peripheral surface of the tubular fitting 12, and as shown in FIG. When the shaft fitting 16 is press-fitted into the tubular body 18, the rubber elastic tubular body 18 is arranged so as to fill the gap between the tubular fitting 12 and the shaft fitting 16.

That is, in the present embodiment, the inner circumferential surface of the flat portion 66 of the tubular fitting 12 and the flat surface 70 of the shaft fitting 16 constitute a circumferentially opposed surface, and the rubber elastic tubular body 18 has the circumferential direction facing surface. The portion interposed between the facing surfaces 66 and 70 serves as the first elastic body portion 54. On the other hand, the inner peripheral surface of the bending portion 68 of the tubular fitting 12 and the bending surface 7 of the shaft fitting 16 are arranged.
2 constitutes an axially-opposed surface, and the portion of the rubber elastic tubular body 18 interposed between the axially-opposed surfaces 68 and 72 is the second elastic body portion 56. .

Further, as shown in FIG. 15, each first elastic body portion 54 has a slit 4 penetrating in the axial direction.
8 is provided, as in the first embodiment, as shown in FIG. 16, after the shaft fitting 16 is press-fitted and fixed to the rubber elastic tubular body 18, the inner peripheral surface of the slit 48 is formed. As shown in FIGS. 13 and 14, the inner member 50 is disposed in the slit 48 by resin molding as the surface.

On the other hand, in each second elastic body portion 56,
A press-contacting projection 52 protruding on the inner peripheral surface is provided, and when the shaft fitting 16 is press-fitted into the inner hole 44 of the rubber elastic tubular body 18, the press-contacting projection 52 is pressed and deformed to cause the second elasticity. Pre-compression is applied to the body portion 56 so that the body portion 56 is pressed against the axially opposed surfaces 68 and 72.

Therefore, in the steering coupling 64 having such a structure, the circumferential facing surfaces 66,
Rotational force is transmitted between the tubular metal fitting 12 and the axial metal fitting 16 via the first elastic body portion 54 interposed between the 70 and 70. When the value is small, a sufficiently soft spring characteristic is exerted and an excellent vibration damping effect is exerted based on the stress reducing action due to the contraction at the time of molding the inner member 50, while the tubular metal fitting 12 and the shaft metal fitting 16 are provided. When the relative rotation angle is larger than the minute angle, the spring rigidity rises sharply based on the deformation restricting action of the inner member 50, and good rotational force transmissibility, that is, steering operability is realized.

The second elastic body portion 56 is pressed against the axially opposed surfaces 68 and 72 of the tubular fitting 12 and the axial fitting 16, so that the axial fitting 16 of the axial fitting 16 with respect to the tubular fitting 12 is moved. The blocking force of relative movement is effectively exerted,
Moreover, since the second elastic body portion 56 is disposed at a portion different from the first elastic body portion 54 in the circumferential direction, even if pre-compression is applied to the second elastic body portion 56, The spring characteristic around the central axis is not greatly affected by the first elastic body portion 54, and the rotational force transmission characteristic around the central axis and the vibration damping characteristic between the tubular fitting 12 and the axial fitting 16 are sufficiently secured. It can be done.

Although the embodiments of the present invention have been described in detail above, these are literal examples, and the present invention should not be construed as being limited to these specific examples.

For example, the first elastic body and the second elastic body interposed between the tubular metal fitting 12 and the shaft metal fitting 16 may be constituted by rubber elastic bodies formed separately from each other.

Further, the circumferentially opposed surface in which the first elastic body is interposed and the axially perpendicularly opposed surface in which the second elastic body is interposed are arranged in the axial direction between the metal fitting 12 and the metal fitting 16. It is also possible to form them in different parts.

Furthermore, in the above-mentioned embodiment, the rubber elastic tubular body 18 mounted on either one of the tubular fitting 12 and the shaft fitting 16.
The second elastic body portion 56 was pre-compressed by press-fitting the other one of the tubular metal fitting 12 and the shaft metal fitting 16 in the above. It is also possible to pre-compress the second elastic body portion 16 by disposing at least one of the tubular metal fitting 12 and the shaft metal fitting 16 after disposing it between the metal shell 12 and the shaft metal fitting 16.

Further, the pre-compression in the first elastic body interposed between the cylindrical metal fitting 12 and the shaft metal fitting 16 facing in the circumferential direction is at least pre-compressed in the second elastic body interposed in the axially facing surface. The compression may be smaller than the compression, and the pre-compression of the first elastic body can be zero.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, the present invention can be implemented in a form in which various changes, modifications, improvements, and the like are made.
It goes without saying that all such embodiments are included within the scope of the present invention, without departing from the spirit of the present invention.

[0066]

As is apparent from the above description, in the shaft coupling having the structure according to the present invention, the cylindrical member and the second elastic body press-contacted to the axially opposed surfaces of the shaft member,
The restraint force with respect to the relative displacement in the axial direction between the tubular member and the shaft member is advantageously exerted, and the compressive stress in the second elastic body is interposed between the circumferentially opposed surfaces of the tubular member and the shaft member. Since it is not transmitted to the first elastic body as it is, it is exerted by the first elastic body,
Good vibration damping performance can be sufficiently ensured.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing a steering coupling as a first embodiment of the present invention, and is a view corresponding to a view taken along the arrow I-I in FIG.

FIG. 2 is an enlarged left side view of FIG.

3 is an enlarged cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

5 is a sectional view corresponding to FIG. 3, showing a vulcanized molded product of the steering coupling shown in FIG. 1.

6 is a cross-sectional view showing a state in which a shaft fitting is press-fitted into the vulcanized molded product shown in FIG.

FIG. 7 is a side view showing a steering coupling as a second embodiment of the present invention.

8 is a sectional view taken along line VIII-VIII in FIG.

9 is a sectional view corresponding to FIG. 8, showing a vulcanized molded product of the steering coupling shown in FIG. 7.

FIG. 10 is a side view showing a steering coupling as a third embodiment of the present invention.

11 is a sectional view taken along line XI-XI in FIG.

12 is a sectional view corresponding to FIG. 11, showing a vulcanized molded product of the steering coupling shown in FIG.

13 is a vertical sectional view showing a steering coupling as a fourth embodiment of the present invention, which is taken along line XI in FIG.
It is a figure corresponding to a II-XIII cross section.

14 is a sectional view taken along line XIV-XIV in FIG.

15 is an axial side view showing a vulcanized molded product of the steering coupling shown in FIG. 13. FIG.

16 is a cross-sectional view showing a state in which a shaft fitting is press-fitted into the vulcanized molded product shown in FIG.

[Explanation of symbols]

 10, 60, 62, 64 Steering coupling 12 Cylindrical metal fitting 16 Shaft metal fitting 18 Rubber elastic cylindrical body 26 Recessed portion 28 Insertion portion 32 Projection portion 34 Circumferential side surface 36 Side surface inner surface 38 Outer peripheral surface 40 Groove inner surface 52 Pressure contact projection 54 First elasticity Body portion 56 Second elastic body portion 66 Flat portion 68 Curved portion 70 Flat surface 72 Curved surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masakazu Ishikawa 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (7)

[Claims] 1. Between the inner peripheral surface of the tubular member and the outer peripheral surface of the shaft member inserted into the inner hole of the tubular member with a predetermined gap,
Forming circumferential facing surfaces that are brought closer to each other by relative rotation around the central axis, and interposing the first elastic body between the circumferential facing surfaces, the rotational force about the central axis between the two members is reduced. In a shaft coupling in which transmission is performed via the first elastic body, in a direction perpendicular to the axis, which is located between the inner peripheral surface of the tubular member and the outer peripheral surface of the shaft member in a direction perpendicular to the axis. Forming facing surfaces, interposing a second elastic body between the facing surfaces in the direction perpendicular to the axis, and applying a precompression larger than that of the first elastic body to the second elastic body. Characteristic shaft coupling. 2. The shaft coupling according to claim 1, wherein the circumferentially facing surface and the axially perpendicularly facing surface are formed at portions substantially different in the circumferential direction between the tubular member and the shaft member. . 3. A protrusion protruding in a direction perpendicular to the axis and a recess into which the protrusion is inserted are provided at respective corresponding positions of the shaft member and the cylindrical member, and a circumferential side surface of the protrusion and the recess. The shaft coupling according to claim 1 or 2, wherein the circumferentially opposed surface is formed by an inner surface of the shaft. 4. The shaft coupling according to claim 1, wherein the axially-opposing faces are formed at at least two positions that sandwich the shaft member in a direction perpendicular to the axis. 5. One of the tubular member and the shaft member on the surface facing in the direction perpendicular to the axis is bonded to the second elastic body, while the other of the tubular member and the shaft member is The shaft coupling according to any one of claims 1 to 4, which is press-fitted and fixed to the second elastic body. 6. The first elastic body and the second elastic body are integrally formed by a cylindrical body that is continuous in the circumferential direction, and the cylindrical body and the inner peripheral surface of the cylindrical member are The shaft joint according to any one of claims 1 to 5, which is continuously interposed in the circumferential direction between the outer peripheral surface of the shaft member. 7. A circumferentially-opposing surface that is made to approach each other by relative rotation about a central axis by being inserted / extracted with a predetermined gap therebetween, and an axially-opposing surface that is positioned to face in the axis-perpendicular direction substantially. A step of preparing a tubular member and a shaft member respectively formed in different parts, a first elastic body interposed between the circumferential facing surfaces, and a second elastic body interposed between the axial facing surfaces. A step of providing a body on either one of the tubular member and the shaft member, and by inserting the other of the tubular member and the shaft member axially in and out of the tubular member and the shaft member. ,
The circumferential facing surface and the axially facing surface are positioned so as to face each other with the first elastic body and the second elastic body interposed therebetween, and the first elastic body and the second elastic body are opposed to each other. And a step of press-fitting the other of the tubular member and the shaft member into the second elastic body so that pre-compression larger than that of the elastic body is applied.