JPH1144327A - Elastic shaft joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and compact elastic shaft joint while securing reliability. SOLUTION: A fitting member 111 is constituted smaller and compacter than an outside diameter of a yoke 103 since it is arranged between tabs of the yoke 103. When relative rotation of a spline part 101b and the fitting member 111 is not less than a prescribed angle, a projecting part 101e comes into contact with an opening part 111e, and since the spline part 101b and the yoke 103 are integrally rotated, when excessive torque is transmitted, twisting rupture of an elastic body can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic shaft coupling, and more particularly to a compact elastic shaft coupling excellent in vibration absorption.

[0002]

2. Description of the Related Art For example, a steering shaft in a steering device of a vehicle extends from a vehicle interior to a front portion of the vehicle body. Have difficulty. Therefore, such a steering shaft is usually divided into a plurality of parts, arranged at an angle, and connected to each other by a universal joint.

FIG. 11 is a diagram showing an intermediate shaft, which is a divided steering shaft, and a universal joint connected to the intermediate shaft, cut in the axial direction. 12 is a diagram of a part of the configuration of FIG. 11 viewed from the side, FIG. 13 is a diagram of the configuration of FIG. 12 cut along line XIII-XIII and viewed in the direction of the arrow, and FIG. FIG. 12 is a view of the configuration of FIG. 11 taken along line XIV-XIV and viewed in the direction of the arrow.

The intermediate shaft 1 has a fitting portion 1a formed on the left end side and having a substantially rectangular cross section, and spline teeth 1b formed on the outer periphery on the right end side. A cover 2 is attached around the intermediate shaft 1. As shown in FIG. 13, the fitting portion 1a includes a pair of tabs 3a extending in parallel on the yoke 3,
The nut 5 is screwed into a bolt 4 inserted into bolt holes 3c and 3d formed in the tabs 3a and 3b.

[0005] The yoke 3 is attached to a yoke 7 on the steering gear side via a cross joint 6. The yoke 3 is a so-called horizontal insertion yoke. When the yoke 3 is connected to the shaft, the yoke is pressed against the side of the shaft without relatively moving the yoke and the shaft in the axial direction, and the shaft is pushed between the tabs. The connection is performed as described above. Yoke 3 and cross joint 6
And the yoke 7 constitute a hook-shaped universal joint.

On the other hand, the intermediate shaft 1 has its spline teeth 1b.
Is fixedly engaged with the female spline 8a of the buffer joint 8 by press fitting or the like. The shock-absorbing joint 8 has an inner cylinder 8c having a female spline 8a formed at one end inner circumference and a projection 8b extending radially at the other end, an outer cylinder 8d including the inner cylinder 8c, and an inner cylinder 8c. And an elastic member 8e formed between the outer cylinder 8d. The buffer joint 8 is connected to the yoke 1 on the steering wheel side via a cross joint 9.
It is attached to 0. The buffer joint 8, the cruciform joint 9, and the yoke 10 constitute a hook-shaped universal joint.

The elastic member 8e is fixed to a cylindrical outer member 8f pressed into the outer cylinder 8d, a cylindrical inner member 8g pressed into the inner cylinder 8c, and between the outer member 8f and the inner member 8g. And an elastic body 8h made of rubber.

As shown in FIG. 14, the inner cylinder 8c has a pair of projections 8b extending radially outwardly at the ends thereof. On the other hand, the outer periphery of the outer cylinder 8d corresponding to each of the projections 8b is cut out, and the locking portions 8 facing in the circumferential direction are cut off.
j.

In such a conventional steering shaft, when a steering wheel (not shown) is in a neutral position or when a relatively small steering force is applied to the steering wheel, the projection 8b of the buffer joint 8 is engaged with the locking portion 8j. Do not abut. Therefore, even if vibration or the like is transmitted from the road surface, the outer cylinder 8d and the inner cylinder 8c
Is absorbed by the elastic body 8h of the elastic member 8e disposed therebetween, thereby improving the steering feeling of the driver.

On the other hand, when a large steering force is applied to the steering wheel, for example, during stationary operation,
The projection 8b of the buffer joint 8 comes into contact with the locking portion 8j, and transmits steering torque directly from the outer cylinder 8d to the inner cylinder 8c, thereby preventing the elastic member 8e of the elastic member 8e from being twisted and broken. .

[0011]

The steering shaft shown in FIG. 11 has the following problems. Since the elastic member 8e is press-fitted and fixed to the inner cylinder 8c and the outer cylinder 8d, respectively, the dimensional tolerance between the outer diameter of the inner cylinder 8c and the inner diameter of the elastic member 8e, and the outer diameter and the outer diameter of the elastic member 8e. It is necessary to strictly control the dimensional tolerance with respect to the inner diameter of the cylinder 8d, so that it is necessary to increase the processing accuracy of each part, and the cost increases.

On the other hand, since the elastic member 8e is arranged between the outer cylinder 8d and the inner cylinder 8c in the radial direction, the radial dimension of the elastic joint 8 increases. In addition, if it is attempted to secure a higher vibration absorbing effect and durability of the elastic body 8h while suppressing the radial dimension, the axial dimension of the elastic joint 8 increases. When the size of the elastic joint is increased in this way, the degree of freedom in design when mounted on a vehicle is reduced.

Further, since the locking portion 8j has a free end, its rigidity is relatively low. Therefore, the projection 8 of the elastic joint 8
When b strongly contacts, the locking portion 8j is deformed (turned).
Or breakage may occur. To prevent this,
It is necessary to take measures such as increasing the thickness of the locking portion 8j. However, doing so causes further increase in the size and weight of the elastic joint 8.

[0014] In view of the above problems, an object of the present invention is to provide an inexpensive and compact elastic shaft coupling while ensuring reliability.

[0015]

In order to achieve the above object, an elastic shaft coupling according to the present invention comprises: a shaft having a projection;
A fitting member disposed around the shaft and having a locking portion, an elastic member fixed between the shaft and the fitting member, and a pair of tabs extending parallel to the axis of the shaft And the fitting member is disposed between the tabs of the yoke, and when the relative rotation between the shaft and the fitting member is equal to or greater than a predetermined angle, the protrusion is The shaft and the yoke are integrally rotated by contacting the locking portion.

[0016]

According to the elastic shaft coupling of the present invention, since the fitting member is disposed between the tabs of the yoke, the fitting member has a compact configuration smaller than the outer diameter of the yoke.
When the relative rotation between the shaft and the fitting member is equal to or greater than a predetermined angle, the protrusion comes into contact with the locking portion, and the shaft and the yoke are integrally rotated. Therefore, when an excessive torque is transmitted, it is possible to prevent the elastic body from being twisted and broken.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an intermediate shaft, which is a divided steering shaft including an elastic shaft coupling according to the present embodiment, and a universal joint connected thereto, cut in the axial direction. FIG. 2 is a side view of a part of the configuration of FIG. 1, and FIG.
It is the figure cut | disconnected by the III line and seen in the arrow direction. The elastic shaft coupling of the present embodiment includes an intermediate shaft 101, a yoke 103
, A fitting member 111, and an elastic member 111b.

The intermediate shaft 101 comprises a tube 101a and a spline portion 101b. Tube 101a
Has a yoke 108 welded to its right end.
Reference numeral 08 is attached to a yoke 110 on a steering wheel (not shown) via a cross joint 109.

On the other hand, the spline portion 101b is formed by connecting spline teeth 101c formed on the outer periphery thereof to the tube 101a.
Is fixedly engaged with the female spline 101d formed on the inner periphery of the left end by press fitting or the like. Therefore, the tube 101a and the spline portion 101b are integrated in the rotation direction, but can be relatively moved in the axial direction when an axial load of a predetermined value or more is applied. Spline part 10
A cover 102 is attached around 1b.
It is to be noted that the cover 102 is connected to the spline portion 101b before the tube 101a and the spline portion 101b are connected.
It is arranged around.

FIG. 4 is a view of the spline portion 101b and the fitting member 111 viewed in the axial direction, and FIG. 5 is a side view thereof. A protrusion 101e (FIG. 4) having a substantially square cross section as viewed in the axial direction is formed at the left end of the spline portion 101b. The fitting member 111 is attached so as to surround the vicinity of the left end of the spline portion 101b.

As shown in FIG. 1, the fitting member 111 includes an outer wall portion 111a having a width substantially equal to the distance between the tabs of the yoke 103, a substantially rectangular cylindrical shape, an outer wall portion 111a and the spline portion 10a.
1b, an elastic member 111b made of rubber fixed by vulcanization molding, press-fitting, bonding or the like, and an end face portion 111c for closing the left end of the outer wall portion 111a.

As shown in FIG. 4, the fitting member 111 has an opening 111e which is similar to the projection 101e of the spline portion 101b but is slightly larger than the projection 111e at substantially the center of the end face portion 111c. . The protrusion 10
The gaps on both sides between the opening 1e and the opening 111e are S1.

As shown in FIG. 3, the fitting member 111 includes a pair of tabs 103 extending in parallel on the yoke 103.
a, 103b are fitted and arranged between the tabs 103a, 103b.
The nut 104 is attached to the yoke 103 by screwing a nut 104 into a bolt 105 inserted into the bolt holes 103c and 103d formed in the hole b.

As is apparent from FIGS.
Four projections 111d extend upward from 1a by a short distance. The convex portion 111d is formed to be driven inward by a distance S2 with respect to both side portions of the outer wall portion 111a. The convex portion 111d is provided with the bolt 105 and the nut 10
4 due to insufficient fastening force with the fitting member 11.
1 moves in the axial direction with respect to the yoke 103,
By contacting the bolt 105, it functions to prevent further movement. Further, even when the tabs 103a and 103b of the yoke 103 are deformed so as to be inclined inward due to the fastening of the bolt 105 and the nut 104, the protruding portion 111d contacts the inner surfaces of the tabs 103a and 103b to provide further protrusions. Functions to prevent deformation.

The yoke 103 is attached to a yoke 107 on a steering gear (not shown) via a cross joint 106.

In the steering shaft according to the present embodiment, when a steering wheel (not shown) is in a neutral position or when a relatively small steering force is applied to the steering wheel, the presence of the gap S1 causes the intermediate shaft 101 to move. Projection portion 10 of spline portion 101b
1e does not come into contact with the opening 111e of the fitting member 111. Therefore, even if vibration or the like is transmitted from the road surface, the fitting member 111 and the spline portion 101b
And is effectively absorbed by the elastic body 111b disposed between them, thereby improving the steering feeling of the driver.

On the other hand, when a large steering force is applied to the steering wheel, for example, during stationary operation,
Projection portion 101e of spline portion 101b of intermediate shaft 101
But, it comes into contact with the opening 111e of the fitting member 111, and transmits the steering torque directly from the spline portion 101b to the fitting member 111, thereby preventing the elastic body 111b from being twisted and broken. That is, the periphery of the opening 111e serves as a locking portion that locks the protrusion 101e.

According to the present embodiment, the fitting member 111 is connected to the tabs 103a, 103a,
By arranging it between 03b, a more compact configuration can be achieved. Further, the intermediate shaft 101 is connected to the yoke 1
08 and can be inexpensive enough to be welded.

In the event of a vehicle collision, the intermediate shaft 10
Numeral 1 receives a compressive load from both ends, and is displaced so that the spline portion 101b enters the tube 101a, thereby functioning to absorb or reduce the impact at the time of collision.

FIGS. 6 and 7 show a fitting member and a spline portion according to a second embodiment of the present invention.
FIG. Note that the second embodiment will be described focusing on differences from the first embodiment, and description of common parts will be omitted.

The second embodiment shown in FIGS.
The difference from the first embodiment is that the end face 2
This is the shape of the opening 211e formed in 11c. That is, the opening 211e has a substantially oval shape.
Correspondingly, the protrusion 201 of the spline portion 201b
The shape of e is also substantially oval.

According to the present embodiment, the contact position between the projection 201e and the opening 211e is larger in the radial direction than in the first embodiment, whereby the stress of the contact portion is reduced. Can be smaller.

FIGS. 8 and 9 show a fitting member and a spline portion according to a third embodiment of the present invention.
FIG. Note that the third embodiment will also be described focusing on differences from the above-described embodiment, and a description of common parts will be omitted.

The third embodiment shown in FIGS.
The difference from this embodiment is the shape of the fitting member 311. More specifically, the fitting member 311 does not form an end surface portion, and instead, the both side surfaces 311c extend a short distance in the axial direction.

On the other hand, the tip of the spline portion 301b has a projection 301e having a substantially oval cross section. The stopper plate 312 has an opening 312a having the same contour as that of the projection 301e. By fitting the projection 301e into the opening 312a, the stopper plate 312 is attached so as to rotate integrally with the spline portion 101b. I have.

In the steering shaft according to the present embodiment, when the steering wheel (not shown) is in the neutral position or when a relatively small steering force is applied to the steering wheel, the stopper plate 31
Due to the existence of the gap S1 between the side surface 311c and the side surface 311c, the stopper plate 312
Do not abut. Therefore, even if vibration or the like is transmitted from the road surface, the fitting member 311 and the spline portion 301b
Is absorbed by an elastic body (not shown) disposed between
Thereby, the steering feeling of the driver is improved.

On the other hand, when a large steering force is applied to the steering wheel, for example, during stationary operation,
A stopper plate 312 that rotates integrally with the spline shaft 301b abuts against a side surface 311c of the fitting member 311 and transmits steering torque directly from the spline portion 301b to the fitting member 311 to thereby prevent the elastic body from being twisted and broken. It is supposed to. In such a case, the stopper plate 312 forms a protrusion, and the side surface 311c forms a locking portion.

FIG. 10 is a sectional view similar to FIG. 1, showing a fourth embodiment according to the present invention. Note that the fourth embodiment will also be described focusing on differences from the first embodiment, and a description of common parts will be omitted.

The fourth embodiment shown in FIG. 10 differs from the first embodiment in the direction of the intermediate shaft 101.
That is, the tube 401a of the intermediate shaft 401 is connected to the universal joint on the steering gear (not shown) side, while the spline portion 401b of the intermediate shaft 401 is connected to the universal joint on the steering wheel (not shown) side.

According to the present embodiment, the size of the cover 402 can be reduced, and the spline portion 401b can be easily inserted into the tube 401a. Also, the fitting member 4
11 and the yoke 409 can be arranged in the vehicle interior,
This facilitates waterproofing measures.

As described above, the present invention has been described with reference to the embodiments. However, the present invention should not be construed as being limited to the above embodiments, and it is needless to say that modifications and improvements can be made as appropriate. is there. For example, the cross-sectional shape of the projection of the spline portion is not limited to a substantially square shape or a substantially oval shape, and may be another shape such as a cross shape.

[0042]

As described above, according to the elastic shaft coupling of the present invention, since the fitting member is disposed between the tabs of the yoke, it has a compact configuration smaller than the outer diameter of the yoke. When the relative rotation between the shaft and the fitting member is equal to or greater than a predetermined angle, the protrusion comes into contact with the locking portion,
Since the shaft and the yoke are integrally rotated, it is possible to prevent the elastic body from being twisted and broken when an excessive torque is transmitted.

[Brief description of the drawings]

FIG. 1 is a diagram showing an intermediate shaft, which is a divided steering shaft, including an elastic shaft coupling according to a first embodiment, and a universal joint connected thereto, cut in an axial direction.

FIG. 2 is a side view of a part of the configuration of FIG. 1;

FIG. 3 is a view of the configuration of FIG. 2 cut along a line III-III and viewed in a direction indicated by an arrow.

FIG. 4 is a view of a spline portion 101b and a fitting member 111 viewed in an axial direction.

FIG. 5 is a side view of the spline portion 101b and the fitting member 111.

FIG. 6 is a view similar to FIG. 4, showing a fitting member and a spline portion according to a second embodiment of the present invention;

FIG. 7 is a view similar to FIG. 5, showing a fitting member and a spline portion according to a second embodiment of the present invention.

FIG. 8 is a view similar to FIG. 4, showing a fitting member and a spline portion according to a third embodiment of the present invention.

FIG. 9 is a view similar to FIG. 5, showing a fitting member and a spline portion according to a third embodiment of the present invention.

FIG. 10 is a sectional view similar to FIG. 1, showing a fourth embodiment according to the present invention;

FIG. 11 is a view of a conventional example showing an intermediate shaft, which is a divided steering shaft, and a universal joint connected thereto, cut in the axial direction.

12 is a side view of a part of the configuration of FIG. 11;

FIG. 13 is a view of the configuration of FIG. 12 cut along a line XIII-XIII and viewed in a direction of an arrow.

FIG. 14 is a view of the configuration of FIG. 11 cut along a line XIV-XIV and viewed in a direction of an arrow.

[Explanation of symbols]

 101, 201, 301, 401 ... Intermediate shaft 101e, 201e, 301e, 401e ... Protrusion 111, 211, 311, 411 ... Fitting member 111e, 211e, 311e, 411e ...

Claims (1)

[Claims] A shaft having a projection; a fitting member disposed around the shaft and having a locking portion; an elastic member fixed between the shaft and the fitting member; A yoke having a pair of tabs extending parallel to the axis, wherein the fitting member is disposed between the tabs of the yoke, and the relative rotation between the shaft and the fitting member is An elastic joint in which the projection comes into contact with the locking portion when the angle is equal to or more than a predetermined angle, and the shaft and the yoke are rotated integrally.