JPH09229085A - Elastic shaft coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost of the whole steering device by enabling a single construction to absorb not only vibration extending over the circumferential direction but vibration extending over the axial direction. SOLUTION: A plurality of holding recessed parts 17 are formed on the inner circumferential face of an inner cylinder 8a of a cushioning cylinder 7a with built-in elastic material 10. A plurality of engaging recessed grooves 18 are formed on the outer circumferential face of the end part of a shaft 6a. Engaging members such as rollers 19 are built in between these respective holding recessed parts 17 and engaging recessed grooves 18. Vibration extending over the axial direction is absorbed by sliding of the rollers 19 against the engaging recessed grooves 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The elastic shaft joint according to the present invention is used in a state where it is incorporated in a steering device of an automobile in order to prevent the vibration of the wheel from being transmitted to the steering wheel.

[0002]

2. Description of the Related Art When vehicle vibrations are transmitted to a steering wheel while a vehicle is running, the driver who operates the steering wheel feels uncomfortable. Therefore, conventionally, an elastic shaft coupling is provided in the middle portion of the steering shaft to prevent the above vibration from being transmitted to the steering wheel. 6 to 9 show an example of a conventionally used elastic shaft coupling.

Both ends (both left and right ends in FIG. 6) of the intermediate shaft 2 which is provided with a spline engaging portion 1 and is configured to be expandable and contractible are connectable to other shafts by universal joints 3a and 3b, respectively. The operating force applied to the steering wheel is
It is transmitted to a steering gear (not shown) through these members 3a, 2 and 3b, and a steering angle corresponding to the operation amount of the steering wheel is given to the front wheels. FIG.
In the case of the structure shown in FIG. 9, the elastic shaft coupling 4 which is the object of the present invention has the base end portion (the right end portion of FIGS. 6 and 8) of the yoke 5 which constitutes one (left side of FIG. 6) universal joint 3a. And the intermediate shaft 2
It is incorporated between the end portion of the shaft 6 (the left end portion in FIG. 6) that constitutes the.

That is, by forming the base end portion of the yoke 5 into a cylindrical shape, the yoke 5 has a function as a cylindrical member having a cylindrical inner peripheral surface. Further, the outer diameter of the end portion of the shaft 6 is smaller than the inner diameter of the base end portion of the yoke 5. A buffer cylinder 7 is provided between the inner peripheral surface of the base end of the yoke 5 and the outer peripheral surface of the end of the shaft 6. The buffer cylinder 7 is provided between the outer peripheral surface of the inner cylinder 8 and the inner peripheral surface of the outer cylinder 9, and the inner cylinder 8 and the outer cylinder 9 which are formed in a cylindrical shape and are arranged concentrically with each other. In addition, the elastic member 10 is made of rubber or the like. The inner peripheral surface of the elastic member 10 is bonded to the outer peripheral surface of the inner cylinder 8 and the outer peripheral surface thereof is bonded to the inner peripheral surface of the outer cylinder 9 by baking, bonding or the like. Further, the inner cylinder 8 is the shaft 6
The outer cylinder 9 is externally fitted and fixed to the outer end of the yoke 5 by an interference fit, and the outer cylinder 9 is internally fitted and fixed to the base end of the yoke 5 by an interference fit.

Further, both ends of the stopper pin 11 penetrating the outer end of the shaft 6 and the buffer cylinder 7 in the respective diametrical directions are located at diametrically opposite positions of the base end of the yoke 5. It inserts in the formed circular holes 12 and 12 concentric to each other. The inner diameter of each of the circular holes 12, 12 is larger than the outer diameter of both ends of the stopper pin 11. Then, in the neutral state where no external force acts, both ends of the stopper pin 11 are located at the central portions of the circular holes 12 and 12, and the outer peripheral surfaces of both end portions and the inner peripheral surfaces of the circular holes 12 and 12 are separated from each other. Between them, a substantially uniform gap is formed over the entire circumference. In addition, circular holes 13 and 14 having the same shape as the circular holes 12 and 12 are also formed at positions where the outer cylinder 9 and a part of the elastic member 10 are aligned with the circular holes 12 and 12. On the other hand, at a position where the inner cylinder 8 and a part of the outer end portion of the shaft 6 are aligned with the circular holes 12 to 14,
Circular holes 15 and 1 each having a diameter slightly smaller than each of these circular holes 12 to 14.
6 are formed. Both ends of the stopper pin 11 are
As shown in FIG. 9, it has a cylindrical shape, and the portion protruding from the outer peripheral surface of the inner cylinder 8 has an enlarged diameter. Therefore, the stopper pin 11 will not fall out from the position shown in FIGS.

In the elastic shaft coupling constructed as described above, the vibration transmitted from the wheel side to the yoke 5 in a straight traveling state is
It is absorbed by the elastic material 10 that constitutes the buffer cylinder 7. On the other hand, when the steering wheel is operated to change the course and the shaft 6 is rotated, the stopper pin 1
The outer peripheral surfaces of both end portions of 1 abut against the inner side surfaces of the circular holes 12, 12 formed in the base end portion of the yoke 5. In this state, the rotation of the shaft 6 is transmitted to the yoke 5 without passing through the elastic material 10. Therefore, excessive shear stress is not applied to the elastic material 10, and the elastic material 10 is damaged or
Alternatively, the durability of the elastic material 10 is not impaired.

[0007]

In the case of the conventional structure shown in FIGS. 6 to 9, it is necessary to absorb vibrations particularly in the axial direction (left and right directions in FIGS. 6 and 8, front and back directions in FIGS. 7 and 9). Is not considered. On the other hand, the magnitude of vibration applied to the steering device may be greater in the axial direction than in the circumferential direction depending on the vehicle type. Therefore, when the elastic shaft coupling as shown in FIGS. 6 to 9 is used, in order to absorb the vibration in the axial direction, a rubber coupling is separately provided in series with the elastic shaft coupling so that the axial vibration It is necessary to provide a structure for absorbing. For example, in the case of the conventional structure shown in FIGS. 6 to 9, the spline engagement portion 1 is provided in the middle of the intermediate shaft 2 so as to absorb the vibration in the axial direction. However, such a spline engaging portion 1 is troublesome to manufacture and causes a high cost. If a structure for absorbing the axial vibration is separately provided in this way, it is not preferable because parts production, parts management, and assembling work are required correspondingly, which causes a cost increase. In view of such circumstances, the elastic shaft coupling of the present invention has been invented to realize a structure capable of effectively absorbing not only vibration in the circumferential direction but also vibration in the axial direction.

[0008]

The elastic shaft coupling of the present invention comprises:
Similar to the conventional elastic shaft coupling described above, a shaft having a cylindrical outer peripheral surface, and provided around the shaft,
A tubular member having a cylindrical inner peripheral surface, and a buffer cylinder configured to include a cylindrical elastic material and fitted and held between the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical member. Equipped with. Particularly, in the elastic shaft coupling of the present invention, the inner cylinder fixed to the inner peripheral surface portion of the buffer cylinder and the inner peripheral surface of the elastic member coupled to the outer peripheral surface thereof and the outer peripheral surface of a part of the shaft. A plurality of holding recesses formed on one peripheral surface of the inner peripheral surface of the inner cylinder and the inner peripheral surface of the inner cylinder, and a part of the outer peripheral surface of the shaft inside the inner cylinder. On the other peripheral surface of the portion facing the peripheral surface and the inner peripheral surface of the inner cylinder, a plurality of engaging concave grooves formed in the axial direction of the shaft and the tubular member, and While fitting one half part in each of the holding recesses, and the other half part in each of the engaging recessed grooves, a plurality of engaging members fitted displaceably along the engaging recessed grooves, respectively. Prepare

[0009]

The operation of the elastic shaft coupling of the present invention constructed as described above when absorbing the vibrations in the circumferential direction is the same as that of the conventional structure described above. In addition, torque transmission between the shaft and the inner cylinder forming the buffer cylinder is sufficient through a plurality of engaging members in which both half portions are fitted in the holding concave portion and the engaging concave groove. It is made rigid. Furthermore, in the case of the elastic shaft coupling of the present invention, the fitting member provided so as to be bridged between the fitting recesses and the engaging recessed grooves provided in plural,
By displacing along the engagement groove, vibrations in the axial direction are absorbed.

[0010]

1 to 5 show an example of an embodiment of the present invention. In this example, as in the case of the conventional structure described above, an elastic shaft coupling is incorporated between the yoke 5 of the universal joint 3a incorporated in the steering device and the shaft 6a constituting the intermediate shaft 2, and, for example, from the universal joint 3a to the intermediate shaft. Two
It is designed to prevent the transmission of vibration to the. Therefore,
In the case of this example, the yoke 5 corresponds to the tubular member in the claims, and the shaft 6a also corresponds to the shaft in the claims. The feature of the present invention resides in that it efficiently absorbs not only vibration in the circumferential direction but also vibration in the axial direction. Since the configuration and operation of the other parts are the same as those of the conventional structure shown in FIGS. 6 to 9 described above, the same parts are designated by the same reference numerals to omit or simplify duplicate description, and hereinafter, the present invention will be described. The characteristic part will be mainly described.

The inner cylinder 8a is fixed to the inner peripheral surface portion of the buffer cylinder 7a, and the inner peripheral surface of the elastic material 10 is joined to the outer peripheral surface of the buffer cylinder 7a by baking, bonding or the like (see FIGS. 1, 2, 4, 5). (In the left-right direction of FIG. 3, the front-back direction in FIG. 3), at the middle portion in the circumferential direction, there are holding recesses 17, 17 each having an arcuate cross section and a long groove shape.
Is formed. The length direction of each of the holding recesses 17, 17 is aligned with the axial direction of the inner cylinder 8a. on the other hand,
The shaft 6a is formed in a hollow tubular shape, and a plurality of engaging recessed grooves 18, 18 each having an arc-shaped cross section are formed in the end of the shaft 6a in the axial direction of the shaft 6a. ing. The holding recesses 17, 17 and the engaging recesses 18, 18 are formed in the same phase in the circumferential direction. Therefore, with the shaft 6a inserted in the inner cylinder 8a, all the holding recesses 17, 17 and the engaging recesses 18, 18 are aligned at the same time. The inner diameter of the inner cylinder 8a is slightly larger than the outer diameter of the outer end of the shaft 6a. Therefore, the inner cylinder 8a is fitted onto the outer end of the shaft 6a by a clearance fit and is displaceable in the axial direction.

These holding recesses 17, 17 and the engaging recess groove 1
A plurality of rollers 19 and 19 each serving as an engaging member are provided between the holding recesses 17 and 17 and the engaging recess groove 1.
8 and 18 are fitted one by one. That is, the outer half of each of the rollers 19 and 19 is connected to each of the holding recesses 17,
While being fitted to 17, the respective inner halves are fitted to the upper engaging grooves 18 and 18 so as to be displaceable along the engaging grooves 18 and 18, respectively.

Further, the base end portion of the yoke 5 (see FIGS.
4 at the right end), the outer cylinder 9, the elastic member 10, and the inner cylinder 8a that form the buffer cylinder 7a, respectively, at two positions on the diametrically opposite sides, which are aligned with each other.
Also, elongated holes 20 to 23 are formed in the axial direction of the yoke 5. The outer end of the shaft 6a is provided with circular holes 24, 24 similar to the above-described conventional structure. Each of these long holes 20
23 to 23 have a width dimension W slightly larger than the outer diameter dimension D of both ends of the stopper pin 11 and a length dimension L sufficiently larger than the outer diameter dimension D. Therefore, the shaft 6a
The stopper pin 11, which is fixed to the outer end portion of the, can be slightly displaced in the torsional direction with respect to the yoke 5, and can be sufficiently displaced in the axial direction.

In the case of the elastic shaft coupling of the present invention constructed as described above, when the rotational force is transmitted between the shaft 6a and the yoke 5 in order to transmit the movement of the steering wheel to the front wheels. First of all,
Transmits this rotational force. That is, when the shaft 6a rotates in accordance with the movement of the steering wheel, the movement of the shaft 6a is transmitted to the plurality of rollers 19 and 19 fitted into the engagement recessed grooves 18 and 18, respectively. Further, the movement of the plurality of rollers 19, 19 causes the plurality of holding concave grooves 1 to move.
It is transmitted to the inner cylinder 8a of the buffer cylinder 7a via 7,17. Therefore, although the inner cylinder 8a is fitted over the outer end portion of the shaft 6a by a clearance fit, the shaft 6a and the inner cylinder 8 are
Rotational force is transmitted to and from a with sufficient certainty. Therefore, while the torque applied to the shaft 6a is small,
Rotational force transmission between the shaft 6a and the yoke 5 is surely performed via the elastic material 10 forming the buffer cylinder 8a. Of course, when the torque becomes large, the rotational force is transmitted by the abutment between both ends of the stopper pin 11 and the inner edges of the slots 20, 20.

When vibrations are applied to the yoke 5 in the axial direction, a plurality of rollers 1 are provided for each roller 1.
9 and 19 are displaced along the engaging recessed grooves 18 and 18 to absorb vibrations in the axial direction. That is, when the yoke 5 is displaced in the axial direction, the holding recesses 17,
The rollers 19, 19 held by 17 are the engaging groove 1
It slides with respect to 8 and 18, and prevents the displacement of the yoke 5 from being transmitted to the shaft 6a. At this time, both ends of the stopper pin 11 are displaced in the axial direction of the yoke 5 inside the elongated holes 20 to 23. Therefore, unlike the conventional structure, the axial vibration can be absorbed without separately providing a structure for absorbing the axial vibration. or,
The work for forming the holding recesses 17 and 17 and the engaging recesses 18 and 18 can be efficiently performed by pressing or drawing, so that the cost is increased by incorporating a structure for absorbing axial vibration. Is minimal (it is cheaper than if it is provided separately).

A plurality of balls are rotatably provided between the holding recesses 17 and 17 and the engaging recesses 18 and 18, respectively. If the balls are used as engaging members, the yoke is formed. The axial displacement between the shaft 5 and the shaft 6a can be absorbed more smoothly. Further, when balls are used as the engaging members, the holding recess may be a spherical concave surface.

[0017]

Since the elastic shaft joint of the present invention is constructed and operates as described above, the number of parts constituting the steering device can be reduced by improving the vibration absorbing performance of the elastic shaft joint itself. It is possible to reduce the size, weight and cost of the steering device.

[Brief description of drawings]

FIG. 1 is a partially cut side view of a steering device incorporating an elastic shaft coupling, showing an example of an embodiment of the present invention.

FIG. 2 is an enlarged view of the left part of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 3;

5 is a view taken in the direction of arrow C in FIG. 2, in which some members are omitted.

FIG. 6 is a partially cut side view of a steering device incorporating an example of a conventional elastic shaft coupling.

7 is an enlarged sectional view taken along line DD of FIG.

FIG. 8 is a view taken in the direction of arrow E in FIG. 6, in which some members are omitted.

FIG. 9 is a view similar to FIG. 7, showing a part of the stopper pin in a cut state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spline engaging part 2 Intermediate shaft 3a, 3b Universal joint 4 Elastic shaft joint 5 Yoke 6, 6a Shaft 7, 7a Buffer cylinder 8, 8a Inner cylinder 9 Outer cylinder 10 Elastic material 11 Stopper pin 12, 13, 14, 15, 16 circular hole 17 holding concave portion 18 engaging concave groove 19 roller 20, 21, 22, 23, 24 long hole

Claims (1)

[Claims] 1. A shaft having a cylindrical outer peripheral surface, a cylindrical member provided around the shaft and having a cylindrical inner peripheral surface, and a cylindrical elastic material. In an elastic shaft joint having a shock absorbing cylinder fitted and held between the outer peripheral surface of the shock absorbing cylinder and the inner peripheral surface of the cylindrical member, the elastic shaft coupling is fixed to the inner peripheral surface portion of the shock absorbing cylinder, and An inner cylinder connecting the inner peripheral surface of the elastic member, a part of the outer peripheral surface of the shaft facing the inner peripheral surface of the inner cylinder, and one of the inner peripheral surfaces of the inner cylinder on the peripheral surface. The plurality of holding recesses formed, a part of the outer peripheral surface of the shaft facing the inner peripheral surface of the inner cylinder, and the inner peripheral surface of the inner cylinder on the other peripheral surface, the shaft and the cylinder. A plurality of engaging recessed grooves formed in the axial direction of the plate-shaped member, and one half of each of them is fitted into each of the holding recesses, and An elastic shaft coupling, comprising: a plurality of engaging members, the other half of which is fitted in the engaging grooves so as to be displaceable along the engaging grooves.