JP2000213552A - Elastic shaft coupling - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To achieve a mass production effect and reduce manufacturing costs by enabling partial sharing of an outer shaft and an inner shaft even in a large number of vehicle types. SOLUTION: In a stage of preparing parts before assembling an elastic shaft coupling, an outer shaft 3 and an inner shaft 6 which are partially shared are prepared irrespective of a vehicle type, and then the inner shaft 6 is attached to the outer shaft 3. After the insertion, the gap S1 between the flat inner peripheral surfaces 7a, 7b of the outer shaft 3 and the flat outer peripheral surfaces 8a, 8b of the inner shaft 6 is narrowed, for example, by press molding, according to the torque required for each vehicle type. To form S2. Therefore, it is possible to obtain a gap S2 between the outer shaft 3 and the inner shaft 6 according to the required torque for each vehicle type while partially sharing the outer shaft 3 and the inner shaft 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering apparatus for a vehicle, for example, in which an elastic body such as rubber is provided between a cylindrical outer shaft connected to a yoke of a universal joint and an inner shaft inserted into the outer shaft. The present invention relates to an elastic shaft coupling that intercepts vibration of an engine and wheels to suppress transmission of vibration to a steering wheel.

[0002]

2. Description of the Related Art Various types of joints in a vehicle steering system include an elastic joint having a built-in elastic member. The elastic joint includes, for example, a cylindrical outer shaft connected to a yoke of a universal joint, and an elastic joint. An elastic body such as rubber is interposed between the solid inner shaft on the main shaft side inserted into the outer shaft, thereby absorbing the vibration of the engine and wheels and transmitting the vibration to the steering wheel. Restrained.

[0003] In such an elastic shaft coupling, the transmission of torque between the outer shaft and the inner shaft is performed via an elastic body in a low torque range, but is performed between the outer shaft and the inner shaft in a high torque range. This is done by direct contact with the shaft.

[0004] Specifically, in the elastic shaft coupling disclosed in Japanese Utility Model Publication No. 59-29147, the outer shaft is formed in a cylindrical shape having a non-circular cross section, and a flat inner shaft is formed inside the outer shaft. A peripheral surface is formed. The inner shaft inserted into the outer shaft also has a non-circular solid cross section and an outer shape substantially similar to the outer shaft. A flat outer peripheral surface is formed so as to face the peripheral surface.
Further, the inner shaft is formed with a concave groove which is stepped from the flat outer peripheral surface, and the elastic body is bonded to the concave groove so as to rise from the flat outer peripheral surface.

Therefore, in a range where the torque is low, the elastic body of the inner shaft that rises from the flat outer peripheral surface is in contact with the flat inner peripheral surface of the outer shaft and elastically deforms, while transmitting torque by the deformation resistance. When the torque is higher than a predetermined level, the flat inner peripheral surface of the outer shaft directly engages with the flat outer peripheral surface of the inner shaft, and the torque is transmitted by this direct engagement.

[0006] Also, FR263 in French Patent Publication
In the elastic shaft coupling disclosed in No. 7334-A1, a substantially "-" shaped stopper is formed by plastic working inside a relatively thick outer shaft, and the outer periphery of the inner shaft is formed. An elastic body is adhered or press-fitted between the surface and the inner peripheral surface of the outer shaft.

Therefore, in the range where the torque is low, the elastic body elastically deforms and transmits the torque by its deformation resistance, while in the range where the torque is higher than a predetermined level, the elastic body protrudes into the outer shaft. The U-shaped stopper directly engages with the outer peripheral surface of the inner shaft, and transmits torque by this direct engagement.

[0008]

However, in the elastic shaft coupling disclosed in Japanese Utility Model Publication No. 59-29147, the direct connection between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft is disclosed. In general, the starting point of the torque transmission depending on the vehicle type is different for each vehicle type.

Therefore, it is necessary to change the gap between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft according to the type of vehicle. As a result, the outer shaft and / or the inner shaft must be manufactured for each vehicle type, and the outer shaft and / or the inner shaft or any type thereof increases, so that the mass production effect cannot be obtained and the manufacturing cost rises. You may be invited.

[0010] In addition, FR 263 of French Patent Publication
In the elastic shaft coupling disclosed in No. 7334-A1, the outer shaft is integrated with the yoke, and the outer shaft needs to have a relatively long fitting length with the shaft, so that the outer shaft has a relatively large thickness. ing. Therefore, the influence of the deformation due to the thick plastic working extends over a wide range, and due to this, the length of the outer shaft must be increased, leading to an increase in manufacturing costs.

Furthermore, since the substantially "L" shaped stopper provided inside the outer shaft is formed by plastic working, the vertex thereof cannot always be manufactured with high accuracy. May be engaged, and as a result, torque may not be transmitted accurately.

The present invention has been made in view of the above-mentioned circumstances, and enables mass production effects by enabling the outer shaft and the inner shaft to be partially shared even in a large number of vehicle types. To provide an elastic shaft coupling that can reduce manufacturing costs.

[0013]

In order to achieve the above-mentioned object, an elastic shaft coupling according to the present invention comprises an outer shaft having a non-circular cylindrical cross section and an outer shaft having a non-circular cross section and having an outer shape. An inner shaft having a substantially similar shape to the shaft is inserted, and the outer shaft has a flat inner peripheral surface formed therein, and the inner shaft has a flat outer peripheral surface opposed to the flat inner peripheral surface. An elastic body is provided on a concave groove formed by stepping down from a flat outer peripheral surface of the inner shaft, or a flat outer peripheral surface of the inner shaft without forming a concave groove. In an elastic coupling, after the inner shaft is inserted into the outer shaft, a gap between a flat inner peripheral surface of the outer shaft and a flat outer peripheral surface of the inner shaft is reduced at least at one position. It is characterized by.

As described above, according to the present invention, after the inner shaft is inserted into the outer shaft, the gap between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft is reduced by, for example, press molding. are doing. Therefore, at the stage of preparing parts before manufacturing, regardless of the vehicle type, prepare the outer shaft and the inner shaft that are shared except for the axial length etc., and then insert the inner shaft into the outer shaft,
For each model, that is, according to the torque required for each model,
The gap between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft is
For example, the width may be reduced by press molding. This allows
While partially sharing the outer shaft and the inner shaft, it is possible to obtain a gap between the outer shaft and the inner shaft according to the required torque for each vehicle type.

Therefore, even with a large number of vehicle types, the outer shaft and the inner shaft can be partially shared, and the production cost can be reduced due to the effect of mass production.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An elastic shaft coupling according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an elastic shaft coupling according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. III-III of 1
FIG. 4 is a sectional view taken along a line, FIG. 4 is a view showing a state in which the elastic shaft coupling shown in FIG. 1 is mounted on a press molding machine, and FIG. 5 is a sectional view taken along a line VV in FIG. FIG.

As shown in FIG. 1, in a vehicle steering system, a yoke 2 of a universal joint 1 is connected to a cylindrical outer shaft 3 having a non-circular (substantially drum-shaped) cross section. 3, a large diameter portion 4 and a small diameter portion 5 are formed. An inner shaft 6 having a non-circular cross section (substantially drum-shaped) and an outer shape substantially similar to the outer shaft 3 is inserted through the small diameter portion 5 of the outer shaft 3.

A flat inner peripheral surface 7 is formed on the small diameter portion 5 of the outer shaft 3, and on both axial sides of the flat inner peripheral surface 7,
As described later, a flat inner peripheral surface 7a,
7b is formed.

The inner shaft 6 has flat inner peripheral surfaces 7a, 7
b, flat outer peripheral surfaces 8a and 8b are formed, and between these flat outer peripheral surfaces 8a and 8b, a concave groove 9 which is stepped down from these flat outer peripheral surfaces 8a and 8b is formed. It is.

The concave groove 9 has an elastic body 10 made of natural rubber or the like.
Are adhered so as to rise from the flat outer peripheral surfaces 8a and 8b. In addition, this elastic body 10, as shown in FIG.
The inner shaft 6 is formed in an annular shape so as to cover the entire circumference.

With the above-described structure, in the range where the torque is low, the raised elastic body 10 of the inner shaft 6 comes into contact with the flat inner peripheral surface 7 of the outer shaft 3 and elastically deforms. While transmitting the torque by the resistance, the flat inner peripheral surfaces 7a, 7b
Directly engages with the flat outer peripheral surfaces 8a and 8b of the inner shaft 6,
The torque is transmitted by this direct engagement.

Further, since the range of torque transmission until the direct engagement is achieved differs for each vehicle type,
It is necessary to change according to the type of vehicle.
Flat inner peripheral surfaces 7a, 7b and inner shaft 6 flat outer peripheral surface 8
It is necessary to change the gaps between a and 8b according to the torque transmission range for each vehicle type.

In the present embodiment, in order to set this gap according to the type of vehicle, in the assembly process of the elastic shaft coupling, after inserting the inner shaft 6 into the small diameter portion 5 of the outer shaft 3, as shown in FIG. The gap S1 between the flat inner peripheral surfaces 7a, 7b of the small diameter portion 5 and the flat outer peripheral surfaces 8a, 8b of the inner shaft 6 is narrowed by press molding, and this gap is formed into S2.

That is, as shown in FIG. 4, the elastic shaft coupling is mounted on a press forming machine, and the flat inner peripheral surface 7 of the small diameter portion 5 is formed.
A pair of press dies P are arranged radially outward of a and 7b. As shown in FIG. 5, the press die P is pressed against the flat inner peripheral surfaces 7a and 7b of the small diameter portion 5 by a predetermined press load.
Thereby, as shown in FIG. 2, the gap can be narrowed from S1 to S2.

Therefore, by adjusting the press load, it is possible to set the gap S2 after molding variously, and to obtain the gap S2 according to the magnitude of the required torque for each vehicle type, even for a large number of vehicle types. be able to. Therefore, before assembling the elastic shaft coupling, the flat inner peripheral surfaces 7a, 7
Regarding the dimensions of the outer peripheral surfaces 8a and 8b of the inner shaft 6 and the inner shaft 6, the same dimensions can be set regardless of the type of the vehicle and shared.

The length of the outer shaft 3 and the inner shaft 6 in the axial direction generally differs for each vehicle type, and it is difficult to share them.

From the above, except for the axial lengths of the outer shaft 3 and the inner shaft 6, the dimensions of the flat inner peripheral surfaces 7a and 7b of the small diameter portion 5 and the flat outer peripheral surfaces 8a and 8b of the inner shaft 6 are determined by the type of the vehicle. Irrespective of this, it is possible to obtain the gap S2 according to the required torque for each vehicle type while setting the same dimensions and partially sharing parts. Therefore, not only the parts can be partially shared, but also production equipment such as a press molding machine can be shared, and the production cost can be reduced due to the effect of mass production.

The size of the gap S1 before press molding is
Even if there is variation, by adjusting the press load, the size of the gap S2 after press molding can be made accurate by absorbing the variation. In the conventional elastic shaft coupling disclosed in Japanese Utility Model Publication No. 59-29147, since the press forming is not performed after the inner shaft is inserted into the outer shaft, the size of the gap is affected by the accuracy of the parts and varies. There is a possibility that there is.

Further, as shown in FIG. 5, the press die P is provided with a recess 11. As a result, as shown in FIG. 2, the projections 12 are formed on the flat outer peripheral surface 7a (7b) of the small-diameter portion 3 by press molding of the recesses 11, and both sides of the projection 12 are connected to the inner shaft. 6 flat outer peripheral surfaces 8a, 8b
Is defined as a range that directly engages the

Further, when a relatively small axial load in normal use is applied to the outer shaft 3 or the inner shaft 6, the elastic member 1
0 has a certain thickness, and the small diameter portion 5 of the outer shaft 3
Cannot pass through the flat outer peripheral surfaces 7a and 7b, so that the inner shaft 6 does not come off from the outer shaft 3 due to a relatively small axial load.

However, when a relatively large axial load is applied as in the case of a vehicle collision, the inner shaft 6 can be moved relative to the outer shaft 3 regardless of the thickness of the elastic body 10. Therefore, safety at the time of a collision can be sufficiently ensured.

The inner shaft 2 does not necessarily have to be solid as shown, but may be a hollow tube.

Next, an elastic shaft coupling according to a second embodiment of the present invention will be described. FIG. 6 is a sectional view of an elastic shaft coupling according to a second embodiment of the present invention, and FIG.
FIG. 8 is a sectional view taken along the line VII-VII of FIG.
FIG. 9 is a sectional view taken along line II-VIII, and FIG.
And FIG. 10 is a cross-sectional view taken along line XX of FIG. 9.

In the second embodiment, the small diameter portion 5 of the outer shaft 3
A flat inner peripheral surface 7c is formed at an intermediate portion of the inner shaft 6. Correspondingly, a flat outer peripheral surface 8c is formed at an intermediate portion of the inner shaft 6. In the place. The elastic body 10 and the concave groove 9 are divided in the axial direction and arranged on both sides of the flat outer peripheral surface 8c. With such a configuration, the torsional rigidity can be improved as compared with the first embodiment.

The press die P is not provided with the recess 11. Thereby, the manufacturing cost of the press die P can be reduced.

The other structure is the same as that of the first embodiment. Therefore, also in the second embodiment, it is possible to obtain the gap S2 according to the required torque for each vehicle type while partially sharing the outer shaft 3 and the inner shaft 6, and to reduce the manufacturing cost due to the mass production effect. Reduction can be achieved.

Next, an elastic shaft coupling according to a third embodiment of the present invention will be described. FIG. 11 is a cross-sectional view of the elastic shaft coupling according to the third embodiment of the present invention.

In the third embodiment, an annular thin elastic body 13 covers the entire outer periphery of the flat outer peripheral surfaces 8a and 8b of the inner shaft 6. Thereby, the flat inner peripheral surfaces 7a, 7 of the outer shaft 3
The noise generated when b contacts the flat outer peripheral surfaces 8a and 8b of the inner shaft 6 is reduced.

Other configurations are the same as those of the first and second embodiments. Therefore, also in the third embodiment,
The outer shaft 3 and the inner shaft 6 can be partially used in common, so that the mass production effect can be obtained and the manufacturing cost can be reduced.

Next, an elastic shaft coupling according to a fourth embodiment of the present invention will be described. Not particularly shown.

In the fourth embodiment, the elastic body 10 is formed without the concave groove 9 for bonding the elastic body
Is adhered to the flat inner peripheral surface. As a result, the manufacturing cost for machining the concave groove can be reduced, but the thickness of the elastic body 10 is slightly reduced, so that the vibration absorption performance and the noise absorption performance may be slightly poor.

The other structure is the same as that of the first to third embodiments. By partially sharing the outer shaft 3 and the inner shaft 6, it is possible to obtain a mass production effect and reduce the manufacturing cost. be able to.

The present invention is not limited to the above-described embodiment, but can be variously modified.

[0045]

As described above, according to the present invention,
After the inner shaft is inserted into the outer shaft, the gap between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft is reduced by, for example, press molding. Therefore, at the stage of preparing parts before manufacturing, regardless of the vehicle type, prepare the common outer shaft and inner shaft except for the axial length etc., and then insert the inner shaft into the outer shaft, The gap between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft may be narrowed, for example, by press molding, in accordance with the required torque transmission range for each vehicle type. As a result, it is possible to obtain a gap between the outer shaft and the inner shaft according to the required torque transmission range for each vehicle type while partially sharing the outer shaft and the inner shaft.

Therefore, even for a large number of vehicle types, the outer shaft and the inner shaft can be partially shared, and the production cost can be reduced due to the mass production effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an elastic shaft coupling according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a view showing a state where the elastic shaft coupling shown in FIG. 1 is mounted on a press molding machine.

FIG. 5 is a sectional view taken along the line VV of FIG. 4;

FIG. 6 is a cross-sectional view of an elastic shaft coupling according to a second embodiment of the present invention.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 6;

9 is a view showing a state where the elastic shaft coupling shown in FIG. 6 is mounted on a press molding machine.

FIG. 10 is a sectional view taken along the line XX of FIG. 9;

FIG. 11 is a sectional view of an elastic shaft coupling according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 universal joint 2 yoke 3 outer shaft 4 large diameter portion 5 small diameter portion 6 inner shaft 7, 7a, 7b, 7c flat inner peripheral surface 8a, 8b, 8c flat outer peripheral surface 9 concave groove 10 elastic body 11 recess 12 protrusion Part 13 Elastic body P Press mold S1 Gap before molding S2 Gap after molding

Claims (2)

[Claims] An inner shaft having a non-circular cross section and an outer shape substantially similar to the outer shaft is inserted into an outer shaft having a non-circular cylindrical shape. An inner peripheral surface is formed, and a flat outer peripheral surface is formed on the inner shaft so as to face the flat inner peripheral surface, and is formed by stepping down from the flat outer peripheral surface of the inner shaft. In the elastic shaft coupling provided with an elastic body on the flat groove of the inner shaft without forming the concave groove or on the outer shaft, after inserting the inner shaft into the outer shaft, An elastic shaft coupling characterized in that a gap between a flat inner peripheral surface of the inner shaft and a flat outer peripheral surface of the inner shaft is narrowed at at least one position. 2. There are two places where the gap between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft is narrow, and they are arranged on both axial sides of the elastic body. The narrow gap between the flat inner peripheral surface of the outer shaft and the flat outer peripheral surface of the inner shaft is one, and is disposed between two elastic bodies divided in the axial direction. The elastic shaft coupling according to claim 1, wherein: