JP2000205263A - Bearing device for steering column - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To sufficiently absorb vibration such as "rattle" of a steering shaft and also to sufficiently suppress friction torque during rotation of the steering shaft. An outer bush (10) made of an elastic body and pressed into a housing of a steering column, and an inner bush (11) inserted into the outer bush (10) and slidably supporting a steering shaft, are provided. A grease storage groove 18 is formed on a sliding inner peripheral surface of the inner bush 11 that slidably supports the steering shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for a steering column mounted on a steering column of an automobile, and more particularly, to a vibration device capable of sufficiently absorbing vibration such as "rattle" of a steering shaft and rotating the steering shaft. The present invention relates to a bearing device for a steering column, in which the friction torque at the time is suppressed sufficiently low to prevent the clinging phenomenon.

[0002]

2. Description of the Related Art In a steering column for an automobile, the requirements for rotational conditions are not so high because the steering shaft has a low rotation and the transmitted torque is low. However, it is necessary to mainly absorb vibrations acting on the steering shaft. Due to the nature, the bearing for rotatably supporting the steering shaft is not a ball bearing but a sliding bearing disclosed in Japanese Utility Model Laid-Open Publication No. Hei 6-57768 and having a rubber bush as shown in FIG. It is common to use a steering column bearing device.

A bearing device for a steering column, which is a slide bearing shown in FIG. 4, includes an outer bush 1 made of an elastic body such as rubber or synthetic resin and pressed into a housing (not shown) of the steering column. An inner bush 2 which is inserted into the outer bush 1 and slidably supports a steering shaft (not shown) is provided.

[0004] A metal ring 3 is fitted around the outer periphery of the end of the outer bush 1 by integral molding, and the outer peripheral surface of the outer bush 1 is pressed into a housing (not shown). A large number of ridges 4 extending in the axial direction are formed. Further, as shown in FIG. 5, a recess 5 extending in the axial direction is formed on the inner peripheral surface of the outer bush 1, and the concave surface 5 has, as shown in FIG. The protruding ridges 6 formed in the axial direction are fitted to each other, thereby preventing the relative rotation between them. Further, a slit 7 is formed in the inner bush 2. When the steering shaft (not shown) is fitted into the inner bush 2, the inner bush 2 is expanded outward by the slit 7. To do that.

[0005]

However, in the bearing device for a steering column disclosed in the above-mentioned Japanese Utility Model Application Laid-Open No. 6-57768 or shown in FIGS. Rattling "
Vibration absorbing performance that absorbs vibrations and the like, and low friction torque performance that suppresses friction torque during rotation of the steering shaft are contradictory performances, and it may be difficult to achieve both.

For example, when the clearance between the steering shaft and the inner bush 2 is increased, vibrations such as "rattle" may occur between the shaft and the inner bush 2. On the other hand, if the clearance is reduced and a margin is provided between the steering shaft and the inner bush 2, vibration such as "rattle" can be absorbed, but on the other hand, the outer bush 1 and the inner As a result of the thermal expansion of the bush 2, the friction torque of the steering shaft is increased, which may result in a phenomenon of clinging to the shaft.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and sufficiently absorbs vibration such as "rattle" of a steering shaft, and at the same time, sufficiently reduces friction torque during rotation of the steering shaft. It is an object of the present invention to provide a steering column bearing device which is kept low.

[0008]

In order to achieve the above object, a bearing device for a steering column according to the present invention comprises an outer bush which is made of an elastic body and is press-fitted into a housing of a steering column, and an outer bush is provided inside the outer bush. An inner bush that is inserted and slidably supports the steering shaft; and a bearing device for a steering column of a slide bearing, wherein the inner bush slidably supports the steering shaft. It is characterized in that a groove is formed.

As described above, according to the present invention, a groove, for example, a groove for storing grease or the like is formed on the inner peripheral sliding surface of the inner bush that slidably supports the steering shaft. Therefore, when the steering shaft rotates, grease or the like spreads between the steering shaft and the inner bush, and the lubricating performance of both can be improved.Therefore, the clearance between the steering shaft and the inner bush is reduced. Therefore, even when the interference is provided between the two, the friction torque at the time of rotation of the steering shaft can be suppressed sufficiently low, and the clinging phenomenon can be prevented.

Therefore, since the clearance between the steering shaft and the inner bush may be reduced, the vibration of the steering shaft can be sufficiently absorbed, and at the same time, the friction torque of the steering shaft is reduced as described above. Since it can be kept sufficiently low, it is possible to achieve both vibration absorption performance and low friction torque performance.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bearing device for a steering column according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a longitudinal sectional view of a bearing device for a steering column according to an embodiment of the present invention.
FIG. 2B is a side view of the steering column bearing device shown in FIG. 1A, and FIG. 2A is a longitudinal section of an inner bush attached to the steering column bearing device shown in FIG. FIG. 2B is a cross-sectional view of the inner bush.

As shown in FIG. 1, an outer bush 10 made of an elastic material such as rubber or synthetic resin is press-fitted into a housing (not shown) of a steering column. An inner bush 11 that slidably supports a steering shaft (not shown) is provided.

A metal ring 12 is inserted into the center of the outer bush 10 by insert molding.

Further, on the outer peripheral surface of the outer bush 10, a number of ridges 13 extending in the axial direction are formed. These ridges 13 are provided for press-fitting into a housing (not shown), may have a continuous shape on the outer peripheral surface of the outer bush 10, or may fill a plurality of valleys for press-fit adjustment. . Further, the interference with respect to the outer diameter of the ridge portion 13 is preferably 1 to 15%.

Further, convex portions 14 are formed at two opposing positions of the outer bush 10, and the convex portions 14 are fitted into holes (not shown) formed in a housing (not shown) of the steering column. The housing (not shown) functions as a stopper.

Further, a plurality of ridges 15 extending in the circumferential direction are formed on the inner peripheral surface of the outer bush 10 to absorb the displacement of the inner bush 11.

Further, as shown in FIG. 2 (b), a slit 16 is formed in the inner bush 11, which is used when a steering shaft (not shown) is fitted into the inner bush 11. This is because the inner bush 11 is expanded outward by the slit 16.

Further, a ridge 17 is formed on the outer peripheral surface of the inner bush 11, and the ridge 17 is formed in a concave portion (not shown, see FIG. 5) formed on the inner peripheral surface of the outer bush 10. 5), thereby preventing the relative rotation between the two.

Further, in the present embodiment, a plurality of grease storage grooves 18 for storing grease and the like are provided on a sliding inner peripheral surface of an inner bush 11 which slidably supports a steering shaft (not shown). Is formed. In the embodiment shown in FIGS. 1 and 2, the grease storage groove 18 extends axially on the sliding inner peripheral surface of the inner bush 11, and both ends of the grease storage groove 18 are connected to the inner bush 11. To the vicinity of the edge.

As described above, since the grease storing groove 18 is formed on the sliding inner peripheral surface of the inner bush 11, the grease or the like is rotated when the steering shaft (not shown) rotates. ) And the inner bush 11, and the lubrication performance of both can be improved. Therefore, the clearance between the steering shaft (not shown) and the inner bush 11 is reduced to reduce the interference between the two. Even if it is provided, the friction torque at the time of rotation of the steering shaft (not shown) can be suppressed sufficiently low, and the clinging phenomenon can be prevented.

Accordingly, since the clearance between the steering shaft (not shown) and the inner bush 11 may be reduced, the steering shaft (not shown) is provided.
Vibration can be sufficiently absorbed, and at the same time, as described above, the friction torque of the steering shaft (not shown) can also be sufficiently suppressed, so that both the vibration absorption performance and the low friction torque performance can be achieved. Can be planned.

Next, a bearing device for a steering column according to a modification of this embodiment will be described with reference to FIG.

In the modification shown in FIG. 3A, the length of the grease storage groove 18 in the axial direction is shorter than that of the embodiment shown in FIGS.

In the modified example shown in FIG. 3B, the grease storage groove 18 extends in the axial direction while being inclined.

In the modification shown in FIG. 3C, the plurality of grease storage grooves 18 are alternately shifted in the axial direction.

Although not particularly shown, the grease storage groove 18 may be formed in a spiral shape.

The present invention is not limited to the above-described embodiment, but can be variously modified. For example, a grease storage groove 18 formed on the sliding inner peripheral surface of the inner bush 11
Need only be a groove, and may be provided for a purpose other than storing grease or the like. Further, the metal ring 12 insert-molded in the outer bush 10 may be provided integrally with the outer peripheral portion of the outer bush 10 as in the conventional case, and may be press-fitted into the housing by the metal ring.

[0029]

As described above, according to the present invention,
A groove, for example, a groove for storing grease or the like is formed on an inner peripheral sliding surface of the inner bush that slidably supports the steering shaft. Therefore, when the steering shaft rotates, grease or the like spreads between the steering shaft and the inner bush, and the lubricating performance of both can be improved.Therefore, the clearance between the steering shaft and the inner bush is reduced. Therefore, even when the interference is provided between the two, the friction torque at the time of rotation of the steering shaft can be suppressed sufficiently low, and the clinging phenomenon can be prevented.

Therefore, since the clearance between the steering shaft and the inner bush may be reduced, the vibration of the steering shaft can be sufficiently absorbed, and at the same time, the friction torque of the steering shaft is reduced as described above. Since it can be kept sufficiently low, it is possible to achieve both vibration absorption performance and low friction torque performance.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view of a steering column bearing device according to an embodiment of the present invention, and FIG. 1B is a side view of the steering column bearing device.

2A is a longitudinal sectional view of an inner bush mounted on the steering column bearing device shown in FIG. 1, and FIG. 2B is a transverse sectional view of the inner bush.

FIGS. 3A, 3B, and 3C are longitudinal sectional views of an inner bush according to a modification of the embodiment of the present invention.

4A is a longitudinal sectional view of a conventional steering column bearing device, and FIG. 4B is a side view of the steering column bearing device.

5A is a longitudinal sectional view of an outer bush mounted on the steering column bearing device shown in FIG. 4, and FIG. 5B is a transverse sectional view thereof.

6A is a cross-sectional view of an inner bush mounted on the steering column bearing device shown in FIG. 4, and FIG. 6B is a longitudinal cross-sectional view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Outer bush 11 Inner bush 12 Metal ring 13 Projection 14 Projection 15 Projection 16 Slit 17 Projection 18 Grease storage groove (groove)

Claims (1)

[Claims] 1. A sliding bearing comprising an outer bush made of an elastic body and pressed into a housing of a steering column, and an inner bush inserted into the outer bush and slidably supporting a steering shaft. A bearing device for a steering column, wherein a groove is formed in a sliding inner peripheral surface of an inner bush that slidably supports the steering shaft.