JP2001020967A - Connecting structure of telescopic shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent rattling at a spline fitting part of an inner shaft and an outer shaft even in the case when a spline tooth is abrased and to easily adjust sliding force of the spline fitting part and rattling. SOLUTION: Both shafts 2, 4 are splined and fitted on each other by forming a slit 7 on a head end part of the outer shaft 2 and inserting the inner shaft 4 in the inside of this outer shaft 2. A tapered part 14 having an engagement groove 15 is formed on an outer peripheral surface, a cylindrical member 10 extending a slit in the axial direction is fitted on the outside diametrical side of the slit 7 on a head end part of the outer shaft 2, and a fastening member 20 is installed on the tapered part 14 on the outer peripheral surface of this cylindrical member 10 while it is engaged with the engagement groove 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a telescopic shaft used in, for example, a steering device for a vehicle, and more particularly, to a joint structure of an inner shaft and an outer shaft even when spline teeth are worn. The present invention relates to a joint structure of a telescopic shaft capable of effectively preventing "play" and easily adjusting a sliding force of a spline fitting portion.

[0002]

2. Description of the Related Art In a vehicle steering system, there is a telescopic system in which the axial length of a steering shaft can be adjusted according to the driving posture of a driver. Specifically, the inner shaft on the front side of the vehicle is spline-fitted or serrated into the outer shaft on the rear side of the inner shaft, whereby the outer shaft on the rear side slides with respect to the inner shaft on the front side. Thus, the axial length of the steering shaft is adjusted.

[0003] In addition, such a telescopic shaft is sometimes used as an intermediate shaft for connecting a steering shaft and a steering gear in terms of assembly and displacement absorption.

[0004] In such a spline fitting portion, a certain degree of "play" may occur between the male spline of the inner shaft and the female spline of the outer shaft due to factors such as limitations on processing accuracy.

In order to prevent such backlash, Japanese Utility Model Laid-Open Publication No. Sho 56-47912 discloses a method in which a plurality of slits are formed at the tip of an outer shaft, and a solid inner portion is formed within the tip of the outer shaft. After the shaft is inserted and spline-fitted, a clip is tightened to the outer peripheral portion of the slit of the outer shaft to prevent "play" at the spline-fitted portion. The adjustment of the sliding force of the spline fitting portion is performed by adjusting the tightening force of a bolt for tightening the clip.

In Japanese Utility Model Laid-Open Publication No. Sho 56-48956, a plurality of slits are formed at the tip of the inner shaft, and the tip is inserted into the outer shaft and spline-fitted. The wedge-shaped member is pushed inward in the radial direction from the outer peripheral surface side of the inner shaft, whereby the slit is pushed and expanded, thereby preventing "play" of the spline fitting portion. The adjustment of the sliding force of the spline fitting portion is performed by adjusting the tightening force of a bolt for attaching the wedge-shaped member.

In Japanese Utility Model Publication No. 2-44609, a plurality of slits are formed at the tip of the outer shaft, and a hollow inner shaft is inserted into the tip of the outer shaft and spline-fitted. In the tapered part formed on the outer peripheral surface of the slit of the outer shaft,
A pressing member having a tapered portion is pressed, and the pressing member is tightened with a nut to prevent "play" of the spline fitting portion. The adjustment of the sliding force of the spline fitting portion is performed by adjusting the axial position of the pressing member and changing the relative position between the tapered portion of the outer peripheral surface of the outer shaft and the tapered portion of the pressing member. I have.

Further, in Japanese Utility Model Publication No. Sho 63-17786, a plurality of slits are formed at the tip of the outer shaft, and a solid inner shaft is inserted into the tip of the outer shaft and spline-fitted. In addition, a ring-shaped elastic tightening member is tightened on the outer peripheral portion of the slit of the outer shaft to prevent "play" of the spline fitting portion.

[0009]

However, according to Japanese Utility Model Application Laid-Open Publication No. Sho 56-47912, when the spline teeth are worn, the clip is loosened, and there is a possibility that "play" may occur at the spline fitting portion. is there.

In Japanese Utility Model Laid-Open Publication No. Sho 56-48956, the inner shaft receives a load (torque) at its slit portion, so that the inner shaft may have low strength.
Further, when the spline teeth are worn, the wedge-shaped member is loosened, and there is a possibility that “play” may occur at the spline fitting portion.

In Japanese Utility Model Publication No. 2-44609, a tapered portion is formed on the outer peripheral surface of the slit.
Since the taper portion of the pressing member is required, and the nut and the male screw portion are also required, the manufacturing cost may be increased.

Further, in Japanese Utility Model Publication No. Sho 63-17786, in order to maintain the sliding force of the spline fitting portion at a predetermined value, the interference between the inner diameter of the tightening member and the outer diameter of the outer shaft is precisely controlled. In some cases, it is difficult to adjust the sliding force of the spline fitting portion.

The present invention has been made in view of the above circumstances, and effectively prevents "play" at a spline fitting portion between an inner shaft and an outer shaft even when spline teeth are worn. Another object of the present invention is to provide a joint structure of a telescopic shaft that can easily adjust the sliding force of the spline fitting portion and the "play".

[0014]

In order to achieve the above-mentioned object, a telescopic shaft connecting structure according to the present invention has a slit formed at a tip end of an outer shaft, and an inner shaft is inserted into the outer shaft. In a joint structure of a telescopic shaft in which both shafts are slidable in the axial direction and non-rotatably connected, a tapered portion having a locking groove is formed on the outer peripheral surface and a slit extends in the axial direction. The cylindrical member is fitted on the outer diameter side of the slit at the end of the outer shaft, and is mounted on the tapered portion of the outer peripheral surface of the cylindrical member while locking the tightening member in the locking groove. I do.

As described above, according to the present invention, the cylindrical member having the tapered portion having the locking groove formed on the outer peripheral surface and having the slit extending in the axial direction can be used as the outer diameter of the slit at the tip of the outer shaft. And a tightening member is mounted on the tapered portion of the outer peripheral surface of the cylindrical member while being locked in the locking groove.

Therefore, since the slit portion of the outer shaft tip can be pressed in close contact with the inner shaft by the tightening member, the two shafts are slidable in the axial direction and non-rotatably connected. When the spline fitting is used, the spline teeth can be meshed with no gap, and even if the spline teeth are worn, "play" at the spline fitting portion can be effectively prevented.

Further, since the tightening member is mounted on the tapered portion on the outer peripheral surface of the cylindrical member while being locked in the locking groove, when the sliding force of the spline fitting portion is heavy, the cylindrical member is not slid. By moving the tightening member to the smaller diameter side of the tapered portion, the tightening force can be reduced, and the sliding force can be reduced. on the other hand,
When the sliding force of the spline fitting portion is light and there is "play", the tightening force can be increased by moving the tightening member to the large diameter side of the tapered portion of the cylindrical member,
The sliding force can be set to a predetermined value, and "play" can be reduced. As described above, by changing the position of the tightening member, the adjustment of the sliding force of the spline fitting portion and the adjustment of "play" can be easily performed.

Further, since the tightening member is locked in the locking groove of the tapered portion of the cylindrical member, the tightening member does not naturally move to the small diameter side of the tapered portion.

Since the sliding force and the "play" can be easily adjusted simply by changing the position of the tightening member, unlike the above-mentioned Japanese Utility Model Publication No. 63-177862, the inner diameter of the tightening member and the outer diameter of the outer shaft are different. There is no need to precisely manage the interference.

Also, even if the spline teeth are worn,
Since the diameter of the tightening member is reduced in accordance with the degree of wear, a necessary tightening force can be continuously secured.

Further, since the inner shaft has no slit portion, unlike the above-mentioned Japanese Utility Model Application Laid-Open Publication No. Sho 56-48956, a large torque can be transmitted through the non-slit portion of the outer shaft, which is advantageous in strength. It is.

In addition, as compared to Japanese Utility Model Publication No. 63-17762, only a cylindrical member is added, so that the manufacturing cost can be reduced.

The outer shaft is hollow, but the inner shaft may be solid or hollow.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing a connecting structure of a telescopic shaft according to an embodiment of the present invention.

FIG. 1 is a longitudinal sectional view of an intermediate shaft of a vehicle steering system, FIG. 2 is an enlarged sectional view of a main part of FIG. 1, and FIG. 3 (a) shows an outer shaft and an inner shaft. FIG. 3B is a cross-sectional view of the tubular member for coupling (a cross-sectional view along the line aa in FIG. 3B), and FIG.
FIG. 4A is a side view of the tubular member, FIG. 4A is a front view of a tightening member for connecting the outer shaft and the inner shaft, and FIG. 4B is a side view of the tightening member. It is.

As shown in FIG. 1, in the intermediate shaft of the vehicle steering device, a lower outer joint 2 is connected to a lower universal joint 1, and a lower outer universal shaft 2 is connected to an upper universal joint 3. And a solid inner shaft 4 on the upper side.

As shown in FIG. 2, a female spline 5 is formed on the inner peripheral surface of the outer shaft 2, and a male spline 6 is formed on the outer peripheral surface of the inner shaft 4. Mated.

A plurality of slits 7 are formed at the distal end of the outer shaft 2 so as to extend in the axial direction, so that the distal end of the outer shaft 2 can be reduced in diameter or increased in diameter. .

Outer shaft 2 and inner shaft 4
The outer peripheral surface of the outer shaft 2
A cylindrical tubular member 10 is fitted. This tubular member 1
3, a slit 11 extending in the axial direction is formed, as shown in FIG. 3, so that the diameter of the cylindrical member 10 can be reduced.

On the inner peripheral surface of the cylindrical member 10, a projecting stopper 12 is formed. The stopper 12 engages with a hole 13 formed in the outer shaft 2 so that the shaft of the cylindrical member 10 is rotated. It prevents movement in the direction.

The outer peripheral surface of the cylindrical member 10 is provided with a tapered portion 14 having a smaller diameter toward the upper side, and a stepped locking groove 15 is formed in the tapered portion 14.

The tapered portion 14 of the tubular member 10 has
A leaf spring-like tightening member 20 made of spring steel or the like is mounted so as to elastically reduce the diameter in a natural state. The tightening member 20 is elastically reduced in diameter, so that the cylindrical member 1
0 is fastened to the tip of the outer shaft 2.

As shown in FIG. 4, a locking claw 21 is formed on the tightening member 20 so as to project slightly inward from the inner diameter (D3) of the tightening member 20.
Are locked in the step-shaped locking groove 15 of the tapered portion 14 to prevent the movement of the tightening member 20. Thereby, it is possible to prevent the tightening force of the tightening member 20 from decreasing.

Further, the tightening member 20 is formed with a pair of flanges 22 which are clamped by a tool in order to increase the inner diameter (D3) when the tightening member 20 is mounted.

As for the dimensional relationship of these members, the outer diameter (D1, FIG. 2) of the outer shaft 2 and the inner diameter (D2, FIG. 3) of the cylindrical member 10 are substantially the same, and the cylindrical member In a state where 10 is attached to the outer shaft 2, both are in a close contact state.

The large diameter side of the tapered portion 14 is d2.
(FIG. 3), and has a tapered shape whose smaller diameter side is d1 (FIG. 3). Further, the length of the tapered portion 14 is slightly shorter than the length of the slit 7 of the outer shaft 2.

Next, when connecting the inner shaft 4 to the outer shaft 2, the male and female splines 5, 6
The inner shaft 4 is inserted into the outer shaft 2 while spline fitting is performed. After fitting the cylindrical member 10 to the tip of the outer shaft 2, the flange 22 of the tightening member 20 is clamped by a tool, and while the diameter of the tightening member 20 is increased, the tapered portion of the outer peripheral surface of the cylindrical member 10 is increased. The tightening member 20 is attached to the locking member 14, and the locking claw 21 of the tightening member 20 is locked in the locking groove 15 of the tapered portion 14.

At this time, when the sliding force of the spline fitting portion is heavy, the small diameter side (d
By moving the tightening member 20 in (1, FIG. 3), the tightening force can be reduced and the sliding force can be reduced. When the tightening member 20 is moved, the flange 22 of the tightening member 20 is clamped by a tool to expand the diameter of the tightening member 20, and the locking claw 21 of the mounting member 20 is released from the locking groove 15 of the tapered portion 14. do it.

On the other hand, the sliding force of the spline fitting portion is light,
In the case where there is "play", the tightening force can be increased by moving the tightening member 10 to the large diameter side (d2, FIG. 3) of the tapered portion of the cylindrical member 10, and the sliding force can be reduced. The value can be set to a predetermined value, and "play" can be reduced.

As described above, by changing the position of the tightening member 20, the adjustment of the sliding force of the spline fitting portion and the adjustment of "play" can be easily performed.

Further, since the slit portion at the end of the outer shaft 2 can be pressed in close contact with the inner shaft 4 by the tightening member 20, the spline teeth can be meshed without gaps, and even if the spline teeth are worn out, the spline fitting is performed. It is possible to effectively prevent "play" in the part. Further, since the tightening member 20 is locked in the locking groove 15 of the tapered portion 14 of the tubular member 10, the tightening member 20 naturally moves to the small diameter side (d1, FIG. 3) of the tapered portion. There is no inadvertent reduction in tightening force.

The present invention is not limited to the above-described embodiment, but can be variously modified. For example, as shown in FIG. 5, the tapered portion 14 of the tubular member 10 may have a tapered shape in which the diameter increases toward the distal end of the outer shaft 2. In this case, since a greater tightening force acts on the distal end side of the slit 7 of the outer shaft 2, the effect of adjusting the position of the tightening member 20 is greater.

The tapered portion 14 of the tubular member 10 may have a plurality of slits.

In the above embodiment, the tightening member 20
Is used, but the wire spring is used as the tightening member 20.
May be used. In this case, the wire spring tightening member 20 is directly fitted and locked in the locking groove 15 of the tapered portion 14 of the tubular member 10.

Further, while the outer shaft is hollow, the inner shaft may be solid or hollow.

[0046]

As described above, according to the present invention,
A cylindrical member having a tapered portion having a locking groove formed on the outer peripheral surface and having a slit extending in the axial direction is fitted to the outer diameter side of the slit at the tip of the outer shaft, and the outer peripheral surface of the cylindrical member is The tightening member is mounted on the tapered portion while being locked in the locking groove.

Therefore, since the slit at the end of the outer shaft can be pressed in close contact with the inner shaft by the tightening member, a structure in which both shafts are slidable in the axial direction and non-rotatably connected, for example, When the spline fitting is used, the spline teeth can be meshed with no gap, and even if the spline teeth are worn, "play" at the spline fitting portion can be effectively prevented.

Further, since the tightening member is mounted on the tapered portion on the outer peripheral surface of the cylindrical member while being locked in the locking groove, when the sliding force of the spline fitting portion is heavy, the cylindrical member is not fixed. By moving the tightening member to the small diameter side of the tapered portion, the tightening force can be reduced, and the sliding force can be reduced. on the other hand,
When the sliding force of the spline fitting portion is light and there is "play", the tightening force can be increased by moving the tightening member to the large diameter side of the tapered portion of the cylindrical member,
The sliding force can be set to a predetermined value, and "play" can be reduced. As described above, by changing the position of the tightening member, the adjustment of the sliding force of the spline fitting portion and the adjustment of "play" can be easily performed.

Further, since the tightening member is locked in the locking groove of the tapered portion of the cylindrical member, the tightening member does not naturally move to the small diameter side of the tapered portion.

Since the sliding force and the "play" can be easily adjusted only by changing the position of the tightening member, unlike the above-mentioned Japanese Utility Model Publication No. 63-177862, the inner diameter of the tightening member and the outer diameter of the outer shaft are different. There is no need to precisely manage the interference.

Also, even if the spline teeth are worn,
Since the diameter of the tightening member is reduced in accordance with the degree of wear, a necessary tightening force can be continuously secured.

Further, since the inner shaft has no slit portion, unlike the above-mentioned Japanese Utility Model Laid-Open Publication No. Sho 56-48956, a large torque can be transmitted through the non-slit portion of the outer shaft, which is advantageous in strength. It is.

Further, as compared with Japanese Utility Model Publication No. 63-17786, only a cylindrical member is added, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an intermediate shaft of a vehicle steering device.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3A is a cross-sectional view of a cylindrical member for connecting the outer shaft and the inner shaft (a cross-sectional view along line aa in FIG. 3B), and FIG. FIG.

FIG. 4A is a front view of a tightening member for connecting the outer shaft and the inner shaft, and FIG.
Is a side view of the tightening member.

FIG. 5 is a sectional view of a cylindrical member according to a modification.

FIG. 6A is a plan view of a tightening member according to a modification, and FIG. 6B is a side view of the tightening member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower side universal joint 2 Outer shaft 3 Upper side universal joint 4 Inner shaft 5 Female spline 6 Male spline 7 Slit 10 Cylindrical member 11 Slit 12 Stopper 13 Hole 14 Taper part 15 Locking groove 20 Tightening member 21 Locking claw 22 Flange

Claims (1)

[Claims] A slit is formed in a tip portion of an outer shaft, and an inner shaft is inserted into the outer shaft so that both shafts are slidable in the axial direction and non-rotatably connected. In the structure, a cylindrical member having a tapered portion having a locking groove formed on an outer peripheral surface and having a slit extending in an axial direction is fitted to a slit outer diameter side of a tip portion of the outer shaft. A coupling structure for a telescopic shaft, wherein a tightening member is mounted on a tapered portion on an outer peripheral surface of the member while being locked in a locking groove.