JPH11303881A - Connection structure of rotating shaft - Google Patents

Abstract

(57) [Problem] To prevent rattling in a radial direction and a rotating direction between an exterior shaft and an elastic body and between an interior shaft and an elastic body at a fitting portion between the exterior shaft and the interior shaft. SOLUTION: An exterior shaft 11 having a hole 11a having a non-circular cross section, and a shaft portion 12a fitted to the hole 11a having a non-circular cross section of the exterior shaft 11 so as to be slidable in the axial direction and capable of transmitting torque. And an elastic body interposed in the fitting portion of the two shafts 11 and 12 to press a part of the shaft part 12a of the interior shaft against a part of the hole 11a having a non-circular cross section of the exterior shaft. In the connecting structure of the rotating shafts, the elastic body is assembled to one of the shafts 11 and 12 so as to be unable to move in the axial direction, and frictionally engages with the other to radially and axially engage the inner shaft 12 and the outer shaft 11, respectively. An elastic body (wire spring 13) that applies a biasing force in the rotation direction is employed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure of a rotating shaft used as, for example, a steering shaft of an automobile.

[0002]

2. Description of the Related Art As one of coupling structures of a rotating shaft,
An exterior shaft having a non-circular cross-section hole, and an interior shaft having a shaft portion fitted into the non-circular cross-section hole of the exterior shaft so as to be slidable in the axial direction and capable of transmitting torque.
And an elastic body interposed between the fitting portions of these two shafts to press a part of the shaft portion of the interior shaft against a part of a non-circular cross-section hole of the exterior shaft.
For example, it is disclosed in JP-A-6-58341.

[0003]

In the connecting structure of the rotating shaft disclosed in the above-mentioned publication, at least three elastic bodies are assembled on the outer periphery of the inner shaft in a circumferentially dispersed manner and each elastic body is assembled. Since the body presses the exterior shaft radially outward and the interior shaft radially inward, the center axis of the exterior shaft and the center axis of the interior shaft are aligned with high precision. Although it is possible to prevent rattling in the radial direction between the two shafts, the elastic body is assembled so as to engage with the bottom surface of the groove having a rectangular cross section formed on both shafts. However, only the radial urging force is applied to the exterior shaft and the interior shaft, but not to the rotation direction. Due to the rotation direction of the clearance required for assembling the exterior shaft, so that the rattling of the respective rotation direction occurs in between the outer shaft and the elastic body and between interior shaft and the elastic member. Also, if the elastic body is at least 3
Since the number of components is large, the number of components is large, and there is a problem in assemblability and cost.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to address the above-mentioned problems, and has an outer shaft having a hole having a non-circular cross section, and a hole having a non-circular cross section of the outer shaft. An interior shaft having a shaft portion fitted so as to be slidable and capable of transmitting torque in the axial direction, and a part of the shaft portion of the interior shaft interposed between the fitting portions of the two shafts, the non-circular shape of the exterior shaft A rotating shaft coupling structure having an elastic body pressed against a part of the cross-sectional hole, wherein the elastic body is assembled to one of the shafts so as to be axially immovable and frictionally engages the other shaft. It is characterized in that an elastic body that applies a biasing force in a radial direction and a rotational direction to each of the inner shaft and the outer shaft is employed.

[0005] In this case, the elastic body is integrally attached to the interior shaft so as not to move in the axial direction,
A part of the outer shaft is resiliently engaged with a tapered portion that expands inward in a hole formed in the hole of the outer shaft, and an outer portion formed on the shaft of the inner shaft in another part. It is preferable that the shaft is a single wire spring that resiliently engages with the tapered portion that expands in the upward direction, or that the two shafts are fitted by spline fitting.

[0006]

In the joint structure of the rotating shaft according to the present invention, the elastic body interposed in the fitting portion between the inner shaft and the outer shaft is assembled to one of the two shafts so as not to move in the axial direction. Since the elastic body that frictionally engages with the other and applies a biasing force in the radial direction and the rotational direction to each of the inner shaft and the outer shaft is adopted, the elastic body can move radially and rotationally with respect to both shafts. Therefore, it is possible to prevent rattling in the radial direction and the rotational direction between the exterior shaft and the elastic body and between the interior shaft and the elastic body, respectively, and it is possible to accurately couple both shafts via the elastic body. .

In practicing the present invention, a part of the tapered portion which is integrally mounted on the interior shaft so as to be axially immovable and expands inward in a hole formed in the hole of the exterior shaft is formed. A single linear spring is elastically engaged with the tapered portion that resiliently engages with the tapered portion formed on the shaft portion of the interior shaft at the other portion and expands outward. In the case of adopting as, the wire springs can be assembled by simply fitting these to the exterior shaft in a state where the wire springs are previously assembled to the interior shaft, and each component can be easily assembled, The number of components is small, which is extremely advantageous in terms of cost. In addition, when the fitting of both shafts is spline fitting, compared to the fitting of both shafts with fitting of a two-face width part or fitting of a polygon, the rotation direction of both shafts is The accuracy (assembly accuracy) can be made high.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 show an example in which a connecting structure of a rotating shaft according to the present invention is applied to a steering shaft 10. In this steering shaft 10, as shown in FIGS.
1 and the inner shaft 12 are spline-fitted so as to be slidable in the axial direction and capable of transmitting torque, and a wire spring 13 having a circular cross section is interposed in the spline-fitted portion in a state where it is compressed and deformed by a predetermined amount. ing.

The exterior shaft 11 is a shaft having a spline-formed hole 11a having a non-circular cross-section, and a universal joint (not shown) is integrally attached to an end (not shown). Wire spring 1 corresponding to hole 11a
3 is formed therein. The accommodation groove 11b is formed in the axial direction, and has a tapered surface S11 (see FIG. 3) that expands radially inward.
It opens to the right at the right end of FIG.

The interior shaft 12 has a non-circular cross-section shaft portion 12 which is spline-fitted to the non-circular cross-section hole 11a of the exterior shaft 11 so as to be slidable in the axial direction and capable of transmitting torque.
a, a universal joint (not shown) is integrally attached to an end not shown, and a shaft 12a
A groove 12b for accommodating the wire spring 13 is formed in correspondence with the above, and a radial hole 12c and an axial hole 12d for assembling the wire spring 13 are provided. The accommodation groove 12b is formed in the axial direction, and has a tapered surface S12 (see FIG. 3) that expands radially outward.
It opens to the left at the left end of the.

The wire spring 13 is interposed in a spline fitting portion between the exterior shaft 11 and the interior shaft 12, and has a wavy central portion 13a accommodated in the accommodation groove 11b of the exterior shaft 11 and the accommodation groove 12b of the interior shaft 12. And an L-shaped mounting end 1 fitted in a radial hole 12c of the interior shaft 12.
3b and a J-shaped mounting end portion 13c fitted into the axial hole 12d of the interior shaft 12, and resiliently strikes the tapered surface S11 of the exterior shaft 11 at two points of the wavy central portion 13a at four points. And the wavy central part 13
The tapered surface S12 of the interior shaft 12 at one point and two points a
Are resiliently engaged. The wire spring 13 is integrally attached to the interior shaft 12 so as not to move in the axial direction, is frictionally engaged with the exterior shaft 11 so as to be movable in the axial direction, and is engaged with each of the exterior shaft 11 and the interior shaft 12. A radial and rotational biasing force is applied, and a portion of the shaft portion 12a of the interior shaft 12 (the lower portion in FIGS. 1 and 2) is partially fitted to a hole portion 11a of the exterior shaft 11 (FIG. 1).
And the lower part of FIG. 2).

In this embodiment constructed as described above, as an elastic body interposed in the fitting portion between the interior shaft 12 and the exterior shaft 11, the elastic body is assembled to the interior shaft 12 and frictionally engaged with the exterior shaft 11. In addition, since the wire spring 13 that applies a biasing force in the radial direction and the rotating direction to each of the inner shaft 12 and the outer shaft 11 is adopted, the wire spring 13 can move in the radial direction and the rotating direction with respect to the shafts 11 and 12. Therefore, it is possible to prevent rattling in the radial direction and the rotational direction between the exterior shaft 11 and the wire spring 13 and between the interior shaft 12 and the wire spring 13, respectively. And can be combined accurately.

A wire spring 13 is integrally attached to the interior shaft 12 so as not to move in the axial direction.
Partially (two places and four points) resiliently engage with the tapered surface S11 formed in the one hole 11a and expanding toward the inside of the diameter,
The shaft part 1 of the interior shaft 12 at another part (one point and two points)
Tapered surface S12 formed in 2a and expanding outward in the radial direction
Because it is a single object that resiliently engages with the interior shaft 1
2, the wire shaft 13 can be assembled by simply fitting the armature shaft 11 with the wire spring 13 in a pre-assembled state, so that each component can be easily assembled and the number of component parts is small. This is extremely advantageous in terms of cost. Further, since the fitting of the shafts 11 and 12 is spline fitting, the fitting of the shafts 11 and 12 is compared with the case where the fitting of the two-face width portion or the fitting of the polygon is performed. It is possible to make the accuracy (assembly accuracy) of the rotation directions of 11 and 12 high.

In the above embodiment, both shafts 1
A single wire spring 13 is employed as an elastic body interposed between the fitting portions 1 and 12 to press a part of the shaft portion 12a of the interior shaft 12 against a part of the hole portion 11a of the exterior shaft 11. The body is not limited to the wire spring 13, but can be changed as appropriate, and can be constituted by a plurality.

In the above embodiment, the wire spring 1
3 is resiliently engaged with the tapered surface S11 of the exterior shaft 11 and resiliently engaged with the tapered surface S12 of the interior shaft 12, so that the two shafts 11 and 12 respectively have radial and rotational directions. I tried to give a bias,
The structure for applying the urging force in the radial direction and the rotational direction to each of the shafts 11 and 12 by the elastic body such as the wire spring 13 can be appropriately changed and implemented.

In the above embodiment, the present invention is applied to the steering shaft 10. However, the present invention relates to an exterior shaft having a hole having a non-circular cross-section, and an axial shaft having a hole having a non-circular cross-section. An interior shaft having a shaft portion fitted so as to be slidable and capable of transmitting torque, and a part of the shaft portion of the interior shaft interposed between the fitting portions of these two shafts having a non-circular cross section of the exterior shaft. The present invention can be similarly implemented as long as the rotary shaft has an elastic body pressed against a part of the hole, and is not limited to the above embodiment.

In the above embodiment, the wire spring 1
3 was integrally mounted on the interior shaft 12 so as to be axially immovable, but the shape of the wire spring 13 was changed so that the wire spring (elastic body) was integrally mounted on the exterior shaft without being axially movable. It is also possible to carry out.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of an essential part showing an embodiment of a coupling structure of a rotating shaft according to the present invention.

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

FIG. 3 is an enlarged sectional view of a portion B in FIG. 2;

[Explanation of symbols]

10 ... steering shaft (rotating shaft), 11 ...
Exterior shaft, 11a: spline-formed hole with a substantially circular cross section, 11b: accommodation groove, 12: interior shaft, 12a
... A shaft portion having a non-circular cross-section to be spline-fitted, 12b... Accommodation groove, 12c, 12d... Mounting hole, 13... Wire spring (elastic body), 13a. Tapered surface, S12: Tapered surface.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Nobuyuki Higashi 12 Aisin Light Metal Co., Ltd. at 12 Nagoe, Shinminato City, Toyama Pref. Inside

Claims (3)

[Claims] 1. An exterior shaft having a hole having a non-circular cross section, and an interior shaft having a shaft fitted into the hole having a non-circular cross section so as to be slidable in the axial direction and capable of transmitting torque. An elastic body interposed between the fitting portions of these two shafts and elastically pressing a part of the shaft part of the interior shaft to a part of the hole having a non-circular cross-section of the exterior shaft. An elastic body is attached to one of the shafts so as to be immovable in the axial direction, and frictionally engages with the other shaft to apply radial and rotational urging forces to the interior shaft and the exterior shaft, respectively. A rotating shaft coupling structure that has been adopted. 2. The elastic body is integrally attached to the interior shaft so as to be axially immovable and partly formed in a tapered portion formed in a hole of the exterior shaft and expanding inward in a radial direction. A single wire spring which resiliently engages with the other portion and which resiliently engages with a tapered portion which is formed on the shaft portion of the interior shaft and expands radially outward at the other part. 2. The connecting structure for a rotating shaft according to claim 1, wherein the connecting structure is provided. 3. The connecting structure of a rotary shaft according to claim 1, wherein the fitting of the two shafts is a spline fitting.