JP2538390Y2 - Telescopic shaft - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a telescopic shaft, particularly for a steering device in a vehicle such as an automobile.

[0002]

2. Description of the Related Art Generally, a steering device for a motor vehicle has a steering column on which a steering wheel is mounted.
It is connected to a steering gear box fixed to the front part of the vehicle body via a universal joint, but the cabin (vehicle compartment) is turned to expose the engine, so that inspection and repair can be performed. In large vehicles such as trucks, the structure between the steering column and the steering gear box must be extendable. For example, an intermediate shaft is connected to the steering shaft via a universal joint, and the intermediate shaft is connected to the upper shaft. Shaft (outer shaft)
And a lower shaft (inner shaft), and a spline and a spline sleeve are formed on them so that they can be nested into each other to enable torque transmission and shrink in the axial direction. I have.

[0003]

However, the conventional structure of the upper shaft and the lower shaft by the spline engagement has sufficient clearance to slide with each other in the engagement structure. For example, there is an inconvenience that unpleasant noise is generated due to the rattling of the two. In order to eliminate such rattling noise, a means has been provided in which a ball is interposed between the upper shaft and the lower shaft to reduce rattling between the two as much as possible (Japanese Patent Application Laid-Open No. 61-1986). -2115
No. 27), which increases the cost because the inner shaft and the outer shaft that contact the ball must be formed in specially shaped cross sections, respectively.

[0004] Therefore, the present invention has been made for the purpose of a low-cost telescopic shaft which can be expanded and contracted with a small force, has little play, and has a simple structure.

[0005]

The telescopic shaft according to the present invention includes an outer shaft and an inner shaft each having a rectangular cross section, which are nested with each other in the axial direction, and the outer shaft and the inner shaft at least on two sides thereof. In addition, an elastic member of a predetermined length and a roller that slides on the elastic member are interposed, and
The elastic member has one end fixed to the inner shaft and the other end locked to a square ring fitted to the inner shaft,
A square hole is formed near the one end, and the roller is fixed near the end of the inner shaft together with the one end of the elastic member, and can be separated into two parts by breaking near the end. Characterized in that the needle bearing is held by a simple cage.

[0006]

According to the invention having the above construction, when the outer shaft is fitted to the inner shaft, the needle bearing of the roller is fitted into the square hole of the elastic member to facilitate the insertion. The outer shaft and the inner shaft can be extended and contracted by bending, and when a stronger force is applied, the retainer is separated from the slit into two members and the fixing is released, and the roller can slide on the elastic member. Becomes Thus, since the roller is interposed between the outer shaft and the inner shaft, the two slide in the axial direction with a small force, and the presence of the elastic member absorbs the play between the two.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional front view in a use state, and FIG. 2 is a cross-sectional front view in a maximum extension state. As shown, an outer shaft 3 is connected to a steering shaft 1 via a universal joint 2.
The outer shaft 3 has an inner shaft 4 slidably fitted in the axial direction, nestedly engaged and axially expandable / contractible. As shown in FIG. 3, the outer shaft 3
The inner shaft 4 is formed of a tube having a substantially regular octagonal cross section, and the inner shaft 4 is formed of a tube having a regular square shape.
A guide portion 7 for slidingly contacting the apex portion 6 of the inner shaft 4 is formed on and engaged with each of the oblique sides 5. Therefore, each side 9 of the outer shaft 3 opposing each side 8 of the inner shaft 4
A certain gap 10 is formed between them.

As shown in FIG. 4, an elastic member 11 composed of a leaf spring and a roller 12 are inserted into the gap 10 at a predetermined length in the axial direction. As shown in FIG. 7, the elastic member 11 has a round hole 13 at one end thereof,
In the vicinity thereof, a rectangular hole 17 into which a needle bearing 16 described later is fitted is formed in the width direction, and an engaging portion 14 wider than a concave portion 18 of a square ring 19 described later and a fitting portion fitted to the concave portion 18 are provided at the other end. 14a is formed. The square hole 17 has a long side slightly longer than the length of the needle bearing 16 and a short side slightly smaller than the outer diameter of the needle bearing 16. The angular ring 19 in which the engaging portion 14 is locked and the concave portion 18 in which the fitting portion 14 a is fitted is formed is fitted to the inner shaft 4. The roller 12 is shown in FIG.
As shown in the figure, a plurality of needle bearings 16 are fitted at predetermined intervals in a retainer 15 made of a plate-like resin having a predetermined length and rotatably held therein. A projection 20 that can be inserted into the projection 13 is formed, and a slit 21 is formed in the width direction near the end. The slit 21 breaks from the slit 21 when a strong force is applied to the retainer 15 in which the needle bearing 16 exists, and separates into a portion having the projection 20 and a portion having the needle bearing 16. . A round hole 22 into which the projection 20 is inserted is formed at the tip of the inner shaft 4.

The cross section of the elastic member 11 is curved toward the inner shaft 4. However, the roller 12 contacts the elastic member 11 to promote the rotation of the needle bearing 16. The shape is roller 1
2 is preferably pressed by the outer shaft 3 so as to form a substantially roof shape in which a surface substantially parallel to the retainer 15 is formed. Further, the elastic member 11 and the roller 12
Are interposed in each of the four gaps 10, but may be interposed in at least two of the sides 9.

The operation of the above embodiment will be described. When assembling the outer shaft 3 to the inner shaft 4,
First, the protrusion 20 of the roller 12 is inserted into the round hole 13 of the elastic member 11 and overlapped with each other, the protrusion 20 is inserted into the round hole 22 of the inner shaft 4, and the engaging portion 14 of the elastic member 11 is By engaging with the concave portion 18 of 19,
An elastic member 11 and a roller 12 are mounted on four sides of the inner shaft 4. Therefore, when the outer shaft 3 is fitted to the inner shaft 4, the first needle bearing 16a is fitted into the square hole 17 to lower the height of the roller 12 from the inner shaft 4, as shown in FIG. Therefore, the work of inserting the inner shaft 4 into the outer shaft 3 is facilitated. In this way, the outer shaft 3 is inserted into the inner shaft 4, and the second and subsequent needle bearings 16 are resistant to insertion. Is interposed between the outer shaft 3 and the inner shaft 4. At this time, since the second needle bearing 16 is pushed by the outer shaft 3 and the cage 15 moves in the axial direction (the direction of the arrow), the cage 15 is broken from the slit 21 as shown in FIG. And separated into a cage 15 portion having a needle bearing 16 and a portion 15a having a projection 20. At this time, the first needle bearing 16a comes out of the square hole 17 of the elastic member 11 and the roller 12 Be able to move in the axial direction.

When the outer shaft 3 configured as described above rotates around the center of the shaft, the inner shaft 4 that slides on the guide portion 7 and the elastic member 11 rotates around the center of the shaft, thereby transmitting torque. This torque transmission is performed by the side 9 of the outer shaft 3 and the roller 12, the elastic member 11 and the side 8 of the inner shaft 4 in the case of a light force, and in the case of a heavier force, by the side 8 of the outer shaft 3. This is achieved by engagement between the guide portion 7 and the apex portion 6 of the inner shaft 4. When the outer shaft 3 is pulled in the axial direction of the arrow in FIG. 1, the needle bearing 16 rotates, and the retainer 15 moves in the axial direction while following the outer shaft 3 while moving. Since the outer shaft 3 and the inner shaft 4 have the elastic member 11 interposed therebetween, the outer shaft 3 and the inner shaft 4 do not rattle with each other and do not generate abnormal noise while the vehicle is running. In addition, when a change occurs in the clearance between the outer shaft 3 and the inner shaft 4 (for example, a state where the axes of the outer shaft 3 and the inner shaft 4 intersect), the roller 12 is elastically supported by the elastic member 11. The outer shaft 3
And buffer the inner shaft 4 without applying excessive force.
Portion 15a having protrusion 20 separated from retainer 15 portion
Acts as a stopper for the roller 12. In addition, there is no need to fix the elastic member with rivets or the like, and since there is no need to provide a hole at the center of the inner shaft, the strength is advantageous and the assembling property is good.

The present invention can be applied to an upper shaft and a lower shaft of a telescopic steering column in which a steering wheel can be extended and contracted in an axial direction, in addition to the above embodiment.

[0013]

According to the invention described above, the outer shaft and the inner shaft having a rectangular cross section are nested with each other in the axial direction, and a predetermined length is provided between at least two sides of the outer shaft and the inner shaft. Since the leaf spring and the roller are interposed, it is possible to obtain a low-cost telescopic shaft that can be expanded and contracted with a light force, has little play, and does not rattle. Therefore, it can be used as an intermediate shaft of a steering device or as a shaft for a telescopic steering column.

When the outer shaft is fitted to the inner shaft, the first needle bearing enters the square hole of the elastic member to reduce the height, so that the outer shaft can be easily inserted and a special jig is used. It is highly practical because it can be incorporated without using.

[Brief description of the drawings]

FIG. 1 is a sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional front view showing a maximum extension state.

FIG. 3 is an enlarged sectional view taken along line BB of FIG. 2;

FIG. 4 is an enlarged sectional view taken along the line CC of FIG. 2;

FIG. 5 is an explanatory diagram of an operation of a main part.

FIG. 6 is an explanatory diagram of an operation of a main part.

FIG. 7 is an exploded perspective view of a main part.

[Explanation of symbols]

3 ... outer shaft, 4 ... inner shaft, 10 ... gap, 11 ...
Elastic member, 12 ... roller, 13, 22 ... round hole, 14 ...
Engaging part, 15: cage, 16: needle bearing, 1
7: square hole, 18: concave portion, 19: square ring, 20: projection, 21
…slit

Claims (1)

(57) [Scope of request for utility model registration] An outer member having a rectangular cross section and an inner shaft are nested in the axial direction with each other in a nested manner, and an elastic member having a predetermined length is slidably contacted between the outer shaft and the inner shaft on at least two sides thereof. Intervening, and
The elastic member has one end fixed to the inner shaft and the other end locked to a square ring fitted to the inner shaft,
A square hole is formed near the one end, and the roller is fixed near the end of the inner shaft together with the one end of the elastic member, and can be separated into two parts by breaking near the end. A telescopic shaft characterized by holding a needle bearing in a simple cage.