JP3087498B2 - Spline connection structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spline connection structure used in a vehicle for connecting an end of a steering shaft to a pinion shaft of a steering gear, and more particularly, to detecting a failure during assembly. The present invention relates to a spline coupling structure having a structure.

[0002]

2. Description of the Related Art A conventional spline coupling structure is disclosed, for example, in Japanese Patent Application Laid-Open No. 51-154747. For example, a spline coupling structure attached to an end of a steering lower shaft in a steering apparatus of an automobile. The joint member is connected to the end of the worm shaft of the steering gear box, and the end of the worm shaft is spline-fitted into the hole of the joint member.

[0003] On the outer peripheral surface of the end of the worm shaft,
A notch is formed at an intermediate position in the axial direction. Further, the hole is cut along the axial direction, and a bolt insertion hole is formed between the cut end faces facing each other so that a bolt can be inserted and a part of the spline hole of the hole interferes. I have. Then, the cut end surfaces of the cut portions are tightened with bolts through the bolt insertion holes to fasten the spline fitting portion, and the notch formed on the shaft end outer peripheral surface with the shaft portion of the bolt has a diameter. The worm shaft is penetrated in a direction to prevent the shaft end of the worm shaft from falling out of the hole.

However, in the above-described structure, the shaft end is free to move in the axial direction when the notched portion of the shaft end is not fitted to the position where the bolt insertion hole is formed at the time of assembly. However, the spline fitting may be performed and the torque transmission may be performed, so that a defective assembly may not be noticed. Conventionally, in order to detect this assembling failure, for example, as shown in FIG. 4, one end is fixed to the outer periphery of the cut portion 6 and a hole is formed between the cut end surfaces at the position where the bolt insertion hole 6a is formed. 5 spline holes 5
A thin plate-shaped elastic member 20 extending to inside a is provided,
Until the elastic body 20 is pushed in by the shaft end 4 inserted into the hole 5a and the elastic body 20 retreats from the position of the bolt hole 6a, the bolt cannot be inserted, so that it is possible to provide a sense of defective assembly. I have.

[0005]

However, in the above-described spline coupling structure, it is necessary to provide the above-mentioned elastic body in order to avoid an improper assembly, so that the number of parts increases and the shaft end 4 is fitted at the time of fitting. A fitting input that only pushes the elastic body 20 is required. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide sensitivity to the assembly failure without increasing the number of parts.

[0006]

In order to achieve the above object, a spline coupling structure of the present invention spline-fits a shaft end into a hole having a cut portion formed along the axial direction, and further comprises: The split end surfaces of the cut portion are tightened with a bolt to fasten the spline fitting portion, and the shaft portion of the bolt penetrates a notch formed in a part of the shaft end outer peripheral surface, thereby forming the shaft. In the spline coupling structure for preventing the end from falling out of the hole, the diameter of the hole in the hole from the shaft insertion side end surface to the bolt insertion hole forming position of the cutout portion can be loosely fitted by the shaft end. It is characterized by its size.

Further, the shaft end is spline-fitted into a hole having a notch formed along the axial direction, and the notch end faces of the notch are tightened with bolts to form the spline-fitting portion. At the same time, the spline coupling structure in which the shaft portion of the bolt penetrates a notch formed in a part of the outer peripheral surface of the shaft end to prevent the shaft end from falling out of the hole,
The shaft end is obliquely deleted in the axial direction from an end face to a position where the notch is formed, leaving a step portion formed in the axial direction of the notch.

[0008]

When the shaft ends are tightened between the split end faces by bolts without inserting the shaft ends into the spline holes of the holes to the positions where the bolt insertion holes are formed, the shaft ends are loosely fitted, so that the torque is transmitted between the two. Cannot be performed, and an assembly failure is detected. In addition, the shaft end is not inserted into the spline hole of the hole, the notch of the shaft end is inserted into the bolt insertion hole forming position, but a part of the shaft end is inserted into the bolt insertion hole forming position. In this case, or when the notch is inserted beyond the position where the bolt insertion hole is formed, the bolt cannot be inserted into the bolt insertion hole.

When the bolt is assembled with the shaft end inserted into the spline hole of the hole with the notch of the shaft end inserted into the bolt insertion hole forming position, the shaft end and the hole are spline-fitted. As a result, when the shaft end is moved in the axial direction, the shaft portion of the bolt is prevented from coming into contact with the axial step in the notch portion and dropping out of the hole portion. .

[0010]

An embodiment of the present invention will be described with reference to the drawings.
This embodiment is an example of a case where the spline connection structure of the present invention is used for connecting a steering shaft and a pinion shaft of a steering gear in a vehicle steering apparatus. First, the configuration will be described. As shown in FIGS. 1 and 2, the end of the steering shaft 1 is connected to the joint member 2 by a universal joint,
The shaft end 4 of the pinion shaft 3 of the steering gear is connected to the joint member 2.

A spline hole 5a into which the shaft end 4 of the pinion shaft 3 can be inserted is formed in the hole 5 of the joint member 2, and a plurality of spline grooves 5b are formed on the inner peripheral surface of the hole 5a. It is formed along the direction. The hole 5 is partially cut in the circumferential direction along the axial direction,
A cut portion 6 having a cut end surface 6a opposed to a predetermined gap is provided.

Further, a bolt insertion hole 6b which penetrates both of the cut end faces 6a is formed in the cut portion 6 with the spline hole 5b.
It is established so as to interfere with a part of a. The spline hole 5a of the hole 5 is formed with a shaft insertion end face 5b.
The spline tooth portion forming the spline groove 5b, which is provided in B between the position and the interference position 7 with the bolt insertion hole 6b, is missing, and the position between the shaft insertion end face and the interference position 7 with the bolt insertion hole 6b is removed. The diameter of the hole is increased, and the shaft end 4 of the pinion shaft 3 can be loosely fitted.

A nut 8 is fixed to one opening end of the bolt insertion hole 6b formed in the cut portion 6. A plurality of splines are formed along the axial direction on the outer peripheral surface of the shaft end 4 of the pinion shaft 3 so as to mesh with the spline grooves 5b of the spline holes 5a. A cutout portion 4a is formed at a part of the circumferential position at an intermediate position.

The shaft end 4 of the pinion shaft 3
And the joint member 2 is assembled as shown in FIG.
Interference position 7 between spline hole 5a and bolt insertion hole 6b
And the notch 4a of the shaft end 4 are aligned in a straight line in the axial direction (see FIG. 3A), and the shaft end 4 is inserted into the spline hole 5a of the hole 5 (b) → (c). By inserting in the order of
The two 4 and 5 are spline-fitted, and the notch 4
With a set at the position where the bolt insertion hole 6b is formed, the bolt is inserted into the bolt insertion hole 6b of the notch 6 so as to penetrate the notch 4a, and the tip is screwed to the nut 8. Thus, the cut end faces 6a are tightly connected. As a result, the spline fitting portion is fastened, and the shaft portion of the bolt engages with the notch portion 4a, thereby preventing the shaft end 4 from dropping out of the spline hole 5a.

If the fitting of the shaft end 4 to the spline hole 5a is tightened by a bolt in the state shown in FIG. Since No. 4 is in a loosely fitted state, the torque cannot be transmitted, and the defective assembly can be detected. In the above embodiment, the notch 4 of the shaft end 4 is used.
Although “a” is formed only in a part of the circumferential direction, it may be formed over the entire circumference in the circumferential direction as in the conventional example.

Next, a second embodiment will be described. In the second embodiment, the spline groove 5b formed in the spline hole 5a of the joint member 2 is formed without dropping to the shaft insertion end face, as in the conventional case. Instead, FIG.
As shown in FIG. 4 (a), the shaft end 4 of the pinion shaft 3 is moved from the end face to the position where the notch 4a is formed.
As shown in the middle and C, it is cut obliquely in the axial direction.

At the time of the above cutting, the stepped portion 4b formed at the axial end of the notch 4a is not cut. Even in the above-described structure, as shown in FIG. 4B, when the bolt is tightened in a state where the notch 4a of the shaft end 4 is not inserted to the position where the bolt insertion hole 6b is formed, the shaft end 4 is loosely fitted. As a result, the torque is not transmitted, and an assembly failure is detected.

As shown in FIG. 4 (c), when the notch 4a of the shaft end 4 is fitted to the position where the bolt insertion hole 6b is formed, and the shaft end 4 is properly assembled, the shaft end 4 is formed. When the bolt moves in the axial direction, the shaft of the bolt abuts on the stepped portion 4b in the notch 4a in the axial direction to prevent the shaft end 4 from dropping off, and to prevent the shaft end 4 from coming into contact with the spline hole 5a. Are spline-fitted with each other, and torque transmission is enabled.

Since the cutting shape of the shaft end 4 is an example, it may be cut obliquely in the axial direction with another cutting shape such as a curved shape or a stepped shape.

[0020]

As described above, according to the spline connection structure of the present invention, torque transmission becomes impossible at the time of an improper assembly and the improper assembling can be sensed by a simple structure without increasing the number of parts. .

[Brief description of the drawings]

FIG. 1 is a partially broken side view showing a spline connection according to an embodiment of the present invention.

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

FIG. 3 is a diagram showing an assembly of a spline connection according to the embodiment of the present invention.

FIG. 4 is a view showing a spline connection of a second embodiment according to the present invention.

FIG. 5 is a diagram showing a conventional spline connection.

[Explanation of symbols]

 4 Shaft end 4a Notch 5 Hole 5a Spline hole 6 Notch 6a Bolt insertion hole B Missing part of spline teeth

Continuation of the front page (56) References JP-A 4-54325 (JP, U) JP-A 58-44508 (JP, U) JP-A 2-98218 (JP, U) JP-A 61-29132 (JP , U) (58) Field surveyed (Int.Cl. ⁷ , DB name) F16D 1/02-1/08 F16D 3/26

Claims (2)

(57) [Claims] An axial end is spline-fitted into a hole having a cut portion formed along the axial direction, and further, the split end faces of the cut portion are tightened with bolts to form the spline fit portion. In the spline coupling structure for fastening the bolt, the shaft portion of the bolt penetrates a notch formed in a part of the outer peripheral surface of the shaft end, and prevents the shaft end from falling out of the hole. A spline coupling structure, wherein a diameter of a hole from an insertion-side end surface to a position where a bolt insertion hole is formed in the cutout portion is a size that allows the shaft end to be loosely fitted. 2. An axial end is spline-fitted into a hole having a cut portion formed along the axial direction, and further, the cut end faces of the cut portion are tightened with bolts to form the spline fit portion. In the spline coupling structure in which the shaft portion of the bolt penetrates a notch formed in a part of the outer peripheral surface of the shaft end to prevent the shaft end from falling out of the hole, the shaft end is cut off. Leaving the step formed in the axial direction of the notch,
A spline coupling structure wherein a portion from an end face to a position where the notch is formed is obliquely deleted in an axial direction.