JPH07317793A - Shaft fastening structure for flexible joint - Google Patents

Abstract

PURPOSE:To prevent loosening of a pinch bolt by forming a plurality of projections on a flange of a nut, at its surface abutting against a fastening part, with specified intervals in a circumferential direction, and thereby making the projections bite the fastening part for fixation. CONSTITUTION:A yoke 20 has an arcuate portion 21 to which a shaft is inserted, and a pair of fastening parts 22 which are integrated therewith, and spaced apart with each other. A nut 30 has a projected shaft 32 on whose outer peripheral surface a serration part 31 is formed. A flange 33 having a diameter larger than that of the projected shaft 32 is integrated with the projected shaft 32 through a stepped portion. A plurality of projections 35 projected in an axial direction are formed on the surface of the flange 33 to be in contact with the fastening part with specified intervals in a circumferential direction. The projections 35 are formed for generating force to bend the flange 33 through abutting against the fastening part, inward around a screw hole 34 with each other when fastening by a pinch bolt is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a universal joint shaft tightening structure for connecting a universal joint and a shaft of a steering device of an automobile, for example.

[0002]

2. Description of the Related Art A steering shaft in a steering apparatus for an automobile extends from a passenger compartment to the outside of the passenger compartment at the front of the vehicle body, and is arranged not by a straight line but by being bent appropriately if necessary. Are connected.

The steering shaft and the universal joint are torque transmitting means for transmitting the rotation of the steering wheel to the steering gear box, and even if there is a power steering device, the steering wheel is directed through the force thereof. It also transmits the necessary force to.

A cardan joint is generally known as this universal joint. As shown in FIG. 6, this cardan joint has a coupling 6 with a washer 9 interposed between shaft portions 5a and 5b of a cross shaft 5. And the coupling 6 is inserted into and connected to the shaft hole 10 in the yoke portion 3 of the yoke 1, the shaft 2 is inserted into the arc portion 4 of the yoke 1, and the tightening portion 11 is provided with the axis line. Is a structure in which the pinch bolt 7 is inserted into the pinch bolt insertion hole 12 formed in the same manner and is fastened with the nut 8.

In this structure, in order to prevent the shaft 2 from loosening, it is preferable to prevent the pinch bolt 7 and the nut 8 from loosening, so various proposals have been made.
For example, the device of Japanese Utility Model Laid-Open No. 59-56424 is shown in FIG.
As shown in FIG. 5, the nut 8 is fixed to the tightening portion 11 via the welded portion 13 to prevent rotation.

Further, in the invention of Japanese Patent Laid-Open No. 58-193935, as shown in FIG. 7B, the pinch bolt insertion hole 12 of one tightening portion 11 is formed as a screw hole 14, and the nut 15 is screwed. A projecting shaft portion 17 in which a screw portion 16 to be screwed into the hole 14 is formed on a different surface is provided.

[0007]

However, in order to prevent the pinch bolt 7 from loosening, it is necessary to interpose a spring washer on the pinch bolt head side in order to fix the nut 8 to the tightening portion 11 by welding. In addition, there is a drawback that the accuracy of the screw is deteriorated or deteriorated by spatter or thermal strain due to welding.

Further, it is necessary to form the screw hole 14 in the tightening portion 11 in order to prevent the pinch bolt 7 from loosening, as a matter of course, it is necessary to interpose a spring washer on the pinch bolt head side. There is a drawback that the workability is poor in screw processing for integration with the attachment portion 11, the cost is high for automation, and the pinch bolt 7 and the nut 15 cannot be changed, so that the variety is lacking.

In addition, in the conventional tightening structure, the nuts 8 and 15 are both prevented from rotating to prevent loosening with the pinch bolt 7, but the loosening due to the rotation of the pinch bolt 7 itself is prevented. It cannot be prevented. That is, even if the nuts 8 and 15 do not rotate, the pinch bolt 7 rotates to cause relaxation.

Therefore, the present invention provides a shaft tightening structure for a universal joint that solves the above-mentioned drawbacks.

[0011]

SUMMARY OF THE INVENTION According to the present invention to solve the above-mentioned problems, a yoke has an arc portion into which a shaft is inserted and a pair of tightening portions protruding in a radial direction from the arc portion. A pinch bolt insertion hole having the same axis is bored in the portion, and a nut having a projecting shaft portion fitted to one of the pinch bolt insertion holes and a flange portion having a diameter larger than the projecting shaft portion is arranged, and the tightening is performed. In a shaft tightening structure of a universal joint in which a pinch bolt is inserted from one side of the portion and tightened with the nut on the other side, a plurality of flange portions of the nut are circumferentially provided at predetermined intervals in a surface abutting the tightening portion. The protrusion is formed in the axial direction.

[0012]

[Operation] Insert the shaft into the arc portion of the yoke, insert the pinch bolt into the pinch bolt insertion hole of one tightening portion, and screw it into the nut fitted into the pinch bolt insertion hole of the other tightening portion, When the tightening parts come close to each other and the shaft is tightened, the projections come into contact with the tightening parts and the flange part of the nut is pushed and bent toward the pinch bolt side, so that the screw hole of the nut becomes the thread part of the pinch bolt. Remove the clearance of the screw part by pressing and integrate the pinch bolt and nut. Further, the protruding shaft portion is pressed into contact with the tightening portion and bites into the tightening portion, and also acts as a detent for the nut itself.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the yoke 20 has an arcuate portion 21 into which the shaft 19 is inserted and a pair of tightening portions 22 that are separated from each other integrally with the arcuate portion 21. The part 23 is formed. The pinch bolt insertion holes 24 formed in the pair of tightening portions 22 with the same axis are holes into which the pinch bolts 18 are loosely fitted, and the nut 30 is press-fitted into one of the pinch bolt insertion holes 24. .

The nut 30 has a protruding shaft portion 32 having a serration portion 31 formed on the outer peripheral surface thereof, and a flange portion 33 having a diameter larger than that of the protruding shaft portion 32 is formed integrally with the protruding shaft portion 32 via a step. Has been done. The nut 30 has an axial screw hole 34
Are formed. The protruding shaft portion 32 has a pinch bolt insertion hole 2
4, the serration portion 31 presses serration on the inner peripheral surface of the pinch bolt insertion hole 24 to stop the rotation of the nut 30.

Further, the flange portion 33 has a structure shown in FIGS.
As shown in FIG. 5, a plurality of protrusions 35 projecting in the axial direction are formed in the circumferential direction on the surface in contact with the fastening portion 22 at predetermined intervals. When the protrusion 35 is tightened with the pinch bolt 18, the protrusion 35 is provided so as to abut against the tightening portion 22 and generate a force such that the flange portion 33 presses the flange portion 33 inwardly around the screw hole 34 and bends them. In addition to the arc shape shown in the figure, any shape such as a circle and a square is possible.

That is, as shown in FIG. 5, the protruding portion 35 has the pinch bolts 18 inserted from the pinch bolt insertion holes 24 of one tightening portion 22 screwed into the screw holes 34 so that the tightening portions 22 are mutually connected. When they are brought close to each other, the protrusions 35 are
The screw hole 34 on the opposite side of the protrusion 35
Since the force that is drawn inward by the pinch bolt 18 acts on the periphery of the flange, the flange portion 33 is bent inward around the screw hole 34 to be deformed (see the arrow), whereby the screw hole 34 is formed. The threaded portion 36 on the inner peripheral surface of the pinch is pressed against the threaded portion 37 on the outer peripheral surface of the pinch bolt 18 to eliminate the clearance between them, and is formed to tighten around the pinch bolt 18 to prevent loosening.

Since the protrusion 35 bites into the tightening portion 22 during tightening, it can function as a rotation stopper for the nut 30. Therefore, the set number of the protrusions 35 is an appropriate number for causing the bending deformation of the flange portion 33, that is, if the number is too large, the bending deformation of the flange portion 33 is caused with the same effect as a flat plane. However, the number is not limited to three, although three are valid.

Thus, the pinch bolt 18 is attached to the nut 30.
When fastened with, the screw part 3 of the screw hole 34 of the nut 30
Since the pinch bolts 6 and 6 are pressed against the threaded portions 37 near the tips of the pinch bolts 18 to eliminate the clearance between them, the pinch bolts 18 and the nuts 30 can be integrated with each other to prevent them from loosening. it can.

Moreover, since the serration portion 31 is press-fitted into the tightening portion 22 to engage the nut 30, and the projection 35 bites into the tightening portion 22, the nut 30 rotates with respect to the tightening portion 22. Without, therefore, the pinch bolt 18 will be provided with a double loosening prevention.

Therefore, the arcuate portion 21 tightens the shaft 19 without loosening it, and the steering performance as a steering device is not hindered, and the operability and safety are extremely high.

[0021]

According to the present invention described above, the pinch bolt and the nut are integrated with each other in the threaded portion that is screwed with each other without clearance, so that loosening between them does not easily occur and the nut is press-fitted in the serration portion. In addition, since the projections bite into the tightening part and are fixed to the tightening part so as not to rotate, the pinch bolt is prevented from loosening twice, and the tightening force of the shaft does not change. No, the effect is great.

[Brief description of drawings]

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

FIG. 2 is a front view of a determination surface of a nut, which is an essential part of the present invention.

FIG. 3 is a bottom view of a nut which is a main part of the present invention.

FIG. 4 is a perspective view of a nut which is an essential part of this Hatsumi.

FIG. 5 is an explanatory view of the operation of the present invention.

FIG. 6 is an exploded perspective view of a conventional example.

7A and 7B are cross-sectional views of a conventional example, respectively.

[Explanation of symbols]

 18 ... Pinch bolt 19 ... Shaft 20 ... Yoke 21 ... Arc part 22 ... Tightening part 24 ... Hole 30 ... Nut 32 ... Projection shaft part 33 ... Flange part 34 ... Screw hole 35 ... Projection part 36, 37 ... Screw part

Claims (2)

[Claims] 1. A yoke has an arc portion into which a shaft is inserted, and a pair of tightening portions protruding in a radial direction from the arc portion,
A pinch bolt insertion hole having the same axis as the tightening portion is bored, and a nut having a protruding shaft portion fitted to one of the pinch bolt insertion holes and a flange portion having a diameter larger than the protruding shaft portion is arranged. In a shaft tightening structure of a universal joint in which a pinch bolt is inserted from one side of the tightening portion and tightened with the nut on the other side, a predetermined interval in the circumferential direction is provided on a surface of the flange portion of the nut that abuts the tightening portion. The shaft tightening structure of the universal joint is characterized in that a plurality of protrusions are formed in the axial direction. 2. The nut rotation stopper is formed by forming a serration portion on the protruding shaft portion of the nut and press-fitting the protruding shaft portion into the pinch bolt insertion hole. Universal joint tightening structure.