JPH09296810A - Shaft fixing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix a shaft to a bracket part in the stable state. SOLUTION: A shaft 10 provided with a taper surface 10E is inserted into and arranged on a bottom part 28 of one yoke 14 of a universal joint. A wave washer 44 is inserted around a fixing bolt 36 for fastening a first side part 24 to a second side part 26, and a collar 42 provided with a taper part 42A is slidably arranged. Accordingly, when the fixing bolt 36 is screwed, energizing force of the wave washer 44 acts on the shaft 10 through the taper part 42A of the collar 42 and presses it to the bottom part 28 side. Since the pressing force is uniquely determined by the spring constant of the wave washer 44, variations are not generated on pressing force, and the shaft 10 can be fixed to one yoke 14 in the stable state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft fixing structure for fixing a shaft to a bracket portion.

[0002]

2. Description of the Related Art A universal joint used to connect members to each other, particularly a universal joint used to connect an intermediate shaft in an automobile and a pinion shaft of a steering gear box, is used as an example. An example of a structure for fixing to a section will be described. As a disclosed example of the shaft fixing structure in this type of universal joint, there is JP-A-8-80029, which will be described below.

FIG. 5 is a sectional view showing a state in which a steering shaft 104 that rotates in response to a steering operation is fixed to one yoke 102 of a universal joint 100. Further, FIG. 6 shows a fixing bolt 1 for fixing the steering shaft 104 to the yoke 102.
06 is shown. With reference to these drawings, first, a single component structure of each component will be described, and then a method of fixing the steering shaft 104 to the yoke 102 will be described.

The cross-section of the shaft fixing portion of the yoke 102 is substantially horseshoe-shaped. On one side portion 102A of the yoke 102, a bolt insertion hole 10 having a predetermined diameter dimension is formed.
8 are formed. Also, on the other side portion 102B,
A screw hole 110 having an internal thread formed on the inner peripheral surface is formed coaxially with the bolt insertion hole 108. Further, the inner surface of the bottom portion 102C of the yoke 102 is a curved surface having a predetermined curvature.

The steering shaft 104 has a pair of side surface portions 104A which are parallel to each other and a top surface portion 104 which is a plane orthogonal to the side surface portions 104A.
B, and a bottom surface portion 104C that is a curved surface that is in close contact with the inner peripheral surface of the bottom portion 102C of the yoke 102.

As shown in FIG. 6, the fixing bolt 106
Is a seated head portion 106A, a large diameter portion 106B set to have a diameter dimension substantially the same as the diameter dimension of the bolt insertion hole 108, a small diameter portion 106C screwed into the screw hole 110, and a large diameter portion 106B.
And a taper portion 106D connecting the small diameter portion 106C and the small diameter portion 106C. Further, in the fixing bolt 106 having the above structure, the taper portion 1 is formed from the middle portion of the small diameter portion 106C.
A cylindrical collar 112 is preliminarily fitted to the portion up to 06D. On the inner circumference of one end of the collar 112,
A plurality of locking protrusions 112A projecting toward the axis are formed at 90-degree intervals. Further, on the inner circumference of the other end of the collar 112, a taper portion 112B having a taper angle that matches the taper angle of the taper portion 106D of the fixing bolt 106.
Are formed.

The steering shaft 104 described above is
It is fixed to the yoke 102 as follows. First, the steering shaft 104 is inserted from the open end side of the yoke 102 and arranged inside the bottom portion 102C. At this time, each surface of the steering shaft 104 and the yoke 102
Are inserted in such a manner that they are in close contact with each other. next,
The fixing bolt 106 in which the collar 112 is integrated is inserted from the bolt insertion hole 108 side of the yoke 102. At this time, the washer 1 is provided between the seated head portion 106A of the fixing bolt 106 and the one side portion 102A of the yoke 102.
14 is interposed. Subsequently, the small diameter portion 106C of the fixing bolt 106 is screwed into the screw hole 110 of the yoke 102.

Here, when the screwing amount of the fixing bolt 106 increases, one end portion of the collar 112 comes into contact with the inner side surface of the other side portion 102B of the yoke 102. Therefore, by increasing the screwing amount, the collar 112 is moved to the yoke 1
02 relatively moves to the side 102A side. Therefore, the taper portion 112B of the collar 112 is fixed to the fixing bolt 10
6 is slid on the taper portion 106D, and the fixing bolt 10
It is deformed outward in the radial direction of 6. As a result, color 1
A part of the deformed taper portion 112B of 12 abuts on the top surface portion 104B of the steering shaft 104 and presses it toward the bottom portion 102C of the yoke 102. As a result, when the steering shaft 104 and the yoke 102 are aligned, the steering shaft 104 moves toward the yoke 1
It is fixed at 02.

[0009]

However, in the case of the above configuration, the pressing force on the top surface portion 104B of the steering shaft 104 fluctuates depending on how the tapered portion 112B of the collar 112 is deformed in the radial direction. There is a problem that 104 cannot be fixed to the yoke 102 in a stable state.

In view of the above facts, an object of the present invention is to obtain a shaft fixing structure capable of fixing the shaft to the bracket portion in a stable state.

[0011]

According to a first aspect of the present invention, there is provided a bracket portion in which a shaft is inserted from an open end side and a fixing portion has a substantially horseshoe-shaped cross section, and one side of the bracket portion. A fixing bolt for fastening the shaft portion to the other side portion and fixing the shaft to the bracket portion in a state of surrounding the shaft between the bracket portion and the bracket portion. A pressing member that is disposed on the outer periphery of the shaft portion of the fixing bolt, is slidable along the axis, and has a taper portion that can abut the shaft at the end portion located on the opposite side to the head of the fixing bolt; , Is interposed between the head of the fixing bolt and the pressing member, and by pressing the pressing member toward the tip side of the fixing bolt, pressing force to the bottom side of the bracket portion is applied to the shaft via the tapered portion of the pressing member. Give It is characterized by having a energizing member.

According to a second aspect of the present invention, in the first aspect of the invention, the pressing member is formed in a tubular shape, and further, in the state where the shaft is fixed, inside the bolt insertion hole formed in the side portion of the bracket portion. The pressing member is inserted into the bolt insertion hole so as to be in surface contact with the peripheral surface.

According to the first aspect of the present invention, the shaft is fixed to the bracket portion using the fixing bolt as follows. First, the shaft is inserted from the open end side of the bracket portion and arranged at the bottom portion of the bracket portion. Next, one side portion and the other side portion of the bracket portion are fastened by the fixing bolt. At this time, the pressing member arranged on the outer periphery of the shaft portion of the fixing bolt receives the urging force of the urging member toward the tip side of the fixing bolt. Therefore, while the pressing member slides along the axis of the shaft portion of the fixing bolt, the taper portion formed at the end of the pressing member contacts the shaft. Therefore, the urging force of the urging member is differentiated through the tapered portion of the pressing member, and the component force acts on the shaft as a pressing force for pressing the shaft toward the bottom side of the bracket portion. As a result, the shaft is securely fixed to the bracket portion by the tightening force of the fixing bolt and the pressing force of the pressing member.

Here, in the present invention, the shaft is not pressed to the bottom side of the bracket portion by utilizing the deformation of the pressing member as in the conventional structure, but the pressing member itself is not deformed and is biased by pressing. Since the shaft is pressed to the bottom side of the bracket portion by utilizing the biasing force of the biasing member, the pressing force acting on the shaft is uniquely determined by setting the biasing force of the biasing member. Therefore, the pressing force acting on the shaft does not vary.

According to the second aspect of the present invention, the pressing member is formed in a tubular shape, and the pressing member is inserted into the bolt insertion hole formed in the side portion of the bracket portion in the shaft fixed state. Then, in this state, the pressing member is in surface contact with the inner peripheral surface of the bolt insertion hole. Therefore, when the shaft is pressed by the pressing member, the reaction force acting on the pressing member from the shaft is received by the inner peripheral surface of the bolt insertion hole of the bracket portion. Therefore, it is possible to prevent bending deformation due to the reaction force from occurring in the shaft portion of the fixing bolt.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 shows the overall structure of the universal joint 12 in relation to the shaft 10 to be fixed.
Further, FIG. 1 shows a sectional structure taken along line 1-1 in FIG. As shown in these figures, the universal joint 12
Is composed of one yoke 14 as a bracket portion, the other yoke 16 and a cross shaft 18 connecting the yokes 14 and 16 so as to be rotatable relative to each other.
The shaft 10 is fixed to one yoke 14 by a swinging method, and another shaft is fixed to the other yoke 16 by a serration fitting method. As described above, one of the yokes 14 and 16 has a different shaft fixing method when, for example, the shaft 10 is an intermediate shaft of an automobile and another shaft is a pinion shaft of a steering gear box. For example, if the steering gear box and the steering column are assembled to the vehicle body in advance, the pinion shaft of the steering gear box and the main shaft in the steering column become immovable. This is because if the medium shaft can be rocked and fixed, the assembling work becomes easy.

In this embodiment, one yoke 1 is used.
4, that is, in the above example, the present invention is applied to the yoke on the side where the intermediate shaft is fixed. Therefore, in the following description, only one yoke 14 side will be mainly described.

The one yoke 14 has a fixed portion 20 for holding the shaft 10 in a fixed state, and the other yoke 16 protruding from the fixed portion 20 in a substantially U shape via a cross shaft 18.
And a connecting portion 22 that is connected to. this house,
The fixed portion 20 includes a first side portion 24 and a second side portion 26 arranged in parallel with each other, and the first side portion 24 and the second side portion 2 of these.
And a bottom portion 28 which is in the shape of an arc plate and which connects 6 with each other. The inner side surface 24A of the first side portion 24 and the inner side surface 26A of the second side portion 26 are flat surfaces parallel to each other, and the inner side surface 28A of the bottom portion 28 is an arc surface having a predetermined curvature. Further, a bolt insertion hole 30 having a predetermined diameter is formed on the open end side of the first side portion 24, and
On the open end side of the side portion 26, a screw hole 32 having a smaller diameter than the bolt insertion hole 30 and having an internal thread formed on the inner peripheral surface is formed.

As shown in FIG. 3, the yoke 1 described above is used.
The shaft 10 fixedly held by the fixed part 20 of FIG.
Is a solid shaft having a substantially oval cross section. Further, a rectangular notch 34 in plan view is formed on the tip end side of the top of the shaft 10. Therefore, when observing the cross-sectional structure of the shaft at the cutout forming portion,
0 is located on the lateral side and is parallel to each other and is a flat surface. The outer surfaces 10A and 10B are on the top side. The top surface 10C is orthogonal to the both outer surfaces 10A and 10B. And a bottom surface 10D which is an arc surface having a predetermined curvature. Further, a tapered surface 10E having a predetermined taper angle is formed on the outer end of the top surface 10C of the shaft 10.

Next, the fixing bolt 36 used for fixing the shaft 10 to the one yoke 14 will be described. As shown in FIG. 4, the fixing bolt 36
Includes a seated head portion 38 and a shaft portion 40 protruding from the axial center portion of the seated head portion 38. Further, the bolt head side of the shaft portion 40 is a smooth portion 40A having a smooth peripheral surface, and the bolt tip side is a male screw portion 40B having a male screw formed on the peripheral surface. The smooth portion 40A of the shaft portion 40
The outer diameter dimension of is set smaller than the inner diameter dimension of the bolt insertion hole 30 described above.

Further, a cylindrical collar 42 is slidably inserted along the axis of the outer periphery of the smooth portion 40A of the fixing bolt 36. The outer diameter dimension of the collar 42 matches the inner diameter dimension of the bolt insertion hole 30 of the first side portion 24 described above. A taper portion 42A is formed at the end of the collar 42 on the bolt tip side, the diameter of which is reduced toward the bolt tip side. The taper angle of the taper portion 42A and the taper angle of the above-described taper surface 10E of the shaft 10 match. Further, a wave washer 44 having a predetermined spring constant is arranged between the end of the collar 42 on the bolt head side and the seat surface of the seat head 38 of the fixing bolt 36.

Next, a procedure for fixing the shaft 10 to the one yoke 14 of the universal joint 12 will be described, and the operation and effect of the present embodiment will be described through the explanation.

First, as shown in FIG. 2, the shaft 10
While swinging, the front end of the shaft 10 is inserted from the open end side of the fixed portion 20 of the one yoke 14 and arranged on the bottom 28 side of the fixed portion 20. In this state, as shown in FIG. 1, the outer surfaces 10A, 10B of the shaft 10 are
Respectively come into contact with the inner side surfaces 24A, 26A of the first side portion 24 and the second side portion 26 of the yoke 14 in a surface contact state, and the central portion of the bottom surface 10D of the shaft 10 has the yoke 1
4 is in contact with the inner surface 28A of the bottom portion 28 of No. 4 in a surface contact state.

Next, the first bolt 24 and the second bolt 26 are fastened to each other by the fixing bolt 36. A wave washer 44 and a collar 42 are previously attached to the fixing bolt 36, that is, the fixing bolt 3
6, the wave washer 44, and the collar 42 are in a pre-assembled state (the state shown in FIG. 4). The fixing bolt 36 in this state is inserted from the bolt insertion hole 30 in the first side portion 24 of the one yoke 14 and screwed into the screw hole 32 of the second side portion 26.

In this process, the collar 42 is attached to the bolt insertion hole 3
The taper portion 42A of the collar 42 comes into contact with the taper surface 10E of the shaft 10 while being inserted into the 0 in a surface contact state. Then, by still screwing the fixing bolt 36, the collar 42 slides the smooth portion 40A of the fixing bolt 36 along the axis thereof toward the seated head portion 38, and elastically deforms (contracts) the wave washer 44. . For this reason,
An urging force from the wave washer 44 acts on the collar 42, and the urging force is divided by the tapered portion 42A of the collar 42 and the tapered surface 10E of the shaft 10 to exert a pressing force P on the tapered surface 10E of the shaft 10. At this point, the seat surface of the seat portion 38 of the fixing bolt 36 is slightly separated from the outer surface of the first side portion 24.

Further, the seating surface of the seated head portion 38 is the first.
The fixing bolt 36 is screwed in until it comes into close contact with the outer surface of the side portion 24, and a complete fastening state is obtained. In this state, it is preferable to determine the size of each part so that the wave washer 44 does not come into close contact with the wire (not to be in the state of a flat washer).

As described above, in the state where the complete fastening state by the fixing bolt 36 is obtained, a relatively large pinching force F _{1 in the} fastening direction acts on the first side portion 24, and the second side portion 24 acts. Since a relatively large clamping force F ₂ in the counter-tightening direction acts on the portion 26, the inner side surface 24A of the first side portion 24 and the second side portion 26
The distance between the inner surface 26A and the inner surface 26A is narrowed, and the shaft 10 is firmly sandwiched. Further, in this state, since the elastic deformation amount (shrinkage amount) of the wave washer 44 is increased, the pressing amount P that presses the shaft 10 toward the bottom portion 28 side of the one yoke 14 is also strong, and the shaft 10 is pressed against the yoke 14. Bottom 2
Firmly press it to the 8 side.

Here, in the present embodiment, the collar 42 itself is not deformed and a pressing force is generated by utilizing the deformation as in the conventional structure, but the collar 42 is pressed and tapered by the urging force of the wave washer 44. A part of the urging force differentiated by the portion 42A is used as the pressing force P and the shaft 10
Therefore, the magnitude of the pressing force P on the shaft 10, which has an important meaning in this embodiment, is uniquely determined by the spring constant of the wave washer 44. As a result, the magnitude of the pressing force P acting on the shaft 10 does not vary, and the shaft 10 can be fixed to the one yoke 14 in a stable state. As a result, the shaft 10 is not fixed to the one yoke 14 in a state where the axis line is displaced, and it is possible to prevent the occurrence of joint position failure and the bolt loosening.

Further, in this embodiment, the collar 42 is formed in a cylindrical shape and is formed on the first side portion 24 of the yoke 14 when the shaft 10 is fixed to the one yoke 14 by the fixing bolt 36. Bolt insertion hole 30
Since the collar 42 is configured to be inserted into the inside in a surface contact state, the shaft portion 4 of the fixing bolt 36 is inserted from the tapered surface 10E of the shaft 10 through the tapered portion 42A of the collar 42.
The reaction force input to 0 is applied to the bolt insertion hole 30 of the first side portion 24.
Can be received on the inner surface of. Therefore, it is possible to prevent bending deformation of the shaft portion 40 of the fixing bolt 36 due to the reaction force. As a result, the fixing bolt 36
Can be prevented from being broken, and loss of tightening torque due to the fixing bolt 36 is eliminated. Further, from this, according to the present embodiment, there is an advantage that the fixing bolt 36 and the like can be reused, because the parts that are permanently deformed are eliminated.

Although the operation and effects of the present embodiment have been described above, additional points other than the above-mentioned matters are listed below.

In the case of the structure of this embodiment, the amount of reduction in the tightening force (axial force) by the fixing bolt 36 is the wave washer 4
Since there is only the contraction load of No. 4, the fastening state by the fixing bolt 36 will not be adversely affected.

Further, in the present embodiment, since the work of fixing the shaft 10 to the yoke 14 is completed only by screwing the fixing bolt 36, the nut can be eliminated in other words, so that the assembling workability is improved. Is excellent.

In the embodiment described above, the intermediate shaft is used as the shaft 10 to which the one yoke 14 is fixed, and the pinion shaft of the steering gear box is used as the shaft to which the other yoke 16 is fixed. However, the present invention is also applicable to the connection of shafts other than automobiles.

In this embodiment, the shaft 10 is fixed to the one yoke 14 of the universal joint 12, but the present invention is not limited to the universal joint, and the shaft is simply fixed to the bracket portion. It is also applicable in the case.

Further, in the present embodiment, the screw hole 32 is formed in the second side portion 26 of the one yoke 14 from the viewpoint of the assembling workability as described above, but it is not necessary to particularly consider the assembling workability. In this case, a nut may be used instead of the screw hole 32, or a weld nut may be welded in advance.

Further, in the present embodiment, the wave washer is used as the urging member for urging the collar 42, but the present invention is not limited to this, and a leaf spring, a disc spring, a spring washer or the like may be used. .

[0038]

As described above, in the shaft fixing structure according to the present invention as set forth in claim 1, a pressing member is arranged on the outer periphery of the shaft portion of the fixing bolt so as to be slidable along the axis, and at the same time, the pressing member is opposite. By providing a taper portion that can contact the shaft at the end portion of the fixing bolt located on the head side, and further urging the pressing member between the head of the fixing bolt and the pressing member toward the tip side of the fixing bolt. Since the biasing member that applies pressing force to the bottom side of the bracket part is provided on the shaft via the taper part, it is possible to prevent variations in the pressing force acting on the shaft, which allows the shaft to be mounted on the bracket. It has an excellent effect that it can be fixed to the part in a stable state.

In the shaft fixing structure according to the present invention as defined in claim 2, in the invention according to claim 1, the pressing member is formed in a tubular shape, and further, in the shaft fixed state, it is formed on a side portion of the bracket portion. Since the pressing member is inserted into the bolt insertion hole so as to be in surface contact with the inner peripheral surface of the bolt insertion hole, it is possible to prevent bending deformation of the shaft portion of the fixing bolt. This has an excellent effect that the fixing bolt can be prevented from being broken and the tightening torque can be prevented from being lost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along line 1-1 of FIG. 2 showing a main part of a shaft fixing structure in a universal joint according to an embodiment.

FIG. 2 is an overall configuration diagram of a universal joint in relation to a shaft.

3 is a partially enlarged perspective view of the shaft shown in FIG.

FIG. 4 is a side view showing a fixing bolt that is sub-assembled.

FIG. 5 is a sectional view corresponding to FIG. 1, showing a main part of a shaft fixing structure in a conventional universal joint.

6 is a side view showing the fixing bolt shown in FIG. 5. FIG.

[Explanation of symbols]

 10 Shaft 14 One yoke (bracket part) 24 First side part (one side part of bracket part) 26 Second side part (other side part of bracket part) 28 Bottom part (bottom part of bracket part) 30 Bolt insertion hole 36 Fixing Bolt 38 Head with Seat 40 Shaft 42 Collar (Pressing Member) 42A Taper 44 Wave Washer (Biasing Member)

Claims (2)

[Claims] 1. A bracket part in which a shaft is inserted from an open end side and a fixing part has a substantially horseshoe-shaped cross-section, and one side part and the other side part of the bracket part are fastened to each other to form a bracket part. And a fixing bolt for fixing the shaft to the bracket in a state where the shaft is surrounded between the fixing bolt and the shaft. Between the head of the fixing bolt and the pressing member, which is slidable and has a taper part that can abut the shaft at the end opposite to the head of the fixing bolt. And an urging member which is interposed and applies a pressing force to the bottom side of the bracket portion to the shaft via the taper portion of the pressing member by urging the pressing member toward the tip side of the fixing bolt. Do Yafuto fixed structure. 2. The pressing member is formed in a tubular shape, and further, when the shaft is fixed, the pressing member is brought into surface contact with an inner peripheral surface of a bolt insertion hole formed in a side portion of the bracket portion. The shaft fixing structure according to claim 1, wherein the shaft fixing structure is inserted into the bolt insertion hole.