JPH06280889A - Yoke for joint and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a yoke for a joint, by which productivity can be improved and the manufacturing cost can be reduced. CONSTITUTION:A yoke 1 for a joint is press- formed using a steel plate provided with a joint part 2 and two bending parts 3, 3, and formed like a flat surface extending from the central part of the bending part 3 to the end part on the opposite side to the joint part 2. Thus, it is possible to reduce the lift up amount required for bending and forming the bending parts 3 by press working and then demounting the yoke 1 for a joint from a metal mold, so that the productivity of the yoke 1 for a joint can be improved and the manufacturing cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint yoke and a method for manufacturing the same, and more particularly, to a joint yoke for connecting shafts of an automobile steering device, for example, between a main shaft and an intermediate shaft, and the manufacture thereof. It is about the method.

[0002]

2. Description of the Related Art For example, a joint yoke, for example, a universal joint yoke is used for connecting a main shaft of an automobile steering device and an intermediate shaft or connecting an intermediate shaft and an input shaft of a gear box. There is.

A conventional universal joint yoke is disclosed in, for example, Japanese Utility Model Laid-Open No. 172930/1982.

The conventional universal joint yoke disclosed in this publication is formed by bending a sheet metal material by press working, and includes a base portion forming a joint,
And an ear-shaped protruding portion forming two bent portions that are bent and connected to the base portion. Each of these two ear-shaped projections has a corrugated cross-sectional shape over the entire length in the lengthwise direction.

[0005]

By the way, the above-mentioned corrugated cross-sectional shape of the ear-like protrusions is formed by pressing the ear-like protrusions using a die having a corrugated cross-sectional shape corresponding to this corrugation. To be done.

Then, in order to convey the universal joint yoke after the cross-sectional shape of the ear-shaped projection portion is corrugated by this press working to the next working step, it is necessary to remove the universal joint yoke from the mold. There is.

However, as described above, the ear-shaped protrusion portion has a corrugated cross section over the entire length in the lengthwise direction, and this corrugated portion engages with the corrugated portion of the mold, so that the ear It is necessary to lift up the entire length of the protrusions and then convey them to the next predetermined processing step.

Therefore, in such a conventional universal joint yoke, since the amount of lift-up when it is conveyed to the next step is large, it is not possible to improve the productivity in line production, and as a result, the manufacturing cost is reduced. There was a problem that it became expensive.

Further, when the ear-like protrusions forming the bent portion are bent by press working using a mold, if the entire ear-like protrusions are uniformly pressed and press-worked, the ear-like protrusions after the working are processed. Due to the elastic restoring force of the ears, the bending accuracy of the ears varies, and as a result, the accuracy of the width (inner width) between the inner surfaces of the tips of the two bending parts cannot be sufficiently secured. .

The present invention has been made in view of the above points, and reduces the lift-up amount at the time of conveyance by forming a flat shape from the center of the bent portion to the tip of the bent portion. Thus, it is an object of the present invention to provide a joint yoke that can improve the productivity and reduce the manufacturing cost.

Another object of the present invention is to manufacture a joint yoke having a good inner width accuracy and a good assembling property by bending the bent portion by pressing while applying a local plastic force. It is an object of the present invention to provide a method of manufacturing a yoke for joints that can be manufactured.

[0012]

The invention according to claim 1 is
A joint yoke, which is press-formed from a steel plate and has a joint portion and a bent portion, wherein the bent portion is bent from the steel sheet, and the joint is formed from a central portion of the bent portion. It is characterized in that a flat shape is formed up to the end opposite to the part.

According to a second aspect of the present invention, there is provided a method of manufacturing a joint yoke, which is press-formed from a steel plate and has a joint portion and a bent portion, wherein the bent portion is bent from the steel sheet. Then, while applying a local plastic force to the central portion of the bent portion, a flat portion is formed from the central portion of the bent portion to the end opposite to the joint portion. Is.

[0014]

According to the first aspect of the present invention, the bending portion of the joint yoke having the joining portion and the bending portion is bent and formed from a steel plate, and the joining is performed from the central portion of the bending portion. Since the part up to the end opposite to the part is formed in a flat shape, the lift-up amount required to lift up from the mold to transfer the joint yoke to the next processing step after forming the bent part Can be made smaller. Therefore, it is possible to improve the productivity in line production and reduce the manufacturing cost.

According to the second aspect of the present invention, the bending portion of the joint yoke having the joining portion and the bending portion is formed by bending from a steel plate, and the bending portion is locally formed in the central portion of the bending portion. Since it is formed into a flat shape by pressing while applying various plastic forces, it is possible to improve the inner width accuracy and the assembling property of the joint yoke.

[0016]

EXAMPLE A first example of the present invention will be described. The first embodiment is an embodiment of the joint yoke according to the present invention, and FIG. 1 is a schematic perspective view of an example of the joint yoke according to the first embodiment.

In FIG. 1, reference numeral 1 is a joint portion 2 and two bent portions 3,
3 is a yoke for joint provided with.

The joint portion 2 has a shaft joint portion 21 and a base portion 2 for connecting a shaft to the central portion of the joint portion 2.
2 and the shaft joint 21 is formed by burring, so that the shaft joint 21 and the base 22 are integral with each other.

The shaft joint portion 21 is formed of a cylindrical body standing upright with respect to the base portion 22, and as shown in FIG. 2, the inner peripheral surface has the same diameter and the outer peripheral surface has an upper portion. The lower part has a larger diameter, and the step surface 21
A is formed. 2 is a vertical cross-sectional view of the joint portion 2.

The two bent portions 3 and 3 are bent and connected to both left and right ends of the base portion 22, respectively. And
These bent portions 3 and 3 are located in the vicinity of the shoulder R from the left and right end portions of the base portion 22 toward the tip of the bent portions 3 and 3, respectively.
1, a fan-shaped portion 32, a V groove portion 33, and a flat surface portion 34.

The shoulder R vicinity portion 31 is connected to the base portion 22 and has a cross-sectional shape of an arc as shown in FIG. 3, and the fan-shaped portion 32 has a shoulder shape. The bent portion 3 is continuously provided in the vicinity of the R portion 31, and is provided at a substantially central portion of the bent portion 3 in the length direction (in the direction indicated by the bidirectional arrow D in FIG. 1).
Note that FIG. 3 is a cross-sectional view of the shoulder R vicinity 31.

As shown in FIGS. 1 and 4, the V-groove 33 has a V-groove whose depth becomes gradually smaller from the left and right ends of the substantially central portion of the bent portion 3 in the longitudinal direction toward the central portion in the width direction. Is formed. Note that FIG. 4 is a vertical cross-sectional view taken along the line AA of FIG.

As shown in FIGS. 1 and 4, the flat portion 34 extends from the substantially central portion of the bent portion 3 to the tip portion thereof, and the cup hole 34A is formed near the center of the flat portion 34. Are formed.

According to the above-described joint yoke of the first embodiment, the flat portion 34 from the substantially central portion of the bent portion 3 in the length direction to the tip portion is formed in a flat shape.
As shown in FIG. 5, after the bending portion 3 is bent by press working, the joint yoke 1 is detached from the mold 11 and conveyed to the next processing step, the lift-up amount L.
May be the L = L ₃ (the length of the bent portion 3) -L ₃₄ (the length of the flat portion 34). That is, the joint yoke 1
After being lifted up from the mold by the length of L ₃ -L ₃₄ , it can be conveyed in the feeding direction to the next processing step shown by arrow B in FIG. The amount of lift-up of the joint yoke of the present embodiment is significantly smaller than that of the conventional universal joint yoke that has been required to be lifted up, and as a result, productivity can be improved. At the same time, the manufacturing cost can be reduced.

Further, according to the joint yoke of the first embodiment, since the flat surface portion 34 in which the cup hole 34A is formed has a flat shape, the joint yoke is formed as shown in FIG. 6 (a). A tool for punching the cup hole 34A by attaching it to a die, for example, a punching die 12, has a simple shape corresponding to the flat shape of the flat surface portion 34 as shown in FIG. Can be 6 (b) is a cross-sectional view taken along the line CC of FIG. 6 (a).

Therefore, as shown in FIG. 6C, the curved surface portion 3
When the cup hole 34A is punched into the 4c, the edge shape of the punch punch 34B can be simplified compared with the case where the edge shape of the punch punch 34B must be a complicated shape corresponding to the curvature of the curved surface portion 34c. it can. Therefore, by punching the cup hole 34A using the tool having the simple cutting edge shape, the accuracy of the hole shape and the dimension of the cup hole 34A can be improved.

Further, according to the joint yoke of the first embodiment, since the shaft joint portion 21 is integrated with the base portion by the burring process, the shaft joint portion 21 is manufactured separately and is manufactured separately. Shaft joint 21
The productivity can be improved and the manufacturing cost can be reduced as compared with the case of welding and joining the base portion 22 to the base portion 22. Further, since the step surface 21A is formed in advance on the outer peripheral surface of the shaft joint portion 21, the shaft joint portion 2 of the joint yoke 1 is improved in order to improve the collision safety of the steering device 4 as shown in FIG. 7, for example.
When fitting and welding the corrugated pipe 41 made of a thin plate to 1 as shown in FIG. 8A, the outer peripheral surface of the shaft joint 21 is machined to join the shaft joint 21 and the corrugated pipe 41. There is no need to newly form a stepped surface for the purpose. Therefore, it is possible to improve productivity when fitting and welding the corrugated pipe 41. When welding a thin plate such as the corrugated pipe 41 to the shaft joint portion 21, the end face of the corrugated pipe 41 and the step surface 21A of the shaft joint portion 21 are butt-welded together as shown in FIG. 8B. This is because the corrugated pipe 41 and the shaft joint portion 21 are positioned by the step surface 21A to ensure the accuracy of the product.

Further, according to the joint yoke of the first embodiment, the cross-sectional shape of the portion 31 near the shoulder R of the bent portion 3 has an arc shape, and the bent portion 32 is provided with the fan-shaped portion 32. Since the section modulus of 3 is increased, the total length L ₃ of the bent portion 3 may be set to 1.3 L ₀ (L ₀ is the total length of the bent portion 3 of the conventional product) as shown in FIG. 9A. it can. Therefore, when the shaft portion 5 is attached to the joint yoke 1, the interference zone where the shaft portion 5 interferes with the joint yoke 1 becomes small, so that the bending angle of the shaft portion 5, that is, FIGS. 9B and 9C. The angles indicated by α and β can be increased from the conventional 45 ° to 110 °. Therefore, for example, by using the joint yoke according to the present embodiment in the steering device 4 shown in FIG. 7, it is possible to further secure the safety at the time of collision.

Next, a second embodiment of the present invention will be described.
The second embodiment is an embodiment of the method for manufacturing the joint yoke according to the present invention, and FIGS. 10 to 12 are explanatory views for explaining the method of the present embodiment. 10 to 12, the same components as those in the first embodiment described above are designated by the same reference numerals.

In the method of manufacturing a joint yoke according to this embodiment, first, as shown in FIG. 10A, a steel plate 7 corresponding to the developed shape of the joint yoke is punched out from a steel plate as a material by punching. A burring hole 71 is similarly formed by punching in the central portion of the steel plate 7.

Next, as shown in FIG. 10B, the surface of the central portion of the steel plate 7 in which the burring holes 71 are formed is formed into a predetermined uneven shape by coining. As a result of this coining, a step surface 21B is formed on the upper outer peripheral edge of the burring hole 71 of the steel plate 7 as shown in FIG. 10C, and a flat surface portion 34 is formed on the steel plate 7 as shown in FIG.
And the V groove portion 33 and the like are formed. Note that FIG. 10C is a vertical cross-sectional view near the burring hole 71. Next, the steel plate 7 is pressed into a U-shaped cross section.

After that, as shown in FIG.
14 having a protruding portion 14A having a V-shaped cross section corresponding to the V groove of the V groove portion 33
By pressing by, a local plastic force is applied to the V groove portion 33 via the protruding portion 14A of the die 14, and the plastic force causes the left and right portions of the steel plate 7 to be the dimensions of the die d. Reserved. In this way, FIG.
As shown in (b), two bent portions 3 and 3 each having a V groove portion 33 in the central portion and a flat portion 34 having a planar shape from the V groove portion 33 to the tip end portion are formed. .

Then, as shown in FIG. 11C, the burring hole 71 is predrilled. This burring hole 7
Since the shape of the burring hole 71 is deformed by the bending forming by the above-mentioned press, the burring hole 7
This is a processing process for making the shape and size of 1 into a predetermined shape and size.

Thereafter, by burring the burring hole 71, as shown in FIG. 12A, a joint having a base portion 22 and a shaft joint portion 21 made of a cylindrical body standing upright with respect to the base portion 22 is joined. The part 2 is formed.
Then, a step surface 21A is formed on the outer peripheral surface of the shaft joint portion 21 by burring the burring hole 71. The step surface 21A is formed by forming the step surface 21B on the outer peripheral edge of the upper portion of the burring hole 71 in advance (see FIG. 10C).

Next, as shown in FIG. 12B, a cup hole 34 is formed in each of the two flat portions 34, 34 by using a die such as a punching die 12 and a tool such as a punching punch 34B.
By forming A, as shown in FIG. 3C, a joint portion 2 having a shaft joint portion 21, a base portion 22 and the like.
The joint yoke 1 including the V-shaped groove portion 33 and the two bent portions 3 and 3 having the flat surface portion 34 in which the cup hole 34A is formed is manufactured.

According to the method for manufacturing the joint yoke of the second embodiment as described above, when the bent portions 3 and 3 are formed by press working with the die 14, only the V groove portion 33 is provided with the die. No elastic restoring force is generated in the flat surface portion 34 on the tip side of the V groove portion 33 after the bending process, which is performed by applying a local plastic force via the protruding portions 14A of the reference numeral 14.
Therefore, as shown in FIG. 11 (a), the processing accuracy of the width (the inner width of the yoke) d between the inner surfaces of the ends of the two bent portions is good, and
It is possible to manufacture a joint yoke that is easy to assemble.

Further, according to the method for manufacturing the joint yoke of the second embodiment, since the flat portion 34 from the substantially central portion in the lengthwise direction of the bent portion 3 to the tip portion is formed in a flat shape.
After the bending portion 3 is bent by press working, the lift-up amount when the joint yoke is removed from the mold and conveyed to the next processing step becomes small, and as a result, productivity can be improved. At the same time, the manufacturing cost can be reduced.

[0038]

According to the first aspect of the present invention, since the bent portion is formed in a flat shape from the central portion to the tip portion, the joint yoke is removed from the mold after bending and the following is performed. Since it is possible to reduce the lift-up amount during the transportation to the processing step, it is possible to improve the productivity of the joint yoke and reduce the manufacturing cost.

According to the second aspect of the present invention, since the bending portion is bent by press working while applying a local plastic force to the central portion of the bending portion, the bending portion is formed from the central portion of the bending portion. Since elastic restoring force does not occur up to the tip portion, it is possible to manufacture a yoke for a joint having good inner width accuracy and good assembling property.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an example of a joint yoke according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a joint portion.

FIG. 3 is a cross-sectional view of a portion near a shoulder R.

4 is a vertical sectional view taken along the line AA of FIG.

FIG. 5 is an explanatory diagram (No. 1) for explaining the effect of the first embodiment of the present invention.

FIG. 6 is an explanatory view (No. 2) for explaining the effect of the first embodiment of the present invention.

FIG. 7 is a schematic perspective view of an example steering device to which the joint yoke according to the first embodiment of the present invention is applied.

FIG. 8 is an explanatory diagram (No. 3) for explaining the effect of the first embodiment of the present invention.

FIG. 9 is an explanatory view (No. 4) for explaining the effect of the first embodiment of the present invention.

FIG. 10 is an explanatory view (Part 1) for explaining the manufacturing method according to the second embodiment of the present invention.

FIG. 11 is an explanatory view (No. 2) for explaining the manufacturing method according to the second embodiment of the present invention.

FIG. 12 is an explanatory view (No. 3) for explaining the manufacturing method according to the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint yoke 2 Joint part 3 Bending part 4 Steering device 5 Shaft part 7 Steel plate 12 Punching die 13, 14 Mold 14A Projected part 21 Shaft joint part 21A, 21B Step surface 22 Base part 31 Shoulder R vicinity part 32 Fan Shaped part 33 V groove part 34 Flat part 34A Cup hole 34B Hole punching punch 41 Corrugated pipe 71 Burring hole

Claims (2)

[Claims] 1. A yoke for a joint, which is press-formed from a steel plate and has a joint portion and a bent portion, wherein the bent portion is bent from the steel sheet, and A yoke for a joint, characterized in that a portion from a central portion to an end portion on the side opposite to the joint portion is formed into a planar shape. 2. A method for manufacturing a joint yoke, which is press-formed from a steel plate and has a joint portion and a bent portion, wherein the bent portion is bent from the steel sheet, and then the bent portion is bent. A method for manufacturing a joint yoke, characterized in that a local plastic force is applied to a central portion of the bent portion, and a flat portion is formed from a central portion of the bent portion to an end portion opposite to the joint portion.