JPH0658125B2 - Universal shaft manufacturing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a universal joint, and more particularly, to increase the processing accuracy of a joint member that connects a pair of yokes and rotate between the yokes. The present invention relates to an improvement for smoothly transmitting motion.

[Prior Art] Generally, a universal joint is used in the case of transmitting rotation even if the angle at which two axes intersect is changed.
The one disclosed in Japanese Patent No. 33 is known.

The universal joint described in the above publication has a joint member in which spherical bodies are joined at equal intervals to four outer circumferences of a ring-shaped connecting base body, and a pair of spherical bodies facing each other among the spherical bodies are rotatably engaged. It is composed of a pair of yokes formed in a bifurcated shape with a matching spherical body receiving portion, and the rotational movement of one yoke is transmitted to the other yoke via a joint member.

Speaking of the manufacturing method of this universal shaft coupling, first, the spherical members are joined to the outer periphery of the ring-shaped connecting base body at four locations by friction welding to form a joint member. Set like a child, a die-cast molten alloy is cast into this mold to cast a pair of yokes. As a result, the yoke having the spherical body receiving portion holding the spherical body of the joint member is formed. Finally, when the sphere receiving portion of the yoke taken out from the mold is hit to form a gap between the sphere receiving portion and the sphere of the joint member held by the sphere receiving portion, each of the pair of yokes joints with the sphere as a fulcrum. The universal joint which is swingably engaged with the member is completed.

[Problems to be Solved by the Invention] However, in this universal joint, the outer circumference 4 of the ring-shaped connecting base body is
Since the spheres are joined to the spots by friction welding, the following problems occur.

That is, in friction welding, it is necessary to bring the connecting base body and the spherical body into contact with each other and to rotate them while applying pressure. In the welding work, the connecting base body and the spherical body are respectively attached to a pair of jigs that rotate with each other. Need to be firmly fixed. Therefore, in order to sequentially weld the four spheres to the connection base, the connection base is removed from the jig after each sphere is welded, and the positioning base is fixed to the fixture again. Although the need arises and the positioning is performed when re-fixing, the accuracy of the welding position of the sphere with respect to the connecting base deteriorates, and the sphere could not be evenly arranged at 90 ° intervals on the outer periphery of the connecting base. . Therefore, the swinging motion of the joint member and the yoke becomes defective, and there is a problem that the rotary motion cannot be smoothly transmitted between the pair of yokes.

Further, since the connecting base body must be positioned and re-fixed every time one sphere is welded, the manufacturing of the joint member becomes very troublesome, which is one of the factors that hinder the automation of the manufacturing process.

The present invention has been made in view of such problems,
The purpose of this is to improve the processing accuracy of the joint member connecting the pair of yokes so that the swinging motion of the yoke with respect to this joint member is made smooth, and thus the rotary motion between the pair of yokes is made smooth. An object of the present invention is to provide a universal shaft coupling capable of transmitting.

[Means for Solving the Problems] That is, according to the invention of the present application, while the electrodes are disposed in contact with the inside of the hollow portion of the ring-shaped connecting base, the sphere installed at the first position on the outer periphery of the connecting base. And disposing electrodes between the electrodes, and joining the connecting base body and the sphere by projection welding by energizing between the electrodes, and carrying out tempering treatment of the welding site by energizing current again in the same electrode joining state. In the same manner as in the previous step, the spheres are sequentially aligned and tempered with respect to the second, third and fourth positions on the outer periphery of the connection base at a predetermined distance from the first position,
A step of forming a joint member in which spheres are joined at four orthogonal positions on the outer peripheral surface of the connecting base; and a pair of spheres joined to the first and third positions of the joint member as cores of the sphere receiving portion. Set in a yoke casting mold, casting the yoke in which these spheres are cast in the sphere receiving portion,
Similar to the previous step, a step of casting a yoke in which a pair of spheres joined to the second and fourth positions of the joint member are cast in a sphere receiving portion, and a sphere receiving portion of the yoke and the joint member And a step of forming an extremely small gap between them by applying an external force between them, and a method for manufacturing a universal joint.

In the present invention, as a method of manufacturing a universal joint having a joint member having a high sphericity of a spherical body, four spheres having a high sphericity are basically used, and these spheres are directly or indirectly Welding may be performed by projection welding, and there are other methods such as heavy projection welding as this projection welding method, but butt projection welding is preferable. According to this projection welding, the occurrence of welding flash is small, and there is no need for cutting work or the like to remove this reception flash.

Further, after the sphere and the connection base body are welded by this projection welding, the tempering treatment of the welded portion can be performed by passing an electric current again in the same state. As a result, for example, when high carbon content steel is left for a long time after welding, cracks occur in the welded portion, so-called misplacement cracking occurs, but by performing tempering treatment following welding in this way, the occurrence of misplacement cracking is completed. Can be prevented.

[Operation] According to the method for manufacturing the universal joint of the present invention, the electrodes are arranged in the hollow portion of the ring-shaped connecting base body, while the electrodes are arranged on the sphere installed on the outer periphery of the ring-shaped connecting base body. Since the connection base and the sphere are joined by projection welding by energizing between the electrodes, after the sphere is joined to the first position on the outer periphery of the connection base, the sphere is attached to the second, third and fourth positions. To join the spheres, the connecting base and the electrode disposed in the hollow portion of the connecting base are moved relative to each other, and the electrode is slid 90 ° to each position along the inner diameter of the connecting base. There is no need to remove the connecting base from the jig and position and re-fix each time the sphere is joined to the position.

Therefore, the four spheres can be accurately equidistantly arranged by 90 ° with respect to the outer circumference of the ring-shaped connecting base body, and the swinging motion of the yoke with respect to the joint member becomes smooth.

Further, it is not necessary to remove the connecting base from the jig for positioning and re-fixing it each time the sphere is joined to each position, and simply move the connecting base and the electrode arranged in the hollow portion thereof. Since the four spheres can be sequentially joined to the ring-shaped connecting base body, the joint member can be easily manufactured, and the joint member can be automatically manufactured.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side view showing a first embodiment of a universal joint of the first invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a view taken in the direction of arrow III of FIG. The universal shaft joint of the present invention,
The connecting portion 12 is provided on one end side and the forked portion 14 is provided on the other end side.
And a pair of yokes 10 each having an elastically deformable ring-shaped coupling base 22 and four spherical bodies 24 are formed by projection welding at four orthogonal positions on the outer peripheral surface of the coupling base 22. And a joint member 20 that is rotatably held by the first receiving portion 16 and that connects the yokes 10 to each other in a swingable manner.

The connection base 22 of the joint member 20 is formed of an elastically deformable material, and the connection base 22 is formed of a short cylindrical member 23a to facilitate elastic deformation. Further, the sphere 24 is formed by containing steel carbon steel having a high sphericity, and the like, and the sphere 24 is welded to the four orthogonal positions on the outer peripheral surface of the connecting base 22 by projection welding. High sphericity is maintained.

In the first embodiment, the connecting portion 12 of the yoke 10 is
Is formed, for example, by a connecting hole 13b having a key groove 13a, and the key is fitted and connected to a driving shaft or a driven shaft (not shown) having a key so that the rotational force is transmitted. ing.

Next, a method of manufacturing the universal joint according to the first embodiment will be described. In this method for manufacturing a universal joint, a spherical body 24 and a connecting base 22 are projection-welded to manufacture a joint member 20, and then the spherical portion (specifically, the spherical body 24) of the joint member 20 is used as a core to form the yoke 10. The manufacturing method is as follows.

That is, as shown in FIG. 4 (a), an electrode is provided in the hollow portion of the connecting base 22 and is brought into contact with the connecting base 22, while the outer peripheral surface of the connecting base 22 faces the electrode. The first spherical body 24 having a high sphericity is brought into contact with the position where
Electrodes are also arranged on the spheres 24, and a predetermined welding current is applied for a predetermined welding time while applying a predetermined pressure F to join them by projection welding. Further, with the electrode arranged as it is, a current is passed again to perform tempering treatment.

Next, as shown in FIG. 4 (b), while the second spherical body 24 is brought into contact with the outer peripheral surface of the connecting base 22 orthogonal to the position where the first spherical body is joined, the hollow of the connecting base 22 is made. The electrode disposed in the section is slid by 90 ° along the inner diameter of the connecting base 22 so as to face the second sphere, and
Projection welding and tempering are performed in the same manner as the spheres.

Similarly, the third sphere 24 is brought into contact with the outer peripheral surface of the connection base 22 orthogonal to the position where the second sphere is joined, and projection welding and tempering are performed (see FIG. 4 (c)). ) Further, the third sphere 24 is brought into contact with the outer peripheral surface of the connection base 22 orthogonal to the position where the third sphere 24 is joined to perform projection welding and tempering treatment (see FIG. 4 (c)). . At this time, the electrodes arranged in the hollow portion of the connecting base 22 are moved along the inner diameter of the connecting base 22 by 90 degrees.
Slide by 3 degrees each to turn the 3rd and 24th spheres 24, 24
It is set at a position opposite to.

Next, as shown in FIG. 5, a pair of spheres 24, 24 facing each other of the joint member 20 is set in the yoke casting mold 30 as a core of the sphere receiving portion 16 when the yoke 10 is cast. Then, after die-cast welding alloy is cast into the yoke 10 casting die 30 to cast one yoke 10, as shown in FIG. 6, the remaining set of spheres of the joint member 20 having the one yoke 10 is formed. 24 and 24 are set in the other yoke casting mold 30 as the core of the spherical body receiving portion 16, and the die casting molten alloy is cast into the yoke casting mold 30 to cast the other yoke 10. Then, the spherical body 2 of the joint member 20 is introduced from within the yoke casting mold 30.
4 takes out the yoke 10 cast in the ball receiving portion 16,
Between the spherical body receiving portion 16 of the yoke 10 and the spherical body portion 24 of the joint member 20, for example, the outer periphery of the spherical body receiving portion 16 is lightly tapped to exert a light impact to form a minute gap therebetween. The sphere 24 of the joint member 20 is allowed to rotate with respect to the sphere receiving portion 16 of the yoke 10.

As a method of forming the gap between the spherical body 24 and the spherical body receiving portion 16, one of the yokes 10 is cast, and then the spherical body receiving portion 16 is hit and impacted to form the gap as described above, and then the other one is formed. A gap may be formed in the same manner after the yoke 10 is cast, or after both the yokes 10 and 10 are cast, an impact is applied to the spherical body receiving portion 16 to simultaneously form both the spherical body receiving portion 16 and the spherical body 24. A gap may be formed between and.

In addition, the yoke casting mold 30 used in the above embodiment
Is composed of an upper die and a lower die which are vertically divided with respect to the paper surface in FIGS. 5 and 6, and a key groove 13a is formed in a portion of the yoke 10 which constitutes the connecting portion 12. A core 32 for setting is provided, and when the yoke 10 is cast by casting the die-cast molten metal into the yoke casting mold 30, the joint member 20 is held so that the positional deviation does not occur. Fixed to.

[Effects of the Invention] As described above, according to the method for manufacturing a universal shaft joint of the present invention, when manufacturing a joint member that swingably connects a pair of yokes to the outer periphery of the ring-shaped connection base body. Since the four spheres can be accurately arranged at equal intervals of 90 °, the swinging motion of the yoke with respect to the joint member becomes smooth, and the rotary motion can be smoothly transmitted between the pair of yokes.

Further, since the joint member can be easily manufactured and the manufacture of the joint member can be automated, it is possible to manufacture the universal shaft joint in large quantities and at low cost.

[Brief description of drawings]

FIG. 1 is a side view showing a first embodiment of a universal joint manufactured by the method of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG.
FIG. 3 is a view taken in the direction of arrow III in FIG. 1, and FIGS. 4 (a) to 4 (d) are explanatory views showing a method of joining the sphere and the connecting base body by projection welding in the present invention, FIG. 5 and FIG. Each of the drawings is an explanatory view showing a method of casting a yoke with the spherical body of the joint member in the present invention as a core. Explanation of symbols (10) …… Yoke, (12) …… Coupling part, (14) ...
… Biforked part, (16) …… sphere receiving part, (20) …… joint member, (22) …… connection base, (24) …… sphere,
(30) …… Yoke casting mold, (32) …… Core

Claims (1)

[Claims] 1. An electrode is provided by abutting it in the hollow portion of a ring-shaped connecting base, and an electrode is placed on a sphere installed at a first position on the outer periphery of the connecting base, and an electric current is applied between these electrodes. Then, the connection base and the sphere are joined together by projection welding, and a step of tempering the welded portion by applying a current again in the same electrode joining state is performed, and a predetermined interval is set from the first position. The second, third, and fourth positions on the outer circumference of the connecting base body were sequentially aligned and tempered in the same manner as in the previous step, and the spherical bodies were formed at four orthogonal positions on the outer peripheral surface of the connecting base body. A step of forming a joint member joined to each other, and a pair of spheres joined to the first and third positions of the joint member are set in the yoke casting mold as cores of the sphere receiving portion, and these spheres are It was cast in the ball receiving part A step of casting the yoke, and a step of casting a yoke in which a pair of spherical bodies joined to the second and fourth positions of the joint member are cast in the spherical body receiving portion in the same manner as the previous step, And a step of applying an external force between the spherical body receiving portion of the yoke and the joint member to form a minute gap therebetween.