JPS63138B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a core in which the ball rolling grooves and the polished relief of the outer ring of a bar-field type constant velocity universal joint are formed simultaneously with the ball rolling grooves by plastic working.

Machining of the ball rolling groove (hereinafter referred to as the groove) on the outer ring of a bar-field type constant velocity universal joint has traditionally been carried out by both machining and plastic working. It is known that by letting both corners of the groove escape or by letting a part of the bottom of the groove escape, the load on the grindstone and the polishing allowance in the polishing finishing process can be reduced. However, with the conventional method, an extra cutting process had to be added to create the relief, which required an expensive specialized processing machine. The effect of the reduction will be weakened.

In view of the above-mentioned drawbacks, the present invention makes it possible to add abrasive relief at the same time as processing the grooves, by devising the shape of the core during plastic working, without adding any extra steps or special machines for attaching the abrasive relief. Moreover, it has a core shape that can be processed by general-shape polishing. In other words, after hot forging is processed by hot forging, a rough shaped material is finished by cold eyeloning, or a rough shaped material processed by cold forging,
The method of finishing the inner peripheral surface with high precision by cold ironing using a set of six divisible cores is the same as the conventional method, but in the present invention,
The shape of the molded part of the core is composed of three curved surfaces that can each be molded: a ball rolling groove, a polishing relief at the bottom of the groove, and a polishing relief at both corners of the groove.Moreover, these curved surfaces can be formed simultaneously by full-form polishing. The centers of rotation of the three curved surfaces in the longitudinal direction are made to coincide so that the

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the core of the present invention, and in the figure, 1 is a molded part of the core;
Point D is the center of rotation of the three curved surfaces constituting the molded part 1 in the longitudinal direction.

FIG. 2 is a cross-sectional view of the core taken along the plane XX including the point D. In the same figure, 2
indicates the ball rolling surface, 3 indicates the polished relief at the bottom of the groove, and 4
are the surfaces on which the polishing reliefs at both corners of the groove are respectively formed. 5 also shows the outline of the ball used in the joint. The relief amount δ ₁ to δ ₃ differs depending on the size of the joint, but in this example, δ ₁ = 0.2 to 1.0 mm, and δ ₂ = 3.0 to 3.0 mm.
10.0 mm, and δ ₃ is in the range of 0.2 to 1.0 mm.

FIG. 3 is a sectional view of a constant velocity universal joint formed by the core shown in FIGS. 1 and 2, and 2', 3', and 4' in the figure are This corresponds to the part formed by surfaces 2, 3, and 4. That is, 2' is a ball rolling surface, 3' is a polishing relief part at the bottom of the groove, and 4' is a polishing relief part at both corners of the groove. Note that 6 is an open end.

As described above, the core for plastic working of the outer ring of a constant velocity universal joint of the present invention has protruding surfaces that form the abrasive relief at the groove bottom of the rough profile material at the top and both corners of the forming surface of the ball rolling groove. and a protruding surface for forming abrasive reliefs at both corners of the groove, the above-mentioned abrasive reliefs can be attached to the rough profile material at the same time as the grooves are processed. In addition, although both corners of the groove are usually chamfered, it is possible to finish both corners of the groove deeper than the center of the inner spherical surface with an appropriate curvature during plastic processing before ironing. In the subsequent ironing process, both corners of the groove from the center of the inner spherical surface to the opening end are relieved using the core of the present invention, thereby making it possible to eliminate chamfering of both corners of the groove, further shortening the process.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along cutting line XX in FIG. 1, and FIG. 3 is a cross-sectional view of a molded product. 1... Molding part of the core, 2... Molding surface of the ball rolling surface, 3... Protruding surface for polishing relief molding at the bottom of the groove, 4... Protruding surface for polishing relief molding at both corners of the groove,
5...Outline of the ball.

Claims (1)

[Claims] 1 A split core for forming the inner peripheral surface of the outer ring rough profile of a bar-field type constant velocity universal joint, a guide punch located inside the core to receive the main pressure, and an ironing die. In the core of a manufacturing device that manufactures products by ironing from the outer ring rough shape material of bar-field type constant velocity universal joint, the groove bottom of the rough shape material is placed on the top and both corners of the forming surface of the ball rolling groove. A core for plastic working of an outer ring of a constant velocity universal joint, characterized by having a protruding surface for forming an abrasive relief and a protruding surface for forming an abrasive relief at both corners of the groove.