JPS6038569B2 - Material for forming the outer ring of constant velocity joints - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding material for the outer ring of a constant velocity joint used for driving force transmission molds for automobiles.

In this type of constant velocity joint, as shown in FIG. 1, a ball c for torque transmission is interposed between an inner ring a and an outer ring b associated with two axes via a ball cage d. As shown in FIG. 2, the balls c are fitted with iron into ball grooves e and f that are equally spaced on the outer circumferential surface of the inner ring a and the inner circumferential surface of the outer ring b.

As shown in Fig. 1, the outer circumferential surface of the inner ring a and the inner circumferential surface of the outer ring b are D spherical surfaces with the center of curvature at the joint center 0. As shown in the figure, the ball groove f has a curved shape with the center of curvature at points A and B, which are shifted by the same distance to the left and right from the joint center ○, that is, the locus of the center point of the ball rolling in the ball groove is the point A,
B is a curve with a center of curvature, so that the ball c
is always oriented on the bisecting plane of the angle formed by the two axes, so that constant velocity can be ensured at any operating angle and any rotation angle.

In other words, the constant velocity in this type of constant velocity joint is a necessary and sufficient condition that the position of the ball c that transmits torque is on the bisecting plane of the angle formed by the two axes. Now, as shown in Fig. 3, when the two axes make an angle of 8, the joint is between the inner spherical surface of the outer ring b and the outer spherical surface of the pole cage d, and between the inner spherical surface of the ball cage d and the outer periphery of the inner ring a. Due to the mutual guidance between the spherical surfaces, an angle is formed around the center ○ of these spherical surfaces, and at this time, the ball c moves into the ball grooves e and f of the outer ring b and the inner ring a whose centers are shifted from the ○ point.
It moves to the plane that bisects the angle formed by both axes.

In this case, the ball cage d not only determines the angular center of the joint, but also controls the inner spherical surface of the outer ring b to absorb the force that acts on the balls c when torque is transmitted, causing them to pop out of the ball grooves e and f. The ball c is supported by being supported by the outer spherical surface of the inner ring a, and the ball c is secured in a predetermined position. At this time, from the angle center ○ of the joint to the outer ring b
Since the distances from the ball book f and the centers A and B of the ball groove e of the inner ring a and the distances from the center P of the ball c to A and B are both designed to be equal, △OAP and △OBP
are congruent because their three sides are equal, and the center P of ball c
The distances L from both axes of the ball c are equal, and the ball c is on the bisector of the angle formed by the two wheels, ensuring uniform velocity. Now, as is clear from the above explanation, the outer ring b of this type of constant velocity joint has a predetermined spherical inner circumferential surface and a predetermined spherical ball groove f, so that the outer ring b of this type of constant velocity joint is In manufacturing b, the outer ring material w having the shape shown in Fig. 4 is produced by forging, and then the inner peripheral surface is cut into a predetermined spherical shape by milling, and the curved ball groove is extremely The cutting process was complicated and inefficient.

That is, in the forging process, the portion 1 corresponding to the inner circumferential surface of the outer ring cannot be formed into a spherical shape because the punch needs to be punched upward, so it has to be made into a substantially straight shape. In addition, the portion 2 corresponding to the pole groove was also on the same aircraft.

For this reason, conventionally, in order to finish the inner peripheral part of the forged outer ring material w into the above-mentioned predetermined spherical surface 3 and to finish the ball groove into the predetermined spherical surface 4, the respective parts are cut and removed by milling. It was something that

However, the conventional manufacturing method described above has disadvantages in that it takes a long time to cut and also has a poor material yield.

In view of the above-mentioned drawbacks of the conventional manufacturing method, the present invention improves and eliminates the drawbacks. That is, when forging the material for the outer ring, the shape of the material to be formed is as described in detail below, By pressing this with a simple press, the inner circumferential surface of the outer ring and the ball groove can be formed into a predetermined shape, thereby reducing post-processing, improving material yield, and lowering the total manufacturing cost. This is what was done.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to embodiments shown in the drawings.

FIG. 5 shows a forged outer ring material 10 according to the present invention.
FIG.

In the outer ring material 10, a cup-shaped outer ring forming portion 12 is formed integrally with the shaft portion 11 by cold forging or hot forging.

In the above cold forging or hot forging, the outer ring forming part 1
An overhanging part 13 is formed on the outer periphery of the inlet part of 2, approximately half of the inner circumferential surface 14 on the deep side is a predetermined spherical surface 14a, and the inlet side half is parallel to the axial direction from the maximum diameter part of the spherical surface 14a. The straight surface 14b extends tangentially in the direction of expansion.

Further, approximately half of the ball grooves 15 equally distributed on the inner circumferential surface on the inner city side are defined as a predetermined spherical surface 15a, and the inlet side half extends approximately tangentially from the vicinity of the maximum folding portion of the spherical surface 15a slightly in the direction of opening the mirror. It has a straight surface 15b.

The cross section of the ball groove 15 is an arcuate surface substantially close to the pole diameter at the inner part, taking into consideration the diameter of the ball used, and is an arcuate surface that gradually becomes larger and deeper toward the entrance side. That is, FIG. 6 shows the rate of change in the cross section of the ball groove 15 as a composite diagram, where the cross section shown in the first quadrant 1 is the one closest to the entrance, the second quadrant 0, and the third quadrant m. These are the cross sections at the innermost position in order, and the one in the fourth quadrant W is the cross section at the innermost position. The radius of the arc of the ball groove 15 in each quadrant is r,>r2>r32r4, and
The position of the center point of each arc is R from the center of the circle, >R2>R3>
It is located in a position related to R4.

The spherical surface 14a has its center of curvature at a position slightly on the inlet side from the joint center ○ already shown in FIG. The center of curvature is located at a position slightly closer to the entrance than the center B.

The reason for doing the above is that the material 10 for the outer ring is finally set in a die 16 having a conical inner diameter as shown in FIG.
This is because by pressing 0, the relationship between the submission section 13 and the dice 16 narrows down to the state shown by the chain line in FIG.

That is, when the spherical surfaces 14a and 15a are squeezed in this manner, the centers of curvature of the spherical surfaces 14a and 15a move toward the inner part in accordance with the amount of reduction.
And the center of curvature of 15a is offset toward the entrance side. It is also for the same reason as above that the size and depth of the circular arc of the cross section at each position in the axial direction of the ball groove 15 are varied.

As explained above, the present invention is a material for forming the outer ring of a constant velocity joint in which the outer ring portion has a spherical inner circumferential surface and a ball groove having a curved ball transfer locus, and the outer ring portion is provided with a material for forming an outer ring of a constant velocity joint. An exit part is provided, and the inner circumferential surface is made into a spherical surface with approximately half of the inner circumferential surface on the far side from the bending center of the bush hand, and approximately half of the inlet side is a substantially cylindrical surface in contact with the spherical surface or a bell-shaped surface that widens toward the inlet side. form,
In addition, the ball groove is formed in a curved shape on the far side from the approximate center of bending of the joint, and the entrance side is formed in a substantially linear shape touching the curve and parallel to the axis of the mirror arm or expanding toward the entrance side, and the cross section of the ball groove is is a material whose shape gradually becomes larger and deeper from the back side toward the entrance side, and using this material, the material is set in a die having a substantially conical inner peripheral surface, and is pushed through in the axial direction with a punch. Since the outer peripheral overhanging portion of the material is narrowed inward in the radial direction, thereby forming a ball groove having a spherical inner peripheral surface and a curved ball transfer locus, the material of the outer ring member can be processed by conventional forging. The dimensions of each part can be appropriately determined by design calculations, the material yield is improved, and the overall manufacturing cost can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of a constant velocity joint product,
FIG. 2 is a Y-Y sectional view of FIG. 2, and FIG.
3 is a sectional view to explain the uniform velocity when the joint takes an operating angle, A in FIG. 4 is a sectional view of a conventional forged outer ring material, the mouth is a front view, and 5 is a sectional view of the forged outer ring material according to the present invention, and FIG. 6 is a cross-sectional view of the material for a forged outer ring according to the present invention. −
It is a composite cross-sectional view in which the cross-sections at the F2-F2, F3-F3, and F4-F4 positions are combined into four 1' quadrants, and FIG. 7 is a schematic diagram showing an example of a drawing machine. It is a diagram. 10...Forged outer ring material, 13...Protruding portion, 14...Inner peripheral surface of outer ring, 15...
Ball groove, 16...Dice, 17""" Punch. Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7

Claims (1)

[Claims] 1. A material for forming the outer ring of a constant velocity joint in which the outer ring member has a spherical inner circumferential surface and a ball groove having a curved ball rolling locus, in which a protrusion is provided at the entrance of the outer circumference, and the inner circumferential surface Approximately half of the rear side of the joint from the bending center is a spherical surface, and approximately half of the inlet side is formed as a generally cylindrical surface in contact with the spherical surface or a generally conical surface that widens toward the inlet side, and the ball groove is formed in the joint. The back side from the approximate bending center is curved, the inlet side is in contact with the curve, and the ball groove is formed in a substantially linear shape parallel to the axis of the joint or expanding toward the inlet side, and the cross section of the ball groove is from the back side to the inlet side. A material for forming the outer ring of a constant velocity joint, which is characterized by a shape that gradually becomes larger and deeper.