JPH03155428A - Manufacture of inner race for constant speed joint - Google Patents

Abstract

PURPOSE:To manufacture the inner race 1 for the constant speed joint with little working volume of grinding by using the specifically constituted intermediate body and forming its corresponding outer peripheral surface to the spherical surface with a small radius set according to the elongation amt. following to the ironing work. CONSTITUTION:The intermediate body 13 having 1st and 2nd corresponding end surfaces 141, 142 corresponding to 1st and 2nd end surfaces 101, 102, the corresponding outer peripheral surface 15 corresponding to the outer peripheral surface 8 and the corresponding guiding groove 16 corresponding to each guiding groove 11 is manufactured. Next, each guiding groove is formed by pressing the 1st corresponding surfaces of the intermediate body 13 with pressurizing force and executing ironing to each corresponding guiding grooves 16. On the squeezing work, the 2nd corresponding end surface 142 and the corresponding outer peripheral surface 15 are kept in un-restricted state to the ironing work die 26. Therefore, the intermediate body 13 is subjected to the elongation outward in the center line direction and in the radius direction. Further, the corresponding outer peripheral surface 15 of the intermediate body 13 can be formed to the spherical surface with radius set small in correspondence with the elongation amt. following to the ironing work.

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Field of Application The present invention relates to a method for manufacturing an inner ring for a constant velocity joint, and in particular, to a method for manufacturing an inner ring for a constant velocity joint, and in particular, a method for manufacturing an inner ring for a constant velocity joint, which has a first end face and a second end face perpendicular to a center line. A plurality of guide grooves extending in the generatrix direction are formed at equal intervals on the circumference on the outer circumferential surface between the first and second end faces, and each guide groove is formed at the center of the torque transmitting ball that rolls along the guide groove. A linear groove whose locus is a straight line parallel to the center line from the first end surface to a virtual inflection surface perpendicular to the center line, and is smoothly connected to the straight line from the virtual inflection surface to the second end surface. In order to manufacture an inner ring for a constant velocity joint, the inner ring is formed of a circular arc-shaped groove that gradually approaches the center line toward the second end surface. An intermediate body having a second corresponding end surface, a corresponding outer circumferential surface corresponding to the outer circumferential surface, and corresponding guide grooves corresponding to each guide groove is manufactured, and then a pressing force is applied to the first corresponding end surface of the intermediate body. and forming each guide groove by applying ironing to each corresponding guide groove, and holding the second corresponding end face and the corresponding outer circumferential surface in a non-restricted state with respect to the ironing die during the ironing process. The present invention relates to an improvement in a method for manufacturing an inner ring for a constant velocity joint in which an intermediate member is caused to elongate outward in the centerline direction and radial direction.

(2) Conventional technology The present applicant previously proposed a manufacturing method of this type in JP-A-62
The technology disclosed in Japanese Patent No.-110831 is proposed.

(3) Problems to be Solved by the Invention However, while the manufacturing method described above can ensure the dimensional accuracy of each guide groove, since the outer circumferential surface is formed into a substantially cylindrical surface, the outer circumferential surface after ironing is lathed. It had to be formed into a spherical surface by machining, and it was desired to reduce the machining allowance.

An object of the present invention is to provide the manufacturing method that can meet the above requirements.

B1 Structure of the Invention (1) Means for Solving the Problem The present invention has a first end surface and a second end surface perpendicular to the center line, and an outer peripheral surface between the first and second end surfaces, A plurality of guide grooves extending in the generatrix direction are formed at equal intervals on the circumference,
Each guide groove is a linear groove in which the locus of the center of the torque transmitting boner rolling along the guide groove becomes a straight line parallel to the center line from the first end surface to a virtual inflection surface perpendicular to the center line; Manufacturing an inner ring for a constant velocity joint, which is formed by an arc-shaped groove that smoothly connects with the straight line from the virtual curved surface to the second end surface and becomes an arc that gradually approaches the center line toward the second end surface. In order to do so, an intermediate body having first and second corresponding end surfaces corresponding to the first and second end surfaces, a corresponding outer circumferential surface corresponding to the outer circumferential surface, and a corresponding guide groove corresponding to each guide groove is manufactured. Then, each guide groove is formed by applying pressure to the first corresponding end surface of the intermediate body and ironing each corresponding guide groove, and during the ironing process, the second corresponding end surface and the corresponding outer periphery are formed. In the method for manufacturing an inner ring for a constant velocity joint, the intermediate body is caused to elongate outward in the centerline direction and radial direction by holding the surface in a non-restricted state with respect to the ironing die, The corresponding outer circumferential surface is formed into a spherical surface whose radius is set to be small according to the amount of elongation caused by the ironing process.

(2) Function By using the above-mentioned intermediate, it is possible to manufacture an inner ring with a spherical outer circumferential surface, so by simply performing grinding on the outer circumferential surface instead of cutting, It becomes possible to form the outer peripheral surface into a spherical surface.

(3) Embodiment In FIG. 1, the constant velocity joint 1 includes an outer ring 3 having a connecting shaft 2, an inner ring 5 housed within the outer ring 3 and connected to the rotating shaft 4 through serrations, and held by a retainer 6. The torque transmitting ball 7 is arranged between an outer ring 3 and an inner ring 5.

Second. The inner ring 5 shown in FIG. 3 has the same structure as that shown in FIG. 1, except that its outer peripheral surface 8 is not ground and the serrated shaft hole 9 is not formed. 5 is a first end surface 10.5 perpendicular to the center line CC0. and a second end surface 10□, and a plurality of guide grooves 11 extending in the generatrix direction are formed at equal intervals on the circumference on the outer peripheral surface 8 between the first and second end surfaces 10+ and 10g.

Balls 7 are rotatably interposed between these guide grooves 11 and corresponding guide grooves 12 on the inner peripheral surface of the outer ring 3.

Each guide groove 11 of the inner ring 5 is such that the locus i of the center 01 of the ball 7 rolling along it is from the first end surface 10° to the center line C+.
The center line C, -c up to the virtual inflection surface S1 perpendicular to C+
, a linear groove 11a that is a straight line parallel to , and a virtual inflection surface S
The line from I to the second end surface 102 is smoothly continuous with the straight line, and gradually changes to the center line C as it goes toward the second end surface 10z.
The radius of the bottom of the 0-circular groove 11b formed by the circular arc-shaped groove 11b that approaches -C, is R5, and its center 0□ is at the intersection of the center line C+ C+ and the virtual inflection surface S. Exists.

Further, the outer peripheral surface 8 of the inner ring 5 has first and second end surfaces 10, .
10. Center 0.0 at the bisecting point of the length between. radius Rt with
It is formed into a spherical surface.

The inner ring 5 is the fourth. The first step of manufacturing the intermediate body 13 shown in FIG. 5 and the second step of ironing the intermediate body 3 are sequentially performed. In FIG. 5, the dashed line indicates the inner ring 5.

The intermediate body 13 has first and second corresponding end surfaces 14I corresponding to the first and second end surfaces 101 and 102.

142, a corresponding outer circumferential surface 15 corresponding to the outer circumferential surface 8, and a corresponding guide groove 16 corresponding to each guide groove 11.

Each corresponding guide groove 16 consists of a corresponding linear groove 16a corresponding to the linear groove 11a and a corresponding arcuate groove 16b corresponding to the circular arc groove 11b. Therefore, both grooves 16a, 16b
Similarly to the above, there is a virtual inflection surface S2 in the continuous portion.

The length between the first and second corresponding end surfaces 14+ and 14g is shorter than the length between the first and second end surfaces 101.10□ of the inner ring 5 (ie, L I < L z). The length between the first corresponding end surface 141 and the virtual curved surface 32 is the first end surface 10. of the inner ring 5. and the length L between the virtual inflection surface S1
4 (ie, Lr > L1). Further, the length between the virtual curved surface S2 and the second corresponding end surface 14z is the length between the virtual curved surface S of the inner ring 5 and the second end surface 10□,
(ie, Ls<L1).

Furthermore, the radius R7 of the corresponding outer circumferential surface 15 which is a spherical surface is:
smaller than the radius R2 of the outer circumferential surface 8 of the inner ring 5 (i.e., R,
<R1), that is, this radius R3 is set smaller than the radius R2 of the inner ring 5 according to the amount of elongation accompanying the ironing process.

Since the ironing process is performed on each corresponding guide groove 16 of the intermediate body 13, each corresponding guide groove 16 is provided with an ironing allowance as shown clearly in FIG. 4. The straining allowance t is maximum at the bottom of the corresponding guide groove 16 and is set to gradually become smaller as it goes from the bottom toward the corresponding outer circumferential surface 15.

FIG. 6 shows a closed forging device 1 for producing an intermediate body 13.
7 is shown. The device 17 includes an upper holder 18 that can be raised and lowered.
and a fixed lower holder 19, and the upper holder 1
An upper die 20 is attached to the lower surface of the lower holder 19, and a lower die 21 is attached to the upper surface of the lower holder 19. An upper punch 22 is disposed so as to pass through the upper holder 18 and the upper die 20, and a lower punch 23 is disposed so as to pass through the lower holder 19 and the lower die 21.

Upper and lower dies 20.21 and upper and lower punches 22.
23 defines a cavity 24 for molding the intermediate body.

In manufacturing the intermediate body 13, upper and lower dies 20.2
1 is closed, and the steel round bar material 25 is sandwiched between the upper and lower punches 22.23, and then the punches 22.2
3, the material 25 is forged to obtain the intermediate body 13.

In this forging process, the corresponding outer circumferential surface 15 of the intermediate body 13 is formed into a spherical surface by restraining the corresponding outer circumferential surface 15 with the cavity surface. In this case, the diameter of the material 25, the forging direction,
The flow of material changes due to forging timing, etc., and the shape changes accordingly, so even if an escape space is formed between the corresponding outer circumferential surface 15 and the cavity surface to prevent the corresponding outer circumferential surface 15 from being constrained by the cavity surface. , it is possible to mold the corresponding outer circumferential surface 15 into a shape that approximates a spherical surface.

Such unrestricted molding is performed using the upper and lower dies 20.
It is effective in prolonging the lifespan of 21-year-olds.

After forging, the intermediate body 13 is subjected to intermediate treatments such as annealing, blasting, and lubrication.

Figure 7 shows the ironing work, and the ironing mold 26
is composed of a fixed die 28 having a die hole 27 that opens upward, and a punch 29 that is inserted into and removed from the die hole 27 and is movable up and down.

A plurality of protrusions 30 for forming each guide groove 11 of the inner ring 5 are provided on the inner circumference of the die hole 27 so as to extend in the direction of the center line Ct~02, and on the outer circumference of the punch 29, a plurality of protrusions 30 for forming each guide groove 11 of the inner ring 5 are provided. A convex line 32 that fits into the concave line 31 between both adjacent convex lines 30 and a concave line 33 that fits with each convex line 30 are provided.

In each concave line 31 of the die 28, the depth d+ in a plane perpendicular to the center line Ct-C is set larger than the depth d2 of the guide groove 11 in the same plane in the inner ring 5 (i.e., d,>d1), thereby the outer circumferential surface 8 of the inner ring 5
There is a radial escape space r+ between
(Fig. 7(b, , b2)) is formed.

Further, in the die hole 27, a machining end surface Ss is defined near the bottom thereof, and a centerline direction escape space "2" is formed between the machining end surface S and the bottom surface of the die hole 27.

In the die 28, a knockout pin 35 is slidably fitted into a pin hole 34 that is open at the bottom of the die hole 27.

When ironing the intermediate body 13, the process shown in FIG.
), the intermediate body 13 is attached to its second corresponding end surface 14.
It is placed in the opening of the die hole 27 with the t facing downward, and each corresponding guide groove 16 is aligned with each protrusion 30.

Next, the punch 29 is lowered and its lower end face punches the first corresponding end face 14. of the intermediate body 13. 7 (b+
), (bz), the intermediate body 13 is ironed.

In this ironing process, each corresponding guide groove 16 of the intermediate body 13 is pressed by each convex strip 30 of the die 28, so that
A flow of material toward the corresponding outer circumferential surface 15 and the second corresponding end surface L4t occurs. In this case, the portion constituting the corresponding outer circumferential surface 15 is held in a non-restricted state with respect to the die 28 due to the radial relief space r1, so that portion expands outward in the radial direction and in the center line direction. Escape space r! Since the second corresponding end surface 142 side is held in a non-restricted state with respect to the die 28, the second corresponding end surface 142 side generates elongation in the direction of the center line Cz Cz force.

The ironing process ends when the second corresponding end face 14t, and thus the second end face 10z of the inner ring 5, reaches the process end surface S.

As mentioned above, specify the strain relief space, and also identify both escape spaces rl.
+ r2 allows each corresponding guide groove 16 to be squeezed in a well-balanced manner by a relatively small ironing load, and each guide groove 1
1 can be improved in dimensional accuracy.

Furthermore, due to the elongation, the radius R2 of the outer circumferential surface 8 of the inner ring 5 becomes larger than the radius R3 of the corresponding outer circumferential surface 15 of the intermediate body 13. This amount of elongation δ is caused by ironing and is therefore extremely small.

In this way, by using the intermediate body 13 as described above, it is possible to manufacture the inner ring 5 whose outer peripheral surface 8 is a spherical surface.
It is possible to form the outer circumferential surface 8 into a spherical surface by simply performing a grinding process on the outer circumferential surface 8 instead of cutting.

For example, the amount of elongation δ between the radii R, , R is approximately 0
．． Therefore, by setting the radius R1 of the corresponding outer peripheral surface 15 in the intermediate body 13 to be approximately equal to the radius of the outer peripheral surface of the inner ring 5 after grinding, a grinding allowance of approximately 0.2 mm can be achieved in the inner ring 5. can be caused.

In the intermediate body 13, each corresponding guide groove 16 may be formed only from the corresponding linear groove 163, and the corresponding linear groove 16a may be ironed to form the guide groove 11.

8 to 10 show an upsetting device 36 for manufacturing the intermediate body 13, and the device 36 is constructed as follows.

A knockout pin 38 is disposed at the center of the hollow cylindrical base 37 so as to be movable up and down, and the upper end of the knockout pin 38 protrudes from the upper end surface of the base 37.

The upper end surface 39 of the knockout pin 38 is used to form the second corresponding end surface 14z of the intermediate body 13.

A die 40 is disposed on the outer periphery of the upper end of the knockout pin 38, and the die 40 includes an annular die body 42 which is raised and lowered by a plurality of actuating cylinders 41, and a die body 4.
It consists of a plurality of sliding molds 43 that are slidably provided on the mold 2. A plurality of protrusions 45 are formed on the inner peripheral surface of the die hole 44 of the die body 42 at equal intervals on the circumference, and each protrusion 45 is formed on the inner peripheral surface of the die hole 44 of the die body 42.
It is used to form each of the three corresponding guide grooves 16.

In addition, in the die body 42, between the two adjacent protrusions 45,
A plurality of sliding grooves 46 extending in the radial direction are formed, and a sliding mold 43 slidably placed on the upper end surface of the base 37 is fitted into each sliding groove 46 . Each sliding mold 43 is used to mold a corresponding outer peripheral surface 15 of the intermediate body 13.

The outer end of each sliding die 46 is formed into an inclined cam plate 47, and the inclined cam plate 47 is slidably fitted into the inclined cam groove 48 of the die body 42, so that when the die body 42 is lowered, When each sliding mold 43 moves forward toward the upper end of the knockout pin 38 and the die body 42 rises, each sliding mold 43 retreats so as to be separated from the upper end of the knockout pin 38.

A punch 49 is disposed above the knockout pin 38 so as to be able to move up and down, and the lower end of the punch 49 can be fitted into the die hole 45. Used to form the 14° end face.

In manufacturing the intermediate body 13, a round bar-shaped steel material 25 is placed on the upper end surface 39 of the knockout bin, and then the die body 42 is lowered to advance each sliding mold 43. The forward end of each sliding mold 43 is regulated by contacting the upper end of the knockout pin 38 . Thereafter, the punch 49 is lowered to forge the material 25 to produce the intermediate body 13.

C1 Effects of the Invention According to the present invention, by using the intermediate body having the specific configuration, it is possible to manufacture an inner ring for a constant velocity gigopoint with a small machining allowance and whose outer peripheral surface can be formed into a spherical surface simply by grinding. This is possible, and this can significantly improve the productivity of the inner ring.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of the constant velocity joint, Figure 2 is a cross-sectional view of the inner ring along the line ■-■ in Figure 1, Figure 3 is a cross-sectional view along the ■-m line in Figure 2,
Fig. 4 is a sectional view of the intermediate body corresponding to Fig. 2, Fig. 5 is a sectional view taken along the line ■-■ in Fig. 4, Fig. 6 is a longitudinal sectional view of the closed forging device, and Figs. bz) shows the ladder processing work, and Fig. 7 (b2) is a cross-sectional view taken along the bz bz line of the same figure (b1),
8 to 10 show the upsetting apparatus, FIG. 8 is a longitudinal sectional view, FIG. 9 is a sectional view taken along the line IX--IX in FIG. 8, and FIG. 1O is a perspective view of a sliding type.

Claims (6)

[Claims] (1) It has a first end surface (10_1) and a second end surface (10_2) perpendicular to the center line (C_1-C_1), and an outer peripheral surface ( 8), a plurality of guide grooves (11) extending in the generatrix direction are formed at equal intervals on the circumference, and each guide groove (11) follows the locus of the center of the torque transmission ball (7) rolling along it. (l) is from the first end surface (10_1) to the center line (C
A linear groove (11a) that is a straight line parallel to the center line (C_1-C_1) up to the virtual inflection surface (S_1) perpendicular to the virtual inflection surface (S_1), and a linear groove (11a) that is a straight line parallel to the center line (C_1-C_1), and 10_2) is a constant velocity joint formed by an arc-shaped groove (11b) that smoothly connects with the straight line and gradually approaches the center line (C_1-C_1) as it goes toward the second end face (10_2). In order to manufacture an inner ring for use, first and second corresponding end surfaces (14_1, 14_2) corresponding to the first and second end surfaces (10_1, 10_2) and a corresponding outer circumferential surface (corresponding to the outer circumferential surface (8)) are prepared. 15) and
An intermediate body (13) having a corresponding guide groove (16) corresponding to each guide groove (11) is manufactured, and then the intermediate body (13) is
) by applying pressure to the first corresponding end surface (14_1) and ironing each corresponding guide groove (16) to form each guide groove (11), and during the ironing process, the second corresponding end surface (14_2) and the corresponding outer peripheral surface (15)
A method for manufacturing an inner ring for a constant velocity joint, in which the intermediate body (13) is caused to elongate outward in the centerline direction and radial direction by holding the inner ring in a non-restricted state with respect to the ironing die (26). The corresponding outer circumferential surface (15) of the intermediate body (13) is formed into a spherical surface with a radius (R_3) set to be small according to the amount of elongation (δ) caused by the ironing process. Method of manufacturing inner ring for constant velocity joint. (2) The method for manufacturing an inner ring for a constant velocity joint according to item (1), wherein the intermediate body (13) is manufactured by upsetting. (3) The method for manufacturing an inner ring for a constant velocity joint according to item (2), wherein the intermediate body (13) is manufactured by closed forging. (4) Each corresponding guide groove (16) of the intermediate body (13) is
A corresponding linear groove (16a) to the linear groove (11a)
) and a corresponding arcuate groove (16b) corresponding to the arcuate groove (11b).
3) Method for manufacturing an inner ring for a constant velocity joint as described in section 3). (5) Each corresponding guide groove (16) of the intermediate body (13) is
A corresponding linear groove (16) corresponding to the linear groove (11b)
(1), (2) or (3) consisting only of b)
A method for manufacturing an inner ring for a constant velocity joint as described in . (6) The corresponding outer peripheral surface (1
The radius (R_3) of 5) is the inner ring (5) after grinding.
(1) and (2) are set approximately equal to the radius of the outer peripheral surface of
), the method for manufacturing an inner ring for a constant velocity joint according to item (3), item (4), or item (5).