JP2008194734A - Method for manufacturing outer member for constant velocity universal joint, and device for manufacturing the same outer member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the yield of a forged product at a low cost by reducing variations in the cup part depth, which are generated in forge-molding of the outer member for a constant velocity universal joint. <P>SOLUTION: The outer member for the constant velocity universal joint, which member integrally has a cup part and a shaft part extending from one end of the cup part, is manufactured by performing pre-molding that consists of forward extrusion (A), upsetting (B), and backward extrusion (C), and by performing ironing (D). In the backward extrusion (C), extrusion-molding of the body of a cup part 7 is carried out by pushing an inner die 22 into a solid large-diameter part 5, and further the opening side edge face is formed on the cup part 7 by pressing the opening side edge part 8a of the cup part 7 with a pressure die 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an outer member for a constant velocity universal joint, and more particularly to a method for manufacturing an outer member for a constant velocity universal joint having a shaft portion integrally therewith.

  For power transmission systems of automobiles and various industrial machines, such as front wheel drive vehicles and independent suspension type rear wheel drive vehicles, only angular displacement is used as a means to transmit the rotational force from the engine of the vehicle to the wheels at a constant speed. There are used fixed type constant velocity universal joints that allow and sliding type constant velocity universal joints that allow both angular displacement and axial displacement.

  Examples of the drive shaft include a propeller shaft that transmits a rotational driving force from a transmission to a differential, and a drive shaft that transmits a rotational driving force from a differential to a wheel. In addition, the Barfield type constant velocity universal joint (BJ) is well known as the fixed type constant velocity universal joint, and the double offset type constant velocity universal joint (DOJ) is widely used as the sliding type constant velocity universal joint. Are known.

  For example, a BJ type fixed type constant velocity universal joint includes an outer member (also referred to as an outer joint member) in which a plurality of track grooves extending in the axial direction are formed on a spherical inner peripheral surface, and a track groove of the outer member, A pair of axially extending track grooves are formed between the inner member (also referred to as the inner joint member) formed on the spherical outer peripheral surface, and the track groove of the outer member and the track groove of the inner ring member. A plurality of balls for transmitting torque and a cage for holding the balls interposed between the spherical inner peripheral surface of the outer member and the spherical outer peripheral surface of the inner member are provided as main components.

  In addition, the DOJ type sliding constant velocity universal joint has an axial direction in which a plurality of axially extending track grooves are paired with an outer member in which a cylindrical inner peripheral surface is formed and a track groove of the outer member. An inner member in which a track groove extending in a spherical outer peripheral surface is formed, a plurality of balls that are interposed between the track groove of the outer member and the track groove of the inner member, and transmit the torque, and the outer member And a cage for holding the ball interposed between the cylindrical inner peripheral surface and the spherical outer peripheral surface of the inner member.

  The outer members of these fixed type constant velocity universal joints or sliding type constant velocity universal joints are conventionally manufactured by the following procedure. First, a billet as a material is formed into a finished product shape of an outer member or a shape close to the finished product by pre-forging (hot forging, warm forging or cold forging), and then ironed into the molded product ( Sizing). If necessary, the outer peripheral surface, inner peripheral surface and end surface of this molded product are turned and heat treated, and the inner peripheral surface and track grooves are finished by grinding or hardened steel cutting. Get the finished product.

Among these, in pre-forging, a rod-shaped material (billet) is subjected to a forward extrusion process to form a molded body integrally having a shaft portion and a solid body portion, and then upsetting is performed on this molded body. By applying, a solid main-body part is extruded and an upsetting part is formed, and a cup part is formed by performing a backward extrusion process further to this upsetting part (for example, refer patent document 1).
JP-A-11-179477

  Thus, when producing an outer member by performing forging, what is important is the yield. In other words, the forged product described above is obtained by forming a material (billet) cut into an appropriate length through a plurality of forging processes, so that the amount of cutting in the subsequent cutting process is reduced as much as possible. It is important to improve the yield. However, with this type of molding means, when the cup portion is molded, the opening side end of the cup portion is free-molded. For example, if there is a variation in the initial weight of the material, the variation is directly applied to the cup portion. It tends to appear as variations in depth. In particular, when finishing the inner periphery of the cup portion by ironing, the cup portion is pressed and stretched in the axial direction, so that the variation in the initial weight of the material tends to appear more prominently as the variation in the cup portion depth. In this case, it is necessary to take a large machining allowance for the opening side end face of the cup portion in the subsequent process, which may lead to the result that the original purpose of the forging (near net shape) is lost.

  In view of the above circumstances, in the present invention, it is a technical problem to improve the yield of forged products at low cost by reducing the variation in the depth of the cup portion that occurs during forging of the outer member for a constant velocity universal joint. And

  In order to solve the above-described problems, the present invention provides an outer member for a constant velocity universal joint having a cup portion that houses an internal part including a rolling element for torque transmission and a shaft portion that extends from one end of the cup portion. This is a method in which an intermediate molded body integrally having a shaft portion and a solid large-diameter portion having a diameter larger than that of the shaft portion is subjected to a backward extrusion process so that the cup portion is restrained by an outer mold when forged. In addition, the cup part is extruded by pressing the inner mold into the solid large-diameter part, and the opening side end face is formed in the cup part by pressing the opening side end part of the extruded cup part with a holding mold. A method for manufacturing an outer member for a constant velocity universal joint is provided.

  In order to solve the above-mentioned problem, the present invention provides an outer surface for a constant velocity universal joint that integrally includes a cup portion that houses an internal part including a rolling element for torque transmission and a shaft portion that extends from one end of the cup portion. A manufacturing apparatus for a side member for forging a cup portion by subjecting an intermediate formed body integrally having a shaft portion and a solid large-diameter portion having a larger diameter than the shaft portion to a backward extrusion process. An outer mold that restrains the outside of the solid large-diameter portion, an inner mold that extrudes the cup portion by being pushed into the solid large-diameter portion constrained by the outer mold, and extruded by extrusion molding. An apparatus for manufacturing an outer member for a constant velocity universal joint provided with a presser mold that forms an opening-side end surface on a cup by pressing the opening-side end of the cup.

  In this way, in addition to the inner mold and outer mold for extruding the cup body, it is possible to form an intermediate molded body by molding the opening side end face using a presser mold that presses the opening side end of the cup section. The acting load and the reaction force received by the mold (inner mold, outer mold, etc.) from this intermediate molded body are increased, and the entire press apparatus (molding apparatus) including the outer mold and the inner mold is deformed. In this way, the deformation of the entire press device due to the increase in load can provide a larger space for escaping the surplus material, and the variation in the material weight is cut at the opening side end than the side wall of the cup. It is possible to leave a part of the surplus of the material on the shoulder portion or the shaft portion of the cup portion having a small influence on the machining allowance. This is because the proportion of the surplus remaining in the region contributes to the extension of the side wall in the ironing process in the subsequent process is small, and as a result, the variation in the material weight appears as the variation in the depth of the cup. Can be kept as small as possible. From the above, since it is not necessary to make a large machining allowance for the opening side end face, or a cutting process is not required, it is possible to improve productivity and thus reduce production cost.

  In addition, if the depth dimension of the cup part is controlled more accurately, the opening side end face of the cup part is preferably molded while the axial position of the presser mold with respect to the inner mold is managed. By performing molding in a state where the positional relationship between the molds is managed in this way, the size can be controlled within a desired range while reducing variations in the cup portion depth.

  Further, it is preferable to hold the opening side end by the holding die in a state where the intermediate formed body is constrained so that there is no free forming surface. By pressing (compressing) the intermediate molded body in a constrained state so that there is no free molding surface, the load acting on the intermediate molded body and the reaction force received by the mold (inner mold, outer mold, etc.) from this intermediate molded body As a result, the entire press apparatus (molding apparatus) including the outer mold and the inner mold is deformed. As described above, due to the deformation of the entire press apparatus due to the increase in load, a larger space for escaping the surplus material can be obtained, and the cutting allowance can be further reduced.

  As described above, according to the present invention, it is possible to improve the yield of forged products at low cost by reducing the variation in cup portion depth that occurs during forging of the outer member for a constant velocity universal joint. Become.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Note that the “up and down” direction in the following description is merely specified for easy understanding of the positional relationship between the components in each figure, and does not specify the installation direction or usage mode of the manufacturing apparatus. Absent.

  4 and 5 show an embodiment of a constant velocity universal joint having an outer member manufactured by the manufacturing method or manufacturing apparatus according to the present invention. Here, a so-called double offset type sliding constant velocity is shown. A universal joint (DOJ) is illustrated. The constant velocity universal joint includes an outer ring 31 as an outer member in which a plurality of (here, six) track grooves 32 extending in the axial direction are formed on a cylindrical inner peripheral surface 33 at equal intervals in the circumferential direction, and an outer ring 31. An inner ring 34 as an inner member in which a plurality (six in this case) of track grooves 35 extending in the axial direction in pairs with the track grooves 32 are formed on the spherical outer peripheral surface 36 at equal intervals in the circumferential direction, and an outer ring A plurality of (six in this case) balls 37 interposed between the track grooves 32 of the 31 and the track grooves 35 of the inner ring 34, the cylindrical inner peripheral surface 33 of the outer ring 31 and the spherical surface of the inner ring 34. And a cage 38 that is interposed between the outer peripheral surface 36 and holds the ball 37. The plurality of balls 37 are accommodated in pockets 39 formed in the cage 38 and arranged at equal intervals in the circumferential direction. In this embodiment, the number of balls 37 and the number of both track grooves 32 and 35 are both six, but it is of course not limited to this. For example, 8 (eight) can be arbitrarily set according to the type of the constant velocity universal joint or the application.

  Among these, the outer ring | wheel 31 is integrally provided with the cup part 40 and the axial part 41 extended from the end of the cup part 40, and is forge-formed by the pre-forging described below.

  In the front forging, forward extrusion (A), upsetting (B), and backward extrusion (C) are performed, and a forged molded product having a shape close to the outer ring 31 as a finished product is obtained. Further, in this embodiment, ironing (D) is subsequently performed, and the outer ring 31 having a finished product shape is obtained.

(A) Forward Extrusion Processing First, a material (also referred to as a billet) 1 having a shape shown in FIG. 1A is prepared, and a molding die 14 having a shape shown in FIG. By performing forward extrusion processing, the initial molded body 4 integrally having the solid body portion 2 and the shaft portion 3 extending from one end of the solid body portion 2 is forged.

(B) Upsetting Next, upsetting is performed on the initial molded body 4 obtained by forward extrusion (A) using a molding die 16 having a shape shown in FIG. By pressing and expanding the actual main body portion 2 toward the outer diameter side, the intermediate formed body 6 integrally having the shaft portion 3 and the solid large-diameter portion 5 larger in diameter than the shaft portion 3 is forged. As the molding die 16 used in this process, a mold having a shape for reshaping the shaft portion 3 molded by the forward extrusion process (A) into a shape closer to a finished product is used.

(C) Backward Extrusion Process A forged formed body integrally having the shaft portion 3 and the cup portion 7 by subjecting the intermediate formed body 6 thus obtained to a backward extrusion process (pre-forged product 10). Is molded. FIG. 2 shows a cross-sectional view of a molding apparatus provided with a mold used for such extrusion processing, and a material (intermediate molded body 6) arranged in the apparatus. In FIG. 2, the left side shows a cross-sectional view before molding, and the right side shows a sectional view when the molding is completed.

  This device is arranged on the outer mold 21 that holds and restrains the outer side of the shaft portion 3 and the solid large-diameter portion 5 of the intermediate molded body 6 and the opposite shaft portion 3 side of the solid large-diameter portion 5. The inner mold 22 that pushes the solid large-diameter portion 5 toward the shaft portion 3 and the outer periphery of the inner die 22 are formed by pushing the inner die 22. And a presser mold 23 for pressing the opening side end of the cup part 7. In this embodiment, the presser mold 23 is formed separately from the outer mold 21 and the inner mold 22, and is configured to be relatively movable in the axial direction with respect to the outer mold 21 and the inner mold 22. Further, the inner mold 22 has a step, and the presser mold that can come into contact with the step surface 22a by setting the axial distance between the step surface 22a and the tip 22b of the inner mold 22 to a predetermined value. The axial distance from the holding surface 23a of the 23 to the tip 22b is managed. The presser surface 23a of the presser mold 23 is formed flat and horizontal (in a direction orthogonal to the central axis of the shaft portion 3).

  First, the inner mold 22 is lowered from the state shown on the left side of FIG. 2, and the inner mold 22 is pushed into the solid large-diameter portion 5 of the intermediate molded body 6. As a result, a plastic flow occurs along the radial gap between the inner mold 22 and the outer mold 21 which are free spaces, and the main body of the cup portion 7, here, the cylindrical side wall portion 8 and the bottom of the side wall portion 8. A shoulder portion 9 is formed.

  In this way, the cup part 7 body is extruded by pushing the inner mold 22 into the solid large-diameter part 5, and the opening end 8 a of the pushed cup part 7 body is pressed by the presser mold 23. An opening side end face is formed on the cup portion 7. Here, the presser mold 23 is fitted and disposed on the outer periphery of the inner mold 22, and is lowered integrally with the inner mold 22 after contacting the inner mold 22 in the axial direction as the inner mold 22 is lowered. It is supposed to be. Accordingly, as described above, the side wall portion extending in the direction away from the shaft portion 3 by lowering the presser die 23 in a state where the axial distance from the press surface 23a of the presser die 23 to the tip 22b of the inner die 22 is controlled. 8 and the presser mold 23 come into contact with each other. Then, by further lowering the inner mold 22, the opening side end of the cup part 7 is pushed by the presser mold 23 to a position where the depth dimension of the cup part 7 becomes the above-described axial dimension. In this state, the inner mold 22 has been lowered to the position where the extrusion molding of the main body of the cup portion 7 is completed (the state shown on the right side of FIG. 2).

(D) Ironing After the pre-forged product 10 is formed as described above, the pre-forged product 10, particularly the cup portion 7, is ironed using the ironing punch 24 and the ironing die 25 shown in FIG. Apply processing. Here, the left side in FIG. 3 shows a cross-sectional view before the ironing process and the right side when the ironing process is completed.

  Specifically, as shown in FIG. 3, in the state in which the ironing punch 24 is fitted to the inner periphery of the pre-forged product 10 obtained by the backward extrusion (C), By pressing the ironing punch 24 into the inner periphery of the ironing die 25, the side wall part 8 of the cup part 7 is mainly ironed and the side wall part 8 is finished to a predetermined dimension. The right side of FIG. 3 shows the forged molded body (finished ironing product 11) after ironing, and the side wall portion 12 is stretched in the axial direction. In addition, by providing the forming part of the shape corresponding to the track groove 32 and the cylindrical inner peripheral surface 33 (see FIG. 4) to be formed on the outer periphery of the ironing punch 24, the side wall part 8 is ironed together. The track groove 32 and the cylindrical inner peripheral surface 33 can be formed inside the side wall portion 8.

  The outer ring 31 as a finished product is obtained by performing the above forging and ironing. Here, although the case where the ironing finished product 11 is used as the outer ring 31 as a finished product has been illustrated here, processing related to finish grinding, heat treatment, or a combination thereof may be performed as necessary.

  Thus, while the cup part 7 main body is extruded by the outer mold 21 and the inner mold 22, the opening side end 8a of the extruded side wall part 8 is pressed by the pressing mold 23, thereby acting on the intermediate molded body 6. The load and the reaction force received by the mold (such as the outer mold 21 and the inner mold 22) from the intermediate molded body 6 are increased, and the outer mold 21 and the inner mold 22 are deformed. Therefore, a part of the surplus material can be left on the shoulder portion 9 that forms the bottom of the cup portion 7 by this deformation. The surplus remaining in the shoulder 9 has a small influence on the side wall portion 8 in the above-described ironing (D), and as a result, it is not necessary to take a large machining allowance for the opening side end face. Accordingly, productivity can be improved at low cost.

  Further, in this embodiment, the opening side end face of the cup portion 7 is molded in a state where the axial position of the presser mold 23 relative to the inner mold 22 is managed. Thus, by performing molding in a state where the positional relationship between the inner mold 22 and the presser mold 23 is managed, the size can be controlled within a desired range while reducing the variation in the depth of the cup portion 7. Is possible.

  Further, in this embodiment, the intermediate molded body 6 is held by the outer mold 21, the inner mold 22, and the presser mold 23, and the opening side end 8 a is pressed. By compressing the intermediate molded body 6 so that there is no free molding surface, the load acting on the intermediate molded body 6 and the reaction force received by the outer mold 21 and the inner mold 22 from the intermediate molded body 6 are increased. The entire molding apparatus including the outer mold 21 and the inner mold 22 that restrain the cup portion 7 is deformed. Thus, the space for escaping the surplus of the material can be increased by the deformation of the entire press device (forming device) due to the increase in load. Therefore, the variation in the depth of the cup part 7 as a finished product can be further reduced.

  Moreover, if the presser die 23 formed separately from the inner die 22 is lowered integrally with the inner die 22 from a predetermined position as in this embodiment, the earlier the material 1 is, the earlier it is. Pressing of the opening side end 8a by the presser mold 23 is started, and the inner mold 22 is lowered to a position where the extrusion molding of the main body of the cup part 7 is completed. Can be completed and efficient. In addition, with such a configuration, since only one drive mechanism (press mechanism) is required, it becomes easy to incorporate the above-mentioned pre-forging steps (A) to (C) into the multi-stage press mechanism, thereby improving productivity. Further, by making the presser mold 23 separate from the inner mold 22, the molded work (pre-forged product 10) can be easily removed from the inner mold 22.

  As mentioned above, although the structure and manufacturing process of the outer member (outer ring 31) for constant velocity universal joints which concern on one Embodiment of this invention were demonstrated, of course, it is not limited to this but takes a structure and process other than the above. It is also possible.

  For example, in the above-described embodiment, the presser mold 23 is lowered integrally with the inner mold 22, and at the same time as the extrusion molding of the cup portion 7 by the inner mold 22 is completed, the presser (opening) of the opening side end 8 a by the presser mold 23 is completed. Although the case where the side end face molding) is completed has been described, it is not necessary to limit the timing of pressing by the pressing mold 23 to the above-described stage. For example, with regard to the timing of starting the presser, the inner die 22 and the presser die 23 are driven (lowered) independently by separate driving means, and the molding of the cup portion 7 by the pressing of the inner die 22 is started. It is also possible to form the opening-side end face immediately after or by lowering the presser mold 23 by another driving means.

  In the above-described embodiment, the case where the presser mold 23 is provided separately from the inner mold 22 and is relatively movable is described. However, the presser mold 23 may be provided integrally with the inner mold 22. Of course, the effect of reducing the cutting allowance after ironing by the presser mold 23 can be obtained in the same manner regardless of whether it is integral or separate.

  FIG. 6 shows an example thereof, and the molding apparatus according to FIG. 6 differs in structure from the molding apparatus shown in FIG. 2 in that the pressing mold 23 is formed integrally with the inner mold 22. Further, if the presser mold 23 is formed integrally with the inner mold 22 as in this illustrated example, for example, for the purpose of increasing the joint operating angle, a taper-shaped second is formed on the inner side of the presser surface 23a of the presser mold 23. It is also possible to provide two pressing surfaces 23b.

  Moreover, although the case where this invention was applied to the outer member of what is called a double offset type sliding constant velocity universal joint (DOJ) was demonstrated in the said embodiment, this invention is not restricted to the said structure, other The present invention can also be applied to an outer member for a constant velocity universal joint having a configuration. For example, in the case of a sliding type constant velocity universal joint, a so-called tripod type constant velocity universal joint in which a roller is interposed instead of a ball or a fixed type constant velocity universal joint represented by a barfield type constant velocity universal joint is used. The present invention can also be applied to the outer member.

  A forged molded product of an outer member for a constant velocity universal joint manufactured by a conventional method (a method of extruding a cup portion with the opening side end of the cup portion as a free forming surface), and a method according to the present invention (a cup portion) Comparison and verification of the effect of variation in material weight on the depth dimension of the cup part with a forged product manufactured by extruding the cup part while pressing the opening side end of the cup with a presser die did.

  In detail, with the conventional method and the method according to the present invention, pre-forging and ironing are performed on materials having different weights, and the cup portion depth dimension of the molded product (pre-forged product) upon completion of forging, and The cup part depth dimension of the molded product when the ironing process was completed (the ironing process completed product) was measured. This operation was performed on a plurality of materials having different weights at the time of charging, and the relationship between the cup depth of each molded product and the material weight was determined. Here, the method according to the present invention and the apparatus used in the method are the same as those described in the above embodiment. Further, in both the conventional method and the method according to the present invention, ironing was performed by the apparatus and method described in the above embodiment.

  FIG. 7 shows the relationship between the cup depth [mm] and the material weight [g] of the pre-forged product. Here, the slope of each straight line indicates the increase rate of the cup depth with respect to the material weight. In other words, the greater the gradient value, the greater the variation in material weight that is reflected in the cup depth. The straight line A1 indicates a theoretical formula in the case where all of the surplus of the material is included in the cup portion of the pre-forged product. Further, the straight line A2 shows the relationship (approximate straight line) between the cup part depth and the material weight in the molded product produced by the conventional method, and the straight line A3 shows the cup part depth and the material weight in the molded product produced by the method according to the present invention. (Approximate straight lines) are shown respectively. Accordingly, the degree of the influence of the surplus of the material on the cup portion depth can be measured by the ratio (percentage here) of the gradient of the straight line A2 or the straight line A3 to the gradient of the straight line A1.

  According to the above-mentioned idea, when the influence of the surplus of the material on the depth of the cup portion was compared, it was 88% in the conventional forging, and 4% in the forging according to the present invention, the opening side end portion. It was found that by the embossing of 8a, most of the surplus escaped to locations other than the side wall portion 8 of the cup portion 7 (for example, the shoulder portion 9).

  Next, FIG. 8 shows the relationship between the cup portion depth [mm] and the material weight [g] of the ironing finished product. Here, the straight line B1 shows a theoretical formula in the case where all the surplus material is included in the cup portion of the ironing finished product. In addition, the straight line B2 shows the relationship (approximate straight line) between the cup portion depth and the material weight in the case where the pre-forging is performed by the conventional method and the ironing is performed, and the straight line B3 is the pre-forging by the method according to the present invention. The relationship (approximate straight line) between the cup part depth and the material weight in the case where the ironing process is performed and the ironing process is performed is shown.

  In this case, the ratio of the gradient of the straight line B2 to the gradient of the straight line B1 was 101%, whereas the ratio of the gradient of the straight line B2 to the gradient of the straight line B1 was 45%. For this reason, most of the surplus escapes to a portion other than the side wall portion 8 of the cup portion 7 (for example, the shoulder portion 9) due to the embossing of the opening side end portion 8a, and even after ironing is performed, However, it was found that the ratio contained in the side wall portion 8 was less than half.

It is sectional drawing which shows notionally the front forging process of the outer member for constant velocity universal joints which concerns on one Embodiment of this invention, Comprising: (a) is sectional drawing of the raw material before pre-forging, (b) is forward extrusion. Sectional drawing of the metal mold | die and raw material in a process, (c) is sectional drawing of the metal mold | die and raw material in an upsetting process. It is sectional drawing of the apparatus and raw material which are used for back extrusion. It is sectional drawing of the apparatus and material which are used for ironing. It is sectional drawing which shows the constant velocity universal joint which concerns on one Embodiment of this invention, Comprising: It is sectional drawing which follows the BOB line of FIG. It is sectional drawing which shows the constant velocity universal joint which concerns on one Embodiment of this invention, Comprising: It is sectional drawing which follows the AA line of FIG. It is sectional drawing of the back extrusion apparatus and raw material which concern on another structure. It is a figure which shows the relationship between the cup part depth and raw material weight of the forge completed product manufactured by the conventional method, and the relationship between the cup part depth and raw material weight of the pre-forged completed product manufactured by the method according to the present invention. is there. Relationship between cup part depth and material weight of ironing completed product manufactured through conventional pre-forging, and relationship between cup part depth and material weight of ironing completed product manufactured through pre-forging according to the present invention FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Material 3 Shaft part 5 Solid large diameter part 6 Intermediate molded object 7 Cup part 8 Side wall part 8a Opening side edge part 9 Shoulder part 10 Forging completed product 11 Ironing completion product 12 Side wall part 21 Outer mold 22 Inner mold 23 Presser Die 24 Ironing punch 25 Ironing die 31 Constant velocity universal joint outer member 40 Cup part 41 Shaft part

Claims (5)

A method for producing an outer member for a constant velocity universal joint having a cup portion containing an internal part including a rolling element for torque transmission and a shaft portion extending from one end of the cup portion,
When forging the cup part by subjecting the intermediate molded body integrally having the shaft part and a solid large diameter part larger in diameter than the shaft part,
The cup part is extruded by pressing the inner mold into the solid large-diameter part constrained by the outer mold, and the opening side end of the extruded cup part is pressed by the press mold to the cup part. A method for producing an outer member for a constant velocity universal joint, wherein an opening side end face is formed.   The method for manufacturing the outer member for a constant velocity universal joint according to claim 1, wherein the opening side end face is formed in a state where the axial position of the presser mold with respect to the inner mold is managed.   The method for manufacturing an outer member for a constant velocity universal joint according to claim 1, wherein the opening side end surface is molded in a state where the intermediate molded body is constrained so that there is no free molding surface.   The method of manufacturing an outer member for a constant velocity universal joint according to claim 1, wherein ironing is performed on the cup portion after the cup portion is formed. An apparatus for manufacturing an outer member for a constant velocity universal joint that integrally includes a cup portion that contains internal parts including rolling elements for torque transmission and a shaft portion that extends from one end of the cup portion,
The cup part is forged by subjecting the shaft part and a solid large-diameter part having a larger diameter than the shaft part to an integrally formed back extrusion process.
An outer mold that restrains the outside of the solid large-diameter portion;
An inner mold for extruding the cup part by pushing into the solid large diameter part constrained by the outer mold;
An apparatus for manufacturing an outer member for a constant velocity universal joint, comprising: a pressing mold for forming an opening-side end surface of the cup portion by pressing the opening-side end portion of the cup portion extruded by the extrusion molding.

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