JP2015199081A - Manufacturing method for metal member having external flange part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method capable of: manufacturing a stepped columnar member to be used as a hub body of a wheel supporting roller bearing unit, for example, lightly while preventing the occurrence of a drop; and retaining the durability of a die.SOLUTION: Onto the upper face of a preliminary intermediate stock 27, there is pushed a coarsely shaping punch having an external diameter smaller than that of an upper end part of the preliminary intermediate stock 27, thereby to attain an intermediate stock 28 having a large diameter recess 29 and an outward flange part 30. A finish-molding punch having a smaller external diameter than that of the portion near the internal diameter of the large diameter recess 29 of that intermediate stock 28 is pushed into the bottom central part of that large diameter recess 29. As a result, a small-diameter recess 45 is formed in the bottom face of that large diameter recess 29, and the axial length of a small-diameter step part 12a is enlarged.

Description

  The present invention is, for example, a bearing ring member constituting a wheel bearing rolling bearing unit, that is, a metal member with an outward flange portion having an outward flange portion on an outer peripheral surface, such as a hub main body constituting a hub in combination with an inner ring. It relates to the improvement of the manufacturing method of

  2. Description of the Related Art A wheel bearing rolling bearing unit is widely used to rotatably support a wheel constituting a wheel of an automobile and a disk or drum which is a rotating member for braking on a knuckle constituting a suspension device. FIG. 9 shows an example of a wheel bearing rolling bearing unit 1 for a driven wheel (a front wheel of an FR vehicle and an MR vehicle, a rear wheel of an FF vehicle) that has been widely known. The wheel supporting rolling bearing unit 1 supports a hub 3 on the inner diameter side of an outer ring 2 via a plurality of rolling elements 4 and 4 in a freely rotatable manner. In the state of use, the outer ring 2 is coupled and fixed to the knuckle, and the wheel and the brake rotating member are supported and fixed to the hub 3. Then, these wheels and the brake rotating member are rotatably supported with respect to the knuckle.

  For this purpose, double-row outer ring raceways 5 and 5 are arranged at two positions on the inner peripheral surface of the outer ring 2 at a part of the outer peripheral surface, slightly inwardly in the axial direction from the central part in the axial direction. 9 means the side that is the center side in the width direction of the vehicle body in use, and the right side of Fig. 9. Conversely, the left side of Fig. 9 that is outside in the width direction of the vehicle body in use state is called outside in the axial direction. The same applies to the entire specification), and the stationary side flanges 6 are respectively formed. On the other hand, the outer peripheral surface of the hub 3 is provided with a rotation-side flange 7 for supporting and fixing the wheel and the brake rotating member on a portion near the outer end protruding outward in the axial direction from the outer ring 2. Double-row inner ring raceways 8 and 8 are formed on the portion near the inner end. A plurality of rolling elements 4, 4 are arranged between the inner ring raceways 8, 8 in both rows and the outer ring raceways 5, 5 in both rows, and the inner diameter of the outer race 2 is set. The hub 3 can freely rotate on the side.

  The hub 3 includes a hub body 9, an inner ring 10, and a nut 11, and the inner ring raceways 8 and 8 are formed in an intermediate portion of the hub body 9 and an outer peripheral surface of the inner ring 10. Further, the inner ring 10 is fixed to the hub body 9 by the nut 11 in a state where the inner ring 10 is externally fitted to a small-diameter step portion 12 formed near the inner end of the hub body 9 in the axial direction. A structure in which the inner ring 10 is fixed to the hub body 9 by a caulking portion formed at the inner end of the hub body 9 in the axial direction is also widely known. A cylindrical portion 13 called a pilot portion is provided at the axially outer end portion of the hub body 9 for externally positioning the wheel and the braking rotator. A recess 14 is formed at the center of the axially outer end surface of the hub body 9 at the axially outer end of the hub body 9 including the inner diameter side of the cylindrical part 13.

  The hub body 9 constituting the wheel support rolling bearing unit 1 as described above is manufactured by subjecting a metal material such as carbon steel to plastic working. The structure of the hub body produced by such plastic working and the method of such plastic working have been widely known, for example, as described in Patent Documents 1 to 4. Among these, the structure of the hub main body and the manufacturing method thereof described in Patent Document 4 will be described with reference to FIGS.

Of these, the hub body 9a shown in FIG. 10 has a radial rotation side flange 7a near the axially outer end portion of the outer peripheral surface, the inner ring raceway 8 at the middle portion, and the small-diameter step portion 12 at the inner end portion. , Each formed.
Such a hub main body 9a is manufactured by the steps shown in FIGS. First, by cutting a long raw material made by extrusion molding, rolling molding or the like into a predetermined length, a cylindrical raw material 15 as shown in FIG. Next, a first intermediate material 16 shown in (B) of each figure is produced by subjecting the raw material 15 to a first-stage forward extrusion process, which is a kind of cold forging process. Next, the second intermediate material 17 shown in (C) of each figure is obtained by subjecting the first intermediate material 16 to a second-stage forward extrusion process, which is also a kind of cold forging. Next, the shaft of the second intermediate material 17 is set in a state where the second intermediate material 17 is set in a split die having a predetermined inner peripheral surface shape as described in Patent Document 4. A punch is pressed against the direction outer end face {upper end face in (C) of each figure}. And each figure is given by carrying out the side extrusion processing which is a kind of cold forging which makes the metal material which constitutes this 2nd intermediate material 17 flow radially outward while making this axial direction end face concave. A third intermediate material 18 having a rotation-side flange 7a as shown in FIG. Next, the third intermediate material 18 is subjected to a sizing process for forming seating surfaces 21 and 21 for contacting the axial side surfaces of the head 20 (see FIG. 9) of the stud 19 (see FIG. The fourth intermediate material 22 shown in E) is assumed.

  An axially inner end {lower end of (E) in each figure} of the fourth intermediate material 22 is formed with a male screw part on the outer peripheral surface (as shown in FIG. The inner ring 10 is prevented from coming off by the nut 11), or as shown in FIG. A peripheral portion of the concave hole 23 is a cylindrical portion 24 and is a fifth intermediate material 25. Such a cylindrical portion 24 is plastically deformed radially outward (clamped) in a state in which the inner ring 10 is externally fitted to the small-diameter stepped portion 12, and the axial inner end face of the inner ring 10 is suppressed. The inner ring 10 is prevented from coming out of the small diameter step portion 12. Further, predetermined cutting processing such as drilling for forming a circular hole for inserting the stud 19 in the fourth intermediate material 22 to the fifth intermediate material 25, deburring, processing of the inner ring raceway 8, and the like; The hub body 9a is obtained by grinding.

  It is desired to reduce the weight of the hub body 9a manufactured as described above. That is, the wheel-supporting rolling bearing unit 1 (see FIG. 9) in which the hub body 9a is incorporated is a so-called unsprung load provided on the road surface side of the spring constituting the suspension device. In order to improve the driving performance centering on the characteristics, it is desirable to reduce the weight as much as possible. In order to reduce the weight of the hub body 9a, the amount of plastic deformation of the second intermediate material 17 in the side extrusion process shown in FIGS. 11C to 13D is increased. It is effective to reduce the amount of the metal material constituting the hub body 9a. That is, when the punch is pressed against the outer end surface in the axial direction of the second intermediate material 17 and the recess 14 is formed in the outer end surface in the axial direction during the side extrusion, the recess 14 in the hub body 9a is formed. The hardness of the outer diameter side portion of the is increased (work hardening). Therefore, even when the inner diameter of the recess 14 is increased and the thickness of the axially outer end portion (cylindrical portion 13) of the hub body 9a is reduced during the side extrusion, the strength and Rigidity can be secured.

  However, when the thickness of the portion near the outer end in the axial direction of the hub body 9a is reduced as described above, the following problem may occur. That is, as shown in FIG. 14, when the thickness of the cylindrical portion 13 provided at the axially outer end portion of the hub body 9a is reduced, the inner peripheral surface of the concave portion 14 provided at the axially outer end surface of the hub body 9a is reduced. Of these, there is a possibility that sink marks (thickness) 26 may occur in a portion located on the radially inner side of the axially outer side surface of the rotation-side flange 7a. If such a sink mark 26 is generated, it is disadvantageous in terms of ensuring the fatigue strength of the rotating flange 7a and the rigidity in the axial direction.

JP 2006-111070 A JP 2006-142983 A JP 2008-296694 A JP 2009-255751 A

  In view of the circumstances as described above, the present invention can obtain a lightweight metal member with an outward flange while preventing the occurrence of sink marks, and also suppresses the surface pressure applied to the die during processing, and the durability of the die. It was invented to realize a manufacturing method capable of securing the property.

A metal member with an outward flange, which is an object of the present invention, is a large-diameter recess provided at the center of one end surface in the axial direction, and a portion located on the outer diameter side of the large-diameter recess in the axial direction among the outer peripheral surfaces And an outward flange portion provided so as to protrude outward in the radial direction.
And the manufacturing method of the metal member with an outward flange part of the present invention makes the above-mentioned metal member with an outward flange part by performing plastic working on a metal material.

In particular, the manufacturing method of the outward flange portion metal member according to claim 1 includes a rough forming step and a finish forming step.
Of these, the rough forming step is a state in which a rough forming die having an outward flange portion forming cavity for processing the outward flange portion is disposed around the material, and an axial end surface of the raw material is disposed. A rough forming punch having an outer diameter smaller than the outer diameter is pushed into one end face in the axial direction of the material. And the intermediate material provided with the said large diameter recessed part and the said outward flange part is obtained.
Further, in the finish molding step, a finish molding die having an inner peripheral surface commensurate with the outer peripheral surface shape of the intermediate material is disposed around the intermediate material, and is smaller than the inner diameter of the large-diameter recess. A finish forming punch having an outer diameter is pushed into the bottom surface of the large-diameter recess. As a result, a small-diameter concave portion is formed on the bottom surface of the large-diameter concave portion, and the metal material existing ahead in the pressing direction of the finish forming punch is moved forward in the pressing direction.

  In the case of carrying out the above-described method for manufacturing a metal member with an outward flange portion according to the present invention as described above, the finish forming die is preferably placed in a ram of a press device as in the invention described in claim 2. It comprises a one-side die that is supported so as to be movable up and down with respect to the ram and is given elasticity in the other axial direction by an elastic member, and another die that is supported by a support base of the press device. Then, the ram is displaced in the other axial direction, and the other side in the axial direction of the one-side die is elastically restrained on one side in the axial direction of the outward flange portion. The finish-forming punch is pushed into the bottom surface of the large-diameter recess by being displaced in the direction directed.

Preferably, as in the invention described in claim 3, in the rough forming step, the finish forming punch is simultaneously pressed against the bottom surface of the large-diameter concave portion (in the same process, instantaneously) (Including the case of back-and-forth), a plurality of circumferential positions on the other side surface in the axial direction of the outward flange portion are pressed by the seat surface forming punch. As a result, a seating surface is provided on the other side surface in the axial direction of the outward flange portion so that one side surface in the axial direction of the head of a coupling member (stud or the like) for supporting and fixing the wheel comes into contact.
In the case of carrying out the invention described in claim 3, preferably, as in the invention described in claim 4, the other-side die can be moved up and down with respect to the support table of the press device. It supports and gives the elasticity which turned to one axial direction by another elastic member. In addition, the other axial end of each seat surface forming punch is fixed to the support base, and one axial end is penetrated in a plurality of circumferential directions of the other die, and the other die is penetrated in the axial direction. It penetrates the through-hole provided in the state to do. Also, the elastic force directed to one axial direction applied to the other die by the another elastic member is made larger than the elastic force directed to the other axial direction applied to the one die by the elastic member.

  According to the method for manufacturing a metal member with an outward flange portion of the present invention configured as described above, a lightweight metal member with an outward flange portion is manufactured while preventing the occurrence of sink marks. For example, the outward flange portion is manufactured. The wheel bearing rolling bearing unit using the attached metal member as the hub body can be reduced in weight. That is, the amount of plastic deformation at the time of making the metal member with the outward flange portion can be increased by subjecting the metal material to plastic processing by the amount of the small diameter recess provided on the bottom surface of the large diameter recess portion. The amount of the metal material constituting the attached metal member can be reduced. Further, in the finish forming step for forming the small-diameter concave portion, the metal material existing ahead in the pressing direction of the finish forming punch moves forward in the pressing direction of the finish forming punch. Therefore, it is possible to prevent sink marks from occurring on the inner peripheral surface of the large-diameter recess. In the case of the present invention, the small diameter concave portion is obtained by subjecting the raw material to an intermediate material including the large diameter concave portion and the outward flange portion by subjecting the raw material to a rough molding step, and then subjecting the intermediate material to the finish molding step. Form. Therefore, it is possible to suppress the surface pressure applied to the dies (rough forming dies and finish forming dies) from being increased with processing, and to ensure the durability of the dies.

Sectional drawing which shows the 1st example of embodiment of this invention in process order. Sectional drawing which shows the state at the time of the lower surface of an upper die | dye, and the upper surface of a lower die | dye contact | abutted regarding the implementation condition of the finish molding process which processes a 2nd intermediate material into a 3rd intermediate material. Sectional drawing which shows the state which lowered | lowered the ram of the press apparatus similarly. Sectional drawing for demonstrating the problem of forming a large diameter recessed part and a small diameter recessed part simultaneously. Sectional drawing which shows the 2nd example of embodiment of this invention in order of a process. The same figure as FIG. Sectional drawing which shows the state which lowered | lowered the ram of the press apparatus and the elastic member provided between this ram and the upper surface of the upper side die was elastically deformed. Sectional drawing which shows the state which further lowered | lowered the ram of the said press apparatus rather than the state of FIG. Sectional drawing which shows an example of the rolling bearing unit for wheel support incorporating the hub main body used as the object of the manufacturing method of this invention. The end view (a) and side view (b) which show an example of the hub body known conventionally from the forging process by cold. The figure which showed the end surface shape about one part while showing the change of a side surface shape in order of a process regarding one example of the manufacturing method of the hub main body conventionally known. The figure which similarly shows the change of side surface shape thru | or cross-sectional shape. The perspective view which similarly shows the change of surface shape. Sectional drawing (A) for demonstrating the problem at the time of making the thickness of a cylindrical part small, and the X section enlarged view (B) of (A).

[First example of embodiment]
1 to 3 illustrate a first example of an embodiment of the present invention corresponding to claims 1 and 2. In the case of this example, first, in the pre-forming step, a forward extruding process is performed on the metal raw material 15a made of metal such as medium carbon steel shown in FIG. The preliminary intermediate material 27 corresponds to the material described in the claims in the stepped cylindrical shape shown in 1 (B). That is, the raw material 15a has a shape corresponding to the shape of the outer peripheral surface of the preliminary intermediate material 27 (a plurality of cylindrical surface portions having different inner diameters are provided, and adjacent cylindrical surface portions are continuous by step portions). The upper surface of the raw material 15a in the state of being set in a pre-molding die having a cylindrical surface shape) (the one axial end surface described in the claims, outside the hub body 9 after completion (see FIG. 9)) Press the preforming punch onto the side}. Thus, the preliminary intermediate material 27 is obtained by subjecting the raw material 15a to forward extrusion. The basic implementation status of such a preforming step is the same as the first forward extrusion process in the conventional manufacturing method shown in FIGS.

  In the next rough forming step, the preliminary intermediate material 27 is subjected to a side extrusion process to obtain the intermediate material 28 shown in FIG. That is, the preliminary intermediate material 27 is set in a split-type die (rough forming die) whose inner peripheral surface shape matches the outer peripheral surface shape of the intermediate material 28. A rough forming punch having an outer diameter smaller than the outer diameter of the upper surface of the preliminary intermediate material 27 is pushed into the upper surface. Thereby, the upper surface of the preliminary intermediate material 27 is recessed, and a large-diameter recess 29 is provided on the upper surface. At the same time, the metallic material constituting the preliminary intermediate material 27 is caused to flow radially outward, and the outer peripheral surface is radially outwardly positioned on the outer diameter side of the large-diameter recess 29 with respect to the axial direction. An outward flange portion 30 is provided in a protruding state. The basic implementation status of such a rough forming process is almost the same as the side extrusion process in the conventional manufacturing method. However, in the case of this example, the axial length of the small-diameter step 12a provided at the lower end of the intermediate material 28 is set to the axis of the small-diameter step 12 (see FIGS. 11 to 13) of the hub body 9a after completion. It is shorter than the direction length.

  Next, a finish forming step is performed on the intermediate material 28 to obtain a final intermediate material 31 shown in FIG. This finish forming step is performed using a press device 32 as shown in FIGS. The press device 32 includes an upper die 33, a lower die 34, a finish forming punch 35, and a counter punch 36. Of these, the upper die 33 is supported on the lower surface of the ram 37 of the press device 32 so as to be movable up and down with respect to the ram 37, and is directed downward by elastic members 38, 38 having a large elasticity such as compression coil springs. Has been given a great elasticity. The lowering amount of the upper die 33 relative to the ram 37 is regulated by abutting the upward step portion 39 on the ram 37 side and the downward step portion 40 on the upper die 33 side. On the other hand, the rising amount of the upper die 33 relative to the ram 37 is limited by abutting the lower surface of the block 41 provided on the lower surface of the ram 37 with the upper surface of the upper die 33. Accordingly, the upper die 33 moves up and down together with the ram 37 in a normal state. However, when a large upward force is applied, the upper die 33 resists the elasticity of the elastic members 38 and 38 and rises with respect to the ram 37. To do. The finish forming punch 35 is fixed to the ram 37 in a state of being disposed on the inner diameter side of the upper die 33. That is, the upper die 33 is supported around the finish molding punch 35 so as to be able to be displaced (lifted and lowered) in the axial direction by a predetermined amount with respect to the finish molding punch 35.

  On the other hand, the lower die 34 is fixed to the upper surface of the support base 42 of the press device 32. On the upper surface of the lower die 34, a lower cavity 43 having an inner surface shape corresponding to the outer peripheral surface shape of the lower half portion of the intermediate material 28 is opened. In addition, the counter punch 36 is substantially free of any gap in a state where an upward elasticity is applied in a cylindrical space 44 provided at the center of the lower die 34 (the counter punch 36). Even if there is a minute gap for enabling relative displacement between the punch 36 and the lower die 34, there should be a gap through which the metal material enters so as to cause burrs that may lead to deterioration of the material yield. Not) However, the counter punch 36 does not substantially interpose a gap in the cylindrical space 44 in a state where the tip end face is located at a predetermined position in the vertical direction (without applying upward elasticity). It can also be fitted inside. In this case, in the state where the intermediate material 28 is set in the lower cavity 43, an axial gap is interposed between the front end surface of the counter punch 36 and the lower end surface of the small diameter step portion 12a.

  In order to use the press device 32 having the above-described configuration and subject the intermediate material 28 to the finish forming step to obtain the final intermediate material 31, first, the lower half portion of the intermediate material 28 is the Set in the lower cavity 43. Then, by lowering the ram 37, the upper die 33 and the finish forming punch 35 are lowered. As shown in FIG. 2, the lower surface of the upper die 33 and the outward flange portion 30 of the intermediate material 28 are formed. The upper surface is brought into contact with the lower surface, and the lower surface of the finish forming punch 35 is brought into contact with the central portion of the bottom surface of the large-diameter concave portion 29 of the intermediate material 28. From this state, by further lowering the ram 37 and lowering the finish forming punch 35, the center of the bottom surface of the large-diameter recess 29 of the intermediate material 28 faces downward as shown in FIG. A small-diameter recess 45 is formed at the center of the bottom. At the same time, the metal material existing in the forward (downward) direction of the finish forming punch 35 is moved downward in the cylindrical space 44 against the elasticity applied to the counter punch 36, and the small diameter The length in the axial direction of the stepped portion 12a is increased so as to be substantially the same as the axial length of the small-diameter stepped portion 12 of the hub body 9 after completion (the same except for the machining allowance in finishing). At this time, the upper die 33 is displaced upward with respect to the ram 37 against the elastic force of the elastic members 38, 38 while holding the outward flange portion 30 downward. This prevents the lower surface of the outward flange portion 30 from floating from the lower die 34 as the finish molding punch 35 is pushed. Further, in the case of this example, since upward elasticity is applied to the counter punch 36, the lower end surface of the small diameter step portion 12a and the front end surface of the counter punch 36 from the initial stage of the finish forming step. Can be brought into contact. This is advantageous in terms of preventing damage such as cracking of the final intermediate material 31 in the finish forming step and ensuring the shape accuracy of the lower end portion of the small-diameter stepped portion 12. However, when the pressing force by the finish forming punch 35 is sufficiently large, the intermediate material 28 is set in the lower cavity 43 and the tip surface of the counter punch 36 and the lower diameter step portion 12a If a gap in the axial direction is interposed between the end face and the counter punch 36, it is not always necessary to apply upward elasticity to the counter punch 36.

  The final intermediate material 31 is taken out from the press device 32 by raising the counter punch 36 after raising the ram 37. Then, in order to externally fix the inner ring 10 to the small-diameter step portion 12a, a male screw portion is formed on the outer peripheral surface of the lower end portion (the inner end portion in the axial direction) of the small-diameter step portion 12a, or the small-diameter step is formed on the lower surface. A bottomed circular recess is formed for caulking and expanding the lower end of the portion 12a. Further, the hub main body 9 is subjected to predetermined cutting and grinding processes such as drilling for forming a circular hole for inserting the stud 19, deburring, and processing of the inner ring raceway 8 (see FIG. 9). To do.

According to the hub body manufacturing method of this example as described above, the lightweight hub body 9 (see FIG. 9) can be manufactured while preventing the occurrence of sink marks. That is, in the case of this example, in the process of forming the final intermediate material 31 by subjecting the columnar raw material 15a to plastic processing because the small diameter recess 45 is provided on the bottom surface of the large diameter recess 29 of the final intermediate material 31. By increasing the amount of plastic deformation, the amount of the metal material constituting the final intermediate material 31 can be reduced. For this reason, the hub main body 9, and hence the wheel bearing rolling bearing unit 1 (see FIG. 9) incorporating the hub main body 9 can be reduced in weight.
Further, since the amount of the metal material is reduced by providing the small-diameter concave portion 45, the thickness of the cylindrical portion 13a provided at the upper end portion (axially outer end portion) of the final intermediate material 31 becomes excessively small. You can prevent things. Further, in the case of this example, the finish forming punch 35 is pushed forward in the pushing direction of the finish forming punch 35 when the small diameter recessed portion 45 is formed by pushing the finish forming punch 35 into the center of the bottom surface of the large diameter recessed portion 29. The metal material moves in the cylindrical space 44 of the lower die 34 downward toward the front of the finish forming punch 35 in the pressing direction. Therefore, it is possible to prevent sink marks from occurring on the inner peripheral surface of the large-diameter recess 29.

  Further, the preliminary intermediate material 27 is subjected to a rough forming process to form the intermediate material 28 having the large-diameter concave portion 29 and the outward flange portion 30, and then the intermediate material 28 is subjected to a finish forming step to thereby form the small-diameter concave portion. 45, the press device 32 can be prevented from being increased in size, and dies (rough forming dies used in the rough forming process and upper dies used in the finish forming process) in connection with processing. 33 and the lower die 34) can be prevented from increasing the surface pressure, and the durability of the die can be ensured. The reason for this will be described with reference to FIG. By pressing a stepped cylindrical pressing punch into the upper surface of the preliminary intermediate material 27, the outward flange portion 30, the large-diameter concave portion 29a and the small-diameter concave portion 45a are simultaneously formed (within the same process), and the final intermediate material 31a is formed. In the final step of pushing, the metal material constituting the preliminary intermediate material 27 is formed rearward in the pushing direction of the pressing punch toward the outward flange portion 30 by forming the small-diameter recess 45a. Move to. For this reason, the load required to push the pressure punch is increased, the press device is increased in size, and the surface pressure applied to the die arranged around the preliminary intermediate material 27 is increased at the time of processing, and the durability of the die is increased. It becomes difficult to secure sex. On the other hand, in the case of this example, since the large-diameter concave portion 29 and the outward flange portion 30 and the small-diameter concave portion 45 are formed in separate steps, the load required for the formation can be reduced. As a result, it is possible to prevent the press device 32 from being increased in size and to ensure the durability of the die used for processing.

[Second Example of Embodiment]
FIGS. 5-8 has shown the 2nd example of embodiment of this invention corresponding to Claims 1-4. In the case of this example, in the finishing forming step shown in FIGS. 5C to 5D, the small-diameter concave portion 45 is formed, the axial length of the small-diameter stepped portion 12a is increased, and the outward flange portion 30a. Seat surfaces 21 and 21 for abutting the outer surface of the head 20 (see FIG. 9) of the stud 19 are formed at a plurality of positions in the circumferential direction on the lower surface (the inner surface in the axial direction) of the stud 19. For this reason, a press device 32a as shown in FIGS. 6 to 8 is used in the finish forming step of the manufacturing method of the hub body of this example. The pressing device 32 a includes an upper die 33, a lower die 34 a, a finish forming punch 35, a counter punch 36, and seat surface forming punches 46 and 46. Of these, the upper die 33 is supported on the lower surface of the ram 37 of the press device 32a so as to be movable up and down with respect to the ram 37, as in the case of the first example of the embodiment described above. The elastic members 38, 38 having a large elasticity are given a large elasticity facing downward. The finish forming punch 35 is fixed to the ram 37 in a state of being disposed on the inner diameter side of the upper die 33.

  On the other hand, the lower die 34a is supported on the upper surface of the support base 42 of the press device 32a so as to be movable up and down with respect to the support base 42, and by elastic members 47 and 47 having a large elasticity such as a compression coil spring, Large elasticity is given upwards. In the case of this example, the upward elasticity given to the lower die 34a by each of the elastic members 47, 47 is greater than the downward elasticity given to the upper die 33 by the elastic members 38, 38. It is getting bigger. The rising amount of the lower die 34a with respect to the support base 42 is regulated by abutting the downward step portion 48 of the support base 42 and the upward step portion 49 of the lower die 34a. The counter punch 36 is fitted into a cylindrical space 44 provided at the center of the lower die 34a with substantially upward elasticity with no upward gap. ing. Further, each of the seat surface forming punches 46 and 46 fixes the lower end portion to the upper surface of the support base 42 of the press device 32a, and the upper end portion of the cylindrical space 44 in the lower die 34a. In the periphery, it fits in the through-holes 50 and 50 provided in the state which penetrates this lower die 34a to an up-down direction, substantially without interposing a clearance gap.

  In order to use the press device 32a having the above-described configuration and subject the intermediate material 28 to the finish forming step to obtain the final intermediate material 31a having the seating surfaces 21, 21, first, the intermediate material 28 is used. Is set in the lower cavity 43 opened on the upper surface of the lower die 34a. Then, by lowering the ram 37, the upper die 33 and the finish forming punch 35 are lowered, and the lower surface of the upper die 33 and the outward flange portion 30 of the intermediate material 28 as shown in FIG. And the bottom surface of the finish molding punch 35 and the center of the bottom surface of the large-diameter recess 29 of the intermediate material 28 are brought into contact with each other. From this state, by further lowering the ram 37 and lowering the finish forming punch 35, a small-diameter recess 45 is formed at the center of the bottom surface of the large-diameter recess 29 of the intermediate material 28 as shown in FIG. Simultaneously with the formation, the metal material existing in front of the finish forming punch 35 in the pushing direction is moved downward in the cylindrical space 44, and the axial length of the small-diameter step portion 12 a provided at the lower end portion of the intermediate material 28. Increase the length. At this time, the upper die 33 is displaced upward with respect to the ram 37 against the elastic force of the elastic members 38, 38 while holding the outward flange portion 30a downward. In the case of this example, since the elasticity of each elastic member 47, 47 is larger than the elasticity of each elastic member 38, 38, it is provided on the upper surface of the upper die 33 and the lower surface of the ram 37. Until the lower surface of the block 41 comes into contact, the lower die 34a is not lowered. That is, the steps up to here are the same as the finish forming step of the first example of the embodiment.

When the ram 37 is further lowered from the state in which the upper surface of the upper die 33 and the lower surface of the block 41 are in contact with each other, as shown in FIG. It is displaced downward against the elasticity of 47 and 47. As a result, the lower surface of the outward flange portion 30a is pressed by the respective seat surface forming punches 46 and 46, and the respective seat surfaces 21 and 21 are formed in the corresponding portions, thereby forming the final intermediate material 31a.
According to this example, since the sizing process for forming the respective seating surfaces 21 and 21 can be performed in the finish molding process, the production efficiency can be improved. Further, since upward elasticity is applied to the lower die 34a, while the respective seat surface forming punches 46 and 46 are pressing the lower surface of the outward flange portion 30a, the outward flange portion 30a The outer peripheral surface and the lower surface can be constrained, and the shape of the outward flange portion 30a can be prevented from collapsing. The configuration and operation of the other parts are the same as in the first example of the embodiment described above.

DESCRIPTION OF SYMBOLS 1 Rolling bearing unit for wheel support 2 Outer ring 3 Hub 4 Rolling body 5 Outer ring raceway 6 Stationary side flange 7, 7a Rotation side flange 8 Inner ring raceway 9, 9a Hub body 10 Inner ring 11 Nut 12, 12a Small diameter step part 13 Cylindrical part 14 Recessed part 15, 15a Raw material 16 First intermediate material 17 Second intermediate material 18 Third intermediate material 19 Stud 20 Head 21 Seat surface 22 Fourth intermediate material 23 Recessed hole 24 Cylindrical portion 25 Fifth intermediate material 26 Sink 27 Preliminary intermediate material 28 Intermediate material 29 Large diameter recess 30, 30a Outward flange portion 31, 31a Final intermediate material 32, 32a Press device 33 Upper die 34, 34a Lower die 35 Finish molding punch 36 Counter punch 37 Ram 38 Elastic member 39 Upper step 40 downward step 41 block 42 support base 43 lower cavity 4 Cylindrical space 45 punch small diameter recess 46 seating surface formed 47 elastic member 48 downward stepped portion 49 upward stepped portion 50 through hole

Claims (4)

A large-diameter recess provided in the center of one axial end surface;
Outward flange portion provided in a state of projecting radially outward in a portion located on the outer diameter side of the large-diameter concave portion in the axial direction in the outer peripheral surface;
A metal member with an outward flange portion comprising a metal member with an outward flange portion made by subjecting a metal material to plastic working,
An outer diameter smaller than the outer diameter of one end surface in the axial direction of the material is disposed around the material with a rough forming die provided with a cavity for forming the outward flange portion for processing the outward flange portion. A rough forming step of making the intermediate material provided with the large-diameter concave portion and the outward flange portion by pushing a rough forming punch having one end surface in the axial direction of the material;
A finish molding punch having an outer diameter smaller than the inner diameter of the large-diameter concave portion in a state where the intermediate material is disposed in a finish molding die having an inner peripheral surface commensurate with the outer peripheral surface shape of the intermediate material. By pushing into the bottom surface of the large-diameter concave portion, a small-diameter concave portion is formed on the bottom surface of the large-diameter concave portion, and the metal material existing in the forward direction of the finish forming punch is moved toward the front in the indentation direction. A method for producing a metal member with an outward flange portion, comprising: a finish forming step. The finish forming die is supported by the ram of the press device so as to be movable up and down with respect to the ram, and is supported by a one-side die that is given elasticity in the other axial direction by an elastic member, and a support base of the press device. It consists of the other side die,
The ram is displaced in the other axial direction, and the ram is further displaced in the other axial direction while the other axial side surface of the one-side die is elastically restrained on one axial side surface of the outward flange portion. The manufacturing method of the metal member with an outward flange part according to claim 1, wherein the finish forming punch is pushed into the bottom surface of the large-diameter recess.   In the rough forming step, the finish forming punch is pressed against the bottom surface of the large-diameter concave portion, and simultaneously, a plurality of circumferential positions on the other axial side surface of the outward flange portion are pressed by the seat surface forming punch. The seating surface for abutting the one axial side surface of the head of the coupling member for supporting and fixing the wheel is provided on the other axial side surface of the outward flange portion. The manufacturing method of the metal member with an outward flange part described in 1 item | term. The other side die is supported on the support base of the press device so as to be movable up and down with respect to the support base, and an elastic force directed to one axial direction is given by another elastic member,
A state in which the other axial end portion of each seating surface forming punch is fixed to the support base, and one axial end portion is penetrated in the circumferential direction of the other die and the other die is penetrated in the axial direction. Inserted through the through-hole
3. The elastic force directed to one axial direction applied to the other die by the another elastic member is made larger than the elastic force directed to the other axial direction applied to the one die by the elastic member. The manufacturing method of the metal member with an outward flange part described in Claim 3 quoted.

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