Manufacturing method of ring member for bearing

Abstract

To provide a manufacturing method of a ring member for a bearing which can manufacture a ring member for a bearing having high strength.SOLUTION: A manufacturing method of a ring member for a bearing includes, in a written order, a preparation step in which a workpiece member 3 having a toric workpiece main part 31, an inner flange part 32 extending from an inner edge of the workpiece main part 31 to the first side SA, and an outer flange part 33 extending from an outer edge of the workpiece main part 31 to the first side SA is prepared, a thickness increasing step in which the inner flange part 32 and the outer flange part 33 are sandwiched in an axial direction by a thickness increasing punch 54 and a thickness increasing die main part 53 to increase thicknesses of the inner flange part 32 and the outer flange part 33 so that the thicknesses of the inner flange part 32 and the outer flange part 33 in a radial direction become thickner than a thickness of the workpiece main part 31 in the axial direction; and an inversion step in which the workpiece member 3A is sandwiched in the axial direction by an inversion punch and an inversion die to invert the workpiece member 3A so that the workpiece main part 31 is formed into a cylindrical shape.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a bearing ring member. [Background technology]

[0002] Patent Document 1 describes a method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges. In this manufacturing method, a bearing shell member (bearing ring member) is manufactured through a reversal process in which a work member having an annular work body and a pair of work flanges is sandwiched between a punch and a die and deformed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-36186 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-described bearing ring members may be required to have increased strength. Therefore, an object of the present invention is to provide a method for manufacturing a bearing ring member that can produce a bearing ring member having high strength. [Means for solving the problem]

[0005] The manufacturing method of a ring member for a bearing of the present invention is [1] "a manufacturing method of a ring member for a bearing, comprising, in this order: a preparation step of preparing a work member having an annular work main body portion, an inner flange portion extending radially from an inner edge of the work main body portion to one side in the axial direction, and an outer flange portion extending radially from an outer edge of the work main body portion to the one side in the axial direction; a thickening step of sandwiching the inner flange portion and the outer flange portion in the axial direction between a thickening punch and a thickening die, and performing a thickening process to increase the thickness of the inner flange portion and the outer flange portion so that the thickness of the inner flange portion and the outer flange portion in the radial direction is thicker than the thickness of the work main body portion in the axial direction; and an inversion step of sandwiching the work member axially between a reversing punch and a reversing die, and inverting the work member so that the work main body portion becomes cylindrical."

[0006] In this method for manufacturing a bearing ring member, the thicknesses of the inner and outer flange portions are increased in the thickening process so that they are thicker than the workpiece body, and the workpiece is then inverted in the inversion process. As a result, the thickness of the pair of flange portions in the manufactured bearing ring member is thicker than the body. As a result, the strength of the bearing ring member can be increased. That is, for example, if a bearing ring member with a uniform overall thickness is manufactured by simply inverting a plate workpiece, the resulting bearing ring member may not have sufficient strength. In contrast, this method for manufacturing a bearing ring member can manufacture a bearing ring member in which the thickness of the pair of flange portions is thicker than the body, thereby increasing the strength of the bearing ring member. Thus, this method for manufacturing a bearing ring member can manufacture a bearing ring member with high strength. The finding that inversion can be performed well even when the inner and outer flange portions are made thicker than the workpiece body by thickening processing is a finding discovered by the present inventor based on the analysis described below.

[0007] This manufacturing method of a bearing ring member may be [2] "the manufacturing method of a bearing ring member according to [1], wherein the preparation step includes a burring step of obtaining the work member by performing a burring process in which an annular processed member disposed on an inner die and an outer die so as to span between the inner die and the outer die is deformed by a burring punch that moves so as to enter between the inner die and the outer die." In this case, a work member having an annular work main body portion, an inner flange portion, and an outer flange portion can be obtained from the annular processed member.

[0008] This manufacturing method for a bearing ring member may be [3] "the manufacturing method for a bearing ring member according to [1] or [2], wherein in the thickening step, the thickening process is carried out while pressing the workpiece main body from the one side in the axial direction with a pressing member." In this case, the thicknesses of the inner flange portion and the outer flange portion can be increased while suppressing an increase in the thickness of the workpiece main body.

[0009] The method for manufacturing a bearing ring member of the present invention may be [4] "the method for manufacturing a bearing ring member according to any one of [1] to [3], wherein in the thickness increasing step, the thickness of each of the inner flange portion and the outer flange portion is increased so that the thickness of each of the inner flange portion and the outer flange portion is 1.2 to 3 times the thickness of the work body portion." In this case, the strength of the bearing ring member can be further increased.

[0010] The method for manufacturing a bearing ring member of the present invention may be [5] "the method for manufacturing a bearing ring member according to [2], wherein the shape of the burring dies including the inner die and the outer die used in the burring step is the same as the shape of the thickening dies used in the thickening step." In this case, the burring dies and the thickening dies are interchangeable, thereby reducing costs.

[0011] The manufacturing method of this bearing ring member is [6] "A manufacturing method of a bearing ring member, comprising the steps of: (1) a first process, (2) a second process, and (3) a third process using a common punch and die; (1) a first process in which a first work member having a circular first work body portion is sandwiched between the punch and the die in the axial direction, and the first work member is inverted so that the first work body portion becomes cylindrical, thereby forming a bearing ring member; (2) a second process in which a second work member having a circular second work body portion is sandwiched between the punch and the die in the axial direction, and the second work member is inverted so that the second work body portion becomes cylindrical; (2) a second process for forming a bearing ring member by bending a workpiece body; and (3) a third process for forming a bearing ring member by axially sandwiching a third workpiece member having a circular third workpiece body between the punch and the die, bending the third workpiece body, and inverting the third workpiece member so that the third workpiece body becomes cylindrical, wherein the inner diameter of the first workpiece body used in the first process is larger than the inner diameters of the second workpiece body and the third workpiece body used in the second and third processes. In this method for manufacturing a bearing ring member, a bearing ring member can be manufactured by at least two of the first process, the second process, and the third process using a common punch and die, and a plurality of different bearing ring members can be manufactured using a single set of punch and die. Note that the finding that different processes, the first process, the second process, and the third process, can be performed using a common punch and die by changing the inner diameter of the workpiece body, is a finding discovered by the inventor based on the analysis described below. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a method for manufacturing a bearing ring member that can manufacture a bearing ring member having high strength. [Brief explanation of the drawings]

[0013] [Figure 1]1 is a cross-sectional view of a cylindrical roller bearing manufactured by a method for manufacturing a bearing ring member according to a first embodiment. [Figure 2] 3 is a flowchart showing a method for manufacturing a bearing ring member according to the first embodiment. [Figure 3] FIG. 10 is a diagram illustrating a punching process. [Figure 4] 10(a), (b), (c) and (d) are cross-sectional views for explaining the burring step. [Figure 5] 10(a), (b) and (c) are cross-sectional views for explaining the thickness increasing step. [Figure 6] 5(a), (b) and (c) are cross-sectional views illustrating the inversion step of forming the inner ring. [Figure 7] 5(a), (b), and (c) are cross-sectional views illustrating the inversion step of forming the outer ring. [Figure 8] 10(a) and 10(b) are cross-sectional views for explaining factors in the reversal process. [Figure 9] This is an orthogonal table in which the extracted factors are assigned. [Figure 10] 10 is a graph showing the contribution rate of each factor to reversal processing. [Figure 11] FIG. 4 is a cross-sectional view of a ball bearing manufactured by a second process. [Figure 12] 10 is a flowchart showing a second machining process. [Figure 13] 12(a), (b), and (c) are cross-sectional views illustrating the bending step of FIG. 11 when forming an outer ring. [Figure 14] 12(a) and 12(b) are cross-sectional views for explaining the correction step of FIG. 11. [Figure 15] 12(a), (b), and (c) are cross-sectional views illustrating the bending step of FIG. 11 when forming an inner ring. [Figure 16] 10 is a flowchart showing a third machining process. [Figure 17] 1(a), (b), (c), (d) and (e) are cross-sectional views for explaining the bending and inversion process. [Figure 18]FIG. 10 is a perspective view of a workpiece used in another example of the third machining process. [Figure 19] FIG. 10 is a perspective view of a radial cage manufactured by another example of the third process. [Figure 20] 10(a), (b), (c) and (d) are cross-sectional views illustrating a bending and inverting step in another example of the third processing. [Figure 21] 10(a), (b) and (c) are cross-sectional views for explaining bending and reversing steps in another processing example. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted. [First embodiment]

[0015] The rolling bearing 1 shown in Fig. 1 comprises a plurality of rolling elements 11, an outer ring (bearing ring member) 12, and an inner ring (bearing ring member) 13. In this example, the rolling bearing 1 is configured as a cylindrical roller bearing. The outer ring 12 is a bearing ring member used as the outer ring of the rolling bearing 1. The outer ring 12 has a center axis CL. The outer ring 12 has an outer ring body 121 and a pair of outer ring flanges 122. The outer ring body 121 is formed in a cylindrical shape and has a raceway surface 121a on its radially inner side.

[0016] The pair of outer ring flanges 122 extend radially inward from both axial ends of the outer ring body 121. That is, one outer ring flange 122 protrudes radially inward from one axial end of the outer ring body 121, and the other outer ring flange 122 protrudes radially inward from the other axial end of the outer ring body 121. The thickness T2 (axial length) of the outer ring flange 122 is thicker than the thickness T1 (radial length) of the outer ring body 121. The thickness T1 (maximum thickness) of the outer ring body 121 is, for example, approximately 0.5 mm or more and 3 mm or less. The thickness T2 of the outer ring flange 122 is, for example, 1.2 times or more and 3 times or less the thickness T1 of the outer ring body 121.

[0017] The inner ring 13 is a bearing ring member used as the inner ring of the rolling bearing 1. The inner ring 13 has a central axis common with the central axis CL of the outer ring 12. The inner ring 13 has an inner ring main body 131 and a pair of inner ring flanges 132. The inner ring main body 131 is formed in a cylindrical shape and has a raceway surface 131a on the radially outer side.

[0018] The pair of inner ring flanges 132 extend radially outward from both axial ends of the inner ring body 131. That is, one inner ring flange 132 protrudes radially outward from one axial end of the inner ring body 131, and the other inner ring flange 132 protrudes radially outward from the other axial end of the inner ring body 131. The thickness T2 of the inner ring flanges 132 is thicker than the thickness T1 of the inner ring body 131. The thickness T1 (maximum thickness) of the inner ring body 131 is, for example, approximately 0.5 mm or more and 3 mm or less. The thickness T2 of the inner ring flanges 132 is, for example, 1.2 times or more and 3 times or less the thickness T1 of the inner ring body 131.

[0019] In this example, each rolling element 11 is a cylindrical roller. The multiple rolling elements 11 are lined up in the circumferential direction. The multiple rolling elements 11 are held, for example, by a cage (not shown) so that the intervals between adjacent rolling elements 11 in the circumferential direction are constant. When the rolling bearing 1 is in use, each rolling element 11 rolls on the raceway surface 121a and the raceway surface 131a on its outer circumferential surface. Note that although FIG. 1 shows one cross section perpendicular to the circumferential direction, the rolling bearing 1 has a uniform shape in the circumferential direction.

[0020] In the method for manufacturing a bearing ring member according to the first embodiment, the outer ring 12 and the inner ring 13 are manufactured as ring members. However, the outer ring 12 may be manufactured by further processing the ring members. Similarly, the inner ring 13 may be manufactured by further processing the manufactured ring member.

[0021] As shown in Fig. 2, the method for manufacturing a bearing ring member according to the first embodiment includes, in this order, a punching step S1, a burring step S2, a thickness increasing step S3, and an inversion step S4. As shown in Fig. 3, in the punching step S1, first, a disk-shaped member is punched out to obtain an annular disk-shaped processed member 2.

[0022] Next, as shown in FIG. 4, in the burring step S2, the workpiece 2 is subjected to burring. In the burring step S2, first, as shown in FIG. 4(a), the workpiece 2 is placed on an inner die 41 and an outer die 42 that are arranged apart from each other, so as to be bridged between the inner die 41 and the outer die 42. The inner die 41 has a cylindrical shape. The outer die 42 has a cylindrical shape that surrounds the inner die 41. The height (axial position) of the upper surface of the inner die 41 and the height (axial position) of the upper surface of the outer die 42 are, for example, the same. The lower ends of the inner die 41 and the outer die 42 are connected to each other by a connecting portion 40. The upper surface of the connecting portion 40 is flat. The inner die 41, the outer die 42, and the connecting portion 40 constitute a burring die 46 used as a die in the burring step S2.

[0023] Next, as shown in Figures 4(b), 4(c), and 4(d), the burring punch 43 moves to enter between the inner die 41 and the outer die 42, thereby changing the cross-sectional shape of the processed member 2 from a circular plate shape to an approximately U-shape, and a work member 3 is obtained.

[0024] The workpiece 3 has an annular workpiece main body 31, and an inner flange 32 and an outer flange 33 extending from the workpiece main body 31. The inner flange 32 extends from the inner edge of the workpiece main body 31 in the radial direction to a first side SA (upper side in FIG. 4) in the axial direction. The outer flange 33 extends from the outer edge of the workpiece main body 31 in the radial direction to the first side SA in the axial direction.

[0025] More specifically, in the burring step S2, a deformation suppression member 44 is used to contact the workpiece 2 from the side opposite the burring punch 43. The workpiece 2 is sandwiched between the burring punch 43 and the deformation suppression member 44, and burring is performed. That is, in the burring step S2, burring is performed using the burring punch 43 and the burring die 46. The deformation suppression member 44 has a spring 44a extending upward from the connecting portion 40, and as the burring punch 43 moves, the deformation suppression member 44 moves while maintaining the workpiece 2 sandwiched between the burring punch 43 and the deformation suppression member 44. As a result, the workpiece 2 is constantly biased upward. In the state shown in FIG. 4(d) where the burring punch 43 has entered between the inner die 41 and the outer die 42, the amount of contraction of the spring 44a is greater than in the state shown in FIG. 4(a) before the burring punch 43 moves, and the biasing force acting on the workpiece 2 is therefore greater. During burring, the processed member 2 is tightly clamped, but the deformation suppression member 44 functions as a cushion to prevent the processed member 2 (workpiece member 3) from bending at the location pressed by the burring punch 43. Therefore, the biasing force of the spring 44a is preferably strong enough to prevent the portion of the processed member 2 corresponding to the workpiece main body 31 from bending during burring.

[0026] As described above, in the manufacturing method of a bearing ring member according to the first embodiment, the punching step S1 and the burring step S2 are performed to prepare the work member 3. In other words, the manufacturing method of a bearing ring member according to the first embodiment includes the punching step S1 and the burring step S2 as preparation steps for preparing the work member 3.

[0027] Following the burring step S2, as shown in Fig. 5, in the thickening step S3, the workpiece member 3 is subjected to a thickening process. In the thickening step S3, the thickening process is performed using a thickening punch 54 and a thickening die 56. The thickening die 56 has a thickening inner die 51, a thickening outer die 52, and a thickening die main body 53.

[0028] In this embodiment, the shape of the thickening inner die 51 is the same as the shape of the inner die 41 of the burring die 46, and the shape of the thickening outer die 52 is the same as the shape of the outer die 42 of the burring die 46. Furthermore, the shape of the thickening die main body 53 is the same as the shape of the connecting portion 40 of the burring die 46. That is, the shape of the thickening die 56 (thickening inner die 51, thickening outer die 52, and thickening die main body 53) used in the thickening step S3 is the same as the shape of the burring die 46 (inner die 41, outer die 42, and connecting portion 40) used in the burring step S2.

[0029] In this way, when the thickening die 56 has the same shape as the burring die 46, the burring die 46 used in the burring step S2 may be used as the thickening die 56 in the thickening step S3. Conversely, the thickening die 56 to be used in the thickening step S3 may be used as the burring die 46 in the burring step S2. That is, the burring die 46 and the thickening die 56 may be common (one die). Alternatively, a thickening die 56 may be prepared separately from the burring die 46 used in the burring step S2, and the thickening step S3 may be performed using the thickening die 56.

[0030] 5(a), in the thickening step S3, first, the workpiece 3 is placed between a thickening inner die 51 and a thickening outer die 52 that are arranged at a distance from each other. The workpiece 3 is sandwiched in the axial direction between a thickening die body 53 that connects the thickening inner die 51 to the thickening outer die 52, and a thickening punch 54 that is spaced apart from the thickening die body 53 in the axial direction.

[0031] The thickening punch 54 is disposed on the first side SA relative to the thickening die body 53. The thickening die body 53 may be integrated with or separate from the thickening inner die 51 and the thickening outer die 52. The thickening punch 54 has a U-shaped cross section that opens toward the second side SB. The thickening punch 54 has an inner flange 54a that contacts the inner flange 32, an outer flange 54b that contacts the outer flange 33, and a connecting portion 54c that connects the inner flange 54a to the outer flange 54b.

[0032] In the thickening step S3, the workpiece 3 is sandwiched in the axial direction between the thickening punch 54 and the thickening die body 53, thereby increasing the thickness of the inner flange 32 and the outer flange 33 so that the radial thickness of the inner flange 32 and the outer flange 33 is greater than the axial thickness of the workpiece body 31. Specifically, the inner flange 32 and the outer flange 33 are compressed in the axial direction, thereby increasing their thickness.

[0033] In the thickening step S3, the workpiece main body 31 is pressed from the first side SA by the pressing member 55, while the thickening process is performed. In other words, the workpiece 3 is sandwiched between the thickening punch 54, the pressing member 55, and the thickening die main body 53, while the thickening process is performed. The pressing member 55 has a spring 55a and a main body 55b, and the main body 55b is biased toward the second side SB by the spring 55a. The main body 55b has a cross-sectional shape corresponding to the cross-sectional shape of the workpiece 3. The main body 55b has a U-shaped cross section that opens toward the first side SA.

[0034] The main body portion 55b has an inner flange 55c extending along the inner flange portion 32 and an outer flange 55d extending along the outer flange portion 33. As shown in FIG. 5(a), before the thickening process, the distance between the inner flange 55c and the thickening inner die 51 is longer than the thickness of the inner flange portion 32. The inner flange portion 32 is located between the inner flange 55c and the thickening inner die 51. Before the thickening process, the distance between the outer flange 55d and the thickening outer die 52 is longer than the thickness of the outer flange portion 33. The outer flange portion 33 is located between the outer flange 55d and the thickening outer die 52.

[0035] 5(b) and 5(c), when the thickening punch 54 moves toward the second side SB (descending), the inner flange portion 32 is sandwiched axially between the inner flange portion 54a and the thickening die body portion 53, and the outer flange portion 33 is sandwiched axially between the outer flange portion 54b and the thickening die body portion 53. As the thickening punch 54 descends, the volume of the space defined by the thickening die body portion 53, the inner flange portion 54a, the thickening inner die 51, and the inner flange 55c decreases, and the inner flange portion 32 deforms to fill the space. Similarly, as the thickening punch 54 descends, the volume of the space defined by the thickening die body portion 53, the outer flange portion 54b, the thickening outer die 52, and the outer flange 55d decreases, and the outer flange portion 33 deforms to fill the space. This increases the thickness of the inner flange portion 32 and the outer flange portion 33, making the radial thickness of the inner flange portion 32 and the outer flange portion 33 thicker than the axial thickness of the workpiece main body 31. The biasing force of the spring 55a is set to a strength that prevents the thickness of the workpiece main body 31 from changing during thickening processing. Note that the spring 55a may be omitted, and a cushion member may be placed between the thickening die main body 53 and the workpiece main body 31.

[0036] In the thickness increasing step S3, for example, the thicknesses of the inner flange portion 32 and the outer flange portion 33 are increased so that each of the inner flange portion 32 and the outer flange portion 33 is 1.2 to 3 times the thickness of the workpiece main body 31. Note that in the thickness increasing step S3, the thicknesses of the inner flange portion 32 and the outer flange portion 33 may be increased so that each of the inner flange portion 32 and the outer flange portion 33 is thicker than the thickness of the workpiece main body 31 but less than 1.2 times the thickness of the workpiece main body 31. Alternatively, in the thickness increasing step S3, the thicknesses of the inner flange portion 32 and the outer flange portion 33 may be increased so that each of the inner flange portion 32 and the outer flange portion 33 is more than three times the thickness of the workpiece main body 31.

[0037] Following the thickening step S3, as shown in Figure 6, in the reversing step S4, the workpiece member 3 is sandwiched between a punch 61 and a die 62 along the axial direction, and reversing processing is performed to deform the workpiece member 3 so that the workpiece main body 31 becomes cylindrical. At the start of the reversing step S4, first, as shown in Figure 6(a), the punch 61 (reversing punch) is arranged on the first side SA relative to the die 62 (reversing die), and the die 62 is arranged on the second side SB relative to the punch 61. When viewed in the axial direction, the punch 61 has a cylindrical shape, and the die 62 has a cylindrical shape and surrounds the punch 61.

[0038] The punch 61 has a punch body 61b formed in a substantially cylindrical shape with an axis parallel to the axial direction, and a punch protrusion 61a formed at the end of the first side SA of the punch body 61b and protruding radially inward from the punch body 61b. An R-surface 61c is formed on the inner edge of the second side SB of the punch body 61b. The R-surface 61c is a curved surface formed by rounding the corners of the second side SB of the punch body 61b, and is formed in an arc shape in a cross section parallel to the axial direction (FIG. 6). The die 62 has a die body 62b formed in a substantially cylindrical shape with an axis parallel to the axial direction, and a die protrusion 62a formed at the end of the second side SB of the die body 62b and protruding radially outward from the die body 62b. The R-surface 62c is formed on the outer edge of the first side SA of the die body 62b. The R surface 62c is a curved surface formed by rounding the corners of the first side SA of the die body 62b, and is formed in an arc shape in a cross section parallel to the axial direction (FIG. 6).

[0039] At the start of the reversing step S4, the workpiece 3A is placed on the die 62 with the workpiece main body 31 of the workpiece 3A in contact with the upper surface of the die 62. Then, for example, by moving (lowering) the punch 61 along the axial direction to approach the die 62, the workpiece 3A is sandwiched between the punch 61 and the die 62 in the axial direction, and the workpiece 3A is deformed so that it rises outward in the radial direction ( FIG. 6( b) ). That is, in the reversing step S4, the workpiece 3A is deformed so that the surface 31 a of the workpiece 3A facing the punch 61 side (first side SA) before the reversing step S4 faces outward in the radial direction after the reversing step S4, and the inner ring 13 is formed.

[0040] In this way, in the inversion process S4, the workpiece member 3A (first workpiece member) having a circular workpiece main body portion 31 (first workpiece main body portion) is clamped axially between the punch 61 and the die 62, and the workpiece member 3A is inverted so that the workpiece main body portion 31 becomes cylindrical, thereby forming the inner ring 13.

[0041] In the reversing step S4, as shown in Fig. 7, the workpiece member 3 may be subjected to reversing processing to form the outer ring 12. The reversing step S4 for forming the outer ring 12 differs from the reversing step S4 for forming the inner ring 13 in that a punch 63 (reversing punch) and a die 64 (reversing die) are used instead of the punch 61 and the die 62. When viewed in the axial direction, the die 64 has a cylindrical shape, and the punch 63 has a cylindrical shape and surrounds the die 64.

[0042] At the start of the reversing step S4, the workpiece 3 is placed on the die 64 with the workpiece main body 31 of the workpiece 3 in contact with the upper surface of the die 64. Then, for example, by lowering the punch 63 and bringing it closer to the die 64, the workpiece 3A is sandwiched axially between the punch 63 and the die 64, and the workpiece 3A is deformed so that it rises radially inward (FIG. 7(b)). That is, in the reversing step S4, the workpiece 3A is deformed so that the surface 31a faces radially inward after the reversing step S4, and the outer ring 12 is formed.

[0043] In this way, in the inversion process S4, the outer ring 12 may be formed by clamping the workpiece member 3A having a circular workpiece main body portion 31 axially between a punch 63 and a die 64, and inverting the workpiece member 3A so that the workpiece main body portion 31 becomes cylindrical. [Analysis by experimental design]

[0044] The finding that the reversal process S4 can be performed well even when the inner flange portion 32 and the outer flange portion 33 are thicker than the workpiece main body portion 31 is a finding discovered by the present inventor based on the following analysis. As will be explained below, in this analysis, data sets were set using an experimental design method, and 3D-CAE analysis was performed on each data set.

[0045] The factors shown in Figures 8(a) and 8(b) were extracted as factors that affect the reversing process in the reversing step S4. In Figure 8(a), h is the radial width of the workpiece. t is the axial length of the workpiece body of the workpiece, i.e., the thickness. b is the axial length of the flange of the workpiece. In Figure 8(b), r is the inner diameter of the workpiece. R1 is the radius of curvature of the R-surface of the die. R2 is the radius of curvature of the R-surface of the punch. f is the protrusion amount of the punch protrusion relative to the punch body.

[0046] Next, the extracted factors were assigned to an orthogonal array as shown in Figure 9, and eight data sets, No. 1 to No. 8, were created (using the experimental design method). In Figure 9, the "1" and "2" in the control factor columns "h," "t," "b," "r," "R1," "R2," and "f" indicate the level at which each control factor was set in each data set. For the first level of width h, the width h was set to 60 mm. For the second level of width h, the width h was set to 50 mm. For the first level of thickness t, the thickness t was set to 2 mm. For the second level of thickness t, the thickness t was set to 3 mm. For the first level of length b, the length b was set to 6 mm. For the second level of length b, the length b was set to 9 mm. For the first level of inner radius r, the inner radius r was set to 120 mm. For the second level of inner radius r, the inner radius r was set to 130 mm. For the first level of curvature radius R1, the curvature radius R1 was set to 10 mm. In the second level of curvature radius R1, curvature radius R1 was set to 15 mm. In the first level of curvature radius R2, curvature radius R2 was set to 2 mm. In the second level of curvature radius R2, curvature radius R2 was set to 4 mm. In the first level of length f, length f was set to 1 mm. In the second level of length f, length f was set to 0.5 mm. Note that although the curvature radius R1 in No. 6 is set to the first level in a normal orthogonal array, it was performed at the second level, so this analysis was conducted at the second level.

[0047] Next, each of the eight data sets was analyzed using 3D-CAE to evaluate whether the workpiece could be successfully inverted during inversion. In Nos. 4, 6, and 8, the workpiece was successfully inverted during inversion. In Nos. 5 and 7, the workpiece could not be inverted during inversion. In Nos. 1, 2, and 3, the results were intermediate. Based on these evaluation results, the contribution rate of each factor, shown in Figure 10, was calculated. As shown in Figure 10, the contribution rate to inversion was highest for the inner diameter r, followed by the width h and the radius of curvature R1, while the thickness t, length b, radius of curvature R2, and length f had almost no contribution.

[0048] 10, it can be seen that the dimensions of the inner flange portion 32 and the outer flange portion 33 of the workpiece member 3 do not have a significant effect on the reversing process. From the above, the inventors have discovered that the reversing process S4 can be carried out well even when the inner flange portion 32 and the outer flange portion 33 are made thicker than the workpiece main body portion 31 by the thickening process S3. [Action and effect]

[0049] In this manufacturing method of a bearing ring member, the thicknesses of the inner flange portion 32 and the outer flange portion 33 are increased in the thickness-increasing step S3 so that they are thicker than the workpiece main body portion 31, and the workpiece 3 is then inverted in the inversion step S4. As a result, the thicknesses of the pair of flanges of the manufactured outer ring 12 and inner ring 13 are also thicker than the main body portion. As a result, the strength of the outer ring 12 and the inner ring 13 can be increased. That is, for example, if a bearing ring member with a uniform overall thickness is manufactured by simply inverting a workpiece member made of a plate member, the resulting bearing ring member may not have sufficient strength. In contrast, this manufacturing method of a bearing ring member can manufacture an outer ring 12 in which the pair of outer ring flanges 122 are thicker than the outer ring main body 121, and an inner ring 13 in which the inner ring flange 132 is thicker than the inner ring main body 131, thereby increasing the strength of the outer ring 12 and the inner ring 13. As such, this manufacturing method of a bearing ring member can manufacture a bearing ring member with high strength.

[0050] The preparation process includes a burring process S2 in which a workpiece 3 is obtained by performing burring processing on an annular processed member 2 arranged on an inner die 41 and an outer die 42 so as to bridge between the inner die 41 and the outer die 42, by deforming the annular processed member 2 with a burring punch 43 that moves so as to enter between the inner die 41 and the outer die 42. From the annular processed member 2, a workpiece 3 having an annular work main body 31, an inner flange 32, and an outer flange 33 can be obtained.

[0051] In the thickness increasing step S3, the thickness increasing process is performed while the workpiece main body 31 is pressed from the first side SA by the pressing member 55. In this case, the thickness of the inner flange portion 32 and the outer flange portion 33 can be increased while suppressing an increase in the thickness of the workpiece main body 31.

[0052] In the thickness increasing step S3, the thicknesses of the inner flange portion 32 and the outer flange portion 33 are increased so that the thickness of each of the inner flange portion 32 and the outer flange portion 33 is 1.2 to 3 times the thickness of the work body portion 31. In this case, the strength of the outer ring 12 and the strength of the inner ring 13 can be further increased.

[0053] The shape of the burring die 46 (inner die 41, outer die 42, and connecting portion 40) used in the burring step S2 is the same as the shape of the thickening die 56 (thickening inner die 51, thickening outer die 52, and thickening die main body portion 53) used in the thickening step S3. This makes the burring die 46 and the thickening die 56 interchangeable, thereby reducing costs. Also, the burring die 46 and the thickening die 56 can be made common. In this case, there is no need to replace the die between the burring step S2 and the thickening step S3, which simplifies the manufacturing process. [Second embodiment]

[0054] If the manufacturing method of the bearing ring member according to the first embodiment described above is referred to as the first process, the manufacturing method of the bearing ring member according to the second embodiment involves the first process and at least two of the second and third processes described below. For example, all of the first, second, and third processes may be performed, or only two of the first, second, and third processes may be performed. The order in which these processes are performed is not limited and may be any order. The first, second, and third processes use the same punch 61 and die 62. The first, second, and third processes are selected by changing the inner diameter of the workpiece body of the workpiece member. [1st processing]

[0055] As described above, in the first processing, the workpiece member 3 (first workpiece member) having the annular workpiece main body portion 31 (first workpiece main body portion) is clamped in the axial direction between the punch 61 and the die 62, and the workpiece member 3 is turned over so that the workpiece main body portion 31 becomes cylindrical, thereby forming the outer ring 12 (bearing ring member). Also, the workpiece member 3 (first workpiece member) is clamped in the axial direction between the punch 63 and the die 64, and the workpiece member 3 is turned over so that the workpiece main body portion 31 becomes cylindrical, thereby forming the inner ring 13 (bearing ring member). [Second processing]

[0056] The bearing 7 shown in FIG. 11 is, for example, an angular contact ball bearing. The rolling bearing 7 includes a plurality of rolling elements 71, an outer ring (bearing ring member) 72, and an inner ring (bearing ring member) 73. The outer ring 72 is a bearing ring member used as the outer ring of the rolling bearing 7. The outer ring 72 has a central axis CL. The outer ring 72 includes an outer ring main body 721 and a pair of outer ring flanges 722. The outer ring main body 721 is formed in a cylindrical shape and has a raceway surface 721a on its radially inner side. In this specification, a member that extends around the central axis CL and has a length along the direction in which the central axis CL extends is referred to as a cylindrically formed member. Therefore, a member in which the outer ring main body 721 curves outward, such as the outer ring 72, is also included in the category of a cylindrically formed member.

[0057] The pair of outer ring flanges 722 extend from both axial ends of the outer ring body 721 on the side opposite the rolling elements 71. That is, one outer ring flange 722 protrudes from one axial end of the outer ring body 721 on the side opposite the rolling elements 71, and the other outer ring flange 722 protrudes from the other axial end of the outer ring body 721 on the side opposite the rolling elements 71. The thickness of the outer ring flanges 722 is the same as the thickness of the outer ring body 721.

[0058] The inner ring 73 is a bearing ring member used as the inner ring of the rolling bearing 7. The inner ring 73 has a central axis that is the same as the central axis CL of the outer ring 72. The inner ring 73 has an inner ring main body 731 and a pair of inner ring flanges 732. The inner ring main body 731 is formed in a cylindrical shape and has a raceway surface 731a on its radially outer side. The pair of inner ring flanges 732 extend from both axial ends of the inner ring main body 731 on the side opposite the rolling elements 71. That is, one inner ring flange 732 protrudes from one axial end of the inner ring main body 731 on the side opposite the rolling elements 71, and the other inner ring flange 732 protrudes from the other axial end of the inner ring main body 731 on the side opposite the rolling elements 71. The thickness of the inner ring flanges 732 is the same as the thickness of the inner ring main body 731.

[0059] Each rolling element 71 is a ball. The multiple rolling elements 71 are lined up in the circumferential direction. The multiple rolling elements 71 are held, for example, by a cage (not shown) so that the intervals between adjacent rolling elements 71 in the circumferential direction are constant. When the rolling bearing 7 is in use, each rolling element 71 rolls on the raceway surface 721a and the raceway surface 731a on its outer circumferential surface. Note that although FIG. 11 shows one cross section perpendicular to the circumferential direction, the rolling bearing 7 has a uniform shape in the circumferential direction.

[0060] In the second processing, the outer ring 72 and the inner ring 73 are manufactured as ring members. However, the outer ring 72 may be manufactured by further processing the ring members. Similarly, the inner ring 73 may be manufactured by further processing the manufactured ring member.

[0061] As shown in FIG. 12, the second process includes a punching step S1, a burring step S2, a bending step S5, and a straightening step S6. In the second process, the punching step S1 and the burring step S2 are performed to obtain a workpiece member 3B (second workpiece member) from the disk-shaped member shown in FIG. 3. The workpiece member 3B includes a workpiece body portion 36 (second workpiece body portion) having an inner diameter smaller than the inner diameter of the workpiece body portion 31 (first workpiece body portion) used in the first process, and an inner flange portion 32 and an outer flange portion 33 extending from both radial ends of the workpiece body portion 36 to the first side SA. In the second process, the inner flange portion 32 and the outer flange portion 33 are not thickened. However, the above-mentioned thickening step S3 may be performed between the burring step S2 and the bending step S5. That is, the thicknesses of the outer ring flange 722 and the inner ring flange 732 may be thicker than the thickness of the outer ring body 721.

[0062] Next, as shown in Fig. 13, in the bending step S5, the workpiece member 3B is bent. At the start of the bending step S5, first, as shown in Fig. 13(a), the punch 61 is disposed on the first side SA relative to the die 62, and the die 62 is disposed on the second side SB relative to the punch 61. Note that the shapes of the punch 61 and the die 62 shown in Fig. 13 are illustrated as being different from the shapes of the punch 61 and the die 62 shown in Fig. 6, but the punch 61 and the die 62 shown in Fig. 13 are the same as the punch 61 and the die 62 shown in Fig. 6, respectively.

[0063] At the start of the bending step S5, the workpiece member 3B is placed on the die 62 with the workpiece body 36 of the workpiece member 3B in contact with the upper surface of the die 62. Then, for example, by lowering the punch 61 and bringing it closer to the die 62, the workpiece member 3B is sandwiched between the punch 61 and the die 62 in the axial direction, and the workpiece body 36 is deformed so as to be curved radially outward (FIG. 13(b)).

[0064] As the punch 61 further descends, the portion of the workpiece member 3B that protrudes radially outward from the die 62 approaches the radially outward surface of the die 62. When that portion of the workpiece member 3B comes into contact with the radially outward surface of the die 62, the punch 61 stops, and an outer ring workpiece 72A is formed.

[0065] Next, as shown in FIG. 14 , in the straightening step S6, the outer ring workpiece 72A is subjected to straightening processing. In the straightening step S6, the outer ring workpiece 72A is clamped between straightening dies (not shown) to form the shape of the outer ring 72. The shape of the straightening dies corresponds to the shape of the outer ring 72, and by clamping the outer ring workpiece 72A between the dies, the shape of the outer ring workpiece 72A is formed (straightened) into the shape of the outer ring 72. When the outer ring workpiece 72A is clamped between the dies, springback occurs in the outer ring workpiece 72A immediately after it is clamped. The shape of the straightening dies is set so that the shape of the outer ring workpiece 72A after springback occurs becomes the shape of the outer ring 72.

[0066] In this way, in the second processing, the workpiece member 3B (second workpiece member) having the annular workpiece main body portion 36 (second workpiece main body portion) is clamped axially between the punch 61 and the die 62, and the workpiece main body portion 36 is bent to form the outer ring 72.

[0067] In the bending step S5, as shown in Fig. 15, the workpiece member 3B may be bent to form an inner ring 73. At the start of the bending step S5 for forming the inner ring 73, the workpiece member 3B is placed on the die 62 with the inner flange portion 32 in contact with the upper surface of the die 62 so that the inner flange portion 32 and the outer flange portion 33 extend to the second side SB. The punch 61 and the die 62 shown in Fig. 15 are the same as the punch 61 and the die 62 shown in Fig. 6. Then, for example, by lowering the punch 61 and bringing it closer to the die 62, the workpiece member 3B is sandwiched between the punch 61 and the die 62 in the axial direction, and the workpiece main body portion 36 is deformed so as to be curved radially inward (Fig. 15(b)).

[0068] As the punch 61 continues to descend, the portion of the workpiece member 3B that protrudes radially inward from the punch 61 approaches the radially inward surface of the punch 61. When that portion of the workpiece member 3B comes into contact with the radially inward surface of the punch 61, the punch 61 stops, and an inner ring workpiece 73A is formed. Next, the inner ring workpiece 73A is subjected to correction processing, thereby forming the inner ring 73. The shape of the correction die used when correcting the inner ring workpiece 73A corresponds to the shape of the inner ring 73.

[0069] In this way, in the second processing, the workpiece member 3B having the annular workpiece main body 36 may be sandwiched between the punch 61 and the die 62 in the axial direction, and the workpiece main body 36 may be bent to form the inner ring 73.

[0070] The 3D-CAE analysis using the above-mentioned experimental design method revealed that the inner diameter of the workpiece main body 31 of the workpiece member 3 has a significant effect on the reversal process. From this result, the inventor discovered that the first process, the second process, and the third process can be properly performed by changing the inner diameter of the workpiece main body 31. For example, by using a workpiece member 3B (second workpiece member) having a workpiece main body 36 (second workpiece main body) with an inner diameter smaller than the inner diameter of the workpiece main body 31 (first workpiece main body) used in the first process, the bending step S5 of the second process is performed when the workpiece member 3B is axially sandwiched between the punch 61 and the die 62. [Third processing]

[0071] In the third process, a pulley-shaped ring member 8 (bearing ring member) (see FIG. 17) is manufactured. As shown in FIG. 16, the third process includes a punching step S1, a burring step S2, and a bending and inversion step S7. In the third process, a workpiece member 3C (third workpiece member) is obtained from the disk-shaped member shown in FIG. 3 by performing the punching step S1 and the burring step S2. The workpiece member 3C has a workpiece body portion 37 (third workpiece body portion) having an inner diameter smaller than the inner diameter of the workpiece body portion 31 (first workpiece body portion), and inner flange portions 32 and outer flange portions 33 extending from both radial ends of the workpiece body portion 37 to the first side SA. In the third process, a thickness increasing step S3 may be performed between the burring step S2 and the bending and inversion step S7. That is, the thicknesses of the inner flange portions 32 and outer flange portions 33 may be thicker than the thickness of the workpiece body portion 37.

[0072] Next, as shown in Figure 17, in the bending and reversing step S7, the workpiece member 3C is subjected to bending and reversing processing. At the start of the bending and reversing step S7, first, as shown in Figure 17(a), the punch 61 is positioned on the first side SA relative to the die 62, and the die 62 is positioned on the second side SB relative to the punch 61. The punch 61 and die 62 shown in Figure 17 are the same as the punch 61 and die 62 shown in Figure 6. At the start of the bending and reversing step S7, the workpiece member 3C is placed on the die 62 with the workpiece main body portion 37 of the workpiece member 3C in contact with the upper surface of the die 62. The workpiece main body portion 37 has a surface 37a facing the first side SA at the start of the bending and reversing step S7.

[0073] Then, for example, by lowering the punch 61 and bringing it close to the die 62, the workpiece member 3C is sandwiched between the punch 61 and the die 62 in the axial direction, and the workpiece main body 37 is deformed so as to be curved radially outward (FIG. 17(c)). Next, the punch 61 is further lowered, and a backup block having multiple block members 65 is moved radially outward, thereby inverting the workpiece member 3C so as to form a cylindrical shape (FIG. 17(c)). That is, in the bending and inverting step S7, the workpiece main body 37 is inverted while being bent. When the surface 37a faces radially outward, the punch 61 stops, and the ring member 8 is formed.

[0074] When the workpiece 3C is inverted, the block members 65 push the workpiece 3C radially outward, urging the workpiece 3C to be inverted. The block members 65 can move radially outward on the upper surface of the die 62. A plurality of block members 65 are provided on the upper surface of the die 62, and the plurality of block members 65 are arranged at equal intervals around the central axis CL. The force for pushing the block members 65 may be a force from any mechanism or power source, such as a spring, hydraulic pressure, air, a motor, or a cam. When the workpiece 3C is inverted, the block members 65 do not have to be used. In other words, the block members 65 do not have to be provided above the die 62.

[0075] In the third processing, a workpiece member 3C (third workpiece member) having an annular workpiece main body portion 37 (third workpiece main body portion) is clamped in the axial direction between a punch 61 and a die 62, and the workpiece main body portion 37 is bent and inverted so that the workpiece main body portion 37 becomes cylindrical, thereby forming a ring member 8. The ring member 8 has two portions curved radially inward and a portion curved radially outward between the two portions. The ring member 8 is formed in a cylindrical shape. Note that a straightening process may be performed after the bending and inversion process S7.

[0076] This method of manufacturing a bearing ring member involves performing at least two of the following (1) first processing, (2) second processing, and (3) third processing using a common punch 61 and die 62. (1) In the first processing, a workpiece member 3 (first workpiece member) having an annular workpiece main body portion 31 (first workpiece main body portion) is sandwiched axially between the punch 61 and the die 62, and the workpiece member 3 is inverted so that the workpiece main body portion 31 becomes cylindrical, thereby forming the outer ring 12 or the inner ring 13. (2) In the second processing, a workpiece member 3B (second workpiece member) having an annular workpiece main body portion 36 (second workpiece main body portion) is sandwiched axially between the punch 61 and the die 62, and the workpiece main body portion 36 is bent, thereby forming the outer ring 72 or the inner ring 73. (3) In the third processing, a workpiece member 3C (third workpiece member) having an annular workpiece body portion 37 (third workpiece body portion) is clamped axially between a punch 61 and a die 62, and the workpiece body portion 37 is bent and inverted so that the workpiece body portion 37 becomes cylindrical, thereby forming a ring member 8. The inner diameter of the workpiece body portion 31 used in the first processing is larger than the inner diameters of the workpiece body portions 36 and 37 used in the second and third processing.

[0077] In this method for manufacturing a bearing ring member, a common punch 61 and die 62 can be used to manufacture a bearing ring member through at least two of the first, second, and third processes, and a plurality of different bearing ring members can be manufactured using a single set of punch 61 and die 62. The finding that different processes, the first, second, and third processes, can be performed using a common punch 61 and die 62 by changing the size of the inner diameter of the work body is a finding discovered by the present inventor based on the above analysis. [Another example of third processing]

[0078] The workpiece member 3D shown in FIG. 18 has, for example, the shape of a thrust cage. In another example of the third processing, a radial cage 9 shown in FIG. 19 is manufactured from the workpiece member 3D. The workpiece member 3D (third workpiece member) has a workpiece main body portion 38 (third workpiece main body portion), an inner flange portion 32 extending from the radially inner end of the workpiece main body portion 38 to the first side SA, and an outer flange portion 33 extending from the radially outer end of the workpiece main body portion 38 to the first side SA. The workpiece main body portion 38 has a plurality of through holes 38a formed therein. The workpiece member 3D has a central axis CL. The plurality of through holes 38a are arranged around the central axis CL. The through holes 38a are rectangular. The workpiece main body portion 38 has pillars 38b located between two adjacent through holes 38a.

[0079] The radial cage 9 has a cylindrical cage body 91. The cage body 91 has a plurality of through holes 91a. The radial cage 9 has a central axis CL. The plurality of through holes 91a are arranged around the central axis CL. The through holes 91a are rectangular. The cage body 91 has pillars 91b located between two adjacent through holes 91a. The pillars 91b have raised portions 91c that rise toward the central axis CL. The raised portions 91c are located at the axial center of the pillars 91b. Although not shown in FIG. 19, the radial cage 9 has flange portions that correspond to the inner flange portion 32 and outer flange portion 33 of the workpiece member 3D.

[0080] In another example of the third processing, the radial cage 9 is manufactured as a ring member. However, the radial cage 9 may be manufactured by further processing the manufactured ring member.

[0081] Another example of the third processing includes a punching step S1, a burring step S2, a through-hole forming step, and a bending and inverting step S7. In this example of the third processing, by performing the punching step S1 and the burring step S2, a work member 3D without through-holes 38a formed therein is obtained from the disk-shaped member shown in Fig. 3. In the through-hole forming step following the burring step S2, the through-holes 38a are formed in the work member 3D without through-holes 38a formed therein.

[0082] As shown in Figure 20, in the bending and inverting step S7, the workpiece member 3D is subjected to bending and inverting processing. At the start of the bending and inverting step S7, first, as shown in Figure 20(a), the punch 61 is positioned on the first side SA relative to the die 62, and the die 62 is positioned on the second side SB relative to the punch 61. The punch 61 and die 62 shown in Figure 20 are the same as the punch 61 and die 62 shown in Figure 6. At the start of the bending and inverting step S7, the workpiece member 3D is placed on the die 62 with the workpiece main body portion 38 of the workpiece member 3D in contact with the upper surface of the die 62. The workpiece main body portion 38 has a surface 38c facing the first side SA at the start of the bending and inverting step S7.

[0083] Then, for example, by lowering the punch 61 and bringing it closer to the die 62, the workpiece 3D is sandwiched between the punch 61 and the die 62 in the axial direction, and the workpiece 3D is deformed so as to rise radially outward (FIG. 20(b)). That is, in the reversing step, the workpiece 3D is deformed so that the surface 38c of the workpiece 3D facing the punch 61 side (first side SA) before the reversing step S4 faces radially outward after the reversing step S4.

[0084] By further lowering the punch 61, the inverted workpiece 3D is sandwiched between the punch protrusion 61a and the die protrusion 62a in the axial direction and buckled, causing the axial central portion of the inverted pillar 38b to bulge radially inward, thereby forming the bulged portion 91c of the radial cage 9.

[0085] In this other example of the third processing, a workpiece member 3D (third workpiece member) having a circular workpiece main body portion 38 (third workpiece main body portion) is clamped axially between a punch 61 and a die 62, the workpiece main body portion 38 is bent, and the workpiece member 3D is inverted so that the workpiece main body portion 38 becomes cylindrical, thereby forming a radial retainer 9.

[0086] Referring to FIG. 21 , yet another processing example is shown. In this processing example, a ring member 100A shown in FIG. 21(b) or a ring member 100B shown in FIG. 21(c) is manufactured. The ring member 100A has a cylindrical main body portion 101, a flange portion 102 protruding radially outward from one axial end of the main body portion 101, and a flange portion 103 protruding radially outward from the other axial end of the main body portion 101 and extending toward the flange portion 102. In the ring member 100A, the main body portion 101 and the flange portion 103 are double-layered. The ring member 100B has a cylindrical main body portion 101, a flange portion 102 protruding radially outward from one axial end of the main body portion 101, and a ring-shaped flange portion 103 protruding radially outward from the other axial end of the main body portion 101 and wrapped around the main body portion 101.

[0087] Another processing example includes a punching step S1, a burring step S2, and a bending / reversing step S7. In this processing example, a workpiece member 3E is obtained from the disk-shaped member shown in FIG. 3 by performing the punching step S1 and the burring step S2. The workpiece member 3E has a workpiece main body portion 31, an outer flange portion 33 extending from the radially outer end of the workpiece main body portion 31 to the first side SA, and a flange portion 39 extending from the radially inner end of the workpiece main body portion 31 to the first side SA. The axial length of the flange portion 39 is longer than the axial length of the outer flange portion 33. This processing example can be considered as another example of the first processing.

[0088] Next, as shown in Fig. 21, in the bending and inverting step S7, the workpiece member 3E is subjected to bending and inverting processing. At the start of the bending and inverting step S7, first, as shown in Fig. 21(a), the punch 61 is positioned on the first side SA relative to the die 62, and the die 62 is positioned on the second side SB relative to the punch 61. At the start of the bending and inverting step S7, the workpiece member 3E is placed on the die 62 with the workpiece main body 31 of the workpiece member 3E in contact with the upper surface of the die 62.

[0089] Then, for example, by lowering the punch 61 and bringing it closer to the die 62, the workpiece 3E is sandwiched between the punch 61 and the die 62 in the axial direction, and the workpiece 3E is deformed so that it rises outward in the radial direction (FIGS. 21(b) and 21(c)). That is, in the reversing step S4, the workpiece 3E is deformed so that the surface 31a of the workpiece 3E facing the punch 61 side (first side SA) before the reversing step S4 faces outward in the radial direction after the reversing step S4.

[0090] By further lowering the punch 61, the inverted workpiece 3E is sandwiched in the axial direction between the punch protrusion 61a and the die protrusion 62a, and in the example of Fig. 21(b), the flange portion 39 is bent toward the flange portion 33, forming the flange portion 102. In the example of Fig. 21(c), the flange portion 39 is rolled radially inward, forming the flange portion 103.

[0091] In this other processing example, a workpiece member 3E having a circular workpiece main body portion 31 is clamped axially between a punch 61 and a die 62, and the workpiece member 3E is inverted so that the workpiece main body portion 31 becomes cylindrical, and the flange portion 39 is deformed in a rolling manner to form a flange portion 103, thereby forming a ring member 100A or 100B.

[0092] Ring members 100A, 100B having flange portion 103 have higher strength than ring members having only a flange portion that is not rolled up, unlike flange portion 103. Bearings using ring members 100A, 100B can be incorporated into locations where strength is required or where press fitting is required, for example. As explained above, by changing the processing conditions, many types of bearings can be formed by reversing thin plate.

[0093] The present invention is not limited to the above-described embodiment and modifications. For example, the materials and shapes of each component are not limited to those described above, and various materials and shapes can be used. The shapes of the burring die 46 and the thickening die 56 may be different from each other.

[0094] In the above-described embodiments, the workpiece members 3, 3B, 3C, 3D, and 3E are prepared by the punching step S1 and the burring step S2, but the workpiece members 3, 3B, 3C, 3D, and 3E may be prepared by a method other than the punching step S1 and the burring step S2. The holding member 55 may not be used in the thickening step S3. For example, the thickening process may be performed without holding down the workpiece main body 31.

[0095] The first, second, and third processes involve common steps (for example, a punching step S1 and a burring step S2). The common steps may be performed each time the first, second, and third processes are performed, or may be performed all at once before the first, second, and third processes are performed. The rolling elements may be any rolling elements, such as tapered rollers or needle rollers. The bearings may be tapered roller bearings or needle bearings. [Explanation of symbols]

[0096] 2...Workpiece, 3...Workpiece (first workpiece), 3A...Workpiece, 3B...Workpiece (second workpiece), 3C...Workpiece (third workpiece), 8...Ring member (bearing ring member), 12...Outer ring (bearing ring member), 13...Inner ring (bearing ring member), 31...Workpiece body (first workpiece body), 32...Inner flange, 33...Outer flange, 36...Workpiece body (second workpiece body), 37...Workpiece body (Third workpiece main body), 41...inner die, 42...outer die, 43...burring punch, 46...burring die, 53...thickening die main body, 54...thickening punch, 55...holding member, 56...thickening die, 61...punch (reverse punch), 62...die (reverse die), 72...outer ring (bearing ring member), 73...inner ring (bearing ring member), S2...burring process, S3...thickening process, S4...reverse process, SA...first side.

Claims

1. a preparation step of preparing a workpiece member having an annular workpiece main body, an inner flange portion extending from an inner edge of the workpiece main body in a radial direction to one side in an axial direction, and an outer flange portion extending from an outer edge of the workpiece main body in a radial direction to the one side in the axial direction; a thickening process in which the inner flange portion and the outer flange portion are sandwiched in the axial direction by a thickening punch and a thickening die, and a thickening process is performed to increase the thickness of the inner flange portion and the outer flange portion so that the thickness of the inner flange portion and the outer flange portion in the radial direction is thicker than the thickness of the workpiece main body in the axial direction; an inversion process of axially clamping the workpiece between an inversion punch and an inversion die and inverting the workpiece so that the workpiece main body portion becomes cylindrical, in this order.

2. 2. The method for manufacturing a bearing ring member according to claim 1, wherein the preparation process includes a burring process for obtaining the work member by performing a burring process in which an annular processed member arranged on an inner die and an outer die so as to bridge between the inner die and the outer die is deformed by a burring punch that moves so as to enter between the inner die and the outer die.

3. The method for manufacturing a bearing ring member according to claim 1 or 2, wherein in the thickening step, the thickening process is performed while pressing the work body from the one axial side with a pressing member.

4. 3. The method for manufacturing a bearing ring member according to claim 1, wherein in the thickening process, the thickness of the inner flange portion and the outer flange portion is increased so that the thickness of each of the inner flange portion and the outer flange portion is 1.2 times or more and 3 times or less the thickness of the work main body portion.

5. 3. The method for manufacturing a bearing ring member according to claim 2, wherein the shape of the burring dies including the inner die and the outer die used in the burring step is the same as the shape of the thickening dies used in the thickening step.

Images