Manufacturing method of bearing shell member and manufacturing method of bearing

Abstract

To manufacture a bearing shell member having a pair of shell flanges well.SOLUTION: A method for manufacturing a bearing shell member is for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending from both ends of the shell body in an axial direction to the outside in a radial direction. This method for manufacturing the bearing shell member comprises an inversion step of carrying out an inversion process for holding, between a punch 41 disposed on a first side and a die 42 disposed on a second side opposite the first side, and deforming a workpiece member 20 having a cylindrical workpiece body 21, an inner workpiece flange 22 extending from the inner end of the workpiece body 21 in a radial direction to the first side, and an outer workpiece flange 23 extending from the outer end of the workpiece body in the radial direction to the first side. In the inversion step, by using the punch 41 having a hook 44, the hook 44 is hooked in the outer workpiece flange 23 to carry out the inversion process.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] Patent Document 1 describes a method for manufacturing a cylindrical member having a cylindrical main body and a protrusion protruding radially outward from the outer circumferential surface of the axial end of the main body. In this manufacturing method, a circular annular intermediate material is subjected to a reversal process, in which the diameter of the inner radial portion is enlarged and the diameter of the outer radial portion is reduced, thereby rotating the cross-sectional shape by 90 degrees, to form the cylindrical member. This cylindrical member is used, for example, as the outer ring of a rolling bearing. Patent Documents 2 to 5 also describe the formation of bearing raceways by reversal processing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-22987 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-123003 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-341255 [Patent Document 4] Japanese Patent Application Laid-Open No. 2006-090407 [Patent Document 5] Patent No. 4572644 Summary of the Invention [Problem to be solved by the invention]

[0004] Some bearing shell components used as the outer or inner raceways of bearings have a pair of shell flanges extending radially from both axial ends of a cylindrical shell body. Using the manufacturing method described above, it is difficult to manufacture bearing shell components having such a U-shaped or inverted U-shaped (C-shaped or inverted C-shaped) cross section.

[0005] Therefore, an object of the present invention is to provide a method for manufacturing a bearing shell member that can effectively manufacture a bearing shell member having a pair of shell flanges, and a method for manufacturing a bearing that can effectively manufacture a bearing that includes such a bearing shell member. [Means for solving the problem]

[0006] The method for manufacturing a bearing shell member of the present invention is a method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending radially outward from both axial ends of the shell body, and includes an inversion process in which a workpiece having a circular ring-shaped workpiece body, an inner workpiece flange extending from the radial inner end of the workpiece body to a first axial side, and an outer workpiece flange extending from the radial outer end of the workpiece body to the first side is sandwiched between a punch arranged on the first side and a die arranged on a second side opposite the first side to perform inversion processing, and in the inversion process, a punch having a hook portion is used, and the hook portion is hooked onto the outer workpiece flange to perform the inversion processing.

[0007] In this method for manufacturing a bearing shell member, in the inversion step, a workpiece having an inner workpiece flange and an outer workpiece flange extending from a workpiece body to a first side in the axial direction is sandwiched and deformed between a punch disposed on the first side and a die disposed on a second side opposite the first side. Simply performing inversion on a workpiece having such a shape can result in the workpiece not standing up properly and becoming bent. In contrast, in the inversion step of this method for manufacturing a bearing shell member, a punch having a hook is used, and the hook is hooked onto the outer workpiece flange to perform the inversion. This makes it easier to stand up the workpiece during the inversion step, allowing for satisfactory standing of the workpiece. Therefore, this method for manufacturing a bearing shell member can successfully manufacture a bearing shell member having a pair of shell flanges.

[0008] The method for manufacturing a bearing shell member of the present invention is a method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending radially inward from both axial ends of the shell body, and includes an inversion process in which a workpiece having a circular ring-shaped workpiece body, an inner workpiece flange extending from the radial inner end of the workpiece body to a first axial side, and an outer workpiece flange extending from the radial outer end of the workpiece body to the first side is sandwiched between a punch arranged on the first side and a die arranged on a second side opposite the first side to perform inversion processing, and in the inversion process, a punch having a hook portion is used, and the hook portion is hooked onto the inner workpiece flange to perform the inversion processing.

[0009] In the inversion step of this method for manufacturing a bearing shell member, a punch having a hook is used, and the hook is hooked onto the inner workpiece flange to perform the inversion process. This makes it easier to raise the workpiece during the inversion process, and the workpiece can be raised properly. Therefore, this method for manufacturing a bearing shell member can properly manufacture a bearing shell member having a pair of shell flanges.

[0010] In the reversing step, the hooking portion may move to the second side while moving radially inward, in which case the hooking portion can be hooked well.

[0011] In the reversing step, the hooking portion may move to the second side while moving radially outward, in which case the hooking portion can be hooked well.

[0012] The hook portion may include a plurality of portions arranged in the circumferential direction, in which case the hook portion can be hooked in a good manner.

[0013] The punch may have a main body and a hook portion that is movable relative to the main body. In this case, the hook portion can be hooked well.

[0014] The method for manufacturing a bearing shell member of the present invention may further include a sizing step of deforming the workpiece body before the inversion step to generate a difference in thickness between a first portion on the inner work flange side and a second portion on the outer work flange side of the workpiece body after the inversion step, so that the difference in thickness between the first portion and the second portion can be reduced. In this case, the difference in thickness between the first portion and the second portion after the inversion step can be reduced, and the shell body of the bearing shell member can be formed straight.

[0015] The method for manufacturing a bearing shell member of the present invention further includes a burring step, prior to the reversing step, in which a workpiece is obtained by performing burring on an annular workpiece disposed on the inner die and the outer die so as to bridge between the inner die and the outer die, using a burring punch that moves so as to enter between the inner die and the outer die. In the burring step, a deformation suppressing member that contacts the workpiece from the side opposite to the burring punch may be used, and burring may be performed while the workpiece is sandwiched between the burring punch and the deformation suppressing member. In this case, bending of the workpiece at the location pressed by the burring punch can be suppressed, and the workpiece body of the workpiece can be formed straight.

[0016] The method for manufacturing a bearing shell member of the present invention may further include a backward extrusion step of forming the workpiece by backward extrusion before the inversion step. In this case, the degree of curvature between the workpiece body and the inner and outer workpiece flanges can be reduced compared to when the workpiece members are obtained by, for example, burring, and as a result, the strength of the bearing shell member can be ensured to be high.

[0017] The method for manufacturing a bearing shell member of the present invention may further include a backward extrusion step of forming the work member by backward extrusion before the inversion step, in which the work member has a difference in thickness between the first portion on the inner work flange side and the second portion on the outer work flange side in the work body after the inversion step, such that the difference in thickness between the first portion and the second portion is reduced. In this case, the difference in thickness between the first portion and the second portion after the inversion step can be reduced, and the shell body of the bearing shell member can be formed straight.

[0018] In the inversion process, the inversion process may be performed by using a backup block to push the inner work flange from the inside to the outside in the radial direction, while using a punch to push the outer work flange from the first side to the second side. In this case, the workpiece can be more easily raised during the inversion process, and the workpiece can be raised more satisfactorily.

[0019] In the inversion process, the outer work flange may be pushed from the first side to the second side by the punch while the backup block pushes the outer work flange from the outside to the inside in the radial direction, thereby performing the inversion process. In this case, the workpiece can be more easily raised during the inversion process, and the workpiece can be raised more satisfactorily.

[0020] The method for manufacturing a bearing of the present invention includes the steps of obtaining a bearing shell member by the above-mentioned method for manufacturing a bearing shell member, and assembling a plurality of rolling elements and a cage that rollably holds the plurality of rolling elements to the bearing shell member so that the cage is held by the bearing shell member and the plurality of rolling elements can roll on the shell body. For the reasons described above, this method for manufacturing a bearing can successfully manufacture a bearing that includes a bearing shell member having a pair of shell flanges. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a method for manufacturing a bearing shell member that can satisfactorily manufacture a bearing shell member having a pair of shell flanges, and a method for manufacturing a bearing that can satisfactorily manufacture a bearing that includes such a bearing shell member. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a cross-sectional view showing an example of a rolling bearing according to an embodiment. [Figure 2] FIG. 4 is a cross-sectional view showing another example of a rolling bearing according to an embodiment. [Figure 3] 5(a), (b), (c) and (d) are cross-sectional views illustrating a method for manufacturing a bearing shell member used as an inner ring. [Figure 4] 10(a) and 10(b) are cross-sectional views for explaining the burring step. [Figure 5] 10(a) and 10(b) are cross-sectional views for explaining the sizing step. [Figure 6] 10(a) and 10(b) are cross-sectional views for explaining the inversion step. [Figure 7] FIG. 10 is a cross-sectional view illustrating a reversing step. [Figure 8] FIG. 10 is a plan view of the backup block. [Figure 9] FIG. [Figure 10]10(a) and 10(b) are cross-sectional views illustrating a reversing step according to a first modified example. [Figure 11] FIG. 10 is a cross-sectional view illustrating a reversing step according to the first modified example. [Figure 12] FIG. 10 is a cross-sectional view illustrating a rearward pushing step according to a second modified example. [Figure 13] 10(a) and 10(b) are cross-sectional views illustrating a reversing step according to a third modified example. [Figure 14] FIG. 11 is a cross-sectional view illustrating a reversing step according to a third modified example. [Figure 15] 5(a) and 5(b) are cross-sectional views illustrating a method for manufacturing a bearing shell member used as an outer ring. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements will be designated by the same reference numerals, and redundant description will be omitted. [Rolling bearings]

[0024] The rolling bearing 1 shown in FIG. 1 is used, for example, in a vehicle transmission or the like, by being installed between a housing and a rotating shaft. The rolling bearing 1 includes a plurality of rolling elements 2, a cage 3, and an outer ring shell (bearing shell member) 4. Each rolling element 2 is, for example, a cylindrical roller, but is not limited to this and may be any rolling element. For example, the rolling elements 2 may be tapered rollers, needle rollers (needles), or balls. That is, the rolling bearing 1 may be, for example, a cylindrical roller bearing, a tapered roller bearing, a needle bearing, a ball bearing, or the like. The plurality of rolling elements 2 are rotatably held by a cage 3 and are arranged at equal intervals along the circumferential direction. The cage 3 is formed in an annular shape. The cage 3 is formed with a plurality of pockets (openings) 3a in which the rolling elements 2 are arranged.

[0025] The cage 3 is held by an outer shell 4. The outer shell 4 is a bearing shell component used as the outer ring of the rolling bearing 1. The outer shell 4 has a shell body 11 and a pair of shell flanges 12. The shell body 11 is formed in a cylindrical shape and has a raceway surface 11a on its radially inner side. The thickness (maximum thickness) of the shell body 11 is, for example, approximately 2 mm.

[0026] The pair of shell flanges 12 extend radially inward from both axial ends of the shell body 11. That is, one shell flange 12 protrudes radially inward from one axial end of the shell body 11, and the other shell flange 12 protrudes radially inward from the other axial end of the shell body 11. Each shell flange 12 is formed in a substantially annular plate shape. In this example, each shell flange 12 curves up from the shell body 11, and a curved portion (R portion) is formed between each shell flange 12 and the shell body 11. That is, each shell flange 12 is also a curled portion that curves up from the shell body 11.

[0027] The plurality of rolling elements 2 and the cage 3 are assembled to the outer ring shell 4. More specifically, the plurality of rolling elements 2 are held by the cage 3, and the cage 3 is fitted inside the outer ring shell 4, thereby holding the plurality of rolling elements 2 and the cage 3 by the outer ring shell 4. In this state, the plurality of rolling elements 2 held by the cage 3 come into contact with the raceway surface 11a of the shell body 11 and are able to roll on the raceway surface 11a. The rolling bearing 1 is used, for example, assembled so that the housing is located on the outer diameter side and the shaft is located on the inner diameter side.

[0028] The rolling bearing 1 shown in Fig. 2 has an inner shell 5 instead of the outer shell 4. The inner shell 5 is a bearing shell component used as the inner ring of a rolling bearing. The inner shell 5 has a shell body 51 and a pair of shell flanges 52. The shell body 51 is formed in a cylindrical shape and has a raceway surface 51a on the radially outer side.

[0029] The pair of shell flanges 52 extend radially outward from both axial ends of the shell body 51. That is, one shell flange 52 protrudes radially outward from one axial end of the shell body 51, and the other shell flange 52 protrudes radially outward from the other axial end of the shell body 51. Each shell flange 52 is formed in a substantially annular plate shape. In this example, each shell flange 52 curves and rises from the shell body 51, and a curved portion (R portion) is formed between each shell flange 52 and the shell body 51. That is, each shell flange 52 is also a curled portion that curves and rises from the shell body 51.

[0030] 2 is configured in the same manner as the rolling bearing 1 shown in Fig. 1 described above, except that the rolling elements 2 and cage 3 are assembled to the inner shell 5 so that they are located on the outer diameter side. That is, in this rolling bearing 1, the rolling elements 2 are held by the cage 3, and the cage 3 is fitted to the outside of the inner shell 5, so that the rolling elements 2 and cage 3 are held by the inner shell 5. In this state, the rolling elements 2 held by the cage 3 come into contact with the raceway surface 51a of the shell body 51 and are able to roll on the raceway surface 51a. [Method of manufacturing bearing shell components]

[0031] A manufacturing method for manufacturing the inner shell 5 will be described below, but as will be described later, the outer shell 4 can also be manufactured by a similar manufacturing method.

[0032] As shown in FIG. 3, the manufacturing method of the inner shell 5 (bearing shell component) according to this embodiment includes a punching step (FIG. 3(a)), a burring step (FIG. 3(b)), a sizing step (FIG. 3(c)), and an inversion step (FIG. 3(d)), in this order. In general, in this manufacturing method, the inner shell 5 is obtained by performing an inversion process on a substantially annular plate-shaped workpiece component 20 obtained through the punching, burring, and sizing steps. In the inversion process, the cross-sectional shape of the workpiece component 20 is rotated by 90 degrees. Each step will be described below. Note that while FIG. 3 omits a portion of the radial center, each component has a uniform shape in the radial direction. This also applies to FIGS. 4 to 7 and 10 to 13.

[0033] First, a plate-shaped metal material is punched to obtain a circular plate-shaped processed member 6 (punching step, FIG. 3(a)). Next, a burring process is performed to deform the processed member 6 into a substantially U-shaped cross section, thereby obtaining a workpiece member 20 (burring step, FIG. 3(b)).

[0034] The workpiece member 20 has an annular plate-shaped workpiece body 21, an inner workpiece flange 22, and an outer workpiece flange 23. The inner workpiece flange 22 extends from the radially inner end of the workpiece body 21 to a first axial side (upper side in FIG. 3 ). The outer workpiece flange 23 extends from the radially outer end of the workpiece body 21 to the first axial side. The inner workpiece flange 22 and the outer workpiece flange 23 are formed in a substantially cylindrical shape. The workpiece body 21, the inner workpiece flange 22, and the outer workpiece flange 23 are portions that will become the shell body 51 and the pair of shell flanges 52 of the inner shell 5 after the inversion process, and have shapes corresponding to the shell body 51 and the pair of shell flanges 52.

[0035] In the burring process, first, as shown in Fig. 4(a), a processed workpiece 6 is placed on an inner die 31 and an outer die 32 that are arranged apart from each other so as to bridge between the inner die 31 and the outer die 32. Next, as shown in Fig. 4(b), a burring punch 33 moves to enter between the inner die 31 and the outer die 32, thereby deforming the cross-sectional shape of the processed workpiece 6 from an annular plate shape to a substantially U-shape.

[0036] More specifically, in the burring process, a deformation suppressing member 34 is used to contact the workpiece 6 from the side opposite the burring punch 33, and burring is performed while the workpiece 6 is sandwiched between the burring punch 33 and the deformation suppressing member 34. The deformation suppressing member 34 has a spring 34a inside and moves as the burring punch 33 moves, maintaining the workpiece 6 sandwiched between the burring punch 33 and the deformation suppressing member 34. In the state shown in FIG. 4(b) where the burring punch 33 is inserted between the inner die 31 and the outer die 32, the amount of contraction of the spring 34a is greater than in the state shown in FIG. 4(a) before the burring punch 33 moves, and the biasing force acting on the workpiece 6 is therefore greater. In the burring process, the workpiece 6 is tightly sandwiched, but the deformation suppressing member 34 functions as a cushion, preventing the workpiece 6 (workpiece 20) from bending at the point pressed by the burring punch 33.

[0037] Following the burring process, a sizing process is carried out to adjust the shape of the workpiece 20 (FIG. 3(c)). The sizing process will be described with reference to FIG. 5. As described above, in the inversion process, the cross-sectional shape of the workpiece 20 is rotated 90 degrees so that the workpiece 20, which was in a horizontal position, is raised to a vertical position. In the inversion process, the first portion 21a (the radially inner portion) of the workpiece body 21 on the inner workpiece flange 22 side is enlarged in diameter, and the second portion 21b (the radially outer portion) of the workpiece body 21 on the outer workpiece flange 23 side is reduced in diameter. Therefore, as shown in FIG. 5(a), if the thickness of the workpiece body 21 is uniform before the inversion process, the first portion 21a becomes thinner and the second portion 21b becomes thicker as a result of the inversion process, resulting in a difference in thickness between the first portion 21a and the second portion 21b.

[0038] Therefore, in the sizing step, as shown in FIG. 5(b), the workpiece body 21 is deformed so that a difference in thickness between the first portion 21a and the second portion 21b in the workpiece body 21 after the inversion step is reduced (e.g., so that the difference in thickness is substantially eliminated). In this example, the first portion 21a is thickened and the second portion 21b is thinned. This reduces the difference in thickness between the first portion 21a and the second portion 21b in the workpiece body 21 after the inversion step (e.g., so that the difference in thickness is eliminated), and the workpiece body 21 (the shell body 51 of the inner shell 5) can be formed straight. The processing for deforming the workpiece body 21 in the sizing step is performed, for example, by pressing the workpiece body 21 using a mold or a roller.

[0039] Following the sizing process, an inversion process is carried out in which the workpiece 20 is subjected to inversion processing (FIG. 3(d)). In the inversion process, as shown in FIGS. 6 and 7, the workpiece 20 is sandwiched and deformed between a punch (pool punch) 41 arranged on a first axial side (upper side in FIGS. 6 and 7) and a die 42 arranged on a second axial side (lower side in FIGS. 6 and 7) opposite the first side. Hereinafter, for convenience of explanation, the first side and the second side will also be referred to as the upper side and the lower side.

[0040] As shown in Figure 6(a), in the initial state, the workpiece body 21 is placed on the die 42. Then, as shown in Figures 6(b) and 7, the punch 41 moves downward and presses the outer workpiece flange 23, causing the workpiece member 20 to rise outward and rotating the cross-sectional shape of the workpiece member 20 by 90 degrees. As a result, the workpiece body 21, the inner workpiece flange 22, and the outer workpiece flange 23 become the shell body 51 and the pair of shell flanges 52 of the inner shell 5, respectively, and the inner shell 5 is obtained.

[0041] In the inversion process, the backup block 43 pushes the inner work flange 22 from the inside to the outside in the radial direction, while the punch 41 pushes the outer work flange 23 from the top to the bottom, thereby performing inversion processing. As shown in FIG. 8 , the backup block 43 is formed in an overall annular shape. The backup block 43 includes multiple (eight in this example) block members 43a arranged at equal intervals along the circumferential direction. Each block member 43a is formed, for example, in an annular fan shape. Each block member 43a is disposed on the die 42 and is movable radially along the die 42. As the block members 43a move radially outward, the backup block 43 pushes the inner work flange 22 radially outward. This pushing force may be a force from any mechanism or power source, such as a spring, hydraulic pressure, air, a motor, or a cam.

[0042] In the reversing process, a punch 41 having a hook portion 44 is used, and the hook portion 44 is hooked onto the outer work flange 23 (curl portion) to perform the reversing process. As shown in FIG. 9, the punch 41 is formed in an annular shape in a plan view (when viewed from the axial direction). The punch 41 includes a plurality of divided portions 45 (eight in this example) arranged at equal intervals along the circumferential direction. Each divided portion 45 is formed, for example, in an annular fan shape in a plan view and is movable in the radial direction.

[0043] In this example, the hook portion 44 is provided in each divided portion 45. That is, each divided portion 45 has a main body portion 45a and a protruding portion 45b that protrudes radially inward from the upper end portion of the main body portion 45a, and the protruding portion 45b functions as the hook portion 44. In other words, the hook portion 44 includes a plurality of portions (protruding portions 45b) arranged along the circumferential direction.

[0044] In the reversing process, the hook portion 44 moves downward (to the second side) while moving radially inward. Specifically, a cam 46 is disposed below the punch 41. The cam 46 has an inclined guide surface 46a facing the punch 41. The punch 41 (each divided portion 45) has an inclined surface 41a corresponding to the guide surface 46a. The inclined surface 41a and the guide surface 46a are inclined so as to move radially inward as they move downward. During the reversing process, the punch 41 is pushed downward by the pushing jig J, causing the inclined surface 41a to come into contact with the guide surface 46a, and the inclined surface 41a is guided by the guide surface 46a. As a result, the punch 41 moves obliquely radially inward and downward.

[0045] During reversing, this movement of the punch 41 causes the hook portion 44 to hook onto the outer work flange 23, pulling the outer work flange 23 radially inward, as shown in Figures 6(b) and 7. During this hooking operation, the hook portion 44 comes into contact with the inner surface of the outer work flange 23. Concurrently with this hooking operation, the inner work flange 22 is pushed outward by the backup block 43 on the inner diameter side, as described above. As shown in Figure 7, the punch 41 finally moves straight downward, thereby completing the reversing operation. The punch 41 then moves upward, returning to the position it was in before the reversing operation.

[0046] The above steps yield the inner shell 5. Thereafter, for example, when manufacturing a rolling bearing including the inner shell 5, the plurality of rolling elements 2 and the cage 3 are assembled to the inner shell 5 so that the cage 3 is held by the inner shell 5 and the plurality of rolling elements 2 are able to roll on the shell body 51. In this way, the rolling bearing is obtained. [Action and effect]

[0047] In the above-described method for manufacturing a bearing shell member, a reversing process is performed in which a workpiece member 20 having an inner workpiece flange 22 and an outer workpiece flange 23 extending from a workpiece body 21 to a first side in the axial direction is sandwiched between a punch 41 disposed on the first side and a die 42 disposed on a second side opposite the first side and deformed. Simply performing reversing on a workpiece member 20 having such a shape can result in the workpiece member 20 not standing up properly and becoming bent. For example, the punch may come into contact with an unintended portion of the outer workpiece flange 23, causing the outer workpiece flange 23 to bend. In the manufacturing of the bearing shell member described above, such unintended deformation is likely to occur because the workpiece member 20 (inner ring shell 5) is extremely thin and the outer workpiece flange 23 is prone to buckling and bending. In contrast, in the reversing process of this method for manufacturing a bearing shell member, a punch 41 having a hook 44 is used, and the hook 44 is hooked onto the outer workpiece flange 23 to perform the reversing process. This makes it easier to raise the workpiece 20 during reversal processing, and allows for satisfactory raising of the workpiece 20. Therefore, according to this method for manufacturing a bearing shell member, the inner shell 5 (bearing shell member) having the pair of shell flanges 52 can be manufactured satisfactorily.

[0048] In the reversing step, the hooking portion 44 moves downward (to the second side) while moving radially inward, thereby enabling the hooking portion 44 to be hooked properly.

[0049] The hook portion 44 includes a plurality of portions (protrusions 45b) arranged along the circumferential direction, which allows the hook portion 44 to be hooked in a good manner.

[0050] Before the inversion step, a sizing step is carried out to deform the work body 21 so that a difference in thickness is generated between the first portion 21a on the inner work flange 22 side and the second portion 21b on the outer work flange 23 side in the work body 21 after the inversion step, so that the difference in thickness between the first portion 21a and the second portion 21b is reduced. This makes it possible to reduce the difference in thickness between the first portion 21a and the second portion 21b after the inversion step, and to form the shell body 51 of the inner shell 5 straight.

[0051] Before the reversing step, a burring step is carried out to obtain the workpiece 20 by burring an annular workpiece 6 arranged on the inner die 31 and the outer die 32 so as to bridge between the inner die 31 and the outer die 32, using a burring punch 33 that moves between the inner die 31 and the outer die 32. In the burring step, a deformation suppressing member 34 is used to contact the workpiece 6 from the side opposite to the burring punch 33, and burring is performed while the workpiece 6 is sandwiched between the burring punch 33 and the deformation suppressing member 34. This makes it possible to prevent the workpiece 6 from bending at the location pressed by the burring punch 33, and to form a straight workpiece body 21 of the workpiece 20. [Variations]

[0052] As in a first modified example shown in Figures 10 and 11, the contact surface 43b of the backup block 43 with the workpiece 20 (inner workpiece flange 22) may be inclined so as to approach the workpiece 20 as it moves downward (to the second side). In this example, the contact surface 43b is a tapered surface that is inclined radially outward as it moves downward. Also, in the first modified example, the punch 41 has a main body 47, a hooking portion (hooking jig) 44 that is movable relative to the main body 47, and a guide member (extrusion jig) 48 that guides the movement of the hooking portion 44. The main body 47 is composed of a single member that is formed, for example, in a circular ring shape in a plan view.

[0053] The hook portion 44 has an inclined surface 44a, and the guide member 48 has an inclined guide surface 48a. The inclined surface 44a and the guide surface 48a are inclined so that they move radially inward as they move downward. During the reversing process, as shown in FIG. 10(b), the push jig J pushes the hook portion 44 downward, and the inclined surface 44a is guided by the guide surface 48a, causing the hook portion 44 to move diagonally radially inward and downward. This causes the hook portion 44 to protrude (jump out) from the main body 47. Concurrently with this protruding movement, the backup block 43 on the inner diameter side pushes the inner work flange 22 outward. Then, as shown in FIG. 11, the tip 44b of the hook portion 44 hooks onto the outer work flange 23 and pushes the inner surface of the outer work flange 23 downward. This completes the reversing process. The hook portion 44 then moves upward and returns to its position before the reversing process. The hook portion 44 is made up of, for example, a plurality of members arranged at equal intervals along the radial direction. The punch 41 comes into contact with a receiving member 49 at a guide member 48.

[0054] As with the above embodiment, this first modified example also makes it possible to satisfactorily manufacture an inner shell 5 (bearing shell component) having a pair of shell flanges 52. Furthermore, since the punch 41 has a main body 47 and a hooking portion 44 that is movable relative to the main body 47, the hooking portion 44 can be satisfactorily hooked. Furthermore, since the contact surface 43b of the backup block 43 that comes into contact with the workpiece 20 is inclined so as to approach the workpiece 20 as it moves downward (to the second side), the backup block 43 can satisfactorily raise the workpiece 20.

[0055] As a second modified example, a backward extrusion process may be performed instead of the burring process (see FIG. 3(b)). In the second modified example, the punching process, backward extrusion process, sizing process, and inversion process are performed in this order. In the backward extrusion process, the processed member 6 placed in the mold is pushed backward (opposite to the moving direction of the punch) by a punch, thereby obtaining a work member 20 having a shape shown in FIG. 12, for example.

[0056] As with the above embodiment, this second modified example also makes it possible to satisfactorily manufacture an inner shell 5 (bearing shell component) having a pair of shell flanges 52. Furthermore, compared to obtaining the workpiece component 20 by, for example, burring, the degree of curvature between the workpiece body 21 and the inner and outer workpiece flanges 22 and 23 can be reduced (for example, to approximately right angles), thereby ensuring high strength for the bearing shell component. Furthermore, the fracture surfaces formed in the punching process are crushed by plastic deformation in the backward extrusion process, which prevents the workpiece component 20 from cracking during the reversing process.

[0057] Furthermore, by using the same shape of the punch used in the backward extrusion process of the second modified example as the workpiece body 21 after the sizing process, the sizing process can be omitted. That is, in the backward extrusion process, the workpiece member 20 may be formed so that there is a difference in thickness between the first portion 21a on the inner workpiece flange 22 side and the second portion 21b on the outer workpiece flange 23 side of the workpiece body 21 after the inversion process. In other words, in the backward extrusion process, the workpiece member 20 may be formed into the shape shown on the left side of FIG. 5(b). In this case, the difference in thickness between the first portion 21a and the second portion 21b after the inversion process can be reduced, and the shell body 51 of the inner shell 5 can be formed straight.

[0058] 13 and 14, the backup block 43 does not have to be used in the reversing step. This third modification also makes it possible to satisfactorily manufacture an inner shell 5 (bearing shell member) having a pair of shell flanges 52, as in the above embodiment.

[0059] While the above embodiment and the first to third modified examples have described methods for manufacturing the inner shell 5, the above embodiment and the first to third modified examples can also be applied to the manufacture of the outer shell 4. Figure 15 shows the movement of the punch 41 and die 42 in the reversing step when manufacturing the outer shell 4. In this reversing step, the punch 41 presses against the inner work flange 22, causing the work member 20 to rise inward, and the cross-sectional shape of the work member 20 is rotated 90 degrees. As a result, the work body 21, the inner work flange 22, and the outer work flange 23 become the shell body 11 and the pair of shell flanges 12 of the outer shell 4, respectively, and the outer shell 4 is obtained.

[0060] In the inversion process when manufacturing the outer shell 4, the inversion process may be performed by using a backup block 43 to push the outer work flange 23 from the outside to the inside in the radial direction, while using a punch 41 to push the inner work flange 22 from the top to the bottom. The backup block 43 may include a plurality of block members 43a arranged along the circumferential direction. The contact surface 43b of the backup block 43 with the work member 20 (outer work flange 23) may be inclined so as to approach the work member 20 as it moves downward (to the second side). In this case, the contact surface 43b is a tapered surface that is inclined so as to move radially inward as it moves downward.

[0061] In the inversion process for manufacturing the outer shell 4, a punch 41 having a hook portion 44 is used, and the hook portion 44 is hooked onto the inner work flange 22 (curl portion) to perform the inversion process. The hook portion 44 may move downward (to the second side) while moving radially outward. For example, by inclining the inclined surface 41a of the punch 41 and the guide surface 46a of the cam 46 described above so that they move radially outward as they approach the lower side, contrary to the embodiment, the punch 41 can be moved obliquely radially outward and downward during the inversion process. During the inversion process, the hook portion 44 may hook onto the inner work flange 22, pulling the inner work flange 22 radially outward due to such movement of the punch 41. During this hooking operation, the hook portion 44 may come into contact with the inner surface of the inner work flange 22. In parallel with this hooking operation, the outer work flange 23 may be pushed outward on the outer diameter side by the backup block 43 as described above.

[0062] According to such a method for manufacturing the outer shell 4, the outer shell 4 (bearing shell member) having the pair of shell flanges 12 can be manufactured satisfactorily.

[0063] The present invention is not limited to the above-described embodiment and modifications. For example, the materials and shapes of the components are not limited to those described above, and various materials and shapes can be adopted.

[0064] In the reversing step, the backup block 43 may start pressing the inner work flange 22 or the outer work flange 23 simultaneously with the start of the reversing process, or may start pressing the inner work flange 22 or the outer work flange 23 midway through the reversing process. The contact surface 43b of the backup block 43 with the work member 20 may have any shape that fits into the R portion between the work main body 21 and the inner work flange 22 or the outer work flange 23, and may have a curved shape instead of a tapered shape.

[0065] When the above-described manufacturing method for a bearing shell member is applied to a manufacturing method for a shell member used as an inner ring or outer ring in a deep groove ball bearing, ball grooves may be formed in the workpiece member 20 in the sizing process. Similarly, when the above-described manufacturing method for a bearing shell member is applied to a manufacturing method for a shell member used as an inner ring in a tapered roller bearing, grooves may be formed in the workpiece member 20 in the sizing process. [Explanation of symbols]

[0066] 1...rolling bearing, 2...rolling element, 3...retainer, 4...outer ring shell (bearing shell component), 5...inner ring shell (bearing shell component), 6...machined component, 11, 51...shell body, 12, 52...shell flange, 20...workpiece component, 21...workpiece body, 21a...first part, 21b...second part, 22...inner workpiece flange, 23...outer workpiece flange, 31...inner die, 32...outer die, 33...burring punch, 34...deformation suppression member, 41...punch, 42...die, 43...backup block, 44...hook portion, 45b...protrusion, 47...main body.

Claims

1. A method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending radially outward in a plate-like shape from both axial ends of the shell body, the method comprising: The method includes a reversing process for performing a reversing process in which a workpiece member having an annular workpiece body, an inner workpiece flange extending in a plate shape from a radially inner end of the workpiece body to a first side in the axial direction, and an outer workpiece flange extending in a plate shape from a radially outer end of the workpiece body to the first side is sandwiched between a punch arranged on the first side and a die arranged on a second side opposite to the first side, and deformed, In the inverting step, the punch having a hook portion is used, and the hook portion is hooked onto the outer work flange to perform the inverting process.

2. A method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending radially inward in a plate-like shape from both axial ends of the shell body, the method comprising: The method includes a reversing process for performing a reversing process in which a workpiece member having an annular workpiece body, an inner workpiece flange extending in a plate shape from a radially inner end of the workpiece body to a first side in the axial direction, and an outer workpiece flange extending in a plate shape from a radially outer end of the workpiece body to the first side is sandwiched between a punch arranged on the first side and a die arranged on a second side opposite to the first side, and deformed, In the inverting step, the punch having a hook portion is used, and the inverting process is performed by hooking the hook portion onto the inner work flange.

3. A method for manufacturing a shell member for a bearing having a cylindrical shell body and a pair of shell flanges extending radially outward from both axial ends of the shell body, comprising: a reversing step of performing reversing processing to sandwich and deform a workpiece member having an annular workpiece body, an inner workpiece flange extending from a radially inner end of the workpiece body to a first side in the axial direction, and an outer workpiece flange extending from a radially outer end of the workpiece body to the first side, between a punch arranged on the first side and a die arranged on a second side opposite to the first side; In the inverting step, the punch having a hook portion is used, and the hook portion is hooked onto the outer work flange to perform the inverting process. In the inverting step, the hook portion moves to the second side while moving radially inward.

4. A method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending radially inward from both axial ends of the shell body, comprising: a reversing step of performing reversing processing to sandwich and deform a workpiece member having an annular workpiece body, an inner workpiece flange extending from a radially inner end of the workpiece body to a first side in the axial direction, and an outer workpiece flange extending from a radially outer end of the workpiece body to the first side, between a punch arranged on the first side and a die arranged on a second side opposite to the first side; In the reversing step, the punch having a hook portion is used, and the hook portion is hooked onto the inner work flange to perform the reversing process. In the inverting step, the hook portion moves to the second side while moving radially outward.

5. The method for manufacturing a bearing shell member according to any one of claims 1 to 4, wherein the hook portion includes a plurality of portions arranged along the circumferential direction.

6. 6. The method for manufacturing a bearing shell member according to claim 1, wherein the punch has a main body portion and the hook portion that is movable relative to the main body portion.

7. 7. The method for manufacturing a bearing shell member according to claim 1, further comprising a sizing step of deforming the work body before the inversion step so that a difference in thickness between a first portion on the side of the inner work flange and a second portion on the side of the outer work flange is generated in the work body after the inversion step, so that a difference in thickness between the first portion and the second portion is reduced.

8. The method further includes a burring step, which is performed before the inversion step, to obtain the workpiece by performing a burring process in which an annular workpiece disposed on the inner die and the 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, 8. The method for manufacturing a bearing shell member according to claim 1, wherein in the burring step, a deformation suppressing member is used that contacts the processed member from an opposite side to the burring punch, and the burring process is performed while the processed member is sandwiched between the burring punch and the deformation suppressing member.

9. The method for manufacturing a bearing shell member according to any one of claims 1 to 7, further comprising a backward extrusion step of forming the workpiece by backward extrusion before the inversion step.

10. The method further includes a backward extrusion step of forming the workpiece by backward extrusion before the inversion step, 7. The method for manufacturing a bearing shell member according to claim 1, wherein in the backward extrusion step, the workpiece member is formed such that a difference in thickness exists between a first portion on the side of the inner work flange and a second portion on the side of the outer work flange in the workpiece body after the inversion step, so that a difference in thickness between the first portion and the second portion is reduced.

11. A method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending radially outward from both axial ends of the shell body, comprising: a reversing step of performing reversing processing to sandwich and deform a workpiece member having an annular workpiece body, an inner workpiece flange extending from a radially inner end of the workpiece body to a first side in the axial direction, and an outer workpiece flange extending from a radially outer end of the workpiece body to the first side, between a punch arranged on the first side and a die arranged on a second side opposite to the first side; In the inverting step, the punch having a hook portion is used, and the hook portion is hooked onto the outer work flange to perform the inverting process. In the inversion process, the inner work flange is pushed from the radial inside to the radial outside by a backup block, while the outer work flange is pushed from the first side to the second side by the punch, thereby performing the inversion process.

12. A method for manufacturing a bearing shell member having a cylindrical shell body and a pair of shell flanges extending radially inward from both axial ends of the shell body, comprising: a reversing step of performing reversing processing to sandwich and deform a workpiece member having an annular workpiece body, an inner workpiece flange extending from a radially inner end of the workpiece body to a first side in the axial direction, and an outer workpiece flange extending from a radially outer end of the workpiece body to the first side, between a punch arranged on the first side and a die arranged on a second side opposite to the first side; In the reversing step, the punch having a hook portion is used, and the hook portion is hooked onto the inner work flange to perform the reversing process. In the inversion process, the outer work flange is pushed from the radial outside to the radial inside by a backup block, while the inner work flange is pushed from the first side to the second side by the punch, thereby performing the inversion process.

13. A step of obtaining the bearing shell member by the method for manufacturing a bearing shell member according to any one of claims 1 to 11; and assembling a plurality of rolling elements and a retainer that rotatably holds the plurality of rolling elements to the bearing shell member so that the retainer is held by the bearing shell member and the plurality of rolling elements can roll on the shell body.

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