JP2011025312A - Method and apparatus for manufacturing inner and outer ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing inner and outer rings, a method that can improve the yield and reduce cost of materials while manufacturing of the inner and outer rings is facilitated. <P>SOLUTION: In the method for manufacturing inner and outer rings, first, a heated disk-like base stock is subjected to cold-heading, and a first formed product with a circular hole formed, the product including a tapered recess with a tapered inner face inward in the center of one end face and including a thin bottom part C2 with a diameter smaller than the inner diameter of the inner ring to be manufactured in the center part of the bottom face of the tapered recess. Second, the thin bottom part C2 of the first formed product is blanked to form a second formed product D with a circular through hole D2. Thereafter, while the periphery of the circular through hole D2 of the second formed product D is pushed forward and at the same time the diameter is expanded, one piece of a third formed product is formed composed of an outer ring, a middle ring and an inner ring. Lastly, the third formed product is blanked in two steps using two inner/outer dies and two inner/outer punches, thereby forming the outer ring, the inner ring, and the middle ring as a blank scrap. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention mainly relates to an inner / outer ring manufacturing method and an apparatus for manufacturing an inner / outer ring in a bearing from a single cylindrical material.

Conventionally, as a method for manufacturing the inner and outer rings of a ball bearing, for example, as shown in FIG. 27, a cylindrical material 10A that is heated and cut to a predetermined size is upset, and the disk shown in FIG. In the first step, the disk-shaped material 10B is formed by forging, and the outer ring portion 11 having a large diameter and the intermediate ring portion concentrically integrated with the outer ring portion 11 shown in FIG. The first molded product 10C formed by the small-diameter bottomed inner ring portion 12 projecting through 13 is formed, and then in the second step, the first molded product 10C is placed in each recess of the punch and the die. The bottom part 12a of the bottomed inner ring part 12 is punched out by a punching punch that is slidably provided at the center of the punch under the state to form a second molded product 10D shown in FIG. Then, in the third step, the second molded product 10D is divided into two dies And two inner and outer punches to form two separate parts, an outer ring R1 ', an inner ring R2', and an intermediate ring R3 'as a punching waste as shown in FIG. This is known.
Japanese Patent Publication No.54-3477

  By the way, according to the manufacturing method of the inner and outer rings described above, the outer ring part 11 having a large diameter suddenly starts from the disc-shaped material 10B, and the small-diameter bottomed inner ring part 12 projecting through the intermediate ring part 13 concentrically with the outer ring part 11. There is a problem that a large molding load is required to form the first molded product 10C. Further, when the bottom portion 12a of the bottomed inner ring portion 12 is punched out, an intermediate ring (punching residue) R3 'generated when the inner ring R2' and the outer ring R1 'are separated is generated. At this time, the removal of the bottom 12a in the bottomed inner ring portion 12 has the same diameter as the inner diameter of the inner ring R1 ′ to be manufactured, and in the manufacturing process of forming the first molded product 10C suddenly from the disk-shaped material 10B. Accordingly, the bottom 12a is left with a thick wall, which causes a great deal of material loss. For this reason, there was a problem that yield was bad and material cost was high.

  Accordingly, the present invention has been invented in view of the above-described problems. An inner / outer ring manufacturing method and apparatus capable of improving the yield and reducing the material cost while being able to easily manufacture the inner / outer ring. The issue is to provide

In order to solve the above-described problem, the invention according to claim 1 of the present application is a method of manufacturing inner and outer rings from a single cylindrical material. A cylindrical recess is formed by forging and forming a circular cylindrical outer periphery, and has a tapered recess having a tapered inner surface that gradually decreases inward toward the center of one end surface, and a bottom center portion of the tapered recess. The first molded product having a small diameter smaller than the inner diameter of the inner ring to be manufactured and formed with a circular hole having a thin bottom portion is formed. Next, in the second step, the first molded product is punched and punched with a thin bottom portion of the circular hole. To form a second molded product having a circular through hole having a diameter smaller than the inner diameter of the inner ring to be manufactured at the center, and then, in a third step, the second molded product is formed in the circular through hole. The diameter is expanded while pushing around Forging is carried out to form one third molded product consisting of an outer ring part and an inner ring part that is concentrically integrated with the outer ring part and protrudes through an intermediate ring part. The molded product is punched in two steps with two inner and outer dies and two inner and outer punches, so that the inner and outer rings are simultaneously punched to form an inner ring, an outer ring, and an intermediate ring as a punching waste. And
The columnar material is a concept including a disk-shaped material obtained by upsetting a columnar material.

In the invention according to claim 2 of the present application, as a method of manufacturing the inner and outer rings from one columnar material, first, in the first step, one columnar material heated and cut to a predetermined dimension. The inner periphery of the inner ring to be manufactured at the center of the bottom surface of the tapered recess, and the tapered recess having a tapered inner surface whose outer periphery is formed into a circular shape and gradually decreases inward toward the inside. Forming a first molded product having a smaller diameter and a thin hole having a thin bottom, and then, in the second step, the first molded product is punched by punching the thin bottom of the circular hole, Forming a second molded product having a circular through-hole having a diameter smaller than the inner diameter of the inner ring to be manufactured, and then, in the third step, simultaneously extruding the second molded product forward around the circular through-hole. Forging molding while expanding the diameter And a third molded product formed of an inner ring part that is concentrically integrated with the outer ring part and is connected to the inner circumference of one end part of the outer ring part and has an outer ring projecting from the other end part. In the process, the third molded product is separated into two by punching out the inner and outer rings with a die and a punch to form an outer ring and an inner ring.
The inner and outer rings without the intermediate ring portion are concepts including inner and outer rings of ball bearings (inner and outer blanks) that are enlarged by cold ring rolling and inner and outer rings of tapered roller bearings (inner and outer blanks having a tapered surface).

Further, the invention according to claim 3 of the present application is a taper convex portion having a tapered outer surface that gradually becomes smaller in diameter toward the inward at the center of one end surface as an inner / outer ring manufacturing apparatus for manufacturing inner and outer rings from a single cylindrical material. A punch formed concentrically with a circular protrusion protruding forward from the center of the tip of the taper protrusion, and a die having a molding recess whose inner peripheral surface is circular. One cylindrical material that has been heated and cut to a predetermined size is formed by forging, the outer periphery is formed into a circular shape, and a tapered recess having a tapered inner surface that gradually decreases inward toward the center of one end surface; A first forging station for forming a first molded product in which a circular hole having a thin bottom portion with a diameter smaller than the inner diameter of the inner ring to be manufactured is formed at the center of the bottom surface of the tapered recess, and substantially the same as the circular hole of the first molded product. Diameter punch and die A thin molded bottom portion of a circular hole is punched by a punch in the first molded product by using these punches and a die, and a second molded product having a circular through hole having a diameter smaller than the inner diameter of the inner ring to be manufactured at the center portion. A second forging station to be formed, a cylindrical portion for forming the inner surface of the outer ring protruding through the stepped portion, and an enlarged diameter forming pin for forming the inner surface of the inner ring provided concentrically with the tip of the cylindrical portion. And a die having an outer ring-forming annular portion for forming the outer surface of the outer ring, and an annular portion for forming the outer surface of the inner ring and a recess, and the second molded product is surrounded by the punch and die around the circular through-hole. One piece consisting of an outer ring part and an inner ring part that is concentrically integrated with the outer ring part and is connected to the inner periphery of one end part of the outer ring part and one end part of which is protruded at the other end part. The 3rd forging forming the third molded product And a fourth forging station that includes an annular die into which only the inner ring portion can be fitted, and a punch that can be fitted into the outer ring portion and the annular die, and is formed by punching with the punch and die to separate the outer ring and the inner ring. It is characterized by comprising.
The inner and outer rings without the intermediate ring portion are concepts including inner and outer rings of ball bearings (inner and outer blanks) that are enlarged by cold ring rolling and inner and outer rings of tapered roller bearings (inner and outer blanks having a tapered surface).

  According to the method for manufacturing the inner and outer rings according to claim 1 of the present application, in the first step, a taper recess having a tapered inner surface that gradually becomes smaller inward at the center of one end surface, and a bottom center portion of the taper recess. A first molded product having a small diameter smaller than the inner diameter of the inner ring to be formed and formed with a circular hole having a thin bottom part is molded, and in the second step, the thin bottom part is punched out and smaller in diameter than the inner diameter of the inner ring to be manufactured at the center part. Since the second molded product having the circular through hole is formed, it becomes possible to suppress the punching of the central circular hole as much as possible. In addition, in the third step, the inner and outer rings are molded while expanding the diameter of the tapered through hole by pushing forward around the circular through hole. Therefore, the outer ring part and this are reduced by using the tapered recessed part and the circular through hole. It is possible to easily mold the inner ring portion protruding forward. As a result, the molding load can be reduced and the inner and outer rings can be easily manufactured, while the punching of the center circular hole can be suppressed as much as possible to improve the yield, and the material cost can be reduced.

  Further, according to the method for manufacturing the inner and outer rings according to claim 2 of the present application, as in the method for manufacturing the inner and outer rings according to claim 1 described above, it is possible to suppress the punching debris of the center circular hole as much as possible, and The outer ring part and the inner ring part projecting forward of the outer ring part can be easily formed using the circular through-hole with less molding load, and the intermediate ring part compared to the inner / outer ring manufacturing method according to claim 1. Since the inner and outer rings are formed in a small size without producing any material, the yield can be further improved and the material cost can be reduced. Especially when molding inner and outer rings (inner and outer blanks) of ball bearings and inner and outer rings (tapered inner and outer blanks with tapered surfaces) of tapered roller bearings that are expanded by cold ring rolling without using the intermediate ring part by the conventional machine method. Compared with punching waste, in the present invention, the weight of punching can be reduced to 1/3 to 1/4.

  Furthermore, according to the inner / outer ring manufacturing apparatus according to claim 3 of the present application, in the first step, a tapered recess having a tapered inner surface that gradually decreases inward toward the center of the one end surface, and a bottom center portion of the tapered recess. A first molded product having a smaller diameter than the inner diameter of the inner ring to be manufactured and formed with a circular hole having a thin bottom part is formed. In the second step, the thin bottom part is punched out, and the inner diameter of the inner ring to be manufactured at the center part is determined. Since the second molded product having a small-diameter circular through hole is formed, it is possible to suppress the punching of the central circular hole as much as possible. Moreover, in the third step, the inner and outer rings are formed while expanding the diameter of the tapered through hole by pushing forward around the circular through hole, and in the fourth step, the outer ring and the inner ring are formed separately without taking out the intermediate ring portion. Therefore, the outer ring part and the inner ring part protruding forward are easily formed with a small molding load by using the tapered recessed part and the circular through hole of the second molded product while minimizing the punching of the central circular hole. be able to. In addition, since the inner and outer rings are formed small without taking out the intermediate ring portion, the yield can be improved and the material cost can be reduced. Especially when molding inner and outer rings (inner and outer blanks) of ball bearings and inner and outer rings (tapered inner and outer blanks with tapered surfaces) of tapered roller bearings that are expanded by cold ring rolling without using the intermediate ring part by the conventional machine method. Compared with punching waste, the present invention can reduce the weight of punching by about one third.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 6 show step by step the manufacturing process of a ball bearing composed of an outer ring R2 and an inner ring R1.

  FIG. 1 shows one cylindrical material A that has been heated and cut to a predetermined size. The columnar material A is obtained by sizing and feeding a round bar wire heated in a multistage hot former to the front side of the die block by a feeding device and cutting it to a predetermined size with a cutting blade.

  The columnar material A is subjected to upsetting while hot. As a result, the disk-shaped material B having an arcuate outer peripheral surface as shown in FIG. 2 is formed. And the disk-shaped raw material B is transferred to the 1st process of a hot former. Note that the upsetting process from the columnar material A to the disk-shaped material B can be omitted, and the columnar material A may be directly transferred to the first step.

  In the first step, the disk-shaped material B is first formed in the first forging station S1 of the hot former shown in FIG. Here, the first forging station S1 includes a die 1 and a punch 2, and the punch 2 is supported by a moving ram (not shown) that moves forward and backward with respect to the die 1 supported on the machine body side, and its tip portion. The taper convex part 2a which has the taper outer surface which becomes a small diameter gradually toward the center part from the outer periphery, and the circular protrusion 2b which protrudes ahead from the front-end | tip center part of the taper convex part 2a are formed concentrically. . The die 1 includes a split die 1a, 1b for forming an outer surface, a molding pin 1c fixed at the center of the split die 1b, and a knockout sleeve 1d that is slidably interposed between the die 1b and the molding pin 1c. And have.

  Then, as shown in FIG. 7, the disk-shaped material B is formed by forging with a die 1 and a punch 2, the outer periphery is formed into a circular shape, and the tapered inner surface gradually decreases in diameter toward the center at one end surface. 3 and a circular hole C3 having a thin bottom portion C2 having a diameter smaller than the inner diameter of the inner ring R2 to be manufactured are formed in the center of the bottom surface of the tapered recess C1. The At this time, since a simple preforming hole is formed by a combination of the tapered recess C1 and the small-diameter circular hole C3 at the center of the bottom surface thereof, the thickness of the thin bottom C2 is suppressed as much as possible.

  Next, the first molded product C is transferred to the second process, and in the second process, the first molded product C is secondarily molded at the second forging station S2 of the hot former shown in FIG. Here, the second forging station S2 includes a die 3 and a punching punch 4. The punch 4 is supported by the moving ram and has a punch 4a at the center of the tip of the punch 4 having the same diameter as the circular hole C3, that is, a diameter smaller than the inner diameter of the inner ring R2 to be manufactured. The die 3 has divided dies 3a and 3b for receiving the first molded product C, and a central die 3d having a through hole 3c for allowing the punch 4a to be inserted at the center of the divided die 3b and punching the thin bottom portion C2. Is provided. Further, the split die 3b is provided with a knockout pin 3e constituting a part of the die so as to freely slide. At the center of the divided die 3b, there is formed a discharge hole 3f that allows the punched debris to move to the back side, and at the back of the die 3 is a discharge port 3g for discharging the punched debris to the outside. Is formed. Further, in FIG. 7, a knockout sleeve 4b is provided on the outer periphery of the punch 4 so as to be freely slidable so that the second molded product D molded in the second step is reliably left in the die 3a when the punch 4 is retracted. Yes. Since the knockout mechanism for pushing out the knockout sleeve 4b has a known structure, its structure and operation are omitted.

  Then, as shown in FIG. 8, the first molded product C has an inner ring R2 to be manufactured at the center of the bottom of the tapered recess D by punching the thin bottom C2 of the circular hole C3 at the center by the punch 4a of the punch 4. The 2nd molded product D shown in FIG. 4 in which the circular through-hole D2 smaller than the internal diameter of this was shape | molded is formed.

  Thereafter, the second molded product D is transferred to the third step, and in this third step, the second molded product D is subjected to tertiary molding at the third forging station S3 of the hot former shown in FIG. Here, the third forging station S3 includes a die 5 and a punch 6. The die 5 includes an annular divided die 5a for forming the outer surface of the outer ring R1, an annular divided die 5b for forming the outer surface of the inner ring R2, and a recess. And a central die 5d having 5c. The central die 5d is slidably supported in the axial direction and also serves as a knockout sleeve. The punch 6 is supported by the moving ram, and is provided concentrically with the columnar part 6b for forming the inner surface of the outer ring R1 and the intermediate ring R3 projecting through the stepped part 6a and the intermediate ring R3. And an enlarged diameter forming pin 6c for forming the inner surface of the inner ring R2. Further, in FIG. 9, a knockout sleeve 6d for reliably leaving the third molded product E molded in the third step in the annular split dies 5a, 5b when the punch 6 is retracted is provided on the outer periphery of the cylindrical portion 6b. The knockout sleeve 6d is provided so as to be freely slidable, and the tip end surface of the knockout sleeve 6d constitutes the step 6a. Since the knockout mechanism for pushing out the knockout sleeve 6d has a known structure, its structure and operation are omitted.

  Then, as shown in FIG. 9, the second molded product D is forged by a die 5 and a punch 6. At this time, the diameter-enlarged molding pin 6c of the punch 6 pushes the periphery of the circular through hole D2 in the second molded product D forward, and at the same time the diameter is expanded, the shape of the molding space formed by the die 5 and the punch 6 is obtained. In addition, the inner and outer ring portions E1 and E2 are formed, and one third molded product E including the outer ring portion E1 shown in FIG. 5 and the inner ring portion E2 concentrically with the outer ring portion E1 and protruding through the intermediate ring portion E3. Is formed.

  Thereafter, the third molded product E is transferred to the fourth step, and in this fourth step, the fourth molded product E is subjected to quaternary molding at the fourth forging station S4 of the hot former shown in FIG. Here, the fourth forging station S4 includes a die 7 and a punch 8. The die 7 includes an annular die 7a in which the inner ring portion E2 is fitted in the hollow portion and supports the outer ring portion, and an inner ring die 7b that is slidable in the axial direction. And a knockout sleeve 7c for supporting the inner ring die 7b. The punch 8 is supported by the moving ram and is inserted into the inner ring die 7b to punch out the inner ring portion E2 from the intermediate ring portion E3. The punch 8 is abutted against the tip of the inner ring die 7b and the outer ring die 7a. And an outer ring punch 8b for separating the intermediate ring part E3 from the outer ring part E1. The outer ring punch 8b is fitted to the outer peripheral part of the inner ring punch 8a and slides in the axial direction, and its tip protrudes from the tip part of the inner ring punch 8a so as to advance and retract. The knockout sleeve 7c is formed with a discharge passage / opening 7d that allows movement of the separated inner ring R2 to the inner side, and corresponds to the discharge passage / opening 7d on the back side of the die 3. A discharge port 7e for discharging the separated inner ring R2 to the outside is provided.

  Then, as shown in FIG. 10, the third molded product E is hit in two steps by a die 7 consisting of an outer ring die 7a and an inner ring die 7b, and a punch 8 consisting of an inner ring punch 8a and an outer ring punch 8b. The rings R1 and R2 are punched at the same time and separated into an inner ring R2, an outer ring R1, and an intermediate ring R3 as a punching waste as shown in FIG. That is, first, the inner ring punch 8a is punched out so that the inner ring part E3 of the third molded product E is separated from the intermediate ring R3, while the remaining outer ring part R2 and intermediate ring R3 are outer ring part R1 by the outer ring punch 8b. The outer ring R1 and the inner ring R2 are formed by punching so that the intermediate ring R3 is separated from the outer ring R3.

  After the separation, the inner ring R2 is taken out from the discharge port 7e through the discharge passage / opening 7d of the knockout sleeve 7c. Further, the outer ring R1 is recovered by being extracted from the punch 8, and the intermediate ring R3 is further pushed out from the die 7 by the knockout sleeve 7c and the inner ring die 7b.

  When the outer ring R1 and the inner ring R2 manufactured as described above are used, for example, as ball bearings as shown in FIG. 11, a raceway groove or the like is appropriately provided on each facing surface of the outer ring R1 and the inner ring R2 in a later step. Used after being processed by a processing means.

  As described above, according to the present invention, in the first step S1, the tapered recess C1 having a tapered inner surface that gradually decreases in diameter toward the bottom at the center of one end surface, and the inner ring to be manufactured at the center of the bottom surface of the tapered recess C1. A first molded product C formed with a circular hole C3 having a smaller diameter than the inner diameter of R2 and having a thin bottom portion C2 is formed, and in a second step S2, a circular penetration having a diameter smaller than the inner diameter of the inner ring R2 to be manufactured is formed at the center. Since the second molded product D having the hole D2 is formed, it is possible to suppress the punched and broken C2 of the central circular hole as much as possible. In addition, in the third step S3, the inner and outer ring portions E1 and E2 are formed by expanding the diameter around the circular through hole D2 of the tapered recess D1 by pushing forward, so that it protrudes forward of the outer ring portion E1 while suppressing the forming load. The inner ring portion E2 can be easily formed. As a result, the molding load is reduced and the inner and outer rings R1 and R2 can be easily manufactured, but the yield of the center circular hole can be reduced by minimizing as much as possible, and the material cost can be reduced.

  FIGS. 12 to 21 show another embodiment. When the inner and outer rings are simultaneously manufactured by punching, the inner and outer rings (inner and outer blanks constituting the bearing) are formed small without taking out the intermediate rings, Thereafter, a method and an apparatus for manufacturing the inner and outer rings in the case where the inner and outer rings separated into two without taking out the intermediate ring are enlarged and formed into ball bearings of a predetermined shape by cold ring rolling will be described.

  First, FIG. 12 to FIG. 17 show step by step the manufacturing process of a ball bearing (an inner / outer blank constituting the bearing) composed of an outer ring R1 and an inner ring R2. Note that the subsequent process of forming the outer ring R1 into an outer ring having a predetermined shape by cold ring rolling and processing the raceway grooves on the opposing surfaces of the outer ring R1 and the inner ring R2 is not a gist and will not be described.

  FIG. 12 shows one columnar material A that has been heated and cut to a predetermined size, as in the previous embodiment. The columnar material A is obtained by sizing and feeding a round bar wire heated in a multistage hot former to the front side of the die block by a feeding device and cutting it to a predetermined size with a cutting blade.

  Then, as in the previous embodiment, the columnar material A is upset to form a disk-shaped material B having an arcuate outer peripheral surface shown in FIG. This disk-shaped material B is transferred to the first step of the hot former. Note that the upsetting process from the columnar material A to the disk-shaped material B can be omitted, and the columnar material A may be directly transferred to the first step.

  In the first step, the disk-shaped material B is first formed in the first forging station S1 of the hot former shown in FIG. Here, the first forging station S1 includes a die 10 and a punch 20, and the punch 20 is supported by a moving ram (not shown) that moves forward and backward with respect to the die 10 supported on the machine body side, and its tip portion. The taper convex part 20a which has the taper outer surface which becomes a small diameter gradually toward a center part from near the perimeter, and the circular projection part 20b which protrudes ahead from the tip central part of taper convex part 20a are formed concentrically. . The die 10 is slidably interposed between the divided dies 10a and 10b for forming the outer surface supported on the machine body, the forming pin 10c fixed at the center of the divided die 10b, and the die 10b and the forming pin 10c. And a knockout sleeve 10d.

  Then, as shown in FIG. 18, the disk-shaped material B is forged by the forward movement of the punch 20 toward the die 10, the outer periphery is formed into a circular shape, and gradually increases inward toward the center of one end surface. The first molding shown in FIG. 14 is formed with a tapered recess C1 having a tapered inner surface with a small diameter, and a circular hole C3 having a smaller bottom diameter C2 than the inner diameter of the inner ring R2 to be manufactured at the center of the bottom surface of the tapered recess C1. Product C is formed. The first molded product C is pushed out of the die 30 by the knockout sleeve 10d as the punch 20 moves backward, is held by a material transfer chuck (not shown), and is transferred to the third step.

  Next, in the second step, the first molded product C is secondarily molded at the second forging station S2 of the hot former shown in FIG. Here, the second forging station S2 includes a die 30 and a punching punch 40. The punch 40 is supported by the moving ram and has the same diameter as that of the circular hole C3 at the center of the tip of the punch 40, that is, manufacturing. A punch 40a having a smaller diameter than the inner diameter of the inner ring R2 to be tried and a plurality of stripper rods 40b. The die 30 has an annular die 30a for receiving the first molded product C, while receiving the first molded product C at the center of the annular die 30a and having a through hole 30b for punching the thin thin bottom portion C2 while allowing the punch 40a to be inserted. A central die 30c is provided. In addition, on the back side of the central die 30c, a sliding body 30e communicating with the through hole 30b and having a through hole 30d for discharging punched debris and a knockout pin 30f are slidably arranged in the axial direction. It is installed. Further, a discharge port 30g for discharging the punched debris in the through hole 30d of the sliding body 30e to the outside is formed in the inner part of the machine body that supports the die 30. In FIG. 19, 30h is a stopper body for restricting the movement of the sliding body 30e, and 30i is a return spring for the stopper body 30h interposed between the stopper body 30h and the annular die 30a.

  Then, as shown in FIG. 19, in the first molded product C, the thin bottom portion C2 of the circular hole C3 in the central portion is punched by the punch 40a of the punch 40 by the forward movement of the punch 40 toward the die 30, and the taper is tapered. A second molded product D shown in FIG. 15 is formed in which a circular through hole D2 having a smaller diameter than the inner diameter of the inner ring R2 to be manufactured is formed at the center of the bottom of the recess D. At this time, the punching waste of the thin bottom portion C2 is suppressed as much as possible. The second molded product D is pushed out of the die 30 by the knockout pin 30f and the sliding body 30e while being supported by the strippers 40b... 40b as the punch 40 moves backward, and is held by a material transfer chuck (not shown). And transferred to the third step.

  Thereafter, the second molded product D is thirdarily molded in the third forging station S3 of the hot former shown in FIG. 20 in the third step. Here, the third forging station S3 includes a die 50 and a punch 60. The die 50 includes an annular split die 50a for forming the outer surface of the outer ring R1, an annular split die 50b for forming the outer surface of the inner ring R2, a central die 50d having a recess 50c, and a knockout pin 50e. The central die 50d is slidably supported in the axial direction and also serves as a knockout sleeve. The punch 60 is supported by the moving ram and is slidable in the axial direction and serves as a stripper, and a cylindrical portion 60b for forming an inner surface of the outer ring R1 protruding from the cylindrical portion 60a. It has a cylindrical portion 60b and an enlarged diameter forming pin 60c for forming an inner surface of the inner ring R2 that is provided concentrically and integrally.

  Then, as shown in FIG. 20, the second molded product D is forged by the forward movement of the punch 60 toward the die 50 side. At this time, the diameter expansion molding pin 60c of the punch 60 pushes the periphery of the circular through hole D2 in the second molded product D forward, and at the same time the diameter is expanded, the shape of the molding space formed by the die 50 and the punch 60 is obtained. In addition, inner and outer ring portions E1 and E2 are formed, and an outer ring portion E1 shown in FIG. 16 and an inner ring whose one end portion is connected to the inner periphery of one end portion of the outer ring portion E1 concentrically with the outer ring portion E1 and the other end portion protrudes. One third molded product E composed of the portion E2 is formed. The third molded product E is pushed out of the die 50 by the knockout pin 50e and the central die 50d while being supported by the cylindrical portion 60a as the punch 60 moves backward, and is held by a material transfer chuck (not shown). And transferred to the fourth step.

  Thereafter, in the fourth step, the third molded product E is subjected to quaternary molding at the fourth forging station S4 of the hot former shown in FIG. Here, the fourth forging station S4 includes a die 70 and a punch 80, and the die 70 includes an annular die 70a in which only the inner ring portion E2 is fitted and the outer ring portion E1 is supported on the outer surface, and a knockout sleeve 70b. ing. The punch 80 is supported by the moving ram, and has a separation punch 80a that fits into the annular die 70a and punches and separates the inner ring portion E2 from the outer ring portion E1, and a knockout sleeve 80b.

  As shown in FIG. 21, the third molded product E is punched out by the annular die 70a and the separation punch 80a by the forward movement of the punch 80 toward the die 70, and is separated into the outer ring R1 and the inner ring R2. The separated outer ring R1 and inner ring R2 are pushed forward from the die 70 by the knockout sleeve 70b and the knockout sleeve 80b and taken out. In addition, the inner ring R2 may be discharged from the machine body to the outside in addition to being pushed to the front side of the die 70.

  Further, the outer ring R1 and the inner ring R2 manufactured in two without taking out the intermediate ring as described above are used as ball bearings as shown in FIG. The diameter is expanded so that the raceway groove is rolled. Since this rolling molding is an existing molding method, its description is omitted.

  According to the method and apparatus for manufacturing the inner and outer rings that do not provide such an intermediate ring portion, the inner and outer rings R1 and R2 can be easily manufactured by reducing punching as much as possible and reducing the molding load as in the previous embodiment. However, since the inner and outer rings R1 and R2 are formed smaller without taking out the intermediate ring part as compared with the previous embodiment, the inner and outer rings (inner and outer blanks) of the ball bearing that is enlarged by cold ring rolling can be used. When molding, the yield can be further improved and the material cost can be reduced.

  Incidentally, as a method of manufacturing an inner / outer ring (inner / outer blank) of a ball bearing which does not take out an intermediate ring part and expands by cold ring rolling in the past, a large-diameter outer ring part 14 as shown in FIG. One intermediate molded product 10C composed of the outer ring portion 14 and a small-diameter bottomed inner ring portion 15 projecting concentrically and integrally is formed, and then the bottom portion of the bottomed inner ring portion 15 as shown in FIG. The outer ring R1 and the inner ring R2 are separated from the outer ring R1 and the inner ring R2 at the same time as the punching punch 15a is punched, but the manufacturing method of the present invention described above is compared with the punched residue (bottom 15a) of this conventional manufacturing method. And according to the manufacturing apparatus, the weight of the punching (bottom C2) can be reduced from 1/3 to 1/4.

  The above-described inner and outer ring manufacturing method and apparatus can also be applied to a method and apparatus for manufacturing tapered roller bearing inner and outer rings (inner and outer blanks having a tapered surface) as shown in FIGS.

  In that case, basically, the same manufacturing apparatus as in the previous embodiment is used. At that time, as shown in FIG. 25, the outer ring of the third molded product E is formed on the cylindrical portion 60b of the punch 60 in the third step. A taper portion 60b 'for forming a tapered inner surface E4 is formed on the inner surface of E1, while a round portion 50b' for forming an outer connection portion between the outer ring E1 and the inner ring E2 in a round shape on the annular split die 50b of the die 50. A structure in which is formed may be used. Since other configurations are the same as those in the previous embodiment, the same reference numerals are given, and detailed descriptions thereof are omitted.

  Thus, in the third step, as shown in FIG. 25, the diameter expansion molding pin 60c of the punch 60 pushes forward around the circular through hole D2 in the second molded product D and expands the diameter at the same time. Inner and outer ring portions E1 and E2 are formed in accordance with the shape of the forming space formed by the punch 60. At this time, as shown in FIG. 23, an outer ring portion E1 having a tapered inner surface E1 ′, an outer peripheral end portion connected to the inner periphery of one end portion of the outer ring portion E1 concentrically with the outer ring portion E1, and the other end are connected via a rounded portion E2 ′. One third molded product E formed by the inner ring portion E2 from which the portion protrudes is formed. The third molded product E is pushed out of the die 50 by the knockout pin 50e and the central die 50d while being supported by the cylindrical portion 60a as the punch 60 moves backward, and is held by a material transfer chuck (not shown). And transferred to the fourth step.

  Thereafter, in the fourth step, the third molded product E is subjected to quaternary molding at a fourth forging station S4 of a hot former similar to that of the previous embodiment shown in FIG. That is, as shown in FIG. 26, the third molded product E is punched by the annular die 70a and the separation punch 80a by the forward movement of the punch 80 toward the die 70a, and the outer ring R1 and the rounded portion E2 having the tapered inner surface E1 ′. And an inner ring R2 having a '. The separated outer ring R1 and inner ring R2 are pushed out from the die 70 by the knockout sleeve 70b and the knockout sleeve 80b and taken out.

  As described above, the outer ring R1 and the inner ring R2 having two tapered surfaces that are manufactured without using an intermediate ring are used as tapered roller bearings as shown in FIG. The diameter is expanded so as to constitute a rolling groove, and the raceway groove is rolled. Since this rolling molding is an existing molding method, its description is omitted.

  Also with the tapered roller bearing tapered inner and outer rings manufacturing method and apparatus, the inner and outer rings R1 and R2 having tapered surfaces can be produced by reducing the dropping load as much as possible and reducing the molding load as in the previous embodiment. This can be performed easily, yield can be improved, and material costs can be reduced.

  Incidentally, as a manufacturing method of a tapered inner / outer ring (inner / outer blank) of a tapered roller bearing that is conventionally enlarged by cold ring rolling, a large-diameter outer ring part 16 and the outer ring part 16 are shown in FIG. An intermediate molded product 10C composed of a small-diameter bottomed inner ring portion 17 projecting concentrically and integrally is integrally formed, and then the bottom portion 17a of the bottomed inner ring portion 17 is punched as shown in FIG. 29 (b). The outer ring R1 and the inner ring R2 are separated into the outer ring R1 and the inner ring R2 at the same time as punching, but the tapered shape of the tapered roller bearing of the present invention described above is compared with the punching debris (bottom portion 17a) of the conventional machine method. According to the manufacturing method and the apparatus for the inner and outer rings (inner and outer blanks), the weight of the punched (bottom C2) can be reduced from 1/3 to 1/4.

  It is a partially cutaway front view of the cylindrical raw material showing the manufacturing process of the ball bearing manufactured using the manufacturing method and apparatus for the inner and outer rings according to the present invention.   It is a partially cutaway front view of the disk-shaped raw material which shows the manufacturing process of the same bearing.   It is a partially cutaway front view of the 1st molded product which shows the manufacturing process of the bearing.   It is a partially cutaway front view of the 2nd molded product which shows the manufacturing process of the bearing.   It is a longitudinal front view of the 3rd molded product which shows the manufacturing process of the bearing.   It is a vertical front view of the 4th molded product which shows the manufacturing process of the bearing.   It is a principal part longitudinal section top view of the 1st forging station.   It is a principal part longitudinal section top view of the 2nd forging station.   It is a principal part longitudinal section top view of the 3rd forging station.   It is a principal part longitudinal section top view of the 4th forging station.   It is a longitudinal cross-sectional view of a ball bearing.   It is a front view of the column-shaped raw material which shows the manufacturing process of the ball bearing of another embodiment.   It is a front view of the disk-shaped raw material which shows the manufacturing process of the bearing.   It is a longitudinal cross-sectional view of the 1st molded product which shows the manufacturing process of the bearing.   It is a longitudinal cross-sectional view of the 2nd molded product which shows the manufacturing process of the bearing.   It is an expanded longitudinal cross-sectional view of the 3rd molded product which shows the manufacturing process of the same bearing.   It is an expansion longitudinal cross-sectional view of the 4th molded product which shows the manufacturing process of the same bearing.   It is a principal part longitudinal section top view of the 1st forging station.   It is a principal part longitudinal section top view of the 2nd forging station.   It is a principal part longitudinal section top view of the 3rd forging station.   It is a principal part longitudinal section top view of the 4th forging station.   It is a longitudinal cross-sectional view of a tapered roller bearing.   It is a longitudinal cross-sectional view of the 3rd molded product which shows the manufacturing process of the bearing.   It is a longitudinal cross-sectional view of the 4th molded product which shows the manufacturing process of the bearing.   It is a principal part longitudinal section top view of the 3rd forging station.   It is a principal part longitudinal section top view of the 4th forging station.   It is conventional explanatory drawing.   It is another conventional explanatory drawing.   It is another conventional explanatory drawing.

DESCRIPTION OF SYMBOLS 10 Die 20 Punch 20a Tapered convex part 20b Circular convex part 30 Die 40 Punch punch 50 Die 60 Punch 60a Annular step part 60b Cylindrical part 60c Expanding molding pin 70 Die 80 Punch C 1st molded product C1 Tapered recessed part C2 Thin bottom part C3 Circular Hole D Second molded product D2 Circular through hole E Third molded product E1 Inner ring portion E2 Outer ring portion E3 Intermediate ring portion R1 Outer ring R2 Inner ring R3 Intermediate ring

Claims (3)

  An inner and outer ring manufacturing method for manufacturing inner and outer rings from a single cylindrical material. First, in the first step, a cylindrical material that has been heated and cut to a predetermined size is formed by forging, and the outer periphery is circular. And a circular hole having a tapered inner surface with a tapered inner surface that gradually becomes smaller inward at the center of one end surface, and a thinner bottom portion having a smaller diameter than the inner diameter of the inner ring to be manufactured at the center of the bottom surface of the tapered recessed portion. Then, in the second step, the first molded product is punched into the thin bottom portion of the circular hole by a punching punch, and the inner diameter of the inner ring to be manufactured at the center portion is cut. A second molded product having a small-diameter circular through hole is formed, and then, in the third step, the second molded product is pushed forward around the circular through hole and simultaneously formed by forging while expanding the diameter. An intermediate ring concentrically with the outer ring and the outer ring By forming a third molded product consisting of the inner ring portion protruding through the inner ring portion, and then, in the fourth step, the third molded product is punched in two steps with two inner and outer dies and two inner and outer punches. An inner / outer ring manufacturing method, wherein the inner and outer rings are punched simultaneously to form an outer ring, an inner ring, and an intermediate ring as a punching waste.   An inner and outer ring manufacturing method for manufacturing inner and outer rings from a single cylindrical material. First, in the first step, a cylindrical material that has been heated and cut to a predetermined size is formed by forging, and the outer periphery is circular. And a circular hole having a tapered inner surface with a tapered inner surface that gradually becomes smaller inward at the center of one end surface, and a thinner bottom portion having a smaller diameter than the inner diameter of the inner ring to be manufactured at the center of the bottom surface of the tapered recessed portion. Then, in the second step, the first molded product is punched into the thin bottom portion of the circular hole by a punching punch, and the inner diameter of the inner ring to be manufactured at the center portion is cut. A second molded product having a small-diameter circular through hole is formed, and then, in the third step, the second molded product is pushed forward around the circular through hole and simultaneously formed by forging while expanding the diameter. And an outer ring that is concentrically integrated with the outer ring portion One end part of the outer periphery is connected to the inner periphery of the one end part and the other end part protrudes from the inner ring part to form one third molded part. Then, in the fourth step, the third molded part is formed with a die and a punch. An inner / outer ring manufacturing method, wherein the inner and outer rings are separated into two by punching to form an outer ring and an inner ring.   An inner and outer ring manufacturing apparatus that manufactures inner and outer rings from a single cylindrical material, from a taper convex part having a tapered outer surface that gradually decreases in diameter toward the inside at one end surface center, and a tip center part of the taper convex part. A punch having a circular protrusion projecting forward is formed concentrically and a die having a molding recess whose inner peripheral surface is circular, and the punch and the die are heated and cut into a predetermined size. A cylindrical material should be formed by forging, and the outer periphery should be formed into a circular shape, with a tapered recess having a tapered inner surface that gradually becomes smaller inward at the center of one end surface, and a bottom central portion of the tapered recess. A first forging station for forming a first molded product in which a circular hole having a thin bottom with a diameter smaller than the inner diameter of the inner ring is formed; a punching punch and a die having substantially the same diameter as the circular hole of the first molded product; These punches and da A second forging station for punching a thin bottom portion of a circular hole with a punch in the first molded product to form a second molded product having a circular through hole smaller in diameter than the inner diameter of the inner ring to be manufactured at the center, A punch having a cylindrical portion for forming the inner surface of the outer ring protruding through the annular stepped portion, and a diameter increasing molding pin for forming the inner surface of the inner ring concentrically provided at the tip of the cylindrical portion, and the outer surface of the outer ring A die having an annular portion for forming, an annular portion for forming the outer surface of the inner ring and a recess, and the punch and the die are used to push the second molded product forward around the circular through-hole and simultaneously expand the diameter. While forming by forging, a third molded product is formed that includes an outer ring portion and an inner ring portion that is concentrically integrated with the outer ring portion and has one outer peripheral end connected to the inner periphery of the outer ring portion and the other end protruding. Only the 3rd forging station and the inner ring are inserted It comprises an annular die to be obtained, a punch that can be fitted into the outer ring portion and the annular die, and a fourth forging station that punches and processes the outer ring and the inner ring by punching with the punch and the die. Manufacturing equipment for inner and outer rings.

Images