JP2013006218A - Manufacturing method for bearing outer ring - Google Patents

Abstract

When an outer ring 3 constituting a back-row combined double-row angular ball bearing is manufactured by plastic deformation of a cylindrical material 10, both outer ring raceways 2 and 2 are cleaned by the material 10 A manufacturing method capable of exposing the intermediate metal material 29 having a high degree is realized.
(A) → (B) upsetting process, (C) → (D) backward extrusion process, (D) → (E) punching process, (E) → The outer ring 3 is formed by sequentially performing the rolling process and finishing process of (F). The outer diameter of the first intermediate material 11a produced by the upsetting process is equal to or smaller than the inner diameter of the inner peripheral surface side large diameter portion 18 of the inner peripheral surface of the die 13 used for the backward extrusion process. Larger than. In the rear extrusion process, the first intermediate material 11a is pushed by the tip end surface of the punch 14 in a state in which the outer diameter portion of the first intermediate material 11a is hooked on the inner peripheral surface side inclined portion 20 over the entire circumference. Push toward the bottom of the die 13.
[Selection] Figure 1

Description

  The present invention relates to an improvement in a manufacturing method of a bearing outer ring constituting a double-row angular type rolling bearing incorporated in a rotation support portion of various machines such as automobiles, machine tools, industrial machines, and the like. The bearing outer ring which is the object of the manufacturing method of the present invention is provided with double-row rear combination type outer ring raceways at two axial positions on the inner peripheral surface. In such a bearing outer ring, the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface has the smallest inner diameter in the axial direction intermediate portion. However, the shape is inclined in a direction in which the inner diameter gradually increases as it goes toward both ends in the axial direction. The cylindrical surface whose outer diameter does not substantially change in the axial direction refers to a shape in which the outer diameter does not change except for chamfered portions provided at both end edges in the axial direction. Moreover, if the bearing outer ring | wheel used as the object of the manufacturing method of this invention is a double row angular type, it will not be restricted to the outer ring | wheel for ball bearings, but the outer ring | wheel for tapered roller bearings is also included.

  In order to constitute the rotation support part of various mechanical devices, a double-row angular ball bearing 1 of a rear combination type as shown in FIG. 7 is widely used. This double-row angular ball bearing 1 includes an outer ring 3 having double-row outer ring raceways 2 and 2 on its inner peripheral surface, a pair of inner rings 5 and 5 having inner ring raceways 4 formed on their outer peripheral surfaces, A plurality of balls 6, 6 are provided between the outer ring raceways 2, 2 and the inner ring raceways 4, 4 of the inner races 5, 5, respectively, for holding these balls 6, 6. A pair of cages 7 and 7 are provided. In such a double-row angular ball bearing 1, for example, the outer ring 3 is fitted and fixed to the housing 8, and the inner rings 5 and 5 are fitted and fixed to the rotary shaft 9. The rotating shaft 9 is rotatably supported inside the housing 8.

  The outer ring 3 and the both inner rings 5 and 5 constituting such a double-row angular ball bearing 1 are described in, for example, Patent Documents 1 to 5, etc., forging, rolling, cutting or cutting. By grinding, it is processed into a predetermined shape and size. For example, the outer ring 3 has been conventionally manufactured by a process as shown in FIG. First, the conventional method for manufacturing a bearing outer ring will be described.

In the conventionally known method for manufacturing a bearing outer ring shown in FIG. 8, first, a cylindrical material 10 as shown in (A) is cut into a predetermined length from a long raw material. obtain.
Next, the material 10 is subjected to upsetting by crushing in the axial direction between the pressing surfaces facing each other in a pair of molds, so that the outer peripheral surface is a convex arc surface as shown in FIG. The first intermediate material 11 is
Next, the second intermediate material 12 shown in (D) is obtained by subjecting the first intermediate material 11 to backward extrusion shown in (C) → (D).

  In the backward extrusion process, the radially central portion of the first intermediate material 11 is crushed in the axial direction between the die 13 and the punch 14, and the radially outward portion is plastically deformed backward in the pushing direction of the punch 14. To do. The die 13 has a bottomed cylindrical shape, and includes a circular bottom plate portion 15 and a peripheral wall portion 16 rising upward from an outer peripheral edge portion of the bottom plate portion 15. An annular groove 17 is formed over the entire circumference of the bottom plate 15 near the outer shape. Further, the inner peripheral surface of the peripheral wall portion 16 has an inner peripheral surface side large diameter portion 18 near the opening (intermediate portion or upper end portion) and an inner peripheral surface side small diameter portion 19 near the bottom plate portion 15 (lower end portion). Are made into a stepped shape that is made continuous by the inner peripheral surface side inclined portion 20 in the portion near the bottom plate portion in the axial direction. Of these, the inner peripheral surface side small-diameter portion 19 is located on the inner peripheral surface near the outer diameter of the annular groove 17 and on a single cylindrical surface. Further, the punch 14 has an outer peripheral surface of an outer peripheral surface side small-diameter portion 21 near the distal end (lower half portion) and an outer peripheral surface-side large diameter portion 22 near the base end (upper half portion). The stepped shape is made continuous by the outer peripheral surface side inclined portion 23. The die 13 and the punch 14 each configured as described above are supported and fixed concentrically with each other on a table and a ram of a press machine. That is, the die 13 is fixed to the upper surface of the table, and the punch 14 is fixed to the lower end surface of the ram.

  When performing the backward extrusion process, the first intermediate material 11 is set in the die 13 with the punch 14 raised together with the ram. In the case of the conventional manufacturing method, the outer diameter of the first intermediate material 11 is smaller than the inner diameter of the inner peripheral surface side small-diameter portion 19 at least at a portion near the lower end and enters the inner peripheral surface-side small diameter portion 19. It was. Therefore, in a state where the first intermediate material 11 is set in the die 13, the lower surface of the first intermediate material 11 is the upper surface of the bottom plate portion 15 and the inner side of the annular groove 17 as shown in FIG. Abuts the part. Therefore, the punch 14 is lowered by the ram from this state, and the first intermediate material is placed between the tip surface of the punch 14 and the upper surface of the bottom plate portion 15 of the die 13 as shown in FIG. 11 is crushed in the axial direction.

  By this crushing, the metal material pushed radially outward from between the upper surface of the bottom plate portion 15 and the tip end surface of the punch 14 is a metal present in the radially outward portion of the first intermediate material 11. It moves to the rear (upward) in the pushing direction of the punch 14 together with the material. In this way, the metal material that has moved rearward in the pressing direction of the punch 14 follows the shape of the outer peripheral surface of the punch 14 and the inner peripheral surface of the peripheral wall portion 16, and both the inner and outer peripheral surfaces are stepped cylindrical surfaces. It becomes a stepped cylindrical shape. A part of the metal material enters the annular groove 17 and the shape of the part is a thread bottom. As a result of the backward extrusion performed in this way, the second intermediate material 12 having both a cylindrical inner surface and a bottomed cylindrical surface as shown in FIG.

  Next, the second intermediate material 12 is subjected to a punching process for punching and removing the bottom portion 24 of the second intermediate material 12 to thereby form a stepped cylindrical third intermediate material 25 as shown in FIG. And This punching is performed by piercing the second intermediate material 12 with a punching punch using a plus processing machine.

  After the third intermediate material 25 is made in this way, the third intermediate material 25 is cold rolled (CRF) to form a fourth intermediate material 26 as shown in FIG. In this cold rolling process, for example, the third intermediate material 25 has an inner diameter that matches the outer diameter of the third intermediate material 25 (on the large diameter side), and the outer peripheral side has an inner peripheral surface as a cylindrical surface. Fits into the roller. The outer diameter of the third intermediate material 25 is sufficiently smaller than the inner diameter of the third intermediate material 25, and the bus bar shape of the outer peripheral surface matches the bus bar shape of the inner peripheral surface of the fourth intermediate material 26 (unevenness is reversed). The shaped inner diameter side roller is pressed against the inner peripheral surface of the third intermediate material 25. Then, the inner diameter side roller is pressed against the inner peripheral surface of the third intermediate material 25 while rotating. Since the outer diameter side roller is supported for rotation only (in a state where radial displacement is prevented), the third intermediate material 25 is moved to the outer diameter side as the inner diameter side roller rotates. Rotates with the roller. For this reason, the bus bar shape of the outer peripheral surface of the inner diameter side roller is transferred to the inner peripheral surface of the third intermediate material 25 over the entire periphery, and the outer peripheral surface of the third intermediate material 25 is processed into a cylindrical surface. Is done.

  In the rolling process, a part of the third intermediate material 25 is sandwiched between a pair of rollers rotating in opposite directions, and the two rollers are pressed in a direction approaching each other. In some cases, the shape of the outer peripheral surface is transferred to both the inner and outer peripheral surfaces of the third intermediate material 25. In any case, the fourth intermediate material 26 as shown in the above (F) can be obtained. In the fourth intermediate material 26, the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface has the smallest inner diameter in the axial intermediate portion, and the inner diameter increases toward both axial end portions. Is a shape inclined in the direction of gradually increasing.

  The fourth intermediate material 26 thus obtained is finished as the outer ring 3 constituting the double-row angular ball bearing 1 as shown in FIG. To do. That is, by cutting off the surplus portion of the fourth intermediate material 26, the outer ring 3 having the shape shown by the chain line in FIG. Further, the pair of outer ring raceways 2 and 2 formed on the inner peripheral surface of the outer ring 3 is subjected to processing for adjusting the surface properties of both the outer ring raceways 2 and 2 such as grinding and super finishing.

  By the way, the said raw material 10 for making the said outer ring | wheel 3 uses the column-shaped thing produced by cut | disconnecting the elongate material of the cross-sectional circular shape extruded by the steel manufacturer to predetermined length. It has been conventionally known that the composition (cleanliness) of the columnar material 10 obtained in this way is not uniform, as described in Patent Document 6. That is, in the range of 40% of the central portion of the material 10 (a columnar portion near the center from the center to 40% of the radius), non-metallic inclusions are likely to be present, as described in Patent Document 6 above. Conventionally known. In addition, the range of 20% closer to the outer diameter of the material 10 (cylindrical portion existing on the outer peripheral surface side than 80% of the radius from the center) is also clean due to the presence of oxides and non-metallic inclusions. It is known that the degree is low. Of the outer ring raceways 2, 2 provided on the inner peripheral surface of the outer ring 3, the metal material having a low cleanliness is a metal material that is present in any part of the outer ring 3, particularly the ball. When the rolling surfaces of 6 and 6 (FIG. 7) are exposed to the portion that comes into contact with rolling, it becomes difficult to ensure the rolling fatigue life of this portion.

  In consideration of these matters, and taking into account variations in the distribution of oxides and non-metallic inclusions in the material and various variations (such as pressing force) that occur during manufacturing operations, the central portion 50 of the material 10 is used. %, And the metal material existing in the range of 30% of the outer diameter of the material 10 is not exposed to at least the portion of the outer ring races 2 and 2 where the rolling contact surface is in rolling contact. Things are preferable. In other words, an intermediate cylindrical portion having a radius from the center in the range of 50 to 70% in the material 10 is a portion of the outer ring raceways 3 and 3 where at least the rolling contact surface is in rolling contact. 27 {A portion in FIG. 1 to 6 and FIGS. 8B to 8F and FIG. 9 also, the portion with the oblique lattice is the metal material (intermediate metal material 29) existing in the intermediate cylindrical portion 27. It represents that it is composed. } Is preferably exposed.

  However, the inner diameter of the intermediate portion in the axial direction, which is the object of the manufacturing method of the present invention, is small, and two rows of outer ring raceways are provided on both sides of the portion where the inner diameter is reduced at two axial positions on the inner peripheral surface. When the outer ring 3 is made by forging, it is difficult to expose the metal material present in the intermediate cylindrical portion 27 on the both raceway surfaces. For example, when the outer ring 3 shown by the chain line in FIG. 9 is made by the method shown in FIG. 8, the metal material of each part in the material 10, that is, near the center from the center to 50% of the radius. The center side metallic material 28 present in the cylindrical part, the intermediate part metallic material 29 present in the intermediate cylindrical part 27 having a radius from the center in the range of 50 to 70%, and the range closer to the outer diameter 30%. The outer diameter side metallic material 30 existing in the cylindrical portion near the outer diameter is distributed in the outer ring 3 as shown in FIG. As described above, after the fourth intermediate material 26 shown by the solid line in FIG. 9 is formed by forging, the outer ring 3 is cut into the state shown by the chain line in FIG. 9 by cutting and grinding. The intermediate material 26 is scraped off to complete the outer ring 3.

  In FIG. 9 showing such a fourth intermediate material 26 and the outer ring 3, the intermediate metal material 29 present in the intermediate cylindrical portion 27, which is indicated by a diagonal lattice, is formed by a pair of outer ring raceways 2, 2. Among these, if at least the rolling surface of the ball is exposed to the rolling contact portion, the rolling fatigue life of both the outer ring raceways 2 and 2 is secured, and the durability of the double row angular ball bearing 1 including the outer ring 3 is ensured. It is easy to ensure the performance. However, as apparent from FIG. 9, when the outer ring 3 is manufactured by the conventional manufacturing method, the center-side metal material 28 of the central cylindrical portion is one of the outer ring raceways 2 and 2 (FIG. 9). Exposed to the entire surface of the outer ring raceway 2. For example, the arrows α and α in FIG. 9 indicate that the contact angles of the balls 6 and 6 (see FIG. 7) are 40 degrees (the angle with respect to the central axis that is the remainder of the contact angle = 50 degrees). The direction of action of the load applied from the balls 6 and 6 to the outer ring races 2 and 2 is shown. If the intermediate metal material 29 is present in the portion indicated by the arrows α and α on the chain line in FIG. 9 representing the cross-sectional shape of the outer ring 3, the rolling fatigue life of the outer ring raceways 2 and 2 is achieved. However, with respect to the inner ring raceway 2 in the lower part of FIG. 9, the center side metal material 28 exists in the part indicated by the arrows α and α on the chain line in FIG. 9. For this reason, the conventionally known methods for manufacturing a bearing outer ring limit the degree of freedom in design for ensuring the durability of the double-row angular ball bearing 1.

JP-A-9-176740 JP-A-9-280255 JP-A-11-140543 JP 2002-79347 A JP 2003-230927 A JP 2006-250317 A

  In view of the circumstances as described above, the present invention has an inner diameter in the axial direction intermediate portion of the inner peripheral surface that is smaller than the inner diameters of both side portions, and is positioned at two positions in the axial direction across the portion where the inner diameter is reduced. When a bearing outer ring having an outer ring raceway in a row is made by plastically deforming a cylindrical material, at least a portion where the rolling element load acts on both outer ring raceways, the cleanliness is high among the materials. The invention was invented to realize a method of manufacturing a bearing outer ring that can expose the metal material of the intermediate cylindrical portion.

Among the methods for manufacturing a bearing outer ring according to the present invention, the manufacturing method described in claim 1 is installed on a cylindrical material in the same manner as the conventionally known method for manufacturing a bearing outer ring shown in FIG. Bearing outer ring with double-row rear combination type outer ring raceway in two axial positions on the inner peripheral surface by sequentially carrying out indentation, backward extrusion, punching, rolling and finishing And
In the upsetting process, the material is crushed in the axial direction between the pressing surfaces of the pair of molds facing each other to obtain a first intermediate material.
In the backward extrusion process, the central portion of the first intermediate material is crushed in the axial direction between the die and the punch. Of these, the die has a bottomed cylindrical shape, and the inner peripheral surface is inclined with the inner peripheral surface side large-diameter portion near the opening and the inner peripheral surface-side small diameter portion near the bottom portion on the inner peripheral surface side in the axial intermediate portion. It is a stepped shape made continuous by the part. In the punch, the outer peripheral surface has a stepped shape in which the outer peripheral surface side small-diameter portion near the distal end and the outer peripheral surface-side large diameter portion near the base end are continuously connected by the outer peripheral surface-side inclined portion in the intermediate portion in the axial direction. . In the backward extrusion process, the central portion of the first intermediate material is crushed in the axial direction between the tip end face of such a punch and the bottom plate portion of the die. Then, the metal material pushed outward in the radial direction along with the crushing is moved rearward in the pushing direction of the punch together with the metal material present in the radially outward portion of the first intermediate material, Both circumferential surfaces are stepped cylindrical surfaces and the whole is a second intermediate material having a bottomed cylindrical shape.
In the punching process, the bottom portion of the second intermediate material is punched and removed, so that the inner and outer peripheral surfaces are stepped cylindrical surfaces and the whole is a cylindrical third intermediate material.
In the rolling process, both the inner and outer peripheral surfaces of the third intermediate material are plastically deformed, and the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface is the intermediate in the axial direction. The fourth intermediate material has the smallest inner diameter and is inclined in a direction in which the inner diameter gradually increases as both side portions of the axial intermediate portion move toward both axial end portions. The meaning that the outer diameter does not substantially change in the axial direction is as described above.
Further, in the finishing process, the outer peripheral raceway is formed on the inner peripheral surface by scraping the inner peripheral surface of the fourth intermediate material.

In particular, in the bearing outer ring manufacturing method according to the present invention, the outer diameter of the first intermediate material produced by the upsetting process is set so that the inner peripheral surface side large-diameter portion of the die is the outer diameter. The inner diameter is less than the inner diameter and larger than the inner diameter of the inner peripheral surface side small diameter portion. That is, the amount of processing (crushing amount) of the material in the upsetting process is made larger than in the case of the conventional manufacturing method described above, and the outer diameter of the first intermediate material is set to the conventional method. To make it larger than the outer diameter of the first intermediate material.
Further, in the backward extrusion processing, the first intermediate material is placed on the tip end surface of the punch in a state in which the portion near the outer diameter of the first intermediate material is hooked on the inner peripheral surface side inclined portion of the die over the entire circumference. To push toward the bottom of the die. Then, the first intermediate material is plastically deformed into a shape inclined in the direction toward the opening of the die as the portion closer to the outer diameter, and then the central portion of the first intermediate material is crushed in the axial direction, A portion closer to the outer diameter of the one intermediate material is moved rearward in the pressing direction of the punch to obtain the second intermediate material.

  In the case of the method for manufacturing a bearing outer ring according to claim 2, the pressing surface of one of the pair of molds used in the upsetting process is made flat and the other mold is used. At least a portion near the outer diameter of the pressing surface of the mold is an inclined surface that is inclined in a direction away from the pressing surface of the one mold as it goes to the outer peripheral edge. And the 1st intermediate material produced by the said upsetting process makes it the shape where the axial direction one side is dented with respect to an outer-periphery edge part in the radial direction, and an other axial direction surface is a flat surface. And in the case of back extrusion, this recessed surface is made to oppose the bottom part of die | dye.

On the other hand, in the case of the method for manufacturing a bearing outer ring according to claim 3, an upsetting process, a front / rear coextrusion process, a punching process, a rolling process, and a finishing process are sequentially performed on a cylindrical material. Thus, the bearing outer ring is provided with a double-row rear combination type outer ring raceway at two axial positions on the inner peripheral surface. That is, instead of the backward extrusion process in the method for manufacturing a bearing outer ring described in claims 1 and 2 described above, a front-rear simultaneous extrusion process is employed. The structure of the bearing outer ring manufacturing method described in claim 3 is the same as that of the invention described in claim 1 except that this front-rear simultaneous extrusion is employed.
In the front-rear coextrusion process, a circular convex portion having a bottomed cylindrical shape and having a height dimension less than 1/2 of the depth dimension is provided at the center of the bottom surface, and an outer peripheral surface and an inner peripheral surface of the circular convex portion are provided. The central portion of the first intermediate material is crushed in the axial direction between a die having a cylindrical forming space between the die and a punch having an outer diameter smaller than the inner diameter of the die. Then, the metal material extruded radially outward along with this crushing, together with the metal material present in the radially outward portion of the first intermediate material, the pushing direction of the cylindrical molding space and the punch A second intermediate provided with a partition wall portion on the inner diameter side in the axial direction intermediate portion of the cylindrical portion by being moved (simultaneously) rearward to a cylindrical space existing between the outer peripheral surface of the punch and the inner peripheral surface of the die. The material. Then, the second intermediate material is processed into a bearing outer ring in the same manner as in the manufacturing method described in claim 1.

According to the bearing outer ring manufacturing method of the present invention configured as described above, both outer ring raceways formed at two axially spaced positions sandwiching a portion having the smallest inner diameter on the inner peripheral surface. Among them, the metal material of the intermediate cylindrical portion having a high cleanliness among the materials can be exposed to at least a portion where the rolling element load acts. For this reason, the rolling fatigue life of the both outer ring raceways can be secured, and the degree of freedom in design for ensuring the durability of the double row rolling bearing including the bearing outer ring provided with these outer ring raceways can be improved.
Further, when carrying out the invention described in claim 1, by adopting the configuration described in claim 2 as necessary, the metal material of the intermediate cylindrical portion is made to be the surface portion of the outer ring raceways. It can be effectively exposed to a wider range.
Furthermore, according to the method for manufacturing a bearing outer ring according to the third aspect of the present invention, the metal material of the intermediate cylindrical portion having high cleanliness among the raw materials can be more sufficiently disposed on the both outer ring raceways. The degree of freedom of design for ensuring the durability of the rolling bearing can be further improved.

A first example of an embodiment of a method for manufacturing a bearing ring member of the present invention, in the order of steps, a metal material of a cylindrical portion closer to the center, a metal material of an intermediate cylindrical portion, a metal material of a cylindrical portion closer to an outer diameter, Sectional drawing of a raw material thru | or a 4th intermediate material, and a die | dye and a punch shown with the condition where the distribution condition of [2] changes. Sectional drawing which shows the distribution condition of the metal material of the cylindrical part near the center, the metal material of the intermediate cylindrical part, and the metal material of the cylindrical part near the outer diameter at the stage of the fourth intermediate material. The figure similar to FIG. 1 which shows the 2nd example of embodiment of this invention. The same figure as FIG. The figure similar to FIG. 1 which shows the 3rd example of embodiment of this invention in the state which abbreviate | omitted the dice | dies and the punch. The same figure as FIG. Sectional drawing which shows an example of the rotation support part provided with the angular type double row ball bearing provided with the bearing outer ring used as the object of the manufacturing method of this invention. The figure similar to FIG. 1 which shows the manufacturing method of the bearing outer ring | wheel conventionally known. The same figure as FIG.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention corresponding to only claim 1. The manufacturing method of this example is a metal cylindrical material that can be quenched and hardened after plastic working, such as an iron-based alloy such as medium carbon steel, bearing steel, and carburized steel, as shown in FIG. 10 is sequentially subjected to plastic working or punching. Then, after passing through the first intermediate material 11a shown in (B), the second intermediate material 12a shown in (D), and the third intermediate material 25a shown in (E), the fourth intermediate material shown in (F). 26a is obtained. Further, the fourth intermediate material 26a is subjected to necessary cutting and grinding to form the outer ring 3 constituting the double row angular ball bearing 1 as shown in FIG. Hereinafter, the process of processing the material 10 into the fourth intermediate material 26a will be described in order. Of the following processes, the upsetting process, the backward extrusion process, and the punching process shown in (A) → (E) are basically performed hot or warm. ) → The rolling process shown in (F) is performed cold, but if possible, the entire process can be cooled if a small outer ring 3 is formed and a metal material having excellent ductility is used. You may go between.

First, in the upsetting process, as shown in FIG. 1 (A) → (B), the outer diameter is expanded while the material 10 is crushed in the axial direction, and the intermediate portion in the axial direction swells. The first intermediate material 11a is used. The basic implementation status of such an upsetting process is the same as the upsetting process in the conventional manufacturing method shown in FIG. However, in the case of this example, the closest approach distance between the pressing surfaces of a pair of molds that crush the material 10 in the axial direction in the upsetting process is shorter than in the case of the conventional manufacturing method. To do. That is, the amount of processing (crushing amount) of the material 10 in the upsetting process is made larger than that in the conventional manufacturing method. For this reason, the shape of the first intermediate material 11a is closer to a thick disk rather than a beer barrel. Then, the outer diameter D ₁₁ of the first intermediate material 11a building by upsetting the outer diameter d ₁₁ of the first intermediate material 11 to build in the middle course of the conventional manufacturing method _{shown in FIG. 8 (B) see} (D ₁₁ > d ₁₁ ). Specifically, the inner diameter R ₁₈ or less of the inner peripheral surface side large-diameter portion 18 formed on the inner peripheral surface of the die 13 {see (C) and (D) of FIG. 1} used for the subsequent backward extrusion, larger than the inner diameter _{R 19} of the inner peripheral surface side small-diameter portion 19 similarly _{(with R 18 ≧ D 11> R 19} ).

As described above, the first intermediate material 11a is plastically processed into the second intermediate material 12a as shown in (C) → (D) of FIG. In such a backward extrusion process, a die 13 and a punch 14 similar to those in the above-described conventional manufacturing method are used to compress the radially central portion of the first intermediate material 11a in the axial direction, While moving the material outward in the radial direction, the material is moved to both sides in the axial direction (both in the front-rear direction, but mainly the rear side). However, in the case of the manufacturing method of this example, only the amount the outer diameter D ₁₁ is greater in the first intermediate material 11a, as follows, not the case processing conditions of the conventional manufacturing method.

  That is, in the case of this example, in the backward extrusion process, first, as shown in FIG. 1C, the portion near the outer diameter of the first intermediate material 11a is set to the intermediate portion in the axial direction of the inner peripheral surface of the die 13. The inner peripheral surface side inclined portion 20 provided on the inner periphery is hooked over the entire periphery. Then, from this state, the punch 14 is lowered, and the first intermediate material 11a is pushed toward the upper surface of the bottom plate portion 15 of the die 13 by the front end surface of the punch. In the initial stage of the pushing, that is, in the state before the lower surface central portion of the first intermediate material 11a comes into contact with the upper surface of the bottom plate portion 15, the first intermediate material 11a has a portion closer to the outer diameter. Plastic deformation occurs in a direction (upward) toward the opening of the die 13.

  Then, after the lower center portion of the first intermediate material 11a contacts the upper surface of the bottom plate portion 15, when the punch 14 is further lowered, the center portion of the first intermediate material 11a is crushed in the axial direction. The metal material pushed out in the radial direction along with the crushing is mainly rearward (upward) in the pushing direction of the punch 14 together with the metal material present in the radially outer portion of the first intermediate material 11a. Move. As described above, the inner and outer peripheral surfaces of the metal material moved rearward in the pressing direction of the punch 14 are stepped shapes corresponding to the outer peripheral surface of the punch 14 and the inner peripheral surface of the peripheral wall portion 16 constituting the die 13. It becomes. As a result, by the backward extrusion process, the first intermediate material 11a shown in FIG. 1 (C) is shown in (D) of FIG. It becomes the cylindrical second intermediate material 12a. Further, a part of the metal material is moved forward in the pushing direction to enter the annular groove 17 formed in a portion near the outer diameter of the bottom plate portion 15.

  Such a second intermediate material 12a is removed from the die 13 by pressing the bottom 24 upward with a counter punch (not shown), and then punching and rolling as in the conventional manufacturing method described above. As a result, the fourth intermediate material 26a as shown in FIG. 1 (F) and FIG. 2 is obtained. In the punching process, a punching punch (not shown) is pushed into the inner diameter side of the second intermediate material 12a while the second intermediate material 12a is held on the inner peripheral surface of the receiving die (not shown), and the bottom 24 is punched out. Remove. By such a punching step, the third intermediate material 25a having a stepped cylindrical shape as shown in FIG. Next, in the rolling process, the inner and outer peripheral surfaces of the third intermediate material 25a are plastically deformed into a shape corresponding to the peripheral surfaces of both rollers by a pair of rollers (not shown) to obtain the fourth intermediate material 26a.

  The fourth intermediate material 26a is thicker than the completed outer ring 3 {see FIG. 1 (F) and the chain line in FIG. 2}. Therefore, the fourth intermediate material 26a is subjected to predetermined cutting (turning) processing and grinding processing to complete the outer ring 3. FIGS. 1A to 1F show the change in the distribution state of the metal materials 28 to 30 on the center side, the intermediate portion, and the outer diameter side as the processing proceeds. 2 shows the distribution state of the metal materials 28 to 30 and the cross-sectional shape of the outer ring 3 after completion at the stage of the fourth intermediate material 26a.

  As is apparent from these drawings, according to the method of manufacturing the outer ring 3 of this example, at least the rolling of the outer ring raceways 2 and 2 formed at two positions spaced apart in the axial direction of the inner peripheral surface of the outer ring 3. The intermediate metal material 29 of the intermediate cylindrical portion 27 having a high degree of cleanliness among the raw materials 10, which is indicated by a diagonal grid in each drawing, can be exposed to the portion where the moving body load acts. For this reason, the rolling fatigue life of both the outer ring raceways 2 and 2 is ensured, and the degree of freedom in design for ensuring the durability of the wheel bearing rolling bearing unit including the outer ring 3 provided with the both outer ring raceways 2 and 2 is improved. Can be planned.

[Second Example of Embodiment]
FIGS. 3-4 has shown the 2nd example of embodiment of this invention corresponding to Claim 1,2. In the case of this example, the pressing surface of one of the pair of dies used in the upsetting process in the process of (A) → (B) in FIG. A portion closer to the outer diameter of the pressing surface of the mold is an inclined surface inclined in a direction away from the pressing surface of the one mold as it goes toward the outer peripheral edge. And let the shape of the 1st intermediate raw material 11b produced by the said upsetting process be the shape where the radial direction center part was dented with respect to the outer-periphery edge part. In the case of this example, the central portion of this one axial surface is a flat surface, and the portion near the outer periphery is a partially conical concave surface, so that this one axial surface is an inverted conical concave surface. On the other hand, the other surface in the axial direction is a flat surface. In the case of the above-described first intermediate material 11b having such a shape, as apparent from comparing (B) and (C) of FIG. 3 with (B) and (C) of FIG. Along with this, the extent to which the central metal material 28 and the intermediate metal material 29 are displaced radially outward becomes significant on one axial side.

The first intermediate material 11b having such an asymmetric shape with respect to the axial direction is formed so that the concave axial one surface of the die 13 is formed in the backward extrusion shown in FIG. 3 (C) → (D). It is made to oppose the upper surface of the baseplate part 15. As shown in FIG. Then, in the same manner as in the first example of the above-described embodiment, the rear extrusion process shown in (C) → (D) is performed to form the second intermediate material 12b, and (D) → (E). The third intermediate material 25b is formed by punching, and the rolling process shown in (E) → (F) is performed to obtain the fourth intermediate material 26b. As a result, as apparent from a comparison between FIG. 3F and FIG. 4 and the above-described FIG. 1F and FIG. 2, it is cleaner than the first example of the above embodiment. The intermediate metal material 29 can be effectively exposed to a wider range of the surface portion of the pair of outer ring raceways 2 and 2.
Since the configurations and effects of the other parts are the same as those in the first example of the above embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[Third example of embodiment]
5 to 6 show a third example of the embodiment of the invention corresponding to claim 3. FIG. In the case of this example, in the case of the first example of the embodiment described in FIGS. 1 and 2 described above, instead of the backward extrusion process performed in (C) → (D) of FIG. B) The front-rear simultaneous extrusion process shown in (C) is performed. In the case of this example, this front-rear coextrusion process is adopted, and the first intermediate material 11 according to this is the same as the beer barrel type as in the conventional example described above, except for the first example of the above embodiment. This is the same as the manufacturing method.
In the case of this example, the first intermediate material 11 shown in FIG. 5B is processed into the second intermediate material 12c shown in FIG. Thus, in the front-rear co-extrusion process for processing the first intermediate material 11 into the second intermediate material 12c, a die having an inner surface shape that matches the surface shape of the second intermediate material 12c and a punch having an outer surface shape are used. Is used. The inner surface shape of the die is a bottomed cylindrical shape as shown in the shape of the second intermediate material 12c shown in FIG. 5C, and is less than half of the depth dimension at the center of the bottom surface. The circular convex part which has the height dimension of is provided. A space between the outer peripheral surface and the inner peripheral surface of the circular convex portion is a cylindrical molding space for forming a lower portion of the second intermediate material 12c. The punch is pressed into the upper portion of the second intermediate material 12c to process the inner surface shape of the upper portion, and has an outer diameter smaller than the inner diameter of the die.

  In order to process the first intermediate material 11 into the second intermediate material 12c by the front-rear simultaneous extrusion process, the first intermediate material 11 is placed in the die on the one side surface in the axial direction of the first intermediate material 11 ( The center portion of the lower surface is set in a state of contacting (mounting) the circular convex portion. Then, the central portion of the other surface in the axial direction of the first intermediate material 11 is strongly pressed by the punch, and the first intermediate material 11 is moved between the tip surface (lower surface) of the punch and the tip surface (upper surface) of the circular convex portion. Crush the middle part of one intermediate material in the axial direction. Then, the metal material pushed out in the radial direction along with the crushing is pushed into the cylindrical forming space and the punch together with the metal material present in the radially outward portion of the first intermediate material 11. It moves to the cylindrical space which exists between the outer peripheral surface of this punch and the inner peripheral surface of the said die behind in the direction. And it is set as the said 2nd intermediate material 12c which provided the partition part 32 in the axial direction intermediate part internal diameter side of the cylindrical part 31 as shown to (C) of FIG. Then, the second intermediate material 12c is punched as shown in (C) → (D) of FIG. 5, and the rolling shown in (D) → (E) as in the case of the first example of the above embodiment. By machining and further finishing, the shape shown by the chain line in FIG. 5E and FIG. 6 is cut out and processed into an outer ring 3 for a double row ball bearing.

  In the case of this example, the processing from the first intermediate material 11 to the second intermediate material 12c is performed in a substantially symmetric state with respect to the axial direction of both the materials 11, 12c by the front-rear simultaneous extrusion process. As shown in FIGS. 5C to 5E and FIG. 6, the intermediate metal material 29 having a high degree of cleanness is exposed over the entire portion that forms the double-row outer ring raceways 2 and 2. For this reason, the rolling fatigue life of both the outer ring raceways 2 and 2 can be sufficiently secured. And the freedom degree of the design for ensuring durability of the rolling bearing unit for wheel support including the outer ring 3 provided with both the outer ring raceways 2 and 2 can be further improved.

  Each example mentioned above demonstrated about the case where the outer ring | wheel 3 which comprises the double row angular type ball bearing 1 was made with the manufacturing method of this invention. On the other hand, the method for manufacturing a bearing outer ring according to the present invention can also be used when an outer ring constituting a double-row angular tapered roller bearing is manufactured. In this case, in order to carry out the invention described in claims 1 and 2, it is used for backward extrusion in consideration of the width of the double row outer ring raceway formed on the inner peripheral surface of the outer ring, the machining allowance due to finishing, etc. The axial position of the inner peripheral surface side inclined portion provided on the inner peripheral surface of the intermediate portion of the die to be devised is exposed to expose the intermediate metal material in the material on the surface of the outer ring raceway.

DESCRIPTION OF SYMBOLS 1 Double row angular contact ball bearing 2 Outer ring raceway 3 Outer ring 4 Inner ring raceway 5 Inner ring 6 Ball 7 Cage 8 Housing 9 Rotating shaft 10 Material 11, 11a, 11b First intermediate material 12, 12a, 12b, 12c Second intermediate material 13 Die 14 Punch 15 Bottom plate portion 16 Peripheral wall portion 17 Annular groove 18 Inner peripheral surface side large diameter portion 19 Inner peripheral surface side small diameter portion 20 Inner peripheral surface side inclined portion 21 Outer peripheral surface side small diameter portion 22 Outer peripheral surface side large diameter portion 23 Outer periphery Surface side inclined portion 24 Bottom portion 25, 25a, 25b Third intermediate material 26, 26a, 26b Fourth intermediate material 27 Intermediate cylindrical portion 28 Center side metal material 29 Intermediate portion metal material 30 Outer diameter side metal material 31 Cylindrical portion 32 Partition Part

  The present invention relates to an improvement in a manufacturing method of a bearing outer ring constituting a double-row angular type rolling bearing incorporated in a rotation support portion of various machines such as automobiles, machine tools, industrial machines, and the like. The bearing outer ring which is the object of the manufacturing method of the present invention is provided with double-row rear combination type outer ring raceways at two axial positions on the inner peripheral surface. In such a bearing outer ring, the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface has the smallest inner diameter in the axial direction intermediate portion. However, the shape is inclined in a direction in which the inner diameter gradually increases as it goes toward both ends in the axial direction. The cylindrical surface whose outer diameter does not substantially change in the axial direction refers to a shape in which the outer diameter does not change except for chamfered portions provided at both end edges in the axial direction. Moreover, if the bearing outer ring | wheel used as the object of the manufacturing method of this invention is a double row angular type, it will not be restricted to the outer ring | wheel for ball bearings, but the outer ring | wheel for tapered roller bearings is also included.

  In order to constitute the rotation support part of various mechanical devices, a double-row angular ball bearing 1 of a rear combination type as shown in FIG. 7 is widely used. This double-row angular ball bearing 1 includes an outer ring 3 having double-row outer ring raceways 2 and 2 on its inner peripheral surface, a pair of inner rings 5 and 5 having inner ring raceways 4 formed on their outer peripheral surfaces, A plurality of balls 6, 6 are provided between the outer ring raceways 2, 2 and the inner ring raceways 4, 4 of the inner races 5, 5, respectively, for holding these balls 6, 6. A pair of cages 7 and 7 are provided. In such a double-row angular ball bearing 1, for example, the outer ring 3 is fitted and fixed to the housing 8, and the inner rings 5 and 5 are fitted and fixed to the rotary shaft 9. The rotating shaft 9 is rotatably supported inside the housing 8.

  The outer ring 3 and the both inner rings 5 and 5 constituting such a double-row angular ball bearing 1 are described in, for example, Patent Documents 1 to 5, etc., forging, rolling, cutting or cutting. By grinding, it is processed into a predetermined shape and size. For example, the outer ring 3 has been conventionally manufactured by a process as shown in FIG. First, the conventional method for manufacturing a bearing outer ring will be described.

In the conventionally known method for manufacturing a bearing outer ring shown in FIG. 8, first, a cylindrical material 10 as shown in (A) is cut into a predetermined length from a long raw material. obtain.
Next, the material 10 is subjected to upsetting by crushing in the axial direction between the pressing surfaces facing each other in a pair of molds, so that the outer peripheral surface is a convex arc surface as shown in FIG. The first intermediate material 11 is
Next, the second intermediate material 12 shown in (D) is obtained by subjecting the first intermediate material 11 to backward extrusion shown in (C) → (D).

  In the backward extrusion process, the radially central portion of the first intermediate material 11 is crushed in the axial direction between the die 13 and the punch 14, and the radially outward portion is plastically deformed backward in the pushing direction of the punch 14. To do. The die 13 has a bottomed cylindrical shape, and includes a circular bottom plate portion 15 and a peripheral wall portion 16 rising upward from an outer peripheral edge portion of the bottom plate portion 15. An annular groove 17 is formed over the entire circumference of the bottom plate 15 near the outer shape. Further, the inner peripheral surface of the peripheral wall portion 16 has an inner peripheral surface side large diameter portion 18 near the opening (intermediate portion or upper end portion) and an inner peripheral surface side small diameter portion 19 near the bottom plate portion 15 (lower end portion). Are made into a stepped shape that is made continuous by the inner peripheral surface side inclined portion 20 in the portion near the bottom plate portion in the axial direction. Of these, the inner peripheral surface side small-diameter portion 19 is located on the inner peripheral surface near the outer diameter of the annular groove 17 and on a single cylindrical surface. Further, the punch 14 has an outer peripheral surface of an outer peripheral surface side small-diameter portion 21 near the distal end (lower half portion) and an outer peripheral surface-side large diameter portion 22 near the base end (upper half portion). The stepped shape is made continuous by the outer peripheral surface side inclined portion 23. The die 13 and the punch 14 each configured as described above are supported and fixed concentrically with each other on a table and a ram of a press machine. That is, the die 13 is fixed to the upper surface of the table, and the punch 14 is fixed to the lower end surface of the ram.

  When performing the backward extrusion process, the first intermediate material 11 is set in the die 13 with the punch 14 raised together with the ram. In the case of the conventional manufacturing method, the outer diameter of the first intermediate material 11 is smaller than the inner diameter of the inner peripheral surface side small-diameter portion 19 at least at a portion near the lower end and enters the inner peripheral surface-side small diameter portion 19. It was. Therefore, in a state where the first intermediate material 11 is set in the die 13, the lower surface of the first intermediate material 11 is the upper surface of the bottom plate portion 15 and the inner side of the annular groove 17 as shown in FIG. Abuts the part. Therefore, the punch 14 is lowered by the ram from this state, and the first intermediate material is placed between the tip surface of the punch 14 and the upper surface of the bottom plate portion 15 of the die 13 as shown in FIG. 11 is crushed in the axial direction.

  By this crushing, the metal material pushed radially outward from between the upper surface of the bottom plate portion 15 and the tip end surface of the punch 14 is a metal present in the radially outward portion of the first intermediate material 11. It moves to the rear (upward) in the pushing direction of the punch 14 together with the material. In this way, the metal material that has moved rearward in the pressing direction of the punch 14 follows the shape of the outer peripheral surface of the punch 14 and the inner peripheral surface of the peripheral wall portion 16, and both the inner and outer peripheral surfaces are stepped cylindrical surfaces. It becomes a stepped cylindrical shape. A part of the metal material enters the annular groove 17 and the shape of the part is a thread bottom. As a result of the backward extrusion performed in this way, the second intermediate material 12 having both a cylindrical inner surface and a bottomed cylindrical surface as shown in FIG.

  Next, the second intermediate material 12 is subjected to a punching process for punching and removing the bottom portion 24 of the second intermediate material 12 to thereby form a stepped cylindrical third intermediate material 25 as shown in FIG. And This punching is performed by piercing the second intermediate material 12 with a punching punch using a plus processing machine.

  After the third intermediate material 25 is made in this way, the third intermediate material 25 is cold rolled (CRF) to form a fourth intermediate material 26 as shown in FIG. In this cold rolling process, for example, the third intermediate material 25 has an inner diameter that matches the outer diameter of the third intermediate material 25 (on the large diameter side), and the outer peripheral side has an inner peripheral surface as a cylindrical surface. Fits into the roller. The outer diameter of the third intermediate material 25 is sufficiently smaller than the inner diameter of the third intermediate material 25, and the bus bar shape of the outer peripheral surface matches the bus bar shape of the inner peripheral surface of the fourth intermediate material 26 (unevenness is reversed). The shaped inner diameter side roller is pressed against the inner peripheral surface of the third intermediate material 25. Then, the inner diameter side roller is pressed against the inner peripheral surface of the third intermediate material 25 while rotating. Since the outer diameter side roller is supported for rotation only (in a state where radial displacement is prevented), the third intermediate material 25 is moved to the outer diameter side as the inner diameter side roller rotates. Rotates with the roller. For this reason, the bus bar shape of the outer peripheral surface of the inner diameter side roller is transferred to the inner peripheral surface of the third intermediate material 25 over the entire periphery, and the outer peripheral surface of the third intermediate material 25 is processed into a cylindrical surface. Is done.

  In the rolling process, a part of the third intermediate material 25 is sandwiched between a pair of rollers rotating in opposite directions, and the two rollers are pressed in a direction approaching each other. In some cases, the shape of the outer peripheral surface is transferred to both the inner and outer peripheral surfaces of the third intermediate material 25. In any case, the fourth intermediate material 26 as shown in the above (F) can be obtained. In the fourth intermediate material 26, the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface has the smallest inner diameter in the axial intermediate portion, and the inner diameter increases toward both axial end portions. Is a shape inclined in the direction of gradually increasing.

  The fourth intermediate material 26 thus obtained is finished as the outer ring 3 constituting the double-row angular ball bearing 1 as shown in FIG. To do. That is, by cutting off the surplus portion of the fourth intermediate material 26, the outer ring 3 having the shape shown by the chain line in FIG. Further, the pair of outer ring raceways 2 and 2 formed on the inner peripheral surface of the outer ring 3 is subjected to processing for adjusting the surface properties of both the outer ring raceways 2 and 2 such as grinding and super finishing.

  By the way, the said raw material 10 for making the said outer ring | wheel 3 uses the column-shaped thing produced by cut | disconnecting the elongate material of the cross-sectional circular shape extruded by the steel manufacturer to predetermined length. It has been conventionally known that the composition (cleanliness) of the columnar material 10 obtained in this way is not uniform, as described in Patent Document 6. That is, in the range of 40% of the central portion of the material 10 (a columnar portion near the center from the center to 40% of the radius), non-metallic inclusions are likely to be present, as described in Patent Document 6 above. Conventionally known. In addition, the range of 20% closer to the outer diameter of the material 10 (cylindrical portion existing on the outer peripheral surface side than 80% of the radius from the center) is also clean due to the presence of oxides and non-metallic inclusions. It is known that the degree is low. Of the outer ring raceways 2, 2 provided on the inner peripheral surface of the outer ring 3, the metal material having a low cleanliness is a metal material that is present in any part of the outer ring 3, particularly the ball. When the rolling surfaces of 6 and 6 (FIG. 7) are exposed to the portion that comes into contact with rolling, it becomes difficult to ensure the rolling fatigue life of this portion.

  In consideration of these matters, and taking into account variations in the distribution of oxides and non-metallic inclusions in the material and various variations (such as pressing force) that occur during manufacturing operations, the central portion 50 of the material 10 is used. %, And the metal material existing in the range of 30% of the outer diameter of the material 10 is not exposed to at least the portion of the outer ring races 2 and 2 where the rolling contact surface is in rolling contact. Things are preferable. In other words, an intermediate cylindrical portion having a radius from the center in the range of 50 to 70% in the material 10 is a portion of the outer ring raceways 3 and 3 where at least the rolling contact surface is in rolling contact. 27 {A portion in FIG. 1 to 6 and FIGS. 8B to 8F and FIG. 9 also, the portion with the oblique lattice is the metal material (intermediate metal material 29) existing in the intermediate cylindrical portion 27. It represents that it is composed. } Is preferably exposed.

  However, the inner diameter of the intermediate portion in the axial direction, which is the object of the manufacturing method of the present invention, is small, and two rows of outer ring raceways are provided on both sides of the portion where the inner diameter is reduced at two axial positions on the inner peripheral surface. When the outer ring 3 is made by forging, it is difficult to expose the metal material present in the intermediate cylindrical portion 27 on the both raceway surfaces. For example, when the outer ring 3 shown by the chain line in FIG. 9 is made by the method shown in FIG. 8, the metal material of each part in the material 10, that is, near the center from the center to 50% of the radius. The center side metallic material 28 present in the cylindrical part, the intermediate part metallic material 29 present in the intermediate cylindrical part 27 having a radius from the center in the range of 50 to 70%, and the range closer to the outer diameter 30%. The outer diameter side metallic material 30 existing in the cylindrical portion near the outer diameter is distributed in the outer ring 3 as shown in FIG. As described above, after the fourth intermediate material 26 shown by the solid line in FIG. 9 is formed by forging, the outer ring 3 is cut into the state shown by the chain line in FIG. 9 by cutting and grinding. The intermediate material 26 is scraped off to complete the outer ring 3.

  In FIG. 9 showing such a fourth intermediate material 26 and the outer ring 3, the intermediate metal material 29 present in the intermediate cylindrical portion 27, which is indicated by a diagonal lattice, is formed by a pair of outer ring raceways 2, 2. Among these, if at least the rolling surface of the ball is exposed to the rolling contact portion, the rolling fatigue life of both the outer ring raceways 2 and 2 is secured, and the durability of the double row angular ball bearing 1 including the outer ring 3 is ensured. It is easy to ensure the performance. However, as apparent from FIG. 9, when the outer ring 3 is manufactured by the conventional manufacturing method, the center-side metal material 28 of the central cylindrical portion is one of the outer ring raceways 2 and 2 (FIG. 9). Exposed to the entire surface of the outer ring raceway 2. For example, the arrows α and α in FIG. 9 indicate that the contact angles of the balls 6 and 6 (see FIG. 7) are 40 degrees (the angle with respect to the central axis that is the remainder of the contact angle = 50 degrees). The direction of action of the load applied from the balls 6 and 6 to the outer ring races 2 and 2 is shown. If the intermediate metal material 29 is present in the portion indicated by the arrows α and α on the chain line in FIG. 9 representing the cross-sectional shape of the outer ring 3, the rolling fatigue life of the outer ring raceways 2 and 2 is achieved. However, with respect to the inner ring raceway 2 in the lower part of FIG. 9, the center side metal material 28 exists in the part indicated by the arrows α and α on the chain line in FIG. 9. For this reason, the conventionally known methods for manufacturing a bearing outer ring limit the degree of freedom in design for ensuring the durability of the double-row angular ball bearing 1.

JP-A-9-176740 JP-A-9-280255 JP-A-11-140543 JP 2002-79347 A JP 2003-230927 A JP 2006-250317 A

  In view of the circumstances as described above, the present invention has an inner diameter in the axial direction intermediate portion of the inner peripheral surface that is smaller than the inner diameters of both side portions, and is positioned at two positions in the axial direction across the portion where the inner diameter is reduced. When a bearing outer ring having an outer ring raceway in a row is made by plastically deforming a cylindrical material, at least a portion where the rolling element load acts on both outer ring raceways, the cleanliness is high among the materials. The invention was invented to realize a method of manufacturing a bearing outer ring that can expose the metal material of the intermediate cylindrical portion.

The method of manufacturing a bearing outer ring according to the present invention includes a cylindrical material that is subjected to upset processing, front-rear coextrusion processing , punching processing, rolling processing, and finishing processing in order, so as to The bearing outer ring is provided with a double-row rear combination type outer ring raceway at two positions in the direction.
In particular, in the case of the method for manufacturing a bearing outer ring according to the present invention, a material having an intermediate cylindrical portion having a high cleanliness within a radius of 50 to 70% from the center is used as the material.
In the upsetting process, the material is crushed in the axial direction between the pressing surfaces of the pair of molds facing each other to obtain a first intermediate material.
In the front-rear coextrusion process, a circular convex portion having a bottomed cylindrical shape and having a height dimension less than ½ of the depth dimension is provided at the center of the bottom surface, and the outer circumferential surface and inner circumference of the circular convex portion are provided. The central portion of the first intermediate material is crushed in the axial direction between a die having a cylindrical forming space between the surface and a punch having an outer diameter smaller than the inner diameter of the die. Then, along with this crushing, the intermediate metal material is moved to the entire portion that becomes the double-row outer ring raceway, and the metal material extruded radially outward is moved in the radial direction of the first intermediate material. Along with the metal material present in the outer portion, the cylindrical forming space and the cylindrical space existing between the outer peripheral surface of the punch and the inner peripheral surface of the die at the rear of the punch in the pushing direction (simultaneously) It is made to move and it is set as the 2nd intermediate material which provided the partition part in the axial direction intermediate part internal diameter side of the cylindrical part.
In the punching process, the partition wall portion of the second intermediate material is punched and removed, so that the third intermediate material is formed into a cylindrical shape as a whole .
In the rolling process, both the inner and outer peripheral surfaces of the third intermediate material are plastically deformed, and the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface is the intermediate in the axial direction. The fourth intermediate material has the smallest inner diameter and is inclined in a direction in which the inner diameter gradually increases as both side portions of the axial intermediate portion move toward both axial end portions. The meaning that the outer diameter does not substantially change in the axial direction is as described above.
Further, in the finishing process, the outer peripheral surface of the fourth intermediate material is scraped off to form the outer ring raceways on the inner peripheral surface and the intermediate metal material is exposed to the entire outer ring raceway. To do.

According to the bearing outer ring manufacturing method of the present invention configured as described above, both of the inner peripheral surfaces of the bearing outer ring formed at two axially spaced positions sandwiching a portion having the smallest inner diameter. The metal material of the intermediate cylindrical portion having high cleanliness among the materials can be exposed on the entire outer ring raceway. For this reason, the rolling fatigue life of the both outer ring raceways can be secured, and the degree of freedom in design for ensuring the durability of the double row rolling bearing including the bearing outer ring provided with these outer ring raceways can be improved.
That is, according to the bearing outer ring manufacturing method of the present invention, it is possible to sufficiently arrange the metal material of the intermediate cylindrical portion having a high cleanliness among the raw materials on both the outer ring raceways , and the durability of the double row rolling bearing. The degree of freedom in design for securing can be sufficiently improved.

A first example of a reference example relating to a method of manufacturing a bearing ring member according to the present invention includes, in order of process, a metal material of a cylindrical portion near the center, a metal material of an intermediate cylindrical portion, and a metal material of a cylindrical portion near an outer diameter. Sectional drawing of a raw material thru | or a 4th intermediate raw material, a die | dye, and a punch shown with the condition where distribution conditions change. Sectional drawing which shows the distribution condition of the metal material of the cylindrical part near the center, the metal material of the intermediate cylindrical part, and the metal material of the cylindrical part near the outer diameter at the stage of the fourth intermediate material. The figure similar to FIG. 1 which shows the 2nd example of the reference example regarding this invention. The same figure as FIG. The figure similar to FIG. 1 which shows one example of embodiment of this invention in the state which abbreviate | omitted the dice | dies and the punch. The same figure as FIG. Sectional drawing which shows an example of the rotation support part provided with the angular type double row ball bearing provided with the bearing outer ring used as the object of the manufacturing method of this invention. The figure similar to FIG. 1 which shows the manufacturing method of the bearing outer ring | wheel conventionally known. The same figure as FIG.

[First example of reference example of the present invention ]
1 and 2 show a first example of a reference example related to the present invention . The manufacturing method of this reference example is made of a metal and cylindrical shape that can be quenched and hardened after plastic working, such as iron-based alloys such as medium carbon steel, bearing steel, and carburized steel shown in FIG. The material 10 is sequentially subjected to plastic working or punching. Then, after passing through the first intermediate material 11a shown in (B), the second intermediate material 12a shown in (D), and the third intermediate material 25a shown in (E), the fourth intermediate material shown in (F). 26a is obtained. Further, the fourth intermediate material 26a is subjected to necessary cutting and grinding to form the outer ring 3 constituting the double row angular ball bearing 1 as shown in FIG. Hereinafter, the process of processing the material 10 into the fourth intermediate material 26a will be described in order. Of the following processes, the upsetting process, the backward extrusion process, and the punching process shown in (A) → (E) are basically performed hot or warm. ) → The rolling process shown in (F) is performed cold, but if possible, the entire process can be cooled if a small outer ring 3 is formed and a metal material having excellent ductility is used. You may go between.

First, in the upsetting process, as shown in FIG. 1 (A) → (B), the outer diameter is expanded while the material 10 is crushed in the axial direction, and the intermediate portion in the axial direction swells. The first intermediate material 11a is used. The basic implementation status of such an upsetting process is the same as the upsetting process in the conventional manufacturing method shown in FIG. However, in the case of this reference example , the closest distance between the pressing surfaces of a pair of molds that crush the material 10 in the axial direction in the upsetting process is greater than in the case of the conventional manufacturing method. shorten. That is, the amount of processing (crushing amount) of the material 10 in the upsetting process is made larger than that in the conventional manufacturing method. For this reason, the shape of the first intermediate material 11a is closer to a thick disk rather than a beer barrel. Then, the outer diameter D ₁₁ of the first intermediate material 11a building by upsetting the outer diameter d ₁₁ of the first intermediate material 11 to build in the middle course of the conventional manufacturing method _{shown in FIG. 8 (B) see} (D ₁₁ > d ₁₁ ). Specifically, the inner diameter R ₁₈ or less of the inner peripheral surface side large-diameter portion 18 formed on the inner peripheral surface of the die 13 {see (C) and (D) of FIG. 1} used for the subsequent backward extrusion, larger than the inner diameter _{R 19} of the inner peripheral surface side small-diameter portion 19 similarly _{(with R 18 ≧ D 11> R 19} ).

As described above, the first intermediate material 11a is plastically processed into the second intermediate material 12a as shown in (C) → (D) of FIG. In such a backward extrusion process, a die 13 and a punch 14 similar to those in the above-described conventional manufacturing method are used to compress the radially central portion of the first intermediate material 11a in the axial direction, While moving the material outward in the radial direction, the material is moved to both sides in the axial direction (both in the front-rear direction, but mainly the rear side). However, in the case of the manufacturing method of the present embodiment, only the partial outer diameter D ₁₁ is greater in the first intermediate material 11a, as follows, not the case processing conditions of the conventional manufacturing method.

That is, in the case of this reference example , in the backward extrusion process, first, as shown in FIG. 1C, the portion closer to the outer diameter of the first intermediate material 11a is set in the middle in the axial direction of the inner peripheral surface of the die 13. The inner peripheral surface side inclined part 20 provided in the part is hooked over the entire circumference. Then, from this state, the punch 14 is lowered, and the first intermediate material 11a is pushed toward the upper surface of the bottom plate portion 15 of the die 13 by the front end surface of the punch. In the initial stage of the pushing, that is, in the state before the lower surface central portion of the first intermediate material 11a comes into contact with the upper surface of the bottom plate portion 15, the first intermediate material 11a has a portion closer to the outer diameter. Plastic deformation occurs in a direction (upward) toward the opening of the die 13.

  Then, after the lower center portion of the first intermediate material 11a contacts the upper surface of the bottom plate portion 15, when the punch 14 is further lowered, the center portion of the first intermediate material 11a is crushed in the axial direction. The metal material pushed out in the radial direction along with the crushing is mainly rearward (upward) in the pushing direction of the punch 14 together with the metal material present in the radially outer portion of the first intermediate material 11a. Move. As described above, the inner and outer peripheral surfaces of the metal material moved rearward in the pressing direction of the punch 14 are stepped shapes corresponding to the outer peripheral surface of the punch 14 and the inner peripheral surface of the peripheral wall portion 16 constituting the die 13. It becomes. As a result, by the backward extrusion process, the first intermediate material 11a shown in FIG. 1 (C) is shown in (D) of FIG. It becomes the cylindrical second intermediate material 12a. Further, a part of the metal material is moved forward in the pushing direction to enter the annular groove 17 formed in a portion near the outer diameter of the bottom plate portion 15.

  Such a second intermediate material 12a is removed from the die 13 by pressing the bottom 24 upward with a counter punch (not shown), and then punching and rolling as in the conventional manufacturing method described above. As a result, the fourth intermediate material 26a as shown in FIG. 1 (F) and FIG. 2 is obtained. In the punching process, a punching punch (not shown) is pushed into the inner diameter side of the second intermediate material 12a while the second intermediate material 12a is held on the inner peripheral surface of the receiving die (not shown), and the bottom 24 is punched out. Remove. By such a punching step, the third intermediate material 25a having a stepped cylindrical shape as shown in FIG. Next, in the rolling process, the inner and outer peripheral surfaces of the third intermediate material 25a are plastically deformed into a shape corresponding to the peripheral surfaces of both rollers by a pair of rollers (not shown) to obtain the fourth intermediate material 26a.

  The fourth intermediate material 26a is thicker than the completed outer ring 3 {see FIG. 1 (F) and the chain line in FIG. 2}. Therefore, the fourth intermediate material 26a is subjected to predetermined cutting (turning) processing and grinding processing to complete the outer ring 3. FIGS. 1A to 1F show the change in the distribution state of the metal materials 28 to 30 on the center side, the intermediate portion, and the outer diameter side as the processing proceeds. 2 shows the distribution state of the metal materials 28 to 30 and the cross-sectional shape of the outer ring 3 after completion at the stage of the fourth intermediate material 26a.

As is clear from these figures, according to the manufacturing method of the outer ring 3 of this reference example , at least of the outer ring raceways 2 and 2 formed at two positions spaced apart in the axial direction of the inner peripheral surface of the outer ring 3. The intermediate metal material 29 of the intermediate cylindrical portion 27 having a high cleanliness among the raw materials 10, which is indicated by a diagonal grid in each drawing, is exposed to the portion where the rolling element load acts. For this reason, the rolling fatigue life of both the outer ring raceways 2 and 2 is ensured, and the degree of freedom in design for ensuring the durability of the wheel bearing rolling bearing unit including the outer ring 3 provided with the both outer ring raceways 2 and 2 is improved. Can be planned.

[Second Example of Reference Example of the Present Invention ]
FIGS. 3-4 has shown the 2nd example of the reference example regarding this invention . In the case of this reference example , the pressing surface of one mold of the pair of molds used in the upsetting process performed in the process of (A) → (B) in FIG. The portion closer to the outer diameter of the pressing surface of the other mold is an inclined surface that is inclined in a direction away from the pressing surface of the one mold toward the outer peripheral edge. And let the shape of the 1st intermediate raw material 11b produced by the said upsetting process be the shape where the radial direction center part was dented with respect to the outer-periphery edge part. In the case of this reference example , the central portion of this one axial surface is a flat surface, and the portion near the outer periphery is a partially conical concave surface, so that this axial one surface is an inverted conical concave surface. On the other hand, the other surface in the axial direction is a flat surface. In the case of the above-described first intermediate material 11b having such a shape, as apparent from comparing (B) and (C) of FIG. 3 with (B) and (C) of FIG. Along with this, the extent to which the central metal material 28 and the intermediate metal material 29 are displaced radially outward becomes significant on one axial side.

The first intermediate material 11b having such an asymmetric shape with respect to the axial direction is formed so that the concave axial one surface of the die 13 is formed in the backward extrusion shown in FIG. 3 (C) → (D). It is made to oppose the upper surface of the baseplate part 15. As shown in FIG. Then, in the same manner as in the first example of the reference example described above, the backward extrusion process shown in (C) → (D) is performed to form the second intermediate material 12b, and (D) → (E). A punching process is performed to obtain a third intermediate material 25b, and then a rolling process shown in (E) → (F) is performed to obtain a fourth intermediate material 26b. As a result, as apparent from a comparison between FIG. 3F and FIG. 4 and the above-described FIG. 1F and FIG. 2, it is cleaner than the first example of the reference example . The intermediate metal material 29 can be effectively exposed to a wider range of the surface portions of the pair of outer ring raceways 2 and 2.
Since the configurations and effects of the other parts are the same as those in the first example of the reference example , the same parts are denoted by the same reference numerals, and redundant description is omitted.

[ Example of Embodiment ]
5 to 6 show an example of the embodiment of the present invention . In the case of this example, in the case of the first example of the reference example described in FIGS. 1 and 2 described above, (B) in FIG. ) → A front-rear simultaneous extrusion process shown in (C) is performed. In the case of this example, the front and rear co-extrusion process is adopted, and the first intermediate material 11 is manufactured according to the first example of the above reference example , except that the first intermediate material 11 has a beer barrel shape similar to the conventional example described above. It is the same as the method.
In the case of this example, the first intermediate material 11 shown in FIG. 5B is processed into the second intermediate material 12c shown in FIG. Thus, in the front-rear co-extrusion process for processing the first intermediate material 11 into the second intermediate material 12c, a die having an inner surface shape that matches the surface shape of the second intermediate material 12c and a punch having an outer surface shape are used. Is used. The inner surface shape of the die is a bottomed cylindrical shape as shown in the shape of the second intermediate material 12c shown in FIG. 5C, and is less than half of the depth dimension at the center of the bottom surface. The circular convex part which has the height dimension of is provided. A space between the outer peripheral surface and the inner peripheral surface of the circular convex portion is a cylindrical molding space for forming a lower portion of the second intermediate material 12c. The punch is pressed into the upper portion of the second intermediate material 12c to process the inner surface shape of the upper portion, and has an outer diameter smaller than the inner diameter of the die.

In order to process the first intermediate material 11 into the second intermediate material 12c by the front-rear simultaneous extrusion process, the first intermediate material 11 is placed in the die on the one side surface in the axial direction of the first intermediate material 11 ( The center portion of the lower surface is set in a state of contacting (mounting) the circular convex portion. Then, the central portion of the other surface in the axial direction of the first intermediate material 11 is strongly pressed by the punch, and the first intermediate material 11 is moved between the tip surface (lower surface) of the punch and the tip surface (upper surface) of the circular convex portion. Crush the middle part of one intermediate material in the axial direction. Then, the metal material pushed out in the radial direction along with the crushing is pushed into the cylindrical forming space and the punch together with the metal material present in the radially outward portion of the first intermediate material 11. It moves to the cylindrical space which exists between the outer peripheral surface of this punch and the inner peripheral surface of the said die behind in the direction. And it is set as the said 2nd intermediate material 12c which provided the partition part 32 in the axial direction intermediate part internal diameter side of the cylindrical part 31 as shown to (C) of FIG. Then, the second intermediate material 12c is punched as shown in (C) → (D) of FIG. 5, and the rolling shown in (D) → (E) as in the case of the first example of the above embodiment. By machining and further finishing, the shape shown by the chain line in FIG. 5E and FIG. 6 is cut out and processed into an outer ring 3 for a double row ball bearing.

  In the case of this example, the processing from the first intermediate material 11 to the second intermediate material 12c is performed in a substantially symmetric state with respect to the axial direction of both the materials 11, 12c by the front-rear simultaneous extrusion process. As shown in FIGS. 5C to 5E and FIG. 6, the intermediate metal material 29 having a high degree of cleanness is exposed over the entire portion that forms the double-row outer ring raceways 2 and 2. For this reason, the rolling fatigue life of both the outer ring raceways 2 and 2 can be sufficiently secured. And the freedom degree of the design for ensuring durability of the rolling bearing unit for wheel support including the outer ring 3 provided with both the outer ring raceways 2 and 2 can be further improved.

Both the above-described reference examples and the above-described example of the embodiment have been described for the case where the outer ring 3 constituting the double-row angular ball bearing 1 is manufactured. On the other hand, the method for manufacturing a bearing outer ring according to the present invention can also be used when an outer ring constituting a double-row angular tapered roller bearing is manufactured .

DESCRIPTION OF SYMBOLS 1 Double row angular contact ball bearing 2 Outer ring raceway 3 Outer ring 4 Inner ring raceway 5 Inner ring 6 Ball 7 Cage 8 Housing 9 Rotating shaft 10 Material 11, 11a, 11b First intermediate material 12, 12a, 12b, 12c Second intermediate material 13 Die 14 Punch 15 Bottom plate portion 16 Peripheral wall portion 17 Annular groove 18 Inner peripheral surface side large diameter portion 19 Inner peripheral surface side small diameter portion 20 Inner peripheral surface side inclined portion 21 Outer peripheral surface side small diameter portion 22 Outer peripheral surface side large diameter portion 23 Outer periphery Surface side inclined portion 24 Bottom portion 25, 25a, 25b Third intermediate material 26, 26a, 26b Fourth intermediate material 27 Intermediate cylindrical portion 28 Center side metal material 29 Intermediate portion metal material 30 Outer diameter side metal material 31 Cylindrical portion 32 Partition Part

Claims (3)

By applying upsetting, backward extrusion, punching, rolling, and finishing to a cylindrical material in sequence, a double-row back combination type is placed at two axial positions on the inner peripheral surface. To make a bearing outer ring with an outer ring raceway,
In the upsetting process, the material is crushed in the axial direction between the pressing surfaces of the pair of molds facing each other, to become a first intermediate material,
In the backward extrusion process, the inner peripheral surface is inclined with the inner peripheral surface side large diameter portion near the opening and the inner peripheral surface side small diameter portion near the bottom portion on the inner peripheral surface side of the axial intermediate portion. A die having a stepped shape made continuous by a portion, and an outer peripheral surface, an outer peripheral surface side small-diameter portion near the tip and an outer peripheral surface-side large diameter portion near the base end are continuously connected by an outer peripheral surface-side inclined portion in the axial direction intermediate portion. The center portion of the first intermediate material is crushed in the axial direction between the punch having a stepped shape, and the metal material extruded radially outward along with the crushing is converted into the first intermediate material. Along with the metal material present in the radially outer portion of the above, the punch is moved backward in the pushing direction, the inner and outer peripheral surfaces are stepped cylindrical surfaces and the whole is a bottomed cylindrical second intermediate material,
In the punching process, by punching and removing the bottom of the second intermediate material, the inner and outer peripheral surfaces are stepped cylindrical surfaces and the whole is a cylindrical third intermediate material,
In the rolling process, both the inner and outer peripheral surfaces of the third intermediate material are plastically deformed so that the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface is the axial intermediate portion. The fourth inner material having the smallest inner diameter and the shape in which the both sides of the axial intermediate portion are inclined in a direction in which the inner diameter gradually increases toward both axial end portions,
In the finishing process, in the method for manufacturing the bearing outer ring, the both outer ring raceways are formed on the inner peripheral surface by scraping the inner peripheral surface of the fourth intermediate material.
The outer diameter of the first intermediate material produced by the upsetting process is less than the inner diameter of the inner peripheral surface side large diameter portion of the die and larger than the inner diameter of the inner peripheral surface side small diameter portion,
In the backward extrusion process, the first intermediate material is put on the die by the tip end surface of the punch in a state where the portion near the outer diameter of the first intermediate material is hooked on the inner peripheral surface side inclined portion of the die over the entire circumference. The first intermediate material is plastically deformed into a shape inclined toward the opening of the die as the portion closer to the outer diameter, and then the central portion of the first intermediate material is pushed in the axial direction. A method for producing a bearing outer ring, wherein the outer intermediate portion of the first intermediate material is crushed and moved to the rear of the punch in the pushing direction to form the second intermediate material.   The pressing surface of one of the pair of molds used in the upsetting process is a flat surface, and at least a portion closer to the outer diameter of the pressing surface of the other mold is moved toward the outer edge. By making the inclined surface inclined in a direction away from the pressing surface of the mold, the axial one side of the first intermediate material has a shape in which the central portion in the radial direction is recessed with respect to the outer peripheral edge, and during the backward extrusion process The method for manufacturing a bearing outer ring according to claim 1, wherein the concave surface is opposed to the bottom of the die. Double column backside combination at two axial positions on the inner peripheral surface by sequentially performing upsetting, front / rear coextrusion, punching, rolling, and finishing on a cylindrical material A method for manufacturing a bearing outer ring, which is a bearing outer ring provided with a mold outer ring raceway,
In the upsetting process, the material is crushed in the axial direction between the pressing surfaces of the pair of molds facing each other, to become a first intermediate material,
In the front-rear coextrusion process, a circular convex portion having a bottomed cylindrical shape and having a height dimension less than 1/2 of the depth dimension is provided at the center of the bottom surface, and the outer peripheral surface and inner peripheral surface of the circular convex portion are provided. The center portion of the first intermediate material is crushed in the axial direction between a die having a cylindrical forming space between the die and a punch having an outer diameter smaller than the inner diameter of the die. The metal material extruded outward in the direction, together with the metal material present in the radially outward portion of the first intermediate material, and the outer peripheral surface of the punch and the punching space behind the cylindrical forming space and the punch in the pushing direction. Move to a cylindrical space existing between the inner peripheral surface of the die, and a second intermediate material provided with a partition wall portion on the inner diameter side in the axial direction intermediate portion of the cylindrical portion,
In the punching process, by removing the partition wall of the second intermediate material by punching, the whole is a cylindrical third intermediate material,
In the rolling process, both the inner and outer peripheral surfaces of the third intermediate material are plastically deformed so that the outer peripheral surface is a cylindrical surface whose outer diameter does not substantially change in the axial direction, and the inner peripheral surface is the axial intermediate portion. The fourth inner material having the smallest inner diameter and the shape in which the both sides of the axial intermediate portion are inclined in a direction in which the inner diameter gradually increases toward both axial end portions,
In the finishing process, a method for producing a bearing outer ring, wherein the outer ring raceways are formed on the inner peripheral surface by scraping the inner peripheral surface of the fourth intermediate material.

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