JP2006181638A - Raceway ring for radial ball bearing and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a manufacturing method which can obtain an outer ring 2a used for a radial ball bearing, while maintaining a practically sufficient accuracy at low cost. <P>SOLUTION: A highly precise workpiece 8 shown in (A) is formed into the outer ring 2a shown in (E), through a preparatory intermediate workpiece 9 shown in (B), a first intermediate workpiece 10 shown in (C), and a second intermediate workpiece 11 shown in (D). In each processing step, cold processes such as forging and rolling are applied, none of which causes removal of material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  This invention requires a high degree of rotational accuracy, such as an electric motor incorporated in various household electric appliances such as a vacuum cleaner and a ventilation fan, or a radial ball bearing incorporated in a rotation support portion of various auxiliary equipment for automobiles. TECHNICAL FIELD The present invention relates to an improvement in a bearing ring that constitutes a radial ball bearing that is not used and a manufacturing method thereof.

  A radial ball bearing 1 as shown in FIG. 25 is incorporated in a rotation support portion of various rotating devices. This radial ball bearing 1 is a deep groove type, and is formed by installing a plurality of balls 4, 4 between an outer ring 2 and an inner ring 3 that are arranged concentrically with each other. Of these, a deep groove type outer ring raceway 5 is formed on the axially intermediate portion of the inner peripheral surface of the outer ring 2, and a deep groove type inner ring raceway 6 is formed on the entire outer periphery of the inner ring 3. is doing. The balls 4 and 4 are arranged so as to be able to roll between the outer ring raceway 5 and the inner ring raceway 6 while being held by a cage 7. With this configuration, the outer ring 2 and the inner ring 3 can freely rotate relative to each other. In the example shown in FIG. 25, a metal corrugated cage is used as the cage 7, but a synthetic resin crown-shaped cage is often used. Further, the outer peripheral edge of each sealing plate (including a contact-type seal plate and a non-contact-type shield plate; the same applies throughout the present specification) is engaged with the engaging grooves formed on the inner peripheral surfaces of both ends of the outer ring 2. In many cases, a structure that stops is used. In this case, the inner peripheral edges of the both sealing plates are slidably contacted or closely opposed to the outer peripheral surfaces of both end portions of the inner ring 3 over the entire periphery.

  Conventionally, in order to construct the races such as the outer ring 2 and the inner ring 3 constituting the radial ball bearing 1 as described above, generally, first, the shape and dimensions close to the finished product are obtained by forging and cutting. Had an intermediate material to have. The intermediate material is subjected to a heat treatment for curing the surface, and then the surface and the surface including the raceway surface such as the outer ring raceway 5 and the inner ring raceway 6 are made to have predetermined dimensions and surface roughness. Polishing was performed to obtain the above-described race. Such an inner ring manufacturing method is not only troublesome in material yield, but also cumbersome and costly.

Patent Documents 1 and 2 describe a method of making a raceway ring of a radial ball bearing centering on forging.
First, in the case of the invention described in Patent Document 1, a composite intermediate material in which an intermediate material for making an outer ring and an intermediate material for making an inner ring are integrated by forging, then the composite intermediate material is An invention is described in which an outer ring intermediate material for making an outer ring and an inner ring intermediate material for making an inner ring are divided. In the case of the invention described in Patent Document 1, an inner ring having a deep groove type inner ring raceway on the outer peripheral surface is obtained by expanding the diameter of a part of the intermediate material for the inner ring for making the inner ring. I have to.
Next, Patent Document 2 discloses that a ring-shaped material formed by cutting a steel pipe made by hot extrusion is axially cold-compressed (upsetting) by a vertical press to form an inner peripheral surface. An invention relating to a method for producing an intermediate material for an outer ring having a deep groove type outer ring raceway is described.

  Among the inventions described in Patent Documents 1 and 2 as described above, in the case of the invention described in Patent Document 1, a composite intermediate material having a large volume is produced by forging at the initial stage of processing. For this reason, the processing load at the time of manufacturing this composite intermediate material and the stress applied to the die including the punch and receiving die of the forging device are increased, and the amount of elastic deformation of each part of the forging device including this die is increased. As a result, it is difficult to sufficiently improve the dimensional accuracy and shape accuracy of the obtained composite intermediate material, the intermediate material for manufacturing the outer ring and the inner ring made from the composite intermediate material, and further the outer ring and the inner ring. In particular, when the process of producing the composite intermediate material having a large volume is performed by cold forging, the load applied to the mold or the like becomes excessive, and it becomes difficult to ensure the durability of the mold or the like. Therefore, the processing of the composite intermediate material is made by hot forging or warm forging. In the case of hot forging or warm forging, the molds can be connected to each other regardless of the difference in temperature expansion. In order to ensure the fitting, the gap between the fitting portions must be set larger than in the case of cold forging. For this reason, it becomes difficult to sufficiently secure the shape and dimensional accuracy centered on the concentricity between the inner and outer diameters of the obtained composite intermediate material and the inner and outer peripheral surfaces. As a result, it is difficult to sufficiently secure the dimensional accuracy and run-out accuracy of the inner and outer diameters of the outer ring and inner ring obtained in the above-described applications that do not require a high degree of rotational accuracy. In addition, the locking groove for locking the outer peripheral edge of the sealing plate at both ends of the inner peripheral surface of the outer ring cannot be formed by plastic processing, and the processing of this locking groove is due to cutting, The manufacturing cost cannot be reduced sufficiently.

  Moreover, in the case of the invention described in Patent Document 2, since the ring-shaped material is obtained by cutting a steel pipe made by hot extrusion, the inner and outer diameter dimensions and both inner and outer peripheral surfaces of this material are obtained. It is difficult to ensure a high degree of shape and dimensional accuracy centering on the concentricity between each other. As a result, it becomes difficult to ensure high dimensional accuracy and runout accuracy of the inner and outer diameters of the obtained outer ring. Also, the work of cutting the steel pipe to make the ring-shaped material is troublesome, the productivity is poor, and the cost increases. Furthermore, it is necessary to perform cutting by decarburization on the intermediate material for the outer ring, which also increases the cost.

  Further, in Patent Documents 3 and 4, by pressing the peripheral surface of a ring-shaped material having a smaller diameter than the raceway to be manufactured with a mandrel, the outer peripheral surface shape of the mandrel is transferred to the peripheral surface of the ring-shaped material. In addition, an invention relating to a method for manufacturing a radial ball bearing raceway, in which the diameter of the ring-shaped material is expanded to obtain a raceway having a desired diameter, is described. However, in the case of the conventional methods described in Patent Documents 3 and 4, the behavior of the ring-shaped material in a state where the mandrel is pressed is not stable, and the shape of the outer peripheral surface of the mandrel is changed to the ring. Cannot be accurately transferred onto the surface of the material. It is also difficult to ensure sufficient roundness of the obtained race. For this reason, it is difficult to sufficiently secure the dimensional accuracy of the obtained bearing ring even if it is used for an application that does not require a very high rotational accuracy as described above. Further, in the case of the invention described in Patent Document 4, it is necessary to remove the material after plastic working, and the cost reduction effect is limited.

Japanese Patent Laid-Open No. 5-277615 Japanese Patent Laid-Open No. 2001-150082 JP 59-212142 A JP-A-56-111533

  In view of the circumstances as described above, the present invention is practically used as an inner ring and an outer ring, which are race rings that constitute a radial ball bearing that is used for the above-described applications and does not require a high degree of rotational accuracy. The present invention was invented to realize a radial ball bearing raceway ring and a manufacturing method thereof that can be obtained at low cost while ensuring sufficient accuracy.

The raceway ring for radial ball bearings that is the subject of the present invention has a raceway surface having an arc cross section in the middle of one of the peripheral surfaces in the axial direction.
In particular, the radial ball bearing raceway described in claim 1 is processed by a rolling process applied to an intermediate material having a predetermined shape.
The intermediate material is formed by plastically deforming a cylindrical material having substantially the same volume as the volume of the finished product.
And, as described in claim 2, for example, the shape of the outer peripheral surface of the intermediate material is such that the direction of change of the outer diameter is not reversed from the portion with the largest outer diameter toward both end surfaces in the axial direction, The shape does not have a cut part.
Further, in the case of the invention described in claim 2, the shape of the inner peripheral surface of the intermediate material is reversed from the portion having the smallest inner diameter toward both end surfaces in the axial direction, and the direction of change of the inner diameter is reversed. No shape with no undercut portion.

A radial ball bearing raceway manufacturing method according to claim 3 is a manufacturing method for manufacturing the radial ball bearing raceway according to claim 2, wherein the first step and the second step A process and a third process.
Of these, in the first step, a first cold forging process is performed in which a cylindrical material having substantially the same volume as the finished product is pressed between a pair of dies that are relatively displaced in the axial direction. Apply. Then, the diameter of the half piece in the axial direction of the material is changed to form a curved surface for the raceway surface having a cross-sectional arc shape to be a part of the raceway surface on the outer peripheral surface in the axial direction. Along with this, a first intermediate material is obtained with the one half portion in the axial direction as the small diameter portion and the other half portion in the axial direction as the large diameter portion across the curved surface for the raceway surface.
In the second step, second cold forging is performed in which the first intermediate material is pressed between a pair of dies different from the first step in which the first intermediate material is displaced in the axial direction. And, the distribution in the axial direction of the thickness dimension in the radial direction of at least the portion where the raceway surface should be formed in the first intermediate material matches the distribution in the portion forming the raceway surface of the raceway ring after completion. To get a second intermediate material.
Further, in the third step, a part of the second intermediate material is partially rolled by a rolling process in which the inner peripheral surface and the outer peripheral surface of the second intermediate material are pressed toward each other while rotating the second intermediate material. The raceway surface is formed by plastic deformation in the radial direction.
It should be noted that the volume substantially the same as the volume of the finished product is a volume obtained by adding a machining allowance for the finished product to the volume of the finished product when finishing such as polishing after heat treatment is performed. Say. On the other hand, when the finishing process accompanied by the removal of the material is not performed, it means that the volume is the same as the volume of the finished product, excluding inevitable manufacturing errors.
In addition, the volume of the material is not only substantially the same as the volume of the finished product, but also the aspect ratio of the cross-sectional shape (the ratio of the length dimension in the axial direction to the thickness dimension in the radial direction) It is preferable to set the optimum value in order to create the sectional shape of the finished product.

Furthermore, in the case of the invention of the method for manufacturing a radial ball bearing raceway described in claim 5, a circular circular arc is formed at the axially intermediate portion of any one of the peripheral surfaces which are cylindrical and become the processed peripheral surface. A shaped raceway is formed over the entire circumference.
In particular, in the method for manufacturing a radial ball bearing raceway ring according to claim 5, it has a volume substantially the same as the volume of the finished product, and the circumferential surface on the side opposite to the surface on which the raceway surface is formed. A cylindrical material having a diameter of a non-processed side peripheral surface substantially the same as the diameter of the finished product is substantially equal to the support-side peripheral surface provided on the receiving member. It is supported by this receiving member by fitting without gaps (as much as possible).
Then, the processing side peripheral surface of the processing side rotating member having a bus bar shape that matches the bus bar shape of the processing side peripheral surface in a finished product state is pressed against the processing side peripheral surface in the radial direction of the material. Meanwhile, the processing-side rotating member and the receiving member are relatively rotated.
And by this relative rotation, the said process side peripheral surface is processed into the shape as a finished product which has at least the said track surface (the shape of the process side peripheral surface is transcribe | transferred to a process side peripheral surface).

The radial ball bearing raceway and the manufacturing method thereof according to the present invention configured as described above are used, for example, in the above-described applications. A bearing ring constituting a radial ball bearing that does not require a very high degree of rotational accuracy can be obtained at low cost while ensuring sufficient accuracy in practice.
That is, cold-working a cylindrical material (high-precision material) with a volume that matches the volume of the raceway to be manufactured (in the state where the machining allowance is accompanied by removal of the material). Therefore, the shape accuracy and dimensional accuracy of this race ring can be secured to a high degree.
Of course, by improving the processing accuracy, the present invention can naturally be applied to a bearing ring for a ball bearing that requires higher accuracy than the above-described applications.

Preferably, when the invention described in claim 3 is carried out, as described in claim 4, the bearing ring locks the peripheral edge portion of the sealing plate at both axial end portions of the peripheral surface forming the raceway surface. It is assumed that a locking groove is provided. Before the first step, a preliminary step is provided to form a preliminary intermediate material by forming step portions that are recessed in the radial direction from the axial intermediate portion at both axial end portions of the material. The above-mentioned locking groove is formed.
If comprised in this way, it can manufacture at low cost also about the bearing ring provided with the locking groove for forming the peripheral part of a sealing board.

Further, when the invention described in claim 5 is carried out, preferably, as described in claim 6, this processed side periphery is provided at both ends in the axial direction of the processed side peripheral surface of the finished race. In order to form a step portion that is recessed in the radial direction from the axially central portion of the surface over the entire circumference, step portions are formed at both end portions in the axial direction of the processed peripheral surface of the material. Then, both the step portions are processed simultaneously with the raceway surface in accordance with the pressing of the processing side rotating member to the processing side peripheral surface.
If such a structure is employ | adopted, the said both step part required in order to install a seal ring can be processed easily and with sufficient precision.

Further, when carrying out the invention described in claim 6 as described above, preferably, as described in claim 7, both stepped portions provided at both end portions in the axial direction of the processed peripheral surface of the material, The step surface existing between the axially central portion is an inclined surface that is inclined in a direction approaching each other with increasing distance from the non-processed peripheral surface with respect to the radial direction. Then, the inclination angle of the two step surfaces with respect to a virtual plane existing in a direction orthogonal to the central axis of the material is 15 degrees from the inclination angle of the step surface existing in the corresponding part of the completed raceway ring. Increased within the following range.
If these two step surfaces are inclined in this manner, the force applied to the processing side rotating member can be kept low, and the durability and processing accuracy of the processing side rotating member can be improved.

Further, when the inventions described in claims 5 to 7 are carried out, preferably, as described in claim 8, the axially opposite end surfaces of the material for making the race are separated from the non-processed side peripheral surface. The inclined surfaces are inclined in a direction approaching each other. And the inclination angle of the said axial direction both end surface with respect to the virtual plane which exists in the direction orthogonal to the central axis of the said raw material shall be 20 degrees or less.
By inclining these axial end faces in this way, the force applied to the processing-side rotating member can be kept low, and the durability and processing accuracy of the processing-side rotating member can be improved.

  FIGS. 1 to 5 show the case where the present invention is applied to the manufacture of the outer ring 2a {see FIG. 1 (E)} as Embodiment 1 of the present invention corresponding to claims 1 to 4. The feature of the present embodiment is that a high-precision cylindrical material 8 {see FIG. 1A} having a volume substantially the same as the volume of the outer ring 2a is made in advance, and then this high-precision material 8 is cold-worked. Is plastically deformed to form the outer ring 2a. Although there is no particular limitation on the method for producing the high-accuracy material 8, a long wire (coil) is cut into a predetermined length from the viewpoint of improving the material yield and reducing the cost. It is preferable to produce by cold plastic working. Alternatively, the high-precision material 8 can be obtained by punching a plate material into a ring shape and twisting the cross-sectional shape by 90 degrees. Furthermore, it is also possible to use a metal plate wound in a circular tube shape and welded at a butt portion so that the volume is adjusted by turning. Even if the high-precision material 8 is made by any method, the high-precision material 8 is plastically deformed by cold working in the following steps to obtain the outer ring 2a.

  In the case of the present embodiment, the high-precision material 8 shown in FIG. 1A is replaced with the preliminary intermediate material 9 shown in (B), the first intermediate material 10 shown in (C), and (D). After passing through the second intermediate material 11 shown in FIG. 4, the outer ring 2a shown in FIG. All of the preliminary intermediate material 9, the first intermediate material 10, and the second intermediate material 11 have an outer peripheral surface whose shape is changed from the portion having the largest outer diameter toward both end surfaces in the axial direction. The shape does not reverse and does not have an undercut. Further, the shape of the inner peripheral surface is such that the direction of change of the inner diameter is not reversed from the portion having the smallest inner diameter toward both end surfaces in the axial direction and does not have an undercut portion. Therefore, each of the intermediate materials 9 to 11 can be made with high accuracy by strongly pressing between molds relatively displaced in the axial direction. The process will be described below in order.

  In order to use the high-precision material 8 as the preliminary intermediate material 9, the outer peripheral surface of the high-precision material 8 is fitted into an inner circumferential surface of a holding die (not shown), and the inner circumferential surface is also fitted onto the core. Then, the tip end face of the punch (not shown) is pressed over the entire circumference to the inner diameter side halves of both end faces in the axial direction (vertical direction in FIG. 1) of the high-precision material 8. As a result, the preliminary intermediate material 9 having the stepped portions 12 and 12 recessed in the radially outward direction in the inner diameter side halves of the axially opposite end surfaces of the high-precision material 8 is recessed in the axial direction. can get. At this time, the meat that has flowed outward in the radial direction (left-right direction in FIG. 1) with the formation of these stepped portions 12 and 12 has the outer-diameter-side halves at both ends in the axial direction projecting in the axial direction. It is absorbed by doing. In addition, the outer diameter of the preliminary intermediate material 9 manufactured in this way matches the outer diameter of the outer ring 2a to be manufactured.

Therefore, the diameter of the part of the preliminary intermediate material 9 {the part excluding one end in the axial direction (the upper end in FIG. 1)} is once reduced to an outer diameter smaller than the outer diameter of the outer ring 2a. The preliminary intermediate material 9 is applied. This contraction processing is performed as shown in FIG.
First, as shown in (A), the preliminary intermediate material 9 is fitted (set) into the large diameter portion 15 of the processing hole 14 provided in the die 13. Next, as shown in (B), the preliminary intermediate material 9 is pushed into the processed hole 14 by the punch 16. The machining hole 14 is formed by connecting the large-diameter portion 15 and a small-diameter portion 17 provided on the back side of the large-diameter portion 15 with a smooth curved surface portion 18. Further, the inner diameter of the large diameter portion 15 is matched with the outer diameter of the outer ring 2a. Therefore, the outer diameter of a part of the preliminary intermediate material 9 pushed into the small diameter portion 17 existing in the inner part of the processing hole 14 by the punch 16 is reduced until it becomes smaller than the outer diameter of the outer ring 2a. As a result, the first intermediate material 10 is obtained.

  The diameter of the inner peripheral surface of the first intermediate material 10 is such that the inner peripheral surface of the outer ring raceway 5 {see FIG. It changes only in the direction of enlargement toward the axial end face. The diameter of the inner peripheral surface has a portion that does not change in the axial direction, but does not have a portion that changes in the smaller direction. In other words, there is no undercut portion when viewed in the direction in which the punch 16 is inserted. Therefore, the processing of the first intermediate material 10 by the punch 16 and the die 13 can be performed with high accuracy.

  In the illustrated example, a convex curved surface portion 19 is formed on a part of the front end surface of the punch 16 so that a concave curved surface portion 20 having an arcuate cross section is formed on a part of the inner peripheral surface of the first intermediate material 10. , It is formed over the entire circumference. The punch 16 forms the concave curved surface portion 20 at an initial stage of processing using the preliminary intermediate material 9 as the first intermediate material 10. Therefore, in the course of the operation of reducing the outer diameter in order to reduce the outer diameter of a part of the preliminary intermediate material 9 as described above to the first intermediate material 10, the processing stress is excluding the initial stage, Only the contact portion between the curved surface portion 18 and the outer peripheral surface of the preliminary intermediate material 9 is added. Therefore, the plastic processing of the outer peripheral surface of the first intermediate material 10 by the curved surface portion 18 of the processing hole 14 can be performed with high accuracy. It is important to accurately process this portion from the standpoint of ensuring the accuracy of the outer ring raceway 5 obtained (see FIG. 1E or FIG. 25). The first intermediate material 10 made in this way is pushed out of the processed hole 14 by the knockout ring 21 and sent to the next step.

In this next step, an inner diameter extrusion process for forming a portion to be the origin of the axial half piece (the lower half portion in FIG. 1) of the outer ring raceway 5 on the inner peripheral surface of the first intermediate material 10. Apply. This inner diameter extrusion is performed as shown in FIG.
First, as shown in FIG. 3A, the first intermediate material 10 is fitted into a machining hole 23 provided in the die 22 and one end surface in the axial direction of the first intermediate material 10 (lower end surface in FIG. 3). Is abutted against (set to) the front end surface (the upper end surface in FIG. 3) of the counter ring 24 inserted into the processing hole 23. In this state, the outer peripheral surface of the first intermediate material 10 is in contact with the inner peripheral surface of the processing hole 23 and the one end surface in the axial direction is in contact with the front end surface of the counter ring 24 without any gap. The positional relationship between the counter ring 24 and the die 22 in the axial direction (vertical direction in FIG. 3) is strictly regulated.

  When the first intermediate material 10 is set as described above, the inner peripheral surface of the first intermediate material 10 is then handled by the punch 25 as shown in FIG. The tip of the punch 25 is a small-diameter portion 26 that can be displaced in the axial direction with respect to the counter ring 24 while being inserted into the counter ring 24 without a gap (with the concentricity strictly regulated). . The small-diameter portion 26 and the small-diameter portion 26 and the concentric large-diameter portion 27 that are provided near the base end (upward in FIG. 3) are connected by the convex curved surface portion 28. The cross-sectional shape of the convex curved surface portion 28 is an arc shape that substantially matches (but does not completely match) the cross-sectional shape of one half of the axial direction of the outer ring raceway 5 to be processed. In the inner diameter extrusion process, the convex curved surface portion 28 of the punch 25 is abutted against the concave curved surface portion 20 existing on the inner peripheral surface of the first intermediate material 10, and the shape of the concave curved surface portion 20 is corrected while The concave curved surface portion 20 is moved to a predetermined position toward one end portion in the axial direction of the first intermediate material 10 (a portion closer to the inner diameter is handled).

  As a result, the second intermediate material 11 provided with the concave curved surface portion 20a that is the original half portion of the outer ring raceway 5 in the axial direction end portion of the inner peripheral surface can be obtained. In this way, when the second intermediate material 11 is manufactured, the concave curved surface portion that is moved to a predetermined position while correcting the shape of the concave curved surface portion 20 as described above and becomes one half of the axial direction of the outer ring raceway 5. In the process of progressing the handling operation, the processing stress is applied only to the contact portion between the convex curved surface portion 28 and the concave curved surface portion 20. Therefore, plastic working of the concave curved surface portion 20a, which is a half portion in the axial direction of the outer ring raceway 5, by the convex curved surface portion 28 can be performed with high accuracy. Of the second intermediate material 11 manufactured in this way, the shape of the portion near the one end in the axial direction {lower half of FIG. 3B) provided with the concave curved surface portion 20a is the shape of the outer ring 2a to be manufactured. It almost matches the shape of the corresponding part (not exactly). Further, in the contraction processing shown in FIG. 2, the inner diameter extrusion processing shown in FIG. 3 is completed for the portion processed into the stepped shape by the curved surface portion 18 provided in the intermediate portion of the processing hole 14. At that time, the axial distribution of the wall thickness in the radial direction is the distribution of the corresponding part of the outer ring 2a to be manufactured (after considering the change in the wall thickness as the diameter expands during the outer ring raceway forming process described below) )Match. For this reason, the shape of the curved surface portion 18 and the amount of the punch 16 inserted into the die 13 are strictly regulated during the contraction processing shown in FIG.

Even when the second intermediate material 11 is processed as described above, the diameter of the inner peripheral surface from the portion that should become the bottom of the outer ring raceway 5, the insertion side of the punch 25 that should form this inner peripheral surface It changes only in the direction of enlargement toward the axial end face. The diameter of the inner peripheral surface has a portion that does not change in the axial direction, but does not have a portion that changes in the smaller direction. In other words, there is no undercut portion when viewed in the direction in which the punch 25 is inserted. Therefore, the processing of the second intermediate material 11 by the punch 25 and the die 22 can be performed with high accuracy.
The second intermediate material 11 manufactured in this way is pushed out of the processing hole 23 by the counter ring 24 and sent to the next step.

  In this next step, the outer diameter of the second intermediate material 11 near the other end in the axial direction (near the lower end in FIGS. 3 and 5) is increased, and the outer diameter is reduced (except for the chamfered portions at both ends). The outer ring raceway forming process is performed to make the outer ring raceway 5 uniform on the inner peripheral surface while making it uniform over the entire axial length. This outer ring raceway forming process is performed by a rolling process as shown in FIGS.

  In this rolling process, a part of the second intermediate material 11 in the circumferential direction is radially arranged between the circumscribed roller 29 and the inscribed roller 30 that are supported in parallel with each other and relatively rotatable in opposite directions. This is done by pressing. Of these, the circumscribed roller 29 has a thick disk shape and is supported only for rotation in a state where radial displacement is suppressed, and has a width larger than the width (axial length) of the outer ring 2a to be manufactured. , And a cylindrical outer peripheral surface (parallel to the rotation center axis). Further, the inscribed roller 30 has a cylindrical shape, and has a processed curved surface portion having a cross-sectional shape (bus shape) that matches a cross-sectional shape (bus shape) of the inner peripheral surface of the outer ring 2a to be formed on a part of the outer peripheral surface. 31 is provided. Further, the inscribed roller 30 can be driven to rotate while being pressed against the outer peripheral surface of the inscribed roller 29 by a driving mechanism and a pressing mechanism (not shown).

  In order to process the second intermediate material 11 into the outer ring 2a, the inner roller 30 is placed on the outer peripheral surface of the outer roller 29 while the second intermediate material 11 is loosely fitted to the inner roller 30. Rotating drive while pressing. The second intermediate material 11 is pressed against the outer peripheral surface of the circumscribed roller 29 while being rotated in the same direction as the inscribed roller 30 by the inscribed roller 30. For this reason, the circumscribing roller 29 rotates (rotates) with the second intermediate material 11 and the inscribed roller 30 in the opposite direction. The second intermediate material 11 is partially pressed in the circumferential direction between the outer peripheral surfaces of the rollers 29 and 30. Further, the portion pressed in the radial direction in this way continuously changes in the circumferential direction. As a result, the diameter of the second intermediate material 11 is gradually increased until the portion near the other end in the axial direction contacts the outer peripheral surface of the circumscribed roller 29.

  The portion of the second intermediate material 11 near the other end in the axial direction is expanded in diameter, and the outer diameter of the second intermediate material 11 is uniform over the entire length in the axial direction (excluding the chamfered portions at both ends). After that, the shape of the processed curved surface portion 31 of the inscribed roller 30 is transferred to the inner peripheral surface of the second intermediate material 11. The processed curved surface portion 31 is provided with a convex curved surface portion 32 having an arcuate cross section in which the outer ring raceway 5 is to be formed at the central portion in the axial direction. Further, at both ends in the axial direction, ridges 33, 33 for forming locking grooves for locking the outer peripheral edge of the sealing plate are formed on the stepped portions 12, 12, respectively. Therefore, in a state where the shape of the processed curved surface portion 31 is transferred to the inner peripheral surface of the second intermediate material 11, the outer ring raceway 5 is formed at the axial center portion of the inner peripheral surface, and the locking grooves 34 are also formed at both end portions. , 34, respectively, can be obtained.

  The outer ring 2a thus obtained is subjected to heat treatment (quenching) in order to cure the outer ring raceway 5 portion in order to ensure a rolling fatigue life. The heat-treated outer ring 2a can be combined with the inner ring 3 and the balls 4 and 4 as they are to form a radial ball bearing 1 as shown in FIG. Further, when it is necessary to keep the rotation accuracy or vibration and noise low during rotation, the outer ring raceway 5 can be polished to improve the surface roughness after the heat treatment.

  6 to 7 show a second embodiment of the present invention, which also corresponds to claims 1 to 4. In the case of the present embodiment, the circumscribed roller 29a constituting the rolling processing device for processing the second intermediate material 11 shown in FIG. 1D described above into the outer ring 2a shown in FIG. It is formed in an annular shape. The inscribed roller 30 is inserted inside the circumscribed roller 29a in a state where the rotation center axes are arranged in parallel with each other and the rotation center axes are decentered from each other. When performing the rolling process for processing the second intermediate material 11 into the outer ring 2a, the inscribed roller 30 is rotated while being pressed against the inner peripheral surface of the outer roller 29a. Since the configuration and operation of the other parts are the same as those of the first embodiment, overlapping illustrations and descriptions are omitted.

  8 to 9 show a third embodiment of the present invention, which also corresponds to claims 1 to 4. In the case of the present embodiment, the circumscribed roller 29b constituting the rolling processing device for processing the second intermediate material 11 shown in FIG. 1D to the outer ring 2a shown in FIG. The outer diameter of the circumscribed roller 29b is made to coincide with the outer diameter of the outer ring 2a (= the maximum outer diameter of the second intermediate material 11). The inscribed roller 30 is inserted inside the circumscribed roller 29b with the rotation center axes arranged in parallel to each other and with the rotation center axes decentered from each other. When performing the rolling process for processing the second intermediate material 11 into the outer ring 2a, the inscribed roller 30 is moved in a state in which the second intermediate material 11 is fitted in the outer roller 29b without rattling. Then, it is rotated while being pressed against the inner peripheral surface of the circumscribed roller 29b. Since the configuration and operation of other parts are the same as those of the first embodiment and the second embodiment described above, overlapping illustrations and descriptions are omitted.

  FIGS. 10 to 14 show the case where the present invention is applied to the production of the inner ring 3a as the fourth embodiment of the present invention, which also corresponds to the first to fourth aspects. A feature of the present embodiment is that after a cylindrical high-precision material 8a {see FIG. 1 (A)} having a volume substantially the same as the volume of the inner ring 3a {see FIG. 10 (E)} is made in advance, This high precision material 8a is plastically deformed by cold working to form the inner ring 3a. The method for producing the high-precision material 8a is the same as that in the first embodiment described above. However, regardless of the method used to produce the high-precision material 8a, the high-precision material 8a is produced as follows. The inner ring 3a is formed by plastic deformation by cold working in the process.

  In the case of the present embodiment, the high-precision material 8a shown in FIG. 10A is replaced with the preliminary intermediate material 9a shown in FIG. 10B, the first intermediate material 10a shown in FIG. The inner ring 3a shown in (E) is obtained through the second intermediate material 11a shown in FIG. In both the preliminary intermediate material 9a and the second intermediate material 11a, the shapes of the outer peripheral surface and the inner peripheral surface are shapes that do not have an undercut portion, as in the above-described embodiments. Accordingly, each of the intermediate materials 9a to 11a can be made with high accuracy by strongly pressing between the dies that are relatively displaced in the axial direction. The process will be described in turn.

  In order to use the high-precision material 8a as the preliminary intermediate material 9a, a state in which the outer peripheral surface of the high-precision material 8a is fitted into an inner peripheral surface of a holding mold (not shown) and the inner peripheral surface is also fitted onto the core. Thus, the punch end surface (not shown) is pressed over the entire circumference on the outer diameter side half of both end surfaces in the axial direction of the high-precision material 8a. As a result, the preliminary intermediate material 9a is obtained in which the outer diameter side halves of both end surfaces in the axial direction of the high-accuracy material 8a are recessed in the axial direction and have stepped portions 12a and 12a in the portions. At this time, the flesh that has flowed radially inward along with the formation of the two stepped portions 12a and 12a is absorbed when the inner-diameter-side halves at both ends in the axial direction protrude in the axial direction. The inner diameter of the preliminary intermediate material 9a manufactured in this way is almost the same as the inner diameter of the inner ring 3a to be manufactured (it is not necessary to be exactly the same).

In such a preliminary intermediate material 9a, an inner ring raceway 6 having a part {the part excluding one end in the axial direction (the upper end in FIG. 10) outer diameter formed on the outer peripheral surface of the intermediate part of the inner ring 3a {FIG. 10 (E) and FIG. 14} is performed to reduce the groove bottom diameter (the outer diameter of the portion where the outer diameter is the smallest at the center in the width direction of the deep groove type inner ring raceway 6). This contraction processing is performed as shown in FIG.
First, as shown in (A), the preliminary intermediate material 9a is fitted (set) into the large-diameter portion 15a of the processing hole 14a provided in the die 13a. Next, as shown in (B), the preliminary intermediate material 9a is pushed into the processed hole 14a by the punch 16a. The machining hole 14a is formed by connecting the large diameter portion 15a and the small diameter portion 17a provided on the back side of the large diameter portion 15a by a smooth curved surface portion 18a. The cross-sectional shape of the curved surface portion 18a coincides with the cross-sectional shape of one half portion (the upper half portion in FIG. 10) of the inner ring raceway 6 formed on the outer peripheral surface of the inner ring 3a to be manufactured, and the small diameter portion 17a. The inner diameter of the groove is matched with the groove bottom diameter. Accordingly, the outer diameter of a part of the preliminary intermediate material 9a pushed into the small-diameter portion 17a existing in the deep part of the processing hole 14a by the punch 16a is reduced to a state matching the groove bottom diameter. The first intermediate material 10a.

  In the illustrated example, a convex curved surface portion 19a is formed in a part of the axially intermediate portion of the punch 16a, so that a concave curved surface having a circular arc cross section is formed at a portion near one end of the inner peripheral surface of the first intermediate material 10a. The part 20b is formed over the entire circumference. The punch 16a forms the concave curved surface portion 20b at an initial stage of processing using the preliminary intermediate material 9a as the first intermediate material 10a. Therefore, in the course of the progress of the work of reducing the outer diameter to reduce the outer diameter of a part of the preliminary intermediate material 9a as described above to the first intermediate material 10a, the processing stress is excluding the initial stage, Only the contact portion between the curved surface portion 18a and the outer peripheral surface of the preliminary intermediate material 9a is added. Therefore, the plastic working of the outer peripheral surface of the first intermediate material 10a by the curved surface portion 18a of the processing hole 14a can be performed with high accuracy. It is important from the aspect of ensuring the accuracy of the obtained inner ring raceway 6 {refer to (E) in FIG. 10 or FIG. 25} to accurately process this portion. The first intermediate material 10a thus produced is pushed out from the processed hole 14a by the knockout ring 21a and sent to the next step.

  The first intermediate material 10a processed as described above should form this outer peripheral surface from the portion where the diameter of the outer peripheral surface should be the bottom of the inner ring raceway 5 {see FIG. 10 (E)}. It changes only in the direction of expansion toward the insertion side axial end face of the die 13a. The diameter of the outer peripheral surface is not changed in the axial direction even though there is a portion that does not change in the axial direction. In other words, there is no undercut portion when viewed in the insertion direction with respect to the die 13a. Therefore, the first intermediate material 10a can be processed with high accuracy by the die 13a and the punch 16a.

In the next step, in the first intermediate material 10a, the distribution in the axial direction of the wall thickness in the radial direction of the portion corresponding to the other half part in the axial direction of the inner ring raceway 6 (the lower half part in FIG. 10), An inner diameter extrusion process is performed to match the distribution of the corresponding portion of the inner ring 3a to be manufactured. This inner diameter extrusion is performed as shown in FIG.
First, as shown in (A), the first intermediate material 10a is fitted into a machining hole 23a provided in the die 22a, and one end surface in the axial direction of the first intermediate material 10a (the lower end surface in FIG. 12). Is abutted against (set) the front end surface (upper end surface in FIG. 12) of the counter ring 24a inserted into the processing hole 23a. In this state, the outer peripheral surface of the first intermediate material 10a is in contact with the inner peripheral surface of the processing hole 23a and the one end surface in the axial direction is in contact with the front end surface of the counter ring 24a without any gap. Further, the positional relationship between the counter ring 24a and the die 22a in the axial direction (vertical direction in FIG. 12) is strictly regulated.

  When the first intermediate material 10a is set as described above, the inner peripheral surface of the first intermediate material 10a is then handled by the punch 25a as shown in FIG. The tip of the punch 25a is a small-diameter portion 26a that can be displaced in the axial direction with respect to the counter ring 24a while being inserted into the counter ring 24a without any gap (with the concentricity strictly regulated). . The small-diameter portion 26a and the small-diameter portion 26a and the large-diameter portion 27a that are concentric with each other are provided on a portion near the base end (upward in FIG. 12) by a convex curved surface portion 28a. The cross-sectional shape of the convex curved surface portion 28a matches the distribution in the axial direction of the thickness in the radial direction of the portion corresponding to the other half portion in the axial direction of the inner ring raceway 6 with the distribution of the corresponding portion of the inner ring 3a to be formed. Therefore, it is strictly regulated. In the inner diameter extrusion process, the convex curved surface portion 28a of the punch 25a is abutted against the concave curved surface portion 20b existing on the inner peripheral surface of the first intermediate material 10a, and while correcting the shape of the concave curved surface portion 20b, The concave curved surface portion 20b is moved to a predetermined position toward the one end portion in the axial direction of the first intermediate material 10a (a portion closer to the inner diameter is handled).

  As a result, a concave curved surface portion 20c for adjusting the wall thickness distribution of the portion that should be the other half portion in the axial direction of the inner ring raceway 6 is provided near the axial end of the inner peripheral surface (lower side in FIG. 12). The second intermediate material 11a can be obtained. When the second intermediate material 11a is manufactured in this way, the portion to be moved to a predetermined position while correcting the shape of the concave curved surface portion 20b as described above, and to be the other half portion in the axial direction of the inner ring raceway 6 In the process of handling the concave curved surface portion 20c for adjusting the wall thickness distribution, the processing stress is applied only to the contact portion between the convex curved surface portion 28a and the concave curved surface portion 20b. Therefore, the plastic processing of the concave curved surface portion 20c for adjusting the thickness distribution by the convex curved surface portion 28a can be performed with high accuracy. Of the second intermediate material 11a thus produced, the portion on the opposite side to the portion provided with the concave curved surface portion 20c in the axial direction {the upper half of FIG. 10 (D) and FIG. 12 (B). The shape of the portion} substantially matches the shape of the corresponding portion of the inner ring 3a to be manufactured. Further, regarding the portion where the concave curved surface portion 20c is formed, the distribution in the axial direction of the wall thickness in the radial direction matches the distribution of the corresponding portion of the inner ring 3a to be manufactured. For this reason, at the time of the inner diameter extrusion processing, the shape of the convex curved surface portion 28a and the insertion amount of the punch 25a into the die 22a are strictly regulated. The second intermediate material 11a thus produced is pushed out of the processed hole 23a by the counter ring 24a and sent to the next step.

  In this next step, the inner diameter of the second intermediate material 11a closer to the other end in the axial direction (near the lower end of FIGS. 12 and 14) is increased, and the inner diameter is increased in the axial direction (excluding the chamfered portions at both ends). The inner ring raceway forming process is performed to make the inner ring raceway 6 uniform on the outer peripheral surface while making it uniform over the entire length. This inner ring raceway forming process is performed by a rolling process as shown in FIGS.

  In this rolling process, a part of the second intermediate material 11a in the circumferential direction is radially formed between the circumscribed roller 29c and the inscribed roller 30a, which are supported in parallel with each other and relatively rotatable in opposite directions. This is done by pressing. Of these, the circumscribed roller 29c has a thick disk shape and is supported only for rotation in a state where radial displacement is suppressed, and has a width larger than the width of the inner ring 3a (the length in the axial direction) to be manufactured. Have. In addition, a processing curved surface portion 31a having a cross-sectional shape (bus shape) that matches the cross-sectional shape (bus shape) of the outer peripheral surface of the inner ring 3a to be manufactured is provided in the axially intermediate portion of the outer peripheral surface of the circumscribed roller 29c. . On the other hand, the inscribed roller 30a has a columnar shape, and the outer peripheral surface is a simple cylindrical surface (parallel to the rotation center). The inscribed roller 30a can be driven to rotate while being pressed against the inner peripheral surface of the outer roller 29c by a driving mechanism and a pressing mechanism (not shown).

  In order to process the second intermediate material 11a into the inner ring 3a, the inner roller 30a is placed on the outer peripheral surface of the outer roller 29c while the second intermediate material 11a is loosely fitted to the inner roller 30a. Rotating drive while pressing. The second intermediate material 11a is pressed against the outer peripheral surface of the circumscribed roller 29c while being rotated in the same direction as the inscribed roller 30a by the inscribed roller 30a. For this reason, the circumscribed roller 29c rotates (rotates) along with the second intermediate material 11a and the inscribed roller 30a in the opposite direction. The second intermediate material 11a is partially pressed in the circumferential direction between the outer peripheral surfaces of the rollers 29c and 30a. Further, the portion pressed in the radial direction in this way continuously changes in the circumferential direction. As a result, the diameter of the second intermediate material 11a is gradually increased until a portion near the other end in the axial direction contacts the outer peripheral surface of the circumscribed roller 29c.

  The portion near the other end in the axial direction of the second intermediate material 11a is expanded in diameter, and the inner diameter of the second intermediate material 11a is uniform over the entire length in the axial direction (excluding the chamfered portions at both ends). Thereafter, the shape of the processed curved surface portion 31a of the circumscribed roller 29c is transferred to the outer peripheral surface of the second intermediate material 11a. The processed curved surface portion 31a is provided with a convex curved surface portion 32a having an arcuate cross section in which the inner ring raceway 6 is to be formed at the central portion in the axial direction. Further, on both ends in the axial direction, there are formed processing surfaces for processing the stepped portions 12a, 12a into sealing surfaces for making the inner peripheral edge of the sealing plate slidably contact or close to each other. Therefore, in a state where the shape of the processed curved surface portion 31a is transferred to the inner peripheral surface of the second intermediate material 11a, the inner ring raceway 6 is provided at the axial center portion of the inner peripheral surface, and the seal surfaces are also provided at both end portions. The inner ring 3a provided respectively can be obtained.

  The inner ring 3a thus obtained is subjected to heat treatment (quenching) in order to cure the inner ring raceway 6 portion in order to ensure a rolling fatigue life. The inner ring 3a subjected to the heat treatment can be directly combined with the outer ring 2 and the balls 4 and 4 to form a radial ball bearing 1 as shown in FIG. Further, when it is necessary to keep the rotation accuracy or vibration and noise low during rotation, the inner ring raceway 6 can be polished to improve the surface roughness after the heat treatment.

  15 to 16 show a fifth embodiment of the present invention, which also corresponds to claims 1 to 4. In the case of the present embodiment, the circumscribed roller 29d constituting the rolling processing device for processing the second intermediate material 11a shown in FIG. 10D to the inner ring 3a shown in FIG. It is formed in an annular shape. The inscribed roller 30a is inserted inside the circumscribed roller 29d with the rotation center axes arranged in parallel to each other and with the rotation center axes decentered from each other. When performing the rolling process for processing the second intermediate material 11a into the inner ring 3a, the inscribed roller 30a is rotated while being pressed against the inner peripheral surface of the circumscribed roller 29d. Since the configuration and operation of other parts are the same as those in the above-described fourth embodiment, overlapping illustrations and descriptions are omitted.

  FIGS. 17 to 18 show Embodiment 6 of the present invention, which also corresponds to claims 1 to 4. In the case of the present embodiment, in order to constitute a rolling processing apparatus for processing the second intermediate material 11a shown in FIG. 10D described above into the inner ring 3a shown in FIG. A pair of circumscribed rollers 29e and 29e each having a thick disk shape are provided. Further, instead of the inscribed roller, a cylindrical mandrel 35 for rotatably supporting the second intermediate material 11a is provided. The central axis of the mandrel 35 and the rotational central axes of the two circumscribed rollers 29e and 29e are on a single virtual plane and are parallel to each other. Further, the outer diameter of the mandrel 35 coincides with the inner diameter of the inner ring 3a to be processed. In the case of this embodiment, the second intermediate material 11a is formed so that the inner diameter of the second intermediate material 11a near the one end in the axial direction (lower side in FIG. 18) matches the inner diameter of the inner ring 3a. Yes.

  When performing the rolling process for processing the second intermediate material 11a into the outer ring 3a, both the circumscribed rollers 29e and 29e are brought close to each other with the second intermediate material 11a fitted on the mandrel 35. Rotate in the same direction while pressing in the direction. As a result, the inner ring raceway 6 and the seal surface are formed on the outer peripheral surface while the outer diameter of a part of the second intermediate material 11a is reduced. Since the configuration and operation of other parts are the same as those of the above-described fourth embodiment and the above-described fifth embodiment, overlapping illustrations and descriptions are omitted.

19 to 21 show a seventh embodiment of the present invention corresponding to claims 1 and 5 to 8. In the case of the present embodiment, the processing from the preliminary intermediate material 9 shown in FIG. 1B to the outer ring 2a shown in FIG. The inner diameter extrusion process as shown in (D) is not performed, but only the rolling process is performed. That is, in the case of the present embodiment, the preliminary intermediate material 9 as shown in FIG. 21A is fitted into the die 22b as shown in FIGS. That is, the outer peripheral surface of the preliminary intermediate material 9 which is the non-processed peripheral surface is brought into contact with or close to the inner peripheral surface of the die 22b which is the support side peripheral surface over the entire periphery. In this state, the outer ring 2a is obtained by pressing the outer peripheral surface of the mandrel 35a which is the processing side peripheral surface against the inner peripheral surface of the preliminary intermediate material 9 which is the processing side peripheral surface. The mandrel 35a is the processing side rotating member described in the claims. The volume of the preliminary intermediate material 9 and the volume of the outer ring 2a that is a finished product are equal to each other. Further, the outer diameter D ₉ of the pre-intermediate material 9 outer diameter D _2a of the outer ring 2a, substantially equal (D ₉ ≒ D _2a). Further, both the width W ₉ of the pre-intermediate material 9 width W _2a of the outer ring 2a, approximately equal (W ₉ ≒ W _2a).

  The die 22b is annular and has an inner diameter that allows the preliminary intermediate material 9 to be fitted substantially without gaps. The die 22b is rotatably supported by a support portion (not shown) while being prevented from being displaced in the radial direction. Has been. Further, the mandrel 35a has an outer diameter that can be freely inserted into and removed from the inner diameter side of the preliminary intermediate material 9 and the outer ring 2a. In addition, the portion of the mandrel 35a that faces the inner peripheral surface of the die 22b on the outer peripheral surface of the intermediate portion matches the generatrix shape of the processed peripheral surface in the finished product state, that is, the inner peripheral surface of the outer ring 2a. A processing side peripheral surface 36 having a bus bar shape is provided. Such a mandrel 35a is strongly driven toward the inner peripheral surface of the die 22b by a pressing device (not shown) while being rotated by a driving device (not shown).

  In order to process the preliminary intermediate material 9 into the outer ring 2a, first, the preliminary intermediate material 9 as shown in FIG. 21A is formed on the die 22b without a gap as shown in FIG. Fits inside. Step portions 37 and 37 are formed at both axial ends of the inner peripheral surface of the preliminary intermediate material 9, respectively. Each of the step portions 37 and 37 is provided with a locking groove for locking the outer peripheral edge portion of the seal ring on the inner peripheral surfaces of both ends of the outer ring 2a in accordance with the processing by the mandrel 35a and the die 22b. Stepped. Stepped surfaces 38, 38 exist between the two stepped portions 37, 37 and the axially central portion of the inner peripheral surface of the preliminary intermediate material 9, respectively. Both the step surfaces 38, 38 are inclined surfaces that are inclined in a direction approaching each other as they go radially inward.

  And the inclination angle α of the two step surfaces 38, 38 with respect to a virtual plane existing in a direction orthogonal to the central axis of the preliminary intermediate material 9 is shown in FIG. Are regulated by the relationship with the inclination angle β of the step surfaces 38a, 38a existing in the corresponding portions. That is, the inclination angle β of the stepped surfaces 38a, 38a of the outer ring 2a after completion is suppressed to 15 degrees or less, and the inclination angle of the stepped surfaces 38, 38 of the intermediate material 9 is set to the stepped surface 38a of the outer ring 2a after completion. It is larger than the inclination angle β of 38a within a range of 15 degrees or less (α> β, β ≦ 15 degrees, α−β ≦ 15 degrees). Further, the axially opposite end faces 39, 39 of the preliminary intermediate material 9 are also inclined surfaces that are inclined in a direction approaching each other inward in the radial direction. The inclination angle γ of the axial end surfaces 39 and 39 with respect to a virtual plane existing in a direction orthogonal to the central axis of the preliminary intermediate material 9 is restricted to 20 degrees or less (γ ≦ 20 degrees).

  If the preliminary intermediate material 9 as described above is fitted into the die 22b without rattling, then, as shown in FIG. 19B, the mandrel 35a is inserted into the preliminary intermediate material 9, The axial positions of the preliminary intermediate material 9 and the mandrel 35a are regulated. In the case of this embodiment, the outer diameter of the preliminary intermediate member 9 is substantially the same as the outer diameter of the outer ring 2a after completion from the beginning. Therefore, as in the case of the invention described in Patent Document 3 described above, a mandrel 35a having a larger diameter can be used as the mandrel 35a compared to the case where the outer ring is processed while expanding the diameter of the material, and the mandrel 35a is pressed. The force can be increased and the durability of the mandrel 35a can be secured.

  When the mandrel 35a is inserted into the preliminary intermediate material 9, the mandrel 35a is then pressed against the inner peripheral surface of the preliminary intermediate material 9 while being driven to rotate by the driving device and the pressing device. As a result, the shape of the processing side peripheral surface 36 provided on the outer peripheral surface of the intermediate portion of the mandrel 35a is transferred to the inner peripheral surface of the preliminary intermediate material 9 in the process shown in FIGS. A rolling process is performed. That is, by pressing the processing side peripheral surface 36 of the mandrel 35a against the inner peripheral surface of the preliminary intermediate material 9 while rotating, the metal material constituting the preliminary intermediate material 9 flows in the direction of the arrow in FIG. . Then, the shape of the inner peripheral surface of the preliminary intermediate material 9 gradually becomes a shape following the processed side peripheral surface, and the outer ring 2a can be obtained.

  In such a rolling process, the outer peripheral surface of the preliminary intermediate material 9 is constrained by the die 22b over the entire circumference, and the diameter does not increase. Therefore, the amount of plastic deformation required to make the inner peripheral surface shape of the outer ring 2a can be reduced. For this reason, the force which presses the process side peripheral surface 36 of the said mandrel 35a to the internal peripheral surface of the said preliminary | backup intermediate material 9 can be restrained low, and the stress which arises in this preliminary | backup intermediate material 9 can be restrained low. And each part of the said inner ring | wheel 2a can be processed accurately including the latching groove | channel for latching the outer periphery of the seal ring which exists in the axial direction both ends inner peripheral surface of the said outer ring | wheel 2a. In addition, the processing time can be shortened and the cost can be reduced. Furthermore, the roundness of the obtained outer ring 2a is also improved. If the outer ring 2 having no locking groove is formed as shown in FIG. 25, the shape of the processing intermediate peripheral surface of the preliminary intermediate material and the mandrel may be simpler than that shown in the figure.

  Further, in the preliminary intermediate material 9, the two step surfaces 38, 38 inclined by the angle α become smaller and become both step surfaces 38 a, 38 a inclined by the angle β. Further, in the preliminary intermediate material 9, the inclination angle of the axial end faces 39, 39 inclined by the angle γ is reduced to become axial end faces 39 a, 39 a existing substantially perpendicular to the axial direction. In the case of this embodiment, the inclination angles α and γ of the respective parts of the preliminary intermediate material 9 are appropriately regulated in relation to the inclination angles of the respective parts of the outer ring 2a after completion as described above. By reducing the force applied to the mandrel 35a during processing, the durability of the mandrel 35a and the processing accuracy of the outer ring 2a obtained can be improved. That is, since the inclination angles α and γ are given to the preliminary intermediate material 9, the metal material flows smoothly inward in the radial direction during the rolling process, and is added to the mandrel 35a. Force can be kept low.

  22 to 24 show an eighth embodiment of the present invention, which also corresponds to claims 1 and 5 to 8. In the case of the present embodiment, the processing from the preliminary intermediate material 9a shown in FIG. 10B to the inner ring 3a shown in FIG. The inner diameter extrusion process as shown in (D) is not performed, but only the rolling process is performed. That is, in this embodiment, the technique of the above-described seventh embodiment is applied to the production of the inner ring 3a by reversing the inside and outside in the radial direction.

  For this reason, in the case of the present embodiment, the preliminary intermediate material 9a as shown in FIG. 24A is removed from the arbor 40 as shown in FIGS. Fit. That is, the inner peripheral surface of the preliminary intermediate material 9a, which is the non-processed peripheral surface, is brought into contact with or close to the outer peripheral surface of the arbor 40, which is the support side peripheral surface, over the entire periphery. In this state, the outer peripheral surface of the pair of rollers 41 and 41, each of which is a processing side peripheral surface, is pressed against the outer peripheral surface of the preliminary intermediate material 9a, which is the processing side peripheral surface, to obtain the inner ring 3a. Example 7 described above, except that the volume of the preliminary intermediate material 9a and the volume of the inner ring 3a, which is a finished product, are equal to each other, and the relationship between the dimensions and the inclination angle of each part is reversed in the radial direction. Since this is the same as in the case of, overlapping description is omitted.

Sectional drawing which shows the outer ring | wheel processing process of Example 1 of this invention. Sectional drawing which shows the reduced tube process of the outer ring process. Sectional drawing which similarly shows an internal diameter extrusion process. The side view which similarly shows an outer ring track | orbit formation process. FIG. 5A is a cross-sectional view taken along the line II of FIG. 4, showing a state immediately after the start of the outer ring raceway forming process, and FIG. The figure similar to FIG. 4 which shows Example 2 of this invention. FIG. 7A is a cross-sectional view of FIG. 6 showing a state immediately after the start of the outer ring raceway forming process, and FIG. The figure similar to FIG. 4 which shows Example 3 of this invention. FIG. 9A is a cross-sectional view of FIG. 8 showing a state immediately after the start of the outer ring raceway forming process, and FIG. Sectional drawing which shows the inner ring | wheel manufacturing process of Example 4 of this invention. Sectional drawing which shows the reduced tube process of an inner ring | wheel process. Sectional drawing which similarly shows an internal diameter extrusion process. The side view which similarly shows an inner ring track formation processing process. FIG. 14A is a cross-sectional view of FIG. 13 showing a state immediately after the start of the inner ring raceway forming process and FIG. The figure similar to FIG. 13 which shows Example 5 of this invention. 15A is a sectional view of the hoof of FIG. 15, showing a state immediately after the start of the inner ring raceway forming process, and FIG. The figure similar to FIG. 13 which shows Example 6 of this invention. FIG. 18A is a cross-sectional view of FIG. 17 that shows a state immediately after the start of the inner ring raceway forming process, and FIG. Sectional drawing which shows the state which processes the cylindrical intermediate material to an outer ring | wheel by rolling processing which shows Example 7 of this invention in order of a process. The G part enlarged view of (B) of FIG. Sectional drawing of an outer ring | wheel obtained from an intermediate material and this intermediate material. The side view which shows Example 8 of this invention. (A) is the state before the start of processing, and (B) is the state of the state immediately before the end, and is a cross-sectional view of FIG. Sectional drawing of an inner ring | wheel obtained from an intermediate material and this intermediate material. The partial cut perspective view which shows an example of the radial ball bearing incorporating the bearing ring used as the object of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radial ball bearing 2, 2a Outer ring 3, 3a Inner ring 4 Ball 5 Outer ring raceway 6 Inner ring raceway 7 Cage 8, 8a High precision material 9, 9a Preliminary intermediate material 10, 10a First intermediate material 11, 11a Second intermediate material 12 , 12a Stepped portion 13, 13a Die 14, 14a Processing hole 15, 15a Large diameter portion 16, 16a Punch 17, 17a Small diameter portion 18, 18a Curved surface portion 19, 19a Convex curved surface portion 20, 20a, 20b, 20c Concave surface portion 21 , 21a Knockout ring 22, 22a, 22b Die 23, 23a Processing hole 24, 24a Counter ring 25, 25a Punch 26, 26a Small diameter part 27, 27a Large diameter part 28, 28a Convex curved surface part 29, 29a, 29b, 29c, 29d 29e circumscribed roller 30, 30a inscribed roller 31, 31a processed curved surface portion 32, 32a convex Surface 33 protrusions 34 engaging grooves 35,35a mandrel 36 machined side peripheral surface 37 stepped portion 38,38a stepped surface 39,39a end surface 40 arbor 41 roller

Claims (8)

  A radial ball bearing raceway that is cylindrical and has a raceway with an arc-shaped cross-section formed in the middle in the axial direction of one of the circumferential surfaces. It is substantially the same as the volume of the finished product. By rolling the intermediate material formed by plastically deforming a cylindrical material having a volume in a cold manner, at least a part of the intermediate material is plastically deformed in the radial direction to obtain a surface shape including the raceway surface. Radial ball bearing raceway, characterized by being processed into the same shape as the finished product.   The shape of the outer peripheral surface of the intermediate material is a shape that does not reverse the direction of change of the outer diameter from the portion having the largest outer diameter toward the both end surfaces in the axial direction and does not have an undercut portion. 2. The radial ball according to claim 1, wherein the shape of the inner peripheral surface is a shape in which the direction of change of the inner diameter does not reverse and does not have an undercut portion from the portion having the smallest inner diameter toward both end surfaces in the axial direction. Bearing ring for bearings.   In a manufacturing method of a radial ball bearing race which is cylindrical and has an arc-shaped raceway surface formed in the axially intermediate portion of any circumferential surface over the entire circumference, the volume and substantial volume of the finished product are substantially reduced. The cylindrical material having the same volume is pressed between a pair of dies that are relatively displaced in the axial direction, and the diameter of the half of the axial direction of the material is changed. A first step of obtaining a first intermediate material by performing a first cold forging process with a small-diameter portion and the other half portion in the axial direction as a large-diameter portion, and the first step of relative displacement in the axial direction, Presses the first intermediate material between another pair of molds, and at least the radial dimension of the portion of the first intermediate material where the raceway surface is to be formed is related to the axial direction. Second cold forging with a second intermediate material whose distribution matches the distribution of the part that formed the raceway surface of the raceway after completion A part of the second intermediate material is radially applied by a second process to be applied and a rolling process in which the inner peripheral surface and the outer peripheral surface of the second intermediate material are pressed toward each other while rotating the second intermediate material. And a third step of forming the raceway surface by plastic deformation to a radial ball bearing raceway manufacturing method.   The bearing ring is provided with a locking groove for locking the peripheral edge of the sealing plate at both axial ends of the circumferential surface forming the raceway surface. 4. A preliminary step for forming a stepped portion that is recessed in the radial direction from the axially intermediate portion in the portion to form a preliminary intermediate material, and the locking groove is formed in the stepped portion in the third step. Method of manufacturing a radial ball bearing raceway.   In a method of manufacturing a radial ball bearing raceway ring, which is formed in a cylindrical shape and has an arc-shaped raceway surface over the entire circumference in an axially intermediate portion of any circumferential surface to be processed. A cylinder having substantially the same volume as the volume of the finished product, and having a diameter of the non-machined side circumferential surface, which is the circumferential surface opposite to the surface on which the raceway surface is formed, substantially the same as the diameter of the finished product The non-processed side peripheral surface is supported on the receiving member by fitting the non-processed peripheral surface to the support side peripheral surface provided on the receiving member with substantially no gap, and the processed side peripheral surface is in a finished product state. The processing-side rotating member and the receiving member are pressed while pressing the processing-side peripheral surface of the processing-side rotating member having a generatrix shape that matches the busbar shape of the processing-side peripheral surface in the radial direction of the material. By relative rotation, the processing side peripheral surface is processed into a shape as a finished product having at least the track surface. Method of manufacturing a bearing ring for a radial ball bearing according to symptoms.   In order to form a stepped part that is recessed in the radial direction from the axially central portion of the processed peripheral surface at both ends in the axial direction on the processed peripheral surface, Step portions are formed at both end portions in the axial direction of the processing side peripheral surface, and both the step portions are formed on the raceway surface along with the pressing of the processing side rotating member to the processing side peripheral surface. The manufacturing method of the raceway ring for radial ball bearings of Claim 5 processed simultaneously.   The stepped surfaces existing between the two stepped portions at the axially opposite ends of the workpiece side circumferential surface and the axially central portion are inclined in the direction of approaching each other with increasing distance from the non-machined circumferential surface with respect to the radial direction. The inclination angle of both step surfaces with respect to a virtual plane existing in a direction perpendicular to the central axis of the material is greater than the inclination angle of the step surfaces existing in the corresponding portions of the raceway ring after completion. The method for manufacturing a radial ball bearing raceway ring according to claim 6, wherein the diameter is increased within a range of 15 degrees or less.   Both end surfaces in the axial direction of the material for making the bearing ring are inclined surfaces that are inclined toward each other as they are away from the peripheral surface on the non-processed side, and the above described virtual plane that exists in a direction orthogonal to the central axis of the material The manufacturing method of the raceway ring for radial ball bearings in any one of Claims 5-7 whose inclination-angle of an axial direction both end surface is 20 degrees or less.

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