JP2006123003A - High precision ring manufacturing method and manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a manufacturing method capable of easily producing a high precision ring 8 which is a material for producing a bearing ring constituting a radial ball bearing by cold working.
A billet shown in (A) is passed through a disc-like intermediate material 22 shown in (B) and a second disc-like intermediate material 24 shown in (C), and then a ring shape shown in (D). An intermediate material 26 is made. The circular ring-shaped intermediate material 26 is subjected to reversal processing in which the cross-sectional shape is changed by 90 degrees in the direction in which the inner diameter side having a large thickness is expanded and the smaller outer diameter side is similarly contracted. And it is set as the said cylindrical highly accurate ring 8 which made the inside diameter, the outer diameter, and the axial direction length the regulation value.
[Selection] Figure 1

Description

  The method and apparatus for manufacturing a high-accuracy ring according to the present invention are used, for example, to manufacture a high-accuracy ring that is a material for manufacturing an inner ring or an outer ring constituting a radial ball bearing by cold working. In addition, radial ball bearings incorporating an inner ring or outer ring made of such a high-accuracy ring can be used for rotating electric motors incorporated in various household electrical products such as vacuum cleaners and ventilation fans, or various auxiliary machinery for automobiles. Used for parts that do not require a high degree of rotational accuracy, such as support parts.

  A radial ball bearing 1 as shown in FIG. 11 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. 11, 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 a manufacturing method of the raceway 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, in Patent Document 2, a material formed by cutting a steel pipe made by hot extrusion is axially compressed (upsetting) with a vertical press, and a deep groove type is formed on the inner peripheral surface. An invention relating to a method for producing an outer ring having an 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.

  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 outer ring and inner ring obtained. Also, the work of cutting the steel pipe to make the material is troublesome, the productivity is poor, and the cost increases. Furthermore, it is necessary to perform cutting by decarburization on the material, and this also increases the cost.

  Patent Document 3 describes an invention in which a ring-shaped part is formed by cold-working a cylindrical material. However, in the case of the invention described in Patent Document 3, since the axial dimension is not restricted during cold working, the accuracy of the axial length of the obtained ring-shaped part is increased. The volume accuracy cannot be secured. For this reason, it is difficult to make a practical race by simply plastically deforming the ring-shaped part.

  On the other hand, in view of the circumstances as described above, the present inventors have practically used a bearing ring that constitutes a radial ball bearing that is used for the above-described applications and does not require a high degree of rotational accuracy. We considered a method that can be obtained at low cost while ensuring sufficient accuracy. In this method, the race is produced by further cold-working a cylindrical high-precision ring made by cold working and having a volume substantially the same as the volume of the finished product. That is, the high-accuracy ring is further plastically deformed by cold working to process the surface shape including the raceway surface into substantially the same shape as the finished product.

FIG. 12 shows a process of manufacturing the inner ring 3a by cold working the high precision ring 8a.
In this case, first, the first intermediate material 9 shown in (B) is pressed by pressing a punch against the radially outer half of both axial end faces of the high-accuracy ring 8a shown in FIG. Get.
Next, an inner ring raceway 6 formed on the first intermediate material 9 with an outer diameter of a part in the radial direction (upper end portion in FIG. 12) formed on the outer peripheral surface of the intermediate portion of the inner ring 3a {FIG. No. 11} is reduced to a 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). A second intermediate material 10 is obtained.
Next, in the second intermediate material 10, the axial direction of the 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. 12) of the second intermediate material 10. The third intermediate material 11 shown in (D) is obtained by applying an inner diameter extrusion process for matching the distribution of the inner ring 3a to the distribution of the corresponding portion of the inner ring 3a to be manufactured.
Next, the inner diameter of the third intermediate material 11 near the other end in the axial direction of the third intermediate material 11 (near the lower end in FIG. 12) is expanded, and the inner diameter is removed (excluding the chamfered portions at both ends). A fourth intermediate material 12 shown in (E) is obtained by making the inner ring raceway 6 uniform on the outer peripheral surface and making the inner ring raceway uniform.
Finally, the fourth intermediate material 12 is subjected to a finishing process such as a rolling process for adjusting the shape and properties of the outer peripheral surface to obtain an inner ring 3a shown in FIG.

FIG. 13 shows a process for manufacturing the outer ring 2a by cold-working the high-precision ring 8b.
In this case, first, a first intermediate material 9a shown in (B) is pressed by pressing a punch against the radially inner half of both axial end faces of the high-precision ring 8b shown in FIG. Get. Next, the first intermediate material 9a is subjected to contraction processing for reducing the outer diameter of a part in the radial direction (the part excluding the upper end portion in FIG. 13) to the outer diameter of the outer ring 2a. The second intermediate material 10a shown in FIG.
Next, the second intermediate material 10a is formed with one half of the axial direction of the outer ring raceway 5 (the lower half of FIG. 13) of the second intermediate material 10a and the other half of the outer ring raceway 5 in the axial direction. An inner diameter extrusion process is performed to match the distribution in the axial direction of the thickness in the radial direction of the portion corresponding to the portion (the upper half of FIG. 13) with the distribution of the corresponding portion of the outer ring 2a to be made (D The third intermediate material 11a shown in FIG.
Next, the outer diameter of the third intermediate material 11a near the other end in the axial direction of the third intermediate material 11a (near the upper end in FIG. 13) is reduced, and this outer diameter is removed (excluding the chamfered portions at both ends). The outer ring raceway 5 is formed on the inner peripheral surface, and the outer ring raceway forming process is performed to obtain the fourth intermediate material 12a shown in (E).
Finally, the fourth intermediate material 12a is subjected to a finishing process such as a rolling process for adjusting the shape and properties of the inner peripheral surface to obtain the outer ring 2a shown in FIG.

  As described above, if the outer ring 2a or the inner ring 3a of the radial ball bearing 1 is manufactured, the outer ring 2a or the inner ring 3a used in a portion where a high degree of rotational accuracy is not required can be achieved while ensuring practical accuracy. Can be built at a low cost. However, even in this case, the radial ball finally obtained that the dimensional accuracy including the shape accuracy and volume accuracy of the high-precision rings 8a and 8b to be the material of the outer ring 2a or the inner ring 3a is sufficiently secured. This is important in terms of ensuring the practical accuracy of the bearing. On the other hand, in the case of the conventional method described in Patent Document 3, as described above, since the axial dimension is not restricted during the cold working, the shaft of the obtained ring-shaped part is used. It is difficult to satisfy the above requirements because the accuracy of the length in the direction, and thus the accuracy of the volume cannot be ensured.

  Upset processing that compresses the axial dimension of billet-shaped material, rear extrusion processing that crushes the central part and escapes surplus material to the outer diameter side and processes it into a bottomed cylindrical shape, and punching processing that punches out the bottom It is also conceivable to obtain a cylindrical high-precision material by combining with. However, in hard hard-working materials such as high carbon steel and bearing steel constituting the races such as the outer ring 2a or the inner ring 3a, the stress applied to the punch used for the backward extrusion process is increased, and the life of the punch is reduced. Since it becomes shorter, it is disadvantageous in terms of cost reduction. On the other hand, as described in Patent Document 4, it is conceivable to produce a high-accuracy ring by reversal processing that converts the cross-sectional shape of an annular material made by punching a metal plate by 90 degrees. This point will be described with reference to FIGS.

  In this method, a long plate material (coil) is cut into a predetermined shape to obtain a disk-shaped material 13 as shown in FIG. Next, the disc-shaped material 13 is subjected to piercing processing for punching the center portion and trimming processing for removing the outer peripheral portion, so that an annular intermediate material 14 as shown in FIG. 14B is obtained. Next, a reversing process is performed on the intermediate material 14 by using a device as shown in FIG. 15 and reversing it by twisting the cross section 90 degrees in the direction of expanding the inner diameter side and shrinking the outer diameter side. A ring-shaped member 15 as shown in FIG.

  As shown in FIG. 15, the reversing process is performed by pushing the intermediate material 14 into a cylindrical die 16 with a punch 17. The die 16 has a central hole in which a large diameter portion 18 provided on the opening side and a small diameter portion 19 concentric with the large diameter portion 18 provided on the back side are continuous by a curved surface 20. . The punch 17 has a tapered portion at the tip. When performing the reversing process, first, as shown in FIG. 15A, the intermediate material 14 is locked (set) inside the large-diameter portion 18. Next, as shown in FIGS. 15B and 15C, the intermediate material 14 is pushed into the small diameter portion 19 by the punch 17. As a result, the cross-section of the intermediate material 14 is inverted 90 degrees, and the cylindrical ring-shaped member 15 as shown in FIGS. 14 and 15 (C) is obtained.

  However, in the case of the method described in Patent Document 4 as described above, since the disk-shaped material 13 is manufactured by punching a plate material, the yield of the material is poor. In addition, a plate material such as high carbon steel is disadvantageous in terms of cost reduction because it has a higher unit price (price per unit weight) than a round bar-like wire. Further, when the ring-shaped member 15 is formed by punching a plate material having a uniform thickness and the ring-shaped member 15 is inverted by 90 degrees, the thickness of the ring-shaped member 15 in the radial direction is determined. The dimensions become non-uniform as shown in FIGS. The reason for this is that while the reversing process is performed, the portion closer to the inner diameter of the intermediate material 14 is stretched to reduce the thickness dimension, whereas the portion closer to the outer diameter is also compressed to increase the thickness dimension. It is to become. For this reason, the method described in Patent Document 4 cannot make a high-accuracy ring for obtaining the raceway ring constituting the radial ball bearing at a low cost while ensuring a practically sufficient accuracy.

Japanese Patent Laid-Open No. 5-277615 Japanese Patent Laid-Open No. 2001-150082 JP 2000-94080 A Japanese Patent Laid-Open No. 10-146642

  In view of the circumstances as described above, the present invention is a material for producing an inner ring or an outer ring constituting a radial ball bearing by cold working, and sufficiently secures the practical accuracy of the finally obtained radial ball bearing. The present invention was invented to realize a manufacturing method and a manufacturing apparatus capable of easily and inexpensively manufacturing a high-accuracy ring that can be produced.

  The method for manufacturing a high-accuracy ring according to the present invention is to first compress a billet-shaped material made of metal and having a volume larger than the volume of the high-accuracy ring to be manufactured in the axial direction, so that the thickness dimension in the axial direction is the center. A disk-shaped intermediate material is made which becomes smaller toward the outer peripheral edge at the part. Next, a circular hole is formed in the central portion of the disc-shaped intermediate material, thereby obtaining an annular-shaped intermediate material having the same volume as that of the high-precision ring. Thereafter, the outer diameter portion of the annular intermediate material is contracted radially inward, and the cross section direction is set in the same direction so that the inner diameter portion is expanded radially outward, and each circumferential portion is parallel to the axial direction. The circular ring-shaped intermediate material is formed into a cylindrical ring with the inner diameter, outer diameter, and axial length as regulation values by reversal processing that is changed by an angle of 90 degrees or less until it becomes.

According to the manufacturing method of the high-accuracy ring of the present invention configured as described above, the inner diameter, the outer diameter, and the axial dimension are restricted to appropriate values, and the central axis of the inner peripheral surface and the central axes of the outer peripheral surface are connected to each other. A high-accuracy ring closely matched can be manufactured easily and efficiently with good material yield. As a result, it is possible to reduce the processing cost of the outer ring and inner ring constituting the radial ball bearing, which is manufactured by processing this high-accuracy ring, while ensuring practically sufficient performance.
Of course, by improving the machining accuracy, the present invention can be applied to a high-accuracy ring used for manufacturing a bearing ring for a ball bearing that requires a higher accuracy than the above-described applications. It is.

In carrying out the present invention, preferably, as described in claim 2, at least one of both side surfaces in the axial direction of a portion to be removed along with the formation of the circular hole in the central portion of the disc-shaped intermediate material The volume of the removed portion is reduced by forming a concave portion on the side surface of the substrate.
If configured in this way, the volume of the part that becomes the waste material is further reduced, the yield of the material is further improved, the manufacturing cost of the high-accuracy ring, and the annular ring such as the race ring made by this high-accuracy ring The cost of parts can be further reduced.

In carrying out the invention described in claim 2 as described above, preferably, as described in claim 3, the disk-shaped intermediate material formed with the recesses is arranged so that the outer diameter does not expand. Press in the axial direction with the peripheral edge restrained. And while reducing the thickness dimension regarding an axial direction to an appropriate value, the surplus volume is escaped to the said recessed part. Then, the center part of the said disk-shaped intermediate material containing this recessed part is punched out, and it is set as a ring-shaped intermediate material.
If comprised in this way, the process for making the volume of this annular | circular shaped intermediate | middle material correspond with the volume of the highly accurate ring which should be produced can be performed easily and reliably.

Alternatively, when carrying out the present invention, as described in claim 4, after forming an elemental circular hole as a base of a circular hole at the center of the disk-shaped intermediate material to form an elemental ring-shaped intermediate material, While pressing the outer ring-shaped intermediate material in the axial direction with the outer peripheral edge restrained so that the outer diameter does not expand, the thickness dimension in the axial direction is reduced to an appropriate value, and the excess volume is Escape to the inner periphery of the round hole. After that, by removing this surplus present at the inner peripheral edge of the elemental hole, an annular material is obtained.
Even if comprised in this way, the process for making the volume of the said annular | circular shaped intermediate | middle material correspond to the volume of the highly accurate ring which should be produced can be performed easily and reliably.

In carrying out the present invention, preferably, as described in claim 5, the outer peripheral edge of the disk-shaped intermediate material is restrained in a state that prevents the outer diameter of the disk-shaped intermediate material from expanding. The concave portion is formed only on one side surface in the axial direction of the portion to be removed as the circular hole is formed in the central portion of the disk-shaped intermediate material. Then, the concave portion forming operation performed in this way reduces the volume of the portion to be removed, and the shape of the disk-shaped intermediate material is such that the portion closer to the outer diameter on the side where the concave portion is formed is a partially conical concave surface. It becomes a substantially conical trapezoid shape. And the angle change part in the case of the reversing process which uses a ring-shaped intermediate material as a cylindrical ring is suppressed to less than 90 degrees.
By adopting such a configuration, the degree of processing (stretching ratio) of the part that expands the diameter during reversal processing is kept low, and it is possible to prevent harmful deformation and cracks from occurring in this part, and relatively A high-precision ring with a large width dimension in the direction can be manufactured with a high yield.

In carrying out the present invention, preferably, as described in claim 6, when a disk-shaped intermediate material is produced by axially compressing a billet-shaped material or a preliminary intermediate material obtained by processing this material. Furthermore, by restricting both ends in the axial direction of this material or the preliminary intermediate material, it is possible to prevent the diameters of both ends in the axial direction of this material or the preliminary intermediate material from expanding. And a circular hole is formed by removing the part containing the axial direction both end surface of the said raw material or a preliminary | backup intermediate material in the center part of the obtained said disk-shaped intermediate raw material, and it is set as a ring-shaped intermediate raw material.
By adopting such a configuration, the portions of the billet-like material or the preliminary intermediate material that are axially opposite end surfaces do not remain in a part of the obtained high-accuracy ring. This billet-shaped material is often obtained by cutting a long wire drawn from an uncoiler into a predetermined length. In this case, both end surfaces in the axial direction of the billet-shaped material are broken surfaces generated at the time of cutting, and the properties of the broken surface remain strongly even on both end surfaces of the preliminary intermediate material. In general, the fractured surface properties are poor, such as a large surface roughness value. Therefore, in order to obtain a good quality product, it may be necessary to remove the fractured surface by cutting or grinding. . On the other hand, if the configuration as described in claim 6 is adopted, the fracture surface portion remains in the portion discarded as scrap, which is advantageous from the viewpoint of obtaining a high-quality product at low cost. .

And when implementing the manufacturing method of the high precision ring described in Claim 6 as described above, preferably, a fixing block, a die, a counter punch, a ring punch, and the like as described in Claim 7 are used. Using a high-precision ring manufacturing apparatus equipped with a punch.
Of these, the fixed block is supported and fixed to a frame of a press working apparatus installed on the floor of the factory.
The die is elastically supported above the fixed block in a state where the die is lowered until it comes into contact with the upper surface of the fixed block when a large pressure is applied, and the billet-like material or the material is processed. The lower intermediate hole which can fit in the lower end part of the preliminary | backup intermediate | middle raw material which can be fitted is provided.
The counter punch is inserted into the lower center hole so as to be movable up and down with respect to the die.
In addition, the ring punch rises until it comes into contact with the lower surface of the ram when a large pressing force is applied to a part of the ram of the press machine provided above the die concentrically with the die. It is elastically supported below the ram and has an upper center hole in which the upper end portion of the billet-shaped material or the preliminary intermediate material can be fitted.
Further, the punch is inserted into the upper center hole so as to be movable up and down with respect to the ring punch.

Further, when carrying out the invention described in claim 7 as described above, more preferably, as described in claim 8, the counter punch is in a state at least before the processing of the disk-shaped intermediate material is completed. The punch is supported on the fixed block without moving up and down with respect to the ram. In addition, with the lower surface of the die in contact with the upper surface of the fixed block, the upper end surface of the counter punch exists at a position recessed below the upper surface of the die, and the upper surface of the ring punch is The dimensions of each part are regulated so that the punch is present at a position recessed above the lower surface of the ring punch in the state of being in contact with the lower surface.
By adopting such a configuration, the manufacturing method described in claim 6 can be efficiently implemented, and a high-quality high-accuracy ring can be obtained at low cost. In the state after the completion of processing, the counter punch is raised with respect to the fixed block as necessary to facilitate the removal of the disk-shaped material after processing.

  1 and 2 show a first embodiment of the present invention corresponding to claims 1 and 2. In this embodiment, first, a long wire is cut into a predetermined length to obtain a billet (columnar material) 21 as shown in FIG. The billet 21 is cut into a length (predetermined length) that is slightly larger than the volume of the high-precision ring 8 to be obtained while pulling out the long wire wound around the drum from the uncoiler. Get by things.

The billet 21 obtained in this way is made into a disk-shaped intermediate material 22 as shown in FIG. 1B by upsetting which compresses in the axial direction. The disk-shaped intermediate material 22 has the largest thickness dimension T ₁ at the center and the smallest thickness T ₂ at the outer peripheral edge with respect to the thickness dimension in the axial direction. And the axial direction both sides | surfaces of the said disk-shaped intermediate raw material 22 are made into the shape of a partial conical surface with a gentle inclination angle so that thickness dimension may reduce gradually toward this outer peripheral part from this center part. The thickness T ₈ of the high-accuracy ring 8 to be manufactured is intermediate between the thicknesses T ₁ and T ₂ of the both parts (T ₁ > T ₈ > T ₁ ). In order to obtain such a disk-shaped intermediate material 22, the billet 21 obtained by cutting the wire into an appropriate volume is provided with a bottomed circular hole having the same inner diameter as the outer diameter D ₂₂ of the disk-shaped intermediate material 22. The billet 21 is set in the receiving mold in a state where the center axis of the billet 21 and the center axis of the circular hole coincide with each other, and the billet 21 is compressed in the axial direction between the bottom surface of the circular hole and the tip surface of the pressing die. . Since the shape of the bottom surface and the front end surface is a shape that matches both side surfaces in the axial direction of the disc-shaped intermediate material 22 (the concave and convex directions are reversed), the bottom surface and the front end surface are strongly pressed against each other. Thus, the disk-shaped intermediate material 22 can be obtained.

In the case of the present embodiment, after the disk-shaped intermediate material 22 as described above is formed (or at the same time as the formation), the disk-shaped intermediate material 22 is centered on both axial sides of FIG. The second disk-shaped intermediate material 24 having a reduced thickness at the center is formed by forming circular recesses 23, 23 as shown in FIG. These recesses 23, 23 are for reducing the volume of the portion to be removed as the circular hole 25 is formed in the step shown in FIG. To form. Therefore, the operation of forming both the concave portions 23 and 23 can be omitted. However, in the disk-shaped intermediate material 22, a portion (a central portion or an outer portion with respect to the radial direction) excluding the central portion forming both the concave portions 23, 23 is within the cavity of the mold partitioned into a predetermined volume. It is also possible to form both the concave portions 23 and 23 in a state of being positioned at the position. In this case, the cavity that has flowed to the outer diameter side along with the formation of the two concave portions 23, 23 is filled in the cavity. If comprised in this way, even if it does not restrict | limit strictly the volume of the said billet 21, the volume of the part except a center part among the said 2nd disk-shaped intermediate materials 24 which should be the said high precision ring 8, It can be strictly regulated according to the volume of the high precision ring 8. In any case, when both the concave portions _{23 and 23} are formed, the diameter D ₂₃ of both the concave portions _{23 and 23} is the inner diameter of the circular hole 25 to be formed in the central portion of the second disc-shaped intermediate material 24. R ₂₅ (see (D) in FIG. 1) is smaller (D ₂₃ <R ₂₅ ).

Once the second disk-shaped intermediate material 24 is formed as described above, the circular hole 25 is then formed in the center of the second disk-shaped intermediate material 24. The forming operation of the circular hole 25 is performed in a state in which the second disc-shaped intermediate material 24 is set in the holding concave portion of the receiving mold, and a punch arranged concentrically with the holding concave portion is arranged in the center of the second disc-shaped intermediate material 24. This is performed by punching, in which the center portion is pushed into a punched hole formed in the center portion of the holding recess. Since the outer diameter of the punch is larger than the diameter D23 of both the concave portions _{23, 23} , the central portion of the second disc-shaped intermediate material 24 including both the concave portions _{23, 23} is punched, and FIG. An annular intermediate material 26 as shown in (D) is obtained. The annular intermediate material 26 has an annular shape in which an inner peripheral edge and an outer peripheral edge are concentric, and has a wedge-shaped cross-sectional shape in which the thickness dimension in the axial direction is larger on the inner diameter side and smaller on the outer diameter side. The volume of the annular intermediate material 26 is the same as the volume of the high-precision ring 8 to be manufactured.

After forming the ring-shaped intermediate material 26 as described above, as shown in FIG. 1E, the portion near the outer diameter of the ring-shaped intermediate material 26 is contracted radially inward, and the portion closer to the inner diameter is also formed. A reversal process is performed in which the direction of the cross section is changed by 90 degrees in the direction of spreading outward in the radial direction. As shown in FIG. 2, the reversing process is performed by pushing the annular material 26 into the cylindrical die 16 with a punch 17. As described above with reference to FIG. 15, the die 16 includes a large-diameter portion 18 provided on the opening side and a small-diameter portion 19 concentric with the large-diameter portion 18 provided on the back side. With a central hole made continuous. Among these, the inner diameter R ₁₉ of the small diameter portion 19 is smaller than the outer diameter of the annular intermediate material 26 and larger than the inner diameter. The punch 17 has a tapered portion at the tip. When performing the reversing process, first, as shown in FIG. 2A, the annular intermediate material 26 is locked (set) inside the large-diameter portion 18. Next, as shown in FIGS. 2B and 2C, the annular material 26 is pushed into the small diameter portion 19 by the punch 17. As a result, the cross section of the annular intermediate material 26 is inverted by 90 degrees, and the cylindrical high-accuracy ring 8 as shown in FIGS. 1E and 2C is obtained.

In accordance with the reversing process performed as described above, the portion near the inner diameter of the annular intermediate material 26 is stretched to reduce the thickness dimension, and the portion closer to the outer diameter is also compressed to increase the thickness dimension. . On the other hand, in the case of the present embodiment, since the thickness dimension in the axial direction of the ring-shaped intermediate material 26 is large in the portion near the inner diameter and small in the portion near the outer diameter, it is obtained in a state where the reversing process is finished. The thickness dimension in the radial direction of the high-accuracy ring 8 is uniform in the axial direction (except for the chamfered portions at both end edges). That is, the ring-shaped intermediate material 26 becomes the cylindrical high-accuracy ring 8 in which the inner diameter, the outer diameter, and the axial length are set as the regulation values after the reversing process is completed. For this reason, the difference between the inner diameter R ₁₉ and earlier half of the outer diameter D ₁₇ of the punch 17 of the small-diameter portion 19, the thickness T ₈ of the high-precision ring 18 should build {in FIG 1 (E) see} (R ₁₉ −D ₁₇ = 2T ₈ ). The high-precision ring 8 as described above is subjected to cold working as shown in FIG. 12 to form the inner ring 3a, or is similarly subjected to cold working as shown in FIG. 13 to form the outer ring 2a.

  FIGS. 3-4 shows Example 2 of this invention corresponding to Claims 1-3. In the case of the above-described first embodiment, the volume of the billet 21 is strictly regulated, or the second disk-shaped intermediate material 24 is formed by forming recesses 23, 23 at the center portions on both sides in the axial direction of the disk-shaped intermediate material 22. In doing so, the volume of the portion excluding the central portion of the second disk-shaped intermediate material 24 is regulated. On the other hand, in the case of the present embodiment, as shown in FIG. 3D and FIG. By applying, the volume of the portion excluding the central portion of the second disk-shaped intermediate material 24 is regulated.

That is, in the case of the present embodiment, the second disk-shaped intermediate material 24 is closely fitted in the circular hole 28 of the die 27 as shown in FIG. Press strongly between tip surfaces. The front end surfaces of both the punches 29 and 29 are conical concave surfaces that are in close contact with both axial side surfaces of the second disc-shaped intermediate material 24 except for the central portion. The punches 29 and 29 having the respective tip surfaces in such a shape reduce the distance between the tip surfaces to an appropriate distance while compressing the second disc-shaped intermediate material 24 in the axial direction. At this time, the surplus meat that has flowed in accordance with the appropriate thickness of the intermediate portion in the radial direction or the outer end portion of the second disc-shaped intermediate material 24 gathers in the concave portions 23 and 23. Accordingly, if the circular hole 25 is formed by punching as shown in FIG. 2E at the center of the second disk-shaped intermediate material 24a subjected to the sizing process, the volume of the high-precision ring 8 to be manufactured A ring-shaped intermediate material 26 having the same volume as is obtained.
Other configurations and operations are the same as those of the first embodiment.

FIG. 5 shows a third embodiment of the present invention corresponding to claims 1 and 4. In the case of this embodiment, the billet 21 is formed by compressing the billet 21 in the axial direction at the center of the disc-shaped intermediate material 22 as shown in FIG. 5B, as shown in FIG. In addition, a raw circular hole 30 that is the base of the circular hole 25 shown in FIG. The inner diameter R ₃₀ of the circular hole ₃₀ is the same as or slightly smaller than the inner diameter R ₂₅ of the circular hole 25 (R ₃₀ ≦ R ₂₅ ). Thereafter, the inner ring-shaped intermediate material 31 is pressed in the axial direction in a state in which the outer peripheral edge is constrained so that the outer diameter does not expand, the thickness dimension in the axial direction is reduced to an appropriate value, and the volume is reduced. The surplus portion is released to the inner peripheral edge of the round hole 30 and sizing is performed.

In this sizing process, for example, as shown in FIG. 4 described above, the above-mentioned non-annular intermediate material 31 is fitted into the circular hole 28 of the die 27, and this un-annular intermediate material 31 is paired with a pair of punches 29, 29. This is performed by compressing in the axial direction between the front end surfaces of each other. As shown in FIG. 5D, the surplus meat that has flowed along with such sizing processing gathers at the inner peripheral edge of the elemental ring-shaped intermediate material 31 and reduces the inner diameter of the elemental hole 30. Therefore, as shown in FIG. 5 (E), if this surplus portion present at the inner peripheral edge of the elemental hole 30 with a reduced inner diameter is removed by piercing or shaving, the high-accuracy ring 8 to be manufactured is to be manufactured. A ring-shaped intermediate material 26 having the same volume as the above is obtained.
In this embodiment, as shown in FIG. 5 (D), the outer peripheral edge portion of the above-mentioned bare ring-shaped intermediate material 31 is compressed in the axial direction, and the excess meat content is reduced to the inner peripheral side. However, the same effect can be obtained by constraining the inner peripheral edge to collect excess meat on the outer peripheral side and then removing the outer peripheral edge by trimming.
The configuration and operation of the other parts are the same as those of the first embodiment described above or the second embodiment described above.

  FIGS. 6-7 has shown Example 4 of this invention corresponding to Claims 1-3 and 6-8. In the case of the present embodiment, as shown in FIGS. 6A to 6C, the process of making the disc-shaped intermediate material 22a by compressing the billet 21 as the material in the axial direction is devised. As a result, fracture surfaces (parts indicated by broken lines in FIGS. 6A to 6E) existing on both end surfaces in the axial direction of the billet are formed into high-precision rings 8, 8a, 8b {for example, FIG. 1 (E), FIG. 3 (F), and FIGS. 12 and 13 (A)}. That is, in the case of the present embodiment, the both end surfaces in the axial direction of the billet 21 are flattened (correcting the fracture surface) to form a beer barrel type preliminary intermediate material 32 as shown in FIG. An upsetting process for crushing the preliminary intermediate material 32 in the axial direction is performed to obtain the disk-shaped intermediate material 22a as shown in FIG. In this process, the both end surfaces in the axial direction of the billet 21 are not expanded in the radial direction so that the fracture surface does not remain on the surface of the ring-shaped intermediate material 31a shown in FIG. ing. Hereinafter, a configuration for preventing the fractured surface from remaining on the surface of the elemental annular intermediate material 31a will be described.

  In the case of the present embodiment, when the preliminary intermediate material 32 shown in FIG. 6B is compressed in the axial direction to form the disk-shaped intermediate material 22a shown in FIG. As shown in (A) to (C), the preliminary intermediate material 32 is crushed in the axial direction while restraining both axial ends of the preliminary intermediate material 32. And it is set as the said disk-shaped intermediate material 22a with the state hold | maintained so that the diameter of the axial direction both ends of this preliminary | backup intermediate material 32 may not expand. A processing apparatus for performing such processing includes a fixed block 33, a die 34, a counter punch 35, a ring punch 36, and a punch 37, as shown in FIG.

  Among these, the fixed block 33 is supported and fixed to a frame or the like of a press working apparatus installed on the floor of the factory. The die 34 is elastically supported above the fixed block 33 by a plurality of elastic members 38, 38 such as compression coil springs. Accordingly, the die 34 is lifted above the fixed block 33 as shown in FIG. 7A in the non-working state, but based on the flow of the metal material during the working. In a state where a large pressure is applied, as shown in FIG. 7C, the elastic member 38 moves downward until it comes into contact with the upper surface of the fixed block 33 against the elasticity of the elastic members 38. At the center of such a die 34 is provided a lower center hole 39 into which the lower end of the preliminary intermediate material 32 can be fitted. The counter punch 35 is inserted into the lower center hole 39 so as to be movable up and down with respect to the die 34.

  The vertical position of the counter punch 35 is regulated as follows. That is, in the non-working state, as shown in FIG. 7A, the upper end surface of the counter punch 35 is made sufficiently lower than the bottom surface of the processing recess 40 provided on the upper surface of the die 34. . In this state, by inserting the lower end portion of the preliminary intermediate material 32 into the lower center hole 39, the preliminary intermediate material 32 and the central axis of the die 34 can be aligned. Further, when the lower surface of the die 34 is in contact with the upper surface of the fixed block at the time of processing, the upper end surface of the counter punch 35 exists in a position slightly depressed below the upper surface of the die 34, and the processing is performed. Even in the final stage, the fracture surface should not flow radially outward.

  The ring punch 36 is elastically supported concentrically with the die 34 by a plurality of elastic members 38a, 38a such as compression coil springs below a ram 41 of a press machine provided above the die 34. ing. Accordingly, the ring punch 36 hangs down below the ram 41 as shown in FIG. 7A in a non-working state, but based on the flow of the metal material during machining. In a state where a large pressing force is applied, as shown in FIG. 7C, the elastic member 38a rises until it comes into contact with the lower surface of the ram 34 against the elasticity of the elastic members 38a, 38a. Further, the lower end portion of the ring punch 36 can be freely inserted into the processing recess 40 of the die 34 without rattling, and in the inserted state, the die 34 and the ring punch 36 are strictly concentric. Like. An upper center hole 42 into which the upper end of the preliminary intermediate material 32 can be fitted is provided at the center of the ring punch 36.

  Further, the punch 37 is inserted into the upper center hole 42 so as to be movable up and down with respect to the ring punch 36. In the case of the present embodiment, the punch 37 is fixed to the ram 41, and the punch 37 and the ring punch 36 are moved up and down relatively as the ring punch 36 moves up and down with respect to the ram 41. I have to. The vertical position of the punch 37 is regulated as follows. That is, in the non-working state, the lower end surface of the punch 37 is positioned sufficiently above the lower end surface of the ring punch 36 as shown in FIG. In this state, by inserting the upper end portion of the preliminary intermediate material 32 into the upper center hole 42, the preliminary intermediate material 32 and the center axis of the ring punch 36 can be aligned. 7C, when the upper end surface of the ring punch 36 is in contact with the lower surface of the ram 41 during processing, the lower end surface of the punch 37 is lower than the lower surface of the ring punch 36. It exists in a position slightly recessed upward, so that the fracture surface does not flow radially outward even at the final stage of processing.

  The preliminary intermediate material 32 as shown in FIG. 6B is crushed in the axial direction by the manufacturing apparatus as shown in FIG. 6, and the disc-like intermediate material 22a as shown in FIG. The work to be done is as follows. First, with the ram 41 and the ring punch 36 and the punch 37 retracted upward, the lower end portion of the preliminary intermediate material 32 is placed at the center of the preliminary intermediate material 32 at the upper end portion of the lower center hole 39. It fits in a state where the shaft and the central axis of the die 34 are aligned. Next, the ram 41 is lowered, and as shown in FIG. 7A, the lower end portion of the ring punch 36 is inserted into the processing recess 40 of the die 34, and the upper end portion of the preliminary intermediate material 32 is inserted. It fits into the lower end of the upper center hole 42. If the ram 41 is further lowered from this state, the preliminary intermediate material 32 is gradually crushed as shown in FIGS. 7 (A) → (B) → (C). Thus, a disk-shaped intermediate material 22a as shown in FIG. With this disk-shaped material 22a, the fracture surface remains at the thick portion 43 at the center.

  In the case of the present embodiment, after the disk-shaped material 22a is formed as described above, the disk-shaped intermediate material 22a is constrained so that the outer diameter does not increase while the disk-shaped material 22a is formed. By forming a circular recess 23a as shown in FIG. 6D in the center of the intermediate material 22a, the second disk-shaped intermediate material 24b having a reduced thickness at the center is obtained. The thickness of the portion near the outer diameter of the second disk-shaped intermediate material 24b becomes larger due to the flow of the metal material accompanying the decrease in the thickness of the central portion. At this time, as the thickness of the central portion is small and the diameter is also increased, the diameter of the portion where the fracture surface exists is increased, but the thickness dimension of the central portion is reduced in the range of this portion. Stay on the part. Note that the outer diameter of the second disk-shaped intermediate material 24b can be expanded along with the processing of the recess 23a, and the outer peripheral edge can be trimmed later.

Therefore, as shown in FIG. 6E, the portion of the fracture surface corresponding to both axial end surfaces of the billet 21 at the center portion of the second disc-shaped intermediate material 24b is removed by piercing. Thus, the circular hole 25 is formed to be the above-mentioned elemental annular intermediate material 31a. By this piercing process, the portion that is the broken surface is removed from the portion that should be a high-accuracy ring together with the scrap 44 (the portion that leaves the history of the broken surface does not remain in the portion of the ring-shaped intermediate material 31a). . Therefore, as shown in FIG. 3E, the high-precision ring 8 is obtained by applying the processing shown in FIGS.
Since the present embodiment employs the configuration as described above, the portions of the billet 21 that are both end surfaces in the axial direction do not remain in a part of the obtained high-accuracy ring 8. For this reason, it is advantageous in terms of obtaining a high-quality product at a low cost.
The configuration and operation of the other parts are the same as those of the first to third embodiments.

  8 to 9 show a fifth embodiment of the present invention corresponding to the first, second, fourth, and fifth aspects. In the case of the present embodiment, by changing the shape of the ring-shaped intermediate material 26a to the shape of a mortar, the amount of angle change during the reversing process using the ring-shaped intermediate material 26a as the cylindrical high-accuracy ring 8 is 90. I try to keep it below a degree. In addition, the degree of processing (stretching ratio) of the part that expands the diameter during reversal processing is kept low to prevent harmful deformation and cracks from occurring in this part, and the width dimension in the axial direction is relatively large. The precision ring 8 can be manufactured with a high yield.

  For this reason, in the case of the present embodiment, for example, as in the former part {step (A) → (B) → (C) in FIG. 6} of the above-described fourth embodiment} (A) → (B ) → In the process shown in (C), the disk-shaped intermediate material 22a is made. Next, the outer peripheral edge of the disk-shaped intermediate material 22a is constrained in a state that prevents the outer diameter of the disk-shaped intermediate material 22a from expanding, and the disk-shaped intermediate material 22a is placed on one side surface in the axial direction at the center of the disk-shaped intermediate material 22a. A recess 23a is formed. The portion where the concave portion 23a is formed at the central portion of the disk-shaped intermediate material 22a is a portion which is removed as the raw circular hole 30a is formed in the step shown in FIG.

  In the case of the present embodiment, the concave portion 23a is formed only on one side of the disc-shaped intermediate material 22a. Further, when pressing the central portion of one side of the disc-shaped intermediate material 22a to form the recess 23, the outer peripheral edge of the disc-shaped intermediate material 22a is used as the inner peripheral surface of the die 45 as shown in FIG. To prevent the outer diameter of the disk-shaped intermediate material 22a from expanding. In this way, when the intermediate portion of the disc-shaped intermediate element 22a is pressed against the counter punch 47 by the punch 46 while restraining the outer peripheral edge portion of the disc-shaped intermediate material 22a, FIG. 8D and FIG. As shown in (C), a dish-shaped second disc-shaped intermediate material 24c having a concave portion 23a at the center and a mortar-shaped inclined annular portion 48 at the outer periphery is obtained.

  Such a second disk-shaped intermediate material 24c is formed by punching out the central portion as shown in FIG. 8E to form an elemental hole 30a to form an elemental ring-shaped intermediate material 31b. As in the case of Example 3 shown in FIG. 8, after sizing as shown in FIG. 8 (F), the inner peripheral edge is pierced as shown in FIG. An annular intermediate material 26a is obtained. Then, the ring-shaped intermediate material 26a has the inner peripheral side with a large axial dimension as it is (without shrinking the diameter once) radially outward, and the outer peripheral side with a small axial dimension remains as it is (without expanding the diameter once). ) By reversing each inward in the radial direction, reversal processing is performed by changing the angle by less than 90 degrees until each part in the circumferential direction becomes parallel to the axial direction, and the height as shown in FIG. The precision material 8 is used.

  Since the present embodiment employs the configuration as described above, when the ring-shaped intermediate material 26a is subjected to reversal processing to form the high-accuracy ring 8, the degree of processing of the inner peripheral edge portion that expands the diameter (stretching) Rate) can be kept low. For this reason, it is possible to prevent the occurrence of harmful deformation and cracks in the portion processed from the inner peripheral edge portion, and to manufacture a high-accuracy ring having a relatively large width in the axial direction with a high yield. This point will be described with reference to FIG.

  First, in order to make the operation and effect of this embodiment easy to understand, as shown in FIGS. 10A to 10A, an annular intermediate material 26b having an extremely small center hole (which is about a pinhole) is formed. Think. When such a ring-shaped intermediate material 26b is subjected to reversal processing in which the direction of the cross section is changed by 90 degrees, a large tensile stress is generated at the inner peripheral edge portion where the diameter becomes wider along with the reversal processing. And the product obtained as a result of this reversal processing becomes a thing with which the axial direction edge cracked as shown to (B)-(a) of FIG. 10, or (B)-(b) of FIG. As shown in the figure, the diameter of the axial end portion becomes small. Such a product cannot be used as a high-accuracy ring which is a material for producing an inner ring or an outer ring constituting a radial ball bearing by cold working. Further, as shown in FIGS. 10B to 10C, the high-accuracy ring 8A having a long axial dimension cannot be made from the annular material 26b having an extremely small center hole.

  Further, as shown in FIGS. 10A to 10C, in the case of the flat annular material 26 having a sufficient center hole diameter but flat as shown in FIGS. As shown in B)-(d), a high-precision material 8 having a relatively short axial dimension can be produced. However, in the case of manufacturing the high-precision ring 8A having a long axial dimension, based on the tensile stress generated in the inner peripheral edge portion whose diameter is increased with the reversing process, (B)-(a) (b) in FIG. ) As shown in FIG. Therefore, the high-accuracy ring 8A shown in FIGS. 10B to 10C cannot be manufactured with good yield from the annular intermediate material 26 shown in FIGS. 10A to 10C. On the other hand, in the case of the present embodiment, as shown in an exaggerated manner in FIGS. 10A and 10B, an angle of less than 90 degrees is formed on the mortar-shaped annular intermediate material 26a inclined from the beginning. Since the reversal process accompanied by the change is performed, the tensile stress generated in the inner peripheral edge portion whose diameter increases with the reversal process can be kept low. For this reason, defects such as those shown in FIGS. 10 (B)-(a) and (b) are less likely to occur in the inner peripheral edge portion whose diameter increases with reversal processing, and the yield can be improved.

Sectional drawing which shows the manufacturing process of Example 1 of this invention. Sectional drawing which shows the implementation condition of the inversion process in Example 1. FIG. Sectional drawing which shows the manufacturing process of Example 2 of this invention. Sectional drawing which shows the implementation condition of the sizing process in Example 2. FIG. Sectional drawing which shows the manufacturing process of Example 3 of this invention. Sectional drawing which shows the manufacturing process of the Example 4. FIG. Sectional drawing which shows the specific condition of a one part processing process in this Example 4. FIG. Sectional drawing which shows the manufacturing process of Example 5 of this invention. Sectional drawing which shows the specific condition of a one part processing process in this Example 5. FIG. FIG. 9 is a schematic diagram for explaining the operation and effect of the fifth embodiment. The partial cutaway perspective view which shows an example of the radial ball bearing which incorporated the inner ring | wheel and outer ring | wheel produced with the high precision ring used as the object of this invention. Sectional drawing which shows an inner ring process. Sectional drawing which shows an outer ring process. Sectional drawing which shows the manufacturing process of the ring-shaped components considered previously. Sectional drawing which shows the implementation condition of inversion processing in this process.

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, 8b, 8A High precision ring 9, 9a First intermediate material 10, 10a Second intermediate material 11 Third Intermediate material 12 Fourth intermediate material 13 Disc material 14 Intermediate material 15 Ring-shaped member 16 Die 17 Punch 18 Large diameter portion 19 Small diameter portion 20 Curved portion 21 Billet 22, 22a Disc-shaped intermediate material 23, 23a Recess 24, 24a, 24b 24c, 24d Second disk-shaped intermediate material 25 Circular hole 26, 26a, 26b Circular annular material 27 Die 28 Circular hole 29 Punch 30, 30a Raw circular hole 31, 31a, 31b Raw annular material 32 Preliminary intermediate material 33 Fixed block 34 Die 35 Counter punch 36 Ring punch 37 Punch 38, 38a Elastic member 39 Bottom Center hole 40 machined recess 41 ram 42 upper central hole 43 thick part 44 Scraps 45 die 46 punch 47 counter punch 48 inclined annular portion

Claims (8)

  A disk-shaped material that is made of metal and has a volume larger than the volume of the high-accuracy ring to be manufactured in the axial direction, and the thickness dimension in the axial direction increases in the center and decreases toward the outer peripheral edge. After making an intermediate material and forming a circular hole in the center of this disk-shaped intermediate material to make a ring-shaped intermediate material having the same volume as the above-mentioned high-accuracy ring, a portion closer to the outer diameter of this annular material Reversing process in which the direction of the cross section is changed in the direction in which the portion closer to the inner diameter is expanded radially outward, and the angle of 90 degrees or less is changed until each part in the circumferential direction becomes parallel to the axial direction. A method for manufacturing a high-accuracy ring, in which the annular intermediate material is a cylindrical ring having inner diameter, outer diameter, and axial length as regulation values.   The volume of the part to be removed is reduced by forming a recess on at least one side surface of both sides in the axial direction of the part to be removed as the circular hole is formed at the center of the disc-shaped intermediate material. The manufacturing method of the high precision ring of Claim 1.   Pressing the disk-shaped intermediate material with the recesses in the axial direction with the outer peripheral edge restrained so that the outer diameter does not expand, the axial dimension is reduced to an appropriate value, and the excess volume 3. The method for manufacturing a high-accuracy ring according to claim 2, wherein after the minute portion has escaped to the concave portion, a central portion of the disc-shaped intermediate material including the concave portion is punched to obtain an annular intermediate material.   After forming an elemental hole that is the origin of the circular hole in the center of the disk-shaped intermediate material to make an elemental ring-shaped intermediate material, the outer peripheral edge of the elemental ring-shaped intermediate material is prevented so that the outer diameter does not expand. In the axial direction in a state of restraining the axial dimension, shrink the thickness dimension in the axial direction to an appropriate value, and let the excess volume escape to the inner peripheral edge of the circular hole, then the inner peripheral edge of the raw circular hole The manufacturing method of the high precision ring described in any one of Claims 1-2 which makes it an annular | circular shaped intermediate material by removing this surplus part which exists in a part.   The outer peripheral edge of the disk-shaped intermediate material is removed as the circular hole is formed at the center of the disk-shaped intermediate material while restraining the outer diameter of the disk-shaped intermediate material from expanding. By forming a recess only on one side surface in the axial direction of the power portion, the volume of the portion to be removed is reduced, and the shape of the disk-shaped intermediate material is partially conical at the portion closer to the outer diameter on the side where the recess is formed. 5. The angle change amount during reversal processing using a ring-shaped intermediate material as a cylindrical ring as a substantially conical trapezoidal shape that is a concave surface is suppressed to less than 90 degrees. Manufacturing method for high precision rings.   When making a disk-shaped intermediate material by compressing billet-shaped material in the axial direction, this material or the preliminary intermediate material is constrained by constraining both axial ends of this material or the preliminary intermediate material formed by processing this material. The diameter of both ends in the axial direction is prevented from expanding, and a circular hole is formed by removing the portion including the axial end faces of the material or the preliminary intermediate material at the center of the obtained disk-shaped intermediate material. The method for producing a high-accuracy ring according to any one of claims 1 to 5, wherein the ring-shaped intermediate material is used.   An apparatus for manufacturing a high-accuracy ring for carrying out the method for manufacturing a high-accuracy ring according to claim 6, wherein the apparatus moves down until it comes into contact with the upper surface of the fixed block when a large pressure is applied. In this state, a die having a lower center hole in which a lower end portion of a billet-like material or a preliminary intermediate material formed by processing this material is elastically supported above the fixed block can be fitted, and the lower center When a large pressing force is applied concentrically to this die to a counter punch inserted into the hole so that the die can be moved up and down, and a part of the ram of the press machine provided above this die, The upper center hole with which the upper end portion of the billet-like material or the preliminary intermediate material, which is elastically supported below the ram and can be fitted, can be fitted in the state where it is raised until it comes into contact with the lower surface. And Gupanchi apparatus for manufacturing a high-precision ring with a punch that is capable of inserting the lifting for the ring punch in the upper center hole.   At least before the processing of the disk-shaped intermediate material is completed, the counter punch is supported on the fixed block and the punch is supported on the ram without moving up and down, and the lower surface of the die contacts the upper surface of the fixed block. In this state, the upper end surface of the counter punch is present at a position recessed below the upper surface of the die, and the upper surface of the ring punch is in contact with the lower surface of the ram, and the lower surface of the ring punch is in contact with the punch. The apparatus for manufacturing a high-accuracy ring according to claim 7, wherein the high-accuracy ring exists at a position recessed upward.

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