JP2001071091A - Production of outer-diameter side spherical shaped ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forging method by which the machining to the inner- and the outer-diameter surfaces after forming is made unnecessary, an outer- diameter side spherically shaped ring developing no harmful flaws on the inner diameter surface is obtd., and the service life of die can be improved. SOLUTION: In a method for producing the outer-diameter side spherically shaped ring in which the outer diameter surface bulges in a spherical shape by a cold forging, after inserting an insert pin 3 having a diameter equal to the inner diameter of the ring into the inner diameter side of a cylindrical blank A having an outer diameter larger than the diameter of the end surface of the ring and smaller than the max. outer diameter of the ring and an almost equal inner diameter as the inner diameter of the ring, the cylindrical blank is compressed from its outer diameter surface sides of both end surfaces with a punch and the die having the outer diameter surface and the forming part of the end surface of the ring in symmetric shapes. The filling-up of the cylindrical blank into the forming space formed by the punch, die and insert pin is formed so as to simultaneously complete near the center of the outer diameter surface and near the end surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an outer-diameter spherical ring, and more particularly, to a method for manufacturing an outer-diameter spherical ring whose outer diameter surface swells spherically by cold forging.

[0002]

2. Description of the Related Art As shown in FIG. 8, a conventional method for manufacturing this kind of outer diameter side spherical ring is a fixed die 51 having a half-shaped spherical molding surface 51a and a central projecting shaft portion 51b.
Is provided so as to face the fixed die 51,
And a punch 5 having a half-shaped spherical shaped portion 51a, a symmetrically shaped half-spherical shaped portion 52a, and a central projecting shaft portion 52b.
By using a forging device equipped with the above 2 and compressing the disk-shaped material formed in advance in the preforming step with the fixed die 51 and the punch 52, the disk-shaped material is axially moved by the bi-projecting shaft portions 51b and 52b. Compressed from both end faces in the direction to form two opposing holes in the center of the material, and the outer peripheral portions are formed in the two half spherical molded portions 51a, 52a provided in the die 51 and the punch 52. To form a forged member 54 ′ having an outer peripheral surface in a spherical shape and an outer diameter side spherical shape having a surplus portion between both holes at the center of the material, and then the forged member 54 ′ is formed.
The through-hole 53 is made by punching out the excess portion between the two holes to form an outer-diameter-side spherical ring 54.

However, in the conventional method of manufacturing a spherical ring on the outer diameter side as described above, when the outer peripheral portion of the disc-shaped material is formed into a spherical shape, the mating surface between the fixed die 51 and the punch 52 of the material is formed. In the corresponding portion, a circumferential strip-like projection (burr) 55 as shown in FIG. 9 is generated, and when punching a surplus portion between the two holes of the forged member 54 ', the two projecting shafts are formed. A step 56 occurs at the boundary between the two holes formed by 51b and 52b and the through hole 53 after punching. Therefore, after the forging process, it is necessary to separately perform each cutting process for removing the band-shaped projection 55 on the outer diameter surface side and the step 56 of the through hole portion on the inner diameter surface side, and the productivity is poor, and There is a problem that the manufacturing cost increases because the processing cost is separately required.

[0004] In order to solve such problems,
For example, Japanese Patent No. 2824410 discloses a method of manufacturing an outer-diameter-side spherical ring that can eliminate the need for cutting the outer and inner surfaces of an outer-diameter-side spherical ring, thereby improving productivity and manufacturing at low cost. Have been. This is because, as shown in FIGS. 10 and 11, the cylindrical material X ₃ having the same outer diameter as the diameter of the end face at the outer diameter side spherical ring as a final product, symmetrical half spherical shaped portion 21a, The die 21 and the punch 3 are brought into close contact with each other, and the center guide pin 23 is inserted on the inner diameter side.
1 and the central guide pin 23, the cylindrical material X ₃ is embedded in the sealed molding space, and the cylindrical molding 24 on the die side and the cylindrical pressing body 32 on the punch side are used to form the cylindrical material X _3. by compressing the axial end surfaces of the material X _3, the intermediate portion of the material intended to form the spherical shape of the outer periphery by bulges the both half spherical shaped portion, the outer diameter of the final product shown in FIG. 11 the side spherical ring X ₂ step is not generated in the through hole of the belt-like projections and the inner diameter side of the outer diameter side circumferential direction.

Accordingly, the invention disclosed in Japanese Patent No. 2842410 does not require cutting of the outer and inner diameter surfaces, and has the effect of improving productivity and reducing manufacturing costs. There is a problem that it causes early damage. That is, in this patented invention, the compression in the axial direction of both end faces of the cylindrical material X ₃ is carried out by a cylindrical molded body 24 and the punch side of the cylindrical pressing member 32 of the die-side, these tools 24, portions near the contact with the 32 material X ₃ of becomes very thin cylindrical shape having a thickness of not withstand high loads. However, since the deformation resistance of the material is particularly large in cold forging as compared with hot forging, excessive pressure acts on the cylindrical molded body 24 on the die side and the cylindrical pressing body 32 on the punch side. However, there is a problem that these tools are damaged at an early stage and frequent replacement of the tools is required, resulting in a decrease in productivity, and a high tool cost is required, resulting in a high manufacturing cost.

In the invention of Japanese Patent No. 2824410, in the case of a so-called thin ring in which the outer diameter and the inner diameter of the outer-diameter spherical ring are close to each other, for example, Japanese Patent No.
825800 No. As disclosed in Japanese, as shown in FIG. 12, the both end surfaces of the cylindrical material X ₁ is compressed in the axial direction by a cylindrical molded body 24 and the punch side of the cylindrical pressing member 32 of the die-side Te, die 21 and a punch 3 having an intermediate portion of the cylindrical material X ₁ half spherical shaped portion 21a of the symmetrical shape, the 31a
When the outer periphery is formed into a spherical shape by swelling into a hermetically formed portion formed by the first and central guide pins 23, the diameter of the inner surface also increases so as to be pulled by the bulging deformation on the outer surface. I will. Therefore, for molding into a predetermined length dimension of the outer diameter side spherical ring, further in the case where the both end surfaces of the cylindrical material X ₁ is compressed in the axial direction, as shown in FIG. 13, the outer diameter side spherical ring There has been a problem that a circumferential scratch K occurs on the inner diameter surface of X, and a sound thin outer diameter side spherical ring cannot be obtained.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems. In the case where an outer-diameter-side spherical shaped ring is manufactured by cold forging, forming is performed. No need to cut the inner and outer diameter surfaces later,
It is another object of the present invention to provide a forging method capable of improving a mold life while obtaining an outer-diameter-side spherical ring having no harmful scratches on an inner diameter surface.

[0008]

In order to achieve the above-mentioned object, the present invention is a method for manufacturing an outer-diameter-side spherical shaped ring, characterized by the following constitution. That is, the invention according to claim 1 is a method for manufacturing an outer-diameter-side spherical ring having an outer-diameter surface bulging into a spherical shape by cold forging, wherein the outer-diameter-side spherical ring is formed in advance as a product. Forming a cylindrical material having an outer diameter larger than the diameter of the end face of the ring, smaller than the maximum outer diameter of the spherical ring, and having an inner diameter substantially equal to the inner diameter of the outer spherical ring; and then forming the cylindrical material. After inserting an insert pin having a diameter equal to the inner diameter of the outer-diameter spherical shape ring on the inner-diameter side, the outer-diameter surface and the end-face molding of the outer-diameter spherical shape ring are each formed into a symmetrical shape on one end surface side. When the cylindrical material is compressed from the outer diameter side of both end surfaces thereof with a punch and a die, and the vicinity of the center of the outer diameter surface of the cylindrical material is expanded and formed into a spherical shape, the outer surface near the both end surfaces is mainly obtained. Squeezing the diameter surface and molding into a spherical shape, Inch, filling of the cylindrical material to the molding space portion formed by the die and the insert pin, and is characterized in that shaped to complete outer surface near the center and the end face near the simultaneously.

The invention according to claim 2 is a method for manufacturing an outer diameter side spherical ring having an outer diameter surface bulging into a spherical shape by cold forging. A cylindrical material having an outer diameter larger than the diameter of the end face of the outer spherical ring, which is a product, and smaller than the maximum outer diameter of the spherical ring, and an inner diameter substantially equal to the inner diameter of the outer spherical ring. Then, after inserting an insert pin having a diameter equal to the inner diameter of the outer spherical ring on the inner diameter side of the cylindrical material, forming the outer diameter surface and end surface of the outer spherical ring The cylindrical material is compressed from the outer diameter side of both end surfaces thereof by a punch and a die each having a symmetrical shape on one end surface side, and the vicinity of the center of the outer diameter surface of the cylindrical material is expanded to a spherical shape. Once formed, squeeze the outer diameter surfaces near both end faces. And forming into a spherical shape so that the filling of the cylindrical material into the forming space formed by the punch, die and insert pin is completed simultaneously near the center of the outer diameter surface and near the end surface. It is characterized by the following.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in FIGS. 1 to 6. FIGS. 1 and 2 show a state immediately before starting forging in the forging method of the present invention. In the figure, reference numeral 1 denotes a punch, and 2 denotes a die. On the front side of each of the punch 1 and the die 2, when the front sides of the punch 1 and the die 2 come into contact with each other, an outer-diameter-side spherical ring (shown in (IV) of FIG. 6) becomes a product. ring) so that the outer diameter surface R ₁ of R is the spherical shape of predetermined size, a half spherical shaped portion 1a of the symmetrical shape of increments one end face side 2
a is provided. The diameter of each of the inner diameter surface 1b and 2b of the punch 1 and the die 2 are respectively set to the same size and the end surface R ₂ of the diameter a of the outer diameter side spherical ring R.

In the punch 1, an insert pin 3 having an outer diameter equal to the inner diameter c of the outer diameter side spherical ring R is provided so as not to move relative to the punch 1. A cylindrical punch-side material protruding sleeve 4 is slidably disposed between the inner diameter surface 1b of the punch 1 and the outer diameter surface of the insert pin 3. When the punch-side material protrusion sleeve 4 is retracted to the rearmost position, the distal end surface 4a is positioned at the rearmost portion of the half spherical surface forming portion 1a of the punch 1 and the outer diameter side spherical ring R
Of the outer diameter surface R ₁ and the end surface R ₂ of FIG. After the forging is completed, the punch-side material protruding pin 6A moves forward to move the punch-side material protruding sleeve 4 in the front direction, and separates and discharges the outer-diameter-side spherical ring R from the punch 1 and the insert pin 3. I do.

On the other hand, the outside surface of the die 2
A cylindrical die-side material protruding sleeve 5 which is inscribed in the inner diameter surface 2b of which the inner diameter surface can be fitted with the aforementioned insert pin 3 is slidably provided. At the time of retreat, the front end surface 5a is located at the rearmost portion of the half spherical surface forming portion 2a of the die 2, and forms the outer diameter surface R1 and the end surface R2 of the outer diameter side spherical ring R. In the drawing, 6B is a die-side material protruding pin.

The tip of the insert pin 3 protrudes from the front surface of the punch 1. The tip of the protruded insert pin 3 is located within a molding space formed by the punch 1, die 2 and insert pin 3. The material penetrates through the inner diameter side of the cylindrical material (material shown in (III) of FIG. 6) A, and the tip protrudes slightly from the cylindrical material A. The outer diameter of the insert pin 3 inserted into the inner diameter side of the cylindrical material A has a diameter equal to the inner diameter c of the outer diameter side spherical ring R.

Further, the cylindrical material A has the same volume as the outer-diameter-side spherical ring R as a product, and the outer diameter is equal to the end surface R _{2 of the} outer-diameter-side spherical ring R.
Of the punch 1 or the inner surface 1 of the die 2
b, greater than 2b diameter) a, and the maximum outer diameter of the spherical face ring R (i.e., is smaller than the outer diameter) b of the maximum bulging portion in the vicinity of the center of the outer diameter surface R _1. Therefore, immediately before the start of machining shown in FIGS. 1 and 2, the cylindrical material A is a half spherical surface forming portion 1 a of the punch 1 and the die 2.
2a to 2a, they come into contact with each other at an intermediate position from the front side of the punch 1 or the die 2 to the rearmost part of the half spherical surface forming portions 1a to 2a.

FIG. 3 shows a state during processing in the forging method of the present invention. From the state shown in FIGS. 1 and 2, the punch 1 moves relatively forward with respect to the die 2, and the formed portion of the outer diameter surface R ₁ and the end surface R ₂ of the outer diameter side spherical ring R is formed. That is, the cylindrical material A is compressed in the axial direction from the outside near the both end surfaces thereof by the punch 1 and the die 2 having the symmetrical half spherical surface forming portions 1a and 2a on one end surface side. Therefore, this cylindrical material A
The, as shown in FIG. 3, the deformation outside diameter is enlarged its outer diameter surface central area A ₁ is bulged, both end surfaces near the A _2, A ₂
The outer diameter of the cylindrical material A is narrowed, and both end surfaces of the cylindrical material A are located at the rearmost side of the half spherical surface forming portions 1a and 2a of the punch 1 and the die 2 (that is, the punching side and the die side material punching sleeves 4 and 4).
5 (toward the end faces 4a, 5a) simultaneously occur.

FIG. 4 and FIG. 5 show the forging method of the present invention at the end of processing and at the time of completion of processing, respectively. Here, punch 1, die 2 and insert pin 3
In in the molding space portion that is formed filling the cylindrical material A is of the cylindrical material A complete outer surface around the center A ₁ and both end surfaces near the A _2, A ₂ and at the same time each, in FIG. 6 An outer-diameter-side spherical ring R shown in (IV) is formed. Thereby, when the outer diameter surface of the cylindrical material A is formed into a spherical shape,
A circumferential projection (burr) does not occur in a portion of the cylindrical material A corresponding to the mating surface between the punch 1 and the die 2.

In the majority of the machining process from the initial stage shown in FIG. 2 to the final stage shown in FIG. 4, the axial compression of A ₂ and A ₂ near both end surfaces of the cylindrical material A is performed.
The tip surfaces 4a and 5a of the punch-side or die-side blanking sleeves 4 and 5 which are formed by the half spherical surface forming portions 1a and 2a of the punch 1 and the die 2, respectively, and are thin and cylindrical, are shown in FIG. As shown, it is pressed only at the end of processing by the end face of the cylindrical material A. Also, at this time, since the forming portions 1a and 2a of the punch and the die also receive the processing load in a shared manner, even if the punching-side or die-side material protruding sleeves 4 and 5 have a thin cylindrical shape, the material of the material does not matter. Even in the case of cold forging having high deformation resistance, the material projection sleeves 4 and 5 are not damaged at an early stage.

Further, during the processing, the cylindrical material A is constantly pressed from the outer diameter surfaces of both end surfaces by the half spherical surface forming portions 1a and 2a of the punch 1 and the die 2. A pressure acts from the outer diameter side to the inner diameter side. For this reason, it is difficult for the inner diameter surface side of the cylindrical material A to increase in diameter. Further, since the inner diameter surface side of the cylindrical material A is pressed by the insert pin 3, the inner diameter surface having the same diameter as the insert pin 3 is accurately formed on the outer diameter side spherical ring R.

In the above embodiment, the respective components of the punch and the die are divided into a punch 1 and a blanking sleeve 4 on the punch side, and a die 2 and a blanking sleeve 5 on the die side. Each of the material-projecting sleeves 4 and 5 is slidably installed, and the formed outer-diameter-side spherical ring R is formed by the material-projecting sleeves 4 and 5 into the punch 1 and the insert pin 3 or the die 2. However, another method may be used in which the outer-side spherical ring R after molding is separated and discharged from the punch 1 or the die 2.

For example, after the insert pin 3 is slidably mounted on the punch 1, the insert pin 3 is once advanced after molding to project the outer-diameter-side spherical ring R toward the front of the punch, and then the front face of the punch and the outer diameter are formed. If a stopper (not shown) is inserted between the spherical ring R and the insert pin 3 is then retracted, and the insert pin 3 is pulled out from the outer spherical ring R by the stopper using the stopper, a punch on the punch side is used. 1 and the material protruding sleeve 4 may be integrated, and on the die side, the die 2 and the material protruding sleeve 5 may be integrated.

On the other hand, in the above embodiment, the outer-diameter-side spherical ring which becomes a product when the respective front surfaces of the punch 1 and the die 2 are in contact with each other is provided on the front surface side of the punch 1 and the die 2. as the outer diameter surface R ₁ of R is spherical shape having a predetermined size, but half spherical shaped portion 1a and 2a of the symmetrical shape of increments one end face side is an example provided, shown in Figure 7 as described above, when each of the front face of the punch 1 'and the second' comes close with a slight gap S, spherical outer diameter surface R ₁ of the outer diameter side spherical ring R which is a product having a predetermined size In such a manner, the symmetrically shaped substantially half spherical shaped portions 1a 'and 2a' may be provided on one end face side.

That is, the filling of the cylindrical material A into the roughly forming space formed by the punch 1 ′, the die 2 ′, and the insert pin 3 ′ is caused by A ₁ near the center of the outer diameter surface and A near the both end surfaces.
₂ and A ₂ at the same time, so that when the outer diameter surface of the cylindrical material A is formed into a spherical shape, the punch 1 ′
The cylindrical material A is not greatly extruded into the gap S between the die and the die 2 '. Therefore, a circumferential band-like projection (burr) which is harmful to the post-processing is not generated at a portion corresponding to the mating surface between the punch 1 'and the die 2' of the outer-diameter spherical ring R.

[0023]

EXAMPLES Next, examples of the present invention and comparative examples will be described. Forging material is cut out from a wire rod of bearing steel (SUJ2) by shearing, and the maximum outer diameter (spherical diameter) of the outer diameter surface is about 21.1 m.
m, end face diameter about 16.8mm, inner diameter about 13.9mm,
An outer-diameter-side spherical ring having a length of about 12.7 mm was produced by the manufacturing method of the present invention.

FIG. 6 shows the forging process of the present invention.
(I) is an upsetting process, (II) is an extruding process, (III) is a punching process of an inner diameter side excess portion, and (IV) is a forming process of an outer diameter side spherical ring. Molding process (IV)
The material of the outer-diameter-side spherical ring R formed by the above, that is, the cylindrical material A shown in the above (III) is formed in the forging process from the upsetting process (I) to the punching process (III), and then forming It was manufactured by a series of forging processes using a multi-stage parts former so that the outer-diameter-side spherical ring R was formed in the step (IV).

Here, the outer diameter of the cylindrical material A formed in the punching step (III) is 20.6 mm, which is 98% of the maximum outer diameter of the outer diameter side spherical ring R. The inner diameter of the cylindrical material A is slightly larger than the outer diameter of the insert pin 3 so that the insert pin 3 can be easily inserted in the molding step (IV). , The volume of which is adjusted to be the same as that of the outer-diameter-side spherical ring R as a product.
0.8 mm.

In the above molding step (IV),
By performing the outer-diameter-side spherical molding on the cylindrical material A molded in (III), the filling of the cylindrical material A into the molding space formed by the punch, the die, and the insert pin causes the center of the outer diameter surface to be reduced. simultaneously completed in the vicinity of a ₁ and both end surfaces near the a _2, a _2. Therefore, when the outer diameter surface of the cylindrical material A is formed into a spherical shape, a circumferential band-like projection (burr) does not occur at a portion corresponding to the mating surface between the punch and the die of the material. Also, a sound thin outer-diameter-side spherical-shaped ring R having no circumferential scratches on the inner diameter surface could be manufactured. Further, despite the fact that the punching side or die side material protruding sleeve in the above forming step (IV) has a very thin cylindrical shape having a thickness of about 1.5 mm, no breakage occurred even in mass production forging.

In addition, the outer diameter of the cylindrical material A formed in the step (III) of punching the inner diameter side excess portion is changed to the outer diameter side spherical ring with respect to the outer diameter side spherical ring of the present embodiment. By setting the maximum outer diameter of R within the range of 95 to 99%, a sound thin outer diameter side spherical ring could be manufactured.
On the other hand, if the outer diameter of the cylindrical material A is further increased, in the process of filling the cylindrical material A into the molding space, the vicinity of the center of the outer diameter surface A ₁ has already been completely filled during processing,
Circumferential band-like projections (burrs) were generated in the material at the portion corresponding to the mating surface of the punch and the die, and underfilling occurred at the end surface of the outer-diameter spherical ring R.

On the other hand, when the outer diameter of the cylindrical material A is made smaller than the above range, faster for the filling of the vicinity of the end face A ₂ than filling of the outer diameter surface near the center A _1, outer diameter spherical ring When a circumferential scratch is generated at the center of the inner diameter surface of R and the outer diameter of the cylindrical material A is further reduced, the material is punched out on both the punch side and the die side in the forming step (IV). The sleeve was damaged prematurely.

As described above, the outer diameter of the cylindrical material A formed in the punching step (III) is changed to the outer diameter side spherical ring R of the outer diameter side spherical ring of the present embodiment. By setting it within the range of 95 to 99% with respect to the maximum outer diameter, a sound thin outer diameter side spherical ring could be manufactured.
The outer diameter range of the cylindrical material A varies depending on the ratio and length of the inner and outer diameters of the outer diameter side spherical ring R as a product. In the present invention, the outer diameter of the cylindrical material is determined by a plastic deformation simulation of the material by a finite element method.

That is, the forging method of the present invention for each cylindrical material having various outer diameters is simulated on a computer as if actual forging was performed, and the obtained forged shape was calculated. The optimum outer diameter of the cylindrical material is selected from the results. When a plastic deformation simulation of the material was actually performed by the finite element method for the present example, a reasonable result is that the outer diameter of the cylindrical material A is preferably 98% of the maximum outer diameter of the outer-diameter spherical ring R. was gotten.

In this embodiment, a cylindrical material A to be formed into an outer-diameter spherical ring R is formed by the forging steps (I) to (III), and then the outer diameter is formed in a forming step (IV). To form the side spherical ring, it was manufactured by a series of forging with a multi-stage part former, but in the present invention, the cylindrical material to be formed into the outer spherical ring is formed by another method, and the forming process Various modifications are possible, such as implementing only the forging method (IV) with an independent forging machine.

[0032]

As described above, according to the method for manufacturing an outer diameter side spherical ring according to the present invention, the punch having the outer diameter side and the end surface forming portion of the outer diameter side spherical shape ring in a symmetrical shape, one end surface at a time. With a die, the material is compressed from the outer diameter surfaces of both end surfaces of the cylindrical material and expanded near the center of the outer diameter surface of the cylindrical material to form a spherical shape. At the same time, the outer diameter near the end surface is narrowed down. It was formed so that the filling of the cylindrical material into the forming space formed by the punch, die and insert pin was completed simultaneously near the center of the outer diameter surface and near the end surface. When the outer diameter surface is formed into a spherical shape, a circumferential band-like projection (burr) does not occur in a portion corresponding to a mating surface of a material punch and a die. In addition, since the inner surface of the cylindrical material is pressed by the insert pin and the predetermined inner surface is accurately formed, a highly accurate outer spherical surface ring can be manufactured as it is forged, and the outer surface of the post-process is processed. In addition, cutting of the inner diameter surface is not required, and productivity can be improved, and the outer diameter side spherical ring can be manufactured at low cost.

In the present invention, the outer diameter of the cylindrical material is larger than the diameter of the end face of the spherical ring on the outer diameter side as a product and smaller than the maximum outer diameter of the spherical ring. In most of the processing process over the last stage, the compression of the cylindrical material from the outer diameter side of both end surfaces in the axial direction is performed by the half spherical surface forming part of the punch and the die, and the punch side or the thin cylindrical shape is formed. The tip surface of the die-side material protruding sleeve is pressed by the end surface of the cylindrical material only at the end of processing. Also, at this time, since the half spherical surface forming part of the punch and the die bears the processing load in a shared manner, even in the case where the material piercing sleeve has a thin cylindrical shape, it is also possible to perform cold forging, which has a high deformation resistance of the material. Even so,
These material protruding sleeves are not damaged at an early stage, so that the tool cost can be minimized, the frequency of tool change is small, the production is stable, and the manufacturing cost can be reduced.

Further, during the processing, the cylindrical material is constantly pressed from the outer diameter surfaces of both end surfaces by the half spherical surface forming portions of the punch and the die, and the cylindrical material is pressed from the outer diameter surface to the inner diameter surface by the cylindrical material. Directing pressure is acting, and the inner diameter side of the cylindrical material is less likely to increase in diameter. Therefore,
Even in the case of a so-called thin ring whose outer diameter and inner diameter of the outer diameter side spherical ring are close to each other, the middle part of the cylindrical material is bulged into both the half sphere forming part of the punch and die, and the outer periphery is formed into a spherical shape In doing so, the diameter on the inner diameter side is not expanded by being pulled by the bulging deformation on the outer diameter side, and it is possible that circumferential scratches will occur on the inner diameter surface of the outer diameter spherical ring after processing. Thus, there is an effect that a sound thin outer-diameter-side spherical shape ring can be manufactured.

[Brief description of the drawings]

FIG. 1 is an overall view showing a state immediately before the start of processing in a forging method of the present invention.

FIG. 2 is an enlarged partial view of FIG.

FIG. 3 is an enlarged partial view showing a state during processing in the forging method of the present invention.

FIG. 4 is an enlarged partial view showing a state at the end of processing.

FIG. 5 is an enlarged partial view showing a state at the time of completion of the processing.

FIG. 6 is a view showing a forging step of the present invention.

FIG. 7 is an enlarged partial view showing a state at the time of completion of processing in another forging method of the present invention.

FIG. 8 is an overall view showing a state at the time of completion of processing in a conventional forging method.

FIG. 9 is a cross-sectional view of a product manufactured by the above method.

FIG. 10 is an overall view showing a state immediately before starting processing in a conventional forging method.

FIG. 11 is an overall view showing a state at the time of completion of the machining.

FIG. 12 is an enlarged partial view showing a state during processing in a conventional forging method.

FIG. 13 is an enlarged partial view showing a state at the time of completion of the machining.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Punch 1a Half spherical surface forming part 1b Inner surface 2 Die 2a Half spherical surface forming portion 2b Inner surface 3 Insert pin 4 Punch side material protruding sleeve 4a Tip surface 5 Die side material protruding sleeve 5a Tip surface A Cylindrical material A ₁ Near the center of the outer diameter surface A ₂ Near the end surface R Outside diameter side spherical shaped ring R ₁ Outer diameter surface R ₂ End surface a End surface diameter b Outer diameter of maximum bulging part c Inner diameter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoko Kawada 3-10-15, Yawatacho, Shinminato-shi, Toyama Japan High-frequency Steel Industry Co., Ltd. No. 10-15 Japan High Frequency Steel Industry Co., Ltd.Toyama Factory (72) Inventor Sadayoshi Furusawa 3- 10-3 Yawatacho, Shinminato City, Toyama Prefecture Japan High Frequency Steel Industry Co., Ltd. Toyama Factory (72) Inventor Mitsuaki Nakata Toyama Prefecture (72) Inventor Masami Yamamoto at 708 Ishimaru, Takaoka-shi F-term (reference) 4E087 CA12 CA24 CB03 EC01 HB08 at 708 Ishimaru, Takaoka-shi, Toyama

Claims (2)

[Claims] 1. A method for manufacturing an outer-diameter-side spherical ring having an outer-diameter surface bulging into a spherical shape by cold forging, wherein a diameter of an end surface of the outer-diameter-side spherical ring to be a product is determined in advance. Forming a cylindrical material having a large outer diameter smaller than the maximum outer diameter of the spherical ring and an inner diameter substantially equal to the inner diameter of the outer spherical ring, and then forming the cylindrical material on the inner diameter side of the cylindrical material. After inserting an insert pin having a diameter equal to the inner diameter of the outer-diameter spherical shape ring, a punch and a die each having a symmetrical shape of the outer-diameter surface and the end surface of the outer-diameter spherical shape ring on one end surface side are used. When the cylindrical material is compressed from the outer diameter surface side of both end surfaces thereof, and the vicinity of the center of the outer diameter surface of the cylindrical material is expanded and formed into a spherical shape, the outer diameter surface near the both end surfaces is narrowed down immediately. Punch, die and in A method for manufacturing an outer-diameter-side spherical shaped ring, characterized in that molding is performed such that filling of the cylindrical material into a molding space formed by a support pin is completed simultaneously near the center of the outer diameter surface and near the end surface. 2. A method of manufacturing an outer-diameter-side spherical ring having an outer-diameter surface bulging into a spherical shape by cold forging, wherein the outer-diameter-side spherical surface to be a product is forged in advance in a forging process in a previous step. Forming a cylindrical material having an outer diameter larger than the diameter of the end face of the shaped ring, smaller than the maximum outer diameter of the spherical shaped ring, and an inner diameter substantially equal to the inner diameter of the outer diameter side spherical shaped ring; After inserting an insert pin having a diameter equal to the inner diameter of the outer-diameter spherical shape ring into the inner-diameter side of the shaped material, the outer diameter surface and the end surface of the outer-diameter spherical shape ring are formed in a symmetrical shape on one end surface side. When the cylindrical material is compressed from the outer diameter side of both end surfaces thereof by a punch and a die respectively, and the center of the outer diameter surface of the cylindrical material is bulged and formed into a spherical shape, the vicinity of both end surfaces is obtained. Squeezing the outer diameter surface and molding it into a spherical shape, An outer-diameter-side spherical shape characterized by being formed so that the filling of the cylindrical material into a molding space formed by a punch, a die, and an insert pin is completed simultaneously near the center of the outer diameter surface and near the end surface. Ring manufacturing method.