JP5446787B2 - Ring material manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a ring material used for an inner ring, an outer ring, and the like of a rolling bearing and a sliding bearing.

  As a conventional method for manufacturing a ring material, a method is known in which a round bar material is obtained by a plurality of forging processes and a cutting process to obtain a ring material having a shape and size close to a finished product. For example, a method of manufacturing a ring material used for an inner ring and an outer ring of a rolling bearing disclosed in Patent Document 1 will be described with reference to FIG.

  In the first step, the round bar material 1 is cut to a predetermined length to produce a disk-shaped material 2, and in the second step, an inner ring inner diameter hole is formed by press punching in the disk-shaped material 2 to form a cylindrical material 3. To do. Next, after forming the annular grooves 4 and 5 on both end faces of the cylindrical material 3 by cutting in the third and fourth steps, the cylindrical material 3 is formed by pressing in the fifth step. And a ring material 8 for the outer ring.

  However, in the above method, it is necessary to prepare a round bar material having the same outer diameter as the outer ring to be manufactured, and there is a problem in that the material is discarded due to cutting and the material yield is poor.

  As a countermeasure, in FIG. 2 of Patent Document 1, the bearing steel columnar material is cut into a predetermined length, and this is separated into a ring-shaped material for the inner ring of the bearing and a ring-shaped material for the outer ring by pressing, After that, a method of reducing the number of processes and improving the material yield is shown by expanding the diameter by cold rolling and forming it into a ring material for an inner ring of a bearing and a ring material for an outer ring. Further, in FIG. 1 of Patent Document 2, a method of improving the material yield by cutting a bearing steel pipe into a predetermined length and forging it to form a ring material for an outer ring of a bearing and a ring material for an inner ring. It is shown.

JP-A-8-090129 JP 2007-130673 A

However, in these prior arts, when manufacturing the ring material for the inner ring and the ring material for the outer ring whose width is changed as it is, the outer diameter of the pipe-shaped material, the punch for punching the inner ring inner diameter hole, the ring for the inner ring It is necessary to change the separation punch for separating the material and the ring material for the outer ring, and it takes time to change the set. Moreover, the raw material and punches according to the dimension of the ring to manufacture are needed, and a running cost becomes high.
Furthermore, in the methods of Patent Document 1 and Patent Document 2, when only one of the ring material for the outer ring and the ring material for the inner ring is necessary due to some trouble, an unnecessary material is generated. There was.

  Therefore, an object of the present invention is to provide a manufacturing method that can reduce the labor of changing the set, or hardly spend it, has a low running cost, and can manufacture various rings.

In order to solve the above problem, claim 1 of the present invention provides:
A first step of forming a pipe-shaped material from a round bar material;
A second step of producing a ring-shaped material having a predetermined length from the pipe-shaped material;
After inserting the upsetting mandrel into the ring-shaped material so as to be in a press-fitted state, the ring-shaped material is installed to a predetermined upsetting height by cold forging to form an upsetting ring-shaped material. Process,
Using a forming roll and a cold rolling mandrel each having a recess having the same width as the upset ring-shaped material on the outer peripheral surface, the upset ring-shaped material is expanded to the target outer diameter by cold rolling. has a higher fourth Engineering shaping the the ring blank,
By simply changing the length of the ring-shaped material cut out from the pipe-shaped material, the same inner and outer diameter pipe-shaped material, the same upset mold, the same cold rolling forming roll and the cold rolling mandrel Mold ring materials with different diameters ,
As a method for producing a pipe-shaped material, a pipe-shaped material is formed from a round bar material by backward extrusion and punching .

Further, according to claim 2 of the present invention, in the backward extrusion step, if the cross-sectional area of the material before backward extrusion is As and the cross-sectional area of the material after backward extrusion is Ak, 30 ≦ (Ak / As × 100) ≦ 50.

  The present invention has the above-described configuration, and ring materials having different outer diameters can be formed simply by changing the length of the ring-shaped material. Also, ring materials having different outer diameters and widths can be formed by changing the length of the ring-shaped material, the upsetting height, and the cold rolling mold. As described above, it is possible to reduce the labor of changing the set by changing the dimensions of the ring material, and since there are fewer materials and forging dies to be prepared, there is an effect that the running cost is low and a variety of rings can be produced.

It is a figure which shows the manufacturing method (when forming the ring raw material of outer diameter D1 from the ring-shaped raw material of length H1) by this invention. It is a figure which shows the manufacturing method (when forming the ring raw material of outer diameter D2 from the ring-shaped raw material of length H2) by this invention. It is a figure which shows the process of shape | molding a pipe-shaped raw material from a round bar raw material. It is a figure which shows the manufacturing method of a bearing inner ring | wheel and an outer ring | wheel by the conventional method.

  Embodiments of the present invention will be described below with reference to the drawings.

1, 2 and 3 show the steps of the embodiment according to the present invention.
In FIG. 1, first, in a first step, a cutting billet 23 is manufactured from a round bar material 22 by any one of press cutting, saw cutting, and parting off. When the cutting billet 23 is cut out by press cutting, cracks are likely to occur because the surface roughness of the cutting surface is not good, and the perpendicularity to the axial direction of the cutting surface is bad. Mold.

  In the case of cutting by saw cutting or parting off, since the surface roughness of the cut surface and the perpendicularity of the surface to the billet axis direction are good, it is not necessary to perform upsetting and end face forcing.

  Next, the upset billet 24 is extruded backward to form the inner diameter of the pipe, and the backward extruded billet 25 is formed.

  In the backward extrusion, since the applied load and the surface pressure are high, the deformation resistance is lowered, and the molding is performed with the load reduced and the low surface pressure.

Specifically, as shown in FIG. 3, assuming that the cross-sectional area of the maximum outer diameter portion of the upset billet 24 is As and the cross-sectional area Ak of the rear extrusion billet 25,
It is desirable to perform rear upsetting within a range of 30 ≦ (Ak / As × 100) ≦ 50 (%).

  Finally, the bottom of the rear extrusion billet 25 is punched to form the pipe-shaped material 11.

  Next, in a second step, the pipe-shaped material 11 is cut into a length H1 according to the required outer diameter D1 of the ring material 20 which is the final form, and the ring-shaped material 12 is manufactured. The inner diameter of the pipe-shaped material 11 is determined to be a value slightly larger than the maximum outer diameter on the basis of the maximum outer diameter of the cold rolling mandrel 18.

  Next, in the third step, the inner diameter of the ring-shaped material 12 obtained in the second step is passed through the mandrel 15 and sandwiched between the up and down flat mounting dies 14a and 14b, and then installed to the target installation height h. A ring-shaped material 16 is formed.

  By using the mandrel 15, buckling when the ring-shaped material 12 is installed can be prevented.

  The inner diameter of the ring-shaped material 12 and the outer diameter of the mandrel 15 are set so as to have a slight gap.

  However, when upsetting is performed by cold forging, the inner diameter of the ring-shaped material 12 and the mandrel 15 may be press-fitted to reduce the molding load.

  Next, in the fourth step, the mandrel 18 is set on the inner diameter side of the upset ring-shaped material 16 obtained in the third step, and the forming roll 19 is set on the outer diameter side, and the mandrel 18 and the forming roll 19 are set up. The upset ring-shaped material 16 is expanded in diameter by a cold rolling process in which the ring-shaped material 16 is sandwiched and pressed from both sides in the radial direction, and the ring material 20 having a target outer diameter D1 and width h is formed.

  The maximum outer diameter of the cold rolling mandrel 18 is determined by the material strength of the mandrel 18.

  The formed ring material 20 is subjected to cutting, heat treatment, grinding, and polishing to form a bearing ring.

  Next, a case where the length of the ring-shaped material is changed longer than that in FIG. 1 will be described with reference to FIG.

  In FIG. 2, the pipe-shaped material 11 is formed from the round bar material 22 in the first step. Since the first step is the same as that described in FIG.

  Next, in the second step, the pipe-shaped material 11 obtained in the first step is cut into a length H2 according to the required outer diameter D2 of the ring material 21 which is the final form, and the ring-shaped material 13 is manufactured. At this time, H2> H1 and D2> D1. Next, in the third step, the ring-shaped material 13 obtained in the second step is set up to a setting height h by the mandrel 15 and the setting molds 14a and 14b, and the upset ring-shaped material 17 is formed. The outer diameter of the upset ring-shaped material 17 at this time is larger than the outer diameter of the upset ring-shaped material 16 obtained in the third step of FIG.

  Next, in the fourth step, the upset ring-shaped material 17 obtained in the third step is cold-rolled by the mandrel 18 and the forming roll 19, thereby forming the ring material 21 having the target outer diameter D2 and width h. To do.

  As is clear from the description of FIGS. 1 to 3 above, the same pipe-shaped material, the same upsetting mold, the same rear extrusion mold, and the same punching mold can be obtained simply by changing the lengths H1 and H2 of the ring-shaped materials 12 and 13. The ring materials 20 and 21 having different outer diameters can be formed using the same cold rolling mold.

  According to the manufacturing method described above, the ring-shaped materials 12 and 13 can be alternately passed through the manufacturing process. In addition, when the ring material 20 is manufactured as the inner ring material of the bearing and the ring material 21 is manufactured as the outer ring material, when one of the ring materials 20 and 21 is insufficient due to a problem in a later process, etc. Only the ring material that is insufficient to make up for the shortage can be manufactured, and the waste of material can be minimized.

  Further, when changing the width h of the ring material, it is only necessary to change the upsetting height h, the cold rolling mandrel 18 and the forming roll 19.

  In addition, according to the manufacturing method of the ring-shaped material of the present invention, it is possible to manufacture a pipe-shaped (tubular or cylindrical) material that is not commercially available with a high yield.

  The method for producing a ring-shaped material according to the present invention can be suitably applied to the production of inner and outer rings of a rolling bearing.

DESCRIPTION OF SYMBOLS 1 Round bar material 2 Disc-shaped material 3 Ring-shaped material 4 Annular groove 5 Annular groove 6 Ring material for inner ring 7 Inner ring 8 Ring material for outer ring 9 Outer ring 10 Material of difference between inner and outer diameters of inner ring and outer ring 11 Pipe-shaped material 12 Ring-shaped material (Length H1)
13 Ring material (length H2)
14a Upset mold upper mold 14b Upset mold lower mold 15 Upset mandrel 16 Upset ring-shaped material (upset 12)
17 Upset ring-shaped material (upset 13)
18 Cold rolling mandrel 19 Forming roll 20 Ring material (outer diameter D1)
21 Ring material (outer diameter D2)
22 round bar material 23 cutting billet 24 upset, end face forced billet 25 rear extrusion billet

Claims (2)

A first step of forming a pipe-shaped material from a round bar material;
A second step of producing a ring-shaped material having a predetermined length from the pipe-shaped material;
After inserting the upsetting mandrel into the ring-shaped material so as to be in a press-fitted state, the ring-shaped material is installed to a predetermined upsetting height by cold forging to form an upsetting ring-shaped material. Process,
Using a forming roll and a cold rolling mandrel each having a recess having the same width as the upset ring-shaped material on the outer peripheral surface, the upset ring-shaped material is expanded to the target outer diameter by cold rolling. has a higher fourth Engineering shaping the the ring blank,
By simply changing the length of the ring-shaped material cut out from the pipe-shaped material, the same inner and outer diameter pipe-shaped material, the same upset mold, the same cold rolling forming roll and the cold rolling mandrel Mold ring materials with different diameters ,
As a method for producing a pipe-shaped material, a method for producing a ring material characterized by forming a pipe-shaped material from a round bar material by backward extrusion and punching .   30. (Ak / As.times.100) .ltoreq.50, where As is a cross-sectional area of a material before backward extrusion and Ak is a cross-sectional area of the material after backward extrusion in a backward extrusion step. A method for producing a ring material according to 1.

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