JPH10225737A - Production of washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more effectively eliminate spring back, to arrange the dimensions of the internal circumference side and the external circumference side in the axial direction and to form a washer with well dimensional precision by forming an annular recessed part on the end face of a band-like blank at the time of coining process. SOLUTION: When a band-like blank 3 is set inside an annular groove of a die 1 so that the back metal layer 3A side is made to the lower side, next, a punch 2 is lowered. Then at first, the projection part 2A of the punch 2 is fitted inside the band-like blank 3, and succeedingly, an annular pressing face 2b is abutted on the upper end face of the band like blank 3. Further succeedingly, the punch 2 is lowered, the upper and lower faces of the band like blank 3 are pressed, an annular recessed part 3a of a cross-section reverse V shape is formed on the central part of the lower end face of the band-like blank 3 with an annular bulged part 1d, further an outside facing part and an inside facing part are formed on each corner part of the outside and inside of the lower end face of the band like blank 3 with an outside inclining face 1e and an inside inclining face 1f, thereby producing the washer completely.

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 a washer, and more particularly, to a method for manufacturing a washer having a coining step of pressing an end face of an annular material.

[0002]

2. Description of the Related Art Conventionally, when a washer is manufactured, a straight band material is bent into an annular shape, and then a coining process is performed by pressing an end face of the annular material which is curved in an annular shape. . When the linear band-shaped material is curved in an annular shape, the axial dimension on the inner peripheral side of the annular curved material is slightly larger than the axial dimension on the outer peripheral side, and springback occurs. Therefore, by performing the above-mentioned coining step, while aligning the axial dimension on the inner peripheral side and the axial dimension on the outer peripheral side,
Spring back is eliminated.

[0003]

However, in order to make the axial dimension on the inner peripheral side equal to the axial dimension on the outer peripheral side and to eliminate springback, it is necessary to apply a considerably high pressure to the end face of the strip-shaped material. As a result, it has been difficult to form the washer with high dimensional accuracy. In view of such circumstances, the present invention makes it possible to more effectively eliminate the springback, and to make the axial dimension on the inner peripheral side and the axial dimension on the outer peripheral side uniform so that the washer can be accurately dimensioned. An object of the present invention is to provide a method for manufacturing a washer that can be formed.

[0004]

According to the present invention, there is provided a method for manufacturing a washer having a coining step of pressing an end face of a band-like material curved in an annular shape. Is to be molded.

[0005]

According to the above-described manufacturing method, the annular concave portion is simultaneously formed on the end face of the belt-shaped material at the time of the coining step. Therefore, when the annular concave portion is not formed due to the flow of the material by forming the annular concave portion. In comparison, the springback can be eliminated more effectively, and the axial dimension on the inner peripheral side and the axial dimension on the outer peripheral side can be made uniform, whereby the washer can be formed with high dimensional accuracy. .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In FIGS. 1 and 2, a die 1 for coining a strip material is fixed to a base of a press (not shown). Is raised and lowered by the press machine. An annular groove 1A is formed on the upper end surface of the die 1 to fit the band-shaped material 3 therein. The die 1 and the punch 2 form the band-shaped material 3 with the band-shaped material 3 fitted therein. By pressing the end face, coining can be performed. As shown in an enlarged view in FIG. 3, the annular groove 1A is separated from an outer peripheral surface 1a extending vertically downward from the upper surface of the die 1 by an amount corresponding to the radial dimension of the strip-shaped material 3 inside the outer peripheral surface 1a. And an inner peripheral surface 1b extending in parallel with the outer peripheral surface 1a, and a bottom surface 1c extending in a horizontal direction for connecting the outer peripheral surface 1a and a lower portion of the inner peripheral surface 1b. In addition, an inverted V-shaped annular bulging portion 1d projecting upward is formed at the center of the bottom surface 1c, and between the outer peripheral surface 1a and the bottom surface 1c, and between the inner peripheral surface 1b and the bottom surface 1c. Between them, an outer slope 1e and an inner slope 1f extending obliquely are formed.

The inner peripheral surface 1b of the annular groove 1A is lower than the outer peripheral surface 1a of the annular groove 1A, and when the annular material 1 is accommodated in the annular groove 1A, the outer peripheral surface of the annular material 1A is formed. Is accommodated in the annular groove 1A, but about the upper half of the inner peripheral surface of the band-shaped material 3 is exposed to the outside of the annular groove 1A. On the other hand, the punch 2 is formed in a columnar shape, and has a columnar protrusion 2A formed in the center of the lower end surface. The outer diameter of the main body portion of the punch 2 is the same as the diameter of the outer peripheral surface 1a of the annular groove 1A, and the outer diameter of the protrusion 2A is the same as the diameter of the inner peripheral surface 1b of the annular groove 1A.
The amount of protrusion of the protrusion 2A below is determined by the amount of the protrusion 2A.
When the end face of the band-shaped material 3 is pressed by the annular press face 2B formed on the outer peripheral side of A, the lower surface of the projection 2A
Is set so that it does not abut.

Next, the die 1 and the punch 2 having the above structure
The coining process for coining the strip-shaped material 3 will be described. The strip-shaped material 3 is formed by bending a linear strip-shaped material into an annular shape in advance by an appropriate bending process known in the related art. The strip-shaped material 3 includes a thick back metal layer 3A and a thin lining layer 3B covering the surface of the back metal layer 3A.
Is curved in an annular shape such that the surface of the belt-shaped material 3 becomes one end face of the band-shaped material 3. At this time, the surface of the back metal layer 3A is flat, and the continuous portion between the surface of the back metal layer 3A and the outer peripheral surface,
The corners between the surface of the back metal layer 3A and the inner peripheral surface are substantially right angles. However, by bending the linear strip-shaped material in an annular shape, the axial dimension on the inner peripheral side of the strip-shaped material 3 is slightly larger than the axial dimension on the outer peripheral side,
Further, springback occurs, and the abutting surfaces at both ends of the strip-shaped material are slightly opened by the springback, although not shown.

The belt-shaped material 3 formed as described above
Is set in the annular groove 1A of the die 1 with the back metal layer 3A side down, and then the punch 2 is lowered. Then, first, the protruding portion 2A of the punch 2 is fitted into the strip material 3, and subsequently, the annular press surface 2B is brought into contact with the upper end face of the strip material 3. When the punch 2 is further lowered, the end surface, that is, the upper and lower surfaces of the band-shaped material 3 is pressed, and as shown in FIG. 4, an inverted V-shaped cross section is formed at the center of the lower end surface of the band-shaped material 3 by the annular bulging portion 1d. Annular recess 3a
At the same time, the outer slope 1e and the inner slope 1f are used to form an outer facing portion 3b and an inner facing portion 3c at each of the outer and inner corners of the lower end surface of the belt-shaped material 3, so that the washer 3 is formed. Be completed. Thereafter, when the punch 2 moves upward and the coining process is completed, the washer 3 is taken out from the annular groove 1A.

According to the above-described manufacturing method, the annular concave portion 3a is formed on the end face of the strip-shaped material 3 during the coining step, so that the annular concave portion 3a is not formed.
At the same time, the springback can be effectively eliminated, and at the same time, the torsion, undulation, distortion, and the like of the band-shaped material 3 can be made flat, so that the washer can be formed with high dimensional accuracy. At this time, if the springback is simply taken, the annular bulging portion 1d attached to the die 1 is used.
Is better. However, in order to obtain a difference in thickness between the inner and outer peripheries of the belt-shaped material 3, the annular bulge 1d hinders the flow of the material from the thick inner perimeter to the thin outer perimeter. Better. Therefore, the size and height of the annular bulging portion 1d are set such that the difference in thickness between the inner and outer circumferences can be effectively obtained while eliminating springback. Also, since the outer facing portion 3b and the inner facing portion 3c are formed simultaneously during the coining process, a comparison is made between the case where the outer facing portion 3b and the inner facing portion 3c are turned after the coining process. As a result, the manufacturing process can be simplified, so that the manufacturing cost of the face washer can be reduced as compared with the conventional case.

In the above embodiment, the annular press surface 2B of the punch 2 is formed flat, and the annular groove 1A of the die 1 is provided with the annular bulge 1d. 2B, the annular bulge 1d, the outer slope 2 and the inner slope 2
While forming d, the bottom surface of the annular groove 1A of the die 1 may be formed flat, and the band material 3 may be coined such that the lining layer 3B of the band material 3 is on the lower side.

[0012]

As described above, according to the manufacturing method of the present invention, the annular concave portion is formed during the coining step.
The springback of the washer can be effectively eliminated, thereby obtaining an effect that the dimensional accuracy of the washer can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of a die 1 and a punch 2.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of a die 1, a punch 2, and a strip material 3 along the line AA in FIG.

FIG. 4 is a sectional view showing the band-shaped material 3 after coining.

[Explanation of symbols]

1 ... die 1A ... annular groove 1d
... annular bulge 1e ... outer slope 1f ... inner slope 2 ...
Punch 2A ... Projection 2B ... Annular press surface 3 ...
Band-shaped material 3a: annular concave portion 3b: outer surface mounting portion 3c
… Inner side attachment

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuru Hibino 3-65 Midorigaoka, Toyota-shi, Aichi Prefecture Inside Daitoyo Kogyo Co., Ltd. (72) Inventor Teruaki Inoshi 3-65, Midorigaoka, Toyota-shi, Aichi Pref. Daitoyo Kogyo Co., Ltd. Inside

Claims (3)

[Claims] 1. A method of manufacturing a washer having a coining step of pressing an end surface of an annularly curved annular raw material, wherein a washer is formed in the end surface of the annular raw material during the coining step. Manufacturing method. 2. The method for manufacturing a washer according to claim 1, wherein the annular recess has a V-shaped cross section. 3. The method according to claim 1, wherein at the time of the coining step, an imposed portion is formed on at least one of an inner peripheral portion and an outer peripheral portion of the end surface of the annular material. Washer manufacturing method.