JPS6384732A - Manufacture of toothed cup shaped body - Google Patents

Abstract

PURPOSE:To restrain the upper part movement of a cup shaped blank metal, to eliminate an underfill part and to make a tooth profile part in a correct good shape by forming an annular projecting part over the whole periphery of the uneven profile upper part on the outer peripheral face of a punch corresponding to the uneven tooth profile on the inner face of a die forming aperture. CONSTITUTION:A cup shaped blank 1 is placed on the counter punch 35 of the die 33 having uneven tooth profile parts 33A, 33B on the inner face of a forming aperture 34, the punch 11 having the uneven tooth profiles 11A, 11B engaged with the outer peripheral face of the upper part corresponding to the tooth profile of the die 33 is press-fitted with its descent and the cup shaped blank 1 is made in the toothed cup shaped body 16 having tooth profiles on the outer peripheral face 2. In case of the press-fitting of the die 33 with its descent, the upper part transfer of the cup shaped blank 1 metal is restrained by the annular projecting part 13 extending over the whole periphery located at the prescribed height of the tooth profiles 11A, 11B, the generation of an underfill part is eliminated and a tooth profile part 17 is made in a correct good shape. A projecting part 23 may be provided on the projection part 21B of a punch tooth profile.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of manufacturing a toothed cup-shaped object from a steel plate cup-shaped material using a punch or die, such as a timing pulley, a gear, or something similar thereto. Concerning the methods available for manufacturing.

[Background technology and its problems]

Conventionally, the method shown in FIG. 7 has been used to manufacture the toothed cup-shaped object 36 shown in FIG. 8 from the steel sheet cup-shaped material 1 shown in FIG. 6 using punches and dies.

Concave portions 31A and convex portions 31B are alternately formed in the circumferential direction on the outer peripheral surface of the punch 31 which is moved up and down by a pressurizing means such as a ram,
Furthermore, concave portions 33A and convex portions 33B are alternately formed in the circumferential direction on the inner circumferential surface of the molding hole 34 of the die 33 fixed to the die housing 32. The cup-shaped raw material 1 is placed on a counter punch 35 that can be moved up and down, and when the punch 31 descends, the cup-shaped raw material 1 is pushed into the forming hole 34 of the die 33, and the bottom of the cup-shaped raw material 1 is aligned with the slope of the upper surface of the convex part 33B. After contacting the guide surface 33C, by further lowering the punch 31, the peripheral wall portion 2 of the cup-shaped material 1 is moved against the punch 3.
1 concave portion 31A, convex portion 31B and convex portion 33B of die 33
The two recesses 33A receive the force of extruding the cup-shaped material 1 in the radial direction.

As a result of this extrusion process, a large number of toothed portions 37 are formed on the outer circumferential surface of the molded product 36 which is taken out by lifting the punch 31 and lifting the counter bunch 35, as shown in FIG.

According to the conventional manufacturing method described above, as shown in FIG. 9, a gap 38 is formed at the bottom of each toothed part 37 for the reasons described below. Due to the missing portion 38, the contact area with the timing belt is reduced, resulting in a problem in which the driving force transmission efficiency is reduced.

FIGS. 10 and 11 are diagrams illustrating the cause of the occurrence of the missing portion 38. FIG. In these figures, the cup-shaped material 1 is shown as a flat plate with the peripheral wall 2 omitted and only the bottom part, and the recess 31A.
, the outer circumferential surface of the punch 31 in which the convex portion 31B is formed, and the inner circumferential surface of the forming hole 34 of the die 33 in which the convex portion 33B and the concave portion 33A are formed are shown as straight planes, and the convex portion 3
The inclined guide surface 33C on the upper surface of 3B is omitted.

When the punch 31 descends relative to the die 33 as indicated by the arrow in FIG. 10 and the outer edge of the cup-shaped material 1 contacts the inclined guide surface 33C of the convex portion 33B, the punch 31 further descends and contacts the inclined guide surface 33C. The portion of the cup-shaped material 1 that has been removed is the convex portion 33B, as shown by the arrow in FIG.
is pushed inward to form a gap 3. The protrusions 4 that are between the gaps 3 and will become the tooth profile parts 37 after tooth formation are held down by the protrusions 31B, but the flesh of the protrusions 4 is not dragged when the flesh in the gaps 3 is pushed up. and move upward. Originally, the cup-shaped material 1 was provided with the peripheral wall portion 2, and this peripheral wall portion 2 was tooth-formed with convex portions 33B over its entire height and received an upward forming force from the inclined guide surface 33G. The amount of movement increases, and as a result, a gap 38 is formed at the lower part of the tooth profile 37.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a toothed cup shape that can mold a toothed portion of a predetermined shape without causing a lack of thickness in the lower part of the toothed portion.

[Means and effects for solving the problem] In order to achieve this object, the present invention provides a cup-shaped material made of a steel plate, in which tooth-forming uneven portions are formed on the outer circumferential surface of the punch and the inner circumferential surface of the forming hole of the die. In the method for manufacturing a toothed cup-shaped article, the teeth are pushed into a forming hole of a die with a punch, and a tooth-shaped part is formed on the circumferential wall of the cup-shaped material using the uneven part. I try to do this while applying pressure.

According to this, the tooth forming process is performed while the upper surface of the circumferential wall of the cup-shaped material is pushed downward due to the pressing force, which prevents the meat from moving upward, resulting in the occurrence of underfill areas. Things will disappear.

Application of the pressing force to the upper surface of the peripheral wall is performed from the next IILitl. That is, an annular protrusion extending over the entire circumference of the bunch is formed above the uneven portion of the punch, and this annular protrusion applies a pressing force to the entire circumference of the upper surface of the peripheral wall portion of the cup-shaped material.

According to this method, it becomes possible to apply a large pressing force to the cup-shaped material.

On the other hand, in order to avoid interference between the annular protrusion and the convex part of the die, the downward movement of the punch is stopped midway, and the toothed part is formed at a part of the height of the peripheral wall of the cup-shaped material.

As another embodiment B, a protrusion is formed on the upper part of each convex part of the punch, and the protrusion is pressed against a part of the upper surface of the peripheral wall of the cup-shaped material that will become the tip of the tooth profile after tooth formation. Apply pressure. According to this method, since the protrusion and the convex part of the die do not interfere with each other, the punch can be lowered to its lower limit, and the toothed part can be formed to the full height of the peripheral wall of the cup-shaped material.

〔Example〕

FIGS. 1 and 2 show a first embodiment of the present invention, and FIGS.
FIG. 4 shows a second embodiment. In the following description, the same reference numerals will be used for the same members or members having the same function as those already described and whose shapes and the like are not changed.

A large number of recesses 11A and protrusions 11B for tooth formation are formed in the lower part of the outer peripheral surface of the punch 11 shown in FIG. An annular protrusion 13 is provided above the recess 11A and the protrusion 11B. In addition, the height Hl is equal to the inner height Hz of the peripheral wall 2 of the cup-shaped material 1 shown in FIG. It is set to be the same or smaller than Hz.

When the punch 11 descends for forming, the recess 11A,
The lower part of the punch 11 on which the convex portion 11B is formed fits into the inner circumferential side of the peripheral wall portion 2 of the cup-shaped material 1 placed on the counter bunch 35, and when the punch 11 continues to descend, the cup-shaped material 1 is placed on the die 33. After being pushed into the forming hole 34 and the bottom of the cup-shaped material 1 comes into contact with the inclined guide surface 33C of the convex part 33B of the die 33, the peripheral wall part 2 is pushed into the concave part 11 of the punch 11.
A, convex part 11B, convex part 33B of die 33, concave part 3
Tooth formation begins at 3A.

During the tooth forming process, the annular protrusion 13 is always in contact with the upper surface of the peripheral wall 2, and a downward pressing force is applied to the upper surface of the peripheral wall 2. For this reason, even if the flesh of the portion of the peripheral wall 2 that will become the tooth shape attempts to move upward during the tooth forming process, this is prevented, and the annular protrusion 13
The upper surface is recessed to push the meat downwards, thereby preventing the occurrence of underfill areas.

In particular, in this embodiment, the annular protrusion 13 contacts the entire circumference of the upper surface of the peripheral wall 2, and a pressing force is applied to the entire upper surface of the peripheral wall 2, so that the large pressing force reliably prevents the occurrence of a lack of thickness. It can be prevented.

In this embodiment, the punch 11 is used to prevent interference between the annular protrusion 13 and the inclined guide surface 33C of the convex portion 33B.
The lowering of the toothed cup 16 is stopped midway, and the toothed portion 17 is formed by a portion of the height of the outer circumferential surface, that is, H3 shown in FIG.

The second embodiment is an embodiment in which tooth-shaped portions can be formed over the entire height of the peripheral wall portion 2 of the cup-shaped material 1. Of the concave portion 21A1 and the convex portion 21B provided at the bottom of the haunch 21 shown in the third example, the convex portion 21B is formed from the bottom surface 22 to a height H, as in the first embodiment, but the concave portion 21A is longer than HI. It is formed. Therefore, the protrusions 23 provided on the outer peripheral surface of the punch 21 are discontinuous in the circumferential direction, and each protrusion 21B
A protruding portion 23 is provided only on the upper part of.

Also in this embodiment, the recessed portion 21A of the punch 21 and the convex portion 2
1B and the convex portion 33B and concave portion 33A of the die 33 to form teeth on the peripheral wall portion 2 of the cup-shaped material 1, the protruding portion 23
comes into contact with the upper surface of the peripheral wall 2, and as shown in Fig. 5, this contact is made at a part 5 of the upper surface of the peripheral wall 2, which will become the tip of the tooth after the tooth preparation. Since this corresponds to the location where a lack of thickness occurs, even if a pressing force is applied only to a part of the upper surface of the peripheral wall portion 2, the occurrence of a lack of thickness can be effectively prevented.

In this embodiment, the protrusion 23 is formed only on the upper part of the convex part 21B, so even if the punch 21 is lowered to the lower limit, the protrusion 23 and the inclined guide surface 33B of the die 33
3C, therefore, the entire height of the peripheral wall portion 2 can be formed into a toothed shape, and the outer peripheral surface of the manufactured toothed cup-shaped object 26 has toothed shaped portions 27 that reach both the upper and lower ends.
is formed.

It should be noted that only the method of the first embodiment explained above or the method of the second embodiment may be used.
Although only the method of the embodiment may be carried out, the method of the first embodiment may be first carried out on the same cup-shaped material, and then the method of the second embodiment may be carried out. This makes it possible to increase the pressing force applied to the surface and form the tooth profile over the entire height of the peripheral wall portion 2.

〔Effect of the invention〕

According to the present invention, the tooth profile can be accurately formed into a predetermined shape without causing a lack of thickness in the lower part of the tooth profile.

[Brief explanation of the drawing]

Fig. 1 is a bottom perspective view of a punch used in the method according to the first embodiment, Fig. 2 is a half-cut composite view before and after forming, showing the method of the first embodiment, and Fig. 3 is a diagram showing the method of the second embodiment. FIG. 4 is a view similar to FIG. 2 showing the method of the second embodiment, FIG. 5 is a sectional view taken along the line V-V in FIG. 4, and FIG. 7 is a perspective view of a cup-shaped material, FIG. 7 is a view similar to FIG. 2 showing the conventional method, FIG. 8 is a perspective view of a toothed cup-shaped product manufactured by the method of FIG. 7, and FIG. 9 is a perspective view of a cup-shaped material with teeth. A partially enlarged view of FIG. 8, FIG. 10, and FIG. 11 showing the occurrence of a lack of thickness are diagrams for explaining the cause of the occurrence of a lack of thickness. 1... Cup-shaped material, 2... Peripheral wall portion, 11.21.
...Punch, IIA, 21A...Concavity, IIB, 21
B...Convex part, 13...Annular protrusion, 23...Protrusion part, 16°26...Toothed arm-shaped object, 17.27.
... tooth profile, 33... die, 33A... recess, 3
3B... Convex portion, 34... Molded hole. Agent Patent attorney Otama Kinoshita (and 1 other person) Figure 5 Figure 6 Figure 8 Figure 9 Wang

Claims (3)

[Claims] (1) A cup-shaped material made of a steel plate is pushed into a forming hole of a die with a punch that moves up and down, and the cup-shaped material is A method for manufacturing a toothed cup-shaped article in which a tooth-shaped portion is formed on a peripheral wall portion, the method comprising applying a pressing force to the upper surface of the peripheral wall portion of the cup-shaped material when forming the tooth-shaped portion. . (2) In claim 1, an annular protrusion extending over the entire circumference of the punch is formed at the upper part of the tooth forming unevenness of the punch, and the annular protrusion forms an upper surface of the peripheral wall of the cup-shaped material. A method for manufacturing a toothed cup-shaped article, characterized in that the pressing force is applied to the entire circumference. (3) In claim 1, a protrusion is formed on the upper part of each tooth forming convex part of the punch,
A method for manufacturing a toothed cup-shaped article, characterized in that the protruding portion applies the pressing force to a part of the upper surface of the peripheral wall portion of the cup-shaped material that will become the tip of the tooth profile after tooth formation.