JP2791625B2 - Manufacturing method of toothed molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a toothed molded product used for, for example, an engine of an automobile, and more particularly to a cylindrical shape having a through hole at the center and having both axial ends projecting outward. The present invention relates to a method for manufacturing a toothed molded product having a flange-like shape and having teeth formed on one or both ends of the outer periphery of the flange.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a toothed molded product having a circumferential flange portion whose both ends in the axial direction protrude outward, and having a tooth portion formed at one end or at an outer periphery of the flange at both ends, has been known in advance. A circumferential relief groove is formed by cutting on the outer periphery near the center in the axial direction of the material, and further, a tooth portion is formed on the outer periphery of the flange by cutting with a hob cutter or a gear shaper.

[0003] However, when the tooth portion is formed on the outer periphery of the flange by such a hobbing cutter or a gear shaper, there is a problem in that the tooth cutting takes a long time.

Therefore, instead of gear cutting, as shown in FIG. 5, the cylindrical material 101 is formed into an intermediate molded product 130 having a tooth portion 137 by warm forging, and then the intermediate molded product 1 is formed.
A circumferential relief groove 128 was formed by cutting around the outer periphery near the center in the axial direction of No. 30 to form a toothed molded article 131 having flanges 135 and 136 at the outer periphery of both ends 132 and 133 in the axial direction. The molding of the intermediate molded article 130 having the tooth portions 137 in this case will be described with reference to FIG. 6. First, as shown in the left half, a plurality of tooth forming portions 153 project circumferentially from the inner peripheral surface. The cylindrical material 101 is inserted into the molding space 156, and the lower end of the cylindrical material 101 is disposed so as to be seated on the upper end of the tooth forming portion 153. Then, as shown in the right half, the upper punch 142 is lowered, and the cylindrical material 101 is lowered.
Is further pressed into the engraving space 156 to form the tooth portion 137 by the tooth forming portion 153 on the outer periphery of the lower end 133 of the cylindrical material 101. Thereafter, the punch 142 retreats upward, and subsequently, the knockout punch 155
Rises, and the intermediate molded product 130 in which the tooth portion 137 is molded at one end of the cylindrical material 101 is taken out from the lower die 151.

[0005]

According to the above-described method, since the tooth portion 137 can be formed by forging, the processing time of the tooth portion 137 can be shortened as compared with the hobbing cutter or the gear shaper. There are advantages.

However, according to this method, FIG.
As shown in the figure, the intermediate molded product 13 in which the tooth portions 137 are formed in advance.
Since the circumferential clearance groove 128 is formed by cutting at 0, a burr 138 is generated at the end of the tooth portion 137 on the side where the circumferential clearance groove 128 is formed, and the burr 138 must be removed in another step. Instead, it may take time and money.

Further, since the machining of the circumferential relief groove 128 is made by cutting a separate process from the forging, an increase of equipment cost, etc. Nitsu <br/> Ru long. Therefore, cutting may be performed across the already formed tooth portion 137 so that the burr 138 does not occur.
It is conceivable, however, that the machining is interrupted and the cutting tool is worn out.

Accordingly, an object of the present invention is to solve the conventional problems and to provide a method for manufacturing a toothed molded product that can manufacture a desired tooth portion at low cost in a short time.

[0009]

The configuration of the present invention is as follows.

A first step of forming a preform having a peripheral outer peripheral flange having one end protruding outward and a peripheral inner peripheral flange protruding inward at the other end; The preformed product is inserted from the other end into the lower die-cutting space in which the tooth forming portion protrudes circumferentially from the inner peripheral surface, and the inner diameter of the preformed product is substantially equal to the inner diameter at one end of the through hole of the preformed product. A second step of forming an intermediate molded product having an outer peripheral flange with an inner peripheral flange protruding outward by inserting a punch having the same diameter into the through hole and pressing the intermediate molded product upward with a knockout punch and tooth profile The third part which forms the tooth part on the outer peripheral flange by the forming part
Process.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a cylindrical blank 1 according to the manufacturing method of the present invention.
(A) sequentially represents a state in which the toothed molded product 31 is molded from
Is a cylindrical cylindrical material 1, and (a) has a peripheral outer flange 15 whose one end 12 protrudes outward and has the other end 13.
(C) is an intermediate molded article 2 having outer peripheral flanges 15, 26 whose both end portions 12, 13 project outward.
1 and (d) show a toothed molded product 31 as a completed product in which a tooth portion 37 is formed on the outer peripheral flange 26.

First, the first step of forming the preform 11 from the cylindrical material 1 will be described. The outer periphery of the end 13 of the cylindrical material 1 on the insert side of the forging device is squeezed toward the inner diameter by extrusion of a general forging device. At the same time as the excess
The inner circumference protrudes inward.

Next, a second step of forming the intermediate molded product 21 from the preformed product 11 will be described with reference to FIGS.

FIG. 2 shows a state in which the preform 11 is provided in the forging device 41, 42 is a punch movable in the vertical direction, and 51 is a lower die. The lower mold 51 includes a die 52 for regulating the preform 11 and a backup plate 54 provided below the die. The backup plate 54 has a through hole 57 that is vertically movable concentrically with the punch 42. Knockout punch 55 is inserted. A plurality of tooth forming parts 53 project from the inner peripheral surface of the die 52 in a circumferential shape. The tooth forming part 53 is provided with the preform 11 in a state where the preform 11 is disposed in the engraving space 56 of the lower mold 51.
Is provided slightly below the position of the outer peripheral flange 15 so as to protrude inward.

When the second step is performed by the above-described apparatus, first, the preformed article 11 formed in the first step is disposed in the die-cutting space 56 of the lower die 51 from the end 13 having the inner peripheral flange 16. . At this time, the upper end surface of the knockout punch 55 and the upper end surface of the backup plate 54 are set to be flush. Then, from above, a punch 42 having substantially the same diameter as the inside diameter of the through hole 4 of the preformed product 11 at the one end 12 is lowered, and the punch 42 is inserted into the through hole of the preformed product as shown in FIG. The intermediate molded product 21 is molded by pressing the inner peripheral flange to project outward. After the molding, the punch 42 is retracted upward, and the second step is completed.

Finally, as a third step, the intermediate molded product 21 in the state where the second step has been completed is pressed upward by the knockout punch 55. At this time, a tooth profile is formed on the outer peripheral flange 26 as shown in FIG. 4 by the plurality of tooth forming portions 53 provided on the lower die 51, and upon completion of the knockout, the finished toothed molded product 31 is taken out from the lower die 51. Manufacturing is completed.

Therefore, according to the method of manufacturing the toothed molded product 31 as described above, the desired tooth portion 37 and the outer peripheral flanges 1 at both ends are provided.
5, 26 can be formed only by forging.

In the above-described embodiment, the toothed molded product 31 has the tooth portion 37 formed only on the outer peripheral flange 26. However, the tooth portion may be continuously formed on the other outer peripheral flange 15 by forging. .

[0020]

As described above, according to the present invention, one end has a peripheral outer flange protruding outward, and the other end has a peripheral inner flange protruding inward. A first step of forming a preform, and inserting the preform from the other end into a lower mold engraving space in which a plurality of tooth forming parts project circumferentially from the inner peripheral surface; A second step of forming an intermediate molded product having an outer peripheral flange in which a punch having substantially the same diameter as the inner diameter at one end of the through hole of the product is inserted into the through hole and pressed to project the inner flange outward. The third step of pressing the molded product upward with the knockout punch and molding the teeth on the outer peripheral flange by the tooth forming shape part.
Since a desired tooth portion and outer peripheral flanges at both ends can be formed only by forging, a toothed molded product can be formed in a short time and at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional plan view sequentially showing a molding state of a toothed molded product according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional plan view illustrating a state before molding in a second step according to an embodiment of the present invention.

FIG. 3 is a partial cross-sectional plan view illustrating a state during second step molding according to an embodiment of the present invention.

FIG. 4 is a partial cross-sectional plan view illustrating a state during the third step of molding according to the embodiment of the present invention.

FIG. 5 is a sectional plan view sequentially showing a molding state of a toothed molded product according to a conventional example.

FIG. 6 is a partial cross-sectional plan view showing a molding process of a toothed molded product according to a conventional example, in which a left half portion is before molding and a right half portion is after molding.

[Explanation of symbols]

 Reference Signs List 4 through hole 11 preformed product 12 end 13 end 15 outer peripheral flange 16 inner peripheral flange 21 intermediate molded product 26 outer peripheral flange 37 tooth 42 punch 51 lower die 53 tooth forming part 55 knockout punch 56

Claims (1)

(57) [Claims] 1. A cylindrical shape having a through hole (4) at the center, and has circumferential outer flange portions (15) and (26) whose both ends (12) and (13) in the axial direction protrude outward. And
In a method for manufacturing a toothed molded product in which a tooth portion (37) is formed on the outer periphery of an outer peripheral flange at one or both ends, one end portion (1
2) A preform (11) having a circumferential outer flange (15) projecting outward and a circumferential inner flange (16) projecting inward at the other end (13). A first step of molding, and inserting the preform (11) into the engraving space (56) of a lower mold (51) in which a plurality of tooth forming parts (53) project circumferentially from an inner peripheral surface; (13) side, and the one end (1) of the through hole (4) of the preform (11).
2) An intermediate molded product (21) having an outer peripheral flange (26) having an inner peripheral flange (16) projecting outward by pressing a punch (42) having substantially the same diameter as the side inner diameter into the through hole (4). )
And pressing the intermediate molded product (21) upward with a knockout punch (55) and forming the tooth portion (3) on the outer peripheral flange (26) by the tooth forming shape portion (53).
7) A method for producing a toothed molded product, comprising: a third step of molding.