JPH04258336A - Method for working various kinds of raw materials by forging - Google Patents

Abstract

PURPOSE:To prevent rising-up at a center part due to the flowing of a raw material into a hole and to improve releasing from a die by pressurizing a raw material with the die after forming a hole in advance in the raw material before forging to execute the die forging of a formed product. CONSTITUTION:In the raw material 1 before working, the hole 3 is penetrated into the center part and by executing coining-work to this raw material 1 with the upper and lower dies, the formed product 2 can be obtained. At this time, the raw material 1 flows to the hole 3 side, and the hole 3 is squeezed to generate a crack 4 and also the rising-up is difficult to develop at the center part and thickness in cross section at each part becomes constant, and inner bottom face in the recessed part 2a on the front side and back 2b are made to almost flat and forming pressure on the die is reduced and the releasing from the die is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing various materials by forging, and particularly relates to coining in cold forging.

0002

2. Description of the Related Art For example, when coining the side plate of a knife handle, a material 1 shown in FIGS. 9 and 10 is pressed by an upper mold and a lower mold to form the material as shown in FIG. 11. next,
As shown in FIGS. 12 and 13, the outer periphery of the molded product 2 is trimmed. However, in the conventional coining process, there was a problem in that the thickness of each part of the cross section of the molded product 2 was not constant because the center part of both the front and back surfaces of the molded product 2 were raised. Therefore, when other parts are stacked on both the front and back sides of the molded product 2, there is a drawback that a gap is created between them. In order to prevent this, it was necessary to grind the molded product 2.

0003

SUMMARY OF THE INVENTION As described above, a problem with the conventional method is that the molded product bulges closer to the center, and the object of the present invention is to prevent such bulges.

0004

[Means for Solving the Problems] In view of this object, the method of processing various materials according to the present invention includes forming holes 3 in advance in the material 1 before forging, as shown in the drawings of the embodiments described later. This raw material 3 is pressurized with a die to form a molded product 2.

[0005]

[Operation] During die forging, the material 1 flows to the hole 3 side, crushing the hole 3 and creating a crack 4 in the molded product 2.

[0006]

[First Embodiment] First, a first embodiment in which the present invention is applied to a side plate of a knife handle will be described with reference to FIGS. 1 to 5. As shown in FIGS. 1 and 2, a hole 3 is provided in the center of the material 1. When this material 1 is coined using an upper mold and a lower mold, a molded product 2 shown in FIG. 3 is obtained. During the coining process, the material 1 also flows toward the hole 3 side, crushing the hole 3 and creating a crack 4 in the molded product 2, and a flash 5 on the outer periphery of the molded product 2. When the outer periphery of this molded product 2 is trimmed to remove the flash 5, the molded product 2 shown in FIGS. 4 and 5 is obtained.

According to the coining process according to this embodiment, since the hole 3 is provided in the material 1 in advance before processing, the material 1 is less likely to flow toward the hole 3 and form a bulge in the center of the molded product 2. The thickness of each section of the molded product 2 becomes constant. Therefore,
The inner bottom surface and back surface 2b of the recess 2a on the front side of the molded product 2 become nearly flat. Therefore, even if other parts are stacked on the inner bottom surface or back surface 2b of this recessed portion 2a, a gap will hardly be formed between them. In addition, the molding pressure against the mold is lower,
The molded product 2 can be easily released from the mold.

[0008]

[Second Embodiment] Next, a second embodiment in which the present invention is applied to a pressing lever for nail clippers will be described with reference to FIGS. 6 to 8. The molded product 2 shown in FIGS. 6 and 7 is manufactured by coining in the same manner as in the first embodiment described above. Although not shown, holes are previously formed through the material before processing. Then, this hole is crushed by the coining process and remains as a crack 4 in the molded product 2. During the coining process, the material flows toward the hole, so that the inner bottom surfaces of the recesses 2a on both the front and back sides of the molded product 2 become nearly flat. As shown in FIG. 8, even if the decorative plate 6 is fitted into the recess 2a on the front side or the nail file 7 is fitted into the recess 2a on the back side, a gap is unlikely to be formed between them.

[0009] In the first embodiment, the holes 3 are provided through the material 1, but the holes 3 do not necessarily have to be provided in a penetrating state as long as there is a space through which the material 1 can flow. Note that the present invention can be applied not only to other cold forgings but also to hot forgings.

0010

According to the present invention, since the hole 3 is previously provided in the material 1 before forging, the material 1 flows toward the hole 3 during forging, making it difficult to form a bulge in the center of the molded product 2.
The molding pressure against the mold is lowered, and the molded product 2 is more easily released from the mold.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a material before coining in a first embodiment.

FIG. 2 is a cross-sectional view of the material shown in FIG. 1;

3 is a perspective view showing a molded product obtained by coining the material shown in FIG. 1 before edge cutting; FIG.

4 is a perspective view showing a state where the molded product shown in FIG. 3 is edge-trimmed; FIG.

FIG. 5 is a sectional view of the molded product shown in FIG. 4.

FIG. 6 is a perspective view showing a state in which the edges of the molded product are cut after the material is coined in the second embodiment.

7 is a sectional view of the molded product shown in FIG. 6. FIG.

8 is a sectional view showing a state in which a decorative plate and a nail file are fitted into the molded product shown in FIG. 7. FIG.

FIG. 9 is a perspective view showing a conventional material.

FIG. 10 is a cross-sectional view of the material shown in FIG. 9;

11 is a perspective view showing a molded product obtained by coining the material shown in FIG. 9 before edge cutting; FIG.

FIG. 12 is a perspective view showing the molded product shown in FIG. 11 with edges cut off;

FIG. 13 is a sectional view of the molded product shown in FIG. 12.

[Explanation of symbols]

Claims (1)

[Claims] [Claim 1] A forging method characterized by forming a hole (3) in advance in a material (1) before forging, and then pressurizing this material (3) with a die to die forge a molded product (2). Processing methods for various materials.