JPH04210844A - Manufacture of clamping work tool like pliers, etc. - Google Patents

Abstract

PURPOSE:To offer the manufacturing method of a clamping work tool excellent in mass-production by forming a curving inclining part at the inside of a clamp in a press semi-product and pressing it in the condition laying this inclining part upward and abutting back face of the clamp on the insert bottom part of R face in a press die. CONSTITUTION:The insertion bottom part in a press die inserting and abutting the back face 2a of clamping part 2 in the press semi-product (a) is formed as a radius face state. The press semi-product (a) is punched out to a shape having width a little larger than the prescribed shape of clamping part 2. The curving inclining part 4 is formed at the inside of the clamping part 2 in the semi-product (a) formed in such a manner. This curving inclining part 4 in the clamping part 2 is turned to upside and the back face 2a in the clamping part 2 is abutted on the insertion bottom part, and this is pressed from upper part to form the clamping part 2 having clamping width L thicker than plat thickness of the raw material. By this method, the prescribed shape of clamping part can be finished finely.

Description

[Detailed description of the invention]

[00011

[Industrial Field of Application] The present invention relates to a method for manufacturing a clamping tool such as pliers that can be mass-produced. [0002] Conventionally, pliers have been manufactured using a combination of die forging and machining, which has made mass production impossible, and the cost of the product has increased accordingly. [0003]Recently, as shown in Figure 7, pliers have been mass-produced by press processing using plate material as a material, but in this press product, the clamp width of the clamp part (clamping part) is the same as the plate thickness. Because of this, the width is narrow (1/1 of forged products)
2 or less), this causes the object to wobble when clamped, making it impossible to securely and stably clamp the object. [0004] Furthermore, if the clamp width is narrow, there is a drawback that the product value is diminished. [0005] Furthermore, in the past, for example, Japanese Patent Application Laid-Open No. 1983-1976
As shown in Publication No. 235, a manufacturing method has been developed to mass produce clamping work tools such as pliers, pliers, and nippers that are pressed products but have a wider clamp width and exert the same clamping force as forged products. ing. [0006F

[Problems to be Solved by the Invention] In the conventional press working method, as shown in Fig. 8, the clamp part is inserted into the press mold with its back side facing the bottom, and pressure is applied from above to produce a material with a thickness that is thicker than the thickness of the material. The clamp is bulged and has a clamp width of . (0007) However, at this time, the material plate must be bulged to about twice the size only in one side direction, so there is a drawback that the composition structure of the press-formed clamp part becomes non-uniform; Because of this, the molded clamp part inevitably bends toward the front side in a U-shape as shown by the imaginary line in Figure 8, and as shown in Figure 9, a crack K (seam fault) appears as a trace of this bending in the clamp. There was a drawback that the product remained on the front surface of the part, resulting in inferior commercial value.
As in Publication No. 5, we gave up on such a "one-way bulging means" using a press, and the process was complicated, but the clamp part was bulged out from the center of the material plate from the center of the material plate by 1 degree. The clamp part was bent and deviated by /2, and the clamp part was bulged in both directions on the inner side and the back side to form a clamp part having a clamp width thicker than the thickness of the material plate. [00091] In view of the current situation, the present invention simply punches a part into a shape slightly wider than the predetermined shape of the clamp part, bends and slopes it slightly in one direction, and presses it with a press die with an R-shaped bottom. By molding, press molding is performed using a method similar to the "unidirectional expansion means" which is completely different from the above-mentioned Japanese Patent Application Laid-Open No. 60-76235, and the structure does not become non-uniform, and the front surface of the clamp part after molding. There are no cracks on the side (
The present invention provides a method for manufacturing a clamping work tool such as pliers that does not cause seam faults. [00101 [Means for solving the problem] Handle part 1 from the material plate
When cutting out a set of press semi-finished products a in which the clamp part 2 and the clamp part 2 are integrated, the clamp part 2 has a predetermined shape in order to obtain a clamp width that is thicker than the material plate thickness. The handle part 1 of the pressed semi-finished product a is cut out into a shape slightly wider than the above, and the handle part 1 of the pressed semi-finished product a is pressed to form a handle part 2 of a predetermined shape and a clamp part 2 having a clamp width that is thicker than the thickness of the material plate. In the method for manufacturing a clamping work tool such as pliers, the press semi-finished product a is assembled into a product A by assembling the two sets of press finished products in a conventional manner so as to be able to open and close freely. Clamp part 2
The insertion bottom 3 of the press mold B, which the
Clamp part 2 of press semi-finished product a formed into a planar shape and die-cut into a shape slightly wider than the clamp part of the predetermined shape.
The inner part 2b of the clamp part 2 is bent and inclined, the bent inclined part 4 of this clamp part 2 is placed on the upper side, and the back surface 2a of the clamp part 2 is brought into contact with the insertion bottom part 3 and pressed from above to make the wall thicker than the material plate thickness. A method of manufacturing a clamping work tool such as pliers, characterized by forming a clamp portion 2 having a clamp width of (
It is related to this. [00111] [Operation] As shown in FIG. 5, the back surface 2a of the clamp part 2 of the press semi-finished product a is brought into contact with the insertion bottom part 3 of the press mold B, and the folded inclined part 4 of the clamp part 2 is placed on the upper side. As shown in FIG. 6, a clamp portion 2 having a clamp width thicker than the thickness of the material is formed by pressing from above. [0012] During this pressing, a bending slope portion 4 is formed on the upper side.
is formed, so it is pressed and bent toward the inclined side, and the lower side is in contact with the two-sided insertion bottom 3, so it is pressed and bent along this two-sided insertion bottom 3. Go. [0013] Because of this pressing and bending action on both the upper and lower sides, it is pressed in a rounded state, so it cannot be folded into a simple U-shape as shown in Fig. 8 mentioned above. Therefore, the clamp portion 2 of a predetermined shape can be finished neatly without leaving any cracks K as shown in FIG. [0014] [0014] As shown in Fig. 1, when cutting out the die, it is desirable to cut out the die so that the bent inclined part 4 is formed on the inside of the clamp part 2 in advance. (0015) The press semi-finished product a with the bent inclined portion 4 formed in this way is finished into a press finished product as shown in FIG. 2 (the non-slip teeth 5 are also press-molded together), and the shaft hole 6 etc., to finish the product A as shown in Fig. 4. [0016] The shape of the insertion bottom 3 of the press mold B, the bending degree and shape of the bending inclined part 4, etc. are determined by repeating experiments as appropriate. It is desirable to set the dimensions to the optimum size. [0017] In addition, the press die B shown in this embodiment is provided with side molds that are slidable so that it can be easily taken out when taking out the finished press product. [0018 ]

[Effects of the Invention] The present invention can be achieved by simply inserting it into a mold and pressing it, similar to the one-way expansion means that was previously abandoned due to product deterioration (consistency of product value 1'afi due to cracks). This makes it a method for manufacturing clamping work tools such as pliers that is extremely mass-producible. [00,19] In addition, in the present invention, when pressing the clamp part, since the bending slope part is formed on the upper side, it is pressed and bent to the inclined side, and the lower side has a two-sided shape. Since it is in contact with the insertion bottom, it is pressed and folded along this two-sided insertion bottom, and due to the pressing and bending action on both the upper and lower sides,
Since it is pressed in a rolled-up state, it is not simply folded into a U-shape as shown in Fig. 8, and is folded into a predetermined shape without leaving any cracks K as shown in Fig. 9. The clamp part will be finished neatly.

[Brief explanation of the drawing]

[Figure 1] Perspective view of semi-finished pliers product

[Figure 2] Perspective view of completed pliers

[Figure 3] Perspective view of completed pliers with shaft hole attached

[Figure 4] Perspective view of pliers product

[Figure 5] Explanatory diagram of the state inserted into the press mold

[Figure 6] Explanatory diagram of pressed state

[Fig. 7] Explanatory diagram of a conventional pressed product

[Fig. 8] An explanatory diagram of a press performed using a conventional unidirectional expansion means.

[Fig. 9] A plan view of a completed pressed product showing cracks when the conventional unidirectional expansion means is used.

[Explanation of symbols]

A Product B Press type L Clamp width a　Press semi-finished products b　Press finished product ■　Handle part 2 Clamp part 2a Back side of clamp part 2b Inside part of clamp part 3 Insertion bottom 4　Folding slope part

Claims (1)

[Claims] Claim 1: When cutting out a set of two press semi-finished products with a handle part and a clamp part integrated from a material plate,
In order to obtain a clamp width L that is thicker than the thickness of the material plate, the clamp part is die-cut into a shape that is slightly wider than the clamp part of a predetermined shape, and the handle part of the pressed semi-finished product is pressed into a handle of the predetermined shape. Pliers, etc. that form a clamp part with a clamp width L that is thicker than the thickness of the material plate to form a pressed finished product, and then assemble the two pressed finished products in a conventional manner so that they can be opened and closed to make a product. In the method for manufacturing a clamping work tool, the insertion bottom of the press die into which the back surface of the clamp part of the press semi-finished product is inserted and abutted is formed into an R surface shape, and has a shape slightly wider than the clamp part having the predetermined shape. The inside part of the clamp part of the pressed semi-finished product that has been cut out is bent and tilted, and the folded and tilted part of this clamp part is placed on the upper side, and the back of the clamp part is brought into contact with the bottom of the insertion part and pressed from above to make the material thinner than the thickness of the material. A method for manufacturing a clamping work tool such as pliers, which comprises forming a clamp portion having a clamp width L that is thick.