JPH0263049B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for manufacturing a press die.

(Prior Art) The applicant of the present application first inserted and set a punch into a recess of a die body, then injected and hardened a resin agent made of hard urethane into the recess, and then punched the punch into the recess. We proposed a system in which a resin mold with the shape transferred is integrally formed.

According to this, troublesome finishing and machining of the inner surface of the recessed part of the die main body and matching work with a punch are no longer necessary, making it possible to significantly reduce costs.

(Problem to be Solved by the Invention) However, in the above-mentioned product, if the punch shape is directly transferred to the resin mold, the resin mold will come into full contact with the blank during press molding, causing a rapid increase in internal stress and decreasing its durability. There's a problem.

An object of the present invention is to provide a die manufacturing method that solves these problems.

(Means for Solving the Problems) In order to achieve the above object, the present invention involves inserting and setting a punch into a recess of a die body, and then injecting a resin other than hard urethane into the recess and curing the punch. In the case where a resin mold having a punch shape transferred thereto is integrally formed in the recessed part, an object is affixed in advance to the shaped part of the punch corresponding to the molded part of the blank punch, and the resin mold is It is characterized in that during formation, a recessed part is formed by transferring the shape of the impurities.

(Example) The present invention will be explained with reference to the illustrated embodiments.

Referring to FIG. 3, 1 is a die, 2 is a punch below the die, 3 is a blank holder fitted onto the outer periphery of the punch 2, and the die 1 is attached downward to an elevating frame (not shown) to form a press machine. The blank W was press-formed by lowering the die 1. In addition, the part marked A in the figure is the punch-fitted forming part where the blank W is pressed by the punch 2 and formed, and the part marked B is the die-fitted forming part where the blank W is pressed by the die 1 and formed. .

Here, the die 1 is constructed by integrally forming a resin mold 5 with a punch shape transferred into a recess 4 of a die body 1a made of FC material. As shown in the first figure, the punch 2 and the blank holder 3 are assembled in a predetermined mold lowered state during press molding, that is, in a shaft height state, and in this case, the punch 2 is housed in the recess 4 with a gap. The recess 4 is formed large in advance,
Next, a resin agent was injected into the recess 4 through an injection port 6 formed in the die body 1a and hardened.

In addition, as a resin agent, for example, the main component is ureol (registered trademark of Nippon Ciba Kaigy Co., Ltd.) 6414A, and the Shore D hardness (IS0868) after curing is 65 ~
70, tensile strength and elongation at break (IS0527) respectively
A hard urethane agent prepared at 40-50N/mm ² and 100-150% is used.

Although the above is not particularly different from the above-mentioned previous proposal, according to the present invention, the shape part of the punch 2 corresponding to the punch-compatible forming part of the blank W, that is, the upper part of the punch 2 in the illustrated one. As shown in FIG. 2, an insert 7 such as sheet wax is pasted in advance on the circumferential surface extending over the shoulder and the upper surface of the protrusion at the top, and the shape of the insert 7 is transferred to this when molding the resin mold 5. The relief portion 5a is recessed.

In the illustrated example, the opening 4a of the recess 4 of the die body 1a is formed to have a relatively small diameter, and the inner circumferential surface of the opening 4a is formed with a predetermined clearance between the outer circumferential surface of the punch 2 and the thickness of the blank W. The molded shape was previously finished, and this clearance was marked with sheet wax 7' or the like attached to the punch 2.

(Function) To explain the function during press forming of the die 1 obtained by the method of the present invention, the blank W is sandwiched between the lower surface of the die body 1a and the blank holder 3 as the die 1 descends, and the blank W As shown in FIG. 3a, the resin mold 5 in the recess 4 of the die body 1a is drawn into a shape that roughly follows the punch shape, and then the resin mold 5 in the recess 4 of the die body 1a is blanked in the part where the punch shape is transferred except for the relief part 5a. W, and in the shaft height state, as shown in FIG. It is pressed upward by the shape portion of the punch 2 corresponding to the shape, and is press-molded into a predetermined shape.

At this time, the portion of the resin mold 5 is compressively deformed to some extent and the internal stress increases, but this stress is dispersed in the relief portion 5a and the internal stress does not increase excessively.

(Effects of the Invention) As described above, according to the present invention, the relief part is recessed in the part of the resin mold corresponding to the punch-compatible molding part that does not particularly require pressing by the resin mold, and the inside of the resin mold is formed during press molding. The stress is dispersed in the relief part, the increase in internal stress is controlled, and the durability of the resin mold is improved.The relief part is also used to transfer the shape of the impurities attached to the punch beforehand when molding the resin mold. This method eliminates the need for post-processing for molding the relief part, and has the same advantages as the previous proposal, such as reducing mold costs.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional side view of a die manufactured by the method of the present invention, Fig. 2 is an enlarged cross-sectional side view of the main parts thereof, and Fig. 3 is a and b, respectively, a press apparatus using a die obtained by the method of the present invention. FIG. 2 is a cutaway side view of the main part of the engine in an operating state. DESCRIPTION OF SYMBOLS 1...Die, 1a...Die body, 2...Punch, 4...Recessed part, 5...Resin mold, 5a...Escape part, 7...Includes.

Claims (1)

[Claims] 1. A resin mold having a punch shape transferred thereto is integrally formed by injecting a hard urethane or other resin into the recess and curing the punch with the punch inserted and set into the recess of the die body, An object is affixed in advance to a shaped part of the punch corresponding to a molded part of the blank that is compatible with the punch, and when forming the resin mold, a recessed part is formed by transferring the shape of the object. A method for manufacturing a press die, characterized by: