JPH0526574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a mold for use in a press machine.

BACKGROUND TECHNOLOGY A conventionally used press mold is mainly composed of an upper mold 1, a lower mold 2, and a blank holder 3 inserted between the two, as schematically shown in FIG. A workpiece 4 is press-molded by moving an upper mold 1 and a lower mold 2 relatively close to each other and separating them from each other.

Usually, castings are often used as the upper mold 1 and the lower mold 2, and after casting a casting having the desired shape by a means called the film molding method, tracing and finishing are performed to form a mold with a smooth surface. I try not to get it.

Problems to be Solved by the Invention However, according to such a conventional method of manufacturing a mold for a press machine, an extremely large number of steps are required to complete the mold, and material is wasted. This has problems in terms of time and cost. In other words, since the casting surface obtained by molding is rough, the surface must be finished with a grinder and polished with a whetstone after going through the steps of rough machining, intermediate finishing, and final finishing. Therefore, the number of man-hours required to complete the process is extremely large. Furthermore, castings have the property of shrinking at a predetermined rate when cooled after casting, and in particular, in the example of the lower mold 2 shown in Fig. 7, the shrinkage rate in the longitudinal direction is high. The dimensions of the casting must be set larger to account for the shrinkage rate. Therefore, it is difficult to control the dimensions during manufacturing, and the outer surface of the casting must be cut before the mold is completed, resulting in material waste.

Therefore, the present invention solves the problems that conventional casting molds have, as described above, and shortens the process.
The purpose is to obtain a casting mold with a good finish.

Means to solve the problem Small block pieces that have been precisely divided and cast in advance using separate molds are assembled and fixed together without performing a finishing process, and the spaces created in the adjacent parts of each small block piece are It has a structure filled with spacers.

Function Small block pieces can be manufactured by applying the precision casting method, and surface treatment of the casting surface can be omitted; however, after the small block pieces are collectively fixed, shrinkage after casting occurs The spacer also makes it possible to fill the space created between the adjacent small block pieces, and a split casting mold with no external gaps can be obtained.

Embodiments The structure and manufacturing means of a split casting mold according to the present invention will be explained below with reference to the drawings.

Fig. 1 shows small block pieces 11a, 1 that have been cast in advance by precision casting using separate molds.
1b,... is shown, and this small block piece 11
a is composed of a main body 13a and a base 14a. The main body 13a and the base 14a are integrally formed, and the base 14a is formed longer than the main body 13a by a distance ρ in the longitudinal direction to cover shrinkage after casting. The above-mentioned precision casting method is a casting method using a wax mold, and can be applied when the shape of the casting has a relatively small shape such as the above-mentioned small block piece, and the surface condition after casting is is an extremely good method. Small block piece 11 obtained in this way
a, 11b... as shown in FIG. 2, the board 12
are assembled and fixed on top of each body 13a, 13b,
Spacers 15, 15, .
is completed. The spacers 15, 15 are suitably made of high-density thermoplastic or thermosetting synthetic resin, but they can also be fixed by interposing a metal plate with a thickness selected in advance. Small block piece 11
Any method may be used to assemble and fix the blocks 11a, 11b, etc., but for example, tightening bolts (not shown) or the like may be used to secure the board 12 and each of the small block pieces 11a, 1.
The base portions 14a to 14e of 1b may be fastened and fixed to the board 12.

FIG. 3 shows another embodiment of the present invention, in which a spacer 15 is filled between the small block pieces 11a, 11b as in the previous embodiment, while the bases 14a, 14b of each small block piece 11a, 11b... Long holes 16, 16, .
The structure is such that a synthetic resin 15a forming the structure is injected and solidified. By adopting such a mold structure, each small block piece 11a, 11b and the spacer 1
A mold 11 with increased bonding strength between the mold 5 and the plate 12 is obtained.

The casting mold 11 thus obtained was placed in the fourth
By fixing it to the upper part of the lower mold 2 as shown in the figure, a press apparatus using the split casting mold according to the present invention can be obtained. The method for fixing the casting mold 11 is as follows:
In addition to the structure shown in Fig. 4, as shown in Fig. 5,
A part of the casting mold 11 may be fitted into the recess 2a provided in the lower mold 2 and fixed therein. Furthermore, casting mold 11
can be applied not only to the lower mold 2 but also to the upper mold 1.

Effects of the Invention As explained in detail above, the casting mold according to the present invention is produced by precisely dividing and casting in advance using separate molds, and by assembling and fixing small block pieces that are not subjected to a finishing process. The feature is that spacers are filled in the spaces created adjacent to each block piece, making it possible to eliminate the various surface finishing processes required when manufacturing conventional casting molds, making it easier to manufacture. In addition to shortening the time required, it is possible to reduce costs. Also, by making the base of each block piece longer in advance in anticipation of the shrinkage rate after casting each block piece,
It is possible to control the total length of the mold obtained by collectively fixing it to the board to a predetermined size, and the spacer filled in the space created in the adjacent part of the block body makes it possible to smooth the mold surface. Since it can be measured, a mold with a good external shape can be obtained. Furthermore, since no material is wasted when casting each small block piece, material costs can also be saved. Furthermore, it has many advantages such as easy control of the manufacturing process and good dimensional accuracy of the completed mold, so it can be used to great effect in molds for various molding press machines.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a small block piece forming a divided casting mold according to the present invention, FIG. 2 is a perspective view showing the divided casting mold as a whole, and FIG. 3 is a perspective view showing another embodiment of the present invention. FIG. 4 is a sectional view of an essential part showing an example of a press apparatus using a casting mold according to the present invention; FIG. 5 is a sectional view of an essential part showing another embodiment of the present invention; FIG. 6 is a schematic sectional view showing an example of a conventional press device, and FIG. 7 is a partial perspective view showing an example of a conventional lower die. 11... Casting mold, 11a, 11b... Small block piece, 12... Board plate, 13a to 13e... Main body, 14a
~14e...Base, 15...Spacer.

Claims (1)

[Scope of Claims] 1. A press device that molds a workpiece into a desired shape using a pair of molds that are composed of an upper mold and a lower mold that are relatively close to each other and move away from each other, the mold comprising: It is characterized by the fact that small block pieces that are precisely divided and cast in advance using separate molds and that do not undergo a finishing process are assembled and fixed together, and that spacers are filled in the spaces created in the adjacent parts of each block piece. Split casting mold.