JPH0231659B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin molding mold and a method for manufacturing the same, and aims to provide a molding mold that can be used very easily and at low cost.

Conventionally, molds for synthetic resin molding, particularly molds used for foam molding, have been manufactured by making a wooden mold, casting a casting from the wooden mold, and processing an aluminum alloy casting. However, if you are producing hundreds of thousands of fish boxes, etc., the above mold manufacturing is fine.
When molding parts related to automobiles, etc., it is sufficient to first mold 20 to 30 sets of parts as prototypes, conduct assembly experiments, and then manufacture the actual mold if it is good. The same molds as the actual molds were used for the 30-set trial production stage, which had the disadvantage of requiring a large amount of cost and production time.

Therefore, in this invention, we have invented a molding mold and its manufacturing method that make it possible to reduce the costs and manufacturing time required in the conventional methods. A feature of the mold is that the part facing the molded product has a thin film formed by spraying metal, and a reinforcing layer made of FRP or the like is formed on the outside of the film.

Next, as a method for manufacturing a molding mold, a cavity mold and a core mold may be manufactured separately, but in the case of the present invention, a removable mold made of plaster or other material having the same or approximately the same shape as the molded product is used. Separate the parting part of the cavity mold and core mold with a partition material with the inner side, and form a thin film by metal spraying on the part facing the molded product surface, and then apply FRP etc. on the above film. After coating the reinforcing layer and curing it, remove the partition material from the parting area, divide it, and take out the inner removable mold to create a cavity consisting of a thin coating made by metal spraying and a reinforcing layer made of FRP, etc. It is characterized by forming a mold and a core mold, respectively.

The above-described mold according to the present invention will be exemplified below with reference to the drawings, along with embodiments of the above-described manufacturing method which is suitable as a method for providing the same.

Reference numeral 1 is a removable mold made of plaster that has the same or approximately the same shape as the molded product to be molded, and is preferably made about 1/100 times larger because it will shrink. Wooden molds may also be used instead of plaster.

During mold manufacturing, the mold 1 for removal is placed on the inside. The parting area between the cavity mold and the core mold is separated from the beginning by partition plates 2 and 2' made of thin metal plates or the like (see FIG. 1).

Next, metal thermal spraying with aluminum is applied to the half side of the removable mold 1 that is partitioned by the partition members 2 and 2', which will become the molded product surface.
A thin film A of ~3 mm is formed (see Figure 2).

Then, a reinforcing layer B made of FRP (glass fiber reinforced plastic) having a thickness of 8 to 15 mm is formed on top of the film A (see FIG. 3).

As the reinforcing layer B, a reinforcing layer B made of concrete may be formed instead of the above-mentioned FRP, and it can be manufactured at low cost, but it will be inferior in terms of workability and strength of steam holes, etc., which will be described later.

After the reinforcing layer B has hardened, the removable mold 1 is turned over, and a thin film A' is formed by metal spraying in the same manner as above on the part that will become the molded product surface on the opposite half (see Figure 4), and then FRP is applied. The reinforcing layer B' is formed in the same manner as described above (see FIG. 5).

After curing, the partition material 2 at the parting location,
When the inner removable mold 1 is separated from point 2' and taken out to the outside, molding molds M and M', which will become the cavity mold and core mold, are formed with thin coatings A and A' made by metal spraying and FRP, respectively. A structure having reinforcing layers B and B' will be provided (see FIG. 6).

In addition, coating A sprayed with aluminum,
The surface of the molded product A' is polished, steam injection holes C and C' are drilled, and raw material filling holes D are drilled in a part of the molded product surface.

In the above case, the case of metal thermal spraying using aluminum has been described, but any material can be used as a coating material, such as iron, copper, or SUS (stainless steel) as long as it becomes a wire rod that can be easily thermally sprayed.

To give an example of the molding method using the molding molds M and M' manufactured as described above, after the molds are clamped with bolts 3 etc. (see Fig. 7), from the filling hole D of the raw material. The mold is filled with expandable thermoplastic resin particles such as polystyrene as a raw material, and then the filling hole D is plugged with a stopper 4, and in this state it is placed in an autoclave 5 or the like and heated and molded. (see figure), it is very easy to use and can be particularly suitable for prototyping automobile-related parts using foamed molded products.

The synthetic resin molding mold according to the present invention described above has a very simple and lightweight structure and is easy to handle and use, and is particularly suitable for molding 20 to 30 sets of prototypes. According to the manufacturing method for molding, there is no need to make molds using aluminum castings, molds can be manufactured easily, mold manufacturing costs are significantly reduced, and the delivery time for prototypes has been reduced from the conventional three months to approximately This will shorten the time to about two weeks.

Therefore, the molding die and the method for manufacturing the same according to the present invention can greatly contribute to synthetic resin molding, especially prototype production by foam molding.

[Brief explanation of drawings]

The figures illustrate embodiments and usage examples according to the present invention, and FIGS. 1 to 6 are schematic cross-sectional views showing the manufacturing process, and FIG. 7 is a schematic cross-sectional view showing the state before filling raw materials when using a mold. FIG. 8 is a schematic sectional view showing the process of molding using a mold. 1...Removable mold, 2, 2'...Partition material, A,
A′……thin film by metal spraying, B, B′……
Reinforcement layer made of FRP etc., M, M'... mold for molding.

Claims (1)

[Claims] 1. A mold for molding a synthetic resin, characterized in that the part facing the molded product is formed with a thin film by metal spraying, and a reinforcing layer made of FRP or the like is formed on the outside of the film. A mold for synthetic resin molding. 2 With a removable mold made of plaster or other material of the same or approximately the same shape as the molded product inside, separate the parting area between the cavity mold and core mold with a partition material, and spray metal on the part facing the molded product surface. to form a thin film, and further on the above film.
After forming and curing a reinforcing layer made of FRP, etc., remove the partition material from the parting area, divide it, and take out the inner removable mold. 1. A method for manufacturing a synthetic resin molding mold, comprising forming a cavity mold and a core mold, respectively. 3. A method for manufacturing a synthetic resin molding mold according to claim 2, using a wooden mold as the removable mold. 4. The method for manufacturing a mold for synthetic resin molding according to claim 2, wherein metal spraying is performed on aluminum, iron, copper, SUS, etc.