JPS6142447A - Manufacture of simple die - Google Patents

Abstract

PURPOSE:To manufacture easily and inexpensively a simple die having high accuracy by subjecting the outside surface of a prototype consisting of a low melting alloy to nickel plating and spraying thermally a high melting metal to the outside surface thereof then subjecting the prototype to insert casting with aluminum, etc. and eluting the inside low melting alloy. CONSTITUTION:The prototype 1 provided witha core print 1 is manufactured of the low melting alloy of a tin base or zinc base and the outside surface thereof is subjected to the nickel plating. The high melting alloy is thereafter thermally sprayed to several mm. thickness to the outside surface thereof to reinfoce the plating layer. The prototype 1 after the thermal spraying is set in a sand mold 4 and the melt of aluminum or iron casting is poured thrpugh a sprue 5 into the mold to fill a space part 8. The sand is removed after cooling and the above- mentioned prototype 1 is made into the block shape insert-cast by the aluminum or iron casting. Such block is machined with upper and lower reference planes 10, knock holes, etc. and is then cut and divided by a wire cutter, etc. at the dividing part 9 to cut the core print 2 part. The cur castings are thereafter heated to elute the low melting alloy of the prototype 1 and required mating knock pins 12, mandres 13, etc. are attached thereto, by which the dies are obtd.

Description

[Detailed Description of the Invention] The present invention is a simple mold for the purpose of easily and inexpensively manufacturing molds with complex shapes such as plastic molding molds or aluminum alloy casting molds with high precision. This concerns the manufacturing method.

Conventional simple mold manufacturing methods include the following methods.

(b) A method in which a low melting point alloy is sprayed onto a model made of wood, plaster, metal, etc., and after the model is separated, the sprayed low melting point alloy is used as a mold.

(b) A method of spraying a high melting point metal on a stainless steel base onto a master mold made of a low melting point alloy, and then removing the low melting point alloy and using the sprayed high melting point alloy as a mold.

In method (a), in order for the low melting point alloy of the mold to withstand the clamping pressure of plastic injection molding, it must be reinforced with a machined metal frame. Also, it had to be made in two halves from the beginning, which took an hour and cost a lot of money. In addition, low melting point alloys have drawbacks such as low hardness, low strength, and short lifespan of rounding molds.

Method (b) involves making a prototype from a low-melting point alloy, then spraying it with a high-melting point alloy, and fabricating it in two steps in the same way as method (), which requires the same amount of time and cost. and
Furthermore, since a high melting point alloy is thermally sprayed, the mold surface after the melting of the fusible metal is porous and surface roughness is unavoidable.

The present invention aims to eliminate the above-mentioned drawbacks by using the manufacturing method described in the claims, and is characterized by reducing the surface roughness of the mold and making it mirror-finished. The strength of the mold is greater than that of the conventional method.

It is easy to manufacture.

The manufacturing method will be described below with reference to Examples.

Figure 1 shows the shape of the product. First, as shown in Figure 2, create a wooden mold with the same shape as the product (1) and a core (2) with the same diameter as the product's inner diameter, and use this wooden mold to make a silicone rubber mold. The prototype is made from a tin-based or zinc-based low melting point alloy.

Nickel plating is applied to this surface. Furthermore, a high melting point alloy is thermally sprayed to a thickness of several millimeters to reinforce the plating metal.

After thermal spraying, it is set in a sand mold (4) as shown in FIG. Molten aluminum or iron castings are poured into this sand mold through the sprue (5). The molten metal rises from the sprue (5) at a molten metal speed (7), fills the space (8) and reaches the upstream point V), and the low melting point alloy prototype is cast in the molten metal. After cooling and removing the sand, the result will be as shown in Figure 4.

Next, as shown in FIGS. 5 and 6, the upper and lower reference surfaces (10) are machined to form dowel holes (11) for mold matching after one division. After machining, the divided portion (9) is divided by wire cutting or the like, and the book block (2) portion is cut. This is heated to elute the low melting point alloy, and a pair of dowel pins (12) and a core metal (13) are attached, and the mold is completed.

A sectional view thereof is shown in FIG.

[Brief explanation of drawings]

Figure 1 is an external view of the product. Figure 2 is a prototype drawing for mold production. Figure 3 is a cross-sectional view of the sand mold for mold casting. Figure 4 is an external view after casting. Figures 5 and 6 are processing diagrams. Figure 7 is a cross-sectional view of the completed mold.

Claims (1)

[Claims] (a) Manufactured from a low melting point alloy such as an original tin base or zinc base. (b) Apply nickel plating to its outer surface. (c) A high melting point alloy is thermally sprayed on the outer surface of the plating. (d) Make this into a cast block shape using aluminum casting or iron casting. (e) Cut and divide the predetermined dividing portion using wire cutting or the like. (f) After splitting, the low melting point alloy inside is eluted to create split molds. This invention relates to a simple mold manufacturing method manufactured as described above.