JP2001246445A - Precision casting method using ice pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing precision casting parts only by using the ordinary water and an inexpensive mold. SOLUTION: The water is poured into a synthetic resin-made mold, in which the reverse outlines corresponding to the outlines of the parts are recessedly arranged as plural cavities, and this water in the mold is frozen in a freezing chamber to form ice patterns. The ice patterns are taken out by disassembling the mold and these are dipped into a slurry having suspended fine powder of refractory, and after coating the slurry film on the surface of the ice pattern, these are taken out from a vessel and dried. A refractory-made mold formed by repeating such works of prescribed times, is carried out from the freezing chamber and the ice patterns in the mold are melted and eliminated when these are left in a room temperature. After burning the mold formed as the cavity state in a burning furnace, molten metal is poured into the cavity. After cooling, cast parts are cut off from a sprue and runners and carried out to a prescribed finish process to manufacture a necessary product.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a precision casting method, and more particularly, to a precision casting method using an ice pattern.

A precision casting method conventionally used industrially is a lost wax precision casting method using a wax pattern, and is also called a dewaxing casting method. In this lost wax precision casting method, a large number of wax patterns molded under pressure in the molten state according to the contour of the required metal parts are used to form a hot block into a wax block consisting of sprues and runners. The tree is molded by welding and used, and the tree is immersed in a slurry in which refractory powder is suspended, the slurry is coated on the surface of the tree, and the tree is pulled up from a tank of the solution containing the slurry and dried. By repeating such operations a predetermined number of times, a refractory mold is formed, the mold is dewaxed in a high-temperature atmosphere, and the hollow refractory mold is fired in a high-temperature furnace. The molten metal is poured into the mold cavity of the refractory mold, and after cooling, the cast metal part is cut off from the sprue and runner and subjected to predetermined finishing. To have. When producing many small parts, industrial synthetic resins are used instead of wax.

[0003] In carrying out the conventional lost wax precision casting method, an expensive wax that is disposable for each dewaxing process and an expensive wax that is formed by molding a melted or semi-molten wax under high pressure. Metal molds, expensive injection molding machines operated at high pressure, expensive dewaxing equipment, etc. are required, so that equipment costs are increased and production costs of necessary parts are inevitably increased. Could not.

According to the present invention, a conventional lost wax precision casting, which could not be produced at a low cost, uses ordinary water, and a plurality of patterns having required contours are used in a freezer using a mold. An ice pattern is formed by freezing an inexpensive mold without immersion in a slurry in which a refractory is suspended on the surface of the ice pattern, and the slurry is attached to the surface of the ice pattern, The pattern of the attached ice is pulled up from the tank containing the slurry and dried, and a mold of a refractory is formed by repeating such operations a predetermined number of times, and the mold is taken out of the freezing room and kept at room temperature. Precision casting that melts the ice in the mold, removes it from the mold, burns, injects, cuts, and finishes the molten metal at high temperature. It is intended to provide the law. According to the present invention, since an expensive wax, an expensive mold, an expensive injection molding machine, an expensive dewaxing device, and the like are not required, required parts can be manufactured at very low cost.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings illustrating preferred embodiments of the present invention. In FIG. 1, for example, a plurality of cavities 2 and 2 ′ having opposite contours corresponding to the contours of required components are recessed in substrates 1 and 1 ′ made of synthetic resin, and mold halves 3 and 3 are formed. 'Are assembled together to provide a mold 4 for making a pattern. Water is poured into the mold 4, the mold 4 is carried into a freezer (not shown), the water is frozen, and the mold 4 is decomposed to form an ice pattern. The ice pattern thus formed is immersed in a slurry prepared by suspending the refractory, and a film of the slurry is adhered to the surface of the ice pattern. A tank for storing the pattern slurry (not shown)
Take out and dry in the freezer. By repeating such operations a predetermined number of times, a mold of a refractory is formed.

[0006] The refractory mold thus produced is taken out of the freezer and left standing at room temperature while being held upside down. With time, the ice pattern in the mold melts and falls off the mold and disappears. The mold in the hollow state is fired in a firing furnace (not shown), and after a predetermined time, a molten metal of high temperature is poured into the cavity of the mold. After cooling, the part of the part is cut off from the sprue and the runner and sent to a predetermined finishing step.

As is apparent from the above description, expensive wax, expensive metal molds for injection molding, expensive injection molding machines operated under high pressure, expensive dewaxing equipment and the like are required. Instead, the present invention can be carried out only by using water and an inexpensive mold, so that required precision parts can be manufactured at a significantly low cost.

FIG. 2 is a cross-sectional view of the mold 4 taken along a vertical plane to facilitate understanding of the present invention. 1
And 1 ′ are substrates, instead of metal materials, for example,
It is made of synthetic resin. 2 and 2 'are cavities recessed in the substrates 1 and 1', and 3 and 3 'are paired mold halves. Guide pins 5 and 5 'are provided at each corner of the mold halves 3 and 3' so that they can be accurately combined with one another. After separating cavities 2 and 2 ', an ice pattern (not shown) is removed from cavities 2 and 2'. Without using tool steel with high hardness, the mold 4 is manufactured using a synthetic resin plate, rod, etc. and using an adhesive, so the mold 4 is replaced with a conventional molding mold using steel. It can be manufactured at a significantly lower price.

[Brief description of the drawings]

FIG. 1 is an exploded top plan view of the mold used to carry out the method of the present invention in an open state.

FIG. 2 is a cross-sectional view of the mold cut along a vertical plane.

[Explanation of symbols]

 1, 1 'substrate 2, 2' cavity 3, 3 'mold half 4, mold 5, 5' guide pin

Claims (1)

[Claims] 1. A slurry prepared by suspending a fine powder of a refractory having a pattern having an opposite contour corresponding to the shape of a desired part molded in a mold by freezing water in a freezer. The pattern of ice coated with the slurry is pulled up from the suspension and dried in the freezer, and then the above operation is repeated a predetermined number of times, and the pattern of the refractory dried from the freezer is removed. Take out and hold at room temperature to melt and eliminate the ice pattern to form a mold, bake the mold in a high temperature atmosphere, and melt in the high temperature fired mold Using an ice pattern characterized by the steps of pouring molten metal and cutting, after cooling, the parts from sprues and runners, and separating them to achieve the required finishing. Precision casting method used.