JPH09182938A - Manufacture of mold in precision casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a mold in a precision casting method using a lost foam pattern in a simple process and at a low cost. SOLUTION: A product pattern 3 having a sprue is manufactured by the lost foam material of foaming resin, etc., and fitted into a flask 5 and slurry of an alumina base ceramic 6 is poured into the flask 5. This slurry is burnt and the product pattern 3 is lost to mold a cavity 3a having the same shape as the product pattern 3 in the solidified alumina base ceramic 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a mold in a precision casting method using a vanishing model made of foamed resin.

[0002]

2. Description of the Related Art In a casting method using an extinguishing model, in Japanese Patent Application No. 3-60846, a coating material composed mainly of refractory particles or powder or flakes is applied to the wall surface of the extinguishing model consisting of wax and foamed resin. After disappearing, the vanishing model casting method is generally known in which the vanishing model is buried in the casting sand filled in the frame, and a cast object having a shape corresponding to the vanishing model is cast by the subsequent casting step. It is disclosed.

[0003]

By the way, the transmissions and cylinder covers of automobiles are made of aluminum. It is cast by die casting at the time of production of this, but at the time of trial production, a wooden model of the product model is made,
A sand mold is made from this wooden mold and the shape is solidified to produce an aluminum casting prototype.

However, between the product cast by die casting (mold) at the time of production and the product cast by the sand mold at the time of trial production, product properties such as product dimensional accuracy, material strength and casting surface There was a case that the evaluation of the product did not match due to the difference in surface roughness.

Therefore, when the vanishing model casting method is adopted in the production of the aluminum casting prototype, there is an advantage that a casting product in actual production can be obtained as the casting prototype, but in the conventional vanishing model casting method, , A step of applying a coating material mainly composed of refractory particles or powder or flakes on the wall surface of the vanishing model made of foamed resin, a step of drying it, and embedding this vanishing model in the foundry sand filled in the frame There is a problem that the manufacturing cost of a casting prototype similar to die casting becomes high because it has to go through many troublesome processes.

An object of the present invention is to make it possible to manufacture a mold in a precision casting method using a vanishing model with a simple process and low cost.

[0007]

Means for Solving the Problems The object of the present invention to achieve the above-mentioned object is to make a product model having a sprue from a vanishing material such as foamed resin, and load the product model in a frame. It is characterized in that a slurry having the same shape as the product model is formed in the solidified alumina ceramic by pouring a slurry of alumina ceramic into the frame and burning the slurry to remove the product model.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 (A), reference numeral 3 is a product model, which includes a sprue 1 and a runway 2. The product model 3 including the sprue 1 and the runner 2 is made of a disappearing material such as foamed resin.

As shown in FIG. 1B, the product model 3 is
For example, it is loaded in the frame 5 placed on the surface plate 4,
As shown in (C), the alumina-based ceramic 6 is provided in the frame 5.
Pour the slurry of.

By firing the slurry of the alumina-based ceramic 6 poured into the frame 5, the product model 3 existing in the slurry of the alumina-based ceramic 6 disappears due to heat during firing, as shown in FIG. 1 (D). As described above, the slurry of the alumina-based ceramic 6 is solidified, and the cavity 3a having the same shape as the product model 3 is molded on the solidified alumina-based ceramic 6.

The wall surface of the cavity 3a having the same shape as that of the product model 3 molded on the alumina-based ceramic 6 is a fine smooth surface with little thermal deformation and a high density due to the characteristics of the material of the alumina-based ceramic 6. The sprue 1 which is empty in 3a
By injecting the molten metal from a and pouring it through the runner 2, a cast product in which the dimensional accuracy and the surface roughness of the surface of the casting are similar to those of die casting (die) can be obtained.

According to the above-mentioned method of the present invention, as in the conventional method, a step of applying a coating material mainly composed of refractory particles or powders or flakes to a wall of the vanishing model, a step of drying the same, Only the step of pouring the slurry of the alumina-based ceramic 6 into the frame 5 loaded with the product model 3 made of the disappearing material and the step of firing the same without adopting the step of burying it in the molding sand filled in the frame. Thus, a mold of alumina ceramic 6 is obtained.

[0013]

As described above, according to the present invention, a cast product in which dimensional accuracy, material strength and surface roughness of the surface of the casting are similar to die cast (die) can be obtained by a simple process. A ceramic mold can be manufactured at low cost, and it can be used as a mold for general production, and when casting a trial and error prototype, the mold can be manufactured easily and at low cost. , Has the advantage that a casting product similar to die casting can be obtained during trial manufacture.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of the method of the present invention.

[Explanation of symbols] 1 gate (type) 1a gate (cavity) 2 runner (type) 2a runner (cavity) 3 product model 3a cavity of the same shape as the product model 4 surface plate 5 frame 6 alumina ceramic

Claims (1)

[Claims] 1. A product model having a sprue made of a disappearing material such as foamed resin is loaded into the frame, and an alumina-based ceramic slurry is poured into the frame, and the product model is fired. A method for producing a mold in a precision casting method, characterized in that a cavity having the same shape as a product model is formed on an alumina-based ceramic which is solidified by disappearance of a mold.