JPH0523790A - Manufacture of lost foam pattern - Google Patents

Abstract

PURPOSE:To provide the manufacture for lost foam pattern precisely holding a filmy formed body to the prescribed position in a hollow part in a foaming formed mold to manufacture of the lost foam pattern having the prescribed thickness. CONSTITUTION:At first, the filmy formed body 1 composed of consumable material having the prescribed shape, is formed with a forming mold. Successively, the above filmy formed body 1 is set in a foaming formed mold 9 providing the hollow part 11 having the prescribed shape. Then, supporting members 8 composed of the consumable material for holding gap between a hollow part 11 in the foaming formed mold and the filmy formed body 1 to the prescribed interval, are set. Further, at the time of manufacturing the lost foam pattern providing the prescribed hollow part by packing and foaming the foaming beads between the hollow part 11 in the foaming formed mold and the filmy formed body 1, position of the filmy formed body 1 is not unnecessarily moved and the lost foam pattern having the prescribed shape can be always manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a disappearing model, and more particularly to a method for forming a disappearing model having a predetermined shape by preventing movement of a film-shaped molded body during foam molding.

[0002]

2. Description of the Related Art As one of methods for producing a disappearing model, there is a method of forming a disappearing model using a film-shaped molded body made of a disappearing material. In this manufacturing method, first, a film-shaped molded body made of a fusible material having a hollow portion of a predetermined shape is molded. The film-shaped molded product is made of a fusible material (for example, polyethylene, polypropylene, etc.) and is a hollow product molded by blow molding or the like, the inner surface of which is formed into a predetermined shape of the inner surface of the hollow part of the product casting. Has been done. Next, a vanishing model is manufactured using the formed film-shaped molded body. The foaming mold is provided with a hollow portion having a predetermined shape, and the film-shaped molded body is placed in the hollow portion.

Then, while filling the inside of the hollow portion with foamed beads through a blowing port, for example, 1.2 kg / cm at 120 ° C.
Blow about ² steam to expand the foam beads and mold the vanishing model. When the vanishing model is formed, the foamed resin portion and the film-shaped molded body are joined together, thereby forming one vanishing model.

[0004]

In the case of the disappearing model manufacturing method using such a film-shaped molded product, there are the following problems. First, the film-shaped molded product is a thin film formed by blow molding a fugitive material, and is extremely lightweight. For this reason, there is a problem that the film-shaped molded product moves in the hollow portion when the film-shaped molded product is placed in the hollow portion of the foaming mold and foam-molded. That is, when the foamed bead is filled in the hollow part of the foaming mold and steam is blown in, the film-shaped molded body moves from a predetermined position, and the foaming is performed in that state, whereby the wall thickness of the disappeared model is reduced. It fluctuated carelessly. In particular, when the film-shaped molded product was supported by one side and foam-molded, it was easy to move.

The present invention has been made on the basis of such a point, and an object thereof is to accurately hold a film-shaped molded product at a predetermined position in the hollow portion of a foaming mold to eliminate a predetermined wall thickness. It is an object of the present invention to provide a method for manufacturing an extinguishing model, which makes it possible to manufacture a model.

[0006]

In order to achieve the above object, the method for producing a disappearing model according to the present invention comprises forming a film-shaped molded body made of a fusible material having a hollow portion of a predetermined shape, and forming the film-shaped molded body as described above. Was placed in a foaming mold having a hollow part of a predetermined shape, and foam beads were filled between the hollow part of the foaming mold and the film-shaped molded product to foam, thereby providing a hollow part of a predetermined shape. A method for producing a disappearance model for producing an disappearance model, characterized in that a support member made of an extinguishing material for holding the hollow part of the foaming mold and the film-like molded body at a predetermined interval is provided. is there.

[0007]

First of all, a film-shaped molded body made of a fusible material having a hollow portion of a predetermined shape is molded by a molding die. Next, the above film-shaped molded product is placed in a foaming mold provided with a hollow portion having a predetermined shape. At that time, a supporting member made of a fusible material for holding the hollow portion of the foaming mold and the film-shaped molded body at a predetermined interval is provided. Then, foam beads are filled between the hollow portion of the foam molding die and the film-shaped molded article to cause foaming, whereby a vanishing model having a predetermined hollow portion is manufactured. The foamed resin portion, the film-shaped molded product, and the support member are joined together to form a vanishing model. With this, when the foam beads are filled between the hollow portion of the foam mold and the film-shaped product and the foam is blown by blowing steam, the position of the film-shaped product does not change carelessly and always has a predetermined shape. Disappearance models can be manufactured.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. First, a film-shaped molded body (shown in FIG. 2) 1 for manufacturing a vanishing model is molded. The film-shaped molded product 1 is made of a fusible material (eg, polyethylene, polypropylene, etc.) and is hollow. At the time of molding the film-shaped molded body 1, the fusible material is placed in the blow molding die 3 as the film-shaped molded body mold shown in FIG.
Blow air etc. through. A hollow portion 7 having a predetermined shape is formed inside the blow molding die 3, so that the fugitive material is molded into a thin film along the shape of the hollow portion 7. The inner surface of the film-shaped molded product 1 is formed into a predetermined shape of the inner surface of the product casting.

Next, the support member 8 is previously attached to the above-mentioned film-shaped molded body 1. The support member 8 is made of a fusible material (eg, polyethylene, polypropylene, etc.).
It is formed from and has a rod shape. And
As shown in FIG. 3, the support member 8 is to be attached in a protrusion shape at an appropriate position on the surface of the film-shaped molded product 1. This is because, when the film-shaped molded product 1 is placed in the hollow portion 11 of the foaming mold 9, the mounting position, size, and the like are taken into consideration in advance so that the film-shaped molded product 1 is held at a predetermined position. For example, in the illustrated case, the film-shaped molded body 1 is supported by one side,
The support members 8 are provided at two locations on the free end side of the film-shaped molded product 1, and four support members 8 are projected in each direction toward the hollow portion 11 of the foam molding die 9. The length of each support member 8 is set to the distance between the hollow portion 11 of the foam molding die 9 and the film-shaped molding 1 at the mounting position.

Such a film-shaped molded body 1 is inserted and arranged in the hollow portion 11 of the foam molding die 9 having a predetermined shape. At that time, one side of the film-shaped molded body 1 is supported by the foam molding die 9, and the free end side is held at a predetermined position in the hollow portion 11 by the supporting member 8 (shown in FIGS. 5 and 6).

Next, the inside of the hollow portion 11 is filled with the foam beads through the blow-in port 15 and, for example, at 120 ° C. for 1.
About 2 kg / cm ² of steam is blown into the foam beads to form the extinction model (shown in FIG. 6) 17. that time,
In order to regulate the deformation of the film-shaped product 1, a fluid such as water, air, or oil is supplied to the inside of the film-formed product 1 at a pressure of about 1.2 kg / cm ² in accordance with the pressure of steam. .. Vanishing model 1
At the time of molding 7, the foamed resin portion, the film-shaped molded body 1 and the support member 8 are joined together, and thereby one vanishing model 17 is formed.

After the vanishing model 17 is manufactured, it is taken out from the foaming mold 9 and, as shown in FIG. 6, the protruding portion of the film-shaped molded body 1 is removed to obtain the state shown in FIG. .. Then, as shown in FIG.
Adhere and fix Next, as shown in FIG. 9, the coating mold 20 is applied to the surface. And as shown in FIG. 10, it arrange | positions in the flask 19 and fills the periphery with the molding sand 21, and performs casting. That is, when the molten metal is poured through the runner gate 18, the disappearance model 17 gradually melts and disappears,
Molten metal enters that part. Thereby, FIG.
A casting 22 as shown in 1 is cast. After that, unnecessary parts such as the runner gate 18 are deleted from there to obtain a product 25 as shown in FIG. The hollow portion of the disappearance model 17 is also filled with the molding sand 21.

According to this embodiment, the following effects can be obtained. First, the film-shaped molded product can be accurately held at a predetermined position in the hollow portion of the foaming mold. This is because a supporting member made of a dissipative material is provided, and thereby the film-shaped molded product is held at a predetermined position in the hollow portion of the foam molding die, and therefore the disappearance model always has a predetermined wall thickness. be able to. Further, since the supporting member is made of a disappearing material and becomes a part of the disappearing model and disappears together with the casting, it is easy to handle.

The present invention is not limited to the above-mentioned embodiment. First, as a method of attaching the support member 8, the support member 8 may be integrally molded with the film-shaped molded body 1, or when the film-shaped molded body is placed in the hollow portion of the foam molding die, it is supported separately. The member 8 may be sandwiched.
Further, the material of the supporting member may be any extinguishing material, and may be, for example, foam. Further, the shape thereof is not limited to the rod shape and may be any shape. Further, the position and the number of supporting members are arbitrary, and for example, when the film-shaped molded product is arranged so as to be supported at both ends, it is provided at an intermediate portion to prevent the film from drooping.

[0015]

As described in detail above, according to the method for producing a disappearing model according to the present invention, when the film-shaped molded product is placed in the hollow part of the foaming mold and foam-molded, the hollow part of the foaming mold and the film-like structure are formed. Since the supporting member made of a fusible material is provided between the molded product and the molded product to hold it at a predetermined position, the film molded product can be accurately held at a predetermined position and always has a predetermined wall thickness. Can be produced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a film-shaped molded body showing an embodiment of the present invention.

FIG. 2 is a view showing an embodiment of the present invention and is a cross-sectional view of a film-shaped molded product.

FIG. 3 is a cross-sectional view showing a state in which a supporting member is attached to a film-shaped molded body, showing an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an embodiment of the present invention, showing a state in which a film-shaped molded body is arranged in a hollow portion of a foam molding die.

5 is a view showing a first embodiment of the present invention and is a view taken along the line VV of FIG.

FIG. 6 is a cross-sectional view of the vanishing model manufactured in the drawing showing the embodiment of the present invention.

FIG. 7 is a cross-sectional view of a vanishing model manufactured by the drawing showing an embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a state in which a runner gate is bonded and fixed to a vanishing model in a view showing an embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a state in which a coating mold is applied according to an embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a state of casting in a view showing an embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a product cast by the drawing showing one embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a product cast by the drawing showing one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Membrane-shaped molded body 3 Blow molding die (membrane-shaped molded body die) 8 Support member 9 Foaming molding die 11 Hollow part of foaming molding die 17 Disappearance model

Claims (1)

Claim: What is claimed is: 1. A film-shaped molded body made of a fusible material having a hollow portion having a predetermined shape is molded, and the film-shaped molded body is provided in a foaming mold having a hollow portion having a predetermined shape. In the disappearance model manufacturing method, the foaming bead is filled between the hollow part of the foaming mold and the film-shaped molded article to be foamed to produce a disappearing model having a hollow part of a predetermined shape. A method for producing an extinguishing model, characterized in that a supporting member made of an extinguishing material for holding the hollow portion of the foaming mold and the film-shaped molded article at a predetermined interval is provided.