JPS60177931A - Production of casting mold - Google Patents

Abstract

PURPOSE:To prevent deformation of a pattern, etc. by heating and to improve irradiating efficiency in curing of a casting mold using electromagnetic microwave irradiation by forming a shielding layer which reflects electromagnetic microwaves on the surface of the pattern or molding material consisting of a wooden material, etc. susceptible to thermal deformation. CONSTITUTION:An electromagnetic wave shielding copper or nickel paint 8 which reflects electromagnetic waves 9 is coated on a pattern 5 consisting of a wooden material, etc. susceptible to thermal deformation or in some cases, the surface of a wooden molding board 5 and molding flask 4. The electromagnetic microwaves 9 in the irradiating chamber are reflected by said paint and the wooden part 5 is not heated by said waves and therefore the wooden material part is kept free from deformation. The curing of molding sand 6 by heating is further accelerated by the reflection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a mold, and particularly to a method for manufacturing a mold by heating and curing sand using two microwaves.

[Technical background of the invention and its problems]

When making molds, it is known to accelerate hardening by applying electromagnetic waves (or microwaves) to foundry sand filled in the mold.

This method is as shown in Figure 2. The microwave generator 1 and the irradiation chamber 3 are connected by a waveguide 2, the ffi L device is installed, and the inside of this irradiation chamber 3 (the two devices are The molding sand 6 in which the model 5 is buried is irradiated with microwaves. 4 is a casting flask, and 7 is a surface plate.

However, when the model 5 is made of a material that is highly thermally deformed, such as wood, the model 5 is heated and dried by the microwaves that have penetrated into the sand, causing the model 5 to deform.

Therefore, the Kotobukikan of Imo-type 5 was short and the dimensional accuracy of the sand mold was reduced.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing a mold that maintains the original shape of the model even when exposed to microwave irradiation and allows the model to saponify for a long time.

[Summary of the invention]

The above purpose? In order to achieve this (2), the present invention is characterized by forming a shield layer that reflects electromagnetic microwaves on the surface of the model, and irradiating the molding sand in which the model is buried with microwaves. This is to prevent it from affecting the Kaoru model.

[Embodiments of the invention]

An embodiment of the U sewage invention will be described with reference to the drawings.

FIG. 2 shows a mold made according to the present invention (2), in which a shielding layer 8 for microwaves 9 is formed on the surface of a model 5 made of wood (and this model 5 is It is placed on a metal surface plate 7. It is further surrounded by a metal casting flask 4, and the inside is filled with molding sand 6.

The mold constructed as described above is placed inside the irradiation chamber 3 as shown in FIG. 1, and the molding sand 6 is heated and hardened by irradiation with microwaves.

Here, the shield layer 8 will be described in detail. This layer may be one that reflects electromagnetic waves to shield it, and a suitable treatment method is to coat it with a conductive paint. Does conductive paint mainly contain copper as a conductor? A variety of products using nickel and those using nickel are in practical use. Among others &i
In the case of using Y, the conductivity of copper is close to that of silver and about four times that of nickel, so it has a great electromagnetic shielding effect. Copper yarn electromagnetic shielding system is, for example, Sprayrat [product name:
Nikkei Kagaku Co., Ltd.] and EM-9500 [Dainippon Ink Co., Ltd.]. Examples of nickel-based electromagnetic shielding paints include 15OLEX (Nippon B Chemical Co., Ltd.) and Chemitite CT-240 (trade name Ni-Toshiba Chemical Co., Ltd.).

Next, the effect will be explained. As mentioned above, when microwaves hit the model 5 on which the shield layer 8 is formed, the microwaves are reflected by the shield layer 8 (2) and do not penetrate into the model 5. Therefore, the model 5 is not heated and does not deform. Furthermore, there is an advantage that the reflected waves of the microwave 9 further accelerate the hardening of the molding sand 6.

Further, since the casting flask 4 and the surface plate 7 are made of metal, they reflect microwaves and are not deformed.

In addition, when making a casting flask 4 and a fixed '1lI7'2 wood,
The surface may be treated with a conductive paint.

〔Effect of the invention〕

As described above, according to the present invention, even when a material such as wood that undergoes large thermal deformation is used for the model, there is no deformation due to microwaves, the life of the model is maintained long, and it is extremely effective for producing large lids.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a molding sand hardening device using microwaves.
FIG. 2 is a sectional view of a mold showing a state in which the mold manufacturing method according to the present invention is being carried out. ■... Microwave generator, 3... Irradiation chamber, 4... Casting flask, 5... Model, 6... Foundry sand, 7... Surface plate, 8... Shield layer, 9...Microwave. Agent: Patent Attorney Noriyuki Tane (and 1 other person) Figure 1 Figure 2

Claims (1)

[Claims] In a mold manufacturing method in which a vFl mold made of a thermally deformable material such as wood is hardened with molding sand, electromagnetic microwaves are irradiated to heat and harden the molding sand.
i4 Model Electromagnetic microwave on the model surface? A method for manufacturing a mold characterized by forming a reflective shield layer.