JPH0469202A - Production of retaining core material utilized for pressure casting mold - Google Patents

Abstract

PURPOSE:To enhance the dimensional precision of a core material and also to make production and handling easy by manufacturing a pressing mold which is obtained by stereoscopically sketching the shape of a tube for suction and pressurization to be arranged to the inside of a casting mold and covering the surface of the pressing mold with the elastic sheet material having projections provided on the whole surface and coating the outward surface thereof with resin material and curing the resin material and thereafter releasing the pressing mold and the elastic sheet material. CONSTITUTION:A stereoscopic pressing mold 12 is manufactured by intactly sketching the whole shape of a tube 7 for suction and pressurization to be arranged to the inside of a casting mold. The outward surface is covered with the elastic sheet material 13. Many projections 14, 14,... are provided over the whole surface of the outward surface 13a of this elastic sheet material 13. This outward surface 13a is coated with resin body becoming the material for forming the retaining core material 10. After this resin body is cured, the pressing mold 12 and the elastic sheet material 13 are peeled. In this retaining core material 10 obtained by such a way, many aperture parts 11, 11,... for exhibiting water-permeability and air- permeability are provided on the whole surface thereof. The small unevennesses and a composite curved surface can be formed by winding and fixing the tube 7 on the retaining core material 10 and forming a filter medium layer 2.

Description

[Detailed description of the invention] "Object of the invention" (Industrial application field) The present invention relates to a pressure casting mold (hereinafter referred to as "casting mold")
The present invention relates to a method for manufacturing a holding core material used to hold the configuration of the suction and pressurizing tube when manufacturing the same.

(Prior Art) Pressure casting is a process in which pressure is applied mainly during sludge casting, and is widely used today as a method for manufacturing sanitary ware such as toilet bowls and wash basins.

To give an overview of this pressure casting casting method, by injecting slurry as a raw material into the molding space in the casting mold and pressurizing it, unnecessary water in the slurry permeates into the inside of the mold, and the powder and granules that remain are removed. The soil was deposited on the inner surface of the mold, the excess slurry was drained out of the mold, and then the casting mold was separated and the molded product was taken out.

The above-mentioned casting mold is shown in a side sectional view in FIG.

The casting mold 1 shown in the figure is for molding a wash basin, and the blank space within the mold is the molding space. The casting mold 1 is composed of a filtering material layer 2 made of porous synthetic resin (or gypsum) so as to surround the molding space, and the filtering material layer 2 includes a backing layer 3 and pressure-resistant reinforcement. Also, the casting mold l, which was backed up by ii4,
The entire mold could be separated into an upper mold 5 and a lower mold 6. Note that the backing layer 3 was formed of a non-porous resin (or vasa mortar), and the pressure reinforcement [ii4] was formed of an iron plate or the like.

A tube 7 was embedded in the filtering material layer 20 so as to surround the molding space. The tube 7 is a flexible hollow body made of woven or nonwoven fabric mixed with glass fiber or the like. Therefore, the tube 7 has water permeability through its inner and outer surfaces, and has the following important function during sewing. That is, when slurry is injected into the molding space of the casting mold 1, by creating negative pressure in the tube 7, the water in the slurry is forcibly suctioned to penetrate into the filtering material layer 2. In addition, when demolding the molded product, by pressurizing the inside of the tube 7 contrary to the above, the water sucked into the filter material layer 2 is pushed back into the molding space, and the molding surface 2a is filled with water for promoting demolding. Form a film. The tube 7 that performs such a suction pressurizing action is the filter material W1.
Maintaining the embedding distance from the molding surface 2a of No. 2 at a predetermined depth corresponding to the undulations of the molding surface 2a improves the molded product's inkling condition and prevents a decrease in yield due to poor demolding. Yes, it was extremely important.

Therefore, conventionally, prior to forming the filter material layer 2, a mesh basket-shaped core material 8 as shown in FIG. 4 was manufactured.

The core material 8 is for holding the arrangement shape of the tube 7, and the thick line portions indicated by arrows A and B in FIG. 3 correspond to this core material 8. To manufacture the core material 8, a mold (not shown) that is similar in shape to the molding surface 2a of the filter material layer 2 is used, and a synthetic resin mesh plate is pressed while heating the mold. was.

(Problems to be Solved by the Invention) Although the core material 8 has been plastically deformed through heat pressing, its shape retention strength is extremely unstable, and it will flex significantly even when lifted by hand. Met. Therefore, in the past, a wire material 9 or the like was attached to the corner portion of the core material 8 for reinforcement. However, even with this reinforcement, the shape retention strength was still insufficient. Therefore, when the tube 7 in the core material 8 is fixed and then sealed with the material forming the filter material rf12, in the obtained filter material ii2, the tube 7 may be too close to the molding surface 2a, or On the other hand, sometimes they were too far apart.

The present invention was made in view of the above-mentioned circumstances, and in order to improve the adhesion state of the molded product and prevent a decrease in yield due to poor demolding, the present invention is aimed at improving the molding surface of the casting mold (filtering material layer). It is an object of the present invention to provide a method for manufacturing a holding core material (hereinafter referred to as the method of the present invention) that can maintain the buried distance of a tube at a predetermined depth.

"Structure of the Invention" (Means for Solving the Problems) The gist of the method of the present invention is to provide a method for manufacturing a holding core material embedded in a pressure casting mold to fix a suction pressurizing tube. An elastic sheet material having a large number of outward protrusions distributed over the entire surface is covered with an elastic sheet material which is a three-dimensional sketch of the shaped object, and the amount of protrusion of the protrusions does not exceed the amount of protrusion of the protrusions on the outward surface of the elastic sheet material. The point is that a resin material is applied thickly, and after the resin material is cured, the pressing mold is released and the elastic sheet material is peeled off.

(Function) The patch mold is a three-dimensional version of the overall shape of the tube to be placed inside the casting mold (filtering material layer). Therefore, if the surface of the corresponding mold is covered with an elastic sheet material and a resin material is applied to the outward facing surface, the holding core material obtained when the resin material hardens will correspond to the configuration of the tube. Become something. That is, unlike conventional core materials, the holding core material can have extremely high external dimensional accuracy. Moreover, the shape-retaining strength of the holding core material can be easily adjusted by increasing or decreasing its wall thickness or by incorporating glass fiber or the like, so there is no need to take the trouble of reinforcing it with a wire material or the like.

By the way, the elastic sheet material is provided with a large number of outward protrusions on its entire surface. Therefore, openings corresponding to the projections can be easily distributed over the entire surface of the holding core. The opening portion is located in the casting mold (filtering material layer) and can exhibit water permeability and air permeability.

(Example) Hereinafter, the present invention will be described based on drawings showing examples thereof.

FIG. 1 shows a holding core material 10 manufactured by the method of the present invention.
FIG. The holding core lO is integrally formed of a resin material such as epoxy. The holding core material 10 also has openings 11.11. ...are provided in large numbers. It should be noted that the structure of the casting mold in which the holding core material 10 is embedded is difficult to clearly show the difference in shape from the conventional one even if it is shown in a side cross section (although the effect will be explained later). There are huge differences such as
Therefore, the overall structure will be explained below using FIG. 3. Of course, the holding core material 10 corresponds to the portions indicated by arrows A and B in the figure.

In the method of the present invention, a pressing mold 12 as shown in FIG. 2 is used. The mold 12 is a three-dimensional model obtained by directly copying the overall shape of the suction and pressure tube 7 disposed inside the casting mold (see the filter layer 2 in FIG. 3). Therefore, the outward contour of the corresponding mold 12 has a curve substantially similar to the cross-sectional curve indicated by arrow A in FIG.

However, the cross-sectional curve in this case refers to the molding surface 2 of the filter material layer 2.
The most preferable ideal position for positioning the tube 7 at each molding point is accurately determined with respect to the undulations provided in a, and each ideal position is connected with a line.

Therefore, the cross-sectional shape of the conventional core material (see No. 41m) is significantly different in its density and accuracy. This mold 12 can be made of an appropriate material such as plaster, synthetic resin, wood, metal, or the like.

Once the abutting mold 12 as described above is prepared, the corresponding outward facing surface of the mold 12 is then covered with an elastic sheet material 13.

The elastic sheet material 13 is made of a silicone-based or urethane-based rubber material. Further, the elastic sheet material 13 has a shape that conforms to the outward surface of the mold 12 before being coated on the mold 12,
It doesn't matter whether it's flat or whether it's coated with adhesive or not.
The elastic sheet material 13 has an outward facing surface 13a.
Numerous protrusions 14.14. ...are distributed and provided. The protrusion 14 is formed so that its protrusion height is equal to or slightly exceeds the wall thickness of the holding core material 10 (see FIG. 1). Note that the outer shape, diameter size, number of protrusions, density related to dispersion, etc. of the protrusions 14 are appropriately determined.

Next, a resin material (e.g., epoxy fruit tree a), which is a material for forming the holding core material 10, is applied to the outward facing surface 13a of the elastic sheet material 13. Appropriate methods such as brushing, spraying, or pouring may be used to apply the resin material.

In this case, the coating thickness of the resin material is 14.14. Take care not to exceed the protruding height of... Then, in this state, the resin material is waited for to harden.Of course, if the resin material is thermosetting, it is heated.

After the resin material is cured, the application mold 12 is released from the cured resin body, and then the elastic sheet material 13 is peeled off.

Alternatively, only the cured resin body may be taken out from the mold 12 with the elastic sheet material 13 still being covered.The cured resin body taken out in this way is
Each protrusion 14.14 of the elastic sheet material 13. Since the resin material is not applied to the part corresponding to ..., this corresponding part becomes the opening part (see reference numerals 11, 11, etc. in Fig. 1). Therefore, this cured resin body , after that, the holding core material 10 (first
(see figure).

In addition, the holding core material 1o obtained as described above is formed by winding and fixing the tube 7 to form the filtering material layer 2 in substantially the same manner as the conventional mesh basket-shaped core material 8 (see FIG. 4). Then, the backing layer 3 and the pressure-resistant reinforcement N4 are formed to complete the production of the casting mold (see FIG. 3). In the method of the present invention, since the holding core material 10 is integrally formed from a resin material, it is possible to form small irregularities and complex curved surfaces, and the configuration of the tube 7 can be adapted to the external shape of the molded product. It can be done.

(Study of Alternative Embodiments) The resin material that is the material of the holding core material 10 may be polyester-based, urethane-based, or the like. Also,
By mixing glass fiber or the like into this resin material, its shape retention strength can be made even stronger. In this way, the detailed structure of the method of the present invention can be changed as appropriate depending on the embodiment.

"Effects of the Invention" As is clear from the above explanation, since the holding core material manufactured by the method of the present invention is integrally formed of a resin material, it is difficult to accurately arrange the suction and pressure tube. , can be held securely and firmly. Therefore, the embedding distance of the tube with respect to the molding surface of the casting mold (filtering material layer) immediately corresponds to a predetermined depth corresponding to the undulations of the molding surface.

Therefore, molded products manufactured using this casting mold,
The wall thickness dimension is formed to the set dimension. Further, since there is no shortage or excess of water film during demolding, it is possible to prevent a decrease in yield due to poor demolding. Further, in the method of the present invention, a large number of openings can be formed at the same time as the overall shape of the holding core material is formed, so manufacturing thereof is extremely simple. Moreover, it has many excellent advantages, such as being lighter than the conventional net cage-shaped core material, making it easier to manufacture and handle the casting mold as a whole. There is.

[Brief explanation of the drawing]

11th! 1 is a perspective view showing the holding core material manufactured by the method of the present invention, FIG. 2 is a side sectional view showing the patch mold and elastic sheet material used in the method of the present invention, and FIG. 3 is a side sectional view showing the casting mold. , FIG. 4 is a perspective view showing a conventional mesh basket-shaped core material. 1... Casting mold 2... Filter material layer 2a...
Molding surface 7...Tube for suction and pressure...
・Holding core material 11...Opening part 12...Available mold 13...Elastic sheet material 13a...Outward surface of elastic sheet material 14...Protrusion

Claims (1)

[Claims] 1. In a method for manufacturing a holding core material that is embedded in a pressure casting mold to fix a suction pressurizing tube, a large number of outward protrusions are formed on the entire surface of the mold, which is a three-dimensional reproduction of the arrangement shape of the tube. A resin material is applied to the outward facing surface of the elastic sheet material to a thickness not exceeding the amount of protrusion of the protrusion, and after the resin material is cured, the applying mold is released. A method for manufacturing a holding core material used in a pressure casting mold, characterized by peeling off an elastic sheet material at the same time.