JPH03207604A - Manufacture of pressure casting mold - Google Patents

Abstract

PURPOSE:To prevent the above mold from being deformed, cracked and damaged by combining a case mold set with a porous tube and a pressure-resistant frame to each other, casting a porous material for forming a filter medium into a space between the pressure-resistant frame and the case mold, and releasing the case mold after the porous material is hardened. CONSTITUTION:A sealing resin 12 is coated on the inner surface of a pressure- resistant frame 11. Before this resin 12 is hardened, the pressure-resistant frame 11 is then combined with a case mold 14 disposed thereon with a porous tube 13 in such a way that the case mold 14 is covered with the pressure-resistant frame 11. Then, a porous material is cast into a space between the pressure- resistant frame and the case mold through the casting port 15 of the case mold 14. When the case mold 14 is removed after this porous material is hardened, a mold 10, in which the layer of the sealing resin 12 is formed over the entire surface of an interface between the pressure-resistant frame 11 and a filter medium 16, is produced. The mold 10 thus produced has an airtightly sealed space between the pressure-resistant frame 11 and the filter medium 16, and this removes the possibility of leakage of water, air or the like being generated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a mold used for casting for molding sanitary ware, etc. This invention relates to a method for manufacturing a mold for pressure casting that is improved to prevent air leakage.

[Conventional Techniques] Pressure casting mainly involves applying pressure 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 method, by injecting slurry (sludgy powder made from powdered clay for preforms) into the molding space formed in the mold and pressurizing it, unnecessary parts are removed in the slurry. The liquid (e.g. water) that will become The molded product is then removed.

FIG. 4 shows a side sectional view of the mold used for this pressure casting. The illustrated mold 1 is for casting a washbasin, and the blank space within the mold is the molding space. The mold 1 is formed by polymerizing a filter material 2 and a pressure frame 4 from the molding space side, and the mold as a whole can be separated into an upper mold 5 and a lower mold 6. There is.

The filter material 2 is made of porous synthetic resin (or gypsum), and the pressure frame 4 is made of an iron plate or the like. In addition, in the filtering material layer 2, water is supplied under pressure to remove water in the slurry by suction during casting, and to form a water film on the molding surface 2a during demolding of the shaped product. A porous tube 7 is buried therein.

[Problem to be Solved by the Invention] In the conventional pressure casting mold, the pores in the filtering material 2 easily communicate with the atmosphere through the interface between the filtering material 2 and the pressure frame 4. Therefore, for example, even if the pressure inside the tube 7 is reduced during inking, the atmosphere will pass through the gap between the pressure frames 4, 4, and the interface between the pressure frame 4 and the filter material 2, and enter the filter material 2. , and reached the tube 7 through this, so that sufficient vacuum for inking could not be obtained. Also,
In the vicinity of areas where air inflow is strong, the infill becomes extremely thin, and conversely, in the vicinity of areas where air inflow is not intense, ink buildup is promoted, resulting in uneven thickness of infill on the inner surface of the filter medium. Sometimes it happened.

Furthermore, when water pressure or air pressure is applied inside the tube 7 during demolding, this pressure flows in the opposite direction to the above and leaks into the atmosphere, making demolding difficult. In this case, if the pressure is increased, the fleshy material will remain attached to the filter material 2 near areas where pressure leakage is severe, and the fleshy material will swell greatly in the direction of peeling off from the filter material near areas where pressure leakage is small. An uneven mold release phenomenon occurs,
Deformation, cracks, and damage easily occur in the molded product.

[! I! Means for Solving the Problem] The method for manufacturing a mold for pressure casting of the present invention is a mold for pressure casting in which the inner surface of a pressure-resistant frame is composed of a porous filter material, and a porous tube is embedded in the filter material. In the method of manufacturing a high-profile mold, a sealing resin is applied to the inner surface of a pressure frame, and before the resin hardens, the pressure frame is combined with a case mold in which a porous tube is set, and then the filter material is applied to the pressure frame. A porous material for forming the pressure frame is poured between the pressure frame and the case mold, and after the porous material is hardened, the case mold is removed from the mold.

[Function] In the pressure casting mold manufactured by the method of the present invention, the sealing resin is completely present at the interface between the pressure frame and the filter material, so that the crushing of the sake and the filter material are prevented. The space between them becomes airtight. Therefore, when the inside of the porous tube inside the filter medium is depressurized or pressurized, these pressures will not leak from the interface between the filter medium and the pressure frame.

[Examples] The present invention will be described below based on drawings showing examples thereof.

In the present invention, first, a sealing resin 12 is applied to the inner surface of the pressure frame 11 as shown in FIG. Next, before this resin 12 hardens, this pressure frame 11 is assembled by covering it with a case mold 14 in which a porous tube 13 is arranged as shown in FIG. Then, the porous material is poured from the casting spout 15 of the case mold 14. After this porous material has hardened, when the case mold 14 is removed, a layer of sealing resin 12 is formed entirely on the interface between the pressure frame 11 and the filter material 16, as shown in FIG. A mold 10 is manufactured. In the mold 10 manufactured in this manner, the space between the pressure frame 11 and the filter material 16 is airtightly sealed, and there is no leakage of water, air, etc.

In the present invention, suitable porous materials for forming the filter medium 16 include gypsum, as well as synthetic resins such as epoxy, acrylic, and urethane. Further, as the sealing resin, epoxy, polyester, urethane, silicone, etc. are suitable.

As the porous tube 13, a cotton tube, a glass fiber tube, a metal fiber tube, etc. are suitable. When disposing this porous tube 13, it is sufficient to attach the tube 13 to a mesh 17 formed in a cage shape, and install the cage mesh 17 together with the case mold 14.

[Effects of the Invention] As described above, according to the method for manufacturing a mold for pressure casting of the present invention, a mold is manufactured without pressure leakage from the interface between the filter medium and the pressure frame. According to this mold, uniform inking is promoted during inking. Further, when demolding, a uniform water belly is formed on the inner surface of the filter material, and it becomes possible to quickly demold the molded object without deforming or damaging it. Therefore, the working efficiency of the entire casting operation is improved, leading to an improvement in production efficiency.

The method of the present invention can be applied to manufacturing methods for sanitary ware such as wash basins and toilet bowls, as well as molds for molding various types of ceramics.

[Brief explanation of drawings]

1, 2 and 3 are cross-sectional views showing the method of the present invention,
FIG. 4 is a side sectional view showing a conventional mold. 2, 16... Filtering material, 2a... Molding surface, 4, 1
DESCRIPTION OF SYMBOLS 1... Liquor pressure frame, 8, 9... Split mold, 10... Molding mold, 12... Sealing resin, 1 3... Porous tube, 1 4... Case mold.

Claims (1)

[Claims] In a method for manufacturing a mold for pressure casting in which the inner surface of a pressure frame is composed of a porous filter material and a porous tube is embedded in the filter material, a sealing resin is applied to the inner surface of the pressure frame. Then, before this resin hardens, the case mold to which the porous tube is attached and the pressure frame are combined, and then the porous material for forming the filter material is poured between the pressure frame and the case mold. A method for manufacturing a mold for pressure casting, characterized by removing the case mold after the porous material has hardened.