JPH047963B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to improvements in a casting mold used for slurry casting of sanitary ware bodies, pottery bodies, etc., and a method for manufacturing the same. [Prior Art] As a conventional casting mold, there is one described in European Patent No. 0234360. As shown in FIG. 5, this casting mold 1 forms a casting space H inside support layers 2 and 3 made of a porous material with coarse pores, and a filter material is placed so as to surround the casting space H. The layers 4, 5 are bonded to the inner surfaces of the support layers 2, 3. The filter material layers 4 and 5 are made of microporous resin and have a layer thickness A of 20 to 50 mm. The support layers 2, 3 are made of a substantially incompressible material and are intended to suppress deformation of the filter media layers 4, 5 within an acceptable range. The support layers 2 and 3 are, for example, made by bonding quartz particles with a resin only at mutual contact points, and forming a large number of water-permeable coarse pores. The casting mold 1 was manufactured by bonding preformed filter material layers 4 and 5 to support layers 2 and 3. As shown in Figure 6, this connection method includes adhesive bonding (see figure A), dovetail leg/dovetail groove engagement (see figure B), screw connection (see figure C), and uneven engagement (see figure C). There is a mechanical connection such as a spiral steel wire connection (see Figure D) or a spiral steel wire connection (see Figure E). As shown in FIG. 5, duct networks 6, 7 useful for draining filtrate water are arranged as necessary in the boundary area between the support layers 2, 3 and the filter material layers 4, 5. [Problems to be Solved by the Invention] However, the conventional casting mold and its manufacturing method have the following problems. (a) The process is complicated and requires a lot of effort because it involves a process of manufacturing the support layers 2, 3 and the filter material layers 4, 5 separately and a process of joining them together.
As a result, production costs have traditionally increased,
There was a problem that led to an increase in the molding cost of cast molded products. (b) The support layers 2, 3 and the filter media layers 4, 5 are mechanically bonded, which causes a decrease in strength. SUMMARY OF THE INVENTION In view of the above problems, the present invention aims to provide a casting mold that is inexpensive to manufacture and strong in strength, and a method for manufacturing the same. [Means for Solving the Problems] The gist of the casting mold according to the present invention is that the casting mold has a casting space formed inside a support frame by a porous layer having a large number of micropores. The layer, from the layer surface facing the casting space to the layer back surface, consists of an integrated molded layer in which particulate filler is bonded with microporous resin, and the particle size of this filler is determined by the distribution of the porous layer cross section. , the particles become finer to coarser as they go from the surface of the layer to the back of the layer. The gist of the method for producing a cast molding mold according to the present invention is that in the method for producing a cast molding mold having a porous layer having a large number of micropores, a fluid material consisting of a resin base, a hardening agent, an emulsifier, and water and a fine A molding material that is a mixture of particles or coarse particles with a filler, in which the finer the filler particles are, the higher the specific gravity is, and the specific gravity of the finest particles is greater than the specific gravity of the fluid material. The filling space formed by the inner surface of the mold and the upper surface of the model is filled with the molding material, and the filled molding material is vibrated to cause the fine particles of the filler to settle, resulting in a hardened mold. The process involves removing the emulsifier and water from the material to obtain a mold. [Function] In the cast molding mold according to the present invention, since the porous layer from the layer surface to the layer back surface is an integral molding layer in which particulate filler is bonded with a microporous resin, The porous layer has excellent strength with no mechanical bonding points, and the particle size distribution of the filler changes from fine particles to coarse particles as it goes from the surface of the layer to the back of the layer. The distribution of fine pores opened on the surface of the layer becomes dense and uniform. In the method for manufacturing a casting mold according to the present invention, when the filled molding material is vibrated to cause fine particles of the filler to settle, the finer the particles of the filler, the greater the specific gravity. In addition, since the specific gravity of the finest particles is greater than the specific gravity of the fluidized material, the particle size distribution of the filler in the molding material gradually increases as it moves away from the top surface of the model. Therefore, in a mold obtained by curing a molding material with an adjusted particle size distribution and removing the emulsifier and water from the hardened molding material, the diameter of the continuous ventilation holes is from the filter surface to the back surface. Gradually increases in size toward the sides. [Example] Hereinafter, the present invention will be explained based on the process order of the example shown in FIG. The first step is to prepare the model 11, frame 12, and molding material 20 in advance. As shown in FIG. 1A, the model 11 is made of a material such as metal or synthetic resin into a desired shape, and has a built-in vibrating device 13. The model 11 has an upper surface 11a
A filling space 14 is formed which is surrounded by a frame 12. A mold release agent is applied to the upper surface 11a of the model 11 and the inner surface 12a of the frame 12, if necessary. Note that the model 11 and the frame 12 may be formed integrally. The molding material 20 is a mixture of a fluid material consisting of a resin base, a curing agent, an emulsifier, and water, and a filler containing fine particles to coarse particles. The filler is made of particles made of inorganic materials such as silica stone, glass, or ceramics, metal oxides such as iron oxide, or synthetic resins, and has a particle size of 5.
Those in the range of ~2000μm are prepared in appropriate proportions.
The specific gravity of the filler particles increases as they become finer, and the specific gravity of the finest particles is greater than the specific gravity of the fluidizing material. For example, the fine particles are metal oxide particles, the medium-fine particles are inorganic particles, and the coarse particles are synthetic resin particles. As the resin base material, for example, any one of epoxy resin, acrylic resin, polyurethane resin, or furan resin is selected, and its viscosity is 1000
~3000cps is used. The hardening agent is
A material corresponding to the resin base material (for example, an aliphatic amine in the case of an epoxy resin) is selected. As the emulsifier, sorbitan fatty acid ester, polyoxyethylene oleyl ether, polyoxyethylene sorbitan fatty acid ester, etc. are selected, and their viscosity

[Table] As shown in Figure B, the second step is to fill the filling space 14.
After filling the molding material 20 with the molding material 20, the filled molding material 20 is vibrated by a vibration device 13 to cause fine particles with a large specific gravity in the filler to settle.
As shown in FIG.
Repeat this until it gradually increases in size as you move upward away from 1a. The temperature of the molding material 20 during vibration application is a temperature that provides resin viscosity that does not inhibit sedimentation of the fine particles of the filler, and at a temperature that suppresses resin hardening (for example, 20 to 30°C). When the granulation of the filler in the molding material 20 is completed, the vibrating device 13 is stopped. The third step is to remove the emulsifier and water from the molding material 20 after the molding material 20 is initially cured. This initial curing temperature is, for example, 30 to 55°C in the case of epoxy resin. The intermediate material 21 obtained after the initial curing is separated from the filling space 14 formed by the model 11 and the frame 12, and is inserted into the pressurized container 15 as shown in FIG. In addition, when the frame 12 also serves as the pressurized container 15, the separation of the frame 12 and the intermediate material 21 is omitted. The surface 21a of the intermediate material 21 in the pressurized container 15 is loaded with water pressure at an appropriate pressure. The pressure water W seeps into the intermediate material 21 to form communication holes and removes the remaining emulsifier and water from the back surface 21.
Let it ooze out to the b side. After the removal of the remaining emulsifier is completed, the intermediate material 21 is gradually heated (for example, from 35° C. to 70° C.) to perform final hardening and form the casting mold 22 according to the present invention.
get. The obtained casting mold 22 is separated from the inside of the pressurized container 15. In addition, when the frame body 12 serves both as the pressurized container 15 and the airtight containers 32 and 33 of the cast molding tool 31 described later, the above separation of the cast molded piece 22 is omitted. Next, slurry casting using the casting molds 22 and 23 according to the present invention obtained by the manufacturing method according to the present invention will be explained. As shown in FIG. 2, the casting tool 31 to be prepared consists of pressure-resistant airtight containers 32, 33 and casting molds 22, 23 inserted into the containers 32, 33, and is used for casting molding. A casting space H is formed between the inner surfaces 22a and 23a of the molds 22 and 23. 34 in the figure is a slurry supply and discharge pipe with an end 34a opened in the casting space H; 35;
36 is a filtered water suction pipe for discharging filtered water;
37 and 38 are the inner surfaces 22 of the casting molds 22 and 23 when demolding the molded product 40 (see FIG. 4).
A, 23a is a compressed air supply pipe for forming a separated water film for promoting demolding. The procedure of the sludge casting method using the casting tool 31 is as follows. First, as shown in FIG. 2, the split joining mold parts 31a and 31b constituting the casting molding tool 31 are brought together in a water-tight manner to form a casting space H therein. Next, slurry (not shown) is supplied into the casting space H from the slurry supply/discharge pipe 34, and after the supplied slurry overflows from the overflow pipe (not shown), the slurry supply pipe 34 is closed. Subsequently, while pressurizing the slurry through the overflow pipe and depressurizing the casting molds 22 and 23 through the filtered water suction pipes 35 and 36, the inking operation is performed for a predetermined time, and then As shown in Figure 3,
The unattached slurry 39 in the casting space H is transferred to the slurry supply and discharge pipe 34.
discharge from. When the inking operation is completed, the cast molding mold 22 is pressurized via the compressed air supply pipe 37 of the split joining mold part 31a.
After the residual water in the cast molding mold 22 is allowed to ooze out to the boundary between the surface of the casting mold 22 and the inked part, the split joining mold part 31a is separated and removed as shown in FIG. Finally, although not shown, the casting mold 23 is depressurized in advance through the filtered water suction pipe 36 of the split joint mold part 31b to adsorb and suspend the casting molded product 40, and then the compressed air supply pipe Casting mold 2 through 38
3 is pressurized to ooze out the residual water in the casting mold 23, and the cast molded product 40 is lowered onto the mounting table. In addition, although the particles of the filler constituting the casting mold according to the present invention are made so that the specific gravity increases as they become finer in the above embodiments, this is by no means limited to this. Of course, it is also possible to form everything from small objects to coarse objects using homogeneous materials with the same specific gravity. [Effects of the Invention] As detailed above, the cast molding mold and the manufacturing method thereof according to the present invention have the following excellent effects. Since the entire mold can be formed at the same time without distinguishing between the support layer and the filter layer, the process is simpler than in the past, and labor can be saved. As a result, manufacturing costs can be dramatically reduced. Since the entire mold can be formed in one piece,
A casting mold with strong strength can be obtained. The fine pores opened on the surface of the mold, which serves as the filtration surface, have a dense and uniform distribution, making it possible to deposit uniformly over the entire surface of the mold, and to wick residual water from the surface of the mold. When demolding is performed, residual water oozes out densely and uniformly from the entire surface of the mold, allowing smooth demolding. As a result, the yield can be improved.

[Brief explanation of drawings]

FIGS. 1A to 1D are cross-sectional views showing each step of the manufacturing method according to the present invention, and FIGS. 2 to 4 show an example of casting using the casting mold according to the present invention. FIG. 2 is a longitudinal sectional view showing a state in which a casting space is formed inside the casting mold.
Fig. 3 is a longitudinal sectional view showing the state after mud removal, Fig. 4 is a longitudinal sectional view showing the middle of demolding, Fig. 5 is a longitudinal sectional view showing a conventional slurry casting mold, and Fig. 6 is a longitudinal sectional view showing the state after mud removal. FIG. 2 is an enlarged cross-sectional view showing a bonding structure between a support layer and a filter layer in a conventional slurry casting mold. 11...Model, 12...Formwork, 13...Vibration device, 2
0... Molding material, 22... Cast molding mold.

Claims (1)

[Scope of Claims] 1. In a casting mold in which a casting space is formed inside a support frame by a porous layer having a large number of micropores, the porous layer has a layer surface facing the casting space to a back surface of the layer. It consists of an integral molded layer in which particulate filler is bonded with a microporous resin, and the particle size of this filler varies from fine particles to fine particles as it goes from the surface of the layer to the back of the layer, when viewed from the cross-sectional distribution of the porous layer. A casting mold characterized by having coarse particles. 2. A method for producing a casting mold with a porous layer having a large number of micropores, in which a fluid material consisting of a resin base, a curing agent, an emulsifier, and water is mixed with a filler containing fine particles to coarse particles. A molding material is prepared in which the specific gravity increases as the particles of the filler become finer, and the specific gravity of the finest particles is greater than the specific gravity of the fluid material, and the material is surrounded by the inner surface of the mold and the upper surface of the model. The formed filling space is filled with molding material, the filled molding material is vibrated to sediment the fine particles of the filler, and the emulsifier and water are removed from the hardened molding material to form a mold. A method of manufacturing a casting mold, characterized in that: