JPH01257006A - Casting mold and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a casting mold at low production cost with excellent strength by a method in which a porous layer is composed of the integral molding layer in which granular fillers are combined with fine porous resin from the front surface of the layer facing a casting space to the rear surface thereof, and the grain size of the filler changes to coarse grain from fine grain with advancing to the rear surface of the layer from the front surface thereof. CONSTITUTION:In the casting molds 22, 23 in which a casting space is formed with the porous layer having a plurality of fine holes inside of a supporting frame, the porous layer is composed of the integral molding layer in which granular fillers are combined with fine porous resin from the front surfaces 22a, 23a of the layer to the rear surface thereof. The grain size of the filler changes from fine grain to coarse grain with advancing from the front surfaces 22a, 23a of the layer to the rear surface thereof in the distribution on the cross section of the porous layer. Since in the integral molding layer, granular fillers are combined with the fine porous resin, it is excellent in strength due to nonmechanically connected parts in the porous layer. Further, since the grain size-distribution in the filler changes to coarse grain from fine grain with advancing from the front surface of the layer to the rear surface thereof, the distribution of many fine holes opening on the surface of the porous layer as a filtration surface, is caused to be fine and uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial 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] Conventionally, as a casting mold, the European Patent No. 02
There is one described in Japanese Patent No. 34360. As shown in FIG. 5, this casting mold 1 forms a casting space H inside a support layer 2.3 made of a porous material with coarse pores, and a filter material is placed so as to surround the casting space H. @4.5 is coupled to the inner surface of the support W12,3. The filter material layer 4.5 is made of microporous resin and has a layer thickness A of 20 to 5.
It is 0mm. The support layers 2, 3 are made of a substantially incompressible material and are intended to suppress deformation of the filter medium 11!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 media 1II4, 5 to supports 1i2, 3.

As shown in Fig. 6, adhesive bonding (
(see hole in the same figure), dovetail leg/dovetail groove engagement (see B in the same figure),
Screw connection (see figure C1), engagement by unevenness (figure F
(see D+) or mechanical connection such as a spiral steel wire (see the same figure (see El). Support!! 2゜3 and filter material @
4. As shown in FIG. 5, a duct network 6.7 serving for draining the filtered water is arranged as necessary in the boundary area between the filter and the filtrate.

[Problems to be Solved by the Invention] However, the conventional casting mold and its manufacturing method have the following problems.

(a) Since the support 12 (3) and the filter material layer 4 (5) are manufactured separately and the two are joined, the process is complicated and requires a lot of effort. As a result, conventionally, there has been a problem in that the manufacturing cost has increased, leading to an increase in the molding cost of the cast molded product.

(1)) Since the support 12 (3) and the filter medium 114 (5) are mechanically connected, this 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 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 coarser as they go from the layer surface to the layer surface.

The gist of the method for producing a cast molding mold according to the present invention is to provide a method for producing a cast molding mold having a porous layer having a large number of micropores.

It is a mixture of a fluid material consisting of an emulsifier and water and a filler made of fine to coarse particles, and the finer the filler particles, the higher the specific gravity, and the specific gravity of the finest particles becomes fluid Prepare a molding material that is larger in specific gravity than the molding material, fill the filling space surrounded by the inner surface of the mold and the upper surface of the model, and apply a motion to the filled molding material to make the fine details of the filling material. The purpose is to obtain a mold by allowing the particles to settle and removing the emulsifier and water from the molding material, which has progressed to faeces.

[Function] In the cast molding mold according to the present invention, since the layer surface to the layer surface of the porous layer 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 layer surface to the layer surface. 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 toward .

[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. 8 (8), the model 11 is made of a material such as metal or synthetic resin into a desired shape, and has a built-in imaging device @13.

The model 11 has a filling space 14 surrounded by a frame 12 around the upper surface 11a. 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 filling material is
It consists of particles made of inorganic materials such as silica stone, glass, or ceramics, gold-11151 compounds such as iron oxide, or synthetic resins, and particles having a particle size in the range of 5 to 2,000 μm are mixed 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, for example, any one of epoxy resin, acrylic resin, polyurethane resin, or furan resin is selected,
The viscosity used is about 1,000 to 3,000 cps.

The curing agent is selected to be compatible with the resin base (for example, an aliphatic amine in the case of an epoxy resin).

As the emulsifier, sorbitan fatty acid ester, polyoxyethylene oleyl ether, polyoxyethylene sorbitan fatty acid ester, etc. are selected, and the viscosity thereof is 1.
~ioo cps is used. The mixing ratio of the components of the molding material 20 is as shown in the following table.

In the second step of Table 1, as shown in FIG. is to sediment large fine particles. The imaging operation is continued until the particle size distribution of the filler in the molding material 20 gradually increases as it moves upward away from the upper surface 11a of the model 11, as shown in FIG.

The temperature of the molding material 20 during imaging is a temperature at which a resin viscosity that does not inhibit the settling of fine particles of the filler is obtained,
and a temperature that suppresses resin curing (for example, 20 to 30°C)
Let's do it. 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. For example, in the case of epoxy resin, this initial curing temperature is 30~
Perform at 55°C. Intermediate material 2 obtained after completion of initial curing
1 is separated from the filling space 14 formed by the model 11 and the frame 12, and as shown in FIG.
It is inserted within 5. 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 pressurized water W percolates into the intermediate material 21 to form communication holes and causes the remaining emulsifier and water to ooze out toward the back surface 21b. Once the remaining emulsifier has been removed, the intermediate material 21
is gradually heated (for example, from 35° C. to 70° C.) to perform final curing, thereby obtaining a casting mold 22 according to the present invention. The obtained casting mold 22 is separated from the inside of the pressurized container 15. Note that the frame 12 is a pressurized container 15 and an airtight container 32 (3
3), the above-mentioned 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 above manufacturing method according to the present invention will be explained. As shown in FIG. 2, the casting molding tool 31 to be prepared includes pressure-resistant airtight containers 32 and 33, and containers 32.
33, the casting molds 22, . 23, and the inner surfaces 22a, 23 of the casting mold 22.23.
A casting space H is formed at a. 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, 37.38
is a compressed air supply pipe for forming a separated water film for promoting demolding on the inner surfaces 22a, 23a of the casting mold 22, 23 when demolding the molded product 40 (see FIG. 4).

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, the slurry is pressurized via the overflow pipe, while the casting mold 2 is pumped via the filtered water suction pipe 35,36.
2. After carrying out the inking operation for a predetermined time while reducing the pressure of 23, as shown in FIG.
is discharged from the slurry supply and discharge pipe 34. When the inking operation is completed, the casting mold 22 is pressurized via the compressed air supply pipe 37 of the split joining mold part 31a to remove residual water in the casting mold 22 and remove it from the surface of the casting mold 22. After it oozes out to the boundary with the flesh part, as shown in FIG.
Divide and remove a. 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 The cast molded product 40 is lowered onto the mounting table while pressurizing the cast mold 23 via the mold 38 to ooze out residual water in the cast mold 23.

In addition, although the particles of the filler constituting the mold for casting according to the present invention are made so that the specific gravity increases as they become finer in the above-mentioned example, the particle size is not limited to this. Of course, it is also possible to form all the objects, from small ones to coarse ones, from 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.

- The entire mold can be formed at the same time without distinguishing between the support layer and the filter layer, making the process simpler and labor-saving compared to conventional methods. As a result, manufacturing costs can be dramatically reduced.

■ Since the entire mold can be formed in one piece, a strong casting mold can be obtained.

■ The distribution of fine pores opened on the surface of the mold, which serves as the filtration surface, is dense and uniform, making it possible to deposit homogeneously over the entire surface of the mold, and also to ooze out residual water from the surface of the mold. When demolding is carried out, 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 the drawing]

Figures 1 to (D) are cross-sectional views showing each step of the manufacturing method according to the present invention, and Figures 2 to 4 show examples of casting using the casting mold according to the present invention. Fig. 2 is a longitudinal cross-sectional view showing the state in which a casting space is formed inside the casting mold, Fig. 3 is a longitudinal cross-sectional view showing the state after mud removal, and Fig. 4 is a longitudinal cross-sectional view showing the state after removing mud. FIG. 5 is a vertical cross-sectional view showing a conventional slurry casting mold, and FIG. 6 is an enlarged view of the bonding structure between the support layer and the filter layer in the conventional slurry casting mold. FIG. 11...Model 12...Formwork 13...
Imaging device M 20... Molding material 22... Casting mold Fig. 2 11 1J Fig. 3 Fig. 4 Fig. 5 Fig. 6

Claims (1)

[Claims] 1. In a mold for casting, in which a casting space is formed inside a support frame by a porous layer having a large number of micropores, the porous layer extends from the layer surface facing the casting space to the layer surface. , consists of an integral molded layer in which particulate filler is bonded with a microporous resin, and when looking at the distribution of the cross section of the porous layer, the particle size of this filler becomes finer as it goes from the layer surface to the layer surface. A casting mold characterized by having coarse particles. 2. In a method for producing a casting mold having a porous layer having many micropores, 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 inner surface of the mold and the upper surface of the model are The surrounding filling space is filled with a molding material, the filled molding material is vibrated to sediment 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 mold for casting molding, characterized in that: