JPH0753307B2 - Fluid permeable material and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fluid-permeable material and a method for producing the same, and in particular, a fluid such as a cast product capable of transmitting a fluid through continuous pores formed therein. The present invention relates to a fluid permeable material, which is a permeable molded article and can be suitably used as a vent hole material for a molding die, and a method for producing the same.

(Background Art) Conventionally, many methods have been developed for a molding operation for obtaining a molded product having a predetermined shape. For example, molding by cutting, molding by forging, press molding, casting, injection molding, blow molding. Molding is pervading the general industry. Among them, several methods are adopted in which a molding material (raw material) is molded in a molding (product) cavity of a molding die in a plastic state or a fluidized state. For example, injection molding or blow molding of plastic, or glass product Molding and the like are known.

Then, in the method using this molding die, the molding operation is performed by transferring the raw material in a fluidized state to the surface (inner surface) of the molding die under a predetermined pressure to transfer the material. In some cases, gas such as air is trapped between the raw material and the mold, which may hinder the molding.Therefore, in order to eliminate such defects, be sure to check the exhaust holes on the product cavity surface of the mold. Or, a vent hole is provided, and the present situation is that it is designed by interlocking many factors such as the molding method, the raw material, and the speed. For example, the shape and size of the exhaust hole are selected according to the physical properties of the material such as viscosity and surface tension, and the molding pressure such as blow pressure and injection pressure. Also, the exhaust hole is selected according to the molding speed such as blow speed and injection speed. The structure, size and quantity of the exhaust holes are selected, and the structure and material of the exhaust holes are appropriately selected from the viewpoint of durability such as clogging, corrosion and abrasion.

By the way, conventionally, there are roughly two types of degassing means provided in the molding die.
One of them is to make holes directly in the mold itself, or to make the mold with a porous material, and the other is to make a cylindrical member having vent holes called vent holes into the mold. The latter is used in many cases, and the typical structure is slit type, small hole type, etc., which is manufactured by machining (cutting), electric discharge machining, sintering molding. Has been done. The shape and size of the holes are about 0.1 to 0.3 mm width x 3 mm depth for the slit type and about 0.1 to 0.5 mmφ for the small hole type.

However, in such a venthole material, since the pore cross-sectional shape is the same, it is necessary to reduce the pore size in order to eliminate the transfer of the venthole to the product surface. If it is made smaller, problems such as a decrease in exhaust efficiency and the occurrence of clogging become a problem. In addition, in a vent hole made of a sintered body, which is also used in filters, etc., the opening size is 2 to 30
It has a range of μm, but large size has insufficient strength and poor surface roughness, and if it is tried to improve it, there are problems such as clogging due to difficult cutting of the metal particles of the raw material, and it was adapted to the application. It was difficult to select an exhaust hole structure, exhaust hole size, and exhaust capacity.

On the other hand, one of the applicants of the present application has continuous pores,
As a novel fluid permeable material that has the property of being fluid permeable and can replace conventional sintered bodies, etc.
Japanese Patent No. 49825, Japanese Patent Publication No. 3-72034, Japanese Patent Laid-Open No. 63-1667
No. 76, JP-A-63-176378, etc., the skeleton itself forming the porous structure is a hollow structure, using a ceramic porous body in which continuous pores are formed in the skeleton as a whole, The matrix material is allowed to enter the voids of the porous structure to form an integral structure, so that the pores formed in the skeleton of the porous structure of the ceramic porous body can be used to allow the fluid to permeate. The new composite molded material was clarified.

Therefore, the present inventors have studied the use of such a novel fluid permeable material as a material for the above-mentioned forming die, particularly as a vent hole material,
It became clear that there was one problem to be solved. That is, the size of the pores (pores) formed in the fluid permeable material is 200 to 800 μm.
However, it became clear that when holes of such a size were opened on the mold surface, the problem that the opening shape was transferred to the product surface still existed. , Therefore, the application of such a fluid permeable material to a mold requires that the size of the pore openings, or pores, be further reduced.

(Object of the Invention) Here, the present invention has been made in view of the circumstances as described above, and an object of the present invention is to provide an empty space formed in a skeleton of a ceramic porous body embedded inside. In a fluid permeable material such as a cast product having fluid permeability imparted by pores, its surface condition is improved without significantly reducing the fluid permeability ability utilizing the pores, and for example, a vent hole material, etc. It is intended to provide a structure capable of preventing such a hole opening from being transferred to a product surface when used as a mold material, and to provide an effective method for realizing such a structure. Especially.

(Structure of the Invention) In order to achieve the above object, the present invention provides a skeleton of a ceramic porous body in which a skeleton constituting a porous structure itself has a hollow structure and continuous pores are formed in the skeleton. The matrix material enters the gap of the matrix, and the ceramic porous body is embedded in a continuous matrix of the matrix material to form an integral composite structure,
A porous thermal sprayed layer having a predetermined thickness is formed on a surface portion including at least a portion where pores of the skeleton of the ceramic porous body are opened, and the porous thermal sprayed layer covers the hole opening portion, and a fluid is formed. In the fluid permeable material, the size of the pores that allow the permeation of the fluid is substantially reduced.

In addition, in the present invention, in order to produce such a fluid-permeable material, the skeleton itself that constitutes the porous structure has a hollow structure, and the presence of a ceramic porous body in which continuous pores are formed in the skeleton is present. A molding operation of the fluid matrix material is performed below, and the matrix material is allowed to enter the gaps of the skeleton of the ceramic porous body to form an integral composite molded article, and then the composite molded article is processed. It is preferable to open the pores of the skeleton of the ceramic porous body on the surface thereof, and then form a porous sprayed layer on the surface of the composite molded article including at least the processed portion by a spraying operation. Will be adopted by.

(Specific Structure / Example) In the case of producing a fluid-permeable casting product according to the present invention as described above, first, as shown in FIG. 1, a predetermined position in the mold is set. In the state in which the porous ceramic body having the specific structure as shown in FIG. 2 is arranged, by pouring a predetermined molten metal, three-dimensionally as shown in FIG. A cast product having continuous pores (pores) and having a property of allowing a fluid to pass therethrough is manufactured.

In FIG. 1, 10 is a mold composed of an upper mold 12 and a lower mold 14, which is generally made of green sand or self-hardening mold sand using a resin as a hardening medium. Alternatively, it is composed of a permanent mold (mold) or the like. In addition, in the mold 10, the ceramic runner 1
6, a feeder 18 and a casting cavity 20 having a predetermined shape are formed. The ceramic porous body 22 having a predetermined three-dimensional mesh structure is set in the cavity 20. Further, a molten metal pool 24 is provided below the cavity 20 of the mold 10 as described above, and further, a predetermined molten metal is used.
26 will be poured from the ladle 28 through the hot water inlet 30.

Further, in FIG. 1, as shown in FIG. 5, the porous ceramic body 22 is formed over the entire casting 32.
In order to obtain a cast product, the ceramic porous body 22 is set in a state of being positioned over the entire casting cavity 20, and the arrangement position and shape of the ceramic porous body 22 in the cast product 32. Is not limited and can be appropriately determined depending on the intended product. For example, when the ceramic porous body 22 is set with some of its outer surfaces floating from the inner surface of the casting cavity 20. For this, a suitable stopper such as keren is used.

Here, the ceramic porous body 22 arranged and fixed in the casting cavity 20 is one in which the skeleton itself forming the porous structure is hollow, and continuous pores are formed in the skeleton, For example, as shown in FIG. 2, after foaming a resin such as ester polyurethane,
By removing the film-like substance (foamed film) remaining around the skeleton using compressed air, etc., the synthetic resin foam having a skeleton structure with a three-dimensional network structure is formed on the surface of the skeleton. The skeleton 34 itself having a three-dimensional network structure, which is obtained by adhering a ceramic material such as a ceramics slurry and further drying and firing to burn off the resin foam, is a hollow, and a continuous pore 36 as a whole.
What is formed in the skeleton 34 is used.

As the ceramic material forming such a ceramic porous body 22, known materials such as cordierite, alumina, alumina-cordierite, silicon carbide, mullite, and zirconia are used according to the characteristics required for the intended product. It is selected and adopted appropriately.

Then, the ceramic porous body 22 having such a structure, as described above, is a molten metal having a chemical component controlled according to the physical properties required for the cast product under the condition of being disposed in the casting cavity 20. 26 is poured. Incidentally, as the molten metal 26, those of cast iron or cast steel composition are generally used, but in addition, the present invention can be advantageously applied to the casting of various metal products such as copper alloys and aluminum alloys. Needless to say, the molten metal 26 is appropriately selected according to the raw material of the product.

Further, the molten metal 26 thus poured is generally introduced into the casting cavity 20 through the inlet 30 and the runner 16 as shown in FIG.
While reaching the feeder 18 while filling the gap between the skeletons 34 of the three-dimensional mesh structure 22, the pouring work is completed.

As described above, the molten metal 26 is not limited to non-ferrous and ferrous metals, but when introduced into the casting cavity 20, a temperature drop due to contact with the inner wall surface of the mold 10 is unavoidable. Since the tendency is further promoted by the installation of the ceramic porous body 22, it is desirable to set the molten metal temperature at the time of pouring higher than usual. Further, in order to allow the molten metal 26 to evenly enter between the skeletal tissues of the ceramic porous body 22 (within the cells) and solidify, an appropriate amount of feeder is set as necessary to provide an appropriate molten metal head. However, it doesn't matter.

In this way, after the pouring work of the molten metal 26 is completed, the solidification is performed, and in the casting product in which the solidification is completed, as shown in FIG. A structure in which the cast metal 40 enters a cell composed of a skeleton 34 having a three-dimensional network structure of the porous body 22, and the cast metal 40 constitutes a matrix for the ceramic porous body 22 and has an integral structure. (Composite molded article).

Then, the cast product as the composite molded product obtained in this way
In 32, after the solidification is completed, in order to make the target fluid permeable product, through the steps of open frame, cooling, cleaning by shot blasting, etc., similar to normal casting work, grinder finishing, Machining such as cutting and polishing is performed, and as a result, holes 36 are formed in the exposed surface 38 of the skeleton 34 of the ceramic porous body 22 which is embedded therein, as shown in FIG. The void 36 is the cast product 32 having the surface 38 opened to the outside.

Thereafter, in this way, by the predetermined processing, the pores 36 in the skeleton 34 of the ceramic porous body 22 are opened to the outside. For the cast product 32, roughening treatment such as blasting treatment is performed. It will be given as needed. By this roughening treatment, at least the pore opening surface becomes a roughened surface, and the mechanical bonding force of the porous sprayed layer formed thereon is further improved.

Then, with respect to such a roughened or non-roughened casting 32, a predetermined thermal spraying material is sprayed by a normal thermal spraying operation on the surface including at least the pore opening surface thereof, and there, Thus, a porous sprayed layer will be formed. As a result of this thermal spraying treatment, the hole opening surface 38 of the casting 32 is covered with the porous thermal spray layer 42, as shown in FIGS.
The structure covers the openings of the holes 36 of the skeleton 34 of the ceramic porous body 22 so that the openings of the holes are not directly exposed.

By the way, the thermal spraying technology enables coating using materials such as low to high melting point metals, alloys, ceramics, and plastics, and has little heat effect on the base metal, and is limited in shape and size. While having the characteristic of being difficult, the bond between particles is weak, the adhesion to the substrate is poor, and it has the drawback of being porous, but in the present invention, the thermal spray layer (42), which has been a defect from the past, is Utilizing the porous properties,
By forming the porous layer on the surface of the fluid permeable material, the large opening of the hole 36 of the skeleton 34 of the ceramic porous body 22 inside is covered so that it is not directly exposed. At the same time, the communication with the outside of the hole 36 is effectively maintained. Bareback, 6th
As shown in the drawing, even if the opening of the hole 36 is covered with the thermal spray layer 42, the thermal spray layer 42 is formed of a laminated structure of thermal spray particles 44 made of a predetermined material. There are many pores 46 formed between the spray particles 44, 44,
And by communicating such pores 46 with each other,
The pores 36 of the casting 32 are communicated with the outside through the pores 46, and the pores 46 are much smaller in size than the pores 36.

It should be noted that the porous thermal spray layer 42 covering the surface (38) including at least the pore openings of the cast product 32 is generally formed by a normal thermal spraying technique including a plasma thermal spraying method in recent years. As the material to be sprayed by this spraying operation, not only metal (including alloy) but also known spraying materials such as ceramics, cermet and plastics can be appropriately selected according to the purpose. It will be.

Further, the thickness of the porous sprayed layer 42 formed on the surface (38) including at least the hole opening portion of the cast product 32 will also be appropriately selected according to the purpose, but in general, The thickness is about 50 μm to 800 μm, and it is possible to form a sprayed layer having a thickness of up to 2.5 mm depending on the spraying method.
The size of the pores 46 of 42 is generally 10 to 150 μm,
The size is preferably about 40 to 100 μm. As described above, since the thermal sprayed layer 42 is thin, the pressure loss is small and the clogging is reduced despite the small pore size.

Further, in order to form the porous sprayed layer 42 as described above, it is necessary to control the temperature, the particle speed, the spraying distance, the particle size of the raw material powder (sprayed material), and the material, and the pores of the sprayed layer 42. Since the rate is the temperature and velocity of the sprayed particles, and the pore size thereof depends on the material and particle size of the powder, they are variously controlled in order to realize the target sprayed layer 42 having a porous structure. However, particularly in the present invention, as the thermal spraying powder, a powder having a particle size of about 30 to 70 μm is advantageously used.

Then, in this manner, the cast product 32 in which the porous sprayed layer 42 is formed on the surface (38) including at least the hole opening portion.
Is further subjected to necessary processing, for example, the surface of the sprayed layer 42 is ground as required to form a flat surface as shown in FIG. 6 (b). Based on the pores 36 in the skeleton 34 of the 22 skeleton 34, the skeleton 34 is used as a target fluid-permeable material imparted with a property that allows fluid to pass therethrough.

In particular, the fluid-permeable material thus obtained has a porous sprayed layer 42 with a small pore size on the openings of the pores 36.
Since it is formed and the hole opening is not exposed, even if it is used as a material forming at least a part of the mold cavity forming surface such as a vent hole material, the product surface is not exposed. A material or material which can be advantageously used in such a field because there is no possibility that the hole opening is transferred, and other materials which are affected by the direct opening of the hole opening. Needless to say, is effectively applied to products, and is also effectively used not only as an intake material such as a vent hole, but also as a material or a product for ejecting various fluids to the outside through the holes 36. I will get it.

The present invention has been described in detail above based on a cast product as an example of a fluid-permeable material and a specific example of manufacturing the cast product. However, the present invention is directed to such a specific example and a specific configuration related thereto. Needless to say, it should not be construed as being limited to the description of.

For example, as the ceramic porous body used in the present invention, in addition to the resin foam having a three-dimensional network structure as shown in the examples, a skeleton of a structure made of a burnable material such as a comb-shaped product or a sword-shaped product is provided. Those obtained by adhering a predetermined ceramic material and then firing and sintering it are all well used.

Further, in the above example, as the fluid permeable material according to the present invention,
Although the fluid permeable cast product was clarified, in addition to the cast product of this example, a plastic material, a glass material, and a ceramic material are used as a matrix material, and they are provided with a three-dimensional network structure of a predetermined ceramic porous body. To manufacture the intended fluid-permeable product by filling it in the tissue gap and by sintering such a filling material in the case of a ceramic material to form a structure integral with the porous ceramic body. Is also possible.

In addition, although not listed one by one, the present invention can be carried out in various modified, modified, and improved modes based on the knowledge of those skilled in the art. Unless departing from the gist of the present invention,
It should be understood that all are within the scope of the present invention.

(Effects of the Invention) As is apparent from the above description, the present invention is a composite molded article such as a cast article integrally including a ceramic porous body having a hollow structure with a continuous skeleton, and such ceramic porous body A porous thermal sprayed layer is formed on the surface including the pore opening portion so as to include at least the portion where the pores of the skeleton of the skeleton are opened, and the intended fluid permeable material is obtained. Thereby, while maintaining the fluid permeability characteristics due to the pores of the skeleton of the ceramic porous body of the fluid permeable material, it has been possible to advantageously achieve the improvement of the surface roughness thereof, and at least that of the sprayed layer. By changing the thickness, porosity, and pore size, it was possible to obtain effects such as easy control of the fluid permeation performance, and there is a great industrial significance of the present invention. is there.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing a step for producing a fluid-permeable material according to the present invention, and FIG. 2 is an enlarged cross-sectional explanatory view of a main part showing a ceramic porous body used therein. FIG. 3 is an enlarged cross-sectional explanatory view of an essential part showing a cast product obtained by such a manufacturing method, and FIG. 4 is an enlarged explanatory view showing a machined surface of the cast product in FIG.
FIG. 5 is an overall perspective view of the cast product in FIG.
FIG. 6 (a) is an enlarged cross-sectional explanatory view of a main part showing a state in which a porous sprayed layer is formed on the processed surface of such a cast product.
Drawing (b) is a figure corresponding to Drawing 6 (a) showing the state where the surface of the porous sprayed layer was ground. 10: Mold, 20: Casting cavity 22: Porous ceramics 26: Molten metal, 32: Cast product 34: Skeleton, 36: Pores 38: Processed surface, 40: Cast metal 42: Porous sprayed layer, 44: Sprayed particles 46: Pore

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomihiko Teramoto 1-1-1, Sanhonmatsucho, Atsuta-ku, Nagoya-shi, Aichi Japan Vehicle Manufacturing Co., Ltd. (72) Inventor Shinichi Hoshino 2-266 Kitafucho, Kasugai-shi, Aichi Prefecture (56) References JP-A 61-163224 (JP, A) JP-A 62-30038 (JP, A)

Claims (8)

[Claims] 1. A matrix material is made of the matrix material, wherein the skeleton constituting the porous structure itself has a hollow structure, and the matrix material enters the gaps of the skeleton of the ceramic porous body in which continuous pores are formed in the skeleton. It has an integrated composite structure in which the ceramic porous body is embedded in a continuous matrix, and porous spraying is performed on a surface portion including at least a portion where pores of the skeleton of the ceramic porous body are opened. A fluid permeable material, characterized in that a layer is formed and the porous sprayed layer covers the pore openings to substantially reduce the size of the fluid permeable pores. 2. The ceramic porous body is a structure having a skeletal structure of a three-dimensional network structure.
A fluid-permeable material according to item. 3. The fluid permeable material according to claim 1, wherein the porous sprayed layer has a pore size of 10 to 150 μm. 4. The fluid-permeable material according to any one of claims 1 to 3, wherein the matrix material is cast iron or cast steel. 5. A molding operation of a fluid matrix material is carried out in the presence of a ceramic porous body having a hollow structure in a skeleton constituting a porous structure and having continuous pores in the skeleton, The matrix material is allowed to enter the gaps of the skeleton of the ceramic porous body to form an integrated composite molded article, and the composite molded article is processed, and the surface thereof has pores of the skeleton of the ceramic porous body. A method for producing a fluid-permeable material, characterized in that a porous sprayed layer is formed on the surface of the composite molded article including at least the processed portion by a spraying operation. 6. The ceramic porous body is a structure having a skeletal structure of a three-dimensional network structure.
The manufacturing method described in the item. 7. The method according to claim 5, wherein a surface roughening treatment is performed on a surface of the composite molded article including at least the processed portion prior to the thermal spraying operation. 8. A molten molded product of cast iron or cast steel is used as the fluidity matrix material to carry out a casting operation to form a composite molded product in which the ceramic porous body is embedded in the resulting cast product. The manufacturing method according to any one of claims 5 to 7.