JPS63176378A - Manufacture of fluid-permeable product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method for manufacturing fluid-permeable products, and in particular to a method for producing a fluid-permeable product, such as a cast product or cast product that has continuous pores and has the property of being able to permeate fluids. The present invention relates to an improvement in the manufacturing method, which is advantageous without metallurgical or mechanical treatments.

(Background Art) As a method for advantageously manufacturing products such as cast products that have continuous pores and have the property of being permeable to fluids without adding any metallurgical or mechanical treatment, the present applicant has First,
Patent Application No. 1983-246360 and Patent Application No. 1983-28146
In No. 7, etc., sintering the ceramic material attached around the skeleton of the skeletal structure of a structure such as a three-dimensional network structure made of synthetic resin, and causing the synthetic resin part constituting the skeletal structure to disappear. obtained by,
A ceramic porous body in which a three-dimensional network structure is maintained by sintering the adhered ceramic material, while the skeleton of the three-dimensional network structure itself is hollow, and continuous pores are formed within the skeleton as a whole. The pores formed in the skeleton of the three-dimensional network structure of the ceramic porous body are utilized by inserting a predetermined matrix material into the gaps of the three-dimensional network structure to form an integral structure. As a result, we have clarified a method for producing products that allow fluid to pass through, such as cast products, cast products, and sintered bodies thereof.

By the way, the three-dimensional network structure made of synthetic resin that provides the ceramic porous body used in the manufacturing method of such fluid-permeable products is generally obtained using a specified synthetic resin foam; Synthetic resin foams have a three-dimensional network structure skeletal weave composed of resin parts that exist between spherical cells generated within a given synthetic resin material. The cross-sectional shape is extremely acute and has a deep triangular shape. Therefore, by attaching a certain ceramic material around the skeleton with such a cross-sectional shape and sintering it, such a skeleton can be made. When the constituent synthetic resin part disappears, pores with a significantly acute triangular cross-sectional shape corresponding to the skeleton shape are formed within the skeleton made of the sintered body of the adhered ceramic material. It will be done.

On the other hand, in fluid-permeable products such as those mentioned above, the permeation loss during permeation varies depending on the type of fluid flowing through the internal pores, even if the cross-sectional area and arrangement form of the pores are the same. For example, when a fluid with a larger kinematic viscosity coefficient than air, such as oil or water, is allowed to permeate depending on the purpose, the permeation loss is This results in a significant increase.

Therefore, as mentioned above, if the cross-sectional shape of the skeleton of the three-dimensional network structure made of synthetic resin that provides the ceramic porous body has extremely acute corners, such as an acute triangular shape, such cross-section Since pores corresponding to the shape are formed within the framework of the porous ceramic body, the problem is that the permeation loss increases or the amount of permeation decreases depending on the type of fluid being permeated. is inherent.

In addition, impurities contained in the permeating fluid accumulate at the sharp corners of such pores, causing problems that not only reduce the amount of fluid permeated, but also, in extreme cases, cause the pores to become clogged. Furthermore, in order to obtain a porous ceramic body, the area around the skeleton of the three-dimensional network structure of synthetic resin increases, which reduces the amount of ceramic material to be attached. This has inherent problems, such as increasing the amount of ceramic material introduced into the final fluid-permeable product, which can reduce the absolute strength of the desired product. .

(Structure of the Invention) The present invention has been made against the background of the above-mentioned circumstances, and its object is to provide a cast article having continuous pores and having the property of being able to permeate fluid. It is an object of the present invention to provide an improved method by which products such as molded products can be advantageously produced without metallurgical or mechanical treatment, and other objects of the invention are
The pores formed in the framework of the porous ceramic body have a rounded shape without sharp corners, and the cross-sectional area is increased, thereby increasing the amount of fluid permeation in the fluid-permeable product obtained. In addition, it aims to improve pressure loss by increasing the number of sharp corners and reducing the number of sharp corners, and also effectively suppresses problems such as the accumulation of foreign matter contained in the fluid in the pores and the resulting clogging. There is a particular thing.

In order to achieve such an objective, the present invention
The attached ceramic material is obtained by sintering the ceramic material attached around the skeleton of the skeletal structure of a three-dimensional network structure made of a synthetic resin, and at the same time eliminating the synthetic resin part that constitutes the skeletal structure. While the three-dimensional network structure is maintained through sintering, the skeleton of the three-dimensional network structure itself is made hollow, and continuous pores are formed within the skeleton. By inserting a predetermined matrix material into the gaps of the original network structure to create an integrated structure, fluid can pass through by utilizing the pores formed within the skeleton of the three-dimensional network structure of the ceramic porous body. When manufacturing a product in which the porous ceramic body is made of a material that can be bonded, a predetermined material made of a burnable material is placed around the skeleton of the skeletal structure of the three-dimensional network structure made of the synthetic resin prior to the attachment of the ceramic material. A material obtained by forming a thick coating layer to thicken the skeleton, depositing the ceramic material on top of the skeleton, and firing the ceramic material was used.

(Specific Structure/Example) By the way, when manufacturing, for example, a fluid-permeable cast product according to the method of the present invention, as shown in FIG. By pouring a predetermined molten metal into a ceramic porous body having a specific structure as shown in FIG. 2, a three-dimensional structure as shown in FIGS. The desired cast product is produced, which has continuous pores (pores) and has the property of being able to permeate fluid.

In addition, in FIG. 1, IO is the upper mold 12 and the lower mold 1.
The self-hardening mold is generally manufactured using a permanent mold (mold) or the like using green sand or resin as a hardening medium. Also,
In the mold 10, a ceramic runner 16, a riser 18, and a product cavity 20 of a predetermined shape are formed. A ceramic porous body 22 having a predetermined three-dimensional network structure is set within this cavity 20. Further, a molten metal 24 is provided at the bottom of the cavity 20 of the mold 10, and a predetermined molten metal 2
6 is poured from the ladle 28 through the inlet 30.

In addition, in FIG. 1, in order to obtain a product in which a porous ceramic body is cast throughout the casting as shown in FIG. However, the placement position and shape of the ceramic porous body 22 in the cast product are not limited, and are determined as appropriate depending on the intended product.
For example, if the porous ceramic body 22 is set with some of its outer circumferential surfaces floating from the inner surface of the product cavity 20, a suitable fastener such as a keren will be used.

Here, the ceramic porous body 22 having a three-dimensional network structure according to the present invention, which is placed and fixed in this cavity 20, is arranged around the skeleton of the skeletal tissue of the three-dimensional network structure made of a predetermined synthetic resin, that is, around the skeleton of the three-dimensional network structure made of a predetermined synthetic resin. By forming a coating layer of a predetermined thickness made of a burnt-out material over the entire surface to thicken the skeleton, attaching a predetermined ceramic material thereon, and drying and firing it, That's what you get.

The ceramic material to be attached to the surface of the skeleton of such a three-dimensional network structure of synthetic resin may be cordierite, alumina, SiC, mullite or Zirconia or the like is selected and adopted as appropriate.

By the way, the three-dimensional network structure made of synthetic resin that provides the ceramic porous body 22 is generally made of a film-like substance (foamed film) remaining around the skeleton after foaming a resin such as ester polyurethane. ) is removed using compressed air or the like according to a known method, and a synthetic resin foam having a three-dimensional network structure is advantageously used. In addition, foaming in such resin foams such as polyurethane foam is performed by the action of gases such as carbon dioxide gas generated by chemical reactions and/or evaporated gases of volatile blowing agents, and thereby A large number of spherical bubbles are formed,
The resin parts existing between these cells form a three-dimensional network skeleton structure that forms a dodecahedron, but immediately after foaming, polyurethane foam, etc.
Since a thin film of material such as polyurethane is attached around the skeleton, the thin film other than the skeleton is removed using known methods such as heat treatment, dissolution with a solvent, and removal using water pressure (water jet). becomes.

However, the cross-sectional shape of the skeleton of the three-dimensional network structure obtained in this way is theoretically composed of continuous arcs at the junctions of spherical gas bodies, as shown in Fig. 6. The cross-sectional shape is close to an acute triangle as shown in FIG. 7(a). In these figures, 50 is a cell of the foam, 52 is a skeleton of a three-dimensional network structure made of a foamed resin material, and 54 is a foam membrane that connects the skeletons 52 and 52. It is. In this way, when there are extremely acute and deep corners 56 in the cross-sectional shape, such as the skeleton 52 of the skeletal tissue of a three-dimensional network structure obtained from a foam such as polyurethane foam, , pores having a cross-sectional shape corresponding to such a shape are formed in the skeleton of the obtained porous ceramic body.

Therefore, in the present invention, for a three-dimensional network structure composed of a skeleton having sharp corners 56, such as a foam from which the foam membrane has been removed, first, the skeleton of the skeletal tissue is examined. A coating layer made of a predetermined burn-out material is formed around it to a predetermined thickness to thicken the skeleton. That is, by impregnating such a three-dimensional network structure with a predetermined burn-out material, for example, using a treatment liquid in the form of a solution or dispersion thereof, the structure shown in FIG. 7(b) is obtained. As shown in FIG.
8, and its skeletal shape is shaped by its sharp corners (
56) has been eliminated to create an overall rounded structure.
The cross-sectional area of the skeleton itself is also increased, making it thicker.

Note that various burnable materials made of natural or synthetic materials or substances may be used to form the burnable coating layer 58, and such burnable materials may be used to form a three-dimensional network structure. By treating the body, a burnable coating layer 58 of a desired thickness is created around its skeleton.
However, in the present invention, an ordinary resin paint, preferably an emulsion paint such as vinyl chloride resin, vinyl acetate resin, urethane resin, or rubber, is used. By immersing the three-dimensional network structure in such a coating liquid and repeating the immersion process an appropriate number of times as necessary, a coating layer 58 having a desired thickness is formed. Furthermore, the coating layer 58 formed around the skeleton 52 in this manner must be of a type that does not have an adverse effect on the subsequent deposition operation of the ceramic material, for example, it must be such that the ceramic material is deposited in a slurry state. If such a slurry is used, the coating layer 58 will be such that it cannot be dissolved in such a slurry.

Here, forming such a burnable coating layer 58,
To give a more specific example, first, a commercially available vinyl chloride resin emulsion liquid (vinyl chloride resin powder surfactant + water) is prepared with a viscosity of 300 to 1000 centivoise, and then the desired shape, A three-dimensional network structure of a predetermined size cut to size is immersed, and after impregnating it one to several times depending on the required thickness of the coating layer, it is squeezed with a roll or the like, as shown in Fig. 7. As shown in (b),
After obtaining the desired coating layer (58) and coating state, 1 to 4
It is dried for about an hour. Then, the burnable coating layer 58 made of vinyl chloride resin is coated on the skeleton 5.
2, its apparent specific gravity is 0.0 before coating.
35 to about 0.08, an increase in the skeleton (thickness) is recognized, and the cross-sectional area increases by about 1.5 times.

Of course, the predetermined burn-out material forming such a coating layer 58 is not limited to a vinyl chloride resin emulsion paint, but may also be advantageously used a vinyl acetate resin-based, urethane resin-based, or rubber-based emulsion paint. However, in general, it is desirable that the burnable material constituting the coating layer 58 has a relatively low thermal decomposition temperature and leaves little residue. Various known methods other than coating methods may be employed as appropriate depending on the material.

The burnable coating layer 58 is thus formed, the sharp corners are removed, and the three-dimensional network structure has a rounded cross-sectional shape. Ceramic materials are impregnated and adhered in a slurry state, and excess slurry is removed.
Furthermore, after drying, a firing operation corresponding to the attached ceramic material is performed, so that the skeleton 52 made of synthetic resin and the coating layer 58 made of burnable material are burned out at the same time as the ceramic material is sintered. As a result, holes 36 corresponding to the shape are formed in the skeleton 34 of the three-dimensional network structure made of the sintered ceramic material 35, as shown in FIG. 7(C). . In other words, the predetermined ceramic material 35 deposited to a predetermined thickness on the surface of the coating layer 58 is sintered to form a three-dimensional network structure skeleton 34, and the structure shown in FIG. Since a hollow portion 36 corresponding to the cross-sectional shape as shown in (b) will be formed, such a hollow portion (hole) 36
has a rounded cross-sectional shape with no sharp corners.

In short, the ceramic porous body 22 used in the present invention obtained by such a method is as shown in FIG.
) has a skeleton 34 having holes 36 without sharp corners in a three-dimensional network structure as shown in FIG. 2, and the skeleton 34 itself is hollow, Overall, continuous pores 36 are formed within the skeleton 34. The ceramic porous body 22 having such a structure generally has a porosity of about 60 to 90%, and the number of cells is 2 to 40/25.
It is about the size of a dragon.

Then, a porous ceramic body 2 having such a structure
2 is placed in the cavity 20,
A molten metal 26 having chemical compositions controlled according to the physical properties required of the cast product is poured. Although cast iron and cast steel are generally used as the molten metal 26, the present invention can also be advantageously applied to casting various metal products such as copper alloys and aluminum alloys. , therefore, such molten metal 26
Needless to say, the material is selected depending on the raw material of the product.

Moreover, the molten metal 26 poured in this way is generally
As shown in FIG.
6 into the product cavity 20, and while filling the gaps between the skeletons 34 of the three-dimensional network structure of the ceramic porous body 22, it reaches the feeder 8, thereby completing the pouring operation.

In addition, as this molten metal 26, as mentioned above, non-ferrous metal,
Although there is no limitation on iron-based materials, when introduced into the product cavity 20, a temperature drop due to contact with the inner wall surface of the mold 10 is unavoidable, and the installation of the ceramic porous body 22 further aggravates this tendency. Therefore, there is a possibility that cementite m-weave may occur in thin-walled corners, etc.
It is desirable that the temperature of the molten metal during pouring be set higher than normal. Furthermore, in order to allow the molten metal 26 to evenly penetrate between the skeletal structures (inside the cells) of the ceramic porous body 22 and solidify it, it is necessary to set an appropriate amount of the riser 18 and provide an appropriate molten metal head. desirable.

In addition, in FIG. 1, the molten metal 24 is filled with molten metal 2.
6 is provided so that the space between the skeletons 34 of the ceramic porous body 22 can be uniformly filled at a constant speed, and its capacity and position are determined depending on the shape of the intended cast product. , size, material, etc., and are generally removed by machining or the like after casting is completed.

In the thus obtained cast product 32 that has been solidified, as shown in FIGS. 3 and 4, cells constituted by a skeleton 34 having a three-dimensional network structure of the porous ceramic body 22 The cast metal 40 enters into the ceramic porous body 22, forming an integral structure with the cast metal 40 forming a matrix for the ceramic porous body 22, while filling the voids in the skeleton 34 of the cast ceramic porous body 22. Intrusion of the molten metal 26 into the holes 36 is suppressed by its surface tension, so the holes 36 are maintained in a communicating state.

After the solidification of such a cast product is completed, it undergoes the same processes as normal casting work, such as cracking, cooling, cleaning by shot blasting, finishing with a grinder, etc., and then becomes the desired finished cast product 32. However, in particular, in the cast product of the present invention, the openings of the holes 36 in the exposed surface 38 of the skeleton 34 of the ceramic porous body 22 embedded therein are closed with the cast metal 40. for,
By cutting or polishing the exposed surface 38, the holes 36 are opened to the outside, as shown in FIGS. 3 to 5.
As shown in the figure, the desired cast product 32 is obtained, which has fine continuous pores with a three-dimensional mesh structure inside and has the property of being able to permeate fluid.

In addition, in FIGS. 3 and 4, since the cross section of the cast product 32 according to the present invention is shown two-dimensionally, the cast metal 40 is shown in a divided form, but the ceramic porous The body 22 is composed of a skeleton 34 having a three-dimensional network structure, and has a cellular structure in which continuous cells are formed inside, so that it has a continuous and integral structure in three dimensions. It should be understood that

The above is based on a specific example of manufacturing a fluid-permeable cast product.
Although the present invention has been described in detail, the present invention is not to be construed as being limited only to the description of such specific examples and specific configurations related thereto; Also, plastic materials, glass materials, and even ceramic materials are used as matrix materials, and they are filled into the interstitial spaces of the three-dimensional network structure of a predetermined ceramic porous body. By sintering the filler material to form an integral structure with the ceramic porous body, it is also possible to produce the desired fluid permeable product.

Furthermore, on the upper side, a synthetic resin foam from which the foam membrane has been removed, to which the present invention can be advantageously applied, is used as a three-dimensional network structure of synthetic resin that provides the ceramic porous body, in particular polyurethane foam. It goes without saying that there is no problem in using various three-dimensional network structures made of synthetic resins manufactured by other methods, and furthermore, the skeleton of such three-dimensional network structures is Application of the present invention can advantageously thicken the skeletal tissue not only of cross-sectional shapes with acute corners, but also of other cross-sectional shapes.
This makes it possible to advantageously increase the cross-sectional area of the pores formed in the framework of the porous ceramic body.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. added based on the knowledge of those skilled in the art, and such embodiments are the same as the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not depart from the spirit of the invention.

(Effects of the Invention) As is clear from the above description, according to the present invention, the pores formed in the skeleton of the three-dimensional network structure of the porous ceramic body that provide the characteristics of the fluid-permeable product have sharp corners. It has a rounded cross-sectional shape as a whole, with no parts.
Furthermore, since the cross-sectional area of the pores increases, the amount of fluid permeation is effectively increased in fluid-permeable products obtained using the pores. The pressure loss of the flowing fluid is effectively improved, and problems such as the accumulation of impurities contained in the fluid, which reduces the amount of fluid passing through it, and even the pores are clogged, can be effectively improved. This meant that it could be resolved.

In particular, the fluid-permeable product obtained in accordance with the present invention is particularly effective in permeating fluids with relatively high coefficients of kinematic viscosity, such as water and oil, as opposed to gases such as air, which have low coefficients of kinematic viscosity.
This results in even better effects.

In addition, the fluid-permeable product obtained according to the present invention has continuous pores with a three-dimensional network structure and a fine cross-sectional shape, and has the property of being able to permeate fluid. Products with such characteristics have never been seen before, and depending on the purpose of use, fluids such as air, gas, water, hot water, or oil can be introduced into the pores. Since it is possible to communicate freely, it can be widely used in various members that take advantage of this property.

Furthermore, according to the method of the present invention, the desired fluid-permeable product can be advantageously manufactured with good productivity without adding any metallurgical or mechanical treatment and according to the same conventional method. It goes without saying that it is possible.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing one step of the method of the present invention, FIG. 2 is an explanatory enlarged cross-sectional view of the main part showing the ceramic porous body used therein, and FIG. FIG. 4 is an enlarged explanatory view of a main part of the cast product obtained in FIG. 3, and FIG. 5 is an overall perspective view of the cast product. Moreover, FIG. 6 is an explanatory cross-sectional view of the main part schematically showing the structure of a synthetic resin foam used for manufacturing a porous ceramic body, and FIG. FIG. 7(b) is an explanatory diagram showing a cross section, and FIG. 7(C) is an explanatory cross-sectional diagram showing a state in which a predetermined coating layer is provided on the surface of such a skeleton. ) is an explanatory view showing the cross-sectional structure of the skeleton of a porous ceramic body obtained by attaching a ceramic material to the cross-sectional structure shown in FIG. 10: Mold 20: Product cavity 22: Porous ceramic body 26: Molten metal 34: Skeleton 36: Holes 40: Cast metal 50: Bubbles 52: Synthetic resin foam skeleton 54: Foamed membrane 58: Burnable coating layer Applicant Stock Company Subeya Figure 2 Figure 4 Figure 5

Claims (4)

[Claims] (1) The adhesion obtained by sintering the ceramic material attached around the skeleton of the skeletal structure of the three-dimensional network structure made of synthetic resin and eliminating the synthetic resin portion that constitutes the skeletal structure. The three-dimensional network structure is maintained by sintering the ceramic material, while the skeleton of the three-dimensional network structure itself is hollow, and continuous pores are formed in the skeleton as a whole. By inserting a predetermined matrix material into the gaps of the three-dimensional network structure to form an integral structure, the pores formed in the skeleton of the three-dimensional network structure of the ceramic porous body are utilized. When manufacturing a product that allows fluid to pass through, as the ceramic porous body, a burnable material is added around the skeleton of the skeletal structure of the three-dimensional network structure made of the synthetic resin, prior to the attachment of the ceramic material. A fluid-permeable product characterized by using a product obtained by forming a coating layer of a predetermined thickness, thickening the skeleton, attaching the ceramic material thereon, and firing it. manufacturing method. (2) The manufacturing method according to claim 1, wherein the coating layer is formed using an emulsion paint. (3) The manufacturing method according to claim 1 or 2, wherein the three-dimensional network structure is a polyurethane foam obtained by removing a foam membrane. (4) The manufacturing method according to any one of claims 1 to 3, wherein the matrix material is cast iron or cast steel.