JPS63192549A - Production of fluid permeable product - Google Patents

Abstract

PURPOSE:To improve fluid permeability characteristic by forming a fluid basin connecting through void formed in skelton of a ceramic porous body and working uniform fluid pressure at whole void opening in the fluid basin. CONSTITUTION:In the ceramic porous body 28 fixing a core at one face, the molten metal is poured in a casting cavity. In the casting obtd. by solidifying the molten metal, the casting metal 44 is impregnated in a cell composing of the skelton 30 forming the porous structure in the ceramic porous body 28. The casting metal 44 is made to the integrated structure composing of a matrix to the ceramic porous body 28. The core burried in the inner part to the casting is removed, and the fluid basin 48 connecting through the void 32 formed in the skelton 30 in the porous body 28 is formed. Therefore, in the porous casting 50, the uniform fluid pressure is worked over the whole body.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method for manufacturing fluid-permeable products, and particularly to cast or cast products that have the property of allowing fluid to permeate through continuous pores formed inside. The present invention relates to a method for advantageously producing products such as those having even further improved fluid permeation properties without any particular metallurgical or mechanical treatment.

(Background Art) As a product such as a cast product that has continuous pores and has the property of being able to permeate fluid, the applicant of the present application previously filed a Japanese patent application filed in 1983.
No. 246360, Japanese Patent Application No. 61-281467, Japanese Patent Application No. 61-304744, etc. disclose porous ceramics in which the skeleton itself forming the porous structure is hollow, and continuous pores are formed within the skeleton as a whole. By using a ceramic porous body and injecting a predetermined matrix material into the gaps of the porous structure to form an integral structure, the pores formed in the framework of the porous structure of the porous ceramic body are utilized.
We have revealed new products that allow fluid to pass through, such as cast products, cast products, and sintered products.

Incidentally, in such fluid-permeable products, for example, a porous ceramic body having pores that allow fluid to permeate in the framework of the porous structure is placed at a predetermined position in a product cavity formed by an appropriate mold. By supplying a predetermined matrix material into the product cavity under the condition that the product is placed in Therefore, by forming fluid supply holes or discharge holes that communicate with the holes formed inside such products through post-processing, air float bases, air suction tables, bearings, etc. It becomes possible to manufacture parts, heat exchange members, filters, catalysts, etc. with a single structure extremely advantageously without adding difficult metallurgical or mechanical treatments.

However, in a fluid-permeable product in which a ceramic porous body is buried inside and fluid supply or discharge holes are formed to communicate with the pores, it is difficult to connect the fluid supply or discharge holes. With respect to the fluid pressure acting in the hole through the hole, a pressure loss will be caused depending on the distance from the fluid supply hole or the discharge hole. Therefore, depending on the shape of the fluid supply hole or the discharge hole, There is a risk that the pressure and flow rate distribution of the circulating fluid within the holes may become non-uniform.

Therefore, for example, pores in a porous ceramic body buried inside are opened on one side of the product to form a fluid ejection surface, and fluid supply holes communicating with the pores are formed in the wall of the product. In hydrostatic fluid bearings, air float bases, etc., which have a structure in which the In products where uniformity of fluid ejection amount is important, there has been a problem in that sufficient performance or characteristics cannot be obtained.

By the way, as a method to equalize the fluid pressure that is applied through the pores formed inside such products, it is possible to supply or discharge fluid to the back of the ceramic porous body embedded in such products. By forming a space as a fluid reservoir in which the pores communicate, and by opening the pores of the ceramic porous body on a plane parallel to the fluid jetting surface and communicating with the space, the pores in the pores are It is conceivable to make the distance from the fluid supply port to the ejection port uniform over the entire area, but when forming such a space by mechanical processing, such a product must have at least a two-part structure. Therefore, an increase in cost due to an increase in processing steps is unavoidable, and the shape may be extremely difficult, so it cannot be called an effective method.

(Solution Means) Here, the present invention has been made against the background of the above-mentioned circumstances, and its purpose is to eliminate voids formed within the framework of a ceramic porous body embedded within a product. In order to improve the fluid permeability properties of a product imparted with fluid permeability through pores, a fluid reservoir is provided in communication with the pore openings in at least a portion of a predetermined surface of the ceramic porous body. An object of the present invention is to provide a method that can advantageously produce a fluid-permeable product formed inside a fluid-permeable product without particularly applying any metallurgical or mechanical treatment.

In order to achieve this objective, the present invention is characterized by porous! The skeleton forming the 1111 weave itself is hollow, and a ceramic porous body with holes formed in the skeleton is placed in a predetermined product cavity, and a predetermined matrix material is placed in the product cavity. By supplying the matrix material into the gaps of the framework of the porous ceramic body to form an integral structure, the matrix material is formed within the framework of the porous structure of the porous ceramic body. When manufacturing a product that allows fluid to permeate by utilizing the pores formed in the ceramic body, the pores formed in the skeleton of the ceramic porous body are used as the ceramic porous body at least on a predetermined surface to be embedded in the product. In addition to being partially opened,
A fluid reservoir forming member made of a material that does not disappear due to contact with the matrix material during the integral molding operation and can be removed after the integral molding operation is placed on the surface where the holes are opened, and the openings are removed. While using a material fixed to cover the fluid reservoir, after the integral molding operation, the fluid reservoir forming member is removed, so that the fluid reservoir formed within the framework of the ceramic nox porous body is inside the obtained product. This is because a fluid reservoir communicating with the hole is formed.

(Specific Structure/Example) In order to clarify the present invention more specifically, reference will now be made to the examples shown in the drawings for the case where, for example, a fluid-permeable cast product is manufactured according to the method of the present invention. However, I will explain it in detail.

First, in FIG. 1, a large number of pores formed inside and communicating with each other are opened on one side (surface) of the product, forming an exposed surface, and communicating with the pores. A process for manufacturing a cast product, such as an air float base or an air suction table, in which fluid supply or discharge holes are formed in the wall of the product according to the method of the present invention is shown. .

That is, in this figure, 10 is a mold, which is composed of an upper mold 12 and a lower mold 14, and is generally used for self-hardening mold making using green sand or resin as a hardening medium, or for permanent mold making (metal molding). It was manufactured using a mold (type) etc. Also, inside the mold 10, there is a receiving inlet 16, a runner 18, and a runner 18.
A casting cavity 22 having a predetermined shape is formed, and a predetermined molten metal 24 is guided into the casting cavity 22 from a ladle 26 through the receiving port 16 and the runner 18. A ceramic porous body 28 is set at a predetermined position within this casting cavity 22.

Here, the ceramic porous body 28 placed and fixed in the casting cavity 22 is one in which the skeleton itself forming the porous structure is hollow, and pores are formed in the skeleton, for example. , as shown in Figure 2, is obtained by foaming a resin such as ester-based urethane and then removing the film-like material (foamed film) remaining around the skeleton using compressed air or the like. It is obtained by attaching a ceramic material such as a ceramic slurry to the surface of the skeleton of a synthetic resin foam having a three-dimensional network structure, and then drying and firing to burn out the resin foam. , the skeleton 30 of the three-dimensional network structure itself is hollow, and the pores 32 are continuous as a whole.
is formed within the skeleton 30, etc., will be used.

Note that as the ceramic material forming the ceramic porous body 28, cordierite, alumina, SiC, mullite, zirconia, etc. may be selected and employed as appropriate depending on the characteristics required for the intended product. It is.

In such a ceramic porous body 28, as shown in FIG. The holes 32 are opened in the exposed surface of the surface that is opposite to the surface that should be exposed to the outside, and the holes 32 are made of a non-disappearing material and have a predetermined size with respect to the opened surface. Core 3 as a fluid reservoir forming material
4 is fixed so as to cover the opening of the hole 32.

That is, the skeleton 3 of such a ceramic porous body 28
The holes 32 formed in the 0 are normally formed in a closed state on the outer peripheral surface thereof, but these holes 32 are buried in the cast product and are used as fluid supply or discharge holes. Openings are made by polishing, cutting, etc. on one surface where the holes 32 are to be communicated, and then a core is placed on the surface where the holes 32 are opened so as to cover the openings of the holes 32. 34 is fixed.

By the way, the material for forming the core 34 is a material that does not disappear when it comes into contact with the molten metal 24 during casting.
Any material can be used as long as it can maintain its shape and can be removed after casting, as will be described later, but foundry sand is particularly suitable for cast products such as those shown in the example. It will be suitably used.

Further, when fixing such a core 34 to the ceramic porous body 28, an appropriate adhesive 36 is used as appropriate, and an adhesive layer (3
In step 6), by preventing the molten metal 24 from entering between the two members during casting, the openings of the pores 32 in the ceramic porous body 28 can be effectively secured. In addition, as the adhesive 36,
Like the core 34, it must be able to maintain its shape without disappearing upon contact with the molten metal 24 during casting, and must also be removable after casting, as will be described later. For example, a known material such as a core adhesive that dries quickly at room temperature and is composed of polyvinyl acetate, asbestos, methanol, ethyl acetate, and an activator is preferably used.

Then, the ceramic porous body 28 with the core 34 fixed to its surface in this way is placed in the casting cavity 22, for example, as shown in FIG. It is set in a state floating from the inner surface of the cavity 22 using a suitable stopper 38 such as a keren, but in addition, especially in the method of the present invention, as shown in FIG. Core 40 with skirting board
By using the core 40, the ceramic porous body 28 can be held at a predetermined position in the casting cavity 22, and thereby, as will be described later, the fluid supply or discharge hole (the communication hole 46 ) can be formed simultaneously with casting. In addition, in FIG. 7, in order to facilitate understanding, the same reference numerals are given to members having the same structure as in the embodiment shown in FIG. 1. .

In this way, a molten metal 24 having a chemical composition controlled according to the physical properties required of the cast product is poured into the casting cavity 22 in which the ceramic porous body 28 is placed at a predetermined position. I am forced to pour hot water. Although cast iron and cast steel are generally used as the molten metal 24, the present invention can also be advantageously applied to casting various metal products such as copper alloys and aluminum alloys. , Therefore, such molten metal 2
It goes without saying that No. 4 is appropriately selected depending on the raw material of the product.

Moreover, the molten metal 24 poured in this way is generally
As shown in FIG. 1, the molten metal is introduced into the casting cavity 22 through the inlet 16 and the runner 18, and fills the gap between the porous skeletons 30 of the ceramic porous body 28.
The pouring operation is completed by filling the casting cavity 22 with the molten metal.

Therefore, as shown in FIG. 4, in a cast product 42 obtained by solidifying the molten metal 24 according to such a casting method, the ceramic porous body 2
A cast metal 44 is inserted into the cell formed by the skeleton 30 forming a porous structure of 8, and the cast metal 44 forms a matrix for the ceramic porous body 28 to form an integral structure. The intrusion of the molten metal 24 into the pores 32 in the skeleton 30 of the cast ceramic porous body 28 is caused by the fact that the openings of the pores 32 are closed, so that the pores 32 are maintained in a communicating state. The Rukoto. Furthermore, in such a cast product 42, the core 34 and the adhesive 36 cover the openings of the holes 32 formed in the skeleton 30 on one surface of the ceramic porous body 28, It is formed with a structure embedded in cast metal 44.

Next, the solidified cast product 42 is unframed and cooled using the same method as in normal casting operations, and the cast product 42 taken out is then supplied with fluid or As shown in FIG. 6, a communication hole 46 serving as a discharge hole is formed by machining or the like so as to reach from the outer surface to the core 34 buried inside.

Thereafter, the cast product 42 is subjected to mechanical treatment using hydroblasting, shot blasting, etc., or chemical treatment using appropriate chemicals, so that the core buried therein is removed. 34, and even adhesive 36
is removed or eluted through the communication hole 46. That is, by removing the core 34 and the adhesive 36, the ceramic porous body 21 is removed inside the cast product 42, as shown in FIGS. 5 and 6.
In this way, a fluid reservoir 48 is formed which communicates with the hole 32 formed in the skeleton 30 of 8.

In addition, in such a cast product 42, the openings of the pores 32 on the exposed surface (the surface of the cast product) of the skeleton 30 of the ceramic porous body 2B buried therein are usually formed in the ceramic or cast metal 44. Therefore, by cutting or polishing the exposed surface, the holes 32 are opened to the outside, and are further processed by sanding, cleaning, and grinding according to the usual method. etc. will be performed as necessary, and the desired porous cast product 50 will be obtained.

Therefore, the porous cast product 50 thus obtained has a fluid reservoir 48 therein, and has a back surface relative to the exposed surface 51 of the ceramic porous body 28 embedded in the cast product 50. Since the openings of the holes 32 located in the holes 32 are communicated with the fluid reservoirs 48, the fluid is supplied to or discharged from the holes 32 through the communication holes 46. This is done through the reservoir 48, and as a result, uniform fluid pressure can be applied to the rear openings of the holes 32 over the entire surface.

Therefore, in such a porous cast product 50, the exposed surface 5 where the pores 32 of the ceramic porous body 28 are opened.
1 and the back surface where the hole 32 opens into the fluid reservoir 48 are formed so that they are parallel surfaces, so that the fluid is ejected or inhaled from the opening of the hole 32 located on the exposed surface 51. This makes it possible to equalize the flow rate and pressure of the fluid over the entire surface.

That is, according to the method of the present invention, a cast product with excellent fluid permeation properties that can be suitably used for air foot bases, air suction tables, etc. can be produced without any special metallurgical or mechanical processing. It can be manufactured easily and at low cost, and furthermore, by using a ceramic porous body with a three-dimensional network structure as exemplified in this example, the pores that open on the exposed surface 51 of the product can be reduced. It is extremely easy to set the distribution of 32 to be approximately uniform over the entire surface, and therefore, the product has the advantage that excellent performance can be stably obtained.

By the way, in the above embodiment, the horizontal casting method was adopted as the casting method, but it goes without saying that the vertical casting method can also be successfully adopted in the present invention.
An example of its application will be shown in FIGS. 8 and 9. In addition, even when casting by such a vertical casting method, the casting method is basically the same as that of the above embodiment, so in the drawings, the same reference numerals are used for the members corresponding to the above embodiment. The detailed explanation will be omitted.

That is, as shown in these figures, the cores 52 and 52 used in the method of the present invention are formed in a shape having a baseboard, and at the same time as such casting, fluid supply or discharge holes (communication holes) are formed. 46), the vertical mold 54 can be held in a predetermined position in the casting cavity 22 by the ceramic porous body 28 without using special fasteners or the like. be.

Note that in the cast products manufactured using the mold 54 and the core 52 shown in FIGS. 8 and 9, the ceramic porous body 28 must be completely embedded in the cast metal. As a result, continuous pores are formed inside the product, and communication holes for supplying and discharging fluid to and from the pores are connected to the pores located on both sides of the ceramic porous body 28, which form a front and back relationship. It has a structure in which the fibers are connected to each other, and is suitable for use as filters, catalysts, etc.

And even for cast products with this kind of structure,
Similar to the embodiment described above, on the fluid supply side and discharge side surfaces of the ceramic porous body 28 embedded therein, there are fluid reservoirs of a predetermined volume in which the hole openings located on each surface are communicated. A uniform fluid pressure is created for the cavity openings located on those surfaces, since the supply of fluid to these cavities or the discharge thereof is to be carried out through such fluid reservoirs. , and its fluid permeation properties can be effectively improved, so that its performance can be advantageously improved by using it as a filter, catalyst, etc.

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, a plastic material, a glass material, or even a ceramic material is used as the matrix material, and these materials are filled into the tissue gaps that form the framework of a predetermined ceramic porous body. It is also possible to manufacture the desired fluid-permeable product by sintering it to form an integral structure with a ceramic porous body.

Furthermore, as the porous ceramic body used in the method of the present invention, in addition to a resin foam having a three-dimensional network structure as illustrated, comb-shaped bodies or Products obtained by attaching a specified ceramic material around the skeleton of a sword-shaped product, etc., and then firing and sintering it.
Any of these methods can be well adopted, and in particular, in the present invention, the pores formed in the framework of such a porous ceramic body are formed in the product on the fluid supply side or the discharge side. Since these pores are communicated with each other by the fluid reservoir, it is not necessary that these pores are three-dimensionally continuous within the ceramic porous body.

Furthermore, in the embodiment, the fluid reservoir 48 is in a state where the openings of the holes 32 located there communicate with each other over the entire predetermined surface of the ceramic porous body 28 embedded in the product. However, it should be understood that such a fluid reservoir 48 does not necessarily have to be provided over the entire surface, but may be formed at an arbitrary position and with an arbitrary shape 2 υ, for example. In a hydrostatic fluid bearing in which the inner peripheral surface of a cylindrical ceramic porous body buried in the product is exposed and used as a fluid ejection surface, on the outer peripheral surface of the buried ceramic porous body, By forming a plurality of fluid reservoirs extending in the circumferential direction, the ejection pressure and ejection amount at the fluid ejection surface can be made uniform over the circumferential direction.

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 those of 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) According to the present invention, the fluid reservoir communicating with the openings of the pores on at least one surface of the porous ceramic body embedded in the product can be formed at the same time as the shaping operation of the product. Since it can be formed without special metallurgical or mechanical processing, a fluid-permeable product with such a fluid reservoir can be advantageously manufactured with good manufacturability. be.

In the fluid-permeable product obtained according to the method of the present invention, the fluid supply or discharge hole is provided in a form that communicates with the fluid reservoir, so that all the holes opening into the fluid reservoir are connected to each other. On the other hand, a uniform fluid pressure can be applied thereto, and thereby the fluid permeability properties of such fluid permeable products can be improved very effectively.

Therefore, for example, in a product in which the pores of a porous ceramic body buried therein are opened on one side of the product to form a fluid ejection surface, the pores are opened on the back of the porous ceramic body. The distance from the fluid supply port to the ejection port in the hole can be made uniform over the entire hole by forming a fluid reservoir that communicates with the portion on a plane parallel to the fluid ejection surface. This makes it possible to equalize the ejection pressure and amount of fluid on the ejection surface over the entire surface.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram showing one step of the method of the present invention,
FIG. 2 is an enlarged cross-sectional view of the main part of a ceramic porous body used therein, and FIG. 3 is an important diagram for explaining the state in which a core serving as a fluid reservoir forming member is fixed to the ceramic porous body. It is an enlarged sectional view of the fourth part.
The figure is an explanatory cross-sectional view showing a cast product obtained by such a manufacturing method, FIG. 5 is an explanatory cross-sectional view showing a cast product obtained by finishing the cast product, and FIG. FIG. 2 is an explanatory cross-sectional view showing an enlarged main part of such a cast product. Further, FIG. 7 is a cross-sectional explanatory view corresponding to FIG. 1, showing a state in which a ceramic porous body is placed at a predetermined position in a casting cavity using a core provided with a baseboard, and FIG. 9 is a cross-sectional explanatory view corresponding to FIG. 1, showing another embodiment according to the method of the present invention, and FIG.
It is IX-IK sectional view in a figure. 10.54: Mold 22: Casting cavity 24; Molten metal 28; Ceramic porous body 30: Skeleton
32: Hole 34.40.52=core

Claims (1)

[Claims] In a state in which a ceramic porous body in which the skeleton forming the porous structure itself is hollow and pores are formed in the skeleton is placed in a predetermined product cavity, the product cavity is By supplying a predetermined matrix material into the ceramic porous body, an integral molding operation is carried out in which the matrix material is introduced into the gaps of the skeleton of the ceramic porous body to form an integral structure, and the porous structure of the ceramic porous body is changed. When manufacturing a product that allows fluid to pass through by utilizing the pores formed in the framework of the ceramic porous body, the pores formed in the framework are embedded in the product. The pores are opened in at least a part of a predetermined surface, and the holes are not lost by contact with the matrix material during the integral molding operation, and are removable after the integral molding operation. A fluid reservoir forming member made of material,
While using a member that is fixed to cover the opening, after the integral molding operation, the fluid reservoir forming member is removed, thereby forming a fluid within the framework of the ceramic porous body inside the resulting product. A method for manufacturing a fluid-permeable product, characterized in that a fluid reservoir is formed that communicates with the pores.