JP2545384B2 - Fluid-permeable product manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a fluid-permeable product, and in particular,
Products such as castings and castings that have the property of allowing fluid to permeate through the continuous pores formed inside, and products with further improved fluid permeation properties can be produced by metallurgical or mechanical The present invention relates to a method which can be advantageously manufactured without any treatment.

(Background Art) As a product such as a cast product having continuous pores and having a property of allowing a fluid to pass therethrough, the applicant of the present invention has previously described that the Japanese Patent Application No.
No. 246360, Japanese Patent Application No. 61-281467, Japanese Patent Application No. 61-304744, etc., the skeleton itself which forms the porous structure is made hollow, and continuous pores as a whole are formed into a ceramic porous structure. By using a body and by inserting a predetermined matrix material into the gap of the porous structure to form an integral structure, the pores formed in the skeleton of the porous structure of the ceramic porous body are used to make the fluid A new product, such as a cast product or a cast product, and a sintered body thereof have been clarified.

By the way, in such a fluid permeable product, for example, a state in which a ceramic porous body having pores in a skeleton of a porous structure is placed at a predetermined position in a product cavity formed by an appropriate molding die. The ceramic porous body is embedded in a part of the product by supplying a predetermined matrix material into the product cavity, and continuous pores through which a fluid can pass are formed. Therefore, by forming a fluid supply hole or a discharge hole that communicates the holes formed inside such a product by post-processing, etc., an air float base, an air adsorption table, a bearing, etc. A single member, or heat exchange member, filter, catalyst, etc. without adding difficult metallurgical or mechanical treatment It become possible to very advantageously produced with a granulation.

However, in such a fluid permeable product in which the ceramic porous body is embedded inside and a fluid supply or discharge hole communicating with the hole is formed, the fluid supply or discharge hole is A pressure loss corresponding to the distance from the fluid supply or discharge hole is caused with respect to the fluid pressure applied to the inside of the hole through the fluid pressure. Therefore, depending on the form of the fluid supply hole or the discharge hole, The distribution of the pressure and the flow rate of the circulating fluid in the pores may be non-uniform.

Therefore, for example, the pores of the ceramic porous body embedded inside are opened on one surface of the product to form the fluid ejection surface, and the fluid supply hole communicating with the pore is formed on the wall of the product. In a hydrostatic bearing, an air float base, or the like having the structure formed, the fluid ejection pressure or the ejection amount on the fluid ejection surface becomes smaller as the distance from the fluid supply port increases. A product in which uniformity of the amount of ejected fluid is considered important has a problem that sufficient performance or characteristics cannot be obtained.

By the way, as one method for achieving uniform fluid pressure exerted through the pores formed inside such a product, fluid is supplied or discharged to the back of the ceramic porous body embedded in the product. By forming a space as a fluid reservoir in which the holes communicate with each other, and by opening all the holes facing the space of the ceramic porous body on a plane parallel to the fluid ejection surface and communicating with this space. It is conceivable to make the distance from the fluid supply port to the jet port in such holes uniform throughout, but at the time of forming such a space by mechanical processing, at least such a product should be used. Since it has to be a two-part structure, an increase in cost due to an increase in the number of processing steps cannot be avoided, and it may be extremely difficult in terms of shape, which is effective. Than is not intended to be called the technique.

(Solution) 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 in a product. In a product to which fluid permeability is imparted by the pores, in order to improve the fluid permeability characteristic, the fluid reservoir communicated with the pore opening in at least a part of the predetermined surface of the ceramic porous body is It is an object of the present invention to provide a method capable of advantageously producing a fluid-permeable product formed in the inside of a steel without any metallurgical or mechanical treatment.

In order to achieve such an object, the feature of the present invention resides in that the skeleton itself that forms the porous structure is hollow, and a porous ceramic body in which continuous pores are formed in the skeleton as a whole is formed. By using a predetermined matrix material in the pores of the porous structure to form an integral structure, the pores formed in the skeleton of the porous structure of the ceramic porous body are used to permeate the fluid. When manufacturing a product that can be pressed, a skeleton-forming member having a three-dimensionally continuous skeleton structure and formed on at least part of a predetermined surface of a skeleton-forming member formed of a burn-out material has a predetermined size. For a combustible structure integrally formed with a space forming member, a predetermined ceramic material is attached around the skeleton of the skeleton forming member and on the surface of the space forming member. , And voids formed by the ceramic material adhered to the skeleton-forming member, which are obtained by burning and sintering it to burn off the combustible structure, and have continuous pores inside as a whole. And a skeleton portion having a ceramic material adhered to the space forming member,
A ceramic structure provided with a space forming portion having a space of a predetermined volume in which pores formed in the skeletons are opened is used as the ceramic porous body, and the ceramic is provided inside the obtained product. The purpose is to form a fluid reservoir that communicates with the pores formed in the skeleton of the porous body.

(Specific Structure / Example) By the way, according to the method of the present invention as described above, for example, in the case of producing a fluid-permeable casting, as shown in FIG. As shown in FIG. 3, it is buried inside by pouring a predetermined molten metal under the condition that the porous ceramic body having the specific structure as shown in FIG. 2 is arranged. A fluid pool communicated with at least a part of the pore openings on a predetermined surface of the ceramic porous body (structure),
The intended fluid-permeable casting product formed inside the product is produced.

In FIG. 1, 10 is an upper die 12 and a lower die 14
The mold is composed of and, and is generally manufactured by a self-hardening mold sand using a raw sand or a resin as a hardening medium, a permanent mold (mold), or the like. Further, in the mold 10, a hot water inlet 16, a runner 18 and a casting cavity 20 having a predetermined shape are formed, and a predetermined molten metal 17
However, the ladle 19 is introduced into the casting cavity 20 through the hot water inlet 16 and the runner 18. The ceramic porous body 22 having a specific structure is set at a predetermined position in the casting cavity 20.

Further, in FIG. 1, as shown in FIG. 5, the exposed surface is formed by opening holes formed inside the product on one surface (front surface) of the product. In order to obtain a cast product such as an air float base or an air suction table having a structure, the ceramic porous body 22 is set with a stopper 24 such as a keren in a state in which one surface thereof is in contact with the inner surface of the casting cavity 20. However, the arrangement position and the shape of the ceramic porous body 22 in the cast product are not limited in any way, and are appropriately determined according to the intended product. That is, according to the method of the present invention, for example, as shown in FIGS. 6 and 7, the porous ceramic body 22 is exposed on the cylindrical inner peripheral surface to form a sliding surface there. A product such as a bearing member having the above structure or, as shown in FIG. 8, by completely burying the porous ceramic body 22 in the cast metal, continuous voids are formed inside the product. With the structure formed, it can be applied to various casting products such as products such as catalysts and filters, and the shape of the ceramic porous body 22 is determined according to such products. In addition, it is arranged at an appropriate position in the casting cavity 20 by using a squeegee, a core or the like.

Here, the ceramic porous body 22 having a porous structure according to the present invention, which is arranged and fixed in the casting cavity 20, is formed of a burnable material having a three-dimensionally continuous skeleton structure. For a flammable structure in which a space-forming member of a predetermined size made of a burnable material is integrally provided on at least a part of a predetermined surface of the skeleton-forming member, around the skeleton and the space in the skeleton-forming member. It is obtained by depositing a predetermined ceramic material on the surface of the forming member, and then firing and sintering it to burn off the combustible structure, which is attached to the skeleton forming member. A skeleton part formed of a ceramic material having continuous pores inside and a ceramic material adhered to the space forming member. And a space forming portion formed of a material and having a space of a predetermined volume in which the space formed in the skeleton forming portion is opened.

More specifically, such a skeleton-forming member is formed of a material having a low thermal decomposition temperature and has a three-dimensionally continuous porous skeleton structure, and is shown in FIG. 4, for example. As described above, after foaming a resin such as ester-based urethane, a film-like substance (foamed film) remaining around the skeleton
A synthetic resin foam 26 having a three-dimensional network structure skeleton structure obtained by removing the above by using compressed air or the like is preferably used. On the other hand, the space forming member is made of a material having a low thermal decomposition temperature and has a solid structure. For example, as shown in FIG. 4, a resin plate 28 of ester urethane or the like is used. Is preferably used. The resin plate 28 is made of synthetic resin foam.
26, a synthetic resin foam 26 is formed by using a burnable adhesive 30 having a low thermal decomposition temperature on the outer surface corresponding to a portion where a fluid pool is to be formed in a target casting product, which will be described later.
They are integrally fixed so as to cover the skeleton gap on the surface of the, and thereby a burnout mold 32 as a combustible structure is formed.

Then, in accordance with a known method, the burnable mold 32 composed of the synthetic resin foam 26 as a skeleton forming member and the resin plate 28 as a space forming member is coated with a predetermined ceramic material. By the operation, a ceramic layer having a predetermined thickness is formed around the skeleton of the synthetic resin foam 26 and the surface of the resin plate 28 constituting the burnable mold 32. In addition,
As the ceramic material to be attached to the burnout mold 32, cordierite, alumina, SiC, mullite, zirconia, or the like is appropriately selected and adopted according to the characteristics required for the intended product. It is a thing. Then, the predetermined ceramic material is, for example, adhered in a slurry state, and after the excess slurry is removed and further dried, by performing a firing operation according to the adhered ceramic material,
Simultaneously with the sintering of the ceramic material, the burnable mold 32 is burnt out.

That is, the firing operation of the ceramic material causes the synthetic resin foam 26, the resin plate 28, and the adhesive material 30 interposed therebetween to be burned off, respectively, and as shown in FIG. like,
A skeleton portion 38 formed of a skeleton 36 having a three-dimensional network structure, which has pores 34 continuous to each other inside thereof, and the skeleton portion
On the outer surface of the predetermined position of 38, the holes 34 located there
22. A ceramic porous body 22 having a box-shaped space forming portion 42 in which a space 40 of a predetermined volume, which is opened and communicated with each other and which is closed to an external space, is formed inside.
Is obtained.

When the space 40 inside the space forming portion 42 is formed with a large area or volume, as shown in FIG. Providing an appropriate number of 45 and their through holes
By filling the ceramic material in 45,
As shown in FIG. 2, with respect to the space forming portion 42,
It is desirable that the reinforcing piece 46 be formed in the space 40.

And, a ceramic porous body having such a structure
In a state where 22 is placed in the casting cavity 20, a molten metal 17 having a chemical component controlled according to the physical properties required for the cast product is poured. As the metal melt 17, cast iron and cast steel are generally used, but in addition, casting of various metal products such as copper alloys and aluminum alloys, the present invention can be advantageously applied. Therefore, it goes without saying that the molten metal 17 is appropriately selected according to the raw material of the product.

In addition, the metal melt 17 poured in this way is generally
As shown in FIG. 1, while being introduced into the casting cavity 20 through the inlet 16 and the runner 18 and filling the gap between the skeletons 36 of the three-dimensional mesh structure in the ceramic porous body 22,
The casting cavity 20 is filled, thereby completing the pouring operation.

As the molten metal 17, as described above, non-ferrous metal,
Although there is no limitation on the iron type, when introduced into the casting cavity 20, a temperature drop due to contact with the inner wall surface of the mold 10 cannot be avoided, and the installation of the ceramic porous body 22 further promotes this tendency. Therefore, since a cementite structure may occur in a thin corner or the like, it is desirable to set the molten metal temperature at the time of pouring higher than usual. Further, the molten metal 17 is made to invade uniformly between the skeletal structures (in the cell) of the ceramic porous body 22,
In order to solidify, it is desirable to set a feeder or the like so as to provide an appropriate molten metal head.

In the thus obtained solidified cast product 48, as shown in FIG.
An integrated structure in which the cast metal 50 enters the cells of the skeleton portion 38 formed of the skeleton 36 having the three-dimensional network structure 22 and the cast metal 50 forms a matrix for the ceramic porous body 22. On the other hand, the intrusion of the molten metal 17 into the holes 34 in the skeleton 36 of the cast ceramic porous body 22 is prevented because the openings on the surfaces of the holes 34 are in a closed state, Its holes 34
Will be maintained in communication.

In particular, in the cast product 48, since the space 40 formed inside the space forming portion 42 of the ceramic porous body 22 is shown as a closed space as described above, It is possible to prevent the molten metal 17 from invading into the cast product 48, so that the pores 34 formed in the skeleton 36 of the ceramic porous body 22 in the cast product 48.
Thus, a fluid reservoir 52 having a predetermined volume communicating with is formed.

Incidentally, such a cast product 48, after the completion of solidification, the same open frame as a normal casting operation, cooling, cleaning by shot blasting, etc., through a process such as grinder finishing, and finish processing is performed. In particular, in the cast product of the present invention, as described above, one surface of the ceramic porous body 22 embedded therein is exposed to one surface of the product, and the exposed surface is a fluid suction or discharge surface. In a product such as, for example, an air front base as shown in FIG. 5 or a bearing member as shown in FIGS. 6 and 7, the ceramic porous body 22
Since the openings of the pores 34 in the exposed surface of the skeleton 36 of the skeleton are in a state of being closed by the ceramics or the cast metal 50, the exposed surface is subjected to cutting or polishing, so that The holes 34 are to be opened to the outside, so that the desired fluid-permeable casting product is obtained.

Therefore, according to the method as described above, the voids 34 formed in the skeleton 36 of the skeleton portion 38 by the space forming portion 42 of the ceramic porous body 22 embedded in the cast metal,
The fluid reservoir 52, which is opened and communicated with a predetermined surface of the skeleton portion 38, can be formed with any shape and at any position at the same time as casting without adding metallurgical or mechanical treatment. Of.

Therefore, for example, as shown in FIG. 5, in the air float base 54 in which the fluid ejection surface 56 is formed by exposing the porous ceramic body 22 on one surface thereof, the porous ceramic body 22 is formed. A fluid reservoir 52 is formed on the back of the fluid reservoir 52, and the hole (34) is opened and communicated with the fluid reservoir 52 on a plane parallel to the fluid ejection surface 56, and the fluid supply hole 57 is communicated with the fluid reservoir 52. The fluid is supplied to the holes through the fluid reservoir 52, so that the fluid pressure applied to the rear openings of the holes is entirely covered. It is possible to make the flow rate and pressure of the fluid ejected from the openings of the holes located on the fluid ejection surface 56 uniform over the entire surface. is there

Further, as shown in FIG. 6 and FIG. 7, in the hydrostatic fluid bearing 58 in which the fluid ejection surface 60 is formed by exposing the cylindrical ceramic porous body 22 on the inner peripheral surface thereof. A fluid reservoir 52 extending in the circumferential direction is formed on the outer peripheral surface of the ceramic porous body 22, and a fluid supply hole 62 is formed so as to communicate with the fluid reservoir 52 so that the fluid is ejected from the liquid ejection surface 60. It is possible to make the flow rate and pressure of the generated fluid uniform in the circumferential direction.

Furthermore, as shown in FIG. 8, in the filter 64 formed by completely burying the ceramic porous body 22 inside, the pores formed by the ceramic porous body 22 are formed. The fluid reservoir 52 is formed on the surfaces corresponding to the fluid supply side and the fluid discharge side with respect to (34), and the fluid supply hole 66 and the fluid discharge hole 68 are formed so as to communicate with the fluid reservoir 52. By being provided, the fluid permeation characteristics can be improved, and the performance can be advantageously improved.

That is, according to the method of the present invention, a cast product having excellent fluid permeation characteristics can be easily manufactured at low cost without particularly adding metallurgical or mechanical processing, Furthermore, by using the ceramic porous body 22 having a three-dimensional network structure as shown in the above-mentioned embodiment, the distribution of the pores 34 formed in the cast product can be set uniformly over the whole. It also has the advantage that it becomes extremely easy and therefore excellent performance can be stably obtained in the product.

Although the present invention has been described in detail based on the specific example of manufacturing the fluid permeable cast product, the present invention is limited to the description of the specific example and the specific configuration related thereto. It should not be construed that, for example, in addition to the production of the exemplified cast product, a plastic material, a glass material, and a ceramic material are used as a matrix material, and these are placed in a tissue gap forming a skeleton of a predetermined ceramic porous body. It is also possible to manufacture a desired fluid-permeable product by filling and, in the case of a ceramic material, sintering such a filling material to form an integrated structure with the ceramic porous body. .

Further, the burnout mold 32 used in the method of the present invention is used.
Examples of the skeleton-forming member include a resin foam 26 having a three-dimensional network structure as illustrated, a comb-shaped body or a sword-shaped product formed of a burnable material, and at least one component of the yarn is burnable. A woven fabric or the like formed of a material and woven using a plurality of component threads can be favorably adopted.

Further, in the present embodiment, the voids in the skeleton in the skeleton portion formed by using such a skeleton forming member can be communicated with each other in the fluid reservoir formed by the space forming member. , The holes need not be three-dimensionally continuous in the skeleton itself.

In addition, the burnable mold 32 in the above-mentioned embodiment is formed by integrally fixing the synthetic resin foam 26 as a skeleton forming member and the resin plate 28 as a space forming member with the adhesive 30. But other,
For example, it is conceivable to form the space forming member at the same time as forming the skeleton forming member.

In addition, although not enumerated one by one, the present invention can be carried out in a mode in which various alterations, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. Needless to say, all of them are included in the scope of the present invention without departing from the spirit of the above.

(Effect of the Invention) According to the present invention as described above, the voids formed in the skeleton of the skeleton portion by the space forming portion of the ceramic porous body embedded in the product have a predetermined surface of the skeleton portion. At the same time, it is possible to form an opening, a fluid pool to be communicated with, at the same time as the molding operation of such a product, with any shape and at any position without adding metallurgical or mechanical treatment, A fluid permeable product provided with such a fluid reservoir can be advantageously manufactured with good manufacturability.

And in the fluid permeable product obtained according to the method of the present invention as described above, by providing the fluid supply or discharge hole with a form that communicates with the fluid reservoir, all the holes that open to the fluid reservoir are provided. On the other hand, a uniform fluid pressure can be exerted, whereby the fluid permeation characteristics of such a fluid permeable product can be improved very effectively.

Therefore, for example, in a product in which the pores in the skeleton portion of the ceramic porous body embedded therein are opened on one surface of the product to form the fluid ejection surface, the pores in the back portion of the skeleton portion are formed. The opening forms a fluid pool that communicates with the surface parallel to the fluid ejection surface, so that the distance from the fluid supply port to the ejection port in the hole is substantially uniform over the entire surface. By doing so, it is possible to extremely effectively make the ejection pressure and the ejection amount of the fluid on the ejection surface uniform over the entire surface.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing one step in one embodiment of the method of the present invention, FIG. 2 is an enlarged cross-sectional view of an essential part showing an example of a ceramic porous body used therein, and FIG. FIG. 4 is an enlarged cross-sectional view of an essential part showing a cast product obtained by the manufacturing method, and FIG. 4 is an enlarged cross-sectional explanatory view showing a combustible structure used when forming the ceramic porous body shown in FIG. Is. Further, FIGS.
FIG. 5 is a cross-sectional explanatory view showing a specific example of a cast product obtained by the method of the present invention. FIG. 5 shows an air float base, FIG. 6 shows a hydrostatic bearing, and FIG. 7 shows in FIG. VII-VII cross section, and FIG. 8 is a view showing a filter. 10: Mold, 17: Molten metal 20: Casting cavity 22: Porous ceramics 26: Synthetic resin foam, 28: Resin plate 32: Burnout mold, 34: Pore 36: Skeleton, 38: Skeleton part 40: Space , 42: Space forming part 48: Cast product, 50: Cast metal 52: Fluid reservoir 54: Air float base 58: Hydrostatic bearing, 64: Filter

Claims (1)

(57) [Claims] 1. A ceramic porous body in which a skeleton forming a porous structure itself is hollow and continuous pores are formed in the skeleton as a whole, and a predetermined matrix material is provided in the voids of the porous structure. When a product that allows fluid to pass through is manufactured by using pores formed in the skeleton of the porous structure of the ceramic porous body by forming a three-dimensional structure Flammability in which a space forming member of a predetermined size made of a burnable material is integrally provided on at least a part of a predetermined surface of the frame forming member formed of a burnable material having a continuous skeleton structure With respect to the structure, a predetermined ceramic material is attached around the skeleton of the skeleton-forming member and on the surface of the space-forming member, and it is fired and sintered to obtain the flammable structure. A skeleton portion formed of a ceramic material adhered to the skeleton-forming member, which has a continuous pore inside, and is adhered to the space-forming member, which is obtained by burning out the structure. A ceramic structure provided with a space forming portion formed of a ceramic material and having a space of a predetermined volume in which the holes formed in the skeleton are opened, is obtained by using the ceramic porous body. A method for producing a fluid permeable product, characterized in that a fluid reservoir communicating with the pores formed in the skeleton of the ceramic porous body is formed inside the product.