JPS63180357A - Production of casting having fluid permeability - Google Patents

Abstract

PURPOSE:To stably produce a casting having fluid permeability by constituting a mold supporting ceramic porous body, which the skeleton itself is hollow three-dimensional mesh structure in a cavity, by combining a cope and a drag and casting molten metal in the cavity. CONSTITUTION:Slurry of ceramic, such as alumina, SiC and others, is stuck on the surface of three-dimensional mesh structural body obtd. by foaming the foaming resin, dried and burnt, to produce the ceramic porous body 20 having three-dimensional mesh skeleton 26 and penetrating porosity 22. This ceramic porous bodies 20 are fitted in casting cavities 16 of plural molds 10 formed by fastening the combination of cope and drag, by supporting tools 32. The molten metal is cast into the cavity 16 from a sprue 12 through a runner 14, and the casting 24 making the casting metal 42 as matrix and having ceramic body 26 of three-dimensional mesh skeleton, in which exists plural penetrating porocity 22, and having fluid permeability, is stably produced.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method for manufacturing a fluid-permeable cast product, and particularly relates to a method for manufacturing a fluid-permeable cast product, in which a ceramic porous body having continuous pores is integrally embedded in a skeleton exhibiting a three-dimensional network structure. When obtaining a fluid-permeable cast product having a property of allowing fluid to pass therethrough, the ceramic porous body can be easily and efficiently placed at a predetermined position in a casting cavity, thereby preventing such fluid permeation. The present invention relates to a method for producing a fluid-permeable cast product that can be produced inexpensively and stably.

(Prior art) Cast iron, cast steel, copper alloys, aluminum alloys, etc. have traditionally been manufactured by introducing a predetermined molten metal into a product cavity formed in a predetermined mold and solidifying it. Cast products are widely used as parts for machine tools and general industrial machinery. However, there has not yet been a method to create three-dimensionally continuous fine pores to provide the property of permeating fluids such as gas or liquid. It was extremely difficult to form it by post-processing such as machining.

Therefore, the applicant of this application first filed the patent application No. 61-24636.
In No. 0, the skeleton of the three-dimensional network structure itself is hollow, and a porous ceramic body in which continuous pores are formed within the skeleton is integrally embedded in a predetermined cast metal. , and the cast metal enters into the three-dimensional network structure of the porous ceramic body and forms a matrix for the porous ceramic body, so that the metal is formed within the skeleton of the three-dimensional network structure of the porous ceramic body. A novel fluid-permeable casting product has been disclosed that allows a predetermined fluid to pass through the pores.

By the way, in such a fluid-permeable cast product, for example, a ceramic porous body having a three-dimensional network structure as described above is placed in a predetermined position in a casting cavity of a mold, and the molten state is It is produced by pouring molten metal, allowing the poured molten metal to enter the three-dimensional network structure of the ceramic porous body, and coagulating it together with the surrounding molten metal.

On the other hand, when casting products such as cast iron products, conventionally, an upper mold and a lower mold are used as molds, and a predetermined molten metal is guided into a casting cavity formed by stacking them one above the other. A horizontal casting method has been adopted for casting, but in recent years, a vertical casting method, known as the so-called disamatic molding method, has become extremely effective for casting cast products that are produced in large quantities. By overlapping vertical molds horizontally,
A method is attracting attention in which a predetermined casting cavity is formed between these molds, and molten metal poured from above is guided into the casting cavity to form a desired cast product.

However, when such a vertical casting method is adopted for casting a fluid-permeable casting product as described above, it is difficult to maintain the ceramic porous body to be embedded inside the casting product at a predetermined position within the casting cavity. This is difficult, and as a result, there has been a problem in that the advantages of high-speed casting, which the vertical casting method has, cannot be effectively utilized.

In other words, in the conventional horizontal casting method, the ceramic porous body is placed in the hollow part of the casting cavity during pouring with a normal chaplet used as a mold holder for cores, etc. This can be done relatively easily by holding the upper and lower surfaces of the body against the inner surface of the casting cavity, but in the vertical casting method mentioned above, where the mold mating surfaces are vertically aligned, Because it is necessary to place the keren not only above and below the ceramic porous body, but also on the left and right sides, it is extremely difficult to install it in the hollow part of the casting cavity, resulting in poor workability. Since it was necessary to insert the mold into the casting cavity using a sanding plate, it was easy to scrape off the sand, and great care was required. In this case, sand is likely to be scraped off when the molds are stacked together, and therefore it takes time to set up, which not only impairs the high-speed casting performance of the vertical casting method, but also causes defects such as sand buildup in the product. There was a risk that this would occur.

(Solution Means) Here, the present invention has been made against the background of the above-mentioned circumstances, and its feature is that the skeleton of the three-dimensional mesh structure itself is hollow, and the entire structure is continuous. A ceramic porous body in which pores are formed in the skeleton is integrally embedded in a predetermined cast metal, and the cast metal enters into the three-dimensional network structure of the ceramic porous body, Fluid permeation as described above, in which the matrix for the ceramic porous body is configured so that a predetermined fluid can be permeated through the pores formed in the skeleton of the three-dimensional network structure of the ceramic porous body. When manufacturing a cast product, the tips are embedded to a predetermined size into the opposing walls of a casting cavity formed between vertical molds by stacking them horizontally. A rod-shaped supporting member is provided that bridges between the two walls, and the porous ceramic body is held by a holding member attached to the supporting member, and the porous ceramic body is heated by the casting. With the metal placed at a predetermined position in the cavity, molten metal is poured, and the poured molten metal enters the three-dimensional network structure of the ceramic porous body and is integrated with the surrounding molten metal. By solidifying the porous ceramic body, a cast product is formed in which the ceramic porous body is integrally embedded in a predetermined position.

(Specific Description/Examples of Configuration) Hereinafter, the configuration of the present invention will be explained in more detail with reference to the embodiments shown in the drawings.

First, FIG. 1 shows a mold 1 that is continuously formed by a conventional method, for example, by compressing and molding sand supplied from a sand hopper using a molding machine.
0 is shown. Both sides of this mold 10 receive predetermined molten metal poured from above, respectively.
Sprue forming recess 12 for forming a sprue opening upward
Following this sprue forming recess 12, a runner forming recess 14 forming a runner for guiding the molten metal to be poured, and a target casting product connected to this runner forming recess 14. A casting cavity forming recess 16 is formed for forming the casting cavity. Although only one casting cavity 16 is shown here, normally, in a form connected to the runner forming recess 14, a large number are formed on the left and right sides of the runner cavity 14, and by overlapping such molds. A large number of casting cavities are formed, and thereby the high-speed casting properties of the vertical casting method are more advantageously exhibited.

Then, as shown in FIG. 2, such molds 10 are stacked horizontally, so that
As is well known, predetermined sprues, runners, and casting cavities are formed in the respective sprue forming recesses 12, runner forming recesses 14, and casting cavity forming recesses 16 on the mating surfaces of the molds 10, 10, respectively. It will be done. That is,
so that the mold matching surface of the mold 10 is in a substantially vertical direction,
By overlapping these molds 10 in the horizontal direction, a predetermined casting cavity 18 is formed between them. , each having a casting cavity 18,18 formed therein.

Then, at predetermined positions within these casting cavities 18,
As shown in FIG. 3, a predetermined molten metal in a molten state is poured into a superimposed mold 10.1 in a state in which a ceramic porous body 20 having a specific structure is arranged.
By pouring the molten metal from above through the sprue formed between the holes and guiding the molten metal from the runner into the casting cavity 18 and filling it, a three-dimensionally continuous mold is formed as shown in FIG. A cast product 24 is manufactured which includes the holes 22 and has the property of allowing fluid to pass therethrough.

As shown in FIG. 2, the ceramic porous body 20 disposed within the cavity 18 has a three-dimensional network structure skeleton 26 itself that is hollow, with continuous pores 22 as a whole. is formed within the skeleton 26, for example, a film-like substance (foamed membrane) remaining around the skeleton after foaming a resin such as ester-based urethane.
A synthetic resin foam with a three-dimensional network structure skeleton is obtained by removing the carbon dioxide using compressed air, etc., and a ceramic material such as a ceramic slurry is attached to the surface of the skeleton, and then dried and fired. It is something that can be obtained by forcing people to do something. In addition, as the ceramic material attached to such synthetic resin foam, cordierite, alumina, SiC, mullite, zirconia, etc. can be selected and adopted as appropriate depending on the characteristics required for the target product. It is something that will be done.

That is, when manufacturing such a ceramic porous body 20, for example, the thermal decomposition temperature of the urethane resin used as the synthetic resin foam is about 400°C, while the firing temperature of the ceramic material attached to the surface of the skeleton is: Since the temperature is usually 1,300°C or higher, by attaching the ceramic material to the surface of the skeleton and firing it for about 24 hours, the urethane resin will almost completely decompose and disappear, thereby causing the above-mentioned The skeleton 26 of the three-dimensional network structure itself is hollow, as shown in FIG.
A ceramic porous body 20 in which pores 22 that are continuous as a whole are formed within the skeleton 26 is obtained.

Incidentally, such a porous ceramic body 20 needs to be held at a predetermined position within the casting cavity 18 when pouring molten metal, and a holding device 32 for this purpose is shown in FIGS. 5 and 6. It is shown.

That is, the holding device 32 is a rod-shaped support fitting 28.
and two plate-shaped holding fittings 30.30, and by inserting the supporting fitting 28 into the mounting hole 34 formed in each holding fitting 30, these holding fittings 30.30 is attached to a support fitting 28.

As shown in FIG. 6, the opposing inner surfaces of the holding fittings 30 and 30 are in contact with the side surfaces of the ceramic porous body 20, respectively, and the ceramic porous body 20 is
Such a holding device 3 is held in a state in which the
2, the ceramic porous body 20 will be attached.

In addition, in this embodiment, the mounting hole 34 of the holding fitting 30
is formed to have a diameter that is approximately the same as or slightly larger than the outer diameter of the support metal fitting 28, so that the holding metal fitting 3
0 on the support fittings 28, the distance between the two holding fittings 30, 30 can be adjusted according to the ceramic porous body 20 to be held, and the ceramic When the porous body 20 is placed, the holding fitting 30 is pried outward so that its mounting hole 34 is connected to the supporting fitting 28.
It is secured to the outer peripheral surface so that its position can be regulated.

Moreover, the ceramic porous body 2 using such a holding fitting 30
0 is preferably held by utilizing the springiness (elasticity) of the holding fittings 30 itself, and for this purpose, the distance between the holding fittings 30 and 30 is usually adjusted by the distance between the holding fittings 30 and 30. The width of the porous ceramic body 20 is set slightly smaller than the width of the ceramic porous body 20, and the porous ceramic body 20 is installed by inserting it between the holding fittings 30 and 30.

Furthermore, the support metal fitting 28 to which such a holding metal fitting 30 is attached is formed in a bar shape, and both ends thereof are tapered surfaces 36 and 36 whose diameters are reduced over a predetermined length, respectively. There is.

The tapered surfaces 36, 36 are designed to facilitate installation of the holding fitting 30 and to prevent sand from being scraped off when the holding device 32 is placed in the casting cavity within one day, as will be described later. It is usually formed with a slope of about 1 to 10''.

Note that the support fittings 28 constituting such a holding device 32
And the holding fittings 30 need to be completely welded to the molten metal by being melted or encased in the molten metal at the time of casting. A material or a material whose surface is tin-plated may be used as appropriate. Further, one or more holding devices 32 are used depending on the shape and size of the ceramic porous body 20 to be embedded in the cast product, and in this embodiment, the holding device 32 shown in FIG. As shown, four retaining devices 32 are used.

When the porous ceramic body 20 is held by such a holding device 32, the holding fittings 30 are bridged between the opposing wall portions of the casting cavity 18 of the mold 10 when the molds 10 are fitted together. By doing so, it is placed at a predetermined position within the casting cavity 18.

That is, as shown in FIG. 2, in the casting cavity 18 of the mold 10, the wall portions 3B and 38 that face each other in the horizontal direction (overlapping direction) are provided with ceramics at a predetermined position within the casting cavity 18. When the porous body 20 is placed, support holes 40 are provided at the positions where the ends of both sides of the support fittings 28 of the holding device 32 to which the ceramic porous body 20 is attached are located.

Then, the ends of the support fittings 28 on both sides of the holding device 32 are respectively embedded in the support holes 40, so that the support fittings 28 are inserted into the wall portion 3 of the casting cavity 18.
8.38, so that the ceramic porous body 20 held by the holding device 32 is placed in a predetermined position spaced apart from the surrounding wall surface within the casting cavity 18. It is placed in a certain position.

By the way, is there a holding bag? &32, as shown in FIG. 2, when fitting the mold 10,
One end of the support fitting 30 is supported in a cantilevered manner by a support hole 40 provided in one wall 38 forming the casting cavity 18, and when the mold 10 is fitted, the free end of the support fitting 30 is The tip of the side is inserted into the support hole 40 provided in the other wall 38. Therefore, in this embodiment, the support hole 40 on the side that supports the holding device 32 in a cantilevered state is
It is formed deeper than the other support hole 40, and
These support holes 40 are formed to have an inner diameter smaller than the outer diameter of the support fitting 30 to be inserted, so that sufficient support force for the holding device 32 can be obtained.

By the way, in this embodiment, when setting the ceramic porous body 20 (holding device 32) into the mold 10 as described above, a core setter (core loading device) conventionally used in the vertical casting method is preferably used. This allows the setting work to be performed more quickly and efficiently.

In other words, the core center is, as is well known, a set plate located away from the mold, and a core etc. is placed under negative pressure by a suction pump at the part corresponding to the set position in the mold. After holding the core by suction, the setting plate is moved over the mold and the negative pressure is released to mechanically set the core, etc. held there at a predetermined position in the casting cavity of the mold. In particular, in this embodiment using the holding device 32 as described above, positioning of the holding position of the porous ceramic body 20 with respect to the set plate is as follows.
This can be done easily and reliably by the support fitting 28 of the holding device 32, and by using the flat surface of the holding fitting 30 as a suction surface for the set plate, the porous ceramic body 20 having a three-dimensional network structure can be This means that suction and retention can be achieved satisfactorily.

Then, with the ceramic porous body 20 disposed at a predetermined position within the casting cavity 18, a predetermined molten metal in a molten state is introduced into the casting cavity 18 and filled as described above. As a result, a cast product 24 having three-dimensionally continuous pores 22 and having the property of being permeable to fluid is manufactured, and the solidified cast product 24 thus obtained is manufactured.
As shown in FIG. 4, the cast metal 42 enters the cells of the ceramic porous body 20 which are composed of the skeleton 26 having a three-dimensional network structure, and the cast metal 42 is made of ceramic. While the ceramic porous body 20 has an integral structure constituting a matrix for the porous body 20, the penetration of molten metal into the pores 22 in the skeleton 26 in the embedded ceramic porous body 20 is prevented by its surface tension. Therefore, the holes 22 are maintained in a communicating state.

Furthermore, after the solidification of such a cast product 24 is completed, it undergoes a normal finishing process to become the intended finished product, and as in this embodiment, the porous ceramic body 20 is placed in the center of the cast product 24. In the case of a cast product in which continuous pores 22 are formed inside by being embedded, for example, holes communicating with the continuous pores 22 are bored from both end faces of the cast product, and an inlet and an outlet are formed. By forming such continuous pores 22, it is possible to form a product used as a cooling/heating member for a fluid flowing therethrough, a filter, a catalyst, etc., and by grinding one side of the continuous pores 22. are exposed to the outside, and the continuous pores 22 are formed on the other surface.
It is also possible to form a sliding plate by providing a supply port communicating with the lubricant and supplying the lubricant from the supply port.

Therefore, according to the method of this embodiment as described above, when performing casting by the vertical casting method, the holding device 32 is used to hold the ceramic porous body 20 at a predetermined position in the casting cavity 18 during pouring. This can be carried out reliably and extremely easily, thereby making it possible to effectively take advantage of the high-speed casting that the vertical casting method has, thereby making it possible to produce the desired fluid-permeable cast products advantageously and at low cost. It can be manufactured using

That is, when installing the ceramic porous body 20 into the casting cavity 18, the tip of the support fitting 28 of the holding device 32 attached to the ceramic porous body 20 is attached to the mold 10 forming the casting cavity 18.
It is only necessary to insert the support fittings 28 into the support holes 40 provided in the wall portion 38, and even if there are a plurality of such support fittings 28, they can be inserted at the same time, making the work easier. At the same time, it is possible to effectively prevent sand and the like from being scraped off during the setting process.

Furthermore, since the holding device 32 in this embodiment holds the porous ceramic body 20 with spring properties from both sides, the porous ceramic body 20
It has the advantage that displacement in each direction can be effectively regulated, and that a small number of pieces can be effectively retained.

Furthermore, in this method, as described above, a core setter can be used when setting the ceramic porous body 20 (holding device 32) into the casting cavity 18, and in such a case, a core setter can be used. Since only manual intervention is required when setting the ceramic porous body 20 (holding device 32) on the setting plate, delays in the molding cycle caused by humans, defects such as sand scraping during setting, and accidents are effectively eliminated. This makes it possible to achieve a stable production system, and to more stably set the casting cavity 18 in the ceramic porous body 20 to a fixed position within the space, thereby further improving product quality and productivity. can be achieved extremely effectively.

The method for producing a fluid-permeable cast product according to the present invention has been described in detail by showing one example, but the present invention is limited to the explanation of such a specific example and the specific configuration.
It shall not be construed as limiting.

For example, in the holding device 32 in the above embodiment,
Although the supporting metal fitting 28 and the holding metal fitting 30 were formed as separate members, it is also possible to form them with an integral structure, and the shape of the holding metal fitting 30 can also be made of a ceramic porous body as illustrated. In addition to a plate-like shape that holds the ceramic porous body 20 therebetween, it is possible to form it in various shapes, such as one that covers the entire circumference of the ceramic porous body 20.

Furthermore, the casting cavity 18 of such a holding device 32
When installing it inside, it is also possible to bridge the supporting metal fittings 28 between opposing walls in one mold 10, and it can be used not only in the horizontal direction as shown in the example but also in the vertical direction. It is also possible to construct a bridge spanning between wall parts facing each other in the direction, and the supporting form depends on the shape of the casting cavity 18 and the ceramic porous body 20 to be buried.
It will be selected and set as appropriate depending on the shape etc.

In addition, as the ceramic porous body 20 used in the production of such a fluid permeable cast product, in addition to the resin foam having a three-dimensional network structure from which the foam membrane has been removed, as shown in the example, the ceramic porous body 20 can be Any of these can be obtained by adhering a certain ceramic material around a skeleton of a comb-shaped body or a sword-shaped product made of a material that can be burnt out, and then firing and sintering it. can also be well adopted.

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 not limited to 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) Therefore, according to the method of the present invention, when casting is performed by the vertical casting method, the ceramic porous body is reliably and extremely held at a predetermined position in the casting cavity during pouring. It can be easily carried out, thereby making it possible to effectively take advantage of the high-speed casting that the vertical casting method has, and thereby making it possible to advantageously produce the desired fluid-permeable cast product at a constant cost. Furthermore, when setting such a porous ceramic body into a casting cavity, scraping off of sand, etc. can be effectively prevented, and the quality of the cast product can be extremely advantageously improved.

Furthermore, with this method, a core setter can be used to set the ceramic porous body into the casting cavity, which eliminates human-induced delays in the molding cycle and sand scraping during setting. Defects or accidents can be effectively prevented, a stable production system can be established, and the casting cavity of the ceramic porous body can be more stably set in a fixed position within the space, thereby improving product quality and Further improvement in productivity can be achieved extremely effectively.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a state in which a ceramic porous body is set in a casting cavity of a mold used in manufacturing a fluid-permeable cast product according to the present invention;
The figure is an explanatory cross-sectional view showing one step of the manufacturing method of such a fluid-permeable cast product, FIG.
The figure is an explanatory enlarged cross-sectional view of a main part showing a cast product obtained by such a manufacturing method. Further, FIG. 5 is an enlarged front view showing a holding device for a porous ceramic body used in such manufacturing, and FIG. 6 is a perspective view of the holding device. 10: Mold 18: Casting cavity 20: Ceramic porous body

Claims (1)

[Claims] A ceramic porous body in which the skeleton of a three-dimensional network structure itself is hollow and continuous pores are formed within the skeleton is integrally embedded in a predetermined cast metal. The cast metal enters the three-dimensional network structure of the porous ceramic body and forms a matrix for the porous ceramic body, so that the cast metal is formed within the skeleton of the three-dimensional network structure of the porous ceramic body. Through the holes created,
When producing a cast product that allows the passage of a predetermined fluid, the tip is placed against the opposing walls of a casting cavity formed between vertical molds by stacking them horizontally. By embedding each part to a predetermined size, a rod-shaped support member is provided that bridges between the two wall parts, and the porous ceramic body is held by a holding member attached to the support member. Then, with the ceramic porous body disposed at a predetermined position in the casting cavity, molten metal is poured, and the poured molten metal is allowed to enter the three-dimensional network structure of the ceramic porous body. A method for producing a fluid-permeable cast product, characterized in that the ceramic porous body is solidified integrally with the surrounding molten metal to produce a cast product in which the ceramic porous body is integrally embedded in a predetermined position.