JP2002192303A - Heat insulating material and heat insulating unit using heat insulating material and method for manufacturing unit therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a heat insulating material and to achieve better performance of heat insulation. SOLUTION: A porous metal wiring stock mat 11 is constituted by laminating a metal wire group 10 that a plurality of metal thin lines 10a cross at random on substantially a flat surface in the substantially orthogonal direction against the flat surface made by the metal wire group 10 and the heat insulating material 1 is composed by plating or impregnating with a sealing pore stock 12 to the metal wiring stock mat 11. The heat insulating material 1 is composed mainly of the metal thin lines 10a, obtaining a sufficient strength. The metal wiring stock mat 11 has a large pore rate, can get a big insulating effect and coefficient of heat conductivity becomes smaller since the metal thin lines are mutually on point contact especially in the laminating direction. The sealing pore material 12 blocks a minute pore of the metal wiring stock mat 11 and prevents vapor or liquid that contacts the heat insulation material 1 from infiltrating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating material for interrupting the flow of heat, a heat insulating device using the heat insulating material, and a method of manufacturing the device.

[0002]

2. Description of the Related Art In casting for molding automobile parts and the like, a feeder is provided adjacent to a product cavity in order to prevent so-called sink marks or the like from appearing on a product surface due to heat shrinkage during solidification of a casting material. I have to. And
The feeder may be formed of a heat insulating material so that the function as the feeder is reliably exhibited until the molten metal in the product cavity is sufficiently solidified during casting.

[0003] Techniques for forming the feeder with a heat insulating material include, for example, those described in JP-A-59-152706 and those described in JP-A-10-152706.

The heat insulating material described in the former is formed by hardening fibrous ceramics or diatomaceous earth into a predetermined shape.
The heat insulating material described in the latter is obtained by sintering powder metal into a predetermined shape to form a porous base material, immersing the base material in a heat insulating liquid, and then drying the base material.

[0005]

However, although the former heat-insulating material can provide a relatively large heat-insulating effect, it is easily broken by thermal shock or external force such as insertion of burrs since the constituent materials are brittle in material. Frequent parts replacement and repairs are required. Therefore, there is a problem that the maintenance is complicated and the cost for the maintenance increases.

On the other hand, although the latter heat insulating material is relatively strong in material, it cannot obtain a higher heat insulating effect as compared with the former heat insulating material.

Therefore, the present invention has high durability and
An object of the present invention is to provide a heat insulating material capable of obtaining a sufficient heat insulating effect, a heat insulating device using the heat insulating material, and a method of manufacturing the device.

[0008]

Means for Solving the Problems As means for solving the above-mentioned problems, the invention according to claim 1 is directed to a method of forming a metal wire group in which a plurality of fine metal wires randomly intersect on substantially one plane. Laminated in a direction substantially perpendicular to the plane formed by the metal wire group, a porous metal wire mat was formed, and the metal wire mat was covered or impregnated with a sealing material to constitute a heat insulating material.

In the case of the present invention, the metal wire mat has a high porosity, so that a large heat insulating effect by air can be obtained, and since the metal wire mat is mainly composed of the thin metal wire, a large strength can be obtained. be able to. Further, since the fine holes formed between the wires of the metal wire mat are closed by the sealing material, the gas or liquid facing the heat insulating material is less likely to enter the inside of the metal wire mat. Since the thin metal wires constituting the metal wire mat are in point contact in the stacking direction of the metal wire group, the thermal conductivity in that direction is particularly low.

[0010] In the invention according to claim 2, the sealing material is
The base material mainly composed of metal and the skin material mainly composed of ceramics are formed in two layers.

In the present invention, since the base material is mainly composed of metal, it is bonded to the metal surface of the metal wire mat with high strength, and the surface of the base material is coated with a skin material mainly composed of ceramics. . Therefore, the skin material mainly composed of ceramics is firmly adhered to the surface of the metal wire mat.

According to a third aspect of the present invention, a heat insulating wall is formed by the heat insulating material such that the laminating direction of the metal wire group of the metal wire mat is the wall thickness direction, and the heat insulating device is formed using the heat insulating wall. To be configured.

In the case of the present invention, the heat insulating wall of the heat insulating device is used in a direction in which the metal mat constituting the heat insulating material has the highest heat insulating efficiency (low thermal conductivity).

According to a fourth aspect of the present invention, a storage chamber of a heat retaining device for storing a high or low temperature substance is formed by the heat insulating wall.

In the case of the present invention, since the storage chamber is constituted by a heat insulating wall having high heat insulation efficiency, the temperature change of the substance in the storage chamber can be suppressed to a small value.

According to a fifth aspect of the present invention, a riser of a casting mold is constituted by the heat insulating wall.

In the case of the present invention, the heat flow of the molten metal flowing into the riser is suppressed by the heat insulating wall, and the solidification time of the molten metal in the riser room is sufficiently delayed. For this reason, the temperature of the molten metal can be reduced to a lower temperature, energy saving in the manufacturing process can be achieved, and the quality of the cast product can be improved. That is, when the temperature of the molten metal rises, an oxide film is formed on the surface of the molten metal, which is entangled in the product shape portion when the molten metal is poured, and is likely to cause a defect. be able to. Further, in the heat insulating material constituting the heat insulating wall, since the fine holes in the skin of the metal wire mat are closed by the sealing material, the molten metal does not enter the inside of the metal wire mat.

According to a sixth aspect of the present invention, there is provided a metal wire group comprising a plurality of fine metal wires randomly intersecting on substantially one plane,
A porous metal wire mat formed by laminating in a direction substantially orthogonal to the plane formed by the metal wire group is cut into a predetermined shape, and the cut mat pieces are bonded with an inorganic adhesive to form an outer shape of the storage chamber. Then, at least the inner surface side of the storage chamber is covered or impregnated with a sealing material to manufacture a heat retaining device.

In the case of the present invention, after the mat pieces are bonded, a sealing material is adhered to the whole including the bonding portion, and the fine holes between the fine metal wires of each mat piece are closed by the sealing material. The gaps between the parts are filled with the sealing material.

According to a seventh aspect of the present invention, a metal wire group formed by a plurality of fine metal wires randomly intersecting on substantially one plane is provided.
A storage chamber is formed by press-forming a porous metal wire material mat formed by laminating in a direction substantially orthogonal to the plane formed by the metal wire group, and thereafter, a sealing material is formed on at least the inner surface side of the storage chamber. The insulation device was manufactured by coating or impregnating.

In the case of the present invention, no bonding step is required,
The storage chamber can be shaped by one press molding. Further, since all the metal wire groups are similarly bent at the time of press molding, the contact surface with the substance in the storage chamber is always substantially perpendicular to the lamination direction of the metal wire groups.

In the invention according to claim 8, when the sealing material is coated, first, a base material mainly composed of a metal is coated, and then a skin material mainly composed of a ceramic is coated. .

In the case of the present invention, the sealing material mainly composed of ceramics is firmly adhered to the surface of the metal wire mat with the base material mainly composed of metal as an intermediary.

[0024]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG.

FIG. 1 shows a heat insulating material 1 according to the present invention. As shown in FIG. 2, the heat insulating material 1 is composed of a plurality of thin metal wires 10a (diameter: 20 to 100 μm) containing iron, chromium, silicon, and a rare earth metal as components. Specifically, by laminating a metal wire group 10 composed of a plurality of fine metal wires 10a randomly intersecting on substantially one plane in a direction substantially orthogonal to a plane formed by the metal wire group 10, and performing sinter molding. A porous (wire porosity: 50 to 95%) metal wire mat 11 is formed, and the metal wire mat 11 is covered or impregnated with a sealing material 12 such as ceramics. The sealing material 12 functions to prevent gas or liquid in contact with the heat insulating material 1 from entering the metal wire mat 11.

FIG. 2A shows an enlarged cross section of the metal wire mat 11 cut in a direction orthogonal to the laminating direction of the metal wire group 10 (direction along the laminating surface). The enlarged cross section of the mat 11 cut along the stacking direction of the metal wire group 10 is shown. As is clear from these figures, the thin metal wires 10a in the metal wire mat 11 extend in the stacking direction. The thin lines are almost in contact with each other. Therefore, as described above, the metal wire mat 11 has a high porosity and can hold a large amount of air.
In particular, in the laminating direction (thickness direction), the metal thin wire 10
The thermal conductivity is smaller due to the direction of a.

In this embodiment, the sealing material 12
As shown in FIG. 1, a base material 12a mainly composed of a metal such as chromium and alumina (Al ₂ O ₃ ) or zircon (ZrO ₂ + S
A skin material 12b mainly composed of ceramics such as iO ₂ ) is used in two layers. This is because when ceramics are sprayed directly on the metal wire mat 11, the ceramics itself such as alumina are fragile and stress concentration tends to occur, so that the bonding strength of the mat 11 to the fine wire 10a tends to decrease. , Base material 12a mainly composed of metal
Is sprayed first, ceramics (skin material 12b) can be firmly bonded to the fine wire 10a with the base material 12a serving as an intermediary. When nichrome is used as the base material, the thermal shock resistance can be further improved.

Therefore, the heat insulating material 1 forms a heat insulating wall so that the laminating direction of the metal wire group 10 of the metal wire mat 11 is the wall thickness direction, and the heat insulating material is used as another heat insulating device for keeping the molten metal molten. In addition to the above, it is possible to obtain high heat insulation performance (when used for a wall of a riser, the same heat insulation performance as when ceramics, diatomaceous earth, or the like is used). Large strength can be obtained from this.

FIGS. 3 and 4 show that the heat retaining material 1 is made of an aluminum casting mold (in this embodiment, a part of the mold constitutes a heat retaining apparatus according to the present invention). In the figure, 3 is a mold body, 4 is a core, 5 is a product cavity formed by the mold body 3 and the core 4, and 6 is a gate for pouring a molten metal. Reference numeral 7 denotes a runner, and reference numeral 8 denotes a weir for supplying molten metal from the runner 7 to the product cavity 5. A pair of feeders 2 are provided on both upper sides of the product cavity 5 of the mold body 3. Each feeder chamber 2 is formed in a substantially square shape, and is surrounded on four or five sides by a heat insulating wall 9 made of the heat insulating material 1, and has a lower end portion connected to the product cavity 5.

As a method of manufacturing the feeder 2, it is conceivable to use the finished heat insulating material 1 as it is, but in this embodiment, the feeder 2 uses the metal wire mat 11 as shown in FIG. As shown in the figure, the mat pieces 11a to 11d are cut into mat pieces 11a to 11d each having a predetermined shape.
FIG.
As shown in FIG. 7, the mat pieces are adhered to each other with an inorganic adhesive 13 and, as shown in FIG. In FIGS. 5 to 7, FIG.
Although the feeder 2 having four heat insulating walls 9 different from the above is shown, both have the same basic structure except that the number of the heat insulating walls 9 is different. In addition, the above mat pieces 11a-
The shape of the feeder 2 that cannot be dealt with only by cutting and bonding of 11d is appropriately dealt with by cutting or the like.

Thereafter, the sealing material 12 is sprayed on the riser 2 formed by the mat pieces 11a to 11d to cover the surface. The sealing material 12 used here is made of alumina (Al ₂ O ₃ ) or zircon (ZrO) from the viewpoint of suppressing the insertion of the molten metal into the metal wire rod mat 11 and the wettability (affinity) and improving the releasability. _Although it is effective to use ceramics such as ₂ + SiO ₂ ), in this embodiment, as shown in FIG. 1, a base material 12a mainly composed of a metal such as nichrome is first placed on a metal wire mat 11 as shown in FIG. Thermal spraying is performed, and thereafter, the skin material 12b made of the ceramic is sprayed or impregnated.

The skin of the metal wire mat 11 constituting the feeder 2 is covered with the sealing material 12 in this way, so that insertion and wetting of the molten metal at the skin portion in contact with the molten metal are reliably prevented.

By having the feeder 2 constructed as described above, the thermal conductivity becomes 0.3 to 0.4 w / m · k, and high heat retention can be obtained. Therefore, at the time of casting,
The solidification time of the molten metal in the inside of the product cavity 5 becomes sufficiently slow as compared with the solidification time of the molten metal in the product cavity 5, and the problem of sink marks or the like occurring on the product surface is reliably prevented.

Further, since the heat insulating walls 9 constituting the feeder 2 are formed of the thin metal wires 10a, the bending strength thereof is about 30 MPa, and the strength against input of external force such as thermal shock is greatly increased. , Wear resistance is also increased. For this reason, the feeder chamber 2 thus formed is less likely to be damaged, such as "chip" or "crack", even when repeatedly used, and is less likely to be worn. Therefore, by regularly checking and removing the aluminum adhesion state from the feeder 2, the use of the feeder 2 can be continued for a long period of time.

Further, since the skin of the metal wire mat 11 (mat pieces 11a to 11d) constituting the feeder 2 is covered with the fine holes by the sealing material 12, the heat of the molten metal is thereby reduced. In addition to making it harder to enter the inside of the mat 11, the heat retaining property can be further improved, and the insertion or wetting of the molten metal on the surface of the metal wire mat 11 can be prevented, and the solidified metal can be easily separated.

Next, another embodiment shown in FIGS. 8 to 10 will be described.

In this embodiment, the heat insulating material 1 according to the present invention is applied to a feeder 2 of an aluminum casting mold as in the above-described embodiment. Is different.

That is, the feeder 2 is not formed by cutting and bonding the metal wire mat 11, but before the metal wire mat 11 is sintered and formed, it is put into a press die 15 as shown in FIG. The whole is formed into a predetermined shape at once by applying a load, and then sintering is performed. Further, the sealing material 12 is adhered to the metal wire mat 11 as in the above-described embodiment. If necessary, fine adjustment of the shape of the press-formed metal wire mat 11 is appropriately performed by cutting or the like. Further, sintering may be performed simultaneously with press molding.

In the case of this manufacturing method, since the outer shape of the feeder 2 can be formed at a time by press molding,
The production efficiency is good, and the production cost can be greatly reduced in the case of mass production. Further, unlike the method of the above-described embodiment, this manufacturing method does not have a concern about a variation in adhesive strength.

Further, according to the manufacturing method of this embodiment, since the metal wire material mat 11 is not used by appropriately cutting and bonding, the seam cannot be formed at all in the finished feeder 2 and the surface in contact with the molten metal. In all of the parts, the laminating direction of the metal wire group 10 is substantially perpendicular to the surface (the thin metal wires constituting the metal wire group 10 do not extend substantially perpendicular to the surface). A uniform heat insulating effect can be obtained over the entire area of the hot water 2. That is, the mat pieces 11a to 11
If there is a portion where the thin metal wire 10a crosses the thickness direction of the feeder chamber 2 at a location in contact with the molten metal, as in the joint portion d, the heat insulating effect at that location is partially reduced. Such a problem does not occur when the method is used.

The embodiments of the present invention are not limited to those described above. Even when the same heat insulating material 1 is used for a casting mold, for example, as shown in FIGS. It can be applied to a heat insulating wall of a generally conical feeder 22,
It is also possible to apply to a part of the wall. Further, the use of the heat insulating material 1 according to the present invention is not limited to the above-mentioned feeder,
4, it may be applied to the ladle (ladle) 31 of the casting water heater 30 as shown in FIG.

Further, the heat insulating material 1 can be applied not only to casting tools but also to the barriers of all other heat insulating devices. It may be. The sealing material covering the metal wire mat may be made of, for example, a metal foil depending on the use of the heat insulating material, and the metal foil may be adhered to the surface of the metal mat.

[0043]

As described above, the invention according to claim 1 is
A large amount of air is held inside by a metal wire rod mat having a large porosity, and gas and liquid facing the heat insulating material can be prevented from entering the metal wire mat by a sealing material. Thereby, a large heat retaining effect can be obtained while maintaining the overall strength and durability.

According to the second aspect of the present invention, the skin material can be firmly adhered to the metal wire mat with the base material mainly composed of the metal previously coated on the metal wire mat as an intermediary.

According to the third aspect of the present invention, the metal mat constituting the heat insulating material has the highest heat insulation efficiency (low thermal conductivity).
Because the insulation wall of the heat retention device is formed in consideration of the direction,
The heat retaining performance of the heat retaining device can be further improved.

According to the fourth aspect of the present invention, since the storage chamber is constituted by the heat insulating wall having high heat insulation efficiency, the substance put in the storage chamber can be more reliably maintained in a warm state.

According to the fifth aspect of the present invention, the solidification of the molten metal flowing into the feeder can be sufficiently delayed by the heat insulating wall having high heat insulating efficiency, so that sink marks and the like are generated on the product surface. The quality of the cast product can be further improved by reliably suppressing it, and furthermore, the temperature of the molten metal can be lowered to save energy in the manufacturing process and also prevent the occurrence of defects inside the product due to the formation of an oxide film. can do. In addition, since the fine holes on the surface of the metal wire rod mat constituting the heat insulating wall are closed by the sealing material, insertion of molten metal into the mat is eliminated, and separation of the solidified metal from the heat insulating wall is facilitated. be able to.

According to the sixth aspect of the present invention, the gaps and the like at the bonding portions can be filled with the sealing material, so that the releasability of the substance that comes into contact with the heat insulating wall can be improved.
The storage chamber can be prevented from being damaged. Further, in the present invention, since the degree of freedom of modeling is high, there is an advantage that the present invention can be easily applied to storage chambers of various shapes.

According to the seventh aspect of the present invention, a smooth and seamless storage chamber can be easily formed by a single press molding, and the contact surface with the substance in the storage chamber can be formed in any part. Can also be substantially perpendicular to the lamination direction of the metal wire group, so that a uniform heat insulating effect can be obtained over the entire area of the storage chamber.

According to the eighth aspect of the present invention, at least the inner surface of the storage chamber can be firmly and efficiently coated with ceramics in the process of manufacturing the heat retaining device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat insulating material showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view (A) along the line BB in FIG. 1 and FIG.
The figure which arranged the expanded sectional view (a) along CC line of FIG.

FIG. 3 is a sectional view of a casting mold showing one embodiment of the present invention.

FIG. 4 is a sectional view taken along the line AA in FIG. 3;

FIG. 5 is an explanatory view of assembling the mat pieces according to the embodiment.

FIG. 6 is a perspective view showing the same embodiment.

FIG. 7 is a combination of a perspective view and an enlarged cross-sectional view of the storage chamber showing the embodiment.

FIG. 8 is a sectional view showing another embodiment of the present invention.

FIG. 9 is a plan view showing the same embodiment.

FIG. 10 is a sectional view taken along the line DD in FIG. 9;

FIG. 11 is a sectional view showing another application example of the present invention.

FIG. 12 is a plan view showing the application example.

FIG. 13 is a sectional view taken along the line EE of FIG. 11 showing the application example.

FIG. 14 is a side view showing still another application example of the present invention.

FIG. 15 is a sectional view of a main part of the application example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heat insulation material 2 ... Hot water chamber (reservoir room) 9 ... Heat insulation wall 10 ... Metal wire group 10a ... Fine metal wire 11 ... Metal wire mat 11a-11d ... Mat piece 12 ... Sealing material 12a ... Skin material 13 ... Inorganic adhesion Agent

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiro Katsuya 3-10-10 Fukuura, Kanazawa-ku, Kanagawa Prefecture Japan Incorporated Company (72) Inventor Toru Shiraishi 3-10-10 Fukuura, Kanazawa-ku, Kanagawa Prefecture Japan Incorporated Company ( 72) Inventor Ken Suzuki 3-10-10 Fukuura, Kanazawa-ku, Kanagawa Japan F-term (reference) 4E093 PB01 PB03 PB05

Claims (8)

[Claims] 1. A porous metal wire mat is formed by laminating a metal wire group in which a plurality of fine metal wires randomly intersect on substantially one plane in a direction substantially orthogonal to a plane formed by the metal wire group. A heat insulating material comprising a metal wire mat covered or impregnated with a sealing material. 2. The heat insulating material according to claim 1, wherein said sealing material is formed of two layers of a base material mainly composed of metal and a skin material mainly composed of ceramics. 3. A heat insulating device, wherein the heat insulating material according to claim 1 or 2, wherein a heat insulating wall is formed such that a lamination direction of a group of metal wires of the metal wire mat is a wall thickness direction. 4. The heat retention device according to claim 3, wherein a storage chamber for storing a high-temperature or low-temperature substance is formed by the heat-insulating wall. 5. The heat retention device according to claim 4, wherein the storage chamber is a feeder of a casting mold. 6. A porous metal formed by laminating a plurality of metal wires randomly intersecting on substantially one plane in a direction substantially perpendicular to a plane formed by the metal wires. The wire mat is cut into a predetermined shape, the cut mat pieces are adhered with an inorganic adhesive to form the outer shape of the storage chamber, and then at least the inner surface side of the storage chamber is covered or impregnated with a sealing material. A method for manufacturing a heat insulating device, which is characterized by 7. A porous metal formed by laminating a plurality of metal wires randomly intersecting on substantially one plane in a direction substantially orthogonal to a plane formed by the metal wires. A method for producing a heat retaining device, comprising: press-molding a wire mat to form a storage chamber, and thereafter covering or impregnating at least an inner surface side of the storage chamber with a sealing material. 8. The method according to claim 6, wherein, at the time of coating the sealing material, first, a base material mainly composed of a metal is coated, and then a skin material mainly composed of a ceramic is coated.
Or the manufacturing method of the heat retention apparatus as described in 7.