JPH10249480A - Core made of paper or the like used for casting mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a core extremely light in weight, economical in cost performance and capable of improving working circumference by forming the core with an organic fiber such as paper by using an original pattern composed of low m.p. material. SOLUTION: An original pattern 2 composed of the material having low m.p. corresponding to a cavity 21 for core 20 is set in a combined frame of the enclosure of pre-manufactured side plate 1 and bottom plate 3 and fluid mold material is charged into a space 4 between the frame and the original pattern 2, and after hardening, a solid material 5 is taken out. The heated and melted material of the low m.p. pattern material is poured into a space 6 in the solid material 5, and after solidifying, a solidified material 19 is obtd. Further, a mold 14 is obtd. with the frames of the side plate 7 and the bottom plate 9. A mold 15 is obtd. with the frame of the side plate 10 and the bottom plate 12 by a prescribed method. The core insert 20 of the paper mold, etc., formed in the remained space 18 is obtd. by melting, flowing out and removing the solidified material 19 and a mold 16. The core 20 is set into the paper-made mold and, an the time of pouring molten metal into the mold, if the refractory coating agent having >=1825 deg.C m.p. is coated, the mold is not broken unit the casting is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to an indispensable technique for installing in a mold used for manufacturing a casting.
This is related to relatively accurate nesting.

2. Description of the Related Art Heretofore, a nest in a casting mold has been made by combining or assembling some sand molds made of wooden or the like so as to be easily removed therefrom. Therefore, it is often in the form of a single nest. In the case of using a mold, it is gradually produced by obtaining precision with extremely high skill. Sand molds are mainly made of sand and sand binder, so they are manufactured under dust, vibration, noise, and unpleasant atmosphere. Therefore, the manufacturing equipment is expensive, and in many cases, the products to be manufactured require careful handling and are relatively light in weight. Even when made with molds, heavy equipment handles heavy tools, requires special care in handling, and the working environment is not very good. In any case, nesting has been made in operations that are often messy, harsh and dangerous. As a casting mold in which the inner nest is installed, a mold made of paper and a processed product thereof has already been filed in Japanese Utility Model Application No. 5-37490 in order to solve the drawbacks of the conventional mold.

[Problems to be Solved by the Invention] The following items are problems to solve the above-mentioned drawbacks of the prior art. (B) Be as light and easy to handle as possible. (B) No unpleasant and harmful gas is generated. (C) The inner nest has no seams or the like and is relatively easy to obtain good accuracy. (D) Production costs are low, experienced skills and highly specialized special skills are almost unnecessary. The date and time required for production must be short. (E) There should be no problem with treatment as industrial waste. The present invention has been made for these.

[Means for Solving the Problems] The nest is made by molding paper or the like, and is made extremely lightweight so that it can be easily handled. After the inner nest is made by injecting organic fiber material such as paper into the space between the outer and inner molds made of low melting material, the low melting material is heated and melted. Then spill and remove. The remaining insert is then removed and used to make a mold and proceed to casting. No organic sand binder is used, which creates harmful gases and an unpleasant working environment.

[Embodiment of the Invention] A low melting point material, for example, wood or the like, for obtaining an intended nesting inside a frame.
A mold with the correct shape and dimensions required to make a mold with a low melting point alloy such as metal or solder is installed, and a relatively low melting point material mold is provided between the mold and the container. Make molds that dissolve or disintegrate at low temperatures. The mold is used to make a mold for nesting of low melting point materials. After injecting a fluid organic fiber material such as paper with an adhesive such as glue into the mold with the low melting point material, consolidating, and then heating, the low melting point material is melted and removed. Then, the nest formed of paper or the like is taken out. A zircon-based mold wash is applied as a paint by brush or spray to the surface of the removed nest, and dried to form a thin layer of refractory.

An embodiment of the present invention will be described below. [FIG. 1] shows the manufacturing steps, and arrows indicate the order of the steps. (A) A low melting point corresponding to the void (21) of the inner nest (20) in a frame obtained by combining the surroundings of the side plate (1) and the bottom plate (3) previously made of wood, metal, organic hardened material or the like. The mold (2), which is made of the following material, is placed in the space (4) between the frame and the mold, which is used in a solid state and then melted or disintegrated at a relatively low temperature. Then, after the mold material is set, the solidified product (5) is taken out. (B) Inject into a space (6) in (5) a heat-melted low-melting mold material such as wood metal as a mold for nesting, and then solidify it. To obtain the solidified product (19). (C) In addition, the same fluid material is put in a space (8) formed by a frame combining the side plate (7) and the bottom plate (9), and the solidified material is made of a material having a low melting point. The mold (14) necessary for producing the solidified mold (16) is used. (D) At the same time, in the frame in which the side plate (10) and the bottom plate (12) are combined, the prototype (1) corresponding to the outside of the mold for forming the inner nest is formed.
1) is installed, and the same fluid material as described above is placed in the space (13) between the frame and the prototype. According to (E) and (D), the solidified product (1
Make a mold (15) to obtain 6). (F) Further, the side plate (10), the bottom plate (12), and the prototype (1)
Similarly, using 1), a solidified material of a low melting point material (16)
Holding mold (1) for holding the
Make 7). The fluidized material for making (5), (14), (15), and (17) described herein is sodium chloride or industrial salt (NaCl) containing about 3% of water (H ₂ O). A mixture of
After filling it into the predetermined spaces (4), (8), and (13), the whole was frozen and solidified, and all the holding frames and the bottom plate were removed to form the formed (5), (14). , (15),
Take out (17). At this time, sand grains may be used instead of salt or industrial salt, but in that case, when the low-melting point material is heated and the solid obtained in the mold obtained by injecting the melted material is mixed with the sand grains. Moisture evaporates, and the frozen and solidified molds (5), (14), (15), and (17) collapse and sand dust is generated. In this regard, when salt or industrial salt is used, it is frozen and solidified (5),
By applying running water to (14), (15) and (17) or immersing them in water, salt or industrial salt flows off as salt water, so that a low melting point material is used without generating dust at all. The solidified product of the mold can be taken out, and there is no environmental problem. The low melting material injected into the space made in (5) and the space (16) in the mold made in (14) and (15),
Low melting point alloy having a melting point of 80 to 90 ° C or less (for example,
Bi 50%, Cd 12.5%, Pb 25%, Sn12.
5% of Wood's Metal
Etc.). Heated to a molten state,
This low-melting material is injected into the space (16) between (14) and (15) to solidify the low-melting material outside the inner nesting mold made of an organic fiber material such as paper. Make thing (16). Similarly, it is poured into the space (6) in (5) to form a solidified material (19) of the low melting point material which strikes the inside. (G) In the space (18) between the solidified material of low melting point material (16) and (19), a mixture of finely crushed organic fiber material such as waste paper and an adhesive such as glue is formed. After filling the fluid mold-making material and curing it, it is dried, and while keeping it from splashing with water, the holding mold (1) of (16) is used.
7) Disintegrate with water. After doing so, it is heated to a temperature at which the remaining low melting point molds (19) and (16) dissolve and flow. (H) The molds (19) and (16) are dissolved, flowed out, and removed to obtain an inner nest (20) such as a paper mold formed in the space (18) that remains. The inner nest (20) formed by a paper mold or the like obtained in this way is accurately placed in a mold, but before that, the inner nest is made of molten metal injected into the mold during casting. A spraying agent or a brush is used to apply a coating agent made of a zircon-based refractory powder to the contacting portion, and then dried to form a thin refractory coating layer on the surface. According to the present invention, the inner nest (20) of the paper mold or the like having the above structure is placed in a paper mold already filed in Japanese Utility Model Application No. 5-37490, and melted for casting. When the metal is injected into the mold, the injection temperature is 1250-145.
Regardless of cast iron at 0 ° C., light alloy casting such as aluminum alloy at 650 to 750 ° C., and copper alloy casting at 950 to 1250 ° C., the time to inject them is several seconds to tens of seconds,
In addition, in the case of a casting having a small thickness in a casting of a steel casting or an alloy containing Ni, Cr, etc., when the casting temperature is 1500 to 1600 ° C., the casting time is several seconds to several tens of seconds. Oxide (zircon (ZrSiO ₄ ), battery stone (ZrO ₄ ) whose refractory layer formed so as to cover the inner nest of a paper mold or the like is mainly made of zirconium having a fire resistance of SK37 or more, that is, a melting point of 1825 ° C. or more. ₂ )
If the mold is filled with molten metal and the casting is completed, there will be no damage to the paper mold or nest, and the casting will cool and solidify from its surface. And the shape is made sufficiently. The casting that has been cast after the injection of the molten metal can be easily removed simply by removing the mold and the inner nest. Even if there is a residue such as a paper mold after removing the casting, it can be incinerated in an incinerator or a heating furnace for heat treatment, and hardly generates industrial waste.

[Effects of the Invention] The following effects can be obtained by using a paper mold or the like instead of a sand mold or a metal mold according to the present invention. (A) Since the inner nest to be manufactured is integrally made in the space of the shape of the inner nest, the conventional seam cannot be made by combining the upper, lower, left and right wooden molds. The accuracy of the nesting is good. (B) Since the nest is formed by a hollow paper mold or the like, there is no danger in all aspects such as handling due to its characteristics. (C) Less experience and special skills are required than expensive and time-consuming molds and combined wood molds, and therefore relatively expensive. It requires less time and can be manufactured in a short time. (D) The process of nesting in a mold that freezes or mixes a mixture of salt and water that melts or disintegrates at a relatively low temperature, and a mold that uses a low melting point material such as wood metal, Since the operation is always performed at a temperature of about 80 to 90 ° C. or less, it is not necessary to control the environment such as temperature and humidity so strictly. Therefore, there is no need for facilities and equipment for environmental management and work management as in the precision casting method, which has conventionally been required to be managed under extremely strict conditions. (E) The equipment used for production must be corrected for shape and dimensions.
The outer and inner molds are made of low-melting material to fit the intended purpose of nesting with high precision. Conventional heavy equipment is not required, and heavy labor for work is reduced. (F) Unpleasant environmental conditions such as noise and vibration of work and workplaces are reduced. (G) Since the nesting made of paper or the like can be incinerated after the completion of casting, no industrial waste is generated in these series of steps, and problems related thereto are almost eliminated. (H) Since an organic sand binder which generates an unpleasant harmful gas is not used, a sanitary environment is improved in operations such as nesting and injecting molten metal into a mold. (I) Low melting point alloys such as wood metal used as low melting point materials are heated to about 80 to 90 ° C.
The removed one can be used again. (V) Resources that are discarded, such as waste paper, can be used. (R) In the case of a small nest or a thin nest, the solidified material (19) having a low melting point is omitted and not used.
It is also possible to form a solid, nested body without 1) without a hollow body. (ヲ) All of the nests manufactured will be lightweight.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of an embodiment of the present invention. (A) A perspective view of a frame for making (5). (B) A perspective view of a mold for making (19). (C) A perspective view of a mold for making (14). (E) Perspective view of the frame for making (15) and (17) (E) Cross-sectional view of the mold for making (16) (F) Cross-sectional view of the mold for creating a space (18) for inserting materials such as paper molds (G) Perspective view of the nested inner nest (20)

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Side plate 2 Prototype 3 Bottom plate 4 Space to make (5) 5 Mold made by freezing a mixture of salt and water 6 Space to make solidified material of low melting point material (19) 7 Space to make side plate 8 (14) 9 Bottom plate 10 Side plate 11 Prototype 12 Bottom plate 13 Space for making (15), (17) 14 Mold made by freezing a mixture of salt and water 15 Mold made by freezing a mixture of salt and water 16 Low melting point material 17 A mold made by freezing a mixture of salt and water 18 A space for holding a material such as a paper mold 19 An inner mold made of a solidified material having a low melting point 20 Paper made by (18) Nesting of molds, etc. 21 Empty space inside nesting

Claims (1)

[Claims] An inner nest for a mold, wherein an organic fiber material such as paper is molded using a mold made of a material having a low melting point.