JP2008036684A - Method for producing low melting point material casting, its production system and ingot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a low melting point material casting where the cost taken for the reproduction of a casting is remarkably reduced, and further, the safety/sanitation of an operator and the quality of a reproduced casting can be improved. <P>SOLUTION: The method comprises: a step where a used low melting point material block 3 is preheated utilizing hot air 22 exhausted from a melting pot 30 in a state of being supported by a supporting member 16, and further, the preheated low melting point material block is melted by a melting furnace 10 for normal-heating by a direct heating means; a step where the dripping of the melt of the low melting point material block is received by a mold 18 for an ingot, and the melt is cooled and solidified, so as to produce an ingot; a step where, in the melting pot provided with an inner pot 42, an outer pot 32 and a whole face heating means for heating the whole face of the inner pot, the inner pot is charged with the ingot, so as to produce a molten metal; and a step where the inner pot charged with the molten metal is discharged from the outer pot, and is carried to a mold, and the molten metal is poured into the mold, so as to produce a casting. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a low-melting point casting, a production system thereof, and an ingot used therein, and more particularly, a method of producing a zinc alloy casting used in a mold, a production system thereof, and an ingot used therein. About.

  For example, injection molding molds are manufactured by precision machining a casting made by pouring a molten metal of a low melting point zinc alloy called ZAS (Zinc Alloy for Stamping) into a mold. (For example, see Patent Document 1). In addition, cutting scrap generated when machining an aluminum or aluminum alloy block is recovered and melted, and after removing impurities, it is agglomerated and reused as a recycled ingot (for example, Patent Documents). 2).

  The used molds that have finished their mission are collected by a specialist, and are crushed by the specialist to crush them. The crushed lump that has been crushed by a specialist is returned to the mold manufacturer and reused for producing the mold. That is, the crushed lump is put into a weight melting pot and melted by heating with a burner, and the molten metal in the weight melting pot is subdivided into a ladle and poured into a mold to produce a new mold. Recycled castings are produced.

  In the prior art in which a used mold is reused as a recycled casting for producing a new mold through such processes, there are various problems as described below.

  Since used dies are transported to a specialized contractor's work site and crushed, there is a manufacturing cost problem that requires a large amount of transportation and crushing costs. In addition, the crushing operation is performed by dropping the used mold onto the floor of the work place, but at that time, a large number of crushed pieces are scattered around, which causes a problem in safety and health. Since the crushed lump of the used mold has an irregular shape, it cannot be densely collected and stored, so that there is a problem in manufacturing cost that a vast storage space is required. In addition, the crushed lump is often piled up and exposed to rain and wind, so that rust and impurities are likely to occur. Moreover, when recovering the crushed lump on the floor, surrounding impurities are mixed. Therefore, castings produced by pouring molten metal made from crushed lumps into a mold have defects such as pinholes and foreign matter, and require a lot of time for machining and finishing of castings. There are quality issues.

  When performing the melting operation of the crushed lump, the crushed lump is hung on a crane in a state of being hooked on a wire, and is put into a heavy weight melting pot. Because the crushed lump has an irregular shape, it is a dangerous work that can be unfamiliar when the hooked state is unstable, and it is also a dangerous work to unwind the wire after throwing it into the heavy metal melting pot There is a health and safety problem.

  In addition to the irregular shape of the crushed lump, small crushed lumps are also included, so the crushed lump is used as a wire to feed the required amount of crushed lump into the melting kettle. There is a problem in manufacturing cost that the number of times of hooking increases.

  Since the weight melting pot used when melting the crushed lump is generally made of a casting, the thickness is large, for example, about 50 mm, and thus the weight is heavy. The size is also a size that allows a necessary amount of crushed lump to be introduced into the melting kettle, for example, having a diameter of 1.8 m and a depth of 0.7 m. Therefore, the weight melting pot filled with the molten metal increases in weight to, for example, about 6 to 10 tons. In order to transport such a heavy load melting pot to the mold, a large heavy machine such as a large crane is required. Therefore, the molten metal in the heavy metal melting pot is divided into small ladles, transported to the mold and poured, and when the molten metal is divided into small ladles, the heavy metal melting pot is tilted. However, it is necessary to provide a robust mechanism and apparatus for tilting the melting pot that can be held. In addition, the conventional heavy-melting kettle has a local heating structure in which the bottom surface of the heavy-weight heavy melting kettle is heated by a burner, and the heat used for heating is discharged, so that the heat conductivity is low. There is a problem in manufacturing cost such as low utilization efficiency.

JP 2000-246387 A Japanese Patent Laid-Open No. 9-241774

  Therefore, the technical problem to be solved by the present invention is a method for producing a low-melting-point material casting that can significantly reduce the cost of casting regeneration and improve the safety and health of the worker and the quality of the recycled casting, It is to provide a manufacturing system and an ingot.

Means and actions / effects for solving the problem

In order to solve the above technical problem, according to the present invention,
While the used low-melting-point material block is supported by the support member, the low-melting-point material block is preheated using the hot hot air exhausted from the melting kettle, and the preheated low-melting-point material block is directly heated by the heating means. Melting the low melting point material block with a heating melting furnace;
Receiving a drop of the melt of the low-melting-point material block with an ingot mold disposed immediately below the support member, and cooling the solid melt to produce an ingot;
The melting kettle has a portable inner kettle, an outer kettle that holds the inner kettle, and a full surface heating means that heats the entire surface of the inner kettle. The ingot is poured into the inner kettle to create a molten metal. And steps to
Removing the inner pot containing the molten metal from the outer pot and transporting it to the mold, pouring the molten metal into the mold and producing a casting;
A method for producing a low-melting-point material casting is provided.

  According to the above method, an ingot is prepared by melting a used low melting point material block in a melting furnace utilizing exhaust heat, and an ingot is melted in an inner pot of a molten kettle that is heated over the entire surface to produce a molten metal. A casting can be manufactured by conveying the inner pot containing the molten metal to the mold and pouring the molten metal into the mold. Since a melting furnace and a kettle with very high heat utilization efficiency and thermal conductivity are used, the manufacturing cost of castings can be greatly reduced. Since used low melting point material blocks are used as they are without being crushed, they contribute to the reduction of crushing costs, eliminate the safety and health problems of scattered block pieces, and are less likely to contain impurities. Since the molten metal is provided in an aspect, the quality of the final product is improved. Since the ingot having a fixed form is easy and efficient in handling, the problem of health and safety and the problem of manufacturing cost can be solved. Since a lightweight inner pot containing molten metal is transported to the mold with a small crane, etc., there is no need for a ladle or a melting pot tilting mechanism / equipment, reducing the cost of molten metal pouring work and melting. Since the production cost of the kettle is reduced, the production cost can be greatly reduced.

  In order to increase the utilization efficiency of heat in the melting pot, the side hot air used for heating the side and bottom surfaces of the inner pot is used. That is, the full surface heating means includes a heating duct that guides the side hot air existing between the inner side surface of the outer hook and the outer side surface of the inner hook to the upper portion of the inner hook.

  When melting a low-melting-point material block that has been used in a melting furnace, the main heating with hot hot air of the direct heating means of the melting furnace may be performed from the beginning without preheating with exhaust hot air from the melting kettle. However, in order to increase the efficiency of heat utilization and prevent the generation of oxidized fragments due to the surface of the low melting point material block coming into contact with the high temperature hot air, the melting pot lower in temperature than the hot air of the direct heating means It is preferable to use the exhaust hot air from. Therefore, an upper lid is provided on the upper part of the inner pot of the melting kettle, and the upper hot air existing in the upper space formed between the upper lid and the molten liquid level in the inner kettle is sent to the upper space of the melting kettle and the melting furnace. Is supplied to the melting furnace through an exhaust heat duct that communicates with the melting furnace.

  The hot air existing in the upper space of the inner pot containing the molten metal is usually at a temperature equal to or higher than the melting point of the low melting point material block, but a temperature drop occurs when the hot air passes through the exhaust heat duct. . Accordingly, the temperature of the exhaust hot air supplied from the melting kettle to the melting furnace is usually lower than the melting point of the low melting point material block.

  The ingot is usually carried by a conveying means such as a crane. Therefore, it is preferable that the ingot has a shape that can be engaged with a hook.

  The low melting point material is a low melting point non-ferrous metal having a melting point of approximately 300 ° C. to 450 ° C., and is aluminum, an aluminum alloy or the like, or a zinc alloy, but is a material for casting of an injection mold or a press mold. As such, zinc alloy is preferable from the viewpoint of material cost.

  The castings targeted by the present invention can also be applied to figurines, bronze statues, benches, tables, etc., but there is an increase in demand and injection molding dies and press working that can achieve significant cost reduction effects It is preferable to apply to a metal mold.

  Below, the manufacturing method of the low melting-point material casting which concerns on one Embodiment of this invention, its manufacturing system, and an ingot are demonstrated in detail, referring FIG.

  FIG. 1 is a diagram illustrating a manufacturing system for a low-melting-point material casting according to an embodiment of the present invention. FIG. 2 is a flowchart of a method for manufacturing a low-melting-point material casting by the low-melting-point material casting manufacturing system shown in FIG. FIG. 3 is a perspective view showing an ingot according to an embodiment of the present invention. FIG. 4 is a view showing an ingot according to another embodiment of the present invention.

  A case where the low melting point casting is applied to an injection mold or press mold made of a zinc alloy called ZAS (Zinc Alloy for Stamping) will be described below. ZAS is, for example, a zinc alloy containing about 4% by weight of aluminum, 3% by weight of copper, and 0.05% by weight of magnesium, and has a melting point of about 400 ° C.

  The low melting point material casting manufacturing system of the present invention comprises a melting furnace 10, a melting pot 30, an exhaust heat duct 60, a mold, an ingot transfer means, and an inner pot transfer means.

  First, a melting furnace 10 for producing an ingot 5 by melting a used zinc alloy mold (block) 3 will be described.

  As shown on the left side of FIG. 1, the melting furnace 10 includes a housing 12 and an upper lid 14 that is detachably disposed on the housing 12. For example, the melting furnace 10 has a length of 3.4 m and a width of 3. The height is 2 m and the height is 2 m. Refractory bricks are laid on the inner surfaces of the casing 12 and the upper lid 14 to provide heat retention inside the melting furnace 10. Inside the housing 12, a support member 16, a burner as a direct heating means, and an ingot mold 18 are provided.

  The support member 16 is a grid-like or mesh-like iron (SS400) mounting table. For example, the product to be processed becomes an old model and ends its role, or the life is reached by forming tens of thousands of shots. A finished zinc alloy mold (block) 3 is placed. A zinc alloy melt drops from the opening of the support member 16. The used zinc alloy mold (block) 3 provided to the melting furnace 10 is a large one, for example, a length of 2.35 m, a width of 1.85 m, a height of 0.65 m, and a small one. For example, the length is 1.35 m, the width is 1.4 m, and the height is 0.4 m. It is also possible to place a zinc alloy member (parts, small pieces, and degreased processing scraps) of the same material on the support member 16 together with the zinc alloy mold (block) 3 and melt it.

  The ingot mold 18 that receives dripping of the melt of the used zinc alloy mold (block) 3 placed on the support member 16 is an iron (SS400) container. For example, a total of 20 ingot molds 18, 10 in a row and 2 in a row, are arranged and arranged directly below the support member 16. Adjacent flange portions of the ingot molds 18 are overlapped with each other so that the melt dripped from between the aligned ingot molds 18 does not leak. Each ingot mold 18 has a molding chamber 19 having a length of 1.3 m, a width of 0.35 m, and a height of 0.15 m, for example. The side surface of the inner portion of the molding chamber 19 is an inclined surface that spreads from the bottom to the top and functions as a draft of the ingot 5. Accordingly, from each ingot mold 18, the size is 1.3 m in length, 0.35 m in width, and 0.15 m in height, and each side surface is inclined downwardly from the bottom to the top. The ingots 5 each having a trapezoidal shape in a cross-sectional view and an inverted trapezoidal shape are obtained.

  Alternatively, the ingot mold 18 may be a large type mold whose vertical and horizontal sizes are substantially the same as those of the melting furnace 10. The large-sized ingot mold 18 is partitioned into a plurality of small molding chambers 19, and has, for example, 10 molding chambers 19 in one row and a total of 20 molding chambers 19. The size of each molding chamber 19 is, for example, 1.3 m in length, 0.35 m in width, and 0.15 m in height. A side surface of the inner portion of each of the molding chambers 19 that is partitioned is an inclined surface that widens from the bottom to the top, and functions as a draft of the ingot 5. Accordingly, from the large type ingot formwork 18, the size is 1.3 m in length, 0.35 m in width, and 0.15 m in height, and each side surface is inclined downward from the bottom to the top. For example, 20 ingots 5 having a trapezoidal shape in a cross-sectional view and an inverted trapezoidal shape are obtained.

  In the state where the iron (SS400) hook 84 is erected in each molding chamber 19, the melt of the zinc alloy mold (block) 3 is dropped, so that the hook 84 as shown in FIG. The ingot 5 can be produced in which the hook 86 is embedded in the hook 82 and the hook portion 86 of the hook 84 protrudes from the upper surface of the ingot main body 82.

  Or the ingot 5 with the hook hole 74 as shown in FIG. 4 can be produced by making a shaping | molding chamber into a slightly complicated shape. The ingot 5 shown in FIG. 4 has a thick plate-like portion 71 and a thin plate-like portion 72, and a hook hole 74 is provided in the thin-walled plate-like portion 72. Similar to the side surface of the ingot itself, the side surface of the hook hole 74 is an inclined surface that spreads from the bottom to the top and functions as a draft of the ingot 5.

  Alternatively, the ingot 5 has a certain hooked part as a motif, such as U-shaped, V-shaped, T-shaped, I-shaped, S-shaped, O-shaped alphabetic characters, hiragana characters, katakana characters, and numbers. The shape can be made. The side surface of the ingot itself with the character motif is an inclined surface that functions as the draft of the ingot 5 and spreads from the bottom to the top.

  Or, in order to increase the surface area per unit weight of the ingot 5 to facilitate melting, the ingot 5 can be formed into an elongated wire shape.

  The exhaust heat introduction port (introduction section) 64 is provided in the lower part of the side surface of the housing 12, and the exhaust heat hot air 41 from the melting pot 30 is introduced through the exhaust heat duct 60. The temperature of the exhaust hot air 22 introduced into the melting furnace 10 is, for example, about 300 ° C. to 350 ° C., and is used for preheating the zinc alloy mold (block) 3. That is, when the exhaust hot air 41 of the melting pot 30 that has been about 400 ° C. becomes the exhaust hot air 22 of the melting furnace 10 by passing through the exhaust heat duct, the temperature of the exhaust hot air 22 is about 300 ° C. to It has dropped to 350 ° C. The temperature of the exhaust hot air 22 is usually about 50 ° C. to 100 ° C. lower than the zinc alloy mold (block) 3 having a low melting point of about 400 ° C.

  The direct heating means is a burner using propane gas, liquefied natural gas, or A heavy oil as a fuel, and the burner is used to surround the used zinc alloy mold (block) 3 placed on the support member 16 from its side surface. Has been placed. Hot heating 24 (for example, the flame temperature is about 1300 ° C.) generated by the burner is blown onto the preheated zinc alloy mold (block) 3 to perform the main heating. In addition, the contribution ratio with respect to the fusion | melting of the zinc alloy metal mold | die (block) 3 between the preheating by the exhaust hot air 22 and the main heating by the high temperature hot air 24 of a direct heating means is about 7: 3.

  The ingot 5 cooled and solidified in the ingot mold 18 is opened by opening the upper lid 14 of the melting furnace 10, hooking a hook of a small crane as an ingot conveying means on the hook portion 84 of the solidified ingot 5, and lifting the ingot. After taking out from the mold 18, the process proceeds to the next step. As shown in FIG. 3, when the ingot 5 has the hook hole 74, the ingot mold 18 containing the ingot 5 is turned over to take out the ingot 5 from the ingot mold 18, so that the ingot 5 After hooking the hook of the small crane on the hook hole 74 and lifting it, the next process is started.

  Next, the melting pot 30 for producing a molten zinc alloy by melting the ingot 5 obtained in the melting furnace 10 will be described.

  As shown on the right side of FIG. 1, the melting pot 30 includes a portable inner hook 42, an outer hook 32 that houses and holds the inner hook 42, an upper lid 50 that covers the inner hook 42, and an inner hook 42. A full surface heating means 36, 38 for heating the entire surface is provided. In other words, the inner hook 42 and the outer hook 32 have a double structure.

  The inner pot 42 is an iron (SS400) bowl-shaped container, and the ingot 5 obtained in the melting furnace 30 is introduced from the upper opening 44. Since the inner hook 42 is made of, for example, a thin iron plate of about 25 mm, it contributes to high thermal conductivity and light weight. The upper opening 44 of the inner hook 42 has an obliquely cut shape. The size of the inner hook 42 is, for example, 1.0 m in diameter and 1.2 m in depth.

  On the longitudinal side of the upper side surface of the inner hook 42 cut obliquely, a molten metal pouring port is provided for pouring the molten metal in the inner hook 42 to the outside. Further, a U-shaped arm that is swingably supported is provided on a side portion of the inner hook 42. The swingable arm is used with the arm laid down when the ingot 5 is heated and melted. When the ingot is taken out, the arm is placed in an upright state, and the arm is hooked on the hook of the crane and the inner hook 42 is lifted and taken out. Is done.

  The outer hook 32 is also an iron container, and receives and holds the inner hook 42. The size of the outer hook 32 is, for example, 1.4 m in diameter and 1.95 m in depth. The side surface of the outer hook 32 and the side surface of the inner hook 42 and the bottom surface of the outer hook 32 and the bottom surface of the inner hook 42 are separated from each other, and a heating chamber 36 is formed in the gap between the outer hook and the inner hook. Since the upper opening portion of the outer hook 32 is in close contact with the upper side surface of the inner hook 42, the molten hot air 31, 33 in the heating chamber 36 is prevented from leaking to the outside. Therefore, the bottom surface and the side surface of the inner pot 42 are heated by the bottom surface molten hot air 31 and the side surface molten hot air 33 in the heating chamber 36, respectively.

  The melting pot 30 has a vertically long shape as a whole, and handles, for example, high-temperature hot air of about 800 ° C. to 1300 ° C. and high-temperature melt of about 420 ° C. Is dangerous. Further, the position of the exhaust heat exhaust port (exhaust part) of the melting pot 30 is preferably low in accordance with the position of the exhaust heat inlet (introduction part) 64 provided at the lower part of the side surface of the casing 12 of the melting furnace 10. . Therefore, it is preferable to arrange the lower half of the outer hook 32 in a recessed accommodation space provided in the ground. Since the high heat of the combustion chamber 34 and the heating chamber 36 is difficult to escape due to the semi-closed space called the recessed housing space, there is an advantage that the heat utilization efficiency is improved. In addition, the height of the vertically long melting pot 30 from the ground is reduced, and the advantage that the connection with the melting furnace 10 via the exhaust duct 60 is facilitated is also obtained.

  The upper lid 50 that covers the inner hook 42 has a shape that fits into the upper opening 44 of the inner hook 42, that is, a shape in which the lower opening is cut obliquely, and the inner lid 42 is covered with the upper lid 50. Sometimes the sealed upper heating chamber 51 is formed. An exhaust heat discharge port (discharge unit) 54 and a hot air introduction port 52 are provided on the longitudinal side (the left side surface in FIG. 1) of the side surface of the upper lid 50. The upper exhaust heat discharge port (discharge unit) 54 is connected to the exhaust heat duct 60, and the lower hot air introduction port 52 is connected to the upper heating duct 38.

  A combustion chamber 34 is provided below the heating chamber 36. The combustion chamber 34 is provided with a burner using propane gas, liquefied natural gas, or A heavy oil as fuel, and high-temperature hot air is generated by combustion of the burner. The hot air is introduced into the heating chamber 36 through the communication hole 35 and heats the bottom and side surfaces of the inner pot 42. The temperatures of the bottom molten hot air 31 and the side molten hot air 33 that heat the bottom and side surfaces of the inner pot 42 are both 800 ° C., for example.

  The upper heating chamber 51 formed between the upper lid 50 and the inner hook 42 by the inner hook 42 being covered with the upper lid 50 is an upper space (between the upper opening and the liquid level of the molten metal). Formed) and a portion of the upper lid space in the upper lid 50.

  The upper heating duct 38 communicates the upper part of the heating chamber 36 with the lower part of the upper lid 50 that covers the inner pot 42. The tip portion of the hot air introduction port 52 existing in the upper heating chamber 51 is bent downward, so that the upper molten hot air 39 is blown downward, that is, the ingot 5 in the inner pot 42 in a solid state and / or a molten metal state. It is comprised so that it may spray on. The side surface hot air 33 is guided to the upper space of the inner pot 42 via the upper heating duct 38 and used to heat the upper portion of the ingot 5 existing in the upper space of the inner pot 42. The temperature of the upper molten hot air 39 introduced into the upper space of the inner pot 42 is, for example, 420 ° C. Therefore, in the melting pot 30 of the present invention, the inner pot 42 is heated entirely by heating the bottom and side surfaces of the inner pot 42 by the heating chamber 36 and heating the upper face of the inner pot 42 by the upper heating duct 38. It has a whole surface heating structure. In addition, the temperature of the melt of the zinc alloy existing in the heated inner pot 42 is 420 ° C., for example.

  The exhaust heat duct 60 communicates the lower part of the side surface of the melting furnace 10 with the side surface of the upper lid 50 that covers the inner pot 42. In order to prevent the temperature of the exhaust heat hot air 41 and 22 from being lowered, the melting pot 30 is disposed near the melting furnace 10 to shorten the length of the exhaust heat duct 60 or the outer wall portion of the exhaust heat duct 60 is a heat insulating material. Wrapping is done. Hot air (hot air temperature is 400 ° C.) existing in the upper lid space after the ingot 5 is heated from the upper surface is supplied as exhaust hot air 41 to the exhaust heat introduction port 64 (introduction section) of the melting furnace 10 through the exhaust heat duct 60. The zinc alloy mold (block) 3 in the melting furnace 10 is guided and preheated. The temperature of the melting furnace side exhaust hot air 22 for heating the zinc alloy mold (block) 3 in the melting furnace 10 is, for example, 300 ° C. to 350 ° C. as described above.

  In addition, a small crane (inner pot conveying means) having a mechanism that lifts the light inner pot 42 containing molten metal and transports it to the mold and tilts the inner pot 42 to pour the molten metal into the mold. It is arranged near the shuttle 30. Since the inner pot 42 containing the molten metal is lighter than the conventional melting pot, a small crane or the like can be used. A hook of a small crane is hooked on an upright arm and the inner hook 42 is lifted, whereby the inner hook 42 is taken out from the outer hook 32. The hook of another small crane is hooked to the bottom portion of the short side of the inner hook 42 in the lifted state, and the bottom portion is lifted by the crane, so that the inner pot 42 containing the molten metal is tilted. As a result, the molten metal in the inner pot 42 flows out from the molten metal pouring port.

  In the present invention, the use efficiency of heat in the melting pot 30 can be greatly improved by adopting the double structure and the full surface heating structure of the melting pot 30 as described above. At the same time, by making the inner pot 42 a thin steel body, the light inner pot 42 containing the molten metal can be transported to the mold with a small crane or the like. The mechanism / equipment becomes unnecessary, the cost of the molten metal pouring work is reduced, and the manufacturing cost of the melting pot 30 is reduced.

  The mold is for producing various castings such as a mold, a figurine, a copper image, a bench, a table, and the like, and is a sand mold formed so as to obtain a casting having a desired shape. The mold is disposed at a distance from the melting pot 30. Therefore, the inner pot 42 containing the molten metal is conveyed by a small crane or the like as the inner pot conveying means. A casting having a desired shape is manufactured by inclining the conveyed inner pot 42 and pouring the molten metal into a mold.

  Instead of arranging one melting kettle for one melting furnace, two or more melting kettles are arranged for one melting furnace and an exhaust duct is connected to each melting kettle. You can also. When two or more melting kettles are used, the molten metal always exists in one of the melting kettles by preparing the molten metal in the other melting kettles until all of the molten metal in one melting kettle is poured. In addition, since exhaust hot air from any melting kettle can always be introduced into the melting furnace, work efficiency and heat utilization efficiency are improved.

  Next, as an example, a method for manufacturing an injection mold or press working mold made of a zinc alloy will be described with reference to FIG.

  In step # 100, a used zinc alloy mold (block) 3 is prepared, and the zinc alloy mold (block) 3 is set on the support member 16 of the melting furnace 10. After covering with the upper lid 14, the exhaust hot air 22 is introduced from the exhaust heat duct 60 to preheat the zinc alloy mold (block) 3, and then the main heating is performed by a burner (step # 120). As a result, the zinc alloy mold (block) 3 is in a molten state (step # 140), and the zinc alloy melt is dropped into each molding chamber 19 of the ingot mold 18 (step # 160). After the melting of the zinc alloy mold (block) 3 is completed, the hook 84 is removed from the ingot 5 even if the upper lid 14 and the support member 16 are removed and the hook of the crane is hooked on the hook 84 and the ingot 5 is lifted. The melt dripped in each molding chamber 19 is cooled to a temperature at which it solidifies to such an extent that it does not come off (approximately 200 ° C.) (step # 180). As a result, a plurality of solidified ingots 5 are obtained in the ingot mold 18 (step # 200). A hook of a crane is hooked on a hook 84 embedded in the ingot 5, and the ingot 5 is lifted and taken out from the ingot mold 18. The taken out ingot 5 is stored in a predetermined storage place or is directly put into the inner pot 42 of the melting pot 30 (step # 220).

  In Step # 240, the inner pot 42 containing the ingot 5 is covered with the upper cover 50, and then the melting pot 30 is heated. At this time, an exhaust heat duct 60 and an upper heating duct 38 are incorporated in the upper lid 50. The inner pot 42 is entirely heated by the hot molten hot air 31 and 33 generated by igniting the burner, and the ingot 5 in the inner pot 42 is melted (step # 260). As a result, a molten zinc alloy is generated in the inner pot 42 (step # 280). At the same time, the exhaust hot air 41 in the upper heating chamber 51 is used for preheating the used zinc alloy mold (block) 3 in the melting furnace 10 through the exhaust heat duct 60 (step # 250).

  In step # 300, the upper lid 50 on the inner hook 42 is removed, the arm of the inner hook 42 is set upright, the arm is hooked on the hook of the crane, and the inner pot 42 containing the molten zinc alloy is lifted and taken out. It is transported to the mold. The hook of another small crane is hooked to the bottom of the short side of the inner hook 42 that is lifted, and the bottom of the short side of the inner hook 42 is lifted, so that the inner pot 42 containing the molten metal is tilted. Then, the molten zinc alloy in the inner pot 42 is poured into the mold (step # 320). When the poured mold is cooled to room temperature, a solidified casting is obtained (step # 340).

  The obtained casting is machined with various machine tools (Step # 360), and then finish processing such as hand polishing is performed (Step # 380), whereby a desired new injection mold or press working is performed. A mold is obtained (step # 400).

  As an example of the low melting point material casting, the zinc alloy injection mold and the press mold have been described. However, a low melting point non-ferrous metal having a melting point of approximately 300 ° C. to 450 ° C., such as aluminum or an aluminum alloy. It can also be applied to other articles made of (such as figurines, bronze statues, benches and tables). Moreover, it is applicable to metals having a melting point of about 450 ° C. or more by making the entire manufacturing system highly heat resistant.

It is a figure explaining the manufacturing system of the low melting-point material casting which concerns on one Embodiment of this invention. It is a flowchart of the method of manufacturing a low melting-point material casting by the low melting-point material casting manufacturing system shown in FIG. It is a perspective view showing the ingot concerning one embodiment of the present invention. It is a figure which shows the ingot which concerns on other embodiment of this invention. (A) is a top view, (B) is a front view, and (C) is a side view.

Explanation of symbols

3 Used zinc alloy mold (block)
5 Ingot 10 Melting furnace 12 Housing 14 Upper lid 16 Support member 18 Ingot mold 19 Molding chamber 22 Waste hot air 24 High temperature hot air 30 Melting pot 31 Bottom melting hot air 32 Outer pot 33 Side melting hot air 34 Combustion chamber 35 Communication hole 35 Heating Chamber 38 Upper heating duct 39 Upper molten hot air 41 Exhaust hot air 42 Inner pot 44 Upper opening 50 Upper lid 51 Upper heating chamber 52 Hot air inlet 54 Exhaust heat discharge port (discharge unit)
60 Waste heat duct 64 Waste heat introduction port (introduction part)
71 Thick plate-like portion 72 Thin-wall plate-like portion 74 Hook hole 82 Ingot body 84 Hook 86 Hook portion

Claims (20)

While the used low-melting-point material block is supported by the support member, the low-melting-point material block is preheated using the hot hot air exhausted from the melting kettle, and the preheated low-melting-point material block is directly heated by the heating means. Melting the low melting point material block with a heating melting furnace;
Receiving a drop of the melt of the low-melting-point material block with an ingot mold disposed immediately below the support member, and cooling the solid melt to produce an ingot;
The melting kettle has a portable inner kettle, an outer kettle that holds the inner kettle, and a full surface heating means that heats the entire surface of the inner kettle. The ingot is poured into the inner kettle to create a molten metal. And steps to
Removing the inner pot containing the molten metal from the outer pot and transporting it to the mold, pouring the molten metal into the mold and producing a casting;
The manufacturing method of the low melting-point material casting characterized by including this.   2. The low melting point material casting according to claim 1, wherein the full surface heating means includes a heating duct for guiding a side hot air existing between the inner side surface of the outer hook and the outer side surface of the inner hook to the upper portion of the inner hook. Production method.   An upper lid is provided at the upper part of the inner pot of the melting kettle, and the upper hot air existing in the upper space formed between the upper lid and the molten liquid level in the inner kettle is connected to the upper space of the melting kettle and the melting furnace. 2. The method for producing a low-melting-point material casting according to claim 1, wherein the melting point is supplied to the melting furnace by a communicating exhaust heat duct.   The method for producing a low-melting-point material casting according to claim 3, wherein the temperature of the exhaust hot air supplied from the melting pot through the exhaust heat duct is lower than the melting point of the low-melting-point material block.   The method for manufacturing a low-melting-point material casting according to claim 1, wherein the ingot has a shape that can be engaged with a hook.   The method for manufacturing a low-melting-point material casting according to claim 1, wherein the low-melting-point material is a zinc alloy.   The method for producing a low melting point material casting according to claim 1, wherein the used low melting point material block is a used low melting point material mold.   The method for producing a low-melting-point material casting according to claim 1, wherein the casting is for producing a mold. A supporting member that supports the used low-melting-point material block, an introduction part that introduces exhaust hot air from the melting kettle, direct heating means that heats the preheated low-melting-point material block, and a support member are disposed directly below. An ingot mold that receives dripping of the melt, and a melting furnace for producing an ingot by melting a used low melting point material block,
A melting pot that has a portable inner pot, an outer pot that holds the inner pot, and a whole surface heating means that heats the entire surface of the inner pot, and that creates a molten metal by melting the ingot;
An exhaust heat duct communicating with the melting furnace and the melting pot;
A mold into which molten metal is poured,
Ingot conveying means for conveying the ingot;
A low melting point material casting manufacturing system, comprising: an inner pot conveying means having a mechanism for tilting the inner pot to convey the inner pot and pour molten metal into a mold.   10. The low melting point material casting according to claim 9, wherein the entire surface heating means includes a heating duct for guiding a side hot air existing between the inner side surface of the outer pot and the outer side surface of the inner pot to the upper portion of the inner pot. Manufacturing system.   An upper lid is provided at the upper part of the inner pot of the melting kettle, and the upper hot air existing in the upper space formed between the upper lid and the molten liquid level in the inner kettle is connected to the upper space of the melting kettle and the melting furnace. The system for manufacturing a low-melting-point material casting according to claim 9, wherein the system is supplied to a melting furnace by a communicating exhaust heat duct.   12. The low melting point material casting manufacturing system according to claim 11, wherein the temperature of the exhaust hot air supplied from the melting pot through the exhaust heat duct is lower than the melting point of the low melting point material block.   The said ingot has a shape which can be engaged with a hook, The manufacturing system of the low melting-point material casting of Claim 9 characterized by the above-mentioned.   The system for producing a low-melting-point material casting according to claim 9, wherein the low-melting-point material is a zinc alloy.   10. The low melting point material casting manufacturing system according to claim 9, wherein the used low melting point material block is a used low melting point material mold.   10. The low melting point material casting manufacturing system according to claim 9, wherein the casting is for producing a mold.   An ingot formed by heating and melting a used low-melting-point material block while still standing in a melting furnace, and dropping the melt into an ingot mold.   The ingot according to claim 17, wherein the ingot has a shape that can be engaged with a hook.   The ingot according to claim 18, wherein the hookable shape of the hook is formed by casting the locking member together when the ingot is molded.   The ingot according to claim 18, wherein the hook-engageable shape is constituted by the ingot itself.

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