JP2009034709A - Molten metal feeding apparatus and molten metal feeding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molten metal feeding apparatus and a molten metal feeding method. <P>SOLUTION: The molten metal feeding apparatus comprises a charging unit for solid raw material, a pipe (a conveying pipe) for conveying the raw material and a molten metal, a casing, a feed amount adjusting valve, and a heat insulator, and the conveying pipe has a heating means. In the molten metal feeding method, the solid raw metal is heated in a step that the metal is passed inside the conveying pipe having the heating means provided between the raw material charging unit and a casting machine, gradually melted and mixed, and at the same time, the metal is discharged from one end of the conveying pipe in its state, and fed to a molding and casting apparatus while minimizing the drop of the temperature associated with the conveyance. A cast member with less oxidation and less mixture of foreign matters can be manufactured under a safe environment with less energy consumption. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a molten metal supply apparatus and a supply method, and more particularly, melting, transporting molten metal for holding, melting, and transporting a metal such as aluminum, magnesium, zinc, or a molten metal of these alloys, The present invention relates to a supply device and a supply method thereof. The present invention includes a solid raw material charging section, a transport pipe for transporting the raw material and the molten metal, a casing and a heat insulating material covering the periphery of the transport pipe, and a supply amount adjusting valve for adjusting the supply amount of the raw material, And a molten metal supply device characterized by being provided with a heating means in the transport pipe, and a molten metal supply method using the device.

  Casting is easy to give shape and is the basis for many machine parts including automobiles. In particular, the demand for lightweight metals such as aluminum and magnesium is expected to increase significantly in the future due to the increasing demand for fuel saving.

  On the other hand, casting has a lot of energy loss in the melting, conveying, and supplying processes until reaching the product. Several methods are currently being carried out, including the molten metal transfer method. In any case, the basic process is that the molten metal melted in the furnace is finally sent to a die casting machine or a low pressure casting apparatus.

  In the meantime, the molten metal is put into a tank / container and transferred / conveyed, and a large amount of heat released into the atmosphere is a factor that consumes a lot of energy for casting. In addition, it is dangerous to transport molten metal that has become hot in tanks and containers, and because it is exposed to the atmosphere, the molten metal will oxidize and become foreign matter, which may cause deterioration in quality. Become.

  In order to solve such problems, it is ideal that the raw material before melting (solid state) is moved as close as possible to the molding and casting apparatus, and the melting and molding are directly connected. Melting suppresses radiation of heat to the outside as much as possible, and in order to prevent oxidation of the molten metal, it is desirable that the atmosphere in the melting process has a small amount of oxygen, and the member that contacts the molten metal has little reaction with the metal Ceramics are desirable.

The following prior arts have been developed as conventional techniques related to the molten metal supply means.
For example, (1) In a molten metal transport container, the upper wall, the side wall, and the bottom wall of the main body all have an inner wall and an outer wall, and a space capable of depressurization serving as a heat insulating portion is provided between the inner wall and the outer wall. By forming, a heat-melting metal transportation container that can improve the heat insulation effect of the molten metal transportation container and can contribute to energy saving by suppressing the temperature drop of the molten metal inside the container has been proposed. (Patent Document 1).

  Also, (2) a ladle body that contains the molten metal, an upper lid that covers the upper end opening of the ladle body, a work lid that covers the opening formed in a part of the upper lid so as to be openable and closable, A pressurizing hot water type ladle transporting ladle having a hot water portion extending from the lower end to the upper side of the ladle main body, and the work lid is an upwardly convex lid body that covers the upper lid opening from above, A gas introduction part provided on the top surface of the lid body and a heat-resistant layer provided inside the lid body, the heat-resistant layer is composed of a breathable refractory material layer, and the gas that pressurizes the ladle body, There has been proposed a ladle for conveying molten metal configured to be introduced into a ladle main body from a gas introduction part through a breathable refractory material layer (Patent Document 2).

  In addition, (3) It is equipped with a refractory lining in order to prevent the molten metal in the ladle from cooling by providing a heat and heat retaining function that is easy to handle, and to realize a ladle structure that is easy to manufacture and maintain. A transport envelope forming a heating chamber with an open top, a crucible housed in the heating chamber of the transport envelope, and a side wall portion of the transport envelope facing inward A ladle equipped with a heater (surface combustion gas burner) for heating the crucible in the heating chamber from the outer periphery has been proposed (Patent Document 3).

  Further, (4) a molten metal container comprising a non-oxide-containing molded sintered body made of a calcium silicate refractory and an integral container-type bath, and an iron shell case made of a super-insulating material. A primary heat insulating layer, a secondary heat insulating layer made of a ceramic board, and a molten aluminum holding furnace provided with a molten metal container made of an integral container type bath formed by casting a non-oxide-containing molded sintered body with a calcium silicate refractory, Has been proposed (Patent Document 4).

  (5) A heat insulating ladle that has a small amount of heat dissipation from the molten metal and can be expected to have a backup lining as a permanent lining, and is composed of a metal cylindrical casing and a lining constructed on the inside thereof. A heat insulating ladle comprising a graphite crucible constituting an innermost layer in direct contact with the molten metal and a backup lining of the graphite crucible, and a heat insulating material layer interposed at the interface between the graphite crucible and the backup lining, has been proposed. (Patent Document 5).

  (6) In addition, according to catalogs, etc., ceramic heaters can be applied to melting and holding furnaces, enabling a horizontal immersion heating method, and energy savings compared to conventional upward immersion, as well as silicon nitride products. Examples of application to aluminum casting are known.

  Further, (7) the endless conveyor is circulated in the vertical direction, the casting material is supplied into the crucible at the upper material supply part, melted by the heating means at the intermediate part, and hot water is supplied at the lower hot water supply part. -A casting material melting and supplying apparatus that aims to reduce the cost and equipment costs has been proposed (Patent Document 6).

  Furthermore, (8) as a manufacturing method and manufacturing system of an aluminum alloy preform body, a forming die having a through hole filled with alloy powder, and a lower punch member is movably inserted below the through hole; A mold heating device that can be transported and preheated integrally with the mold, a filling mechanism that stores the alloy powder and fills the alloy powder in the hole of the mold, and an upper punch member on the filled alloy powder Punch member insertion mechanism for inserting a metal plate, and an energizing electrode for contacting and pressing the upper and lower punch members, a pulse energizing pressure sintering machine that pressurizes and sinters the alloy powder while applying a DC pulse current And an aluminum mechanism including a filling mechanism, a punch member insertion mechanism, a transport mechanism for moving between the pulse current sintering machines, and a drawing mechanism for extracting the preform body and the upper punch member from the molding die. Yuumu alloy preform manufacturing system, has been proposed (Patent Document 7).

  Among the above prior arts, the above (1) to (5) are based on the assumption that the metal is melted in a large furnace and the molten metal is transported for a long distance, put into a holding furnace, and then fed into a casting machine. It relates to the container. However, these have a large heat loss accompanying the transfer from the furnace to the container, and the heat insulation of the transfer container is not sufficient, and heat dissipation during the transfer process is inevitable. In addition, it is very dangerous to transport hot molten metal during operation, and furthermore, the molten metal will oxidize because it is exposed to the atmosphere for a long time, and energy is used to remove it. Incurs quality degradation.

  The above (6) is the most common casting technique. The molten metal that has been melted in large quantities in a centralized furnace is transferred to a tank / vessel, transferred to a holding furnace, and then a ladle-shaped tool called ladle. Is supplied to the molding apparatus and casting is performed. However, this method still requires a long time to reach the casting apparatus in a melted state, heat dissipation is large, and oxidation is inevitable. Further, in (7) above, heat dissipation is unavoidable, and (8) above is a method other than casting. However, in a press, the degree of freedom of shape formation is restricted, and defects are likely to remain in the molded product.

  Taking aluminum casting as an example, for example, a large amount of aluminum ranging from tens to hundreds of tons is melted by heating in a large furnace called a centralized furnace, and then put in a container lined with a refractory inside, forklift , Transferred to a hand furnace or holding furnace, reheated, and further, using a handle like a ladle made of ceramic or metal, scoop a predetermined amount of molten metal, put it into a die casting machine, and mold it The process of doing is taken.

  However, these processes are complicated, and oxidation occurs due to exposure to the atmosphere, which becomes foreign matter and mixes in the aluminum, leading to a decrease in strength, or transporting the molten metal from the melting furnace to a predetermined position. There is a problem that the loss due to heat radiation to the outside is large during the period. That is, there is a problem that a large amount of energy is required for melting, a large heat dissipation loss in the manufacturing process, impurities are likely to be mixed in, resulting in a decrease in product quality, adhesion of molten metal, and a decrease in light weight accuracy. there were. As described above, any of the conventional methods is not a continuous process from the melting to the molding machine, and is a process that requires movement and time. This is a factor that causes heat loss and oxidation. In order to solve these problems, it is considered that the solution is necessary to perform dissolution immediately before molding and not to require movement and time.

JP 2001-340957 A Japanese Patent No. 3613686 JP-A-10-323750 JP-A-9-182957 Japanese Patent Laid-Open No. 11-320080 JP-A-8-174184 JP 2001-329302 A

  In such a situation, in view of the prior art, the present inventors are a molten metal that is continuous from the melting of the metal to the forming and can suppress heat dissipation and oxidation. As a result of intensive research aimed at developing a supply device and a supply method, a ceramic transfer pipe having a heating mechanism provided between the raw material charging and the casting machine was used, and the inside of the transfer pipe was solid metal In order to complete the present invention, it is found that the intended purpose can be achieved by heating, melting, mixing in the process of passing the raw material, discharging from one end of the conveying pipe and supplying it to the casting apparatus. It came.

  It is an object of the present invention to provide a novel metal melt supply apparatus and supply method provided with a specific ceramics transport pipe having a heating mechanism.

The present invention for solving the above-described problems comprises the following technical means.
(1) A molten metal supply device that melts and conveys metal and supplies it to a molding and casting machine, including a solid raw material charging unit, a conveyance pipe for conveying the raw material and the molten metal, and a casing covering the circumference of the conveyance pipe An apparatus for supplying molten metal, comprising: a body, a heat insulating material, and a supply amount adjusting valve for adjusting a supply amount of the raw material, and heating means is provided in the transport pipe.
(2) The molten metal supply apparatus according to (1), wherein a portion of the transport pipe that comes into contact with the molten metal has a predetermined ceramic structure.
(3) The ceramic structure is composed of a plurality of cylindrical units, and a plurality of them are connected in the direction in which the solid or melt existing in the transport pipe moves to form a tubular path. The molten metal supply device according to (2).
(4) The molten metal supply apparatus according to (2) or (3), wherein the ceramics is silicon nitride or a composite material containing silicon nitride as a main component.
(5) The molten metal supply apparatus according to any one of (2) to (4), wherein the ceramic has conductivity and generates heat by energization or high frequency.
(6) The ceramic is cylindrical, and is composed of a plurality of layers having different components from the center toward the outer periphery, the innermost layer contacting the molten metal has poor wettability to the molten metal, and the central portion is conductive. The outermost part is an insulating layer, and the molten metal supply according to any one of (2) to (5), wherein each layer is integrally sintered and firmly bonded to form a transport pipe apparatus.
(7) The ceramic of the hardly wettable layer is composed of silicon nitride as a main component and at least one of 2 to 30 vol% boron nitride and graphite particles, and the conductive part is molybdenum or tungsten silicide or boride. , Titanium nitride, titanium boride, zirconium boride, or silicon carbide is contained in the range of 5 to 95 vol%.
(8) The molten metal supply apparatus according to any one of (4) to (7), wherein a fine protrusion pattern is formed on the inner surface of the ceramic.
(9) The molten metal supply apparatus according to (1), wherein a heating source of a heater or a gas burner and a thermocouple are attached to the transport pipe.
(10) The transport pipe is provided with a depressurization mechanism or a mechanism for introducing an inert gas, and has a function of depressurizing the inside of the transport pipe to remove bubbles generated during the dissolution process, or the inert gas is put into the pipe. The molten metal supply apparatus according to (1), which has a function of suppressing metal oxidation by being introduced.
(11) The molten metal supply apparatus according to (1), wherein a heat insulating material is provided around the transport pipe, and the periphery thereof is protected by a metal pipe or a casing.
(12) The molten metal supply apparatus according to (1), wherein a filter is provided at an outlet of the transport pipe, and impurities can be removed.
(13) The path for transporting the raw material in the transport pipe is spiral and the entire size is compact, and the raw material flows at least from the upper input portion to the lower outlet portion by gravity. ) Metal melt supply device as described.
(14) A method of supplying a molten metal using the molten metal supply device according to any one of (1) to (13), wherein an end of the transport pipe is charged with a metal as a raw material The solid metal raw material charged from the charging port is heated in the process of passing through the inside of the conveying pipe having heating means provided between the raw material charging and the casting machine, and gradually melts. At the same time as mixing, the molten metal is discharged from one end of the conveying pipe, and supplied to the molding and casting apparatus with the temperature drop accompanying the conveyance minimized, and supplied to the molding and casting apparatus.
(15) The molten metal according to (14), wherein the component adjustment is performed in advance before reaching the inlet of the transport pipe so that the solid metal raw material introduced from the inlet is melted into a predetermined component. Supply method.
(16) The connection part of each part of the ceramic transport pipe having a divided structure expands and contracts with respect to stresses generated from solidification and dissolution of metal, vibration, or any internal stress, and external stress, and the stress is relaxed, Thereby, the molten metal supply method according to (14) or (15), wherein the ceramic is prevented from being damaged.
(17) The molten metal supply method according to any one of (14) to (16), wherein the molten metal is an alloy mainly composed of aluminum or magnesium.
(18) The burner flame radiation is directly fed into the transport pipe, the heat radiation to the outside is suppressed by using the transport pipe as a flame conduit, and the amount of oxygen in the transport pipe is reduced, so that the metal is dissolved while suppressing oxidation. The molten metal supply method according to any one of (14) to (17), wherein the molten metal supply method is carried.
(19) Sensing the temperature of each part of the ceramic conveying pipe having a divided structure, and controlling the power or fuel supply amount, thereby detecting the supply state and changing the viscosity of the molten metal to adjust the conveying speed, (14) The molten metal supply method according to any one of (18).

Next, the present invention will be described in more detail.
The present invention relates to a molten metal supply device that melts and conveys a metal and supplies the molten metal to a molding and casting machine, and covers a feeding portion of a solid raw material, a conveyance pipe for conveying the raw material and the molten metal, and a periphery of the conveyance pipe A housing, a heat insulating material, and a supply amount adjustment valve for adjusting the supply amount of the raw material are provided, and the transport pipe is provided with a heating means.

  In this invention, the part which contacts a molten metal among the said conveyance pipes is comprised by the predetermined ceramic structure. Further, the ceramic structure is composed of a plurality of cylindrical units, and a plurality of them are connected in the direction in which the solid or melt existing in the transport pipe moves to form a tubular path. Are preferred.

  In the present invention, the ceramic is preferably silicon nitride or a composite material mainly composed of silicon nitride. Here, a main component means the component which comprises the whole multi-component. In addition, the ceramic is conductive and generates heat when energized or by high frequency. The ceramic is cylindrical and consists of a plurality of layers having different components from the center to the outer periphery, and is in contact with the molten metal. The innermost layer is hardly wettable to the molten metal, the central part is conductive, and the outermost part is an insulating layer, and each layer is integrally sintered and firmly bonded to form a transport pipe It is preferable.

  The ceramic of the layer having poor wettability is, for example, at least one of 2 to 30 vol% boron nitride and graphite particles containing silicon nitride as a main component. The conductive part contains, for example, at least one of molybdenum or tungsten silicide, boride, titanium nitride, titanium boride, zirconium boride, or silicon carbide in the range of 5 to 95 vol%. It is preferable that a fine protrusion pattern is formed on the inner surface of the ceramic.

  In the present invention, a heating source of a heater or a gas burner and a thermocouple are attached to the transport pipe. In addition, the transport pipe is provided with a pressure reducing mechanism or a mechanism for introducing an inert gas, and has a function of depressurizing the inside of the transport pipe to remove bubbles generated during the dissolution process, or introduce an inert gas into the pipe. It is preferable to have a function of suppressing metal oxidation. Those specific configurations are not particularly limited as long as they have the above-described functions.

  Moreover, in this invention, the heat insulating material is provided in the circumference | surroundings of the said conveyance pipe | tube, and the circumference | surroundings are further protected by the metal pipe | tube or the housing | casing. In addition, a filter is provided at the outlet of the transfer pipe so that impurities can be removed, and the path for transferring the raw material of the transfer pipe is spiral and the overall size is compact, and at least It is preferable that the raw material flows by gravity from the upper input portion toward the lower outlet portion.

  Further, the present invention is a method for supplying a molten metal using the molten metal supply device, wherein an end of the transport pipe is connected to a metal inlet as a raw material, and the inlet The solid metal raw material charged from is heated in the process of passing through the inside of the conveyance pipe having the heating means provided between the raw material charging and the casting machine, and gradually melted and mixed, while at that time It is discharged from one end of the conveying pipe, and is supplied to the molding and casting apparatus while minimizing the temperature drop caused by the conveying.

  In the present invention, the component adjustment is performed in advance before reaching the inlet of the transport pipe so that the solid metal raw material introduced from the inlet is melted into a predetermined component. In addition, the connection part of each part of the ceramic transport pipe made of a divided structure expands and contracts against any stress generated from solidification and dissolution of metal, vibration or thermal stress from the inside or outside, and the stress is relaxed. Therefore, it is possible to prevent the ceramics from being damaged.

  The molten metal is, for example, an alloy mainly composed of aluminum or magnesium. In addition, the burner flame radiation is sent directly into the transfer pipe, the heat transfer to the outside is controlled by the transfer pipe as a flame conduit, and the amount of oxygen in the transfer pipe is reduced to reduce the amount of oxygen in the transfer pipe. To do. In addition, by sensing the temperature of each part of the ceramic conveyance pipe having a divided structure and controlling the power or fuel supply amount, the supply state is detected and the viscosity of the molten metal is changed to adjust the conveyance speed. preferable.

  In the present invention, the solid metal raw material is heated in the process of passing through the inside of the ceramic conveying pipe having a heating mechanism provided between the raw material charging and the casting machine, gradually melted, mixed, and finally conveyed. It is discharged from one end of the tube and supplied to the casting apparatus. Moreover, the inside of a pipe | tube may be pressure-reduced and an inert gas. The apparatus of the present invention has a mechanism for carrying and dissolving / mixing in the same tube, thereby reducing heat dissipation loss as much as possible, and the molten metal is not exposed to the atmosphere. It is possible to prevent foreign matter from entering and stabilize the product quality.

  Casting has a lot of energy loss in the melting, conveying and supplying processes until reaching the product. Several methods are currently underway, including molten metal conveyance. In any case, the basic process is that the molten metal melted in the furnace is finally sent to a die casting machine or a low pressure casting apparatus. In the meantime, the molten metal is put into a tank / container and transferred / conveyed, and a large amount of heat released into the atmosphere is a factor that consumes a lot of energy in casting. In addition, it is dangerous to transport the molten metal in a tank / container in a high temperature, and because the molten metal is exposed to the atmosphere, the molten metal oxidizes and becomes a foreign substance and enters the product, leading to a decrease in quality. .

  The present invention is an apparatus for melting and conveying a metal and supplying it to a molding and casting machine, comprising a solid raw material charging portion, a pipe (conveying pipe) for conveying the raw material and molten metal, a casing, a supply amount adjusting valve, In addition, the present invention relates to a molten metal supply apparatus in which a heating means is provided in the transport pipe. In the present invention, the end of the conveying pipe is connected to a metal inlet serving as a raw material, and the solid metal raw material charged from the inlet is provided with heating means provided between the raw material charging and the casting machine. Heated in the process of passing through the inside of the conveying pipe, melted gradually, mixed, and at the same time, discharged from one end of the conveying pipe in that state, and supplied to the molding and casting apparatus with minimal temperature drop due to conveyance Is done.

The present invention has the following effects.
(1) It is possible to provide a new metal melting, transporting and feeding apparatus and method using a transport pipe.
(2) In the present invention, since the raw metal is transported and dissolved / mixed in the same tube, the heat dissipation loss is reduced as much as possible, and the molten metal is not exposed to the atmosphere, so that foreign matter is not mixed due to oxidation of the molten metal. This can prevent and stabilize product quality.
(3) It is possible to provide a molten metal supply apparatus and its process that can be continuously performed from the melting to the forming of the metal.
(4) It is possible to construct and provide a new molten metal supply system for melting, transporting and supplying metals such as aluminum, magnesium and zinc or alloys thereof.
(5) The apparatus of the present invention is compact and can save space.
(6) In the apparatus and method of the present invention, since the melting is performed in the immediate vicinity of the molding machine, the safety of the actual product is improved as compared with the conventional apparatus and method in which the high-temperature molten metal is conveyed.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

  FIG. 1 shows a configuration A of a main part according to the present invention. This shows an example of melting using electric power. First, a container for charging a solid raw material that has been reduced to a predetermined size by crushing or other methods is provided above, and a lid is provided if necessary. The raw material input from the raw material input port moves to a lower transfer pipe by gravity in a spiral transfer pipe. The overall height is 1000 mm. Here, the reason why the transport pipe is spiral is that the overall size is reduced, and the surroundings are covered with a heat insulating material and a casing to improve heat insulation.

  The inside of the transport pipe has a triple structure, and has an inner diameter φ60, a wall thickness of 10 mm, and a height of about 100 mm. The material was silicon nitride with alumina and yttria as auxiliary agents. Individual parts are called units. The unit has a fitting structure. Each unit was assembled in a spiral shape, and the outer periphery of the joint was filled with an inorganic adhesive mainly composed of alumina and silica. A band heater was attached to the surface of the transfer tube as a heating means.

  Furthermore, the surface was covered with a sheet-like ceramic heat insulating material, and a stainless steel casing was attached to the outermost peripheral surface. The inside of the housing can be decompressed by a rotary pump. By heating with a heater, the conveying tube can be heated up to 900 ° C. Further, the transport pipe is provided with a thermocouple and a temperature control circuit, and it is possible to control the temperature of each part of the transport pipe by sending the temperature inside the transport pipe as a signal to the power source. Thereby, fluidity | liquidity changes and a supply amount can be adjusted.

  Aluminum alloy (AC4A: Al—Si—Mg based alloy (Si 8.0 to 10.0, Mg 0.3 to 0.6) was dissolved, and a desired shape was obtained with a mold. The product was analyzed and oxidized As a result of measuring the amount of unsatisfactory materials and iron, it was found that it was below the detection limit ability and contained very little foreign matter, and a 1-ton product was manufactured, and the power consumption at this time was compared with the conventional method. As a result, it was found that the power consumption was reduced by about half because the heat dissipation was small.

  FIG. 2 shows a configuration B of the main part according to the present invention. This shows an example of melting using a gas burner. First, a container for charging a solid raw material that has been reduced to a predetermined size by crushing or other methods is provided above, and a lid is provided if necessary. The raw material input from the raw material input port moves downward to the transport pipe due to gravity in a spiral transport pipe. The overall height is 1000 mm. Here, the reason for the spiral shape is that the overall size is reduced and the heat insulation is enhanced by covering the periphery with a heat insulating material and a casing.

  The inside of the transport pipe has a triple structure, and has an inner diameter φ60, a wall thickness of 10 mm, and a height of about 100 mm. The material was silicon nitride with alumina and yttria as auxiliary agents. Individual parts are called units. The unit has a fitting structure. Each unit was assembled in a spiral shape, and the outer periphery of the joint was filled with an inorganic adhesive mainly composed of alumina and silica. Furthermore, the surface was covered with a sheet-like ceramic heat insulating material, and a stainless steel casing was attached to the outermost peripheral surface.

  The inside of the housing can be decompressed by a rotary pump. By heating with a heater, the conveying tube can be heated up to 900 ° C. Further, the transport pipe is provided with a thermocouple and a temperature control circuit, and it is possible to control the temperature of each part of the transport pipe by sending the temperature inside the transport pipe as a signal to the power source. Thereby, fluidity | liquidity changes and a supply amount can be adjusted.

  An aluminum alloy (AC4B: Al—Si—Cu alloy: Si 7.0 to 10.0, Cu 2.0 to 4.0) was dissolved, and a desired shape was obtained by a mold. As a result of analyzing the product using EDX and measuring the amount of oxides and irons, it was found that it was 1/10 or less compared with the case of the conventional process, and foreign matter contamination was extremely small.

  Moreover, when a 1-ton product was produced, the energy consumed at this time was converted into electric power and compared with the conventional method, it was found that the amount was about 30%. It has been confirmed that it is more economical than electric power because it consumes less heat and reduces power consumption and uses a gas burner as a heating source.

  FIG. 3 shows a configuration (overall view) up to the introduction of raw materials. The secondary alloy (return material) includes various components, and after analyzing them, the overall average component is (AC4D: Al—Si—Cu-based alloy: Si4.5 to 5.5, Mg0 .4 to 0.6, Cu 1.0 to 1.5). Then, the pellet which is 20 mm or less in size was obtained by crushing and fracture | rupturing with a crushing and mixing machine. After mixing well with a mixer, it is conveyed to the molten metal supply device by a belt conveyor, the pellets are sent to the inlet, and similarly to Example 2, after being melted and conveyed by the molten metal supply device connected to the decompressor, The material was supplied to a molding casting machine and molded.

  An aluminum billet corresponding to AC4B was produced and introduced from the inlet of the apparatus shown in FIG. This raw material was gradually moved into the transfer tube by the opening of the lower lid, and was transferred by gravity. The temperature of the transfer tube was set to 800 ° C. in the vicinity of the charging portion and 700 ° C. on the outlet side. First, the outlet valve was closed, and in the process of moving downward by gravity, the raw material was heated in the transfer tube and gradually melted. When the outlet valve was opened, the molten metal was discharged. The flow rate at that time was about 0.63 L / sec. The molten metal was sent to the sample input part of the die casting machine and molded. When the component analysis of the obtained aluminum casting product was performed by EDX, the impurity was 1/10 or less of the conventional.

Silicon nitride, alumina, yttria, boron nitride are mixed powder A in this order of 87: 3: 5: 5 wt%, silicon nitride, alumina, yttria, and WSi ₂ as conductive particles, respectively, in this order 20 : 3: 5: 72 wt% Mixed powder B, and further, silicon nitride, alumina, yttria were mixed powder C in this order, respectively, 92: 3: 5 wt%. Each was granulated using PVA (polyvinyl alcohol) as a binder.

  Each was preformed with a press. The three layers were laminated so that the innermost layer was mixed powder A, the middle portion was B, and the outer layer was C, and CIP-molded and integrated. Degreased and densified. FIG. 4 shows the configuration of the transport pipe. A terminal was attached from the conductive portion, energization heating was performed, and a casting test was conducted in the same manner as in Example 1 to obtain good results.

  Also, the conductive particles are changed to molybdenum or tungsten silicide, boride, titanium nitride, titanium boride, zirconium boride, or silicon carbide, and a paste in which the content is changed in the range of 5 to 95 vol% is prepared. Was formed and integrally sintered, and it was confirmed that the heater had good temperature rise characteristics.

  Subsequently, for the innermost layer, a projection group having a width of 1 mm and a pitch of 0.5 mm was provided by molding on the surface in contact with the molten metal. By forming the protrusion, the contact area with the molten metal is reduced, and the flow resistance is reduced. It was found that the molten metal can be transported more smoothly than when ceramics without protrusions are used.

  The same test as in Example 2 was performed using a magnesium alloy Mg—Al—Zn alloy (AZ91D: containing 9% Al and 1% Zn). The casting temperature was 450 ° C. Since casting was possible with a small amount of oxygen, it was safe and a product with little foreign matter contamination could be obtained. In FIG. 5, the example of a structure of the molding machine into which a molten metal is thrown in from a molten metal supply apparatus through a slot is shown.

  The casting test of 1000 cycles was performed by the method shown in Example 2. It was confirmed that there was no damage or abnormality in the ceramic part and it could operate soundly. In addition, it is possible to integrally manufacture a transfer pipe having the same structure by casting or the like, and although the reliability is lowered due to heat shrinkage and other factors, the transfer pipe can be used sufficiently. Moreover, although the present invention uses solid pellets or the like as raw materials, an energy saving effect and an impurity reduction effect can be expected even when a semi-solidified or molten raw material is used. In the present invention, aluminum and magnesium are targeted, but other metals, composite materials, plastics, and the like can be used as long as they can be melted and solidified.

  As described above in detail, the present invention relates to a molten metal supply apparatus and supply method, and in the present invention, since the raw metal is transported and melted / mixed in the same tube, heat dissipation loss is reduced as much as possible. At the same time, since the molten metal is not exposed to the atmosphere, it is possible to prevent foreign matter from being mixed due to oxidation of the molten metal and to stabilize the product quality. The present invention can provide a new metal melting, conveying and supplying apparatus using a conveying tube and a method thereof. In addition, the present invention can provide a molten metal supply apparatus and a process thereof that can be continuously performed from melting of metal to forming. INDUSTRIAL APPLICATION This invention is useful as what constructs | provides and provides the new molten metal supply system for melt | dissolving, conveying, and supplying metals, such as aluminum, magnesium, zinc, or these alloys.

The main part structure A of the apparatus of this invention is shown. The main part structure B of the apparatus of this invention is shown. The whole figure of conveyance of a solid material is shown. The structure of the conveyance pipe which comprises the molten metal supply apparatus of this invention is shown. The structure of the molding machine into which a molten metal is injected | thrown-in via a charging port from a molten metal supply apparatus is shown.

Claims (19)

  A molten metal supply device that melts and conveys metal and supplies it to a molding and casting machine, including a solid raw material supply section, a conveyance pipe for conveying the raw material and the molten metal, a casing that covers the circumference of the conveyance pipe, and heat insulation A molten metal supply apparatus comprising a material and a supply amount adjusting valve for adjusting a supply amount of the raw material, wherein the transport pipe is provided with a heating means.   The molten metal supply apparatus according to claim 1, wherein a portion of the transport pipe that comes into contact with the molten metal is formed of a predetermined ceramic structure.   The ceramic structure is composed of a plurality of cylindrical units, and a plurality of them are connected in a direction in which a solid or a melt existing in a transport pipe moves to form a tubular path. 2. The molten metal supply apparatus according to 2.   The molten metal supply apparatus according to claim 2 or 3, wherein the ceramic is a silicon nitride or a composite material mainly composed of silicon nitride.   The molten metal supply apparatus according to claim 2, wherein the ceramic has conductivity and generates heat by energization or high frequency.   The ceramic is cylindrical and consists of a plurality of layers having different components from the center toward the outer periphery. The innermost layer that contacts the molten metal is difficult to wet with the molten metal, the central part is conductive, and the outermost part is The molten metal supply apparatus according to any one of claims 2 to 5, which is an insulating layer, and each layer is integrally sintered and firmly bonded to form a transport pipe.   The ceramic of the hardly wettable layer is at least one of 2-30 vol% boron nitride and graphite particles mainly composed of silicon nitride, and the conductive portion is silicide of molybdenum or tungsten, boride, titanium nitride The molten metal supply apparatus according to claim 6, wherein at least one of titanium boride, zirconium boride, and silicon carbide is contained in a range of 5 to 95 vol%.   The molten metal supply apparatus according to any one of claims 4 to 7, wherein a fine projection pattern is formed on an inner surface of the ceramic.   The molten metal supply apparatus according to claim 1, wherein a heating source of a heater or a gas burner and a thermocouple are attached to the transport pipe.   The transport pipe is provided with a pressure reducing mechanism or a mechanism for introducing an inert gas, and has a function of depressurizing the inside of the transport pipe to remove bubbles generated in the dissolution process, or introducing an inert gas into the pipe. The molten metal supply apparatus according to claim 1, which has a function of suppressing oxidation of the metal.   The molten metal supply apparatus according to claim 1, wherein a heat insulating material is provided around the transport pipe, and further, the circumference is protected by a metal pipe or a casing.   The molten metal supply apparatus according to claim 1, wherein a filter is provided at an outlet of the transport pipe so that impurities can be removed.   The metal according to claim 1, wherein a path for conveying the raw material of the conveying pipe is spiral and the entire size is compact, and the raw material flows at least from an input portion above to a lower outlet portion by gravity. Molten metal supply device.   A method for supplying a molten metal using the molten metal supply device according to any one of claims 1 to 13, wherein an end of the transfer pipe is connected to a metal inlet serving as a raw material. The solid metal raw material charged from the charging port is heated in the process of passing through the inside of the conveying pipe having heating means provided between the raw material charging and the casting machine, and gradually melted and mixed. In this state, the molten metal supply method is characterized in that the molten metal is discharged from one end of the transfer pipe and supplied to the molding and casting apparatus with a minimum temperature drop accompanying the transfer.   The molten metal supply method according to claim 14, wherein the component adjustment is performed in advance before reaching the inlet of the transport pipe so that the solid metal raw material introduced from the inlet is melted and becomes a predetermined component.   The stress, vibration, or thermal stress associated with the solidification and dissolution of the metal can be expanded and contracted with respect to the stress generated from the inside and outside of the ceramic transport pipe having a divided structure, thereby reducing the stress, The method for supplying molten metal according to claim 14 or 15, which prevents breakage of ceramics.   The molten metal supply method according to any one of claims 14 to 16, wherein the molten metal is an alloy containing aluminum or magnesium as a main component.   Burner flame radiation is sent directly into the transport pipe, and the heat transport to the outside is controlled using the inside of the transport pipe as a flame conduit, and the amount of oxygen in the transport pipe is reduced, so that it is dissolved and transported while suppressing metal oxidation. The method for supplying molten metal according to any one of claims 14 to 17.   The temperature of each part of the ceramic conveyance pipe having a divided structure is sensed, and the supply state is detected and the viscosity of the molten metal is changed by controlling the power or fuel supply amount, thereby adjusting the conveyance speed. The molten metal supply method according to any one of claims 18 to 18.