JP2010260068A - Compact casting device having melting function and pressurizing function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact casting device with a melting function and a pressurizing function. <P>SOLUTION: The compact casting device includes: a furnace body, which is provided with a molten-metal vessel comprising a melting chamber, a molten-metal holding chamber, and a molten-metal delivery chamber; a heating means for the molten-metal vessel, which is mounted on the furnace body; a mold, which is set in the side of one end of the molten-metal vessel; and a material charging part, which is formed in the side of the other end of the molten-metal vessel and has a closing/opening mechanism. The molten-metal delivery chamber is connected to a sprue of the mold, and the melting chamber is connected to the closing/opening mechanism. The compact casting device is composed so that a massive unmelted material is charged into the material charging part, and the molten metal in the molten-metal delivery chamber is send into the mold to cast it. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a small casting apparatus with a melting function and a pressure function.

  Conventionally, a low-pressure casting apparatus has been used for producing castings such as aluminum, aluminum alloys, and zinc. As an example of such a low-pressure casting apparatus, Patent Document 1 is known. The molten metal pumped from the melting furnace is conveyed to the mold part using the holding furnace, and the holding furnace and the mold part are further connected. After aligning and locking, hot water was supplied to the mold, which was very laborious.

  On the other hand, the apparatus of Patent Document 2 has a holding crucible that is disposed in a melting furnace and has an accommodating space that can be closed inside, and a mold part that is disposed corresponding to the holding crucible. The holding crucible is provided with a hot water outlet that opens in the molten metal in the melting furnace and allows the molten metal to pass through the accommodating space, and is provided with opening / closing means that can open and close the hot water inlet, and is accommodated in the accommodating space of the holding crucible. A pressurizing means capable of pressurizing the molten metal from the outside is provided, and the molten metal in the storage space is pressed through the injection pipe (stalk) by closing the hot water supply port and pressurizing the storage crucible in the closed space. It is configured to be capable of being supplied to a part. Patent Document 3 is similar to this.

These are for filling molten metal into the cavity of the mold part through the stalk, and still have a large molten metal holding capacity, large equipment, high cost, and a large holding capacity, which is also energy efficient. There was a lot of waste.
In order to solve such problems, it has been required to minimize the molten metal holding capacity and melting mechanism, but it is necessary to stably maintain the molten metal temperature and to dissolve the material in a timely manner corresponding to the casting cycle. It could not be realized because it was difficult to supply molten metal.

Japanese Patent Laid-Open No. 2003-290904 JP-A-8-99168 Japanese Patent Application Laid-Open No. 2006-231341

  In view of the above problems, the present invention provides a small casting apparatus with a melting function and a pressure function.

In order to solve the above problems, the invention of claim 1 is directed to a furnace body (50) in which a molten metal tank (30) including a melting chamber (13), a molten metal holding chamber (14), and a tapping chamber (15) is formed. ), Heating means for the molten metal tank (30) provided in the furnace body (50), a mold (9) provided on one end side of the molten metal tank (30), and the molten metal tank (30) In the casting apparatus provided with the material charging part (4) having an opening and closing mechanism provided on the other end side of the metal, the hot water chamber (15) communicates with the gate (3) of the mold (9), The melting chamber (13) is in communication with the opening / closing mechanism, and is configured such that a lump-shaped unmelted material (11) is charged into the material charging unit (4). It is a casting apparatus for casting molten metal by feeding it into the mold (9).
Thereby, while being able to provide a continuous casting apparatus, size reduction of an installation (furnace) and reduction of melt | dissolution retention energy can be aimed at.

  According to a second aspect of the present invention, in the first aspect of the present invention, the molten metal tank (30) is formed in a U-shape. As a result, since the U-shaped furnace is formed, the structure can be made small so that the temperature effect of the melting chamber does not come out to the tap.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the melting chamber (13) is provided with a means for pressurizing the molten metal, and the molten metal is applied to the mold by pressurizing the molten metal. It is characterized by filling. Thereby, the miniaturized continuous casting apparatus which provided the melting part and the pressurization function in the furnace part can be provided.

The invention of claim 4 is the invention of any one of claims 1 to 3, wherein the melting chamber (13), the molten metal holding chamber (14), and the hot water chamber (15) are respectively The heating means (16, 17, 18) are individually installed, and the temperature of each of the heating means (16, 17, 18) can be controlled independently.
As a result, the heating means independent of the furnace is placed at each part of the material charging side, the molten metal outlet side, and the molten metal holding chamber between them to control the temperature, so that the influence of the molten metal temperature fluctuation during the melting of the material is The hot water temperature can be stabilized and the melting efficiency can be ensured without affecting the molten metal temperature.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the casting apparatus further includes a material supply unit (31). A predetermined number of unmelted materials (11) are charged into the material charging unit (4) at a time. Thereby, the material melting | dissolution and molten metal supply corresponding to a casting cycle can be performed.

  The invention of claim 6 is the invention according to any one of claims 1 to 5, wherein the massive unmelted material (11) is a pyramid or spherical aluminum alloy material of 50 mm or less. It is characterized by.

  The invention of claim 7 is the invention of claim 5 or 6, further comprising a control mechanism for variably controlling the input amount of the massive unmelted material (11), and the hot water in the molten metal tank (30). The input amount of the massive unmelted material (11) is varied according to the surface position. Thereby, the tapping temperature can be stabilized and the melting efficiency can be ensured.

  The invention of claim 8 is characterized in that, in the invention of any one of claims 1 to 7, a mold clamping mechanism is attached to the mold (9).

  The invention of claim 9 is the invention of claim 4, wherein the control target value of the temperature of the molten metal from the molten metal chamber (15) is set in a range of 650 to 750 ° C, and the molten metal holding chamber (14). The temperature control target value of the melting chamber (13) is set so as to gradually approach the control target value of the hot water temperature in this order. Thereby, the tapping temperature can be stabilized and the melting efficiency can be ensured.

  According to a tenth aspect of the present invention, in the fourth aspect of the present invention, the temperature control target value of the molten metal holding chamber (14) is set to the temperature of the molten metal discharged from the hot water discharge chamber (15) or the hot water discharge chamber (15). And the molten metal holding chamber (14) according to the internal volume ratio. Thereby, the tapping temperature can be stabilized and the melting efficiency can be ensured.

  The invention of claim 11 is the invention of claim 4, wherein the set temperature of the heating means (16) provided in the melting chamber (13) is the preheating temperature of the massive unmelted material (11), It is set according to the input weight of the unmelted material (11), the molten metal temperature of the molten metal holding chamber, or the molten metal surface position of the molten metal tank (30). Thereby, the tapping temperature can be stabilized and the melting efficiency can be ensured.

  The invention of claim 12 is the invention of any one of claims 1 to 11, wherein a metal bellows (32) is provided between the material charging part (4) and the furnace body (50). It is characterized by that. Thereby, the metal bellows can exert a buffering action so as not to adversely affect the brittle heat insulating material or the like due to vibration or the like in the material charging portion.

  In addition, the code | symbol attached | subjected above is an example which shows a corresponding relationship with the specific embodiment as described in embodiment mentioned later.

It is a schematic diagram showing one embodiment of the present invention. It is a schematic diagram which shows other embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. About each embodiment, the same code | symbol is attached | subjected to the part of the same structure, and the description is abbreviate | omitted.
FIG. 1 is a schematic diagram showing an embodiment of the present invention. In FIG. 1, the outline | summary of the structure of the furnace body 50 of the small casting apparatus of this invention is shown. Reference numeral 1 denotes a furnace wall, which is made of a refractory material (castable or the like) or a ceramic material having heat resistance that can withstand an aluminum melting temperature such as silicon nitride and having a low affinity for molten aluminum.

  In the furnace wall 1, a molten bath 30 including a melting chamber 13, a molten metal holding chamber 14, and a tapping chamber 15 is formed in a U shape as shown in FIG. 1, and holds the molten metal 10. The molten metal tank 30 is heated by the heaters 16, 17, and 18 corresponding to the melting chamber 13, the molten metal holding chamber 14, and the tapping chamber 15, respectively, and is maintained at a constant temperature. Around the furnace wall 1, heaters 16, 17, and 18 are arranged, and the heater is covered with a heat insulating material 2 to insulate the molten metal bath 30. The heating means is not limited to a heater, and a burner or the like may be used.

An air supply path 8 for pressurized air is connected to the material charging unit 4 side, and the air supply in the air supply path 8 is turned on and off by opening and closing the valve 7. An inert gas (nitrogen, argon, etc.) can be used instead of air.
The supply of air through the air supply path 8 constitutes means for pressurizing the molten metal in the molten metal tank 30. When air is supplied from the air supply path 8, the surface of the molten metal on the material inlet side is pressurized, the molten metal is pushed up in the mold direction, and the cavity 24 in the mold is filled with the molten metal.

  On one side of the furnace body 50 (one side of the U-shaped molten metal bath 30), there is a material charging part 4 for charging the material 11 (a lump of unmelted material), and a melting chamber 13 for immersing and melting the material immediately below the material charging part 4. Is provided. The material input unit 4 is provided with an opening / closing mechanism for material input, and has a structure such as a sealable valve that closes the opening when pressurized and does not leak air. As an example of the opening / closing mechanism, a two-way valve that is closed with an electromagnetic valve after the material is charged may be used.

The mold 9 includes a first upper mold 20, a second upper mold 21, a first lower mold 22, and a second lower mold 23, and a cavity 24 is formed therein. A gate 3 is formed in the second lower mold 23. The gate 3 is also a molten metal outlet of the furnace body 50. The mold 9 does not necessarily have to be divided into four as described above, and may be divided into an arbitrary number, or may be a mold divided horizontally instead of the upper mold and the lower mold.
The gate 3 of the mold 9 is brought into close contact with the other side of the furnace body 50 (the other side of the U-shaped molten metal bath 30). The gate 3 communicates with the hot water chamber 15 so that the molten metal 10 can be filled in the cavity 24 in the mold. A packing 12 such as a ceramic fiber is interposed between the second lower mold 23 provided with the gate 3 and the other of the furnace body 50 to seal the molten metal from leaking. The upper and lower molds of the mold 9 are clamped using the same clamping mechanism as that of the well-known toggle type or pressure increasing cylinder type used in injection molding. In addition, an elevating mechanism using a ball screw type electric motor is used.

As an example, the second upper mold 21 is a movable platen of a mold clamping mechanism, the second lower mold 23 is a fixed platen, a support part (toggle support, mold clamping cylinder) of the mold clamping mechanism is a furnace body 50, a furnace It is connected to the base on which the body 50 is installed. The second lower mold 23 as the lower mold fixed platen is brought into close contact with the other side of the U-shaped molten metal bath 30 through the packing 12 using a known clamping mechanism. As a mold clamping mechanism, a servo motor may be attached to the tip of the ball screw, and the movable platen (second upper mold 21) connected to the ball screw may be moved up and down with respect to the fixed platen (second lower mold 23).
As another embodiment, if a seat for receiving a force is provided in the furnace body 50 and the pressing force by the movable platen (second upper mold 21) connected to a ball screw driven by a servo motor is received by this seat, The second lower mold 23 as a mold fixing platen can be brought into close contact with the other side of the U-shaped molten metal bath 30.

A molten metal holding chamber 14 is provided between the hot water chamber 15 and the melting chamber 13. The internal volume of the molten metal holding chamber 14 is set to be twice or more the internal volume of the hot water discharge chamber 15 and the melting chamber 13. In the melting chamber 13, the molten metal holding chamber 14, and the tapping chamber 15, individual heaters 16, 17, and 18 are arranged in pairs (single or plural other than two). (The installation positions of the heaters 16 and 18 in FIG. 1 are illustrated slightly above because there is no space for illustration, but should be illustrated slightly below.)
When the molten metal holding chamber 14 is provided in the bottom straight portion of the U-shaped molten metal bath 30, a hot water heater inserted into the ceramic protective tube so as to penetrate the vicinity of the center of the cross section of the molten metal holding chamber 14 ( It is good also as a structure which installs the ceramic protective tube in which this heater was inserted, and is immersed in molten metal. In this case, it is preferable to install in a straight line through the furnace wall 1 of the melting chamber 13 and the tapping chamber 15. The hot water heater may be additionally installed on the heater 17 or may be installed alone instead of the heater 17.
The heaters 16, 17, 18, etc. may have an output in the range of 1 KW to 5 KW from the molten metal holding capacity, the melted weight, and the material preheating temperature. As an example, the temperature target of each room is as follows.

The case where the temperature of the hot water from the hot water chamber 15 is about 660 ° C. will be described as an example. The molten metal holding temperature of the molten metal holding chamber 14 is set to 680 ° C. in consideration of the hot water temperature and the volume ratio (1/2) between the hot water chamber and the molten metal holding chamber. As an example, the temperature of the molten metal in the melting chamber 13 is about 680 to 720 ° C. depending on the position of the molten metal when the material preheating temperature is 150 ° C., the material charging weight is 250 g, and the molten metal holding temperature of the molten metal holding chamber is 680 ° C. It is preferable to adjust the temperature.
The control target value of the hot water temperature from the hot metal discharge chamber 15 is not limited to about 660 ° C., but is set to a range of about 650 to 750 ° C., and the temperature control target values of the molten metal holding chamber 14 and the melting chamber 13 are set as follows. It is good to set so that it may approach the control target value of gradual hot water temperature in order.
In controlling these temperatures, it is necessary to reduce the control variation in the order of the melting chamber 13, the molten metal holding chamber 14, and the tapping chamber 15. It is important that the temperature at the gate 3 is finally within a range of ± 5 ° C.

  The point that the melting chamber, the molten metal holding chamber, and the tapping chamber are connected in a U shape greatly contributes to the fact that one embodiment of the present invention can be miniaturized. In order to control the temperature as described above, it is necessary to increase the distance between the inlet (melting chamber 13) and the outlet (pouring gate 3).

  In order to control the temperatures of the melting chamber 13, the molten metal holding chamber 14, and the tapping chamber 15, a temperature sensor is installed in each chamber. As an example of the temperature sensor, a thermocouple is used. In the melting chamber 13, a thermocouple is installed at the corner of the U-shape, the molten metal holding chamber 14 is installed immediately above the lower heater of the pair of heaters 17, and the tapping chamber 15 is connected to the melting chamber. A thermocouple is installed at the corner of the U-shape at the same position. The installation location of the sensor is not limited to this, and may be appropriately installed in an appropriate location indicating the temperature of each chamber. Further, a thermocouple may be installed in the vicinity of the gate 3 to compensate the temperature target value of the hot water chamber 15.

Next, the material supply unit 31 will be described.
A material supply unit 31 is installed above the material input unit 4. As the material 11 (the material to be melted in the future), a small block material (aluminum alloy) having a side of 50 mm or less is used. Instead, a chip material can be used. As the physique block material, a quadrangular pyramid without a corner and a spherical shape are preferable. In short, any shape may be used as long as it does not cause clogging.
The preheating means 5 of the material 11 is provided in the material supply part 31, and after preheating to appropriate temperature (100 degreeC-500 degreeC), the material 11 is thrown in intermittently. A mechanism (sliding opening / closing shutter) 6 capable of feeding the preheated material 11 is provided at the lower end position of the material supply unit 31. The amount that is introduced into the melting chamber 13 when the sliding shutter is opened is referred to as one shot. After the material is charged, the opening / closing mechanism (valve) of the material charging unit 4 is closed.

If there is a difference between one shot of the block material (material 11) (integer lump) and the weight of one casting, it is necessary to prevent the amount of molten metal in the melting and holding furnace from overflowing. For this reason, a level sensor is installed at the position of the upper surface of the molten metal in the melting chamber in order to detect the amount of molten metal. If the size of the lump to be added is reduced, handling becomes easier. For example, if it is a lump of pachinko balls, there is no problem in controlling the amount of molten metal. Furthermore, the weight of the metal lump (material 11) to be charged may be pre-weighed and charged, and the amount of the molten metal in the melting and holding furnace may be controlled to be within a certain range.
As a method for measuring the metal lump to be introduced, various methods such as determining the number of pieces as well as weight weighing can be considered. When the number is determined and charged, the level sensor detects the amount of melting, and when it exceeds a certain position, measures such as reducing the number are taken to control the amount of molten metal in the melting and holding furnace. It is also possible to send in with a parts feeder.

In the present embodiment, an unmelted block material is introduced, whereas in the prior art, molten metal is injected from a hot water supply port. Since the unmelted block material is introduced, the temperature of the melting chamber 13, the molten metal holding chamber 14, and the tapping chamber 15 can be independently controlled as described above.
Further, in the present embodiment, the furnace body 50 has a melting function and a pressurizing function. If the cooled metal lump is directly charged into the furnace, for example, if the temperature of the molten metal in the furnace is 700 ° C., the temperature in the furnace decreases as soon as the metal lump is charged. In particular, if the furnace body 50 is small, the temperature drop is significant. For this purpose, the melting chamber 13 suddenly increases in temperature at the moment when the metal lump enters, and as the temperature rises, the molten metal holding chamber 14 is raised, and the outlet 3 is controlled so that there is no temperature change as much as possible. Due to the U-shaped furnace body shape, the temperature effect of the melting chamber 13 is prevented from appearing at the outlet 3 and can be made compact.

  In the configuration of FIG. 1, a mechanism for removing molten metal (tap hole) and a mechanism for preventing deposits and suspended solids such as dross and solidified film from being supplied to the mold from the outlet side (shielding weir and filter) are provided. You can also. It is preferable to provide a tap hole immediately below the melting chamber 13 and the hot water chamber 15. Deposits accumulated at the bottom of the molten metal tank can be taken out.

As another embodiment of the present invention, the following modifications can be considered.
FIG. 2 is a schematic diagram showing another embodiment of the present invention.
A metal bellows 32 is provided between the material charging unit 4 and the furnace body 50. The metal bellows 32 performs a buffering action so that the brittle heat insulating material and the like are not adversely affected by vibrations in the material charging unit 4.
The supply of air in the air supply path 8 may be controlled not to be a constant pressure but to a variable pressure so that the molten metal flows into the cavity of the mold 9 appropriately.
Although the molten metal tank 30 is formed in a U-shape, it may not be a U-shape in a strict sense, and may be a U-shape. Further, the melting chamber 13 and the hot water chamber 15 may be opened outward to have an inverted trapezoidal shape.

DESCRIPTION OF SYMBOLS 3 Sprue 4 Material input part 9 Mold 11 Block-shaped unmelted material, material, block material 13 Melting chamber 14 Molten holding chamber 15 Hot water chamber 30 Molten bath 50 Furnace

Claims (12)

The furnace body (50) in which the molten metal tank (30) which consists of a melting chamber (13), a molten metal holding chamber (14), and a tapping room (15) was formed, and the molten metal provided in the furnace body (50) Heating means of the tank (30), a mold (9) provided on one end side of the molten metal tank (30), and material input having an opening / closing mechanism provided on the other end side of the molten metal tank (30) A casting apparatus comprising a portion (4),
The hot water chamber (15) communicates with the gate (3) of the mold (9), the melting chamber (13) communicates with the opening / closing mechanism, and the lump unmelted material (11) is A casting apparatus configured to feed the molten metal in the hot water discharge chamber (15) into the mold (9) and cast the molten metal in the hot water supply chamber (15), which is configured to be charged into the material charging unit (4).   The casting apparatus according to claim 1, wherein the molten metal tank (30) is formed in a U-shape.   The casting apparatus according to claim 1 or 2, wherein means for pressurizing the molten metal is provided in the melting chamber (13), and the molten metal is filled into the mold by pressurizing the molten metal.   The heating means (16, 17, 18) are individually installed in the melting chamber (13), the molten metal holding chamber (14), and the hot water chamber (15), respectively. 4. The casting apparatus according to claim 1, wherein the means (16, 17, 18) are independently temperature controllable.   The casting apparatus further includes a material supply unit (31), and a lump of unmelted material (11) is input from the material supply unit (31) into the material input unit (4) at a predetermined number of times. The casting apparatus according to any one of claims 1 to 4, wherein:   The casting apparatus according to any one of claims 1 to 5, characterized in that the massive unmelted material (11) is a pyramid or spherical aluminum alloy material of 50 mm or less.   A control mechanism for variably controlling the input amount of the massive unmelted material (11), and the input amount of the massive unmelted material (11) according to the molten metal surface position of the molten metal tank (30). The casting apparatus according to claim 5 or 6, wherein:   The casting apparatus according to any one of claims 1 to 7, wherein a mold clamping mechanism is attached to the mold (9).   The target temperature control value of the molten metal from the hot water discharge chamber (15) is set in a range of 650 to 750 ° C., and the target temperature control values of the molten metal holding chamber (14) and the melting chamber (13) are set as follows: The casting apparatus according to claim 4, wherein the casting apparatus is set so as to gradually approach a control target value of the tapping temperature in this order.   The temperature control target value of the molten metal holding chamber (14) is set to the temperature of the molten metal discharged from the hot water discharge chamber (15) or the internal volume ratio of the molten metal holding chamber (15) to the molten metal holding chamber (14). The casting apparatus according to claim 4, wherein the casting apparatus is set accordingly.   The preset temperature of the heating means (16) provided in the melting chamber (13) is the preheating temperature of the massive unmelted material (11), the input weight of the massive unmelted material (11), and the molten metal holding chamber. The casting apparatus according to claim 4, wherein the casting apparatus is set according to a molten metal temperature or a molten metal surface position of the molten metal tank (30).   The casting apparatus according to any one of claims 1 to 11, wherein a metal bellows (32) is provided between the material charging part (4) and the furnace body (50).

Images