JP2005000926A - Molten metal feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molten metal feeder capable of efficiently heating and melting a metallic material by induction heating for each casting, and feeding the molten metallic material to a casting device. <P>SOLUTION: The molten metal feeder comprises a container 5 having openings 5b and 5c on an upper part side and a lower part side and having a storage space 5a to store a metal, a lower lid body 7 to close the opening 5c on the lower part side, a cylinder 8 to move the lower lid body 7 to the container 5 to open/close the opening 5c, a coil 6 for induction heating which is disposed around the container 5 to generate the magnetic field to heat the metallic material by the induction of the current to the metallic material in the container 5, an upper lid body 3 to hold the metallic material stored in the container 5 between the lower lid body 7 and itself, and a rod-less cylinder 4 to move the upper lid body 3 in the vertical direction with respect to the container 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molten metal supply device that supplies molten metal to a casting apparatus.
[0002]
[Prior art]
In the field of casting apparatuses such as die casting machines, it is necessary to heat and melt a solid metal material such as an aluminum alloy or a magnesium alloy and supply the molten metal to the casting apparatus. Induction heating is known as a method for dissolving a metal. Induction heating is a heating method in which a current is induced in a metal used for casting by electromagnetic induction, and the metal is heated by the Joule heat.
For example, Patent Document 1 discloses an apparatus that melts only an amount of metal necessary for one casting and supplies it to a casting apparatus.
[0003]
[Patent Document 1]
Patent No. 1260945 [0004]
[Problems to be solved by the invention]
By the way, when a metal material is heated and melted using induction heating, the heating coil and the heated body (metal material to be melted) are magnetically tightly coupled to effectively use the power capacity. It is necessary to
For example, when a heated object is accommodated in a cylindrical container and heated, it is most magnetic to arrange the cylindrical coil on the outer periphery of the cylindrical container as the heating coil. Can be tightly coupled.
However, if a large current is passed through the heating coil in order to rapidly heat and melt the metal material that is the object to be heated in the cylindrical container, a pinch effect acts on the metal material, and the metal material is outside the heating coil. There is a possibility to jump out. That is, when a large current flows through the molten metal, a compression force acts on the metal material due to the pinch effect, causing constriction, and a part of the metal material may protrude from the heating coil.
If part of the metal material protrudes outside the heating coil, the magnetic coupling between the metal material that is the object to be heated and the heating coil becomes sparse, making it difficult to efficiently heat and melt the metal material, and to reduce the power capacity. It cannot be used effectively.
[0005]
The present invention has been made in view of the above-described conventional problems, and the object thereof is melting that can efficiently heat and melt a metal material by induction heating for each casting and supply it to a casting apparatus. The object is to provide a metal supply device.
[0006]
[Means for Solving the Problems]
The molten metal supply device of the present invention is a molten metal supply device that heats and melts a metal material and supplies the molten metal, and has an opening on the upper side and the lower side, and an accommodation space for accommodating the metal material. A container having a lower lid that closes the opening on the lower side, an opening / closing means that moves the lower lid relative to the container and opens and closes the opening, and is disposed around the container. An induction heating coil that generates a magnetic field that heats the metal material by induction of current to the metal material, an upper lid that sandwiches the metal material accommodated in the container between the lower lid, and the upper lid Moving means for moving the container in a vertical direction.
[0007]
The moving means positions the upper lid at a desired position.
[0008]
Preferably, the molten metal supply device of the present invention heats and melts the metal material in a state where the metal material accommodated in the container is pressed by the upper lid.
[0009]
More preferably, the molten metal supply apparatus of the present invention further lowers the upper lid after the start of heating of the metal material in a state where the metal material accommodated in the container is pressed by the upper lid.
[0010]
In the present invention, the lower opening of the container is closed with the lower lid. In this state, a metal material is supplied to the container, the metal material is sandwiched between the lower lid body and the upper lid body, and the metal material is heated and melted by the induction heating coil. Due to the pinch effect, the molten metal material is subjected to a force that tends to jump out of the induction heating coil, but the upper lid prevents this.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a molten metal supply apparatus according to an embodiment of the present invention.
The molten metal supply apparatus 1 according to this embodiment is used to supply molten metal to a casting apparatus such as a die casting machine.
[0012]
In FIG. 1, the molten metal supply device 1 includes an upper lid body 3, a rodless cylinder 4, a container 5, an induction heating coil 6, a lower lid body 7, a cylinder 8, and a controller 12.
The container 5, the upper lid 3, the lower lid 7, and the induction heating coil 6 are one embodiment of the container, the upper lid, the lower lid, and the induction heating coil of the present invention. The rodless cylinder 4 is an embodiment of the moving means of the present invention, and the cylinder 8 is an embodiment of the opening / closing means of the present invention.
[0013]
The container 5 is formed of a cylindrical member having a central axis Ct arranged along a substantially vertical direction. The container 5 is supported by a support mechanism (not shown). Moreover, the container 5 is arrange | positioned above the hot-water supply port 20a of the sleeve 20 of the die-casting machine which is not shown in figure.
The container 5 has openings 5b and 5c on the upper end side and the lower end side, respectively, and also has an accommodating space 5a for accommodating a metal material therein.
The opening 5b on the upper end side is used for supplying a metal material.
The opening 5c on the lower end side is used for discharging the metal material dissolved in the container 5 to the outside.
As a forming material of the container 5, for example, a material having electric insulation and high heat resistance such as ceramics is used.
[0014]
The lower lid body 7 is disposed to face the opening 5c on the lower end side of the container 5, and closes the opening 5c. The lower lid body 7 is formed of, for example, a flat plate member, and is formed of a material having electrical insulation such as ceramics and high heat resistance.
The lower lid body 7 is connected to the piston rod 8 a of the cylinder 8.
[0015]
The cylinder 8 moves the lower lid body 7 along the horizontal direction by expanding and contracting the piston rod 8a. When the lower lid body 7 moves in the opening direction B1, the opening 5c on the lower end side of the container 5 opens, and when the lower lid body 7 moves in the closing direction B1, the opening 5c on the lower end side of the container 5 closes.
The cylinder 8 is driven by a driver 11. The driver 11 drives the cylinder 8 in response to a control command 11 s that instructs the controller 12 to open and close the lower lid body 7.
[0016]
The induction heating coil 6 has a cylindrical shape and is arranged around the container 5. The induction heating coil 6 is formed, for example, by forming a conductive metal such as copper into a spiral line shape.
The induction heating coil 6 is disposed substantially concentrically with the central axis Ct of the container 5. In the induction heating coil 6, the lower end portion in the central axis direction is substantially located at the lower end portion of the container 5, and the upper end portion in the central axis direction is located in the middle of the container 5. Therefore, the induction heating coil 6 does not exist around the upper side of the container 5.
[0017]
For example, a high frequency current of about several tens of kHz is supplied from the power supply circuit 10 to the induction heating coil 6. When a high frequency current is supplied to the induction heating coil 6, a magnetic field is generated. When a metal material is present in the container 5, the metal material is heated by induction of current to the metal material.
The power supply circuit 10 supplies and interrupts the high-frequency current to the induction heating coil 6 in accordance with a control command 10 s from the controller 12.
[0018]
The upper lid 3 is inserted into the container 5 and provided to sandwich a metal material with the lower lid 7.
The upper lid 3 has a lid portion 3b and a shaft portion 3c. The shaft portion 3 c is connected to the movable portion 4 a of the rodless cylinder 4 on the upper end side. The shaft portion 3c is held by the movable portion 4a along the vertical direction.
The lid portion 3 b is connected to the lower end side of the shaft portion 3 c and has an outer shape that is substantially fitted to the inner periphery of the container 5. That is, the outer diameter d of the lid 3 b is slightly smaller than the inner diameter D of the container 5. For this reason, the lid 3b can move in the container 5 without contact with the container 5, and when the metal material is sandwiched between the lid 3b and the metallic material, the metallic material does not leak to the upper side of the lid 3b.
[0019]
The surface facing the lower lid body 7 of the lid portion 3 b has a conical surface 3 a that is recessed with respect to the lower lid body 7. The conical surface 3 a has a central axis that substantially coincides with the central axis Ct of the container 5.
The upper lid 3 is made of a material having electrical insulation such as ceramics and high heat resistance. Further, the lid 3b and the shaft 3c may be integrally formed, or the lid 3b and the shaft 3c may be separate members. When the lid 3b and the shaft 3c are separate members, at least the lid 3b is made of a material having electrical insulation such as ceramics and high heat resistance, and a metal material is used for the shaft 3c. May be.
[0020]
The rodless cylinder 4 moves the upper cover 3 up and down in the vertical directions A1 and A2 with respect to the container 5 by moving the movable portion 4a in the vertical directions A1 and A2.
The rodless cylinder 4 is driven by air supplied from a driver 9. The driver 9 drives the rodless cylinder 4 in accordance with the control command 9s from the controller 12, and positions the upper lid 3 at the instructed position. The rodless cylinder 4 has a lock function for locking the movable portion 4a at the position where it is positioned.
[0021]
Further, the rodless cylinder 4 includes a position detector (not shown) that detects the position of the movable portion 4a, and position information from the position detector is sequentially output to the controller 12.
The controller 12 recognizes the position of the upper lid 3 and whether the upper lid 3 is moving or stopped from the position information of the movable part 4a.
The controller 12 controls the rodless cylinder 4, the cylinder 8, and the power supply circuit 10 according to a predetermined sequence.
[0022]
Next, an example of the melting and supplying operation of the metal material of the molten metal supply apparatus 1 having the above configuration will be described with reference to the flowcharts shown in FIGS.
First, as shown in FIG. 4, for example, the granular metal material M is supplied to the container 5 in which the lower opening 5c is closed (step S1).
The metal material M is a metal material such as an aluminum alloy or a magnesium alloy. In the present embodiment, the form of the metal material M is granular in a solid state, but may be a billet or ingot.
Further, the supply of the metal material M to the container 5 may be performed by an operator weighing and supplying a necessary amount of the metal material, or may be automatically performed using an apparatus such as a feeder.
When supplying the metal material M to the container 5, the upper lid 3 is retracted above the container 5.
[0023]
Next, the controller 12 lowers the upper lid 3 toward the container 5 in which the metal material M is stored (step S2).
As shown in FIG. 4, when the upper lid 3 comes into contact with the surface of the metal material M in the container 5, the upper lid 3 is in a state of pressing the metal material M downward. When the metal material M is sandwiched between the upper lid body 3 and the lower lid body 7, the upper lid body 3 is stopped by a reaction force from the metal material M. In addition, let the stop position of the upper cover body 3 be P1.
At this time, the controller 12 determines whether or not the upper lid 3 has stopped from the position information of the upper lid 3 (step S3).
[0024]
When the controller 12 determines that the upper lid 3 has stopped, the controller 12 locks the rodless cylinder 4 and restrains the upper lid 3 at the stop position P1 (step S4).
[0025]
Next, the controller 12 supplies current to the induction heating coil 6 to start induction heating of the metal material M (step S5).
The metal material M in the container 5 starts to melt by induction heating. As shown in FIG. 6, a compression force acts toward the center due to the pinch effect, and the molten metal ML is separated from the inner periphery of the container 5 and extends in the direction of the central axis Ct. The molten metal ML extending in a columnar shape is supported by the lower lid 7 on the lower side and pressed by the upper lid 3 on the upper side. In a state where the solid state metal material M is not completely dissolved, the dissolved metal ML and the fixed state metal material M are mixed.
Moreover, even if there is a gap between the lower lid body 7 and the opening 5c on the lower side of the container 5 due to the compressive force acting toward the center of the molten metal ML due to the pinch effect, the molten metal is removed from this gap. ML does not leak.
[0026]
Here, FIG. 9 shows an example of the state of the molten metal when the metal material in the container 5 is not pressed by the upper lid 3.
As shown in FIG. 9, when the molten metal ML extending in a columnar shape in the container 5 is not pressed by the upper lid 3, a compressive force acts on the molten metal ML in the induction heating coil 6 in a concentrated manner. For this reason, there is a possibility that the upper side of the molten metal ML extending in a columnar shape jumps out from the upper opening 5 b of the container 5. As the current supplied to the induction heating coil 6 is increased, the force acting on the molten metal ML is increased, and the column is more easily extended.
Further, when the molten metal ML (metal material M) elongates in the container 5, the current concentrates in the hatched region HR, and the molten metal ML (metal material M) protruding outside the induction heating coil 6. There is relatively little current flowing through.
If the current flowing in the molten metal ML is biased, the capacity of the power supply circuit 10 cannot be used effectively, and the metal material M in the solid state is efficiently melted to reach the required temperature in a short time. It is difficult to let
[0027]
In the present embodiment, as shown in FIG. 6, the upper side of the molten metal ML extending in a columnar shape is pressed into the container 5 to prevent the molten metal ML from going out of the induction heating coil 6.
Thereby, the capacity | capacitance which the electric power supply circuit 10 has can be utilized effectively, and it becomes possible to melt | dissolve the metal material M of a solid state efficiently, and to reach required temperature in a short time.
[0028]
Further, when the molten metal ML extends in a columnar shape in the container 5, the upper end portion of the molten metal ML is pressed by the conical surface 3 a of the upper lid body 3, and therefore the columnar molten metal ML from the conical surface 3 a of the upper lid body 3. The force acting on the metal tends to be directed toward the central axis of the columnar molten metal ML.
For this reason, the force acting on the columnar molten metal ML from the upper lid 3 is unlikely to deviate from the central axis, and the molten metal ML can be prevented from being dispersed and entering the gap between the upper lid 3 and the inner periphery of the container 5. .
[0029]
Furthermore, in this embodiment, when the molten metal ML extends in a columnar shape in the container 5, the induction heating coil 6 exists only from the lower side of the container 5 and does not exist on the upper side of the container 5.
For example, assuming that the induction heating coil 6 is provided over the entire length of the container 5, the molten metal ML extends in a columnar shape due to the pinch effect. The pressure near the lower end becomes high, and this pressure tends to be larger than the force toward the center due to the pinch effect. When this pressure becomes larger than the force toward the center due to the pinch effect, the molten metal ML may leak from the gap between the opening 5 c on the lower end side of the container 5 and the lower lid body 7.
For this reason, by adopting a structure in which the induction heating coil 6 is not provided on the upper side of the container 5, an increase in pressure near the lower end of the molten metal ML extending in a columnar shape is suppressed, and the opening 5 c on the lower end side of the container 5 and the lower lid It is possible to prevent the molten metal ML from leaking out from the gap with 7.
[0030]
After starting the induction heating, the controller 12 determines whether or not the metal material M is substantially dissolved by the progress of the melting by the induction heating of the metal material M in the container 5 (step S6). Whether or not the metal material M is substantially dissolved is determined from, for example, the heating time, the temperature of the metal material M, or the like.
When the controller 12 determines that the metal material M in the container 5 is almost melted, the controller 12 unlocks the lockless cylinder 8 (step S7), and lowers the upper lid 3 further downward as shown in FIG. Step S8).
When the granular metal material M in the container 5 is almost dissolved, the volume is decreased. Therefore, the upper lid 3 is lowered in accordance with the decrease in the volume. If the upper lid 3 is further lowered, it is possible to prevent the molten metal ML from being securely contained in the induction heating coil 6 and to prevent the current flowing in the molten metal ML from being biased.
[0031]
The controller 12 further lowers the upper lid 3 and then determines whether or not a predetermined stop position P2 has been reached (step S9). When the controller 12 reaches the stop position P2, the upper lid 3 is stopped (step S10). The rodless cylinder 8 is locked again (step S11).
The predetermined stop position P <b> 2 is a position where the molten metal ML does not leak from between the lower lid 7 and the opening 5 c on the lower side of the container 5 due to the lowering of the upper lid 3. That is, if the upper lid body 3 is lowered too much, the volume between the upper lid body 3 and the lower lid body 7 becomes smaller than the volume of the molten metal ML, and the molten metal ML is placed on the lower side of the lower lid body 7 and the container 5. It is because it leaks from between the openings 5c.
[0032]
Next, the controller 12 determines whether or not the molten metal M in the container 5 can be supplied to the sleeve 20 (step S12).
Whether the supply is possible is determined based on whether the molten metal ML has reached a predetermined temperature or heating time.
[0033]
When the controller 12 determines that the molten metal ML in the container 5 can be supplied to the sleeve 20, as shown in FIG. 8, the lockless cylinder 8 is unlocked (step S13), and the upper lid 3 is raised (step S13). Step S14).
When the upper lid 3 is raised before the molten metal ML is supplied to the sleeve 20, the molten metal ML is elongated in a columnar shape due to the pinch effect. Thereby, it is possible to prevent the molten metal ML from adhering to the inner periphery of the container 5. That is, when the upper lid 3 is located at the stop position P2, the molten metal ML extends in a relatively thick column shape, so that the molten metal ML is likely to adhere to the inner peripheral surface of the container 5. By actively utilizing the pinch effect and separating the molten metal ML from the inner peripheral surface of the container 5, adhesion of the molten metal ML to the inner peripheral surface of the container 5 can be reliably prevented.
In addition, the position which raises the upper cover body 3 can be set suitably.
[0034]
The controller 12 raises the upper lid 3, then opens the lower lid 7 (Step S <b> 15), and discharges the molten metal ML in the container 5 to the sleeve 20.
In this state, an electric current is supplied to the induction heating coil 6. Therefore, the pinch effect acts on the molten metal ML even while the lower lid body 7 is moved in the opening direction B1. Therefore, even if the lower lid body 7 is moved in the opening direction B <b> 1, the molten metal ML does not adhere to the inner peripheral surface of the container 5, and the molten metal ML falls in the direction of the substantially central axis Ct of the container 5.
[0035]
The controller 12 confirms the completion of the discharge of the molten metal ML (step S16), and interrupts the current supplied to the induction heating coil 6.
Further, it is determined whether or not the next cycle is performed (step S18). When the next cycle is performed, the lower lid body 7 is closed again (step S19).
[0036]
Here, the example which melt | dissolved the metal material concretely in the molten metal supply apparatus 1 of the said structure is demonstrated.
Granular magnesium was used as the metal material M. The container 5 and the upper lid 3 were made of silicon nitride. The lower lid body 7 was made of boron nitride.
Further, the amount of magnesium was 150 grams, the capacity of the power supply circuit 10 was 50 kW, and the magnesium was heated and melted until it reached 730 ° C. from room temperature.
When the molten metal supply apparatus 1 according to the present embodiment was used under the above conditions, dissolved magnesium at 730 ° C. was obtained in about 17 seconds after the start of heating.
On the other hand, when magnesium was heated and dissolved without using the upper lid 3, it took about 33 seconds to obtain dissolved magnesium at 730 ° C.
As described above, according to the present embodiment, the capacity of the power supply circuit 10 for induction heating can be effectively used. As a result, the metal material is efficiently heated and melted and supplied to the casting apparatus. And the casting cycle time can be shortened.
[0037]
The present invention is not limited to the embodiment described above.
In the above-described embodiment, the case where the cylinder 8 is used as the opening / closing means of the present invention has been described. However, any means can be adopted as long as it can open and close the lower lid body 7.
In the above-described embodiment, the case where the rodless cylinder 4 is used as the moving means of the present invention has been described. However, any means can be adopted as long as it can move the upper lid 3 up and down.
In the above-described embodiment, the upper lid 3 is temporarily stopped at the position P1 and then lowered again to the position P2. However, the upper lid 3 is continuously or stepwise from the position P1 according to the decrease in volume due to dissolution. The sequence of lowering may be changed as appropriate.
[0038]
【The invention's effect】
According to the present invention, it is possible to efficiently heat and melt the metal material by induction heating for each casting, and supply it to the casting apparatus.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a molten metal supply apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing an example of the operation of the molten metal supply apparatus according to the embodiment of the present invention.
FIG. 3 is a flowchart showing the operation following FIG.
FIG. 4 is a cross-sectional view showing a state where a metal material is supplied to a container.
FIG. 5 is a cross-sectional view showing a state where a solid metal material in a container is pressed by an upper lid.
FIG. 6 is a cross-sectional view showing a state in which a solid metal material in a container is dissolved.
FIG. 7 is a cross-sectional view showing a state where the upper lid is further lowered after the metal in the container is dissolved.
FIG. 8 is a cross-sectional view showing an operation of supplying molten metal in a container to a sleeve.
FIG. 9 is a cross-sectional view showing an example of a state of molten metal when the metal material in the container is not pressed by the upper lid.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Molten metal supply apparatus 3 ... Upper cover body 4 ... Rodless cylinder 5 ... Container 5a ... Accommodating space 5b, 5c ... Opening 6 ... Induction heating coil 7 ... Lower cover body 8 ... Cylinder 9 ... Driver 10 ... Electric power supply circuit 11 ... Driver 12 ... Controller 20 ... Sleeve

Claims (13)

A molten metal supply device for heating and melting a metal material and supplying a molten metal,
A container having an opening on the upper side and the lower side and having a storage space for storing a metal material;
A lower lid for closing the opening on the lower side;
Opening and closing means for moving the lower lid relative to the container and opening and closing the opening;
An induction heating coil that is disposed around the container and generates a magnetic field that heats the metal material by induction of current to the metal material in the container;
An upper lid that sandwiches the metal material accommodated in the container with the lower lid; and
The molten metal supply apparatus which has a moving means to move the said upper cover body to an up-down direction with respect to the said container. The molten metal supply apparatus according to claim 1, wherein the moving unit positions the upper lid at a desired position. The molten metal supply device according to claim 1, wherein the metal material is heated and melted in a state where the metal material accommodated in the container is pressed by the upper lid. The molten metal supply apparatus according to claim 3, wherein the upper lid is further lowered after the heating of the metal material in the container. The molten metal supply device according to claim 4, wherein the upper lid body is lowered to a position where the molten metal material does not leak from between the lower lid body and the opening on the lower side of the container. The molten metal according to any one of claims 3 to 5, wherein the upper lid holding the metal material is raised before discharging the metal material melted by opening the lower lid from the opening on the lower side of the container. Feeding device. The molten metal supply according to any one of claims 1 to 6, wherein a current is continuously supplied to the induction heating coil until discharge of the molten metal material is completed after heating of the metal material in the container is started. apparatus. The container is composed of a cylindrical body,
The molten metal supply device according to any one of claims 1 to 7, wherein the upper lid body has an outer shape that is substantially fitted to an inner periphery of the container, and a surface facing the lower lid body has a concave surface. . The molten metal supply device according to claim 8, wherein a surface of the upper lid that faces the lower lid includes a conical surface having a central axis that substantially coincides with the central axis of the container. The molten metal supply device according to claim 8 or 9, wherein the induction heating coil has a cylindrical shape, and is arranged substantially concentrically with a central axis of the cylindrical body around the cylindrical body. The melting | dissolving of Claim 10 arrange | positioned from the lower end side of the said cylindrical body that the length of the said central axis direction of the coil for induction heating is shorter than the length of the central axis direction of the said cylindrical body. Metal supply device. The molten metal supply apparatus according to claim 1, wherein the metal material has a granular shape before melting. The molten metal supply apparatus according to claim 1, wherein the upper lid is made of ceramic.

Images