JPH05174962A - Melt heating device - Google Patents

Abstract

PURPOSE:To eliminate necessity for a heat reserving crucible by melting a melted object by electromagnetic induction heating with the first coil, heating the object to a desired temperature with the second coil, and heat-insulating the object supplied to the next process. CONSTITUTION:A solid-state melted object 2a is changed from a oneend insertion part 3 only by a use amount for a die-cast machine, by a cast magazine attachment 7. An inverter 6 supplies a high frequency current matched with a changed signal to the first coil 5, to melt the melted object 2a accumulated in the vicinity of an another end discharge part 4. An inverter 9 is oscillated to supply a high frequency current to the second coil 8, and a liquid-state melted object 2b is heated to a desired preset temperature. When a temperature sensor 13 detects the object to reach the preset temperature, arm open signal is fed to a shutter opening/closing mechanism 12 from a controller 1, and a shutter 11 is opened to discharge the melted object 2b to the next process. In this way, the melted object 2b of fixed temperature and fixed quantity can be supplied at any time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melting and heating apparatus for metals such as aluminum, zinc, tin and lead.

[0002]

2. Description of the Related Art Conventionally, as a melting and heating apparatus for melting and keeping a temperature of solid metal such as aluminum, a pair of burners (for melting and keeping a temperature) as a heating source, a melting chamber and a crucible for keeping a temperature,
Equipped with a melting burner to melt a large amount of solid metal in the melting chamber, store the melt in a large heat-retaining crucible, and heat the heat-retaining crucible with a heat-retaining burner to keep the molten metal warm. There was something. When manufacturing a die cast or the like, the molten metal was extruded from the heat insulation crucible with a ladle or the like and was supplied to a die cast machine or the like by a predetermined amount.

[0003]

However, in the conventional melting and heating apparatus, the burner serving as the heating source burns fossil fuel such as petroleum or gas to heat the solid metal used in die casting or the like. Since it is melted and stored in a large amount at a time,
There were the following problems.

It takes a long time until the solid metal is completely melted, and the rise time is largely lost.

A large amount of oxide is generated during melting.

Hydrogen gas, which is harmful to casting, is mixed in the molten metal.

Combustion of fossil fuels produces a large amount of pollutants such as sulfur oxides, nitrogen oxides, carbon dioxide and soot.

[0008] It is difficult to keep the temperature of the molten metal constant, and the quality of the die cast molded with the molten metal varies.

[0009] An excess amount of molten metal in the heat-retaining crucible is required in excess of the actual amount used in die casting or the like, which is wasteful.

The entire device becomes large and takes up an installation space.

Therefore, an object of the present invention is to provide a melting and heating apparatus which solves the above-mentioned problems (1) to (3).

[0012]

In order to achieve the above object, the melting and heating apparatus of the first invention comprises a passage through which a material to be melted is inserted from one end insertion portion and is sent to the other end discharge portion, and the one end insertion portion. A first coil that surrounds a portion of the passage and rapidly melts the solid object to be melted inserted from the portion by electromagnetic induction heating; and the melted material that is melted by the first coil to become liquid A second coil that surrounds the vicinity of the other end discharge part and keeps it warm by electromagnetic induction heating, and the liquid substance to be kept warm by the second coil is collected near the other end discharge part of the passage. And a hot water supply means for supplying the liquid substance to be dissolved that has been collected and stored in the next step.

The melting and heating apparatus according to the second aspect of the present invention includes a passage for inserting the substance to be melted from one end insertion portion and sending it to the other end discharge portion, and the solid substance to be melted inserted from the one end insertion portion. A first coil that surrounds the passage and is rapidly melted by electromagnetic induction heating; and a heat-retaining container for accumulating the material to be melted into a liquid state by the first coil and flowing out from the other end discharge portion. And a third coil that surrounds the heat-retaining container and retains the liquid substance to be dissolved by electromagnetic induction heating.

[0014]

According to the melting and heating apparatus of the first aspect of the invention, in the passage, the solid melted material in an amount necessary for the next step is instantly melted to become a liquid melted material at a constant temperature in a short time. can do. Therefore, a constant temperature fixed amount of the liquid substance to be dissolved can be supplied to the next step as needed (without temporarily storing it in a heat-retaining crucible or the like).

According to the dissolution heating apparatus of the second invention, the solid substance to be dissolved is instantaneously and continuously melted, and the liquid substance to be melted is stored in the temperature-retaining container in a short time and kept at a constant temperature. it can. Therefore, the heat insulation container can be made compact with only the (small) volume required for the next process.

[0016]

The present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 exemplifies a melting and heating apparatus of the first invention, in which 1 is a melted material 2 of a metal such as aluminum, zinc, tin, or lead, which is inserted from one end insertion portion 3 and the other end. It is a hollow pipe-shaped passage that is sent to the discharge unit 4.

In this passage 1, the one end insertion portion 3 side is inclined and the other end discharge portion 4 side is horizontal, and the melted substance 2 inserted from the one end insertion portion 3 is the other end discharge portion by its own weight. It is provided so as to reach 4.

The passage 1 has a substantially circular cross-sectional shape, and the passage 1 is made of a non-metallic material such that the melted object 2b does not adhere to its inner surface and does not melt by electromagnetic induction heating ( For example, ceramic etc. are used.

Reference numeral 5 is a first coil for rapidly melting the solid material 2a inserted from the one end insertion portion 3 of the passage 1 by the electromagnetic induction heating by supplying a high-density high-frequency current from the inverter 6. A part of the passage 1 is surrounded by a predetermined axial length.

The first coil 5 having a large capacity is used, and by heating with high energy density, the solid matter 2a within the axial length of the first coil 5 is instantly (for example, 10 seconds). Rapidly dissolves in ~ 20 seconds).

Then, the solid material to be melted 2a that is inserted from the one end insertion portion 3 of the passage 1 and slides down is stopped within the range of the axial length of the first coil 5 (as indicated by a virtual line). A stopper pin or a filter (not shown) made of ceramics, for example, is attached to the passage 1 so that only the liquid substance 2b after dissolution flows down to the other end discharge portion 4.

Reference numeral 7 denotes a loading magazine attachment for automatically feeding a predetermined amount of solid material to be melted 2a, which is an ingot or billet, to the one end insertion portion 3 of the passage 1.

When the loading magazine attachment 7 is actuated and the solid material to be melted 2a is loaded into the passage 1, a loading signal is sent to the inverter 6, the inverter 6 starts oscillating, and the first coil 5 receives a high frequency. Supply current.

Reference numeral 8 denotes a second coil for supplying a high-frequency current from the inverter 9 to the object to be melted 2b which has been melted in the first coil 5 and becomes liquid, and keeps it warm by electromagnetic induction heating. The vicinity of the end discharge part 4 is surrounded by a predetermined axial length.

The second coil 8 has a high precision and a small capacity, and keeps the liquid substance 2b to be accurately kept at a desired set temperature (for example, a temperature used for die casting).

The liquid substance 2b to be kept warm by the second coil 8 is accumulated near the other end discharge part 4 of the passage 1, and the accumulated liquid substance 2b (for example, in a die-cast machine). ) Hot water supply means 10 is provided for supplying to the next step.

The hot water supply means 10 has a shutter opening / closing mechanism 12 for opening and closing the shutter 11 so that the liquid material 2b in the passage 1 can be stored and discharged, and the liquid material to be melted stored in the vicinity of the other end discharge portion 4. If the temperature sensor 13 for detecting the temperature of the substance 2b and the temperature of the liquid substance 2b detected through the temperature sensor 13 are a desired set temperature, an open signal is output to the shutter opening / closing mechanism 12 and the inverter 6, And a controller 14 which outputs an output stop signal to the output terminal 9.

In the normal state, the shutter 11 is closed, and the material 2b to be melted, which is melted by the first coil 5 and becomes liquid, is collected near the other end discharge portion 4. When the liquid substance 2b is accumulated near the other end discharge part 4 (for example, a liquid level meter (not shown) is attached and an output start signal is output to the inverter 9 according to the detection signal. Then, the inverter 9 starts oscillating and supplies a high frequency current to the second coil 8.

Alternatively, the input magazine attachment 7
The oscillation of the inverter 9 may be started by the input signal from the. Reference numeral 15 is an output controller for setting each output of the inverters 6 and 9.

The operation cycle of the melting and heating apparatus of the first aspect of the invention constructed as described above will now be described.

In accordance with the takt time of the die cast machine or the like, the solid magazine 2a is introduced from the one end insertion portion 3 of the passage 1 by the introduction magazine attachment 7 in an amount used for the die cast machine or the like.

Then, the inverter 6 starts oscillating according to the input signal from the input magazine attachment 7,
A high-frequency current is supplied to the first coil 5, and the solid melted object 2a that is stopped like a phantom line is subjected to electromagnetic induction heating and rapidly melted to become a liquid, and the liquid melted object 2b is in the passage 1. And is accumulated near the other end discharge portion 4.

In this way, when the liquid substance 2b is accumulated in the vicinity of the other end discharge portion 4, the inverter 9 starts oscillating, the high frequency current is supplied to the second coil 8 and the electromagnetic induction heating is performed. The temperature of the liquid substance 2b is raised to a desired set temperature.

When the temperature sensor 13 detects that the liquid substance 2b in the vicinity of the other end discharge portion 4 has reached a desired set temperature, an open signal from the controller 14 causes a shutter opening / closing mechanism.
The shutter 11 is opened (shown in phantom line) to 12 and the liquid-like substance 2b in the vicinity of the other end discharge portion 4 is discharged to be supplied to the next step (hot water supply) and the inverter 6 , 9 stops outputting and ends the cycle.

In this way, the required amount of solid substance to be dissolved 2a can be instantaneously dissolved in the next step to form liquid substance to be dissolved 2b at a constant temperature in a short time (for example, a heat-retaining crucible). It is possible to directly supply the liquid substance to be dissolved 2b having a desired temperature to the next step (without temporarily storing it). Therefore, if the above-mentioned cycle is performed when necessary, a constant temperature fixed amount of the liquid substance to be dissolved 2b can be supplied to the next step at any time.

Next, FIG. 2 exemplifies the melting and heating apparatus of the second invention, in which the melted material 2 is inserted from one end insertion portion 3 and sent to the other end discharge portion 4 and one end insertion portion 3 A first coil 5 which surrounds the passage 1 with a solid substance 2a inserted thereinto and rapidly melts by electromagnetic induction heating; and a second coil 4 which is melted by the first coil 5 to become a liquid A heat-retaining container 16 for accommodating the melted substance 2b flowing out of the container, and a third coil 17 for enclosing the heat-insulating container 16 and retaining the liquid melted substance 2b by electromagnetic induction heating. There is.

The passage 1 shown in FIG. 2 has the same structure except that the passage 1 shown in FIG. 1 is made short, and the loading magazine attachment 7 and the first coil 5 are also shown in FIGS.
Those shown in are the same in configuration.

Therefore, the solid substance to be dissolved 2a can be instantaneously and continuously dissolved, and the liquid substance to be dissolved 2b can be stored in the heat insulating container 16 in a short time. A (small) capacity that is necessary for the process is sufficient, and the size can be reduced. Further, it is desirable to use the same material as that of the passage 1 as the material of the heat insulating container 16.

A liquid level gauge 18 continuously supplies a high-frequency current from the inverter 19 to the first coil 5 until the liquid level gauge 18 detects the liquid level of the liquid substance 2b in the heat insulation container 16. Then, the rapid dissolution of the solid to-be-dissolved substances 2a sequentially added is continued, and when the liquid level gauge 18 detects the liquid level of the liquid-to-be-dissolved substances 2b in the heat-retaining container 16, the predetermined storage amount is reached. The output of the inverter 19 and the input of the solid matter 2a are stopped.

Reference numeral 21 denotes a thermometer, and the temperature of the liquid substance 2b in the heat-retaining container 16 detected by the thermometer 21 becomes a desired set temperature (for example, the temperature used in die casting or the like). As described above, the high frequency current is supplied from the inverter 20 to the third coil 17, and is constantly controlled by the electromagnetic induction heating.

Further, the frequency of the current supplied from the inverter 20 to the third coil 17 is set to the frequency at which the liquid substance 2b in the heat-retaining container 16 is agitated to control the weight precipitation of aluminum compounds and the like. You can do it.

Then, the oscillating frequency of the inverter 20 is set so that the optimum stirring condition is obtained according to the material of the material to be melted 2.
The setting can be changed from outside at any time. The oscillation frequency of the inverter 19 can be externally changed at any time.

In the melting and heating apparatus of the second aspect of the invention, the liquid substance 2a in the heat insulation container 16 is supplied (hot water supply) to the next step by using a ladle or the like. Then, if the amount of the liquid substance 2a in the heat-retaining container 16 decreases, the solid substance 2a is dissolved as described above.
a is rapidly dissolved, and a constant amount of the liquid substance to be dissolved 2a is always stored in the heat insulating container 16.

The present invention is not limited to the above-described embodiments, and design changes can be freely made without departing from the gist of the present invention. For example, the cross-sectional shape and overall shape of the passage 1 in FIG. 1 can be freely changed, and the first coil 5 is provided in the vicinity of the one end insertion portion 3 of the passage 1, but the position cannot be changed. Be free.

[0046]

According to the melting and heating apparatus of the first aspect, the following significant effects are obtained.

The required amount of the liquid substance to be dissolved 2b at a desired temperature can be directly supplied to the next step in a short time.

Since the heat-retaining crucible is not necessary, it is not necessary to additionally dissolve the solid substance to be melted, the waste of the melting energy and the heat-retaining energy used therefor is not wasted, and the material (melted substance) is not wasted.

The loss of the startup time is extremely small, and the workability is dramatically improved.

It is possible to reduce the generation of oxides when the solid substance 2a is melted and the mixing of harmful gas into the liquid substance 2b that is melted, thereby improving the quality.

The entire device can be downsized and space can be saved.

The atmosphere temperature is lowered, and the working environment is improved.

The generation of pollutants can be extremely reduced.

The temperature of the liquid substance to be dissolved 2a can be kept constant, and the quality of die casting or the like using the substance to be dissolved 2a becomes stable.

According to the melting and heating apparatus of the second aspect, the following remarkable effects are exhibited.

The heat-retaining container 16 has a small capacity, so that it is possible to reduce the generation of oxides when the solid substance 2a is dissolved and the mixing of harmful gas into the liquid substance 2b.

Loss of start-up time is small and workability is improved.

Liquid to-be-dissolved substance 2b in the heat-retaining container 16
Can be stirred to control the weight precipitation of aluminum compounds and the like.

The entire device can be downsized and space can be saved.

Generation of pollutants can be extremely reduced.

The heating efficiency of the heat-retaining container 16 is good, the temperature of the liquid substance 2b to be melted can be kept constant, and the quality of die casting using the substance to be melted 2b is stable.

The oxide film, gas and inclusions can be easily removed.

[Brief description of drawings]

FIG. 1 is an overall simplified diagram showing an embodiment of a first invention.

FIG. 2 is an overall simplified diagram showing an embodiment of the second invention.

[Explanation of symbols]

 1 passage 2 melted substance 2a solid melted substance 2b liquid melted substance 3 one end insertion part 4 other end discharge part 5 first coil 8 second coil 10 hot water supply means 16 warming container 17 third coil

Claims (2)

[Claims] 1. A passage 1 for inserting a substance to be melted 2 from one end insertion portion 3 and sending it to the other end discharge portion 4, and a solid substance to be dissolved 2a inserted from the one end insertion portion 3 to the passage 1 Coil 5 that surrounds a portion of the coil and rapidly melts by electromagnetic induction heating
A second coil 8 which surrounds the vicinity of the other end discharge part 4 to keep the melted substance 2b melted in the first coil 5 into a liquid state by electromagnetic induction heating, and the second coil A hot water supply means 10 for accumulating the liquid substance 2b to be kept warm in 8 near the other end discharge part 4 of the passage 1 and supplying the accumulated liquid substance 2b to the next step. A melting and heating device characterized by being provided. 2. A passage 1 for feeding a substance to be melted 2 from one end insertion portion 3 and sending it to the other end discharge portion 4, and a solid substance to be dissolved 2a inserted from the one end insertion portion 3 to the passage 1 A first coil 5 that surrounds and rapidly dissolves by electromagnetic induction heating, and a heat insulator for accumulating the melted substance 2b that has been melted by the first coil 5 into a liquid state and flowed out from the other end discharge part 4 Container 16
And a third coil (17) for keeping the temperature of the liquid material (2b) to be melted, which is stored by surrounding the heat insulating container (16), by electromagnetic induction heating.