JPS6236057Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a metal melting device for melting low melting point metals such as aluminum.

(Prior Art) As a metal melting apparatus for melting low-melting point metals such as aluminum, the one described in, for example, Japanese Patent Application Laid-open No. 140810/1983 is known. This kind of conventional melting equipment heats and melts the material charged into the preheating melting chamber until it is almost full to the melting temperature (approximately 660°C) using a melting burner installed at the bottom of the preheating melting chamber. The molten metal is guided onto the molten metal take-out gutter provided continuously at the bottom of the preheating melting chamber, and the molten metal on this gutter is heated to the casting temperature (approximately 720°C) by a heating burner, and then transferred to the ingot case. At the same time, the exhaust gas from the melting burner is guided above the preheating melting chamber to preheat the material present above the melting zone, thereby improving thermal efficiency.

On the other hand, when supplying the molten metal obtained by the above-mentioned metal melting device to a die-casting machine to obtain a die-cast product, a holding chamber for accommodating the molten metal is provided in succession to the preheating melting chamber in place of the molten metal take-out gutter, The molten metal in the holding chamber, heated to the casting temperature by the heating burner, is taken out using a ladle, for example, and is supplied to a heat-retaining furnace attached to the die-casting machine.

Control of the melted amount of metal material supplied to the die-casting machine is based on the amount of molten metal remaining in the insulating furnace of the die-casting machine (residual metal amount), the amount scheduled to be used based on the production plan, and the next required amount (after a specified time period has elapsed). (Required amount)
This is done by controlling the opening degree of the melting burner and the amount of ignition based on control data such as the amount of molten metal in the holding chamber. On the other hand, since the temperature rising burner must raise the temperature of the molten metal in the holding chamber to the casting temperature and maintain this temperature, it continuously operates at an opening controlled by the temperature detection signal of the molten metal in the holding chamber. When activated, the exhaust gas passes through the preheated melting chamber. Therefore, even though the melting burner is stopped when the molten metal level in the holding chamber is nearing full and this state is detected, the exhaust gas from the heating burner may pass through the preheating melting chamber. This accelerates the melting of the material, resulting in a situation where molten metal overflows from the holding chamber.

Conventionally, this kind of situation has been prevented by taking out all the materials in the preheating melting chamber, but since the preheating melting chamber is always filled with materials to ensure effective preheating, The disadvantage is that the extraction work is quite cumbersome, and that energy loss is large as material that has already been preheated is extracted, resulting in a significant drop in thermal efficiency.

(Purpose of the invention) This invention was made to improve the above-mentioned conventional drawbacks. For example, when the melting burner is stopped,
It is an object of the present invention to provide a metal melting apparatus that can prevent materials from being melted by the exhaust gas of a heating burner and overflowing from a holding chamber, and can improve thermal efficiency by ensuring effective preheating.

(Structure of the device) This device consists of a material preheating melting chamber that can be charged from the top and is equipped with a material melting burner at the bottom, and a holding chamber that is continuous to the bottom of the preheating melting chamber and accommodates the melted metal. and a heating burner that raises the temperature of the molten metal in the holding chamber, and a molten metal level detection system that detects the level of the molten metal in the holding chamber so that the exhaust gas from the heating burner in the holding chamber does not pass or pass through the preheating melting chamber. The on-off valve is controlled to open and close based on the detection signal of the device.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

The drawing is a longitudinal sectional view of the metal melting apparatus according to this invention, in which 1 is a preheating melting chamber, 2 is a holding chamber, and the preheating melting chamber 1 has an inlet 1a into which a metal material (for example, aluminum) A is charged. at the top end,
Melting burner 3 for melting metal material A at the bottom
There are several. Further, the metal material A is always charged to a substantially full level H, and the lower part thereof communicates with the holding chamber 2 via a downwardly sloped passage 4.

The holding chamber 2 is for storing and holding the molten metal B melted in the preheating melting chamber 1, and the upper part excluding the outlet 2a for the molten metal B is the heat-resistant peripheral wall 1A of the preheating melting chamber 1.
A heating burner 5 is provided below the dome 2A to raise the temperature of the molten metal B in the holding chamber 2 to the casting temperature (approximately 720° C.).

The heat-resistant dome 2A is provided with an exhaust passage 6 extending upward, and this exhaust passage 6 is provided with an on-off valve 7. 8 is a level sensor for detecting the level of molten metal B in the holding chamber 2; a level sensor 8a for detecting the full level _h1 of the holding chamber 2; and a level sensor 8a for detecting the full level _h1 of the holding chamber ₂ ; When the level sensor 8b detects the hot water level _h2 , the signal from the hot water level detector 8 is input to the burner control 9, and the output signal from the burner control 9 causes melting. The opening degree of burner 3, the amount of ignition, etc. are controlled. Also, the level sensor 8a indicates that the water level is full.
When h ₁ is detected, a signal from the hot water level detector 8 is input to the control circuit 10 that opens the on-off valve 7, and the control signal from the control circuit 10 drives the motor 11 to keep the on-off valve 7 in the open position. be done. Note that when the level sensor 8a does not detect the full hot water level _h1 and the hot water is not full, the on-off valve 7 is held at the closed position shown in the figure. Further, the temperature increasing burner 5 is controlled by the output signal from the burner control 9 to maintain the molten metal in the holding chamber 2 at the casting temperature.

In the above configuration, the metal material A charged into the preheating melting chamber 1 to a substantially full level H is rapidly melted by the melting burner 3 from the lower part thereof.
In this case, the metal material A present in the upper part of the melting zone is preheated by the exhaust gas stream (arrow X) of the melting burner 3. As the metal material A is melted, the upper surface of the metal material A becomes lower than the level H, but this level is detected by a level detector (not shown), and accordingly, the metal material A is heated to the preheating melting chamber 1. It is replenished within a few minutes, and a substantially full level H is ensured.

The molten metal melted by the melting burner 3 is stored in the holding chamber 2 through the passage 4 (see B in the figure), and heated by the temperature rising burner 5 to the casting temperature (approximately 720°C). The temperature is raised. In this case, the on-off valve 7 of the exhaust passage 6 is in the closed position, and the exhaust passage 6
Since the chamber is closed, the exhaust gas from the temperature increasing burner 5 passes through the preheating melting chamber 1 as shown by the arrow Y to promote melting and perform preheating more effectively.

The level sensor 8b detects that the molten metal B in the holding chamber 2 increases and its level reaches _h2 ,
The signal from the hot water level detector 8 is sent to the burner control 9.
The opening degree and ignition amount of the melting burner 3 are controlled by the signal from the burner control 9, and the amount of melting is reduced. The temperature raising burner 5 continues to operate under the control of the burner control 9 in order to raise the temperature of the molten metal B in the holding chamber 2, so that the exhaust gas flow Y passes through the preheating melting chamber 1, causing the melting burner to rise in temperature. Even if the metal material A is controlled to be in a stopped state, the metal material A is slightly melted and introduced into the holding chamber 2. Therefore, the amount of molten metal B taken out from the molten metal outlet 2a and supplied to the heat insulating furnace (not shown) of the die-casting machine is smaller than the amount melted by the exhaust gas flow Y of the heating burner 5. If the amount is small, the level of the molten metal B in the holding chamber 2 reaches the full level _h1 .

When the level of the molten metal B reaches the full level _h1 , the level sensor 8a detects this, the signal from the level detector 8 is input to the control circuit 10, and the control signal from the control circuit 10 controls the motor. 11 is driven, and the on-off valve 7 is held in the open position. Therefore, the exhaust gas from the temperature increasing burner 5 is discharged into the atmosphere through the open exhaust passage 6, as indicated by arrow Z, and does not pass through the preheating melting chamber 1. Therefore, melting of the metal material A by the exhaust gas from the temperature increasing burner 5 is suppressed. Therefore, even if the metal material A charged in the preheating melting chamber 1 is not taken out, the molten metal in the holding chamber 2 will not overflow.

(Effects of the invention) As explained above, according to this invention, when the molten metal level in the holding chamber reaches full capacity, the on-off valve at the top of the holding chamber is held in the open position to direct exhaust gas from the heating burner to the atmosphere. Since the metal material is released and does not pass through the preheating melting chamber, melting of the metal material by the exhaust gas of the heating burner is suppressed, and overflow from the holding chamber can be prevented. In addition, the on-off valve is normally held in the closed position so that the exhaust gas from the heating burner passes through the preheating melting chamber, so that the metal material charged into the preheating melting chamber can be effectively preheated. It is possible to improve thermal efficiency.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of the metal melting apparatus according to this invention. DESCRIPTION OF SYMBOLS 1... Preheating melting chamber, 2... Holding chamber, 3... Melting burner, 5... Temperature raising burner, 7... Opening/closing valve, 8...
…Mold level detector, 10…Control circuit, A…Metal material, B…Molten metal, h ₁ …Full hot water level.

Claims (1)

[Scope of utility model registration request] A material preheating melting chamber into which metal materials can be charged from the top and is equipped with a material melting burner at the bottom; a holding chamber that is continuous to the bottom of the preheating melting chamber and stores the melted metal; A melting device equipped with a heating burner for raising the temperature, the opening position in which the exhaust gas from the heating burner in the holding chamber is directly released to the atmosphere without passing through the preheating melting chamber, and the exhaust gas passing through the preheating melting chamber. an on-off valve in the upper part of the holding chamber which has a closed position, a hot water level detector that detects the level of molten metal in the holding chamber, and a hot water level detector that opens the on-off valve when the hot water level detector detects a full hot water level in the holding chamber. A metal melting device characterized by being provided with a control circuit that opens.