JPH02290663A - Submerged burner type low pressure casting furnace - Google Patents

Abstract

PURPOSE:To improve heating efficiency of molten metal and to reduce thermal breakage of a subject apparatus by specifying a burner for heating the molten metal to submerged type into the molten metal in pressurizing casting apparatus with which the molten metal in a furnace chamber is pressurized and cast into metallic mold through a stoke. CONSTITUTION:The molten metal 3 to be cast is charged in the refractory-made furnace chamber 2 and the stoke 5 for molten metal with which the molten metal 3 is pushed up and cast into the metallic mold 4 is submerged into the molten metal. Further, the submerged type burner 6 having concentrical inner cylinder 8 as well a ceramic-made outer cylinder 7, a fuel supplying pipe 11 and an air supplying hole 16 connected with an air supplying pipe 14 in the inner cylinder 8 is submerged into the molten metal 3. The molten metal 3 surface is pressurized with pressurizing air supplied from an air supplying pipe 17 and the molten metal is risen into the metallic mold 4 through the stoke 5 and cast. The molten metal 3 is heated with the submerged type burner 6 and also high temp. combustion gas thereof is exhausted from an exhaust hole 10 in the burner 6 into the furnace chamber 2, and after heating the molten metal 3, this is discharged to the air from a gas discharging hole 23 together with gas for pressurizing. As the vessel for molten metal, crucible is not used and the molten metal is directly heated with the submerged type burner at good heating efficiency and also damages of the burner and furnace chamber caused by breakage of the crucible are obviated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an immersion burner type low-pressure casting furnace that melts a casting material in a furnace chamber with an immersion burner and sends the molten shoulder into a mold to cast a cast product. .

[Prior Art] Conventionally, a crucible-type casting furnace as shown in Fig. 4 has been used for gas-fired low-pressure casting, and the crucible R in the furnace chamber is heated by a gas burner B provided at the lower part of the furnace body. The casting raw material is melted, and the melt is passed through the stalk S into the mold k.
It was used to feed cast iron products into the interior.

[Problems to be Solved by the Invention] In the case of the crucible-type casting furnace described above, the molten metal y is heated indirectly through the melting pot, so there are problems such as a decrease in thermal efficiency and damage to the crucible. When y leaks out, there are problems in that the furnace walls and gas burners are damaged by the molten water that leaks out, and that the task of replacing the crucible r becomes complicated.

The present invention aims to solve the above problems.

[Means for Solving the Problems] The immersion burner type low-pressure casting furnace of the present invention has a heating part of an immersion burner that is immersed in the molten metal to heat the molten metal in the sealed furnace chamber, and a heating part of the immersion burner that is immersed in the molten metal to heat the molten metal. A stoke connected to the mold is charged in order to supply gas to the mold, and an air supply pipe whose opening and closing circuit is controlled is inserted into the chamber to supply pressurized gas to pressurize the melt into the furnace chamber. and closing of the air supply pipe in order to discharge the pressurized gas and combustion gas of the immersion burner from the furnace chamber when the air supply pipe is closed, and to seal the inside of the furnace chamber when the air supply pipe is opened. and an exhaust pipe line whose opening and opening are controlled in synchronization with the exhaust line.

[Function] When the immersion burner is ignited to heat the smelt in the furnace chamber, the air supply pipe connected to the furnace chamber is closed, the supply of pressurized gas into the furnace chamber is stopped, and the flow of pressurized gas into the furnace chamber is stopped. The connected exhaust pipe is opened to discharge the pressurized gas and the combustion gas from the immersion burner from the furnace chamber, while when the melt is to be fed into the mold, the air supply pipe is opened to discharge the pressurized gas and the combustion gas from the immersion burner from the furnace chamber. supplying pressurized gas to the chamber, and closing the exhaust pipe to seal the inside of the furnace chamber, and alternately and synchronously opening and closing the air supply pipe and closing and opening the exhaust pipe. Proceed to.

[Effects of the Invention] Since the present invention is configured as described above, the supply and exhaust of air into and out of the furnace chamber, and the supply and stop of supply of molten metal to the mold can be performed in synchronized and accurate order. This has the effect of not only allowing efficient casting of cast products, but also eliminating molten metal leakage and troubles associated with molten metal leakage.

In addition, since the molten metal is directly heated by the immersion burner immersed in the molten metal, the thermal efficiency when heating the molten toothpick can be improved, and by using the immersion burner, the combustion gas that flows into the furnace chamber can be transferred to the outside of the furnace chamber. Exhaust processing can be performed accurately in synchronization with the supply and exhaust of pressurized gas.

[Example] Next, an example of the present invention will be described with reference to FIGS. 1 to 3.

In an immersion burner type low-pressure casting furnace that is used to heat a casting raw material with an immersion burner and send the molten metal into a mold to cast a cast product, a furnace body 1 houses a molten metal 3 containing a molten casting raw material. A furnace chamber 2 is formed in a sealed manner to feed the slag 3 into the mold 4 for casting. The stalk 5 charged into the furnace chamber 2 is mounted vertically, and the vicinity of the lower part of the stalk 5 is immersed 1a in the molten metal 3.

An immersion iN burner 6 attached downward to the center of the upper wall 1a of the furnace 1 is inserted into the furnace chamber 2 and immersed in the molten metal 3 in order to directly heat the melt 3. The heating section 6a is equipped with a heating section 6a. The heating part 6a of the immersion burner 6 includes an outer cylinder 7 formed of a ceramic material into a cylindrical shape with a bottom and immersed into the molten metal 3, and a cylindrical inner cylinder inserted concentrically into the outer cylinder 7. A combustion gas passage 9 for circulating combustion gas is formed between the outer cylinder 7 and the inner cylinder 8, and a combustion gas passage 9 for circulating combustion gas is formed in the upper part of the outer cylinder 7. A discharge hole 10 is provided for discharging water from the furnace chamber 2 into the furnace chamber 2. Inside the inner cylinder 8 is a gas fuel supply pipe 1 equipped with an on-off valve 13.
The fuel supply pipe 11 connected to 2 is inserted, and the inner
An on-off valve 15 is connected to the air supply port 16 that communicates with the upper end of the air supply port 8.
The air supply pipe 14 that has leaked is connected, and combustion air is supplied to the end of the fuel supply pipe 11 through the inner cylinder 8.

An air supply pipe 17 equipped with an on-off valve 18 and one pressure regulating valve is connected to an air supply port 20 opened near the right end of the upper wall portion 1a of the furnace 1 in the drawing, and supplies pressurized gas to pressurize the molten metal. An exhaust pipe 2 is connected to feed air into the furnace chamber 2 and has an on-off valve 22 at an exhaust port 23 opened to the right of the air supply port 20.
1 is connected to discharge pressurized gas and exhaust gas from the furnace chamber 2, and the melting edge 3 is pressurized by the pressurized gas sent into the furnace chamber 2 through the air supply pipe 17, and the stalk 5 is connected to the stoke 5. It is fed into the mold 4 through.

An on-off valve 18 for the air supply pipe line 17 and an on-off valve 22 for the exhaust pipe line 21
, the on-off valve 13 of the gas fuel supply pipe 12, and the on-off valve 15 of the air supply pipe 14 are temperature sensors that detect the temperature of the molten metal 3, and outputs of a timer that sets the melt field feeding time to the mold 4. The operation of each on-off valve 1 is synchronously controlled based on the signal.
8, 22, 13, and 15 are air supply pipes 8, 22, 13, and 15, in which the exhaust pipe 21 is closed when the air supply pipe 17 is opened, and the fuel gas supply pipe 12 and the air supply pipe 14 are closed, respectively. They are alternately switched so that when the tracheal line 17 is closed, the exhaust line 21 is closed, and the gas fuel supply line 12 and the air supply line 14 are each opened.

Then, the melt 3 of the necessary material that has risen to the specified temperature is molded into the mold 4.
While the air is being fed into the furnace chamber 2, the air supply pipe line 17 is closed and pressurized gas is fed into the furnace chamber 2, and the supply of gas fuel and combustion air to the immersion burner 6 is stopped and the immersion burner 6 is extinguished, the furnace chamber 2 is tightly closed, and the molten metal 3 is pressurized by pressurized gas. On the other hand, when the supply of the molten metal 3 to the mold 4 is finished, the air supply pipe 17 is closed and the furnace chamber 2 is closed. The supply of pressurized gas to the furnace chamber 2 is stopped, gas fuel and combustion air are supplied to the immersion burner 6, the immersion burner 6 is ignited, and the pressurized gas and combustion gas are discharged from the furnace chamber 2 through the exhaust pipe 21. The molten metal 3 is heated by the immersion burner 6.

Next, the operation and effects of the embodiment having the above configuration will be explained.

In this example, in the sealed furnace chamber 2, there is a heating part 6a of an immersion burner 6 immersed in the molten metal 3 to heat the molten metal 3;
A stalk 5 connected to the mold 4 is charged in order to feed the molten metal 3 into the mold 4, and a pressurized gas for pressurizing the molten metal 3 is fed into the furnace chamber 2. When the air supply pipe 17 is closed, the combustion gas of the pressurized gas immersion burner 6 is discharged from the furnace chamber 2, and when the air supply pipe 17 is closed, A gas fuel supply pipe 12 is connected to an exhaust pipe 21 whose opening and closing are controlled in synchronization with the closing and opening of the air supply pipe 17 to seal the inside of the furnace chamber 2, and is further connected to the immersion burner 6. The air supply pipe 14 and the air supply pipe 14 are configured to be opened and closed in synchronization with the closing and opening of the air supply pipe 17, respectively.

For this reason, the supply and exhaust of air into and out of the furnace chamber 2, the supply and stop of supply of the molten metal 3 to the mold 4, and the extinguishing and ignition of the immersion burner 6 are carried out in synchronized and accurate order. Cast products can be cast efficiently, and 1~
It has the effect of eliminating trouble.

Also, an immersion burner 6 is used to immerse the molten metal 3 into the molten metal 3.
Since the molten metal 3 is directly heated, thermal efficiency can be improved when heating the molten metal 3. Also, by using the immersion burner 6, the combustion gas flowing into the furnace chamber 2 can be replaced with pressurized gas inside and outside the furnace v2. Exhaust treatment can be performed accurately in synchronization with exhaust gas.

[Brief explanation of drawings]

Figures 1 to 3 show one embodiment of the present invention.
The figure is a vertical cross-sectional view of an immersion burner type low-pressure casting furnace showing the molten metal pressurizing state, Figure 2 is a vertical cross-sectional view also showing the molten metal heating state, Figure 3 is a time chart, and Figure 4 is a conventional low-pressure #J casting furnace. FIG. 3 is a longitudinal cross-sectional view of the furnace. 2... Furnace chamber 3... Molten metal 4... Mold 6... Immersion burner 17... Air supply pipe 21... Exhaust pipe 2° Furnace to 3: Molten shoulder 4 Mold 5゛Stoke 6: Immersion burner 17: Air supply pipe Figure 1

Claims (1)

[Claims] A heating part of an immersion burner, which is immersed in the molten metal to heat the molten metal, and a stalk connected to the mold to feed the molten metal into the mold are placed in the sealed furnace chamber. , the furnace chamber includes an air supply pipe whose opening and closing are controlled in order to send pressurized gas that pressurizes the molten metal into the furnace chamber, and when the air supply pipe is closed, the pressurized gas is transferred from the furnace chamber to the immersion burner. The furnace is characterized by being connected to an exhaust pipe line whose opening and closing are controlled in synchronization with the closing and opening of the air supply pipe line in order to discharge the combustion gas and seal the inside of the furnace chamber when the air supply line is opened. Immersion burner type low pressure casting furnace.