WO2011117931A1

WO2011117931A1 - Continuous melt supply system for metal casting

Info

Publication number: WO2011117931A1
Application number: PCT/JP2010/002910
Authority: WO
Inventors: 上妻学而
Original assignee: ロザイ工業株式会社
Priority date: 2010-03-25
Filing date: 2010-04-22
Publication date: 2011-09-29
Also published as: JP2011200900A; CN102292175B; CN102292175A; KR20110132309A; JP5412349B2; KR101238994B1

Abstract

The disclosed continuous melt supply system for metal casting is formed from a holding furnace (2) and a melting furnace (1) for tilting the furnace body and discharging molten metal, and is provided with a casting trough (4) and a melt moving trough (3) for discharging melt (M) at melt discharge openings in the holding furnace (2) and the melting furnace (1). The holding furnace (2) is lifted, and a steady flow amount of melt (M) is supplied to a casting machine casting trough (5) via the casting trough (4). After the lifting of the holding furnace (2), said lifting is stopped and the holding furnace is lowered whilst continuing the discharge of melt. The melting furnace (1) is lifted, and a steady flow amount is melt-moved to the holding furnace (2) which is being lowered, via the melt moving trough (3). As the holding furnace (2) is being lowered said furnace receives melt from the melting furnace (1), and simultaneously discharges a constant flow amount of melt. After the lowering of the holding furnace (2), said lowering is stopped and the holding furnace is lifted whilst continuing to discharge melt. This operation is repeated until casting is completed.

Description

Continuous supply system for molten metal in metal casting

The present invention relates to a molten metal continuous supply system in metal casting capable of continuously casting a plurality of batches in one holding furnace by a combined operation of a tilting melting furnace and a tilting holding furnace.

Conventionally, various devices for supplying a molten metal such as an aluminum alloy to a die casting machine have been proposed. For example, there has been known a method in which a predetermined amount of molten metal is pumped by a ladle from a holding furnace that holds a sufficient amount of molten metal that has been previously melted, and is measured, conveyed, and lubricated (see, for example, Patent Document 1).

In the case of transport by this ladle, the transport distance becomes long and the transport speed cannot be increased due to spilled water, etc., so it takes a long time to transport and the molten metal cools down and the fluidity decreases, or it adheres to the ladle. In addition, there is a problem that an oxide film is formed on the surface due to contact with the outside air, and it is difficult to obtain a good product.

As a supply device that solves the above-mentioned problems, a tilting system that tilts the furnace body with the tilting fulcrum shaft as the base point by the operation of two hydraulic cylinders provided at the bottom of the furnace body and discharges the molten metal from the outlet It is known to supply a casting machine using a holding furnace (for example, refer to Patent Document 2).

Japanese Patent Publication No. 60-25220 Japanese Utility Model Publication No. 6-41964

In discharging the molten metal from the tilt-type holding furnace of Patent Document 2 to the casting machine, a control system is used to adjust the tilting speed of the holding furnace using the casting molten metal level as an index in order to keep the amount of the discharged water constant. .

However, since both the melting furnace and the holding furnace are batch furnaces, casting is inevitably completed when the first batch is discharged, and it is necessary to start over from the start in the next batch. In particular, in the continuous casting process, since the work at the start of casting is complicated and there are many metal losses, a system capable of continuously casting a plurality of batches has been demanded. For this purpose, the problem can be solved by installing two holding furnaces, but not only a large capital investment is required, but also a large installation area must be secured.

The present invention has been researched and developed to solve the above-mentioned problems, and a plurality of batches can be continued in one holding furnace by a combined operation of a tilting melting furnace and a tilting holding furnace. An object of the present invention is to provide a continuous supply system for molten metal that can be cast.

As a means for solving the above problems and achieving the object, the present invention comprises a melting furnace and a holding furnace for tilting the furnace body to discharge the molten metal, and transferring the molten metal to the outlet of the melting furnace. A first operation of supplying a molten metal to the outlet of the holding furnace and discharging a molten metal to the outlet of the holding furnace, and raising the holding furnace to supply a constant flow of molten metal to the casting machine through the casting furnace; The holding furnace is stopped before the ascending limit and descends while continuing the hot water, and the third action is to raise the melting furnace and transfer a constant flow rate to the descending holding furnace via the transfer trough. The holding furnace receives the hot water from the melting furnace while descending and simultaneously discharges a constant flow of hot water, and the holding furnace stops before the lowering limit and rises again while continuing the hot water. For metal casting characterized by repeating the process from the operation to the fifth operation until the completion of casting Kicking developed a molten metal continuous supply system, it was adopted.

In the molten metal continuous supply system in the metal casting constructed as described above, the hot water discharged from the holding furnace in the first operation, the second operation, and the fifth operation is detected by detecting the level level of the cast molten metal with a sensor and transferring a constant flow rate. The molten metal continuous supply system in metal casting, wherein the molten metal is discharged from the melting furnace and the holding furnace in the third operation and the fourth operation, and the level of the cast hot water and the casting hot water are controlled. The molten metal continuous supply system in metal casting, wherein the surface level is detected by a sensor and controlled to transfer a constant flow rate, and the third and fourth operations of the molten metal hot water surface level and casting As long as the hot water level is controlled by two different systems and the hot water level is maintained normally, there is no relation, and if one of the hot water levels is abnormal, Stem not only can the correction operation on the other system side, it developed a melt continuous feed system in a metal casting, characterized in that is controlled by the interlock system complement each other, it was adopted.

According to the present invention, the combined operation of the tilting type melting furnace and the tilting type holding furnace enables even a single holding furnace to continuously cast a plurality of batches without interrupting the molten metal. The complicated work at the start can be omitted and the metal loss can be reduced, the yield is improved and the work efficiency is improved. Moreover, since it is difficult to oxidize and a good cast product is obtained and only one holding furnace is required, the equipment cost is not increased and the installation area does not have to be increased.

FIG. 1 is a front view showing a melting furnace and a holding furnace. FIG. 2 is a simplified front view showing a first operation of the melting furnace and the holding furnace. FIG. 3 is a simplified front view showing a second operation of the melting furnace and the holding furnace. FIG. 4 is a simplified front view showing a third operation of the melting furnace and the holding furnace. FIG. 5 is a simplified front view showing a fourth operation of the melting furnace and the holding furnace. FIG. 6 is a simplified front view showing a fifth operation of the melting furnace and the holding furnace. FIG. 7 is an operation flow diagram of the melting furnace and the holding furnace. FIG. 8 is a system flow diagram of one holding furnace. FIG. 9 is a flowchart of the system of two holding furnaces. FIG. 10 is a simplified cross-sectional view showing a tap pin control system. FIG. 11 is a simplified cross-sectional view showing a spout pin control method.

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a tilting type melting furnace for melting a metal material, 2 is a tilting type holding furnace for maintaining a molten metal M at a constant temperature. The melting furnace 1 and the holding furnace 2 are provided side by side, and a transfer tub 3 protruding in the direction of the holding furnace 2 is provided at the outlet of the melting furnace 1, and the casting machine is cast at the outlet of the holding furnace 2. A casting rod 4 projecting in the direction of the rod 5 is provided, the tip of the transfer kettle 3 reaches the holding furnace 2, the tip of the casting rod 4 reaches the casting machine casting rod 5, and the

furnace bodies

1a and 2a are By tilting, the molten metal M in the furnace is discharged through the transfer tub 3 and the casting tub 4.

Hydraulic cylinders

6 and 7 are provided at the side portions of the melting furnace 1 and the holding furnace 2, and a tilting shaft hinge (not shown) is pivotally supported on the side of the outlet, so that the

cylinders

6 and 7 extend and contract. The molten metal of the melting furnace 1 and the holding furnace 2 is discharged through the transfer tub 3 and the casting tub 4, and the amount of discharged hot water increases or decreases depending on the rising speed (cylinder speed). .

The laser sensors 8 and 9 are sensors that continuously monitor the transition of the molten metal level 3a of the transfer tub 3 and the molten metal level 4a of the casting tub 4. The hot water level 4a of the tub 4 is detected, and the rising speed of the melting furnace 1 and the holding furnace 2 is adjusted to discharge a certain amount of hot water. Further, when casting while receiving hot water from the melting furnace 1, the lowering speed is adjusted.

The front end portion (holding furnace inlet) of the transfer tub 3 has a closed structure, and the molten metal M is discharged from the spout 10 on the bottom surface of the transfer tub 3 and enters the holding furnace 2. Yes. The spout 10 has a variable effective sectional area structure.

The usage aspect of the molten metal continuous supply system in the metal casting thus configured will be described. In order to perform continuous casting continuously, it is necessary to replenish the molten metal M from the melting furnace 1 before the molten metal M of the holding furnace 2 is completely discharged. For this purpose, the melting furnace 1 and the holding furnace 2 are as follows. Complex operations are required.

That is, the tilting-type melting furnace 1 is in a stopped vertical state, and the molten metal M is in the hot water tank of the melting furnace 1 and does not discharge. On the other hand, the tilting type holding furnace 2 is raised by the hydraulic cylinder 7, and the furnace body 2 a is slightly tilted by the tilting shaft hinge, so that the molten metal M in the holding furnace 2 is discharged through the casting rod 4. At this time, the casting bath surface level 4a is detected by the laser sensor 9, and a constant flow is supplied to the casting machine casting rod 5 in the first operation (FIG. 2).

The melting furnace 1 remains in the stopped state of the first operation, and the molten metal M is in the hot water tank of the melting furnace 1 and does not discharge, but the holding furnace 2 rises further than the first operation and stops before the upper limit. To do. In the second operation, the inclination of the furnace body 2a becomes tighter than the inclination of the first operation, and subsequently the molten metal M in the holding furnace 2 tries to enter the descending operation while continuing to discharge the molten metal through the casting rod 4 ( FIG. 3).

The melting furnace 1 is lifted by the hydraulic cylinder 6, the furnace body 1 a is tilted via the tilting shaft hinge, and the molten metal M in the hot water tank is discharged through the hot water transfer tub 3 and transferred to the holding furnace 2 that is being lowered. . At this time, the molten metal level 3a is detected by the laser sensor 8 to supply a constant flow rate, and the molten metal M in the holding furnace 2 is supplied to the casting machine casting rod 5 through the casting rod 4 at a constant flow rate. The third operation is discharging (FIG. 4).

The holding furnace 2 further descends and receives a certain amount of molten metal M discharged from the transfer tub 3 of the melting furnace 1, and at the same time a constant flow rate from the holding furnace 2 through the casting tub 4 to the casting machine casting tub 5. The fourth operation is supplied (FIG. 5).

The fifth operation is to stop the holding furnace 2 before reaching the lowering limit and try to enter the rising operation again while continuing the hot water (FIG. 6).

By repeating the processes of the first operation to the fifth operation until the completion of casting, even one holding furnace can continuously cast a plurality of batches without interruption of the molten metal M.

As described above, in order to continuously cast a plurality of batches, it is necessary to replenish the molten metal M from the melting furnace 1 before the molten metal M in the holding furnace 2 is completely discharged. Replenishment transfer during descent is a requirement. In addition, since the holding furnace 2 continues the fixed amount of hot water during replenishment, the replenished hot water must be accurately discharged in a constant amount. Therefore, when transferring the hot water from the melting furnace 1 to the holding furnace 2, it is necessary to adjust the tilting speed of the melting furnace 1 by controlling the hot water pouring surface level 3a.

At the same time, the holding furnace 2 needs to control the casting pouring surface level 4a by adjusting the descending tilting speed in order to discharge the molten metal M replenished from the melting furnace 1 even during the descending. By executing these two controls in parallel, even one holding furnace 2 can continuously cast a plurality of batches without interruption.

Further, when replenishing and transferring the hot water to the holding furnace 2 that is descending from the melting furnace 1 in the third operation and the fourth operation, the hot

water surface levels

3a and 4a of the hot metal transfer cup 3 and the cast iron 4 are set to the two levels. It is controlled by two different systems and is not relevant as long as the hot

water surface levels

3a and 4a are maintained normally. In addition to this system, the other system side also requires a correction operation and is controlled by an interlocking system that complements each other.

That is, as shown in the operation flow of FIG. 7, in step 21 on the melting furnace side, when the molten iron transfer molten metal reaches the upper upper limit (HH), as shown in step 22, It is only necessary to stop the tilting rise, and the holding furnace 2 downstream may continue the control operation. However, when the casting furnace molten metal reaches the upper limit (HH) in step 31 on the holding furnace side while the holding furnace 2 is descending (in the case of the transfer metal level control and cast iron level control), the process goes to step 32. As shown, it is necessary not only to switch the tilting descending speed of the holding furnace to a high speed, but also to stop the supply of the molten metal by lowering the melting furnace being raised at a high speed as shown in Step 33. The high-speed descending operation of the melting furnace 1 and the holding furnace 2 may be stopped if the cast molten metal level drops to DL in

steps

34 and 35. On the other hand, as shown in step 38, when the casting molten metal reaches the lower level lower limit (LL), as shown in step 36, it is only necessary to stop the tilting descent of the holding furnace, and the melting furnace 1 continues the control operation. Then, the molten metal M must be continuously supplied.

FIG. 8 is a block diagram in the case of comprising one melting furnace 1, one holding furnace 2, and one casting machine 5. Continuous casting is possible. FIG. 9 shows a block diagram in the case of a single melting furnace 1, two holding

furnaces

2 and 2, and two

casting machines

5 and 5. By using this system, two or more kinds of alloys can be continuously cast simultaneously.

As described above, in the embodiment of the present invention, the furnace tilting speed adjustment method has been described as the molten metal flow rate control method. However, the present invention is not necessarily limited thereto. For example, as shown in FIG. A tap pin control system in which the movable pin 12 moves left and right in the opening 11 of the holding furnace 2 or, as shown in FIG. 11, is movable on the cylinder 13 provided at the bottom of the casting rod 4 disposed on the upper surface of the casting machine casting rod 5. Of course, the spout pin control system in which the pin 14 moves up and down is possible, and it is a matter of course that various design changes can be made without departing from the spirit of the invention.

The present invention is useful as it is possible to continuously cast a plurality of batches with each one melting furnace and holding furnace, but even when there are two or more holding furnaces, it is useful by using this system. At the same time, it is also effective when two types of alloys are continuously cast simultaneously.

DESCRIPTION OF SYMBOLS 1 Melting furnace 1a Furnace body 2 Holding furnace 2a Furnace body 3 Transfer hot metal 3a Transfer hot water surface 4 Cast iron 4a Cast hot water surface 5 Casting

machine cast iron

6, 7 Hydraulic cylinder 8, 9 Laser sensor

Claims

It consists of a melting furnace that tilts the furnace body and discharges the molten metal, and a holding furnace, with a transfer tub that discharges the molten metal to the outlet of the melting furnace, and a casting tub that discharges the molten metal to the outlet of the holding furnace A first operation of raising the holding furnace and supplying a molten metal at a constant flow rate to the casting machine through the casting iron, and the holding furnace is stopped before the rising limit and descending while continuing the hot water out. 2 operations, a third operation in which the melting furnace is raised and a constant flow rate is transferred to a holding furnace that is descending via a transfer trough, and the holding furnace receives hot water from the melting furnace while descending, and at the same time a constant flow rate hot water discharge And the holding furnace is stopped before the lowering limit, and the fifth action is raised again while continuing the hot water, and the process from the first action to the fifth action is repeated until the completion of casting. Continuous supply system for molten metal in casting.
The hot water discharged from the holding furnace in the first operation, the second operation, and the fifth operation is controlled so as to detect the level of the cast molten metal with a sensor and transfer a constant flow rate. The molten metal continuous supply system in the metal casting according to claim 1.
In the third operation and the fourth operation, the hot water discharged from the melting furnace and the holding furnace is controlled so that the level of the molten metal and the level of the cast molten metal are detected by a sensor and a constant flow rate is transferred. The molten metal continuous supply system in metal casting according to claim 1, wherein the system is a metal casting.
In the third operation and the fourth operation, the transfer hot water surface level and the cast hot water surface level are controlled by two different systems, and there is no relation as long as the hot water surface level is maintained normally. When an abnormality occurs in the hot water surface level, not only the system in which the abnormality has occurred, but also the other system can perform a correction operation and is controlled by an interlocking system that complements each other. The molten metal continuous supply system in metal casting according to claim 1.