JPS63132764A - Discharge control device for molten metal supplying furnace - Google Patents

Abstract

PURPOSE:To adjust the discharging quantity of molten metal from a pressure room to almost the prescribed quantity at every times by rising the level of molten metal in the pressure room with pressurizing in case the level is lower than the prescribed position and supplying the molten metal in the pressure room to die casting machine from this position. CONSTITUTION:In case the molten metal 16 in the pressure room 19 is positioned to the level La in the discharging hole 23, the pressure room 19 is pressurized and the molten metal 16 in the discharging hole 23 is risen to the level Lb by shifting a slide shaft 36 to drive a cylinder toward advancing direction. The molten metal 16 is reached to the level Lb, and then a sensor 24 detects it and the shift of slide shaft 36 is stopped and the molten metal 16 is held to the level Lb, to stand by. Next, the molten metal supplying command in die casting machine is outputted to molten metal supplying side and then again the slide shaft 36 is started to shift and compressed gas is supplied in the pressure room 19 through a supplying piping 28a and supplying/exhausting piping 26 and the prescribed quantity of molten metal 16 is discharged from the discharging hole 23, to supply to a hopper in the die casting machine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a discharge control device for a metal hot water supply furnace that supplies molten metal such as aluminum alloy to a die casting machine or the like.

(Conventional technology and its W!I issues) As this type of metal hot water furnace,
Those described in Publication No. 704 and the international application No. 80-EP
The one described in No. 84-192 is known.

However, in the former type of hot water furnace, the molten metal is pumped through the discharge port of the holding chamber by sending compressed gas into the holding chamber that stores the molten metal, which increases the air pressure in the entire relatively large space inside the holding chamber. However, there are disadvantages in that the compressed gas supply device becomes large and good accuracy cannot be obtained.

On the other hand, in the case of the latter type of water heating furnace, a separate pressure chamber is provided at the bottom or lower side of the holding chamber, molten metal is supplied from the holding chamber to this, and compressed gas is sent into this pressure chamber to supply the molten metal to the discharge of the pressure chamber. Because it is configured to be fed under pressure from the outlet,
The compressed gas supply device can be downsized. FIG. 4 is a vertical cross-sectional view showing a schematic configuration of this hot water supply furnace, in which a holding chamber 1 and a pressure chamber 2 are separated by a partition wall 3, and a predetermined portion of the partition wall 3 corresponding to the bottom of the holding chamber 1 A supply path 4 for supplying molten metal from the holding chamber 1 to the pressure chamber 2 is formed in the chamber.

This supply path 4 is provided with a tubular plunger 5, and is configured so that when the plunger 5 moves F, the supply path 4 is opened and when it moves downward, it is closed. Further, the pipe line 5a within the plunger 5 can be switched and connected to a gas supply source such as nitrogen gas and the atmosphere via an air supply valve and an exhaust valve (not shown). In this hot water furnace, the filling chamber 7 is connected to the pouring port 6. The molten metal 10 stored in the holding chamber 1 after passing through the soaking chamber 8 and kept at an appropriate temperature by the heater 9 is filled into the pressure chamber 2 through the supply path 4 opened by the upward movement of the plunger 5. Pressure chamber 2
The gas inside is discharged to the outside air through the pipe line 5a of the plunger 5. Next, due to the downward movement of the plunger 5, the supply path 4 is
When I'Iwi is carried out, compressed gas at a predetermined pressure is supplied into the pressure chamber 2 through the pipe line 5a of the plunger 5, and the molten metal 10 in the pressure chamber 2 is pushed by this compressed gas and communicates with the pressure chamber 2. It is supplied from the riser 11 through the discharge port 12 to the hopper 13 of the die-casting machine. The supplied molten metal m is controlled to be constant every time by keeping the pressure of the compressed gas supplied to the pressure chamber 2 at a predetermined pressure with a pressure regulator and setting the supply time υ1111 with a timer or the like. When the supply of the molten metal 10 is finished, the plunger 5 moves upward again and the same operation as described above is repeated.

However, in the case of discharge control in this hot water supply furnace, since the amount of compressed gas supplied to the pressure chamber 2 in each molten metal supply is a constant amount controlled by time, it is There is a problem in that subtle fluctuations occur in the molten metal supply each time. This is because the liquid level of the molten metal 10 in the rising pipe 11 before supplying the melt field is the same as that of the molten metal 10 in the holding chamber 1.
This is because the level is the same as the liquid level of , and the level changes depending on the increase or decrease of the solution s10 in the holding chamber 1. That is, when the liquid level of the molten metal 10 in the riser 11 is lower than the standard level, for example, the molten metal supply rate will not be constant each time unless the amount of compressed gas supplied to the pressure chamber 2 is increased by that amount. In practice, it is not easy to accurately control the supply amount (ie, supply time) of compressed gas in accordance with changes in the amount of molten metal in the molten metal, and a precise control system is required.

(Object of the Invention) The present invention was made to solve the problems of the prior art described above, and it is possible to control the viscosity every time without using complicated control means and without being affected by the increase or decrease of the molten II in the holding chamber. The object of the present invention is to provide a discharge υ control device for a metal hot water supply furnace that can provide good molten metal supply.

(Means for Achieving the Object) In order to achieve the above object, the present invention provides a holding chamber for storing molten metal, and a pressure system which is provided separately from the holding chamber and is supplied with molten metal from the holding chamber via a supply path. A metal hot water supply comprising a chamber and a pipe line connecting the pressure chamber and a gas supply source, and the molten metal in the pressure chamber is delivered from the discharge port of the pressure chamber by the pressure of compressed gas supplied from the pipe line. In a furnace discharge control device, an air supply valve provided in the middle of the pipe is connected to a pipe on the downstream side of the air supply valve, and the air supply valve is driven to advance during rnn wait time to control the downstream pipe. a cylinder for pressure-feeding gas within the pressure chamber to the pressure chamber; a level sensor disposed facing the discharge port of the pressure chamber to detect when the molten metal level at the discharge port reaches a predetermined level; A cylinder drive means for advancing and retracting the cylinder, and the advancing drive of the cylinder by the cylinder drive means consists of a preload stroke drive until the level sensor detects the molten metal surface, and a constant stroke drive thereafter. It is configured. That is, the cylinder drive means first drives the cylinder forward until the molten metal level at the discharge port of the pressure chamber reaches a level detected by the level sensor
Prepressure is applied to the pressure chamber by preloading (preload stroke drive), thereby setting the molten metal liquid level to a partial level, and then the cylinder is further driven to advance by a predetermined stroke by the cylinder drive means (fixed stroke drive). , the amount of molten metal supplied each time is a constant amount corresponding to the constant stroke.

(Example) Fig. 1 shows a schematic view of the entire metal hot water supply furnace to which a discharge control device according to an embodiment of the present invention is applied, and Fig. 2 is a cross-sectional view taken along the line A-A in Fig. 1. 1 The main body of this metal hot water furnace has almost the same structure as the conventional example described in the above-mentioned international application PCT-EP84-192. dripping l'a1
A pressure chamber 19 that is separated from the holding chamber 17 via a partition wall 18 is provided below the holding chamber 17 for storing the molten metal 16 in the holding chamber 17. The chamber 19 is configured to be refilled. As shown in FIG. 2, this supply path 20 is opened and closed by a cock type plug 21, and by rotating this plug 21 by a predetermined amount, the supply path 20 can be opened 171 times.

The discharge port 23, which is the outlet of the riser pipe 22 communicating with the pressure chamber 19, is open at the top, and the liquid level in the melt field 16 at the discharge port 23 is at a predetermined level.

A level sensor 24 for detecting when the level reaches the discharge port 23 is disposed facing the discharge port 23 so that it can be raised and lowered by an air cylinder 25. As the level sensor 24,
Here, a temperature sensor with a small heat capacity, such as a semiconductor temperature sensor, is used.

Further, the supply/exhaust pipe 26 communicating with the pressure chamber 19 is connected to the discharge control [
An exhaust electromagnetic valve 29 is provided in the middle of an exhaust pipe line 28b which is connected to a pipe line 28 of the L device 27 and which is open to the outside air. Air supply pipe 28a connected to the gas cylinder 30 which is a gas supply source among the pipes 28
An air supply valve 31 is provided in the middle of the air supply pipe 28a on the upstream side of the air supply valve 31.
Sequentially from the 0 side, the stop valve 32. regulator 33
, a charge tank 34 are provided. The internal pressure of the charge tank 34 is set to be slightly higher than atmospheric pressure.

On the other hand, a cylinder 35 is connected to the air supply pipe line 28a on the downstream side of the air supply valve 31, and the cylinder 35 is configured to be driven forward and backward by a slide shaft 36 serving as cylinder driving means. The forward and backward stroke of this slide shaft 36 is controlled by a detection signal from the level sensor 24 and an encoder 37 attached to this slide shaft 36. That is, the advance/retreat stroke is the preload stroke (cylinder 35) until the level sensor 24 outputs a detection signal.
) and a predetermined stroke of a predetermined amount set by the encoder 37 (the cylinder 35
(corresponding to the range between b and c shown in ).

A solenoid valve 40 is provided downstream of the connection point of the air supply pipe 28a with the cylinder 35, and the downstream side thereof is connected to the charge tank 34 via the recovery pipe 28G. A recovery valve 38 and a filter 39 are provided in the middle of the recovery pipe 28c so that a part of the compressed gas sent to the pressure chamber 19 can be recovered from the recovery pipe 28c to the charge tank 34. has been done. The electromagnetic valve 40 described above is used to switch between compressed gas supply operation and recovery operation. In addition, in Figure 1, 41
is a pressure gauge for monitoring the internal pressure of the charge tank 34;
42 is a ventilator for the cylinder 35.

Next, the operation of the discharge control device 27 for this metal hot water supply furnace will be explained with reference to the flowchart shown in FIG.

Melt 1 is introduced into the pressure chamber 19 from the holding chamber 17 side via the supply path 20.
16 is replenished, the liquid level of the molten metal at the discharge port 23 is at level L8 as shown in FIG. , the solenoid valve 40 is in an open state.

From this state, the movement of the slide shaft 36 (preload stroke drive) shown in step S1 in FIG. 3 is started,
The cylinder 35 is driven forward from the standby position indicated by symbol a. Then, along with this operation, the inside of the pressure chamber 19 is pressurized,
When the molten metal liquid level at the discharge port 23 rises to level Lb,
As shown in step S2 in FIG. 3, the level sensor 24 detects this, and upon receiving the detection signal, the slide shaft 36 stops moving, and the cylinder 35 stops at the detection position already shown by the reference numeral. At the same time, the air cylinder 25 is operated, and the level sensor 24 is pulled up above the discharge port 23 to protect it, while the output count value of the encoder 37 attached to the slide shaft 36 (for example, counted by a counter (not shown) ) is reset to "0" and enters a standby state in step S3 in which it waits for a heating command from a die-casting machine (not shown).

When the process moves from this state to step S4, where a hot water supply command is given by the die-casting machine to the metal hot water supply furnace side, the slide shaft 36 starts moving again (constant stroke drive), and as a result, tapping of hot water is started in step S5. That is, the molten metal 16 is pumped by the compressed gas that is pressure-fed into the pressure chamber 19 through the air supply pipe 28a and the supply/exhaust pipe 26.
is discharged from the discharge port 23 and supplied to a hopper (not shown) of the die-casting machine. At this time, the movement m of the slide shaft 36 is encoded and counted by the encoder 37. On the other hand, a count value indicating a partial stroke according to the amount of hot water supply is preset, and when the cylinder 35 advances from the previous stop position iab to the position indicated by the symbol C corresponding to the above-mentioned constant stroke amount, the encoder The output count value of 37 reaches the preset count value, and in response, the advancing drive of the slide shaft 36 is stopped. In this way, a certain amount of molten metal 16 corresponding to the advance valves from position AB to position 1lIC of cylinder 35 is discharged from discharge port 23 and supplied to a hopper of a die-casting machine (not shown).

After step S6, in which hot water is completed by the above-described operations, the recovery valve 38 is opened in step S7, while the solenoid valve 40 is closed.
A part of the compressed gas on the downstream side of a passes through the filter 39 and is recovered into the charge tank 34 through the recovery pipe 28C, thereby saving gas. At this time, the powder contained in the recovered gas is removed by the filter 39. In addition, since the charge tank 34 is always subjected to an internal pressure slightly higher than atmospheric pressure as back pressure by the regulator 33,
This prevents the molten metal from rising excessively into the supply/exhaust pipe 26 during gas recovery.

Thereafter, in step S8, the air supply valve 31 is opened, the recovery valve 38 is closed, and the slide shaft 36 is moved backward. This action causes
While receiving gas supply from the charge tank 34, the cylinder 35 is returned from position @C to its original position [a. As a result, the F flow side of the air supply pipe 28a has an internal pressure that is slightly higher than atmospheric pressure.

, then closes the air supply valve 31 while closing the solenoid valve 29.
is opened, and the melt 18 to the pressure chamber 19 shown in step S9 is released.
16 replenishments will be made. This operation is performed by moving the plug 21 shown in FIG. 2 a predetermined number of times to open the supply path 20 of the partition wall 18, and as a result, the gas in the pressure chamber 19 is released to the atmosphere through the exhaust pipe 28b. be discharged.

After the predetermined replenishment opening period has elapsed, the plug 21 is returned to its original rotational position, the replenishment path 20 is closed, and step 810
The molten metal replenishment shown in is completed. After this, the solenoid valve 29 is closed, the solenoid valve 40 is opened, and the level sensor
24 is lowered to the reference height and the process returns to step S1, thereby repeating the same cycle.

(Effects of the Invention) As described above, according to the discharge control device for a metal hot water supply furnace of the present invention, after the molten metal liquid level at the discharge port is once equalized to the reference level, a predetermined amount is set in the pressure chamber. Since the structure is configured to send compressed gas to the
Hot water can always be supplied with high accuracy without using im. Therefore, there is almost no error in the discharge volume due to an increase or decrease in the amount of molten metal in the holding chamber, and it has become possible to suppress the difference in discharge volume each time to approximately ±0.1%. Further, since the configuration is simple and does not require a metering timer or a pressure regulator, effects such as pressure management during hot water supply are extremely easy to obtain.

[Brief explanation of the drawing]

FIG. 1 shows a discharge flilJ I which is an embodiment of the present invention.
A schematic diagram of the entire metal hot water furnace to which the II device is applied,
2 is a sectional view taken along the line A--A in FIG. 1, FIG. 3 is a flowchart showing the operation, and FIG. 4 is a longitudinal sectional view of the conventional example. 16...FB tears, 17...Holding room, 19
...pressure chamber, 20...supply route, 23...
Discharge port, 24... Level sensor, 28...
conduit,

Claims (2)

[Claims] (1) A holding chamber that stores molten metal, a pressure chamber that is separated from this holding chamber and is supplied with molten metal from the holding chamber via a supply line, and a pipe line that connects this pressure chamber and a gas supply source. Prepare,
In a metal hot water furnace in which molten metal in a pressure chamber is sent out from a discharge port of the pressure chamber by the pressure of compressed gas supplied from the pipe, an air supply valve provided in the middle of the pipe, and an air supply valve provided in the middle of the pipe, A cylinder connected to a pipe line downstream of the air valve and driven to advance when the air supply valve is closed to forcefully feed gas in the downstream pipe line to the pressure chamber, and a cylinder arranged facing the discharge port of the pressure chamber. and a level sensor for detecting when the molten metal surface at the discharge port reaches a predetermined level, and a cylinder drive means for driving the cylinder forward and backward, and the advance drive of the cylinder by the cylinder drive means is performed at the level shown in FIG. A discharge control device for a metal hot water supply furnace characterized by comprising a pre-pressure stroke drive until a sensor detects the molten metal liquid level, and a constant stroke drive thereafter. (2) The pipe line is provided with a gas recovery charge tank maintained at a pressure slightly higher than atmospheric pressure on the upstream side of the air supply valve, and a gas recovery charge tank maintained at a pressure slightly higher than atmospheric pressure is provided in the pipe line, and a gas recovery charge tank maintained at a pressure slightly higher than atmospheric pressure is provided between the charge tank and the downstream side of the air supply valve. A discharge control device for a metal hot water supply furnace according to claim 1, wherein the discharge control device is communicated with the pipe through a recovery valve.