JPS59193749A - Automatic charging method of molten metal in die casting machine - Google Patents

Abstract

PURPOSE:To decrease intrusion of air and to obtain an injected product having good quality without any blowhole by using a ladle of which the lower part is made slender to decrease the falling distance of a molten metal and moving upward the ladle while charging the molten metal into an injection sleeve. CONSTITUTION:A molten metal is filled in a ladle 1 of which a molten metal port 4 provided to the bottom end is kept closed. After the bottom end of such ladle 1 is inserted into an injection sleeve 2 down to the lower part, the port 4 is opened to discharge the molten metal into the sleeve 2. The ladle 1 is moved upward after the top surface of the molten metal in the sleeve 2 rises higher than the position of the port 4. The molten metal in the sleeve 2 is charged into the cylinder while the ladle 1 is moved upward in the state of maintaining always the port 4 at the upper surface part of the molten metal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic hot water supply method in a die casting machine.

Conventionally, when feeding molten metal such as aluminum alloy into the injection sleeve of a vertical die casting machine using a ladle, a ladle 1 having a shape as shown in Fig. 1 is used, and the ladle 1 is rotated above the injection sleeve 2. The molten metal was dropped into the injection sleeve 2 by moving the molten metal. In this case, the height from the discharge port 1a of the ladle 1 to the top surface of the plunger tip B, which is the falling point of the molten metal, is relatively high, and when the molten metal is supplied into the injection sleeve 2, it swirls as shown in Figure 2. was. Therefore, the molten metal is disturbed and its contact with air increases, which increases the amount of aluminum oxide and the amount of air involved, and also causes the temperature to drop slightly.

This caused injection products to become defective.

The present invention aims to eliminate these drawbacks.

It also reduces the amount of molten metal coming into contact with air when feeding into the injection sleeve. This allows for quiet hot water heating without entraining air.

In the present invention, a ladle provided at the lower end that can open and close the molten metal inlet is used, and with the molten metal placed in the ladle and the molten metal 1'' closed, the lower end of the ladle is inserted to the bottom of the injection sleeve 14. In this state, the molten metal in the ladle is opened and the molten metal in the injection sleeve begins to be discharged into the injection sleeve. Then start raising the ladle.

The ladle is raised in accordance with the discharge state of the molten metal, and the molten metal 10
The molten metal is supplied so that it is always on the top surface of the molten metal inside the injection sleeve.

Next, the present invention will be explained in more detail with reference to an embodiment shown in the drawings.

In FIG. 2, 2 is an injection sleeve, and 2 is a plunger tip that slides vertically within the injection sleeve 2.

The ladle 1 for hot water supply has a slightly elongated shape so that the lower end can fit into the injection sleeve 2, and the molten metal 1"4 is placed at the lower end.
was provided so that the melting spout 4 could be opened and closed with 2 sho 5. 1
b is a hole through which air enters and exits.

6 is the 7 ring for moving the valve stem 5 up and down, and is placed above the ladle 1. 7 is a link that rotates around the other end (not shown), 8 is a Cheno wheel movably attached to the tip of the link 7 by a shaft 9, and 10 is a Cheno wheel that rotates around the other end of the link 7. The chain wheel 11 is a bracket that integrally connects the chain wheel 8 and the cylinder 6, which is hung around other chain wheels freely provided.
The link 7, the wheel 8, the chain 10, etc. form a ladle transport device 12.

When supplying molten metal into the injection sleeve 2, place the lower part of the ladle 1 into the molten metal in a furnace (not shown), position the molten metal inlet 4 below the oxide film on the surface of the molten metal, and insert the cylinder into the injection sleeve. 6 is operated to raise the valve stem 5, and a desired amount of molten metal is poured into the sill 1 through the molten metal spout 4. In this case, the amount of hot water supplied is determined by the vertical position of the ladle 1 with respect to the molten metal hole in the furnace. Stop the ladle 1 at a predetermined position in the furnace.

The amount of hot water to be supplied can be controlled by the action of a conventionally known electrode rod (not shown) attached to the ladle 1 or the like.

When the desired amount of molten metal is pumped into the ladle 1, the valve stem 5 is lowered by the action of the cylinder O to close the molten metal inlet 4, and the ladle 1 is moved by the action of the ladle conveying device 12, as shown in Fig. 2. As shown, the lower part of the ladle 1 is inserted into the injection sleeve 2 in the standby position. At this time, the melt inlet 4 at the lower end' of the ladle 1 was positioned immediately above the plunger tip B located below within the injection sleeve 2.

At this time, the melt inlet 4 and plunger tip 3 at the lower end of the ladle 1
Although the distance between the ladle 1 and the ladle 1 varies depending on the height of the molten metal in the ladle 1 and the area of the molten metal inlet 4, for example, the distance between the ladle 1 and the ladle 1 is 5 to 10 yen, so that when the bath water flows out, air will not get caught up in the molten metal. The distance was set to a relatively small distance.

In this state, the cylinder 6 is operated, the valve stem 5 is raised to open the molten metal spout 4, and the molten metal in the ladle 1 begins to be discharged into the injection sleeve 2. This state is shown in FIG. 4(a). If the ladle 1 is left stationary, the molten metal will be discharged from the molten spout 4 one after another, and as the molten metal in the injection sleeve 2 will gradually be filled with new molten metal from below without stirring the surface layer. The upper surface of the molten metal in the injection sleeve 2 will soon be above the position of the molten metal inlet 4 at the lower end of the ladle 1. When it is detected that the upper surface of the molten metal in the injection sleeve 2 has risen slightly above the position of the molten metal inlet 4, for example, by about 5 to 1 mm, the cylinder 6 is actuated to discharge the molten metal in the ladle 1. This may be done indirectly by using a timer that starts counting the time from the start, or by directly detecting the upper surface of the molten metal in the injection sleeve 2 using a conventionally known detection rod, etc. Ladle 1 using a stick etc.
This may also be done indirectly by detecting the amount of molten metal below.

When a signal is issued indicating that the upper surface of the molten metal in the injection sleeve 2 is slightly higher than the position of the molten metal spout 4 of the ladle 1, the rattle 1 begins to be moved into two parts with the molten metal spout 4 open.

When raising the ladle 1 without discharging the molten metal, the ladle 1 is divided into two parts according to the state of molten metal discharge, so that the molten metal 1 and the molten metal coming out of the bath spout 4 always flow into the molten metal in the injection sleeve 2. hot water is supplied by placing them one after another on the top surface of the container. When does the upper surface of the molten metal in the injection sleeve 2 which is sequentially discharged from the ladle 1.

State 2 is always located above the molten sprue 4 and near the molten sprue 4, for example, always 5 to 10? I1. You can continue to raise the ladle 1 so that the ladle 1 is about m above the surface of the injection sleeve 2. It is also possible to continue raising the ladle 1 while keeping it at the same height as above or at the same height. Of course, it is also possible to use a combination of both of the above.

When the ladle 1 is raised, the upper surface of the molten metal in the injection sleeve 2 is always located at the molten metal [port 4].
If the head between the head and the top surface of the molten metal becomes smaller, a head-ladle rising speed curve consisting of a predetermined function that slows down the rising speed of the ladle 1 is set in advance.
There is a method in which the ladle 1 is raised sequentially according to the curve, and a method in which the ladle 1 is raised while constantly monitoring the hot water level. Note that the measurement of the head may be carried out in terms of two hours, or may be carried out using a light measuring device, a detection rod made of electrodes, or the like.

To constantly monitor the molten metal level, install 2 or 1 (IW) sensors for molten metal level detection at a position slightly higher than the molten metal inlet 4 directly on the outside of the ladle 1.

The method is to take out the detection rod for detecting the molten metal level from the second part of ladle 1 and place it at a position slightly away from the outer surface of ladle 1. When the molten metal level rises and the upper sensor is activated, remove the rod from the ladle 1. 1
The lower sensor reaches the molten metal level due to the rise of the ladle 1, and the operation of stopping the rise of the activated ladle 1 is repeated. Then, the ladle 1 is raised, so that the upper surface of the molten metal in the injection sleeve 2 is always at 2 points. or located between the sensors, etc.

There is also a method of monitoring the hot water level in the injection sleeve 2 so that it is located at one sensor section. Alternatively, install several detection rods with different heights in the ladle 1, or install a hot water level detection device that increases or decreases the current flowing depending on the height of the bath.
It sequentially detects that the hot water level in Ladle 1 has dropped, and
There is also a way to monitor the water level inside. Then, the hot water level is constantly monitored, and the ladle 1 is raised by a predetermined amount based on it.

In this way, the ladle 1 is raised one after another without discharging the molten metal from the molten metal spout 4, and the molten metal is supplied into the injection sleeve 2.

A method for detecting that the molten metal in the ladle 1 has almost completely been discharged into the injection sleeve 2 is when the ladle 1 is raised based on the head-ladle rising speed curve formed by the above-mentioned function.

This method is performed by detecting that the ladle rising speed has decreased to a certain value, using a position signal transmitting device such as a row reno coder for detecting rotation angle in the drive source of the ladle conveying device 12, so that the ladle 1 reaches a predetermined amount. How to detect that the amount has increased,
A method of detecting the end of the hot water level in the ladle 1 using a detection rod etc., a method of detecting the upper limit of the hot water level in the injection sleeve 2 using a detection rod etc. If two sensors for detecting the hot water level are used at the bottom of the outer surface, each time the ladle 1 is raised by a certain amount, the time it takes for the lower sensor to operate and the upper sensor to operate is measured. If this time is longer than the predetermined time, it means that the molten metal has almost finished being discharged.

Detect when it is completely finished. There is a method that detects the moving speed of the hot water surface.

In this way, once the molten metal in the ladle 1 has been discharged, the ladle 1 is continued to be moved outside the injection sleeve 2, and the hot water supply is finished.

In addition, when ladle 1 is raised quickly at first and then gradually raised later, at the end of position 1.

There is a risk that the rising speed of ladle 1 will be almost OK and the hot water supply time will become longer, but in that case, in order to shorten the hot water supply time as much as possible, the molten metal in ladle 1 will be almost gone and the rising speed of ladle 1 will be below a certain value. When this happens, the ladle 1 can be raised at a speed that hardly entrains air, so that the little remaining molten metal can be quickly discharged from the bath sprue 4.

Once the hot water has been supplied into the injection sleeve 2, the injection sleeve 2
The injection operation is performed by moving the plunger tip with a mold part (not shown).

In the above embodiment, an example was shown in which molten metal is supplied into the injection sleeve 2 of a vertical die-casting machine, but this can also be used when supplying molten metal into the injection sleeve of a horizontal die-casting machine. In that case.

Ladle 1 inserted from the hot water inlet at the top of the injection sleeve
The lower melt spout 4 will be located just above the bottom surface within the injection sleeve.

In this way, the present invention uses a ladle whose lower part is extended to reduce the falling distance of the molten metal.

Molten metal is supplied by the method described in the claims, and the ladle is raised in accordance with the discharge state of the molten metal, so that the molten metal is supplied in such a state that the molten metal inlet is always on the upper surface of the molten metal in the injection sleeve. Therefore, the molten metal in the ladle is constantly and quietly discharged from the lower end of the ladle into the injection sleeve.

Moreover, when there is a lot of molten metal in the ladle and the molten metal is discharged quickly, the ladle can be raised relatively quickly, and if the amount of molten metal in the ladle gradually decreases and the molten metal discharge speed becomes slower, the ladle can be raised relatively quickly. The rising speed of water can be gradually reduced accordingly, and hot water can be efficiently supplied under the same conditions at all times.

Therefore, the molten metal does not swirl inside the injection sleeve during hot water supply, the molten metal rarely comes into contact with air, there is no entrainment of air, and almost no aluminum oxide is generated. Furthermore, since the molten metal is discharged quietly, there is relatively little drop in the temperature of the molten metal. By doing this, it is possible to obtain a high-quality injection product free of cavities.

Note that when raising the ladle at the speed described above,
If you make the ladle rise speed a little faster near the end of hot water supply, the amount of molten metal in the ladle will decrease near the end of hot water supply9. The head between the hot water level in the ladle and the hot water level in the injection sleeve becomes smaller, which can prevent the time it takes to drain the bath water.

In addition, when pouring the molten metal in the furnace into the ladle.

After pouring the molten metal 1 at the lower end of the ladle into the furnace under the oxide film on the surface layer of the molten metal, the molten metal port can be opened and the bath metal can be poured in, so the oxide film will not get inside the ladle. .

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a conventional method similar to the present invention, and FIG.
The figure is a vertical sectional view showing one embodiment of an apparatus for carrying out the method of the present invention, FIGS. 6(a) and 6(b). (c) is an explanatory diagram showing the operation sequence in the method of the present invention. 1...Ladle, 2...Injection sleeve, 3...Plunger chip, 4...Melting spout, 5...Valve stem, 6...
・/Linda, 12... Ladle conveyance device patent applicant
Figure 1 Figure 3 Figure 2 Figure 2

Claims (1)

[Claims] (1) Using a ladle that can open and close the molten metal spout provided at the lower end, pour the molten metal into the ladle and close the molten metal spout.
Insert the lower end of the ladle to the bottom of the injection sleeve. In this state, open the molten metal spout and begin to discharge the molten metal in the ladle into the injection sleeve. When the upper surface of the molten metal in the injection sleeve discharged from the ladle is higher than the position of the molten metal inlet of the ladle, the ladle starts to be raised. An automatic hot water supply method for a die casting machine that supplies hot water to the upper surface of the molten metal in the injection sleeve. (When the ladle is raised after the upper surface of the molten metal in the injection sleeve discharged from the ladle is higher than the position of the molten metal inlet of the ladle, the upper surface of the molten metal in the injection sleeve is always above the bath sprue and 2. The automatic hot water supply method in a die casting machine according to claim 1, wherein the ladle is raised while the ladle is maintained in the vicinity of the molten metal inlet.