JPS6011591B2 - die casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a die-casting apparatus that can perform injection using a mold gas venting device that extracts a large amount of gas from a mold cavity during injection.

Conventionally, in die casting machines, when molten metal is injected into the cavity of a mold at high speed and high pressure, there has been a drawback that the gas in the cavity is not sufficiently exhausted and remains in the product, forming cavities in the product.

Therefore, conventionally, a method has been considered in which an openable/closable valve capable of closing the gas exhaust passage is disposed in the gas exhaust passage of the mold, and this valve is closed by the action of the inertial force of the molten metal during injection.

However, in a die-casting machine, at the start of operation,
In order to raise the mold temperature and protect the mold, injection is often performed only at low speed.

At that time, the inertial force of the rising sun was weak, so the gas vent valve would not close, and there was a risk that molten metal could enter the valve device. Conventionally, each time the valve was pressed, the valve was pressed by hand, or the gas vent groove in front of the valve was plugged with a piece of aluminum. Additionally, if there is a problem with the hydraulic system or electrical system during injection, or if the plunger tip gets stuck against the injection sleeve, the specified high injection speed will not be obtained. The degassing valve did not close due to the action of molten metal, and molten metal entered the valve device, causing problems in operation.

The present invention is intended to eliminate these drawbacks, and when a predetermined high injection speed cannot be obtained, the valve is closed by the action of a solenoid device instead of attempting to close by the inertia of the molten metal. This prevents molten metal from entering the valve device. Next, according to an embodiment shown in the drawings,
The present invention will be explained. In Figure 1, 1 is a fixed plate, 2 is a movable plate, 3 is a fixed mold, 41 is a movable mold, 5 is an injection sleeve, 6 is an injection plunger, 7 is an injection cylinder, 8 is a cavity, and 9 is a gas vent. The groove 10 is a gas vent provided at the separation surface between the fixed mold 3 and the movable mold 4.

However, the fixed portion of the degassing device 10 was fixed to one mold, such as the fixed mold 1, for example. As shown in FIG. 2, the gas venting device 10 includes a valve 11 so that the lower surface of the valve head 11a is substantially perpendicular to the gas venting groove 9, and the valve head 11a is inserted from the middle of the gas venting groove 9. A gas exhaust passage 12 is provided which is made of a vice and detours laterally to the upper side of the valve head 11a. The valve 11 slides in the axial direction of the spool 13 within the spool 13, which is a valve support member, and when the valve 11 moves upward, the valve head is inserted into the valve seat 13a provided at the lower end of the spool 13. 11a are in contact, and the passage 12 is closed to the valve chamber 14 in the spool 13. The valve chamber 14 has an exhaust port 15 .
An elastic body 15 such as a pull spring is provided between the upper end of the valve 11 and the spool 13, and is a first member that applies a force in the direction of moving the valve 11 upward and closing it. A locking mechanism 16 is provided, which is a second member, in which the valve 11 is stopped at a lower position, that is, an open position, with respect to the subur 13, and the lock is released by the closing operation of the valve 11 due to the impact of the molten metal on the valve 11. ing.

The locking mechanism 16 includes a steel ball 2 whose pressing force can be adjusted via a compression spring 19 using a nut 17 and a rod 18.
0 and a solenoid 21 connected to the rod 18, and this steel ball 20 is pressed against a stepped portion 22 provided on the outer peripheral surface of the valve stem 11b. The reason for providing the locking mechanism 16 with such a structure is that even if the molten metal advances to the valve 11 intermittently, the valve 11 will be securely closed during the first operation and will not open again during one injection. This is to ensure that. Note that instead of the above-mentioned elastic body 15, a cylinder or the like that applies a relatively small force can be used as a device that applies a force in the direction of sliding the valve 11 upward and closing it. .

If a cylinder is used here, there is no need to provide a valve opening device consisting of a return punch 23 and a stopper 24, which will be described later.
The spool 13 containing the valve 11 can be moved in the mariline direction by actuation of a piston rod 27 of a sill 26 attached to the stationary mold 3 via a bracket 25, for example.

A stopper mechanism is provided in order to more reliably open the valve 11 when lifting the subur 13, or for empty firing.

That is, the return punch 23 was made to protrude horizontally from the block 28 attached to the valve shaft 11b. The return punch 23 is passed through a through hole 29 provided in the peripheral wall of the spool 13 to the outside of the spool 13, and when the spool 13 is raised by the cylinder 26, the return punch 23 is inserted into the stopper 2 attached to the bracket 25.
4, the valve 11 is lowered relative to the spool 13 as the spool 13 rises. On the other hand, as shown in FIG. 1, the striker 3 moves together with the injection plunger 6.
0 and a fixed part such as the injection cylinder 7, a speed detection sensor 33 such as a photo sensor consisting of a light blocking piece 31 and a phototube section 32 is provided. A photoelectric detector 32 is provided in the middle of the high-speed injection command station, and detects whether a predetermined injection speed is being achieved at a predetermined position where a high-speed injection command is issued. 34 is an IJ mitt switch for high-speed injection command,
35 is a glue mitt switch for confirming the backward limit of the injection cylinder.

Note that the speed detection sensor that operates after a high-speed injection command and before completion of filling is not limited to a photo sensor, and other known devices such as a combination of a Magnescale and a timer can be used. 36 is a comparator that calculates the speed and compares it with a reference value, and 37 is a setting device that closes the valve 11 when the predetermined injection speed has not been reached, that is, issues an opening command to the solenoid 21 device. This is a setting device that sets the reference value of the injection speed for the injection speed.

Note that the comparator 36 is also a device that issues a closing command to the solenoid 21 device when the value of the injection speed detected by the injection speed measuring device 33 is smaller than a predetermined injection speed reference value set in the setting device 37. . For example, if the setting device 37 is set to a speed of 1/sec, if the speed in the high-speed injection command range is less than 1 second, the solenoid 2
1 is immediately energized and valve 1 1 closes, and if its speed is 1 unit/sec or more, the solenoid 21 is not energized and the valve 11' is closed only by the action of the noble force of the molten metal. The control device was designed to be Reference numeral 38 denotes a changeover switch for operating the solenoid, which selects whether or not the input from the speed detection sensor 33 is used as a determining factor for an excitation/de-excitation command to the solenoid 21.

However, in the changeover switch 38, regardless of other factors,
It is also possible to energize the solenoid 21 in advance to close the valve 11, or to deenergize the solenoid 21 in advance so that the valve 11 can be closed only by the inertia of the molten metal. I made it possible to choose. Next, the operation of the present invention will be explained together with the operation of this embodiment configured as described above.

First, with the mold open, the spool 13 is lowered by the cylinder 26 while the stepped portion 22 of the valve shank 11b presses the steel pole 20.

When the fixed mold 3 and the movable mold 4 are vertically aligned in this state,
A passage is formed from the cavity 8 to the outside of the spool 13 via the gas vent groove 9, the passage 12, and the valve chamber 14. first,
By selecting the selector switch 38, the solenoid 21 is kept deenergized.

In this state, the injection cylinder 7 is operated and the molten metal is introduced into the cavity 8. At this time, the molten metal filling the cavity 8 advances through the gas vent groove 9, but the gas inside the cavity 8 passes through the passage 12 and the valve chamber 14 and is discharged to the outside. Note that gas has a small mass, so
The valve 7 will not close due to the action of the gas. On the other hand, following the gas, the molten metal comes into contact with the lower surface of the valve head 11a. At this time, valve 1
The impact applied to valve 11 is much larger than the impact applied to valve 11 by gas because the mass of the molten metal is extremely large compared to gas and its inertia is large, causing valve 11 to be thrown upward.
As a result, the upper surface of the valve head 11a seats on the valve seat 13a, closing the space between the passage 12 and the valve chamber 14, and stopping the outflow of the molten metal at the valve 11 position. At this time, even if the molten metal mixes with gas in the degassing chamber 9 and hits the valve body discontinuously in the form of droplets, the first collision of the molten metal will cause the valve body to be thrown up, and then the gas will come. Even when the upward pressing force from the molten metal is removed, the valve 11 is maintained in the upper position by the action of the elastic body 15, so that the exhaust circuit is reliably closed by the valve 11. At this time, since the spool 13 is reliably engaged with the mold, it will not move in the direction of the marquee even if a large force from the molten metal is applied.

Incidentally, the molten metal that has entered the bypass-like gas exhaust passage 12 advances to the side of the valve 11 and is cut off by the closed valve 11, but at this time, the molten metal flows through the bypass of the passage 12 itself. Due to the action of the passage and the pool 12a provided in the middle of the passage 12, it takes a sufficiently longer time than the time it takes for the valve 11 to close to reach the side part of the valve 11, so that the falling sun does not flow inside the spool 13. It is extremely rare for the particles to advance into the valve chamber 14 or outside the mold.

With the valve 11 of the gas venting device 10 closed, when the coin depositing operation is completed by pressurized cooling for a predetermined period of time, the mold is opened, and then the cylinder 26 is operated to raise the spool 13.

The valve 11 is separated from the solidified metal filling the cavity 8, gas vent groove 9, and passage 12, and the molded product is taken out from the movable mold by a product extrusion device (not shown). Note that when the cylinder 26 is operated to raise the valve 11 together with the spool 13, the valve 11 is prevented from moving upward due to the separation resistance between the valve head 11a and the solidified metal in the gas vent groove 9 and the passage 12. Therefore, when the spool 13 attempts to rise, the valve 11 is caused by the above-mentioned resistance, causing the spool 13 to rise.
The steel pole 20 is positioned below the stepped portion 22 with a delay in the rise of the spool 13 so as to be lowered further. Of course, in order to make this valve opening operation more reliable, the return punch 23 is used.
and the stopper 24 acts. When the spool 13 is pulled up in this way, the valve 11 is located at a lower position within the spool 13. Therefore, when the spool 13 is lowered during the next casting, the valve 11 moves the gas vent groove 9 and the passage 12 into the valve chamber. 1
4 and complete the preparations for the next Kamagome.
During normal injection, the comparator 36 and the like are operated by the changeover switch 38, and the excitation/de-excitation of the solenoid 21 can be controlled in accordance with the operation of the speed detection sensor 33. By doing so, the injection speed can be detected by the speed detection sensor 33 at an appropriate position or time after the high-speed injection start signal is output, while the setting device 37
Since this indicates a predetermined injection speed, these values are compared by a comparator 36, and a command is given or not given to the solenoid 21 based on the comparison.

If a predetermined injection speed necessary for closing the valve 11 is not achieved at a predetermined position or time after the high-speed injection start signal is issued, the solenoid 21 is immediately energized. Then, the valve 11 is automatically closed before the molten metal reaches the valve 11 section. In addition, if the injection plunger 6 advances 20 degrees from the high-speed injection start position until the valve 11 closes due to the inertial force of the molten metal, the position at which it is detected whether the high-speed injection speed is occurring is the high-speed injection position. The position should be approximately 5 mounds from the injection start position. If it is detected that the predetermined high injection speed is not achieved at this point, the solenoid 21 is immediately energized as described above, but during this time,
The distance that the injection plunger 6 moves forward until the valve 11 closes varies depending on the injection speed, but is approximately one stroke. Therefore, the valve 11 can be reliably closed in advance before the molten metal reaches the valve 11. In addition, when it is necessary to cast only with low-speed injection, such as when the mold temperature has not reached a predetermined temperature, such as when starting the operation of the die-casting mason, the changeover switch 38 is switched to start injection. Before energizing solenoid 21, valve 1
Close 1 in advance.

Note that if this device is used, it is also possible to close the valve 11 by detecting the position of the injection stroke.

In this way, in the present invention, as described in the claims, the injection speed is detected, and when the injection speed is such that the gas venting valve can be sufficiently closed by the action of the inertial force of the molten metal, the injection speed is detected. can automatically, instantaneously, and reliably close the degassing valve by the inertial force of the molten metal without activating the solenoid device. At injection speeds where it is not possible to close the valve, the valve can be closed immediately or in advance by actuating a solenoid, so that no molten metal enters the valve arrangement during injection. Therefore, the injection operation is performed smoothly every time, and there is no need to replace the valve device or clean it more than necessary. By using the gas venting device of the present invention, a large amount of gas in the cavity can be sufficiently exhausted through the gas exhaust valve during normal injection, and the gas can be exhausted immediately before the end of injection. The valve can be closed automatically, completely preventing molten metal from coming out of the mold. Furthermore, since the gas in the cavity can be reliably and easily discharged, a high-quality injection product that does not contain gas and has no cavities can be reliably and easily obtained. In addition, in order to close the gas exhaust valve, a valve shaft having a stepped part engaged with a second member such as a solenoid and a rod that retreats under the action of the solenoid, and a valve shaft that applies a force in the direction of closing the valve are provided. If a member such as an elastic body is used as the first material, the rod can simply be used to hold the valve stem in place, and the rod only needs to be retracted by one rod or so due to the action of the solenoid. Once disengaged, the valve can be tightened by the action of a member such as an elastic body.

Therefore, the movement stroke of the rod by the solenoid can be extremely short, and the engagement between the rod and the valve shaft can be quickly disengaged, and the valve can be quickly closed after receiving the finger cooling for closing the valve. Furthermore, once the valve is tightened using an elastic body, it can be kept reliably closed until the valve is opened by the action of a valve opening device, etc. Even when hot water comes, the valve, once vertical, does not open, so molten metal does not enter beyond the valve head, and the valve does not malfunction. In addition, the gas discharge valve can be quickly closed while the injection plunger is moving forward at high speed, so that the gas can be discharged reliably and easily.
It is easy to adjust the installation position and timing of the operation instruction of the injection speed measuring device that gives an operation command to the solenoid device to close the valve when the injection plunger is moving forward and has not reached a predetermined high injection speed.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view and control block diagram showing one embodiment of the apparatus for carrying out the method of the present invention, and FIG.
It is an enlarged sectional view of the degassing device part of the figure. 1...Fixed plate, 2...Movable plate, 3...Fixed mold, 4
......Movable mold, 5...Injection sleeve,
6... Injection plunger, 7... Injection cylinder, 8... Cavity, 9... Gas vent groove, 1
0... Gas venting device, 11... Valve, 13...
- Spool, 15... Elastic body, 16... Sun stop mechanism, 21... Solenoid, 26... Cylinder, 30
...Strike force, 33...Speed detection sensor, 3
6... Comparator, 37... Setting device, 38...
...・Selector switch. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A gas vent having a valve in a gas vent groove led from the cavity of the separation surface of the mold that is closed by the inertial force of the molten metal during injection and also closed by the action of a solenoid device based on a closing command. and an injection speed measuring device in the high-speed injection command range, and the solenoid device is equipped with a setting device for setting the reference value of the injection speed for issuing the close command, and the injection speed measuring device detects A die casting device equipped with a device that issues a closing command to a solenoid device when the value of the injection speed is smaller than a reference value of a predetermined injection speed set in a setting device. 2. The valve device for degassing includes a valve that slides in the axial direction;
A first member that applies a force in the direction of closing the valve, a second member that locks the valve in the open position and releases the lock as the valve closes, and is engaged with the second member. A die-casting apparatus according to claim 1, wherein the die-casting apparatus is constituted by a solenoid device.