JPS6029583B2 - 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, the gas in the cavity escapes and remains in the product, resulting in the formation of cavities in the product.

Therefore, conventionally, a method has been considered in which an openable/closable valve capable of closing the gas exhaust path is placed in the gas exhaust path of the mold, and this valve is closed by the action of the inertial force of the setting sun during injection. However, in a die-casting machine, when starting operation, injection is usually performed only at a low speed in order to raise the temperature of the mold and to protect the mold.

At that time, since the inertia of the molten metal was weak, the gas vent valve would not close, and there was a risk that molten metal would 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. The present invention is intended to eliminate these drawbacks, and when injecting only at low speed, the valve is closed in advance by the action of a solenoid device to prevent molten metal from entering the valve device. It is.

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

In Fig. 1, 1 is a fixed plate, 2 is a movable plate, 3 is a fixed mold, 4 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. This is a gas venting device 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 spool 13, which is a valve support member, in the direction of the spool 13, 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 subur 13.

The valve chamber 14 has an exhaust port 15 . An elastic body 15 such as a tension 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. Valve 11 is spool 1
3, there is provided a locking mechanism 16, which is a second material, which stops at the lower position, that is, the open position, and which is released by the closing action of the valve 11 due to the impact of the molten metal on the valve 11.

The locking mechanism 16 includes a steel pole 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 groove 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, it is not necessary 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 koji line direction by actuation of a piston rod 27 of a cylinder 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 the spool 13 is raised, or in case of blank firing.

That is, the return punch 23 was made to protrude horizontally from the block 28 attached to the valve stem 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, one valve is lowered relative to the spool 13 as the spool 13 rises. On the other hand, as shown in FIG. 1, between the striker 30 that moves together with the injection plunger 6 and a fixed part such as the injection cylinder 7, there is a photo sensor including a light blocking piece 31 and a photoelectric detector 32. A speed detection sensor 33 was provided. Photoelectric Inspector 32
is provided in the middle of the high-speed injection command area, and detects whether the predetermined injection speed is being achieved by using a predetermined light at a predetermined position where the high-speed injection command is issued. 34 is a glue mitt switch for high-speed injection command;
35 is a glue mitt switch for confirming the retraction of the injection cylinder.

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

Note that the comparator 36 is also a device that issues an opening 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 reference value of the injection speed set in the setting device 37. . For example, if the speed lm/sec is set with the setting device 37, if the speed in the high-speed injection command range is less than lm/sec, the solenoid 2
1 is immediately energized, valve 11 closes, and its speed is 1/
sec or more, the solenoid 21 is not energized,
Therefore, the valve 11 is a control device that closes only by the action of the inertial force of the molten metal. Reference numeral 38 denotes a changeover switch for operating the solenoid, which selects whether the input from the speed detection sensor 33 is used as a discriminating factor for an excitation/de-excitation command to the solenoid 21.

However, regardless of other factors, the selector switch 38
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 did it like that. Therefore, the selector switch 38, which is electrically connected to the solenoid 21, activates the solenoid 21 device to control the valve 11 before starting injection.
either a solenoid activation command circuit that forces the solenoid 21 closed or a solenoid inactivation command circuit that deactivates the solenoid 21 device so that the locking mechanism 16, which is the second member of the gas venting device 10, is activated. It can also be referred to as a selector switch 38 for selecting one. 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 stem 11b presses the steel ball 20.

When the fixed mold 3 and movable mold 4 are clamped 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 deenergized.

In this state, the injection cylinder 7 is operated and the molten metal is supplied into the cavity 8. At this time, cavity 8
The lacquer liquid filling the inside 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 since the gas has a small mass, the valve 7 will not become loose 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 11
The impact applied to the valve 11 is much larger than the impact applied by the gas to the valve 11 because the mass of the molten metal is extremely large compared to the gas, and its inertia is large, causing the 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 the gas in the gas vent groove 9 and hits the valve body discontinuously in the form of droplets, the valve body is thrown up by the first collision of the molten metal.
Thereafter, even when the gas is boiled and 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 passage 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 axial direction even if a large force is applied by the molten metal.

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 enters the bypass of the passage 12 itself. Due to the action of the passage and the pool part 12a provided in the middle of the passage 12, it takes a sufficiently longer time than it takes for the valve 11 to rise upright to reach the side part of the valve 11, so that the molten metal 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 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 tries to rise, the valve 11 causes the spool 13 to rise due to the above-mentioned resistance.
The steel balls 2 are positioned below the stepped portion 22, delayed by 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 is activated. When the spool 13 is pulled up in this way, the valve 11 is located at a lower position within the spool 13, so when the spool 13 is lowered the next time the mirror is inserted, the valve 11 will move the gas vent groove 9 and the passage 12 into the valve chamber. 1
4 and complete the preparation for the next rusting.
During normal injection, the comparator 36 and the like are operated by the changeover switch 38, so that 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. If the injection plunger 6 moves forward, for example, 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. Set the boat approximately 5 meters behind the starting 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 about one ship's length. 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, it is possible to inject only at low speed, such as at the start of operation, and close the gas venting valve by the action of the inertial force of the molten metal. If this is not possible, the valve can be closed in advance by activating a solenoid, so that no molten metal enters the valve device during injection. Also,
The valve can be automatically closed by switching the changeover switch, so there is no need to manually push the valve or fill the gas vent groove in front of the valve, unlike with a follower. It is also unnecessary to clean the valve device more than necessary. In addition, if the degassing device of the present invention is used,
During normal injection, a large amount of gas in the cavity can be sufficiently exhausted through the gas exhaust valve, and the gas exhaust valve can be automatically closed just before the end of injection, allowing the molten metal to It is possible to completely prevent it 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 order to close the gas exhaust valve, a valve stem having a stepped portion engaged with a second member such as a solenoid and a rod that retreats under the action of the solenoid, and a valve stem that applies a force in the direction of closing the valve are provided. Since a member such as an elastic body is used as the first member, the rod only needs to be engaged just enough to keep the bento in place, and the rod only needs to be moved back by a small distance due to the action of the solenoid. When the valve is disengaged, the valve can be tightened by the action of a member such as an elastic body.

Therefore, the movement stroke of the rod caused by the solenoid can be extremely short, the engagement between the rod and the valve stem can be quickly disengaged, and the valve can be quickly closed after receiving a command to close 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 if hot water comes,
Once the valve is closed, it will not open, so molten metal will not penetrate beyond the valve head, and the valve will not malfunction.

Also, the gas exhaust valve can be quickly closed during the high speed advancement of the injection plunger, thus ensuring gas exhaustion.
In addition to being easy to perform, it is also easy to adjust the installation position of the injection speed measuring device and the timing of the operation instruction, which gives the solenoid device an operation command to close the valve when the injection plunger is moving forward and has not reached a predetermined high-speed injection speed. .

[Brief explanation of drawings]

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 venting groove, 10...Gas venting device, 11...Valve, 13...Spool, 1
5... Elastic body, 16... Locking mechanism, 21.
... Solenoid, 26 ... Schilling, 30 ... Strike force, 33 ... Speed detection sensor, 36 ...
... Comparator, 37 ... Setting device, 38 ...
...Selector switch. Figure 1 Figure 2

Claims (1)

[Claims] 1 A gas venting valve device that is closed by the action of a solenoid device is provided in the gas venting groove led from the cavity of the separation surface of the mold or in the gas exhausting portion of the cavity, and this gas venting valve device is installed in the axial direction. A sliding valve, 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; A solenoid operation command circuit constituted by the solenoid device engaged with the second member and which operates the solenoid device to close the valve before injection starts, or a solenoid operation command circuit that operates the second member. A die casting device is provided with a changeover switch electrically connected to the solenoid device to select one of the solenoid deactivation command circuits that keep the solenoid device in an inactive state.