JPH0790346B2 - Mold degassing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mold degassing device for extracting gas from a mold cavity during injection molding by an injection molding device such as a die casting machine or an injection molding machine. is there.

[Conventional technology]

FIG. 4 is a block diagram showing a conventional die degassing device,
FIG. 1 is a cross-sectional view showing a general degassing device that constitutes a die degassing device.

4 and 5, the cavity 4 is formed on the dividing surface 3 which is the joint surface between the fixed mold 1 and the movable mold 2 shown in the mold clamped state.
The molten metal 7 is injected and filled into the cavity 4 from the injection sleeve 5 through the gate 6.
Reference numeral 8 denotes a product extruding device for extruding the product obtained by solidifying the molten metal 7 from the cavity 4 of the movable mold 2 after the mold is opened. Mold 1,
A spool hole 11 which is connected to the cavity 4 by a gas vent passage 9 and a gas vent groove 10 is opened to the outside at the upper end of the split surface 3 of 2, and is branched from the middle of the gas vent groove 10. The bypass 12 that is detoured is a spool hole 11 of the gas vent groove 10.
Is connected to the opening.

On the bracket 13 fixed to the upper surface of the fixed mold 1, a fluid pressure cylinder 14 is fixed concentrically with the gas vent groove 10, and a flange 15a which is the working end of a piston rod 15 which moves forward and backward by the fluid pressure. A holder 18 for clamping the upper end of a spool 17 of a gas venting device, which is indicated by reference numeral 16, is fixed to the spool 17, and the spool 17 is held by a retainer 19 and a bolt 20.
It is fixed at 18. The spool 17 is formed in a cylindrical shape with a bottom, and a step portion 17a is provided at the lower end thereof, and the forward / backward movement of the piston rod 15 raises / lowers the entire degassing device 16 so that the step portion 17a becomes the spool hole 11. It is configured to engage with or separate from the spool hole 11.

The spool 17 is divided into a member 17b and a member 17c, and a flange of the valve guide 21 fitted in the inner hole 17d is held between them, and in this state, the members 17b, 17c and the valve guide 21 are integrated. Has been converted. Reference numeral 22 denotes a piston located above the valve guide 21 and slidably fitted in the inner hole 17d of the member 17b. The central screw hole of the piston 22 is fitted in the inner hole 21a of the valve guide 21 so as to be movable back and forth. The threaded portion of the combined valve rod 23 is screwed into and integrated, and the valve body 24 is integrally formed at the lower end of the valve rod 23. On the other hand, at the lower open end of the spool 17, the valve seat 17
The valve seat 24 and the valve seat 17e are formed so that the molten metal 7 rising in the degassing groove 10 from the open state shown in FIG. Is configured. In the valve open state shown in the figure, the valve body 24 engages with the opening step portion of the gas vent groove 10 to close it.

The operation of the die degassing device configured as described above will be described. After the molds 1 and 2 are clamped, the fluid pressure cylinder 14 operates to lower the entire degassing device 16, and the step portion 17a of the spool 17 becomes the spool hole 11 as shown in FIGS. 4 and 5. Mating. Then, the piston 22 descends by inflowing air into the head side chamber 25 from an air source (not shown). After the piston 22 descends, the air supply to the head side chamber 25 is cut off, the air now flows into the rod side main chamber 26, and the lower surface of the piston 22 is pressed against the O-ring 27. As a result,
The valve body 24 and the valve seat 17e maintain the open state as shown in FIG. At this time, the lower surface of the valve body 24 closes the upper end opening of the gas vent groove 10, and the gas vent groove 10 and the spool valve chamber 17g communicate with each other by the bypass 12 and the valve opening portion. In this state, the melt is injected into the injection port of the injection sleeve, and the injection cylinder 51
When the plunger 54 is moved forward, the molten metal 7 is injected and filled into the cavity 4 through the fixed sleeve portion 5 and the gate 6. Along with this, the gas in the cavity 4 is discharged through the gas vent passage.
9, hit the lower end of the valve body 24 through the gas vent groove 10 and bypass
It is discharged from the discharge hole 17f through the valve chamber 17g. Then, the molten metal 7 is almost filled in the cavity 4 and then rises in the gas vent groove 10 and hits the lower surface of the valve body 24 together with the gas. At this time, the mass of the molten metal 7 is much larger than the mass of the gas, and a large inertial force acts on the lower surface of the valve body 24.
The valve body 24 is flipped up. In this way, when the valve body 24 moves slightly upward and the lower surface of the flange 22a of the piston 22 separates from the O-ring 27, the air in the rod-side main chamber 26 moves from the gap between the flange 22a and the O-ring 27 to the rod-side auxiliary member. Entering the chamber 28, the piston 22 rises rapidly. As a result, the valve seat 17
Since e is closed by the valve body 24 and this valve closed state is maintained, the molten metal 7 is blocked from moving at the position of the valve body 24.

In this way, the molten metal 7 is pressurized and cooled for a predetermined time while the valve body 24 closes the gas vent groove 10 and the bypass 12, and then the gas venting device 16 is operated by the fluid pressure cylinder 14 as shown in FIG. When the whole is raised, the valve body 24 separates from the solidified material solidified in the cavity 4, the gas vent groove 10 and the bypass 12, but at this time, the valve body 24 is moved upward due to the separation resistance between the valve body 24 and the solidified material. The movement is hindered, and the valve element 24 opens due to the delay of the rising of the spool 17, and the valve open state is maintained by the action of the air pressure. After cooling, the product in the cavity is opened and the product is extruded by the product extruding device 8. After that, the entire gas venting device 16 is lowered and set in the state shown in FIG. 5, then the air supply to the head side chamber 25 is shut off and the air is supplied to the rod side main chamber 26.

FIG. 4 is a configuration diagram showing a conventional valve opening / closing control system.
In the figure, 50 is an injection sleeve, 50a is a pouring port, 52 is a piston rod, 53 is a coupling, 55 is a plunger tip, 56 is a magnetic scale, 57 is a magnetic sensor, 58 and 60 are comparators, and 59 is condition setting. A device, 61 is a speed setting device for setting the switching injection speed. Above magnetic scale 56 and magnetic sensor
Reference numeral 57 constitutes an injection speed detecting means, the output of the comparator 58 is used for controlling the air described above, and the output of the comparator 60 is used for controlling the air circuit switching valve for opening and closing the valve.

In FIG. 4, a magnetic sensor 57 is arranged near the magnetic scale 56. When the magnetic scale 56 moves together with the plunger 54, a pulse signal is extracted from the magnetic sensor 57, and the pulse signal is sent to and input to the comparators 58 and 60. In the comparator 58, the number of pulses input and the output of the condition setting device 62 are compared, and when they match or when a timer finishes measuring a predetermined time, a signal is emitted, and each room 25, 26, 28 Area is controlled.

On the other hand, the comparator 60 detects the speed from the number of pulses input per unit time and compares it with the input speed setting value. As a result, when the detected speed is lower than the set speed, the valve body 24 may not be closed due to the inertial force, so the valve body 24 can be forcibly closed by the air circuit switching valve. Further, the timing for closing the valve body 24 can be set variously such as one corresponding to the plunger position calculated by the number of input pulses, or a time point when a predetermined time has elapsed from the plunger position.

[Problems to be Solved by the Invention]

As described above, the conventional switching operation of the valve opening / closing switching valve corresponds to the plunger position depending on the number of pulses, and the position where the valve body is actually closed is not accurate in relation to the molten metal.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mold degassing device capable of accurately controlling solenoid operation in relation to molten metal.

[Means for Solving the Problems]

In order to solve such a problem, the present invention closes the gas vent groove guided from the cavity of the separation surface of the mold by the inertia force of the molten metal at the time of injection and also by the action of the solenoid based on the closing command. A mold degassing device having a valve is used, and a valve opening / closing control device is provided which controls an opening / closing of a valve by detecting an elastic wave generated when the molten metal collides with the wall of the degassing groove.

Further, an injection speed detecting means for detecting an injection speed, a speed setting device for setting a switching injection speed, and a valve for controlling an opening / closing of a valve by detecting an elastic wave generated when the molten metal collides with the wall of the gas vent groove. An opening / closing control device and a relay that serves as a gate to the solenoid of the valve opening / closing control device output signal are provided.The relay opens the valve opening / closing control device output signal when the detected injection speed is equal to or lower than the set switching injection speed to turn on the solenoid. It is controlled by the valve opening / closing control device and the output signal of the valve opening / closing control device is closed when the detected injection speed exceeds the set switching injection speed.

[Action]

In the die degassing apparatus according to the present invention, the state of the molten metal can be accurately grasped, and the valve body can be accurately controlled with respect to the movement of the molten metal.

〔Example〕

1 and 3 are a structural view and a sectional view showing an embodiment of a mold degassing device according to the present invention. In FIG. 1, 30 is a valve opening / closing control device, 31 is an elastic wave detection device,
RL is a solenoid 29 (third part of the output signal of the valve opening / closing control device 30).
(Fig.) Is a relay as a gate. In addition, FIG. 3 is obtained by adding a solenoid 29 to FIG. In FIG. 1, the same or corresponding parts as those in FIG. 4 are designated by the same reference numerals, and the operation related to the comparator 58 is the same as that of the conventional example. Therefore, the description thereof will be omitted and the operation related to the comparator 60 will be omitted. The operation performed will be described.

In the comparator 60, when the speed detected by the number of input pulses is smaller than the set speed value input from the speed setting device 61, the RL coil is energized to close its contact and open / close the valve. The control device 30 and the solenoid 29 are connected. As a result, the solenoid 29 is controlled by the valve opening / closing control device 30.

Next, the configuration and operation of the valve opening / closing control device 30 will be described.
FIG. 2 shows an embodiment of the valve opening / closing control device 30, in which 31 is an elastic wave detection device that outputs a signal of detection signal level S1, 32 is a preamplifier, 33 is a bandpass filter, and 34 is a main An amplifier, 35 is a reference elastic wave setting device that outputs a signal of the reference level S2, 36 is a comparator, and 37 is a valve closing mechanism.

The valve opening / closing control device of FIG. 2 detects the arrival of the molten metal 7 by the elastic wave detection device 31 by detecting the amplitude of the elastic wave generated when the molten metal 7 collides with the wall of the gas vent groove 10. To do. The data detected by the elastic wave detecting device 1 for detecting the arrival of the molten metal 7, that is, the amplitude S1 of the amplitude of the elastic wave generated when the molten metal 7 collides is preset by the reference elastic wave setting device 35. The data is compared with a certain reference value, that is, the minimum amplitude S2 of the elastic wave that can detect the arrival of the molten metal 7 which has been obtained through experience or testing in advance by the comparator 36, and the above-mentioned data.
When S1 is equal to or larger than the reference value S2, it is determined that the molten metal 7 has arrived and outputs a valve closing command signal to the solenoid 29. As a result, the valve body 24 is pulled up,
The valve closes. In this way, the valve can be closed by detecting the elastic wave generated in the gas vent groove 10.

When the speed of the injection plunger is slow, by opening and closing the output of the valve opening / closing control device 30 by the output of the comparator 60,
Only the valve opening / closing control device 30 may be operated,
Both the electrical operation by the valve opening / closing control device 30 and the inertial operation by the inertial force may be performed in parallel. That is, when the two are arranged in parallel, the valve is closed by either inertial force or elastic wave detection (which is unknown) regardless of the magnitude of the injection speed. In this case, it is not necessary to set the judgment reference speed in advance.

FIG. 6 is a system diagram showing another embodiment of the valve opening / closing control device constituting the mold degassing device according to the present invention. In the figure, the elastic wave generated by the collision of the molten metal is received by the elastic wave detecting device 31, the output signal of this detecting device 31 (signal of level Sa) is amplified by the preamplifier 32, and passed through the bandpass filter 33. After being amplified again by the main amplifier 34 to obtain a signal of level Sb, it is compared with the level Sc of the reference signal which is set in advance by the reference elastic wave setting device 35 and input to the pulse signal generator 41, and Sb ≧ Sc In this case, the pulse signal generator 41 generates a pulse signal. This pulse signal is counted by the pulse counter 42, and if the counted pulse number Sd is larger than the set pulse number Se from the reference pulse number setting device 43, a valve closing signal is output to the valve closing mechanism 44. Due to the output of the valve closing signal, the solenoid 29 operates and the valve body 24 moves up to close the valve.

FIG. 7 is a system diagram showing still another embodiment of the valve opening / closing control device constituting the mold degassing device according to the present invention.
The elastic wave generated when the molten metal collides is received by the elastic wave detection device 31, the output signal of this detection device 31 (signal of level Sa) is amplified by the preamplifier 32, passes through the bandpass filter 33, and is passed through the main amplifier 34. And re-amplify it to a signal of level Sb, and then set it in advance with the reference elastic wave setting device 35 to generate a pulse signal generator.
Compared with the level Sc of the reference signal input to 41, Sb ≥ Sc
In this case, the pulse signal generation circuit generates the pulse signal Sd. This pulse signal Sd is "H" for a predetermined time (first predetermined time) each time the detection signal level Sb exceeds the reference level Sc.
When the detected signal level exceeds the reference level within the above predetermined time, the signal is continuously at the "H" level. That is, the pulse signal generator 41 is a circuit that is retriggered by a signal of Sb ≧ Sc. The magnitude of the level Sc of the reference signal output from the reference elastic wave setting device 35 is the minimum magnitude of the elastic wave that can be detected when the molten metal 9 has reached, which is obtained by experience or testing in advance. It is the level shown.

The time comparison circuit 42a inputs the pulse signal of the signal Sda and the reference time signal Sea from the reference time setting device 43a, and outputs the signal Sda.
When the total generation time of the molten metal detection pulse and the time indicated by the reference time signal Sea are compared and the total generation time of the molten metal detection pulse signal of the signal Sda exceeds the reference time (second predetermined time) longer than the first predetermined time , A closing signal Sf is output to the solenoid 29 (FIG. 3) to close the valve closing mechanism 44.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a gas vent groove introduced from a cavity of a separation surface of a mold has a valve that is closed by the inertial force of the molten metal at the time of injection and is also closed by the action of a solenoid based on a closing command. Using a mold degassing device, a valve opening and closing control device that controls the opening and closing of the valve by detecting the elastic wave generated when the molten metal collides with the wall of the gas venting groove is provided. Instead, it has the effect of accurately closing the valve by either inertial force or elastic wave detection.

Further, an injection speed detecting means for detecting an injection speed, a speed setting device for setting a switching injection speed, and a valve for controlling an opening / closing of a valve by detecting an elastic wave generated when the molten metal collides with the wall of the gas vent groove. An opening / closing control device and a relay that serves as a gate to the solenoid of the valve opening / closing control device output signal are provided.The relay opens the valve opening / closing control device output signal when the detected injection speed is equal to or lower than the set switching injection speed to turn on the solenoid. Controlled by the valve opening / closing control device, the output signal of the valve opening / closing control device is closed when the detected injection speed exceeds the set switching injection speed, so that the valve opening / closing control is accurately performed by inertial operation when the injection speed is high. And the valve opening / closing control can be accurately performed by an electrical operation when the injection speed is slow.

[Brief description of drawings]

1 and 3 are configuration diagrams and cross-sectional views showing an embodiment of a mold degassing device according to the present invention, and FIG. 2 is an embodiment of a valve opening / closing control device constituting the device of FIG. The system diagram shown in FIG. 4, and FIG. 4 is a block diagram showing a conventional mold degassing device,
FIG. 5 is a sectional view showing a general degassing device, FIG. 6 is a system diagram showing another embodiment of the valve opening / closing control device constituting the device of FIG. 1, and FIG. 7 is the device of FIG. FIG. 6 is a system diagram showing still another embodiment of the valve opening / closing control device constituting the above. 1 ... Fixed mold, 2 ... Movable mold, 3 ... Dividing surface, 4 ...
… Cavity, 5 …… Injection sleeve, 6 …… Gate, 7
…… Molten metal, 8 …… Product extrusion equipment, 9 …… Gas venting passage, 10
…… Gas vent groove, 11 …… Spool hole, 13 …… Bracket, 14 …… Fluid pressure cylinder, 15 …… Piston rod, 15
a …… flange, 16 …… gas release device, 17 …… spool, 17a …… step, 18 …… holder, 19 …… presser, 20
...... Bolt, 21 ...... Valve guide, 30 ...... Valve opening and closing control device,
31 …… elastic wave detector, RL …… relay, 50 …… injection sleeve, 50a …… pouring spout, 51 …… injection cylinder, 52 …… piston rod, 53 …… coupling, 54 …… plunger, 55… … Plunger tip, 56 …… Magnetic scale, 57
...... Magnetic sensor, 58,60 …… Comparator, 59 …… Condition setting device, 61 …… Speed setting device.

Claims (2)

[Claims] 1. A degassing tool for a mold, which has a valve which is closed in a degassing groove introduced from a cavity of a separation surface of the mold by an inertial force of a molten metal at the time of injection and is also closed by an action of a solenoid based on a closing command. A mold degassing device comprising a device, and a valve opening / closing control device that controls an opening / closing of a valve by detecting an elastic wave generated when a molten metal collides with a wall of the degassing groove. 2. A degassing groove for a die, which has a valve which is closed in a degassing groove introduced from a cavity of a separation surface of the die by an inertial force of a molten metal at the time of injection and is also closed by an action of a solenoid based on a closing command. In the apparatus, an injection speed detecting means for detecting an injection speed, a speed setting device for setting a switching injection speed, and an elastic wave generated when the molten metal collides with the wall of the gas vent groove to control opening / closing of the valve. Valve opening / closing control device and a relay serving as a gate of the valve opening / closing control device output signal to the solenoid. The relay outputs the valve opening / closing control device when the detected injection speed is equal to or lower than a set switching injection speed. When the signal is opened and the solenoid is controlled by the valve opening / closing controller, the valve opening / closing controller output signal is output when the detected injection speed exceeds the set switching injection speed. Mold venting apparatus characterized by a.