WO2014167735A1

WO2014167735A1 - Degassing device

Info

Publication number: WO2014167735A1
Application number: PCT/JP2013/061126
Authority: WO
Inventors: 森川　巌
Original assignee: 株式会社ダイエンジニアリング
Priority date: 2013-04-12
Filing date: 2013-04-12
Publication date: 2014-10-16

Abstract

Provided is a degassing device in which a closure valve can be reliably closed even if an injection rate decreases right before molten-metal filling is completed. A molten metal (M) flows from a cavity (C) into an evacuation passage (1), a detection unit (2) disposed part of the way down said evacuation passage (1) detects when the leading edge of the molten metal (M) has reached said detection unit (2), and the closure valve (3) is closed on the basis of an output signal from the detection unit (2). The evacuation passage (1) is thus closed by the closure valve (3) before the leading edge of the molten metal (M) reaches the closure valve (3) via the evacuation passage (1), regardless of the rate at which the molten metal (M) is injected into the cavity (C). As such, the molten metal (M) does not reach an evacuation port (4) downstream of the closure valve (3).

Description

Gas venting device

The present invention relates to a gas venting device used for venting air or gas such as cavities out of a mold in die casting.

Conventionally, as this type of gas venting device, a pressure receiving pin and a closing valve are sequentially arranged in the exhaust passage communicating with the cavity of the mold from the cavity side to the discharge port side of the exhaust passage, and span the pressure receiving pin and the closing valve. The rotation lever is provided, and the operation of the pressure receiving pin pushed out by the flow pressure of the molten metal flowing into the exhaust passage is transmitted to the closing valve via the rotation lever with a delay, and the closing valve is pushed out of the pressure receiving pin. There is one that is pushed out from the exhaust passage to the extrusion side with a delay from the timing, and closes the closing valve (for example, see Patent Document 1).

JP 2000-094112 A

By the way, in recent years, in order to improve die life and reduce burrs and the like in die casting machines, the deceleration control of the injection speed immediately before the completion of the filling of the molten metal is progressing rapidly. In other words, by reducing the injection speed immediately before the completion of the molten metal filling, the mold (mold) life is improved and burrs are reduced.
However, in the conventional gas venting device, since the closing valve is closed by a mechanical valve that operates with the impact load of the molten metal, if the injection speed is reduced to 1 m / s or less immediately before the filling of the molten metal is completed, the impact load on the pressure receiving pin is sufficient. Did not occur. As a result, there is a problem that the closing valve cannot be closed because the rotating lever does not rotate, and the molten metal may enter the discharge port.
On the other hand, if the impact load on the pressure receiving pin is too large, the rotation lever is vigorously rotated by the pressure receiving pin, which may cause damage to the rotation lever.

An object of the present invention is to provide a gas venting device that can reliably close the closing valve even if the injection speed is reduced immediately before completion of filling the molten metal. It is intended.

In order to achieve such an object, the present invention is a degassing apparatus incorporated in a die casting machine, and is provided in the middle of the exhaust passage, which communicates with the cavity and exhausts the gas in the cavity. A detecting portion for detecting the tip of the molten metal flowing in from the cavity, a closing valve provided in the exhaust passage on the downstream side of the detecting portion in the flow direction of the gas and the molten metal, and the closing valve in the exhaust passage. An exhaust port provided on the downstream side of the gas flow direction, and the closing valve is closed before the molten metal tip of the molten metal reaches the closing valve based on a signal output from the detection unit. The exhaust passage is closed by moving.

In the present invention having the above-described features, the detection unit disposed in the middle of the exhaust passage detects that the molten metal has flowed into the exhaust passage from the cavity, and based on the output signal. By closing the closing valve, the exhaust passage is closed by the closing valve before the molten metal reaches the closing valve along the exhaust passage, regardless of the injection speed of the molten metal into the cavity. The molten metal does not enter the exhaust port on the downstream side of the valve.
Therefore, it is possible to provide a gas venting device that can reliably close the closing valve even if the injection speed is reduced immediately before the completion of the molten metal filling.
As a result, compared to the conventional valve that closes the closing valve with a mechanical valve that operates with the impact load of the molten metal, the closure valve can be reliably closed even without the impact load of the molten metal, and no complicated know-how is required. It is possible to reliably prevent the molten metal from entering the exhaust port on the downstream side of the closing valve.
Furthermore, since there is no impact load due to the molten metal, it is possible to prevent the parts from being damaged and to operate stably over a long period of time.

It is explanatory drawing which shows the whole structure of the degassing apparatus which concerns on embodiment of this invention, and is a vertical side view of the whole casting_mold | template. It is a front view of the state which expand | deployed the casting_mold | template, (a) is a casting_mold | template of a stationary side, (b) is a movable side. It is explanatory drawing which shows the outline | summary of a degassing apparatus, (a) is a partial expansion vertical side view of a closed valve open state, (b) is a partial expansion vertical side view of a closed valve closed state. It is an injection operation | movement figure of a molten metal. It is a front view in the state where a mold was developed in a degassing device concerning other examples of the present invention, and (a) is a fixed side mold and (b) is a movable side.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1 to 3, a gas venting apparatus A according to an embodiment of the present invention is incorporated into molds D1 and D2 of a die casting machine D and is formed on a split surface PL of the molds D1 and D2. Is used for extracting air or gas G from the molds D1 and D2.
More specifically, the degassing apparatus A according to the embodiment of the present invention includes an exhaust passage 1 provided so as to communicate with the cavity C of the molds D1 and D2, and a tip of the molten metal M provided in the middle of the exhaust passage 1. The detection unit 2, a closing valve 3 provided downstream of the detection unit 2 in the flow direction of the gas G and the molten metal M in the middle of the exhaust passage 1, and a downstream side of the gas G in the flow direction of the gas G from the closing valve 3 in the exhaust passage 1 And an exhaust port 4 provided as a main component.

The molds D1 and D2 are composed of a fixed mold and a movable mold, and are placed so that they can be opened and closed by facing each other.
The fixed mold D1 has an injection sleeve D3 in which a molten metal such as an aluminum alloy, a magnesium alloy, or a zinc alloy is poured as a molten metal M, and an injection piston D4 that moves along the injection sleeve D3. .
The molten metal M in the injection sleeve D3 is pressed and filled into the cavity C from the runner D5 by the operation of the injection piston D4, and the gas pressure in the cavity C increases accordingly. After filling the cavity C, the molten metal M is pushed out from the gate D6 and flows into the exhaust passage 1 of the gas venting apparatus A described later.

Next, the injection process of the molten metal M according to the moving distance and speed of the injection piston D4 will be described with reference to the injection operation diagram of the molten metal M shown in FIG.
First, as the injection piston D4 starts to move, the injection speed of the molten metal M gradually increases, and the air, gas G, and the like in the cavity C reach the low-speed injection region B1 that passes through the closing valve 3. Following this, the injection speed of the molten metal M further increases and reaches the high-speed injection region B2 in which the molten metal M is filled in the cavity C. Thereafter, when the molten metal M is filled into the cavity C just before completion, it reaches the deceleration region B3 where the injection speed is reduced. Thereafter, the injection speed of the molten metal M is further reduced, and the molten metal M reaches the final deceleration region B4 from the detection unit 2 toward the closing valve 3.
Moreover, in FIG.1 and FIG.2, the code | symbol D11 is an extrusion pin and D12 is a press board.

The degassing device A is composed of a fixed part A1 and a movable part A2. The fixed part A1 and the movable part A2 are opposed to the molds D1 and D2, and they are opened and closed as the molds D1 and D2 open and close. It is attached to be free.
As a specific example of the gas venting apparatus A, as shown in FIGS. 1 to 3, a fixed part A1 is attached to a fixed mold D1, and a movable part A2 is attached to a movable mold D2. An exhaust passage 1 to be described later is formed on the opposing surface of the fixed portion A1 and the movable portion A2 so as to communicate with the cavity C through the gate D6. As shown in FIGS. 2A and 2B, a pair of gates D6 is formed on the dividing surface PL of the movable mold D2 so as to continue to the left and right ends of the cavity C.

The exhaust passage 1 includes one or both of the split surface PL of the fixed mold D1 or the movable mold D2 and one or both of the fixed surface A1 or the movable surface A2 of the degassing device A. The gas vent groove is formed over the inside of the fixed portion A1 of the gas venting device A and allows air, gas G, and molten metal M in the cavity C to flow toward the closing valve 3 described later.
As a specific example of the exhaust passage 1, as shown in FIGS. 2 (a) and 2 (b), a pair of first passages formed along the dividing surface PL of the movable mold D2 so as to be continuous with the pair of gates D6. A first coupling portion 1b formed from the split surface PL of the movable mold D2 to the opposite surface of the movable portion A2 so as to be continuous with the end of the first branching portion 1a, the first coupling portion 1a; A pair of second branch portions 1c formed along the facing surface of the movable portion A2 so as to be continuous with the end of the portion 1b, and fixed from the facing surface of the movable portion A2 so as to be continuous with the end of the second branch portion 1c. And a second coupling portion 1d formed over the inside of the portion A1.
In the middle of the exhaust passage 1, a detection unit 2, a closing valve 3, and an exhaust port 4 which will be described later are sequentially arranged from the cavity C side to the outside.
Further, in the exhaust passage 1, between the position where the detector 2 is disposed and the position where the closing valve 3 is disposed, the flow speed of the molten metal tip of the molten metal M toward the closing valve 3 is reduced to a predetermined speed. It is preferable to form the flow resistance portion 11.
As the flow resistance unit 11, the length from the disposition position of the detection unit 2 to the disposition position of the closing valve 3 in the exhaust passage 1 is set to a predetermined value, and the cross-sectional area of the exhaust passage 1 and the area of the injection piston D4 are set. Is set to a predetermined ratio, the shape of the exhaust passage 1 from the position where the detection unit 2 is disposed to the position where the closing valve 3 is disposed, the position where the detection unit 2 is disposed and the position where the closing valve 3 is disposed For example, an additional groove is formed so that the tip of the molten metal M is delayed between positions, and the weight of the closing valve 3 is reduced. Or a combination of the above is preferable.

The detection unit 2 is a sensor for detecting the tip of the molten metal M flowing into the exhaust passage 1 from the cavity C, and controls the operation of a closing valve 3 described later based on a detection signal output from the detection unit 2. ing. As the detection unit 2, it is possible to use an electrical sensor or a sensor that detects physical quantities such as light, temperature, pressure, and sound and converts them into signals.
As a specific example of the detection unit 2, a terminal 2 a is arranged in the middle of the first branch 1 a of the exhaust passage 1 as shown in FIGS. 1 and 3 (a) and 3 (b). As shown in FIGS. 3 (a) and 3 (b), it is preferable that the molten metal M comes into contact with the terminal 2a to be in an energized state and outputs a detection signal to electrically control the closing valve 3. .
That is, as shown in FIG. 3A, at the start of filling of the molten metal M into the cavity C by the operation of the injection piston D4, the molten metal M does not come into contact with the terminal 2a of the detection unit 2, so that the energized state does not occur. No sensing signal is output to the closing valve 3 described later. Further, as shown in FIG. 3B, a detection signal for closing the closing valve 3 is output when the terminal of the molten metal M comes into contact with the terminal 2 a of the detection unit 2 and is energized. It is configured.

The closing valve 3 is an on-off valve for closing a part of the exhaust passage 1, and the valve body 3 a is disposed so as to be capable of reciprocating, and the valve body 3 a is closed based on a signal output from the detection unit 2. The valve body 3a is controlled to move (open) in the valve opening direction after the molds D1 and D2 are opened (moved in the direction).
As a specific example of the closing valve 3, as shown in FIGS. 2A and 2B, it is arranged in the middle of the second coupling portion 1 d of the exhaust passage 1. As shown in FIG. 3A, the valve body 3a of the closing valve 3 is stopped at the open position when the molten metal M is filled into the cavity C by the operation of the injection piston D4. However, as shown in FIG. 3B, the valve body 3 a of the closing valve 3 is closed before the molten metal tip of the molten metal M reaches the closing valve 3 based on the signal output from the detection unit 2. Accordingly, the passage of the molten metal M is stopped at the second coupling portion 1d of the exhaust passage 1.
Further, in the example shown in FIGS. 3A and 3B, a closing cylinder chamber 3b and an opening cylinder chamber 3c are separately formed around the valve body 3a of the closing valve 3, and the closing cylinder chamber 3b is formed separately. The valve body 3a is opened or closed by the internal pressure difference of the opening cylinder chamber 3c.

The exhaust port 4 is disposed at the downstream end of the exhaust passage 1 in the fixing part A1 of the gas venting apparatus A, and is configured to exhaust air or gas G that has communicated with the outside and passed through the closing valve 3 to the outside. Yes.
Specific examples of the exhaust port 4 are arranged at the end of the exhaust passage 1 and the end of the second coupling portion 1d as shown in FIGS. . A suction pipe 4 a is connected to the exhaust port 4, and a vacuum suction means 5 such as a vacuum pump is disposed. The gas G in the cavity C is discharged from the exhaust passage 1 using the vacuum by the vacuum suction means 5. It is preferable to forcibly exhaust. That is, it is preferable to incorporate the gas venting apparatus A into the vacuum die casting machine D.
The vacuum suction means 5 such as a vacuum pump is in electrical communication with the power source 6.

In the example shown in FIGS. 3 (a) and 3 (b), the power source 6 is used not only for the vacuum suction means 5, but also for the terminal 2a of the detector 2 and the electromagnetic valve 7 for closing the valve body 3a of the closing valve 3. It is electrically communicated and controlled for operation based on a control unit (not shown).
As shown in FIG. 3B, the closing electromagnetic valve 7 includes a valve body 7 a, a valve chamber 7 b in which the valve body 7 a is movably disposed, and a terminal of the detection unit 2 via the power supply 6. And a solenoid 7c electrically connected to 2a. The valve chamber 7b of the electromagnetic valve 7 communicates with the closing cylinder chamber 3b of the closing valve 3 through the through-hole 7d, and is connected to an air supply source (not shown) by connecting a closing air supply pipe 8. ing. The valve element 7a of the electromagnetic valve 7 for closing is operated by opening the valve element 7a when the terminal 2a of the detecting unit 2 and the hot metal tip of the molten metal M come into contact with each other and starting to energize the solenoid 7c from the power source 6. The closing air 8a is instantaneously supplied (spouted) from the supply source to the closing cylinder chamber 3b of the closing valve 3 through the closing supply pipe 8 and the through hole 7d, and the impact load and the closing cylinder chamber 3b are supplied. The valve body 3a of the closing valve 3 is closed by increasing the internal pressure.
Furthermore, an opening air supply pipe 9 is connected to the opening cylinder chamber 3c of the closing valve 3 so as to communicate with an opening electromagnetic valve (not shown) and an air supply source (not shown). The electromagnetic valve for opening is opened after the movable mold D2 is opened from the fixed mold D1 and the cast product is taken out, and the opening air 9a from the air supply source is opened. The valve body 3a of the closing valve 3 is opened by the impact load and the increase of the internal pressure of the opening cylinder chamber 3c.

In addition, the power source 6 is connected to the die casting machine D to energize the detection unit 2 and the vacuum suction means 5 from the power source 6 (DC 24V) before the tip of the molten metal M reaches the detection unit 2 from the cavity C. It is preferable to control the power supply 6 to stop the energization from the power source 6 to the detector 2 and the vacuum suction means 5 after starting the operation and closing the closing valve 3.
As a specific example, the explanation will be given with reference to the injection operation diagram of the molten metal M shown in FIG. 4. After the injection speed of the molten metal reaches the low-speed injection region B1 as the injection piston D4 starts to move, the detection unit 2 The energization of the vacuum suction means 5 is started approximately at the same time or later. Then, after the injection speed of the molten metal M has reached the high-speed injection region B2, the deceleration region B3, and the final deceleration region B4, the energization to the detection unit 2 and the vacuum suction means 5 is stopped.
That is, the terminal 2 a of the detection unit 2 is applied from the power source 6 before the tip of the molten metal M reaches from the cavity C, and the energization from the power source 6 is cut off after the closing valve 3 is closed.

According to the gas venting apparatus A according to the embodiment of the present invention, the molten metal M is filled into the cavity C by the operation of the injection piston D4, and after this filling, the molten metal M flows into the exhaust passage 1 from the cavity C. 1 detects that the molten metal tip of the molten metal M has arrived, and closes the closing valve 3 based on the output signal. Thereby, before the molten metal M reaches the closing valve 3 along the exhaust passage 1 regardless of the injection speed of the molten metal M into the cavity C due to the operation of the injection piston D4, the exhaust passage 1 Therefore, the molten metal M does not enter the exhaust port 4 on the downstream side of the closing valve 3.
Therefore, even if the injection speed is reduced immediately before the filling of the molten metal M is completed, the closing valve 3 can be reliably closed.
As a result, even if there is no impact load of the molten metal M, the closing valve 3 can be reliably closed, and complicated know-how is not required, and the molten metal M enters the exhaust port 4 on the downstream side of the closing valve 3. Can be reliably prevented.
Furthermore, since there is no impact load due to the molten metal M, it is possible to prevent the parts from being damaged and to operate stably over a long period of time.

In particular, when the vacuum suction means 5 is connected to the exhaust port 4 of the exhaust passage 1, it is ensured that the molten metal M enters the vacuum suction means 5 even if the injection speed is reduced immediately before the filling of the molten metal M is completed. Can be blocked.
As a result, failure of the vacuum suction means 5 due to the penetration of the molten metal M can be surely prevented, and high-performance vacuum die casting can be realized.

Further, when the terminal 2a is provided as the detection unit 2, and the tip of the molten metal M contacts the terminal 2a and is energized, when the closing valve 3 is electrically controlled, the closing valve 3 can be quickly operated with a simple structure. Can be closed.
As a result, the structure of the entire apparatus can be simplified and the manufacturing cost can be reduced.

In addition, the power supply 6 is provided to energize the terminal 2a of the detection unit 2, and the power supply 6 is detected from the power supply 6 before the molten metal M reaches the detection unit 2 from the cavity C in conjunction with the die casting machine D. When energization to the terminal 2a of the unit 2 is started and the shutoff valve 3 is closed and then controlled to cut off the energization from the power source 6 to the terminal 2a of the detection unit 2, the gas G from the cavity C is controlled. Even when a conductive material such as vaporized gas or moisture of a release agent different from the molten metal B contacts the terminal 2a of the detection unit 2 at the other timing, the closing valve 3 is energized. Does not close.
Therefore, malfunction of the closing valve 3 can be prevented.
As a result, high-performance vacuum die casting can be realized with certainty.

Next, each embodiment of the present invention will be described with reference to the drawings.
In the first embodiment, as shown in FIGS. 1 to 3, the terminals 2a of the pair of detectors 2 are arranged on both the fixed mold D1 and the movable mold D2 where the cavity C is formed. Yes.
In the example shown in FIGS. 3A and 3B, a current-carrying pin 2b made of a conductive material such as a metal is used as the detection unit 2, and the current-carrying pin 2b is attached to the fixed-side mold D1 and the movable-side mold D2. The terminals 2 a formed at the respective tips are attached so as to face each other with a gap S having a predetermined dimension (about 1 mm) in the exhaust passage 1. An insulating material 2c is installed between the energization pin 2b, the fixed mold D1 and the movable mold D2.
A terminal 2a is applied to the end of the pin 2b through a power source 6 by connecting a conducting wire 6a in electrical communication with a solenoid 7c of an electromagnetic valve 7 for closing the valve body 3a of the closing valve 3. ing.

According to the gas venting apparatus A according to the first embodiment of the present invention, the molten metal M flows into the exhaust passage 1 from the cavity C, and as shown in FIG. The tip of the molten metal M flows into the gap S formed between the two terminals 2a, the terminals 2a are energized with the tip of the molten metal M interposed therebetween, and the solenoid 7c of the solenoid valve 7 is energized.
As a result, the valve body 7a of the electromagnetic valve 7 is opened, and the closing air 8a is instantaneously supplied (spouted) from the air supply source toward the closing cylinder chamber 3b of the closing valve 3, so that the internal pressure of the closing cylinder chamber 3b is increased. The valve body 3a of the closing valve 3 is closed at a stretch.
As a result, the exhaust passage 1 is closed and the molten metal M from the cavity C cannot pass toward the exhaust port 4.

Further, in the example shown in FIGS. 1 to 3, in the exhaust passage 1, the molten metal M traveling from the detection unit 2 to the closure valve 3 is located between the installation position of the detection unit 2 and the installation position of the closure valve 3. As the flow rate resistance unit 11 for reducing the flow rate of the hot water to a predetermined speed, the length from the position where the detection unit 2 is disposed in the exhaust passage 1 to the position where the closing valve 3 is disposed is set to 15 cm or more. Is set to 0.007 to 0.014 times the area of the injection piston D4.
As a specific example, the flow rate of the molten metal tip of the molten metal M from the detection unit 2 toward the closing valve 3 was measured by an experiment.
The length from the arrangement position of the detection unit 2 in the first branch portion 1a of the exhaust passage 1 to the arrangement position of the closing valve 3 in the second coupling portion 1d of the exhaust passage 1 is set to 17 cm, and the cross-sectional area of the exhaust passage 1 is set. Is set to 0.38 cm ² and the outer diameter of the injection piston D4 is 60 mm, the area is 28.3 cm ² , and the cross-sectional area of the exhaust passage 1 is set to about 0.014 times the area of the injection piston D4. The
In addition, the shape from the position where the detector 2 is disposed to the position where the closing valve 3 is disposed in the exhaust passage 1 is formed by combining a plurality of branch channels 11a and a plurality of coupled channels 11b. 2 is formed between the disposition position of 2 and the disposition position of the closing valve 3, a recess groove 11 c for delaying the molten metal tip is formed, the inside of the closing valve 3 is hollowed to reduce the weight, the closing valve 3 and the electromagnetic Making the arrangement | positioning position of the valve 7 close was performed.
According to these settings, in the injection operation diagram of the molten metal M shown in FIG. 4, the injection speed of the molten metal M is 0.25 m / s in the low-speed injection region B1, 2.0 m / s in the high-speed injection region B2, and the cavity C When the speed is reduced to 1.0 m / s in the deceleration area B3 where the injection speed is reduced immediately before the filling of the molten metal M to the molten metal M, the molten metal M flowing from the detection unit 2 to the closing valve 3 in the subsequent final deceleration area B4. It was found that the previous flow velocity was reduced to 0.2 to 0.3 m / s. The time from when the solenoid valve 7 was energized to when the closing valve 3 was closed was 0.006 seconds.

According to the gas venting apparatus A of the illustrated example, the molten metal M passes through the flow resistance unit 11 before reaching the closing valve 3 along the exhaust passage 1, so that the molten metal M passes through the flow resistance unit 11. The flow rate of the hot water tip is reduced, and the closing valve 3 can be closed with a time margin.
Accordingly, it is possible to reliably prevent the molten metal M from entering the downstream exhaust port 4 beyond the closing valve 3.
As a result, there is an advantage that high-performance vacuum die casting can be reliably realized by reliable degassing.

In the second embodiment, as shown in FIGS. 5A and 5B, the terminal 2a ′ of the detection unit 2 is connected to either the fixed mold D1 or the movable mold D2 in which the cavity C is formed. The arrangement is different from that of the first embodiment shown in FIGS. 1 to 4, and other configurations are the same as those of the first embodiment.
In particular, it is preferable to arrange the terminal 2a 'of the detection unit 2 on the fixed mold D1.
In the example shown in FIGS. 5A and 5B, a pair of terminals 2 a ′ of the detection unit 2 are arranged along the respective exhaust passages 1 so as to face the exhaust passage 1 on the dividing surface PL of the fixed mold D 1. The gas G and the molten metal M are arranged so as to line up in a direction intersecting the flow direction.
Although not shown as another example, a pair of terminals 2a of the detection unit 2 are arranged on the dividing surface PL of the fixed mold D1 so as to face the exhaust passage 1, and along each exhaust passage 1, the gas G and It arrange | positions so that it may be located in a line with the flow direction of the molten metal M, or it has crossed the flow direction of the gas G and the molten metal M respectively with a pair of terminal 2a of the detection part 2 along the exhaust path 1 to the dividing surface PL of the movable mold D2. It is also possible to arrange them so as to line up in the direction or arrange them so as to line up in the flow direction of the gas G and the molten metal M.

According to the gas venting apparatus A according to the second embodiment of the present invention, the opening / closing movement of the movable mold D2 with respect to the fixed mold D1 is less likely to affect the terminal 2a 'of the detection unit 2, and troubles such as disconnection are caused. Decrease. In particular, when the terminal 2a ′ of the detection unit 2 is arranged in the fixed mold D1, the opening and closing movement of the movable mold D2 does not affect the terminal 2a ′ of the detection unit 2 at all, and troubles such as disconnection are greatly increased. To decrease.
Therefore, it is possible to simplify the arrangement structure of the detection unit 2 and prevent the occurrence of a failure.
As a result, there are advantages over the first embodiment shown in FIGS. 1 to 4 that it can be used for a long period of time, and maintenance is easy and economical.

In the previous embodiment, the operation of the electromagnetic valve 7 supplies the closing air 8a to the closing valve 3 to close the valve body 3a of the closing valve 3. However, the present invention is not limited to this. Instead, a driving source of the closing valve 3 may be provided and directly opened and closed.
Further, although an electrical sensor is used as the detection unit 2, the present invention is not limited to this, and a sensor that detects a physical quantity such as light, temperature, pressure, and sound and converts it into a signal is used instead of the electrical sensor. May be.

A Degassing device 1 Exhaust passage 2

Detection unit

2a, 2a 'Terminal 3 Closing valve 4 Exhaust port 5 Vacuum suction means 6 Power source 11 Flow resistance unit C Cavity D Die-casting machine D1 Fixed mold D2 Movable mold G Gas M Molten metal

Claims

A gas venting device incorporated in a die casting machine,
An exhaust passage communicating with the cavity and exhausting the gas in the cavity;
A detection unit that is provided in the middle of the exhaust passage and detects a molten metal tip flowing from the cavity;
A closing valve provided on the downstream side in the flow direction of the gas and the molten metal from the detection unit in the exhaust passage;
An exhaust port provided downstream of the closing valve in the exhaust passage in the gas flow direction,
The degassing device, wherein the closing valve is closed before the molten metal tip of the molten metal reaches the closing valve based on a signal output from the detection unit to close the exhaust passage.
The degassing device according to claim 1, wherein a vacuum suction means is connected to the exhaust port of the exhaust passage.
The degassing device according to claim 1 or 2, wherein a terminal is provided as the detection unit, and the closing valve is electrically controlled by contacting the terminal with the tip of the molten metal and energizing the terminal. .
A power supply for energizing the terminal of the detection unit;
The power source is interlocked with the die casting machine to start energization from the power source to the terminal of the detection unit before the molten metal tip of the molten metal reaches the detection unit from the cavity, and the closing valve The degassing device according to claim 3, wherein the degassing device is controlled so as to cut off the energization from the power source to the terminal of the detection unit after closing.
In the exhaust passage, a flow resistance unit is formed between the position of the detection unit and the position of the closure valve so that the flow rate of the molten metal flow toward the closure valve is reduced. The degassing apparatus according to claim 1, 2, 3 or 4.
The gas venting device according to claim 3, 4 or 5, wherein the terminal of the detection unit is arranged in either one of a fixed mold and a movable mold on which the cavity is formed.