KR20060047239A - Diecasting device and reduced-pressure casting method - Google Patents

Abstract

It is an object of the present invention to provide a diecasting apparatus by an oxygen substitution diecatting method capable of producing a high quality diecast product.

After the oxygen gas supply device 80 is filled with oxygen gas in the cavity C and the injection sleeve 16, and further purged in the cavity C and the injection sleeve 16 with oxygen gas, the cavity A part where the outside air may invade into (C), for example, the auxiliary die pressure reduction tank TB and the 3rd opening / closing valve SV which perform decompression exhaust from the fixed mold flow path 2c, the moving mold flow path 3c, The main pressure reduction tank TA and the 1st opening / closing valve MV which depressurize the inside of the cavity C are operated simultaneously and in parallel.

Oxygen gas supply, injection sleeve, cavity, diecast device, stationary mold

Description

Die casting apparatus and reduced pressure casting method {DIECASTING DEVICE AND REDUCED-PRESSURE CASTING METHOD}

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the structure of the die-casting apparatus concerning embodiment of this invention.

FIG. 2 is a partially enlarged view centering on the stationary mold and the moving mold among the die cast apparatus illustrated in FIG. 1, and illustrates the operation of the die cast apparatus from the time point t0 to the time point t3. FIG.

FIG. 3 is a process diagram (flow diagram) showing in time series the operation of the diecast apparatus illustrated in FIG. 1; FIG.

4 to 12 illustrate the operating states of main parts of the die-casting apparatus in each step illustrated in FIG.

<Explanation of symbols for the main parts of the drawings>

1: diecast device

2: fixed mold

2a: internal fixed mold

2b: external fixed mold

2c: fixed mold flow path

2d: cavity surface

2e: valve moving space surface

2f: split plane

3: moving mold

3a: internal fixed mold

3b: external moving mold

3c: moving mold flow path

3f: split plane

Sp: Valve moving space

C: Cavity

10: injection device

11: decompression cylinder

12: piston rod

13: coupling

14: plunger rod

15: plunger chip

15h: home

16: injection sleeve

16h: supply port

17: injection plunger

30: controller

50A, 50B: Vacuum Pump

51: exhaust pipe

52: exhaust passage

60: shut off valve

61: electronic actuator

62: valve member

63: valve shaft

64: valve seat member

64a: first through hole

64b: second through hole

64f: valve seat surface

65: extrusion pin

80: oxygen gas supply device

90, 91: exhaust pipe

TA, TB: 1st, 2nd pressure reduction tank

MV, GV, SV: first to third open / close valves

OV1, OV2: 1st, 2nd open valve

[Reference 1] US Patent No. 2785448

[Document 2] Japanese Unexamined Patent Application Publication No. 10-113757

[Document 3] Japanese Unexamined Patent Application Publication No. 9-1306

The present invention relates to a die casting apparatus (diecast machine) and a pressure reduction casting method for a die casting apparatus.

In particular, the present invention relates to a die casting apparatus to which the oxygen substitution die casting method is applied, and a pressure reduction casting method in the die casting apparatus.

As one of the causes of the deterioration of reliability due to the quality variation of the die cast product, for example, the aluminum die cast product, there is a gas or the like contained in the die cast product. That is, metal molten metal (molten metal) injected (molded) into the injection sleeve under high speed and high pressure conditions, for example, aluminum molten metal becomes turbulent in the cavity of the injection sleeve and the mold, and winds gas such as air or water vapor. Filled in the cavity of the mold, such gas bubbles to cause the cause in the die-cast product to reduce the quality of the die-cast product.

In order to overcome the above problems, casting of a gas into the die-cast product in the cavity is produced by casting using a die-casting machine by a vacuum die-casting method which reduces the inside of the cavity of the mold sealed to the outside air to a state of charge. The technique which suppresses and reduces the fluctuation | variation of the quality of a diecast product by containing gas in a diecast product is known (for example, refer patent document 1).

In the die-casting machine using such a vacuum die-casting method, it is necessary to reduce the pressure in the cavity of a metal mold to a lower pressure in a short time. The reason is described below.

Although the pressure reduction in a cavity is performed by connecting the pressure reduction tank which pressure-reduced to the low pressure beforehand with the sealed cavity, while pressure reduction rapidly in the range where the pressure difference in a pressure reduction tank and a cavity is large, it exhausts from a cavity as the said pressure difference becomes small. Since the flow rate of the gas to be lowered takes a considerable time to reach the desired pressure. In the die-casting machine, it is necessary to depressurize the inside of the cavity while the molten metal (metal melt) is supplied to the sleeve. Therefore, when the time required for decompression becomes long, the molten metal supplied to the sleeve is filled in the sleeve before filling the cavity. It may be cooled and hardened at.

Further, Even though the inside of the mold cavity in the vacuum die casting method, for example, from atmospheric pressure of 1.01325 × 10 ⁵ Pa, for example, can be reduced to a very low pressure of about 5.33289 × 10 ³ Pa, is in the cavity some Gases such as air and water vapor exist. Even if a die-cast product containing such an existing gas does not generate a defect in the die-cast product during heat treatment such as T6 treatment, a small bubble is formed under high temperature conditions at the time of welding, causing a defect of the weld part in the die-cast product. Becomes

In order to prevent the die cast product defects caused by the existing gas in the cavity, the gas in the mold cavity is replaced with oxygen gas, and the molten metal reacts with oxygen gas (oxidizes) to generate bubbles in the cast die cast product. The so-called oxygen substitution diecast method is known (for example, refer patent document 2 and patent document 3).

For example, when the molten metal is aluminum, when aluminum reacts with oxygen gas, fine particles of aluminum dioxide (alumina) (Al ₂ O ₃ ) are produced.

[Patent Document 1] US Patent No. 2785448

[Patent Document 2] Japanese Patent Application Laid-Open No. 10-113757

[Patent Document 3] Japanese Patent Application Laid-Open No. 9-1306

In the oxygen-substituted diecast method, when the amount of the substituted oxygen gas is large, there is a problem that a large amount of oxides of molten metal are generated in the diecast product, thereby degrading the quality of the diecast product. For example, in aluminum and die-cast products containing a large amount of aluminum dioxide (Al ₂ O ₃ ), the characteristics or quality of die-cast products such as malleability are deteriorated. In addition, when the amount of the substituted oxygen gas is large, oxygen gas which does not react with the molten metal remains to generate bubbles by oxygen in the die cast product.

On the other hand, even if the pressure is reduced in a sealed state such as a mold, it is difficult to completely remove the cavity inside the mold and / or the outside air (outside air) of the sleeve that enters and enters from the sealing portion. It is not easy to substitute completely with oxygen gas. The presence of gases other than oxygen gas in the cavity also generates bubbles in the diecast product.

An object of the present invention is that gas such as moisture or oxygen gas, which causes internal defects in a cast product, does not exist in the cavity of the mold and the gas penetration path into the cavity, and the inside of the gas penetration path into the cavity and the cavity is converted into oxygen gas. It can replace reliably and can shorten the time required to reduce pressure in a cavity to predetermined pressure. The present invention provides a diecasting apparatus (diecasting machine) and a vacuum casting method.

According to a first aspect of the present invention, there is provided a die-casting apparatus for filling a cavity with a molten metal to produce a die-cast product, comprising: (a) a first mold and a second mold defining a cavity filled with the molten metal; A) first pressure reducing means, (c) oxygen gas supply means, and (e) mounted on the first mold and / or the second mold, and communicating with the first pressure reducing means or the oxygen gas supply means and the cavity. Injection with a 1st open / close valve means made into a state where it is possible or non-connected, and (f) the supply port which communicates with the said cavity, and injects the said molten metal on the side opposite to the side which communicates with the said cavity. (G) injection plunger means having a plunger chip inserted into the inner cylinder of the injection sleeve so as to be movable, and injecting the molten metal melted in the injection sleeve from the supply port toward the cavity; (h) an injection cylinder means for driving the injection plunger means, and (i) a gap (clearance) in the first mold in which outside air may enter from the outside of the cavity and / or the injection sleeve, And a second decompression means for reducing pressure from at least one of a gap in the second mold, a gap between the injection sleeve and the plunger chip, and a gap between the second mold and the first opening / closing valve means. A diecast apparatus is provided.

The following operation is performed in the diecast apparatus having the above-described configuration.

(1) a period from when the pouring of the molten metal is started from the supply port into the injection sleeve, until the pouring is completed and the first injection of the molten metal into the carrier by the injection plunger at a first speed is performed; The first open / close valve means is opened to communicate the oxygen gas supply means with the cavity, and the second open / close valve means is opened to release oxygen gas from the oxygen gas supply device into the cavity and the injection sleeve. It supplies and discharges from the said supply port, and fills the said cavity and the said injection sleeve with oxygen gas, and also exhausts gas other than oxygen gas.

(2) After the filling of the oxygen gas into the cavity and into the injection sleeve, the second opening / closing valve means is closed to complete the filling of the oxygen gas.

(3) After the second opening / closing valve means is closed, the first opening / closing valve means is opened until a second injection of the molten metal into the cavity by the injection plunger is started at a second speed. The inside of the cavity and the inside of the injection sleeve are depressurized by the first decompression means through the first opening / closing valve means.

(4) After the second opening / closing valve means is closed, the period until the die-cast product is taken out of the cavity, the third opening / closing valve means is opened, and the at least Depressurize one gap.

Preferably, the diecast apparatus has suppression means.

The suppressing means performs the following control operation.

(1) After the pouring of the molten metal from the supply port into the injection sleeve by the movement of the plunger means, the second on-off valve means and the first on-off valve means are operated to operate the oxygen gas supply means and the cavity. Is filled with oxygen gas in the cavity and the injection sleeve, and oxygen gas is discharged from the supply port to exhaust gas other than oxygen in the cavity and the injection sleeve.

(2) After the pouring of the molten metal is finished, the injection cylinder means is driven to move the injection plunger means at a first speed, and the injection of the molten metal poured in the injection sleeve into the cavity is started.

(3) The said 2nd opening-closing valve means is made into the closed state, and the process of filling oxygen gas in the said cavity from the said oxygen gas supply apparatus and into the said injection sleeve is stopped.

(4) After the closing operation of the second on-off valve means, the first on-off valve means is opened in an open state until injection of the molten metal into the cavity by the injection plunger means at a second speed is started. The inside of the cavity and the inside of the injection sleeve are depressurized by the first decompression means through the first opening / closing valve means.

(5) After the closing operation of the second on-off valve means, the third on-off valve means is opened until the die-cast product is ejected, and the portion where the outside air may invade from the outside by the second decompression means. Depressurize.

More preferably, the diecast apparatus has a position sensor for detecting the position of the injection plunger, and the control means obtains the moving speed of the injection plunger by time-differentiating the position detection value by the position sensor, and the injection plunger means. It is determined to eject at the first speed and the second speed.

According to a second aspect of the present invention, there is provided a pressure reduction casting method for a die casting apparatus for producing a die cast product by the oxygen substitution die casting method, (a) after pouring of a molten metal from the supply port into the injection sleeve, Oxygen gas is filled in the cavity and the injection sleeve and discharged from the supply port until the pouring is completed and the injection plunger is moved at the first speed to inject the metal melt into the cavity defined in the mold. And an oxygen purge step of filling the inside of the injection sleeve with oxygen gas and evacuating gas other than oxygen gas. (B) After the completion of the filling of the oxygen gas, the injection plunger is moved at a second speed so that the molten metal is removed. To depressurize in the cavity and in the injection sleeve until injection into the cavity is started 1 depressurizing step and (c) depressurizing the part which may invade outside air from the outside of the said cavity and / or the said sleeve in the said die-casting apparatus after the completion | finish of the said oxygen gas is filled out before a die-cast product is taken out. A reduced pressure casting method for a die cast apparatus having a second reduced pressure process is provided.

<Configuration of Diecast Devices>

The structure of the diecast apparatus of 1st Embodiment of this invention is demonstrated.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the structure around the metal mold | die of the die-casting apparatus which concerns on one Embodiment of this invention.

The die-casting apparatus 1 of this embodiment includes the fixed mold 2, the moving mold 3 moving with respect to the fixed mold 2, the injection apparatus 10, the controller 30, the main pressure reduction tank TA, An auxiliary pressure reduction tank TB, a shut off valve (return valve) 60, and the oxygen gas supply device 80 are provided.

The controller 30 is a part which performs various control of the die-casting apparatus 1 described in detail below, and is implement | achieved using arithmetic processing means, for example, a computer.

The injection device 10 has a hydraulic cylinder 11, a piston rod 12, a coupling 13, an injection plunger 17, and an injection sleeve 16.

The hydraulic cylinder 11 is driven by oil (working oil) of a predetermined pressure, and moves the piston rod 12 from side to side in the state shown in FIG.

The injection plunger 17 has a plunger rod 14 and a plunger chip 15.

The coupling 13 connects the piston rod 12 and the plunger rod 14 connected to the hydraulic cylinder 11.

The injection sleeve 16 is formed of a cylindrical heat resistant and pressure resistant member, and the injection sleeve 16 is a supply port for pouring metal molten metal (molten metal) into the inner cylinder of the injection sleeve 16 to which the plunger chip 15 is moved. 16h is provided. The opposite side to the supply port 16h of the injection sleeve 16 is fixed to the stationary die 2 and communicates with the cavity C defined by the stationary die 2 and the moving die 3.

The plunger chip 15 is connected to the distal end of the plunger rod 14, and the plunger chip 15 is inserted into the inner cylinder of the injection sleeve 16 so as to be movable.

Between the outer circumferential surface of the plunger chip 15 and the inner circumferential surface of the injection sleeve 16 are hermetically sealed to the outside air. As the plunger chip 15 moves forward from the supply port 16h to the cavity C side, the injection sleeve 16 is closed to the outside.

FIG. 2 is an enlarged view of the stationary die 2, the moving die 3, and such a peripheral portion of the die-casting apparatus 1 illustrated in FIG.

The stationary die 2 and the movable die 3 illustrated in Figs. 1 and 2 are in a mold clamping state. The stationary die 2 is fixed to a stationary die plate of, for example, a mold fastening machine (not shown), and the movable die 3 is attached to a stationary die plate of a die fastening device, not shown. It is fixed. For example, by the toggle mechanism or the like, the moving die plate is pressed against the fixed die plate by a predetermined force, whereby the fixed die 2 and the moving die 3 are mold-fastened.

When the stationary mold 2 and the moving mold 3 are combined, a cavity C for filling a molten metal to produce a die cast product is defined.

The fixed mold 2 is combined with an internal movable mold 3a of the movable mold 3 to define a cavity C and an external fixed mold surrounding the internal fixed mold 2a. It has 2b), and the fixed mold flow path 2c is prescribed | regulated in the clearance gap (clearance) of the corner of the joint surface corner between the internal fixed mold 2a and the external fixed mold 2b. The stationary die 2 has an annular split surface 2f having a cross section in contact with the moving die 3 along its outer circumference. Further, the cavity surface 2d defining the cavity C on the side facing the surface in contact with the outer circumferential fixing mold 2b of the inner circumferential fixing mold 2a and the valve member 62 of the shut-off valve 60. It has a valve movement space surface 2c which defines the valve movement space Sp which permits movement.

When the stationary die 2 is viewed from the direction A, the cross section is almost circular, for example, and the stationary die flow passage 2c is illustrated by a broken line, so that the internal stationary die 2a and the external stationary die ( The corner part of 2b) is annular.

An injection sleeve 16 communicating with the cavity C is fixed to the stationary mold 2. Between the stationary mold 2 and the injection sleeve 16 is sealed against this outside.

The moving mold 3 is combined with the internal fixing mold 2a of the fixed mold 2 to define the cavity C, and the external moving mold 3a surrounding the internal moving mold 2a, 3b), the moving mold flow path 3c is prescribed | regulated in the clearance gap of the joint surface corner between the internal moving mold 2a and the external moving mold 3b. The moving die 3 is in contact with the stationary die 2 along its outer circumference, and has an annular split surface 3f having a cross section facing the cavity surface 2d of the stationary die 2.

When the moving mold 3 is viewed from the direction A, the cross section is, for example, almost circular, and the moving mold flow path 3c is illustrated with a broken line, so that the internal moving mold 3a and the external moving mold ( It is located in the corner with 3b) and is annular.

A cavity C is formed (prescribed) for casting a cast between the cavity surface 2d of the internal fixed mold 2a of the fixed mold 2 and the divided surface 3f of the moving mold 3.

Between the outer circumferential annular dividing surface 2f of the fixed mold 2 and the outer circumferential annular portion of the dividing surface 3f of the moving mold 3 facing the dividing surface 2f, that is, the outer fixed mold 2b ) And the sealing member SL which seals between the divided surface 21 and the divided surface 3f in an airtight state so that outside air does not penetrate into the cavity C between the divided surface 21 and the divided surface 3f. ) Is installed.

The sealing member SL is an annular O-ring as seen from the direction A formed of silicone rubber, for example.

The shut-off valve 60 is provided in the moving mold 3.

The shut-off valve 60 is an electronic actuator 61 whose operation is controlled by the control signal 30SC from the controller 30 and the valve moving space surface 2c of the internal fixing mold 2a of the fixing mold 2. ), A valve member 62, a valve shaft 63, and a valve seat member 64.

The valve seat member 64 has a cylindrical member having a first through hole 64a through which the valve shaft 63 is inserted and a second through hole 64b for allowing the valve shaft 63 to move loosely. And embedded in the internal moving mold 3a and the external moving mold 3b of the moving mold 3. Between the valve seat member 64 and the outer movable mold 3b of the movable mold 3, a second sealing member SL2, for example, an O-ring made of silicone rubber is provided in a direction orthogonal to the axial direction.

The valve seat member 64 is disposed at a position where the valve seat surface 64f coincides with the divided surface 3f of the moving valve mold 3.

In the moving mold 3 and the valve seat member 64, an exhaust passage 52 communicating with the second through hole 64b of the valve seat member 64 is formed. The exhaust pipe 51 is connected to the exhaust path 52, and the exhaust pipe 51 is provided with a first open / close valve MV in which the main pressure reduction tank TA is controlled according to the control signal 30SA from the controller 30. Connected via

The valve shaft 63 is inserted into the first through hole 64a of the valve seat member 64 and is driven by the electronic actuator 61 which operates according to the control signal 30SC from the controller 30. It is moved in the perpendicular movement direction L shown in FIG.

Between the valve moving space surface 2e of the internal fixing mold 2a of the fixed mold 2 and the divided surface 3f of the external moving mold 3b of the moving mold 3, a tip portion of the valve shaft 63 is provided. The valve movement space Sp in which the installed valve member 62 can move is formed.

The valve movement space Sp communicates with the cavity C. As shown in FIG. The cavity C passes through the valve moving space Sp and the second through hole 64b of the valve seat member 64 and the exhaust passage 52 when the valve member 62 is separated from the valve seat member 64. It communicates with the exhaust pipe 51.

The valve member 62 provided at the tip end of the valve shaft 63 is moved from the valve movement space surface 2e of the internal fixing die 2a to the valve seat member 64 side in the valve movement space Sp, whereby the valve seat The second through hole 64b is closed by contacting the valve seat surface 64f of the member 64. As a result, the exhaust path connecting the cavity C, the exhaust path 52 and the exhaust pipe 51 is closed. On the contrary, the valve member 62 which is in contact with the valve seat surface 64f of the valve seat member 64 is moved to the valve movement space surface 2e side of the internal fixing mold 2a of the fixing mold 2, The exhaust path connecting the cavity C and the exhaust pipe 51 is opened.

The electromagnetic actuator 61 which performs the movement (opening / closing operation) of the valve member 62 mentioned above is driven by receiving the control command 30SC from the controller 30.

A plurality of extrusion pins 65 are provided so as to be movable with respect to the moving mold 3 through the internal moving mold 3a and the external moving mold 3b.

In the final step of the operation of the die cast apparatus 1, the die cast product cast in the cavity C can be taken out by extruding the extrusion pin 65 toward the cavity C. FIG. The extrusion pin 65 is inserted into a through hole formed by the moving mold 3, and the extrusion pin 65 and the moving mold 3 are hermetically sealed so that outside air does not invade the cavity C from the outside. It is sealed.

As shown in Figs. 1 and 2, in order to detect the moving position and the moving speed of the plunger rod 14, in other words, to detect the moving position and the moving speed of the plunger chip 15, the position detection sensor 35 ) Is provided. Therefore, the magnetic pole is formed in the outer periphery of the plunger rod 14 by a fixed pitch along the axial direction, for example. The position detection sensor 35 detects a change in the magnetic pole of the moving plunger rod 14, for example, converts the change of the magnetic pole into a pulse signal, and outputs it. The position detection sensor 35 outputs a detection signal 35s to the controller 30.

Based on the detection signal 35 of the position detection sensor 35, the controller 30 changes the position and positional time change of the injection plunger 17 (or the plunger chip 15 in the injection sleeve 16). Time derivative) is calculated.

From the reading of the position detection sensor 35, the controller 30 identifies the first speed described below, for example, the injection position at low speed, the second speed, for example the injection position at high speed, or the low speed injection start timing. High speed injection timing can be identified.

The main pressure reduction tank TA is connected to the exhaust pipe 51 via the first opening / closing valve MV. The main pressure reduction tank TA is formed between the moving mold 3 and the fixed mold 2 through the exhaust pipe 51, the exhaust passage 52, the second through hole 64b, and the valve movement space Sp. The inside of the closed space including the cavity C is evacuated under reduced pressure.

The first opening / closing valve MV is opened and closed by the control command 30SA from the controller 30.

A vacuum pump 50A is connected to the main pressure reduction tank TA, and the inside of the main pressure reduction tank TA is decompressed to a predetermined pressure by the vacuum pump 50A. For example, when the vacuum pump 50A is started by the controller 30, the vacuum pump 50A is automatically turned on and off, for example, so that a predetermined vacuum state is maintained in the main pressure reduction tank TA. . The main pressure reduction tank TA is pressure-reduced to predetermined pressure (almost vacuum state) by the vacuum pump 50A before operation | movement of the die-casting apparatus 1 mentioned below.

The oxygen gas supply device 80 is connected to the connection path 53 between the exhaust pipe 51 and the main pressure reduction tank TA through the second opening / closing valve GV.

The second open / close valve GV is opened and closed by the control command 30SD from the controller 30. When the second opening / closing valve GV is opened while the first opening / closing valve MV is closed, oxygen gas O ₂ flows from the oxygen gas supply device 80 to the exhaust pipe 51, the exhaust passage 52, and the second penetration. It is supplied into the cavity C through the hole 64b and the valve movement space Sp.

Spaces in the valve movement space Sp, the cavity C, and the injection sleeve 16 communicate with each other, and these constitute a closed space.

The bonding surface between the divided surface 2f of the external fixed mold 2b of the fixed mold 2 and the divided surface 3f of the external movable mold 3b of the movable mold 3 is formed by the sealing member SL. Sealed against the outside air, the plunger chip 15 moves the inside of the injection sleeve 16 beyond the supply port 16h to the left to close the supply port 16h of the sleeve 16, and also the shut off valve ( In the closed state 60, the closed space composed of the valve movement space Sp, the cavity C, and the inside of the injection sleeve 16 is sealed from the outside.

However, between the divided surfaces 2f and 3f, between the valve moving member 64 and the moving mold 3, between the extrusion pin 65 and the moving mold 3, between the plunger chip 15 and the sleeve 16, and the like. Is completely difficult to seal against the outside air, and the outside air passing through the seal enters a closed space composed of the valve moving space Sp, the cavity C, and the inside of the injection sleeve 16, and within this closed space. There is a possibility of hindering the high vacuum.

In addition, in the fixed mold 2, the clearance (clearance) between the internal fixed mold 2a and the external fixed mold 2b, and the internal movable mold 3a and the external movable mold 3b in the movable mold 3, There is a possibility that outside air invades between the gap between the divided surfaces 2f and 3f, between the valve seat member 64 and the moving mold 3, and between the extrusion pin 65 and the moving mold 3. That is, this part becomes an intrusion path through which outside air intrudes into the closed space consisting of the valve moving space Sp, the cavity C, and the inner space of the injection sleeve 16. Similarly, the plunger chip 15 and the sleeve 16 are intrusion paths of outside air.

In addition, such an intrusion path tends to exist a gas unnecessary for vacuum casting such as air or water vapor.

For this reason, in this embodiment, in the fixed mold 2, the fixed mold flow path 2c formed in a small gap is formed between the internal fixed mold 2a and the external fixed mold 2b, and the fixed mold flow path ( The 2nd auxiliary exhaust pipe 90 is connected to 2c), and it can exhaust.

Similarly, in the moving mold 3, the moving mold flow path 3c formed in a slight gap is also formed between the internal moving mold 3a and the external moving mold 3b, and also the 2nd auxiliary | assistance to the moving mold flow path 3c is also carried out. The exhaust pipe 91 is connected to exhaust gas.

The auxiliary exhaust pipes 90 and 91 are connected to the auxiliary pressure reducing tank TB via the third open / close valve SV.

The third open / close valve SV is opened and closed in accordance with the control signal 30SB of the controller 30.

The groove 15h is formed to almost half of the outer peripheral surface of the cavity C side of the plunger chip 15 fitted to the inner peripheral surface of the injection sleeve 16. This groove 15h communicates with an internal hole from the outer circumferential surface of half of the plunger chip 15, and the hole also communicates with a conduit formed into the plunger rod 14, which is connected to the auxiliary pressure reducing tank TB. It is connected via 3rd opening / closing valve SV.

The groove 15h is formed by the outer circumference of the plunger chip 15 to fit inside the sleeve 16, thereby assisting the gas penetrating into the inner circumferential space of the injection sleeve 16, the cavity C and the valve moving space Sp. It becomes an exhaust flow path.

The auxiliary decompression tank TB has a fixed mold flow path 2c between the internal fixed mold 2a and the external fixed mold 2b of the fixed mold 2 and an internal movable mold 3a of the movable mold 3 and an external movement. The injection sleeve 16 through the moving mold flow path 3c between the mold 3b and the flow path formed between the groove 15h formed of the plunger chip 15 and the plunger rod 14 and the inner circumferential surface of the sleeve 16. The gas in the closed space consisting of the inner circumferential space, the cavity C, and the valve movement space Sp is decompressed and exhausted.

The third open / close valve SV is opened and closed by the control command 30SB from the controller 50.

A vacuum pump 50B is connected to the auxiliary pressure reduction tank TB, and the inside of the auxiliary pressure reduction tank TB is decompressed to a predetermined pressure by the vacuum pump 50B. For example, when the vacuum pump 50B is operated by the controller 30, the vacuum pump 50B is configured to maintain a predetermined depressurization state, for example, almost vacuum state, in the auxiliary decompression tank TB. For example, it automatically turns on and off. In this way, the auxiliary pressure reduction tank TB is depressurized to a predetermined pressure (almost vacuum state) by the vacuum pump 50B before the operation of the die cast apparatus 1.

Preferably, the first open valve OV1 is installed in the connection flow path 53 between the exhaust pipe 51 and the first open / close valve MV, and the second open valve OV2 is provided in the first and second auxiliary exhaust pipes. It is provided in the flow path between 90 and 91 and 3rd opening / closing valve SV. These open valves OV1 and OV2 are on / off valves for bringing the inside of the form into an atmospheric pressure state and are closed during normal operation. When the first open valve OV1 and the second open valve OV2 are in the open state after the completion of the filling of the molten metal into the cavity C, the inside of the mold is in the atmospheric pressure state. Become.

Moreover, in order to heighten the said effect of 1st open valve OV1 further, it is preferable to open the shutoff valve 60 also with opening of 1st open valve OV1.

The control operation of the first open valve OV1, the second open valve OV2, and the shut off valve 60 can be preferably performed by the controller 30.

Hereinafter, the correspondence relationship of the above-mentioned component and the term of this invention is described.

The stationary die 2 corresponds to the first die of the present invention, and the moving die 3 corresponds to the second die of the present invention. The oxygen gas supply device 80 and the second open / close valve GV correspond to the oxygen gas supply means of the present invention.

The main pressure reduction tank TA corresponds to the 1st pressure reduction tank of this invention, and the main pressure reduction tank TA and the 1st opening / closing valve MV correspond to the 1st pressure reduction means of this invention.

The shut-off valve 60 attached to the moving die 3 corresponds to the first on-off valve moving means of the present invention.

The injection sleeve 16 with the supply port 16h corresponds to the injection sleeve of the present invention.

The injection plunger 17 composed of the plunger rod 14 and the plunger chip 15 corresponds to the injection plunger means of the present invention.

The hydraulic cylinder 11 and the piston rod 12 correspond to the injection cylinder means of the present invention.

The auxiliary pressure reducing tank TB corresponds to the second pressure reducing tank of the present invention, and includes a third opening / closing valve SV, an exhaust pipe 90, an exhaust pipe 91, a groove 15h and a pipe line in the plunger rod 14. It corresponds to the 2nd pressure reduction means of this invention.

The controller 30 corresponds to the control means of the present invention.

<Operation method of die casting apparatus, pressure reduction casting method>

With reference to FIGS. 3-12, the operation method and the pressure reduction casting method of the die-casting apparatus 1 are demonstrated.

3 is a flowchart illustrating an operation mode of the diecast apparatus 1 in time series.

4 to 12 are diagrams illustrating operation states of main parts of the die-casting apparatus 1 in the respective steps illustrated in FIG. 3.

The operation in the die casting apparatus 1 described below corresponds to a part of the pressure reduction casting method of the embodiment of the present invention.

In the present embodiment, the controller 30 performs the following main control operations that can be automatically controlled by the diecast apparatus 1.

3 shows the operation of the oxygen gas supply device 80 and the second on / off valve GV showing the overall operation of the diecast device 1, the operating state of the shutoff valve 60, and the operating state of the oxygen gas supply system. State, the operation state of the main pressure reduction tank TA and the first on-off valve MV showing the operation state of the main decompression meter, the auxiliary pressure reduction tank TB and the third on-off valve The operating state of SV is illustrated in time series.

In addition, although the viewpoint t0 thru | or t16 in FIG. 3 are illustrated at equal intervals in order to make illustration suitable, it is not limited to an equal interval actually. Similarly, the length of the time intervals T1 to T4 is not limited to the scale of the illustration.

<Time t0, initial state, Fig. 2>

2 shows an initial state of the time point t0 of the diecast apparatus 1.

In the initial state of the time point t0, the controller 30 is stopped. In the initial state of this die-casting apparatus 1, the 1st switching valve MV, the 2nd switching valve GV, and the 3rd switching valve SV are in the "closed" state, respectively. The first open valve OV1 and the second open valve OV2 are also in a closed state. The 1st, 2nd vacuum pump 50A, 50B is also stopped.

In this initial state, there is no supply of oxygen from the oxygen gas supply device 80 to the cavity C, there is no decompression operation in the cavity C by the main decompression tank TA, and the auxiliary decompression tank TB There is no decompression operation in the cavity C. In this initial state, the inner space of the injection sleeve 16 and the cavity C outside air communicating with the injection sleeve 16 are exposed.

The shut off valve 60 is also de-energized. That is, the valve member 62 of the shutoff valve 60 is seated on the valve seat member 64, and the shutoff valve 60 is closed.

The plunger chip 15 is located on the right side of the supply port 16h of the injection sleeve 16, and the supply port 16h is open.

<Time t1: Type fastening operation (FIG. 3, S1-1), FIG. 2>

At the time point t1, as shown in Fig. 2, the mold clamping of the fixed mold 2 and the moving mold 3 is performed using a mold clamping device (not shown), for example. Thereby, the cavity C in which the metal molten metal ML is filled between the stationary die 2 and the moving die 3 is defined.

Since the supply port 16h of the sleeve 16 is opened, the molten metal ML is in a state which can be melted from the supply port 16h.

<Time t2: Preparation of the Main and Auxiliary Pressure Gauges>

At a time point t2, the controller 30 operates the first vacuum pump 50A. Thereby, 50 A of 1st vacuum pumps make the state inside the main pressure reduction tank TA of a main pressure reduction system near the vacuum state (almost vacuum state). Of course, preferably a vacuum state is good.

Thereafter, the first vacuum pump 50A is preferably automatically turned on and off to maintain the inside of the main pressure reduction tank TA in a predetermined vacuum state until its operation is stopped by the controller 30. Similarly, at time t2, controller 30 operates second vacuum pump 50b. Thereby, the 2nd vacuum pump 50b makes the inside of auxiliary pressure reduction tank TB of an auxiliary pressure reducing system near to a vacuum state. Thereafter, the second vacuum pump 50B is preferably automatically turned on and off to maintain the inside of the auxiliary pressure reducing tank TB in a predetermined vacuum state until its operation is stopped by the controller 30.

The operation of the first vacuum pump 50A is continued until the start of pouring at the time point t3. Similarly, the operation of the second vacuum pump 50B is continued before the start of pouring at the time point t3. As a result, the main pressure reduction tank TA is in a state sufficiently close to a vacuum state for a period of time t2 to time t3. Similarly, the auxiliary pressure reduction tank TB is in a state sufficiently close to a vacuum state for the time period t2 to time t3.

At this time point t2, both the first on-off valve MV and the second on-off valve GV are in a closed state, and the pressure reduction operation of the cavity C is not yet performed.

In this way, the controller 30 operates the first vacuum pump 50A and the second vacuum pump 50B only for the period necessary for preparation of the depressurization operation.

While the start and stop of the first vacuum pump 50A and the second vacuum pump 50B are performed by the controller 30 described above, the operator of the die casting apparatus 1 may be performed manually. In this embodiment, the case where the 1st vacuum pump 50A and the 2nd vacuum pump 50B are driven by the controller 30 is described.

<Time t3: Start of pouring (S1-2), Fig. 4>

At the time point t3, pouring of the metal melt ML into the injection sleeve 16 is started from the supply port 16h of the injection sleeve 16.

<Time t4: Start of oxygen supply (S2-1), FIG. 4>

At the time point t4, the controller 30 opens the shut-off valve 60 in the closed state when detecting the start of pouring operation of the molten metal ML from the supply port 16h into the injection sleeve 16. The control signal 30SC that energizes the state is output to the electronic actuator 61. The controller 30 also outputs a control signal 30SD for pressing the second open / close valve GV in the closed state to the open state.

Thereby, as shown in FIG. 4, the valve member 62 of the shutoff valve 60 moves toward the inside of the valve movement space Sp from the seating state of the valve seat member 64, and the shutoff valve ( 60) becomes an open state. As a result, the second through hole 64b and the valve movement space Sp are in communication. Therefore, the valve movement space Sp, the cavity C, the injection sleeve from the oxygen gas supply device 80 via the second opening / closing valve GV and the exhaust passage 52 through the second through hole 64b. Oxygen gas is filled in the internal space of 16.

The surface of the molten metal ML poured in the injection sleeve 16 is oxidized by the filling of the cavity C and the oxygen gas into the injection sleeve 16 to start the oxygen substitution diecasting method. That is, the oxygen gas O ₂ supplied from the oxygen gas supply device 80 to the cavity C passes through the internal space of the injection sleeve 16 through the cavity C, and the injection sleeve (from the supply port 16h). 16) is released to the outside.

In this state, the closed space composed of the valve moving space Sp, the cavity C, and the internal space of the injection sleeve 16 is satisfied by the oxygen gas O ₂ and from the supply port 16h. By the released oxygen gas, a gas that is harmful to die-casting processing such as outside air gas invading (remaining) in the valve movement space Sp, the cavity C, and the injection sleeve 16 is injected into the injection sleeve 16. Discharged outside). In this manner, the oxygen gas remains in the cavity C or the like to purge gas that damages the quality of the die cast product.

The start of pouring of the molten metal ML into the injection sleeve 16, for example, transmits a detection signal of a temperature sensor disposed near the supply port 16h of the injection sleeve 16 (not shown) to the controller 30. Input, the controller 30 can detect and detect a sudden change in the detection signal of the temperature sensor. Alternatively, the controller 30 can detect the injection of the molten metal ML by an instruction from the operator of the diecast apparatus 1.

In addition, the start of supply of the oxygen gas O ₂ from the oxygen gas supply device 80 into the cavity C and the injection sleeve 16 is carried out to the internal space of the injection sleeve 16 of the molten metal ML. It is good either before or after the start of pouring.

<Time t5: Pouring completed (S1-3), FIG. 4>

At the time point t5, the pouring operation is completed when the amount of the molten metal ML required for producing one die cast product is poured into the injection sleeve 16.

The time T1 from the start of pouring to the completion of pouring is defined by the amount of metal molten metal ML pouring in the injection sleeve 16 and is not constant.

By the end of this pouring, the inside of the injection sleeve 16 near the supply port 16h portion of the injection sleeve 16 is almost closed in the molten metal ML. However, even in this state, the second open / close valve GV is in an open state, and the oxygen charging process from the oxygen gas supply device 80 is still being performed.

<Time t6: Low speed injection start (S1-4), FIG. 5>

At time t6, when detecting that the pouring operation is completed, the controller 30 drives the hydraulic cylinder 11 to drive the piston rod 12 at low speed. As a result, as shown in Fig. 5, the plunger chip 15 connected to the distal end of the plunger rod 14 connected to the piston rod 12 shown in Fig. 2 via the coupling 13 is ejected. The inside of the sleeve 16 is moved at a low speed.

The moved position and the moving speed of the plunger rod 14 or the plunger chip 15 are calculated by the controller 30 on the basis of the detection signal S35 of the position detection sensor 35, Used for driving. The movement speed is obtained by time-differentiating the position of the controller 30.

By the low-speed movement of the plunger chip 15, the molten metal ML introduced into the injection sleeve 16 is enlarged not only in the longitudinal direction but also in the cross-sectional direction in the injection sleeve 16 under pressure.

At this time, the third open / close valve SV is in an open state, and the filling of the oxygen gas from the oxygen gas supply device 80 to the cavity C is continued.

<Time t7: oxygen supply stop (S2-2), FIG. 6>

The controller 30 starts the low-speed injection of the plunger rod 14 (or the plunger chip 15) at the time t6 at the time point t7, and after a predetermined time has elapsed (the time period between the time points t6 and t7), When the molten metal ML reaches the state filled in the injection sleeve 16, the control signal 30SD which ignites the 2nd on-off valve GV and makes it closed is output, and the 2nd on-off valve GV is closed. As a result, the filling of the oxygen gas from the oxygen gas supply device 80 to the cavity C is stopped. Thereby, the filling process of the oxygen gas into the cavity C and the injection sleeve 16 by the oxygen gas supply device 80 is complete | finished.

In addition, the controller 30 burns off the shut-off valve 60 to close the shut-off valve 60, that is, the valve member 62 contacts the valve seat member 64 so that the valve member 62 and the valve seat member are closed. It is assumed that the gap with (64) is closed.

The time period (t2) from the time point t4 to the time point t7 is as much as possible in order to prevent oxidation of the molten metal molten metal ML in the injection sleeve 16 and to prevent a low temperature of the molten metal ML. Short time is preferred.

In the oxygen substitution die-casting method, after pouring molten metal ML from the supply port 16h and starting pouring the plunger rod 14 (or the plunger chip 15) toward the cavity C side, a short time is taken. It is good to substitute the oxygen gas only.

<Time t8: Stopping preparation operation of the main pressure gauge and the auxiliary pressure gauge, FIG. 6>

At the time point t8 after stopping the filling of the oxygen gas into the cavity C and the injection sleeve 16 by the oxygen gas supply device 80 with the second open / close valve GV closed by the controller 30. The controller 30 stops the first vacuum pump 50A to stop the decompression operation in the main pressure reduction tank T4. Similarly, the controller 30 stops the operation of the second vacuum pump 50B to stop the pressure reduction operation in the auxiliary pressure reduction tank TB.

According to the above-mentioned decompression preparation operation, the main decompression tank TA and the auxiliary decompression tank TB are assumed to be depressurized to a sufficiently low pressure state, preferably to a substantially vacuum state.

Further, the stop of the first vacuum pump 50A and the second vacuum pump 50B is such that the pressure state in the main pressure reduction tank TA and the auxiliary pressure reduction tank TB reach a sufficiently low pressure, preferably almost vacuum state, respectively. The stop operation may be performed independently at any time before this timing.

<Time t9: Closing supply port 16h (S1-5), Fig. 7>

The controller 30 drives the hydraulic cylinder 11 while monitoring the detection signal S35 of the position detection sensor 35 at the time point t9 so that the plunger chip 15 supplies the supply port 16h of the injection sleeve 16. ), The plunger chip 15 (plunger rod 14) is injected at low speed until the supply port 16h is closed. As a result, as shown in FIG. 7, the molten metal ML under pressure of the plunger chip 15 in the injection sleeve 16 near the supply port 16h is expanded in the inner wall direction of the injection sleeve 16. The injection sleeve 16 is blocked. Accordingly, the injection sleeve 16 without the valve movement space Sp, the cavity C, and the rapid melt ML filled inside the injection sleeve 16 by the metal melt ML and the plunger chip 15. It becomes the sealed state with respect to As a result, intrusion of outside air from the supply port 16h is eliminated.

<Time t10: Start of decompression of the main pressure reducer, FIG. 8>

After closing the supply port 16h, the controller 30 outputs a control signal 30SA for opening the first open / close valve MV to the first open / close valve MV at a time point t10. In fact, after the time t9 when the controller 30 performs the closing operation of the supply port 16h at the time point t9, a predetermined time in which the injection sleeve 16 near the supply port 16h actually closes in the molten metal ML After the time T4 has elapsed, the first on-off valve MV is opened.

The controller 30 also puts the shut off valve 60 in an open state. Thereby, the valve member 62 is spaced apart from the valve seat member 64.

According to the operation, the main pressure reduction in a vacuum state or near vacuum state is provided through a gap between the exhaust pipe 51, the exhaust passage 52, the second through hole 64b, the exhaust member 62 and the valve seat member 64. The tank TA is closed in the inner space in which the molten metal ML of the injection sleeve 16 is not filled, the cavity C connected to the inner space, the valve moving space Sp, and the exhaust passage 52. The inside of the main pressure gauge defined by the space is decompressed. By this decompression operation, the oxygen gas charged in the closed space is also discharged to the outside.

This decompression operation is referred to herein as the first decompression operation, and continues after the high-speed injection at the time point t13 and to the time point t15 after the completion of the charging at the time point t14.

<Time t11: Start of operation of the auxiliary pressure reducer, FIG. 9>

After closing the supply port 16h at the time point t9, the controller 30 outputs a control signal 30SB for opening the third on-off valve SV to the third on-off valve SV at time t11. .

In reality, after the controller 30 performs the closing operation of the supply port 16h at the time point t9, a predetermined time period in which the injection sleeve 16 near the supply port 16h actually closes in the molten metal ML. After the elapse of T3, the third open / close valve SV is opened.

As a result, the inner tube of the groove 15h of the plunger chip 15 and the plunger rod 14 in the fixed mold flow path 2c through the exhaust pipe 90 and in the moving mold flow path 3c through the exhaust pipe 91. Through the injection sleeve 16, the pressure is evacuated and exhausted by the auxiliary pressure reducing tank TB in a vacuum state or a nearly vacuum state.

That is, the fixed mold flow path 2c and the exhaust pipe 91 through the exhaust pipe 90 are supplied by the cavity C from the oxygen gas supply device 80 and the supply (filling) of the oxygen gas into the injection sleeve 16. Oxygen gas remaining in the moving mold flow path 3c and the groove 15h through the exhaust pipe 90, the fixed mold flow path 2c, the exhaust pipe 91, and the moving mold flow path 3c are also originally formed by the oxygen gas purge. And minute gases that remain in the grooves 15h and the like or cause damage to the diecast such as outside air that has invaded their places afterwards are discharged to the outside by the auxiliary pressure reducing tank TB.

According to the discharge operation | movement of the gas by the auxiliary pressure reduction tank TB, outside air is lost to the stationary mold flow path 2c, the moving mold flow path 3c, etc., and an outside air gas does not enter this part.

This decompression operation is referred to as a second decompression operation in this specification, and is continued until a time point t15 before the take-out operation of the die-cast product at the time point t16.

In the above example, the completion timing of the first decompression operation by the main pressure reduction tank TA and the completion timing of the second decompression operation by the auxiliary decompression tank TB are the same time point t15.

In the above-described example, when the decompression operation (first decompression operation) of the main pressure reducer (first decompression meter) is first performed, and the decompression operation (first decompression operation) of the auxiliary decompression meter (second decompression meter) is performed later. Has been described (predetermined time T4 > T3), but can be set to a predetermined time T3 = T4 after the closing of the supply port 16h.

Alternatively, the controller 30 can simultaneously start depressurization of the main decompression meter by the opening operation of the first open / close valve MV and decompression start of the auxiliary decompression system by the opening operation of the third open / close valve SV.

Contrary to the above, the pressure reduction start of the auxiliary pressure reducer may be performed first, and the pressure reduction start of the main pressure reducer may be performed later (predetermined time T3> T4).

<Time t12: Partial operation stop of the main pressure reducer, Fig. 10>

After a predetermined time T5 after the start of the operation of the main decompression pressure at the time t10 and at a time t12 before the high-speed injection at the time t13, the controller 30 controls the shutoff valve 60 to be in a closed state ( 30SC) is output to the electromagnetic actuator 61, and the shut-off valve 60 is made into the closed state, ie, the valve member 62 seats on the valve seat member 64. As shown in FIG.

As a result, as shown in FIG. 10, the shut-off valve 60 will be in a closed state, and the communication between the valve movement space Sp and the exhaust path 52 will be lost. However, since the 1st opening / closing valve MV is an open state, the pressure reduction operation | movement of the exhaust path 52 and the 2nd through-hole 64b by the main pressure reduction tank TA is performed continuously.

Before the high-speed injection at the time point t13, the shut-off valve 60 is closed, so that the molten metal ML introduced into the cavity C at a high speed and high pressure by the high-speed injection causes the valve movement space Sp, This is because it is prevented from entering the second through hole 64b or the like. On the other hand, even if the auxiliary pressure reducer is operated, there is no concern as described above, so that the operation of the auxiliary pressure reducer is continued.

The period between the time points t10 to t12 or the time points t11 to t12 operates in parallel with the main and secondary pressure reducers.

According to the operation of the main decompression meter, the oxygen gas and the outside air (if present) in the cavity C are discharged to the outside air through the valve movement space Sp, the second through hole 64b, and the exhaust passage 52. On the other hand, the corner of the closed space in the cavity C, the injection sleeve 16, etc. is filled with oxygen gas charged from the oxygen gas supply device 80 into the cavity C, etc., according to the initial operation of the main pressure reducer. It is filled to a corner and the effect of an oxygen substitution diecast method is improved. In addition, in accordance with the operation of the auxiliary pressure reducing system, outside air is discharged from the fixed mold flow path 2c, the moving mold flow path 3c, the groove 15h, and the like through the exhaust pipe 90, the exhaust pipe 91, and the like.

In this way, in accordance with the parallel operation of the main pressure reducer and the auxiliary pressure reducer, the gas that is harmful to the die cast processing in the diecasting apparatus 1 is continuously released at the leading portion of the diecasting apparatus or from the outside. Can't break in.

<Time t13: High Speed Injection (S1-6), Fig. 11>

At the time point t13, the controller 30 drives the hydraulic cylinder 11 to move the piston rod 12 to the left while at high speed in the illustrated state. As a result, the plunger chip 15 connected to the plunger rod 14 moves in the injection sleeve 16 toward the cavity C at high speed.

As a result, the molten metal ML poured into the injection sleeve 16 rapidly fills the cavity C from within the injection sleeve 16. By the high speed injection of the molten metal ML, the pressure in the high speed cavity C of the cavity C increases rapidly after the time point t13.

The plunger chip 15 is held in a predetermined distance and moved within the injection sleeve 16. Thereby, the pressure in the cavity C is kept high.

The molten metal ML filled in the cavity C is filled in the cavity C to become a desired die-cast product.

<Time t14: Charging completed (S1-7), Fig. 11>

After the molten metal ML is filled into the cavity C by high-speed injection, the filling is completed at a time point t14 after a predetermined time has elapsed.

<Time t15: Complete stop of the main pressure reducer, end of operation of the auxiliary pressure reducer, Fig. 12>

After the charging is completed, the controller 30 outputs a control signal 30SA for closing the first on-off valve MV to the first on-off valve MV at a time point t15. As a result, as shown in FIG. 12, the 1st opening / closing valve MV will be in a closed state, and the decompression operation from the main pressure reduction tank TA will be completed.

Moreover, the controller 30 outputs the control signal 30SB for closing the third open / close valve SV to the third open / close valve SV. As a result, as shown in Fig. 12, the first opening / closing valve MV and the third opening / closing valve SV are in a closed state, and the fixed metal flow path (via the exhaust pipe 90 by the auxiliary pressure reducing tank TB) ( 2c), the pressure reduction operation | movement in the injection sleeve 16 via the moving mold flow path 3c through the exhaust pipe 91, the groove 15h of the plunger chip 15, and the plunger rod 14 is complete | finished.

The first open valve OV1 and the second open valve OV2 are closed from the initial state to the above-described time point t15.

Preferably, after a predetermined time elapses from the time point t15, when the die-cast product in the cavity C is cooled and can be removed, that is, after the completion of filling of the molten metal into the cavity C at the time point t15, and before the time point t16, After the cast process is finished, for example, the controller 30 opens the first open valve OV1 and the second open valve OV2 in an open state. As a result, since the inside of the mold is in the atmospheric pressure state, the pressure difference decreases, and the mold opening operation at the time point t16 becomes easy.

In order to further enhance the above-mentioned effect of the first open valve OV1, it is preferable that the controller 30 also opens the shut off valve 60 together with the opening of the first open valve OV1.

<Time t16, take out of die-cast product (S1-8)>

After a predetermined time elapses at the time point t15, when the die cast product in the cavity C is cooled and can be removed, the mold clamping state between the fixed mold 2 and the moving mold 3 is released, and the extrusion pin 65 is removed. By pressing, the die-cast product in the cavity C is taken out.

As described above, according to the embodiment of the present invention, the injection sleeve 16 in the cavity C by the decompression operation by the auxiliary decompression meter in addition to the exhaust in the cavity C by the decompression operation by the main decompression meter. The gas which does not harm diecast in the inside of valve | bulb movement valve Sp etc. is excluded, and the diecast product of high quality can be manufactured.

Moreover, according to this embodiment, a diecast product of high quality can be manufactured by appropriate oxygen supply by a reduced-pressure oxygen substitution diecast method.

In addition, in this embodiment, since a series of operations can be performed in a short time, a large temperature drop does not occur in the molten metal (ML) poured into the injection sleeve 16, and a high quality die cast product can be produced. have.

According to this embodiment, it is effective in extending a cycle.

According to this embodiment, after satisfy | filling the inside of the closed space containing the cavity C with oxygen gas, the stationary die flow path 2c of the stationary die 2 and the moving die 3 by the auxiliary pressure reduction tank TB. In the enclosed space including the cavity C, since exhaust | emission by pressure reduction is performed from the flow path formed between the moving mold flow path 3c of the plunger chip 15, the groove 15h of the plunger chip 15, and the inner peripheral surface of the sleeve 16. It can be reliably blown with oxygen gas to every corner, and can also be reliably substituted with the gas in the gas infiltration path.

Further, even after the inside of the closed space including the cavity C is reliably taken into the oxygen gas, the exhaust gas in the closed space by the auxiliary pressure reducing tank TB is continued, so that unnecessary gas such as air is kept in the cavity C. Do not invade

In addition, since both the auxiliary pressure reduction tank TB and the main pressure reduction tank TA reduce pressure in the cavity C, in the sleeve, and clearance (clearance), the time required for pressure reduction can be shortened. The oxygen gas remaining in the cavity C can be made very small.

The implementation of the die cast apparatus and the reduced pressure casting method of the present invention is not limited to the above-described exemplary embodiments, and various deformation states can be taken.

Although the above-mentioned embodiment demonstrated the case where the main pressure reduction means and the auxiliary pressure reduction means of this invention consisted of the main pressure reduction tank TA and the auxiliary pressure reduction tank TB, it was pressure-reduced directly by a vacuum pump etc. without using a tank. It is also possible to make a configuration.

The part which performs the pressure reduction process of the cavity C by operating the auxiliary pressure reduction tank TB is not limited to the above-mentioned fixed mold flow path 2c, the moving mold flow path 3c, the groove 15h of the plunger chip 15, etc. In addition, it can apply to the part which the outside air may invade in the cavity C etc., and is. As such another part, for example, the gap between the moving mold 3 and the shut-off valve 60 mounted to the moving mold 3, for example, the valve seat member 64 and the external moving mold 3b. Gaps).

As an example of the operation in the die-casting apparatus of the embodiment of the present invention, the case where the metal molten metal ML is injected at low speed and then high-speed injection is described, but in the die-casting apparatus of the embodiment of the present invention, the metal molten metal is described. The injection method of ML or the moving speed of the plunger needle 15 are not limited to the above-described two-step moving speed, for example, at an appropriate moving speed such as only one moving speed or moving speed by three-stage switching. The molten metal can be injected into the cavity.

The above-mentioned control operation by the controller 30 in the die-casting apparatus of the embodiment of the present invention, for example, switching the opening and closing operation of the shut-off valve 60, first to third opening and closing valves MV, GV, SV Can be performed according to a predetermined condition of the state of the entire die-cast apparatus to be performed therefrom, for example, the moving position and the moving speed of the plunger chip 15. Such determined condition is registered in advance in the memory in the controller 30, for example. Therefore, as shown in the above-described example, the controller 30 does not recognize operating conditions such as low-speed injection and high-speed injection of the plunger chip 15 or the molten metal ML, and the detection value of the position detection sensor 35 and the like. With reference to the change, the same control operation as described above can be performed.

In addition, the shut-off valve 60 corresponding to the 1st opening / closing valve means of this invention may not only be attached to the moving metal mold | die 3, but may be attached to the stationary metal mold | die 2. Preferably, the shut off valve 60 can be mounted to the moving mold 3 and the stationary mold 2. Thereby, the decompression time of a cavity can be shortened.

In addition, the main pressure reduction tank TB and the auxiliary pressure reduction tank TB used for the same use may be used as one common tank. By doing so, the installation of the die casting apparatus is simplified and the price of the equipment of the die casting apparatus can be reduced.

In addition, instead of the hydraulic cylinder 11, the piston rod 12 can also be moved to the left and right using the drive means of another hydraulic medium, for example, the drive means for medium pressure.

In addition, it is not limited to the above-mentioned example, It is also possible to move the piston rod 12 by an electric actuator.

According to the present invention, in addition to the depressurization exhaust in the cavity in the mold by the decompression operation by the first decompression means, the decompression operation by the second decompression means is detrimental to die casting production in the cavity and in the injection sleeve. Gases such as outside air from the outside of the sleeve and / or cavity are excluded. As a result, a high quality diecast product can be produced.

Moreover, according to this invention, a high quality diecast product can be manufactured by appropriate oxygen supply by the reduced-pressure oxygen substitution diecast method.

Further, according to the present invention, since a series of operations can be performed in a short time, a large temperature drop does not occur in the molten metal melted on the injection sleeve, and a high quality die cast product can be produced.

According to the present invention, it is effective for extending the cycle for producing die cast products.

In this invention, after satisfy | filling the inside of the closed space used for die-casting of the die-casting apparatus containing the cavity in a metal mold with oxygen gas, the fixed metal mold flow path of a 1st metal mold, for example, a fixed metal mold | die by a 2nd pressure reduction means. And exhaust from the second mold, for example, the movable mold flow path of the moving mold and the flow path formed between the groove of the plunger chip and the inner circumferential surface of the sleeve, so as to exhaust by the second pressure reduction to every corner in the closed space including the cavity. It can be reliably substituted by oxygen gas, and can also be reliably substituted by oxygen gas also in a gas infiltration path.

Moreover, in this invention, after exhausting the inside of a closed space used for die-casting of the die-casting apparatus containing a cavity with oxygen gas reliably, the exhaust gas in the said closed space is continued by a 2nd pressure reduction means, The gas (gas) which does harm to die-casting manufacture, such as outside air, does not penetrate in a sleeve etc.

In addition, in the present invention, since the second decompression means and the first decompression means operate in parallel, the time required for decompression can be shortened, and the oxygen gas filled by the oxygen substitution method can be made very small. Can be.

Claims (13)

Die-casting device for manufacturing die-cast products by filling metal cavities in the cavity, A first mold and a second mold defining a cavity in which the molten metal is filled; First decompression means, Oxygen gas supply means, A first opening / closing valve means mounted to the first mold and / or the second mold, wherein the first decompression means or the oxygen gas supply means and the cavity are in a communicable state or a non-communicating state; An injection sleeve communicating with the cavity and having a supply port for pouring the molten metal on the side opposite to the side communicating with the cavity; An injection plunger means having a plunger chip inserted into the inner cylinder of the injection sleeve so as to be movable, and injecting the molten metal melted in the injection sleeve from the supply port toward the cavity; Injection cylinder means for driving said injection plunger means; Clearance (clearance) in the said 1st metal mold | die, clearance gap in the said 2nd metal mold | die, between the said injection sleeve and the said plunger chip which the outside air may invade into the said cavity and / or the said injection sleeve. And a second decompression means for decompressing the pressure from at least one of the gap between the gap and the gap between the second mold and the first opening / closing valve means. The method of claim 1, wherein the first decompression means has a first decompression tank and a first on-off valve, The oxygen gas supply means has an oxygen gas supply device and a second open / close valve, And said second decompression means has a second decompression tank and a third open / close valve. 3. The method of claim 2, wherein after the pouring of the molten metal from the supply port into the injection sleeve is started, the first on-off valve means becomes an opening means to communicate the oxygen gas supply means and the cavity, and the second on-off valve Is in an open state to supply oxygen gas from the oxygen gas supply device to the cavity and the injection sleeve to be discharged from the supply port, to fill the cavity and the injection sleeve with oxygen gas, and To exhaust the gas, After filling the cavity and the injection sleeve with the oxygen gas, the second on-off valve is closed to terminate the filling of the oxygen gas, After the second opening / closing valve is in a closed state, a first period of time until the filling of the molten metal in the cavity is completed, the first opening / closing valve in the first decompression means becomes an open state, and the Depressurize the inside of the cavity and the injection sleeve by the first pressure reducing tank via a first opening / closing valve means, After the second opening / closing valve is in a closed state, a second period of time until the filling of the molten metal in the cavity is completed, the third opening / closing valve of the second pressure reducing means is in an open state and the second pressure reducing tank Die-casting apparatus for reducing the gap by means of. The molten metal of the molten metal is started from the supply port into the injection sleeve until the molten metal is completed and the first injection of the molten metal into the cavity by the injection plunger at a first speed is performed. In a period of time, the first on-off valve means is in an open state to communicate the oxygen gas supply means with the cavity, and the second on-off valve is in an open state to release oxygen from the oxygen gas supply device into the cavity and the injection sleeve. Supplying gas to discharge from the supply port, filling the cavity and the injection sleeve with oxygen gas and evacuating gas other than oxygen gas, After the filling of the oxygen gas into the cavity and into the injection sleeve, the second opening / closing valve is closed to terminate the filling of the oxygen gas, After the second opening / closing valve is closed, the first opening / closing valve in the first decompression means is opened until the second injection of the molten metal into the cavity by the injection plunger is started at a second speed. To depressurize the cavity and the injection sleeve by the first pressure reducing tank through the first opening / closing valve means in an open state, After the second opening / closing valve is closed, a period until the process of filling the molten metal in the cavity is completed, the third opening / closing valve of the second decompression means is opened to the second decompression tank. Die-casting apparatus for reducing the gap by the. 5. The diecast apparatus of claim 3 or 4 wherein the second speed is faster than the first speed. The die-casting device according to claim 3 or 4, wherein the first speed and the second speed are the same. 4. The apparatus of claim 3, wherein the diecast apparatus further has control means, The control means, After the pouring of the molten metal into the injection sleeve from the supply port by the movement of the plunger means, the first opening / closing valve means is operated to fill the cavity and the injection sleeve with oxygen gas, and further from the supply port. Releasing oxygen gas to exhaust gas other than oxygen in the cavity and in the injection sleeve, After the pouring of the molten metal is completed, driving the injection cylinder means to move the injection plunger means at a first speed, and injecting the molten metal melted in the injection sleeve into the cavity; After filling the cavity and the injection sleeve with the oxygen gas, the second on-off valve is closed to complete the filling of the oxygen gas, After the second opening / closing valve is in a closed state, a first period of time until the filling of the molten metal in the cavity is completed, the first opening / closing valve in the first decompression means is opened and the first opening 1 depressurizes the inside of the cavity and the inside of the injection sleeve by the first pressure reducing tank via an opening / closing valve means, After the second opening / closing valve is in a closed state, a second period of time until the filling of the molten metal in the cavity is completed, the third opening / closing valve of the second decompression means is opened, and the second pressure is reduced. And die-casting the at least one gap by a tank. 4. The apparatus of claim 3, wherein the diecast apparatus further has control means, The control means, The period until the pouring is completed and the first injection of the molten metal into the cavity by the injection plunger is performed at a first speed, the first on-off valve means is opened and the oxygen gas supply means and the cavity , The second on-off valve is opened to supply oxygen gas from the oxygen gas supply device to the cavity and the injection sleeve to inject from the supply port, and oxygen gas is injected into the cavity and the injection sleeve. Filled with exhaust gas other than oxygen gas, After filling the oxygen gas into the cavity and into the injection sleeve, the second on / off valve is closed to complete the filling of the oxygen gas, After the second on / off valve is closed, the first on / off valve in the first decompression means is opened until the second injection of the molten metal into the cavity by the injection plunger at a second speed is started. Depressurize the inside of the cavity and the inside of the injection sleeve by the first pressure reducing tank through the first opening / closing valve means in the open state, After the second opening / closing valve is closed, the second opening / closing valve of the second pressure reducing means is opened to the second pressure reducing tank in a period until the process of filling the metal melt in the cavity is completed. And die-casting the at least one gap. The diecast apparatus according to claim 7 or 8, wherein the diecast apparatus has a position sensor for detecting the position of the injection plunger, And the control means determines that the injection plunger means ejects at the first speed or the second speed with reference to a movement speed obtained by differentiating the detected value of the position sensor. The method according to any one of claims 1 to 4, 7 and 8, wherein the first mold is a fixed mold, With internal fixed molds, An external stationary mold surrounding the internal stationary mold, A fixed mold flow path forming a gap between the internal fixed mold and the external fixed mold, The second mold is a moving mold, With moving mold inside, An outer movable mold surrounding the inner movable mold; Has a moving mold flow path forming a gap between the inner moving mold and the outer moving mold, And said second pressure reducing means is operatively connected to said fixed mold flow path and said moving mold flow path. It is a pressure reduction casting method for the die cast apparatus which manufactures a diecast product by the oxygen substitution diecast method, After the pouring of the molten metal into the injection sleeve from the supply port, oxygen gas in the cavity and the injection sleeve until the pouring is completed and the injection plunger moves at the first speed to inject the molten metal into the cavity defined in the mold. An oxygen purge process that is filled with and discharged from the supply port to fill the cavity and the injection sleeve with oxygen gas and exhaust the gas other than oxygen gas, A first depressurizing step of depressurizing the inside of the cavity and the injection sleeve until the filling of the oxygen gas is completed, and the injection plunger moves at a second speed to start injecting the molten metal into the cavity; After the filling of the oxygen gas, the die-casting device having a second depressurization step of depressurizing the portion where outside air may invade the sleeve and / or cavity in the die-casting device from the outside until the die-cast product is taken out. Decompression casting method for The said oxygen gas supply means of Claim 11 WHEREIN: In the said oxygen purge process, the said oxygen gas supply means and the first opening / closing valve means provided between the cavity and the oxygen gas supply means and between the cavity and the first pressure reducing means are opened. The cavity is in a communicable state, the second on-off valve means provided between the first on-off valve means and the oxygen gas supply means is in an open state, and the cavity is opened from the oxygen gas supply device via the first on-off valve means. And supplying oxygen gas into the injection sleeve to discharge from the supply port, filling the cavity and the injection sleeve with oxygen gas, and exhausting a gas other than oxygen gas, and discharging the gas inside the cavity and the injection sleeve. After filling with oxygen gas, the second on-off valve means is closed and the oxygen gas Completing the charge and, In the first depressurization step, after the second on-off valve means is closed, a first period is provided between the first decompression means and the cavity until the filling of the molten metal in the cavity is completed. The first on-off valve means is opened, and the inside of the cavity and the injection sleeve are decompressed by the first pressure-reducing means via the first on-off valve means in the open state, In the second depressurizing step, after the second on / off valve means is closed, a second period until the filling of the molten metal in the cavity is completed, the second decompression means and the outside air invade. The pressure reduction casting method which pressure-reduces the part which the outside air may invade from the said exterior by the said 2nd pressure-reduction means by making the 3rd open / close valve means provided between the possibility parts. The said oxygen gas supply means and said cavity of Claim 11 in the said oxygen purge process WHEREIN: The 1st opening / closing valve means provided between the said cavity and oxygen gas supply means, and between the said cavity and a 1st pressure reduction means is made into the open state, The said oxygen gas supply means and the said cavity Is in a communicable state, the second on-off valve means provided between the first on-off valve means and the oxygen gas supply means is in an open state, and the cavity and the first through the first on-off valve means from the oxygen gas supply device. Oxygen gas is supplied into the injection sleeve to be discharged from the supply port, and the oxygen gas into the cavity and into the injection sleeve is filled with oxygen gas and exhausts a gas other than oxygen gas, and the oxygen gas into the cavity and into the injection sleeve. The oxygen gas filling with the second on-off valve means in a closed state after And the finished, In the first decompression step, after the second on / off valve means is closed, the first decompression means is started until a second injection of the molten metal into the cavity by the injection plunger at a second speed is started. Depressurizing the inside of the cavity and the injection sleeve by the first pressure reducing means through the first opening / closing valve means provided in the open state with the first opening / closing valve means provided between the cavity and the cavity; In the second depressurizing step, after the second on / off valve means is closed, a period of time between the process of filling the molten metal in the cavity is completed, the second depressurizing means and the outside air may invade. The pressure reduction casting method which pressure-reduces the part which the said external air may invade by said 2nd pressure reduction means by making the 3rd open / close valve means provided between these parts into an open state.

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