JP2006068814A - Vacuum die casting apparatus and vacuum die casting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum die casting apparatus and a vacuum die casting method in which gasified releasing agent and water from a gap between the inner peripheral surface of a fixed holder and the outer peripheral surface of a fixed die and a gap between the inner peripheral surface of a movable holder and the outer peripheral surface of a movable die, are not sucked-out into dividing surfaces of the dies for die casting with a negative pressure, when the pressure is reduced in a cavity. <P>SOLUTION: In the die 2 for die casting in the vacuum die casting apparatus 1, a fixed die inner chamber 3C and a movable die inner chamber 4C are formed. A releasing agent and water are prevented from entering the gap S between the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B, and the gap S between the inner peripheral surface 4d of the movable holder 4A and the outer peripheral surface 4e of the movable die 4B by pressure-supplying the air into the fixed die inner chamber 3C and the movable die inner chamber 4C with a compressed air supplying device 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum die casting apparatus and a vacuum die casting method, and in particular, a vacuum die casting that prevents cooling water and a release agent from being sucked out from a gap between a die and a holder onto a split surface of the die casting mold when the cavity is decompressed. The present invention relates to an apparatus and a vacuum die casting method using the vacuum die casting apparatus.

  The die casting mold of the vacuum die casting apparatus is provided with a fixed die and a movable die that define a cavity, and a pin member such as a cast pin or an extrusion pin protruding into the cavity is formed on the movable die or the fixed die. It is provided penetrating through the pin member through hole. After die casting, the mold is opened and the extrusion pin is operated to separate the die-cast product from the cavity. Thereafter, the die-casting die is externally cooled or a release agent is applied to the cavity. At this time, there is a possibility that a mold release agent or moisture may enter the gap of the die casting mold.

  After the mold clamping, the cavity is filled with molten metal. At that time, there is a possibility that the release agent and water remaining in the gaps of the die casting mold are returned to the cavity. In particular, in order to prevent air from getting into the molten metal, when the molten metal is filled while reducing the cavity after clamping, the mold release agent and water remaining in the gaps of the die casting mold The vacuum is positively sucked into the cavity by the negative pressure at the time of decompression, and pyrolysis gas is generated by contact with the molten metal at the time of injection, and a cast hole is generated due to the entrainment of the gas, or the molten metal is excessively cooled and the molten metal flow is poor. Will occur.

  In order to overcome such a problem, Japanese Patent Publication No. 7-85829 discloses a vacuum in which a release agent interposed in a gap between a pin member and a pin member through hole of a die is discharged before filling the cavity with molten metal. Describes the die casting method. In the vacuum die casting method described in this publication, an in-mold chamber communicating with the pin member through hole is formed in a die supporting the pin member. One end of the in-mold chamber is connected to a vacuum pump via a vacuum tank. Further, this in-mold chamber is provided with a cut-off pin for selectively blocking communication with the cavity. When the cut-off pin is in the forward position, the in-mold chamber is blocked with the cut-off pin, and the cavity is When the pressure is reduced by the vacuum pump and the cut-off pin is in the retracted position, the in-mold chamber is configured to communicate with the vacuum pump.

After a mold release agent is applied to the cavity in the mold open state, the mold is clamped to define the cavity. In the state where the cut-off pin is in the retracted position, the pressure in the mold chamber is lowered by the operation of the vacuum pump. Therefore, the mold release agent in a slight gap between the outer peripheral surface of the pin member and the inner peripheral surface of the pin member through hole is sucked out from the gap into the mold chamber. Next, the cut-off pin is switched to the forward position to fill the cavity with molten metal.
Japanese Patent Publication No. 7-85829

  According to the vacuum die casting method described in the above publication, the release agent interposed between the pin member and the pin member through-hole of the die can be discharged before the molten metal is filled into the cavity. However, no measures are taken for the mold release agent and water that enter the gap between the inner peripheral surface of the holder constituting the die casting mold and the outer peripheral surface of the die. Compared to the slight gap between the pin member and the pin member through hole of the die, the amount of mold release agent and water entering the gap between the inner peripheral surface of the holder and the outer peripheral surface of the die is overwhelmingly large. The release agent and water are vaporized when the cavity is depressurized, and are sucked out by the negative pressure onto the dividing surface of the die casting mold. Since the split surface of the die casting mold communicates with the runner and exhaust runner communicating with the cavity, the vaporized mold release agent and water may affect the die casting product.

  In view of this, the present invention provides a separation between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die and the gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die when the cavity is decompressed. It is an object of the present invention to provide a vacuum die casting apparatus and a vacuum die casting method in which a mold agent and water are not sucked out by a negative pressure onto a dividing surface of a die casting mold.

  In order to achieve the above object, the present invention provides a fixed mold 3 comprising a fixed holder 3A and a fixed die 3B, a movable mold 4 comprising a movable holder 4A and a movable die 4B, the fixed die 3B and the movable die 4B. In the vacuum die casting apparatus 1 having vacuum evacuation means 17 and 18 for depressurizing the cavity 5 defined by the above, the inner surface 3d of the fixed holder 3A is defined by following the rear edge 3c of the fixed die 3B. And a fixed inner chamber 3C communicating with a gap S between the outer peripheral surface 3e of the fixed die 3B and a rear surface edge 4c of the movable die 4B. The inner peripheral surface 4d of the movable holder 4A is defined. And a movable inner chamber 4C communicating with a gap S between the outer peripheral surface 4e of the movable die 4B, and compression for supplying air to the fixed inner chamber 3C and the movable inner chamber 4C under pressure. It provides a vacuum die casting apparatus 1 provided with the air supply device 21.

  Here, it is preferable that the vacuum exhaust means 17 and 18 can depressurize the fixed inner chamber 3C and the movable inner chamber 4C.

  In the present invention, when performing the vacuum die casting method using the vacuum die casting apparatus according to claim 1, at least when the stationary mold 3 and the movable mold 4 are externally cooled or when the release agent is applied to the cavity 5 On the other hand, the compressed air supply device 21 pressurizes and supplies air to the fixed mold inner chamber 3C and the movable mold inner chamber 4C, and the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B The vacuum die casting method is characterized in that air is ejected from the gap S between the gap S and the gap S between the inner peripheral face 4d of the movable holder 4A and the outer peripheral face 4e of the movable die 4B.

  The present invention also relates to a cavity defined by a fixed mold 3 comprising a fixed holder 3A and a fixed die 3B, a movable mold 4 comprising a movable holder 4A and a movable die 4B, and the fixed die 3B and the movable die 4B. In the vacuum die casting apparatus 1 having vacuum evacuation means 17 and 18 for depressurizing 5, the inner surface 3d of the fixed holder 3A and the fixed die 3B are defined along the rear edge 3c of the fixed die 3B. The fixed inner chamber 3C communicated with the gap S between the outer peripheral surface 3e and the rear surface edge 4c of the movable die 4B. The inner surface 4d of the movable holder 4A and the movable die 4B Provided is a vacuum die casting apparatus 1 that includes a movable inner chamber 4C that communicates with a gap S between the outer peripheral surface 4e and can depressurize the fixed inner chamber 3C and the movable inner chamber 4C. I am serving.

  Further, in the present invention, when performing the vacuum die casting method using the vacuum die casting apparatus according to claim 4, before or during the decompression of the cavity 5 by the vacuum exhaust means 17, 18, the fixed inner chamber 3 </ b> C. And a vacuum die casting method characterized by reducing the pressure in the movable inner chamber 4C.

  The present invention also relates to a cavity defined by a fixed mold 3 comprising a fixed holder 3A and a fixed die 3B, a movable mold 4 comprising a movable holder 4A and a movable die 4B, and the fixed die 3B and the movable die 4B. In the vacuum die casting apparatus 1 having vacuum evacuation means 17 and 18 for depressurizing 5, the fixed die is defined in accordance with the rear surface edge of the buried 23 accommodated and fixed in the fixed die 3B or the movable die 4B. 3B or a die inner chamber 4E communicating with a gap S between the inner peripheral surface of the movable die 4B and the outer peripheral surface of the buried 23, and a compressed air supply device 21 that pressurizes and supplies air to the inner chamber 4E. The vacuum die casting apparatus 1 is provided.

  The present invention also relates to a cavity defined by a fixed mold 3 comprising a fixed holder 3A and a fixed die 3B, a movable mold 4 comprising a movable holder 4A and a movable die 4B, and the fixed die 3B and the movable die 4B. In the vacuum die casting apparatus 1 having vacuum evacuation means 17 and 18 for depressurizing 5, the fixed die 3B is defined following the rear surface edge portion of the buried 23 accommodated and fixed in the fixed die 3B or the movable die 4B. 3B or an in-die chamber 4E communicating with a gap S between the inner peripheral surface of the movable die 4B and the outer peripheral surface of the buried 23, and the in-die chamber 4E can be depressurized. A die casting apparatus 1 is provided.

  The present invention also provides a vacuum die casting method in which vacuum die casting is performed using the vacuum die casting apparatus 1 of claim 6 or claim 7.

  According to the vacuum die casting apparatus of the first aspect of the present invention, air is pressurized and supplied to the fixed mold inner chamber and the movable mold inner chamber by the compressed air supply device, so that the fixed mold and the movable mold can be externally cooled and the cavity During application of the release agent to the cooling water, the cooling water or the release agent causes a gap between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die, and a gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die. It is possible to prevent intrusion. Therefore, when the cavity is decompressed, the release agent or water vaporized from the gap between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die or the gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die is removed. It is possible to prevent the die-cast product from becoming defective due to being sucked out by the negative pressure onto the dividing surface of the die-cast mold.

  According to the vacuum die casting apparatus of claim 2 of the present invention, the cooling water or the release agent is applied to the inner peripheral surface of the fixed holder and the fixed die when the fixed mold and the movable mold are externally cooled or when the mold release agent is applied to the cavity. The mold release agent and water are discharged into the fixed mold inner chamber and the movable mold inner chamber even if it enters the gap between the outer periphery of the mold and the gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die. It is possible. Therefore, it is possible to more reliably prevent the vaporized release agent and water from being sucked out by the negative pressure onto the dividing surface of the die casting mold.

  According to the vacuum die casting method described in claim 3 of the present invention, when the vacuum die casting method is performed using the vacuum die casting apparatus described in claim 1, a release agent is applied to the cavity during external cooling of the fixed mold and the movable mold. Since the compressed air is pressurized and supplied to the fixed inner chamber and the movable inner chamber by the compressed air supply device at least at one of the times, the cooling water and the release agent are transferred to the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die. It is possible to prevent intrusion into the gap between the gap and the gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die. Therefore, when the cavity is decompressed, the release agent or water vaporized from the gap between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die or the gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die is removed. It is possible to prevent the die-cast product from becoming defective due to being sucked out by the negative pressure onto the dividing surface of the die-cast mold.

  According to the vacuum die casting apparatus of the fourth aspect of the present invention, the pressure between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die is reduced during decompression of the cavity by reducing the pressure in the fixed inner chamber and the movable inner chamber. The mold release agent and water vaporized from the gap and the gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die are sucked out by the negative pressure to the dividing surface of the die casting mold, and the die cast product becomes defective. Can be prevented.

  According to the vacuum die casting method of the fifth aspect of the present invention, when performing the vacuum die casting method using the vacuum die casting apparatus according to the fourth aspect of the present invention, the chamber is fixed in the fixed mold before or simultaneously with the decompression of the cavity by the vacuum exhaust means. Since the pressure in the movable mold chamber is reduced, the gap between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die and the gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die are reduced when the cavity is depressurized. It is possible to prevent the vaporized release agent and water from being sucked out by the negative pressure onto the dividing surface of the die-casting die and causing the die-cast product to become defective.

  According to the vacuum die casting apparatus of the sixth aspect of the present invention, the air is pressurized and supplied to the chamber in the die by the compressed air supply device, so that the mold release agent is applied to the cavity during the external cooling of the fixed mold and the movable mold. Sometimes, it is possible to prevent the cooling water or the release agent from entering the gap between the inner peripheral surface of the fixed die or the movable die and the outer peripheral surface of the buried die. Therefore, when the cavity is depressurized, the release agent or water vaporized from the gap between the inner peripheral surface of the fixed die or movable die and the outer peripheral surface of the buried die is sucked into the cavity by negative pressure, resulting in a defective die cast product. Can be prevented.

  According to the vacuum die casting apparatus of the seventh aspect of the present invention, by depressurizing the chamber in the die, vaporization is performed from the gap between the inner peripheral surface of the fixed die or the movable die and the outer peripheral surface of the buried member when the cavity is decompressed. It is possible to prevent the mold release agent and water from being sucked into the cavity by negative pressure and causing the die cast product to become defective.

  According to the vacuum die casting method of claim 8 of the present invention, since the vacuum die casting apparatus of claim 6 or claim 7 is used, the inner peripheral surface of the fixed die or the movable die and the outer peripheral surface of the buried die when the cavity is decompressed Vacuum die casting can be performed while preventing the release agent and water vaporized from the gap between them from being sucked into the cavity by negative pressure and causing the die cast product to become defective.

 A vacuum die casting apparatus and a vacuum die casting method according to an embodiment of the present invention will be described with reference to FIGS. The vacuum die casting apparatus 1 includes a die casting mold 2, and the die casting mold 2 includes a fixed mold 3 and a movable mold 4 that contacts and separates from the fixed mold 3. The contact surface between the fixed mold 3 and the movable mold 4 is a divided surface (PL surface) of the die casting mold 2. The fixed mold 3 includes a fixed holder 3A and a fixed die 3B that is housed and fixed in the fixed holder 3A and defines a part of the cavity 5. An injection sleeve 6 having a hot water supply port 6a is connected to the fixed holder 3A. An injection plunger 7 for filling the cavity 5 with the molten metal M such as an aluminum alloy supplied from the hot water supply port 6a is provided in the injection sleeve 6 so as to be reciprocally slidable. An exhaust runner 3a is formed on the split surface of the fixed holder 3A and the fixed die 3B (the split surface of the die casting mold 2), and a vacuum valve 8 communicating with the exhaust runner 3a is accommodated and disposed above the fixed holder 3A. .

  The movable mold 4 includes a movable holder 4A and a movable die 4B accommodated and fixed in the movable holder 4A. The movable die 4B defines the cavity 5 together with the fixed die 3B. A diverter 9 is accommodated and fixed in the movable holder 4A. A runner 4 a that guides the molten metal M to the cavity 5 through the flow divider 9 is formed on the dividing surface of the movable die 4 </ b> B (dividing surface of the die casting mold 2). The movable holder 4 </ b> A and the movable die 4 </ b> B are formed with extrusion pin through holes 10 and 11 having one end opened into the cavity 5. Extrusion pins 12 and 13 are disposed in the extrusion pin through holes 10 and 11, respectively. The rear ends of the extruding pins 12 and 13 are fixed to the extruding plate 14, and the extruding plate 14 is driven by a driving mechanism (not shown) or a mechanism that cooperates with the opening / closing operation of the movable mold 4. It can project and retract with respect to the cavity 5.

  A groove 4g is formed on the surface 4f of the movable holder facing the rear surface 4b of the movable die 4 so as to follow the entire periphery of the rear surface edge 4c of the rear surface 4b of the movable die. The movable die 4B is accommodated and fixed to the movable holder 4A. Thus, a movable inner chamber 4 </ b> C is defined in the movable mold 4. The movable inner chamber 4C is defined along the entire circumference of the rear surface edge 4c of the rear surface 4b of the movable die 4B, and a gap between the inner peripheral surface 4d of the movable holder and the outer peripheral surface 4e of the movable die 4B. S communicates. The movable holder 4A is formed with a movable inner passage 4D that communicates the movable inner chamber 4C with a vacuum tank 17 and a compressed air supply device 21, which will be described later.

  As in the movable mold 4, a groove 3g is formed on the surface 3f of the fixed holder facing the rear surface 3b of the fixed die 3 so as to follow the rear edge 3c of the rear surface 3b of the fixed die, and is fixed to the fixed holder 3A. A fixed mold chamber 3C is defined in the fixed mold 3 by accommodating and fixing the die 3B. The fixed mold inner chamber 3C is defined along the entire circumference of the rear surface edge 3c of the rear surface 3b of the fixed die, and a gap between the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B. S communicates. However, in the part P where the rear surface edge 3c of the fixed die 3 abuts against the injection sleeve 6, the fixed inner chamber 3C is defined following the outer peripheral surface 6b of the injection sleeve 6, and the outer peripheral surface 3e of the fixed die 3B. And the outer peripheral surface 6b of the injection sleeve 6 communicate with each other. The fixed holder 3A is formed with a fixed mold inner passage 3D for communicating the fixed mold inner chamber 3C with a vacuum tank 17 and a compressed air supply device 21 described later.

  A sealing member 15 such as an O-ring for sealing between the fixed holder 3A and the movable holder 4A at the time of mold clamping is provided on the dividing surface of the movable holder 4A (divided surface of the die casting mold 2). Further, a seal member 16 such as an O-ring is provided between the push pin through holes 10 and 11 and the push pins 12 and 13.

  The vacuum valve 8 is held at a communication position where a vacuum tank 17 (described later) and the exhaust runner 3a communicate with each other until a melt detection sensor (not shown) disposed at a predetermined position of the exhaust runner 3a detects the melt. When the detection sensor detects the molten metal, it can be switched to a blocking position that blocks this communication. FIG. 1 shows the vacuum valve 8 held in the communication position.

  A vacuum tank 17 is connected to the vacuum valve 8 via an electromagnetic valve 19. Here, the electromagnetic valve 19 is provided so as to be switchable between a communication position where the vacuum valve 8 and the vacuum tank 17 are communicated with each other and a blocking position where the communication between the two is blocked. The vacuum tank 17 is connected to the fixed inner passage 3D and the movable inner passage 4D via the electromagnetic valve 20. Here, the solenoid valve 20 is provided so as to be switchable between a communication position where the vacuum tank 17 communicates with the fixed inner passage 3D and the movable inner passage 4D and a blocking position where communication between the two is interrupted. The vacuum tank 17 is connected to a vacuum pump 18, and the vacuum tank 17 and the vacuum pump 18 constitute a vacuum exhaust means.

  A compressed air supply device 21 is connected to the fixed inner passage 3D and the movable inner passage 4D via the electromagnetic valve 22. Here, the solenoid valve 22 is provided so as to be switchable between a communication position where the compressed air supply device 21 communicates with the fixed inner passage 3D and the movable inner passage 4D and a shut-off position where communication between the two is interrupted.

  A release agent spray device (not shown) is provided in the vicinity of the die casting mold 2 so that the space between the fixed mold 3 and the movable mold 4 can be moved back and forth when the mold is opened. A robot (not shown) for taking out the die-cast product and a cooling water supply device (not shown) for externally cooling the die-cast die 2 are arranged in the vicinity of the die-cast die 2.

  In the vacuum die casting method, the fixed mold 3 and the movable mold 4 are opened, a release agent spray device (not shown) is inserted into the space between the fixed mold 3 and the movable mold 4, and the mold release agent is put into the cavity 5. Apply. At this time, the electromagnetic valve 22 is switched to the communication position, and the compressed air supply device 21 is operated to pressurize and supply the compressed air to the fixed inner chamber 3C and the movable inner chamber 4C. Thus, air is generated from the gap S between the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B and the gap S between the inner peripheral surface 4d of the movable holder 4A and the outer peripheral surface 4e of the movable die 4B. Is ejected toward the space between the fixed mold 3 and the movable mold 4, and the mold release agent applied by the mold release spraying device is formed between the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B. The gap S and the gap S between the inner peripheral surface 4d of the movable holder 4A and the outer peripheral surface 4e of the movable die 4B are prevented from entering. After the application of the release agent is completed, the compressed air supply device 21 is stopped and the electromagnetic valve 22 is switched to the cutoff position.

  Next, the fixed mold 3 and the movable mold 4 are closed, the electromagnetic valve 20 is switched to the communication position, and the vacuum pump 18 is operated to depressurize the fixed mold inner chamber 3C and the movable mold inner chamber 4C. When the mold 4 is externally cooled, the clearance S between the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B and the clearance between the inner peripheral surface 4d of the movable holder 4A and the outer peripheral surface 4e of the movable die 4B The cooling water that has entered S and the release agent that could not be prevented from entering when the release agent is applied to the cavity 5 are discharged to the fixed inner chamber 3C and the movable inner chamber 4C. Thereafter, in a state where the vacuum valve 8 is held at the communication position, the electromagnetic valve 19 is switched to the communication position to decompress the cavity 5. After the pressure reduction of the cavity 5 is thus started and the cavity 5 is set to a predetermined degree of vacuum, the molten metal M in the injection sleeve 6 is pressurized by the injection plunger 7, and the molten metal M is supplied to the cavity 5 through the flow divider 9 and the runner 4a. Fill. When the molten metal M filling the cavity 5 is detected by a molten metal detection sensor (not shown) disposed in the exhaust runner 3a, the vacuum valve 8 is switched to the cutoff position.

  Thereafter, the mold is opened, and the extrusion plate 14 is driven by a driving mechanism (not shown) or a mechanism that cooperates with the opening / closing operation of the movable mold, so that the extrusion pins 12 and 13 separate the die-cast product from the cavity 5. A robot (not shown) takes out the die-cast product, and a cooling water supply device (not shown) externally cools the fixed mold 3 and the movable mold 4 to complete one cycle of the vacuum die casting method.

  The vacuum die casting apparatus and vacuum die casting method of the present invention are not limited to the above-described embodiments, and various modifications and improvements can be made within the scope described in the claims. For example, in the present embodiment, the compressed air supply device 21 supplies compressed air to the fixed inner chamber 3C and the movable inner chamber 4C at the time of applying the release agent to the cavity 5, but the cooling water supply device Even when the fixed mold 3 and the movable mold 4 are externally cooled, compressed air may be supplied to the fixed mold inner chamber 3C and the movable mold inner chamber 4C. By doing so, the clearance S between the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B and the inner peripheral surface 4d of the movable holder 4A when the fixed mold 3 and the movable mold 4 are externally cooled. It is possible to prevent the cooling water from entering the gap S between the outer peripheral surface 4e of the movable die 4B.

  The compressed air supply device 21 supplies air to the fixed mold inner chamber 3C and the movable mold inner chamber 4C at least one of when the fixed mold 3 and the movable mold 4 are externally cooled or when a release agent is applied to the cavity 5. But you can.

  In the present embodiment, the fixed inner chamber 3C and the movable inner chamber 4C are depressurized. However, in the case where the release of the release agent and water can be sufficiently prevented by compressed air, the fixed inner chamber The decompression of 3C and movable inner chamber 4C may not be performed.

  In the present embodiment, the pressure in the cavity 5 is started after the pressure in the fixed inner chamber 3C and the movable inner chamber 4C is reduced, but the fixed inner chamber 3C and the movable inner chamber 4 bar C are connected to the cavity. The pressure may be reduced simultaneously with 5. That is, the timing for starting depressurization of the fixed inner chamber 3C and the movable inner chamber 4C may be any time before or after the cavity 5 is depressurized.

  In the present embodiment, the fixed inner chamber 3C and the movable inner chamber 4C are depressurized by the evacuating means for depressurizing the cavity 5. However, a different vacuum evacuating means is movable between the fixed inner chamber 3C and the movable inner chamber 3C. The pressure may be reduced by connecting to the in-mold chamber 4C.

  In the present embodiment, the compressed air is supplied to the fixed inner chamber 3C and the movable inner chamber 4C by the compressed air supply device 21 when the release agent is applied to the cavity 5. Alternatively, the pressure in the fixed inner chamber 3C and the movable inner chamber 4C may be depressurized before or simultaneously with the depressurization of the cavity 5.

  Further, in the present embodiment, the fixed inner chamber 3 </ b> C following the outer peripheral surface 6 b of the injection sleep 6 is defined also in the portion P where the rear surface edge 3 c of the fixed die 3 contacts the injection sleeve 6. For the portion where the fixed inner chamber 3C does not communicate with the gap S between the inner peripheral surface 3d of the fixed holder 3A and the outer peripheral surface 3e of the fixed die 3B, such as P, the fixed inner chamber 3C is not defined. Good. The same applies to the movable inner chamber 4C.

  Further, the present embodiment can also be applied to the case where a buried element is accommodated and fixed in the fixed die 3B or the movable die 4B. For example, as shown in FIG. 1, when the buried 23 is accommodated and fixed to the fixed die 3B, it is defined along the entire circumference of the rear edge of the rear surface of the buried 23, and the inner periphery of the movable die 4B is formed. An in-die chamber 4E communicating with a gap S between the surface and the outer peripheral surface of the buried member 23 is provided, and the in-die chamber 4E is connected to at least one of the compressed air supply device 21 and the vacuum exhaust means through a passage. It may be. By doing in this way, it is prevented that the mold release agent and water which were vaporized at the time of pressure reduction of the cavity 5 are sucked into the cavity 5 by the negative pressure from the gap between the inner peripheral surface of the die and the outer peripheral surface of the filling 23. Is possible.

  In the present embodiment, the movable inner passage 4D communicates with the upper corner of the movable inner chamber 4C. However, the present invention is not limited to this. For example, as shown in FIG. 3, if the movable inner passage 4D is communicated with the lower corner of the movable inner chamber 4C, the release agent and water are prevented from remaining in the movable inner chamber 4C. It is advantageous. Similarly, the fixed inner mold passage 3D may be communicated with the lower corner of the fixed inner mold path 3C.

  Further, a blocking means for preventing the molten metal from reaching the seal member 15 may be provided. The damming means is, for example, a protrusion protruding from the dividing surface of the fixed holder 3A and a groove formed in the dividing surface of the movable holder 4A so as to engage with the protrusion during mold matching. Even if the molten metal flows out to the dividing surface, the molten metal is blocked by the protrusions of the blocking means, so that the seal member 15 is not damaged by the molten metal. The damming means may be appropriately provided at a position where the molten metal easily flows out from the dividing surface, such as a position between the seal member 15 and the vacuum valve 8 in FIG.

  The vacuum die casting apparatus and vacuum die casting method of the present invention are extremely useful in the field of vacuum die casting methods for die casting of high quality products.

Sectional drawing of the vacuum die-casting apparatus by this Embodiment. The AA sectional view of Drawing 1 which omitted an extrusion pin penetration hole and an extrusion pin. The AA sectional view of Drawing 1 which omitted an extrusion pin penetration hole and an extrusion pin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum die casting apparatus 2 Die-casting die 3 Fixed mold 3A Fixed holder 3B Fixed die 3C Fixed mold inner chamber 3c Rear surface edge 3d Inner peripheral surface

3e outer peripheral surface 4 movable type 4A movable holder 4B movable die 4C movable type inner chamber 4E die inner chamber 4c rear edge 4d inner peripheral surface 4e outer peripheral surface 5 cavity 8 vacuum valve 17 vacuum tank 18 vacuum pump 21 compressed air supply device 23 buried Child

Claims (8)

  In a vacuum die casting apparatus having a fixed mold composed of a fixed holder and a fixed die, a movable mold composed of a movable holder and a movable die, and a vacuum exhaust means for decompressing a cavity defined by the fixed die and the movable die. The fixed die inner chamber is defined by following the rear surface edge of the fixed die and communicates with the gap between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die, and the rear surface edge of the movable die. A movable inner chamber that is defined by copying and communicates with a gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die, and air is pressurized to the fixed inner chamber and the movable inner chamber. A vacuum die casting apparatus characterized by comprising a compressed air supply device for supplying.   2. The vacuum die casting apparatus according to claim 1, wherein the vacuum evacuation means can depressurize the fixed inner chamber and the movable inner chamber.   A vacuum die casting method using the vacuum die casting apparatus according to claim 1, wherein the compressed air supply device is used at least when externally cooling the fixed mold and the movable mold or when applying a release agent to the cavity. To pressurize and supply air to the fixed mold inner chamber and the movable mold inner chamber, and the gap between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die and the inner peripheral surface of the movable holder and the movable die. A vacuum die casting method, characterized in that air is ejected from a gap between the outer peripheral surface of the vacuum die.   In a vacuum die casting apparatus having a fixed mold composed of a fixed holder and a fixed die, a movable mold composed of a movable holder and a movable die, and a vacuum exhaust means for decompressing a cavity defined by the fixed die and the movable die. The fixed die inner chamber is defined by following the rear surface edge of the fixed die and communicates with the gap between the inner peripheral surface of the fixed holder and the outer peripheral surface of the fixed die, and the rear surface edge of the movable die. A movable inner chamber that is defined by copying and communicates with a gap between the inner peripheral surface of the movable holder and the outer peripheral surface of the movable die, and the fixed inner chamber and the movable inner chamber can be decompressed. A vacuum die casting apparatus characterized by   5. A vacuum die casting method performed using the vacuum die casting apparatus according to claim 4, wherein the fixed inner chamber and the movable inner chamber are depressurized before or simultaneously with depressurization of the cavity by the vacuum exhaust means. Characteristic vacuum die casting method.   In a vacuum die casting apparatus having a fixed mold composed of a fixed holder and a fixed die, a movable mold composed of a movable holder and a movable die, and a vacuum exhaust means for decompressing a cavity defined by the fixed die and the movable die. It is defined by the rear surface edge of the buried member accommodated and fixed in the fixed die or the movable die, and communicates with a gap between the inner peripheral surface of the fixed die or the movable die and the outer peripheral surface of the buried die. A vacuum die casting apparatus, comprising: a chamber in a die to be pressed; and a compressed air supply device that pressurizes and supplies air to the chamber in the die.   In a vacuum die casting apparatus having a fixed mold composed of a fixed holder and a fixed die, a movable mold composed of a movable holder and a movable die, and a vacuum exhaust means for decompressing a cavity defined by the fixed die and the movable die. It is defined by the rear surface edge of the buried member accommodated and fixed in the fixed die or the movable die, and communicates with a gap between the inner peripheral surface of the fixed die or the movable die and the outer peripheral surface of the buried die. A vacuum die casting apparatus comprising: a chamber in a die that is capable of reducing pressure in the chamber in the die.   A vacuum die casting method, wherein vacuum die casting is performed using the vacuum die casting apparatus according to claim 6 or 7.

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