JP5254135B2 - Degassing machine for die casting machine - Google Patents

Description

  The present invention relates to a gas venting device for a die casting machine, in particular, a vacuum passage communicating with a vacuum source is connected to a cavity formed between opposed surfaces of a fixed mold and a movable mold, and the vacuum passage is opened and closed. The present invention relates to an improvement in a control valve provided with a control valve.

Such a degassing machine of a die-casting machine, as disclosed in Patent Document 1 below, opens the vacuum passage by a control valve before the molten metal flows into the cavity and closes it immediately before filling the molten metal into the cavity. , as well as suction and discharge the residual gas in the cavity, it can to Ru enhances the charging efficiency of the molten metal, can be thereby obtaining a high-quality casting dense.

JP 2000-225453 A

  However, in the gas venting device of a die casting machine, when the molten metal is filled into the cavity, a part of the molten metal may enter the control valve as a foreign substance due to the filling pressure. Cleaning was extremely troublesome and contributed to a reduction in casting efficiency.

  The present invention has been made in view of such circumstances, and when a part of the molten metal enters the control valve as a foreign object, it can be easily removed to contribute to the improvement of casting efficiency. An object of the present invention is to provide a degassing device for a die casting machine.

To achieve the above object, according to the present invention, a vacuum passage communicating with a vacuum source is connected to a cavity formed between opposed surfaces of a fixed mold and a movable mold, and the vacuum passage is controlled to be opened and closed. In the degassing apparatus for a die casting machine provided with a control valve that performs the control valve, the control valve is formed in one of the fixed mold and the movable mold so as to intervene in the vacuum passage. A cylindrical valve chamber having one end opened on the outer surface; a valve member that is detachably accommodated in the valve chamber and that can slide between an open position and a closed position; An actuator mounted to close the open end of the chamber and actuating the valve member, and the vacuum passage is divided into an upstream vacuum passage connected to the vacuum source and a downstream vacuum passage connected to the cavity. Split and its The first port downstream end of the flow-side vacuum passage, respectively are opened into the valve chamber upstream end of the downstream-side vacuum channel as a second port, said valve member includes a piston rod connected to the actuator, the piston A valve piston is formed at the tip of the rod and closes and opens the second port according to the closed position and the open position of the valve member. At the open position of the valve member, the second port is connected to the valve piston. The first feature is that the foreign matter that is positioned closer to the piston rod side and enters the valve chamber from the second port gets on the end surface of the valve piston on the piston rod side . The vacuum source corresponds to the vacuum tank 24 and the vacuum pump 25 in the embodiments of the present invention described later.

According to the present invention, in addition to the first feature, the upstream vacuum passage is configured such that the upstream vacuum passage passes through a mating surface of the fixed mold and the movable mold. And

The present invention, in addition to the first feature, forming the valve member, a piston rod connected to said actuator, said valve piston is formed at the tip of the piston rod, the intermediate portion of the piston rod The third feature is that the first port is disposed between the valve piston and the partition piston.

According to the first feature of the present invention, when a part of the molten metal that has passed through the cavity becomes a foreign object during casting and protrudes into a minute gap around the valve piston of the valve member, the valve piston opens the second port. When the open position is reached, the end of the valve piston on the end of the piston rod will ride. Therefore, when the die-casting machine is stopped, if the actuator is removed from the mold that supports it together with the valve member, Foreign matter on board can be easily taken out of the valve chamber, so that the valve chamber can be easily and quickly cleaned, the clogging of the vacuum passage due to foreign matter can be prevented in advance, and good quality of the cast product can be ensured. It can contribute to the improvement of work efficiency.

According to the second feature of the present invention , in the unlikely event that foreign matter in the valve chamber enters the downstream vacuum passage, the mold is opened, and the downstream from the open surfaces facing the fixed mold and the movable mold. Foreign matter in the side vacuum passage can be easily removed.

  According to the third aspect of the present invention, leakage of the vacuum pressure transmitted from the upstream vacuum passage to the valve chamber to the actuator side can be prevented by the partition piston.

The outline side view of the die-casting machine provided with the degassing device concerning the example of the present invention. It is an enlarged view of the control valve periphery part of FIG. 1, and shows the open state of a control valve. FIG. 3 is a view corresponding to FIG. 2 showing a closed state of the control valve. FIG. 3 is a view corresponding to FIG. 2 showing a state in which foreign matter is removed from the valve chamber.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  First, in FIG. 1, a fixed platen 1 that holds a fixed mold 3 is fixed to a machine base (not shown) of a die casting machine, and a movable platen 2 that holds a movable mold 4 is fixed to a movable mold 4. Is supported by the machine base so as to be movable left and right to open and close the fixed mold 3. The fixed mold 3 and the movable mold 4 are formed so as to form a cavity 5 between opposing surfaces when the mold is closed, and an overflow 7 communicating with the cavity 5 via a restriction 5. The fixed mold 3 is provided with a gate 9 and a runner 10 for communicating the cavity 5 with a front end portion of a sleeve 8 fixed to the fixed platen 1.

  A plunger 12 is fitted to the sleeve 8 from behind so that the plunger 12 can move back and forth. When the plunger 12 is in the retracted position, a hot water supply port 8 a that opens to the front is provided at the top of the sleeve 8. An operating rod 14 protruding forward from an injection cylinder 13 installed on the machine base is coaxially connected to the plunger 12 via a joint 15. Therefore, the plunger 12 can be moved back and forth by operating the operating rod 14 back and forth.

  A plunger position sensor 16 for detecting the position of the plunger 12 is attached to one side of the injection cylinder 13, and a rod holder 18 connected to the sensor rod 17 is connected to the operating rod 14. The plunger position sensor 16 includes a first position A immediately after the plunger 12 crosses the hot water supply port 8 a after pouring into the hot water supply port 8 a and a second position of the plunger 12 immediately before the molten metal fills the cavity 5 by the advancement of the plunger 12. When the position B is detected, a signal corresponding to the position B is output to the electronic control unit 20 described later. For example, a linear encoder is used for the plunger position sensor 16.

  Next, the degassing device of this die casting machine will be described.

  This degassing device has a vacuum passage 21 extending from the overflow 7 and passing through the movable die 4 and the stationary die 3 to reach the upper surface of the stationary die 3, and a vacuum joint on the upper surface of the stationary die 3 in the vacuum passage 21. A vacuum conduit 23 connected through the vacuum conduit 22, a vacuum tank 24 connected to the vacuum conduit 23, a vacuum pump 25 for accumulating the vacuum pressure in the vacuum tank 24, and a vacuum passage provided in the movable mold 4. And a control valve 26 that controls the opening and closing of the valve 21.

  Next, the control valve 26 will be described with reference to FIGS.

  The control valve 26 includes a cylindrical valve chamber 29 provided in the movable mold 4 so that one end is opened to the upper surface of the movable mold 4, and a valve member 30 slidably fitted in the valve chamber 29. , And an actuator 31 attached to the movable mold 4 for operating the valve member 30 to the open position D (FIG. 2) and the closed position C (FIG. 3).

  The vacuum passage 21 is divided by a valve chamber 29 into an upstream vacuum passage 27 continuous to the vacuum pump 25 side and a downstream vacuum passage 28 continuous to the cavity 5 side, and the downstream end of the upstream vacuum passage 27 is a first end. The port 27a opens to the valve chamber 29, and the upstream end of the downstream vacuum passage 28 opens as a second port 28a below the first port 27a.

The valve member 30 includes a piston rod 30a connected to the actuator 31, a valve piston formed at the tip of the piston rod 30a and sliding on the valve chamber 29, and formed at an intermediate portion of the piston rod 30a. And a partition piston 30c that slides on the wall. The valve piston is configured to close and open the second port 28a according to the closed position C and the open position D of the valve member 30, and the first port 27a is connected to the closed position C and the open position of the valve member 30. Regardless of the position D, it is always placed in an open state between the partition piston 30c and the valve piston. And the foreign substance F (refer FIG. 2) which penetrate | invaded into the valve chamber 29 from the 2nd port 28a gets on the end surface by the side of the piston rod 30a of a valve piston, and an upper end surface in the example of illustration .

The upstream vacuum passage 27 is configured such that the upstream vacuum passage 27 passes through the mating surfaces of the fixed mold 3 and the movable mold 4. Therefore, when the mold is opened, the upstream-side vacuum passage 27 is opened to the open surfaces of the fixed mold 3 and the movable mold 4 that face each other.

  The actuator 31 is detachably fixed to the upper surface of the movable mold 4 by a plurality of bolts 32 (only one of which is shown in the figure) and is slidably fitted to the hydraulic cylinder 33. The operating piston 34 is divided into an upper second oil chamber 33a and a lower second oil chamber 33b. The piston rod 30a of the valve member 30 is connected to the operating piston 34. .

  The hydraulic cylinder 33 is connected to first and second hydraulic conduits 35 and 36 connected to the first and second oil chambers 33a and 33b, respectively. These first and second hydraulic conduits 35 and 36, a hydraulic pump 37, and An electromagnetic switching valve 40 is interposed between the oil tank 38 and the first and second hydraulic conduits 35 and 36 so as to communicate with the hydraulic pump 37 and the oil tank 38 alternately.

  Thus, when the switching valve 40 occupies the right movement position shown in FIG. 2, the hydraulic pressure discharged from the hydraulic pump 37 is supplied to the second oil chamber 33a, and the second oil chamber 33b is opened to the oil tank 38. As a result, the operating piston 34 descends to operate the valve member 30 to the open position D, and when the switching valve 40 occupies the left movement position shown in FIG. 3, the hydraulic pressure is supplied to the second oil chamber 33b. At the same time, when the second oil chamber 33a is opened to the oil tank 38, the operating piston 34 rises to operate the valve member 30 to the closed position C.

  In FIG. 1, reference numeral 20 denotes an electronic control unit 20, which controls the on-off valve 39 and the switching valve 40 in the following manner according to the output signal of the plunger position sensor 16. That is, when the electronic control unit 20 receives a signal corresponding to the first position A of the plunger 12 from the plunger position sensor 16, the electronic control unit 20 opens the on-off valve 39 and moves the switching valve 40 to the right to move the plunger 12 to the second position. When a signal corresponding to B is received, the on-off valve 39 is closed and the switching valve 40 is moved to the left.

  Next, the operation of this embodiment will be described.

  Now, in order to start casting, as shown in FIG. 1, the movable mold 4 is closed with respect to the fixed mold 3 to form the cavity 5, and a predetermined amount of molten metal is injected into the hot water supply port 8a. When the plunger 12 is advanced together with the actuating rod 14 by the operation of this, and the plunger 12 comes to the first position A immediately after crossing the hot water supply port 8a, the plunger position sensor 16 sends a signal corresponding to the first position to the electronic control unit. Therefore, the electronic control unit 20 opens the on-off valve 39 and moves the switching valve 40 to the right as described above (see FIG. 2).

  Thus, when the on-off valve 39 is opened, the upstream side vacuum passage 27 is opened to the valve chamber 29. On the other hand, according to the right movement of the switching valve 40, the discharge pressure of the hydraulic pump 37 is supplied to the second oil chamber 33a of the hydraulic cylinder 33, and the operating piston 34 lowers the valve member 30 to the open position D by the hydraulic pressure. Therefore, the valve piston opens the second port of the downstream side vacuum passage 28 to the valve chamber 29. As a result, the vacuum passage 21 becomes conductive through the valve chamber 29, and the vacuum pressure of the vacuum tank 24 is transmitted to the overflow 7 and the cavity 5 through the vacuum passage 21 and the valve chamber 29. The gas remaining inside is sucked into the vacuum tank 24 and discharged from the vacuum pump 25 to the outside.

Next, when the plunger 12 further moves forward and reaches the second position B immediately before the molten metal fills the cavity 5, the plunger position sensor 16 outputs a signal corresponding to the second position B to the electronic control unit 20. The electronic control unit 20 closes the on-off valve 39 and moves the switching valve 40 to the left (see FIG. 3) in accordance with the above, so that the upstream vacuum passage 27 is blocked and the hydraulic valve 37 is discharged by the left movement of the switching valve 40. The pressure is supplied to the second oil chamber 33b of the hydraulic cylinder 33, and the operating piston 34 raises the valve member 30 to the closed position C by the hydraulic pressure, and the second port 28a is shut off by the valve piston. As a result, since both the upstream vacuum passage 27 and the downstream vacuum passage 28 are cut off, the molten metal is pressurized and filled into the cavity 5 by further advancement of the plunger 12. At that time, part of the molten metal in the cavity 5, extruding the overflow 7 with impurities such as oxides present in the upper part, but still buy toward the downstream vacuum channel 28, interrupted by the second port 28a is a valve piston Therefore, the molten metal can be prevented from flowing out from the downstream vacuum passage 28 to the valve chamber 29. Thus, in the cavity 5, a high-quality and high-density cast product with extremely few impurities is formed.

  Waiting for the solidification of the cast product, the plunger 12 is retracted to the initial retracted position by the injection cylinder 13 and the movable mold 4 is retracted from the fixed mold 3, that is, the mold is opened. At that time, if the cast product is pushed out of the cavity 5 by using an ejector pin (not shown) by using the retreat of the movable mold 4, the casting unnecessary portion filling the overflow 7 and the downstream side vacuum passage 28 is also simultaneously movable mold. 4 can be taken out.

Thereafter, casting is performed by repeating the same operation, and during this time, a part of the molten metal may protrude from the second port 28a of the downstream side vacuum passage 28 as a foreign substance F into a minute gap around the valve piston. Such foreign matter F gets on the end surface of the valve piston 30b on the piston rod 30a side when the valve piston reaches the opening position D below the second port 28a.

  Therefore, when the die casting machine is stopped, if the bolt 32 is removed and the hydraulic cylinder 33 of the actuator 31 is lifted together with the valve member 30 above the movable mold 4 as shown in FIG. Can be taken out of the valve chamber 29.

  Thus, the foreign matter F in the valve chamber 29 can be taken out of the valve chamber 29 together with the valve piston by a simple operation of simply lifting the valve member 30 out of the valve chamber 29. Therefore, the clogging of the vacuum passage 21 due to the foreign matter F can be prevented in advance, and it is possible to contribute to ensuring good quality of the cast product and improving the efficiency of the casting operation.

Further, the upstream vacuum passage 21 is configured so that the upstream vacuum passage 21 passes through the mating surface of the fixed mold 3 and the movable mold 4, and when the fixed mold 3 and the movable mold 4 are opened, the upstream vacuum passage 21 is Since the passage 27 opens to the open surfaces of the fixed mold 3 and the movable mold 4 that face each other, if the foreign matter F in the valve chamber 29 enters the downstream vacuum passage 28, the mold is opened. Thus, the foreign matter F in the downstream vacuum passage 28 can be easily removed from the open surfaces of the fixed mold 3 and the movable mold 4 facing each other.

  The valve member 30 includes a piston rod 30a connected to the actuator 31, the valve piston formed at the tip of the piston rod 30a, and a partition piston 30c formed at the intermediate portion of the piston rod 30a. Since the first port 27a of the upstream vacuum passage 27 is disposed between the valve piston and the partition piston 30c, leakage of the vacuum pressure transmitted from the upstream vacuum passage 27 to the valve chamber 29 to the actuator 31 side is caused by the partition piston 30c. Can be prevented.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, the control valve 26 can be provided on the fixed mold 3 side. The actuator 31 of the control valve 26 can be configured to be pneumatic or electromagnetic.

C ... Valve member closing position D ... Valve member opening position F ... Foreign matter 3 ... Fixed mold 4 ... Movable mold 5 ... ... Cavity 21 ... Vacuum passages 24, 25 ... Vacuum source (vacuum tank, vacuum pump)
26 ... Control valve 27 ... Upstream vacuum passage 28 ... Downstream vacuum passage 29 ... Valve chamber 30 ... Valve member 30a ... Piston rod 30b ... Valve Piston 30c ... Partition piston 31 ... Actuator

Claims (3)

A vacuum passage (21) communicating with the vacuum source (24, 25) is connected to the cavity (5) formed between the opposed surfaces of the fixed die (3) and the movable die (4). 21) In a gas venting device for a die casting machine provided with a control valve (26) for controlling opening and closing of the vacuum passage (21)
The control valve (26) is formed on one of the fixed mold (3) and the movable mold (4) so as to intervene in the vacuum passage (21), and one end is formed on the outer surface of the one mold. And a valve member (30) that is slidably accommodated in the valve chamber (29) and is slidable between an open position (D) and a closed position (C), An actuator (31) detachably attached to the one mold and attached to close the open end of the valve chamber (29) to operate the valve member (30), and the vacuum passage (21 ) Is divided into an upstream vacuum passage (27) connected to the vacuum source (24, 25) and a downstream vacuum passage (28) connected to the cavity (5), and the upstream vacuum passage (27) The downstream end is the first port (27a) and the upstream end of the downstream vacuum passage (28). The second port (28a) is opened to the valve chamber (29). The valve member (30) includes a piston rod (30a) connected to the actuator (31), and a piston rod (30a). A valve piston (30b) formed at the tip and for closing and opening the second port (28a) in accordance with the closed position (C) and the open position (D) of the valve member (30) is provided. (30) in the open position of (D), the second port (28a) is positioned on the piston rod (30a) side of the valve piston (30b), said valve chamber from said second port (28a) (29 The degassing device for a die-casting machine , wherein the foreign matter (F) that has intruded on the piston rod (30b) is placed on the end surface of the valve piston (30b) on the piston rod (30a) side. In the degassing apparatus of the die-casting machine according to claim 1,
The die casting is characterized in that the upstream vacuum passage (27) is configured such that the upstream vacuum passage (27) passes through the mating surfaces of the fixed mold (3) and the movable mold (4). Machine gas venting device. In the degassing apparatus of the die-casting machine according to claim 1,
The valve member (30) includes a piston rod (30a) connected to the actuator (31), the valve piston (30b) formed at the tip of the piston rod (30a), and the piston rod (30a). And a partition piston (30c) formed in an intermediate portion of the cylinder, wherein the first port (27a) is disposed between the valve piston (30b) and the partition piston (30c). Degassing device.

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