JPS63174772A - Method and apparatus for casting by vacuum die casting - Google Patents

Abstract

PURPOSE:To improve casting efficiency and to prevent trouble by arranging a first and a second exhaust introducing pipes in a vacuum hole connecting through a cavity and also arranging a pressure detecting instrument between the vacuum hole and a solenoid valve for the second exhaust introducing pipe. CONSTITUTION:The vacuum hole 19 is connected through the cavity 13 formed by a movable die 11 and a fixed die 12 and also the first and the second exhaust introducing pipes 21, 22 and each solenoid valve 24, 27 are arranged to be connected with the vacuum hole 19. High temp. molten metal material is poured from a molten metal supplying hole 36 and the hole 36 is shut by a plunger tip 37 and air in the cavity 13 is sucked by both of exhaust introducing pipes 21, 22. Then, the molten metal is injected into the cavity 13. Next, the air is pressed in from the air introducing pipe 31 under closing condition of the solenoid valves 24, 27, to detect clogging of the metallic powder by a pressure detecting instrument 43 through the air pressure. As the piling of metallic powder can be surely detected, the trouble is eliminated and also the casting efficiency is improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a vacuum die-casting method and an apparatus thereof, in which the air in the cavity of a mold is exhausted and the molten metal material is introduced into the cavity. Related to molds for injection molding.

(Prior art) This type of vacuum die-casting equipment is known, for example, from the Japanese Patent Publication No. 59
-As described in Publication No. 1574ON, in order to prevent the formation of blowholes due to gas entrainment during die casting, the air inside the cavity is evacuated using a vacuum device, and molten metal material is injected into the cavity. A device for creating a vJ is known. .

In the conventional die casting apparatus described above, the molten metal material injected into the cavity is driven at high speed and under increased pressure. It turns out. The metal material poured into the cavity becomes fine particles and is sucked into the vacuum device, so it becomes metal powder and flows out from the overflow to the air vent and vacuum hole together with the air. It is deposited little by little in the air vent,
This will close the vacuum hole. For this reason, the above-mentioned casting equipment has a structure in which a strainer made of wire mesh is installed in the exhaust system connected to the vacuum device, and this strainer prevents the metal powder flowing out from the cavity from being sucked into the vacuum device δ. ing.

(Problems to be Solved by the Invention) In the conventional die-casting process described above, metal powder accumulates in the exhaust system such as air vents and vacuum holes, and even in the strainer, which clogs the exhaust system and prevents good casting conditions. There is no means to detect the accumulation of metal powder even if it cannot be maintained, and there is a problem in that it is not possible to detect problems caused by accumulation of metal powder in advance.

The present invention was developed in view of the above problems, and it is possible to reliably and easily detect the jft product of metal powder flowing into an air vent, vacuum hole, etc., and prevent troubles caused by metal powder accumulating in the exhaust system. The purpose of the present invention is to provide a vacuum die-casting method and an apparatus therefor, which can reduce the vacuum build-up time in a mold cavity at the start of injection of a metal material and maintain a good casting condition.

[Structure of the invention]

(Means for Solving the Problems) In the vacuum die casting method of the present invention, after closing the pouring port for molten metal material in a mold with a plunger tip, The electromagnetic valves of the first and second exhaust conduits communicating with the communicating vacuum hole are opened respectively, and the vacuum hole is communicated with a vacuum device via the first and second exhaust conduits, and the mold is heated. The inside of the cavity is evacuated and the metal material supplied from the pouring port is injected into the cavity.
After time f1 has elapsed, the solenoid valve of the first exhaust conduit is closed, and the solenoid valve of the second exhaust conduit is further closed after a predetermined time has elapsed since the hot water supply port is closed, which is later than when the solenoid valve of the first exhaust conduit is closed. After opening the solenoid valve of this second sight conduit, the air supply 1 is communicated with the vacuum hole of the mold! A solenoid valve provided in the pipe is opened for a predetermined period of time, air is force-fed from an air supply device to the vacuum hole of the mold, and a pressure detection device detects the pressure of the at least second exhaust conduit to detect the vacuum of the mold. This system is characterized by detecting clogging caused by metal powder in the exhaust system through the hole.

□Furthermore, the vacuum die casting apparatus of the present invention has a mold consisting of a movable mold and a fixed mold, and has a vacuum hole that communicates with the cavity of the mold via an air vent, and communicates with the vacuum device through the vacuum hole. the first, each with a solenoid valve;
and a second exhaust conduit, further connecting a venting device to the vacuum hole of the mold via a solenoid valve, and forming a hot water supply port communicating with the cavity of the mold in the shot sleeve of the mold, Insert the hot water inlet into this shot sleeve.
A plunger tip that closes M is provided, and the solenoid valve of the first exhaust pipe is controlled to be opened at the beginning of injection of molten metal by being started based on the end of the supply of water to the hot water supply port, and the solenoid valve of the second exhaust pipe is controlled to open. A timer is provided to control the opening of the solenoid valve until the end of the injection of the metal material, and to open the solenoid valve of the air supply conduit for a predetermined time when the solenoid valve of the second exhaust conduit is closed,
A pressure detection device is provided between the vacuum hole of the mold and the solenoid valve of the second exhaust conduit, and a cleaning device is further provided in the vacuum hole of the mold to clean the vacuum hole when the movable mold is separated. It is characterized by:

(Function) In the vacuum die casting method d3 and apparatus of the present invention, after a high temperature molten metal material is injected into a mold from a hot water supply port, when the hot water supply port is closed with a plunger tip, a timer activates the cavity of the mold. the solenoid valves of the first and second exhaust conduits communicating with the vacuum hole communicating with the vacuum hole are respectively spaced;
The first and second exhaust pipes are connected to a vacuum system,
The air in the cavity of the mold is sucked by a vacuum device through the first and second exhaust conduits, the cavity is evacuated, and the metal material supplied from the pouring port is injected into the can and tee. Rapidly reduce the pressure inside the cavity. The solenoid valve of the first exhaust conduit is closed by a timer for a certain period of time at the initial stage of injection, and the timer is further determined that a predetermined period of time has elapsed since the closure of the hot water supply port after the solenoid valve of the first exhaust conduit was closed. Afterwards, the solenoid valve of the second exhaust pipe is opened. After the solenoid valve of the second exhaust pipe is closed, a timer causes the electromagnetic piece provided in the air supply pipe communicating with the vacuum hole of the mold to be connected to the vacuum hole of the mold from the air supply unit U for a predetermined period of time. Pump air.

Then, if the metal powder flowing out from the mold cavity is deposited in the exhaust system from the vacuum hole, the accumulation of the metal powder is detected by a pressure detection device that detects the pressure of the second hot air conduit. Can be done.

Furthermore, in the vacuum die casting apparatus of the second aspect of the invention, the inertia of the metal powder flowing out into the corrugated air vent together with the air is reduced by bending, thereby suppressing the metal powder from flowing out into the vacuum hole. After casting, the movable mold is separated from the fixed mold and the molded product is taken out from the cavity.

When the movable mold is separated from the fixed mold, the vacuum hole is cleaned by a cleaning device, and the metal powder deposited in the vacuum hole is removed, and the air formed at the joint surface of the movable mold with the fixed mold is removed. The vent is opened and the metal powder piled up M1 in the air vent is also removed.

(Example) The configuration of an example of the vacuum die-casting apparatus of the present invention will be described with reference to the drawings.

Reference numeral 10 denotes a gold plate consisting of a movable mold 11 having a movable die plate 11a and a fixed mold 12 having a fixed die plate 12a.A cavity 13 is formed in the movable mold 11 of this mold 10, and the movable mold 11 has A plurality of overflows 15.15 communicating with the cavity 13 are formed on the joint surface 14 with the fixed mold 12, and each overflow 15.
An air vent 16.16 is formed in communication with 15. The air vents 16.16 are formed in a wave shape that is alternately bent on the uneven surface of the joint surface 14 of the movable mold 11 and the fixed mold 12, and the air vent 16. is overflow 15.15
When the movable mold 11 of the mouth is separated from the fixed mold 12, the air vents 16 and 16 are opened.

Further, a vacuum hole 19 is formed in the movable mold 11, which extends from the outer surface 17 of the movable mold 11 to the joint surface 14 with the fixed mold 12, and communicates with each air vent 16.1G through a communication groove 18. has been done. A suction hole 20 is formed in communication with the intermediate part of this vacuum hole 19.
A first J5 and a second exhaust conduit 21,22 are connected to. This first exhaust 8P pipe 21 is connected to a solenoid valve 24 via an air friction filter 23, and a second
The exhaust pipe 22 is connected to the solenoid valve 2 via the high temperature filter 2G.
7 is connected, and both solenoid valves 24 and 27 are connected to the vacuum system @28.
The vacuum tank 29 is connected to a vacuum pump 30.

In addition, the vacuum hole 19 of the movable mold 11 is provided with an air supply pump (
An air supply conduit 31 (not shown) is connected to the air supply conduit 31, and a solenoid valve 32 is connected to this air supply conduit 31.

Further, in the movable mold 11, a flow divider 33 communicating with the cavity 13 is formed on any joint surface 14 of the fixed mold 12,
This shunt 33 is fixed to the movable mold 11! 112, a shot sleeve 35 is opened and protrudes from the outer surface of the fixed mold 12, and communicates with the flow path 34 formed in the fixed mold 12. 36 is opened, and a plunger depth 37 for opening and closing this hot water supply 036 is connected to the shot sleeve 35.
The plunger tip 31 is provided to be movable forward and backward, and upon completion of hot water supply, the plunger tip 31 advances to close the hot water supply port 36.

Further, there are provided timers, ie, first and second timers 40.41, which are activated based on the end of hot water supply, and this first timer 40 is configured such that the plunger tip 37 is connected to the hot water supply port 36.
When the first and second exhaust conduits 21.
22 solenoid valves 24 and 27 are opened, and the vacuum hole 19 is opened.
is communicated with the vacuum device 28 through the first and second exhaust pipes 21 and 22, and the first timer 40 opens the solenoid valve 24 of the first exhaust pipe 21 only in the initial stage until the start of high-speed injection. immediately closes and then this first timer 40
The solenoid valve 27 of the second exhaust conduit 22 is closed after a predetermined period of time has elapsed after the solenoid valve 24 of the first exhaust conduit 21 is closed. Further, the second timer 41 is activated when the solenoid valve 27 of the second exhaust conduit 22 is opened, and opens the solenoid valve 32 of the air supply conduit 31 for a predetermined period of time.

A second hole connected to the vacuum hole 19 of the first floor 11
A pressure detection device 43 is connected to the exhaust conduit 22 located between the filter 26 and the electromagnetic valve 27.

This pressure detection device 43 consists of a pressure switch and a lamp, and the pressure detection device 43 detects the pressure of the second exhaust conduit 22 by forcefully feeding air from the air supply device through the vacuum hole 19. The vacuum hole 19 of the exhaust system can detect clogging caused by metal powder.

Further, 44 is a cleaning device, which is formed by an extrusion plate 45 and a pin 46 provided on this extrusion plate 45.
is inserted through the vacuum hole 19 of the movable mold 11 from the opening on the outer surface 17 side of the movable mold 11 to the opening on the side of the surface that is aligned with the fixed mold 12. Furthermore, this extrusion plate 4
5 is regulated in its retreat position by a regulating plate 47.

Next, the operation of this embodiment will be explained.

The joint surface 14 of the movable mold 11 is joined to the fixed mold 12, and high-temperature molten metal material is injected from the hot water supply port 36. When the hot water supply is completed, this hot water supply port 3G is closed with the plunger depth 31, and the first and A second timer 40°41 is started. The first timer 40 opens the solenoid valves 24.27 of the first and second exhaust conduits 21.22, and the vacuum hole 19 of the movable mold 11 opens the first and second exhaust conduits 21.22.
The vacuum hole 19 of the movable mold 11 is connected to the vacuum tank 29 of the vacuum device 28, and the outer surface 17 side of the vacuum hole 19 of the movable mold 11 is closed by the tip of the pin 46. The air in the cavity 13 of W11 is sucked through the overflow 15.15, air vent 16.16, communication groove 18, and vacuum hole 19, and is supplied to the hot water supply port 3G of the fixed mold 12 at the same time as the air in the cavity 13 is sucked. The high-temperature molten metal material is injected into the cavity 13 of the movable mold 11. At the initial stage of this metal material injection, the first and second exhaust pipes 21
．． 22, the vacuum hole 19 is communicated with the vacuum device 28, so even if the length of the exhaust conduit 21.22 is long, the vacuum in the cavity 13 rises quickly, and the molten metal material is heated at high speed and in an increased pressure state. It is injected into the cavity 13. After the initial injection of the metal material, the first timer 40 closes the solenoid valve 24 of the first exhaust pipe 21 and the second exhaust pipe 22 closes.
15.15, the metal material injected into the cavity 13 becomes metal powder and overflows.
, to suppress the air from flowing out into the air vents 16, 16.

Next, when the metal material is injected into the cavity 13, that is, when the hot water supply port 36 is closed and a predetermined time has elapsed since the opening of the first timer 40, the first timer 40 activates the electromagnetic valve 21 of the second exhaust conduit 22. 11 will be teased.

When the solenoid valve 27 of this second exhaust conduit 22 is closed, the second
The timer 41 is activated, the solenoid valve 32 of the air supply conduit 31 is opened for a predetermined period of time, and air is forced into the vacuum hole 19. Since the solenoid valves 24 and 27 are open, the pressure detection device 43 detects the air pressure and detects a blockage in the exhaust pipe 22. At this time, if a part of the metal powder that has passed through the cavity 13 and flowed into the air vent 16.16 further passes through the air vents 16, 16, flows out into the vacuum hole 19, and is deposited, the pressure is detected. Dressing up! 43 pressure switch does not detect the increase in air pressure,
It is possible to confirm that the vacuum hole 19 is clogged with metal powder by generating an alarm by lighting a lamp or the like.

Note that the inertia of the metal powder passing through the cavity 13 of the mold 10 and flowing out into the air vent 16.16 with the air is reduced by the bending of the air vent 16.16, and the metal powder flows out into the vacuum hole 19. is suppressed. After casting, the movable mold 11 is replaced with the fixed mold 12.
The molded product is taken out from the cavity 13 by separating from the mold. When the movable mold 11 is separated from the fixed mold 12, the push-out plate 45 advances, and the pin 46 is inserted from the outer surface 17 of the movable mold 11 into the vacuum hole 19 formed in the joint surface 14, and the pin 46 is inserted into the movable mold 11. The fixed mold 12 of the fixed mold 12 protrudes from which joint surface 14 and the metal powder deposited in this vacuum hole 19 is removed, and the air vents 16 and 16 formed at which joint surface 14 of the fixed mold 12 of the movable mold 11 are opened. The metal powder accumulated in the air vents 16 and 16 is also removed.

Further, the first and second exhaust pipes 21.22 are provided with filters 23.26 having a mesh of about 120 filter elements made of stainless steel, for example, so that the air flows out to the solenoid valve 24.27, the vacuum device 28, etc. In addition, if metal powder flows into the vacuum tank 29 of the vacuum unit @28, it may cause a failure of the vacuum pump 30, so oil for the vacuum pump is injected into the vacuum tank 29. , prevents metal powder from floating into the vacuum pump 30.

The gap width of the air vent 16.16 is 0.1a.
gt or less, the passage of molten metal is prevented and internal cooling due to thermal expansion of the mold 10 is also not required.

Further, the pin 46 that moves forward and backward into the vacuum hole 19 of the movable mold 11 is arranged so that when the movable mold 11 is separated from the fixed mold 12, the push-out plate 45 is advanced to advance into the vacuum hole 19, or when the movable mold 11 is fixed. The pins 46 can also be positioned so that they are automatically inserted into the vacuum holes 19 when separated from the mold 12.

〔Effect of the invention〕

According to the present invention, a part of the high-temperature molten metal material injected as the air is vented from the mold cavity flows from the air vent into the vacuum hole connected to the vacuum device, resulting in clogging that accumulates in the exhaust system from the vacuum hole. If this occurs, the pressure detection device can reliably and easily detect clogging of metal powder, prevent problems caused by metal powder leakage, and furthermore, the molten metal can be transferred into the mold cavity at high speed by reducing the pressure. When injecting with increased pressure, the exhaust system communicating with the cavity is formed by the 1115 and the second exhaust pipe at the initial stage of injection, so that the pressure in the cavity rises quickly, the molten metal can be reliably injected, and the metal Except for the initial stage of material injection, the first sight system becomes only one of the second first sight conduits, which prevents metal powder from flowing into the exhaust system, reduces the accumulation of metal powder, and enables high-quality casting. be.

Further, according to the second invention, since the air vent on the exhaust side communicating with the mold cavity is bent, the flow of metal powder flowing out with the exhaust air to the first view side is suppressed.
This prevents a large amount of metal powder from accumulating on the exhaust side, and when the movable die of the mold separates from the fixed die, the metal powder that passes through the air vent and accumulates in the vacuum hole is removed by the vacuum hole cleaning device. This makes it possible to maintain good casting condition, enable continuous casting, and improve efficiency.

[Brief explanation of the drawing]

Fig. 1 is an explanatory view of a vacuum die-casting H forming apparatus showing an embodiment of the present invention, Fig. 2 is an explanatory front view of the same mold, Fig. 3 is a front view of a movable mold of the mold apparatus, and Fig. 4 The figure is a front view of the same mold apparatus, the red figure is a front view of the air vent part of the same movable mold, and FIG. 6 is a sectional view of the same air vent part. 10. Mold, 11. Movable mold, 12. Fixed mold, 13.
... Cavity, 14... Joint surface of movable mold 11, 15.
・Overflow, 16. Air vent, 17. Outer surface of movable mold 11, 19. Vacuum hole, 21. 1st
Exhaust conduit, 22...Second exhaust conduit, 24.27°3
2. Solenoid valve, 28. Vacuum device, 31. Air supply pipe,
35...shot sleeve, 36...hot water inlet, 37...
Plunger chip, 40.41...Timer, 43...Pressure detection device, 44...Cleaning device.

Claims (3)

[Claims] (1) After closing the pouring port for molten metal material in the mold with a plunger tip, first and second exhaust conduits are connected to a vacuum hole that communicates with the cavity of the mold via an air vent. The solenoid valves are respectively opened, and the vacuum hole is communicated with a vacuum device through the first and second exhaust conduits to evacuate the inside of the mold cavity and allow the metal material supplied from the pouring port to enter the cavity. The solenoid valve of the first exhaust conduit is closed after the initial injection time has elapsed, and the second exhaust is started after a predetermined time has elapsed since the closure of the hot water supply port, which is later than when the solenoid valve of the first exhaust conduit is closed. The solenoid valve of the conduit is closed, and after the solenoid valve of the second exhaust conduit is closed, the solenoid valve provided in the air supply conduit communicating with the vacuum hole of the mold is opened for a predetermined period of time to supply air to the vacuum hole of the mold. Vacuum die casting casting characterized in that air is sent under pressure from an air device, and clogging by metal powder in the exhaust system is detected from the vacuum hole of the mold by a pressure detection device that detects the pressure of the at least second exhaust conduit. Method. (2) In a mold consisting of a movable mold and a fixed mold, a vacuum hole is formed which communicates with the cavity of the mold via an air vent, and first and connecting a second exhaust conduit and connecting an air supply device to the vacuum hole of the mold via a solenoid valve;
A hot water supply port communicating with the cavity of the mold is formed in a shot sleeve of the mold, a plunger chip for opening and closing the hot water supply port is provided on the shot sleeve, and the first inlet is started upon completion of supplying hot water to the hot water supply port. controlling the solenoid valve of the exhaust conduit to open at the initial stage of injection of molten metal, and controlling the solenoid valve of the second exhaust conduit to open until the end of injection of the metal material;
A timer is provided to open the solenoid valve of the air supply conduit for a predetermined time when the solenoid valve of the second exhaust conduit is closed, and pressure is detected between the vacuum hole of the mold and the solenoid valve of the second exhaust conduit. 1. A vacuum die casting casting apparatus, comprising: a cleaning device which is inserted into a vacuum hole of the mold when the movable mold is separated to clean the vacuum hole. (3) The vacuum according to claim 2, characterized in that the air vent is bent at the joint surface between the movable mold and the fixed mold, and the vacuum hole cleaning device is formed by a pin. Die casting equipment.