JPH0238061B2 - KANAGATAYOGASUNUKISOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a mold gas venting device for extracting gas from a mold cavity during injection molding using a die casting machine or an injection molding device having an injection molding function.

[Conventional technology]

Conventionally, in injection molding equipment such as die casting machines, when molten material is injected into the cavity at high speed and high pressure, the gas in the mold cavity does not escape and remains in the product, resulting in the formation of cavities in the product. There is.

Therefore, the applicant has developed a degassing device for molds that can remove a large amount of gas in a short time. As shown in FIG. 17, which is a cross-sectional view of the main part, this degassing device has a degassing passage 1 that connects the mold cavity and the outside of the mold, and a gas degassing device that slides in the axial direction of the passage 1 in the middle. The dividing surface of the mold is equipped with a valve 2 that opens and closes when the gas venting passage 1 is closer to the cavity than the valve 2, and a bypass 3 for gas exhaust that bypasses the valve 2 to the side of the valve 2 in the gas venting passage 1. During injection, the gas in the cavity flowing in the direction of the arrow is extracted to the outside of the mold through the bypass 3 and the opening of the valve 2, and the injection melt fills the cavity and passes through the end of the gas venting passage 1. When the temperature reaches 1, the valve 2 is pushed up by the action of this large-mass molten material, and the bypass 3 is blocked by the valve 2. 4
are provided at each corner of the bypass 3.

[Problem that the invention seeks to solve]

However, in such conventional degassing devices for molds, a vacuum device that creates a vacuum inside the mold cavity is often installed via the valve 2. When a vacuum device is operated with the valve 2 open prior to the process, aluminum or mold release agent in the form of atomized or small particles passes through the bypass 3 and the opening of the valve 2 and enters the degassing passage 1. This may flow into the valve seat of the valve 2 and prevent the valve 2 from fully closing, causing problems such as the molten metal spouting out of the mold or flowing into the vacuum device. Ta. Further, by simply providing the hot water reservoir 4, it was not possible to fully expect the effect of adhering and capturing the atomized aluminum, etc.

[Means for solving problems]

In order to solve these problems, in the present invention, a cylindrical hole is provided closer to the mold cavity than the valve opening of the degassing passage leading from the mold cavity to the outside of the mold, and this hole At least one of the inlet and outlet of the degassing passage is provided tangentially to the outer peripheral surface of the hole, and the directions of the inlet and outlet of the degassing passage are different from each other with respect to the axial direction of the hole. Set.

[Effect]

For example, after supplying molten metal into the injection sleeve,
When the gas in the mold cavity is sucked out by a vacuum device or the molten metal is injected into the mold cavity, the gas in the mold cavity flows out of the mold through the degassing passage and the open valve. is discharged to. When the mold cavity is filled with molten metal during injection and the molten metal reaches the valve, the valve closes due to the inertia of the molten metal, which has a large mass, and the outflow of the molten metal is blocked. Alternatively, when the gas venting valve is closed by an electrical signal or the like during injection, the outflow of the molten metal is blocked at the valve portion. During this vacuum suction or injection, when gas containing solids such as atomized or small granular aluminum or mold release agent goes to the degassing passage, it enters the cylindrical hole before the valve, but the cylindrical hole Since at least one of the inlet and outlet of the inlet is tangential to the cylindrical hole and the directions of the inlet and outlet are different from each other, the gas entering from the inlet swirls in the cylindrical hole,
Due to the cyclone effect, floating solids are trapped on the hole wall and do not reach the valve. Therefore, there is no possibility of small particles of molten metal condensing adhering to the valve seat of the degassing valve and causing an obstruction to opening the valve, and the degassing valve is always closed securely to ensure long-term operation. Can withstand continuous use.

〔Example〕

1 to 6 show an example in which the present invention is applied to a mold for a die-casting machine. FIG. 1 is a longitudinal sectional view thereof, FIG. The figure is a partially cutaway front view of a mold degassing device and a mold in which it is installed, FIG. 4 is an enlarged cross-sectional view of FIG. 1, FIG. 5 is a cross-sectional view of FIG. 4, and FIG. The figure is a - sectional view of FIG. In the figure, a cavity 14 is formed on both sides of the dividing surface 13, which is the joint surface between the fixed mold 11 and the movable mold 12, which are shown in a clamped state. From there, molten metal 17 is injected and filled through the fixed sleeve portion 15 and gate 16. Reference numeral 18 denotes a product extrusion device that extrudes a product obtained by solidifying the molten metal 17 from the cavity 14 of the movable mold 12 after the mold is clamped. A spool hole 21 that communicates with the cavity 14 through a gas venting path 19 and a gas venting groove 20 is opened to the outside at the upper end of the dividing surface 13 of the molds 11 and 12. A bypass 22 that communicates with the opening of the gas vent groove 20 to the spool hole 21 branches off from the middle. The configuration of the bypass 22 will be explained in detail later.

On the other hand, on the bracket 23 fixed to the upper surface of the fixed mold 11, an air cylinder 24 is fixed on the same axis as the gas vent groove 20, and at the working end of the piston rod 25, which moves back and forth with the air pressure, A mold degassing device, generally designated by the reference numeral 26, has a holder 28 fixed thereto which holds the upper end of a spool 27 therein. The spool 27 is formed into a cylindrical shape with a bottom, and a stepped portion 27a is provided at the lower end of the spool 27. As the piston rod 25 moves back and forth, the entire gas venting device 26 moves up and down, and the stepped portion 27a engages with the spool hole 21. The spool hole 21 is configured so as to be separated from the spool hole 21.

Therefore, the gas venting device 26 will be explained below. The spool 27 is divided into upper and lower members 27b and 27c, and the flange of the valve guide 29 fitted into the inner hole 27d is held between them.
As a result, the upper and lower members 27b, 27c and the valve guide 29 are integrated. 30 is valve guide 2
9 and is slidably fitted into the inner hole 27d of the spool 27, and has a central screw hole fitted into the inner hole 29a of the valve guide 29 so as to be freely retractable. A threaded portion of a valve rod 31 passing through the inner hole 27d of the valve rod 31 is screwed into the valve rod 31, and a valve body 32 is integrally formed at the lower end of the valve rod 31. On the other hand, a valve seat 27e is formed at the lower opening end of the spool 27, and a valve body 32
and the valve seat 27e from the open state shown in the figure to the gas vent groove 2.
It is configured such that the pressure of the molten metal 17 rising above 0 is raised by pushing the valve body, and the valve body is brought into a closed state. In the illustrated valve open state, the valve body 32 engages with the opening step of the gas vent groove 20 to close it. Reference numeral 27f in FIG. 2 is a discharge hole for discharging the gas guided to the valve chamber 27g of the spool 27 through the bypass 22 to the outside when the valve is open.

The gas venting device 26 configured in this way has the following features:
A pneumatic holding mechanism is provided to hold the valve body 32 in an open state and a closed state. That is, the piston 30 has a small hole 3 that communicates the head side chamber 33 and the rod side chamber 34 on both the upper and lower sides thereof.
0a, and a hole 30b that communicates the peripheral surface of the piston 30 and the head side chamber 33. In this case, for example, when the diameter of the piston 30 is 30 mm, the small holes 30a are holes with a diameter of 2 to 3 mm, and the number of holes is 3 to 4, and the total cross-sectional area of the holes 30b is
It was made to be somewhat larger than the total cross-sectional area of a. Further, a port 36 is provided on the peripheral wall of the spool 27, which communicates the head side chamber 33 with the outside in the illustrated valve open state.
and the holeless part of the outer periphery of the piston 30, that is, the hole 3
A port 37 and an annular groove 38 are provided that communicate a part of the outer peripheral surface of the spool 27 with the outside of the spool 27. When the valve body 32 is closed, the piston 30 rises so that the hole 30b communicates with the port 37 and the port 37 and the head side chamber 33 communicate with each other. Furthermore, a solenoid is installed in the piping connecting the port 35 and the air source 39.
A switching valve 40 equipped with SOL-A and SOL-B is provided, and ports 36 and 37 and an air source 3 are also provided.
There is a solenoid SOL- in the piping connecting to 9.
A switching valve 41 with C is provided. 42 is a reducing valve that provides a constant reduced pressure within the circuit. With this configuration, when the valve is open, the solenoid SOL-A,
When SOL-C is de-energized and solenoid SOL-B is energized, air enters the head side chamber 33 from port 36, and air from the rod side chamber 34 enters port 35.
Since it exits into the atmosphere, the valve stem 31 rises and is held in the valve open position, and when the valve is closed, solenoids SOL-A and SOL-C are energized and solenoid SOL-B is de-energized. Air is port 3
Air enters the head side chamber 33 through ports 5 and 37, and air in the rod side chamber 34 exits to the atmosphere through port 36.
The valve stem 31 is lowered and held at the valve open position.

Next, the bypass 22 and the floating solid trapping structure provided therein will be explained. The bypass 22 is provided close to the mold cavity 14 with respect to the valve seat 27e, and is formed in a generally rectangular shape as a whole, and at the four corners of the bypass 22, there are pools 43 and 44 as cylindrical holes. It is divided into a movable mold 12 side and a fixed mold 11 side on both sides of the dividing surface 13. These hot water pools 43, 44
Both have a draft angle during casting so that the diameter becomes smaller toward the bottom surface, and the tundish pool 43 is formed to have a larger diameter than the tundish pool 44.
The flow direction of the molten metal is the direction shown by the arrow in FIG.
The bypasses indicated by b and 22c are both connected to the hot water pool 4.
It is in a tangent state to 3 and 44. Also,
Bypass 2 which is the entrance of the lower hot water pools 43 and 44
2a opens into a hot water pool 43, and a bypass 22c, which is an outlet of the upper hot water pools 43 and 44, opens into the hot water pool 44. Furthermore, bypass 22
b is inclined obliquely across the dividing surface 13 so as to connect the lower pool 44 and the upper pool 43, and serves as an outlet and an inlet of the pools 44 and 43, respectively. That is, as a result, the bypass 22a, which is the inlet of the lower water pools 43, 44, and the bypass 22b, which is the outlet, are out of phase with respect to the axial direction of the water pools 43, 44, and the bypass 22 has a large After entering the large diameter pool 43 and exiting from the small diameter pool 44, the water enters the large diameter pool 43 and exits from the small diameter pool 44.

The operation of the mold degassing device configured as above will be explained. As shown in FIG. 3, the mold 11,
12 is clamped and the molten metal 17 is injected into the inlet of the injection sleeve (not shown), and the plunger of the injection cylinder is advanced, the molten metal 17 flows into the fixed sleeve portion 15.
Injected into the cavity 14 through the gate 16 and
Filled. At this time, since the piston 30 is descending and the valve body 32 and valve seat 27 are open, the gas in the cavity 14 flows from the cavity 14 through the gas vent groove 20, the bypass 22, and the valve opening. It enters the chamber 27g and is discharged from the discharge port 27f. And at this time, solenoid SOL-A,
Since SOL-C is energized and solenoid SOL-B is deenergized, the switching valves 40 and 41 are switched, and air enters the head chamber 33 from ports 35 and 37.
Air from the rod side chamber 34 comes out from the port 36,
Since the discharge resistance of the rod side chamber 34 is much smaller than the pipe resistance of the small hole 30a, and the pressure of the head side chamber 33 is sufficiently higher than the pressure of the rod side chamber 34,
The piston 30 moves until its lower end surface comes into contact with the valve guide 29, thereby opening a space between the outer peripheral upper surface of the valve body 32 and the bypass 22, and this valve open state is maintained by air pressure, thereby opening the valve. Body 32 never closes. In this state, first solenoid SOL-C
When the rod side chamber 34 is degaussed from the port 36,
Although air flows into the chambers 33 and 34 to have the same pressure, the valve is maintained at the open position due to the difference in pressure receiving area of the piston 30. Next, when the solenoid SOL-A is demagnetized, the air pressure passes through the small hole 30a and into the rod side chamber 34.
It flows into the head side chamber 33 from the piston 30 and passes through the annular groove 38 and the gap between the piston 30 and the spool inner circumferential surface, and is about to be discharged from the port 37, but at this time, the exhaust resistance is much smaller than the inflow resistance. Both chambers 33 and 34 are still kept at the same pressure, and the valve is kept open due to the difference in pressure receiving area of the piston 30. However, at this time, the air in the rod side chamber 34 acts on the lower surface of the piston 30 as a force to move the piston 30 in the valve opening direction.

After the cavity 14 is almost filled with the molten metal 17, the molten metal 17 rises in the gas vent groove 20 and hits the concave portion on the lower surface of the valve body 32. The impact applied to the valve body 32 at this time causes the valve body 32 to bounce upward because the mass of the molten metal 17 is much larger than the mass of the gas and has a large inertia. As a result, piston 3
The hole 30b of 0 communicates with the port 37, and the air in the head side chamber 33 is discharged from the port 37, and the molten metal 1
Air pressure acts auxiliary with the inertia force of 7, and the piston 30 moves upward, so the valve body 32 blocks off between the bypass 22 and the valve chamber 27g. Therefore, the outflow of the molten metal 17 is stopped at the position of the valve body. At this time, since the pipe resistance of the hole 30b is sufficiently smaller than the pipe resistance of the small hole 30a, the pressure in the head side chamber 33 becomes sufficiently smaller than the pressure in the rod side chamber 34, and the piston 30 moves toward the head side chamber 23. It is energized and closes the valve not only by the force of the molten metal 17 but also by its own force and maintains this valve closed state.

In the above embodiment, the valves were closed by the inertial force of the molten metal, but this is possible by switching the switching valves 40 and 41 by electric signals such as limit switches or pulse signals from a magnetic scale during injection. It is also possible to close the valve. At this time, the timing must be such that the valve is reliably closed after the molten metal fills the mold cavity 17 and before it reaches the valve seat 27e.

When the molten metal 17 is cooled under pressure for a predetermined period of time with the valve body 32 closing the gas vent groove 20 and the bypass 22, the entire gas venting device 26 is raised by the cylinder 24, and the cavity 14,
After the solidified metal filling and solidifying in the gas vent groove 20 and the bypass 22 is separated from the valve body 32, the movable mold 12 is moved to open the mold, and the product is extruded by the product extrusion device 18. Note that the cylinder 24
When the entire gas venting device 26 is raised, the valve body 32 is separated by the separation resistance between the valve body 32 and the solidified metal.
The upward movement of the spool 27 is regulated, and the valve opening position is maintained by the action of the air pressure, which lags behind the rise of the spool 27.

In such a degassing operation, as described above, solids such as aluminum or mold release agent in the form of atomized or small particles try to flow into the inner hole 27d through the bypass 22 and the valve opening. These solids are captured by the sump 43,44. In other words, the solids mixed with the gas and flowing into the bypasses 22a on both sides flow from the tangential direction into the lower pool 43.
The gas and solids flow through the hot water pool 44 to the bypass 22b, but because the inlet of the hot water pool 43 is opened in a tangential position and the outlet of the hot water pool 44 is opened in a tangential direction, the gas and solids flow through the hot water pool 44. Tamari 43, 44
After rotating inside along the outer wall, a cyclone effect is activated in which the solids move toward the outlet, which is in a phase different from the inlet, so that the solids adhere to the walls of the pools 43 and 44 and are captured. After that, the gas passes through the bypass 22b, enters the upper pool 43 from the tangential direction, passes through the pool 44, exits from the outlet of the pool 44 in the tangential direction, and heads toward the bypass 22c, but the gas enters the upper pool 43 from the tangential direction.
As in cases 3 and 44, the gas swirls and acts as a cyclone, so the lower pools 43 and 44
The solids that were not captured in the valve seat 27e are completely captured, and the clean gas is directed toward the valve seat 27e without entering the valve seat 27e. Note that the diagonal orientation of the bypass 22b also acts as a resistance and is effective in trapping solids. Also, by making the diameter of the hot water reservoir 43 into which the gas enters first greater than the diameter of the hot water reservoir 44,
Solids trapped on the wall of the trough 43 do not enter the trough 44.

The solids thus collected in the tundish pools 43 and 44 are taken out together with the product after the mold is opened, and can be easily taken out by providing draft angles in the tundish pools 43 and 44.

7 and 8 show other embodiments of the present invention, FIG. 7 being a longitudinal cross-sectional view corresponding to FIG. 4, and FIG. 8 being a cross-sectional view taken along the line shown in FIG. 7. In this embodiment, the upper and lower water pools 45, 46 are the same as in the conventional case.
A hot water reservoir similar to that of the previous example was provided in the bypass between them. That is, a large diameter pool 47 and a small diameter pool 48 are provided with the dividing surface 13 as a boundary, and the bypass 22d from the hot water pool 46 is tangentially connected to the inlet of the hot water pool 47, and the bypass to the hot water pool 45 is The bypass 22e and the bypass 22d were connected tangentially to the outlet of the water reservoir 48 in a different phase. By doing this, the solids contained in the gas entering from the bypass 22a and exiting from the bypass 22c enter the tangential direction into the hot water pool 47,
Since it swirls together with the gas within 48, it adheres to the walls of the pools 47 and 48 and is captured by the cyclone effect.

Furthermore, FIG. 9 is a sectional view of the vicinity of the hot water pool showing another embodiment of the present invention corresponding to FIG. A bypass 22e from the cavity 14 side that enters in the tangential direction and a bypass 22f that exits in the tangential direction toward the valve opening are respectively bent. By doing this, a cyclone effect is exerted on the solids swirling in the pools 47 and 48.
This is the same as the embodiment shown in FIGS. 7 and 8, and by bending the bypasses 22e and 22f, the effect of acting as resistance and trapping solids is increased.

Furthermore, FIG. 10 and FIG. 11 show other embodiments of the present invention, FIG. 10 is a cross-sectional view of the vicinity of the hot water pool corresponding to FIG. 5, and FIG.
It is a sectional view of XI. In this embodiment, the hot water pool 4
9 and 50 are provided only on the fixed mold 11 side, the bypass 22f from the cavity 14 side is connected tangentially to the trough 49, and the dogleg-shaped bypass 22h coming out tangentially from the trough 49 is connected to the trough 49. 50 from the tangential direction. Bypass 2 towards valve opening direction
2g was connected to a non-tangential position of the water reservoir 50. By doing this, the gas containing solids is transferred to the pool 4.
The solids are captured by the cyclone action by rotating in the tubes 9 and 50, as in each of the above embodiments.

Furthermore, FIGS. 12 and 13 show other embodiments of the present invention, FIG. 12 is a sectional view of the vicinity of the hot water pool corresponding to FIG. 8, and FIG. 13 is a -
FIG. In this embodiment, the hot water reservoir 5
1 was provided only on the movable mold 12 side, and an insert 52 was provided on the fixed mold 11 side so as to be concentric with the pool 51 and facing the opening thereof. The bypass 22d from the cavity 9 side is tangentially connected to the water reservoir 51, and the bypass 22c toward the valve opening direction is connected to the insert 52 from the axial direction. With this configuration, the gas entering from the bypass 22d swirls in the reservoir 51 and then exits from the insert 52 and heads through the bypass 22e toward the valve opening direction.
Solids contained in the gas are trapped by the cyclone action within the sump 51 and the resistance of the bypasses 22d, 22e and the insert 52. Note that the insert 52 is preferably made of the same material as the molten metal.

Furthermore, FIG. 14 and FIG. 15 show other embodiments of the present invention, FIG. 14 is a cross-sectional view of the vicinity of the hot water pool corresponding to FIG. 8, and FIG. 15 is a cross-sectional view of FIG. 14. It is. In this embodiment, the movable mold 12 is provided with a pool 53, and the fixed mold 11 is formed with a protrusion 54 that is concentric with the pool 53 and enters into the pool 53. Further, the bypass 22d from the cavity 14 side enters the water reservoir 53 in a tangential manner and exits in a tangential manner toward the valve opening. By doing this, the gas entering from the bypass 22d swirls in the water pool 53 and then passes through the bypass 22e toward the valve opening, so that solids contained in the gas are captured by the cyclone action in the water pool 53. This is the same as in each of the above embodiments.

In each of the above embodiments, as shown in FIG. 16, which is a cross-sectional view of the water pool, if the wall surface of the water pool 53 is provided with unevenness, the effect of attaching and trapping solids contained in the gas will be further increased.

In addition, although each of the above embodiments shows an example in which the present invention is applied to a mold degassing device not equipped with a vacuum device,
A vacuum device is connected to the discharge hole 27f and the spool 2
It will be even more effective if it is applied to a vacuum die casting machine that performs injection while sucking the gas inside 7. In addition,
The structure of the main body of the degassing device, such as the valve part and the piston 30, is not limited to the structure shown in FIGS. 1 and 2.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in the mold gas venting device, the cylindrical hole is located closer to the mold cavity than the valve opening of the gas vent passage leading from the mold cavity to the outside of the mold. At least one of the inlet and outlet of the degassing passage in this hole is provided in a state tangent to the outer peripheral surface of the hole, and the direction of the inlet and outlet of the degassing passage is aligned with the axis of the hole. By setting the directions in different directions, the gas heading toward the valve opening during injection is subjected to a cyclone action that swirls within the cylindrical hole provided in front of the valve opening, so that the atomized form contained in the gas is Floating solids such as molten metal, small metal particles, and mold release agents adhere to the wall of the cylindrical hole and are captured, preventing them from heading toward the valve opening, and these floating solids remain in the valve opening. By doing so, it is possible to prevent the molten metal from spouting out of the mold or from flowing into the vacuum device, greatly improving safety and the durability of the device.

[Brief explanation of drawings]

1 to 16 show an embodiment of the mold degassing device according to the present invention, FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a longitudinal sectional view of the main parts, an air circuit diagram, and Fig. 3 is a partially cutaway front view of a mold degassing device and a mold in which it is installed, Fig. 4 is an enlarged sectional view taken along the - line in Fig. 1, and a sectional view taken along the - line in Fig. 5; 4 is a sectional view taken along the - line in FIG. 4, FIG. 6 is a sectional view taken along the - line in FIG. In the second embodiment, FIG. 7 is a vertical sectional view near the cylindrical hole, FIG. 8 is a cross-sectional view at - in FIG.
10, 12, 14, and 16 are longitudinal sectional views of the vicinity of the cylindrical hole showing different embodiments of the present invention, and FIG. 11 is a sectional view taken along line XI-XI of FIG. 10. , FIG. 13 is a cross-sectional view taken from FIG. 12, FIG. 15 is a cross-sectional view taken from FIG. 14, and FIG. 17 is a cross-sectional view of a main part of a conventional mold degassing device. 11...Fixed mold, 12...Movable mold, 13...
...Dividing surface, 14... Cavity, 20... Gas venting groove, 22, 22a to 22h... Bypass, 24
...Mold gas venting device, 27d...Inner hole, 27
e... Valve seat, 32... Valve body, 43-51, 53...
...A puddle of hot water.

Claims (1)

[Claims] 1. In a mold gas venting device in which a gas venting valve that can be opened and closed is provided in the middle of a gas venting passage leading from a mold cavity to the outside of the mold provided in a mold dividing surface, the gas venting valve of the gas venting passage is A cylindrical hole is provided near the mold cavity relative to the valve opening position,
At least one of the inlet and outlet of the gas venting passage in this hole is provided in a state tangent to the outer peripheral surface of the hole, and the directions of the inlet and outlet of the gas venting passage are different from each other with respect to the axial direction of the hole. A gas venting device for a mold, characterized in that it is set in the vertical direction.