JP2002096151A - Venting device for metal die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a venting device for a metal die which is economical, compact and reliable in its operation. SOLUTION: An exhausting vent 2 connected to a cavity C of the metal die has a pressure pin 3 at its inlet side and a shut-off valve 4 at its outlet side. Movement of the pressure pin 3 is transferred to the shut-off valve 4 through an on-off lever 5. Between the pressure pin 3 and the shut-off valve 4, there is a shut-off piston 9, which pushes a lever 5 in the close-direction of the shut-off valve 4. On the opposite side of the piston 7, a release spring 6 is installed, which pushes the lever 5 in the open-direction of the shut-off valve 4 during stripping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die-casting die and a degassing device for degassing a gas in a cavity of a resin die.

[0002]

2. Description of the Related Art As a mold degassing device, as shown in FIG. 9, when a detection pin 103 protruding in a direction of a cavity 102 formed by a fixed die 100 and a movable die 101 is pushed out by pressure, its movement is reduced. The suction pin 105 is transmitted to the suction pin 105 via the connecting member 104 integrated with the detection pin 103, and the cavity 1 is closed.
There is known a configuration in which the suction of the gas in the gas supply chamber 02 is stopped.

[0003] The gas venting device in the die-casting die sucks the gas in the cavity through an exhaust passage by a suction device. However, the molten metal flows into the exhaust passage together with the gas. And a closing valve operated by the receiving pin via an opening / closing lever at the outlet side of the exhaust passage, and the closing valve is closed before the molten metal reaches the closing valve.

In the early operation (low speed) when the mold is cold,
Although it depends on the shape of the cavity and the means for injecting the molten metal, the molten metal may cause irregular pulsation, and the pressure sufficient to operate the pressure receiving pin may not be obtained. Therefore, as shown in FIG. Attempts have been made to provide a closing piston 30 between them, and to forcibly close the opening / closing lever 5 with the closing piston 30. Further, as means for returning the pressure receiving pin, the closing valve, and the closing piston when the mold is opened, an opening piston is provided on the opposite side of the closing piston to forcibly open the opening / closing lever.

[0005]

The closing piston provided in the degassing device only needs to be operated during the initial operation until the mold warms up, and requires only a small load to close the closing valve, so that complicated control is not required. However, the open piston requires a large load to push out the pressure receiving pin, the closing valve and the surplus member, and during any operation, the opening and closing lever is forcibly opened, so that it is operated by air pressure or hydraulic pressure. However, there is a problem that the load is insufficient with pneumatic pressure, and there is a problem that an expensive hydraulic pressure generator and a complicated control device are required with hydraulic pressure. The present invention has been developed in consideration of the above circumstances, and its purpose is to provide an inexpensive, compact,
In addition, it is an object of the present invention to provide a mold degassing device that can operate reliably.

[0006]

According to the present invention, there is provided a mold degassing apparatus comprising: an exhaust passage communicating with a cavity of a mold; a pressure receiving pin disposed on an inlet side of the exhaust passage; and a closing valve disposed on an outlet side of the exhaust passage. An opening / closing lever for transmitting the movement of the pressure receiving pin to the closing valve; and a closing piston for pressing the opening / closing lever in the closing direction of the closing valve between the pressure receiving pin and the closing valve. An opening spring is sometimes provided to press the opening / closing lever in the opening direction of the closing valve.

Here, the exhaust passage is provided with a bypass which communicates with the cavity of the mold, branches off at the inlet side and joins at the outlet side. Here, the pressure receiving pin is disposed at a branch portion of the detour, operates by the pressure of the molten metal flowing into the detour, and swings the open / close lever in the closing direction. Here, the closing valve is arranged at the junction of the detour, releases the gas in the cavity to the suction device, and the operation of the pressure receiving pin is transmitted via the opening / closing lever,
Close before the molten metal arrives to prevent the molten metal from flowing out to the suction device.

Here, the closing piston is operated by gas, especially by air pressure, and forcibly closes the opening / closing lever only at the beginning of the operation when the mold is cold, supplements the operation of the pressure receiving pin, and at the time of normal operation. In free state. Here, the opening spring means that when the mold is opened, the opening / closing lever is pressed in the opening direction by elasticity to return the pressure receiving pin that was operated by the molten metal pressure, and also to release the closed valve that was in the closed state to open and release the gas. It is possible to remove an excess member of the molten metal solidified in the apparatus.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the schematic structure of an injection molding machine will be described with reference to FIG. 1. A cavity C is formed between a fixed mold A and a movable mold B, and the fixed mold A and the movable mold are formed. B, a degassing device 1 is attached, a suction device D is connected to the degassing device 1, and an extruding pin P of the product solidified in the cavity C is formed on a pressing plate b of the movable mold B; Apparatus 1
And an extruding pin P of the surplus member S solidified therein.
The molten metal is pressed into the cavity C from the injection molding machine M, and the gas is sucked into the suction device D via the degassing device 1.

Next, an embodiment of a degassing device according to the present invention will be described with reference to FIGS.
Is provided with an exhaust passage 2 communicating with the cavity C between a fixed mold 10 attached to the fixed mold A and a movable mold 20 attached to the movable mold B, branches into the exhaust passage 2 on the inlet side, and merges on the outlet side. And a switching valve 5 for transmitting the movement of the pressure receiving pin 3 to the closing valve 4, and a pressure receiving pin 3 at a branch 2 a of the bypass 12, a closing valve 4 at a merging portion 2 b, and A closing piston 7 for pressing the opening / closing lever 5 in the closing direction of the closing valve 4 is provided between the pressure receiving pin 3 and the closing valve 4, and the opening / closing lever 5 is opened on the opposite side of the closing piston 7 when the mold is opened. An opening spring 6 for pressing in the opening direction is provided.

The fixed mold 10 has a pin storage chamber 13 communicating with the branch 2a of the detour 12 and a valve storage chamber 14 communicating with the junction 2b, and straddles the pin storage chamber 13 and the valve storage chamber 14. The lever chamber 15 is provided on the side opposite to the exhaust passage 2 side, and the cylinder chamber 1 of the lever chamber 15 on the exhaust passage 2 side is provided.
7 is provided with a spring storage chamber 16 on the opposite side, the cylinder chamber 17 and the spring storage chamber 16 open toward the lever chamber 15, and the valve storage chamber 14 communicates with the suction device D.
4 and a through hole 34 through which the free end 5b of the opening / closing lever 5 passes, and the cylinder chamber 17 is provided with an air passage 27 communicating with an air supply device (not shown). The movable mold 20 forms the exhaust passage 2 and the detour 12 on the fixed mold 10 side.

The pressure receiving pin 3 is slidably fitted in the pin housing 13, the closing valve 4 is slidably fitted in the valve housing 14, the closing piston 7 is slidably fitted in the cylinder chamber 17, and the open spring 6 is fitted in the spring housing 1.
6, and is abutted on the opening / closing lever 5.
When the mold is opened, the contact member 26 protrudes the fixed pin 8 provided on the fixed mold 10 toward the movable mold 20 as shown in FIG. 7, and is pushed back by the fixed pin 8 when the mold is clamped. Confronted slightly away from. The opening / closing lever 5 has a base 5a swingably held on the inlet side of the lever chamber 15, a free end 5b engaged with a locking portion 4a provided on the closing valve 4, and a pressure receiving pin 3 and a closing piston on the closing side. 7, an open spring 6 abuts on the open side. When the closing valve 4 is closed, the opening spring 6 is substantially parallel to the parting line.
Incline toward the side.

Since the degassing device of the present invention has the above structure, the pressure receiving pin 3 and the closing valve 4
, An opening / closing lever 5, an open spring 6, and a closing piston 7, and the fixed mold 10 is attached to the fixed mold A, while the movable mold 20 is attached to the movable mold B, and the discharge port 24 of the fixed mold 10 is attached. The suction device D is connected to the air supply device to the ventilation path 27, and the suction device D, the injection molding machine M, and the air supply device are operated.
If the molten metal is pressed into the cavity C in the mold clamping state,
The gas G in the cavity C is sucked into the exhaust passage 2 as shown in FIG. 3 and passes through the bypass 12 without operating the pressure receiving pin 3, reaches the closed valve 4 in the open state, and reaches the valve storage chamber 14.
Is absorbed by the suction device D from the discharge port 24 of.

During normal operation, the molten metal is
When the pressure increases at the branch portion 2a, the pressure receiving pin 3 is pushed out as shown in FIG. 4 by the pressure of the molten metal, and the operation of the pressure receiving pin 3 causes the opening / closing lever 5 to swing in the closing direction. Since the free end 5 b of the opening / closing lever 5 is engaged with the locking portion 4 a of the closing valve 4, the molten metal is closed before reaching the closing valve 4. As a result, the molten metal does not reach the outlet 24. That is, since the opening / closing lever 5 operates only by the pressure of the molten metal, the closing piston 7 does not need to be operated.

In the early stage of the operation when the mold is cold, the molten metal is filled into the cavity C at a lower speed than in the normal operation, the pressure of the molten metal reaching the exhaust passage 2 is also reduced, and the operation of the pressure receiving pin 3 becomes insufficient. If the closing piston 7 is forcibly closed before the molten metal reaches the closing valve 4 as shown in FIG. 5, the opening / closing lever 5 is connected to the pressure receiving pin 3 operated at a low molten metal pressure and the air pressure. Swings in the closing direction by the closing piston 7 actuated in the step (1) to close the closing valve 4.

After the molten metal in the cavity C and the molten metal in the exhaust passage 2 have been solidified, if the fixed mold A and the movable mold B are opened, the degassing apparatus of the present invention follows the opening. The fixed mold 10 and the movable mold 20 are also opened. When the fixed mold 10 and the movable mold 20 are opened, the opening / closing lever 5 is swung in the opening direction by the repulsive force of the opening spring 6 in accordance with the mold opening, as shown in FIG. Protrudes toward the movable mold 20, the pressure receiving pin 3 returns to the exhaust passage 2 side, and the closing valve 4 returns to the opening direction.
The excess member S solidified in the inside is extruded toward the movable mold 20 separated from the fixed mold 10. Surplus member S attached to movable mold 20
The push pin P of the movable mold 20 is pressed by the pressing plate b of the movable mold B.
And extruded.

[0017]

The position of the closing piston 7 and the opening spring 6 is not limited as long as the opening / closing lever 5 can be operated.
If a coil spring is mainly used as the open spring 6 and the elasticity of the coil spring can be freely adjusted, and if the elasticity of the open spring 6 is adjusted to be slightly higher than the operating pressure of the closing piston 7, the molten metal Until the pressure is applied, even if the closing piston 7 is operated by mistake, the opening / closing lever 5 cannot be pressed in the closing direction. The holding mechanism of the opening / closing lever 5 is not limited to the embodiment, and the base 5
A general method of supporting a with a pin may be used.

[0018]

The degassing apparatus for a mold according to the present invention has the following effects because of the above structure. The opening / closing lever is forcibly operated by the opening spring and the closing piston. However, since the closing piston operates only in the early stage of the operation when the molten metal is at a low speed, the generation of tapping noise is significantly reduced. Since the opening spring always presses the opening / closing lever in the opening direction, the opening spring does not give a strong impact unlike the opening piston, and therefore, the impact damage by the piston is reduced. Moreover, it does not require expensive and complicated control devices, and operates compactly and reliably.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a mold provided with a degassing device according to the present invention.

FIG. 2 is a plan view schematically showing an exhaust passage in the gas venting device.

FIG. 3 is a cross-sectional view at the time of degassing.

FIG. 4 is a cross-sectional view showing closing of a closing valve during normal operation.

FIG. 5 is a cross-sectional view showing closing of a closing valve in an initial operation.

FIG. 6 is a sectional view when the mold is opened.

FIG. 7 is a sectional view of the fixed mold when the mold is opened.

FIG. 8 is a view showing a use state of a hydraulic cylinder in a conventional mold degassing apparatus.

FIG. 9 is a cross-sectional view of a conventional mold degassing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Degassing device 2 Exhaust passage 3 Pressure receiving pin 4 Closing valve 5 Opening / closing lever 6 Opening spring 7 Closing piston C cavity, G gas

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E093 KB05 NA01 4F202 AM28 CA30 CK07 CK75 CP01 CP04

Claims (1)

[Claims] An exhaust passage (2) communicating with a cavity (C) of a mold, a pressure receiving pin (3) arranged on an inlet side of the exhaust passage (2) and a closing valve (4) arranged on an outlet side, An opening / closing lever (5) for transmitting the movement of the pressure receiving pin (3) to the closing valve (4), and closing the opening / closing lever (5) between the pressure receiving pin (3) and the closing valve (4). (4) a closing piston (7) for pressing in the closing direction;
A degassing device for a mold, characterized in that an opening spring (6) for pressing an opening / closing lever (5) in an opening direction of a closing valve (4) when the mold is opened is provided on a side opposite to the closing piston (7). .