JPH11245011A - Vacuum die-cast equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently vacuumize the equipment, eliminate the blowholes of castings, and prevent outflow of the molten material outside the dies by providing an opening formed in one part of a chill vent portion and a shutoff mechanism to open/close the opening interlocking with the casting operation. SOLUTION: A gas vent passage 13 of a cavity 3 consists of a gas vent groove 16 formed by a fixed mold 1 and a movable mold 2, and a chill vent portion 14. At the position of a gas vent groove 16B of the movable mold 2 opposed to a gas vent groove 16A of the fixed mold 1, a block 18 is provided and is linked to a hydraulic cylinder 17 to form the shutoff mechanism. The hydraulic cylinder 17 is connected to a controller 23 and moved back and forth by signals to advance the block 18 into the gas vent portion 16A to close the gas vent groove 16. When vacuuming is started, it moves back and block 18 to open the gas vent groove 16. When the block 18 is moved back, a block front 18a is at a position lower than the bottom 15b of a chill vent member 15B on the movable side and becomes flush with the bottom face of the gas vent groove 16B on the movable side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum die casting apparatus having a chill vent for degassing a mold.

[0002]

2. Description of the Related Art Conventionally, a die casting apparatus having a chill vent for degassing the inside of a mold is disclosed in Japanese Patent Application Laid-Open No. Hei 6-23504 as "Method for detecting degassing state in a mold and its apparatus". The disclosed technique is disclosed. This technique will be described with reference to FIG. In FIG. 10, the degassing state detection device 110 in a mold is disposed on a mold 173 composed of a movable mold 171 and a fixed mold 172. A gas vent (corresponding to a chill vent) 175 communicating with the cavity 174 of the mold 173 is provided between the movable mold 171 and the fixed mold 172, and a part of the gas vent 175 is provided. The gas outlet 176 is formed so as to form a zigzag, and the outlet opposite to the cavity 174 is formed.

The in-mold degassing state detecting device 110 is a flow detecting means for detecting the flow state by detecting the pressure of each part of the flow path in the venturi member 111 disposed on the die 173. The pressure detecting means 130 and the pressure detecting path 11 which is a flow detecting path connecting the differential pressure detecting means 130 and the flow path in the venturi member 111.
6, 117 and the pressure detection passage 11
6 and 117 for cleaning. The venturi member 111 includes a moving mold 171.
And a second venturi member 111B fixedly installed on the fixed mold 172. These venturi members 111A and 111B are joined to each other at a joint end face 112. ing. Venturi members 111A, 111B
A venturi flow path 113 communicating with the gas discharge port 176 is formed at the joint portion of.

In the mold 173 having the above-described structure, a gas vent formed in a corrugated cross section to prevent the molten metal (molten material) from flowing out of the mold when the air is purged by the air purge means 120. 175 is provided, and the molten metal is gradually cooled when flowing through the narrow gap of the gas vent 175, and is cooled before flowing out of the mold.
Is to be solidified.

[0005]

However, the above prior art has the following problems. If the gap of the gas vent is widened to sufficiently perform the evacuation, the molten metal flows out of the mold and the molten metal flows into the vacuum device. Therefore, the gap of the gas vent must be narrowed. For this reason, the evacuation was not performed sufficiently, and air remained in the cavity and was caught in the molten metal, causing cavities in the cast product.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention according to claims 1, 2 and 3 is that vacuum evacuation is sufficiently performed, the casting has no nest, and An object of the present invention is to provide a vacuum die casting apparatus in which a molten material does not flow out of a mold.

[0007]

According to a first aspect of the present invention, there is provided a vacuum die casting apparatus having a chill vent for degassing a mold. And a blocking mechanism for opening and closing the opening in conjunction with the casting operation. According to a third aspect of the present invention, there is provided a vacuum die casting apparatus having a chill vent for degassing a mold, an opening formed in a part of the chill vent, and a shutoff mechanism for opening and closing the opening. A detecting means for detecting a supply amount of the molten material into the mold; and a control means for controlling the shut-off mechanism based on an output of the detecting means.

That is, in the vacuum die casting apparatus according to the first or second aspect of the present invention, when gas is released from the mold, the shut-off mechanism is opened and the opening formed in a part of the chill vent is sufficiently opened. Degassing is performed, and at the time of casting, the opening is closed in conjunction with the casting operation, and the molten material flowing out to the chill vent is solidified while degassing is continued only at the chill vent. In the vacuum die casting apparatus according to the third aspect of the present invention, when degassing the mold, the shutoff mechanism is opened and the degassing is sufficiently performed from the opening formed in a part of the chill vent portion. At the time of casting, the opening is closed by a signal from the control unit that controls the shut-off mechanism based on the output of the detection unit that detects the supply amount of the molten material into the mold, and degassing is continued only at the chill vent. While the molten material flowing out to the chill vent portion is solidified.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the present invention, a block as a part of a shut-off mechanism is retracted by a driving device, and while a cavity is evacuated by a vacuum device, the block is pushed out of an injection sleeve by a plunger tip. The molten metal as the molten material flows into the cavity through the runner, and after filling the cavity, before the molten metal comes to the chill vent portion, the block is advanced by the driving device and provided in a part of the chill vent portion. The gas vent groove as the opening is closed. Thus, a sufficient evacuation path can be maintained before the molten metal flows into the chill vent portion, so that the gas vent passage can be kept wide. In addition, even if the gas vent groove is closed, vacuum can be drawn from the chill vent until the molten metal flows into the chill vent and solidifies. Further, since the molten metal is solidified in the chill vent portion, the molten metal does not flow out of the mold. Hereinafter, specific embodiments will be described.

(Embodiment 1) FIGS. 1 to 4 show Embodiment 1, and FIG. 1 is a longitudinal sectional view of a vacuum die casting apparatus.
2 is a right side view showing a fixed PL surface, FIG. 3 is a left side view showing a movable PL surface, and FIG. 4 is a perspective view showing a movable chill vent portion. In the present embodiment, an example of a single-cavity mold is shown. However, even in the case of multiple-cavity molds, runners, kyates and degassing passages are provided in accordance with the number of molds.
The same can be applied. Also, the shape of the casting is a square block as an example, but it is not limited to the casting having this shape.

In FIG. 1, the vacuum die casting apparatus mainly comprises a fixed mold section A, a movable mold section B, a molten metal supply mechanism C,
It is composed of evacuation means D and control means E.
First, the fixed mold part A will be described. 1 and 2, the fixed die 1 is attached to a fixed die 7 fixed to a die casting machine. The fixed mold 1 is brought into contact with the movable mold 2 of the movable mold section B and the PL surface of each other to clamp the mold, whereby
The cavity 3 is formed. A runner 4 for supplying molten metal as a molten material is continuously provided in the cavity 3, and runners 4 </ b> A and 4 </ b> B recessed in the fixed mold 1 and the movable mold 2, respectively.
Formed by The runner 4A of the fixed mold 1 is
Is connected to the injection sleeve 5 fitted in the injection sleeve 5. The injection sleeve 5 is provided with a supply port 5a, through which the molten metal is supplied.

The cavity 3 is provided with a gas vent passage 13 connected to the fixed mold 1.
And a chill vent portion 14 formed by the gas release groove 16 and the chill vent portion 14 formed by the movable mold 2. The gas vent groove 16 and the chill vent portion 14 are respectively provided with a fixed gas vent groove 16A and a movable gas vent groove 16A provided in the fixed mold 1 and the movable mold 2, respectively.
B, a fixed-side chill vent member 15A, and a movable-side chill vent member 15B. As shown in FIG. 2, the degassing passage 13A on the fixed die 1 side has a fixed-side degassing groove 16A recessed in the fixed die 1 and a fixed-side degassing groove 16A embedded on both sides of the fixed-side degassing groove 16A. And a chill vent member 15A. As shown in FIG.
The fixed side chill vent member 15A has a zigzag groove formed on the surface thereof, and the movable side chill vent member 15 of the movable mold 2 is formed.
A chill vent portion 14 having a narrow gap between the same angle groove as that of B
Is formed, and when the gas vent groove 16 is closed, degassing is continued from the chill vent portion 14, and then the molten metal that has flowed in is cooled and solidified. The fixed-side gas vent groove 16A is formed deeper than the bottom 15a of the angled groove of the fixed-side chill vent member 15A, and forms the gas vent groove 16 together with the movable-side gas vent groove 16B of the movable mold 2.

Next, the movable mold part B will be described. 1, 3 and 4, the movable mold 2 is attached to a movable die 9 fixed to a die casting machine via a spacer block 8. A cavity 3 is formed in the movable mold 2, and a plurality of eject pins 10 for extruding a casting are fitted on the bottom surface of the cavity 3. A flange 10a is formed at one end of the eject pin 10, and the flange 10a is sandwiched between the upper extruding plate 11 and the lower extruding plate 12, so that the sliding distance of the eject pin 10 is limited. A runner 4B is provided in the cavity 3 at a position facing the runner 4A of the fixed mold 1, and the runner 4 is formed by the runners 4A and 4B. Further, a gas vent passage 13B on the movable mold 1 side is continuously provided in the cavity 3, and the gas vent passage 13B is provided with a movable gas vent groove 16B formed in the movable mold 2 and a movable gas vent groove 16B. The movable side chill vent members 15B are embedded on both sides of the groove 16B. As with the fixed chill vent member 15A, the movable chill vent member 15B has zigzag grooves formed on the surface thereof in a zigzag manner.

A block 18 is provided at a position of the movable-side gas vent groove 16B of the movable mold 2 opposite to the fixed-side gas vent groove 16A of the fixed mold 1, and is connected to the hydraulic cylinder 17. The hydraulic cylinder 17 is connected to a control device 23 which will be described later, and moves back and forth according to the signal, and
The block 18 is advanced into A, and the gas vent groove 16 is closed. When the evacuation starts, the block 18 is retracted to open the gas vent groove 16. When the block 18 is retracted, the front surface 18a of the block 18 is located at a position deeper than the bottom 15b of the movable chill vent member 15B and is flush with the bottom surface of the movable gas vent groove 16B. Hydraulic cylinder 1
7 and the block 18 constitute a blocking mechanism.

Next, the molten metal supply mechanism C will be described. In FIG. 1, a plunger 6 is attached to an injection sleeve 5.
The rod 6b having the chip 6a attached thereto is connected to a drive mechanism (not shown), and the plunger 6 is driven back and forth. As the plunger 6 advances, the molten metal supplied into the injection sleeve 5 is pressure-fed into the cavity 3. Also, the rod 6b of the plunger 6 has a collar 2
1 is attached, and a forward movement of the rod 6b abuts on a contact 22a of a limit switch 22 of the control means E, which will be described later, to generate a signal for feeding the molten metal.

Next, the evacuation means D will be described. 1, 2 and 3, the degassing passage 1
A joint 19 is disposed at the open end of the third. The joint 19 includes a fixed joint 19A attached to the fixed mold 1 and a movable joint 19 attached to the movable mold 2.
B, and are separated on the same plane as the PL plane of the fixed mold 1 and the movable mold 2. An L-shaped through hole 19a is formed in the fixed joint 19A, and a pipe 20 is connected to the through hole 19a and connected to a vacuum device (not shown). Also, movable joint 1
9B, a groove 19b is recessed, and the movable side gas release groove 16 is formed.
It is configured to communicate with B and also with the through hole 19a of the fixed side joint 19A. By operating the vacuum device, the gas in the cavity 3 is
The gas is sucked into the vacuum device through the gas vent groove 16, the groove 19b, the through hole 19a, and the pipe 20.

Next, the control means E will be described. In FIG. 1, a limit switch 22 disposed near the plunger 6 of the molten metal supply mechanism C is connected to a control device 23. The control device 23 is connected to the hydraulic cylinder 17 via a control valve of a hydraulic mechanism (not shown). When the collar 21 attached to the plunger 6 comes into contact with the contact 22 a of the limit switch 22, the control device 23 discharges the molten metal. The pumping signal is sent to the controller 23. The controller 23 sends this signal to the hydraulic cylinder 17 to advance the block 18 and close the gas vent groove 16. Before the molten metal reaches the gas vent passage section 13, the position is set so that the collar 21 kicks the contact 22a of the limit switch 22.

Next, a casting method using the vacuum die casting apparatus having the above-described structure will be described. First, the movable die 9
Is moved forward, the movable mold 2 is brought into contact with the fixed mold 1 and the mold is clamped. After the block 18 is retracted to open the gas vent groove 16, the molten metal is supplied into the injection sleeve 5 while the inside of the cavity 3 is evacuated by the vacuum device, and the plunger 6 is advanced to move the molten metal through the runner 4. The pressure is fed to the cavity 3. Before the molten metal reaches the degassing passage 13,
When 1 pushes the limit switch 22, the hydraulic cylinder 17 operates to advance the block 18 and close the gas vent groove 16. Thereafter, only the chill vent portion 14 of the gas vent passage portion 13 is evacuated, and the molten metal flows into the chill vent portion 14 to be cooled and solidified. In this state, the inside of the cavity 3 is cooled, and after the molten metal solidifies, the vacuum device is stopped. By retracting the movable die 9, the movable die 2 is separated from the fixed die 1, the upper extruding plate 11 and the lower extruding plate 12 are actuated, and the cast product is extruded from the cavity 3 by the eject pin 10, thereby completing the casting operation. .

According to the present embodiment, from the start of evacuation to the time before the molten metal reaches the gas venting passage, the gas venting passage has a large suction cross-sectional area, so that gas is sufficiently vented. Thus, even if the gas vent groove is closed by the block in a state where the cavity is not completely filled, the gas can be vented through the chill vent until the molten metal reaches the chill vent, thereby producing a cast product without nests. be able to. Further, since the molten metal is cooled and solidified in the chill vent portion, the molten metal does not flow out of the mold.

In this embodiment, the block is moved back and forth from inside the movable mold to open and close the gas vent groove. However, the block may be moved back and forth from inside the fixed mold. Further, although a hydraulic cylinder is used as the driving member of the block, a pneumatic cylinder or a linearly moving mechanism combining an electric motor and a gear may be used. Further, the signal of the molten metal being pressure-fed is generated by kicking a contact of the limit switch with a collar. However, a configuration may be adopted in which timing is taken by a non-contact sensor such as a photoelectric sensor.

(Embodiment 2) FIGS. 5 to 7 show Embodiment 2, and FIG. 5 is a sectional view of a vacuum die casting apparatus taken along the line ABCD-DE in FIG. FIG. 6 is a right side view showing a fixed PL surface, and FIG. 7 is a left side view showing a movable PL surface. This embodiment is different from the first embodiment only in the gas vent passage, so only the different parts are shown,
The same members are denoted by the same reference numerals, and description thereof will be omitted.

First, the fixed mold part A will be described. 5 and 6, the cavity 3 is provided with a degassing passage portion 33 which is connected to the fixed die 1.
And a chill vent portion 34 formed by a gas vent groove 36 formed by the movable mold 2 and the movable mold 2. The gas vent groove 36 and the chill vent portion 34 are respectively provided with a fixed gas vent groove 36A and a movable gas vent groove 36A provided in the fixed mold 1 and the movable mold 2, respectively.
B, a fixed-side chill vent member 35A, and a movable-side chill vent member 35B. As shown in FIG. 6, the degassing passage 33A on the fixed die 1 side includes a fixed chill vent member 35A embedded in the fixed die 1 and a fixed degas vent formed on both sides of the fixed chill vent member 35A. It is constituted by the groove 36A. As shown in FIG. 5, the fixed-side chill vent member 35A has zigzag grooves formed on the surface thereof in a zigzag manner, and has a narrow gap between the movable-side chill vent member 35B of the movable mold 2 and the same mountain-shaped groove. Is formed, and when the gas vent groove 36 is closed, degassing is continued from the chill vent portion 34, and then the molten metal that has flowed in is cooled and solidified. Fixed side gas vent groove 36A
Is the valley bottom 35a of the angled groove of the fixed side chill vent member 35A.
The movable side gas vent groove 36B of the movable mold 2 is formed deeper.
At the same time, gas vent grooves 36 are formed on both sides of the chill vent portion 34.

Next, the movable mold B will be described. 5 and 7, a gas vent passage portion 33B on the movable mold 2 side is continuously provided in the cavity 3, and the gas vent passage portion 33B has a movable side chill vent member 35B embedded in the movable mold 2 and The movable side gas vent groove 36B is formed on both sides of the movable side chill vent member 35B. The movable chill vent member 35B has a zigzag groove formed on the surface thereof, similarly to the fixed chill vent member 35A.

Two fixed-side gas vent grooves 36 of the fixed mold 1
A, two movable side gas vent grooves 36 of the movable mold 2 facing A
Blocks 38A and 38B are provided at the position B, and are connected to hydraulic cylinders 37A and 37B (not shown). The hydraulic cylinders 37A and 37B are connected to the control device 23, which will be described later, and move back and forth according to the signal to advance the blocks 38A and 38B into the fixed-side gas vent groove 36A to close the gas vent groove 36. When the evacuation starts, the blocks 38A and 38B are retracted to open the gas vent groove 36. Block 38
When A and 38B are retracted, the front surfaces 38a and 38b of the blocks 38A and 38B are located at a position deeper than the valley bottom 35b of the movable chill vent member 35B, and the movable side gas vent groove 36B
It is configured to be flush with the bottom surface of. The hydraulic cylinders 37A and 37B and the blocks 18A and 18B constitute a shut-off mechanism.

The molten metal supply mechanism C and the evacuation means D are the same as in the first embodiment. In the control means E, the control device 23 is connected to two hydraulic cylinders 37A and 37B via control valves of a hydraulic mechanism (not shown). Other configurations of the control unit E are the same as those of the first embodiment.

Next, a description will be given of a casting method using the vacuum die casting apparatus having the above configuration. Hydraulic cylinder 37A,
The operation is the same as that of the first embodiment until the operation of 37B and the advance of the blocks 38A and 38B to close the gas vent groove 36. Thereafter, the chill vent portion 34 of the gas vent passage portion 33
Vacuum is drawn only by this, and the molten metal flows into the chill vent portion 34 and solidifies by cooling. In this state, the inside of the cavity 3 is cooled, and after the molten metal solidifies, the vacuum device is stopped. Subsequent steps are the same as in the first embodiment.

According to the present embodiment, in addition to the effect of the first embodiment, since the chill vent portion is disposed at the center of the gas vent passage, the gas vent passage after the gas vent groove is closed is straight. And the degassing is sufficiently performed.

Also in the present embodiment, the modification shown in the first embodiment can be applied similarly.

(Embodiment 3) FIGS. 8 and 9 show Embodiment 3, and FIG. 8 is a longitudinal sectional view of a vacuum die casting apparatus.
FIG. 9 is a left side view showing a movable PL surface. In the present embodiment, the control means for opening and closing the degassing passage is the first embodiment.
Therefore, only different portions are shown, and the same members are denoted by the same reference numerals and description thereof will be omitted.

In FIGS. 8 and 9, a sensor 41 is disposed in the gas vent groove 16B of the movable die 2 close to the cavity 3 of the fixed die portion B as a detecting means for supplying electricity when the molten metal reaches. The sensor 41 is connected to the
When the molten metal reaches the sensor 41, a signal for notifying the sensor 41 is sent to the control device 23, and the control device 23
This signal is sent to the hydraulic cylinder 17 and the block 18 is advanced to close the gas vent groove 16. The flange 2 attached to the plunger 6 of the molten metal supply mechanism C
1 and the limit switch 22 in the control means E are not arranged together. Other configurations are described in Embodiment 1.
Is the same as

Next, a casting method using the vacuum die casting apparatus having the above configuration will be described. The same operation as in the first embodiment is performed until the molten metal is supplied into the injection sleeve 5 while the inside of the cavity 3 is evacuated by the vacuum device, the plunger 6 is advanced, and the molten metal is pressure-fed to the cavity 3 through the runner 4. is there. When the molten metal fills the cavity 3 and reaches the sensor 41, the hydraulic cylinder 17 is operated by the signal of the sensor 41, and the block 18 closes the gas vent groove 16. Thereafter, the chill vent section 14 of the gas vent passage section 13
The steps after the evacuation is performed only by the evacuation, the molten metal flows into the chill vent portion 14, and the solidification by cooling is the same as the first embodiment.

According to the present embodiment, in addition to the effect of the first embodiment, since the molten metal is detected by the sensor disposed in the gas vent groove and the gas vent groove is closed, the present embodiment is constructed so that every time the mold is replaced. The adjustment of the timing of kicking the limit switch can be omitted.

In the present embodiment, the modification shown in the first embodiment can be similarly applied.

The technical idea of the following configuration is derived from the above specific embodiment. (Supplementary Note) (1) In a vacuum die casting apparatus having a chill vent portion, a fixed type chill vent portion has the same length as the chill vent portion in the flow direction of molten metal and a gas release groove deeper than a concave portion of the chill vent portion, and A block that slides on the chill vent portion by a driving device, retreats from the concave portion of the movable chill vent portion when evacuation starts, and moves forward before the molten metal reaches the chill vent portion to close the gas vent groove. And a vacuum die casting apparatus.

From the start of evacuation to before the molten metal reaches the degassing passage, the degassing passage has a large cross-sectional area, so that degassing is sufficiently performed. Thus, even if the gas vent groove is closed by the block in a state where the cavity is not completely filled, until the molten metal reaches the chill vent part,
Since degassing can be performed through the chill vent portion, a cast product without nests can be manufactured. Further, since the molten metal is solidified in the chill vent portion, the molten metal does not flow out of the mold.

[0036]

According to the first or second aspect of the present invention,
When degassing the mold, open the shut-off mechanism and sufficiently vent the gas from the opening formed in a part of the chill vent.When casting, close this opening in conjunction with the casting operation. Therefore, the molten material flowing out to the chill vent is solidified while continuing degassing only at the chill vent, so that sufficient vacuum is drawn, the casting has no cavities, and the molten material flows out of the mold. There is no.

According to the third aspect of the present invention, when venting the mold, the shut-off mechanism is opened to sufficiently vent the gas through the opening formed in a part of the chill vent portion. In response to a signal from a control unit that controls the shut-off mechanism based on the output of the detection unit that detects the supply amount of the molten material into the mold, the opening is closed, and the degassing is continued only at the chill vent. Since the molten material flowing out to the chill vent portion is solidified, vacuum evacuation is sufficiently performed, there are no cavities in the cast product, and the molten material does not flow out of the mold.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a vacuum die casting apparatus according to a first embodiment.

FIG. 2 is a right side view showing a fixed PL surface according to the first embodiment.

FIG. 3 is a left side view showing a movable PL surface according to the first embodiment.

FIG. 4 is a perspective view showing a movable chill vent of the first embodiment.

5 is a cross-sectional view of the vacuum die casting apparatus according to the second embodiment, taken along the line ABCDE in FIG. 7;

FIG. 6 is a right side view showing a fixed PL surface according to the second embodiment.

FIG. 7 is a left side view showing a movable PL surface according to the second embodiment.

FIG. 8 is a longitudinal sectional view of a vacuum die casting apparatus according to a third embodiment.

FIG. 9 is a left side view showing a movable PL surface according to the third embodiment.

FIG. 10 is a schematic configuration diagram of a conventional device for detecting a state of degassing in a mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 14 Chill vent part 16 Gas release groove 17 Hydraulic cylinder 18 Block

Claims (3)

[Claims] 1. A vacuum die casting apparatus having a chill vent for degassing a mold, wherein the opening is formed in a part of the chill vent and the opening is opened and closed in conjunction with a casting operation. A vacuum die casting apparatus comprising a shut-off mechanism. 2. The apparatus according to claim 1, wherein the shut-off mechanism performs degassing with the opening being opened, and closes the opening before the molten material reaches the chill vent. Item 6. A vacuum die casting apparatus according to Item 1. 3. A vacuum die casting apparatus having a chill vent for degassing a mold, an opening formed in a part of the chill vent, a shut-off mechanism for opening and closing the opening, and the metal mold. A vacuum die casting apparatus comprising: detecting means for detecting a supply amount of a molten material into a mold; and control means for controlling the shut-off mechanism based on an output of the detecting means.