JP2000084651A - Formation of semi-molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a formed body hardly generating cold shut containing gas defect in a confluent part of molten metal even in the case of a product having complicate shape by inserting semi-molten metal having the specific range of a solid phase ratio into a vertical sleeve, connecting the sleeve with a die and forming the semi-molten metal at a high pressure while reducing the pressure of gas in a die cavity. SOLUTION: The solid phase ratio of a semi-molten metal M1 is made to desirably be 20-70% and while reducing the pressure, this metal is formed in the cavity 41 at the high pressure. Then, the semi-molten metal M1 is cast into the die cavity 41 by working an injection cylinder 10 to advance a plunger rod 13. At the time of turning on a limit switch 16 by advancing a striker 14, the electric power is conducted to a solenoid 31 and an exhauster 55 and a gas venting device 50 are connected to exhaust the gas in the die cavity 41. At the same time, a timer 18 is worked and at the time of cutting off the electric conduction of the solenoid 31 after passing the preset prescribed time, the connection between the exhauster 55 and the gas venting device 50 is cut off and the inner part in the gas venting device 50 is released into the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a semi-molten metal, and more particularly, to a method of injecting a semi-molten metal into a mold cavity using a vertical sleeve, and using a gas release valve with the molding. The present invention relates to a method for forming a semi-molten metal having a uniform structure in which fine primary crystals having no air entrainment or hot water boundary are dispersed in a liquid phase by discharging air in a cavity.

[0002]

2. Description of the Related Art A semi-solid metal forming method called a thixocasting method or a rheocasting method has less shrinkage cavities and segregation than a conventional casting method, has a uniform metal structure, has a long mold life, and has a long mold life. It has advantages such as a short cycle, and is a technology that has attracted attention recently.

[0003] In the same method, since it is a semi-molten metal, burrs are not easily blown even at high speed injection molding.
It is also possible to inject at a higher speed than in a conventional high pressure casting method (for example, a squeeze method). Conversely, injection is performed at a higher speed than in the high-pressure casting method in order to fill every corner in the mold cavity.

[0004]

However, in the above-described method, the temperature of the metal to be formed is low, so that a hot boundary including gas defects occurs at the hot junction, and this tendency is strong when the metal is injected at high speed. Further, this defect is likely to occur in a product having a complicated shape or a large product, and there are places where the reliability of the molded product is low.

In a case where a high-quality cast product is to be formed from liquid metal while reducing the pressure in the cavity by using a casting machine having a vertical sleeve, the plunger tip at the bottom of the vertical sleeve is removed with the pressure reduction. Since air was mixed in from the gap between the contact surfaces of the vertical sleeve and was caught in the cast product, a number of gas defects occurred inside the product, and a good product could not be obtained.

[0006]

In the present invention, in order to solve the above-mentioned problems, in the first invention, the solid phase ratio is 20%.
% To 70% of the semi-molten metal is inserted into the vertical sleeve, and the sleeve and the mold having the cavity of the product section are joined. After that, the gas in the mold cavity is passed through a venting device from a venting passage. The semi-molten metal was formed under high pressure while reducing the pressure by the pressure reducing means.

Further, in the second invention, which is mainly based on the first invention, a semi-molten metal is depressurized by a decompression means using a degassing device having a chill vent at the end of a degassing passage from a mold cavity. Was subjected to high pressure molding.

[0008]

A semi-molten metal having a solid fraction of 20% to 70% is inserted into a vertical sleeve, the sleeve and a mold having a cavity are joined, and then the end of a gas vent passage connected to the mold cavity. Machine with high pressure and low pressure through a chill vent provided in the part and high pressure molding, so that even in products with complicated shapes, hot junctions containing gas defects are less likely to occur at the junction of hot water and have a good structure A molded article having excellent mechanical properties can be obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below with reference to the drawings. 1 to 5 relate to an embodiment of the present invention,
1 is a longitudinal sectional view of a degassing device according to the present invention, FIG. 2 is a front view of the degassing device according to the present invention, FIG. 3 is an overall view of a semi-molten metal forming device according to the present invention, and FIG. FIG. 5 is an explanatory view when a semi-molten metal is inserted into a vertical sleeve.

The semi-solid metal forming apparatus 100 will be described with reference to FIG. The semi-solid metal forming apparatus 100 is a degassing apparatus,
It comprises an exhaust device 55 and an injection device 60.
The degassing device 50 includes an exhaust block 4 and gas exhaust holes 5, and the degassing device 50 includes a chill vent that communicates with a degassing passage on a separation surface between the movable mold 42A and the fixed mold 42B. 2 are provided. The chill vent 2 has a zigzag-shaped slit as shown in FIG. 1, forcibly sucks and discharges gas from the narrow zigzag passage by using the vacuum pump 33, and has a semi-molten metal M1 having a large inertia force at the time of injection. Is caught in the zigzag passage to rapidly cool the semi-molten metal M1, and the gas discharge holes 5
The semi-molten metal M1 does not jump out of the mold 4
The degassing of the inside 2 can be performed reliably and easily.

As described above, the slit-shaped chill vent 2
Is provided in order to smoothly discharge the gas in the mold cavity 41 by means of a riser.
Is rapidly cooled while passing through the chill vent 2 having a large resistance so that solidification proceeds and the flow stops. By doing so, the semi-molten metal M
1 can be prevented from flowing out.

The exhaust device 55 includes a striker 14,
It comprises a limit switch 16, a timer 18, a pipe 32, a solenoid 31, and a vacuum pump 33. Further, the injection device 60 includes the injection cylinder 10, the piston rod 13, the tip 19, and the vertical sleeve 20.

The injection device 60 is tilted by a tilting cylinder (not shown) and supplies the semi-molten metal M1 from the metal container 40 into the vertical sleeve 20 at a position where the fixed die 42B is evaded. Is returned to the injection position by the tilting cylinder. Thereafter, both the molds 42 and the vertical sleeve 20 are docked, and the semi-molten metal M1 can be injected into the mold cavity 41 by the tip 19.

Piston rod 11 and plunger rod 1
3 are joined by a coupling 12,
A substantially L-shaped striker 14 is fixed to the coupling 12, and the striker 14 moves up and down by the up and down movement of the piston rod 11. A limit switch 16 is provided on the end face of the striker 14. Then, the limit switch 16 is turned on by the up and down movement of the striker 14, and the switch is turned on. As shown in FIG. 3, when the limit switch 16 is turned off, the timer 18 is turned on. Then, when the timer 18 enters, the solenoid 3
1 is excited, and when the timer 18 is turned on, the solenoid 31 is excited.

The operation of this embodiment will be described below.

The operation of this embodiment will be described below. An injection start switch (not shown) is turned ON. Then,
The injection cylinder 10 is operated to move the plunger rod 13 forward to cast the semi-molten metal M1 into the mold cavity 41. As the plunger rod 13 advances, the striker 14 integral with the plunger also advances, and the contact between the striker 14 and the limit switch 15 is released, and the limit switch 16 is turned on.
When the pressure reaches N, the solenoid 31 is energized, and the exhaust device 55 and the degassing device 50 are connected by a self-holding circuit (not shown) to exhaust the gas in the mold cavity 41. Also,
At the same time, the timer 18 operates, and after a predetermined time elapses, the connection between the exhaust device 55 and the degassing device 50 is cut off when the power supply to the solenoid 31 is cut off,
At the same time, the inside of the degassing device 50 is released to the atmosphere.

FIG. 4 shows a drawing of the ring-shaped mold used in the molding test. In the present invention, the solid phase ratio is 20% to 70%.
% Of the semi-molten metal M1 is inserted into the vertical sleeve 20 and the mold 42 having the vertical sleeve 20 and the mold cavity 41 is inserted.
Then, high-pressure molding is performed while reducing the pressure by using a mold degassing device 50 provided with a chill vent 2 at the end of the gas vent passage 1 connected to the mold cavity 41. If the solid phase ratio is less than 20%, the vertical sleeve 20 and the tip 19
The air sucked from the gap between the first metal and the second metal enters the semi-molten metal M1 and entrains the air into the formed product, so that a good product cannot be obtained as in the case of forming the liquid metal. If the solid phase ratio is 70% or more, there is no air entrainment as described above, but the molding itself cannot be performed well.

The vertical sleeve 20 referred to in the present invention is of a type in which the casting machine is docked to a molding die in a state perpendicular to or close to the floor on which the casting machine is installed. And the clamping direction are parallel or perpendicular.

The structure of the gas venting device 50 according to the present invention and the shape of the chill vent 2 at the end of the gas venting passage 1 are not particularly limited. However, the gas venting device 50 shown in the present invention comprises the gas venting passage 1 led from the mold cavity 41 on the separation surface of the mold 42 and the chill vent 2 forming a corrugated narrow gap at its end. Is what is done.

Table 1 shows a ring-shaped mold (having a thickness of 15 mm) shown in FIG.
mm) using JISAC4CH under various injection conditions.
Shows the quality of the formed material from which the alloy was formed. The molding was performed by inserting the semi-molten metal M1 into the vertical sleeve 20 as shown in FIG. 4 and then using a squeeze casting machine. The molding conditions were such that the metal pressure was 100 MPa and the injection speed was in the range of 0.1 m / s to 1.0 m / s.

In Comparative Example 5, since the liquid phase ratio is high, the pressure is reduced using the degassing device 50, so that air is drawn into the semi-molten metal from the gap between the vertical sleeve 20 and the tip 19. . In Comparative Example 6, since the liquid phase ratio was low, the hot water did not completely merge, so that a hot water boundary was generated and the appearance was poor. In Comparative Example 7, the same results as in Comparative Example 6 are shown even when the pressure is reduced using the degassing device 50. Comparative Example 8,
In Comparative Examples 9 and 10, the liquid phase ratio was 30% and 50%.
% And 70%, but the appearance is good because the pressure is not reduced by using the degassing device 50, but a hot water boundary occurs at the junction of the hot water. In Comparative Example 11, although the liquid phase ratio was high and no hot water boundary occurred, the quality was not good due to the occurrence of shrinkage cavities and segregation. On the other hand, in any of the invention examples, a molded article excellent in both appearance and inside is obtained without any hot water boundary.

[0022]

[Table 1]

[0023]

As is apparent from the above description,
In the method for molding a semi-molten metal according to the present invention, the solid fraction is 2%.
After inserting the 0-70% semi-molten metal into the vertical sleeve, coupling the sleeve with the mold having the cavity of the product part, a chill vent is provided at the end of the gas vent passage connected to the mold cavity. Air entrainment by high-pressure molding while reducing pressure using a mold degassing device to obtain a semi-molten metal compact having a uniform structure in which fine primary crystals without a hot boundary are dispersed in the liquid phase. Can be

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a degassing device according to the present invention.

FIG. 2 is a front view of a degassing device according to the present invention.

FIG. 3 is an overall view of a semi-solid metal forming apparatus according to the present invention.

FIG. 4 is a front view of a ring-shaped mold used in a molding test according to the present invention.

FIG. 5 is an explanatory view when a semi-molten metal according to the present invention is inserted into a vertical sleeve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas vent passage 2 Chill vent 3 Connecting gas passage 4 Exhaust block 5 Gas exhaust hole 10 Injection cylinder 11 Piston rod 12 Coupling 13 Plunger rod 14 Striker 16 Limit switch 18 Timer 19 Tip 20 Vertical sleeve 31 Solenoid 32 Piping 33 Vacuum pump 40 Metal container 41 Mold cavity 42 Mold 42A Movable mold 42B Fixed mold 50 Degassing device 55 Exhaust device 60 Injection device 100 Semi-molten metal forming device M1 Semi-molten metal

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsuneo Ueno 1980, Ogushi-oki, Ube City, Ube City, Yamaguchi Prefecture Ube Industries, Ltd.Ube Machinery and Engineering Office (72) Inventor Naoki Ishibashi, Obe City, Ube City, Yamaguchi Prefecture 1980 Okinoyama Ube Machinery & Engineering Office

Claims (2)

[Claims] 1. A semi-molten metal having a solid phase ratio of 20% to 70% is inserted into a vertical sleeve, and the sleeve is joined to a mold having a cavity of a product part. Forming a semi-molten metal under high pressure while depressurizing the semi-molten metal from a gas vent passage through a gas venting device by a pressure reducing means. 2. A semi-molten metal is formed under high pressure while depressurizing by a depressurizing means, using a degassing device provided with a chill vent at the end of a degassing passage from a mold cavity. Method for forming semi-molten metal.