JP2024008202A - Molten metal feeding apparatus and die cast machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molten metal feeding apparatus and a die cast machine with a simple structure which can suppress the temperature reduction of molten metal in a ladle.

SOLUTION: A die cast machine 1 has a molten metal feeding mechanism 50 and a control device 100. A ladle 51 of the molten metal feeding mechanism 50 has a container 52 for storing molten metal M. A bottom part 54 of the container 52 is provided with a molten metal port 56. The control device 100 immerses the container 52 into the molten metal M to open the molten metal port 56. Then, the control device 100 positions the container 52 to a height position in which the molten metal M in the container 52 reaches a set value Vs based on a molten metal face height of the molten metal M in the container 52 to close the molten metal port 56.

SELECTED DRAWING: Figure 8

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a molten metal supply device and a die casting machine having the molten metal supply device.

Patent Document 1 discloses a conventional molten metal supply device. The molten metal supply device includes a ladle and a vacuum suction device that sucks gas in the ladle. The ladle has an outer cylinder that stores molten metal and a conduit that extends downward from the lower end of the outer cylinder. The conduit is provided with a hot water supply port, and the hot water supply port is opened and closed by an opening/closing means.

Japanese Patent Application Publication No. 2011-121060

The molten metal supply device of Patent Document 1 ensures airtightness of the ladle and suctions the gas in the ladle to suck up the molten metal from the melting furnace, so the configuration of the molten metal supply device is complicated. In addition, in the molten metal supply device, only the lower end of the conduit is immersed in the molten metal and the molten metal is sucked up to a level higher than the melting furnace surface, so the heat of the molten metal is released to the atmosphere through the outer cylinder, and the molten metal in the ladle is The temperature will drop.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a molten metal supply device and a die-casting machine with a simple configuration that can suppress the temperature drop of the molten metal in the ladle.

In order to achieve the above object, a molten metal supply apparatus according to the present invention is a molten metal supply apparatus having a ladle and a ladle control device, wherein the ladle has a container for storing molten metal, and the ladle has a container for storing molten metal, and A molten metal spout is provided at the bottom, and the ladle control device opens the molten metal spout by immersing the container in the molten metal of the melting furnace based on the level of the molten metal in the melting furnace. The method is characterized in that the container is positioned at a height position where the molten metal in the container reaches a set amount based on the height of the molten metal surface, and the molten metal inlet is closed.

According to the present invention, the ladle container is immersed in the molten metal of the melting furnace based on the level of the molten metal in the melting furnace, and the molten metal port provided at the bottom of the container is opened. As a result, the molten metal enters the container of the ladle through the molten metal spout so that the height of the molten metal outside the container is equal to the height of the molten metal inside the container. Then, based on the level of the molten metal in the container, the container is positioned at a height position where the molten metal in the container reaches a set amount, and the molten metal inlet is closed. By doing this, the molten metal can be stored in the container without sucking the gas inside the container. Further, until the container is lifted from the molten metal, the height of the hot water outside the container and the height of the hot water inside the container are the same, so it is possible to suppress the heat of the molten metal from being released into the atmosphere through the container. Therefore, the temperature drop of the molten metal in the container of the ladle can be suppressed with a simple configuration.

1 is a diagram showing a schematic configuration of a die casting machine according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a die plate and its vicinity that the die casting machine of FIG. 1 has. FIG. 2 is an enlarged cross-sectional view of a mold cavity and its vicinity. 2 is a diagram showing a molten metal supply mechanism included in the die casting machine of FIG. 1. FIG. FIG. 2 is an enlarged cross-sectional view of the mold cavity and its vicinity (with the plunger at the high-speed advance starting position). FIG. 2 is an enlarged cross-sectional view of the mold cavity and its vicinity (with the plunger at the deceleration start position). FIG. 2 is an enlarged cross-sectional view of the mold cavity and its vicinity (with the plunger at the pressure increase start position). 2 is a flowchart showing an example of a process according to the present invention executed by a control device included in the die-casting machine of FIG. 1. FIG. It is a figure which shows the state where a ladle is in the position above a melting furnace. It is a figure which shows the state where the container of a ladle is immersed in the molten metal of a melting furnace. It is a figure which shows the state where the melting spout provided in the bottom part of a ladle is open. It is a figure which shows the state where the melting spout provided in the bottom part of a ladle is closed. It is a figure showing the state where inert gas is injected into the space in a ladle. FIG. 6 is a view showing the ladle in a position above the sleeve. It is a figure showing the state where the molten metal in a ladle is supplied to a sleeve.

A die casting machine according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 15.

FIG. 1 is a diagram showing a schematic configuration of a die casting machine according to an embodiment of the present invention. FIG. 2 is a sectional view of a die plate and its vicinity that the die casting machine of FIG. 1 has. FIG. 3 is an enlarged sectional view of the mold cavity and its vicinity. FIG. 4 is a diagram showing a molten metal supply device included in the die casting machine of FIG. 1. 5 to 7 are enlarged cross-sectional views of the mold cavity and its vicinity. 5 to 7 show states in which the plunger is at a high-speed advance start position, a deceleration start position, and a pressure increase start position, in this order. FIG. 8 is a flowchart showing an example of the process (molten metal supply process) according to the present invention executed by the control device included in the die casting machine of FIG. 9 to 15 are diagrams showing each state of the molten metal supply mechanism in the molten metal supply process. Figures 9 to 15 show, in order, a state in which the ladle is located above the melting furnace, a state in which the container of the ladle is immersed in the molten metal in the melting furnace, a state in which the molten metal spout provided at the bottom of the ladle is open, and a state in which the ladle is in a position above the melting furnace. The figure shows a state in which the molten metal inlet provided at the bottom is closed, an inert gas is injected into the space inside the ladle, a state in which the ladle is located above the sleeve, and a state in which the molten metal in the ladle is supplied to the sleeve. In this specification, the left side of FIGS. 1 to 3 and 5 to 7 is referred to as the front, and the right side is referred to as the rear.

The die casting machine 1 according to this embodiment includes an injection mechanism 10, a mold clamping mechanism 30, a molten metal supply mechanism 50, and a control device 100.

As shown in FIG. 1, the injection mechanism 10 includes a piston 11 that operates using hydraulic pressure, and a cylinder 12 that accommodates the piston 11 so as to be movable in the front-rear direction. The cylinder 12 has a rear oil chamber 13 and a front oil chamber 14 that are partitioned by the piston 11 . A plunger 15 is connected to the piston 11. The plunger 15 includes a rod 16 extending forward from the front surface 11a of the piston 11, and a plunger tip 17 provided at the tip of the rod 16.

A drive transmission plate 18 is arranged behind the cylinder 12. The drive transmission plate 18 is moved in the front-rear direction by an electric servo motor 19 and a drive transmission mechanism 20 including a drive transmission gear, a ball screw mechanism, and the like. By moving the drive transmission plate 18 forward, the cylinder 12 is pushed and moved forward. The drive transmission plate 18, the electric servo motor 19, and the drive transmission mechanism 20 constitute an electric pressure increase mechanism. Note that instead of such an electric pressure increasing mechanism, a hydraulic pressure increasing mechanism that pushes the cylinder 12 forward using hydraulic pressure may be provided.

The injection mechanism 10 has an accumulator 21. The accumulator 21 is a hydraulic pressure supply unit that supplies hydraulic oil to the rear oil chamber 13 of the cylinder 12 . The accumulator 21 and the rear oil chamber 13 are connected by an oil passage a. A supply valve 22 is arranged in the oil passage a. The supply valve 22 communicates and blocks the accumulator 21 and the rear oil chamber 13 from each other. In this embodiment, the supply valve 22 is constituted by an electromagnetic valve whose valve body is driven by a solenoid. As the supply valve 22, in addition to the electromagnetic valve, other types of valves, such as one whose valve body is driven by a motor, may be employed.

The front oil chamber 14 of the cylinder 12 and the tank 23 storing hydraulic oil are connected by an oil passage b. A servo valve 24 is arranged in the oil passage b. The servo valve 24 adjusts the amount of hydraulic oil flowing from the front oil chamber 14 to the tank 23 . In this embodiment, the speed at which the plunger 15 moves forward is controlled by adjusting the outflow amount (that is, the amount of hydraulic oil discharged from the front oil chamber 14) using the servo valve 24 (meter-out control). The above-mentioned supply valve 22 may be configured with a servo valve, and the speed at which the plunger 15 moves forward may be controlled by adjusting the amount of hydraulic oil supplied from the accumulator 21 to the rear oil chamber 13 (meter-in control). ).

The injection mechanism 10 includes an oil pressure sensor 25 that outputs a signal depending on the oil pressure in the front oil chamber 14 of the cylinder 12, and a position sensor 26 that outputs a signal depending on the position L of the plunger 15. As the position sensor 26, a known position sensor such as an optical type, a magnetic type, or a magnetostrictive type can be used.

As shown in FIG. 2, the mold clamping mechanism 30 includes a fixed die plate 31 to which a fixed die K1 is attached, and a movable die plate 32 to which a movable die K2 is attached. The fixed die plate 31 has a cylindrical sleeve 33 that communicates with the runner R of the fixed die K1. The plunger 15 is accommodated in the sleeve 33 so as to be movable back and forth. The sleeve 33 has a hot water supply port 34 formed in its upper part. A molten metal M is poured into the sleeve 33 by a molten metal supply mechanism 50 through a molten metal inlet 34 . The mold clamping mechanism 30 opens and closes (clamps) the fixed mold K1 and the movable mold K2 by moving the movable die plate 32 forward and backward with respect to the fixed die plate 31 by a mold clamping drive unit (not shown). .

As shown in FIG. 3, inside the closed fixed mold K1 and movable mold K2, there are a runner R communicating with the sleeve 33, a cavity C communicating with the runner R, and a cavity C communicating with the cavity C. An overflow portion O is formed. Runner R communicates with gate G that opens into cavity C.

As shown in FIG. 4, the molten metal supply mechanism 50 includes a ladle 51, an arm 61, an opening/closing mechanism 71, a molten metal amount measuring device 81, and a gas supply device 91.

Ladle 51 has a container 52. The container 52 has a peripheral wall 53, a bottom portion 54, and an upper portion 55. The peripheral wall 53 has a hollow truncated pyramid shape that becomes thinner from the top to the bottom. The bottom portion 54 is connected to the lower end of the peripheral wall 53. The bottom portion 54 has a melt spout 56 and a valve seat 57 surrounding the melt sprue 56 . The valve seat 57 is an inwardly tapered surface whose diameter decreases from the top to the bottom. An upper surface 54a of the bottom portion 54 is sloped downward toward the molten metal inlet 56. The portion 54b in the bottom portion 54 where the molten metal inlet 56 is formed is made of a material that has relatively high non-wetting properties with respect to the molten metal M (for example, silicon nitride (including a material whose main component is silicon nitride)). preferable. The upper portion 55 has a flat plate shape. The upper part 55 is joined to the upper end of the peripheral wall 53. The container 52 is entirely made of metal such as iron or ceramic. A material with relatively high non-wetting properties for the molten metal M (for example, Lumicast (registered trademark, manufactured by Nichias Corporation)) is applied to the surface (inner surface, outer surface) of the peripheral wall 53 and the surface (inner surface, outer surface) of the bottom portion 54. It is preferable that the

Arm 61 supports ladle 51. The arm 61 moves the ladle 51 between a melting furnace (not shown) and the sleeve 33. A hot water level height sensor 62 is attached to the arm 61. The hot water level height sensor 62 is, for example, a thermocouple. The hot water level height sensor 62 is arranged at the lower end of a rod-shaped sensor support 63 extending downward from the arm 61. The lower end of the sensor support 63 (molten metal level height sensor 62) is arranged above the bottom 54 (molten metal spout 56) of the ladle 51. The hot water level sensor 62 detects the level of hot water in the melting furnace when the container 52 is at a predetermined setting position (for example, a position where the lower part of the container 52 in the height direction is immersed in the melt in the melting furnace). It is placed in contact with the surface. Based on the signal output by the hot water level height sensor 62, it can be determined whether the container 52 of the ladle 51 has moved to the set position.

The opening/closing mechanism 71 includes a valve body 72 and an actuator 73. The valve body 72 has a cylindrical shape. The outer diameter of the valve body 72 is larger than the inner diameter of the molten metal spout 56. The valve body 72 passes through the upper portion 55 of the ladle 51 and extends in the vertical direction. The valve body 72 is made of a material that has relatively high non-wetting properties with respect to the molten metal M (for example, silicon nitride, machinable ceramic, or calcium silicate (including materials containing any one of these as a main component)). Preferably. The actuator 73 is, for example, an air cylinder or an electric cylinder, and is capable of moving the piston rod 74 in the vertical direction and rotating the piston rod 74 around an axis. The piston rod 74 is coaxially connected to the valve body 72 by a coupling 75. The actuator 73 moves the valve body 72 in the vertical direction and rotates it around the axis. When the lower end of the valve body 72 contacts the valve seat 57, the melt inlet 56 closes, and when the lower end of the valve body 72 leaves the valve seat 57, the melt inlet 56 opens.

The molten metal amount measuring device 81 includes a float body 82 and a laser displacement meter 83. The float body 82 includes a rod-shaped displacement member 84 and a spherical float 85 connected to the lower end of the displacement member 84 . The displacement member 84 passes through the upper portion 55 of the ladle 51 and extends in the vertical direction. The float 85 floats on the surface of the molten metal M in the ladle 51. The float body 82 moves in the vertical direction according to the amount of molten metal M in the ladle 51. The laser displacement meter 83 is disposed above the upper portion 55 so as to face the upper end of the displacement member 84 in the vertical direction. Laser displacement meter 83 is fixed to upper part 55. The laser displacement meter 83 outputs a signal according to the distance Dx between the laser displacement meter 83 and the displacement member 84. The distance Dx has a relationship with the height of the molten metal M in the container 52 of the ladle 51 (that is, the amount of molten metal M), and the distance Dx has a relationship with the molten metal M in the container 52 based on the signal output by the laser displacement meter 83. can be measured.

The gas supply device 91 is a device that supplies an inert gas (for example, argon). The gas supply device 91 is connected to a ventilation portion 58 provided in the upper portion 55 of the ladle 51 via a flow path switching valve 92 . The flow path switching valve 92 selectively connects the ventilation section 58 to the gas supply device 91 or the atmosphere (atmosphere opening section 93). The atmosphere opening section 93 is composed of, for example, an air filter. The flow path switching valve 92 and the atmosphere opening portion 93 constitute an atmosphere opening mechanism that communicates the space 59 inside the container 52 of the ladle 51 with the atmosphere.

The space 59 of the ladle 51 is not connected to the atmosphere except for the melt inlet 56 and the ventilation section 58, and is a space separated from the atmosphere. The space 59 is connected to the atmosphere through the gap between the upper part 55 and the valve body 72 and the gap between the upper part 55 and the displacement member 84 of the float body 82, but is generally separated from the atmosphere and is substantially separated from the atmosphere. It is a space where Note that a sealing member may be placed in the gap as long as it does not hinder the movement of the valve body 72 and the displacement member 84.

Control device 100 controls the overall operation of die-casting machine 1 . The control device 100 includes, for example, a microcomputer for embedded equipment having a CPU, ROM, RAM, EEPROM, various I/O interfaces, and the like. The control device 100 controls the operations of the injection mechanism 10, the mold clamping mechanism 30, and the molten metal supply mechanism 50. The control device 100 measures the oil pressure Pf in the front oil chamber 14 based on the signal output by the oil pressure sensor 25. The control device 100 measures the position L and speed V of the plunger 15 based on the signal output by the position sensor 26. The control device 100 determines whether the container 52 of the ladle 51 has moved to the set position based on the signal output by the hot water level height sensor 62. The control device 100 measures the amount of molten metal M in the container 52 of the ladle 51 based on the signal output by the laser displacement meter 83. The control device 100 is an injection control device and a ladle control device. Molten metal supply mechanism 50 and control device 100 constitute a molten metal supply device. The control device 100 controls the operations of various drive units in various processes such as a mold closing process, a molten metal supply process, an injection process (low-speed injection process and high-speed injection process), a pressure increase process, a mold opening process, and a product extrusion process. .

The die casting machine 1 performs the following operations (1) to (5) as a series of operations in product molding.

(1) Clamp the fixed mold K1 and the movable mold K2 (mold closing process).

(2) Supplying the molten metal M to the sleeve 33 of the fixed die plate 31 (molten metal supply step).

(3) The plunger 15 is advanced to inject the molten metal M in the sleeve 33 into the cavity C (injection step).

In the injection process, the hydraulic oil pressure in the accumulator 21 is increased, the supply valve 22 is opened to supply hydraulic oil to the rear oil chamber 13 of the cylinder 12, and the servo valve 24 causes the hydraulic oil to flow out from the front oil chamber 14. to move the piston 11 forward. The amount of hydraulic oil flowing out is controlled by the opening degree of the servo valve 24, and the forward speed of the piston 11 is adjusted. First, the piston 11 is advanced at a low speed, and when the plunger 15 reaches the high-speed advance start position L1 (FIG. 5), the piston 11 is advanced at a high speed, and the plunger 15 injects the molten metal M in the sleeve 33 into the cavity C. When the plunger 15 reaches the deceleration start position L2 (FIG. 6), the piston 11 is decelerated. The deceleration start position L2 is, for example, a position where the entire cavity C is filled with the molten metal M.

(4) Apply pressure to the molten metal M in the cavity C (pressure increase step).

In the pressure increase process, when the plunger 15 reaches the pressure increase start position L3 (FIG. 7), the electric servo motor 19 is operated to advance the drive transmission plate 18 and press the cylinder 12 (ie, the piston 11). The pressure increase start position L3 is, for example, a position where the entire cavity C and overflow part O are filled with the molten metal M. The high-speed forward movement start position L1, the deceleration start position L2, and the pressure increase start position L3 are operation switching positions.

(5) Open the fixed mold K1 and the movable mold K2 (mold opening process) and extrude the product from the cavity C (product extrusion process).

Next, an example of the molten metal supply process according to the present invention in the control device 100 will be described with reference to the flowchart of FIG. 8 and FIGS. 9 to 15. The molten metal supply process is executed in the molten metal supply process.

The control device 100 drives the arm 61 to move the ladle 51 to a position above a melting furnace (not shown) (S110, FIG. 9). At this time, the melt inlet 56 is closed, the space 59 of the ladle 51 is filled with inert gas, and the ventilation section 58 is connected to the atmosphere (atmosphere opening section 93) via the flow path switching valve 92. There is.

Based on the signal output by the hot water level height sensor 62, the control device 100 moves the ladle 51 downward until the ladle 51 (container 52) moves to the set position (N in S120 and S130). When the ladle 51 moves to the set position (Y in S130, FIG. 10), the control device 100 causes the actuator 73 to move the valve body 72 upward to open the molten metal spout 56 (S140, FIG. 11). That is, the control device 100 immerses the container 52 in the molten metal M of the melting furnace and opens the molten metal port 56 based on the height of the molten metal M of the melting furnace. As a result, the molten metal M enters the container 52 of the ladle 51 through the molten metal inlet 56.

The control device 100 measures the amount of molten metal M in the container 52 of the ladle 51 (molten metal amount V1) based on the signal output by the laser displacement meter 83 (S150). When the amount of molten metal V1 is smaller than the set amount Vs set according to the volume of the cavity C (Y in S160), the control device 100 drives the arm 61 to move the ladle 51 downward (S170) and removes the molten metal. The amount V1 is measured again (S150). When the molten metal amount V1 is greater than the set amount Vs (N in S160, Y in S180), the control device 100 drives the arm 61 to move the ladle 51 upward (S190) and measures the molten metal amount V1 again. (S150). That is, the control device 100 positions the container 52 of the ladle 51 at a height position where the molten metal amount V1 becomes the set amount Vs based on the level height of the molten metal M in the container 52 of the ladle 51.

When the molten metal amount V1 is the set amount Vs (N in S160, N in S180), the control device 100 causes the actuator 73 to move the valve body 72 downward and close the molten metal inlet 56 (S200, FIG. 12). At this time, the actuator 73 presses the lower end of the valve body 72 against the valve seat 57 and rotates it around the axis. Thereby, the semi-solid molten metal M adhering to the valve seat 57 is crushed, the valve body 72 is brought into close contact with the valve seat 57, and the molten metal port 56 can be closed more reliably.

When the melt inlet 56 is closed, the control device 100 connects the ventilation section 58 and the gas supply device 91 via the flow path switching valve 92, and injects inert gas into the space 59 in the ladle 51 by the gas supply device 91. (S210, FIG. 13). The inert gas suppresses the formation of an oxide film on the surface of the molten metal M. The control device 100 drives the arm 61 to lift the ladle 51 from the molten metal M in the melting furnace, and moves the ladle 51 to a position above the sleeve 33 (S220, FIG. 14). At this time, the molten metal inlet 56 of the ladle 51 and the molten metal inlet 34 of the sleeve 33 are made to face each other in the vertical direction.

The control device 100 measures the amount of molten metal M in the ladle 51 (molten metal amount V2) based on the signal output by the laser displacement meter 83 (S230). When the molten metal amount V2 is within the appropriate range (Y in S240), the control device 100 causes the actuator 73 to move the valve body 72 upward to open the molten metal inlet 56 (S260, FIG. 15). When the molten metal amount V2 is not within the appropriate range (N in S240), the control device 100 changes the operation switching positions (high-speed advance start position L1, deceleration start position L2, pressure increase start position L3) (S250), and 56 (S260). The appropriate range is a range of the molten metal amount V2 that does not require changing the operation switching position, and in this embodiment is set as a ratio to the set amount Vs (for example, 95 to 100% of the set amount Vs). When the molten metal amount V2 is not within the appropriate range, the operation switching position is changed based on the inner diameter of the sleeve 33, the volume of the cavity C, etc. so that the operation switching is performed at an appropriate position. For example, the control device 100 changes the operation switching position to the front when the molten metal amount V2 is less than the lower limit of the appropriate range, and changes the operation switching position to the rear when the molten metal amount V2 is more than the upper limit of the appropriate range. .

The control device 100 opens the melt inlet 56 and injects inert gas into the space 59 of the ladle 51 using the gas supply device 91 (S270). As a result, the molten metal M in the container 52 of the ladle 51 is supplied to the sleeve 33 through the hot water supply port 34. Further, the space 59 is filled with an inert gas, and the inert gas is also injected into the sleeve 33 through the melt inlet 56 and the inlet 34 . Then, the control device 100 causes the actuator 73 to move the valve body 72 downward to close the melt inlet 56 (S280), and ends this process. Following the molten metal supply process, the control device 100 executes processes related to an injection process and a pressure increase process. When the operation switching position is changed in the molten metal supply process, the control device 100 uses the changed operation switching position in the injection process and the pressure increase process.

The die casting machine 1 according to this embodiment includes an injection mechanism 10, a mold clamping mechanism 30, a molten metal supply mechanism 50 and a control device 100 that constitute a molten metal supply device. The mold clamping mechanism 30 has a sleeve into which molten metal M is supplied to be injected into a cavity C formed inside the fixed mold K1 and the movable mold K2. The molten metal supply mechanism 50 has a ladle 51, and the ladle 51 has a container 52 in which the molten metal M is stored. A melt spout 56 is provided at the bottom 54 of the container 52 . Based on the level of the molten metal in the melting furnace, the control device 100 moves the container 52 of the ladle 51 downward to a set position, immerses it in the molten metal M in the melting furnace, and opens the molten metal port 56. Then, the control device 100 positions the container 52 at a height position where the molten metal M in the container 52 reaches the set amount Vs based on the level of the molten metal M in the container 52, and closes the molten metal inlet 56.

The die casting machine 1 moves the container 52 of the ladle 51 downward to a set position, immerses it in the molten metal M of the melting furnace, and opens the molten metal port 56 provided at the bottom 54. As a result, the molten metal M enters into the container 52 of the ladle 51 through the molten metal inlet 56 so that the height of the melt surface in the melting furnace outside the container 52 and the height of the melt inside the container 52 are the same. Then, based on the level height of the molten metal M in the container 52, the container 52 is positioned at a height position where the molten metal M in the container 52 reaches the set amount Vs, and the molten metal inlet 56 is closed. By doing this, the molten metal M can be stored in the container 52 without sucking the gas inside the container 52. Furthermore, until the container 52 is lifted from the molten metal M, the height of the molten metal outside the container 52 and the height of the molten metal inside the container 52 are the same, so the heat of the molten metal M in the container 52 is released to the atmosphere through the container 52. It is possible to prevent this from happening. Therefore, the temperature drop of the molten metal in the container 52 of the ladle 51 can be suppressed with a simple configuration.

Furthermore, the molten metal supply mechanism 50 includes an opening/closing mechanism 71 that opens and closes the molten metal inlet 56 . The opening/closing mechanism 71 includes a valve body 72 facing the melt spout 56 and an actuator 73 that moves the valve body 72 toward and away from an annular valve seat 57 surrounding the melt spout 56 . Then, the actuator 73 rotates the valve body 72 while pressing it against the valve seat 57 when closing the molten metal spout 56 . By doing so, the semi-solid molten metal M adhering to the valve seat 57 is crushed by the valve body 72, the valve body 72 is brought into close contact with the valve seat 57, and the molten metal port 56 can be closed more reliably. Note that the actuator 73 may be configured to press the valve body 72 against the valve seat 57 without rotating the valve body 72 when closing the molten metal spout 56.

In addition, the valve body 72 is made of a material that has relatively high non-wetting properties with respect to the molten metal M (for example, silicon nitride, machinable ceramic, or calcium silicate (including materials containing any one of these as a main component)). It is preferable that the By doing so, adhesion of the molten metal M to the valve body 72 can be effectively suppressed.

Further, it is preferable that a portion 54b of the bottom portion 54 of the container 52 of the ladle 51, where the melting spout 56 is provided, is made of silicon nitride (including a material whose main component is silicon nitride). By doing so, adhesion of the molten metal M to the inner surface of the molten metal spout 56 and the valve seat 57 can be effectively suppressed.

Further, a space 59 within the container 52 of the ladle 51 is a space separated from the atmosphere. The molten metal supply mechanism 50 includes an atmosphere opening mechanism (flow path switching valve 92 and atmosphere opening section 93) that communicates the space 59 inside the container 52 with the atmosphere when the molten metal inlet 56 is opened and the molten metal M enters the container 52. have By doing so, the gas in the space 59 is discharged through the atmosphere opening mechanism, so that the molten metal M quickly enters the container 52 of the ladle 51 through the molten metal inlet 56. Therefore, the molten metal M can be stored in the container 52 of the ladle 51 in a relatively short time.

The molten metal supply mechanism 50 also includes a gas supply device 91 that injects an inert gas into the space 59 within the container 52 of the ladle 51. By doing so, it is possible to suppress the formation of an oxide film on the molten metal M in the container 52. Note that the gas supply device 91, the flow path switching valve 92, and the atmosphere opening section 93 may be omitted, and the space 59 may be communicated with the atmosphere through the ventilation section 58.

Moreover, it is preferable that the surface of the container 52 of the ladle 51 be coated with a material that has higher non-wetting properties for the molten metal M than the material forming the container 52. By doing so, it is possible to suppress the molten metal M from adhering to the outer surface and inner surface of the container 52. Therefore, it is possible to suppress the amount of the molten metal M in the container 52 from fluctuating and the molten metal M from containing solid matter (solidified molten metal M).

Further, the molten metal supply mechanism 50 includes a molten metal amount measuring device 81 that measures the amount of molten metal M in the container 52 of the ladle 51. The die casting machine 1 includes a plunger 15 housed in a sleeve 33, and a control device 100 that operates the plunger 15 to move forward and switches the operation of the plunger 15 when the plunger 15 moves to an operation switching position. Immediately before supplying the molten metal M to the sleeve 33, the control device 100 measures the amount of the molten metal M (molten metal amount V2) using the molten metal amount measuring device 81, and changes the operation switching position based on the molten metal amount V2. By doing this, even if there is variation in the amount of molten metal M in the container 52, the operation of the plunger 15 can be switched at an appropriate position. Therefore, deterioration in quality of the molded product can be suppressed.

Further, the operation switching positions are a high-speed forward movement start position L1, a deceleration start position L2, and a pressure increase start position L3. Note that the operation switching position changed by the control device 100 may be at least one of the high-speed forward movement start position L1, the deceleration start position L2, and the pressure increase start position L3.

In the embodiment described above, the injection operation is performed using hydraulic pressure and the pressure increase operation is performed using electric power. The present invention may be applied to a configuration in which the operation is performed electrically.

Furthermore, in the embodiment described above, when the container 52 of the ladle 51 moves downward to the set position, the molten metal inlet 56 of the bottom 54 of the container 52 is opened, but when the bottom 54 is immersed in the molten metal M of the melting furnace. Alternatively, the melting spout 56 may be opened at the same time.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. The present invention may include additions, deletions, or design changes to the above-described embodiments by those skilled in the art as appropriate, or combinations of features of the embodiments as appropriate, as long as they do not depart from the spirit of the present invention. included in the range.

DESCRIPTION OF SYMBOLS 1... Die casting machine, 10... Injection mechanism, 11... Piston, 11a... Front, 12... Cylinder, 13... Rear oil chamber, 14... Front oil chamber, 15... Plunger, 16... Rod, 17... Plunger tip, 18... Drive Transmission plate, 19... Electric servo motor, 20... Drive transmission mechanism, 21... Accumulator, 22... Supply valve, 23... Tank, 24... Servo valve, 25... Oil pressure sensor, 26... Position sensor, 30... Mold clamping mechanism, 31 ...Fixed die plate, 32... Movable die plate, 33... Sleeve, 34... Molten metal supply port, 50... Molten metal supply mechanism, 51... Ladle, 52... Container, 53... Peripheral wall, 54... Bottom, 54a... Upper surface, 54b... Part, 55... Upper part, 56... Molten spout, 57... Valve seat, 58... Ventilation part, 59... Space, 61... Arm, 62... Molten metal level height sensor, 63... Sensor support, 71... Opening/closing mechanism, 72... Valve body , 73... Actuator, 74... Piston rod, 75... Coupling, 81... Molten metal amount measuring device, 82... Float body, 83... Laser displacement meter, 84... Displacement member, 85... Float, 91... Gas supply device, 92... Flow path switching valve, 93... Atmospheric opening part, 100... Control device, M... Molten metal, K1... Fixed mold, K2... Moving mold, L1... High speed advance start position, L2... Deceleration start position, L3... Pressure increase start Position, V1, V2...molten metal amount, Vs...setting amount, R...runner, C...cavity, O...overflow part, G...gate

Claims (10)

A molten metal supply device having a ladle and a ladle control device,
The ladle has a container for storing molten metal,
A melting spout is provided at the bottom of the container,
The ladle control device includes:
Based on the height of the molten metal in the melting furnace, immersing the container in the molten metal in the melting furnace and opening the molten metal inlet;
The molten metal supply device is characterized in that the container is positioned at a height position where the molten metal in the container reaches a set amount based on the surface height of the molten metal in the container, and the molten metal inlet is closed. The molten metal supply device has an opening/closing mechanism that opens and closes the molten metal inlet,
The opening/closing mechanism includes a valve body facing the molten metal spout, and an actuator that brings the valve body into contact with and separates from an annular valve seat surrounding the molten metal spout,
The molten metal supply device according to claim 1, wherein the actuator rotates the valve body while pressing it against the valve seat when closing the molten metal inlet. The molten metal supply device according to claim 2, wherein the valve body is made of silicon nitride, machinable ceramic, or calcium silicate. The molten metal supply device according to any one of claims 1 to 3, wherein a portion of the bottom portion where the molten metal inlet is provided is made of silicon nitride. The space inside the container is a space separated from the atmosphere,
Any one of claims 1 to 3, wherein the molten metal supply device has an atmosphere opening mechanism that communicates the space inside the container with the atmosphere when opening the molten metal port and allowing the molten metal to enter the container. The molten metal supply device described in . The molten metal supply device according to claim 5, wherein the molten metal supply device includes a gas supply device that injects an inert gas into the space inside the container. The molten metal supply device according to any one of claims 1 to 3, wherein the surface of the container is coated with a material that has higher molten metal non-wetting properties than the material constituting the container. The molten metal supply device according to any one of claims 1 to 3,
A die-casting machine comprising: a sleeve to which the molten metal injected into the cavity of the mold is supplied by the molten metal supply device. The molten metal supply device includes a molten metal amount measuring device that measures the amount of molten metal in the container,
The die casting machine is
a plunger housed in the sleeve;
an injection control device that operates the plunger to move forward and switches the operation of the plunger when the plunger advances to an operation switching position;
The die casting machine according to claim 8, wherein the ladle control device changes the operation switching position based on the amount of molten metal measured by the molten metal amount measuring device immediately before supplying the molten metal to the sleeve. The die-casting machine according to claim 9, wherein the operation switching position is a high-speed advance start position, a deceleration start position, or a pressure increase start position.

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