JP2021023956A - Control device for die cast machine, and device and method for acquiring index value used in setting control parameter - Google Patents

Abstract

To realize a timely operation of a valve in a simple manner by using an index which takes into account a time lag, when vacuum-suctioning inside a sleeve of a die cast machine.SOLUTION: A control device 30 comprises: a control parameter setting part 303 for setting values in control parameters P0-P4 indicating positions of a plunger 22; and a sleeve vacuum control part 302 for issuing valve operation commands for operating valves 40V, 413 operating a suction state inside a sleeve 21, at the positions indicated by the control parameters. The control parameter setting part 303 acquires an index value corresponding to a position traced back by a time corresponding to a time lag from a valve operation position, by using a valve operation position that is a position determined from a geometrical specification as a position for operating a valve, an injection condition containing a position and speed of the plunger 22, and a time lag of a valve operation relative to a valve operation command. Then, the control parameter setting part can set the index value in a control parameter.SELECTED DRAWING: Figure 5

Description

The present invention relates to a device for controlling a die casting machine, and a device and a method for acquiring an index value used for setting control parameters used for controlling the die casting machine.

Vacuum die-cast molding is performed in which the inside of the cavity is depressurized through a sleeve suction port provided on the wall of the injection sleeve into which the molten metal is injected and a cavity suction port provided on the dividing surface of the mold, and the molten metal is injected into the cavity. (For example, Patent Document 1).
The die casting machine of Patent Document 1 is provided with first to third limit switches for opening and closing solenoid valves provided in the suction path on the sleeve side and the suction path on the cavity side according to the advance / retreat position of the plunger. Has been done. The first to third limit switches are operated by a switch lever attached to the plunger rod.

When the plunger tip reaches the position where the pouring port is blocked by the advancement of the plunger, the first limit switch simultaneously opens the solenoid valve in both the suction path on the sleeve side and the suction path on the cavity side. Then, the pressure inside the sleeve and the cavity are reduced through the suction ports on the sleeve side and the cavity side, respectively.
When the plunger tip reaches the position where the sleeve suction port is closed, the solenoid valve of the sleeve suction path is closed by the second limit switch. When the plunger advances further and the tip reaches the injection completion position, the solenoid valve of the cavity suction path is closed by the third limit switch, and the injection process is completed.

Japanese Unexamined Patent Publication No. 57-72766

If vacuum suction is started through the suction port of the sleeve from the time when the plunger tip closes the pouring port, the vacuum suction time can be maximized until the suction port of the sleeve is closed by the tip. The inside and the cavity of the cavity can be efficiently reached to a predetermined degree of vacuum. If the suction port of the sleeve is blocked by the tip, the valve provided in the suction path connected to the suction port is closed before the suction port is opened to the atmosphere by the advancement of the plunger. ..
Therefore, when vacuum suction is performed inside the sleeve, it is desired to open and close the valve provided in the suction path on the sleeve side in a timely manner according to the position of the plunger with respect to the sleeve.

The exact position of the plunger when the plunger tip closes the pouring port or suction port is difficult to understand from the appearance of the plunger and sleeve.
According to the configuration of Patent Document 1, trial and error work is expected in which the limit switch is installed at an appropriate position so that the limit switch operates reliably at the position where the pouring port and the suction port are blocked by the tip.
Moreover, even if the position of the plunger is accurately detected by the position detecting means installed at an appropriate position such as the limit switch or the encoder described in Patent Document 1, the valve is opened and closed by the operation of the limit switch or the encoder. Since there is a time lag between the issuance of the command and the actual operation of the valve, the valve does not always operate in a timely manner.

For example, if the valve opening operation is delayed with respect to the time when the pouring port is closed by the tip, the vacuum suction time on the sleeve side is reduced, and a part of the suction port is blocked by the tip when the valve is opened. If this is the case, the vacuum suction efficiency will decrease.
Further, if the closing operation of the valve is delayed with respect to the opening of the suction port to the atmosphere after the suction port is closed by the tip, the path through which the suction port communicates and the degree of vacuum of the vacuum tank or the like are lowered. ..
The greater the speed at which the plunger advances with respect to the sleeve (injection speed), the greater the effect of the time lag.

In consideration of the time lag, the timing at which the command to operate the valve is issued is advanced, so that if the valve is closed earlier than the time when the suction port is closed, the vacuum suction time is reduced.
Alternatively, by advancing the timing at which the command to operate the valve is issued, if the valve opening operation is earlier than the time when the pouring port is closed, the outside air flows into the sleeve from the pouring port.
Vacuum suction time and vacuum suction while avoiding the inflow of outside air into the sleeve from the viewpoint of preventing air from being entrained in the molten metal in the sleeve and preventing the suction path from being blocked by the molten metal residue without considering the time lag. It is difficult to determine the timing of the valve operation command that can ensure sufficient efficiency.

From the above, it is an object of the present invention to easily realize a timely operation of a valve by using an index in which a time lag is taken into consideration when vacuum suctioning the inside of a sleeve of a die casting machine.

The control device of the die casting machine of the present invention includes a sleeve into which the molten metal is injected from the pouring port and a plunger for injecting the molten metal toward the cavity, and is configured so that the inside of the sleeve communicating with the cavity can be sucked. It is a device that controls.
This control device operates a control parameter setting unit that indicates the position of the plunger in the advancing / retreating direction and sets a value for the control parameter used for control that sucks the inside of the sleeve, and a valve that operates the suction state inside the sleeve. It includes a sleeve vacuum control unit that issues a valve operation command at a position indicated by a control parameter.
The control parameter setting unit is a position in the advancing / retreating direction determined by the geometrical specifications of the tip and sleeve of the plunger, and is a valve operating position as a position for operating the valve, an injection condition including the position and speed of the plunger, and an injection condition.
By using the valve operation time lag with respect to the valve operation command, it is possible to acquire the index value corresponding to the retroactive position for the time corresponding to the time lag from the valve operation position and set the index value as a control parameter.

The control device of the present invention preferably includes a display unit that displays at least the index value among the index value and the valve operating position.

It is preferable that the control parameter setting unit in the control device of the present invention can set a value input in the recommended range between the index value and the valve operating position as the control parameter.

It is preferable that the control parameter setting unit in the control device of the present invention uses the position / time data converted from the position / velocity of the injection condition into the position / time data for acquiring the index value.

It is preferable that the control parameter setting unit in the control device of the present invention obtains the elapsed time until the plunger reaches an arbitrary position in the advancing / retreating direction for each unit displacement amount as position / time data.

The control device of the present invention preferably includes a storage unit that stores at least position / time data among injection conditions, control parameters, and position / time data.

In the control device of the present invention, the control parameters include a vacuum start position parameter indicating the position of the plunger when a vacuum start command for operating the valve is issued when starting suction inside the sleeve, and the vacuum start position. The valve operating position used to obtain the index value corresponding to the parameter is preferably the position where the tip closes the pouring port from the geometrical specifications of the tip and the sleeve.

In the control device of the present invention, the wall of the sleeve is provided with one or more suction ports used for suction inside the sleeve in front of the pouring port in the advancing / retreating direction, and the control parameter corresponds to the suction port. The suction port blockage position parameter that indicates the position of the plunger when the suction port blockage command to switch the valve to the closed state is included, and the valve operating position used to acquire the index value corresponding to the suction port blockage position parameter is the tip. And from the geometrical specifications of the sleeve, it is preferable that the tip is in a position to close the suction port.

The control device of the present invention includes a plunger that retracts inward in the radial direction with respect to the inner peripheral portion of the sleeve and has a suction recess formed continuously in the circumferential direction, and two or more at intervals in the advancing / retreating direction. A die casting machine provided with a sleeve provided with a suction port, and which is configured to be able to suck the space in front of the front end of the tip and the inside of the suction recess by using two or more suction ports. It is preferably applied to control the suction inside the sleeve.

Further, the present invention is an acquisition device for acquiring an index value used for setting a control parameter of the die casting machine, and the control parameter indicates a position in the advance / retreat direction of the plunger of the die casting machine, and the inside of the sleeve of the die casting machine is displayed. It is used for suction control.
This acquisition device is a position in the advancing / retreating direction determined by the geometrical specifications of the tip and sleeve of the plunger, and is the valve operating position as the position for operating the valve that operates the suction state inside the sleeve, and the position of the plunger. Using the injection conditions including the speed and the time lag of the valve operation with respect to the valve operation command issued at the position indicated by the control parameter, the index value corresponding to the position retroactively for the time corresponding to the time lag from the valve operation position. To get.

Further, the above-mentioned control parameter index value acquisition device can also be applied to a control parameter index value acquisition method.

According to the present invention, it is possible to obtain an index in which the time lag of valve operation with respect to the valve operation command is taken into consideration by using the geometrically determined valve operation position, injection condition, and time lag. It can be easily used to realize the timely operation of the valve.

It is a side view which a part of the die casting machine which concerns on embodiment of this invention is broken. It is a figure which shows typically the system which sucks in the sleeve of the injection device provided in the die casting machine shown in FIG. It is a vertical sectional view of the injection device of the die casting machine shown in FIG. It is a figure which shows the hardware schematic structure of the control device of the die casting machine shown in FIG. It is a figure which shows the display on the screen of the monitor of the control device shown in FIG. 4 (sleeve vacuum condition). It is a figure which shows the display on the screen of the monitor of the control device shown in FIG. 4 (detailed setting). It is a figure which shows the program module used for the control apparatus shown in FIG. (A) to (c) are diagrams for explaining the position where vacuum suction is started. It is a schematic diagram for demonstrating the dimension of each part of a die casting machine injection apparatus. It is a figure which shows the waveform of the injection condition. It is a schematic diagram which shows the elapsed time data for every unit displacement amount of a plunger acquired based on the injection condition shown in FIG. It is a graph which shows the change of the gas pressure over the injection process. It is a schematic diagram which shows each suction system of a sleeve side and a mold side. The location where the gas pressure was measured is shown. It is a figure which shows the procedure of casting by die casting. It is a figure which shows the procedure of the processing by a sleeve vacuum control part. (A) to (c) are diagrams showing the process of the injection process. (A) to (c) are diagrams showing the process of the injection process following FIG. 16 (c). (A) to (c) are diagrams showing the process of the injection process following FIG. 17 (c). (A) to (c) are diagrams showing the process of the injection process following FIG. 18 (c).

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[Outline configuration of die casting machine]
The configuration of the die casting machine 10 will be briefly described with reference to FIGS. 1 to 3.
The die casting machine 10 includes a movable plate 12 provided with a movable mold 11 and a product extrusion mechanism 11A, a fixed plate 14 provided with a fixed mold 13, and a machine base 15 for supporting the movable plate 12 and the fixed plate 14. , A mold opening / closing / molding mechanism (not shown), an injection device 20 provided in the fixing plate 14 for injecting molten metal 17 toward the cavity 16, a control device 30 for controlling the operation of each part of the die casting machine 10, and vacuum suction. It is equipped with a system 40 (FIG. 2).
The vacuum suction system 40 can perform vacuum suction from the inside of the cavity 16 and the sleeve 21 of the injection device 20 communicating with the cavity 16, respectively.

A cavity 16 (product part) is formed between the movable mold 11 of the movable plate 12 that moves freely along the tie bar 18 and the fixed mold 13. At the boundary between the movable mold 11 and the fixed mold 13, a suction portion 19 is provided which communicates with the cavity 16 and connects the vacuum pipe of the vacuum suction system 40. The suction unit 19 is provided in, for example, a Chill-Vent. Alternatively, the suction unit 19 may be a vacuum valve. The walls of the sleeve 21 are provided with suction ports 41 to 44 to which the vacuum pipe of the vacuum suction system 40 is connected.
With the cavity 16 depressurized by the vacuum suction system 40, the injection device 20 injects and fills the molten metal 17 of aluminum, an aluminum alloy, or the like into the cavity 16, thereby producing a cast molded product.

[Injection device]
The injection device 20 does not show a cylindrical sleeve 21 to which the molten metal 17 is supplied inside, a plunger 22 that ejects the molten metal 17 in the sleeve 21 toward the cavity 16, and a plunger 22 that advances and retreats with respect to the sleeve 21. It is equipped with a drive source such as a hydraulic cylinder.

Regarding the injection device 20, the front side in the moving direction of the plunger 22 when injecting the molten metal 17, that is, the side closer to the cavity 16 is defined as "front", and the side far from the cavity 16 is defined as "rear".
The direction in which the plunger 22 moves forward and backward (front-back direction) is defined as the forward / backward direction D1.

The inside of the sleeve 21 communicates with the cavity 16 via the runner 131 and the gate 132.
A pouring port 26 into which molten metal is injected by a ladle (not shown) is formed in the upper part of the rear end portion of the wall of the sleeve 21.
At the upper part of the wall of the sleeve 21, suction ports 41 to 44 used for vacuum suction inside the sleeve 21 are formed in front of the pouring port 26 at intervals in the advancing / retreating direction D1. The suction ports 41 to 44 penetrate the wall of the sleeve 21 in the thickness direction, and are all connected to the vacuum pipe of the vacuum suction system 40 (FIG. 2).

The suction ports 41 to 44 are arranged in the order of suction ports 41, 42, 43, 44 from the rear to the front of the sleeve 21. Hereinafter, these suction ports 41 to 44 may be referred to as a first suction port 41, a second suction port 42, a third suction port 43, and a fourth suction port 44, respectively.
The first suction port 41 is located at the rearmost position, and the fourth suction port 44 is located at the frontmost position.

The plunger 22 advances from a predetermined origin position toward the cavity 16 in the advancing / retreating direction D1 with a predetermined injection stroke, and when the injection is completed, the plunger 22 retracts to the origin position.
The plunger 22 includes a plunger rod 23 and a plunger tip 24 (hereinafter referred to as a tip 24) provided on the front side of the plunger rod 23.
The plunger rod 23 is coupled to a piston rod or the like of a hydraulic cylinder.

It is preferable that the tip 24 is formed with a suction recess 25 that is retracted inward in the radial direction with respect to the inner peripheral portion 21A of the sleeve 21 and is continuous in the circumferential direction.
As shown in FIG. 3, when the suction recess 25 communicates with the suction port 41, the vacuum suction of the suction recess 25 through the suction port 41 and the space in front of the tip 24 through the suction ports 42 to 44 Vacuum suction of 27 (hereinafter, front space 27) is possible.
Note that # 1, # 2, # 3, and # 4 are added to the suction ports 41 to 44, respectively.

By providing a space (inside the suction recess 25) having the same pressure as the front space 27 behind the front space 27 inside the sleeve 21, the outside air outside the sleeve 21 flows into the front space 27. Can be suppressed. This is because there is no difference between the pressure p1 inside the suction recess 25 and the pressure p2 in the front space 27, or even if there is a pressure difference, the pressure difference (p1-p2) is between the atmospheric pressure p0 and the front space 27. This is because the difference from the pressure p2 (p0-p2) is sufficiently small, so that the outside air is suppressed from flowing into the front space 27 through the inside of the suction recess 25.
By suppressing the inflow of outside air into the front space 27, it is possible to prevent the generation of casting cavities (entanglement cavities) due to the entrainment of air in the molten metal 17 stored in the front space 27. Further, it is possible to suppress the scattering of the molten metal 17 due to the inflow of outside air and prevent the suction path from being blocked by the solidified pieces or the like of the molten metal 17.

As will be described later, in the present embodiment, when the plunger 22 advances with respect to the sleeve 21, the plunger 22 is continuously sucked from the front space 27 and the suction recess 25 behind the suction ports 41 to 44. To do.
In addition, vacuum suction of the front space 27 and the suction recess 25 may be performed while the advance of the plunger 22 is temporarily stopped.
According to the plurality of suction ports 41 to 44 distributed in the advancing / retreating direction D1, the suction port 44 located at the frontmost position is closed by the chip 24 after the vacuum suction in the sleeve 21 is started. The front space 27 can be sucked through at least one suction port, and the suction recess 25 can be sucked through at least one suction port.

As shown in FIG. 3, the chip 24 includes a front portion 201 located on the front side, a rear portion 202 located on the rear side, and a small diameter portion 203 arranged between them. The diameter of the front portion 201 and the diameter of the rear portion 202 are equivalent. The space between the small diameter portion 203, which has a smaller diameter than the diameters of the front portion 201 and the rear portion 202, and the inner peripheral portion 21A of the sleeve 21 corresponds to the suction recess 25.

In order to prevent outside air from passing between the outer peripheral portion of the chip 24 and the inner peripheral portion 21A of the sleeve 21, for example, ring-shaped sealing members 28A and 28B are provided on the rear portion 202, or the outer peripheral portion of the chip 24 It is preferable that a sealant is filled between the sleeve 21 and the inner peripheral portion 21A. The lubricant supplied to the tip 24 also contributes to the sealing between the tip 24 and the sleeve 21.

When vacuum sucking the inside of the sleeve 21, the tip 24 does not necessarily have to have a suction recess 25 formed. Further, only one suction port is required for suction from the inside of the sleeve 21. Instead of sucking the suction recess 25 and the front space 27 through the suction port penetrating the wall of the sleeve 21, for example, a suction hole formed in the rear portion 202 of the tip 24 in the axial direction is used for suction of the suction recess 25. It can also be used for suction of the front space 27 through the gap between the front portion 201 and the sleeve 21.

If suction is performed from the suction recess 25 of the tip 24 as in the present embodiment, it is necessary to suppress the runaway of the molten metal 17 due to the inflow of outside air into the front space 27 and efficiently produce the cast product while ensuring the quality of the cast product. Can be done.
If at least two suction ports are formed on the wall of the sleeve 21 in addition to forming the suction recess 25 on the tip 24, one suction port is assigned to the suction of the front space 27 and the other suction port is formed. Is assigned to the suction of the suction recess 25, so that suction from both the front space 27 and the suction recess 25 can be easily realized.

[Vacuum suction system]
The vacuum suction system 40 (FIG. 2) is configured so that the inside of the sleeve 21 and the cavity 16 can be sucked. Since the inside of the sleeve 21 is decompressed by the vacuum suction system 40, the cavity 16 communicating with the inside of the sleeve 21 is also decompressed. The inside of the sleeve 21 and the cavity 16 are referred to as a communication space 29.

An example of the vacuum suction system 40 will be described with reference to FIG. The vacuum suction system 40 has a cavity through a vacuum pump 45, a vacuum tank 46, a sleeve-side suction system 40S that sucks the inside of the sleeve 21 through suction ports 41 to 44, and a suction portion 19 provided on the molds 11 and 13. It is provided with a mold-side suction system 40M for directly sucking 16 and a pressurized air supply system 40P for carrying out an air blow.

The inside of the vacuum tank 46 is depressurized by operating the vacuum pump 45.
According to the example shown in FIG. 2, the sleeve-side suction system 40S and the mold-side suction system 40M are configured as one system that also serves as the vacuum tank 46, but this is not the case. The sleeve-side suction system 40S and the mold-side suction system 40M may be configured separately.

The mold side suction system 40M includes a vacuum filter 401 for vacuum suction from upstream to downstream of the flow of gas sucked from the cavity 16, and a pressure gauge for detecting the pressure in the piping of the mold side suction system 40M. , A pressure detection unit 402 such as a compound meter and a pressure sensor, and a vacuum valve 403 that connects the suction unit 19 with the vacuum tank 46 in a timely manner are provided in this order.

The vacuum filter 401 prevents fine droplets of molten metal that can be mixed in the sucked gas, molten metal residue that is a solidified piece, a mold release agent, dust, and the like from entering the mold-side suction system 40M. Similarly, the vacuum filter 411 provided in the sleeve-side suction system 40S also suppresses molten metal residue, lubricant, dust, etc. from entering the sleeve-side suction system 40S.

When the vacuum valve 403 is opened, the gas in the cavity 16 is sucked from the suction portion 19 into the mold side suction system 40M based on the pressure difference between the inside of the vacuum tank 46 and the cavity 16. At the time of vacuum suction, it is preferable to monitor the pressure detected by the pressure detection unit 402 to confirm that the vacuum suction is normally performed.

The sleeve-side suction system 40S includes a vacuum valve 40V, a suction path 47 individually corresponding to the suction ports 41 to 44 of the sleeve 21, and a merging / distributing unit 48 connected to these suction paths 47.
Each suction path 47 includes a vacuum filter 411 for vacuum suction from upstream to downstream of the flow of gas sucked from the sleeve 21, a pressure gauge, a compound meter, and a pressure for detecting the pressure in the suction path 47. A pressure detection unit 412 such as a sensor and a selection valve 413 that selectively communicates the suction ports 41 to 44 with the vacuum tank 46 are provided in this order.

The vacuum valve 40V has a vacuum suction state in which each suction path 47 communicates with the vacuum tank 46, an air blow state in which each suction path 47 communicates with the pressure tank 422, and each suction path 47 communicates with the vacuum tank 46 and the vacuum tank 46. It is possible to switch to a neutral state in which none of the pressure tanks 422 is communicated. When the vacuum valve 40V is in the vacuum suction state, vacuum suction is possible through the open suction path 47 of the selection valve 413.

By opening and closing the selection valve 413 provided in each suction path 47, each of the suction ports 41 to 44 can be communicated with the vacuum tank 46 in a timely manner.
The suction ports 41 to 44 are the position of the plunger 22 in the advancing / retreating direction D1, the state of suction from the suction ports 41 to 44 based on the pressure detected by the pressure detection unit 412, the filling rate of the molten metal in the sleeve 21, and the like. It is preferable that the vacuum tank 46 is communicated with the vacuum tank 46 in a timely manner.

Of the suction ports 41 to 44, the gas inside the sleeve 21 enters the suction path 47 based on the pressure difference between the inside of the vacuum tank 46 and the inside of the sleeve 21 through the suction port in the state where the corresponding selection valve 413 is opened. Inflow. The gas flowing into the suction path 47 merges with the airflow from the other suction path 47 at the merging / distributing section 48 via the vacuum filter 411, the pressure detection unit 412, and the selection valve 413, and further passes through the vacuum valve 40V to the vacuum tank. It flows into 46.

In the example shown in FIG. 2, the sleeve-side suction system 40S and the suction ports 41 to 44 are also used as the pressurized air supply system 40P. Therefore, without interrupting production due to the replacement of piping, the connection destination of the merging / distributing unit 48 is switched between the vacuum tank 46 and the pressurized tank 422 by the vacuum valve 40V, so that vacuum suction and air blow can be performed. Can be switched.

The pressurized air supply system 40P carries out an air blow that ejects pressurized air to the inside of the sleeve 21 through the sleeve side suction system 40S and suction ports 41 to 44. By carrying out air blow, molten metal residue and the like can be removed from the piping of the suction path 47 and the suction ports 41 to 44.

The pressurized air supply system 40P includes a compressed air source 421, a pressure tank 422 that stores pressure inside by sending air by the compressed air source 421, a pipe of the sleeve side suction system 40S, a selection valve 413, and pressure detection. A section 412 and a vacuum filter 411 are included.

When the vacuum valve 40V is switched to the air blow, air is distributed from the pressurizing tank 422 to each suction path 47 by the merging / distributing unit 48, and is ejected into the sleeve 21 through the suction ports 41 to 44.
Even during air blow, the suction ports 41 to 44 may be communicated to the pressure tank 422 in a timely manner by opening and closing the selection valve 413.

[Control device for die casting machine]
Next, the control device 30 (FIG. 4) that controls the die casting machine 10 will be described.
The control device 30 is molded, poured, injected, vacuum-sucked, pressure-retaining / pressure-increasing, according to the manufacturing conditions set according to the specifications of the molds 11 and 13 used in the product and the injection device 20. Control mold opening, etc.
For example, in the injection process, the control device 30 detects the position of the plunger 22 and follows the injection conditions including the position and speed of the plunger 22 until the molten metal 17 reaches the gate 132 via the runner 131. After performing vacuum suction of the communication space 29 while advancing the plunger 22 at a relatively low speed, the speed of the plunger 22 is increased.
The forward movement of the plunger 22 is controlled from the above speed control to the pressure of the molten metal 17 of the cavity 16 at the timing (speed / pressure switching point; VP (Velocity Pressure) switching point) when the cavity 16 is filled with the molten metal 17. It is switched to the pressure control (holding pressure control / pressure increasing control) based on.

The position of the plunger 22 is preferably detected by, for example, a linear encoder provided on the piston rod of the hydraulic cylinder to which the plunger rod 23 is connected.
In addition, it is also permissible to detect the position of the plunger 22 by using a switch lever provided on the plunger rod 23 and a plurality of limit switches operated by the switch lever.

The control device 30 determines the plunger 22 by sending a command to the hydraulic cylinder which is the drive source of the plunger 22, the vacuum valve 40V and the selection valve 413 constituting the vacuum suction system 40, according to the position of the plunger 22. Drive to position and speed, switch valve state.

The control device 30 includes a control device main body 31, a monitor 32 connected to the control device main body 31, and an input / output interface 33, as shown in FIG. 4 to outline the hardware configuration.
The control device main body 31 displays various information necessary for setting manufacturing conditions, monitoring the operating status, and the like on the monitor 32. It is possible to set values such as control parameters held by the control device main body 31 through the input / output interface 33 by an input operation by an operator or data input from an external device.
5 and 6 show an example of information displayed on the screen of the monitor 32 of the control device 30 regarding the vacuum suction inside the sleeve 21.

The control device main body 31 is composed of a computer device or the like, and includes a calculation unit 311 such as a CPU (Central Processing Unit), a memory 312, and a storage unit 313 that electromagnetically or optically stores data.

The control by the control device 30 is performed by executing a computer program.
FIG. 7 shows an example of a program module read from the storage unit 313 to the memory 312. The programs used to control the die casting machine 10 include the die casting machine control unit 301 that mainly controls the die casting machine 10 such as mold clamping, pouring, injection, vacuum suction, air blow, and mold opening, as well as the inside of the sleeve 21. The sleeve vacuum control unit 302, the control parameter setting unit 303, and the valve response time lag setting unit 304 are included with respect to the vacuum suction of the above.

For control of sucking the inside of the sleeve 21, the position where the vacuum suction inside the sleeve 21 is started (vacuum start position) and the position where the tip 24 closes each suction port 41 to 44 (suction port closing position), respectively. The corresponding control parameters are used.
The control parameter corresponding to the vacuum start position is referred to as a vacuum start position parameter P0.
Further, the control parameter corresponding to the position where the tip 24 closes the suction port 41 is referred to as a first suction port closing position parameter P1. Similarly, the control parameters corresponding to the positions where the tip 24 closes the suction ports 42, 43, and 44, respectively, are the second suction port closing position parameter P2, the third suction port closing position parameter P3, and the fourth suction port closing position. It is referred to as parameter P4. These control parameters P0 to P4 are collectively referred to as "sleeve vacuum control parameters" (FIG. 5).

The control parameter setting unit 303 sets a value in the sleeve vacuum control parameter described above.
The sleeve vacuum control unit 302 issues a valve operation command to operate the vacuum valve 40V or the selection valve 413 at the positions of the plungers 22 indicated by the sleeve vacuum control parameters.
The valve response time lag setting unit 304 sets the valve response time lag, which will be described later.

The control parameter setting unit 303 includes an index value acquisition unit 303A, a control parameter input acquisition unit 303B, and an injection condition data conversion unit 303C.
The control parameter input acquisition unit 303B can acquire an input from the outside of the sleeve vacuum control parameter and set a value in the sleeve vacuum control parameter.
For example, when a value is input to the setting field 32S of the vacuum start position on the screen of the monitor 32 shown in FIG. 5 by an input device of the control console or the like, the control parameter input acquisition unit 303B is input to the setting field 32S. The value can be obtained and set in the vacuum start position parameter.

The injection condition data conversion unit 303C converts the position and velocity of the injection condition into position and time data, as will be described later.

At the position of the plunger 22 indicated by each of the sleeve vacuum control parameters, the valve operation command is issued by the sleeve vacuum control unit 302 to switch the state of the valve of the vacuum suction system 40.
Here, the case where the vacuum start position parameter P0 is set to the position of the plunger 22 when the front end 202A of the rear portion 202 of the tip 24 reaches the front end 26A of the pouring port 26, as shown in FIG. 8B. Think. As shown in FIG. 8B, when the inside of the sleeve 21 is blocked by the rear portion 202 of the tip 24 at the front end 26A of the pouring port 26, the front space 27 partitioned in front of the tip 24 inside the sleeve 21 Vacuum suction is possible. The position of the plunger 22 is referred to as a position where the tip 24 closes the pouring port 26 (pouring port closing position). Typically, vacuum suction of the sleeve 21 is started when the plunger 22 reaches the pouring port closing position.
If a vacuum start command (valve operation command) is issued by the sleeve vacuum control unit 302 at the position shown in FIG. 8B (the pouring port closing position and the vacuum start position) indicated by the vacuum start position parameter P0, the vacuum is created. The valve 40V is switched to the vacuum suction state. Then, the pressure in the communication space 29 is reduced.
It should be noted that the vacuum suction does not necessarily start at the pouring port closed position, but by starting the vacuum suction at the pouring port closed position, the time for performing the vacuum suction can be maximized.

Further, the first to fourth suction port closing parameters P1 to P4 correspond to positions of the suction ports 41 to 44 for closing the suction ports by the rear portion 202 of the tip 24, respectively. For example, if the front end 202A of the rear portion 202 of the chip 24 reaches the front end of the first suction port 41, the first suction port 41 is blocked by the rear portion 202. At this time, if the first blockage command (valve operation command) is issued by the sleeve vacuum control unit 302, the selection valve 413 of the suction path 47 connected to the first suction port 41 is closed, and the suction path 47 is closed. The communication between the outside air and the vacuum tank 46 is cut off. Then, it is possible to avoid a decrease in the degree of vacuum in the vacuum suction system 40 when the first suction port 41 is opened to the outside air by further advancing the tip 24.

As described above, the linear encoder or the like detects that the front end 202A of the chip 24 has reached the front end 26A of the pouring port 26, that is, the plunger 22 has moved to the vacuum start position, and the sleeve vacuum control unit 302 issues a vacuum start command. Is generated and issued, the vacuum valve 40V operates after the vacuum start command, and then the depressurization of the communication space 29 starts.
That is, there is a time lag between the arrival of the plunger 22 at the vacuum start position and the generation of the vacuum start command until the start of depressurization of the communication space 29. This time lag includes the response time of the vacuum valve 40V, the time until the pressure in the communication space 29 starts to decrease, the response time of the pressure gauge for detecting the pressure in the communication space 29, and the like.

For example, if the speed of the plunger 22 at the start of vacuum suction is 0.3 m / s and the time lag from the issuance of the vacuum start command to the operation of the vacuum valve 40V is 100 ms, the vacuum valve 40V is set. At the time of operation, the plunger 22 has moved 30 mm forward from the position where the vacuum start command was issued.
Even with the same time lag (100 ms) as above, if the speed of the plunger 22 is 0.5 m / s, the plunger 22 moves 50 mm forward from the position where the vacuum start command is issued when the vacuum valve 40V operates. doing. That is, as the speed of the plunger 22 increases, a significant shift occurs in the position of the plunger 22 at the time when the vacuum valve 40V operates with respect to the position of the plunger 22 at the time when the vacuum start command is generated due to the time lag.

Then, even if the sleeve vacuum control unit 302 immediately issues a vacuum start command when the vacuum start position is detected by the linear encoder or the like, the vacuum valve 40V does not always operate in a timely manner to start depressurization of the communication space 29. In some cases.
That is, even if the vacuum start command is issued at the position of the plunger 22 shown in FIG. 8 (b), the vacuum valve 40V is delayed from the vacuum start command and at the position where the plunger 22 is advanced as shown in FIG. 8 (a). If, the vacuum suction time cannot be secured to the maximum, and the chip 24 blocks a part of the second suction port 42 as shown in FIG. 8A. , The opening area for suction is reduced.

Considering the time lag, the vacuum start command is given when the plunger 22 reaches a position behind the position of the plunger 22 instead of the position of the plunger 22 when the front end 202A of the rear portion 202 of the tip 24 reaches the front end 26A of the pouring port 26. It is preferable to generate. In other words, the plunger 22 may reach the vacuum start position when the vacuum valve 40V actually operates after the command is generated by accelerating the generation of the vacuum start command in anticipation of a time lag.
However, if there is no index in which the time lag is taken into consideration, it is difficult to determine how far behind the vacuum start command should be generated, that is, the value of the vacuum start position parameter indicating the position where the vacuum start command is generated.
Therefore, it is assumed that the vacuum valve 40V operates at the position shown in FIG. 8 (c) as a result of the early issuance of the vacuum start command at the position behind the pouring port closing position. At this time, since the pouring port 26 and the front space 27 communicate with each other through the suction recess 25 and the gap between the tip 24 and the sleeve 21, outside air easily flows into the front space 27 through the pouring port 26.

The state of the molten metal 17 in the sleeve 21 when the vacuum valve 40V is operated at the positions shown in FIGS. 8A to 8C has been confirmed by a test. According to the test, when the vacuum valve 40V was operated at the positions shown in FIGS. 8A and 8B, the scattering of the molten metal 17 and the fluctuation of the molten metal surface due to the inflow of outside air were not observed by the camera.

Considering the time lag, not only the vacuum start position but also the suction port closing position, the plunger 22 is not at the position of the plunger 22 when the suction port is closed by the rear portion 202 of the chip 24, but at a position behind the position. It is preferable to close the corresponding selection valve 413 before the suction port is opened to the atmosphere by issuing a suction port closing command when the suction port is reached.
However, if there is no index in which the time lag is taken into consideration, it is difficult to determine how far behind the suction port blockage command should be generated, that is, the value of the suction port blockage parameter.
Here, at both the vacuum start position and the suction port closing position, the greater the speed (injection speed) at which the plunger 22 advances with respect to the sleeve 21, the more significant the effect of the time lag becomes. Further, regarding the suction port closing position, the shorter the axial length of the rear portion 202 of the tip 24, the shorter the distance until the suction port is opened to the atmosphere, so that the influence of the time lag becomes more remarkable. That is, the higher the injection speed and the shorter the rear 202 of the chip 24, the greater the need to generate a command at an appropriate time in order to operate each valve in a timely manner.

From the above, in order to ensure the quality of the cast product by efficiently performing vacuum suction of the sleeve 21 while suppressing the inflow of outside air into the sleeve 21, the sleeve vacuum control parameter is simply set to an appropriate value in consideration of the time lag. I want to set it to.
Therefore, the control device 30 of the present embodiment provides an index value of the sleeve vacuum control parameter as an index in which the time lag is taken into consideration.

The vacuum start position index value Pi0 and the first to fourth suction port blockage position index values Pi1 to Pi4 are (1) valve operations determined only from the geometric specifications of the sleeve 21 and the tip 24 without considering the time lag. A series of processing such as (2) injection conditions including data indicating the position and speed of the plunger 22, (3) command generation at the start of vacuum, valve operation such as vacuum valve 40V, and decompression of communication space 29. And the time lag that exists in the phenomenon, and is obtained using.
The index value acquisition unit 303A of the control parameter setting unit 303 acquires the index value corresponding to the position retroactively for the time corresponding to the time lag from the valve operating position.
Hereinafter, the above-mentioned elements (1) to (3) used for acquiring the index value of the sleeve vacuum control parameter will be described.

(1) Valve operating position As shown in FIG. 9, the valve operating position referred to here is the dimension of the advancing / retreating direction D1 with respect to the pouring port 26 and the suction port 41 to 44 of the sleeve 21, the front portion 201 of the tip 24, and the suction recess. It is derived from geometric specifications such as the dimensions of the advancing / retreating direction D1 of 25. As shown in FIG. 9, the valve operating positions Vs0 to Vs4 can be indicated with reference to the position of the tip 24B of the tip 24 of the plunger 22 at the origin position.
The valve operating position Vs0 used to acquire the vacuum start position index value corresponds to the position where the tip 24 closes the pouring port 26 (pouring port closing position). The valve operating position Vs1 used for acquiring the first suction port closing position index value corresponds to the position where the tip 24 closes the suction port 41 (suction port closing position). Similarly, the valve operating positions Vs2 to Vs4 used for acquiring the second to fourth suction port closing position index values also correspond to the positions where the tip 24 closes the corresponding suction port (suction port closing position).

The geometric specifications of the sleeve 21 and the chip 24 are preset before manufacturing and stored in the storage unit 313, as shown in FIG. 6 as an example of the setting screen. In this example, for example, the dimension L0 in the advancing / retreating direction D1 of the pouring port 26, the distance L1 from the front end 26A of the pouring port 26 to the opening center of the first suction port 41, and the second suction port from the opening center of the first suction port 41. Distance L2 to the opening center of 42, distance L3 from the opening center of the second suction port 42 to the opening center of the third suction port 43, from the opening center of the third suction port 43 to the opening center of the fourth suction port 44 Distance L4, diameter φ1 to φ4 of each suction port 41-44, total length L5 of tip 24, tip 24B of tip 24 of plunger 22 at the origin position with respect to normal reference position (rear end 26B of pouring port 26) The shift length L6, the unsealable length L7 corresponding to the width of the tapered portion on the front end side of the chip 24, the length L8 of the front portion 201 excluding the unsealable length L7, and the suction recess 25. The length L9 or the like is set by inputting to an input item on the screen.

The valve operating positions Vs0 to Vs4 can be calculated from the numerical values set by the setting screen of FIG. 6, for example. It should be noted that the respective values of the valve operating positions Vs0 to Vs4 may be input to the items on the setting screen.

(2) Injection conditions The injection conditions are set in advance before manufacturing and are stored in the storage unit 313, like the geometric specifications of the sleeve 21 and the chip 24. FIG. 10 shows an example of the waveform of the position and velocity of the injection condition. The horizontal axis shows the injection stroke from the origin position of the plunger 22, and the vertical axis shows the velocity of the plunger 22.
The injection conditions are set based on the basic operation of pushing the molten metal 17 out of the sleeve 21 by the tip 24 of the plunger 22 moving at a relatively low speed, and then rapidly increasing the speed of the plunger 22.
By setting the position and speed of the injection conditions, it is possible to realize various injection setting waveforms having different accelerations and the like.

The control parameter setting unit 303 uses the position / time data converted from the position / velocity of the injection condition into the position / time data by the injection condition data conversion unit 303C to acquire the sleeve vacuum control parameter. Based on this position / time data, it is possible to specify the position behind the valve operating position geometrically obtained by the time lag.
The "time" in the position / time data is from the reference position in the advancing / retreating direction D1 (here, the origin position of the plunger 22) to reaching an arbitrary position in the advancing / retreating direction D1 based on the injection conditions. Means the elapsed time of. In this sense, the "time" of position / time data is referred to as elapsed time.

The injection condition data conversion unit 303C obtains the elapsed time of the plunger 22 for each unit displacement amount over the entire area of the injection stroke as the position / time data converted from the position and speed of the injection condition into the position and time data. Is preferable.
Based on the position / time data in which the elapsed time is given over the entire area of the injection stroke, it is easy to identify the position corresponding to the time retroactive to the time corresponding to the time lag from the elapsed time at an arbitrary position on the injection stroke. can do.

The injection condition data conversion unit 303C calculates the elapsed time for each unit displacement amount over the entire area of the injection stroke based on the injection conditions including the position and the speed. The elapsed time data calculated by the injection condition data conversion unit 303C is stored in the storage unit 313.
When the value of the injection condition is changed, the elapsed time is recalculated based on the changed injection condition, and the elapsed time data stored in the storage unit 313 is rewritten.
When the elapsed time data corresponding to each of the different injection conditions is calculated in advance from the injection conditions and stored in the storage unit 313, it is not always necessary to recalculate when the injection conditions are changed or rewrite the data in the storage unit 313.

FIG. 11 schematically shows the elapsed time data for each unit displacement amount calculated from the injection conditions. The elapsed time data shown in FIG. 11 shows the correspondence between the position of the plunger 22 from the origin position in units of 1 mm and the elapsed time from the start of movement when the plunger 22 reaches the position over the entire injection stroke (here). 1 mm to 1200 mm).
As long as the position of the plunger 22 and the elapsed time are linked, the elapsed time data may be in any data format. The elapsed time data is, for example, matrix table data, or the elapsed time associated with each position of 1 to 1200 mm is individually stored in the storage area (buffer) prepared in the storage unit 313. It may have been done.

(3) Time lag Next, the time lag used for acquiring the index value of the sleeve vacuum control parameter corresponds to the valve response time lag assuming the time lag from the generation of the valve operation command to the operation of the vacuum valve 40V, the selection valve 413, and the like. ..
This valve response time lag can be determined by using the time lag between the detection of the valve operating position by a linear encoder or the like and the start of decompression of the communication space 29 with respect to the generation of the valve operation command.

In FIG. 12, an example of the time change of the gas pressure R1 of the cavity 16 in the process of vacuum suction performed while advancing the plunger 22 at a low speed is shown by a thick solid line, and the gas in the vicinity of the suction portion 19 of the molds 11 and 13 is shown. An example of the time change of the pressure R2 is shown by a thin solid line. The gas pressure R1 is measured by a pressure gauge G1 (FIG. 13) arranged at a predetermined position in the cavity 16, and the gas pressure R2 is measured by a pressure gauge G2 (FIG. 13) arranged near the suction unit 19.

From FIG. 12, regarding the vacuum suction through the suction ports 41 to 44 of the sleeve 21, the time lag from the time when the vacuum start command is issued (A1) to the start of decompression (B1) when the pressure R1 of the cavity 16 starts to decrease. TL1 is present.
Here, depending on the responsiveness of the vacuum valve 40V and the pressure gauge G1, the volume of the cavity 16, and the like, when the vacuum valve 40V is switched, the decompression of the cavity 16 is instantly started and reflected in the measured value of the pressure gauge G1. Will be done.
However, in many cases, in order to detect the start of depressurization of the cavity 16 based on the measured value of the pressure gauge G1, the inside of the sleeve 21 is changed after the vacuum valve 40V is switched after the generation A1 of the vacuum start command. The pressure of the cavity 16 is reduced by vacuum suction through the suction ports 41 to 44, and it takes time for the pressure gauge G1 to respond to the pressure reduction of the cavity 16.

The pressure R2 near the suction portion 19 of the molds 11 and 13 gradually decreases as compared with the pressure R1 at the start of depressurization (B1), and then the decrease rate increases due to the response to the vacuum suction through the suction portion 19. (B2).
In the example shown in FIG. 12, the command generation of the vacuum suction start of the sleeve 21 (A1) is preceded by the command generation of the vacuum suction start of the cavity 16 through the suction unit 19 (A2). Is an example, and is not limited to this. The time when the vacuum start command is generated (A1, A2) can be appropriately determined so that the cavity 16 reaches the target degree of vacuum.

As shown in FIG. 13, since the distance from the sleeve 21 to the pressure gauge G2 is farther than the distance from the sleeve 21 to the pressure gauge G1, the degree of decrease in pressure R2 in (B1) is the degree of decrease in pressure R1. Although it is smaller than that, the time lag TL1 from the command generation (A1) of the start of vacuum suction of the sleeve 21 to the start of decompression can be obtained based on the time change of the pressure R2.
However, from the viewpoint of stably obtaining the time lag TL1, it is preferable to accurately grasp the start of depressurization of the cavity 16 based on the time change of the pressure R1 detected by the pressure gauge G1 close to the sleeve 21.

The valve response time lag used to acquire the index value of the sleeve vacuum control parameter takes into consideration the time lag TL1, the responsiveness of the vacuum valve 40V and the pressure gauge G1, the variation of the measured value by the pressure gauge G1, the volume of the cavity 16, and the like. Can be determined. Typically, based on the fact that the valve response time lag is shorter than the time lag TL1, it is preferable to adopt a value obtained by multiplying the time lag TL1 by a coefficient less than 1 (for example, 0.5 to 0.9). .. However, it is permissible to adopt the time lag TL1 as the valve response time lag.
The valve response time lag is not limited to multiplication of the coefficients of the time lag TL1, and can be obtained by an appropriate calculation.

The valve response time lag is set in advance by the valve response time lag setting unit 304 before manufacturing and stored in the storage unit 313, as shown in FIG. 6 as an example of the setting screen. In this example, the valve response time lags Vt0 to Vt4 of each valve (vacuum valve 40V and selection valve 413) to the valve operation command can be set by input on the screen. The same value can be set for the valve response time lags Vt0 to Vt4, or different values can be set.

The valve response time lag Vt0 to Vt4 may be set automatically including the acquisition of the time lag TL1 shown in FIG. That is, the valve response time lag setting unit 304 acquires the time lag TL1 from the temporal change of the pressure of the communication space 29 such as the inside of the cavity 16 and the sleeve 21 at the time of casting, and the value obtained by multiplying the time lag TL1 by a predetermined coefficient is the valve. It may be set to the response time lag.

As described above, the control parameter setting unit 303 uses the index value acquisition unit 303A to use the valve operating position, injection conditions, and valve response time lag to valve from the valve operating position of the vacuum valve 40V or the selection valve 413. The index values (vacuum start position index value Pi0, first to fourth suction port blockage position index values Pi1 to Pi4) corresponding to the retroactive position are acquired for the time corresponding to the response time lag, and the index value is controlled by the sleeve vacuum. Can be set in a parameter.

In the present embodiment, the sleeve vacuum control parameter set by the control parameter setting unit 303 can be changed on the screen by the operator.
FIG. 5 shows an example of a screen in which sleeve vacuum control parameters can be set. In this example, setting items (use / non-use) for whether or not to use the vacuum suction function of the sleeve 21 in the die casting machine 10, use / non-use setting items for each suction port 41 to 44, and sleeve vacuum control parameter setting items. 320 to 324 are displayed on the screen.

Next to the setting items 320 to 324 of the sleeve vacuum control parameter, the recommended range of the value of the sleeve vacuum control parameter is displayed. The value of the sleeve vacuum control parameter can be set within this range.
The lower limit of the recommended range on the screen is the sleeve vacuum control parameter index value (Pi0 to Pi4) described above, that is, the position rearward by the valve response time lag with respect to the geometrically obtained valve operating positions Vs0 to Vs4. Corresponds to. For example, the recommended lower limit (Pi0) of the vacuum start position parameter P0 corresponds to the position behind the valve operating position Vs0 by the amount of the valve response time lag Vt0. The lower limit of the recommended range of the first suction port closing position parameter P1 corresponds to the position behind the valve operating position Vs1 by the amount of the valve response time lag Vt1. The same applies to the second to fourth suction port closing position parameters P2 to P4.
The upper limit of the recommended range on the screen corresponds to the geometrically obtained valve operating positions Vs0 to Vs4.

Since the lower limit of the recommended range considers the time lag assuming the response time of the valve, the operator can refer to the data at the time of the manufacturing test as necessary without considering the time lag caused by the response of the valve. Then, an arbitrary value in the range from the lower limit to the upper limit of the recommended range can be set in the setting items 320 to 324 of the sleeve vacuum control parameter by using the input device of the control console or the like. At that time, it is easier to set the value when the upper limit is also displayed as compared with the case where only the lower limit is displayed as the recommended value.
However, even if only the recommended values (Pi0 to Pi4) are displayed on the sleeve vacuum control parameter setting screen, appropriate values are set for the control parameters P0 to P4 based on the recommended values. be able to.

As described above, when controlling the die casting machine of the present embodiment, the valve operating position geometrically obtained by the control parameter setting unit 303 of the control device 30, the injection condition, and the valve response time lag are used. The index value of the sleeve vacuum control parameter can be acquired and set in the sleeve vacuum control parameter.

[Casting method, control example of vacuum suction of sleeve]
An example of the casting procedure by die casting will be briefly described.
FIG. 14 shows each step of die casting. One cycle of casting includes mold clamping (step S1), pouring into the sleeve 21 (step S2), starting injection by the plunger 22 (step S3), and vacuum suction of the sleeve 21 (Yes in step S4). Treatment (step S5), holding pressure / increasing pressure (step S6), cooling the molten metal in the cavity 16 (step S7), opening the mold (step S8), taking out the product from the molds 11 and 13 (step S9), It comprises detecting the product (step S10), supplying the mold release agent to the molds 11 and 13 (step S11), retracting the plunger 22 (step S12), and supplying the lubricant to the chip 24 (step S13).

Of the above steps, step S5 is performed under the control of the sleeve vacuum control unit 302. The other steps are performed under the control of the die casting machine control unit 301.

FIG. 15 showing an example of the detailed processing of step S5 and FIGS. 16 to 19 showing the movement of the plunger 22 in the injection step will be described.

At the start of vacuum suction of the sleeve 21, it is assumed that all of the selection valves 413 corresponding to the suction ports 41 to 44 are open.
As an outline of the vacuum suction process of the sleeve 21, as the plunger 22 advances, the sleeve vacuum control unit 302 issues a valve operation command to the vacuum valve 40V or the selection valve 413 at the positions indicated by the sleeve vacuum control parameters P0 to P4, respectively. Emitted. When the valve operation command is generated, the vacuum valve 40V or the selection valve 413 corresponding to the command operates.
Since the control parameters P0 to P4 are set in consideration of the valve response time lag as described above, the vacuum valve 40V and the selection valve 413 are delayed from the commands issued at the positions indicated by the control parameters P0 to P4, respectively. It will operate in a timely manner.
In the present embodiment, since the tip 24 on which the suction recess 25 is formed is used, each suction port 41 to 44 is used for suction of the front space 27 or the suction recess 25, as described below. To. The selection valve 413 corresponding to each suction port 41 to 44 is switched to the closed state before each suction port 41 to 44 is opened to the atmosphere by the advancement of the plunger 22.

Hereinafter, an example of the process related to vacuum suction of the sleeve 21 will be specifically described.
In step S101, when the pressure gauge detects that the inside of the vacuum tank 46 has reached a sufficient degree of vacuum, a signal that the vacuum suction is ready is issued.
At this time, as shown in FIG. 16A, the plunger 22 is in the original position.

In step S102, a vacuum start command is issued when the plunger 22 reaches the position indicated by the vacuum start position parameter P0. When the vacuum start command is generated, the plunger 22 is located rearward from the position where the tip 24 closes the pouring port 26 (FIG. 16B).
In step S103, the vacuum valve 40V is switched to vacuum suction by the vacuum start command issued in step S102. At this time, the plunger 22 is in the same position as shown in FIG. 16B. That is, the vacuum valve 40V is switched to vacuum suction at a position where the rear portion 202 of the tip 24 closes the pouring port 26. Then, the vacuum suction system 40 (FIG. 2) sucks the suction recess 25 through the suction port 41 and sucks the front space 27 through the suction ports 42 to 44.

After that, as the plunger 22 advances, the second suction port 42 is blocked by the front portion 201 of the tip 24 as shown in FIG. 16 (c). Along with this, the suction of the front space 27 through the second suction port 42 is completed.
Next, as shown in FIG. 17A, the second suction port 42 communicates with the suction recess 25. At this time, the suction recess 25 is sucked through the first suction port 41 and the second suction port 42, and the front space 27 is sucked through the third suction port 43 and the fourth suction port 44.

Subsequently, when the plunger 22 reaches the position indicated by the first suction port closing position parameter P1, the first suction port closing command is issued (step S104). When this command is generated, the plunger 22 is located rearward from the position where the rear portion 202 closes the first suction port 41 (FIG. 17B).
By the first suction port closing command issued in step S104, the first selection valve 413 corresponding to the first suction port 41 is switched to the closed state (step S105). At this time, the plunger 22 is in the same position as shown in FIG. 17B. That is, the first selection valve 413 is switched to the closed state at the position where the rear portion 202 closes the first suction port 41. As a result, vacuum suction through the suction path 47 corresponding to the first suction port 41 is completed.

After that, similarly, the plunger 22 moves to the second suction port closing position through the closure of the third suction port 43 by the front portion 201 (FIG. 17 (c)) and the communication between the third suction port 43 and the suction recess 25. When the position indicated by the parameter P2 is reached, the second suction port closing command is issued (step S106).
By the second suction port closing command, the second selection valve 413 corresponding to the second suction port 42 is switched to the closed state (step S107). At this time, the plunger 22 is in the same position as shown in FIG. 18A. That is, the second selection valve 413 is switched to the closed state at the position where the rear portion 202 closes the second suction port 42. As a result, vacuum suction through the suction path 47 corresponding to the second suction port 42 is completed.
Further, when the second suction port 42 is closed by the rear portion 202, the first suction port 41 is opened to the atmosphere, but the first selection valve 413 corresponding to the first suction port 41 has already been switched to the closed state. Therefore, it is possible to avoid a decrease in the degree of vacuum of the vacuum tank 46 through the suction path 47 corresponding to the first suction port 41.

Further, as shown in FIG. 18B, the front portion 201 closes the fourth suction port 44 located at the frontmost of the suction ports 41 to 44, so that the vacuum suction of the front space 27 ends. However, in order to suppress the inflow of outside air into the front space 27, the suction of the suction recess 25 is continuously continued through the fourth suction port 44.
After that, when the plunger 22 reaches the position indicated by the third suction port closing position parameter P3, the third suction port closing command is issued (step S108).
By the third suction port closing command, the third selection valve 413 corresponding to the third suction port 43 is switched to the closed state (step S109). At this time, the plunger 22 is in the same position as shown in FIG. 18C. That is, the third selection valve 413 is switched to the closed state at the position where the rear portion 202 closes the third suction port 43. As a result, vacuum suction through the suction path 47 corresponding to the third suction port 43 is completed.

Subsequently, when the plunger 22 reaches the position indicated by the fourth suction port closing position parameter P4, the fourth suction port closing command is issued (step S110). After that, the fourth selection valve 413 corresponding to the fourth suction port 44 is switched to the closed state (step S111). At this time, as shown in FIG. 19A, the fourth selection valve 413 is switched to the closed state at the position where the rear portion 202 closes the fourth suction port 44. As a result, all of the first to fourth selection valves 413 corresponding to the first to fourth suction ports 41 to 44 are closed, so that the vacuum suction by the sleeve side suction system 40S is completed. As the fourth selection valve 413 is switched to the closed state, the vacuum valve 40V may be switched to neutral (step S112).
After that, as shown in FIGS. 19 (b) and 19 (c), the fourth suction port 44 is opened to the atmosphere.

When the vacuum suction in the sleeve 21 through the suction ports 41 to 44 is completed, air blow is performed. After the molten metal 17 is pushed out from the sleeve 21 by the tip 24, the air blow is performed in parallel with the processing after step S6 of holding pressure / increasing pressure, following the generation of a command to switch from speed control to pressure control, for example. be able to.
In order to carry out air blow, the vacuum valve 40V is switched to an air blow, and the selection valves 413 corresponding to the suction ports 41 to 44 are opened one by one in order for a set time.
Then, the pressurized air supply system 40P performs an air blow that ejects pressurized air into the sleeve 21 through the suction ports 41 to 44.
After finishing the air blow, switch the vacuum valve 40V to neutral.

According to the control by the control device 30 of the die casting machine 10 described above, the vacuum valve 40V and the selection valve 413 operate in a timely manner by acquiring the index value of the sleeve vacuum control parameter in consideration of the valve response time lag. Therefore, it is possible to easily set the control parameter for generating the valve operation command in advance by the amount of the valve response time lag.
By operating the vacuum valve 40V and the selection valve 413 in a timely manner, the maximum vacuum suction time can be secured, and a sufficient opening area for suction can be secured, so that the inside of the sleeve 21 and the cavity 16 are efficient. The pressure can be reduced well to prevent the formation of entrainment cavities.
According to the above-mentioned control, even when the sleeve 21 is vacuum-sucked by using the plurality of suction ports 41 to 44 formed on the wall of the sleeve 21 and the tip 24 having the suction recess 25 formed therein, FIGS. 16 to 16 to As illustrated in FIG. 19, a series of valve operations of the vacuum valve 40V and the selection valve 413, which are delayed with respect to the valve operation command, are performed at appropriate positions. Therefore, from the viewpoint of suppressing the violence of the molten metal due to the inflow of outside air and preventing the suction path 47 from being blocked, the inside of the sleeve 21 and the cavity 16 can be efficiently depressurized to contribute to ensuring the quality of the cast product.

The control device 30 can also be applied to the existing die casting machine 10. By replacing the control device provided in the existing die casting machine 10 with the control device 30 of the present embodiment, the valve response time lag can be dealt with, so that it is possible to cope with an increase in the injection speed.

The control device 30 may be divided into a plurality of control blocks. For example, a device capable of executing the index value acquisition unit 303A (FIG. 7) of the control parameter setting unit 303 can execute the die casting machine control unit 301, the sleeve vacuum control unit 302, and the like as the control parameter index value acquisition device. It may be configured separately from the device. In that case, the index acquired by the control parameter index value acquisition device can be transmitted to the main control device by communication between the control parameter index value acquisition device and the main control device, and can be used for setting the control parameter.
With the above-mentioned control parameter index value acquisition device, it is also possible to provide the index value of the sleeve vacuum control parameter to the existing control device.

In addition to the above, the configurations listed in the above embodiments can be selected or appropriately changed to other configurations as long as the gist of the present invention is not deviated.

10 Die-casting machine 11 Movable mold 11A Product extrusion mechanism 12 Movable plate 13 Fixed mold 14 Fixed plate 15 Machine base 16 Cavity 17 Molten metal 18 Tie bar 19 Suction part 20 Injection device 21 Sleeve 21A Inner circumference 22 Plunger 23 Plunger rod 24 Plunger tip 24A Front end 24B Tip 25 Suction recess 26 Pouring port 26A Front end 26B Rear end 27 Front space 28A, 28B Sealing member 29 Communication space 30 Control device 31 Control device body 32 Monitor (display unit)
32S Control parameter setting field 33 Input / output interface 40 Vacuum suction system 40M Mold side suction system 40P Pressurized air supply system 40S Sleeve side suction system 40V Vacuum valve 41-44 Suction port 45 Vacuum pump 46 Vacuum tank 47 Suction path 48 Merge Distributor 131 Runner 132 Gate 201 Front 202 Rear 202A Front end 203 Small diameter 301 Die casting machine control 302 Sleeve vacuum control 303 Control parameter setting 303A Index value acquisition 303B Control parameter input acquisition 303C Injection condition data conversion 304 Valve response time lag setting unit 311 Calculation unit 312 Memory 313 Storage unit 320 to 324 Control parameter setting items 401 Vacuum filter 402 Pressure detection unit 403 Vacuum valve 411 Vacuum filter 412 Pressure detection unit 413 Selection valve 421 Compressed air source 422 Pressurized tank D1 Forward / backward directions G1, G2 Pressure gauge P0 Vacuum start position parameter (control parameter)
P1 1st suction port blockage position parameter (control parameter)
P2 2nd suction port blockage position parameter (control parameter)
P3 Third suction port blockage position parameter (control parameter)
P4 4th suction port blockage position parameter (control parameter)
Pi0 to Pi4 Index value R1, R2 Gas pressure TL1 Time lag Vs0 to Vs4 Valve operating position Vt0 to Vt4 Valve response time lag p0 Atmospheric pressure p1, p2 Pressure φ1 to φ4 Diameter

Claims (12)

It is a device that controls a die casting machine that includes a sleeve that injects molten metal from a pouring port and a plunger that ejects the molten metal toward a cavity, and is configured to be able to suck the inside of the sleeve that communicates with the cavity. ,
A control parameter setting unit that indicates the position of the plunger in the advancing / retreating direction and sets a value for a control parameter used for control of sucking the inside of the sleeve.
The sleeve vacuum control unit is provided with a sleeve vacuum control unit that issues a valve operation command at a position indicated by the control parameter to operate a valve that operates a suction state inside the sleeve.
The control parameter setting unit
A valve operating position as a position for operating the valve, which is a position in the advancing / retreating direction determined by geometrical specifications of the tip of the plunger and the sleeve.
Injection conditions including the position and speed of the plunger and
Using the time lag of the valve operation with respect to the valve operation command,
It is possible to acquire an index value corresponding to a position retroactively for a time corresponding to the time lag from the valve operating position and set the index value as the control parameter.
A control device for a die casting machine. A display unit for displaying at least the index value among the index value and the valve operating position is provided.
The control device for a die casting machine according to claim 1. The control parameter setting unit
A value input in the recommended range between the index value and the valve operating position can be set in the control parameter.
The control device for a die casting machine according to claim 1 or 2. The control parameter setting unit uses the position / time data converted from the position / velocity of the injection condition into the position / time data to acquire the index value.
The control device for a die casting machine according to any one of claims 1 to 3. The control parameter setting unit obtains, as the position / time data, the elapsed time until the plunger reaches an arbitrary position in the advancing / retreating direction for each unit displacement amount.
The control device for a die casting machine according to claim 4. A storage unit for storing at least the position / time data among the injection conditions, the control parameters, and the position / time data is provided.
The control device for a die casting machine according to any one of claims 1 to 5. The control parameter includes a vacuum start position parameter indicating the position of the plunger when a vacuum start command to operate the valve is issued when starting suction inside the sleeve.
The valve operating position used to obtain the index value corresponding to the vacuum start position parameter is
From the geometrical specifications of the tip and the sleeve, it is the position where the tip closes the pouring port.
The control device for a die casting machine according to any one of claims 1 to 6. The wall of the sleeve is provided with one or more suction ports used for suction inside the sleeve in front of the pouring port in the advancing / retreating direction.
The control parameter includes a suction port closing position parameter indicating the position of the plunger when a suction port closing command for switching the valve corresponding to the suction port to the closed state is issued.
The valve operating position used to acquire the index value corresponding to the suction port blockage position parameter is
From the geometrical specifications of the tip and the sleeve, it is the position where the tip closes the suction port.
The control device for a die casting machine according to any one of claims 1 to 7. The plunger including a chip that retracts inward in the radial direction with respect to the inner peripheral portion of the sleeve and has a continuous suction recess in the circumferential direction, and two or more suction ports at intervals in the advancing / retreating direction. The die cast is provided with the sleeve provided with the above, and is configured to be capable of sucking the space in front of the front end of the tip and the inside of the suction recess by using the two or more suction ports. Applies to controls that suck inside the sleeve of the machine,
The control device for a die casting machine according to claim 8. It is an acquisition device that acquires the index value used to set the control parameters of the die casting machine.
The control parameter indicates the position of the die casting machine in the advance / retreat direction of the plunger, and is used for controlling the suction inside the sleeve of the die casting machine.
The acquisition device is
A valve operating position as a position in the advancing / retreating direction determined by the geometrical specifications of the tip of the plunger and the sleeve, and as a position for operating the valve that operates the suction state inside the sleeve.
Injection conditions including the position and speed of the plunger and
Using the time lag of the valve operation with respect to the valve operation command issued at the position indicated by the control parameter,
An index value corresponding to a position retroactively obtained for a time corresponding to the time lag is acquired from the valve operating position.
An index value acquisition device for control parameters of a die casting machine. It is an acquisition method to acquire the index value used for setting the control parameters of the die casting machine.
The control parameter indicates the position of the die casting machine in the advance / retreat direction of the plunger, and is used for controlling the suction inside the sleeve of the die casting machine.
The acquisition method is
A valve operating position as a position in the advancing / retreating direction determined by the geometrical specifications of the tip of the plunger and the sleeve, and as a position for operating the valve that operates the suction state inside the sleeve.
Injection conditions including the position and speed of the plunger and
Using the time lag of the valve operation with respect to the valve operation command issued at the position indicated by the control parameter,
An index value corresponding to a position retroactively obtained for a time corresponding to the time lag is acquired from the valve operating position.
A method for acquiring index values of control parameters of a die casting machine. The control parameters are
The plunger including a chip that retracts inward in the radial direction with respect to the inner peripheral portion of the sleeve and has a continuous suction recess in the circumferential direction, and two or more suction ports at intervals in the advancing / retreating direction. The die casting machine provided with the sleeve, and which is configured to be able to suck the space in front of the front end of the tip and the inside of the suction recess by using the two or more suction ports. Used for control when sucking the inside of the sleeve of
The method for acquiring an index value of a control parameter of a die casting machine according to claim 11.

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