JP4030972B2 - Ejector operation control method and ejector operation device for injection molding machine - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an ejector operation control method and an ejector operation device for an injection molding machine, and more specifically, an ejector operation control method for an injection molding machine capable of switching between an ejector operation after mold opening and an ejector operation during mold opening. The present invention relates to an ejector operating device.

  As for the operation procedure in the conventional injection molding machine, the ejector operation is generally performed after the mold is opened. The prior art will be described with reference to FIG. 3. An injection molding machine is provided with a mold opening / closing cylinder 11, an ejector cylinder 12, an injection cylinder 13, etc., and a four-way electromagnetic system for controlling the cylinders 11, 12, 13. Switching valves 14, 15, and 16 are provided, respectively. A large-capacity pump 18 and a small-capacity pump 19 for supplying hydraulic oil to the hydraulic circuit of the injection molding machine are provided, and the pressures are controlled by proportional electromagnetic relief valves 20 and 21, respectively. A proportional electromagnetic flow control valve 17 for controlling the flow rate of the hydraulic fluid is disposed in a pipeline through which the hydraulic fluid is sent from the large capacity pump 18 to the mold opening / closing cylinder 11, the ejector cylinder 12, and the injection cylinder 13. ing. Further, a check valve 31 is disposed in a pipeline through which hydraulic oil is sent from the small capacity pump 19 to the mold opening / closing cylinder 11 and the like. Furthermore, reference numeral 22 denotes an injection molding machine control device for controlling the process of the CPU 23, setting / display unit 24, storage unit 25, process control unit 26, sequence control unit 27, process control unit 26 and injection molding machine. In the input / output unit 28 for inputting / outputting signals between the sensors and valves, the input / output unit 29 for inputting / outputting signals between the sequence control unit 27 and the injection molding machine main body, and the control device 22 It consists of a bus 30 and the like through which each signal is transmitted and received. In the prior art, the process control unit 26 performs process control of the mold opening / closing cylinder 11, the ejector cylinder 12 and the injection device, and the sequence control unit 27 performs sequence control of the injection molding machine. As described above, in the prior art, the process control of the ejector operation cannot be executed unless the process control of the mold opening / closing operation is completed in the process control unit 26. Therefore, in order to improve the molding efficiency, the ejector is operated during the mold opening, and the mold opening and the molded product ejection are simultaneously performed, and the molding cycle time cannot be shortened.

  On the other hand, Patent Document 1 discloses one that performs an ejector operation during mold opening. In Patent Document 1, the ejector operation is performed during mold opening by using the sequence valves 5 and 12. However, in Patent Document 1, when the ejector operation is performed during mold opening, the mold opening speed is changed.

JP 56-78959 A (Claim 1, FIG. 1, FIG. 2)

  Therefore, in the present invention, in an injection molding machine capable of switching between an ejector operation after mold opening and an ejector operation during mold opening, the control of the mold opening / closing cylinder and the control of the ejector cylinder are separately performed during the mold opening ejector operation. It is an object of the present invention to provide an ejector operation control method and an ejector operation device that can be performed. Another object of the present invention is to make it possible to easily modify a conventional machine without separately installing a dedicated pump for operating an ejector cylinder. It is another object of the present invention to facilitate control switching between the ejector operation after mold opening and the ejector operation during mold opening. It is another object of the present invention to eliminate setting mistakes and associated malfunctions when the ejector is operated after opening the mold.

Ejector operation control method for an injection molding machine according to claim 1 of the present invention, the ejector operation control method for a mold opening after ejector operation and die opening in the ejector operation and switchable injection molding machines, high-capacity pump and a small One hydraulic circuit that operates the ejector cylinder when the ejector is operated after opening the mold connected to the capacity pump, and the ejector cylinder that is connected to the small capacity pump and provided with a flow control valve to operate the ejector during mold opening The other hydraulic circuit for operating the ejector is provided, and the ejector cylinder is operated by switching between one hydraulic circuit for operating the ejector after mold opening and the other hydraulic circuit for operating the ejector during mold opening. And

The present invention provides a hydraulic circuit that is connected to a large-capacity pump and a small-capacity pump when the ejector operation after mold opening and the ejector operation during mold opening are switched and operates the ejector cylinder when the ejector is operated after mold opening. And a hydraulic circuit connected to the small capacity pump and provided with a flow control valve to operate the ejector cylinder when the mold is opened , and to operate the ejector after the mold is opened. Since the ejector cylinder is operated by switching to one of the other hydraulic circuits that operate the ejector during mold opening, the control of the mold opening and closing cylinder and the control of the ejector cylinder are controlled separately when the ejector is operated during mold opening. Can be done.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram including an ejector operating device used in the ejector operation control method of the present invention. FIG. 2 is a diagram showing the relationship between the set input value and the flow rate to the ejector cylinder in the ejector actuating device of the present invention. FIG. 3 is a block diagram including an ejector actuation device used in a conventional ejector actuation control method.

  The ejector actuating device used in the ejector actuating control method of the present invention will be described using the same reference numerals for the same parts as those of the above-described conventional technology. The injection molding machine is provided with a mold opening / closing cylinder 11, an ejector cylinder 12, an injection cylinder 13 and the like as actuators. The mold opening / closing cylinder 11 and the injection cylinder 13 are provided with four-way electromagnetic switching valves 14 and 16 for controlling the cylinders 11 and 13, respectively. Further, in the present invention, a plurality of systems of hydraulic circuits 32 and 40 for controlling the cylinder 12 are formed with respect to the ejector cylinder 12, and the plurality of systems of hydraulic circuits 32 and 40 merge with the ejector cylinder 12. It is configured as follows. One hydraulic circuit 32 in the plurality of hydraulic circuits 32 and 40 is a circuit for controlling the ejector cylinder 12 and a circuit for controlling the injection cylinder 13 when the ejector operation is performed after the mold is opened. In the hydraulic circuit 32, a four-way electromagnetic switching valve 15 is disposed. The other hydraulic circuit 40 in the plurality of hydraulic systems 32 and 40 is a circuit for controlling the ejector cylinder 12 when the ejector is operated during mold opening. The hydraulic circuit 40 includes the ejector cylinder 12. A proportional electromagnetic directional flow control valve 33 (flow control valve) for controlling the flow rate sent to is provided. Such an extension of the hydraulic circuit 40 can be easily performed by additionally providing a proportional electromagnetic directional flow control valve 33 and an electromagnetic directional switching valve 36 and related pipes in the conventional machine.

  The one hydraulic circuit 32 is connected to a pipe line 34 connected to the mold opening / closing cylinder 11, and between the pipe line 34 and the large-capacity pump 18 serving as a hydraulic pressure source, the mold opening / closing cylinder 11 and A proportional electromagnetic flow control valve 17 is provided for controlling the flow rate of hydraulic oil sent to the injection cylinder 13 and the flow rate of hydraulic oil sent to the ejector cylinder 12 via the four-way electromagnetic switching valve 15. In the present embodiment, the flow rate that can pass through the four-way electromagnetic switching valve 15 is smaller than the maximum discharge amount of the large-capacity pump 18. In the other hydraulic circuit 40, the proportional electromagnetic direction flow control valve 33 and the small capacity pump 19 are connected by a pipe 35, and an electromagnetic direction switching valve 36 is disposed in the pipe 35. In this embodiment, the large-capacity pump 18 and the small-capacity pump 19 are fixed discharge pumps. However, variable discharge pumps may be used for the large-capacity pump 18 and the small-capacity pump 19. In that case, the proportional electromagnetic flow control valve 17 and the proportional electromagnetic flow control valve 33 can be deleted.

  A pipe 37 is connected to another port that can be switched to the port to which the pipe 35 is connected in the electromagnetic direction switching valve 36. A check valve 31 for preventing the backflow of the hydraulic oil of the large capacity pump 18 is disposed in the pipe line 37, and is connected to the pipe line 34. A proportional electromagnetic relief valve 20 is branched from the pipe line 34 connected to the large-capacity pump 18, and the proportional electromagnetic relief valve 20 connects the mold opening / closing cylinder 11 and the injection cylinder 13 to the four-way electromagnetic switching valve. The pressure of the ejector cylinder 12 controlled via 15 is controlled. Further, a proportional electromagnetic relief valve 21 is provided branched from the pipe line 35 connected to the small capacity pump 19, and the pressure of the ejector cylinder 12 controlled via the proportional electromagnetic relief valve 21 is controlled. Yes.

  The control device 22 of the injection molding machine includes a CPU 23, a setting / display unit 24, a storage unit 25, a first process control unit 26, a second process control unit 38, a sensor for performing process control with the first process control unit 26, and Input / output unit 28 which is a port for inputting / outputting a signal to / from the valve, and input / output which is a port for inputting / outputting a signal between the second process control unit 38 and the valve for performing process control Unit 39, sequence control unit 27, input / output unit 29 that is a port for inputting / outputting signals between sequence control unit 27 and each electromagnetic switching valve, and bus 30 for transmitting / receiving each signal in control device 22 It has become. In the present embodiment, the setting / display unit 24 can display on the same screen a setting screen for performing settings for ejector operation after mold opening, which will be described later, and ejector operation during mold opening. Conventionally, the setting screen for setting the ejector operation after mold opening and the ejector operation during mold opening has been a separate screen. The CPU 23 controls the entire injection molding machine, and the storage unit 25 stores a sequence program for operating the ejector during mold opening of the injection molding machine and various system parameter values.

  The system parameter value corresponds to at least one of the case where the ejector speed and pressure are input as a percentage and the case where the speed (mm / sec) and pressure (Mpa) are directly input as absolute values. Stored. In this embodiment, when the ejector is operated after the mold is opened and when the ejector is activated during the mold opening, the input value by the percentage relating to the speed or pressure when the ejector is operated is the same input value. The system parameter value for the purpose of operating at the same speed or the same pressure is stored.

  System parameter values for controlling the ejector speed will be described with reference to FIG. In the present embodiment, when a set input value of 100% is input during the operation of the ejector after the mold is opened, the maximum flow rate sent from the large capacity pump 18 to the ejector cylinder 12 is compared with that during the operation of the ejector during the mold opening. The maximum flow rate from the small capacity pump 19 to the ejector cylinder 12 (maximum discharge amount of the small capacity pump 19) is 40%. Therefore, when the 100% set input value is input during the operation of the ejector after the mold is opened, the shimtem parameter value is set to the maximum flow rate sent to the ejector cylinder 12 from the small capacity pump 19 during the operation of the ejector during the mold opening. It is obtained by dividing by the maximum flow rate to the ejector cylinder 12 (maximum discharge amount of the small capacity pump 19). In this embodiment, the system parameter value is 2.5. The system parameter value is a value obtained by dividing the maximum flow rate from the small-capacity pump 19 to the ejector cylinder 12 when the ejector is operated during mold opening by the maximum flow rate sent to the ejector cylinder 12 when the ejector is operated after mold opening. In this case, the system parameter value is 0.4. Then, the set value when the ejector is operating during mold opening is divided by 0.4 to calculate the flow rate sent to the ejector cylinder 12.

In the present embodiment, the division value of 2.5 is used as the system parameter value, and is provided when the ejector operation during mold opening is set in the case of ejector operation after mold opening and during ejector operation during mold opening. Up to the set upper limit value, the flow rate to the ejector cylinder 12 is controlled to be equal when the set input values are equal. Specifically, the system parameter value 2.5 is multiplied by the set speed value of the ejector operation (set in% or decimal point and having an upper limit value) when the ejector is operating during mold opening. And the signal value which controls the proportional electromagnetic directional flow control valve 33 at the time of ejector operation during mold opening is obtained. Therefore , as shown in FIG. 2, the upper limit value of the ejector operating speed is 40% on the setting screen for setting and inputting the ejector operation during mold opening, and when the set upper limit value of 40% or more is input as the set input value, The maximum flow rate of the small capacity pump 19 is sent from the small capacity pump 19 to the ejector cylinder 12. As another example, when a setting input value of 30% is input on the setting screen for ejector operation during mold opening, the 30% is multiplied by the system parameter value 2.5 to obtain the maximum value from the small capacity pump 19. The proportional electromagnetic directional flow control valve 33 is controlled so that 75% of the flow rate is sent to the ejector cylinder 12.

  When the set input value is 40% or less during both the ejector operation after mold opening and the ejector operation during mold opening, the same flow rate is sent to the ejector cylinder 12 and the ejector is operated at the same speed. It is like that. Further, when the set input value is input exceeding 40% which is the set upper limit value when the ejector is operated during mold opening, it is natural that there is no ability to send the flow rate exceeding the maximum flow rate from the small capacity pump 19. The ejector speed difference is different from that when a set input value larger than 40% is input in the ejector operation after opening. In the present invention, even if the system parameter value is included, the ejector operation after mold opening is changed to the ejector operation during mold opening, and the hydraulic system for operating the ejector cylinder 12 is changed from the hydraulic circuit 32 to the hydraulic circuit 40. Setting errors and accompanying malfunctions can be eliminated. The system parameter values are the maximum flow rate from the small capacity pump 19 to the ejector cylinder 12 when the ejector is operated during mold opening, and the maximum flow rate from the large capacity pump 18 to the ejector cylinder 12 when the ejector is operated after mold opening. You may use what was calculated by the value divided by the maximum flow rate.

  The first process control unit 26 and the input / output unit 28 are made up of process cards that incorporate a CPU and input / output ports therein, and have input / output ports. A signal is sent from the input / output unit 28 of the first process control unit 26 to the solenoids of the proportional electromagnetic flow control valve 17 and the proportional electromagnetic relief valve 20. Further, signals from the position detection sensor 11 a of the mold opening / closing cylinder 11 and the position detection sensor 13 a of the injection cylinder 13 are input to the input / output unit 28. A signal is sent from the input / output unit 39 of the second process control unit 38 to the solenoid of the proportional electromagnetic directional flow control valve 33 and the proportional electromagnetic relief valve 21. Further, a signal from the position detection sensor 12 a of the ejector cylinder 12 is input to the input / output unit 39. The signal from the position detecting sensor 12a may be switched to the input / output units 28 and 39 to be sent.

  Therefore, in the ejector operating device of the present embodiment, the process control of the mold opening / closing cylinder 11 can be executed in addition to the process control on the injection device side by the first process control unit 26. Further, the process control of the ejector cylinder 12 can be executed by the second process control unit 38. Therefore, the process control of the ejector operation by the second process control unit 38 can be executed in parallel with the process control of the mold opening operation by the first process control unit 26.

  Next, the ejector operation control method of the present invention will be described. For example, when switching from the ejector operation after mold opening to the ejector operation during mold opening, the ejector operation during mold opening is selected and input from the setting screen of the setting / display unit 24. In the present embodiment, when the ejector is operated after the mold is opened and when the ejector is operated while the mold is being opened, the setting input relating to the speed or pressure when the ejector is operated is input as a numerical value in percentage on the same setting screen. Therefore, it is possible to save the operator from switching the setting screen. The input value at this time has a set upper limit value corresponding to the ejector speed of the ejector operation after mold opening as described above. Further, the input value at this time is calculated using the above-mentioned system parameter value, and a signal value for controlling the proportional electromagnetic directional flow control valve 33 is calculated.

  When the input for performing the ejector operation during mold opening is completed and the injection molding machine is started to operate, the ejector switching command sequence control is started. In the ejector switching command sequence control, it is determined for each molding cycle whether the ejector output command is ON or OFF in order to confirm whether or not the ejector is operating during mold opening. When the ejector switching command is ON (when it is determined that the ejector is operating during mold opening), the position detection sensor 12a of the ejector cylinder 12 is input to the second process control unit 38 via the input / output unit 39. The ejector cylinder 12 is controlled by the received signal. Therefore, in this embodiment, it is not necessary to change the wiring connected to the ports of the input / output units 28 and 29 when the ejector operation is performed during mold opening. In the above description, the first process control unit 26 may perform ejector control, and the second process control unit 38 may perform mold opening control.

  When the cooling of the molded product is completed and the ejector switching command sequence control determines that the ejector switching command is ON, the ejector by the ejector cylinder 12 moves in parallel with the movement of the movable platen (not shown) by the mold opening / closing cylinder 11. Operation is performed. At this time, the timing of starting the ejector operation can be performed by separately controlling the control of the mold opening / closing cylinder 11 and the control of the ejector cylinder 12, so that it can be started from an arbitrary position by detecting the position of the movable platen. it can. In the present embodiment, the ejector operation is started simultaneously with the detection of the position where the moving speed of the movable platen shifts to the mold opening low speed. Further, the start timing of the ejector operation may be started by another means such as a timer.

  When the ejector operation is started at the above timing, the electromagnetic direction switching valve 36 is switched from the A port to the B port, and the hydraulic oil of the small capacity pump 19 is directed to the ejector cylinder 12 via the other hydraulic circuit 40. Are supplied in full. At this time, the ejector operating speed and the ejector operating pressure are controlled by the proportional electromagnetic directional flow control valve 33 and the proportional electromagnetic relief valve 21 controlled based on the set input value. Note that the ejector operation at this time is generally controlled by a predetermined open control. When the molded product projected by the ejector is picked up and taken out by the robot, it is desirable to control the robot from the middle of mold opening in accordance with the operation of the ejector of the injection molding machine.

  The present invention is not enumerated one by one, but is not limited to the above-described embodiment, and it goes without saying that the present invention can be applied to those modified by a person skilled in the art based on the gist of the present invention. The hydraulic circuit of the present invention is not limited to the one having the hydraulic circuits 32 and 40 described above. For example, it is possible to appropriately change a plurality of hydraulic systems each provided with a flow control valve such as a servo valve or a flow control valve, or a pump provided with an accumulator. The number of hydraulic systems is not limited to two, and the number of devices such as ejectors, molds, injection devices, and cylinders is not limited to one. Further, regarding the ejector operation during mold opening, the number of ejector operations and the forward / backward positions can be arbitrarily set, and the end of the ejector operation may be during mold opening or after mold opening.

It is a block diagram including the ejector operation device used for the ejector operation control method of the present invention. It is a figure showing the relationship between the setting input value in the ejector actuator of this invention, and the flow volume to the cylinder for ejectors. FIG. 3 is a block diagram including an ejector actuation device used in a conventional ejector actuation control method.

Explanation of symbols

11 Cylinder for opening and closing 12 Ejector cylinder 11a, 12a, 13a Position detection sensor 13 Injection cylinder 14, 15, 16 Four-way solenoid switching valve 17 Proportional electromagnetic flow control valve 18 Large capacity pump 19 Small capacity pump 20, 21 Proportional electromagnetic Relief valve 22 Control device 23 CPU
24 Setting / Display Unit 25 Storage Unit 26 First Process Control Unit 27 Sequence Control Unit 28, 29, 39 Input / Output Unit 30 Bus 31 Check Valve 32 One Hydraulic Circuit 33 Proportional Electromagnetic Directional Flow Control Valve 34, 35, 37 Pipe Path 36 Electromagnetic direction switching valve 38 Second process control unit 40 The other hydraulic circuit

Claims (1)

In an ejector operation control method of an injection molding machine capable of switching between an ejector operation after mold opening and an ejector operation during mold opening,
One hydraulic circuit that operates the ejector cylinder when operating the ejector after opening the mold connected to the large capacity pump and the small capacity pump, and the flow control valve is connected to the small capacity pump to operate the ejector while the mold is open And the other hydraulic circuit for operating the ejector cylinder at the time ,
Switch to either one of the hydraulic circuit that operates the ejector after opening the mold and the other hydraulic circuit that operates the ejector during mold opening,
An ejector operation control method for an injection molding machine, wherein the ejector cylinder is operated.

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