JP2006123357A - Driving control method and driving control device of continuous plasticization type injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving control method and a driving control device of a servomotor used, in order to introduce a plasticized resin from the accumulator device into the injection cylinder chamber of the injection device, as its driving source. <P>SOLUTION: The accumulator device 14, injection device 12 and extrusion device 16 of an on-line blend type injection molding machine are connected through the passages 18, 20. On the extrusion device the feeder device 66 is mounted. In the metering process the plunger tip 56 is driven by the servomotor 44 and synchronously with or in following the driving the plunger tip 30 of the injection device side is driven by the servomotor 38. In the accumulation process the first opening and closing valve 22 is closed and the plasticized resin extruded from the extrusion device is introduced only to the cylinder chamber 42. During the continuous operation, to stabilize the extrusion amount of the plasticized resin from the extrusion device, the revolution of the screw 72 of the feeder device is controlled so as to offset a fluctuated portion in response to the weight detection signal from the load cell 64. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a continuous plasticizing injection molding machine in which a continuous plasticizing device and an injection device are connected via an accumulator device that temporarily accumulates a plasticized molten resin (hereinafter referred to as plasticizing resin). More particularly, the present invention relates to a servo motor drive control method and drive control apparatus used as a drive source for introducing plasticizing resin from the accumulator device into an injection cylinder chamber of the injection device.

Conventionally, in order to improve the efficiency of the injection molding machine, the plasticizing device and the injection device are separated, and an accumulator is provided between them, and the resin plasticized by the plasticizing device is stored in the accumulator, and intermittently from this accumulator. In particular, a device has been proposed in which the operation rate of the plasticizing device is increased by supplying plasticizing resin to the injection device. In particular, in order to enable the plasticizing device to operate completely continuously, it is injected from the accumulator. There has been proposed a continuous plasticizing type injection molding apparatus capable of supplying plasticizing resin from a plasticizing apparatus to an injection apparatus even when the plasticizing resin is supplied to the apparatus.
Patent No. 3303213 "Continuous plasticizing injection molding method and apparatus"

However, in the conventional continuous plasticizing injection molding method and apparatus according to the above-mentioned patent, as shown in FIG. 3 of the patent, the accumulator device side cylinder 21 and the injection device side injection drive cylinder 35 using hydraulic pressure are used. The resin pressure detector 70 and the resin pressure switch 62 are disposed, and the electromagnetic proportional flow rate adjustment valve 56, the electromagnetic proportional pressure adjustment valve 73, and the first switching valve 41 and the second arranged around the electromagnetic proportional flow rate adjustment valve 73 are provided via the controller 71. The switching valve 51, the electromagnetic relief valve 52 and the like are necessary for control, and there are difficulties in terms of the cost of these functional element parts and maintenance work.
Further, an opening / closing valve 37 is provided between the injection cylinder 31 and the nozzle 38, and the installation cost of this valve is also quite expensive.

Further, in the actual weighing process, in claim 1 of the patent,
“······························································································ The continuous plasticizing injection molding method is characterized in that the retreating speed of the injection plunger is controlled to a predetermined value in accordance with the advance / stop operation of the plunger of the accumulator device so as to keep the
However, according to the actual test of the present inventor, when the control signal is given from the controller to the electromagnetic proportional flow rate adjustment valve 56 and the electromagnetic proportional pressure adjustment valve 73 in the metering step, the injection plunger 32 is intermittent. Driving, that is, a stick-slip phenomenon frequently occurs, and there is a difficulty in that smooth backward movement cannot be performed. In this case, the signal processing in the controller is performed instantaneously. However, each of the detectors, the adjusting valves, etc. is slower in response than the electric detector, and detects a phenomenon such as a pressure change at an accurate timing. There is a difficulty that is not transmitted to.

Furthermore, the amount of the synthetic resin raw material introduced from the first feeder 15 into the plasticizing cylinder 11 via the first supply port 14 varies depending on the operation of the injection molding machine, for example, the vibration accompanying the operation of the mold clamping mechanism. As a result, there is a drawback that the amount of plasticized resin extruded from the outflow passage 19 to the accumulator device changes.

As a result of diligent examination of the above-mentioned problems, the present inventor introduced the plasticizing resin into the injection cylinder chamber by driving the hydraulic cylinder, and synchronized or followed the hydraulic cylinder on the accumulator device side and the injection device side. The reason for the difficulty in controlling smooth driving is that the controlled objects are both compressible fluids, that is, plasticized resin and pressure oil, and that the responsiveness of resin pressure switches etc. is slow, It has been found that the problem can be basically solved by adopting an electric servo instead of driving by pressure oil.
Accordingly, an object of the present invention is to provide a drive control method and a drive control device for a servo motor used as a drive source for introducing plasticizing resin from an accumulator device into an injection cylinder chamber of an injection device.

To achieve the above object, a drive control method for a continuous plasticizing injection molding machine according to the present invention is as follows.
A heating barrel, a screw that is transferred by a screw rotation motor to melt and knead the plastic material put into the heating barrel and plasticize it, and a required amount of the synthetic resin material into the heating barrel A continuous feeder device for continuously plasticizing a synthetic resin material.
A cylinder chamber connected to a first outflow path that guides the plasticized resin extruded from the continuous plasticizer, a first plunger provided to be able to advance and retreat in the cylinder chamber, and to drive the first plunger forward and backward An accumulator device having a first servo motor and storing and deriving plasticized resin;
An injection cylinder chamber connected via a first on-off valve to a second outflow path for guiding the plasticized resin extruded from the accumulator device, and an injection nozzle portion formed in communication with the injection direction of the injection cylinder chamber A second plunger provided in the injection cylinder chamber so as to be able to advance and retreat, a second servo motor for driving the second plunger forward and backward by a second servo motor, and driving the second plunger in the injection direction. An injection device for injecting plasticized resin into the mold cavity from the injection nozzle;
A controller for controlling each of these servo motors and a function for controlling each operation step in the injection molding machine, and a controller for controlling the continuous plasticizing device, the accumulator, and the injection device. The first outflow path is a drive control method for a continuous plasticizing type injection molding machine configured to be able to communicate with the second outflow path even when the first plunger of the accumulator device is in an extrusion limit position,
The front machine controller controls the time required for the upward movement of the first plunger of the accumulator device to correspond to the time zone from the mold opening to the end of the pressure holding, and the lower side of the first plunger is used for the next injection. The time required for the metering process for introducing a predetermined amount of the plasticized resin into the injection cylinder chamber by the movement to is the time period of the cooling process following the end of the pressure holding, preferably within the same time period. Corresponding control is a structural feature.
In order to achieve the above object, the continuous plasticizing injection molding machine drive control method according to the present invention is for plasticizing by melting and kneading the heating barrel and the synthetic resin material charged in the heating barrel. A continuous plasticizing device for the synthetic resin material, comprising: a screw that is moved by a screw rotating motor; and a feeder device that continuously supplies a required amount of the synthetic resin material into the heating barrel by a feeder motor;
A cylinder chamber connected to the first outflow passage for guiding the plasticized resin extruded from the continuous plasticizer, a first plunger provided to be able to advance and retreat in the cylinder chamber, and fixedly coupled to the first plunger. A first ball screw shaft, a first ball nut screwed into the first ball screw shaft and regulated in its axial position, and a first ball nut coupled to rotationally drive the first ball nut. An accumulator device that has a servo motor, and district seats / leads out plasticized di-oils;
An injection cylinder chamber connected via a first on-off valve to a second outflow passage for guiding the plasticized resin extruded from the accumulator device, and an injection nozzle portion formed in communication with the injection direction of the injection cylinder chamber A second plunger movably provided in the injection cylinder chamber, a second ball screw shaft fixedly coupled to the second plunger, and screwed into the second ball screw shaft to regulate its axial position. A second ball nut disposed, and a second servo motor coupled to rotationally drive the second ball nut;
An injection device for injecting plasticized resin into the mold cavity from the injection nozzle by driving the second plunger in the injection direction;
A controller having a function of controlling each of the motors, and the first outflow path can communicate with the second outflow path even when the first plunger of the accumulator device is in the push limit position. A drive control method for a continuous plasticizing type injection molding machine configured as described above, wherein the first plunger is advanced and retracted according to a command from the controller during a metering step of introducing a predetermined amount of plasticized resin into the injection cylinder chamber. In order to drive the first servo motor at a predetermined rotational speed corresponding to the position, the driving amount given to the first servo motor is calculated every predetermined time and the first servo motor corresponding to the driving amount is calculated. A first volume of plasticized resin introduced into the injection cylinder chamber by movement of the plunger and a plasticized tree introduced from the plasticizer into the injection cylinder chamber at the predetermined time; The first stage of calculating the second volume amount of the second plunger, and further calculating the backward movement amount of the second plunger corresponding to the sum of the first and second volume amounts, and the calculated drive of the first servo motor And a second stage in which the first and second servo motors are driven and controlled by servo-outputting the amount and the backward movement amount of the second plunger at or after the next predetermined time. is there.
At that time, preferably, the calculation of the drive amount of the first servo motor in the first stage can be corrected so that the load current value of the first servo motor in the weighing process falls within a predetermined allowable range. .
Furthermore, in that case, the servo output for the calculated drive amount of the first servo motor and the backward movement amount of the second plunger is the servo output for the backward movement amount of the second plunger, and the servo output for the drive amount of the first servo motor. Can be delayed more.
Further, in that case, with the completion of the metering step, in the accumulation step of closing the first on-off valve and introducing the plasticized resin only into the cylinder chamber of the accumulator device,
A third step of calculating a backward movement amount of the second plunger corresponding to a second volume amount of the plasticized resin introduced from the plasticizing device to the cylinder chamber of the accumulator device at the predetermined time every predetermined time. And a fourth stage in which the backward movement amount based on the calculation is commanded as a servo output to the second servomotor at or after the next predetermined time.
Furthermore, the calculation of the driving amount of the second servomotor in the third stage can be corrected so that the load current value of the second servomotor during the accumulation step falls within a predetermined allowable range.

  In order to achieve the above object, a drive control device for a continuous plasticizing injection molding machine according to the present invention melts and kneads a heating barrel and a synthetic resin material put into the heating barrel for plasticization. A continuous plasticizing process for plasticizing the synthetic resin material, comprising: a screw that is moved by a feeder motor; and a feeder device that continuously supplies a required amount of the synthetic resin material into the heating barrel by the feeder motor. A device, a cylinder chamber connected to a first outflow passage for guiding the plasticized resin extruded from the continuous plasticizing device, a first plunger provided to be able to advance and retreat in the cylinder chamber, and the first plunger A fixedly coupled first ball screw shaft, a first ball nut that is screwed to the first ball screw shaft and regulated in its axial position, and rotationally drives the first ball nut. A first servo motor coupled to the accumulator device for accumulating and deriving plasticized oil and fat, and a second outlet passage for guiding the plasticized resin extruded from the accumulator device via the first on-off valve. Connected to the injection cylinder chamber, an injection nozzle portion formed in communication with the injection direction of the injection cylinder chamber, a second plunger provided in the injection cylinder chamber so as to be movable forward and backward, and fixed to the second plunger A coupled second ball screw shaft, a second ball nut screwed to the second ball screw shaft and regulated in its axial position, and coupled to rotationally drive the second ball nut. An injection device for injecting plasticized resin into the mold cavity from the injection nozzle by driving the second plunger in the injection direction, and a function for controlling each motor; And a controller having a function of controlling each operation process of the molding machine, and the first outflow path is also provided when the first plunger of the accumulator device is at the extrusion limit position. It is configured to be able to communicate with the outflow channel.

In that case, a second on-off valve may be provided in the injection nozzle portion.
Furthermore, the controller includes a sequencer that controls the operation sequence of the injection molding machine, and calculates command drive amounts to the first and second servo motors in response to a measurement process start signal from the sequencer. A position for calculating a command drive amount to the first servomotor in response to a first program that gives a calculation command to the central processing unit that performs the position control function and a storage process start signal from the sequencer It can comprise so that it may have the 2nd program which gives a calculation command with respect to the central processing unit which performs a control function.
Furthermore, in that case, a detecting means for detecting the weight of the feeder device constituting the continuous plasticizing apparatus is provided, and the controller is further responsive to a detection signal from the detecting means and an operation sequence signal from the sequencer. A third program for giving a calculation command to the central processing unit so as to control the mode of the feeder motor can be provided.

  According to the present invention, in the weighing step, the advance and retreat drive of each of the first and second plungers of the accumulator device and the injection device is driven or controlled by position control in synchronization with or following the first and second servo motors, respectively. The pressure of the plasticizing resin and the position of each plunger are also detected continuously via the load current of each servo motor and the signal from the encoder coupled to the servo motor shaft. Since there is no need to provide a resin pressure switch or the like in the resin flow path, it is possible to significantly reduce the cost of the injection molding machine and maintenance work. In addition, since the position (rotation position) and speed control of the servo motor is controlled by position control, there is no phenomenon such as stick-slip, and it is possible to increase the precision and speed, and the time required for the weighing process compared to the hydraulic method. There is an effect that can be greatly shortened.

  Hereinafter, an example based on an embodiment of the invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of an online blend type injection molding machine 10 to which the present invention is applied. In FIG. 1, reference numeral 12 is an injection device, 14 is an accumulator device, 16 is an extrusion device as a continuous plasticizing device, and these 12 and 14, and 14 and 16 are flow paths 18, 20 respectively. It is communicated by. Reference numeral 22 is a first on-off valve for opening and closing the flow path 18, and 24 is a second on-off valve disposed on the flow path to the nozzle 26 formed at the tip in the injection direction of the injection device 12. In the injection cylinder chamber 28 of the injection device 12, a plunger formed by a ball screw shaft 32 having a plunger tip 30 attached to the tip is disposed so as to be able to advance and retract. On the right end side of the cylinder chamber 28, there is provided a nut portion 34 that is screwed with the ball screw shaft 32 and is restricted from moving in the injection direction X. A timing belt 36 is attached to the outer periphery of the nut portion 34, and the timing belt 36 is attached to the outer periphery of a pulley (not shown) attached to the rotation shaft of the servo motor 38.

  Accordingly, the ball screw shaft 32, that is, the plunger tip 30 is advanced and retracted in the injection cylinder chamber 28 by the rotation of the servo motor 38. An encoder 40 is attached to the servo motor 36, and the rotation amount of the servo motor 38, that is, the advance / retreat position of the plunger which is the ball screw shaft 32 is detected by a signal from the encoder 40. Reference numeral 43 is a current sensor that detects a current corresponding to the load of the servo motor 38.

The accumulator device 14 has the same configuration as the injection device 12, and the plunger tip 56 is advanced and retracted in the cylinder chamber 42 arranged in the Y direction perpendicular to the injection direction X.
Reference numerals 44, 46, 48, 50, 52, 54 correspond to the servo motor 38, the nut portion 34, the timing belt 36, the ball screw shaft 32, the load current detection current sensor 43, and the encoder 40 in the injection device 12, respectively. ing.

As shown in FIG. 1, the lower portion of the plunger tip 56 is formed with a small diameter, and the flow paths 20 and 18 are communicated even at the lower limit position, that is, the extrusion limit position. The power supply signals to the servo motors 44 and 36 and the detection signals from the encoders 54 and 40 are supplied and received through wiring with the controller 100. Reference numerals i 1 and i 2 are detection signals of the current sensors 52 and 43 and are given to the controller 100.
A twin screw extruder 16 coupled to the accumulator device 14 via the flow path 20 is disposed. Reference numeral 58 denotes a pair of screw shafts that rotate in the same direction or different directions, and are driven to rotate by a plasticizing motor 62 via a gear box 60.
A feeder device 66 is mounted on the mounting base behind the extruder 16 via a load cell 64. In this feeder device 66, a predetermined amount of a synthetic resin material 70 is put in a hopper 68 in advance, and the synthetic resin material 70 is rotated by an extruder 16 via a hopper 76 by rotating a feeder screw 72 by a feeder motor 74. It is supposed to be sent in.

The feeder motor 74 is preferably composed of a servo motor, and its rotational speed is detected by an encoder 78 and supplied to the controller 100. The hopper 80 is arranged for online mixing of various additives to the synthetic resin material 70 and / or reinforcing materials such as glass fibers. Reference numeral 82 is a vent port for deaeration. The plasticized resin plasticized in the extrusion device 16 is continuously supplied to the cylinder 42 of the accumulator device 14 through the flow path 20.
In that case, the rotational speed Ns of the plasticizing motor 62 is controlled by the controller 100 so that the extrusion amount Q of the plasticizing resin becomes a predetermined value, preferably constant.
The load cell 64 constantly measures the weight of the feeder device 66, whereby the state in which the synthetic resin material 70 in the hopper 68 is gradually reduced can be confirmed. However, if there is vibration due to, for example, the opening / closing operation of the mold of the injection molding machine, the amount of the synthetic resin material 70 fed from the hopper 68 varies compared to the normal state, and the variation state is detected by the load cell 64. The servo motor 74 is controlled by the controller 100 so as to cancel out the fluctuation.

The left side of FIG. 1 shows that the cavity 88 is formed with the pair of movable molds 84 and fixed molds 86 closed.
In FIG. 1, a feeder device 66 and an extrusion device 16 constitute a continuous plasticizing device in the present invention, and a ball screw shaft 50 and a plunger tip 56 constitute a first plunger in the present invention, and further a ball screw shaft. 32 and the plunger tip 30 constitute a second plunger in the present invention. Furthermore, the servo motors 44 and 38 constitute a first servo motor and a second servo motor in the present invention, respectively.

  FIG. 2 is an enlarged sectional view in the injection axis direction showing a modification of the plunger tip portion of the injection device 12. In FIG. 2, a backflow prevention valve 92 is attached to the left end portion of the rod 90 extending into the space 97 on the left side of the injection plunger tip 30. The plasticized resin 98 extruded from the flow path 18 passes through the space 97, passes through the backflow prevention valve 92, and accumulates in the staying portion space 94 on the nozzle 26 side from the outer periphery of the cone-shaped tip. In this case, the injection plunger tip 30 is arranged so as not to block the flow path 18 as shown in the figure even at the injection advance limit. Compared with the case of FIG. 1, in FIG. 1, the plasticizing resin 98 is directly introduced into the left space 96 of the plunger tip 30. The tip of can be moved.

  The second on-off valve 24 in FIG. 1 may not be on the flow path of the nozzle 26 in FIG. This is because, as will be described later, the so-called “sloping” from the nozzle 26 can be prevented by performing the cooling time and the backward movement of the injection plunger tip 30 (including suck back operation if necessary) in a timely manner. is there.

3 shows a diagram of each operation as the on-line blend type injection molding machine shown in FIG. 1 over two cycles, (a) shows the time required for each operation, and (b) shows an injection device corresponding to each operation. (C) shows the change in the plunger position of the accumulator device 14 corresponding to each operation, and (d) shows the flow path between the accumulator device 14 and the injection cylinder chamber 28 corresponding to each operation. 18 is a view showing an operating state of a first on-off valve 22 provided in FIG.
As shown in (a) above, the molded product is molded in one cycle.
Inter (interval) is a time period during which the molded product is discharged from the mold and the inner surface of the mold cavity is cleaned.
As shown in the diagrams (b), (c), and (d), during the cooling operation, the first on-off valve 22 is in an open state, and the plunger on the accumulator device 14 side is lowered while the injection device side is on the side. The injection plunger is retracted to reach the metering limit position, i.e., the metering process is performed. As shown in the diagram (c), the plunger on the accumulator device 14 side rises from the lower limit (extrusion limit position) to the upper limit from the mold opening after cooling to the completion of the pressure holding operation of the next cycle. During this time, the plasticizing resin 98 extruded from the extrusion device 16 is accumulated in the cylinder chamber 42. As shown in the diagram (b), after the mold closing operation is completed during the accumulation process, the injection plunger moves forward to execute injection / holding pressure. To do.

  In each operation, especially the cooling time varies depending on the size of the molded product, that is, the required resin volume and shape, so the extrusion amount Q per unit time of the plasticized resin 98 from the extruder 16 is set in advance. The screw rotation speed Ns and the resin material input amount Z in the feeder device 66 can be adjusted each time.

FIG. 4 is a detailed block diagram illustrating functions of the controller 100 of FIG. In FIG. 4, a sequencer 200 that performs a sequence function is provided on the left side of the controller 100 that is partitioned by a chain line. The sequencer 200 is online via an i / o unit that is an input / output device. A blend type injection molding machine 10 is connected.
The sequencer 200 includes a program memory 102 that stores a sequence program connected to the central processing unit CPU, i / o status data and data for mold opening / closing (movement amount, speed) by signal exchange with the i / o unit. Etc.), a data memory 104 storing heating / cooling data, extruder driving data, feeder device driving data, and the like.
On the other hand, on the right side partitioned by the chain line, details of a control block by a computer system including a function for controlling the position of each servo motor shown in FIG. 1 are shown.

This computer system basically comprises a central processing unit group 106 having a plurality of CPUs (CPU1, CPU2, CPU3), a data memory 108, a program memory 110, an interface unit 112 and a servo drive unit 116. , 110, 112 and 106 are provided with a bus 114.
A plunger driving servo motor 44 arranged on the accumulator device 14 side, an injection plunger driving servo motor 38 arranged on the injection device 12 side, and a feeder screw rotating servo motor 74 arranged on the feeder device side, respectively. The servo drive unit 116 is connected.

The program memory 110 stores a weighing process processing program 118, an accumulation process processing program 120, a feeder processing program 122, and an injection / pressure holding process processing program 124. Reference numeral 126 is a system program for controlling the entire system.
The weighing process processing program 118 gives a series of calculation processing instructions to the central processing unit CPU1 during the weighing process. The accumulation process processing program 120 gives a series of arithmetic processing instructions to the central processing unit CPU2 during the accumulation process. Similarly, the feeder processing program 122 gives a series of arithmetic processing instructions to the central processing unit CPU3 during the molding cycle.
Further, the injection / pressure holding process processing program 124 gives a series of arithmetic processing instructions to the central processing unit CPU1.
There is a one-to-one correspondence between each processing program and a central processing unit that executes the program. The central processing unit CPU1 is responsible for both the calculation process of the weighing process and the calculation process of the injection / holding process. However, as shown in the diagram (b) of FIG. Measurement, i.e. cooling, can be combined since arithmetic processing does not proceed simultaneously.

The interface unit 112 is supplied with signals from the encoders 54, 40, 78, and is further supplied with signals i1, i2 from the load current sensor and detection signals from the load cell 64.
In a predetermined memory area of the data memory 108, data for controlling the position of each servo motor, starting bit data taken from the sequencer 200 such as weighing, accumulation, injection / holding pressure, weighing process command data, accumulation process command In addition to data and injection / holding process command data, data indicating the current state of each servo motor (positions of the first plunger and second plunger, load current, servo output data) is stored. Other data will become clear from the description of the flowcharts of FIGS.

FIG. 5 is a flowchart for explaining the processing contents of the metering step for introducing the plasticized resin from the accumulator device 14 and the extrusion device 16 to the injection device 12. FIG. 6 is a flowchart for explaining the processing contents of the accumulation step of introducing and accumulating the plasticized resin from the extrusion device 16 to the accumulator device 14.
In FIG. 5, the process of the measurement process is started by starting the measurement process program 118 at the time when the pressure holding is completed.
In step ST1, an index i corresponding to the number of elapsed times of the predetermined time is initialized. (I = 1)
In step ST2, status data is read. In step ST3, it is determined whether or not the first plunger of the accumulator device 14 has reached the push limit position (downward limit).
Since the first plunger is in the upper limit position at the start of measurement, the process proceeds to step ST4, and it is further determined in step ST4 whether the second plunger of the injection device S has reached the measurement completion position. Next, in step ST5, the weighing process command data, the extrusion amount Q of the extrusion device 16, and the screw rotation speed Ns are read. The weighing process command data includes the movement amount and movement speed for each appropriately divided stroke during the downward movement of the first plunger.
Next, in step ST6, the movement amount ΔY (ΔTsi) of the first plunger driven by the servo motor 44 during the next predetermined time (ΔTsi) is calculated.
Next, in step ST7, a first volume amount ΔQ1 of the plasticized resin corresponding to the calculated movement amount ΔY (ΔTsi) of the first plunger is calculated. Further, in step ST8, the second volume amount ΔQ2 of the plasticized resin corresponding to the amount of extrusion from the extrusion device 16 to the injection cylinder chamber 28 is calculated during the predetermined time (ΔTsi). (ΔQ2 = Q × ΔTsi)

In step ST9, the sum of the first and second volume amounts is calculated. In step ST10, the backward movement amount ΔX (ΔTsi) of the second plunger corresponding to this sum is calculated. In step ST11, the calculated movement amounts ΔX (ΔTsi) and ΔY (ΔTsi) of the first and second plungers are saved in the servo output data area.
Then, in step ST12, it is determined whether or not it is the start time of the next predetermined time. If NO, the process waits until arrival of the time in step ST13. If YES, the saved movement amounts ΔX (ΔTsi) and ΔY (ΔTsi) are output to the servo drive unit 116 in step ST14. Further, in step ST15, the index is incremented.
When Steps ST1 to ST15 are executed at each predetermined time and the first plunger reaches the push limit position, it is determined in Step ST16 whether or not the second plunger has reached the measurement completion position. If not, wait for a predetermined time in step ST17.
If it has been reached, a bit for completion of measurement is set in step ST18. This bit signal is given to the measurement completion area in the status data memory on the sequencer 200 side. Further, based on the accumulated waiting time in step ST17, correction is made so that the extrusion amount Q from the extrusion device 16 becomes slightly larger.
On the other hand, if the second plunger reaches the weighing completion position in step ST4 before the first plunger reaches the extrusion limit position, the process proceeds to step ST18 to set the weighing completion bit and the extrusion amount Q Is in an excessive state, so that the extrusion amount Q is corrected to be a little smaller.

FIG. 6 is a flowchart for explaining the processing content of the accumulation step for introducing the plasticized resin from the extrusion device 16 to the accumulator device 14. The accumulation process is started by starting the accumulation process program 120 when the cooling is completed, as shown in the diagram (c) of FIG.
In FIG. 6, the index number i for a predetermined time is initialized in step ST1. (i = 1)
In step ST2, the status data is read, and the process proceeds to step ST3.
In step ST3, it is determined whether or not the first plunger of the accumulator device 14 has reached the accumulation end position that is the upper limit position. Next, in step ST4, the accumulation process command data for driving and controlling the servo motor 44, the screw rotation speed Ns of the extruder 16, and the current value data of the extrusion amount Q are read. Further, in step ST5, the volume amount ΔQ (ΔTsi) of the plasticized resin extruded from the extrusion device 16 in one predetermined time (ΔTsi) is specified. Further, in step ST6, an upward movement amount ΔY (ΔQ (ΔTsi)) of the first plunger corresponding to the volume amount ΔQ (ΔTsi) is calculated. In step ST7, the calculated movement amount ΔY is calculated as a servo output data area. To save. In step ST9, a start time of the next predetermined time (ΔTsi) is awaited. When the time comes, the servo output data ΔY is output to the servo drive unit 116 in step ST10. Next, at step ST11, the index i is incremented by one.

When the above steps ST1 to ST11 are executed every predetermined time and the first plunger reaches the accumulation end position, YES is determined in step ST3, and an accumulation completion bit is set in step ST12. This bit signal is given to the storage completion area in the status data memory of the sequencer 200.
In addition, when the time when it is determined as YES in Step ST3 is before or after the operation time of the predetermined sequence, the extrusion amount Q from the extruder 16 is corrected so as to reduce the difference. It is also possible. This correction can be performed, for example, by correcting the screw rotation speed Ns.

By the processing in the metering process shown in FIG. 5, the second plunger of the injection device 12 is more accurate with respect to the movement of the first plunger of the accumulator device 14 every predetermined time, which is much shorter than the hydraulic method of several milliseconds. Therefore, the plasticizing resin 98 is not introduced or flown out toward the nozzle 26. Also. By the processing in the accumulation process shown in FIG. 6, the upward movement of the first plunger of the accumulator device 14 is controlled following the extrusion amount ΔQ of the plasticized resin extruded every very short predetermined time. Therefore, it does not interfere with the extrusion pressure of the extrusion device 16.
Although not described in the flowcharts of FIGS. 5 and 6 described above, the load currents i1 and i2 of the servo motors 44 and 38 are monitored during the processing in each predetermined time so that they are within a predetermined range. By adjusting the screw rotation speed Ns and the rotation speed of the screw 72 of the feeder device 66, the extrusion amount Q of the plasticized resin extruded from the extruder 16 can be corrected.

  Although the preferred embodiments of the present invention have been described with reference to FIGS. 1 to 6, the spirit of the present invention is not limited thereto, and various modifications can be made by those skilled in the art. For example, FIG. 4 shows an example in which separate central processing units CPU1, CPU2, and CPU3 are used for weighing process processing, accumulation process processing, and control of the feeder device 66, but these are performed by one CPU. It is also possible.

It is a figure showing the whole online blend type injection molding machine composition to which the present invention is applied. It is an injection axis direction expanded sectional view showing the modification of the plunger tip portion of an injection device. The operation diagram of the online blend type injection molding machine shown in FIG. 1 is shown, (a) shows the time required for each operation, (b) shows the change of the injection plunger position of the injection device, and (c) shows the accumulator device. 14 shows a change in the plunger position of FIG. 14, and FIG. 8D is a diagram showing an operating state of the first on-off valve 22 provided in the flow path 18 between the accumulator device 14 and the injection cylinder 28. It is a detailed block diagram explaining the function of the controller 100 of FIG. It is a flowchart explaining the processing content of the measurement process in this invention. It is a flowchart explaining the processing content of the accumulation | storage process in this invention.

Explanation of symbols

10 Online blend injection molding machine
14 Accumulator device
16 Extrusion equipment
18, 20 flow path
22 First on-off valve
24 Second open / close valve
26 nozzles
28, 42 Cylinder chamber
32, 50 Ball screw shaft
34, 46 Nut
30, 56 Plunger tip
38, 44 Servo motor
40, 54, 78 encoder
58 screw
66 Feeder device
68, 76, 80 hopper
74 Feeder motor
92 Check valve
100 controller
102, 110 Program memory
104, 108 Data memory
106 Central Processing Unit Group
118 Weighing process processing program
120 Storage process processing program
122 Feeder processing program
200 sequencer

Claims (12)

A heating barrel, a screw that is rotated by a screw rotation motor to melt, knead, and plasticize the synthetic resin material charged in the heating barrel, and a required amount of the synthetic resin material into the heating barrel A feeder device that is continuously fed by a motor, and a continuous plasticizing device that plasticizes the synthetic resin material,
A cylinder chamber connected to a first outflow path that guides the plasticized resin extruded from the continuous plasticizer, a first plunger provided to be able to advance and retract in the cylinder chamber, and to drive the first plunger forward and backward A first servomotor, and an accumulator device for storing and deriving plasticized resin;
An injection cylinder chamber connected via a first on-off valve to a second outflow path for guiding the plasticized resin extruded from the accumulator device, and an injection nozzle portion formed in communication with the injection direction of the injection cylinder chamber And a second servo motor that can be moved forward and backward in the injection cylinder chamber, and a second servo motor that drives the second plunger to move forward and backward, and by driving the second plunger in the injection direction, the injection nozzle An injection device for injecting plasticized resin into the mold cavity from
A controller for controlling each motor and a function for controlling each operation step in the injection molding machine, and a controller for controlling the continuous plasticizing device, the feeder device, and the injection device;
Drive control of a continuous plastic injection molding machine, wherein the first outflow path is configured to be able to communicate with the second outflow path even when the first plunger of the accumulator device is in an extrusion limit position. A method,
The controller controls the time required for the upward movement of the first plunger of the accumulator device to correspond to the time zone from mold opening to the end of pressure holding,
Further, the time required for the metering process for introducing a predetermined amount of the plasticized resin into the injection cylinder chamber by the downward movement of the first plunger for the next injection is the time zone of the cooling process following the end of the pressure holding. And preferably, it controls so that it may become within the same time slot | zone, The drive control method of the continuous plasticization type injection molding machine characterized by the above-mentioned. A heating barrel, a screw that is rotated by a screw rotation motor to melt and knead the synthetic resin material charged in the heating barrel and plasticize it, and a required amount of the synthetic resin material into the heating barrel A continuous feeding device for continuously plasticizing the synthetic resin material,
A cylinder chamber connected to a first outflow path that guides the plasticized resin extruded from the continuous plasticizer, a first plunger provided to be able to advance and retreat in the cylinder chamber, and the first plunger are fixedly coupled. A first ball screw shaft, a first ball nut that is screwed to the first ball screw shaft and restricts its axial position, and a first ball nut that is coupled to rotationally drive the first ball nut. An accumulator device having a servo motor;
An injection cylinder chamber connected via a first on-off valve to a second outflow passage for guiding the plasticized resin extruded from the accumulator device, and an injection nozzle portion formed in communication with the injection direction of the injection cylinder chamber A second plunger provided in the injection cylinder chamber so as to be able to advance and retreat, a second ball screw shaft fixedly coupled to the second plunger, and screwed with the second ball screw shaft to regulate an axial position thereof. A second servo motor coupled to rotationally drive the second ball nut; and driving the second plunger in the injection direction to plasticize the injection nozzle. An injection device for injecting the resin into the mold cavity;
A controller having a function of controlling each motor and a function of controlling each operation process in injection molding;
A continuous plasticizing injection molding machine configured such that the first outflow passage is configured to be able to communicate with the second outflow passage even when the first plunger of the accumulator device is in an extrusion limit position. A drive control method comprising:
During the metering step of introducing a predetermined amount of plasticized resin into the injection cylinder chamber, the first servo motor is driven at a predetermined rotational speed corresponding to the advance / retreat position of the first plunger according to a command from the controller. And the first volume of plasticized resin introduced into the injection cylinder chamber by the movement of the first plunger corresponding to the drive amount and the plasticizer introduced into the injection cylinder chamber. Calculating a second volume amount of the plasticized resin, and calculating a backward movement amount of the second plunger corresponding to the sum of the first and second volume amounts;
A second stage in which the calculated drive amount of the first servo motor and the backward movement amount of the second plunger are servo-outputted at or after the next predetermined time to drive and control the first and second servo motors;
A drive control method in a metering process of a continuous plasticizing type injection molding machine configured to include: 3. The calculation of the drive amount of the first servo motor in the first stage is modified so that the load current value of the first servo motor in the weighing process falls within a predetermined allowable range. Drive control method in the metering process of a continuous plasticizing injection molding machine. 4. The servo output for the calculated drive amount of the first servo motor and the backward movement amount of the second plunger is the servo output for the backward movement amount of the second plunger. A follow-up drive control method in a metering process of a continuous plasticizing injection molding machine, characterized in that it is delayed from the servo output for The accumulation step of performing the drive control according to claim 2 or 4 during the metering step and closing the first on-off valve and introducing the plasticizing resin only into the cylinder chamber of the accumulator device upon completion of the metering step. In
A third stage of calculating a movement amount of the first plunger corresponding to a volume amount of the plasticized resin introduced from the plasticizing device to the cylinder chamber of the accumulator device at the predetermined time every predetermined time;
And a fourth stage of commanding a movement amount based on the calculation as a servo output to the first servomotor at or after the next predetermined time. Control method. 6. The continuous plasticization according to claim 5, wherein the calculation of the movement amount in the third stage is corrected so that the load current value of the first servo motor during the accumulation step falls within a predetermined allowable range. Drive control method of a type injection molding machine. A heating barrel, a screw that is rotated by a screw rotating motor to melt and knead the synthetic resin material that has been put into the heating barrel, and a feeder, and a feeder of the required amount of the synthetic resin material into the heating barrel A feeder device that continuously feeds by a motor for use, and a continuous plasticizing device that plasticizes the synthetic resin material,
A cylinder chamber connected to a first outflow path that guides the plasticized resin extruded from the continuous plasticizing device, a first plunger provided to be able to advance and retreat in the cylinder chamber, and the first plunger are fixedly coupled. A first ball screw shaft, a first ball nut that is screwed to the first ball screw shaft and regulates its axial position, and a first ball nut that is coupled to rotate the first ball nut. An accumulator device having a servo motor and storing and deriving plasticized resin;
An injection cylinder chamber connected via a first on-off valve to a second outflow path for guiding the plasticized resin extruded from the accumulator device, and an injection nozzle portion formed in communication with the injection direction of the injection cylinder chamber A second plunger provided in the injection cylinder chamber so as to be capable of advancing and retracting, a second ball screw shaft fixedly coupled to the second plunger, and screwing into the second ball screw shaft to regulate its axial position. A second servo motor coupled to rotationally drive the second ball nut; and driving the second plunger in the injection direction to plasticize the injection nozzle. An injection device for injecting the resin into the mold cavity;
A function of controlling each motor, a function of controlling each process in the injection molding machine,
A controller having
Configured with
The first outflow passage is configured to be able to communicate with the second outflow passage even when the first plunger of the accumulator device is in an extrusion limit position. Control device. 8. The drive control apparatus for a continuous plasticizing injection molding machine according to claim 7, wherein the injection nozzle portion is provided with a second on-off valve. 9. The controller according to claim 7, wherein the controller includes a sequencer that controls an operation sequence of the injection molding machine, and in response to a measurement process start signal from the sequencer, drives the first and second servo motors. A first program that gives a calculation command to the central processing unit that performs a position control function for calculating the amount, and a command drive amount to the first servo motor in response to an accumulation process start signal from the sequencer And a second program for giving a calculation command to a central processing unit for performing the position control function. A drive control device for a continuous plasticizing injection molding machine. 10. The continuous plastic injection molding machine according to claim 9, wherein the first program delays the servo output to the second servo motor from the servo output to the first servo motor. Control device. 11. The detection device according to claim 9, further comprising detection means for detecting a weight of a feeder device constituting the continuous plasticizing device, wherein the controller is responsive to a detection signal from the detection device and an operation sequence signal from the sequencer. A drive control device for a continuous plastic injection molding machine, comprising a third program for giving a calculation command to the central processing unit so as to control the mode of the feeder motor. 12. The central processing unit according to claim 9, wherein the central processing unit includes a first central processing unit that executes the first program and a second central processing unit that executes the second program. A drive control device for a continuous plasticizing injection molding machine.

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