JPH0581426B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motor control device for an extrusion molding line, and in particular to a motor control device for an extrusion molding line used for plastic molding of long objects and laminates, including an extrusion molding machine. The present invention relates to an improvement of a motor control device suitable for controlling the rotational speed of a motor.

[Conventional technology]

An extrusion line that extrudes and molds long objects such as plastic pipes and laminates such as plastic sheets is configured by, for example, connecting an extruder to a take-off machine, and the extruder extrudes and molds the melted plastic raw material with a screw. At the same time, the extrusion molded product is taken off by a take-off machine.

In such an extrusion line, in order to maintain a constant molded shape, it is necessary to set the rotational speed of the motor that rotates the extruder's screw and the motor used to take off the molded product in the take-off machine in a predetermined relationship. .

Furthermore, when changing the molding speed in the extrusion molding line or changing the extrusion molding line configuration, it is also necessary to change the rotational speed of the extruder motor and the take-up machine motor under a predetermined speed command.

As a speed command for such a motor, a configuration is known in which, for example, the motor of an extruder and the motor of a take-up machine are set and controlled in the following relationship.

(1) A configuration in which the rotation speeds of the extruder motor and take-up machine motor are individually controlled manually.

(2) A configuration in which the extruder motor is the main motor, the take-up machine motor is the slave motor, and the rotation speed of the slave motor is ratio-controlled at a predetermined ratio according to the rotation control of the main motor.

(3) A configuration in which the extruder motor is a slave motor, the take-up machine motor is a main motor, and the rotation speed of the slave motor is ratio-controlled at a predetermined ratio according to the rotation control of the main motor.

(4) A configuration in which the motors of the extruder and the take-up machine are each slave motors, and the rotation speeds of these slave motors are controlled at a predetermined ratio by a speed setting device.

In configuration (1), each motor is independent, so the speed control does not affect each other, and in configuration (2) and (3), the rotation speed of the slave motor is automatically controlled by the main motor. Although ratio control is possible, the main motor cannot be controlled by controlling only the slave motor.

Furthermore, the configuration (4) has the feature that the motors of the extruder and the take-up machine are each controlled at a constant rotation ratio by a speed setting device as a slave motor.

The speed command control of the motors of these extruders and take-up machines depends on the configuration of the extrusion line, the type of molded product,
It is selected appropriately depending on the molding speed, etc.

Conventionally, a motor control device for an extrusion molding line has been configured to be able to predict the deformation of the extrusion molding line as much as possible and change the motor control circuit in advance so that it can be implemented with various speed control command formats. .

[Problem to be solved by the invention]

However, there are problems in that the structure of the extrusion molding line and the deformation of the molding speed cannot be predicted, and changing the speed command control circuit requires time and is complicated.

The present invention was made to solve these conventional drawbacks, and even if the extrusion molding line is changed, the master-slave relationship of multiple motors can be changed arbitrarily, making it easy to always configure an optimal speed command system. The purpose is to provide a motor control device that can

[Means to solve the problem]

In order to solve such problems, the present invention provides a plurality of motors 100, rotation speed setting means 101, rotation speed It is comprised of measuring means 102, master-slave relationship setting means 103, mode switching means 104, line speed setting means 105, control means 106, and speed command means 107.

The rotation speed setting means 101 sets the rotation speed of the plurality of motors 100, and the rotation speed measurement means 102
is for measuring the rotational speed of each motor 100, and the master-slave relationship setting means 103 is for setting the mutual master-slave relationship between each motor 100.

The mode switching means 104 is configured for at least each motor 1.
This is for switching between 00 single operation and ratio operation.
Line speed setting means 105 is for setting the operating speed of the extrusion molding line.

The control means 106 outputs the rotation speed signal from the rotation speed setting means 101 during independent operation, and outputs the measured rotation speed signal from the rotation speed measurement means 102 or the speed command signal to each motor 100 from the speed command signal 107 during ratio operation. Main and slave motors based on 10
The rotation speed ratio between 0 and 0 is calculated, and the rotation speed of the main motor is calculated based on the speed change instruction from the line speed setting means 105, and the rotation speed of the slave motor is calculated based on the rotation speed of the main motor and its rotation speed ratio. It calculates the number of rotations.

The speed command means 107 outputs speed command signals for the main and slave motors 100 to the corresponding main and slave motors 100 based on the rotational speed signal from the control means 106.

[Effect]

In the present invention equipped with such means, when the mode switching means 104 sets the independent operation mode, the control means 106 outputs the rotation speed signal from the rotation speed setting means 101 to the speed command means 107,
Speed command means 107 outputs a speed command signal to each motor 100.

Further, when the mode switching means 104 switches to the ratio operation, the control means 106 changes the measured rotation speed signal of each motor 100 from the rotation speed setting means 101 or the speed command signal from the speed command means 107 to each motor. Based on this, the rotation ratio between each motor 100 is calculated, and for the main and slave motors 100 set by the master-slave relationship setting means 103, the rotation speed of the main motor is calculated based on the speed setting from the line speed setting means 105. At the same time, the rotation speed of the slave motor is calculated based on the rotation speed of the main motor and the rotation speed ratio, and is output to the speed command means 107.

Then, the speed command means 107 outputs speed command signals to the main and slave motors 100.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram showing an example of an extrusion molding line implementing the motor control device according to the present invention.

In the figure, an extruder 1 includes a main screw 5 in a molding machine table 3, an extrusion motor 7 that rotationally drives this screw, a rotation speed detection sensor 9 such as a tachometer generator that detects the rotation speed of this extrusion motor 7, etc. ,
It has a conventionally known configuration having other configurations.

The molding machine table 3 is equipped with a raw material feeder device 15 having a hopper 11 for supplying plastic raw materials, a sub-screw 13, and the like. A sensor 19 is arranged to detect the rotation speed of the motor 17.

Note that reference numerals 21 and 23 are temperature sensors and pressure sensors arranged on the molding machine stand 3.

The extruder 1 uses a plastic raw material supplied from a raw material feeder device 15 to a main screw 5 section by a feeder motor 17 from a die (not shown) arranged near the tip of the main screw 5 by rotationally driving the main screw 5. This is extruded as a molded product 25.

The extruded molded product 25 is taken up by, for example, two sets of take-off machines 27 and 29, and the rollers 27a and 29a that take up the molded product 25 in each take-off machine 27 and 29 are each driven by a take-up motor 31. , 33, and the rotational speed of the take-up motors 31, 33 is detected by the sensors 9, 19.
It is designed to be detected by sensors 35 and 37 similar to the above.

Those extrusion motor 7, feeder motor 1
7. Pick-up motors 31, 33 and sensors 9, 1
9, 35, and 37 are connected to the motor control device A of the present invention by a cable or the like, and the motor control device A controls the rotational speed of these motors 7, 17, 31, and 33.

FIG. 3 is a block diagram showing the configuration of a motor control device A for an extrusion molding line according to the present invention.

In the figure, a control circuit 39 as a control means
outputs the specified rotation speed signal and also outputs the ratio rotation speed and other information in ratio mode.
It is formed of a CPU 41, a ROM 43 that stores the operating program of the CPU 41, a RAM 45 that temporarily stores data of the calculation process of the CPU 41, an interface (I/O) 47 for data input/output, and the like. It is the main part of microcomputers.

Master-slave relationship setting device 4 connected to control circuit 39
9. The mode switching device 51, the rotation speed setting device 53, and the line speed setting device 55 are formed of a keyboard 57 formed on the operation surface of the device main body, as shown in FIG. 2, and the details will be described later.

Master-slave relationship memory circuit 5 connected to control circuit 39
9. The rotational speed storage circuit 61 and the limit rotational speed storage circuit 63 are external storage circuits 65 as storage means consisting of RAM, and are used by dividing the storage area.

A display device CRT connected to the control circuit 39 is a cathode ray tube display device for displaying input/output data, and a plasma display device or the like may also be used.

The rotation speed measuring device 67 includes rotation speed detection sensors 9, 19, 35, 37 shown in FIG.
7, 31, and 33, and outputs an analog electrical signal according to the rotational speed of the motor.
It is connected to the control circuit 39 via the D conversion circuit 69, and these form a rotation speed measuring means.

The D/A conversion circuit 71 converts the digital rotational speed signal from the control circuit 39 into an analog signal, and is connected to the speed command signal output circuit 73 to form speed command means. 73 is each motor 7, 17, 31, 33 in FIG.
The rotation is controlled by outputting a speed command signal to the motor.

Note that the D/A conversion circuit 71 is configured to continue outputting the most recent signal, and the speed command signal output circuit 73 is also configured to continue outputting speed command signals to each motor 7, 17, 31, and 33. ing.

The mode switching device 51 is a mode setting means for setting whether the motor control device A controls each motor 7, 17, 31, 33 in the individual operation mode or the ratio operation mode. Although each of them is configured to be able to select between manual mode and automatic mode, it is sufficient that the configuration is such that at least switching between independent operation mode and ratio operation mode is possible.

In the independent operation mode, in the manual mode, each motor 7, 17, 3 is operated directly at the rotation speed input from the rotation speed setting device 53 under the control of the control circuit 39.
In the automatic mode, each motor 7, 17, 3 is controlled individually at the rotation speed input from the rotation speed setting device 53 under the control of the control circuit 39.
1 and 33 are automatically controlled individually.

The ratio operation mode is under the control of the control circuit 39.
The rotation of each motor 7, 17, 31, 33 is calculated by calculating the ratio for the main motor from the measured rotation speed signal input from the D/A conversion circuit 71 and for the slave motor from the rotation speed of the main motor to which this slave motor is dependent. It controls the number. The ratio may also be calculated from a signal related to the most recent speed command signal from the D/A conversion circuit 71.

Note that the master-slave relationship setting for each motor 7, 17, 31, 33 will be described later.

The rotation speed setting device 53 is connected to each motor 7, 17, 3.
This is a rotation speed setting means for manually inputting, for example, the rotation speed of 1 and 33, and is configured to be stored in the rotation speed storage circuit 61 under the control of the control circuit 39.

Further, from the rotation speed setting device 53, the control circuit 3
9, it is also possible to input the maximum allowable rotation speed (limit rotation speed) for each motor 7, 17, 31, 33, and each limit rotation speed is stored in the limit rotation speed storage circuit 63. It's getting old.

The master-slave relationship setting device 49 is a master-slave relationship setting device for changing the settings of the master-slave relationship such as which of the motors 7, 17, 31, and 33 in FIG. The master-slave relationship is stored in a master-slave relationship storage circuit 59 under the control of the control circuit 39.

The master-slave relationship may be arbitrary, such as a configuration in which a plurality of motors are the main motors and one or more slave motors are subordinate to each of the main motors, or a configuration in which a slave motor subordinate to the main motor is subordinate to another slave motor.

FIG. 4 shows each motor 7, 17, 3 set by the rotation speed setting device 53 and the master-slave relationship setting device 49.
1 and 33 and the master-slave relationship are shown on the display device CRT, and the number in the item indicating the master-slave relationship is the number of the higher-order motor to which the slave motor is dependent.

The line speed setting device 55 is a line speed command means for setting the molding operation speed of the entire or part of the extrusion molding line shown in FIG.

The control circuit 39 controls each motor 7, 17,
When the rotational speeds 31 and 33 are input, the respective rotational speed signals are directly outputted to the D/A conversion circuit 71 and the rotational speeds are stored in the rotational speed storage circuit 61.

When the mode switching device 51 selects the automatic mode in independent operation, the rotation speed input in advance from the rotation speed setting device 53, for example, the rotation speed stored in the rotation speed storage circuit 61, is read out and the rotation speed of each motor 7, 17 is read out. , 31, and 33 are outputted to the D/A conversion circuit 71 in a predetermined procedure and stored in the rotation speed storage circuit 61.

The control circuit 39 controls the master-slave relationship storage circuit 59 when the mode switching device 51 selects the ratio mode.
With reference to the master-slave relationship data stored in digital signal)
Based on the speed setting for the main motor from the line speed setting device 55, the rotation speed of each main motor is calculated from The D/A conversion circuit 71 calculates the rotation speed of the motor.
It has a function of outputting the rotation speed to the rotation speed storage circuit 61 and storing the rotation speed in the rotation speed storage circuit 61.

The control circuit 39 has a limit rotation speed storage circuit for each measured rotation speed signal of each motor 7, 17, 31, 33 inputted from the A/D conversion circuit 69 or each rotation speed signal outputted to the D/A conversion circuit 71. 63 and monitors whether there is even one motor that exceeds the limit rotation speed, and if there is a motor that exceeds the limit rotation speed, the ratio rotation of the other main and slave motors at the time when the limit rotation speed is exceeded. It has a function of calculating a number and outputting it to the D/A conversion circuit 71 to suppress the rotation speed of the motor so that it does not exceed the limit rotation speed.

Therefore, as shown in Fig. 5, when one motor 7, 17, 31, 33 reaches the rotation speed limit (2), the other motors 7, 17, 31, 33 do not reach the rotation speed limit (1). The rotational speed is controlled while maintaining a predetermined ratio.

The operation of the motor control device A of the present invention configured as described above will become clearer by explaining the operation with reference to the flowchart shown in FIG.

From the rotation speed setting device 53 to the motors 7, 17, 3
After inputting the optimum rotational speed of 1 or 33, the program starts when the mode switching device 51 is operated, and the program determines the setting mode contents from the mode switching device 51.

That is, in step 201, it is determined whether or not the motor is in the ratio operation mode, and if YES, it is determined in step 202 whether or not the motor can move to the ratio operation mode. If so, the operation mode of the motor is switched to the ratio operation mode in step 203.

In the subsequent step 204, the control circuit 39 reads the master-slave relationship data from the master-slave relationship storage circuit 59,
Each motor 7, 17, 31, 33 is determined from a signal based on the measured rotational speed signal input from the A/D conversion circuit 69 or the speed command signal from the D/A conversion circuit 71.
For the main motor, the rotation speed is calculated based on the speed setting from the line speed setting device 55, and for the slave motor, the rotation speed is calculated from the ratio relationship, and the D/A conversion circuit 71 to control the ratio of the motors 7, 17, 31, and 33, and output the rotation speed to the ratio rotation speed storage circuit 6.
1 and exit.

If step 201 is NO, it is determined in step 205 whether the mode is manual mode or automatic mode, and if YES, it is determined in step 206 whether the motor operation is in manual mode.

If step 206 is YES, step 207 switches the motor operation mode to automatic mode.
The control circuit 39 calculates the rotation speed and outputs it to the D/A conversion circuit 71, automatically controls the motors 7, 17, 31, and 33, and ends the process.

If step 206 is NO, step 208 switches the motor operation mode to manual mode and the process ends; if step 205 is NO, step 209
Switch to another operation processing mode and end the process.

〔Effect of the invention〕

As explained above, the motor control device of the present invention has a master-slave relationship setting means for a plurality of motors arranged in an extrusion molding line including an extrusion molding machine. The control means calculates the rotation speed ratio between each motor based on the measured rotation speed signal from the rotation speed measurement means or the speed command signal from the speed command means, and the speed setting from the line speed setting means. Therefore, the rotation speed of the main motor is calculated and the rotation speed of the slave motor is calculated as a ratio and outputted to the speed command means.

Therefore, when the master-slave relationship of multiple motors in an extrusion line is arbitrarily changed and set, the rotation speed of the slave motor can be calculated as a ratio from the rotation speed of the main motor and output easily. Even if various changes are made, there is an advantage that an optimal speed command system for various extrusion molding lines can be easily configured using each motor once connected, without changing the connection configuration of each motor as in the conventional case.

[Brief explanation of drawings]

FIG. 1 is a claim correspondence diagram corresponding to the claims related to the present invention, FIG. 2 is a schematic diagram showing an example of an extrusion molding line including the motor control device of the present invention,
FIG. 3 is a block diagram showing an embodiment of a motor control device according to the present invention, FIG. 4 is a diagram showing an example of setting the master-slave relationship of each motor in the present invention using the display device of FIG. 3, and FIG. is a diagram explaining the limit rotation speed of each motor, and FIG. 6 is a flowchart explaining the operation of the present invention. 1... Extruder, 3... Molding machine stand, 5... Main screw, 7... Extrusion motor, 9, 19, 35,
37...sensor, 13...subscrew, 15...
... Raw material feeder device, 17 ... Feeder motor, 25 ... Molded product, 27, 29 ... Taking machine, 3
1, 33... take-up motor, 39... control circuit,
41... CPU, 49... Master-slave relationship setting device, 5
1... Mode switching device, 53... Rotation speed setting device, 55... Line speed setting device, 59... Master-slave relationship storage circuit, 61... Ratio rotation speed storage circuit, 6
3... Limit rotation speed storage circuit, 67... Rotation speed measuring device, 69... A/D conversion circuit, 71...
D/A conversion circuit, 73...Speed command signal output circuit, A...Motor control device, CRT...Display device,
100... Motor, 101... Rotation speed setting means,
102... Rotation speed measuring means, 103... Master-slave relationship setting means, 104... Mode switching means, 105...
... Line speed setting means, 106 ... Control means, 1
07...Speed command means.

Claims (1)

[Scope of Claims] 1. A plurality of motors arranged in an extrusion molding line including an extrusion molding machine, a rotation speed setting means for setting the rotation speed of the plurality of motors, and a rotation speed for measuring the rotation speed of each of the motors. a master-slave relationship setting means for setting a mutual master-slave relationship between the motors; a mode switching means for switching at least between independent operation and ratio operation of each motor; and an operation speed of the extrusion molding line. line speed setting means; speed command means for outputting speed command signals for the main and slave motors to the corresponding main and slave motors from the input rotational speed signal; and during the ratio operation, from the rotational speed measuring means. The rotation speed ratio between the main and slave motors is calculated based on the measured rotation speed signal or the speed command signal from the speed command means, and the rotation speed of the main motor is calculated based on the speed setting from the line speed setting means. and a control means for calculating the rotation speed of the slave motor based on the rotation speed of the main motor and the rotation speed ratio and outputting it to the speed command means, and is compatible with any extrusion molding line. A motor control device for an extrusion molding line, characterized in that an arbitrary master-slave relationship can be set between the motors, and the motors can be operated at a ratio in the set master-slave relationship.