JPH02270528A - Controlling device of motor in extrusion line - Google Patents

Abstract

PURPOSE:To make the optimum ratio control of motors possible by a method wherein the ratio control is ensured by suppressing the rise of rotational frequencies of the remaining motors when the rotational frequency of even one motor out of all the motors reaches the maximum allowable rotational frequency. CONSTITUTION:When mode is changed over to ratio control action mode by a mode changing- over means 104, a control means 106 calculates the rotational frequency ratio among respective motors 100 on the basis of the rotational frequency signals of the respective motors 100 sent from a rotational frequency setting means 101 or of the speed command signals sent from a speed commanding means 107. On the master and slave motors 100, the relationship among which is set by a setting means 103 of the relationship of the master motor and slave motors, the control means 106 proportionally calculates the rotational frequency signals of the master motor and of the slave motors through the speed setting done by a line speed setting means 105 and outputs them to a speed commanding means 107, which outputs speed command signals to the master motor and slave motors 100. In the ratio control action mode, the control means 106 detects the presence or absence of even one motor, the rotational frequency of which reaches the maximum allowable rotational frequency. At the time, when said presence is detected, the control means 106 outputs the rotational frequency signals of the remaining motors with the ratios at the time of detection to the speed commanding means 107.

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 molding line that extrudes and molds long objects such as plastic pipes and laminates such as plastic sheets is constructed by connecting a take-up machine to an extrusion molding machine. At the same time, the extrusion molded product is taken up by a taking-off machine.

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

Furthermore, when changing the molding speed on the extrusion line or changing the extrusion 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.

In order to issue such motor speed commands, a known configuration is known in which, for example, the motors of an extruder and a take-up machine are controlled in the following relationship.

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

(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 the slave motors are controlled at a predetermined ratio by a speed setting device.

In the configuration (1), each motor is independent, so speed control does not affect each other, and (2)
) and (3), it is possible to automatically control the rotation speed of the slave motor by the main motor.

There is a characteristic that the main motor cannot be controlled by controlling only the slave motor.

Furthermore, the configuration (4) is characterized in 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 is
Configuration of extrusion line and types of molded products.

It is selected appropriately depending on the molding speed, etc.

[Problem to be solved by the invention]

However, the variable speed motor used in the extrusion molding line mentioned above has a maximum allowable rotation speed called the rated rotation speed or limit i rotation speed, and the motor speed cannot be increased beyond this, so ratio control is required. While one motor in operation still has room to increase its speed, the other motor in proportion to this motor may have reached its rotational speed limit.

Therefore, if you increase the rotation speed of one motor without noticing this situation, the rotation speed ratio between each motor will change from the moment the other motor reaches its limit rotation speed, causing an abnormality on the extrusion line. .

In this way, when the extrusion molding line is in operation and the molding speed is increased during ratio control, it is necessary to monitor whether even one of all the motors has reached the rotational speed limit.

The present invention was made under these circumstances.

An object of the present invention is to provide a motor control device capable of optimal ratio control of motors even if one of a plurality of motors in an extrusion molding line reaches the maximum allowable rotation speed.

[Means to solve the problem]

In order to solve such problems, the present invention has a plurality of motors 1G0.11! arranged in an extrusion molding line including an extrusion molding machine, as shown in the diagram corresponding to the claims in FIG. How to set iE number! ! t101. Rotation speed measuring means 102, master-slave relationship setting means 103. Mode switching means 104. Line speed setting device vltt 05. It is configured to include a control means 106 and a speed command means 107.

The rotation speed setting means 101 is for setting the rotation speed of a plurality of motors 100, and the zero rotation speed measuring means 102 is for setting the rotation speed of each motor 100.
0 rotation speed, the master-slave relationship setting means 103
is used to set a mutual master-slave relationship between the motors 100.

The mode switching means 104 switches at least between individual operation and ratio operation of each motor 100.

Line speed setting means 105 is for setting the operating speed of the extrusion molding line.

The control means 106 controls the rotation speed measuring means 102 during ratio operation.
Measurement rotation speed signal or speed command means 10 for each motor from
Line speed setting means 105 calculates the rotation speed ratio between each motor based on the speed command signal sent from 7 to each motor
The speed command means 107 calculates the ratio rotation speed signal of the main and slave motors based on the rotation speed ratio according to the speed setting from
This is what is output to.

Further, the control means 106 determines whether even one of the measured rotation speed signals and speed command signals corresponding to each motor 100 from the rotation speed measurement means 102 or the speed command means 107 has reached the maximum allowable rotation speed of the motor. The rotational speed of the other motors is calculated as a ratio based on the motor that has reached this point, and is output to the speed command means 107.

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

[For production]

In the present invention equipped with such means, the mode switching means 1
When the ratio operation is switched by 04, the control means 1
06 calculates the rotation ratio between each motor 100 based on the 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, and sets it by the master-slave relationship setting means 103. Regarding the main and slave motors 100 that have been set, the ratio of the rotation speed signals of the main and slave motors is calculated based on the speed setting from the line speed setting means 105 and output to the speed command means 107, and the speed command means 10
7 outputs speed command signals to the main and slave motors 100.

Under the ratio operation, the control means 106 detects the presence or absence of even one motor that has reached the maximum allowable rotation speed, and if detected, sends the rotation speed signal of the other motors to the speed command means 107 at the ratio at the time of detection. Output.

〔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, the extrusion fil includes a main screw 5 in the molding machine table 3, an extrusion motor 7 that rotationally drives it, and a rotation speed detection sensor 9 such as a tacho generator that detects the rotation speed of the extrusion motor 7. etc.

It has a conventionally known configuration having other configurations.

The molding machine table 3 is equipped with a material feeder device 15 having a hopper 11 for supplying plastic raw materials, a sub-screw 13, and others, and the material feeder device 15 includes a feeder motor 1 that rotationally drives the sub-screw 13.
7 and a sensor 19 for detecting the rotation speed of this feeder motor 17 are arranged.

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

This extruder 1 has a plastic raw material fed to a main screw 5 portion by a feeder motor 17 from a raw material feeder 15, and is placed in the vicinity of the tip of the main screw 5 by rotational drive of the main screw 5. The molded product 25 is extruded from the molded product 25.

The extruded molded product 25 is transferred to 5, for example, two sets of take-off machines 27.2.
9, each collection machine 2
At 7.29, the roller 27a that takes over the molded product 25;
29a are each rotated by a take-up motor 31, 33, and the rotational speed of the take-up motor 31, 33 is detected by a sensor 35, 37 similar to the sensors 9, 19.

The extrusion motor 7, the feeder motor 17, the take-up motor 31.33, and the sensors 9, 19, 35.37 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 these motors. 7.17', 31
．． This controls the rotation speed of 33.

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

In the figure, a control circuit 39 is a control means.

A CPU 41 which outputs an inputted rotation speed signal and outputs a calculation of the ratio rotation speed in the ratio mode;
ROM43 storing the operating program of PU41 and C
RAM that temporarily stores data in the calculation process of PU41
45 and data input/output interface (Ilo)
47, etc., and is the main part of a so-called microcomputer.

A master-slave relationship setting device 49 and a mode switching device 51 connected to the control circuit 39. As shown in FIG. 2, 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 main body of the device, and the details will be described later.

The master-slave relationship storage circuit 59, rotation speed storage circuit 61, and limit rotation speed storage circuit 63 connected to the control circuit 39 are as follows:
The external storage circuit 65 is a storage means consisting of a RAM, and is used by dividing the storage area.

The display device CRT connected to the control circuit 39 is a cathode ray tube display device for displaying input/output data, and in addition to this, for example, a plasma display device may be used.

The rotation speed measuring device 67 is the rotation speed detection sensor 9 shown in FIG.
, 19, 35.37 including motor 7.17.31.33
It outputs an analog electrical signal according to the rotation speed of the
It is connected to the control circuit 39 via an A/D conversion circuit 69 that converts an analog signal into a digital signal and outputs a measured rotational speed signal, and these constitute a rotational 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 in FIG.
．． 17, 31, and 33 to output speed command signals to control rotation.

The mode switching device 51 is configured so that the motor control device A controls each motor 7.
．． 1? , 31. This is a mode setting means for setting whether or not to control 33 in an individual operation mode or a ratio operation mode, and is configured so that manual mode and automatic mode can be selected under each of the individual operation mode and the ratio operation mode. , it suffices if the configuration is such that at least switching between the single operation mode and the ratio operation mode can be set.

In the independent operation mode, the 1 manual mode is for individually controlling each motor 7, 17, 31° 33 under the control of the control circuit 39 at the rotation speed input from the 9 rotation speed setting device 53, and the automatic mode is for controlling each motor 7, 17, 31° 33 individually. Under the control of the circuit 39, each motor 7.
17, 31, and 33 are automatically controlled individually.

The ratio mode of operation is under the control of control circuit 39.

For the main motor, the ratio is calculated from the measured rotation speed signal input from the D/A conversion circuit 71, and for the slave motor, the ratio is calculated from the rotation speed of the main motor to which this slave motor is dependent.
．． It controls the rotation speed of 17, 31, and 33. D
The ratio may be calculated from the signal related to the most recent speed command signal from the /A conversion circuit 71.

In addition, each motor 7.1? , 31.33 will be described later.

The rotation speed setting device 53 is connected to each motor 7.1? , 31.33
A rotation speed setting means for manually inputting the rotation speed of, for example,
Under the control of the control circuit 39, it is stored in the one rotation speed storage circuit 61.

Further, the one-rotation speed setting device 53 controls each motor 7.17, 31. It is a means to input the maximum allowable rotation speed (limit rotation speed) for 33.
Each rotation speed limit is stored in a rotation speed limit storage circuit 63.

The master-slave relationship setting device 49 is connected to each motor 7.17 in FIG.
, 31, 33 is a master-slave relationship setting means for changing the setting of a master-slave relationship such as which one becomes the main motor and which one becomes the slave motor with respect to the main motor, and under the control of the control circuit 39, the master-slave relationship is a master-slave relationship. The data is stored in the memory circuit 59.

Regarding the master-slave relationship, any configuration is possible, such as a configuration in which a plurality of motors are used as a main motor and a slave motor of 1 f1 m or more is subordinate to each main motor, or a configuration in which a slave motor subordinate to the main motor is subordinated to another slave motor.

FIG. 4 shows the rotation speed setting device 53 and the master-slave relationship setting device 4.
The number of revolutions and master-slave relationship of each motor 7.17, 31°33 set in 9 is shown on the display device CRT, and the number in the item indicating the master-slave relationship indicates the higher motor to which the slave motor is dependent. This is the number.

The 1-line speed setting holder 55 is a line speed command means for setting the molding operation speed of the entire extrusion molding line or a part of the extrusion molding line shown in FIG.

The control circuit 39 is in a situation where the mode switching device 51 selects the manual mode in independent operation.

From the rotation speed setting device 53 to each motor 7.17.31°33
When the rotation speed is input, each rotation speed signal is directly input to D/
Output to the A conversion circuit 71 and the rotation speed storage circuit 61
The number of revolutions is memorized.

When the mode switching device 51 selects the automatic mode in independent operation, the rotation speed 1 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. A rotation speed signal of .31.33 is output to the D/A conversion circuit 71 in a predetermined procedure.

When the mode switching device 51 selects the ratio operation mode, the control circuit 39 refers to the master-slave relationship data stored in the master-slave relationship storage circuit 59 and outputs the measured rotational speed signal from the A/D conversion circuit 69 or D The rotation speed ratio of the main and slave motors is calculated from a signal related to the most recent speed command signal from the /A conversion circuit 71 (a digital signal substantially equivalent to the speed command signal).

Based on the speed setting for the main motors from the line speed setting device 55, the rotation speed of each main motor is calculated, and the rotation speed of the slave motor is calculated from the rotation speed of the main motor according to the rotation speed ratio, and the D/A conversion circuit 71 and stores the rotation speed in the 3 rotation speed storage circuit 61.

The control circuit 39 compares each rotational speed signal 1 outputted to the D/A conversion circuit 71, for example, each rotational speed stored in the rotational speed storage circuit 61, with the limit rotational speed from the rotational speed limit storage circuit 63, and determines whether even one signal is detected. Monitor whether there is anything exceeding the limit rotation speed.

If there is a motor that exceeds the rotation speed limit, the motor that exceeds the rotation speed is used as a reference, I! ! D/A by calculating the ratio of the rotational speed of other main and slave motors at the time of turning 4.
It has the function of outputting to the conversion circuit 71 and suppressing the rotation speed of the motor so that it does not exceed the limit rotation speed.

In addition, it is possible to detect whether the rotation speed exceeds the limit.

Each motor 7°17. input from the A/D conversion circuit 69.
31 and 33 may be compared with each measured rotational speed signal.

Therefore, as shown in FIG. 5, a certain motor 7°17.
31. When 33 reaches the limit rotation speed (2), other motors? , 17.31.33 Even if the rotational speed does not reach the rotational speed (1), the rotational speed is ratio-controlled while maintaining a predetermined ratio.

In addition, with the above-mentioned configuration, it is possible to arbitrarily change the master-slave relationship of multiple motors in the extrusion molding line, and it is also possible to calculate the ratio of the rotation speed of the slave motor to the rotation speed of the main motor and output it. Even if the line is changed in various ways, an optimal speed command system for various extrusion molding lines can be easily configured without changing the connection configuration of each motor.

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

From the rotation speed setting device 53 to the motor 7.1? , 31.degree. 33, and then set the mode switching device 51 to the ratio operation mode to start the program.

In step 201, the control circuit 39 checks all the numbers of the slave motors, stores the correspondence between the slave motors and their corresponding numbers in the master-slave relationship storage circuit 59, and in the subsequent step 202, the control circuit 39 determines the rotation speed of the main motor. 39 and stored in the one rotation number storage circuit 61.

Subsequently, in step 203, it is determined whether the main motor exceeds the limit rotation speed, and if YES, step 204 is performed.
At step 205, the rotation speed of the main motor is stored as a limit value in the rotation speed storage circuit 61, and step 2
If 03 is NO, the process moves directly to step 205.

In step 205, the counter of the slave motor is cleared,
In the following step 206, the control circuit 39 calculates the ratio of the rotation speed of the n-th slave motor to the rotation speed of the main motor and stores it in the rotation speed storage circuit 61.

Note that the counter is formed by the CPU 41.

In the next step 207, it is determined whether the slave motor exceeds the rotation limit value, and if YES, step 207
At step 8, the rotation speed of the slave motor is stored as a limit value in the rotation speed storage circuit 61, and the process moves to step 209.

In step 209, the rotation speed of the main motor is calculated from the rotation speed of the n-th slave motor and stored in the rotation speed storage circuit 61, and in the subsequent step knob 210, the counter of the slave motor is set to the value immediately before the count-a-knob. death.

The process moves to step 211.

In step 211, "1" is added to the counter of the slave motor, and in step 212, it is determined whether the count value force (matches the number of slave motors), and if YES, the calculated rotational speed of the main and slave motors is calculated. In the following step 213, the rotation speed is read from the rotation speed storage circuit 61 and outputted to the D/A conversion circuit 71, and the process ends.

If step 207 is No, directly operate the steering knob 211.
If step 212 is No, step 20
Return to 6.

In this way, in the motor control device A of the present invention, each motor 7.1? , 31 and 33 exceed the individual limit rotation speeds, and if they exceed even 1+11,
Other motors 7.1 based on the motor beyond that? ,3
1.33, the rotational speed is calculated as a ratio to obtain each rotational speed.

〔Effect of the invention〕

As explained above, the motor control device of the present invention is provided.

For multiple motors arranged in the extrusion molding line that connects the extrusion molding machine, it detects whether even one of the nine motors has reached the limit rotation speed or not, and also sends a signal of the ratio rotation speed of the other motors at the time of detection. This is because the configuration is such that it outputs and controls the motor's ratio rotation.

If there is even one motor that has reached its rotation speed limit.

The rotational speeds of other motors are maintained without increasing, and a consistent ratio speed command system can be constructed while maintaining the rotational speed limit of each motor.

Therefore, even if the molding speed of the extrusion molding line during ratio control operation is increased, the rotational speed ratio between the respective motors is maintained, making it difficult for abnormalities to occur in the extrusion molding line.

[Brief explanation of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, and 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, and FIG. 4 is a diagram showing an example of setting the master-slave relationship and limit rotation speed of each motor in the present invention using the display device of FIG. , FIG. 5 is a diagram for explaining the limit rotation speed of each motor, and FIG. 6 is a flowchart for explaining the present invention in detail. l・・・・・・・・・・・・・・・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・・・・・・・Take-up machine

Claims (1)

[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 measuring means for measuring the rotation speed of each of the motors. , master-slave relationship setting means for setting a mutual master-slave relationship between the motors; mode switching means for switching at least between independent operation and ratio operation of each motor; and line speed setting means for setting the operating speed of the extrusion molding line. and speed command means for outputting speed command signals for the main and slave motors to the corresponding main and slave motors based on the input rotation speed signal, and a speed command means for outputting speed command signals for the main and slave motors to the corresponding main and slave motors, and measurement of each motor from the rotation speed measuring means during the ratio operation. The rotation speed ratio between the motors is calculated based on the rotation speed signal or the speed command signal sent from the speed command means to each of the motors, and the rotation speed ratio is calculated based on the rotation speed ratio by the speed setting from the line speed setting means. A control means for calculating rotational speed signals of the main and slave motors, the control means calculating at least one of each measured rotational speed signal from the rotational speed measuring means corresponding to each motor or the rotational speed signal to the speed command means. control means for detecting whether or not the maximum allowable rotation speed of the motor has been reached, calculating a ratio of the rotation speeds of other motors based on the reached motor, and outputting the ratio to the speed command means; A motor control device for an extrusion molding line, characterized in that when one of the motors reaches a maximum allowable rotation speed, the rotation speed of the other motors is suppressed from increasing to ensure ratio operation.