JPH10229692A - Speed control system for equipment motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the number of revolutions of a motor within the optimum duration without applying an excessive load to equipment drive section by interposing a PID setter between a speed command output section of a computer and a speed command input section of the equipment motor and thereby reducing the load to the control computer. SOLUTION: Signals from a computer 7 are sent to a PID setter 8, and the signals from the PID setter 8 control the rotation of a motor M1 of an extruder 1, a motor M2 of a raw material feeder 13, a motor M3 of a glazing equipment 3, and a motor M4 of a pinch roll 5. The number of revolutions of a motor M1 of an extruder 1 gradually increases from the start of operation, and finally reaches a predetermined value by drawing a gentle curve by the action of the PID setter 8. In this case, the command output of the computer 7 occurs only once for PID constants for rotation set point and the gradient of speed, its load is suppressed to the minimum, and thus no excessive load is applied to the drive section of the extruder 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a motor speed control system for various devices using a motor as a drive source. Here, as a device, for example, a rolling roll of steel or the like that dislikes rapid acceleration or deceleration at the time of start or stop, an electric vehicle or a train that does not want to suddenly start or stop, that is, a sharp acceleration or The present invention is applied to a material that dislikes deceleration, or a material such as an audio / video tape that dislikes rapid acceleration and deceleration at the start and end of winding.

The fields of application of the present invention are metal working machinery, mining machinery, civil engineering machinery, cargo handling machinery, chemical machinery, textile machinery, food processing or beverage processing machinery, pulp manufacturing. Machinery, papermaking or paperwork machinery, printing machinery, plastic processing machinery, semiconductor manufacturing equipment, and the like. Furthermore, medical equipment, vehicles, water supply / drainage / humidification / dehumidification equipment, and the like are also included.

[0003]

2. Description of the Related Art Conventionally, as described in Japanese Patent Publication No. 7-2370, it is known to control the operations of an extruder and a motor of ancillary equipment by a computer.

Conventionally, when the operation of an extruder is started, the screw of the extruder is initially driven by a motor, for example, at 10 r.
Rotation is performed at a low speed of about pm, and the rotation speed is increased with time according to a control signal from a computer. The same applies to the motor of equipment such as a take-off machine attached to the extruder.

[0005] In such a case, the screw rotation speed is set to 1
It is not preferable to rapidly increase the speed from about 0 rpm to about 70 rpm because an excessive torque, that is, a load is applied to the driving unit of the extruder. Therefore, it has been common to incorporate software or hardware capable of gradually increasing the number of rotations of a screw into a computer.

As another example, in the case of sheet forming by an extruder, the rotation speed of a raw material feeder, a glazing roll, a pinch roll, etc., must be increased stepwise almost in proportion to the rotation speed of the screw. There may be.

In response to such a demand, the hardware of the speed setting mechanism is provided together with the main computer, or
Separately provided ones have been used in the past. Here, as a speed setting mechanism, for example, a motor operation unit (often a digital input or display unit) including a proportional operation function and the like and an analog output interface are generally incorporated in a computer.

[0008]

As an example of a case where the problem is solved by software, a raw material feeder, which is proportional to the rotation speed of a main motor for driving a main screw of an extruder, is used.
When gradually increasing the rotation speed of a motor such as a glazing roll or a pinch roll, incorporating software for proportional operation increases the load on the computer.

Although the above-mentioned various motors are often made to be proportional to the speed in the end, they are not exactly proportional to the speed, but are transitory in consideration of factors such as a delay in material flow from upstream to downstream. Needs to be corrected.

In any case, except for driving the main screw of the extruder, software for gradually increasing or decreasing the rotation speed of a plurality of motors including the motors of the auxiliary equipment is incorporated in the computer. There is a problem of increasing the load on the side.

When inputting data for shifting to the best molding conditions in the shortest possible time to a computer, the type and grade of the synthetic resin, the size of the extruder / die, the temperature condition, the type / size of the product, All factors such as required physical properties and appearance must be considered. The automatic operation based on the above data by the scheduler is one method, but does not have a function of correcting disturbance. Also, the content differs depending on each equipment and product.

In order to provide versatility, a method of monitoring the molded product, feeding back the data, and reflecting the data on the operating conditions through a computer to drive the molding conditions to the best can be considered. Increase the side load. In other words, the communication circuit is congested in order to transmit the monitored data to the computer, and the computer side instructs new operation conditions to the device, and it also requires time to perform calculations in the computer. Requires ability.

In addition, software for increasing the rotation speed of a motor such as a raw material feeder, a glazing roll, and a pinch roll in proportion to the rotation speed of a main motor for driving the main screw of the extruder is included. However, there is a problem in the processing capability of a computer, and a normal personal computer cannot handle it.

As an example of reflecting the operating conditions through a computer, an artificial intelligence system (expert system) in which past experience values are stored in advance in a database, and the computer selects and outputs the best operating conditions. Conceivable. However, also in this case, since a lot of information is transmitted from the computer, it is inevitable that the communication circuit becomes congested, and in any case, the load on the computer is too large in the conventional motor control system of the extruder to process the data. There was a problem.

In order to cope with such a problem, a plurality of computers must be used, or as described above, the hardware of the motor speed setting mechanism must be provided together with or separately from the main computer. There was a problem that the hardware was expensive.

The present invention has been made in view of such a problem in a conventional motor speed control system of a device driven by a motor such as an extruder. To solve the problems in the motor speed control system of a device driven by a motor such as a machine, and to provide an inexpensive motor speed control system of a device driven by a motor without imposing a large load on a motor control computer. It is in.

[0017]

According to the first aspect of the present invention, there is provided a motor speed control system for a device driven by a motor to which a speed command is given by a control signal from a computer. A PID setting device is interposed between a speed command output section of the computer and a speed command input section of a motor of the apparatus.

According to a second aspect of the present invention, there is provided a motor speed control system according to the first aspect of the present invention, wherein the apparatus is an extruder. .

According to a third aspect of the present invention, there is provided a motor speed control system according to the first aspect of the present invention, wherein the apparatus is an extruder and ancillary equipment thereof. Is what you do.

According to a fourth aspect of the present invention, there is provided a motor speed control system according to the first aspect of the present invention, wherein the apparatus is a film manufacturing apparatus. is there.

In the present invention, the device is a device driven by a motor, and is not particularly limited. For example, a rapid acceleration or deceleration at the time of start or stop of a rolling roll of steel or the like. Those who dislike, those who dislike rapid starting and stopping of electric vehicles and trains, that is, those who dislike rapid acceleration or deceleration, or audio
Similarly, the present invention is applied to a video tape or the like that does not like rapid acceleration and deceleration at the start and end of winding.

The motor is not particularly limited as long as it is a variable speed motor whose rotation speed can be changed by inputting an electric signal. That is, it may be an electromagnet slip motor, an inverter motor, a servomotor, or any other. Further, the motor may have a PID control function in the speed control circuit of the motor itself to maintain the set speed. However, since the PID setting device described later needs to detect the rotation speed of the motor, if a rotation speed monitor output cannot be taken out from the motor, a separate mechanism for monitoring the rotation speed of the motor is required.

In the present invention, the computer
A computer capable of outputting set values to the PID setting device, for example, a commercially available personal computer or the like can be used as it is, and is not particularly limited. For example, a microcomputer chip or the like is also included in this.

In the present invention, the PID setting device includes:
An adjustment device, unit, or circuit that employs the so-called PID control theory (P represents proportional, I represents integration, and D represents differentiation), for example, conventionally referred to as a PID controller or a digital indicating controller. Things can be used. By using such a PID setting device, the rotation speed of the motor is gradually accelerated or decelerated with respect to the set value.

As the proportional function of the PID setting device, if the rotation speed of the motor reaches within the set proportional band, the difference between the set value and the measured value (actual value) (hereinafter simply referred to as “deviation value”) ), The voltage value or current value of the electric signal for drive system control, the number of pulses, or the like increases or decreases.

The integration function of the PID setting device is a function of integrating the deviation value of the rotation speed of the motor within a time set over time. Further, the differentiation function of the PID setting device is a function of differentiating the deviation value of the rotation speed of the motor within a time set over time. Proportional band width, integration time,
The derivative time should be set so as to eliminate overshoot and undershoot (hunting), to ensure that the deviation value does not ultimately remain, and as long as the motor is not overloaded.
It is selected and adjusted to stabilize in the time that is most appropriate for the task.

In the present invention according to claim 3, as the auxiliary equipment of the extruder, the equipment conventionally used as the equipment associated with the extruder can be used as it is, and is not particularly limited. For example, ancillary equipment driven by a motor such as a take-up machine such as a glazing roll or a pinch roll.

[Operation] In the motor speed control system according to the first aspect of the present invention, the PID setting device is interposed between the speed command output section of the computer and the speed command input section of the motor of the apparatus. The PID setting device receives the speed command signal from the computer as a set value, and the PID set device adjusts the motor speed based on the set value to minimize the load on the computer, and The number of rotations of the motor can be increased or decreased to a set value in a short time and without applying an excessive load to the drive unit of the apparatus, and can be stabilized. Moreover, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

According to a second aspect of the present invention, in the motor speed control system of the apparatus, the apparatus is an extruder, and a PID setting is provided between a speed command output section of the computer and a speed command input section of the motor of the extruder. The speed command signal from the computer is used as a set value for P
The ID setting device receives the ID value, and the PID setting device adjusts the motor rotation speed based on the set value, thereby minimizing the load on the computer and reducing the rotation speed of the motor of the extruder in a short time. The set value can be increased or decreased and stabilized without applying an excessive load to the drive unit. Moreover, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

According to a third aspect of the present invention, there is provided a speed control system for a motor of an extruder and ancillary equipment thereof, wherein a speed command output section of the computer and a speed command input section of a motor of the extruder and ancillary equipment are provided. Since the PID setter is interposed, the PID setter receives a speed command signal from the computer as a set value, and the PID setter adjusts the motor rotation speed of the extruder and its auxiliary equipment based on the set value. To minimize the load on the computer and increase the number of rotations of the motor of the extruder and its ancillary equipment to a set value in a short time and without applying an excessive load to the drive unit of the extruder and its ancillary equipment. Alternatively, it can be reduced and stabilized. Moreover, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

According to a fourth aspect of the present invention, in the motor speed control system for a film manufacturing apparatus, a PID setting device is interposed between a speed command output section of a computer and speed command input sections of various motors of the film manufacturing apparatus. The PID setter receives the speed command signal from the computer as a set value, and the PID setter adjusts the rotation speeds of various motors of the film manufacturing apparatus based on the set value to minimize the load on the computer. In addition, it is possible to increase or decrease the number of rotations of various motors of the film manufacturing apparatus to a set value in a short time and without applying an excessive load to a driving unit of the apparatus, and to stabilize the set value. Moreover, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

[0032]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing an embodiment in which an extruder is used as a device of a motor control system of the device of the present invention. In FIG. 1, 1 is an extruder, 11 is a screw shaft provided in the extruder 1, and the screw shaft 11 is driven and rotated by a motor M1. Reference numeral 12 denotes a hopper of the extruder 1;
2 is supplied with a synthetic resin raw material by a raw material feeder 13. M2 is a motor of the feeder feeder 13, 14 is a thermometer provided in the middle of the barrel of the extruder 1, and 15 is a pressure gauge provided at the tip of the barrel of the extruder 1.

Reference numeral 2 denotes a die provided at the tip of the extruder 1. The synthetic resin extruded from the extruder 1 is formed into a sheet shape by the die 2. Reference numeral 3 denotes a glazing device provided behind the die 2. The glazing device 3 is configured such that a worm gear 32 provided on the shaft of three glazing rolls 31 meshes with a worm 34 provided on a drive shaft 33, and drives the glazing device 3. A bevel gear 35 provided at the lower end of the shaft 33 meshes with a bevel gear 36 provided on the drive shaft of the motor M3. Each glazing roll 31 is rotated by the rotation of the motor M3.

Reference numeral 4 denotes a guide roll provided behind the glazing device 3 for guiding the sheet S fed from each glazing roll 31. Reference numeral 5 denotes a pinch roll provided behind the guide roll 4, and the pinch roll 5 is driven by a motor M4.

Reference numeral 6 denotes a thickness measuring device for the sheet S provided behind the pinch roll 5. Reference numeral 7 denotes a computer, 71 denotes a display device provided in the computer 7, 72 denotes a keyboard for inputting extrusion conditions and the like, and 73 denotes a mouse. Extruder 1
The data from the thermometer 14 and the pressure gauge 15 provided in the barrel and the data from the thickness gauge 6 are input to the computer 7.

Reference numeral 8 denotes a PID setting unit.
Is sent to the PID setting device 8 and the PID setting device 8
M1 of the extruder 1, motor M2 of the raw material feeder 13, and motor M3 of the polisher 3
And the rotation of the motor M4 of the pinch roll 5 is controlled.

Since the motor control system for an extruder of the present invention shown in FIG. 1 has the above-described configuration, as shown in the graph of FIG. 2, the rotation speed of the motor of the extruder is low at the start of operation. However, it gradually increases, draws a gentle curve until it reaches a predetermined 70 rpm by the action of the PID setting unit 8, and finally reaches a predetermined 70 rpm.
The same effect can be obtained when the operating speed is slightly changed.

Therefore, in this case, the command output from the computer is a rotation set value = 70 rpm and a PI for the speed gradient.
Since the D constant is output only once, the load on the computer is minimized, and no excessive load is applied to the drive unit of the extruder. The gradient of the graph shown in the graph of FIG. 2 can be adjusted by selecting an appropriate PID constant of the PID setting device 8.

[0039]

FIG. 1 shows an embodiment of the motor control system shown in FIG. As the extruder, a single screw extruder (trade name “GT-40-A” manufactured by Plastic Engineering Laboratory Co., Ltd.) was used, and the diameter of the screw shaft was 40 mmΦ and L / D = 2.
It is equipped with a 4, 15 KW vector inverter motor. As the PID setting device, a device manufactured by Shinko Technos Co., Ltd. (trade name “SCR-13A”) was used. In addition, low-density polyethylene (trade name “LF-405”) manufactured by Mitsubishi Chemical Corporation was used as a raw material.

The speed setting value from the computer to the PID setting device is converted into the rotation speed of the screw shaft (the rotation speed of the motor is 18 times the rotation speed of the screw shaft) as shown by a rough dotted line (a) in FIG. 20, 40, 20, 0, 20, 40, 20 rpm from zone to E zone
It is set to rotate with. In FIG. 3, the vertical axis represents the rotation speed of the screw shaft, and one scale is 10 rpm.
m. The set value of the PID in each zone is shown in the lower part of FIG.

Note that the PID is
It is shown that the speed command from the setter to the motor behaves with a time delay when the speed rises and falls as shown by the solid line (b) in FIG.

As shown by the fine dotted line in FIG. 3, the actual rotational speed of the motor has a value close to the solid line (b) of the speed command from the PID setting device to the motor.
Depending on how each numerical value is selected, some deviation may occur. For example, in section D shown in FIG.
There is a slight difference between the speed command and the actual rotational speed of the motor.

From the viewpoint of protection and safety of the extruder,
Although the torque applied to the screw shaft is important, it is difficult to directly measure the torque. Therefore, the actual current value of the motor (indicated by the thin dotted line (d) in FIG. 3) is measured, and the It was thought that a large torsional torque would be applied to the screw when it increased. In FIG. 3, one graduation on the vertical axis represents 8 amps.

[Evaluation] The results of the above embodiments are summarized as follows. Each set value of PID is P = 80 to 500,
The operation was performed while changing the values in the range of I = 2 to 10 and D = 0 to 2, respectively. However, the D zone (I = 2) and the F zone (P = 8
In 0), the actual current value of the motor changed irregularly.

The range that each set value of the PID can take is as follows. If the set value of D is set to 2 or more, hunting occurs and measurement becomes impossible. It can be seen from the fact that the speed command value and the actually measured value of the motor tachometer are almost the same, but the response speed of the motor is fast. It can be considered. As for the set value of I, as shown in the D zone in FIG. 3, if the set value is set to 2 or less, hunting occurs and becomes unstable. When three or more set values are set, the larger the set value is, the gentler the curve is drawn and the set value is approached.

As for the set value of P, as shown in the F zone of FIG. 4, if a set value of 80 or less is set, hunting occurs and becomes unstable. When the set value is 100 or more, the control change due to the set value is not so large, but the PID curve tends to appear earlier at the start. Therefore, the set values of D and P are set such that the control is stabilized within the above range, and a gradual or sharp set curve can be obtained by changing the value of I.

Although this tendency is as described above for various motors, the selection of specific numerical values differs depending on the characteristics of each motor. if,
If the motor speed command input is given as a rectangle,
It can be seen from the above-described embodiment that the current value sharply increases and decreases at the rise of the rectangle. This means that a load is applied to the extruder motor. As shown in the G zone in FIG. 4, the current value can be suppressed to a gradual change by introducing a gradual setting curve.

Note that the above result is obtained as a PID setting device
Originally, the case of using a PID setting device (trade name "SCR-13A") manufactured by Shinko Technos Co., Ltd. for temperature control, using a PID setting device with a different manufacturer and purpose of use In this case, the numerical value of the PID is considered to be different from the above value.

FIG. 5 is an explanatory view showing another example of the motor control system of the apparatus of the present invention. The motor control system of the apparatus of the present invention shown in FIG. 5 is used for producing a stretched film. In FIG. 5, F is a lay flat film obtained by flattening a tubular film of a thermoplastic resin. Reference numeral 1a denotes a turn roll, and the turn roll 1a is provided to change the traveling direction of the film. Reference numerals 2a and 2a denote upper pinch rolls. The lay flat film F is pulled downward by the upper pinch rolls 2a and 2a, and the tubular film F1 is taken up.
It has the effect of sealing and sealing the air inside. The upper pinch rolls 2a, 2a are driven by a motor (not shown).

Reference numeral 4a denotes a tube preheating section, and an infrared heater 43a is provided in a tube preheating chamber 42a in a cover 41a of the tube preheating section 4a, and the tube film F1 is stretched in the tube preheating chamber 42a immediately before an appropriate temperature. Is heated until the temperature reaches the intermediate temperature. 44a
Is a trochanter for steadying the tubular film F1.

A heating unit 5a is provided with a cover 51a, and a heating chamber 52a in the cover 51a.
An air ring 53a is provided therein. The tubular film F in the preheating portion 4a is formed by the air ring 53a.
Hot air is blown around the outer periphery of the tubular film F1 in order to further uniform the temperature in the circumferential direction of 1. An infrared heater 54a provided in the heating chamber 52a heats the tubular film F1 to the stretching heating temperature by the infrared heater 54a. During this time, the tubular film F1 is stretched and stretched to a required diameter.

Reference numeral 6a denotes a cool air air ring, which blows cool air from the cool air air ring 6a to the tubular film F1 to solidify the caliber of the tubular film F1 to a required caliber and wall thickness.

Reference numeral 7a denotes a guide plate device provided below the cool air ring 6a, and the guide plate device 7a includes a bubble F2.
Guide plates 71a, 71a serving as guides for guiding the sheet to the lower pinch rolls 81a, 81a, and a plurality of pressing rolls 72a are rotatably provided on the two guide plates 71a, 71a. A female screw block 73a is provided on each of the two guide plates 71a, 71a.
A male screw 741a of a drive shaft 74a is screwed into a.

External threads 741a, 741a of the drive shaft 74a
Are spirals in mutually opposite directions. One end of the drive shaft 74a is connected to one end of a universal joint 75a by a joint fastening nut 751a, and the other end of the universal joint 75a is connected to a drive shaft 761a of a reduction motor 76a.

A center position holding projection 742a is provided at the center of the drive shaft 74a, and the center position holding projection 742a is provided.
One end of a slide support plate 743a is bearing on both sides of
The other end of the slide support plate 743a is a support plate guide 74.
4a so as to be able to move up and down. The two guide plates 71 are driven by the forward and reverse drive rotation of the reduction motor 76a.
a, 71a, that is, the opening degree θ can be increased or decreased.

Reference numeral 8a denotes a take-up unit provided below the guide plate device 7a.
A pair of lower pinch rolls 81a, 81a is supported on a, and the distance between the lower pinch rolls 81a, 81a can be adjusted by rotating the handle 82a.

The take-up unit 8a is mounted on the base frame 83a. A female screw block 831a is provided on the base frame 83a, and a male screw near the lower end of the screw rod 85a is screwed into the female screw block 831a. Supporting frame 87
a.

A sprocket wheel 851a and a bevel gear 852a are provided at the lower end of the screw rod 85a. The sprocket wheels 851a are connected to each other by a chain 855a. The screw rod 85a is rotated by the rotational drive of the elevating deceleration motor 853a, so that the base frame 83a can be raised and lowered. 9a is a turn roll provided on the side of the take-up unit 8a.

In the above system, the drive motors (not shown) of the upper pinch rolls 2a, 2a and the lower pinch rolls 81a, 81a, the deceleration motor 76a, and the motors for lifting and lowering 853a are all controlled by a computer (not shown). The signal is controlled via a PID setting device (not shown).

Therefore, it is not preferable that all of these motors start and stop suddenly. Particularly, although the speed is low at the start of operation, the rotation speed gradually increases, and the PID setting device (not shown) sets the PID in advance. It reaches a predetermined rotation speed determined by the setting of the vessel.

The embodiment of the present invention has been described with reference to the drawings. However, the specific embodiment of the present invention is not limited to the illustrated embodiment, and is not limited to the scope of the present invention. Design changes are included in the present invention. For example, in the system shown in FIG. 1, a control panel may be used in combination with a conventional extruder motor control. Also, as in the illustrated embodiment, the present invention may be applied to the molding of synthetic resin pipes and other extruded products instead of applying the present invention to the molding of synthetic resin sheets and films.

[0062]

According to the first aspect of the present invention, there is provided a speed control system for a motor of an apparatus according to the present invention.
Since the ID setter is interposed, the PID setter receives a speed command signal from the computer as a set value, and the PID setter adjusts the motor speed based on the set value to minimize the load on the computer. In addition, the rotation speed of the motor of the apparatus can be stabilized by increasing or decreasing to a set value within an optimum time for the operation and without applying an excessive load to the extruder driving section and the like.

Further, even after the rotation speed of the motor reaches the set value, if the rotation speed is likely to change due to disturbance, the PID setting device itself takes charge of the adjustment, and there is an advantage that the computer is not loaded.

Further, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

According to a second aspect of the present invention, in the motor speed control system of the present invention, the apparatus is an extruder, and a PID setting is provided between a speed command output section of the computer and a speed command input section of the motor of the extruder. The speed command signal from the computer is used as a set value for P
The ID setting device receives the setting value, and the PID setting device adjusts the motor rotation speed based on the set value, thereby minimizing the load on the computer, and setting the rotation speed of the motor of the extruder to an optimal time for the work. It is possible to increase or decrease the set value and stabilize it without applying an excessive load to the extruder drive section and the like.

Further, even after the rotation speed of the motor reaches the set value, if the rotation speed is likely to change due to disturbance, the PID setting device itself takes charge of the adjustment, and there is an advantage that the computer is not loaded. Moreover, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

According to a third aspect of the present invention, there is provided a speed control system for a motor of an extruder and ancillary equipment thereof, wherein a speed command output section of the computer and a speed command input section of a motor of the extruder and ancillary equipment are provided. Since the PID setting device is interposed, the speed command signal from the computer is received by the PID setting device as a set value, and the PID set device adjusts the rotation speed of the motor of the extruder and its auxiliary equipment based on the set value. This minimizes the load on the computer and sets the number of revolutions of the motor of the extruder and its auxiliary equipment within the optimal time for the work and without applying an excessive load to the extruder drive section. Can be increased or decreased to stabilize.

Further, even after the rotation speed of the motor reaches the set value, if the rotation speed is likely to change due to disturbance, the PID setting device itself takes charge of the adjustment, and there is an advantage that the computer is not loaded. Moreover, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

According to a fourth aspect of the present invention, there is provided a motor speed control system for a film manufacturing apparatus, wherein a PID setting device is interposed between a speed command output section of a computer and speed command input sections of various motors of the film manufacturing apparatus. The PID setter receives the speed command signal from the computer as a set value, and the PID setter adjusts the rotation speeds of various motors of the film manufacturing apparatus based on the set value to minimize the load on the computer. And to stabilize the number of rotations of various motors of the film production equipment to the set value within the optimum time for the work and without increasing the load on the drive part of the equipment. Can be.

Further, even after the rotation speed of the motor has reached the set value, if the rotation speed is likely to change due to disturbance, the PID setting device itself takes charge of the adjustment, and there is an advantage that the computer is not loaded. Moreover, since the PID setting device is relatively inexpensive, it can be provided at low cost as the whole system.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a motor control system of the apparatus of the present invention.

FIG. 2 is a graph showing a relationship between a motor rotation speed and time by a motor control system of the extruder according to the present invention.

FIG. 3 is a graph showing a motor rotation speed set value, an actual motor rotation speed, and the like.

FIG. 4 is a graph showing a motor rotation speed set value, an actual motor rotation speed, and the like.

FIG. 5 is an explanatory view showing another example of the motor control system of the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 11 Screw shaft 12 Hopper 13 Raw material feeder 14 Thermometer 15 Pressure gauge 2 Die 3 Glazing device 4 Guide roll 5 Pinch roll 6 Thickness measuring device 7 Computer 8 PID setting device M1 Motor of extruder M2 Motor of raw material feeder M3 Motor for polisher M4 Motor for pinch roll

Claims (4)

[Claims] In a speed control system for a motor driven by a motor to which a speed command is given by a control signal from a computer, a PID is provided between a speed command output portion of the computer and a speed command input portion of the motor of the device. A speed control system for a motor of a device, wherein a setting device is interposed. 2. The system according to claim 1, wherein the device is an extruder. 3. The system according to claim 1, wherein the apparatus is an extruder and ancillary equipment thereof. 4. The system according to claim 1, wherein the apparatus is a film manufacturing apparatus.