JPH08113343A - Twin-motor driving method by torque control in textile printing machine - Google Patents

Abstract

PURPOSE: To prevent the action failure in machinery constitution from being happened, restrain the elasticity of a belt, and improve the position accuracy without using a roll periphery length detector in driving the torque control for a textile printing machine. CONSTITUTION: In a twin-motor driving method for imtermittently positioning an endless belt 3 supported by two rolls 1 and 2 in a printing machine, belt elongation, caused by the ununiformity of two roll periphery lengths, is restrained by controlling the movement quantity of a driving motor 5 for one side roll 1, and making a driving motor 10 for another roll 2 be for auxiliary drive by torque control to control the size of the output torque of both the rolls. Consequently, since the position control of only the servomotor of a driving roll can be sufficient, equalizing respective roll periphery lengths or attaching a detector for measuring a roll periphery length can be eliminated to reduce the burden on a machinery side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a twin motor drive method in which a twin motor is intermittently driven by a twin motor in a textile printing machine, and the twin motor is drive-controlled by torque control.

[0002]

2. Description of the Related Art As is well known, in an automatic screen printing machine for intermittently driving an endless belt supported by a pair of rolls, the thickness of the endless belt or the inhomogeneity of mechanical properties may occur. It is required to drive the endless belt accurately and intermittently without being affected. As a conventional intermittent driving method for an endless belt, a structure shown in Japanese Patent Publication No. Sho 60-31728 is known. This is because the detectors (pulse generators) 13 and 14 for measuring the circumferential length are attached to the driving roll 1 and the driven roll 2, respectively, as shown in FIG. By inputting a pulse to the controller 18 and counting the input pulse, the movement amount of the endless belt 3 is obtained. Thereby, the endless belt 3 is driven regardless of the non-uniformity of the roll circumference and the error of the intermediate speed reducers 4 and 9. In FIG. 4, reference numerals 5 and 10 are AC servomotors, reference numerals 16 and 21 are tachogenerators for detecting the rotational speeds of the servomotors 5, 10, and reference numeral 17 is provided.
Reference numerals 22 and 22 are servo amplifiers.

[0003]

However, the Japanese Patent Publication Sho 60
In the prior art as disclosed in Japanese Patent Publication No. 31728, the gears of the speed reducers 4 and 9 that come into contact with the rolls 1 and 2 when the detectors 13 and 14 attached to the rolls 1 and 2 have poor mounting accuracy. If the accuracy of the
From the servo motor 5, 10
It has been pointed out that there is a problem in that a smooth intermittent positioning operation cannot be performed due to a disturbing operation during stoppage or driving.

Further, when the roll circumferences of the two rolls 1 and 2 and the ratio of the intermediate speed reducers 4 and 9 are not uniform, the amount of movement of the belt due to the rotation angle of the servomotors 5 and 10 is different, and the mutual motors are different. As the belt is pulled and stretched, the mutual interference of the motors occurs, resulting in an overload condition.

The problem to be solved by the present invention is to prevent malfunction of the mechanical structure without using such a roll circumference detector, to minimize expansion and contraction of the belt, and to improve position accuracy. is there.

[0006]

In order to solve the above-mentioned problems, the twin motor drive system by torque control in the textile printing machine of the present invention is a driving method for intermittently positioning an endless belt supported by two rolls in the textile printing machine. In the above, by controlling the movement amount of the driving motor of one roll and the auxiliary driving by the torque control of the driving motor of the other roll, and controlling the magnitude of the output torque of the both rolls, the two roll circumferences are controlled. It is intended to suppress belt extension caused by uneven length.

[0007]

The twin motor driving method by torque control in the textile printing machine according to the present invention configured as described above is as follows:
It works as follows. First, a detector attached to the drive motor on the drive roll side converts the amount of roll rotation or the amount of belt movement to perform intermittent positioning. Further, by controlling the driving motor on the driven roll side by torque control and driving the driving motor in synchronization with the driving motor on the driving roll side, the force applied to the belt is controlled to be smaller and constant, and the expansion and contraction of the belt is suppressed. With these, the mechanical configuration and the control configuration are simplified.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A twin motor driving method by torque control in a textile printing machine according to the present invention will be described in detail below with reference to specific embodiments shown in the drawings. FIG. 1 is a schematic block diagram showing a basic configuration example for a twin motor driving method by torque control in a textile printing machine according to the present invention, and FIG. 2 particularly shows an internal configuration of a controller by a transfer function. It is a schematic block diagram.

As shown in FIG. 1, the endless belt 3
Is supported by two rolls, a drive roll 1 and a driven roll 2, and is intermittently positioned and driven by the rotation of the two rolls. In this method of driving an endless belt, an AC servomotor 5 for driving a driving roll is connected to a driving roll 1 via a speed reducer 4, and a driven roll 2 is driven to a driven roll via a speed reducer 9. The AC servo motor 10 for driving is connected. These roll drive motors 5 and 10 are provided with encoders 6 and 1 for detecting the feed length of the endless belt 3, respectively.
1 is connected to the rear of the motor.

The method for positioning the drive roll 1 is deviation control by a subtraction method, which is a conventional technique, and the controller 8 is used.
The motor rotation command is issued to the SERVOPACK 7 and the drive roll 1 is rotated. At this time, in order to keep the tension of the belt constant, the driven roll 2 is rotated in the same direction.

The peripheral length of the drive roll 1 or the error correction of the speed reducer 4 can be determined by the pulse generated from the encoder 6 when the drive roll 1 is rotated once. In the present invention, the difference between the pulse number at this time and the preset reference pulse number is the correction amount. The difference between the number of pulses generated from the encoder 6 and the preset number of reference pulses is calculated by the controller 8 and used as the command set value of the actual movement amount.

The control method of the driven roll 2 is torque control, the torque of the drive servomotor 5 of the drive roll 1 is detected, and a torque command is given to the drive servomotor of the driven roll 2 according to the change of the torque. ing. Details of the torque control will be described with reference to FIG. When performing this torque control, it is premised that the SERVOPACK 12 has a torque control mode. This servo pack 1
The torque command to 2 basically takes in the current flowing in the drive roll driving servomotor 5 into the controller 8 and gives the result of calculating this current value as a command to the servo pack 12, but the drive roll driving servomotor 5 Since the current is almost 0 at the time of start, the initial torque command is given by using the start signal as a trigger, and when the speed of the drive roll driving servo motor 5 reaches the torque command switching point, the drive roll driving servo motor is driven. The current value of 5 is used as the torque command. This prevents the belt from stretching at the start.

Further, a driven roll driving servomotor 10 is provided.
The speed of the drive roll drive servo motor 5 is detected, and the speed of the drive roll drive servo motor 5 is always −α.
Control to rotate at the speed of. As a result, the driven roll 2 can be prevented from proceeding further than the drive roll 1, the load of the drive roll driving servomotor 5 can be stabilized, and disorder between the motors can be prevented. The torque diagram at this time is shown in FIG.

Further, if the processing time by the controller 8 becomes long, the time from receiving each speed and current data from the driving roll driving servo motor 5 to outputting to the driven roll driving servo motor 10 becomes long, resulting in In some cases, the speed and torque commands are out of phase with each other, mutual interference between motors similar to the above occurs, and irregularity occurs. Therefore,
The controller 8 uses a controller capable of high-speed processing and suppresses the delay time between the driving roll 1 and the driven roll 2 to several milliseconds.

[0015]

According to the twin motor driving method by torque control in the textile printing machine of the present invention having the above-mentioned structure,
Since only the servo motor on the drive roll side needs to be position controlled, it is not necessary to make each roll circumference the same or to install a detector for measuring the roll circumference, thereby reducing the load on the machine side. It can be said that it is extremely effective in these respects.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a basic configuration example for a twin motor driving method by torque control in a textile printing machine according to the present invention.

FIG. 2 is a schematic block diagram showing, in particular, an internal configuration of a controller by a transfer function in a basic configuration example for a twin motor driving method by torque control in a textile printing machine according to the present invention.

FIG. 3 is a torque diagram schematically showing torque fluctuations according to the control method of the present invention.

FIG. 4 is a schematic block diagram showing a typical configuration example of an endless belt driving method in a conventional automatic screen printing machine.

[Explanation of symbols]

 1 Drive roll 2 Driven roll 3 Endless belt 4 Drive roll side reducer 5 Drive roll drive AC servo motor 6 Drive roll side encoder 7 Drive roll side servo pack 8 Controller 9 Driven roll side reducer 10 Driven roll drive AC servo motor 11 Driven roll side encoder 12 Driven roll side servo pack

Claims (1)

[Claims] 1. In a textile printing machine, in a drive method for intermittently positioning an endless belt supported by two rolls, a drive motor of one roll is controlled by a moving amount and a drive motor of the other roll is controlled by torque control. An auxiliary drive is used to control the output torque of both rolls so as to suppress the belt elongation caused by the nonuniformity of the two roll circumferences. Torque control in a textile printing machine. Twin motor drive method by.