JPH03182468A - Rewinder control device - Google Patents

Abstract

PURPOSE:To perform high-precision speed control and prevent a deflection wrinkle on a sheet by providing a comparing circuit comparing the signal of an overload setter and the signal of a current detecting circuit and outputting the result for the control signal of a motor, and performing the drooping control of an intermediate roll only when the overload set value is attained, not ordinarily. CONSTITUTION:The speed of an intermediate roll 3 is lowered by the output signal of an overload setter 27 outputted to a speed control amplifier 13, and the overload of the roll 3 is prevented. When the output signal of a power converter 18, i.e., the drive motor current, is smaller than the set signal S7 of the setter 27 while the speed set signal S3 is not changed and the speed detected signal S2 is changed, the current reference of the converter 18 is changed following the signal S3. When the current reference of the converter 18 reaches the signal S7 of the setter 27, the output signal of a comparing circuit 26 and the signal S3 are inputted to an amplifier 13, the speed of an intermediate roll drive motor 15 is lowered, and the overload is prevented. When the current value of the motor 15 is within the set range of the converter 18, control can be performed without reducing the precision of speed control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to a rewinder control device that winds a sheet material wound around an unwinder onto the winder with a predetermined tension via an intermediate roll.

(Prior Art) As shown in FIG. 3, in a conventional rewinder control device, an unwinder 1 is centrally driven by an unwinder motor 7, and includes a power converter 8 serving as a drive source for the unwinder motor 7, a tension control amplifier 10, and a current It is controlled via a control amplifier 9.

Further, the intermediate roll 3 is surface-driven by the intermediate roll motor 15, and includes a power converter 18 and a speed control amplifier 1 with drooping, which serve as a driving source for the intermediate roll motor 15.
3. The speed control amplifier 13 is provided with drooping because the intermediate roll 3 and the winder 5 are mechanically connected via a sheet material. The winder 5 is driven by a winder machine 19, is surface-driven by speed control via a power converter 20 serving as a driving source for the winder machine 19, and a speed control amplifier 21, and winds the sheet material 2 with a constant tension by a tension roll 4. take. In addition, as shown in Fig. 4, the tension roll 4
The detection signal (front tension) T2 is the tension detector 6
becomes the tension detection signal S2 via the winding tension setting device 11.
tension control amplifier 1 along with tension setting signal S1 set in
0, the current of the unwinder motor 7 is controlled so that the tension setting signal Sl and the tension detection signal S2 are equal, and both the unwinder tension Tt and the winder tension T are controlled to the tension setting Si.

The intermediate roll 3 manually inputs the output signal of the speed detector 16 attached to the intermediate roll motor 15 to the speed detection circuit 17, and outputs the output signal S4 of the speed detection circuit 17 and the speed setting device 1.
It is input to the speed control amplifier 13 together with the speed setting signal S3 set in step 2, and the intermediate roll motor 15 is controlled.

Similarly to the intermediate roll 3, the winder 5 also inputs the output signal of the speed detector 22 attached to the winder motor 19 to the speed detection circuit 23, and sets the output signal S6 of the speed detection circuit 23 and the speed setting device 24. It is input to the speed control amplifier 21 together with the speed setting signal S5,
is controlled.

(Problems to be Solved by the Invention) Rewinding devices that unwind a sheet material such as paper into a center-driven unwinder and wind it into a surface-driven winder are often used in paper factories and the like.

In this case, the tension of the unwinder is controlled to keep the winder winding tension of the sheet material constant, but a tension roll set between the winder and an intermediate roll provided between the unwinder and the winder is used to detect the tension. There are many things that happen. The intermediate roll and winder are mechanically connected via a sheet material, but both are speed controlled, so they interfere with each other, and the torque of two machines is shared by one machine due to the error of the control device. Since this may become a load, drooping control is applied to the intermediate roll to prevent overload. However, since drooping control always returns the torque output to speed control and sharpens speed control accuracy, in rewinder equipment that requires high precision and uniform speed, the amount of drooping can cause the difference between the intermediate roll and the winder. There is a problem in that the tension applied to the tension roll changes due to a speed difference, which causes the sheet material to warp or wrinkle.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a rewinder control device using drooping control for an electric motor, which includes a current detection circuit that detects a current of the electric motor, and a current detection circuit that detects a current of the electric motor. an overload setting device for setting an allowable amount of a power converter that converts alternating current into direct current and supplies electric power; and controlling the motor by comparing a signal from the overload setting device and a signal from the current detection circuit. A rewinder control device is provided, characterized in that it includes a comparison circuit that outputs a signal as a signal.

(Function) With this configuration, the accuracy of speed control can be improved by not normally performing drooping control of the intermediate roll, but by performing drooping control when the overload set value is reached. can.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of a rewinder control device according to the present invention.

In the figure, speed setting signal S3 of intermediate roll 3 and speed detection circuit 1
The speed detection signal S4, which is the output signal of 7, is input to the speed control amplifier 13, and the speed is controlled. The output signal of the power converter 18, that is, the current of the drive motor 15 of the intermediate roll 3, is detected by the current detection circuit 25, and the output signal of the power converter 1 is detected by the current detection circuit 25.
The setting signal S7 of the overload setting device 27 for setting the converter allowable amount of 8 is input to the comparison circuit 26. This comparison circuit 26 does not output a signal if it is within the setting range of the overload setting device 27, and outputs the setting signal of the overload setting device 27 to the speed control amplifier 13 when the overload setting value is reached. FIG. 2 is a characteristic curve diagram showing the drive motor current, speed setting signal, and speed detection signal of the rewinder control device according to the present invention. The output signal of the overload setter 27 outputted to the speed control amplifier 13 has the opposite polarity to the speed setting signal S3, and this output signal operates the speed of the intermediate roll 3 in the downward direction, thereby reducing the overload of the intermediate roll. prevent.

Furthermore, even though the speed detection signal S2 changes while the speed setting signal S3 does not change, the output signal of the power converter 18, that is, the drive motor current does not change to the overload setting device 27.
If the speed setting signal S7 is smaller than the speed setting signal S7, the current reference of the power converter 18 changes to follow the speed setting signal S3. However, when the current reference of the power converter 18 reaches the setting signal S7 of the overload setting device 27, the output signal of the comparison circuit 26 and the speed setting signal S3 are respectively input to the speed control amplifier, and the intermediate roll drive motor 15 reduce the speed of the motor to prevent overload. Further, if the current value of the intermediate roll drive motor 15 is within the setting range of the power converter, speed control can be controlled without reducing accuracy.

[Effects of the Invention] As described in detail below, according to the present invention, by providing an overload setting device, a current detection circuit, and a comparison circuit, drooping control of intermediate rolls is normally performed. figure,
By performing drooping control when the overload setting value is reached, highly accurate speed control can be performed. Furthermore, it is possible to prevent the sheet material from being bent or wrinkled due to tension fluctuations caused by the speed difference between the intermediate roll and the winder due to the amount of drooping, which is also effective in terms of efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a characteristic curve diagram of the present invention, FIG. 3 is a block diagram showing the configuration of a conventional control device, and FIG. FIG. 4 is a characteristic curve diagram of a conventional control device. 15... Intermediate roll electric motor 18...
......Power converter 25...Current detection circuit 26...Comparison circuit 27...Overload setting device

Claims (1)

[Claims] A rewinder control device that uses drooping control for an electric motor includes a current detection circuit that detects the electric current of the electric motor, and an overload that sets an allowable amount of a power converter that converts alternating current into direct current and supplies electric power to the electric motor. A rewinder control device comprising: a load setter; and a comparison circuit that compares a signal from the overload setter with a signal from the current detection circuit and outputs the result as a signal for controlling the motor.