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5.3 Tension control for the winding operation of printers
This function is useful for rolling up a sheet of paper into a printer.
The inverter torque is controlled by the tension control, inertia compensation and mechanical loss compensation. Dancer rolls
and tension controllers are not required to roll up a sheet of paper.
(1)
Feature
This control method is suitable for a winding application where a reasonable finish is required in about half the dancer-roll-
winding machine speed.
Purpose
Cost reduction
Eliminate the dancer roll and the tension controller (by tension control).
Keep the tension steady during operation including acceleration/deceleration (by inertia compensation, mechanical
Stable tension
loss compensation).
(2)
Outline
The FR-A700-A1 series inverters are dedicated to winding machines.
FR-A700-A1 controls the motor output torque to make paper tension constant. The winding diameter of a paper roll is
calculated to perform such operation.
Usually, the paper tension loosens when paper feeding speed to a printer is accelerated (decelerated). To make the paper
tension constant, the acceleration (deceleration) torque, which is calculated based on the paper roll inertia, is used in
controlling the motor.
A taper ratio can be also set to prevent the roll from getting too tight.
The FR-A700-A1 series inverters have the following additional functions compared to the FR-A700 series inverters.
Added Function
Winding diameter calculation function,
tension control
Taper function
Inertia compensation function
Mechanical loss compensation function
*1 To make the tension constant, the torque is controlled based on the winding diameter. Tension T = Torque / Radius r
Feature
Controls the motor torque based on the paper roll diameter to make the paper tension
constant.
Reduces the tension when the winding diameter increases in order to prevent the roll
from getting too tight. This reduction ratio can be set to a parameter.
The acceleration torque and deceleration torque are used to keep the paper tension
constant even when the paper feeding speed are being accelerated/decelerated.
The torque command, which is calculated in consideration of the mechanical loss
amount, is given to avoid tension changes due to mechanical losses.
Printing
machine
Main speed command
Start command
Dancer/tension control selection
Inertia compensation acceleration signal
PLC
Inertia compensation deceleration signal
Winding diameter clear
Winding diameter calculation
Stall operation signal
Torque command
Tension control for the winding operation
Description
Nip roll
*1
Torque T
Encoder
IM
FR-A700-A1
FR-A7AP
2
Speed limit
4
STF/STR
X83
X57
X58
X55
X91
X92
6
FR-A7AZ
of printers
Radius r
Vector control
5
73
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