73
Tension control for the winding operation
of printers
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.
(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.
*1 To make the tension constant, the torque is controlled based on the winding diameter. Tension T = Torque
/ Radius r
Purpose
Feature
Cost reduction
Eliminate the dancer roll and the tension controller (by tension control).
Stable tension
Keep the tension steady during operation including acceleration/deceleration (by inertia compensation, mechanical
loss compensation).
Added Function
Description
Winding diameter calculation function,
tension control
Controls the motor torque based on the paper roll diameter to make the paper tension
constant.
Taper function
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.
Inertia compensation function
The acceleration torque and deceleration torque are used to keep the paper tension
constant even when the paper feeding speed are being accelerated/decelerated.
Mechanical loss compensation function
The torque command, which is calculated in consideration of the mechanical loss
amount, is given to avoid tension changes due to mechanical losses.
FR-A700-A1
STF/STR
X58
X57
Nip roll
*1
4
Dancer/tension control selection
Inertia compensation acceleration signal
X83
Torque command
FR-A7AZ
Start command
6
Inertia compensation deceleration signal
Stall operation signal
Encoder
FR-A7AP
Vector control
Radius r
X92
Printing
machine
IM
Torque T
Speed limit
X55
Winding diameter clear
Winding diameter calculation
X91
2
Main speed command
PLC
