Method for braking a running metal strip and unit for carrying out the method
View Patent ↗The method and unit for braking a metal strip ( 1 ), running off a wind-out coiler ( 2.1 ) in the form of a coil ( 1.1 ) and running onto a wind-on coiler ( 2.2 ) again, are to guarantee that a surface of the metal strip remains undamaged and a full effective braking force is exerted on the metal strip ( 1 ) by means of an eddy current brake ( 3.1 ) with a rotating magnet system ( 3.2 ). The above is achieved, whereby the braking force is exerted on the metal strip ( 1 ) by means of an induced counter-torque against a support bearing ( 4 ) to one side in a non-contact manner, whereby the support bearing ( 4 ) may be embodied as a counter roller ( 4.1 ).
1. A method for braking a metal strip, comprising:
providing an unwinding reel and a winding-up reel;
running the metal strip off from the unwinding reel as a coil;
running the metal strip onto the winding-up reel;
providing a braking assembly having an eddy-current brake having a rotating magnet system for generating a braking action on the metal strip and an abutment;
wherein the eddy-current brake remains apart from the metal strip in a contactless fashion;
running the metal strip through the braking system;
supporting the metal strip with the abutment as the metal strip runs through the braking system; and
generating an eddy-current with the rotating magnet system for causing a braking action against the metal strip.
2. The method as claimed in claim 1 , wherein the metal strip is subjected at least to lengthwise division.
3. The method as claimed in claim 1 , wherein the braking action is set by the rotation speed of the magnet system independently of the speed of the metal strip.
4. The method as claimed in claim 1 , wherein the braking action is set by the local adjustment of the magnet system independently of the speed of the metal strip.
5. The method as claimed in claim 1 , wherein the braking action is set by the local adjustment of the mating roller independently of the speed of the metal strip.
6. The method as claimed in claim 1 , wherein the braking action is set by the local adjustment of the respective magnet system within a drum independently of the speed of the metal strip.
7. The method as claimed in claim 1 , further comprising the step of:
providing a computer-assisted program for an open-loop/closed-loop control of braking of the rolled metal strip, the computer-assisted program having at least one of the following program steps:
input/recording of data for setting the speed of the metal strip;
input/recording/output of data for setting the braking action of the rotating magnet system;
input/recording/output of data for setting the rotation speed of the magnet system;
input/recording/output of data for adjusting the local position of the magnet system;
input/recording/output of data for setting the air gap as a distance between the rotating magnet system and the metal strip;
input/recording/output of data from the dimensions of the coils; and
input/recording/output of data for adjusting a local position of the abutment.
8. The method as claimed in claim 1 , further comprising the step of:
providing a computer-assisted program having at least one of the following functions:
recording/input of the actual values from a braking-tension measurement and/or speed measurement of the metal strip;
input of required setpoint values;
output of a rotational-speed value for the rotating magnet system;
output of a distance value for the rotating magnet system in relation to the metal strip; and
display of the control values on a display.
9. The method as claimed in claim 1 , further comprising the step of:
providing a frequency converter for setting the rotational speed of the rotating magnet system.
10. The method as claimed in claim 9 , further comprising the steps of:
providing a preselection program for receiving values for at least one of the following parameters of the metal strip:
thickness;
width;
material;
number of items;
desired tension; and
desired braking force;
determining a distance of the mating roller or the rotational speed of the rotating magnet system with preselection program;
controlling the frequency converter while the metal strip is running by measuring the tension or the braking force; and
changing the tension or the braking force by changing the distance of the mating roller or the rotational speed of the rotating magnet system.
11. A unit for braking a metal strip, comprising:
an unwinding reel;
a coil operably associated with the unwinding reel;
a winding-up reel; and
a braking assembly having:
an eddy-current brake; and
an abutment;
wherein the metal strip passes between the eddy-current brake and the abutment; and
wherein the metal strip comes into contact with the abutment and remains apart from the eddy-current brake in a contactless fashion.
12. The unit as claimed in claim 11 , wherein the eddy-current brake is a rotating magnet system arranged in a contactless fashion in relation to the metal strip.
13. The unit as claimed in claim 12 , wherein the rotating magnet system is arranged so as to pivot about a center point of a drum.
14. The unit as claimed in claim 12 , wherein the rotating magnet system is configured for radial adjustment.
15. The unit as claimed in claim 12 , wherein a distance may be set in a stepless manner as a contactless distance between the rotating magnet system and the drum.
16. The unit as claimed in claim 12 , further comprising:
an edge on the rotating magnet system for absorbing tangential forces of permanent magnets.
17. The unit as claimed in claim 12 , further comprising:
a casing operably associated with the rotating magnet system for absorbing centrifugal forces.
18. The unit as claimed in claim 12 , further comprising:
a control system comprising:
a frequency converter;
a control loop;
a means for measuring the tension of the metal strip and the braking force; and
a means for varying the distance between the abutment and the eddy-current brake.
19. The unit as claimed in claim 18 , further comprising:
a PLC data line;
an input module;
a control part having a supply line and a display for displaying data;
a first actuator for actuating the means for varying the distance between the abutment and the eddy-current brake;
a second actuator for actuating a motor of the rotating magnet system; and
lines for measuring the speed of the metal strip, the tension of the metal strip, and the braking force.