JPH0839139A - Method for controlling payoff reel - Google Patents

Abstract

PURPOSE:To adequately control the tension of a coil and to lessen generation of flaws on this coil by adjusting a regulator by an air pressure and controlling the torque of an air brake. CONSTITUTION:The coiling diameters at a payoff reel 1 are successively measured and the momentarily changing measured values are exchanged to electric currents which are inputted to an arithmetic unit. The rigidity of the coil is determined from these input values and the width and thickness, etc., of the coil 2 previously inputted to the unit. The adequate set pressures of the air brake 6 are successively calculated and the signals based on the set values are outputted to a regulator 9 to regulate the braking of the air brake 6, by which the reverse tension of the un-coiled coil 2 is so controlled as to be kept adequate at all times. As a result, the torque of the air brake is controlled and, therefore, the tension of the coil 2 between the payoff reel 1 and a processor 3 is adequately controlled and the generation of the flaws on the coil is lessened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a pay-off reel in which a coiled steel plate is rewound and fed at a constant speed in a processing line for processing or surface-treating a steel plate.

[0002]

2. Description of the Related Art Conventionally, in order to unwind a coil-shaped steel plate, it is necessary to apply a certain tension to a slack in the steel plate in a pay-off reel device. on the other hand,
The coil-shaped steel sheet has a smaller coil diameter as it is sent out, so there is a problem that the torque applied in the rotation direction of the payoff reel will sag in the steel sheet unless it is changed to a value inversely proportional to the diameter. As a control method, generally, a constant tension control (current control) is often performed by using a DC motor or an AC motor capable of controlling torque in the drive unit of the payoff reel. However, this method is complicated, requires space, and is expensive. Although there is a method of directly measuring the tension, there is a problem in that the equipment becomes large and complicated and the cost is high.

As a simple method, there is a method of applying a constant reverse torque by a pay-off reel air brake. However, this method also has the following problems. When the coil diameter becomes small, over tension is applied to the coil, coil tightening occurs, and scratches occur. At that time, an excessive momentary reverse torque is applied to the processor, which may cause a drive motor trip, resulting in a line pause. Further, the tension fluctuation causes the coil to move up and down, resulting in an impact flaw.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems in the prior art as described above, in which the torque of the air brake is controlled and the tension of the coil between the payoff reel and the processor is controlled. An object of the present invention is to provide a method for controlling a pay-off reel in which the occurrence of coil scratches is extremely reduced by performing the control properly.

[0005]

That is, according to the present invention, the coil winding diameter in a pay-off reel is successively measured, and the ever-changing measured value is converted into an electric current and input to an arithmetic unit. The coil stiffness is calculated from the width and plate thickness of the coil, and the appropriate set pressure of the payoff reel air brake is calculated sequentially, and a signal based on this set value is output to the regulator to adjust the braking of the air brake. By this, the reverse tension of the coil to be unwound is controlled so that it is always appropriate.

[0006]

The present invention will be described in detail below with reference to the drawings. 1 is an explanatory view showing the configuration of the present invention, FIG. 2 is a relationship diagram of a coil diameter and a coil diameter sensor output, FIG. 3 is a relationship diagram of a regulator input and output air pressure, and FIG. 4 is a coil diameter and air pressure. It is a relationship diagram. In FIG. 1, 1 is a payoff reel,
Reference numeral 2 is a coil, and 3 is a processor which is operated by a drive motor 4 to remove rust on the steel plate surface and determine the line threading speed. A coil diameter sensor 5 is a distance meter of any type such as an ultrasonic type, a photoelectric type, and a laser type, and is connected to the control device 8. Reference numeral 6 is an air brake for braking the payoff reel 1. Reference numeral 9 is a regulator installed between the air brake 6 and the compressed air source 10. The operation of the regulator is controlled by an electric signal from the controller 8. Reference numeral 7 is a coil width / thickness setting device, which sets values such as the width and thickness of the coil in advance and inputs the values to the control device 8 to obtain the rigidity value.

In order to control the pay-off reel according to the present invention, first, the width and thickness values of the coil to be rewound are set by the coil width / thickness setter 7, and the set values are input to the controller 8. Keep it. Next, the drive motor 4 is rotated, and the coil passing through the processor 3 is controlled so as to have a predetermined plate passing speed. On the other hand, in the control device 8, since the coil diameter is measured every moment by the coil diameter sensor 5 and the value is input to the control device 8, the value and the width of the coil,
The air pressure for keeping the tension of the coil between the pay-off reel 1 and the processor 3 constant based on the thickness is performed by calculating the following equation (1), and the value of the output Pi is output from the control device 8 to the regulator 9. And the regulator 9 is controlled based on the signal, so that the compressed air source 1
The air pressure from 0 to the air brake 6 is adjusted to a predetermined value. Pi = k × t ² × b × ri (1) Pi: Pressure applied to the processor k: Constant t: Coil thickness b: Coil width ri: Coil radius On the other hand, the air brake 6 is as described above. When the air pressure is applied to the pay-off reel 1, the torque is changed according to the pressure, and as a result, the coil tension between the pay-off reel 1 and the processor 3 is controlled to a proper constant value. The respective relationships are illustrated in FIGS. 2 to 4. That is, FIG. 2 shows the relationship between the coil diameter that increases or decreases during winding or unwinding, and the output of the coil diameter sensor that measures the coil diameter, and FIG. 3 shows the relationship between the output air pressure and the regulator input. 4 shows the coil diameter and
A specific example (a plate thickness of 2.0 mm and a plate width of 925 mm) with respect to the air pressure that gives an appropriate braking tension to the coil diameter will be shown. As a result, the coil tension can be maintained at an appropriate constant value.

[0008]

Example: coil width 500 to 1300 mm, coil thickness 1.
As a concrete example of the control result for the coil of 0 to 4.0 mm, the result of automatic operation of the target steel plate (constant 5.0, plate thickness 2.0 mm, plate width 925 mm) is shown. Coil radius (mm) Brake pressure (kg / cm ² ) 900 1.66 850 1.57 800 1.48 750 1.38 700 1.29 650 1.20 600 1.11 550 1.01 500 0.92 450 0.83 400 0.80 When the control is performed so that the above brake pressure is obtained,
There were no scratches.

[0009]

As described above, according to the present invention, the regulator is installed between the air brake and the compressed air source, and the regulator is adjusted by the air pressure calculated from the coil width, thickness and coil diameter. Since the torque of the air brake is controlled by doing so, the tension of the coil between the payoff reel 1 and the processor 3 can be properly controlled, and therefore the occurrence of coil scratches can be compared with the conventional method. Can be much less, and the effect is extremely large.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of the present invention.

FIG. 2 is a diagram showing a relationship between a coil diameter and a coil diameter sensor output.

FIG. 3 is a diagram showing a relationship between regulator input and output air pressure.

FIG. 4 is a diagram showing an example of a relationship between a coil diameter and air pressure.

[Explanation of symbols]

 1 Payoff reel 2 Coil 3 Processor 4 Drive motor 5 Coil diameter sensor 6 Air brake 7 Coil width / thickness setter 8 Control device 9 Regulator 10 Compressed air source

Claims (1)

[Claims] 1. A coil winding diameter on a pay-off reel is sequentially measured, and an ever-changing measured value is converted into a current and input to an arithmetic unit. The input value and the width and plate thickness of the coil that are input in advance. Reverse tension of the coil to be unwound by adjusting the brake stiffness of the coil by calculating the coil stiffness from the above, calculating the appropriate set pressure of the payoff reel air brake one after another, and outputting a signal based on this set value to the regulator. A method for controlling a pay-off reel, wherein the pay-off reel is controlled so that the value is always appropriate.