GB2119968A - Apparatus for controlling the shape of rolls in metal rolling mills - Google Patents

Abstract

An apparatus for controlling the shape of rolls (1) in metal rolling mills, particularly in steel wide-strip rolling mills, with varying wear along the length of the roll, is constructed such that contactless measured value receivers (2) are provided in the rollstand along the length of the roll (1), for continuous measurement of actual diameter values of the roll (1) differing from the nominal shape, which are connected for transmission of the diameter values to and processing of them in a computer (3), by which, based on the deviations from the nominal shape so detected, the thermal expansion of the roll (1) is controllable by a locally- differentiated supply of heat and/or cold to the interior of the roll along its length, without adapting the rolling programme to the expected wear of the roll (1), so that the shape of the roll (1) can be controlled in a simple way during the rolling process. <IMAGE>

Description

SPECIFICATION Apparatus for controlling the shape of rolls in metal rolling mills The invention relates to an apparatus for controlling the shape of rolls in metal rolling mills, particularly in steel wide-strip rolling mills, with varying wear over the length of the roll.

It is known that the shape of rolls in rolling mills, particularly hot rolling mills, is influenced in a variable and not easily controllable manner by wear during long periods of time.

These variations in shape have effects upon the shape and profile of the rolled strips. In order to take these variations into account, it has previously been necessary to adapt the rolling programme to the expected wear of the rolls, which is costly and not sufficiently accurate.

From this standpoint, it is the purpose of the invention to provide an apparatus for controlling the shape of rolls in metal rolling mills, particularly in steel wide-strip rolling mills, with varying wear over the length of the roll, which, without adapting the rolling programme to the expected wear of the rolls, allows control of the shape of the roll in a simple way during the rolling process.

According to the invention, the purpose is solved in that contactless measured value receivers, for continuously measuring the varying actual diameter values of the roll differing from the nominal shape, along the length ofthe roll are provided in the roll-stand and are connected so as to transmit the measured values to and process them in a computer, by which, based on the deviation from the nominal shape thus detected, the thermal expansion of the roll is controllable by supplying heat to the interior of the roll locally differentiated over its length. In an advantageous manner, additional cooling devices for the external surface of the roll are connected to the computer.By means of these additional controllable cooling devices, the differentiated heating inside the roll brings about a relatively rapidly-attained stationary state of temperature distribution and thus a stationary altered roll diameter. Since the heat transfer in the roll is thus considerably reduced, the local limitation of the zonal heating is especially effective. Moreover, it is advantageous for the roll to be provided with two reference diameter lines on either side, which are arranged opposite detectors connected to the computer.

The advantages of the apparatus according to the invention, in particular, are that it renders completely unnecessary adaptation of the rolling programme to the wear of the roll, previously required, and in a simple way allows so-called "anticipation-free rolling" and maintenance of a constant roll gap, so that rolling of flat strips with the prescribed profile can be effected.

In the following, an embodiment of the invention is explained in conjunction with a diagrammatic drawing.

In a roll 1 installed in a rollstand (not shown), with variable wear over the length of the roll, contactless measured value receivers 2 are arranged, along the roll, for continuous measurement of the actual diameter values of the roll differing from the nominal shape. The harsh environment in a rolling mill, particularly in a hot wide-strip rolling mill, imposes particularly heavy requirements on the contactless measured value receivers 2.These special requirements can be provided for by carrying out the known method of relative measurement by mounting the measured value receivers 2, which for example are inductive movement detectors, in a rigid support, not shown, providing the roll 1 with two reference diameter lines at either end, producing reference values from detectors located opposite these reference lines and transmitting the reference values to a computer 3, to which all the other measured diameter values are transmitted.

From the sequentially-measured values for separate regions of the roll 1, information is derived about the trend in diameter variation, e.g. through wear, by which the appropriate heating zones 4, 5, 6, 7 and 8 inside the roll can be supplied with heat via the computer 3 and a heat supply device 9 connected to it. In this way, maintenance of a constant roll gap and thus the rolling of flat strips with the prescribed profile can be carried out.

1. Apparatus for controlling the shape of rolls in metal rolling mills, particularly in steel wide-strip rolling mills, with varying wear over the length of the roll, wherein contactless measured value receivers (2), for continuously measuring the varying actual diameter values of the roll (1 ) differing from the nominal shape, are arranged in the rollstand along the length of the roll (1 ) and are connected so as to transmit the diameter measurements to and process them in a computer (3), by which, based on the deviation from the nominal shape thus detected, the thermal expansion of the roll (1 ) is controllable buy a supply of heat to the interior of the roll locally differentiated over its length.

2. Apparatus according to claim 1, wherein additional cooling devices for the external surface of the roll (1 ) are connected to the computer (3) and are controllable from it.

3. Apparatus according to claim 1 or 2, wherein the roll (1) has two reference diameter lines on either side arranged opposite detectors which are connected to the computer (3).

4. Apparatus according to claim 1, substantially as described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Apparatus for controlling the shape of rolls in metal rolling mills The invention relates to an apparatus for controlling the shape of rolls in metal rolling mills, particularly in steel wide-strip rolling mills, with varying wear over the length of the roll. It is known that the shape of rolls in rolling mills, particularly hot rolling mills, is influenced in a variable and not easily controllable manner by wear during long periods of time. These variations in shape have effects upon the shape and profile of the rolled strips. In order to take these variations into account, it has previously been necessary to adapt the rolling programme to the expected wear of the rolls, which is costly and not sufficiently accurate. From this standpoint, it is the purpose of the invention to provide an apparatus for controlling the shape of rolls in metal rolling mills, particularly in steel wide-strip rolling mills, with varying wear over the length of the roll, which, without adapting the rolling programme to the expected wear of the rolls, allows control of the shape of the roll in a simple way during the rolling process. According to the invention, the purpose is solved in that contactless measured value receivers, for continuously measuring the varying actual diameter values of the roll differing from the nominal shape, along the length ofthe roll are provided in the roll-stand and are connected so as to transmit the measured values to and process them in a computer, by which, based on the deviation from the nominal shape thus detected, the thermal expansion of the roll is controllable by supplying heat to the interior of the roll locally differentiated over its length. In an advantageous manner, additional cooling devices for the external surface of the roll are connected to the computer.By means of these additional controllable cooling devices, the differentiated heating inside the roll brings about a relatively rapidly-attained stationary state of temperature distribution and thus a stationary altered roll diameter. Since the heat transfer in the roll is thus considerably reduced, the local limitation of the zonal heating is especially effective. Moreover, it is advantageous for the roll to be provided with two reference diameter lines on either side, which are arranged opposite detectors connected to the computer. The advantages of the apparatus according to the invention, in particular, are that it renders completely unnecessary adaptation of the rolling programme to the wear of the roll, previously required, and in a simple way allows so-called "anticipation-free rolling" and maintenance of a constant roll gap, so that rolling of flat strips with the prescribed profile can be effected. In the following, an embodiment of the invention is explained in conjunction with a diagrammatic drawing. In a roll 1 installed in a rollstand (not shown), with variable wear over the length of the roll, contactless measured value receivers 2 are arranged, along the roll, for continuous measurement of the actual diameter values of the roll differing from the nominal shape. The harsh environment in a rolling mill, particularly in a hot wide-strip rolling mill, imposes particularly heavy requirements on the contactless measured value receivers 2.These special requirements can be provided for by carrying out the known method of relative measurement by mounting the measured value receivers 2, which for example are inductive movement detectors, in a rigid support, not shown, providing the roll 1 with two reference diameter lines at either end, producing reference values from detectors located opposite these reference lines and transmitting the reference values to a computer 3, to which all the other measured diameter values are transmitted. From the sequentially-measured values for separate regions of the roll 1, information is derived about the trend in diameter variation, e.g. through wear, by which the appropriate heating zones 4, 5, 6, 7 and 8 inside the roll can be supplied with heat via the computer 3 and a heat supply device 9 connected to it. In this way, maintenance of a constant roll gap and thus the rolling of flat strips with the prescribed profile can be carried out. CLAIMS

1. Apparatus for controlling the shape of rolls in metal rolling mills, particularly in steel wide-strip rolling mills, with varying wear over the length of the roll, wherein contactless measured value receivers (2), for continuously measuring the varying actual diameter values of the roll (1 ) differing from the nominal shape, are arranged in the rollstand along the length of the roll (1 ) and are connected so as to transmit the diameter measurements to and process them in a computer (3), by which, based on the deviation from the nominal shape thus detected, the thermal expansion of the roll (1 ) is controllable buy a supply of heat to the interior of the roll locally differentiated over its length.

2. Apparatus according to claim 1, wherein additional cooling devices for the external surface of the roll (1 ) are connected to the computer (3) and are controllable from it.

3. Apparatus according to claim 1 or 2, wherein the roll (1) has two reference diameter lines on either side arranged opposite detectors which are connected to the computer (3).

4. Apparatus according to claim 1, substantially as described with reference to the accompanying drawing.