Abstract
The invention relates to a roll stand (1) as a constituent part of a roll stand group (2) in a high-speed wire mill, having at least one roll pair or roll ring pair (5) and a drive shaft (7) which is connected to a motor (6), characterized in that each roll stand (1) of this roll stand group (2) is assigned a motor (6) and a drive shaft (7), and the motor (6), the drive shaft (7) and the at least one roll pair or roll ring pair (5) are arranged linearly with respect to one another.
Claims
1. In a high speed wire rod mill line having a roll-stand group including a plurality of roll stands and outputting wire at a speed of 60 m/s to 130 m/s, the improvement wherein the roll stands are spaced at between 800 mm and 1000 mm, each roll stand has at least one pair of rolls or pair of roll rings, each roll stand has its own drive with a respective motor and a respective drive shaft for rotating the respective pair of rolls or roll rings at a respective angular speed, the motor, the drive shaft and the pair of rolls or pair of roll rings of each roll stand are aligned in a respective straight line with one another, and the motors of the roll-stand group are all connected to a common controller that synchronizes the angular speed of each roll stand dynamically with the angular speed of at least one adjacent roll stand with respect to longitudinal tension and pressure in such a manner as to suppress resonance vibration.
2. The roll stand according to claim 1, wherein the group of roll stands is part of a prefinisher or finishing roll unit.
3. The roll stand according to claim 1, wherein the roll-stand group comprises ten roll stands.
4. The roll stand according to claim 1, wherein the roll stands of the roll-stand group are arranged alternately with predetermined angular offset relative one another.
5. The roll stand according to claim 1, wherein the roll stands of the roll-stand group are arranged in a V-shape relative one another at an angular offset of about 90°.
6. The roll stand according to claim 1, wherein each roll stand is attached to a respective roll block at a predetermined angle to a mill floor.
7. The roll stand according to claim 6, wherein the predetermined angle is about 45°.
8. The roll stand according to claim 6, wherein the predetermined angle for a first half of the roll stands of the roll-stand group is about 90° and for a second half of the roll stands of the roll-stand group is about 180°.
9. The roll stand according to claim 1, wherein each motor is a controllable electric motor or hydraulic motor.
10. The roll stand according to claim 1, wherein a respective integrated transmission is provided for each drive shaft.
11. A high-speed wire rod mill line, comprising at least two roll stands according to claim 1.
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) The invention is explained in more detail below with reference to four FIGS. 1-4, in which FIG. 1 represents the prior art, FIGS. 1-3 [2-4] in contrast represent diagrammatically preferred embodiments of the invention. Therein:
(2) FIG. 1a is a diagrammatic detail view of a drive train of a wire roll stand according to the prior art as well as an illustration of the bend angle inside the drive,
(3) FIG. 1b shows the bend angle from FIG. 1a,
(4) FIG. 2 is a diagrammatic plan view of a roll block comprising six roll stands,
(5) FIG. 3 is an enlarged view of a detail of a transmission structure in one of the roll stands from FIG. 1; and
(6) FIG. 4 is a schematic diagram of the electric controller for three roll stands connected one downstream of the other.
WAYS OF CARRYING OUT THE INVENTION
(7) FIG. 1a shows a diagrammatic sectional view of a drive train of a wire roll stand (not shown) according to the prior art as well as an illustration of the bend angle α, β between the planes A, B, C inside the drive. Half of the roll stands of a roll block arranged in a V-shape at an angle of 45° to the mill floor are driven via a common drive shaft 20. The roll stand drive shaft 22 is driven via a bevel gear transmission 21, comprising two bevel gears 21a, 21b set at an angle of 90° to one another. This roll stand drive shaft 22 in turn extends (not shown) to a transmission (not shown) for driving the rolls or roll rings (not shown) of the roll stand. The entire drive of the roll stand according to the prior art thus has two spatial bends or deflections, namely a first bend by an angle α=90° between the plane A parallel to the mill floor and in which the drive shaft 20 extends, and plane B that is perpendicular to the plane A and in which the roll stand drive shaft 22 extends, as well as a second bend at an angle β=45° between the plane A and the plane C in which the roll stand drive shaft 22 also extends. FIG. 1b shows these planes A, B, C as well as their angular offset to one another again separately for easier comprehension, without showing the transmission arrangement from FIG. 1a.
(8) FIG. 2 shows a roll-stand group 2 having roll stands 1a-1f mounted on a roll block 3. The roll stands 1a-1f extend at an angle of 45° to the mill floor 4 relative one another with the left-side roll stands 1a, b, c alternate with the right-side roll stands 1d, e, f at an angle of 90° to one another. The roll stands 1a-1f are mounted in the roll block 3 such that the roll gaps of the respective roll pairs 5a-5f are essentially aligned with respect to one another so that a wire (not shown) can be guided without bends or kinks through all of the roll stands 1a-1f of the roll-stand group 2. The individual roll stands 1a-1f each basically have a motor 6, a drive shaft 7, a transmission 8 and finally the respective pair of rolls 5. As shown, these parts 5, 6, 7, 8 of each roll stand 1 are arranged in a straight line with one another without spur gear and bevel gear combinations and without the necessity of longitudinal shafts running along the roll block 3. The longitudinal axes of these parts 5, 6, 7, 8 accordingly lie essentially on one line, so that in particular in the region of the rolls of course parallel displacement can be carried out to the extent predetermined by the transmission arrangement 8 overall, without hereby deviating from the principle of the straight-line arrangement in the respective roll stand 1a-1f.
(9) FIG. 3 shows an enlarged plan view of the transmission 8 of the roll stand if from FIG. 1, which serves as speed-change transmission and drive transmission. As shown, the transmission 8 is between the motor 6 and the drive shaft 7 on the one side and the pair of rolls 5f. At the end of the drive shaft 7 facing the pair of rolls 5f, is a transmission gear 9 (indicated diagrammatically) that meshes with an intermediate shaft 10 for the rolls of the pair of rolls 5f. A predetermined ratio between the angular speed of the drive shaft 7 and the angular speed of the intermediate shaft 10 is the result of the different number of teeth of the gears of the drive shaft 7 and the intermediate shaft 10. A transmission gear 11 shrunk on the intermediate shaft 10 in turn meshes with a roll drive shaft 12a for a roll of the pair of rolls 5f and with the auxiliary shaft 13 that in turn meshes with the second roll drive shaft 12b for a roll of the pair of rolls 5f, with a predetermined gear ratio between the intermediate shaft 10 or the auxiliary shaft 13 and the roll drive shafts 12a, 12b, the two roll drive shafts 12a, 12b being driven at the same angular speed but with different rotation directions. Replacement of the rolls 5f is done individually or by pairs, while changing the drive shafts 12a, 12b preferably takes place with a module comprised of the pairs of rolls 5f, their roll drive shafts 12a, 12b, the holder plate 15, and the (unillustrated) adjuster for the roll gap pulled out of the speed-change transmission 8 and replaced by inserting a replacement module.
(10) Finally FIG. 4 shows a circuit diagram of an example of an electric controller 15 for roll stands 1d, 1b, 1e, shown only by way of example. The controller 15 is comprised essentially of a computation unit 17 and respective drive operators 19. The controls (angular speed and torque) of each drive operator 19 can be adjusted individually in terms of vibration engineering for each roll stand. Furthermore, adjustable notch filters 19a counteract residual resonances for each drive train. The computation unit 17 is connected to all of the roll stands 1d, 1b, 1e of the roll module 2 and receives therefrom actual values of all measuring sensors. Relative the roll stands 1d, 1b, 1e, the angular speed of the respective motors 6 and the respective loads (motor current, torque and in the case of hydraulic motors pressure and flow) are measured. The computation unit 17 determines by means of technological and mechanical parameters the operating speed of the individual roll stands. The motors 6 of the individual roll stands are connected to one another by the computation unit 17 as well as via a drive data bus 16. A multi-layered, dynamic synchronization of the individual roll stands is thus achieved. Optionally dimension measuring devices 14a and 14b can be connected on the inlet side and outlet side to detect the dimensional change of the rod wire (height, width, ovalness). In the computation unit 17 a first additional desired angular speed value is derived from the nominal angular speed difference from the adjacent drive per roll stand 1d, 1b, 1e. To this end, the computation unit 17 is equipped with an observer that determines a dynamic real-time set point correction for each stand based on a mathematical model. The angular speed correction per stand is transmitted to the drive operators. Parallel to this, a nominal actual-value comparison of the speeds on the other roll stands is carried out via the drive data bus 16. The coupling of the angular speed controls can be controlled and is engaged and deactivated depending on the material tracking of the wire head in a stepwise manner. Material tracking is controlled by sensors 18a, 18b upstream of and downstream of the roll stands 1d, 1b, 1e by the motor currents and corrected by calculation depending on material speed and forward creep. The computation unit 17 is equipped with a further variable second additional set point for each roll stand, so as to limit for each roll stand 1d, 1b, 1e the individual drop in angular speed in the pass operation. This second additional set point is engaged or deactivated in a stepwise manner depending on the material tracking inside the computation unit. The effects of the second additional set point are monitored by measuring technology, evaluated in an adaptation algorithm and varied for the next pass. A third additional set point for the angular speed of each roll stand 1d, 1b, 1e serves to change the angular speed ratios of the roll stands to one another. The third additional set point can be derived from a manual correction or from a first computed value of the computation unit 17, which during the rolling with the aid of a mathematically simulation model represents the tension pressure ratios, or from a second computed value, which comes for example from the dimension-measuring devices 14a, 14b upstream or downstream of the roll stands 1d, 1b, 1e and the computed shape and diameter deviation. The third additional set point can be engaged or deactivated in a stepwise manner depending on the material tracking. Furthermore, material tracking inside the computation unit 17 controls a state-dependent set point specification that defines different desired angular speed values for the case of threading, rolling and unthreading.
(11) A memory circuit 17b detects the correction values currently determined and ensures an adaptive correction of the synchronization for the next rod wire.
