High speed shear for the cross section of rolling strip
FIELD OF THE INVENTION The invention relates to a high-speed shear with a blade disposed at least on one of the two drums located opposite each other, in particular a chisel blade with blade edge, which can be accelerated at the speed of advance of a rolling strip to be cut and the drums can be adjusted opposite each other for the execution of a cut, the drums being able to be accelerated, by means of at least one driving device assigned for these, at a tangential speed suitable for the speed of the rolling strip in question and a separate piloted driving device can be assigned to at least one of the drums. STATE OF THE ART In the production of hot broadband, it tends more and more to continuous rolling. The application material is produced by welding of previous bands or in casting machines. However, the hot-rolled strip is also processed in the course of a semi-continuous rolling process in which the applied material can have multiple lengths of pre-strip that can be stored intermediate in roller tracks, in roll hearth furnaces or in drawers of rolls. The finished strip after the hot rolling process has to be cut to the band lengths corresponding to the required roll weights. The cutting must be carried out in continuous operation, that is, at the rolling speed. For this reason, it has to be carried out at the currently customary speeds of hot-rolled broadband mills in the range of 5 m / sec to 30 m / sec, preferably 10 m / sec. The band thicknesses are between 0.5 mm and 30 mm, preferably between 0.6 mm and 1.5 mm. Known drum and connecting rod shears used for hot-band cutting are not designed for such high speeds. But also the flying shears that are usually applied in connection with tandem cold rolling mills, currently work normally at band speeds only up to about 6 m / sec; here, too, there is a demand for considerably greater speed. Known shearing processes, in which the knife drums have to be accelerated for cutting at a belt speed of up to 30 m / sec and then braked again, can not be performed already for these high speeds with Affordable costs. As a solution, it had already been proposed that the acceleration of the knife drums at the speed of the belt or the operation of the knife drums at the speed of the belt be piloted separately from the movement performed perpendicularly to the belt, and arranged at least for one of the drums a regulating device operable separately. Thus, for one of the drums a blade can be provided and for the other drum an anvil that acts in conjunction with the blade or a shell area acting as an anvil. However, with this shearing configuration, an exact separation of the strip is guaranteed only if the cutting space between the cutting edges of the blade and the counter or the envelope area of the counter-drum is zero. In another case - .ej. , due to excess length of the blade - the blade and the anvil can be overloaded until the break, and in the case of a shorter length of the blade the separation cut is incomplete. But the adjustment of a cutting space to "zero", due to one or more magnitudes of influence that act jointly by thermal expansion, wear, elastic behavior of the adjustment device, acceleration forces, manufacturing tolerances, etc. , it can not be achieved, or at least not with the necessary security. For this reason it is necessary to project the blade out of the cutting circle in order to reliably separate the strip. But this protrusion of the cutting edge produces a rapid increase in cutting forces and thus phenomena of wear in all the components of the cutting elements, of the adjustment device, reaching up to the bearings of the drums. SUMMARY OF THE INVENTION The invention, based on the aforementioned state of the art, is based on the objective of perfecting a high-speed shear for hot-band and cold-band cutting, eliminating the aforementioned drawbacks and technical limits, such as so that exact cuts are guaranteed at band speeds of up to 30 m / sec. also for minimum band thicknesses, avoiding in particular the overloading of the blade, the counter and the area of the backtack cover, and / or incomplete cuts. MODES OF THE INVENTION For achieving the objective, for a high-speed shear of the type characterized in the preamble of claim 1, it is proposed with the invention that the chisel blade of the blade drum protrudes from the cutting circle with respect to the or the shroud area that acts as an anvil of the second drum and that is supported with flexible support against a preset recovery force. In this, a configuration provides that the chisel blade be supported with flexible support in a radial guide of the blade drum. Instead of the radial guide it can also be envisaged that the chisel blade can support with a rigid support on a rocker arm, the pivot point of the rocker being located on the blade drum. However, an alternative solution can also be used, the chisel blade being held non-flexible in the blade drum and the adjustment device that houses the blade drum with its bearings with flexible support against a pre-adjustable restoring force being supported. With both technical solutions, the same result can be achieved, since in fact the blade that protrudes first from the cutting circle in the cutting process, by collision with the anvil or the area of the casing acting as an anvil of the second drum, can yield both that an impermissible increase in cutting forces and thus wear phenomena in all the components of the cutting elements and of the adjustment device to the bearings of the drums can be safely avoided. One configuration of the invention provides that one of the drums be equipped with a chisel knife and the other drum with an anvil that acts in conjunction with the knife. But alternatively one can also make use of the possibility that one of the drums is equipped with a chisel blade which acts in conjunction with the envelope area of the second drum which serves as an anvil. As a whole, with the invention it is achieved that the chisel blade with the rotation of the drum contacts the band, the cut and then contacts the anvil or the area of the casing that acts as an anvil and then expands and flexes. The advantage of the joint action between the chisel blade and the anvil drum is that the synchronization of the tangential speeds of the two drums does not need to be particularly exact. On the contrary: for a difference of the tangential speeds between the chisel blade and the hammer drum, the entire perimeter of the hammer drum can be used in conjunction with the blade, thereby achieving a distribution of wear and improving favorably. the availability of the shear. Consequently, the principle described above is very particularly suitable for the hard work in hot rolling mills for high belt speeds. Other configurations of the invention are provided corresponding to the subordinate claims. BRIEF DESCRIPTION OF THE DRAWINGS The following explanation of some exemplary embodiments represented schematically in the drawings give particularities, attributes and advantages of the invention. They show: Fig. 1 in side view and partly in section, a drum of blades acting together with a drum of an anvil, Fig. 2 in side view and partly in section, another embodiment of a blade drum acting in conjunction with an anvil drum, Fig. 3 in section perpendicular to the axis of rotation and on an enlarged scale, a blade drum with a blade of elastically supported chisel; Fig. 4 in section and in joint action with an anvil drum, a
blade drum with pneumatic / hydraulically supported chisel blade; Fig. 5 side view, a setting device for the
shaving knife of the anvil drum with elastic support of a setting beam; Fig. 6 in side view and partially in section, a blade of
chisel that can support with a large number of elastic support elements of a blade drum. Fig. 7 a schematic representation
of the blade drum and the hammer drum with a segmented chisel blade, deformed by the action of the load. Fig. 8 the schematic representation according to Fig. 7 with a segmented chisel blade. DETAILED DESCRIPTION OF THE INVENTION Fig. 1 shows a cantilever high-speed shear with a blade drum 6 and an anvil drum 7 which cooperates with that for cutting a rolling strip 4. The two drums 6, 7 they can be accelerated with a drive device not shown at the feed speed of the rolling strip 4 to be cut and can be adjusted with respect to each other for the execution of a cut with a setting device 36 (Fig. 5) in yes known. By means of a setting device of this type, the two drums 6, 7, independently of the adjustment process intended for the execution of a cut, are carried at a tangential speed corresponding to the speed of advance of the band 4 to be cut , and for the rest of the duration of operation is maintained at this tangential speed, while the setting for shearing immediately after the cut is returned to an open neutral position to pass without cutting through the shear a preset length of piece of band. According to the invention, it is provided that the chisel blade 1 of the blade drum 6 is supported with resilient support, protruding out of the cutting circle 40 with respect to an anvil 24 (Fig. 5) or a shell area of the drum 7 which it acts as an anvil, and against a block of steel springs 12, with a recovery force that can be preset. In this, the chisel blade 1 can be supported with elastic support in a radial guide 9 of the blade drum 6. With such an execution of the blade support according to Fig. 1, the radial guide 9 accommodates the chisel blade 1 with its handle 11 which is guided in the radial direction. In the handle 11 there is a flange 10 against which the steel spring block 12 rests and with this the chisel knife 1 rests with elastic support in its protruding cutting position with a predetermined restoring force. The flange 10 is maintained in the radial direction by a closing element 8, the closing element 8 being fixed by means of screws 20 in the drum 6. In this way, the chisel blade 1 can be elastically retracted in FIG. such a measure, for example, against the elastic force in the direction of the center of the drum in the cutting process after the separation of the rolling strip 4, which prevents the deterioration of the cutting edge of the blade 3 or of the area of the anvil drum casing 7. On the other hand, the anvil drum 7 can be of a relatively soft material to protect the chisel blade 1. The separate pilotable setting device 36 is shown in the representation of FIG. 2 in purely schematic form as a double arrow. Its execution is known by the specialist. By way of example only, an adjustment device 36 with rocker arms 25, 26 which can be operated by means of adjusting cam 22, 23 is illustrated in FIG. 5. It comprises an alternative embodiment of the invention, the chisel blade being 2 fixed non-elastically in the blade drum 6 and the adjusting device 36 which houses the blade drum 6 with its support resting with a flexible support against a spring leg 29 with a predetermined restoring force. Also in this embodiment, the blade 2 can flex elastically outside the cutting circle 40 against the anvil 24 upon reaching a predetermined loading point., then the rocker 25 is raised a corresponding amount against the force of the spring 30 to avoid an overload of the blade 2, of the anvil 24 and of the other constructive elements, including those of the support of the drums 6 and 7. In Fig. 3 an embodiment of the invention according to Fig. 1 is shown on an enlarged scale. Equal elements are provided with identical reference figures. Here it is shown that the cutting edge of the blade 3 projects a protrusion measurement Ü with respect to the circumferential perimeter of the blade drum 6. In this embodiment, the blade handle 11 elastically resiliently supports the spring block. of steel 12, the blade handle 11 is extended upwards with a pressure rod 16. The pressure plate 15 serves as a limitation of the displacement path which is indicated purely schematically by a double arrow of the knife handle 11. The The pressure rod 16 is fixed with screws in a screw connection 17 which allows an adjustment of the prestressing force of the steel spring block 12. In an alternative variant of the execution of the object of the invention according to Figs. 1 and 3, Figs. 2 and 4 show an arrangement in which the chisel blade 1 has a support that can rest against a compressed gas spring 21. This transmits the pressure to the piston 13 guided in the cylinder 14, which in turn transmits the force of Prefixed cut for the chisel blade 1 through the flange 10 and in the blade handle 11 to the cutting edge of the blade 3. The different spring elements 12 and 21 consist in principle of means of equal effect whose choice is of the responsibility of the specialist. In the enlarged representation of FIG. 4, a shut-off valve 19 of the pressure accumulator 18 is also shown by means of which the compressed gas charge of the pressure chamber 8 and the variation of the gas pressure can be realized. The lower pressure chamber can optionally be charged with a hydraulic fluid 35 or with compressed gas. Otherwise the function of the devices in Fig. 2 and Fig. 4 is in principle equal and meets the predetermined objectives. The executions illustrated here are only examples of possible executions. Other executions that resiliently grip the chisel blade can be: elastomers, as they are known for elastic clamping and damping of moving mass, combinations of gaseous media and hydraulic means, as are known for piston accumulators in the installations hydraulic, etc. In Fig. 5 the alternative embodiment already mentioned above is represented purely schematically. Here, the blade drum 6 has a non-flexible clamp blade 3 which cuts through the cutting strip 4 in a joint action with the anvil 24 of the hammer drum 7 by a suitable adjustment of the regulating device 36. Since the adjustment eccentrics 22, 23 of the adjusting device 36 describe an invariable eccentric trajectory, in order to achieve a cutting space of zero magnitude, a protrusion Ü of the chisel knife 2 with respect to the anvil 24 would be necessary. This would inevitably lead to a spontaneous increase in the action of the forces between the cutting edge of the blade 3 and the anvil 24 and thus of the entire adjustment device 36 including the supports of the eccentrics, of the drums and of the joint 27, 28 in the rocker arms 25, 26. To avoid in this, according to the model of the invention, the overload of all the construction elements by the support of the chisel blade against a n spring element with a predetermined restoring force, the rocker 25, for example, is resiliently supported with its articulation 28 against the helical spring 30 illustrated by way of example. In this, the spring leg 29 adopts a linear guidance in the element 31 and the spring leg 29 can be limited in its downward movement by the adjusting screw 32. For practicing the model according to the invention, an elastic support of the chisel knife 1 in the cutting position is not absolutely essential that the elements that exert the recovery force are directly in the blade drum 6. Rather, it depends on the specialist's judgment that in the choice of the means of equal action available the integration of a suitable spring element also in other components of the high speed shear, as, for example, in the adjustment device according to FIG. 5. It would also be possible, in principle, to rest on other components of the adjustment device on elastic supports and, for example, to involve the support elements of the adjustment device. the drums 6, 7 or of the adjustment gears 22, 23 or of the rocker arms 27, 28. In any case, it must be ensured that the active forces between the knife 2 and the counter 24 can not exceed a predetermined maximum magnitude. . Fig. 6 shows another alternative execution. In the blade drum 6, a chisel blade 1 is supported on a radial guide 9. This, in order to achieve the required cutting force, is resiliently supported by a series of blocks of disk springs 12 'which flex radially. By means of a setting mechanism 33 with a series of tensioned wedges with inclined wedge surfaces, the elastic pre-tension and thus the elastic travel and the elastic progression can be varied with the help of the adjustment path 34. The drum support 6 is carried out on free supports 37, 38 on both sides by means of cylindrical roller bearing bodies. In this, for the equalization of the wear, the blade drums 6 can be displaced from one side to the other in the axial direction with a small degree of axial freedom. For the achievement of a constant cutting force through the band width the chisel knife 1 has a low resistance to bending; Fig. 7. In alternative, the blade is segmented through segments of chisel blade 1 '; Fig. 8. The adaptation to the deformation of the blade drum 6 and the hammer drum 7 is thus possible. For clarification the deformations of the blade drum 6 and the hammer drum 7 have been reproduced thicker. The damping 12 formed in segments can also be in the suction drum 7 instead of in the knife drum 1. The damping principle in segments of the chisel blade can also be used, for example, as overload safety in other shears that do not have any chisel blade but "proper" cutting blades. The invention optimally optimizes a high-speed shear with the achievement of clean separation cuts without overloading the shearing elements, especially for transport speeds of the rolling strip to be cut up to 30 m / sec.