Roller stand having elastically mounted supporting rollers

Abstract

A roller stand for a continuous billet casting machine, having a carrying frame for mounting at least one lower supporting roller and at least two lateral supporting rollers. The lateral supporting rollers are mounted elastically on the carrying frame by means of at least one passive elastic element, and have an amount of elasticity at least in a direction perpendicular to the axes of rotation of the lateral supporting rollers. A method for determining the position and/or the shape of a billet is provided. During passage through at least one roller stand, alterations in the position at least of the lateral supporting rollers relative to a reference are detected and, on the basis of this information, the shape of the billet and/or the position of the billet in relation to the center line of the billet-guide channel are/is determined.

Claims

1. A roller stand for a billet strand casting system, comprising: a support frame for mounting at least one lower support roller; at least two lateral support rollers provided with respective position measuring devices, the respective position measuring devices configured to measure a position of a respective one of the at least two lateral support rollers; and a controller configured to: receive detected position changes of at least the lateral support rollers with respect to a reference during passage of a billet strand through a strand guide channel of the at least one roller stand, and determine, based on the detected changes, at least one of the position of the billet strand with respect to a center line of the strand guide channel and a form of the billet strand; wherein the at least two lateral support rollers are elastically mounted on the support frame by at least one passive elastic element having an elasticity at least in a direction perpendicular to axes of rotation of the at least two lateral support rollers.

2. The roller stand as claimed in claim 1, further comprising at least one upper support roller elastically mounted on the support frame and having an elasticity at least in a direction perpendicular to an axis of rotation of the at least one upper support roller.

3. The roller stand as claimed in claim 1, wherein the at least one lower support roller and the at least two lateral support rollers are arranged in a single plane.

4. The roller stand as claimed in claim 3, further comprising: at least one upper support roller elastically mounted on the support frame and having an elasticity at least in a direction perpendicular to an axis of rotation of the at least one upper support roller; wherein the at least one upper support roller is provided with a further position measuring device.

5. The roller stand as claimed in claim 4, wherein the at least one upper support roller is mounted on a rocker.

6. The roller stand as claimed in claim 1, wherein: the at least two lateral support rollers are arranged in a first plane; the at least one lower support roller is arranged in a second plane; and the first and second planes are different.

7. The roller stand as claimed in claim 6, further comprising: at least one upper support roller elastically mounted on the support frame and having an elasticity at least in a direction perpendicular to an axis of rotation of the at least one upper support roller; wherein the at least one upper support roller is arranged in the second plane.

8. The roller stand as claimed in claim 6, further comprising: at least one upper support roller elastically mounted on the support frame and having an elasticity at least in a direction perpendicular to an axis of rotation of the at least one upper support roller; wherein the at least one upper support roller is arranged in the second plane; and wherein the at least one upper support roller is provided with a further position measuring device.

9. The roller stand as claimed in claim 1, wherein the elastically mounted support rollers are elastically spring-loaded.

10. The roller stand as claimed in claim 1, further comprising: at least one upper support roller elastically mounted on the support frame and having an elasticity at least in a direction perpendicular to an axis of rotation of the at least one upper support roller; wherein the at least one upper support roller is provided with a further position measuring device.

11. The roller stand as claimed in claim 1, wherein the at least one passive elastic element comprises at least one coiled spring.

12. The roller stand as claimed in claim 1, wherein the at least two lateral support rollers are mounted in rockers.

13. A strand guide of a billet strand casting system, comprising at least one roller stand as claimed in claim 1.

14. A billet strand casting system, comprising at least one roller stand as claimed in claim 1.

15. A roller stand for a billet strand casting system, comprising: a support frame for mounting at least one lower support roller; at least two lateral support rollers provided with respective position measuring devices; at least one upper support roller elastically mounted on the support frame and having an elasticity at least in a direction perpendicular to an axis of rotation of the at least one upper support roller; and a controller configured to: receive detected position changes of at least the lateral support rollers with respect to a reference during passage of a billet strand through a strand guide channel of the at least one roller stand, and determine, based on the detected changes, at least one of the position of the billet strand with respect to a center line of the strand guide channel and a form of the billet strand; wherein the at least two lateral support rollers are elastically mounted on the support frame by at least one passive elastic element having an elasticity at least in a direction perpendicular to axes of rotation of the at least two lateral support rollers; and wherein the at least one upper support roller is provided with a further position measuring device.

16. The roller stand as claimed in claim 15, wherein the at least two lateral support rollers are mounted in rockers.

17. The roller stand as claimed in claim 15, wherein the at least one upper support roller is mounted on a rocker.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained with reference to schematic exemplary representations of embodiments.

(2) FIG. 1 schematically shows the general diagram of a billet strand casting system having conventional elements including a curved guide with support rollers for the metal strand in roller stands, on both sides as well as at the top and bottom.

(3) FIG. 2 shows a cross section through the strand guide channel along the broken line A-A in FIG. 1 as seen in the direction of the mold.

(4) FIG. 3 shows an oblique view of a roller stand from FIG. 1.

(5) FIG. 4 shows an oblique view of a roller stand according to the invention.

(6) FIG. 5 shows an oblique view of another embodiment of a roller stand according to the invention.

(7) FIG. 6 shows an embodiment of a roller stand according to the invention with position measuring devices.

(8) FIGS. 7a, 7b, 7c show the use of position measuring devices.

(9) FIG. 8 shows the arrangement of roller stands according to the invention at different points of the illustrated detail of a billet strand casting system.

DETAILED DESCRIPTION

(10) FIG. 1 schematically shows an oblique view of the manner in which, in a billet strand casting system 1, a metal strand 2, for example a steel strand, is guided in a strand guide 3 in an arc from the mold 4 via the secondary cooling chamber 5 and WSU 6 to the roller table 7. Support rollers 10, which are mounted in roller stands 8 in the support frame 9, support and guide said metal strand; said support rollers virtually form a strand guide channel, the center line of which coincides with the center line of the centrally and symmetrically positioned metal strand; said center line is indicated by the dashed line 11. For better clarity, cooling bars with cooling nozzles are not illustrated. The inner arc of the metal strand has the radius R1; the outer arc has the larger radius R2.

(11) FIG. 2 shows a cross section through the strand guide channel along the broken line A-A from FIG. 1 as seen in the direction of the mold. The metal strand is positioned centrally and symmetrically with respect to the center of the strand guide 3, i.e. with respect to the center line of the strand guide channel. The center line of the strand guide channel is indicated by a point 12.

(12) FIG. 3 schematically shows an oblique view of a roller stand 8 having a support frame 9 and support rollers 10. The center line of the strand guide channel 12 is indicated by a dashed line.

(13) FIG. 4 shows an oblique view of a roller stand 13 according to the invention. On the support frame 14, a lower support roller 15a and two lateral support rollers 16a, 16b are mounted and arranged in one plane. The two lateral support rollers 16a, 16b are elastically mounted on the support frame. The mounting of said support rollers has an elasticity in the direction perpendicular to the axes of rotation of said support rollers. In the case illustrated, the elastic mounting consists of rockers 17a, 17b which hold the lateral support rollers 16a, 16b and can oscillate about rocker axes 18a, 18b. The pivot axes 18a, 18b are parallel to the axes of rotation of the lateral support rollers 16a, 16b. The springs 19a, 19b provide the mounting with the elasticity perpendicular to the axes of rotation of the rollers.

(14) FIG. 5 shows an oblique view of a roller stand 20 according to the invention. Parts which are analogous to FIG. 4 are not provided with reference signs for better clarity. The roller stand 20 also comprises an upper support roller 21, which is elastically mounted on the support frame and has an elasticity in the direction perpendicular to the axis of rotation of the upper support roller 21. All support rollers are arranged in one plane. In the case shown, the elastic mounting consists of the rocker 22 which holds the upper support roller 21 and can oscillate about a rocker axis parallel to the axis of rotation of the upper support roller. The spring 23 provides the mounting with the elasticity perpendicular to the axis of rotation of the roller.

(15) FIG. 6 shows a roller stand 24, largely analogous to FIG. 5, from the front. Parts which are analogous to FIG. 5 are not provided with reference signs for better clarity. The lateral support rollers are provided with position measuring devices 25a, 25b.

(16) FIG. 7a shows a metal strand 26 of width b and without form defects which is positioned centrally and symmetrically with respect to the center of the strand guide, i.e. with respect to the center line 27 of the strand guide channel, between two lateral support rollers 28a, 28b. FIG. 7b shows the manner in which a metal strand of width b and without form defects is positioned asymmetrically with respect to the center of the strand guide. X is greater than b/2 of FIG. 7a. FIG. 7c shows the manner in which a metal strand is positioned centrally and symmetrically with respect to the center of the strand guide, but has a form defect. The cross section of the metal strand is rhombic, i.e. is rhomboidally warped. Y is greater than b of FIG. 7a. Position measuring devices can be used to measure b, X, Y. This makes it possible for the operator to determine whether form defects or asymmetrical positioning are present. The signals from the position measuring devices are preferably converted in a PLC (programmable logic controller) for simple display in an HMI (human machine interface).

(17) FIG. 8 shows the manner in which roller stands according to the invention are present at different points of a detail of a billet strand casting system 28. As illustrated, two roller stands 30a, 30b according to the invention are arranged in the secondary cooling chamber 29—there could of course in principle also be more or fewer. The roller stand 32 is present in the WSU 31. A roller stand 34 is present in the outflow region 33 of the roller table. The region with a dashed outline represents a support frame for mounting a lower support roller and two lateral support rollers. The lateral support rollers are elastically mounted on the support frame and have an elasticity at least in the direction perpendicular to the axes of rotation of the lateral support rollers. For better clarity, cutting devices have not been illustrated.

(18) Position measuring devices, not shown in detail, on the roller stands 30a, 30b, 32, 34 are connected to a PLC 35, which in HMI 36 displays information about the positioning and form and/or form errors of the billet strand.

(19) FIGS. 2, 4, 5, 6 schematically illustrate an indirect elastic mounting of the support rollers on the support frame in rockers, wherein the rockers are mounted on the support frame such that they can be pivoted about a pivot axis and the rockers can be pivoted elastically by a spring between the rocker and the support frame.

(20) Although the invention has been illustrated more closely and described in detail by the preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.

LIST OF REFERENCE SIGNS

(21) 1 Billet strand casting system 2 Metal strand 3 Strand guide 4 Mold 5 Secondary cooling chamber 6 WSU 7 Roller table 8 Roller stand 9 Support frame 10 Support rollers 11 Center line of the strand guide channel 12 Center line of the strand guide channel 13 Roller stand 14 Support frame 15a Lower support roller 16a, 16b Lateral support rollers 17a, 17b Rockers 18a, 18b Rocker axes 19a, 19b Springs 20 Roller stand 21 Upper support roller 22 Rocker 23 Spring 24 Roller stand 25a, 25b Position measuring devices 26 Metal strand 27 Center line of the strand guide channel 28 Billet strand casting system 29 Secondary cooling chamber 30a, 30b Roller stands 31 WSU 32 Roller stand 33 Outflow region 34 Roller stand 35 PLC 36 HMI