TH20162B - Methods and machines for extruding strips - Google Patents

Abstract

DC60 (17/03/41) Method of strip extrusion in a strip extrusion line with at least two extrusion tables. Each extrusion table has upper and lower horizontally adjustable working rollers, which act individually, in a table with two working rollers, or each working roller is supported directly or through an intermediate roller by support rollers, or act in a reverse extrusion table through which the material is extruded at least twice, through which the strip material is fed into the extrusion table until structural changes occur, and by which adjusting parts act on the strip material to achieve profile and surface uniformity. The method includes pre-assigning the shape of the desired surface irregularities along the width of the strip in at least one area of the strip material, determining the actual shape of the surface irregularities in that area of the strip material, and comparing the actual shape of the surface irregularities with the pre-assigned shape of the irregularities, calculating the difference between the shapes of those irregularities, and acting on the adjusting parts in a way that minimizes that difference. The process can be carried out in a single press with two working rollers, or with each working roller directly supported or via an intermediate roller by support rollers, or in a reverse rolling press where the material is rolled through at least twice, where the material strip is fed into the press until structural changes occur, and where adjusting parts are applied to the material strip to achieve profile and surface uniformity. The methods include pre-assigning the shape of the desired surface irregularities along the width of the strip in at least one area, determining the actual shape of the surface irregularities in that area, comparing the actual shape of the irregularities to the assumed shapes, calculating the difference between the shapes of those irregularities, and performing adjusting operations in a way that minimizes that difference.

Claims (18)

1. Hot rolling method: The strip of material (3,4) is rolled in a hot rolling line (6) which has at least two rolling stands (7,8) with upper and lower working rollers that are horizontally adjustable (10,11) and which act independently or in which each roller is supported by a support roller (9) directly or via an intermediate roller, or in a reverse rolling stand through which the material is rolled at least twice, in which or where the rolled strip of material (3,4) is introduced into a specific deformation such that for the acquisition of an optimal pre-determination at least in the area of the strip of material, in one aspect, the shape of the target nonflattening, which is determined depending on the intended use, together with the continued cooling of the hot strip of material (3,4) on the outlet roller path and in the coil of material, is pre-determined above the body area and the upper edge of the strip of material, and in another aspect, the shape of the actual nonflattening obtained, it is determined and compared with the shape of the pre-determined nonflatting. The difference is calculated from this and the determining part has a mechanical or physical effect. (12,13,14,15,16,17,18) were used in such a way that the difference was minimized as much as possible, in which the shape of the nonflatness of the hot material strip was assumed to result in the desired flatness of the cold material strip after cooling of the material strip (3,4). 2. The method specified in Claim 1 is characterized by the fact that, in addition to the predetermination of the shape of the target nonflatness, the profiles of the target stress distribution or target elongation of the material strip (3,4) across its width are predetermined and compared to the actual stress distribution or elongation, in which case the calculated differences and the defined sections (12,13,14,15,16,17,18) are used in a manner that minimizes those differences. 3. Method as defined in Claim 1, which is specified that for the production of a flattened strip of material (3,4) in a cold state, the shape of the different non-flattening is predetermined for the hot strip of material (3,4) along the length of the strip. 4. Any of the methods specified in claims 1 through 3 shall, in the event that the minimization of the difference is insufficient, the initial condition, i.e., the characteristics of the incoming strip material (3, 4), such as the strip material profile, shape of flatness or temperature distribution of the strip material of the associated rolling mill, shall be altered and the resulting effect shall be optimized. 5. The method specified in Claim 1 is defined as follows: for the formulation of the non-flatness of the strip of material, at least the curvature of the working roller (13), the specified angle of the PC roller and the sliding angle of the CVC (12) are defined to be constant or vary along the length of the strip of material. 6. Any of the methods specified in Claims 1 through 5, which define the characteristics of the description of the target value, the shape of the nonflatness, and the mathematical evaluation by dividing the width of the material strip into body and edge regions, are accepted. 7. The method described in Claims 1 and 6 is characterized as follows: the shape of the nonflatness is described by the polynomial function y* = A2X2+A4X4+A6X8+AnXn, where y* represents the coordinate for the elongation of the strip, the nonflatness of the strip, or the stress of the strip, and X represents the coordinate of the width of the strip. 8. Any of the methods specified in claims 1 through 7 are characterized in such that the shape of the nonflat is described by choice as a sequence of (x,y) points. 9. Any of the methods specified in Reputations 1 through 6 are characterized in such that the target values for the shape of the nonflat are described by a polynomial function as specified in Reputation 7 or by a sequence of points (x-y) as specified in Reputation 8. 10. One of the methods defined in Requisitions 1 through 9 is characterized in such that positive and negative limits (e.g., material strip stress, flatness, material strip elongation/shrinkage) are set around target values and specified parts (12,13,14,15,16,17,18) are used in such such a way that the distribution of material strip stress, flatness distribution, and material strip elongation/shrinkage distribution are within the limits or the excess of the limits is minimized. 11. Any of the methods specified in Reputations 1 through 10 that define the characteristics of the limits for the allowable shape of nonflatness are described by a polynomial function as specified in Reputation 7 or by a sequence of points (x-y) as specified in Reputation 8. 12. Any of the methods specified in Requisitions 1 through 11 that define the characteristics of the shape of the target nonflatness, including the limits of flatness, can be determined by passing the width of the material strip (3, 4) for different rolling mills or by passing different shapes and levels. 13. In any of the methods specified in Requisitions 1 through 12, which define the characteristic that for the elongation/contraction of the material strip of parabolic or superoriented form across the width of the material strip, the designating parts (12,13) are used, which affect the elastic properties of the designated rollers. These designating parts consist of a horizontal sliding device (12) for the working rollers (10, 11) or a bending device (13) for these, or both of these devices together. 14. Any of the methods specified in Requisitions 1 through 13 shall be characterized in that, for the avoidance of distortion waves in the hot material strip (3,4) as well as in the cold material strip (3,4), the distribution of the rolling force is ensured in the sense that the rolling force is reduced at least in the final rolling stage (8) and the rolling force of the rolling stage positioned upstream is increased. 15. Any of the methods specified in claims 1 through 14 are defined as follows: that the cooling action of the rolled strip (3, 4) on the path of the exit roller, as well as in the coil, and that the stretching/contraction of the strip caused by this method are analyzed not only in the body area but also in the edge area of the strip, and that the length change is such that the discovered or calculated case is compensated for by the appropriate pre-determination of the specified parts (12,13,14,15,16,17,18) at least in the final roller (8). 16. Any of the methods specified in Requisitions 1 through 15 are characterized by the mechanical acting of the designated parts (12,13) being used and assisted by non-mechanical thermal acting parts, for example, positive or negative (14,15,16,17,18). 17. Any of the methods set forth in Reputations 1 through 16 are characterized in such that the measured shape of the flatness is compared to the shape of the target flatness and the difference is used for optimization purposes. 18. Any of the methods specified in Requisitions 1 through 7 are characterized in which the difference between the calculated or measured shape of the nonflatness and the shape of the target flatness is analyzed and divided into parabolic segments, as well as higher-level segments, and defining segments (12,13,14,15,16,17,18) are subsequently applied as a result of the operation.