Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
  • B21B37/48—Tension control; Compression control
  • B21B37/52—Tension control; Compression control by drive motor control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
  • B21B37/72—Rear end control; Front end control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
  • B21B1/18—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section in a continuous process
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2261/00—Product parameters
  • B21B2261/02—Transverse dimensions
  • B21B2261/08—Diameter
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2265/00—Forming parameters
  • B21B2265/02—Tension
  • B21B2265/04—Front or inlet tension
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2265/00—Forming parameters
  • B21B2265/02—Tension
  • B21B2265/06—Interstand tension
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2265/00—Forming parameters
  • B21B2265/02—Tension
  • B21B2265/08—Back or outlet tension
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2273/00—Path parameters
  • B21B2273/12—End of product
  • B21B2273/16—Tail or rear end

Definitions

• the present invention is related to method for controlling the dimensions of an elongated material rolled in a rolling mill comprising at least three mill stands arranged after each other, wherein a first stand is arranged upstream of a second stand, which is arranged upstream of a third stand, each of said stands comprising two spaced rolls, said elongated material being fed between the rolls of each stand by rotating the rolls, wherein an interstand tension is controlled between at least two of said stands.
• the invention is a control method for continuous and semi-continuous rolling mills for the production of profiles other than sheet or strip, that is, for hot rolling rod or bar profile of various types. More particularly the invention relates to dimensional control over the tail portion of the rolled material.
• the present invention is further related to a device for controlling the dimensions of an elongated material rolled in a rolling mill.
• an alternating series of rolls are typically arranged in a train of mill stands grouped in rolling pairs.
• a rolling mill is usually arranged in three sections, with a roughing, intermediate and finishing section.
• Each pair of mill stands in a section usually consists of a first mill stand with rolls set, for example for horizontal rolling thus changing the vertical dimension, and the rolls of a second stand arranged perpendicular to the first stand, vertical in this example.
• the rolls of each mill stand have a groove shaped in a specific profile. The depth of the groove and the gap between the rolls determines the resultant height of the rolled material.
• the width dimension As the rolled material is deformed in the height dimension it also spreads out in a direction perpendicular to the height, the width dimension.
• the material spreads out in width, preferably to a specified degree. If the material spreads out beyond the contours of the groove, it is called overfill, and if it spreads less than groove contour it is called underfill.
• the term width is used hereafter to describe a diameter dimension of the rolled material that is parallel to the axis of the rolls of a mill stand.
• the separation of the rolls in each mill stand and the relative speeds in each mill stand necessary to produce the right dimensions on the finished product are specified in a schedule before rolling starts.
• the dimensions of the rolled material may be changed in two ways, by changing the separation of the rolls, the roll gap, so deforming the rolled material to a greater or lesser extent.
• the other principal method is by adjusting the tension in the rolled material.
• a tension in the rolled material between any two stands is described hereafter as an interstand tension.
• the physical dimensions of the rolled material, in particular the width, may be affected by changing the interstand tension.
• the interstand tension is changed by adjusting the speed of the rolls of a one mill stand relative to the rolls of a second mill stand.
• the interstand tension in rolled material moving downstream towards a point of reference is known as back tension.
• Interstand tension in rolled material moving downstream away from a point of reference is called front tension.
• Methods are known for manipulating rolled material which use front tension and methods which use back tension. Adjustments to back tension are more commonly used as a control method because it is up to three times more effective in affecting the width dimension of rolled material than front tension. It is known for example from GB 2,009,974 to measure back tension and use that measurement to control roll speeds.
• the object of the invention is to control the width of the tail of the rolled material.
• a further object of the invention is to improve control over width of the tail of the rolled material in any section of the rolling mill.
• the present invention is a method for controlling the width of a tail of the rolled material between any pair of mill stands in any part of a rolling mill Control is switched to front tension for each successive pair of mill stands as the tail travels through a rolling mill
• the present invention extends control over the width of the rolled material to the tail Adjustments to increase or decrease interstand tension for the purpose of adjusting width of the tail of the rolled material by means of front tension may be made between any pair of mill stands using this method
• control method reduces the amount of substandard rolled material in each rolled billet
• a further advantage is that it may be applied to any pair of mill stands with the sole exception of the final pair of stands of a finishing section
• this control method may be applied in any section of the mill, the roughing section, intermediate section or the finishing section
• this method may be easily refitted to existing rolling mills because it requires measurement and control equipment only, and new mill stands with automatic roll gap separation for example are not required
• control throughout all sections of the mill means that smaller, fewer corrections required in the finishing section It also means reduced wear of the rolls and guide rails due to rolled material that is more consistent in its dimensions
• Fig 1 shows schematically a tail of a rolled material before passing through a first mill stand according to the invention.
• Fig 2 shows schematically the tail of the rolled mate ⁇ al after it has left a first mill stand according to the invention.
• Fig 3 is a block diagram of the device for controlling the dimensions of an elongated material rolled in a rolling mill.
• width is used hereafter to describe a diameter of a rolled material that is parallel to the axis of the rolls of a mill stand.
• Figure 1 and 2 illustrates a part of the rolling mill comprising three mill stands 1 , 2, 3. Each stand comprises two spaced, parallell rolls 4, 5. An elongated material 6 is fed between the rolls. A tail of the material has the reference numeral 7. The arrow 14 indicates the feeding direction.
• Figure 3 illustrates a block diagram of a device according to the invention for controlling the dimensions of the elongated material.
• Means 8, 9, 10 are arranged for controlling the rotational speed of the rolls in each stand. These rotation means 8, 9, 10 are preferably formed by electric motors.
• a means 11 is arranged for controlling interstand tension between at least two of said stands.
• a means 12 is arranged for detecting a tail of the rolled material leaving said first stand. Said detection means 12 is connected to said interstand control means 11.
• Said control means 11 is arranged to, after having received a detection signal from the detection means, switch off a back tension control between the first 1 and the second stand 2 for the period while the tail 7 travels between the first stand and the second stand, and to switch on a front tension control between the second 2 and the third stand 3, arranged downstream of said second stand, for the period while the tail travels between the first stand and the second stand.
• Means 13 is arranged for measuring the width of the material between said second stand 2 and said third stand 3.
• the measuring means is connected to said interstand tension control means 1 1 in order to adjust the interstand tension based on the measured width.
• the measuring means 13 are arranged for substantially continuously determining the width of the rolled material after one or more mill stands.
• the means 8, 9, 10 are arranged for independently controlling the speed of the rolls of each mill stand.
• the means 12 are arranged for detecting tail position in any mill stand.
• a control method according to the invention is carried out in a rolling mill that is equipped with measuring means for substantially continuously measuring and storing the width after a first mill stand and after a second mill stand of any pair of mill stands.
• the speed of each mill stand is independently controlled via a cascade system.
• the mill stand motors are also arranged with means for measuring the motor current in each mill stand, which is used to detect when a tail of rolled material leaves the roll gap of a mill stand. This is possible because motor current changes as the load in the mill stand changes due to the exit of the tail of the rolled material. Also other means are of course applicable for performing said detection, such as optical means and sensors.
• -a signal is sent to the second mill stand, switching off back tension control for the period while the tail travels between the first mill stand and the second mill stand
• -a signal is sent to the second mill stand switching on front tension control for the period that the tail travels between the first mill stand and the second mill stand.
• Measurements of the height and width of the rolled material is preferably carried out using U-gauges manufactured by ABB Industrial Systems AB. Within the scope of the invention it is also possible to use optical equipment such as lasers or cameras to measure the diameters of the rolled material, or a combination of optical methods and mechanical sensors.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Control Of Metal Rolling (AREA)
• Metal Rolling (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=20412046

Family Applications (1)

Country Status (7)

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Family Cites Families (4)

• 1998
  • 1998-07-10 SE SE9802493A patent/SE513923C2/sv not_active IP Right Cessation
• 1999
  • 1999-07-09 AT AT99933449T patent/ATE233134T1/de not_active IP Right Cessation
  • 1999-07-09 DE DE69905578T patent/DE69905578D1/de not_active Expired - Lifetime
  • 1999-07-09 AU AU49502/99A patent/AU4950299A/en not_active Abandoned
  • 1999-07-09 EP EP99933449A patent/EP1097008B1/de not_active Expired - Lifetime
  • 1999-07-09 WO PCT/SE1999/001248 patent/WO2000002678A1/en active IP Right Grant
  • 1999-07-09 JP JP2000558928A patent/JP2002520160A/ja active Pending

Non-Patent Citations (1)

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