US3908423A - Rod and bar mill - Google Patents

Rod and bar mill Download PDF

Info

Publication number
US3908423A
US3908423A US471832A US47183274A US3908423A US 3908423 A US3908423 A US 3908423A US 471832 A US471832 A US 471832A US 47183274 A US47183274 A US 47183274A US 3908423 A US3908423 A US 3908423A
Authority
US
United States
Prior art keywords
work
axes
rolls
roll
workpiece
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US471832A
Other languages
English (en)
Inventor
Alexander Ian Wilson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Davy Mckee Sheffield Ltd
Original Assignee
Hille Engineering Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hille Engineering Co Ltd filed Critical Hille Engineering Co Ltd
Application granted granted Critical
Publication of US3908423A publication Critical patent/US3908423A/en
Assigned to DAVY MCKEE (SHEFFIELD) LIMITED, PRINCE OF WALES ROAD SHEFFIELD S9 4EX reassignment DAVY MCKEE (SHEFFIELD) LIMITED, PRINCE OF WALES ROAD SHEFFIELD S9 4EX ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HILLE ENGINEERING COMPANY LIMITED
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B13/00—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories
    • B21B13/18—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories for step-by-step or planetary rolling; pendulum mills

Definitions

  • the present invention relates to rod and bar mills and is particularly concerned with continuous multi-stand mills for rolling rod and bar from billets, which are introduced into the stand at high temperature.
  • the mill stand is capable of effecting a high reduction, only if the work is caused to move through the stand at a relatively high speed, well in excess of the speed of 0.08 m/sec referred to above: the fact that the rolls are rotated about their own axes solely by contact with the work has the result that all forward movement of the work must be accomplished by the downstream pinch rolls which must additionally restrain the work against the substantial rearwardly directed reaction forces applied to the work by the work rolls.
  • the pinch rolls must therefore apply a considerable pressure on the work to an extent that they themselves perform a reduction.
  • the high pressure applied by the pinch rolls to the work is not necessarily detrimental where the work is moving at a high speed and on strip material, but would be impractical for low speed rolling, because of the fire cracking of the pinch rolls that would occur, as explained above.
  • the arrangement of the British patent specification cannot therefore be applied to solve the problem that exists in rod and bar rolling and that has been previously explained.
  • the mill stand of that specification has the further disadvantage that, if it were used for rod or bar rolling at a high speed, multi-stand operation would be difficult, because the absence of forward driving of the work by the work rolls, due to those rolls being stand, without increase in the cross-sectional area of I the billet, enables a lower exit speed from the final stand to be achieved, with a reduction in the complexity of the coiler and other delivery equipment.
  • British patent specification No. 871997 describes equipment for reducing in a single pass the thickness of metals in slab, plate or strip form, the metal being fed by feed rollers through a heating chamber to a rolling mill stand, where a large reduction takes place, and thence by pinch rolls to a strip coiler.
  • the rolling mill stand has a pair of work rolls, each of which is carried by a separate compound pendulum so arranged and freely rotatable, results in there being no synchronisation of the strands by the stand itself; a result it would be necessary to provide external means to synchronise the strands, those means having sufficient power to withstand the rearward forces applied to the strands by the stand.
  • the invention resides in a rod or bar mill stand for giving a primary reduction to a workpiece, comprising a housing, a pair of mountings swingingly supported by the housing on opposite sides of the pass-line, a work roll carried by each mounting and designed to effect a first reduction of the workpiece to a rod or bar, means for driving the mountings in synchronisation, the arrangement being such that the work roll axes are constrained to move in closed paths which, over a limited part approach the pass-line so that, in use, the rolls intermittently and simultaneously engage the workpiece on opposite sides, and means for driving each work roll about its axis.
  • the means for driving the work rolls about their own axes are so arranged that the resulting peripheral speed of the rolls differs from the peripheral speed of the roll surfaces due to the driving means for the mountings to an extent that the workpiece is urged by the work rolls in the feed direction.
  • the drive means for the mountings and for the work rolls are so chosen that the roll surfaces in contact with the work have a net peripheral speed, of a direction and magnitude that the work is urged in the feed direction. Consequently, the mill stand is largely self-feeding, any feed means that may be provided being required to apply little traction to the work during rolling.
  • the self-feeding effect of the work rolls on the rolls has the further advantage that it enables multi-strand rolling to be performed, the strands being synchronised by the mill stand itself.
  • Each work roll mounting may additionally carry one or more back-up roll or rolls for the work roll, where there is a danger of the work roll bending unduly under the rolling load to which it is subject during contact with the work.
  • the work rolls engage and reduce the work when the work rolls are moving arcuately in the direction opposite to the movement of the work, since then skidding of the work rolls on the work is reduced.
  • the peripheral speed of the work rolls due to their rotation about their own axis is in excess of the peripheral speed of work roll surfaces due to swinging movement of the mountings, in order to achieve the desired urging of the work in the feed direction.
  • the invention includes a continuous rod or bar mill having a train of rod or bar mill stands, of which at least the first stand is as set out above.
  • the invention further includes a method of continuous rod or bar rolling comprising passing a workpiece through a train of rod or bar mill stands, causing the axes of each work roll of at least the first stand of the train to follow a closed path so that the work rolls contact and reduce the workpiece over a part only of the paths, and driving the work rolls of that stand about their axes to give a peripheral speed differing from the peripheral speed of the roll surfaces due to the movement of the roll axes, so that the workpiece is urged in the feed direction.
  • the mean linear speed of the workpiece is less than 0.08 m/sec.
  • FIG. 1 is a side view of the stand
  • FIG. 2 is an end view of the stand
  • FIG. 3 illustrates an alternative form of gear box for the stand
  • FIG. 4 shows the stand diagrammatically in relation to the furnace and the second stand
  • FIGS. 5A, 5B, 5C, and 5D illustrate the operation of the arrangement, while FIG. 5E shows the elliptical path of a roll of the stand in relation to the work,
  • FIG. 6 shows a preferred modification of the mill stand of FIGS. 1 and 2
  • FIG. 7 illustrates the movements of the rolls of the stand of FIG. 6 in relation to the work.
  • the rod stand illustrated in FIGS. 1 and 2 of the drawings has a pair of spaced housings 12 mounted on a base 13 and carrying in bearing sleeves 14 two eccentric shafts I5, 16.
  • Eccentric shaft 15 carries two rocking frames 17, 18, which are secured integrally together by a tie and which are forked to receive roll chocks 21.
  • the frames l7, l8 carry a rod 22 which is restrained to movement in the vertical plane by a pair of links 23 pivoted to the rod 22 and to the housings 12.
  • the chocks 21 support the ends of a rod work roll 24, which is shown as having four grooves for multi-strand operation, but which may equally be constructed for single strand operation.
  • a similar work roll 25 is mounted by a mechanism similar to that described for roll 24, the various parts of the mechanism for supporting roll 25 being given similar reference numerals with the suffix A.
  • FIG. 1 the direction of movement of the work, the direction of rotation of the rolls 24, 25 about their own axes, and the direction of swinging of the mounting frames during contact of the rolls with the work are indicated by the arrows A, B and C respectively.
  • Shafts 15, 16 and the rolls 24, 25 are driven, the gear box being shown at the right-hand side of FIG. 2.
  • the input shaft 30 of the gear box has keyed to it a large gear wheel 31 meshing with a similar gear wheel 32 keyed to a shaft 33.
  • Shaft 30 is coupled directly to eccentric shaft 16 through propeller shaft 34 and universal couplings 35.
  • shaft 33 is coupled to shaft 15 through propeller shaft 36 and couplings 37.
  • Shaft 30 also carries a small gear wheel 38 in mesh with gear wheel 40, which is splined to a shaft 41.
  • Shaft 41 drives roll 25 about its own axis through couplings 42 and a propeller shaft.
  • a gear wheel 43 keyed to shaft 33 drives a gear wheel 44 on a further shaft 45, which in turn drives roll 24 about its axis through universal couplings 46 and a propeller shaft.
  • FIG. 5 The operation of the stand is illustrated in FIG. 5, where the movements are much exaggerated.
  • the frames 17, 18 and 17A, 18A lie in a common plate at right angles to the pass-line and the eccentric shafts 15, 16 are so disposed that the rolls 24, 25 are in the position at which their separation is smallest; this arrangement is shown in FIG. 5A, where the work to be reduced is illustrated as a billet 50.
  • the shafts 15, 16 are rotated to cause the frames l7, l8 and 17A, 18A to swing away from the vertical in the direction contrary to the direction of movement of the work and are also moved progressively away from the pass-line until the position shown in FIG. 5B is reached.
  • the rolls 24, 25 are in contact with the work and are turned about their axes in the directions opposite to the directions of swinging of the frames so that the rolls 24, 25 roll over the work and thereby progressively reduce the billet.
  • the rolls are withdrawn from the work, as shown in FIG. 5B. Thereafter, the rolls return from left to right above the work as shown in FIGS. 5C and 5D, before moving again from right to left to execute the next reduction of the work.
  • the axes of the rolls 24, 25 cyclically execute closed paths, which approximate to ellipses, and the rolls 24, 25 are in contact with the work over a part only of those elliptical paths, the billet 50 being progressively reduced by the intermittent contact.
  • the amplitude of movement of the roll axes is sufficiently small to permit the rolls 24, 25 to be driven through the universal couplings 42, 46.
  • the torque to be applied to the rolls is however only a fraction of that of normal rod mills, because of the intermittent contact with the work.
  • each roll 24, 25 is driven about its axis at a peripheral speed which is equal to the peripheral speed given to the surfaces of the roll in contact with the work by the swinging movement of their mounting frames, plus an additional component equal to the required forward speed of the work and the likely slipping of the rolls on the aides-1423 work.
  • additional component of the roll speed enif suresthat the work 50 is urged forward in the feed direction. and applies a forward force to thework countering the rearward reaction forceapplied to the work by the reducing action of the stand.
  • the mill stand is 4 thus largely self-feeding, any feed means for the work,
  • the rolls 24,25 are caused to rotate about their axes I .at a steady speed at all times, thus avoiding the need to speed up, or even start from rest during-each revolution of the eccentric shafts 15, 1 6. v
  • the stand illustrated in FIGS. 1 and 2 of the drawings it is possible to achieve a reduction in the one stand of approximately 50%.
  • the speed of the second stand of the train maybe 0.08 m/sec., the recognised minimum speed for a conventional rod stand, and the final finishing speed of the train is half what it would otherwise have been.
  • the r011 24, 25 are driven at a fixed speed relative to the eccentric movement of the rolls.
  • the rolls 24, 25 can be driven independently'of the eccentric shafts 15, 16, for example as shown in FIG. 3.
  • the gear box of FIG. 3 has a second, independently driven, input shaft 60, which drives a lay shaft 61 through gear wheels 62, 63. Shaft 61 is coupled to roll 25 through universal couplings,
  • Shaft 61 also drives a further shaft 64 through a pair of gear wheels 65 and shaft 64 is coupled to roll 24 through universal couplings, one of which is shown at 46.
  • the rolls 24, 25 may have a torque or soft drive, as by using hydraulic couplings in the drive connections'to provide the whole or a part only of the rolling torque.
  • each of the rolls 24, 25 (FIGS. 1 and 2) is caused to move cyclically along a closed path, which approximates to an ellipse.
  • the major axis of the ellipse' is'parallel to the pass-line, the work being rolled over an arc of the ellipse between the minor axis and the major axis i.e. between the points 70 and 71 in FIG. 5E which demonstrates the elliptical path 73 of the working surface of one of the rolls.
  • the finishing stand speed may be maintained at a high value, and the cross-sectional area of the ingoing billet doubled so that the final coil weight is doubled over conventional practice.
  • entry and-stripping guides can be fitted to the stand without interference with the moving I roll chocks.
  • the angle the major axis of each elliptical path makes withuthe pass line is preferably 20.
  • a rod orbar mill stand for giving a primary reduction to a workpiece comprising a housing, a pair of mountings swingingly supported by the housing on opposite sides of the pass-line, a work roll carried by each mounting and designed to effect a first reduction of the workpiece to a rod or bar, means for driving the mountings in a synchronous movement in which the work roll axes are constrained to move in closed paths which, over a limited part, approach the pass-line so that, in use, the rolls intermittently and simultaneously engage the workpiece on opposite sides; and means for driving each work roll about its axis to give a peripheral speed differing from the peripheral speed of the roll surfaces due to the driving means for the mounting, such that the workpiece is urged by the work rolls in the feed direction.
  • a mill stand according to claim 1 in which the mountings are such that the work roll axes are constrained to paths which approach ellipses.
  • a mill stand according to claim 2 in which the major axes of the ellipses are inclined to the pass-line.
  • a mill stand according to claim 3 in which the major axes of the ellipses are inclined at angles of about to the pass-line.
  • a mill stand according to claim 2 in which the means for driving the mountings are such that the roll axes, when moving in the parts of the path closer to the pass-line, move in the direction opposite to the feed direction of the workpiece, and the means for driving the rolls about their axes are arranged to rotate the rolls at peripheral speeds in excess of the peripheral speeds of the roll surfaces due to the driving means for the mountings.
  • each mounting is a compound pendulum.
  • each mounting comprises a frame mounted on an eccentric drive shaft, and constrained at a point on the side of the drive shaft distant from the work roll to a substantially linear path.
  • each frame is constrained by a link or links pivoted to the frame and to the housing.
  • a 'mill stand according to claim 1, in which the means for driving the mountings comprise a gear box having an input shaft and output shafts connected to give equal and opposite movements to the mountings, and the means for driving the rolls about their axes comprise gearing operatively connected to the work rolls and to the input shaft to give a desired ratio between the speeds of rotation of the work rolls about their axes and the speeds at which the mountings are driven.
  • each work roll has a plurality of aligned grooves for multistand rolling.
  • a continuous rod mil bar mil comprising a train of stands, of which at least the first stand is as claimed in claim 1.
  • a method of continuous rod or bar rolling comprising passing a workpiece through a train of rod or bar mill stands, causing the axes of each work roll of at least the first stand of the train to follow a closed path so that the work rolls contact and reduce the workpiece over a part only of the paths, the roll axes moving during such time as they contact the workpiece in a direction generally opposite to the direction of movement of the workpiece through. the stand, and driving the work rolls of that stand about their axes to give a peripheral speed in excess of the peripheral speed of the roll surfaces due to the movement of the roll axes, and in a direction to cause the workpiece to be urged in the feed direction.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Rolling (AREA)
  • Feeding Of Workpieces (AREA)
US471832A 1973-05-18 1974-05-20 Rod and bar mill Expired - Lifetime US3908423A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2369973A GB1440938A (en) 1973-05-18 1973-05-18 Rod and bar mill

Publications (1)

Publication Number Publication Date
US3908423A true US3908423A (en) 1975-09-30

Family

ID=10199849

Family Applications (1)

Application Number Title Priority Date Filing Date
US471832A Expired - Lifetime US3908423A (en) 1973-05-18 1974-05-20 Rod and bar mill

Country Status (6)

Country Link
US (1) US3908423A (de)
CA (1) CA997596A (de)
DE (1) DE2423751C3 (de)
ES (2) ES426428A1 (de)
GB (1) GB1440938A (de)
IT (1) IT1011837B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070143970A1 (en) * 2005-12-23 2007-06-28 The Swatch Group Management Services Ag Link element including a casing formed of a plate and a back plate

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19619134C2 (de) * 1996-05-11 1999-06-17 Kocks Technik Walzblock zum Walzen von Draht, Stäben, Rohren oder flachem metallischem Walzgut

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3049948A (en) * 1954-06-11 1962-08-21 Sendzimir Tadeusz Dual drive planetary reducing mills
US3103139A (en) * 1958-01-03 1963-09-10 Ici Ltd Method of and apparatus for reducing the thickness of metals
US3690138A (en) * 1967-06-23 1972-09-12 Demag Ag Process and apparatus for stretch forming metal

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3049948A (en) * 1954-06-11 1962-08-21 Sendzimir Tadeusz Dual drive planetary reducing mills
US3103139A (en) * 1958-01-03 1963-09-10 Ici Ltd Method of and apparatus for reducing the thickness of metals
US3690138A (en) * 1967-06-23 1972-09-12 Demag Ag Process and apparatus for stretch forming metal

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070143970A1 (en) * 2005-12-23 2007-06-28 The Swatch Group Management Services Ag Link element including a casing formed of a plate and a back plate
US7430787B2 (en) 2005-12-23 2008-10-07 The Swatch Group Management Services Ag Link element including a casing formed of a plate and a back plate

Also Published As

Publication number Publication date
CA997596A (en) 1976-09-28
IT1011837B (it) 1977-02-10
ES447429A1 (es) 1977-07-01
DE2423751A1 (de) 1974-12-05
DE2423751B2 (de) 1980-04-03
ES426428A1 (es) 1976-09-16
DE2423751C3 (de) 1980-11-20
GB1440938A (en) 1976-06-30

Similar Documents

Publication Publication Date Title
US3709017A (en) Method of rolling metal sheet articles between the driven rolls of the roll mill
EP1679133B1 (de) Plattenpressvorrichtung
US4998338A (en) Method and arrangement for manufacturing hot-rolled steel strip
US4817703A (en) Strip casing unit with downstream multi-stand continuous rolling mill
US3427848A (en) Devices for cold-rolling and planishing metal sheet
US2742949A (en) Leveler apparatus and method
US4852383A (en) Press apparatus for reducing widths of hot slabs
US3908423A (en) Rod and bar mill
US3848447A (en) Rolling method and a rolling mill for carrying out the method
US3580033A (en) Rolling mill for producing thin strip stock
US3871221A (en) Continuous strip rolling mill
CN212238621U (zh) 一种用于全无头热轧带钢生产线上的卷取机夹送装置
US3657913A (en) Crown control
US3955391A (en) Rolling mill
US3690138A (en) Process and apparatus for stretch forming metal
US3487671A (en) Methods of and apparatus for rolling structural shapes such as h,i and rails
US3643488A (en) Rolling mill
US3818744A (en) Method of, and entry-guide for, feeding stock to a rod-rolling reduction mill
GB1288934A (de)
EP0109235A2 (de) Walzwerksteuerung für Tandem-Walzen
US3555862A (en) Apparatus for continuously rolling steel
US3143010A (en) Method of and apparatus for reducing the thickness of metal
US4306440A (en) Methods and apparatus for rolling bars, rods and wire
JP3202623B2 (ja) 熱間圧延方法及び設備
JPS5910843B2 (ja) 異速圧延方法および異速圧延機

Legal Events

Date Code Title Description
AS Assignment

Owner name: DAVY MCKEE (SHEFFIELD) LIMITED, PRINCE OF WALES RO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:HILLE ENGINEERING COMPANY LIMITED;REEL/FRAME:004611/0274

Effective date: 19850809

Owner name: DAVY MCKEE (SHEFFIELD) LIMITED, PRINCE OF WALES RO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HILLE ENGINEERING COMPANY LIMITED;REEL/FRAME:004611/0274

Effective date: 19850809