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Publication numberUS3201962 A
Publication typeGrant
Publication dateAug 24, 1965
Filing dateNov 13, 1961
Priority dateNov 13, 1961
Publication numberUS 3201962 A, US 3201962A, US-A-3201962, US3201962 A, US3201962A
InventorsHautau Charles F
Original AssigneeHautau Charles F
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Rolling mill position control
US 3201962 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Aug. 24, 1965 c. F. HAUTAU ROLLING MILL POSITION CONTROL 2 Sheets-Sheet 1 Filed Nov. 13, 1961 INVENTOR. CHARZJ ES F HAUTAU M @A I47'TORIVE) 1965 c. F. HAUTAU 3,201,962

ROLLING MILL POSITION CONTROL Filed Nov. 13, 1961 2 Sheets-Sheet 2 CHARLES F. FQ XWAU United States Patent 3,201,962 ROLLING MILL POSITIUN (IUNTRQL Charles F. Hautau, 146 Hilltop Road, flxford, Ohio Filed Nov. 13, 1961, Ser. No. 151,924 7 Claims. (Cl. 72-9) This invention relates to apparatus for adjusting the product thickness in rolling mills, and more particularly to apparatus for thermally controlling the roll spacing in such mills.

The conventional rolling mill consists of a pair of rotatable cylindrical rolls disposed with their axes in parallel relation and their ends journaled in bearings. At least one of the rolls and its bearings are movable in a plane passing through the axes of both rolls. The rolling operation is accomplished by passing metal sheets or strips between the rolls, the roll spacing having been preset to a value less than the thickness of the metal. As the metal is passed through the gap between the rolls, it is squeezed to a reduced thickness corresponding roughly to the size of the roll gap.

Adjustment of the roll spacing is normally achieved by rotation of large power-activated screws. The axes of the screws lie in the plane passing through the axes of both rolls and extend perpendicularly to the axes of the roll-s. The screws are attached to adjusting blocks or pads which in turn are fixed to the bearings of the adjacent roll so that rotation of the screws causes movement of the roll and a change in the size of the gap between the rolls.

The forces exerted on the rolls by the metal sheet or strip during the rolling operation are often substantial and since the rolls are supported only at their ends, bowing of the rolls may occur. To prevent such distortion of the rolls, back-up rolls, consisting of larger diameter journaled rolls disposed with their axes parallel to the axes of the standard rolls and situated immediately adjacent the standard rolls, are frequently employed to provide additional support.

Although the roll spacing may be adjusted by rotation of the screws to produce a desired product thickness at a given moment, constant variations in the hardness and thickness of the incoming metal will result in an uneven product thickness unless means are provided to continu-ally measure the product thickness and utilize such information to adjust the roll spacing. Precise-thickness gages are available which convert the product thickness readings into electrical signals. The output from these gages may be fed back to the screws in order to adjust the roll gap. Due to the size and inherent inaccuracy of these screws, however, small controlled increments of adjustment are unattainable in practice. The lack of precision typical of this conventional adjusting means is especially critical in the rolling of very thin stock such as foil. Although precise-thickness gages maybe accurate in measuring the product thickness within millionths of an inch, such gaging information is of no value unless means are available for utilizing that information to make incremental adjustments of the roll gap.

. r The present invention contemplates a system in which precise gaging information is utilized to control thermal expansion and contraction of blocks of steel or other suitable material located immediately adjacent the rolls in such manner that expansion or contraction of the blocks induces a corresponding decrease or increase in the size of the gap between the rolls.

In a preferred embodiment of the present invention which will be subsequently described in detail, the blocks are interposed between the adjusting pads and the journaled ends and bearings of the back-up rolls in a conventional four-high rolling mil-l. The screws are rotated so ice as to adjust the rolls roughly to the desired spacing. A temperature controlled fluent is arranged to circulate through channels in the blocks causing thermal expansion and contraction of the blocks. As the dimensions of the blocks vary, the working rolls are moved, altering the size of the roll gap; expansion of the blocks moves the working rolls closer together, reducing the roll spacing, while contraction of the blocks increases the separation or gap between the rolls.

A precise-thickness gage, positioned immediately after the rolls, measures the thickness of the metal as it issues from the rolls and transmits this information in the form of electrical signals to an error detector circuit. The desired thickness is similarly transmitted to this circuit which derives the algebraic difference between the two signals to regulate the flow of hot and cold fluent through servo valves into the block. A pump circulates the fluent through the blocks and maintains the pressure in the system. As the servo valves are opened and additional fluent introduced to the blocks, the excess fluent overflows into a sump. This arrangement allows fluent to be continuously circulated until a roll gap adjustment is required and a servo valve opened.

An alternative method of supplying temperature controlled fluent to the blocks consists of utilizing continuously flowing streams of hot and cold fluent as a fluent source. The two streams pass through a mixing valve which is actuated by the output signal from the error detector circuit so as to allow the correct mixture of hot and cold fluent to pass through to the blocks. This mixture will have a temperature suitable to vary the size of the roll gap so as to result in a product thickness equal to the desired thickness.

It is therefore an object of the present invention to provide in a rolling mill, a positioning system for controlling the roll spacing consisting of expansible blocks situated between the screws and the rolls, having interior channels into which is introduced fluent that is maintained at a temperature suitable to expand or contract the blocks in such fashion that the roll gap is increased or decreased to vary the desired thickness.

Another object of the present invention is to provide in a conventional rolling mill, apparatus for controlling the roll spacing consisting of a precise-thickness gage which measures the product thickness, and an electrical circuit which utilizes the gage information as to departures from the desired product thickness to control the entry of temperature controlled fluent into channels in an expansible block situated between the screws and the journaled end of the rolls.

Other objects and advantages will be more readily apparent from the following detailed description of a preferred embodiment of the present invention. The description makes reference to the accompanying drawings in which:

FIG. 1 is a perspective View of a preferred embodiment of the pesent invention, with parts broken away.

FIG. 2 is a schematic view of the hydraulic and electrical systems employed with the structure of FIG. 1.

FIG. 3 is a detailed side view of the expansible metal block shown in FIG. 2, with parts broken away.

The invention is illustrated as employed in a conventional four-high rolling mill. Two cylindrical rolls 1t and 12 having ends 14- and 16 journaled in bearings 18 and 20 are disposed with their axes in horizontal parallel relation. The rolls 10 and 12 are situated adjacent one another defining a rectangular gap or space 22 through which the metal sheet or strip 24 is passed. Back-up rolls 26 and 28, of larger diameter than the Working rolls 1t) and 12, are disposed with their axes parallel to the axes of the working rolls and are in contact with them. The back-up rolls 26 and 28 have ends 30 and 32 journaled in bear of the working-rolls 10. and 12.

A frame 37 having vertical members 38and. a hori- V zontal deck 39 supports two motors 40 and 42, each hav.

ing output'through a right-angle drive 48 and 50 situated on the surface of the'deck39; The bearings '18, 20, 34

and 36 are supported between the vertical'members38 so as tobe free for vertical movement." Screws 52jfixed at' their. upper ends to the deck 39'and journaled along theirj upper length in bearings 53 in the deck, terminate .at' their lower ends in nuts 54 which are fixedly attached'to distributing or adjusting pads 56 which distrihutethe" 7 force exerted by the screws over a larger area. i r r Expansible blocks 58 of steel or other suitable material are interposed between andpermaneritly afiii'red to the bearings 34 of the upper back-up r'oll 26andthedistributing pads 56. Similar expansible blocks 60 are situated between'the bearings 360i the lower back-up roll28 and a 3 support pad 62. The. blocks 58 'an d '60jare fitted with" channels 62tthrough which a fluent is arranged to circu- 1 late, All four of the blocks 58 and 60'are connected to a single hydraulic and electrical system.. Fluent'is stipplied from hot andcold reservoirs 64 and 66 where the; fluentis maintained at a fixed, known temperature and is; transferred under pressurethrough hotand cold inlet lines 7 6S and 70, each having aservo'valve 72 and 74, to a pump 76. The 'pump 76 forces the fluent'throu'gh thevchannels t a 62 inthe blocks 58 and tl and'maintains a constant pres- V sure'in'thersystem. Thefluent is moved through, the systern between the pump 76 and the .l blQCkSr 58 and 60 through a network of tubing78 Whichis'connected to; the

block by nozzles 80 A'sump 82 'is'positioned' sufficiently j higher in elevation than the blocks 58' and 60 and pump 76 so that the sump receives fluentfrom the'system only when one of the'servo valves 72,. 74 is, opened and hot or cold fluent allowed'to enter.

The electrical system is comprised of an-errorfdetector circuit or analog substracter 84'which determinesthe algebraic'dififerences of two input signals. One inputsignal is f produced by aprecise-thickness gage '86'whicih is located immediately after the rolls 10 and 12 so as to measure the'pr'oduct thicknessas the metal'issues from the rolls;

The gage'86, which maybe'an X-ray or nuclear thickness gage or may consist of a precision micrometerdevice, transmitsrto the detector circuit 84-a signal which is'prog 'portional to'thethickness readinglof the gage; The seci ond input signal is supplied by a potentiometer 88 whichis preset to tr ans'mitta signal equal inmagnitude to. that 'transmittedby, the gage 86 when metal of the desired thickness is passed through the gage. V, 7 r

a The detector circuit v84 produces a signal which is the atlgebraicdifierence ofthe tworinput Signals and trans-r j mits it to a' single-pole' doubleethrow polarized relay 90; which is connected to each of the servofvalves 72 and 74:

As the signal reaches the relay 99, the relayfwill close the circuit leading to one of the servo valves 72 1and,74 and a signal equalito the algebraic difierence of the two. input;

signals will be transmittedto the servo valves 72. and .74; a

the algebraic sign of the outputsignalfrom the error detector 84 determines'which'of the servo valves 72, 7 4 will be activated The magnitude of-the output signalf trans-1 mitted to the'valves 72 and 74 controlslth cxtent -to which the valve -is opened, thus' determining thelrate of flow of fluent through thevalves-72an-d'74.

The electrical'system is'arrangedso that the output signal from the error detector circuit-84,wl1ich istrans f mitted when theproduct-thickness feiiceedsthe desired thickness,.will open the: servoval ve '72 mine-net inlet line 68 sufliciently .to'allow hot marina enter the blocks product thickness "equal tothedesired thickness f V Similarly, if the produ: t thickness is lessthanltheide j .sired'thickness, thefiow of cold fluent must'be sufficient-f,

rto result'in a productthickness equal to the desired thickness. Ifthe product thickness equals the desired thickness, no signal will be transmitted fromthei subtracter i circuit 84'since the two input signals will be. numerically equal. As a result, the relay'90 willnot-be activated and the servo valveswill remain closed. The" pump 76ivill then recirculate the fluent already flo wi ng in the system. 7 In operation, the motors 40 and-'42 are activated to rotate the screws:52'unti1 the rollf gap 22 closely matches I the thickness of'the incoming rnetal' 24.; The potentiomlQ eter' SS isset tojtransrnitfa signal corresponding in'magn'itudejto the signal'emitted by the thickness gage 86 when metal of the desired thickness is passed throughhthe gage86. r "The'working'irollsj10 1and 12' are:rotated bypowet '15 means "(not shown). j The'metal' sheet 24 is passed through theroll. gapj'22 and the gage86. Departures of the product" thickness from the desired thickness are communicated to thea'p'propria'te servo valves 72 and 74; the flow ,of fluent at anew temperature through the-blocks 58 and 6t) causes atcorresponding expansion'gor.contractioniof the Yblocks This, in turn; causes a change in the spacing of c the workingrolls 10. and 12; expansion of'the blocks 58 and 60 reducezthe roll; gap 22 :while. contraction of the 'blocks58 and 60 increases the roll'gap Y Theefi-ct of this expansion or contraction of the blocks 58, 60 orr-theproductthickness will benoted by the'thickness gage-8 6. The new signal emitted by the gage86 will direct further openingor closing of the servo valves 72 and '74. This process-is, continued until the product thickness 'exa ctlytequals the? desired thicknes'sQat which time the fluent the servo-valves 72 and 74 will be closedand in the blocks 58 and 60 recirculated; t

1 An alternative positioning system consists of two gages 86', each'located at .gppositeedges of the metal as i't 'is- 35 sues from the rolls wand 12; Each gage is connected i to an'independentfhydraulic and electric system of the type previously described in detail; each hydraulic system feeds fluent into .the'pair ofiblock's 58 and 69 located on the same edge'ofithe metal: sheet 24as'thev gage. ,With this arrangement the present invention can be adapted to produce a product sheet, having a thickness which, varies unifermlyffrom edge to'edgeythis may be accomplished simply by settingqeach of the otentiometers 88 at a different value; a I i t An alterna 've method-oftransferring'heat with respect to the expansible blocks or material consists of the use of electrical resistors as heating elements" in conjunction with'asuitable'cooling process. Q 1 Although the presentfinvention has beenillustrated in c'onjunction'with .afour-high rolling mill, it maybe employed in a similar manner in conventional'rolling mills or any size, having any number, of standard' or back-up -r olls.

Having described the inventionin its simplest terms, it iSftO be-understood that the, features: of construction "ma be: changed and variedrin'r greateror lesserv degree "withqutdeparting from the essence of 'theinvention'fdea fined in the .append'edclaims; 1 claim: a 1 ,7

LfIn' a rolling millfihaving astationary "frame, and cylindrical rollsdisposedwiththeiraxes, parallel to'jone 4 another and journaled ,inbearings whichgare 'jmovable ,7 within said frame, -a positioning fsystem'tor' controlling the'spa'cing between said rolls, comprising? i the thicknessof the rolled gage; means-tor, measuring 'x-proglucty" fand'zmeans, under the control of the gage'fmea'ns; for

i j maintaining :said' material at a temperature a function of there'ading otjsaid gage. 7 t

. 2.31 1 ar'olling mill havi'ng a's't'ationary frame; and cylindricalirolls disposed; with their axes parallel-to .one, an-

?fin' saidz frame, a; positioning'system forv controlling the :spacing betweensaid rolls,[co mprising;

expansible material 'fixed'totlie bearings of said @0118;

which 'is t otherand journaled-in bearingsiwhich' are movable with-t expansible metal blocks fixed to the bearings of said rolls, said blocks having interior channels adapted to receive fluid;

rotatable screw means each having one end attached to said frame and a second end attached to one of said blocks, the axes of said screw means lying in the plane of the axes of both of said rolls and extending perpendicularly to the axes of said rolls;

means for rotating said screws so as to move said blocks and said bearings within said frame;

and means for introducing fluid at controlled temperatures into said channels in said blocks.

3. In a rolling mill having a stationary frame, and cylindrical rolls disposed with their axes parallel to one another and journaled in bearings which are movable within said frame, a positioning system for controlling the spacing between said rolls, comprising:

expansible metal blocks fixed to the bearings of said rolls, said blocks having interior channels adapted to receive fluid;

rotatable screw means each having one end attached to said frame and a second end attached to one of said blocks, the axes of said screw means lying in the plane of the axes of both of said rolls and extending perpendicularly to the axes of said rolls;

means for rotating said screws so as to move said blocks and said bearings within said frame;

gage means for measuring the thickness of the rolled product;

and means, under control of the gage means for maintaining the fluid introduced into said channels at a temperature which is a function of the product thickness.

4. In a rolling mill having a stationary frame, and cylindrical rolls disposed with their axes parallel to one another and journaled in bearings which are movable within said frame, a positioning system for controlling the spacing between said rolls, comprising:

a source of fluid;

expansible metal blocks fixed to the bearings of said rolls, said blocks having interior channels adapted to receive fluid from said source;

rotatable screw means each having one end attached to said frame and a second end attached to one of said blocks, the axes of said means lying in the plane of the axes of both of said rolls and extending perpendicularly to the axes of said rolls;

means for rotating said screws so as to move said blocks and said bearings Within said frame;

gage means for measuring the thickness of the rolled product;

servo valves situated between said source of fluid and said blocks;

and means for actuating said servo valves as a function of said product thickness.

5. In a rolling mill having a stationary frame, and cylindrical rolls disposed with their axes parallel to one another and journaled in bearings which are movable within said frame, a positioning system for controlling the spacing between said rolls, comprising:

a reservoir of hot fluid;

a reservoir of cold fluid;

expansible metal blocks fixed to the bearings of said rolls, said blocks having interior channels adapted to receive fluid from said reservoirs;

rotatable screw means each having one end attached to said frame and a second end attached to one of said blocks, the axes of said means lying in the plane of the axes of both of said rolls and extending perpendicularly to the axes of said rolls;

means for rotating said screws so as to move said blocks and said bearings within said frame;

gage means for measuring the thickness of the rolled product, said gage means being adapted to transmit a signal proportional in magnitude to the measured product thickness;

means for supplying a signal proportional in magnitude to the desired product thickness;

servo valves situated between each of said reservoirs and said blocks; and means provided for receiving said signals and producing a signal which is a function of the difference between said desired and said measured thicknesses, said last signal being adapted to actuate said servo valves. 6. In a rolling mill having a stationary frame, and cylindrical rolls disposed with their axes parallel to one another and journaled in bearings which are movable within said frame, a positioning system for controlling the spacing between said rolls, comprising:

expansible material fixed to the bearings of said rolls; means for measuring a dependent variable associated with the operation of the rolling mill;

and means, under control of the measuring means for maintaining said expansible material at a temperature which is a function of said dependent variable.

7. In a rolling mill having a stationary frame and cylindrical rolls disposed with their axes parallel to one another and journaled in bearings which are movable within said frame, a positioning system for controlling the spacing between said rolls, comprising:

expansible material fixed to the bearings of said rolls;

rotatable screw means each having one end attached to said frame and a second end attached to said expansible material, the axes of said screw means lying in the plane of the axes of both of said rolls and extending perpendicularly to the axes of said rolls;

means for rotating said screws so as to move said bearings within said frame; means for measuring a dependent variable associated with the operation of the rolling mill;

and means, under control of said measuring means,

for maintaining said expansible material at a temperature which is a function of said dependent variable.

References Cited by the Examiner UNITED STATES PATENTS 1,112,269 9/ 14 Crellin 82-900 1,150,885 8/15 Rittenberger 55.1 2,128,826 8/38 Jung 80-551 FOREIGN PATENTS 137,260 9/52 Sweden.

WILLIAM J. STEPHENSON, Primary Examiner. LEON PEAR, Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1112269 *Nov 23, 1911Sep 29, 1914James R CrellinMetal-working machine.
US1150885 *Sep 29, 1914Aug 24, 1915William RittbergerMill-roll lubricator.
US2128826 *Jul 1, 1937Aug 30, 1938Jung Albert HCooled bearing
SE137260A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3429155 *Jan 12, 1966Feb 25, 1969Hines & Ass E WPositioning control system
US7431579 *Aug 24, 2004Oct 7, 2008The Goodyear Tire & Rubber CompanyCalender gap control
US7897075 *Sep 23, 2008Mar 1, 2011The Goodyear Tire & Rubber CompanyCalender gap control
Classifications
U.S. Classification72/9.4
International ClassificationB21B37/58
Cooperative ClassificationB21B37/58
European ClassificationB21B37/58