US3776298A - Apparatus for controlling the pressure force in multi-roll drives for equipment withdrawing an ingot from a continuous casting machine along a curved path - Google Patents

Apparatus for controlling the pressure force in multi-roll drives for equipment withdrawing an ingot from a continuous casting machine along a curved path Download PDF

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Publication number
US3776298A
US3776298A US00267317A US3776298DA US3776298A US 3776298 A US3776298 A US 3776298A US 00267317 A US00267317 A US 00267317A US 3776298D A US3776298D A US 3776298DA US 3776298 A US3776298 A US 3776298A
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United States
Prior art keywords
pressure
rolls
ingot
withdrawal
driven
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Expired - Lifetime
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US00267317A
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English (en)
Inventor
G Vogt
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Vodafone GmbH
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Mannesmann AG
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Publication date
Priority claimed from DE19712133937 external-priority patent/DE2133937C/de
Application filed by Mannesmann AG filed Critical Mannesmann AG
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Publication of US3776298A publication Critical patent/US3776298A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/128—Accessories for subsequent treating or working cast stock in situ for removing
    • B22D11/1282—Vertical casting and curving the cast stock to the horizontal

Definitions

  • ABSTRACT [30] Foreign Application Priority Data A withdrawal stand for continuously cast, curved in- J l 2 1971 G P 21 33 937 7 gets is disclosed wherein the contact pressure of u y emany driven rolls is controlled to normally exceed only slightly the internal pressure of the ingot; the contract [52] US. Cl. 164/154, 164/282 pressure is increased if the traction resistance In- [51] Int. Cl 822d 11/12 creases 4 [58] Field of Search 164/82, 154, 282,
  • the present invention relates to an apparatus for control of the pressure applied, for example, hydraulicallyto the rolls in a withdrawal train which has dual rolls and withdraws a continuously cast ingot from the casting mold. More particularly,'the invention relates to equipment of this type wherein the exerted pressure force is larger than the expansion force exerted by the casting upon the respective roll.
  • Equipment of the type referred to above is generally known, and the knowndevices include particularly adjusted pressure reducing devices, for reducing the hydraulic pressure imparted upon the roll, so that the resulting contact pressure exerted by the roll upon the casting is predetermined primarily on the basis of cal culation and experience which went into the design of the equipment.
  • the pressing force is selected in these cases so that the casting will be pulled out of the mold at the required rate even if one or several of the many rolls are blocked for one reason or another; for example, because of damage to the bearings or the like. Therefore, the contact pressure exerted by any individual roll upon the casting is higher than required for undisturbed operation of all rolls.
  • this apparent need for providing a larger contact pressure than actually needed, just because of the possible need for compensation and as margin of safety is quite disadvantageous from a different point of view.
  • These rolls as pressing on the ingot at a high rate of force may cause an undesired reduction in the thickness dimension of the casting by roller action.
  • the partially liquidous casting is subjected to fissures or cracks developing on the inside; i.e., in or near the interface between the already solidified skin portion of the liquidous interior. This is even more dangerous in case the cast ingot is relatively wide.
  • pressure regulating means for the hydrostatic pressure used to impart pressure force upon the driven rolls for obtaining particular contact pressure on the ingot.
  • the pressure regulating means is to be under control of a variable command input which is determined in accordance with the traction and pulling force needed for withdrawing the continuously cast ingot at a particular rate.
  • the command value for the hydrostatic pressure regulating means will increase if the drive and pulling force needed is increased, and such increase has been sensed and has occurred; e.g., as a result of dropout of one or more of the withdrawal rolls.
  • the driven rolls are usually driven by electric motors. Traction and pulling force of the withdrawing equipment is usually controlled for a constant travel rate of the ingot commensurate with a constant rate of casting.
  • the current fed to the motors will increase above the normal value if one or more of the rolls have dropped out. Therefore, the sum of the motor currents is preferably used to generate the command value that controls the pressure regulator or regulators for theseveral hydraulic means that impart pressure upon the rolls.
  • Some casting machines and withdrawal stands are constructed that several hydraulic piston-cylinder devices are controlled individually or in small groups. In this case, it may be necessary to provide as many pressure regulators as there are hydraulic drives. In order to simplify the construction, it may thus be of advantage to provide such pressure control only to the rolls in the horizontal train portion as the hydrostatic pressure will be the same along that path so that these rolls as they are pressurized can be subject to control by a single pressure regulator.
  • the FIGURE illustrates somewhat schematically a side view of ingot withdrawal equipment in a continuous casting machine.
  • FIGURE illustrates a Mold 1 for continuous casting which may be of conventional construction.
  • a casting is withdrawn from and through the bottom of the opening'of Mold 1, and is taken up by the withdrawal and transport equipment which provides for a curved travel path of the ingot until it has been bent to continue movement in horizontal direction.
  • the casting is substantially liquidous as withdrawn from the mold and there is usually only a very thin so lidified shell or skin.
  • the diameter of the liquidous core 3 of the casting reduces along the travel path, and, usually, the casting is completely solidified in the range of the last transport rolls of the withdrawal stand.
  • the several rolls are arranged and organized in groups.
  • the rolls of Group A are usually joumaled and mounted for rotation ,in a fixed position, and they are not driven; they just serve as support of the withdrawal casting and providivg particular support along the first portion of the curved withdrawal path.
  • the remaining rolls are organized in Groups B and C. This organization scheme is taken along the withdrawal path.
  • the rolls as being divided in those which are disposed along the underside of the casting and those disposed on top thereof.
  • all of the rolls along the underside are mounted in fixed bearings so that additional pressure is not exerted by them upon the casting.
  • the rolls on the upper side of Groups B and C are individually subjected to pressure respectively provided by hydraulic piston-cylinder units 4.
  • the individually marked rolls are driven by DC drive motors.
  • the motors are connected to electric current busses 6 and 7 as is schematically indicated. Electric current is supplied from the common bus to the individual motors via respective branch lines or cables 5.
  • the common busses 6 and 7 (6 for the motor of the upper side; 7 for the motor on the underside), all run through a current measuring device which provides an electrical signal in representation of the total current drawn from the supply and fed to all of the motors.
  • connection of the cylinders 4 to a source of pressure fluid is illustrated only to the extent necessary for explaining the present invention.
  • the feeder pipe 9 runs through a pressure regulator 10 whose input is connected to the source of pressure supply.
  • the pressure regulator 10 provides some pressure reduction from a maximum pressure applied to it by the source, and the reduction is subject to automatic control.
  • the rolls of Group C include all those driven rolls having pressure force applying cylinders which are connected to that particular pipe 9. From a different point of view, the roll Group C extends along the horizontal portion of the finally solidifying casting, and the rolls of Group B are disposed intermediate Group A and Group C and cover the last portion of the curved path of the withdrawal stand.
  • the cylinders providing pressure forces to the upper rolls of Group B are connected to a preadjusted pressure reducer that may also connect to the same source which supplies regulator 10 with pressure fluid. Also, the cylinders of Group C providing pressure force to undriven rolls are connected individually to pressure reducers.
  • the pressure reducers for those hydraulic system cylinders that are not connected to pipe 9, are, for example, adjusted so that the contact pressure provided by the rolls is about percent of the local expansion force of the casting where engaging these rolls.
  • the pressure reducing portion of regulator 10 provides such a pressure reduction in response to the particular constant motor current as supplied in case of normal operations to all of the roll drive motors.
  • a controller 1 1 responds to current flow as monitored by instrument 8 in response to normal withdrawal operation, by providing a command signal to the pressure regulator 10, so that the pressure regulator 10 provides to the line 9 basically the same pressure that is supplied to most of the cylinders pertaining to all of Group C, but imparting pressure force upon the non-driven rolls thereof.
  • the withdrawal equipment may become partially defective in that for example, the bearings of one or severa] of the rolls are blocked, and such rolls do no longer participate in the withdrawal operation. Accordingly, the mechanical resistance offered to the still driven rolls increases, and the electric current that flows into the electric drive system increases accordingly. Therefore, the instrument 8 will proportionally indicate an increase in load current, and that increase is approximately proportional to the increase in transport resistance.
  • the controller 11 responds to the increase in current consumption and provides a change in the command signal as fed to pressure regulator 10.
  • the changed command signal causes an increase in pressure for the hydraulic system of the driven rolls of Group C, which means that the pressure reducing effect of regulator 10 is by itself reduced, to provide higher hydraulic pressure into the pipeline 9. Such operation may lead to an increase of the pressure forces provided by the driven rolls of Group C up to of the local expansion force of the ingot in that region.
  • the transfer characteristics of the control system as a whole requires, of course, accurate calculation and emperical determination of needed values; i.e., in any individual case it must be determined how much current increase as monitored by instrument 8 would provide a particular increase in the effective pressure in line 9.
  • the pressure increase in line 9 can occur practically without delay. This is an important aspect as the driven rolls must not stop, slow down or slide on the casting for any instant. Sufficient traction must be continuously provided for, as the casting continues uninterruptedly. It can thus be seen that it is important to provide a very accurate increase in the pressure force urging the drive rolls of Group C against the casting, because if the pressure force is increased too much, the damage that may occur will still occur.
  • the inventive method therefore, provides for steps that insure normal operation without excess contact pressure on the casting. Normal operation is not and must not be carried out on the basis of worst case conditions such as multiple dropouts of driven rolls. On the other hand, the pressure increase as a result of such dropout must not be excessive either. It should be noted also, that the dropout situation does not occur very frequently. It can occur but it is, in fact, an exception as was found emperically from existing multi-roll withdrawal stands. This fact makes the invention particularly useful as previously built stands used excess contact pressure just to be able to take up the rarely occurring worst case condition.
  • a modification of the system illustrated can readily be derived from the drawing.
  • first means responsive to the driving power as provided by at least some of the motor means to the respective driven withdrawal rolls and providing a control signal representative thereof;
  • pressure regulator means included in the hydraulic means and determining the hydraulic pressure which provides the pressure force for the contact pressure of at 'least some of said driven rolls, the pressure regulator means connected for receiving the control signal and for increasing said pressure force upon increase of the driving power needed by the motor means to cause the rolls to withdraw the ingot at a predetermined rate.
  • the motor means includes plural electric motors and the first means is responsive to the sum of the electric current flowing thzough the motors to provide the control signals as representation thereof.
  • the pressure regulator means includes a pressure regulator controlling the contact pressure of driven rolls arranged along the horizontal withdrawal path for the ingot.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
US00267317A 1971-07-02 1972-06-29 Apparatus for controlling the pressure force in multi-roll drives for equipment withdrawing an ingot from a continuous casting machine along a curved path Expired - Lifetime US3776298A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19712133937 DE2133937C (de) 1971-07-02 Einrichtung zur Steuerung der Anpreßkraft bei dem Vielrollen antrieb einer Bogenstranggußanlage fur Brammen

Publications (1)

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US3776298A true US3776298A (en) 1973-12-04

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US00267317A Expired - Lifetime US3776298A (en) 1971-07-02 1972-06-29 Apparatus for controlling the pressure force in multi-roll drives for equipment withdrawing an ingot from a continuous casting machine along a curved path

Country Status (4)

Country Link
US (1) US3776298A (enrdf_load_stackoverflow)
CA (1) CA962032A (enrdf_load_stackoverflow)
FR (1) FR2144750B1 (enrdf_load_stackoverflow)
GB (1) GB1399378A (enrdf_load_stackoverflow)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4003236A (en) * 1975-03-19 1977-01-18 Secim Process of hot continuous rolling
US4042010A (en) * 1974-12-20 1977-08-16 Mannesmann Aktiengesellschaft Apparatus for withdrawal of continuously cast ingots
US4090549A (en) * 1974-07-12 1978-05-23 United States Steel Corporation Method and mechanism for determining forces on a solidifying casting
US4122888A (en) * 1975-04-30 1978-10-31 Vereinigte Osterreichische Eisen- Und Stahlwerke - Alpine Montan Aktiengesellschaft Method of guiding a cast strand and arrangement for carrying out the method
US4148349A (en) * 1976-05-08 1979-04-10 Yutaka Sumita Method for controlling slippage between rolls and a slab in a continuous compression casting apparatus
EP0008692A1 (de) * 1978-08-11 1980-03-19 Concast Holding Ag Verfahren zur Vermeidung von Beschädigungen an Strangführungselementen einer Stranggiessanlage für Stahl
EP0068814A1 (en) * 1981-06-25 1983-01-05 Nippon Steel Corporation A bow-type continuous-casting method and apparatus
EP0071448A1 (en) * 1981-07-28 1983-02-09 Nippon Steel Corporation Method of continuous casting of steel and apparatus therefor
US4799535A (en) * 1987-04-09 1989-01-24 Herbert Lemper Modular continuous slab casters and the like
US4953614A (en) * 1987-04-09 1990-09-04 Herbert Lemper Modular continuous caster
US5343934A (en) * 1993-02-01 1994-09-06 Southwire Company Multiple pinch roll apparatus and method for advancing a continuous rod
US6386268B1 (en) * 1998-03-09 2002-05-14 Sms Schloemann-Siemag Aktiengesellschaft Method for adjusting a continuous casting installation roll segment
CN108380832A (zh) * 2018-04-09 2018-08-10 燕山大学 一种生产无缝金属管的柔性成型装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI76721C (fi) * 1982-05-24 1988-12-12 Makrotalo Oy Foerfarande foer framstaellning av byggnadselement med styv stomme fylld med haordcellplast.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3263284A (en) * 1963-12-20 1966-08-02 United States Steel Corp Constant-pressure pinch rolls for continuous casting
US3438425A (en) * 1966-02-17 1969-04-15 Vladimir Alexandrovich Butkevi Guiding device for ingots in secondary cooling zone in continuous casting plants
US3543830A (en) * 1967-01-18 1970-12-01 Demag Ag Method and apparatus for straightening arc-type continuous casting
US3557865A (en) * 1968-03-18 1971-01-26 United States Steel Corp Mechanism for measuring loads on pinch rolls of continuous-casting machine
US3638713A (en) * 1968-04-09 1972-02-01 Concast Ag Continuous casting method including strand support adjustment
US3707180A (en) * 1970-01-29 1972-12-26 Mannesmann Ag Method for advancing a continuously cast ingot along a curved withdrawal path

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3263284A (en) * 1963-12-20 1966-08-02 United States Steel Corp Constant-pressure pinch rolls for continuous casting
US3438425A (en) * 1966-02-17 1969-04-15 Vladimir Alexandrovich Butkevi Guiding device for ingots in secondary cooling zone in continuous casting plants
US3543830A (en) * 1967-01-18 1970-12-01 Demag Ag Method and apparatus for straightening arc-type continuous casting
US3557865A (en) * 1968-03-18 1971-01-26 United States Steel Corp Mechanism for measuring loads on pinch rolls of continuous-casting machine
US3638713A (en) * 1968-04-09 1972-02-01 Concast Ag Continuous casting method including strand support adjustment
US3707180A (en) * 1970-01-29 1972-12-26 Mannesmann Ag Method for advancing a continuously cast ingot along a curved withdrawal path

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4090549A (en) * 1974-07-12 1978-05-23 United States Steel Corporation Method and mechanism for determining forces on a solidifying casting
US4042010A (en) * 1974-12-20 1977-08-16 Mannesmann Aktiengesellschaft Apparatus for withdrawal of continuously cast ingots
US4003236A (en) * 1975-03-19 1977-01-18 Secim Process of hot continuous rolling
US4122888A (en) * 1975-04-30 1978-10-31 Vereinigte Osterreichische Eisen- Und Stahlwerke - Alpine Montan Aktiengesellschaft Method of guiding a cast strand and arrangement for carrying out the method
US4148349A (en) * 1976-05-08 1979-04-10 Yutaka Sumita Method for controlling slippage between rolls and a slab in a continuous compression casting apparatus
EP0008692A1 (de) * 1978-08-11 1980-03-19 Concast Holding Ag Verfahren zur Vermeidung von Beschädigungen an Strangführungselementen einer Stranggiessanlage für Stahl
EP0068814A1 (en) * 1981-06-25 1983-01-05 Nippon Steel Corporation A bow-type continuous-casting method and apparatus
EP0071448A1 (en) * 1981-07-28 1983-02-09 Nippon Steel Corporation Method of continuous casting of steel and apparatus therefor
US4799535A (en) * 1987-04-09 1989-01-24 Herbert Lemper Modular continuous slab casters and the like
US4953614A (en) * 1987-04-09 1990-09-04 Herbert Lemper Modular continuous caster
US5343934A (en) * 1993-02-01 1994-09-06 Southwire Company Multiple pinch roll apparatus and method for advancing a continuous rod
US6386268B1 (en) * 1998-03-09 2002-05-14 Sms Schloemann-Siemag Aktiengesellschaft Method for adjusting a continuous casting installation roll segment
CN108380832A (zh) * 2018-04-09 2018-08-10 燕山大学 一种生产无缝金属管的柔性成型装置
CN108380832B (zh) * 2018-04-09 2019-09-27 燕山大学 一种生产无缝金属管的柔性成型装置

Also Published As

Publication number Publication date
FR2144750B1 (enrdf_load_stackoverflow) 1976-08-06
DE2133937A1 (enrdf_load_stackoverflow) 1972-08-31
FR2144750A1 (enrdf_load_stackoverflow) 1973-02-16
CA962032A (en) 1975-02-04
GB1399378A (en) 1975-07-02

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