EP0411962A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Control device and method for twin-roll continuous caster
Assignee: Mitsubishi Heavy Industries Ltd
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Filing: 1990-08-03
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Granted: —
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Expires: 2010-08-03
Abstract
Abstract A control device for a twin-roll continuous caster, comprising a plurality of maps, each of which teaches the relationship between the thickness of a cast strip and the roll separating force under a fixed casting speed, and teaches stable casting conditions under which bulging and surface cracks do not occur. The device detects the cast thickness and the height of the molten pool and selects an appropriate map from among the plurality of maps, by the detected height, and controls the casting conditions such that the target thickness of the cast strip is obtained under stable casting conditions by using the selected map.
Inventors
- 👤 Shigenori Tanaka
- 👤 Takashi Furuya
- 👤 Hiroyuki Kajioka
- 👤 Kunimasa Sasaki
- 👤 Atsumu Uamane
- 👤 Shigeru Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 07:38
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/04; B22D11/06; B22D11/0622
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
286 words
A control device for a twin-roll continuous caster in which in operation a pair of opposed cooling rolls rotating in opposite directions define a molten pool therebetween into which molten metal is supplied, a solidified shell being formed on each cooling roll by contact with said molten metal and said solidified shells being bonded at the nip between said cooling rolls to continuously produce a cast strip, said control device comprising; a plurality of maps prepared prior to the operation of said twin-roll continuous caster and stored in a memory of said control device, each of said maps corresponding to a height of said molten pool and a casting speed, teaching the relationship between the thickness of said cast strip and the roll separating force under a fixed casting speed and a fixed height of said molten pool, and defining stable casting conditions under which bulging and surface cracks do not occur and which consist of a combination of a specific range of said thickness of cast strip and a specific range of said roll separating force; thickness detecting means for detecting the actual cast thickness of said strip being cast; height detecting means for detecting the actual height of said molten pool; selecting means for selecting from among said plurality of maps an appropriate map corresponding to the detected actual heigh of the molten pool, and control means for controlling at least one of said casting speed and said roll separating force in accordance with the difference between said actual cast thickness of said cast strip and a target thickness thereof, in such a manner that a strip of said target thickness can be cast under said stable casting conditions of said selected appropriate map.
Claim 2
Dependent Claim
286 words
A control device for a twin-roll continuous caster in which in operation a pair of opposed cooling rolls rotating in opposite directions define a molten pool therebetween into which molten metal is supplied, a solidified shell being formed on each cooling roll by contact with said molten metal and said solidified shells being bonded at the nip between said cooling rolls to continuously produce a cast strip, said control device comprising; a plurality of maps prepared prior to the operation of said twin-roll continuous caster and stored in a memory of said control device, each of said maps corresponding to a height of said molten pool and a casting speed, teaching the relationship between the thickness of said cast strip and the roll separating force under a fixed casting speed and a fixed height of said molten pool, and defining stable casting conditions under which bulging and surface cracks do not occur and which consist of a combination of a specific range of said thickness of cast strip and a specific range of said roll separating force; thickness detecting means for detecting the actual cast thickness of said strip being cast; height detecting means for detecting the actual height of said molten pool; selecting means for selecting from among said plurality of maps an appropriate map corresponding to the detected actual heigh of the molten pool, and control means for controlling at least one of said casting speed and said roll separating force in accordance with the difference between said actual cast thickness of said cast strip and a target thickness thereof, in such a manner that a strip of said target thickness can be cast under said stable casting conditions of said selected appropriate map.
Claim 3
Dependent Claim
29 words
A control device according to claim 1, wherein said thickness detecting means comprise a cast thickness sensor for detecting the distance between said cooling rolls at the nip therebetween.
Claim 4
Dependent Claim
26 words
A control device according to claim 1 or 2 wherein said height detecting means comprise a level sensor for detecting the height of said molten pool.
Claim 5
Dependent Claim
50 words
A control device according to claim 1 or 2 or 3 wherein said control means comprise an actuator by which said roll separating force can be varied, a drive circuit for activating said actuator, a drive motor for rotating said cooling rolls, and a drive circuit for driving said motor.
Claim 6
Dependent Claim
14 words
A control device according to claim 4 wherein said actuator is a hydraulic cylinder.
Claim 7
Dependent Claim
46 words
A control device according to claim 4 or 5 wherein when a difference between said target thickness and said actual thickness of said strip being cast is detected, said control means operate said drive circuit to drive said actuator and thereby vary said roll separating force.
Claim 8
Dependent Claim
48 words
A control device according to claim 6 wherein said control means calculate the ratio of variation of said cast thickness relative to variation of said roll separating force, to determine whether the casting operation is being carried out under said stable casting conditions of said selected appropriate map.
Claim 9
Dependent Claim
43 words
A control device according to claim 7 wherein when it is determined that said casting operation is not being carried out under said stable casting conditions, said control means operates said drive circuit to drive said drive moter to vary said casting speed.
Claim 10
Dependent Claim
272 words
A control method for a twin-roll continuous caster including a pair of opposed cooling rolls which rotate in opposite directions and define a molten pool therebetween into which molten metal is supplied, a solidified shell being formed on each cooling roll by contact with said molten metal and the solidified shells being bonded at the nip between the cooling rolls to continuously produce a cast strip, the control method comprising; preparing a plurality of maps prior to the operation of the twin-roll continuous caster and storing said plurality of maps in a memory of the control device, each of the maps corresponding to a height of the molten pool and a casting speed, teaching the relationship hetween the thickness of the cast strip and the roll separating force under a fixed casting speed and a fixed height of the molten pool, and defining stable casting conditions under which bulging and surface cracks do not occur and which consist of a combination of a specific range of the thickness of the cast strip and a specific range of the roll separating force; detecting the actual cast thickness of the strip being cast; detecting the actual height of the molten pool; selecting from among tbe plurality of maps an appropriate map corresponding to the detected actual height of the molten pool; and controlling at least one of the casting speed and the roll separating force in accordance with the difference between the actual cast thickness of the cast strip and a target thickness thereof so that a strip of the target thickness is cast under the stable casting conditions of the selected appropriate map.
Claim 11
Dependent Claim
272 words
A control method for a twin-roll continuous caster including a pair of opposed cooling rolls which rotate in opposite directions and define a molten pool therebetween into which molten metal is supplied, a solidified shell being formed on each cooling roll by contact with said molten metal and the solidified shells being bonded at the nip between the cooling rolls to continuously produce a cast strip, the control method comprising; preparing a plurality of maps prior to the operation of the twin-roll continuous caster and storing said plurality of maps in a memory of the control device, each of the maps corresponding to a height of the molten pool and a casting speed, teaching the relationship hetween the thickness of the cast strip and the roll separating force under a fixed casting speed and a fixed height of the molten pool, and defining stable casting conditions under which bulging and surface cracks do not occur and which consist of a combination of a specific range of the thickness of the cast strip and a specific range of the roll separating force; detecting the actual cast thickness of the strip being cast; detecting the actual height of the molten pool; selecting from among tbe plurality of maps an appropriate map corresponding to the detected actual height of the molten pool; and controlling at least one of the casting speed and the roll separating force in accordance with the difference between the actual cast thickness of the cast strip and a target thickness thereof so that a strip of the target thickness is cast under the stable casting conditions of the selected appropriate map.
References Cited (Backward Citations)
No citation records indexed.
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