US3793860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System to compensate for roll eccentricity effects and/or to simulate a mill with variable stretch characteristics
Assignee: AEG Westinghouse Industrial Automation Corp
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Filing: 1972-12-04
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Granted: 1974-02-26
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Expires: 1992-12-04
Abstract
Abstract A rolling mill control system which, in one aspect, compensates for the effects of roll eccentricity during operation of the rolling mill. The control system includes circuitry which produces a control signal for rapid and accurate adjustments to hydraulic roll force actuators in a manner to prevent increases in the roll separating force. This circuitry further includes an outer gage control loop and/or tension control loop for automatic gage control of the rolling mill. According to another aspect of the disclosure, the control system simulates a rolling mill structure having variable spring constants whereby an operator may select a desired mode of rolling mill control. To simulate an infinitely stiff mill construction, the control system provides a control signal for rapid adjustments of the roll force actuators in a direction and by the exact amount to compensate for changes in the housing stretch. The control system simulates infinitely soft mill construction by rapid adjustments to the roll force actuator in a direction and by the exact amount to resist changes in the rolling force.
Inventors
- 👤 A Silva
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:27
CPC Classifications
B; B21; B21B; B21B37/00; B21B37/58; B21B37/66
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
168 words
A method of controlling the gap between processing rolls of a rollIng mill to simulate a rolling mill structure selected to have a stretch characteristic within a range of infinitely stiff and infinitely soft during operation of rolling mill, said rolling mill including a housing for resisting the rolling force produced between said processing rolls and hydraulic force actuators carried in said housing for adjusting said roll gap, said method of controlling comprising the steps of: generating a first signal representing a change in the roll gap proportional to a first change in the stretch of said rolling mill structure; generating a second signal to represent a change in the roll gap proportional to a second change in the housing stretch in a direction opposite to said first change; selecting a roll gap position control signal within a range defined by said first and second signals; and controlling said hydraulic roll force actuator in such a way to reduce the said roll gap position control signal to zero.
Claim 2
Independent Claim
168 words
A method of controlling the gap between processing rolls of a rollIng mill to simulate a rolling mill structure selected to have a stretch characteristic within a range of infinitely stiff and infinitely soft during operation of rolling mill, said rolling mill including a housing for resisting the rolling force produced between said processing rolls and hydraulic force actuators carried in said housing for adjusting said roll gap, said method of controlling comprising the steps of: generating a first signal representing a change in the roll gap proportional to a first change in the stretch of said rolling mill structure; generating a second signal to represent a change in the roll gap proportional to a second change in the housing stretch in a direction opposite to said first change; selecting a roll gap position control signal within a range defined by said first and second signals; and controlling said hydraulic roll force actuator in such a way to reduce the said roll gap position control signal to zero.
Claim 3
Dependent Claim
63 words
The method of claim 1 including the steps of: generating an initial electrical signal proportional to said rolling force developed between said processing rolls; and modifying said initial electrical signal in accordance with the equation h P/Mm to generate said first electrical signal, where h equals the actual roll gap, P equals rolling force, and Mm equals modulus of said rolling mill structure.
Claim 4
Dependent Claim
31 words
The method of claim 2 including the steps of: generating a position feedback signal from said roll force actuator; and modifying said roll position control signal with said position feedback signal.
Claim 5
Dependent Claim
26 words
The method of claim 3 including the steps of: generating a gage control error signal; and modifying said second signal with said gage control error signal.
Claim 6
Dependent Claim
26 words
The method of claim 3 including the steps of: generating a tension controller error signal; and modifying said second signal with said tension controller error signal.
Claim 7
Dependent Claim
30 words
The method of claim 1 wherein said roll gap position control signal produces a frequency of response by said hydraulic roll force actuator of up to 20 cycles per second.
Claim 8
Independent Claim
128 words
A method for controlling a rolling mill wherein eccentric characteristics of the rolls rotating in the mill produce cyclic changes in the rolling force developed between the processing rolls, said rolling mill including a housing for resisting the rolling force produced between said processing rolls and hydraulic roll force actuators carried by said housing for adjusting the gap between said processing rolls, said method comprising the steps of: computing a change in the housing stretch as a function of a change in the rolling force due to said eccentricity characteristics of the rolls; and controlling said hydraulic roll force actuator in such a way to compensate for a change in the said housing stretch by preventing rolling force increases between said processing rolls due to said eccentricity characteristics.
Claim 9
Independent Claim
128 words
A method for controlling a rolling mill wherein eccentric characteristics of the rolls rotating in the mill produce cyclic changes in the rolling force developed between the processing rolls, said rolling mill including a housing for resisting the rolling force produced between said processing rolls and hydraulic roll force actuators carried by said housing for adjusting the gap between said processing rolls, said method comprising the steps of: computing a change in the housing stretch as a function of a change in the rolling force due to said eccentricity characteristics of the rolls; and controlling said hydraulic roll force actuator in such a way to compensate for a change in the said housing stretch by preventing rolling force increases between said processing rolls due to said eccentricity characteristics.
Claim 10
Dependent Claim
60 words
The method of claim 7 including the steps of: generating a first electrical signal proportional to said rolling force; and modifying said first electrical signal in accordance with the equation h P/Mm for computing an actual change in the housing stretch, where h equals the actual roll gap, P equals rolling force, and Mm equals modulus of the mill housing.
Claim 11
Dependent Claim
42 words
The method of claim 8 including the steps of: generating a second electrical signal proportional to said change in the rolling force; generating a gage control error signal; and modifying sid electrical signal by the combination with said gage control error signal.
Claim 12
Dependent Claim
43 words
The method of claim 8 including the steps of: generating a second electrical signal proportional to said change in the rolling load; generating a tension control error signal; and modifying said second electrical signal by the combination with said tension control error signal.
Claim 13
Dependent Claim
37 words
The method of claim 7 including the step of producing an error signal having a response time by said actuator of up to 20 cycles per second for said step of controlling said hydraulic roll force actuator.
Claim 14
Dependent Claim
169 words
A control system for a rolling mill of the type employed to simulate a stretch characteristic of the rolling mill structure selected from a range of stretch characteristics between infinitely stiff and infinitely soft under the rolling forces developed between the processing rolls during the rolling of strip-like material comprising: means for generating a first signal proportional to the rolling force developed between said processing rolls; means receiving said first signal for generating a second signal proportional to a change in the housing stretch due to a change in said rolling force; means receiving said second signal for generating a third signal representing an inverted housing stretch signal having an electrical polarity opposite to said second signal; control signal selection means receiving said second and third signals for delivering a roll gap adjusting signal selected to simulate a rolling mill structure having a desired stretch characteristic; and means inlcuding a fluid actuator for adjusting said gap formed between said processing rolls in response to said roll gap adjusting signal.
Claim 15
Dependent Claim
169 words
A control system for a rolling mill of the type employed to simulate a stretch characteristic of the rolling mill structure selected from a range of stretch characteristics between infinitely stiff and infinitely soft under the rolling forces developed between the processing rolls during the rolling of strip-like material comprising: means for generating a first signal proportional to the rolling force developed between said processing rolls; means receiving said first signal for generating a second signal proportional to a change in the housing stretch due to a change in said rolling force; means receiving said second signal for generating a third signal representing an inverted housing stretch signal having an electrical polarity opposite to said second signal; control signal selection means receiving said second and third signals for delivering a roll gap adjusting signal selected to simulate a rolling mill structure having a desired stretch characteristic; and means inlcuding a fluid actuator for adjusting said gap formed between said processing rolls in response to said roll gap adjusting signal.
Claim 16
Dependent Claim
52 words
A control system according to claim 12 wherein said control signal selection means including a potentiometer having a movable tap, said potentiometer having a first input contact receiving said second signal, said potentiometer further including a second input contact electrically opposed to said first input contact and receiving said third electrical signal.
Claim 17
Dependent Claim
132 words
A control system for a rolling mill of the type employed to compensate for eccentricity characteristics of rolls while rotating in a mill which produce cyclic changes in the gap defined by the processing rolls, said rolling mill including housing means for rotatably supporting said rolls, fluid actuated means carried by said housing means for adjusting said roll gap defined by the processing rolls, the improvement comprising: means for generating a signal proportional to elastic changes of the housing means as a function of said eccentricity characteristics of the rolls in the mill; a control circuit receiving said signal for generating a roll eccentricity compensating signal proportional to a roll gap change for eliminating said elastic changes; and control means receiving said roll eccentricity compensating signal for adjusting said fluid actuated means.
Claim 18
Dependent Claim
132 words
A control system for a rolling mill of the type employed to compensate for eccentricity characteristics of rolls while rotating in a mill which produce cyclic changes in the gap defined by the processing rolls, said rolling mill including housing means for rotatably supporting said rolls, fluid actuated means carried by said housing means for adjusting said roll gap defined by the processing rolls, the improvement comprising: means for generating a signal proportional to elastic changes of the housing means as a function of said eccentricity characteristics of the rolls in the mill; a control circuit receiving said signal for generating a roll eccentricity compensating signal proportional to a roll gap change for eliminating said elastic changes; and control means receiving said roll eccentricity compensating signal for adjusting said fluid actuated means.
Claim 19
Dependent Claim
28 words
A control system according to claim 14, the improvement further comprising: gage error signal generating means for modifying said signal proportional to elastic changes of the housing means.
Claim 20
Dependent Claim
31 words
A control system according to claim 14, the improvement further comprising: means for generating a tension control error signal to modify said signal proportional to elastic changes of the housing means.
References Cited (Backward Citations)
US3478551A
Cited
US3543549A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |