US3889504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thickness control device for rolling mill
Assignee: Hitachi Ltd
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Filing: 1974-08-09
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Granted: 1975-06-17
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Expires: 1994-08-09
Abstract
Abstract An input side thickness of a strip and rolling pressure are continuously measured whereby an output side thickness of the strip is obtained based on the measurements thus obtained. Subsequently, the autocorrelation function and cross-correlation function are obtained according to the thickness both on the input and output sides to obtain a power spectra, after which coherence function is obtained from those spectra thereby determining a contribution factor of the input side thickness to the output side thickness. Thus, when the contribution factor is low, the roll eccentricity is considered to exert a great influence, so that the eccentricity obtained from the aforesaid coherence is fed as a command value in a gagemeter type thickness control system to compensate for the thickness of the strip.
Inventors
- 👤 Ken Ichiryu
- 👤 Masayuki Shigeta
- 👤 Toshiyuki Kajiwara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:51
CPC Classifications
B; B21; B21B; B21B37/00; B21B37/58; B21B37/66
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
180 words
In a gagemeter type automatic thickness control system in a rolling mill consisting of rolls for rolling a strip, hydraulic jack for imparting a rolling pressure to said rolls, a flow rate control valve for adjusting a roll gap by adjusting the amount of oil in said hydraulic jack, a valve control device, a setting device for feeding a desired thickness command to said control device, and a position detector for detecting the roll gap and feeding back the detected value to said valve control device; a thickness control device, comprising means for detecting an input side thickness and an output side thickness of said strip; a computing device for obtaining the respective power spectra phi h1, phi h2, phi h3 from the autocorrelation functions Rh1 and Rh2 and the cross-correlation function Rh1h2 and then for obtaining from said power spectra the roll eccentricity based on the coherence defined by ( phi 2h1 h2)/ phi h1. phi h2); and means for feeding as a command value the roll eccentricity obtained from said computing device, to said plate thickness control device.
Claim 2
Dependent Claim
180 words
In a gagemeter type automatic thickness control system in a rolling mill consisting of rolls for rolling a strip, hydraulic jack for imparting a rolling pressure to said rolls, a flow rate control valve for adjusting a roll gap by adjusting the amount of oil in said hydraulic jack, a valve control device, a setting device for feeding a desired thickness command to said control device, and a position detector for detecting the roll gap and feeding back the detected value to said valve control device; a thickness control device, comprising means for detecting an input side thickness and an output side thickness of said strip; a computing device for obtaining the respective power spectra phi h1, phi h2, phi h3 from the autocorrelation functions Rh1 and Rh2 and the cross-correlation function Rh1h2 and then for obtaining from said power spectra the roll eccentricity based on the coherence defined by ( phi 2h1 h2)/ phi h1. phi h2); and means for feeding as a command value the roll eccentricity obtained from said computing device, to said plate thickness control device.
Claim 3
Dependent Claim
44 words
A thickness control device for a rolling mill as set forth in claim 1, wherein said output thickness detecting means consists of input side thickness detecting means, rolling pressure detecting means and computing measn for calculating an output thickness from said both detecting means.
Claim 4
Dependent Claim
119 words
A thickness control device for a rolling mill as set forth in claim 1, wherein said device further comprises: a filter capable of passing only an output signal tunning with a roll eccentricity frequency, among output signals from said output side thickness detecting means; a coefficient multiplier for taking out a roll eccentricity component along by multiplying the signal passed through said filter by coefficient represented by a function of Beta 1 - gamma 2; means for obtaining a deviation between the output signal passed through said coefficient multiplier and the signal prior to the passage through said filter; and means for feeding as an input said deviation signal to said plate thickness control device as a command value.
Claim 5
Dependent Claim
96 words
A thickness control device for a rolling mill as set forth in claim 4, said device further comprises: means for monitoring the decrease of the coherence from 1, continuously; means for determining due to said monitoring if the decrease of coherence falls within allowance; means for computing the eccentricity vector according to the correlation between a reference signal from the rolling mill rotation system and the output side thickness (or rolling pressure); and means for feeding the output signal from said computing device as an input, to said plate thickness control device as a command value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |