外文翻译--对电控带式铣床运用液压自动精度控制和宽度控制（可编辑）.doc

外文翻译--对电控带式铣床运用液压自动精度控制和宽度控制 Appication of hydraulic AGC and width control to a hot strip mill D.Alan Davies,Project Sale Manager,Engineering and Construction Div. Davy Mckee Sheffie idLid, Sheffieid, U. KTHE Pohang Iron Steel Co.POSCO No.2 hot strip mill at Pohang, South Korea,is a modern, three-quarter continuous mill built by Mitsubishi in 1980.The mill is 2050mm wide,has four roughing stands and seven finishing srands.The seven finishing srands have a combined power of 56,000kw with a imum strip speed of 21 metres/s.Coil weight is up to 35.3 tonnes. Annual mil capacity is 3.56 million tonnesTo improve width and gage tolerances,POSCO decided to install hydraulic automatic width contol HAWC on the last edger E4 and hydraulic automatic gage control HAGC on finishing stands F4 to F7Davy McKees contract was for the total ackage associat-ed with modernization of the mechanical and hydraulic systems,the computer-bassd AWC/AGC controls, new widthmeter, mechanical installation, commissioning and training. The new equipment was put into service during a 14-day shutdown in 1987. Outline of new facilitiesA priority requirement was that the new equipment should be integrated with the existing facility in such a way as to permit reversion to conventional operation in a few seconds. Accordingly, hydraulic AGC and AWC cylinders were designed to withstand normal rolling conditions when in a collapsed stateAll of the control systems had to be in parallel with the existing systems which were retained and existing operators desk contromechanical system, depending on which system was selectedThe AWC system comprises short-stroke, single-acting cylinders four in total engineered between the ends of the horizontal screwa and the vertical roll chocksThese cylinders are servo-controlled, with a stroke speed of 100 mm/s 4 ips to provide in -bar width control. With the bar being typically 50 mm thick at this stage, only a limited amount of