Study On Shape Control Features Of Hydraulic Bulging Roller And Key Technology

Shape is the most important index of strip quality. As a key part of strip quality control system, the shape control technology-is the soul of the system. For the demand of high quality products and high productivity in strip milling, the shape control technology is expected to ensure high precision and high on-line controllability. Among the effective shape control technologies adopted currently, the hydraulic bulging roller technology of unique advantages meets the two above-mentioned demands with increasing application in international field of strip manufacturing and better promise. The technology, however, is seldom applied in domestic plants and even relevant reports are rare. Although some plants show their desire to the said technology, it is hardly used because of absence of related references.Considering the research projects of national key scientific and technological programs according to the ninth five-year plan of National Mechanical Ministry, load features and their key technologies of hydraulic bulging roller system are studied further and important results are obtained that are feasible and innovative to direct real productionFirstly, the effective solution is found to the technological problem of high pressure sealing joint and a couple of hydraulic bulging rollers are made. The experiment is conducted of dead-load crown feature of hydraulic bulging roller to draw the conclusion of roller crown under different control pressure. With the hydraulic bulging roller as backup one, the aluminum strip denting experiments are conducted on 300mm cold roll mill in rolling laboratory of Yanshan University. As a result, both acquired strains at some typical points under various rolling loads and other numerous experimental measures embodying technological features of hydraulic bulging roller provide numerical analysis model with boundary conditions and testing criterion.The aluminum strip rolling experiment is performed in order to test further the capacity of hydraulic bulging roller in improving the strip shape. With different rolling force and hydraulic bulging roller as backup roller, the defects of middle waves or edge waves emerge in strip specimen with the uniform original condition and property. And good shape is also available. The facts demonstrate confidently the capacity of hydraulic bulging roller in controlling the strip shape and availability of good shape.With the aid of established FEM model, the effect is studied of forming features ofhydraulic bulging roller under rolling load and structure parameters on load features of roller system. Further, determination principles and methods of roller structure parameters are obtained to take into shape the key designing and manufacturing technologies of hydraulic bulging roller.Based on the analysis and studies, the mechanical principle is illustrated of hydraulic bulging roller in controlling and improving shape, namely, the capacity of hydraulic bulging roller in controlling shape consists in the fact that bulging effect of control pressure brings out additional bending moment to work roller by rolling load. Thereof, the shrunk-fit length between sleeve and arbor is the key to push the shape control capacity of hydraulic bulging roller to the maximum.According to its load features, only within the scope of critical controlling rolling force could the hydraulic bulging roller come into effect in controlling shape. When the rolling force demanded by rolling process is larger than the critical controlling rolling force of hydraulic bulging roller, combination of roller bending technology and the said technology contributes to produce load gap with crown less than or equal to zero and corresponding products.Base on the shape control principle of hydraulic bulging roller, a new design of shape control is produce. That is to say, combination of bi-chamber hydraulic bulging roller and uni-chamber hydraulic bulging roller can obtain roller gap of different shapes, which is of both effect of CVC roller and the online control capa...