Research On The Oversized Four Rollers Bending Machine

A heavy-duty plate bending machine is the key equipment in the making of thick wall and high pressure vessels. Some researching work has been done in the studying and making of the W12NC-260×3500 oversized four rolls bending machine.Some research analysis has been done in the general conditions of development and research on domestic and foreign status. The cold rolling capacity of the machine that is studied and made by myself and my factory is in the first place in Asia and third place in world.In order to design the plate bending machine scientifically and rationally, some essential research work has been put up in the basic theory of the plate rolling technics. The bending process of mental plate is the plastic bending deformation. According to the principle of three points making a circle, the plate bending is the process of three points sequence bending of plate stuff. In generally, the making of cylindrical shell section is made up of the working procedures of centering, pre-bending, coiling block and setting round. When the capacity plate bending is deficiency, the hot rolling can be considered. The hot rolling has many limitations. Some common fallacies and their causation have been discussed and analyzed and the corresponding measures have been put in the paper.The specialty of different kinds of plate bending machine has been discussed in the paper. Plate bending machines is fell into two rolls, three rolls and four rolls according to the number of rolls and its distribution. Although the four rolls machine has the defects of complex and heavy, it has many virtues, such as easy centering, pre-bending in small margin, and high precision in the setting round. It is used broadly in the bending of thick plate. In order to give full play to the virtues of the machine, right manipulate approach is given in the paper.The design proposal of the W12NC-260×3500 oversized four-roll bending machine is conformed, according to the foundation of sufficiency reasoning and combining the characteristics in corporation. The initiative roll is the top roll. Main drive chain is mechanical transmission. The rise and drop of low and side rolls are assistive fluid drive movement.In order to ensure the accuracy of rolling functional and the safety of the structure and design, the parameters calculation had been done in the bending process, the working roll strength and stiffness of checking, hydraulic system design. A finite element analysis to the rolling machine frame has been done with the software of WORKBENCH, which is designed by the structural design experience and the analogy. The strength and stiffness have been checked in the paper.The manufacturing of large plate bending machine has been concerned with many methods of manufacturing process, such as the casting, pressure processing, welding, machining, heat treatment, assembly. Several key links, such as manufacturing process of the rack manufacturing, work roll and the manufacture of transmission gear, processing of tanks and final assembly of equipments, are discussed in the paper. The program optimization process and quality control points are also given.At last the research work of oversized plate bending machine has been summed up and some propose improvements are given.