Roll bending machine with ratchet mechanism

Abstract

Metal forming can be defined as a process in which the desired size and shapes are obtained through plastic deformation of a material without any significance loss of material. Bending is a metal forming process in which straight length is transformed into a curved length. Roller forming is a continuous bending operation in which a long strip of metal is passed through consecutive sets of rollers, until the desired cross sectional profile is obtained. The roller bending process usually produces larger parts of cylindrical or conical cross sections in large quantity. This project is to design and construct a portable roller bending machine. This machine is used to bend metal strips into curve and the other curvature shapes. The size of machine is very convenient for portable work. It is fully made by steel. Moreover, it is easy to be transported and use at any time and any place. It reduces human effort and also required less skill to operate this machine. We are designing manually operated roller bending machine with use of rollers, chain sprockets and support (frame). The roller bending machine is manually operated. Therefore, our objective is to increase accuracy at low prize without affecting the bending productivity. This machine works on simple kinematic system instead of complicated design. Due to its portability it can be used by small workshop or fabrication shop. In the three roller bending machine, the three rollers rotate. Bending can be done in both sheet metal and bars of metal. For designing a three roller bending machine, it is required to calculate the exact force for bending. Based on this force, the machine parameters and motor power are decided. Various factors that should be considered while calculating this force are material properties, width, and thickness, number of passes, bending radius, force developing mechanism and link.