Research The CNC Incremental Forming Of Straight-wall Parts

The forming problem of sheet metal parts with straight walls was studied in the paper,and the corresponding forming methods were proposed according to different types of straight-wall parts to improve the forming effect of straight wall parts.First,a CNC incremental forming method for the open slot part based on the half-constraint fixing method was proposed,and the corresponding toolpath was planned for the fixing method.Its feasibility was verified by forming experiments at next.Then,a CNC incremental forming method based on a virtual auxiliary body was proposed aiming at the sheet parts with straight-wall on all sidewalls.In the method,the sheet posture was adjusted by setting virtual reference objects in the straight-wall parts to realize the forming of straight-wall parts.In the paper,the generation algorithms of the virtual auxiliary body and corresponding forming toolpath was given,and the effectiveness of the method was verified by numerical simulation and forming experiment.At the same time,in order to improve the forming quality of the method,the influence rule of corresponding parameters on thickness uniformity was studied through single factor experiment and factorial experiment,and the optimal parameters combination was determined.The experiment showed that the sheet metal parts formed by the optimized parameters have better thickness distribution.Finally,for sheet parts with straight walls and easy forming surfaces on the sidewalls,a selective multi-stage two point incremental forming method based on forming angles was proposed.The forming region is divided by identifying the forming angles of triangular faces in the method,and multi-stage forming is used for large forming angle areas with single-stage forming is used for small forming angle areas.In the paper,the algorithms of the first stage model construction,the first stage toolpath generation and the second stage inclined toolpath generation were given.In next,numerical simulations and forming experiments verify that the method can realize the forming of the sheet metal parts with the vertical-wall partially and irregularly distributed on sidewalls,and has a better profile and thickness distribution than traditional multi-stage incremental forming.