Design and Analysis of a New Type Forging Manipulator

Large-scale forging manipulator is the indispensable equipment in the operations of automated forging. Because of the increasing demand of forging manipulator, large and medium-sized enterprises pay more and more attention to the forging operation in production. Lower freedom parallel mechanism is obtained by using the constraint-synthesis method based on the screw theory, then a mechanism of forging manipulator is designed including raising and lowering, pitching, lateral swing, lateral movement, forth or back and clamp rotation. The new type forging manipulator is a hybrid serial-parallel mechanism. The degree of freedom of the parallel mechanism is calculated by using the modified Grübler-Kutzbach criterion, and then the degree of freedom of the machine is determined. Through closed geometric method, the kinematic position analysis is performed, and the correctness of the theoretical analysis results is verified.

Hydraulic systems control based on the characteristics of major-motion mechanism for an open-die forging manipulator

In the open-die forging process, the forging manipulator must cooperate closely with the forging press. Terrible working conditions of open-die forging have resulted in significant demand on the hydraulic control systems of the forging manipulator. This article analyzes the characteristics of major-motion hydraulic systems with the aim of proposing a novel hybrid serial–parallel heavy-duty forging manipulator. Kinematic and dynamic models of the major-motion mechanism are developed to investigate the control and comply with performance of hydraulic lifting, pitching, and buffering systems. Simulation shows that the three hydraulic systems are coupled in the position and posture control of the clamp. A separate posture control method based on the characteristic of the major-motion mechanism is designed for the hydraulic systems, and the position tracking performance of the hydraulic systems is studied in a stretching process of a plat-tool.