Conceptual Design of an Exactly Straight Lifting Forging Manipulator

Abstract

The gripper lifting track of a forging manipulator should keep as close to a straight line as possible, especially for the manufacturing of long or high-precision forged pieces. However, the lifting tracks of most forging manipulators are arc, such as DANGO & DIENENTHAL in Siegen (DDS) and Schloemann-SiemagAG Meer (SMS Meer). This paper proposes a new forging manipulator whose gripper lifting track is exactly a straight line. First, a planar 3-degrees-of-freedom (3-DOF) mechanism whose gripper moves along a straight line is proposed. Second, replace the lifting drive of the planar mechanism with a parallel mechanism which only generates one translation, and obtain a major-motion mechanism. Finally, a new forging manipulator is constructed based on this major-motion mechanism. The new manipulator has the advantages of exactly straight lifting, high load-bearing capacity, and decoupling the lifting from other motions. It not only can improve forging precision for long axial forged pieces but also make coordinated control of two forging manipulators much easier.