An improved polishing method by force controlling and its application in aspheric surfaces ballonet polishing

Ballonet polishing tools, soft gasbags filled with compressed gas, are taking priority over other tools in curved surfaces polishing for their adaptability to change their shape to fit the machined surfaces. However, the real contact stress would be changed by the tensile stress of the bag's material with the change of the workpiece's shape even if the internal pressure of the gasbag is kept at a constant value. This paper studies how the tensile stress influences the contact conditions and the contact stress, and it advances an improved ballonet polishing method by contact force controlling. As a typical application, geometry arithmetic and parameter optimization are studied on the process of aspheric surfaces polishing. Theory study and real experiments show that, it is a better way by controlling the contact force rather than by controlling the internal pressure of the ballonet.