ACTIVE CENTERING APPARATUS WITH IMBEDDED SHEAR LOAD SENSOR AND ACTUATOR

摘要

An apparatus for sensing and correcting force levels and vibrational frequencies in a cylindrical grinding machine which has active centers. The active centers have imbedded shear load sensors and imbedded actuators. The sensors provide real time grinding information and allow for a determination of undesirable force levels and vibrational frequencies. The actuators are a pair of piezoelectric stacks disposed on opposing sides of the center body in indentations. A voltage applied by a controller causes the piezoelectric stacks to expand and contract. The action of the piezoelectric stacks causes the tip of the center to laterally displace and apply a lateral force to the workpiece. An AC voltage waveform may be applied for force control. A DC voltage may be appliedfor displacement; for example, to rapidly remove the workpiece from the grinding wheel or to correct for misalignment between the workpiece and the wheel. Because the sensors and actuators are imbedded, they do not interfere with the work space or machine components. In addition, the sensors and actuators are formed in standard sized centers so that the active centers may easily retrofit existing machines.