Showing papers by "Katsushi Furutani published in 2002"

In-process measurement of topography change of grinding wheel by using hydrodynamic pressure

Abstract: This paper deals with an in-process measurement method for topography change of a grinding wheel, which can apply to wet grinding. A pressure sensor is set beside a grinding wheel with a small gap. When grinding fluid is dragged into the gap, hydrodynamic pressure, which corresponds to the gap length and the topography, can be measured. This method is applied to a cylindrical grinding machine. No electromagnetic properties of a workpiece and a grinding wheel affect measured results. The pressure is decreased with the increase of the gap length when the grinding fluid is supplied in the tangential direction of the grinding wheel. Spectra of the pressure are measured with an FFT analyzer. Higher frequency components are increased with the progress of grinding because of turbulent flow. Loading and dulling of a grinding wheel can be detected by the proposed method as well as its wear.

Positioning performance of L-shaped seal mechanism with 3-degree of freedom

Abstract: This paper deals with a small mobile device, "seal mechanism", with three degrees of freedom (DOFs). An L-shaped structure of seal mechanism is proposed. This device consists of two controlled electromagnets FA and FB connected by two piezoelectric actuators EA and EB with electromagnet FC that generates a constant friction. The friction at FA and FB are alternated by an on-off control. The whole device wriggles with electromagnets FC by deforming piezoelectric actuators. The 3-DOF device can move up to micrometer steps in the x- and y-directions and rotates up to submilliradian steps in the /spl theta/-direction. The seal mechanism performs as well as the inchworm mechanism. Positioning accuracy in each direction is twice as small as the moving step. The seal mechanism has a smaller number of controlled actuators and is driven by a smaller number of steps than the multiple-DOF positioning stages employing the inchworm mechanism.