Development of Chucking Condition Sensor for Three-jaw Scroll Chuck

Abstract

The chucking pressure plays an important role in chucking a cylindrical workpiece with a three-jaw scroll lathe chuck, however, it has not been investigated in the earlier works. In the present study, the chucking pressure is investigated by measuring the strains induced on the chuck jaw surfaces. From the present investigation, the following observations are obtained. (1) The chucking condition can be expressed by a simple diagram so-called "chucking triangle" based on the measured strains of the jaw surfaces. (2) The chucking triangle shows the chucking pressure distributions at the individual jaws and can be displayed automatically on the CRT after processing the strain data with micro-computer. A new sensing method for chucking condition is developed using the chucking triangle. The newly developed method has been tested by chucking specially formed specimens, and it is proved that the new sensing method has satisfactory performances.