METHOD AND APPARATUS FOR MEASURING PITCH CIRCLE DIAMETER

摘要

PROBLEM TO BE SOLVED: To highly accurately measure a pitch circle diameter of an object to be measured such as a screw shaft of a ball screw and a ball nut without the need for skill in work. SOLUTION: The object to be measured is restrained into a state in which center line of the object to be measured is moved in one plane through use of a reference plane (ST1). A pair of balls for measurement provided in the one plane in such a way as to sandwich the center line of the object to be measured are each positioned on thread grooves of the object to be measured at locations displaced by half a lead in an axial direction of the object to be measured (ST2). A measuring force is exerted to bring each of the pair of balls for measurement into contact with the thread grooves of the object to be measured at two points (ST3). The pitch circle diameter of the object to be measured is measured on the basis of relative locations of the pair of balls for measurement (ST4 and ST5). COPYRIGHT: (C)2004,JPO