公开(公告)号：US09802263B2

公开(公告)日：2017-10-31

申请号：US14635400

申请日：2015-03-02

申请人： DENSO CORPORATION

发明人： Kouichirou Yasuda ,  Yasuji Inobe ,  Akira Itoh ,  Nobuhiko Nagai ,  Tetsuji Yamaguchi ,  Hiroyuki Ootani

IPC分类号： B23H1/04 ,  B23H7/30 ,  B23H9/14 ,  B23H1/00 ,  B23H7/38 ,  B23H11/00

CPC分类号： B23H1/04 ,  B23H1/00 ,  B23H7/30 ,  B23H7/38 ,  B23H9/14 ,  B23H11/00

摘要： In an electrical discharge machine that applies a voltage between an electrode and a workpiece to generate electrical discharge, an electrode holder holds the electrode. An ultrasonic motor has a fingertip that comes into contact with electrode holder, and moves electrode holder in a driving direction by moving the fingertip in an annular manner at an ultrasonic-range frequency. A roller bearing guides the movement of the electrode holder in the driving direction. A control circuit controls a position of the electrode in the driving direction by driving the ultrasonic motor, and moves the electrode holder based on an abnormality occurring in resistance against the movement of the electrode holder in the driving direction such that the electrode holder is moved by a movement distance equivalent to when the largest roller element among a plurality of roller elements of the roller bearing rolls and rotates once without sliding or longer.