| 摘要 |
PURPOSE:To obtain a cheap swingingly grinding device by disposing three electrostriction elements with the interval of 120 deg. between a swinging spindle, where a grinding tool is mounted, and a fixed frame, and swinging the spindle according to the change of mechanical sizes of the elements. CONSTITUTION:Three electrostriction elements 300a, 300b, 300c are provided with the interval of 120 deg. between the inner peripheral surface of a fixing frame 21 and a swinging cylinder 25 where a swinging spindle 14 is mounted. When voltage, whereby those elements 300a, 300b, 300c extract or contract differentially to each other with respect to the standard size of a grinding tool mounted on the downwardly suspended end of the spindle 14, is applied to those elements 300a, 300b, 300c, they swing in proportion to the magnitude of the applied voltage and repeating cycle, so that the grinding tool is swung through the spindle 13 to grind the surface of a work such as metal molding, etc. Thus, there is no need for using such power source whose phase differs 90 deg. as used in the case of four electrostriction elements, and three phase commercial power source or three phase inverter power source can be used, thereby it is possible to make the cost of the captioned device cheap with minimum electrostriction elements. |
