Abstract: A Z axis driving device (21) is controlled to be driven by a control device (23), and the processing power is supplied between the electrodes of a discharge surface processing electrode (14) and a punch (1). Thus, electric discharge is occurred between the end surface (4) of the punch (1) and the discharge surface processing electrode (14) to thereby form a hard coating film (24) on the end surface (4) of the punch (1) and also form a carved portion (14a) with a predetermined depth at the discharge surface processing electrode (14). Next, an X axis driving device (19) and a Y axis driving device (20) are controlled to be driven by the control device (23), and the processing power is supplied between the electrodes of the discharge surface processing electrode (14) and the punch (1) while relatively orbiting the punch (1) and the discharge surface processing electrode (14) within the horizontal plane. Thus, a hard coating film (25) is formed on the side surfaces (5) of the punch (1).

Abstract: In a robot for compensating gravitational torque, various types of installation postures, including installation of a floor and hanging from a ceiling, can easily be realized. Namely, the characteristics of the gravitational balancer are selected in order to compensate for various postures of the robot, such as that when installed on a floor or hung from a ceiling. Also, a direction of the compensation torque can freely be changed by adjusting a spring mounting position in the rotational link or in the stationary link. Further, adjustment of the compensation torque can freely be carried out by providing a plurality of spring set positions in the stationary link as well as in the rotational link. In addition, adjustment of the compensation torque can freely be carried out also by adjusting the mounting length of a spring set between the stationary link and the rotational link.