| 摘要 |
PROBLEM TO BE SOLVED: To provide a band saw for executing an effective preventive measure, by predicting the occurrence of a lock state of the band saw.SOLUTION: In a band saw for rotating the band saw of forming a loop by a motor, a control device stops normal rotation of the motor (the time t) when detecting a predetermined load by a motor current 42, and reversely rotates the motor (the time t-t), and moves the band saw in the inverse direction by a predetermined quantity. A rotating speed of the motor in reverse rotation is set as a lower speed than a rotating speed of the motor in normal rotation, and the motor is stopped once after moving the band saw in the inverse direction by the predetermined quantity, and is constituted so as to normally rotate the motor thereafter (on and after the time t). Thus, since "a lock-avoidance reverse rotation mode" for avoiding a lock of the motor is provided, blade chipping of the band saw and breakage of the band saw can be restrained.SELECTED DRAWING: Figure 3 |
