| 摘要 |
PURPOSE:To prevent a tool from breakage due to erroneous operation in such a way that only feed of control signals for converting speeds is interrupted by depression of a control switch, but just control signals to display the completion of machining can be fed even if the control switch has been depressed. CONSTITUTION:A grinding wheel 10 is hung axially on a tool rest 11, which is driven into rotation by a motor 12. A control switch 25 is used for accelerating feed speed of the tool in case of machining a small diametral work W. In case where the control switch 25 is controlled, feed of control signals AS1 and AS2 is stopped irrespective of the size of the work W. Control signals AS1-AS3 are given through signal lines SL1-SL3 to a servo motor driving device 29, at the same time, to display lamps D1-D3. When the control switch 25 has been controlled, the grinding wheel 10 makes a dash at fast forward speed to the work W because the signals AS1, AS2 are brought into disconnection, and when the work becomes finishing size, cutting of the grinding wheel 10 comes to a standstill. |
