| 摘要 |
A machine tool is disclosed having an inverted spotfacer chucked in a rotatable tapered spindle socket. The inverted spotfacer comprises an actuation shaft being rigidly axially connected to a tapered shank which, in turn, is chucked in the socket. A shoulder element can be displaced on the actuation shaft against the force of a spring. Further, a positive control mechanism acts between the actuation shaft and the shoulder element. Due to the action of the positive control mechanism, when axially displacing the actuation shaft relative to the shoulder element, a cutting tool arranged tiltably at the lower end of the actuation shaft may be tilted between two operational positions. In the first operational position the cutting tool extends parallel to the longitudinal axis of the spotfacer, whereas in the second operational position the cutting tool extends perpendicularly to the spotfacer axis, the second operational position being the position in which the spotfacer may make countersunk bores on workpieces. A sensor is provided for sensing the relative position of the shoulder element on the actuation shaft. The sensor is connected to an electronic control unit comparing the detected axial position with a reference value. |
