CENTER HEIGHT MEASURING DEVICE FOR CUTTING TOOL

PURPOSE:To ensure easy and reliable adjustment for cutting tool center height by providing a contactor at a position with which the edge of a cutter gets in contact, and a detecting slope formed aslant upward or downward for a datum plane orthogonal with the machining direction of the cutting tool. CONSTITUTION:When the edge of a cutting tool mounted on a numerically controlled tool rest is made in contact with the datum plane 44 of a contactor 40 at the tip of a housing 20, said contactor 40 moves finely to push the sensing part 33 of a contact detecting sensor 30, thereby turning 'ON' the sensor 30 and detecting a distance Z1 from a machining datum O, which position agrees to the horizontal center line a of a detecting slope 46. Then, the detecting 46 is contacted by a cutter edge and if said edge improperly contacts a point b due to misalignment, the sensor 30 begins to work and the position of the point b is measured as a distance Z2 from the machining datum O. The value of Z1-Z2 is a deviation in an X direction, but as the inclination of the detecting slope is 45 deg., it is possible to measure said position as a deviation S=Z1-Z2 for center height. If the cutter is lowered by a distance corresponding to the deviation, therefore, an error of center height can be made zero, thereby improving accuracy.