Patent ID: 8631727
Filing Date: 2014-01-21
Classification: B23B,B23Q,G05B,Y10T

Abstract:
1. A machine tool which comprises: a headstock arranged to rotatably support a spindle including a tip provided with a chuck to hold a work; a tool post having a tool fitted thereto; a machine bed on which the headstock and the tool post are arranged to move relative to each other in a spindle radial direction and a spindle axial direction; a spindle side position measuring unit including a first scale extending in the spindle radial direction, and a first readout unit arranged to read the first scale and to measure a spindle axial position in the spindle radial direction relative to a first reference position, one of a base end portion of the first scale and the first readout unit being provided on a portion of the headstock or a member that is movable in the spindle radial direction together with the headstock in an area of the spindle axis in the spindle radial direction, and the other of the base end of the first scale and the first readout unit being provided at the first reference position; a tool side position measuring unit including a second scale extending in the spindle radial direction, and a second readout unit arranged to read the second scale and to measure the position of the tool post relative to a second reference position, one of a base end portion of the second scale and the second readout unit being provided on the tool post or a member that is movable together with the tool post in the spindle radial direction, and the other of the base end portion of the second scale and the second readout unit being provided at the second reference position; the first reference position and the second reference position being fixed in position relative to the spindle radial direction; and a calculating block arranged to calculate a relative distance between a spindle axis and a cutter edge that corresponds to a distance between the spindle axis and the cutter edge in the spindle radial direction, or to calculate a value that is used in correcting an amount of relative movement between the headstock and the tool post in the spindle radial direction based on a reading of the spindle side position measuring unit and a reading of the tool side position measuring unit.