Abstract A numerical controlled machine tool adapted to process a bore in a work-piece by the use of a single point cutting tool supported in the main spindle of the machine tool in which a main spindle assembly comprising a main spindle sleeve having an axially extending eccentric opening and said main spindle received in said eccentric opening and having a tool mounting portion. The diameter of a bore to be processed can be adjusted by varying the eccentricity of the tool mounting portion of the main spindle with respect to the main spindle sleeve and the eccentricity of the tool mounting portion with respect to the sleeve can be varied in accordance with a control signal from a numerical control device. A numerical control shaft for measuring the diameter of a bore processed is provided independently of numerical control shafts for positioning and the numerical control shaft is adapted to measure the bore diameter by moving a measuring element in accordance with a bore diameter predetermined by a numerical control program and in order to compensate for any difference between the predetermined bore diameter and the measured bore diameter, prior to the following finish boring operation, the eccentricity of the tool mounting portion of the main spindle with respect to the sleeve is adjusted by the measured deviation amount of bore diameter so that a desired bore diameter can be obtained in the finish boring operation.
A numerical controlled boring machine having a numerical control device and a control device for controlling the processing of a workpiece, comprising; an automatic bore diameter measuring and compensating apparatus which comprises a spindle head having a main spindle for rotation therewith, said main spindle being adapted to support a single cutting tool; a compensating device for adjusting the radius of gyration of an edge point of said cutting tool; and a measuring device including, a bore diameter measuring element, adapted to be displaced along a bore diameter, for measuring in response to a signal from said control device, and a control shaft provided independently of positioning control shafts and including; a measuring result register whereby the measuring result of said measuring device are given to said compensating device so as to compensate for any difference between the diameter of a bore processed during a trial boring operation and a desired diameter for a complete bore to be processed in a finish boring operation, in which said apparatus further includes: a main spindle sleeve having an axial eccentric opening for receiving said main spindle on which a single cutting tool is adapted to mounted, a differential gear mechanism and rotary coupling means for connecting said main spindle sleeve and main spindle for usual rotating in cutting operation while maintaining the two members in an angular phase difference and a servo motor adapted to impart a numerical control rotational movement to said necessary angular phase difference.
Claim 2
Dependent Claim
245 words
A numerical controlled boring machine having a numerical control device and a control device for controlling the processing of a workpiece, comprising; an automatic bore diameter measuring and compensating apparatus which comprises a spindle head having a main spindle for rotation therewith, said main spindle being adapted to support a single cutting tool; a compensating device for adjusting the radius of gyration of an edge point of said cutting tool; and a measuring device including, a bore diameter measuring element, adapted to be displaced along a bore diameter, for measuring in response to a signal from said control device, and a control shaft provided independently of positioning control shafts and including; a measuring result register whereby the measuring result of said measuring device are given to said compensating device so as to compensate for any difference between the diameter of a bore processed during a trial boring operation and a desired diameter for a complete bore to be processed in a finish boring operation, in which said apparatus further includes: a main spindle sleeve having an axial eccentric opening for receiving said main spindle on which a single cutting tool is adapted to mounted, a differential gear mechanism and rotary coupling means for connecting said main spindle sleeve and main spindle for usual rotating in cutting operation while maintaining the two members in an angular phase difference and a servo motor adapted to impart a numerical control rotational movement to said necessary angular phase difference.
Claim 3
Dependent Claim
72 words
An automatic bore diameter measuring and compensating apparatus as set forth in claim 1, in which feed means are provided on said spindle head parallel to the axis of said main spindle for moving said measuring device along said feed means between its measuring position, and retracted position whereby the relative position between the axis of rotation of said main shaft and the position of the measuring device is always maintained constant.
Claim 4
Dependent Claim
154 words
An automatic bore diameter measuring and compensating apparatus as set forth in claim 2 in which said apparatus comprises: a measuring head assembly which is provided with a pair of measuring elements, said servo motor, and a fine displacement instrument, said measuring elements being adapted to be in contact with the inner periphery of said bore processed during said trial boring operation to measure and determine the difference between the diameter of said bore and the desired diameter of a complete bore to be processed, said servo motor being arranged to be driven in accordance with a programmed signal to move said measuring elements until said elements come to have a predetermined space therebetween which is equal to the desired diameter of said complete bore, and said fine displacement instrument serving to determine said difference and thereby convert said difference into a voltage to be transmitted to the control means of said control device.