| 摘要 |
1,244,624. Programmed control of machine tools. GENERAL ELECTRIC CO. Oct. 29, 1968 [Nov. 21, 1967], No. 51293/68. Heading G3N. An on-machine inspection system, for cooperation with a machine member controlled in response to coded input data, comprises a probe, positioned according to commanded data and then brought to a null position, to derive an output representative of deviation from the commanded position which is stored. As shown, a known numerical control system for a machine tool comprises a tape input 18 feeding a control 14, wherein error between a programmed and an actual position is determined and through a command phase counter 13 and resolver feedback control 20 to a discriminator and digital to analogue converter 21 providing an analogue position signal to a servo-drive 23 for a machine part. The known system is modified to enable on-machine inspection by the addition of an inspection and control system 30 and a switching arrangement 31. Machine inspection is initiated by a block of data from tape input 18 calling for insertion of a probe 40 in a tool position and selection of the mode of operation in circuit 45. The probe is moved under control of the command data to the programmed position by the discriminator 21 and thereafter in response to probe deflection by a circuit 31. Count control circuits 17, 43 develop a digital value, representing the phase difference of the actual position from the commanded position, which controls the command phase counter 13 and is fed to a deviation counter 46. The information in the deviation counter is used, in dependence on the programmed operating mode, for 1) a display in unit 50 2) a read-out by a printer 49 in dependence on limit values set by programme unit 47 and comparator 48 3) re-machining when it is fed to a store 51. The store 51, containing the offset deviations, is called up by programmed data from unit 18 during re-machining through a machining situation de-coding circuit 52 and a tool and offset control 53. The offset values from store 51 are fed through a gate 54, whereby manually set-in probe offsets from a unit 55 are added, to pre-set a data transfer counter 44 controlling the counting of pulses into position control 14. |
