| 摘要 |
963,529. Programmed control of machine tools. BENDIX CORPORATION. Feb. 18,1963 [March 1, 1962], No. 6456/63. Heading G3N. In a numerical control system for a machine tool the set feed-rate is modified in dependence on the resolute of the co-ordinate displacements forming an increment of tool movement. As snown, a punched tape 10 passes through a tape reader and temporary storage 10 whereby the digital data,representative of desired increments of movements along coordinate axis DX,DY,DZ and the feed rate FR, is fed to a controller and active storage 14. Signals from the active storage T4 are fed to a decode and hold unit 34 deriving analogue voltage representations VDX, VDX, VDZ, VFR. The feed rate analogue signal VFR is fed through an acceleration deceleration network 36, comprising a by-pass filter, which eliminates any sharp discontinuities in the feed rate to control in direct ratio the pulse rate of a voltage-controlled pulse generator 26. The co-ordinate analogue signals VDX, VDX, VDZ are fed to a reactor magnitude circuit 38 which generates an analogue voltage VR representative of the geometric sum of the co-ordinate distances. The voltage VR is fed to the voltage-controlled pulse generator 26 to vary the pulse rate in an inverse ratio. The output pulse rate of the generator 26 being proportional to the ratio between the desired feed rate and the resultant path length of an increment. The rate controlled pulses are fed to the controller 14 which develops three pulse trains which are transmitted to the X, Y, Z servomechanism 16, 18, 20 to effect an increment of movement of a controlled device 22. In a modification, a pulse multiplier, as disclosed in Specification 848,647 is utilized to allow the controller and pulse generator to operate at a fraction of the rate at which pulses must be provided to the servomechanisms. In a further modification a transducer senses some factor of the cutting conditions of the controlled device, for example by means of a strain-gauge, and controls an adaptive factor summer between the decode and hold unit and the pulse generator to decrease the cut with increase in strain on the controlled device. |
