Method and apparatus for automatic programmed control of a machine tool

Claim 3

A method as claimed in claim 1, wherein the machine tool is a turning machine and the velocity of the workpiece is varied in dependence upon the feed in said perpendicular direction.

Claim 4

A method as claimed in claim 1, wherein a decrease in feed velocity in dependence upon the material removing rate is directly effected and an increase in feed velocity in dependence upon the material removing rate is effected with delay.

Claim 5

A method as claimed in claim 1, wherein the feed velocity in said perpendicular directions is controlled in dependence upon the derivative dPz /dt of the removing rate.

Claim 6

Apparatus for automatic programmed control of a machine tool for removal of material from a workpiece, comprising feeding means for rapidly feeding the machine tool until it comes into contact with a workpiece; and work feeding means for work feeding the tool with the programmed velocity as long as a magnitude depending upon the material removing rate does not exceed a longitudinal processing threshold level and for reducing the feeding velocity as long as the magnitude depending upon the forming power exceeds said processing threshold level, and reducing the work feeding in a direction perpendicular to that direction when the feed velocity decreases to less than a specific magnitude Vmin, said work feeding means operating repeatedly until the actual contour of the workpiece coincides with a programmed contour and having inputs connected to said tool or workpiece for supplying signals representing the speed and torque of the tool or workpiece, said work feeding means having a multiplier connected to said inputs for providing a signal Pz corresponding to the material removing rate, and integral regulating means, reference magnitude means, voltage-frequency converting means, critical value indicating means and gate means for producing a first control signal for controlling the feed velocity Vz in one direction of movement of the tool or workpiece in dependence upon the material removing rate and for producing a second control signal for controlling the feed velocity Vx in a direction perpendicular to the one direction in dependence upon the removing rate as long as that rate exceeds a specific magnitude and outputs connected from said gate means to said tool or workpiece for supplying the first and second control signals to said tool or workpiece.

Claim 7

Apparatus for automatic programmed control of a machine tool for removal of material from a workpiece, comprising feeding means for rapidly feeding the machine tool until it comes into contact with a workpiece; and work feeding means for work feeding the tool with the programmed velocity as long as a magnitude depending upon the material removing rate does not exceed a longitudinal processing threshold level and for reducing the feeding velocity as long as the magnitude depending upon the forming power exceeds said processing threshold level, and reducing the work feeding in a direction perpendicular to that direction when the feed velocity decreases to less than a specific magnitude Vmin, said work feeding means operating repeatedly until the actual contour of the workpiece coincides with a programmed contour and having inputs connected to said tool or workpiece for supplying signals representing the speed and torque of the tool or workpiece, said work feeding means having a multiplier connected to said inputs for providing a signal Pz corresponding to the material removing rate, and integral regulating means, reference magnitude means, voltage-frequency converting means, critical value indicating means and gate means for producing a first control signal for controlling the feed velocity Vz in one direction of movement of the tool or workpiece in dependence upon the material removing rate and for producing a second control signal for controlling the feed velocity Vx in a direction perpendicular to the one direction in dependence upon the removing rate as long as that rate exceeds a specific magnitude and outputs connected from said gate means to said tool or workpiece for supplying the first and second control signals to said tool or workpiece.