Numerical control drive system
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorToshiki Tanaka
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Abstract
In a numerical control system of the invention, a motor drive power converter 1a comprises input current determination means 12 for comparing an input current found by input current detection means 11 with an allowable current value with respect to less-than, equal-to, or greater-than relation, and acceleration/deceleration command change signal output means 13 for outputting a control signal to a drive unit 2a, 3a based on the determination result of the input current determination means 12. If the input current determination means 12 determines that input current Ii> allowable current value I0, acceleration/deceleration command generation means 15a, 15b of the drive unit 2a, 3a changes an acceleration/deceleration command (lessens the inclination of a speed command), thereby lowering the input current Ii.
Claims8
A numerical control drive system having two or more drive units, said numerical control drive system comprising a servo drive unit for driving a motor, a spindle drive unit, a numerical control unit for outputting a control command for driving the motor to said two or more drive units, and a motor drive power converter for converting AC power supplied from an AC power supply into DC power and supplying the DC power to said two or more drive units, wherein said motor drive power converter comprises input current detection means for finding an input current of the AC power supplied from the AC power supply, input current determination means for comparing the input current found by the input current detection means with an allowable current value with respect to at least one of a less-than, equal-to, and greater-than relation, and control signal output means for inputting at least one of motor drive currents or motor speeds from said two or more drive units to which the DC power is supplied, selecting the drive unit providing a large effect of lowering the input current, and outputting a control signal thereto if the input current determination means determines that the input current is greater than the allowable current value, wherein said drive unit comprises control signal execution means for changing the control command from said numerical control unit based on the control signal output from the control signal output means, and wherein the control signal execution means of said drive unit inputting the control signal changes the control command from said numerical control unit, thereby lowering the input current.
Dependencies are inferred from the claim text.