Numerical control machining system
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorYutaka Shimizu
Life of this patent
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Abstract
The load current of a spindle motor adapted to drive the tool of a numerical control machining apparatus or a feed motor adapted to move a machining table on which a workpiece is placed is detected during machining, the detection signal is applied to the input unit of a numerical control device to obtain the load output, and the load output is compared with an allowable value, so that the comparison signal is utilized to control the feed speed of the feed motor adapted to move the machining table of the apparatus or to output an alarm signal.
Claims21
A numerical control machining system of the type including a spindle motor for rotating the spindle of a machining apparatus to which a tool is connected, a feed motor means for moving the table of said machining apparatus to which a workpiece is fixedly secured, and a numerical control device for controlling the speed of rotation of said spindle motor and the feed speed of said table, so that said workpiece is machined with said tool, characterized in that:
- said system further comprises detection means for detecting a machining load current of said spindle motor and sampling means for sampling said load current thus detected periodically at predetermined time intervals to provide an input to said numerical control device, and
- said numerical control device comprises means for averaging a predetermined number of load current data to obtain a load output of said spindle motor, means for comparing said load output with an allowable load output of said spindle motor which has been calculated in advance, and control means for controlling the feed speed of said feed motor means in accordance with said comparison.
A numercial control machining system of the type including a spindle motor for rotating the spindle of a machining apparatus to which a tool is connected, a feed motor means for moving the table of the machining apparatus to which a workpiece is fixedly secured, and a numerical control device for controlling the speed of rotation of said spindle motor and the feed speed of said table, so that said workpiece is machined with said tool, characterized in that:
- said system further comprises detection means for detecting a machining load current of said feed motor, and sampling means for sampling said load current thus detected periodically at predetermined time intervals to provide an input to said numberical control device, and
- said numerical control device comprises averaging means for averaging a predetermined number of load current data to obtain a load torque of said feed motor, means for calculating in advance an allowable load torque for said motor, and comparison means for comparing said load torque with said allowable load torque, so that when the former is equal to or larger than the latter, the feed speed of said feed motor is controlled.
A numerical control machining system of the type including a spindle motor for rotating the spindle of a machining apparatus to which a tool is connected, a feed motor menas for moving the table of said machining apparatus to which a workpiece is fixedly secured, and a numerical control device for controlling the speed of rotation of said spindle motor and the feed speed of said table, so that said workpiece is machined with said tool, characterized in that:
- said system further comprises detection means for detecting a machining load current of said spindle motor in synchronization with rotation of said spindle, and sampling means for sampling said load current thus detected periodically at predetermined time intervals to provide an input to said numerical control device,
- said numerical control device comprises means for calculating a load output of said spindle motor from said load current thus detected, means for calculating in advance an allowable load output for said spindle motor, and means for comparing said load output with said allowable load output of said spindle motor, so that when the former is equal to or larger than the latter, the feed speed of said feed motor is controlled.
Dependencies are inferred from the claim text.