Abstract: In a threading control system for performing a threading operation by moving, in synchronization with rotation of the main-spindle, either a cutter or a workpiece in the feeding spindle direction so that the ridge is not damaged nor the dimensional accuracy of the thread is lowered even if the main-spindle speed is variable, a threading computing section 3 and a main-spindle angle computing section 4 are provided to alter the threading start timing based on the servo-spindle acceleration time-constant of the feeding spindle.

Abstract: An NC apparatus controls a position of a tool by driving a plurality of shafts with a plurality of servomotors. The shafts includes at least one clamp shaft that can be mechanically clamped or non-clamped. A clamp determining unit determines whether a state of the clamp shaft and outputs a signal based on the state. A correcting unit corrects a position instruction value or a position detection value of at least one shaft other than the clamp shaft based on the signal and a correction value so as to cancel an error in a position of the tool due to movement of the tool performed by the clamp shaft.

Abstract: In a threading control system for performing a threading operation by moving, in synchronization with rotation of the main-spindle, either a cutter or a workpiece in the feeding spindle direction so that the ridge is not damaged nor the dimensional accuracy of the thread is lowered even if the main-spindle speed is variable, a threading computing section 3 and a main-spindle angle computing section 4 are provided to alter the threading start timing based on the servo-spindle acceleration time-constant of the feeding spindle.

Abstract: An NC apparatus controls a position of a tool by driving a plurality of shafts with a plurality of servomotors. The shafts includes at least one clamp shaft that can be mechanically clamped or non-clamped. A clamp determining unit determines whether a state of the clamp shaft and outputs a signal based on the state. A correcting unit corrects a position instruction value or a position detection value of at least one shaft other than the clamp shaft based on the signal and a correction value so as to cancel an error in a position of the tool due to movement of the tool performed by the clamp shaft.

Abstract: A numerical control device according to the present invention progressively analyzes a machining program stored in a storage device by one program block or by a plurality of program blocks, computes a migration rate and a feed speed in each axial direction from an instructed moving position of a tool and a feed speed of the tool in an interpolating section, outputs a positional instruction to an object for control for each given cycle, and has a sampling time interval computing section for computing a sampling time so that a number of instruction pulses for each sampling time under a given feed speed is kept at a constant value when a migration rate for 1 block computed in the interpolating section is divided to a number of pulses for each sampling time, and an interruption controlling section for setting a variable sampling time.

Abstract: A multi-system numerical control device which receives input commands for each system and is operative to control the speed and acceleration/deceleration of corresponding moveable objects, such as a motors. Each system has an interpolation unit and an acceleration/deceleration unit that is responsive to a corresponding time constant. A speed override device is operative to generate a speed reduction control signal that is applied to the interpolation unit to reduce the speed and to the acceleration/deceleration unit to reduce the time constant, thereby ensuring that the position relationship between the systems will not be lost even when override is applied.