Abstract: A motor control device calculates a velocity difference based on a velocity command and a velocity detection value of a motor and an excitation current common phase voltage difference based on an excitation current command value and an excitation current detection value, and judges that demagnetization occurs when the following conditions are all met: the excitation current common phase voltage difference exceeds a voltage threshold; the velocity difference exceeds a velocity threshold; and acceleration is being performed.

Abstract: A motor control device calculates a velocity difference based on a velocity command and a velocity detection value of a motor and an excitation current common phase voltage difference based on an excitation current command value and an excitation current detection value, and judges that demagnetization occurs when the following conditions are all met: the excitation current common phase voltage difference exceeds a voltage threshold; the velocity difference exceeds a velocity threshold; and acceleration is being performed.

Abstract: A coordinate data converter converts plural shape data of the movable parts from a direction and of the parts that may interfere with the movable parts into the shape data of the three-dimensional coordinate system unique to the machining system, the number of structural shape elements of those parts being different from one another. A generator projects thus converted shape data on the three planes of said three-dimensional coordinate system; an arithmetic operator determines whether or not projected data overlap each other in each of the three planes, and a detector determines that an interference has occurred if the projection data on respective planes overlap and if projected data based on the shape data overlap in all of the three planes.

Abstract: A numerically controlled lathe capable of machining a workpiece by numerically controlling a machining table provided with a machining tool. In order to prevent a local uneven abrasion of parts, which make a sliding contact, due to a mass production of workpieces having a simple form or a machining in a non-circular shape, there are provided a main carriage and a sub carriage. A machining tool is positioned on the sub carriage, and the sub carriage traverses on the main carriage along an axis which the main carriage and the sub carriage have in common. When a circular machining is carried out, the main carriage and the sub carriage respectively traverse by an equal amount in directions opposite to each other, and the cutting tool is constantly maintained at a position designated by an instruction.

Abstract: A numerical control apparatus for controlling a numerical lathe has a superimposing Z-axis control function in which, when a work is machined by the control of movement of a tool holder in the Z2- and X2-axis directions driving movement of a spindle in the Z1-axis direction, the variance of the position of the spindle in the Z1-axis direction as detected by a Z1-axis position detector is added to the value derived from a Z2-axis position detector which detects the position of the tool holder in the Z2-axis direction, and the position of the second tool holder in the Z2-axis direction is controlled using the result of the addition as the feedback value of the Z2-axis position of the second tool holder.

Abstract: A tool retracting method and apparatus is for retracting a tool in an NC machine tool upon the detection of the occurrence of an abnormal machining condition during operation of the NC machine tool. The tool retraction direction is determined which is counter to the direction of the cutting load acting on the work at the moment of the occurrence of the machining abnormality, so that the tool can be promptly retracted without interfering with the work.

Abstract: During synchronous control, a first servo motor controls a position of a first spindle system and a second spindle system having a second servo motor makes calculations for estimating the torque required for the second servo motor and gives a command, so that, when a rotational phase difference between the two servo motors exceeds a predetermined value, the rotational phase difference is made equal to zero by a rotational phase difference signal. A torque command to the first servo motor, an inertia ratio between the first and second servo motors, the rotational resistance of the two spindle systems and so on are input to a torque estimator which makes calculations for estimating the torque required for the second servo motor. The estimated torque is used to control the second servo motor. The two servo motors thus generate the appropriate torque when a work held between the two spindle systems is processed. It is therefore possible to significantly reduce the torsional torque applied to the work.

Abstract: A reference point detection pulse generator determines normally-equidistant reference points which provide references over the whole control axis range of a numerically controlled machine. On the basis of the outputs of the reference point detection pulse generator and a moving amount detection pulse generator, the position of a moving part is numerically calculated by a moving part position calculator means. The position of the moving part based on the output of the moving amount detection pulse generator is compared with that based on the output of the moving part position calculator means, and if an error is present therebetween an alarm is issued.