Numerical control device

A numerical control device which controls positions of respective axes of a machine tool according to a machining program, the numerical control device comprising:

• an analyzing unit which obtains movement data and a movement type by analyzing a command instructed to the machining program;
• an acceleration-deceleration data selection unit which selects specific acceleration-deceleration data according to the movement type from acceleration-deceleration data in which acceleration-deceleration methods are set in advance for each movement type of a usual mode and each fixed cycle or each fixed cycle group;
• and
• an interpolation and acceleration-deceleration unit which generates a position command by performing interpolation on a movement route, which is instructed to the movement data, according to a command speed and performing acceleration-deceleration according to the acceleration-deceleration data,
• characterized in that
• in a case where the movement type is the particular fixed cycle or fixed cycle group, the acceleration-deceleration data selection unit selects the acceleration-deceleration data, in which the acceleration-deceleration method is the post-interpolation acceleration-deceleration of the constant inclination angle type, and also selects acceleration-deceleration data, in which the acceleration-deceleration method is post-interpolation acceleration-deceleration of a constant time-constant type, and further, in a case of selecting the acceleration-deceleration data, in which the acceleration-deceleration method is the post-interpolation acceleration-deceleration of the constant time-constant type, the acceleration-deceleration data selection unit selects the acceleration-deceleration data, in which the acceleration-deceleration method is the post-interpolation acceleration-deceleration of the constant time-constant type, so that a sum of an acceleration-deceleration time, which is determined by dividing a feeding speed by an inclination angle set in the acceleration-deceleration data in which the acceleration-deceleration method is the post-interpolation acceleration-deceleration of the constant inclination angle type, and a time constant, which is set in the acceleration-deceleration data in which the acceleration-deceleration method is the post-interpolation acceleration-deceleration of the constant time-constant type, is smaller than a sum of an acceleration-deceleration time, which is determined by dividing a feeding speed by an inclination angle set in acceleration-deceleration data selected in a case where the movement type is the usual mode, and a time constant of the post-interpolation acceleration-deceleration of the constant time-constant type, which is set in the acceleration-deceleration data selected in a case where the movement type is the usual mode, and
• the interpolation and acceleration-deceleration unit performs the acceleration-deceleration according to the acceleration-deceleration data, in which the acceleration-deceleration method is the post-interpolation acceleration-deceleration of the constant inclination angle type, and also performs the acceleration-deceleration according to the acceleration-deceleration data, in which the acceleration-deceleration method is the post-interpolation acceleration-deceleration of the constant time-constant type.