Nc program generating device and nc program generating method

An NC program generating device that generates an NC program that is used when performing laser machining of a workpiece by irradiating the workpiece with laser beam from a machining head, the device comprising:

• an NC program generating unit to generate the NC program by including a first command, a second command and a third command in a series of machining processes of a machining route,
• wherein the first command moves the relative position without irradiation of the laser beam from a first point to a second point on the workpiece, according to a first movement command that moves the relative position between the machining head and the workpiece at a first movement speed by separating a distance between the machining head and the workpiece to be larger than the distance during the laser machining,
• the second command moves the relative position, while performing the laser machining, by irradiation of the laser beam from a third point to a fourth point on the workpiece, according to a second movement command that moves the relative position at a second movement speed lower than the first movement speed, while causing the machining head to trace the workpiece, and
• the third command moves the relative position without irradiation of the laser from a fifth point to a sixth point on the workpiece according to the second movement command.

A method for generating an NC program that generates an NC program used in laser machining, using a rapid traverse command and a linear interpolation movement command, the rapid traverse command moving a relative position between a machining head and a workpiece at a first movement speed by separating a distance between the machining head and the workpiece to be greater than the distance during the laser machining, and the linear interpolation movement command moving the relative position at a second movement speed lower than the first movement speed such that a distance between the machining head and the workpiece is equal to the distance during the laser machining, while causing the machining head to trace the workpiece, the method comprising:

• calculating a first movement time required when the relative position moves between machining points from a machining end point to the next machining start point in the case of using the rapid traverse command on the basis of a movement route of the machining head and the first movement speed when performing laser machining of the workpiece, and calculating a second movement time required when the relative position moves between the machining points in the case of using the linear interpolation command on the basis of the movement route and the second movement speed;
• selecting the movement command corresponding to the shorter one of the first movement time and the second movement time, as the movement command between the machining points;
• and
• generating the NC program by setting the selected rapid traverse command or the linear interpolation movement command between the machining points.