A numerical value controller includes: a storage unit storing a machining program involving executing canned cycles including a first operation for moving a tool to a return point, a second operation for positioning a drilling position of a workpiece relative to the tool, a third operation for moving the tool from the return point to a hole bottom point, and a fourth operation for moving the tool from the hole bottom point to a terminal point located toward the hole bottom point relative to the return point; a control unit controls relative movement between the tool and the workpiece based on the machining program and moves the tool along curved paths by starting the second operation before the first operation ends and by starting the third operation before the second operation ends; and a distance calculating unit calculates a retraction distance from the workpiece to the return point.

A numerically controlled machine tool has at least one movement axis and is connected to a numerical controller which includes a parts program. Movements of each movement axis are limited by maximum permissible axis dynamics. The parts program has a sequence of instructions for machining a workpiece which specify different maximum desired speeds for the machining of the workpiece which change abruptly over time. The numerical controller approximates the different maximum desired speeds which change abruptly over time with a desired speed profile that is continuous over time and has a profile of the maximum desired speeds which is also continuous over time. The numerical controller uses the continuous desired speed profile to calculate the desired values of an actual movement profile of the movements for each movement axis.

The invention relates to a method for machining a workpiece by means of a milling tool arranged on a rotatable spindle, the spindle being moved relative to the workpiece or the workpiece being moved relative to the spindle along a machining path and, at the same time, the spindle rotating about a spindle axis. In said method, an improvement in the surface quality is achieved by controlling the rotational speed and/or the phase position of the rotation of the spindle along the machining path, the machining path comprising linear parallel tracks and the phase position of the spindle along the machining path being substantially the same on adjacent tracks, the phase position being controlled by varying the rotational speed of the spindle and/or the advancing speed of the spindle relative to the workpiece along the machining path.

Machine elements can be displaced along disjoined path sections by position-controlled machine axes. Movement guidance of the machine elements from the end of a path section to the beginning of a directly following path section along a previously unknown path is provided, wherein location, velocity and acceleration are continuous along the previously unknown path and at the transitions between the path sections and the previously unknown path. Velocity, acceleration and jerk are limited. A preliminary axis guidance and a corresponding required axis time is determined for each of the axes. A greatest required axis time is determined therefrom which is then set as a final axis guidance for this axis. For other axes whose preliminary axis times are smaller than the greatest required axis time, the respective preliminary axis guidance is matched to the greatest required axis time, which is then adopted for the other axes as final axis guidance.

Machine elements can be displaced along disjoined path sections by position-controlled machine axes. Movement guidance of the machine elements from the end of a path section to the beginning of a directly following path section along a previously unknown path is provided, wherein location, velocity and acceleration are continuous along the previously unknown path and at the transitions between the path sections and the previously unknown path. Velocity, acceleration and jerk are limited. A preliminary axis guidance and a corresponding required axis time is determined for each of the axes. A greatest required axis time is determined therefrom which is then set as a final axis guidance for this axis. For other axes whose preliminary axis times are smaller than the greatest required axis time, the respective preliminary axis guidance is matched to the greatest required axis time, which is then adopted for the other axes as final axis guidance.

Provided is a numerical control system of a machine tool that can shorten a cycle time. A command unit of a numerical control system of a machine tool includes: an interpolation block waveform drawing unit that performs a simulation of an NC program, calculates an interpolation pulse of a relationship between speed and time indicating an operation of the respective axes from a command value of an axis address of the respective axes, and sequentially outputs an interpolation command of the respective axes for each block to draw a waveform of the relationship between speed and time in a case of operating the machine tool; a different axis block specifying unit that compares two blocks adjacent in time series which are drawn by the interpolation block waveform drawing unit, and specifies the two adjacent blocks calculated from command values of different axis addresses; and an interpolation overlap block waveform creating unit that obtains an overlappable amount of the two adjacent blocks specified by the different axis block specifying unit, and overlaps the two adjacent blocks on a basis of the overlappable amount to create a waveform of the relationship between speed and time in a case of operating the machine tool.

The invention relates to a method for machining a workpiece by means of a milling tool arranged on a rotatable spindle, the spindle being moved relative to the workpiece or the workpiece being moved relative to the spindle along a machining path and, at the same time, the spindle rotating about a spindle axis. In said method, an improvement in the surface quality is achieved by controlling the rotational speed and/or the phase position of the rotation of the spindle along the machining path, the machining path comprising linear parallel tracks and the phase position of the spindle along the machining path being substantially the same on adjacent tracks, the phase position being controlled by varying the rotational speed of the spindle and/or the advancing speed of the spindle relative to the workpiece along the machining path.

In a control method for the movement of a tool with a machine tool, the machine tool involves a numerically controlled machine tool, in order to produce an arbitrary required surface of a workpiece by machining. A numeric path program is created which describes the machining of the workpiece with the tool at machining points and which controls the control device. The numeric path program produces a path with respect to the geometric nature of the surface of the workpiece to be machined, with the path including a plurality of sample points and individual paths, with each individual path connecting a pair of the sample points to each other. The numeric path program is evaluated and selected on the basis of a geometric quality criterion, with the geometric quality criterion having continuity as at least one criterion.

A numerically controlled machine tool has at least one movement axis and is connected to a numerical controller which includes a parts program. Movements of each movement axis are limited by maximum permissible axis dynamics. The parts program has a sequence of instructions for machining a workpiece which specify different maximum desired speeds for the machining of the workpiece which change abruptly over time. The numerical controller approximates the different maximum desired speeds which change abruptly over time with a desired speed profile that is continuous over time and has a profile of the maximum desired speeds which is also continuous over time. The numerical controller uses the continuous desired speed profile to calculate the desired values of an actual movement profile of the movements for each movement axis.

Provided is a numerical control system of a machine tool that can shorten a cycle time. A command unit of a numerical control system of a machine tool includes: an interpolation block waveform drawing unit that performs a simulation of an NC program, calculates an interpolation pulse of a relationship between speed and time indicating an operation of the respective axes from a command value of an axis address of the respective axes, and sequentially outputs an interpolation command of the respective axes for each block to draw a waveform of the relationship between speed and time in a case of operating the machine tool; a different axis block specifying unit that compares two blocks adjacent in time series which are drawn by the interpolation block waveform drawing unit, and specifies the two adjacent blocks calculated from command values of different axis addresses; and an interpolation overlap block waveform creating unit that obtains an overlappable amount of the two adjacent blocks specified by the different axis block specifying unit, and overlaps the two adjacent blocks on a basis of the overlappable amount to create a waveform of the relationship between speed and time in a case of operating the machine tool.