Patent ID: 8432120

Claim:
A tool path display apparatus for a machine tool with a numerical controller which controls relative positions and postures of a tool and a workpiece to machine the workpiece by means of a plurality of drive axes, comprising: a first position command calculation unit which calculates a first position command of each of the drive axes based on a path shape and a tangential speed of the tool commanded by a machining program; a second position command calculation unit which restricts the tangential speed of the tool so as to satisfy a previously specified condition and converts the first position command into a second position command based on the restricted speed; a status information output unit which outputs a status information indicative of the achievement of the restriction of the tangential speed of the tool so as to satisfy the previously specified condition and the conversion of the first position command into the second position command based on the restricted speed; a drive axis control unit which controls the respective drive axes in motion in response to the second position command for the drive axes; a tool command position coordinate calculation unit which calculates two- or three-dimensional coordinate values of a tool command position as viewed from a coordinate system fixed to the workpiece, based on the second position command for each drive axis of the machine tool at each time and information on a machine configuration of the machine tool; a display color command unit which commands a predetermined display color corresponding to the status information output from the status information output unit; and a tool path display unit which displays a two- or three-dimensional path of the tool in the display color commanded by the display color command unit, based on the coordinate values of the tool command position calculated by the tool command position coordinate calculation unit, wherein the second position command calculation unit prepares a plurality of conditions for the speed restriction in advance, restricts the tangential speed of the tool so as to satisfy all the conditions, and converts the first position command into the second position command based on the restricted speed; the status information output unit restricts the tangential speed of the tool under one of the conditions and outputs status information indicative of the achievement of the conversion of the first position command into the second position command, corresponding individually to the conditions; the display color command unit previously sets display colors which correspond individually to the conditions, previously sets the order of priority of the status information output from the status information output unit, and commands the display colors in the set order of priority, whereby the condition under which the speed restriction on the tool is achieved is allowed to be determined by the color display at each point on the tool path.