Method and apparatus for preparing data on tool moving path, and machining method and system

A method of generating tool movement path data for moving a machining tool and a workpiece relative to each other for machining a desired three-dimensional surface, characterized by comprising:

• a first constraining surface determining step of determining a first constraining surface for constraining said machining tool to machine said three-dimensional surface, said first constraining surface corresponding to said three-dimensional surface;
• a second constraining surface determining step of determining a second constraining surface for constraining a movement path of said machining tool, said second constraining surface consisting of a straight or curved surface which is other than said three-dimensional surface, and intersecting said first constraining surface and said three-dimensional surface to be machined;
• an intersection line calculating step of obtaining a three-dimensional curved line equation representing a line of intersection between said first and second constraining surfaces;
• a normal vector calculating step of obtaining normal vectors of said first constraining surface on the intersection line between said first and second constraining surfaces, at a predetermined spacing interval;
• a normal curved line calculating step of obtaining a smooth normal curved line passing end points of said normal vectors;
• and
• a movement path data generating step of obtaining said movement path data including data representing an attitude of said machining tool, based on the intersection line between said first and second constraining surface and said normal curved line.

A device for generating tool movement path data for moving a machining tool and a workpiece relative to each other for machining a desired three-dimensional surface, characterized by comprising:

• first constraining surface determining means for determining a first constraining surface for constraining said machining tool to machine said three-dimensional surface, said first constraining surface corresponding to said three-dimensional surface;
• second constraining surface determining means for determining a second constraining surface for constraining a movement path of said machining tool, said second constraining surface consisting of a surface other than a straight surface and other than said three-dimensional surface, and intersecting said first constraining surface;
• intersection line calculating means for obtaining a three-dimensional curved line equation representing a line of intersection between said first and second constraining surfaces;
• and
• movement path data generating means for obtaining said movement path data including data three-dimensional curved line equation obtained by said intersection line obtaining means.

A method of machining a desired three-dimensional surface in a workpiece, by moving a machining tool and a workpiece, said method comprising:

• a first constraining surface determining step of determining a first constraining surface for constraining said machining tool to machine said three-dimensional surface, said first constraining surface corresponding to said three-dimensional surface;
• a second constraining surface determining step of determining a second constraining surface for constraining a movement path of said machining tool, said second constraining surface consisting of a surface other than a straight surface and said three-dimensional surface, and intersecting said first constraining surface;
• an intersection line calculating step of obtaining a three-dimensional curved line equation representing a line of intersection between said first and second constraining surfaces;
• a movement path determining step of determining the movement path of the machining tool by using said three-dimensional curved line equation obtained in said intersection line obtaining step;
• and
• a tool moving step of determining successive target positions on the movement path which is determined in said movement path determining step and which is a three-dimensional curved line represented by said three-dimensional curved line equation, and moving said machining tool relative to said workpiece.

A machining system for machining a desired three-dimensional surface in a workpiece by moving a machining tool and a workpiece relative to each other said machining system comprising:

• first constraining surface determining means for determining a first constraining surface for constraining said machining tool to machine said three-dimensional surface, said first constraining surface corresponding to said three-dimensional surface;
• second constraining surface determining means for determining a second constraining surface for constraining a movement path of said machining tool, said second constraining surface consisting of a surface other than a straight surface and said three-dimensional surface, and intersecting said first constraining surface;
• intersection line calculating means for obtaining a three-dimensional curved line equation representing a line of intersection between said first and second constraining surfaces;
• movement path determining means for determining the movement path of the machining tool by using said three-dimensional curved line equation obtained in said intersection line obtaining step;
• and
• tool movement control means for determining successive target positions on the movement path which is determined in said movement path determining step and which is a three-dimensional curved line represented by said three-dimensional curved line equation, and moving said machining tool relative to said workpiece.

A method of generating tool movement path data for moving a machining tool and a workpiece relative to each other for machining a desired three-dimensional surface, characterized by comprising:

• a first constraining surface determining step of determining a first constraining surface for constraining said machining tool to machine said three-dimensional surface, said first constraining surface corresponding to said three-dimensional surface;
• a second constraining surface determining step of determining a second constraining surface for constraining a movement path of said machining tool, on the basis of a geometry of said three-dimensional surface, in such a manner that makes it possible to avoid abrupt changes in a direction in which said machining tool and said workpiece are moved relative to each other, said second constraining surface consisting of a surface other than a straight surface and other than said three-dimensional surface, said second constraining surface intersecting said first constraining surface and being parallel to an axis of said machining tool;
• an intersection line calculating step of obtaining a three-dimensional curved line equation representing a line of intersection between said first and second constraining surfaces;
• and
• a movement path data obtaining step of obtaining said movement path data including said three-dimensional curved line equation obtained in said intersection line calculating step.