Method and apparatus for a cutting process automatic generation tool of CAM

Patent metadata

Field	Value
Publication number	US-9581992-B2
Application number	US-201314133156-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Dec 25, 2012
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

In a conventional CAM apparatus, cutting regions and a tool axis angle by which the cutting time is minimized cannot be automatically set for a finish shape having a free formed surface shape. Accordingly, the CAM apparatus generates quadrangle-shaped patterns of cutting regions using coordinate data of a finish shape and an initial shape. Triangle-shaped cutting regions are generated for concave-convex faces of the finish shape. For cutting regions generated by subtraction by boolean operation with a subtract shape calculated by subtraction by boolean operation between the initial shape and the finish shape, the tool axis angle is set so that the tool does not interfere and the face is maximized. For other regions, the tool axis is set so as to satisfy a remainder standard and to minimize a tool path length.

First claim

What is claimed is:

1. An computer aided manufacturing (CAM) apparatus to control a cutting machine to process an initial workpiece into a finish shape according to numerical control (NC) data which includes a plurality of cutting regions, the CAM apparatus comprising:
a processor; and
a memory which stores instructions that, when executed by the processor, cause the processor to perform a method of CAM to process the initial workpiece including:
creating a rectangular shape including the finish shape from a shape of the initial workpiece and creating a swept shape by projecting the finish shape from a first direction;
creating a subtract shape A obtained by subtracting the rectangular shape from a shape of the initial workpiece;
dividing the subtract shape A into a plurality of hexahedron cutting regions;
creating a subtract shape B obtained by subtracting the swept shape from the rectangular shape;
dividing the subtract shape B into a plurality of pentahedron cutting regions that define a polyhedron from the rectangular shape;
creating a plurality of finish shape cutting regions for forming the finish shape from the polyhedron;
creating the cutting regions of the NC data from the hexahedron cutting regions, the pentahedron regions, and the finish shape cutting regions;
obtaining a plurality of linear travelling distances and a plurality of rotational angles of one or more tools of the cutting machine on a basis of the cutting regions; and
controlling the cutting machine on the basis of the linear travelling distances and rotational angles of the tools to process the initial workpiece into the finish shape.

2. The apparatus for a cutting process automatic generation tool of CAM according to claim 1 , wherein the memory further stores instructions that, when executed by the processor, cause the processor to perform the method of CAM to process the initial workpiece which further includes:
setting a plurality of tool axis angles for the hexahedron cutting regions and pentahedron cutting regions so that the tools do not interfere with a current cutting shape of the workpiece and the cutting machine and the tools are vertical to a largest face of the respective hexahedron regions and the respective pentahedron regions, and that sets a plurality of tool axis angles for the finish shape cutting regions to satisfy a remainder standard requested by a CAM operator and to make a tool path length shortest on a basis of the tools and machining conditions.

3. The apparatus for a cutting process automatic generation tool of CAM according to claim 1 , wherein the memory further stores instructions that, when executed by the processor, cause the processor to perform the method of CAM to process the initial workpiece which further includes:
allocating the tools and machining conditions for the hexahedron cutting regions, the pentahedron cutting regions, and the finish shape cutting regions to generate a tool path, and
calculating a cutting time on a basis of the machining conditions of a length of the tool path and a tool feed rate.

4. The apparatus for a cutting process automatic generation tool of CAM according to claim 1 , wherein the memory further stores instructions that, when executed by the processor, cause the processor to perform the method of CAM to process the initial workpiece which further includes:
calculating a combination of the cutting regions with a shortest cutting time among a plurality of combinations of the hexahedron cutting regions, the pentahedron regions, and the finish shape cutting regions.

5. A method of computer aided manufacturing (CAM) by a cutting machine when the cutting machine processes an initial workpiece into a finish shape according to numerical control (NC) data which includes a plurality of cutting regions, the method comprising the steps of:
creating a rectangular shape including the finish shape from a shape of the initial workpiece and creating a swept shape by projecting the finish shape from a first direction;
creating a subtract shape A obtained by subtracting the rectangular shape from a shape of the initial workpiece;
dividing the subtract shape A into a plurality of hexahedron cutting regions;
creating a subtract shape B obtained by subtracting the swept shape from the rectangular shape;
dividing the subtract shape B into a plurality of pentahedron cutting regions that define a polyhedron from the rectangular shape;
creating a plurality of finish shape cutting regions for forming the finish shape from the polyhedron;
creating the cutting regions of the NC data from the hexahedron cutting regions, the pentahedron regions, and the finish shape cutting regions;
obtaining a plurality of linear travelling distances and a plurality of rotational angles of one or more tools of the cutting machine on a basis of the cutting regions; and
controlling the cutting machine on the basis of the linear travelling distances and rotational angles of the tools to process the initial workpiece into the finish shape.

6. A non-transitory computer-readable storing medium that stores a program to execute a method of computer aided manufacturing (CAM) by a cutting machine when the cutting machine processes an initial workpiece into a finish shape according to numerical control (NC) data which includes a plurality of cutting regions, the method stored in the program comprising the steps of:
creating a rectangular shape including the finish shape from a shape of the initial workpiece and creating a swept shape by projecting the finish shape from a first direction;
creating a subtract shape A obtained by subtracting the rectangular shape from a shape of the initial workpiece;
dividing the subtract shape A into a plurality of hexahedron cutting regions;
creating a subtract shape B obtained by subtracting the swept shape from the rectangular shape;
dividing the subtract shape B into a plurality of pentahedron cutting regions that define a polyhedron from the rectangular shape;
creating a plurality of finish shape cutting regions for forming the finish shape from the polyhedron;
creating the cutting regions of the NC data from the hexahedron cutting regions, the pentahedron regions, and the finish shape cutting regions;
obtaining a plurality of linear travelling distances and a plurality of rotational angles of one or more tools of the cutting machine on a basis of the cutting regions; and
controlling the cutting machine on the basis of the linear travelling distances and rotational angles of the tools to process the initial workpiece into the finish shape.

Assignees

• Hitachi Ltd
• Mitsubishi Hitachi Power Sys

Inventors

• Nakano Takahiro
• Arai Hiroshi
• Inoue Reiko
• Tsutsumi Daisuke
• Igarashi Daisuke
• Okubo Masakazu

Classifications

• G05B19/4097 Primary

  characterised by using design data to control NC machines, e.g. CAD/CAM (G05B19/4093 takes precedence) · CPC title

• G05B2219/45147

  Machining blade, airfoil · CPC title

• G05B2219/35166

  Virtual boundary method to plan coarse and then fine machining · CPC title

• G05B2219/35097

  Generation of cutter path, offset curve · CPC title

• B23P15/02

  turbine or like blades from one piece · CPC title