JPH07129221A - 3D tool path simulation method - Google Patents

Abstract

(57) [Summary] [Object] To provide a three-dimensional tool path simulation method capable of rapidly verifying whether or not a target machining shape can be obtained from three-dimensional tool path data created by CAD / CAM. [Structure] Three-dimensional tool path data created using CAD / CAM, tool shape data expanded in the observation axis direction by distance, and material shape and jig shape data expanded in the observation axis direction by distance Based on this, a process for obtaining the machining process shape based on this, and a process for comparing the machining process shape and the model shape developed in the observation axial direction by distance, and determining whether overcutting or uncutting is performed depending on the size of the axial distance. A step of applying a color designated in advance to the over-grinded portion and the uncut portion and displaying it on the display.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional tool path simulation method, and more particularly to a tool path data verification method using CAD / CAM.

[0002]

2. Description of the Related Art In a conventional method for verifying tool path data, a tool that has three-dimensional tool path data and data on a modeled material shape, jig shape and tool shape in a computer, and moves on the tool path. When the shape overlaps with the material shape and the jig shape, the processing shape is calculated by subtracting the tool shape from the material shape and the jig shape,
The machining process shape is displayed on the screen. Then, the operator visually confirms the displayed shape to check for excessive cutting and uncut portion.

By the way, Japanese Patent Laid-Open No. 3-184104 also discloses a verification method of this kind. However, the method disclosed here is for a three-dimensional tool path created by CAD / CAM for a workpiece. By displaying the (model shape) and the tool on the display and changing the color of the location where the interference (gouge) occurs, the operator can visually check it.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Although the verification method disclosed in Japanese Patent No. 4 is performed as described above, CAD data is used as it is. Therefore, there is a problem that the calculation is complicated and the execution speed becomes slow. Further, since the verification is performed visually, there is a problem that it is difficult to accurately identify the excessively cut and uncut portions.

The present invention has been made in order to solve such a problem, and promptly verifies whether or not a target machining shape can be obtained from three-dimensional tool path data created by CAD / CAM. An object of the present invention is to provide a method for simulating a three-dimensional tool path that can be performed.

[0006]

A method for simulating a three-dimensional tool path according to the present invention includes three-dimensional tool path data created by using CAD / CAM and tool shape data developed by distance in the observation axis direction. , Comparing the machining process shape with the model shape expanded in the observation axis direction based on the material shape and jig shape data expanded in the observation axis direction and the process direction There is a step of discriminating overcutting and uncut portion from each other depending on the size of the distance, and a step of applying a predetermined color to the overcutting and uncut portion and displaying it on the display. Another simulation method of a three-dimensional tool path according to the present invention has a step of marking the corresponding part of the numerical data of the three-dimensional tool path when overcutting or leaving occurs in the above simulation method.

[0007]

According to the present invention, for example, the tool shape is moved on the tool path by using the data on the material shape, the jig shape, the tool shape and the model shape which are modeled in the computer from the CAD shape data into the structure suitable for the simulation. The tool
When it overlaps with the material shape and the jig shape, the tool shape is subtracted from the material and the jig shape to obtain the machining process shape. Compare the obtained machining process shape and model shape,
If the difference between the machining shape and the model shape is within the specified range, the color is changed from that of the machined portion for display.
When the shape of the machining process becomes smaller than the model shape by exceeding the specified range, it is determined that a gouge has occurred, and the display is changed to the specified color. This simulation is performed using, for example, computer graphics (CG). When a gouge occurs, the generated process route data is marked. As a result, it becomes possible to easily distinguish between the over-cut portion and the uncut portion. Also,
It is possible to easily determine where to correct the over-cutting tool path data.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 are flow charts showing the processing steps of a three-dimensional tool path simulation method according to an embodiment of the present invention. (1) Modeling of material and CAD model shape (S1 to S
12) CAD material data is modeled and used in a structure suitable for simulation using material and model data. The modeling image approximates a three-dimensional shape as a collection of columns in arbitrary directions, as shown in FIG. Here, an arbitrary reference plane is assumed in the three-dimensional space where the shape exists. Then, the figure when the shape is projected on this plane is displayed on the screen. Divide the material shape, jig shape, and model shape into pillars in the same direction as the normal to the plane. The distance between the two end faces of the pillar and the reference plane is obtained, and the distance (Dmin) closer to the reference plane and the distance (Dmax) farther from the reference plane, and one set of information for obtaining the color when the screen is displayed are included. The shape is represented by the created data.

This modeling is executed in the following procedure. 1) Assume an arbitrary reference plane in a three-dimensional space (S1).
The normal direction of this plane is the direction of the line of sight when displayed on the screen. 2) Divide the reference plane into a grid pattern (S2). 3) Here, consider the material shape as shown in FIG. From the center of each lattice, light rays parallel to the normal line of the reference plane are projected on the material shape to obtain the lattice range (S3). Then, the coordinates of the intersection of the ray and the shape, the normal direction of the shape at that intersection, and the distance between the intersection and the reference plane are obtained (S4). Assuming that the topology of the shape is perfect, an even number of intersections can be found. Here, the distance to the intersection on the reference plane side is Smin, the data for determining the color is Scolor, and the distance to the intersection on the side far from the reference plane is Smax. 4) The intersections are arranged in ascending order of distance between the intersection and the reference surface (S5). A set of two intersections. Focusing on a set of intersections, the intersections with a small distance are on the front side (with respect to the reference plane) and the ones with a large distance are on the back side. 5) The distance Smin on the front side and the color information obtained from the normal are Scolo
Let r be the distance on the back side and Smax be one set of data (S
6). The total number Snum of material shape data sets for each lattice is calculated and recorded (S7). 6) The above processes 3) to 5) are performed for each grid.

7) Next, consider the model shape. The same processing as 3) to 6) is performed on the model shape. That is, a ray parallel to the normal line of the reference plane is projected on the material shape from the center of each lattice to obtain the lattice range (S8). Then, the coordinates of the intersection of the ray and the shape, the normal direction of the shape at that intersection, and the distance between the intersection and the reference plane are obtained (S
9). Then, the intersections are arranged in ascending order of the distance between the intersections and the reference surface (S10), and the intersections with the smaller distances and the larger distances are paired and added to the rear part of the material data (S1).
1). The above processing is performed for each grid to obtain the total number of data sets (S12). The data in FIG. 6 is created by the above processing. This processing method can be expressed even if there is a shadowed portion. Note that the data in FIG. 6 has the number of sets of material data, the number of sets of model data, and actual data in each of which the reference plane is divided, and the actual data is one array of the material data and the model data. The model data is described after the material data.

(2) Screen display of material shape (S13) The grid of the reference plane is made to correspond to screen pixels. When the number of divisions of the reference plane is larger than the number of screen pixels, several grids correspond to one pixel. In this case, a representative grid is determined and made to correspond to pixels. Material shape data is
The grids are arranged in order from the reference plane. When the number of data of material shape is 1 or more, pay attention to the first data and Sco
Create display data from lor. If the number of data is 0, there is no material in the grid, so a predetermined background color is set.

(3) Modeling of tool (S14 to S18) The position where the tool exists is obtained based on the path data of the tool (S14). The tool shape is projected on the reference plane to obtain the range of the grid (S15). As shown in FIG. 7, light rays are projected from a grid existing within the range of the grid, and the intersection of the tool shape and the light and the normal direction at the intersection are obtained (S16). Next, the distance between the intersection and the plane is calculated, and the position (x,
y), the distance on the near side is Tdist1, the normal is Tnrm1, and the distance on the far side is Tdist2 and the normal Tnrm2, and the tool is represented by a data structure as shown in FIG. 8 as a set of data (S17). . The above processing is performed for each grid, and finally the total number of tool data is obtained (S18). Note that FIG.
The tool data of 1 is composed of the positions X and Y of the corresponding reference planes and the calculated distance and normal line data.

(4) Calculation of cutting process shape (S19, S2
0) The tool shape and the material shape data are compared in a grid in the range where the tool exists (S19). At this time, there are six cases (case 1 to case 6) shown in FIG.
The following process shown in is performed (S20). -Case 1: Tdist2 <Smin At this time, since the tool and the material do not overlap with each other, the material shape data is not updated. Determine the tool display color from Tnrm 1 and update the display data. Case 2: Tdist1 <Smin and Smin <Tdist2 <
Smax At this time, the tool and the material have an overlap. Smin to Tdist2
And change Scolor to the value calculated from Tnrm 2. The tool display color is determined by Tnrm 1 and the display data is updated. Case 3: Smax>Tdist1> Smin and Smin <T
dist2 <Smax This is the case where the tool divides the material. As shown in FIG. 10, the target material data A is copied to create a set of data A ′, which is inserted after A. Smax of data A
Put Tdist1 in. Change Smin of A'to Tdist2 and change Scolor to a value calculated from Tnrm2. The number of data sets Snum of the material is increased by 1.

Case 4: Smin <Tdist1 <Smax and Tdist2> Smax There is an overlap between the tool and the material. Put Tdist1 in Smax. -Case 5: Tdist1> Smax Since the tool and the material have no overlap, the material data is not updated.・ Case 6: Tdist1 <Smin and Tdist2> Smax This is the case where the front side and the back side of the material are inserted between the front side and the back side of the tool. In this case, the material is scraped off. As shown in FIG. 11, the target material data is deleted and the number of material data sets Snum is reduced by one. Determine the tool display color from Tnrm 1 and update the display data. By the above processing, the shape of the machining process and the screen display data are obtained, and when the comparison of all the lattices is completed, the screen is updated.

(5) Checking for over-cutting and uncutting (S21 to S25) The shape data (material data) in the working process and the model shape data are compared (S20). When the machining is within the specified range (tol) (Mmin-tol <= Smin <=
Smin data and display data are updated to the designated color at (Mmin + tol) (S21). If it has been trimmed beyond the specified range, whether it is the front or the back, Mmin +
The judgment is made based on the condition of tol <Smin or Mmax-tol> Smax (S23). In the case of the former condition, over-cutting has occurred on the reference plane side (the part displayed on the screen), that is, the table. In this case, the Scolor data and the display data are updated to the designated color (S24), and the tool path data is marked with an overcut (S25). In the case of the latter condition, it means that overcutting has occurred in the part that is not displayed, that is, the back. In this case, an overcut mark is added to the tool path data (S25). (6) Display (S26) An arbitrary observation direction can be selected by setting an arbitrary direction designated by the operator as the normal line of the reference plane. The defective portion can be easily identified by setting the normal cutting range to the ground color, and the excessively cut and uncut portions to the noticed colors (for example, red and yellow). Further, since the tool path data is marked, the correction becomes easy.

[0016]

As described above, according to the present invention, CAD /
The machining process shape is obtained based on the three-dimensional tool path data created using the CAM and expanded in the observation axis direction and the material and jig data expanded in the observation axis direction. By comparing the model shape developed in the observation axial direction with distance, the over-cut and uncut areas are identified according to the size of the axial distance, and the pre-specified color is applied to the over-cut and uncut areas. Since it is displayed on the display, it is possible to verify the tool path data for 2.5 to 5 axes, and it is also possible to shorten the idle time of the machine tool currently being performed. . Also, the memory used for simulation can be saved. Further, when a gouge occurs, the generated process route data is marked, so that it is possible to easily distinguish between an over-cut portion and an uncut portion. In addition, it is possible to easily determine the location of over-cutting tool path data correction.

[Brief description of drawings]

FIG. 1 is a flowchart (part 1) showing a processing procedure of a method according to an embodiment of the present invention.

FIG. 2 is a flowchart (part 2) showing a processing procedure of a method according to an embodiment of the present invention.

FIG. 3 is a flowchart showing details of step S20 of FIG.

FIG. 4 is a conceptual diagram of modeling of the above embodiment.

FIG. 5 is an explanatory diagram showing a method of calculating a material shape according to the embodiment.

FIG. 6 is an explanatory diagram showing a structure of shape data according to the embodiment.

FIG. 7 is an explanatory diagram showing a method for calculating the tool shape according to the embodiment.

FIG. 8 is an explanatory diagram showing a structure of tool data of the embodiment.

FIG. 9 is an explanatory diagram of various cases of the simulation of the above embodiment.

FIG. 10 is an explanatory diagram showing a change in data in case 3 of FIG. 9.

FIG. 11 is an explanatory diagram showing a change in data in case 6 of FIG. 9.

Claims (2)

[Claims] 1. A three-dimensional tool path data created by using CAD / CAM, tool shape data expanded in the observation axis direction, and material shape and jig shape data expanded in the observation axis direction. And a step of obtaining a machining process shape based on the above, and comparing the machining process shape and the model shape developed in the observation axial direction by distance, the over-cutting and the uncut portion are respectively cut depending on the size of the axial distance. A method for simulating a three-dimensional tool path, comprising: a step of discriminating; and a step of applying a predetermined color to the overcut and uncut portions and displaying them on a display. 2. The method for simulating a three-dimensional tool path according to claim 1, further comprising a step of marking a corresponding portion of numerical data of the three-dimensional tool path when the excessive cutting or the uncut portion occurs.