JPH0661675B2 - Method of drawing tool locus of compound curved surface - Google Patents

Description

The present invention relates to a tool trajectory drawing method for a compound curved surface, and more particularly to a tool trajectory drawing method for distinguishably drawing a tool trajectory on each curved surface.

<Prior Art> A curved surface on a design drawing of a three-dimensional mold or the like is generally represented by a plurality of cross-section curves, and there is no shape data between one cross-section curve and the next cross-section curve. By the way, in the case of numerically controlled processing, it is required to perform processing so as to smoothly connect between the above-mentioned two cross-section curves, although no intermediate shape is given. In other words, this means that a curved surface between the two cross-section curves is generated from the data of the cross-section curve and the like, data regarding the generated curved surface is stored in the NC tape, and a command from the NC tape is used. It means that it must be processed. Therefore, a method for generating a three-dimensional curved surface has been developed and has already been put to practical use.

Further, depending on the processing, processing of a composite curved surface formed by combining two or more three-dimensional curved surfaces may be required, and a method of automatically generating NC data by generating such a composite curved surface has also been developed.

Then, according to the conventional compound curved surface generation method, the tool path can be drawn on the CRT for checking after generating the compound curved surface.

<Problems to be Solved by the Invention> However, in the past, the tool path was drawn on the same line as a whole.

Therefore, there is a problem that it is difficult to recognize which portion is the tool locus of which curved surface, and thus it is not easy to check the generated curved surface. In particular, a complicated curved surface is roughly programmed at the first programming stage and then corrected by referring to the drawn curved surface. However, the conventional method has a problem that the correction work is troublesome.

In view of the above, an object of the present invention is to provide a tool trajectory drawing method for a compound curved surface, which makes it possible to easily recognize which portion is the tool trajectory of which curved surface.

<Means for Solving Problems> FIG. 1 is a schematic explanatory view of the present invention.

11 is a compound curved surface, 12a, 12b, 12c are the 1st, 2nd, 3rd curved surfaces, 13a, 13b, 1 which comprise a compound curved surface.
3c is a tool locus on the first, second and third curved surfaces, CR _ij
Is the intersection of the i-th curved surface and the j-th curved surface.

<Operation> When the complex curved surface 11 is generated, the boundary points CR _ij of the curved surfaces 12a to 12c are stored so as to be distinguishable, and the tool loci 13a to 13c on each curved surface can be distinguished when the tool locus is drawn, for example, the color is changed. To draw.

<Embodiment> FIG. 2 is a block diagram of an automatic programming device for implementing the method of the present invention. In the figure, 101 is a keyboard for data input, 102 is a processor, 103 is a RAM for storing a control program, 104 is a RAM, 105 is a curved surface for storing curved surface data of the generated complex curved surface and NC program data for curved surface processing. A storage memory 106 is a disk drive device that outputs curved surface data and NC data to a floppy FLP, 107 is a graphic display device (CRT), and 108 is an XY plotter that outputs a curved surface. The CRT is capable of color drawing, and the XY plotter is also capable of color drawing.

FIG. 3 to FIG. 4 are explanatory views of the generation of the complex curved surface. Hereinafter, a method of drawing a tool locus of a compound curved surface according to the present invention will be described with reference to FIGS. 1 to 4.

(a) First, the first three-dimensional curved surface 12a, the second three-dimensional curved surface 12b, the third three-dimensional curved surface 12c, ... Which compose the compound curved surface 11 (see FIG. 3) are specified from the keyboard 101. Each data is input and stored in the RAM 104.

(b) Next, data for specifying a number of cross sections perpendicular to the XY plane for cutting the composite curved surface 11 from the keyboard 101 is input and stored in the RAM 104. That is, X
-Enter a rule for identifying one line segment on the -Y plane and a large number of intersecting lines on the XY plane based on the line segment.

For example, when the respective cross sections are parallel to each other and perpendicular to the XY plane and the interval between the adjacent cross sections is constant, the intersection line CLi (i = 1, 2, 1) between each cross section and the XY plane is obtained. ，
3, ...) are as shown in FIG. Therefore, in such a case, data specifying the first intersection line CL1
Enter the distance d between two lines of intersection adjacent to each other.

(c) If each data is input, the processor 102 first
Set 1 → i.

(d) Next, the processor 102 uses the first intersection line data and the interval d between the intersection lines given in step (b) to determine the intersection line CLi on the ith XY plane. Ask.

(e) If the i-th intersection line CLi is obtained, the processor 10
2 is a well-known method that has already been proposed, and the first, second, and third curved surfaces 12 are formed by the cross section corresponding to the intersection line CLi.
Sectional curves 13a, 1 when cutting a, 12b, 12c
3b and 13c are obtained as a discrete point sequence (see FIG. 3).

(f) Then, the uppermost point sequence of each cross-section curve is the point sequence (A _i ·· CR ₁₂ , ··· C) that constitutes the compound curved surface 11.
It is stored as R ₂₃ , ... B ₁ ). In the point sequence of this composite curved surface, the point sequence of the first curved surface 12a is changed to the second curved surface 12a.
Boundary point CR _{12 and} second curved surface 1 when transferring to the point sequence of b
The boundary point CR ₂₃ at the time of transferring from the point sequence of 2b to the point sequence of the third curved surface 12c is stored.

(g) After that, i is updated by i + 1 → i, and the processing from step (e) above is repeated to finally generate the composite curved surface 11 with the point group.

(h) When the generation of the compound curved surface is completed, the processor traces the point sequence on the compound curved surface 11 in the generation order, and the tool loci 13a, 13
b and 13c are drawn on the CRT 107 as shown in FIG. 1 or drawn by the XY plotter 108.

However, tool path 13a, 13b, 13c is a tool path on each curved surface 12a, 12b, 12c, or solid respectively different colors, identifying the composite surface generation boundary points are stored at the time CR _12, CR ₂₃ , Dotted line, and one-dot chain line.

(i) Then, referring to the image output by the CRT, XY lotter, it is checked whether or not it is necessary to correct it, and finally a composite curved surface is generated and NC data is generated.

<Advantages of the Invention> As described above, according to the present invention, the boundary line of each curved surface is stored at the time of generating a complex curved surface, and the tool path on each curved surface is drawn in a distinguishable manner. It is possible to easily recognize whether or not it is a tool locus, and it is easy to recognize how the complex curved surface is generated, and it is possible to easily perform correction and the like.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of the present invention, FIG. 2 is a block diagram of an apparatus for carrying out the present invention, and FIGS. 3 and 4 are explanatory views of the method of the present invention. 11 ... Compound curved surface, 12a, 12b, 12c ... Curved surface, 13a, 13b, 13c ... Tool locus, CR _ij ... Intersection point of i-th curved surface and j-th curved surface

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP 59-75309 (JP, A) JP 60-213423 (JP, A)

Claims (1)

[Claims] 1. A tool trajectory drawing method for a compound curved surface, which is a compound curve of two or more three-dimensional curved surfaces, wherein a point sequence on a compound curved surface is obtained, a compound curved surface is generated by the point sequence, and boundary points of each curved surface are obtained. When machining a compound curved surface by moving a tool along the point sequence, it is characterized in that the tool locus on each curved surface is drawn in a distinguishable manner by changing the color etc. with the boundary point as a boundary. Method for drawing tool locus on compound curved surface.