JPH0594207A - Generation system for cutter path for rough cutting - Google Patents

Abstract

PURPOSE:To decrease the amount of NC data for rough cutting by generating a data-compressed cutter path (dot array data) between a path for finishing and a path obtained by moving the path for finishing in the plus direction of a Z axis by a rough machining tolerance. CONSTITUTION:A rough cutting path selecting means 2 reads paths out of a finishing path storage device 1 in order and selects paths as objects of rough cutting. A path offset means 3 move the dot array constituting the paths, selected by the selecting means 2, in parallel in the positive direction of the Z axis by the rough cutting tolerance to generate a dot array. Then a rough machining path generating means 4 generates the rough machining path between the dot array constituting the path before the offsetting and the dot array constituting the path after the offsetting. Then this rough machining path is stored in a rough cutting path storage device 5 in the same form with the storage of the finishing path.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roughing cutter path generation system, and more particularly to an N for machining a three-dimensional composite curved surface shape.
The present invention relates to a roughing cutter path generation system used when generating C (numerical control) data.

[0002]

2. Description of the Related Art Conventionally, machining of a three-dimensional composite curved surface shape is performed by generating a roughing cutter path and a finishing cutter path. The difference between the roughing and finishing passes is that the interval between the passes is wider for roughing, and there is nothing if it is limited to one pass. That is, for only one pass, both the roughing pass and the finishing pass are obtained by the finishing pass generation method.

[0003]

In the above-described conventional rough-cutting cutter path generation system, the data amount of the cutter path becomes large, and it takes time to transfer the NC data to the NC machining opportunity, or the dot sequence is formed. Although the NC data is data for instructing a slight movement, a large amount of point sequence data for instructing the movement is generated, and there is a drawback that the tool shakes during machining.

[0004]

SUMMARY OF THE INVENTION A rough cutting hatter path generation system according to the present invention includes a roughing path interval from a roughing path storage device in which a finishing path for finishing a three-dimensional composite curved surface shape is stored. The rough-cutting path selecting means for reading the path at, the path-offset means for generating a path obtained by translating the rough-cutting path in the positive direction of the Z-axis by the rough machining tolerance, and the offsetting It is characterized by including a rough machining path generation unit for generating a rough machining path between the path and the original path to be offset, and a rough machining path storage device for storing the rough machining path.

[0005]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention.

In FIG. 1, a finishing path storage device 1
_Stores in advance the finishing paths for processing the three-dimensional composite curved surface, for example, the paths PS ₁ , PS ₂ ... PS ₁ shown in FIG. The path PS _i (i = 1, 2, ..., L) is shown in FIG.
As shown in FIG. In addition, each path P
S _i is composed of a point sequence P _k (k ... 1, 2, ..., N) as shown in FIG. At this time, the plane PL on which each path is placed
Are parallel to each other and the plane PL is perpendicular to the XY plane. That is, when each path is projected onto the X and Y planes, the path shown in FIG.
become that way.

Next, the rough-cut required path selecting means 2 in FIG.
From the finishing path storage device 1, the path PS _i (i = 1, 2,
... l) are read in order. First, the path PS ₁ is set as the target of the rough cutting path, and then the farthest path PS ₃ within the rough cutting path interval is determined as shown in FIG. The same process is repeated thereafter, and the path to be rough-selected is selected as shown in FIG.

For each path selected by the path offsetting means 3 and the roughing-out path selecting means 2, as shown in FIG. 9, a point sequence P _k (k = 1, 2 ... n) constituting the path. Of the rough machining tolerance, the point sequence Q _k translated in the positive direction of the Z axis
(K = 1, 2 ... n) is generated.

Next, the roughing pass generating means 4 includes a point sequence P _k (k = 1, 2 ... N) forming a path before offset and a point sequence Q _k (k = 1, _k ) forming a path after offset. 2 ... n)
Generate a roughing pass between and.

In the rough machining pass generation procedure, first, as shown in FIG. 10, a point P ₁ , a point Q ₁ , a middle point S, and a starting point of a rough machining pass are set. Next, a straight line L ₁ connecting the midpoint S and the point P ₂ , the midpoints S and Q
Obtains a straight line L ₂ connecting the _two, the roughing path generation target region surrounded by the straight line L ₁ and the straight line L ₂ as shown in FIG. 11, the line segment P
_It is checked whether or not _k Q _k (k = 2, 3, 4 ... N) is included in part. All line segments P ₂ Q ₂ are included.
The line segment P ₃ Q ₃ is partially included.

At this time, the straight line L ₁ and the line segment P ₃ Q ₃ have an intersection, but the straight line L ₂ and the line segment P ₃ Q ₃ do not have an intersection. Therefore, a straight line passing through the midpoint S and the point Q ₃ included in the area between the straight line L ₁ and the straight line L ₂ at the end point of the line segment P ₃ Q ₃ is newly defined as the straight line L ₂ . At this time, since the next line segment P ₄ Q ₄ is not included in the area between the straight lines L ₁ and L ₂ , the constituent point M of the point sequence of the roughing pass is generated on the line segment P ₃ Q _3. ..

The point M that constitutes the point sequence of the roughing path is divided into line segments P ₃ Q
_In the method of generating on the line ₃ , the midpoint of the line segment P ₃ Q ₃ included between the straight line L ₁ and the straight line L ₂ is set as the constituent point M. 12
In (A), when the intersection of the straight line L ₁ and the line segment P ₃ Q ₃ is I, the midpoint between the points I and Q ₃ becomes the constituent point M.

In the case of FIG. 12B, the straight line L ₁ and the line segment P
The intersection of the _j-1 Q _j-1 and I _1, the straight line L ₂ and the line segment P _j-1
And when the intersection of the Q _j-1 and I _2, the midpoint between the point I ₁ and the point I ₂ is configured point M. The constituent point M obtained here is defined as a point M ₁ .

Next, as shown in FIG. 13, a straight line L ₁ connecting M ₁ and P ₄ is defined as a line L ₂ connecting M ₁ and the point Q ₄ .
As before, in the region between the straight line L ₁ and the straight line L ₂ , the line segment P _k
Check if Q _k (k = 4,5, ... N) is included. As shown in FIG. 14, line segment Q _j Q _j , line segment L ₁ and straight line L
_If both ₂ have an intersection, go to the next P _j Q _j and check.

Further, as shown in FIG. 15, one of the end points of the line segment P _j Q _j is included in the region of the straight lines L ₁ and L ₂ , and the other end point is other than the region between the straight lines L ₁ and L _2. , The straight line L _k (k = 1 or 2) having no intersection with the straight line P _j Q _j is included in the region between the point M ₁ and the straight line L ₁ and the straight line L _2. Generate a straight line connecting _j Q _j and the end point,
Again, let the straight line be L _k (k = 1 or 2).
In the case of FIG. 19, a straight line connecting the point M ₁ and the point Q _j is defined as a straight line L ₂ . Next, the line segment P _j Q _j (j = 5, 6 ... N) that falls between these two straight lines L ₁ and L ₂ is checked, and the same processing is repeated.

In the example of FIG. 13, the two straight lines representing the area indicated by W ₃ finally become straight lines L ₁ and L ₂ . The last line segment included in this area is the line segment P ₇ Q ₇ . The constituent points M of the point sequence of the roughing pass are generated on the line segment P ₇ Q ₇ . The generation method is the same as the one previously described. The above operation is repeated until the constituent points of the point sequence of the roughing pass are obtained on the last line segment P _n Q _{n as} shown in FIG. Let this point be E.

As a result of the above, as shown in FIG. 17, a midpoint S → point M ₁ → point M ₂ → midpoint E is generated as a roughing pass.
The roughing path is stored in the roughing path storage device 5 in the same manner as the storage of the finishing path.

[0019]

As described above, according to the system of the present invention, a cutter path (point sequence) that is data-compressed between the finishing path and the path obtained by moving the finishing path by the rough machining difference in the positive direction of the Z axis is used. Data is generated, it is possible to reduce the amount of NC data for rough machining.
It is possible to shorten the NC data transfer time to the machine tool.

Since the point sequence data for instructing a slight movement is also obtained, the tool does not shake during machining.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing an example of a finishing pass for processing a complex curved surface.

FIG. 3 is a diagram in which a finishing pass for complex curved surface processing is projected on an XY plane.

FIG. 4 is a diagram showing selection of a roughing pass from a finishing pass.

FIG. 5 is a diagram in which a roughing pass is selected from finishing passes and the pass is projected onto an XY plane.

FIG. 6 is a diagram in which a roughing pass is selected from finishing passes.

FIG. 7 is a diagram showing that one pass lies on a plane.

FIG. 8 is a diagram showing that each path is composed of a point sequence.

FIG. 9 is a diagram showing an example of an offset path.

FIG. 10 is a diagram showing an example of first processing of a roughing pass.

FIG. 11 is a diagram showing a target region when obtaining a roughing pass.

FIG. 12 is a diagram showing a relationship among a region for which a rough machining path is obtained, an offset path, and an original path.

FIG. 13 is a diagram illustrating an example of a process of obtaining a roughing pass on the way.

FIG. 14 is a diagram showing a relationship among a region for which a rough machining path is obtained, an offset path, and an original path.

FIG. 15 is a diagram showing a relationship among a region for which a rough machining path is obtained, an offset path, and an original path.

FIG. 16 is a diagram showing an example of processing for obtaining a final roughing pass.

FIG. 17 is a diagram showing an example of a roughing pass.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Finishing pass storage device 2 Roughing pass selection means 3 Pass offsetting means 4 Roughing pass generating means 5 Roughing pass storage device

Claims (1)

[Claims] 1. A rough removing path selecting means for reading out paths at a rough removing path interval from a finishing path storing device storing finishing paths for finishing a three-dimensional composite curved surface shape, and the rough removing. A rough machining path between the offset path and the original path to be offset, and a path offset means for generating a path in which the path selected for translation is translated in the positive direction of the Z axis by the rough machining tolerance. A roughing cutter path generating system comprising: a roughing path generating means for generating; and a roughing path storage device for storing the roughing path.