JPH0446731A - Tool interference check system in contour machining - Google Patents

Abstract

PURPOSE:To obtain such a cutter path generation that prevents a tool from cut-in and a tool interference check system, by cutting off an offset shape area intersecting a processing tool as a tool interference area and by reconnecting a remaining offset shape to form a cutter path. CONSTITUTION:An offset shape L' facing to a contour shape L is produced by an offset shape generating means 2, and a tool interference check means 3 judges tool interference status relative to the offset shape L'. An area (segment marked with X) of the contour element L before offset, which corresponds to an area (tool interference area) of an element to be cut off by the tool interference check means 3, is judged by a non-machinable area judging means 4 as an area that cannot be machined, and information thereof is memorized by a cutter path memory device 6 and is read out as required. An offset shape reconnecting means 5 reconnects an offset shape without tool interference, produced by the tool interference check means 3, to form a cutter path.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a tool interference check system in contour machining, and is particularly used when creating NC (numerical control) data for machining two-dimensional contour shapes. This invention relates to a tool interference check system during cutter path generation that controls the movement of a tool along the cutter path.

[Prior Art] Conventionally, when generating a cutter path for such a two-dimensional contour shape, in order to prevent the tool from cutting into the contour shape, the contour shape must be recreated, or after the cutter path (offset shape) is generated, the NC data creator must , the tool interference area is visually checked and the cutter path (offset shape) is corrected.

[Problems to be Solved by the Invention] In the conventional tool interference checking method described above, it is necessary to correct the two-dimensional contour shape or the cutter path (offset shape) in order to avoid cutting into the tool contour shape. The correction cannot be clearly predicted, and therefore, when actually machined, there is a drawback that the contour shape may be cut into, or uncut parts may be left.

Another disadvantage is that if the number of line segments or circular arcs that make up the contour shape increases, or if the shape becomes complicated, correction of the contour shape or cutter path (offset shape) to avoid tool bite becomes complicated.

[Objective of the Invention] The present invention has been made to solve the above-mentioned drawbacks of the prior art, and its objectives are to generate a cutter path in which the tool does not cut into the two-dimensional contour shape, and to An object of the present invention is to provide a tool interference check system that determines parts that cannot be machined.

[Means and effects for solving the problem] According to the present invention, in a tool interference check system when generating a cutter path in contour machining, a tool that is separated by an offset amount from a line segment and/or arc constituting the contour shape is provided. line segment and/
or an offset shape generating means that generates an offset element consisting of a circular arc and connects the offset elements to generate an offset shape, and checks the intersection between the offset shape and a processing tool, and prevents the intersected offset shape portion from tool interference. A tool interference check means for removing the part as a part; a means for detecting the contour shape part that cannot be machined with the tool; and a means for reconnecting the offset shape remaining after the tool interference part has been deleted to generate the cutter path. By using a tool interference check system in contour machining, which is characterized by including a means for , the system can automatically determine.

[Example] Next, embodiments of the present invention will be described using the drawings.

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

In the figure, the contour shape data storage device 1 stores in advance a two-dimensional contour shape to be processed, for example, in a state in which a plurality of line segments and a plurality of circular arcs C are successively connected as shown in FIG. ing. At this time, the line segment and arc C are the second
It has directionality, as shown by the arrow in the figure.

Next, the offset shape generation means 2 reads the target contour shape from the contour shape data storage device 1, and offsets each element (line segment or arc C) constituting the contour shape as shown in FIG. Generate a line segment L° and arc C° that are offset by an amount d (m < tool radius in this example), and connect the respective offset elements (line segment L° or arc C') to generate an offset shape. .

This connection method differs depending on the contour pattern.

The first pattern of these contour shapes is shown in Fig. 4 (
There are convex joint shapes shown in A) to (E), the second pattern is concave joint shapes shown in FIGS. 5A to 5E, and the third pattern is as shown in FIG. (A) ~ (B
) There is a bond shape shown in the figure.

As a method of connecting the offset elements of the first convex joint shape portion shown in FIG. 4, as shown in FIG. 7(A), each offset element L° is extended and the offset element L° is There are two methods: extending the end of the tool by a line segment e, and inserting an arc f having the same radius as the tool diameter (offset amount) as shown in (B). Only one of these methods can be used. However, as shown in FIGS. 7C and 7D, if there is no intersection even after extending each offset element C' or L', an arc g is inserted to connect them.

Next, as a method of connecting the offset elements of the second concave joint shape portion shown in FIG. 5, as shown in FIG. 8, a line segment β is inserted between each offset element L°. .

Moreover, in the case of the third joint shape shown in FIG. 6, each offset element is already in a connected state.

As described above, the offset shape generating means 2 generates, for example, when the contour shape shown by the solid line in FIG. 9 is L, the offset shape L° shown by the dotted line is generated.

Hereinafter, a process will be described in which the system of the present invention extracts an offset shape excluding the tool interference part from the contour shape shown in FIG. 9 and generates a cutter path.

The tool interference checking means 3 is the offset shape generating means 2.
As shown in FIG. 10, each intersection i1. i2.・・・
・Find i6.

Before describing the operation of the tool interference checking means 3, the principle of the present invention will be explained using FIG. 11. Assuming that for each of the above-mentioned intersections in, there is a traveling vector ■ of the offset element PS (this is the traveling direction of the original element to be offset) shown in FIG. 11, and an offset direction vector U of the offset element C8 that intersects this. In the present invention, the tool interference state is determined as follows based on the value of this inner product (U, V). That is, if the inner product (U, V) is negative, the tool interference starts at the intersection in, and if the inner product (U, V) is positive, the tool interference ends at the intersection in.

Therefore, in the tool interference checking means 3, as shown in FIG. 12, each offset element is checked at each intersection i1. i2. ...
i6, and for example, the first element ■ is divided into Sl, S2, etc. as shown in the figure. It is divided into S3. Next, start with Sl,
First, set 0 to the element of Sl. And from Sl to S
Proceeding in the direction of movement toward l (the direction of movement of the original element 2), the inner product (U, V) described above is found to be positive at the first intersection i6. Therefore, the value of 82 is obtained by adding 1 to the value 0 of 81. Similarly, for each offset element shown in Fig. 10, the above-mentioned inner product (
Check the dot product (U, V).

■) is positive, the value of the element is the value of the previous element plus 1, and when the inner product (U, V) is negative, the value of the element is the value of the previous element minus 1. The value of the relevant element.

In this way, when each individual is determined, in the case of this example, the first
As shown in Figure 2, the value of each element is O or 1. Here, the part other than the minimum value of each element is the tool interference part, and the remaining figure after removing the tool interference part is the shape of the part without tool interference, which is found by the tool interference check means. In this example, the shape is shown by the dotted line in FIG. 13, and at this point, the elements are arranged in the order of ■■...■.

Next, in the unprocessable portion 1j determining means 4, O
The part of the contour element before offset corresponding to the part (tool interference part) of the element (element deleted by the tool interference check means 3) having the value (the line segment marked with X shown in FIG. 13)
is determined to be an unprocessable portion, and information to that effect is stored in the cutter path storage device 6 and read out as necessary.

Next, the offset shape reconnecting means 5 reconnects the offset shapes without tool interference generated by the tool interference checking means 3 to form a cutter path. 1st
Figure 3 is an example of this, ■.

Connect in the order of ■...■. This first connects the element ■ that matches the end point of the element ■, and then connects it to the element ■ that matches the end point of the element ■. Since the end point of element (2) coincides with the end point of element (2), one offset shape connection is completed. Similarly, similar connection processing is performed for other elements, starting from the element with the lowest order.

In this way, multiple reconnected offset shapes
A cutter path as shown in FIG. 14 is generated, stored in the cutter path storage device 6, and read out as needed.

[Effects of the Invention] As explained above, in the system of the present invention, tool interference check can be performed to prevent the tool from digging into the two-dimensional contour shape, so that the two-dimensional contour shape or the cutter path (offset shape) can be checked. An optimal cutter path can be generated without any modification by the operator.

At the same time, since unprocessable portions can be detected, the shape of the uncut portion can be obtained in advance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a diagram showing an example of a two-dimensional contour shape. FIG. 3 is a diagram showing basic elements (line segments or circular arcs) constituting the contour shape and their offset shapes. FIG. 4 is a diagram showing types of convex connections. FIG. 5 is a diagram showing types of concave connections. FIG. 6 is a diagram showing types of connection tables. FIG. 7 is a diagram showing an offset shape in a convex joint shape. FIG. 8 is a diagram showing an offset shape in a concave joint shape. FIG. 9 is a diagram showing the contour shape of the example and its offset shape. FIG. 10 is a diagram showing the intersections of the offset shapes. FIG. 11 is a diagram showing a tool interference check method. FIG. 12 is a diagram of an offset shape showing the result of tool interference check. FIG. 13 is a diagram showing a diagram in which the interference portion has been removed after tool interference check and a diagram showing the contour shape. FIG. 14 is a diagram showing a cutter path in which the offset shape from which the interfering portion has been deleted is reconnected. DESCRIPTION OF SYMBOLS 1... Contour shape data storage device 2... Offset shape generation means, 3... Tool interference check means, 4... Unworkable portion determination means, 5... Offset shape reconnection means, L. ...Contour element (line segment), L゛...offset shape of contour element (line segment), C...contour element (arc), Co
...Offset shape of contour element (arc), d...Tool radius (offset amount), T...Tool shape, S...
Contact point, e...extension of line segment, β...inserted line segment, 1 to i6...intersection of offset shape.

Claims (2)

[Claims] (1) In a tool interference check system during cutter path generation in contour machining, an offset element consisting of a line segment and/or arc separated by an offset amount from the line segment and/or arc constituting the contour shape is generated, an offset shape generation means that connects the offset elements to generate an offset shape; a tool interference check means that checks the intersection of the offset shape and a machining tool, and deletes the crossed offset shape portion as a tool interference portion; The method is configured to include means for detecting the contour shape portion that cannot be machined by the tool, and means for reconnecting the offset shape remaining after the tool interference portion has been deleted to generate the cutter path. A tool interference check system for contour machining. (2) the tool interference checking means calculates, at the intersection of each offset element of the offset shape, the inner product of the progress vector of the offset element and the offset direction vector of the other offset element that intersects the progress vector; The tool for contour machining according to claim 1, wherein if the calculation result is negative, it is determined that tool interference starts from the intersection, and if the calculation result is positive, it is determined that the tool interference ends at the intersection. Interference check system.