JPH05113811A - Path pattern determination device for nc machine tool for surface machining - Google Patents

Abstract

PURPOSE:To determine the path pattern which does not interfere with a jig and generates no burr at a contour when a work which is fixed by the jig is machined. CONSTITUTION:This path pattern determination device is equipped with a means 4 which decides whether or not the jig is present in an area expanded outside the contour by almost a half of a tool diameter, a means 5 which artificially sets a 'wall' halfway between the contour and jig when the jig is present, and a means 8 which selects the path pattern on condition that the 'wall' is not exceeded. Consequently, the path pattern which disallows the extension of the tool to project from the contour and interfere with the jig is obtained and no burr is generated at the contour.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing machine for surface-working a work while moving a tool such as an end mill within a certain plane,
In particular, the present invention relates to an apparatus for determining a path pattern when moving a tool and a work relative to each other in order to control an NC machine tool for surface machining in which the relative movement of the tool and the work is numerically controlled.

[0002]

2. Description of the Related Art In the case of surface processing, for example, as shown in FIG. 2, an "entire surface" pattern for processing the entire surface of a work, a "closed pocket" pattern for processing in a closed pocket shape, and a processing for leaving a wall B ". It can be divided into a plurality of processing area shape patterns such as a "flat wall" pattern. In addition, with respect to a specific processing region shape pattern, there are usually some path patterns capable of processing the shape pattern. For example, the “entire surface” processing area shape pattern can be processed by either a “one-way without parallel wall” path pattern or a “reciprocating without parallel wall” path pattern illustrated in FIG.

Therefore, the applicant has means for storing a processing area shape pattern group and a path pattern group, and means for inputting processing shape information to be processed, and which processing area is input when the processing shape information is input. We propose a device that determines whether the pattern is a shape pattern and which path pattern can be used for processing. According to this, the path pattern is determined by inputting the processing shape information. However, as illustrated in FIG. 4, for example, when the "entire surface" R is machined and the path pattern P of "reciprocation without parallel walls" is selected and machining is performed, the tool T1 and the jig J for fixing the workpiece
There may be cases where and interfere with each other.

Therefore, the present applicant has developed a method of calculating a primary processing area which is expanded a predetermined distance outside the contour and preliminarily considering the interference between the primary processing area and the jig, and is currently applying for it. It has not been published at the time of application). Here, as shown in FIG. 5 (a), if the tool T is protruded to the outside of the contour B by a radius or less, the uncut portion X may remain, so as shown in FIG. The primary processing area E is calculated by expanding outward by the radius of T or more. In this way, the path pattern with no uncut residue is set in the primary processing area E.
Can be determined within.

Here, if the temporary machining area E and the jig J do not interfere with each other, a path pattern which does not cause the uncut portion X and does not interfere with the jig J is selected. However, if the primary processing area E and the jig J interfere with each other, interference with the jig will occur depending on the selected path pattern.

[0006] Therefore, the applicant has developed a method in which the contour where the primary processing area E and the jig J interfere with each other is imitated as a "wall" (this technique has not yet been published at the time of the application). is there). Here, the “wall” means a boundary that the tool should not cross, and for example, the contour B in the example of the “flat wall” in FIG. 2 corresponds to the “wall”. The processing area R in FIG. 4 is “all surface”, but the contour B of the processing area R is a “wall” because the temporary processing area and the jig J interfere with each other.
As a result, the processed region R is grasped not as the "entire surface" but as a "flat wall" pattern having the contour B as a "wall" (however, in this case, the wall thickness is zero). This way,
The selected path pattern is “wall” as illustrated in FIG.
The pass pattern Q does not exceed B, and the tool T and the jig J are prevented from interfering with each other.

[0007]

According to the above-mentioned method, the extension of the tool T moves along the contour B at the portion where the contour B and the jig J are close to each other. Interference with J can be avoided. However, when the extension of the tool T moves along the contour B, burrs may occur on the contour B. Therefore, in the present invention, while enjoying the advantages that the applicant has solved up to now (that is, it is possible to obtain a path pattern that does not cause uncut residue and does not cause interference with a jig), and yet, it is possible to obtain a flash with a contour. It is intended to develop a device in which a path pattern that does not occur is determined.

[0008]

Therefore, according to the present invention,
As the concept is schematically shown in FIG. 1, a surface machining NC for machining while moving a tool relative to a workpiece in a plane.
A path pattern determination device for a machine tool 9, which is means for inputting information indicating the position of a jig for fixing a workpiece, and processing shape information indicating the position and shape of the processing area of the workpiece fixed by the jig. Means 2, means 3 for calculating the primary machining area in which the contour other than the wall of the contour of the machining shape defined by the machining shape information is expanded outward by the width obtained by multiplying the tool diameter by a constant, Means 4 for determining the presence or absence of interference between the primary machining area and the input jig position, means 5 for making the contour in which the interference is determined to be a pseudo wall, and the position of the pseudo wall for repairing the contour. Means 6 for offsetting to an intermediate position between the tool and means 8 for selecting a path pattern capable of processing a contour having an offset false wall from the path pattern group stored in the path pattern group storage means 7. For surface processing N
We created a pass pattern determination device for C machine tools.

[0009]

According to the present invention, the contour that the jig approaches, that is, the contour B in the example of FIG. However, the position of the "wall" is set to the intermediate position G between the contour B and the jig J by the pseudo type offset means 6. That is, the “wall” G in this case is set to a distance F which is shorter than the contours B to C, but is not zero, where C is the actual distance from the contour B to the jig J. When the "wall" is offset in such a manner, the selected path pattern moves along the "wall" G in which the extension of the tool T is offset. Therefore, the tool T does not interfere with the jig J. Further, no burrs are generated on the contour B.

[0010]

FIG. 6 shows an example of the system configuration of an NC machine tool incorporating a path pattern determining device according to the present invention. In the figure, reference numeral 20 denotes a machine tool main body, and this main body 20 is provided with a movable base 25 which is movable in a horizontal plane by an X-axis motor 21 and a Y-axis motor 22. The work W is fixed to the movable table 25 by a jig 29. In the figure, reference numeral 24 denotes an upper frame, on which the spindle 26 is assembled so as to be rotated by the spindle motor SM. The vertical height of the main shaft 26 is variable by the Z-axis motor 23. Incidentally, reference numeral 27 in the drawing denotes a tool magazine in which a plurality of tools are set. The selected tool is attached to the spindle 26 by the tool changer 28.

In the machine tool body 20, the selected tool is attached to the spindle 26, and when the tool height is adjusted by the Z-axis motor 23, the tool is rotated by the spindle motor SM and the X-axis motor 21 and the Y-axis are rotated. The movable table 25 moves along the path pattern created by the shaft motor 22, and the workpiece W is surface-machined according to the path pattern.

Each of the motors 21, 22, 23 is X
It is controlled by the numerical controller 10 via the axis, Y axis, and Z axis servo units DUX, DUY, DUZ. Also the spindle motor SM
Is the spindle motor drive circuit 15 and the sequence controller 1
1 and the numerical control device 10. Numerical control device 10
The sequence controller 11 is connected to the computer 12. The computer 12 is a processing unit (MP
U) 12a, clock signal oscillation circuit 12b, ROM 12
A C, a RAM 12d, a fixed disk 12e, interfaces 12f, 12g, 12h, etc. are connected to each other by a bus 12i. Interface 12
A keyboard 13 and a CRT display device 14 are connected to h, and an operator inputs machining shape information indicating the position and shape of the machining surface area of the work and information indicating the position of the jig 29 for fixing the work from the keyboard 13. You can do it. In this embodiment, the machining shape information input means 2 and the jig position information input means 1 are composed of a keyboard 13.

The ROM 12c stores a program for executing the processing shown in FIG. In the process of FIG. 7, processing shape information is input in step S2. Further, in step S4, jig position information is input. In step S6, the primary processing area is calculated. The processed shape information is shape information indicating a contour, and the contour is composed of "wall" and "non-wall" contours. Therefore, the primary machining area is calculated without changing the "wall", and for the contour "other than the wall", an area in which 60% of the tool diameter is expanded outside the contour. By expanding 60% of the tool diameter outward in this way, as described with reference to FIG. 5, it is possible to select a pass pattern having no uncut residue in the primary processing region.

In step S8 of FIG. 7, it is determined whether or not there is interference between the primary processing area and the jig position. If there is no interference, a path pattern is selected in the primary processing area without leaving the processing area left uncut (S28), and processing is performed according to the path pattern (S30).

However, if there is interference, a process for avoiding interference with the jig is executed. For that purpose, first, in step S10, a contour in which the primary processing region and the jig interfere with each other is extracted. For example, a case where the work W shown in FIG. 8 is fixed by jigs J1 and J2 and the work surface R is processed will be described as an example. In this case, the contour is, as shown in FIG. 9, an arc wall B1, a straight wall B2, an arc wall B3, an arc B4, a straight line B5.
B6 and. With respect to the walls B1, B2, B3, the primary processing area E is not expanded outward, and no interference with the jig occurs. However, for the straight line contour B5, when 60% of the tool diameter is expanded outward and the primary machining area E is calculated, it interferes with the jig J2. Step S10 in FIG.
Then, such a contour is extracted. Note that the contour B4
For example, the case where the jig J1 is sufficiently separated and no interference occurs is illustrated.

Before the applicant completes the present invention, the contour B5 extracted in this way is artificially made into a "wall" as illustrated in FIG. Here, the double hatch indicates the original "wall" and the single hatch indicates the pseudo wall. Then, after that, a path pattern as illustrated in FIG. 12, that is, a path pattern in which the extension of the tool is not outside the “wall” is selected.

However, in this embodiment, step S in FIG.
The processes of 12 to S26 are added. First step S
In 12, the distance between the contour B5 and the jig J2 (La or Lb in the case illustrated in FIG. 12) is calculated. Then in step S14 it is compared to 30% of the tool diameter. 12
In the left side, the jig J2a on the left side is 30% of the tool diameter D (D3
When the distance is 0) or more, the jig J2b on the right side has a tool diameter D
30% (D30) is not distant. When the distance is D30 or more like the jig J2a, the answer is YES in step S14, and in this case, the tool diameter is 30%.
That is, D30 is the offset amount. (S16). On the other hand, if the distance is less than D30 or less like the jig J2b, the result of step S14 is NO, and at this time, the distance Lb is 50 or less.
%, That is, 0.5 Lb is the offset amount. Then, in step S20, the wall B5a or B5b is artificially set outside the contour B5 by the offset amount. After the above processing, in step S22, a path pattern in which the tool extension is not outside the "wall" is selected. It should be noted that various types of pass patterns are previously prepared for the fixed disk 1.
2e, which is selected from among these.

Since the above-described processing is added, conventionally, the outer extension of the tool T was moved along the contour B5, and burrs were easily generated at the contour B5.
Does not interfere with the jig, it moves with the outline protruding, so the occurrence of burrs is prevented.

Step S24 in FIG. 7 is to determine whether or not uncut residue will occur when the path pattern is selected from the walls thus offset. As illustrated in FIG. 13 (b), when the jig is located close to both the contours B8 and B9 and the offset wall shown in B8E to B9E is set, the uncut portion X is generated. There is a possibility. Therefore, if it is found in step S24 that uncut parts will occur, step S26
Then, the machining along the contour is performed using the tool TS having a small diameter. According to this, as shown in FIG. 13A, it is possible to prevent the uncut portion from occurring.

After the above processing is completed, the processing of step S30 is carried out, so that there is no uncut residue.
A path pattern is obtained in which the jig and the tool do not interfere with each other and burrs do not occur in the contour, and the processing is performed according to the path pattern.

FIG. 14 shows a process of connecting offset walls between partial contours. When straight contours are in contact with each other as shown in (a1), each offset wall is extended as it is as shown in (a2). If the straight line contour and the circular arc contour are in contact as in (b1) and the extensions of the offset walls intersect, (b2)
As shown in (c1), if the offset walls do not intersect as shown in (c1), the arc-shaped offset walls are asymptotic to the linear offset walls as shown in (c2). Where the arcs are connected to each other as in (d1), the offset walls are set by connecting the offset walls with tangent lines as in (d2).

FIG. 15 shows a portion for connecting the actual wall and the offset wall, and the offset wall is connected to the actual wall in the same manner as in the case of FIG. In step S22 of FIG. 7, the path pattern is selected within the range of the wall thus connected.

[0023]

According to the present invention, in the case where the jig exists at a position where it interferes with the tool when the tool radius is extended beyond the contour of the machining area so as not to cause uncut residue, By adding a process to set an offset wall in a pseudo position between the contour and the jig, it is possible to obtain a path pattern in which the tool extension extends beyond the contour and does not interfere with the jig. Therefore, it is possible to prevent the uncut portion, the jig and the tool from interfering with each other, or the occurrence of burrs along the contour, and it is possible to perform a high-quality unmanned processing.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing the concept of the present invention.

FIG. 2 is a diagram illustrating a processed shape pattern.

FIG. 3 is a diagram illustrating a path pattern.

FIG. 4 is a diagram illustrating the operation of the present invention.

FIG. 5 is a diagram showing a relationship between a contour and a tool.

FIG. 6 is a diagram showing a system of an embodiment.

FIG. 7 is a diagram showing a processing procedure of an embodiment.

FIG. 8 is a diagram illustrating an object to be processed in the example.

FIG. 9 is a diagram illustrating a primary processing area.

FIG. 10 shows a false wall that is not offset.

FIG. 11 is a diagram illustrating a path pattern when a pseudo wall that is not offset is used.

FIG. 12 is a diagram showing offset false walls.

FIG. 13 is a diagram illustrating uncut parts.

FIG. 14 is a diagram showing connection of offset walls.

FIG. 15 is a diagram showing a connection between an offset wall and an actual wall.

[Explanation of symbols]

 1 jig position information input means 2 machining shape information input means 3 primary machining area calculation means 4 interference presence / absence determination means 5 pseudo-wall setting means 6 pseudo-wall offset means 7 path pattern group storage means 8 path pattern selection means 9 faces NC machine tool for processing

Claims (1)

[Claims] 1. A path pattern determining device for an NC machine tool for surface machining, which performs machining while moving a tool relative to a workpiece in a plane, and means for inputting information indicating a position of a jig for fixing the workpiece. Means for inputting machining shape information indicating the position and shape of the machining area of the workpiece fixed by the jig, the contour of the machining shape defined by the machining shape information other than the wall is multiplied by the tool diameter by a constant. Means for calculating the primary machining area expanded outward by a certain width, means for determining the presence or absence of interference between the calculated primary machining area and the input jig position, contour for which the occurrence of interference has been determined As a pseudo wall, a means for offsetting the position of the pseudo wall to an intermediate position between the contour and the jig, and a pseudo pattern offset from the path pattern group stored in the path pattern group storage means. A contour that can be machined with a wall Path pattern determination device surface machining NC machine tool having means for selecting a pattern.