JPH04210352A - Interference simulation method for exchanging tool - Google Patents

Abstract

PURPOSE:To execute the simulation of the interference state of a tool and change arm and work from a display scope by making a work on a table as an approximate body to a rectangular parallelopiped, etc., and expressing the revolving locus of a change arm including an exchange tool as a multiple stage cylinder. CONSTITUTION:A work 2 on a table 1 is made the approximate body W2 of a rectangular parallelopiped, etc., also the revolving locus of a change arm 3 including an exchange tool T is expressed as a multi-stage cylinder A0. The simulation of an interference zone AZ where the tip A3 of the multi-stage cylinder A0 and one part of the approximate body W2 are interfered each other executes 'the picture drawing of the work shape on an XZ horizontal plane and a tool revolving locus'. On one part, 'the picture drawing of the work shape on an XY vertical plane and the tool revolving locus' is executed in parallel. In case of viewing this in a figure, the tip A3 of the multistage cylinder A0 of the revolving locus becomes '1' with its superposition on the approximate body W2, also all of the multistage cylinder A0(A1-A3) become '1, 1, 1' with their superposition on the approximate body W2. Consequently, 'the decision of interference' becomes (there is interference), and 'the arithmetic process of the simultaneous interference zone on horizontal and vertical planes' is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a simulation in which the state of interference between a tool or a change arm and a workpiece in a machining center is monitored on a display screen of a computer.

[Prior art and its problems] Conventionally, if a workpiece placed on the table of a machine tool were to rotate the change arm or interfere with the tool, this would result in an accident that would damage the change arm or the tool. .

As countermeasures for these, for example, placing the workpiece on the table away from the tool side and the ATC side, and measuring and inputting the interference distance between the workpiece and the tool and between the change arm in advance and detecting this as an interference part in the NC program. is provided. In the case where the workpiece placement position is moved away from the spindle tool and the change arm side, as the workpiece size increases, the interference area expands, making it impossible to accurately grasp the interference area. Furthermore, in the method of measuring the interference distance between a tool and a workpiece, this measurement work must be performed manually, which requires a lot of time and effort to check for tool interference.

In addition, instead of interference between the tool and workpiece during ATC operation,
A tool interference check method for checking whether a tool interferes with a workpiece that becomes an obstacle on its movement path was developed in Japanese Patent Laid-Open No. 6
No. 2-35910. This check method approximates the workpiece with a rectangular parallelepiped or cylinder, specifies the projected shape and position of this approximation object on the XY plane, and the maximum height in the Z direction.
When the Y simultaneous two-axis path intersects an obstacle in the XY plane projection and the Z-direction position of the tool is lower than the maximum Z-direction position of the obstacle, it is determined that the two tools interfere with the obstacle.

This tool interference checking method determines that tool interference has occurred when there is an overlap between the approximate object (projected shape of the workpiece) and the projected tool's position in the XY plane and Z direction. cannot be applied to the technology for determining whether a change arm or tool in ATC operation interferes with a workpiece. For example, the ATC arm and the tool gripped by it have a multi-stage cylindrical turning trajectory, and a workpiece placed on a table is positioned at an arbitrary turning index position on an indexing table. It is from.

"Problems to be Solved by the Invention" The present invention has been made in view of the problems of the conventional tool interference checking method, and provides a method for simulating the state of interference between a tool and a change arm and a workpiece from a computer display screen. The task is to do so.

[Means to be Solved by the Invention] The specific means for solving the above problems in the present invention are as follows.

The first aspect of the present invention is to express the turning locus of the change arm including the change tool as a multi-stage cylinder while making the workpiece on the table an approximate body such as a rectangular parallelepiped, and to express the rotation locus of the change arm including the exchange tool as a multi-stage cylinder, and to compare the approximate body and the multi-stage cylinder projected in the horizontal plane direction. and an overlap between the approximation body projected in the vertical direction and the multistage cylinder simultaneously exist, the replacement tool interference simulation method determines that there is tool interference. The second aspect of the present invention is to express the turning locus of the change arm including the changeable tool as a multistage cylinder, while making the workpiece on the table an approximate body such as a rectangular parallelepiped, and to express the orbit of the change arm including the exchange tool as a multistage cylinder, and to compare the workpiece with the approximate body projected in the horizontal direction. This is an interference simulation method for an exchange tool in which the overlap with the multistage cylinder is calculated by calculating a simultaneous interference area by position division, and it is determined that there is tool interference when the division overlap exists simultaneously. Furthermore, the third aspect of the present invention is that the workpiece on the table is an approximate object such as a rectangular parallelepiped, while the turning locus of the change arm including the exchange tool is expressed as a multi-stage cylinder, and the approximate object and the multi-stage cylinder projected in the horizontal direction are expressed. When an overlap between the above-mentioned approximate body projected in the vertical plane direction and the above-mentioned multistage cylinder exists at the same time, three overlaps are further calculated by calculating the simultaneous interference area by position division, and the said division overlap exists at the same time. This is a replacement tool interference simulation method that determines that there is tool interference when The fourth aspect of the present invention is the interference of the replacement tool, which displays on the screen the overlap of the simultaneous interference area by the position division of the workpiece approximation and the multi-stage cylinder created by the turning locus of the tool and the change arm with a band of the interference zone. This is a simulation method.

"Operation" The method of simulating interference of an exchange tool of the present invention determines whether or not the work interferes with the change arm and the tool in ATC operation by comparing an approximation of the work and a multi-stage cylinder of the rotation locus of the change arm including the tool. This can be done by determining the presence or absence of simultaneous overlap in the horizontal and vertical planes. Furthermore, when a workpiece on the table is indexed and positioned at an arbitrary turning angle by the indexing table, simultaneous overlap can be accurately determined as an overlap of simultaneous interference areas by position division. and,
This overlap of the interference areas can be displayed on the screen as a band of interference zones, and the operator can be informed of the interference location between the workpiece and the tool.

"Example" Hereinafter, the interference simulation method for an exchangeable tool of the present invention will be explained using an example shown in the drawings. FIG. 1 is a block diagram showing the hardware configuration of a computer for executing the interference simulation method of the present invention.

The computer includes a central processing unit (CPU) 100,
Display screen (CRT)10. Manually operated keyboard 20. Printer 30 and volatile storage (RAM)
) 50 and a non-volatile memory (ROM) 40 constitute the main part. 70 is a storage medium that stores a library 708 and application software for executing the interference simulation of the present invention, and a central processing arithmetic unit (
The CPU 100 controls the operation of the machine tool M via the NC device 60. In Figures 2 and 3, the work 2 on the tape) Ii I is expressed as an approximate body W such as a rectangular parallelepiped, and the turning locus of the change arm 3 including the exchange tool T is expressed as a multistage cylinder A. ing.

The main shaft 4 and change arm 3 in the figure represent a horizontal machining center, and the multi-stage cylinder A. is the turning trajectory A1. of the change arm 3. A turning trajectory A of the tool holder 5, a turning trajectory A of the tool T including insertion and removal movement from the main spindle.

Contains. The approximate body W is indexed and rotated at an arbitrary angle by the rotation center O of the indexing table 1.

The above approximate body is a tool T at an indexed position parallel to the tool direction like W, and an approximate body W, and an approximate body where the approximate body is indexed and positioned clockwise at an arbitrary angle O, including any interference simulation. An interference simulation between W1 and tool T is also performed.

Next, Section 3.4 describes a method for simulating the interference between the workpiece 2 and the replacement tool T when the approximate body W, which is the workpiece, is placed on the table l and indexed in parallel to the tool direction.
This will be explained with reference to the figure and FIG.

First, the computer 100. ``Start'' the NC device 60 and others (a), and ``set up the workpiece W on the table'' (b). After this, "each surface projection calculation process of the workpiece shape and tool rotation trajectory shape" (handling) is performed.Now, on the display screen (CRT) 10, as shown in FIG.
z Draw the workpiece shape on the horizontal plane and the tool rotation locus shape of the change arm (d). On the other hand, as shown in Fig.
``Drawing the workpiece shape on the rXY vertical plane and the shape of the tool rotation trajectory of the change arm'' (e) are performed in parallel. The above two drawings (d).

From (e) to “Arithmetic processing of simultaneous interference areas in horizontal and vertical planes”
Do (to). If this is seen in Fig. 3, the turning path A of the tool in the multistage cylinder A of the turning path is r
lJ and overlaps with the approximation body W1, and if you look at it in Figure 4, it is a multistage cylinder A. are all r apart from the approximation field W1
o, O, OJ. Therefore, this "interference judgment"
(G) is determined to be NO (no interference) and the
"No tool interference" (nu) is displayed on the screen (not shown)
.

Next, when the workpiece 2 on the table is positioned at an arbitrary index angle θ as shown in FIG. 2, a multistage cylinder A is formed. There is a possibility that an interference area AZ will occur where the tip A of the approximate body W2 interferes with a part of the approximate body W2. This simulation of the interference area AZ is performed in two steps shown in FIGS. 3 and 4 and FIG. 5, and the flowchart thereof is the entire flow shown in FIG. First, as shown in Figure 3.
Perform (d) "Drawing the workpiece shape and tool rotation trajectory on the rxz horizontal plane". On the other hand, as shown in Fig. 4, "drawing the workpiece shape in the rxy vertical plane and the tool rotation locus" (e) is performed in parallel. From the above two drawings (d) and (e), “Horizontal,
Perform the calculation process for the simultaneous interference area in the vertical plane (see below). If you look at this in Figure 3, it is a multistage cylinder A with a turning trajectory. tip A,
is the approximate field W.

It overlaps with RlJ. As seen in FIG. 4, all the multistage cylinders A, (A, ~A,) overlap with the approximation W, rl, 1. It has become IJ. Now, the "judgment of interference" (g) is YES (there is interference), and the "arithmetic processing of simultaneous interference areas in the horizontal and vertical planes j (ch)" shown in Figure 5.
Execute. That is, the horizontal axis shows position division points (search points) p, , p, ~Pn, and the "presence or absence of simultaneous interference areas in the horizontal and vertical planes" at each search point p,, p, ~Pn is calculated. do. The interference area on the horizontal plane is P4
~P, and the interference area in the vertical plane is P.

~P. Therefore, there is no simultaneous interference timing on both sides, and the "judgment of interference" becomes No (no interference), and the message "No work/tool interference" appears on the CRT screen.
(nu) is displayed.

On the other hand, when the height of the workpiece is increased and the workpiece is W, I, interference between "the tip A of the multi-stage cylinder and the workpiece W,'" is seen on the horizontal plane as shown in Fig. 6, and on the vertical plane. Interference between "all of the multi-stage cylinders A and the workpiece Wt'" is observed, and the area of simultaneous interference between the two becomes "the tip A of the multi-stage cylinder and the workpiece W,'". Therefore, the search points for simultaneous interference by position division are limited to the interval P, ~Pゎ, the interference area in the horizontal plane is [P, ~P, J, and in the vertical plane
P, ~Plo" section.

The simultaneous interference area of the above interference area is ``P, ~P, J,'' which is determined as the ``interference determination'' result [YES (interference exists)], and the ``work/tool interference screen display'' (le) is determined. Execute. The above screen display is drawn on the CRT as a band G of the "interference zone" as shown in FIG. Therefore, even if the workpiece is positioned at an arbitrary index angle O with respect to the table, the interference zone can be clearly determined (with high precision), and the interference location can be quickly checked by viewing the image. is possible. It should be noted that the present invention is not limited to the above-mentioned embodiments; it goes without saying that design changes can be made within the scope of the invention.

"Effect" According to the present invention, the workpiece on the table is an approximate body such as a rectangular parallelepiped, and the turning locus of the change arm including the exchange tool is expressed as a multistage cylinder, and the approximate body is projected in the horizontal shearing force direction. When an overlap with the multi-stage cylinder and an overlap between the approximation body projected in the vertical direction and the multi-stage cylinder exist at the same time, it is determined that there is tool interference, and this overlap is further divided into positions to calculate a simultaneous interference area. Since it is determined that there is tool interference when the divisional overlap exists at the same time, it is not only easy to determine simultaneous interference from horizontal and vertical interference diagrams, but also when the workpiece is arbitrarily allocated to the table. Even when the position is fixed at an angle, the interference zone can be determined clearly (with high accuracy).

Furthermore, since the overlap of the simultaneous interference area created by the position division of the approximation of the workpiece and the multi-stage cylinder created by the rotational trajectory of the tool and change arm is displayed on the screen as a band of interference zone, the rotational trajectory of the workpiece, tool and changearm is displayed on the screen. It is possible to quickly check on the CRT screen the points of interference with the multi-stage cylinder created by the cylinder.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a computer system for carrying out the interference simulation method for changeable tools of the present invention, and Fig. 2 shows an approximation of the workpiece shape to a rectangular parallelepiped, etc., and a multi-stage circular trajectories of the tool and change arm. Figure 3 is a CRT screen diagram showing an approximation of the workpiece and the turning locus of the tool and change arm on the XZ plane, Figure 4 is a CRT screen diagram showing the XY plane, and Figure 5 is a perspective view showing the area of interference between the two. The figure is an action diagram for detecting the interference state between the approximation body and the multistage cylinder from the XZ plane and the XY plane using the position division method, Figure 6 is an action screen diagram showing the interference zone between the approximation body and the multistage cylinder, and Figure 7 is FIG. 3 is a flowchart diagram illustrating an interference check procedure of the present invention. 1...Table, 2...Work [W,~W! ′
... workpiece rectangular parallelepiped (approximate body)], 3... change arm, 4... main shaft, 5... tool holder, T
-・-(S') -IIc 1n,,,('',T
? T IAA--CPU, e...Arbitrary indexing angle, A, (A,. At, A,)...-Swivel cylinder, P,, P, ~
Pn ---Search point, G...Interference zone.

Claims (4)

[Claims] (1) While the workpiece on the table is an approximate body such as a rectangular parallelepiped, the turning locus of the change arm including the replacement tool is expressed as a multi-stage cylinder, and the overlap between the approximate body and the multi-stage cylinder projected in the horizontal direction is . A replacement tool interference simulation method, characterized in that when an overlap between the approximate body projected in a vertical plane direction and the multistage cylinder simultaneously exists, it is determined that there is tool interference. (2) While the workpiece on the table is an approximate body such as a rectangular parallelepiped, the turning locus of the change arm including the exchange tool is expressed as a multi-stage cylinder, and the overlap between the approximate body and the multi-stage cylinder projected in the horizontal direction is A replacement tool interference simulation method, characterized in that the calculation is carried out by calculating a simultaneous interference area by position division, and it is determined that there is tool interference when the above-mentioned division overlaps exist simultaneously. (3) While the workpiece on the table is an approximate body such as a rectangular parallelepiped, the turning locus of the change arm including the replacement tool is expressed as a multi-stage cylinder, and the overlap between the approximate body and the multi-stage cylinder projected in the horizontal direction is When the approximate body projected in the vertical direction and the multistage cylinder overlap at the same time, this overlap is further calculated by position division to calculate a simultaneous interference area, and when the divided overlap exists at the same time, tool interference occurs. A method for simulating interference of a replacement tool, characterized in that it is determined that there is a replacement tool. (4) In the interchangeable tool interference simulation method according to claims 2 and 3, a simultaneous interference area is obtained by positional division between an approximation of the workpiece and a multistage cylinder created by the turning loci of the tool and the change arm. An interference simulation method for an exchange tool characterized by displaying the overlap of the interference zone on a screen using a band of an interference zone.