KR0168070B1 - Moving route compensating method based on diameter of machine tool - Google Patents

Abstract

According to the present invention, when machining a workpiece by a computer numerical controller, the first machining block is an arc, and the second block is a straight line whose intersection angle ( ) Has 0 The movement path compensation method according to the tool diameter that can generate the compensation of the tool movement path in the case of 90˚, the CNC machine tool that processes the workpiece to the desired shape while moving the corrected tool movement path according to the tool diameter The code is read to determine whether to correct the left or right side of the tool movement direction when the first path is ignored by the first microprocessor while the start point of the arc, the intersection point of the arc and the straight line, and the end point of the straight line are set. Is a first step, and a second step of determining whether the moving path correction is in progress after the first microprocessor reads a program of one block from the NC program, and if the moving path correction is in progress, the tool radius is determined. A third step for obtaining the arc vertical vector V1 and the straight line vertical vector d2 of magnitude, and the tool according to the tool diameter calculated by the first microprocessor; A fourth step for obtaining a radial horizontal vector d1 and a straight line vertical vector V2 having a radius size, a fifth step for obtaining vectors V1 'and V1' perpendicular to the intersection point of the arc and a straight line, and a first step for obtaining the first intersection vector C1; A sixth step, a seventh step for obtaining the intersection vector C2 between the second circular arc and a straight line, an eighth step for obtaining an intersection vector C3 between the third straight line and the circular arc, and a tool corrected by connecting the points obtained in the respective steps And a ninth step of driving the servomotor according to the movement path.

Description

Moving path correction method according to tool diameter

1 is a conceptual diagram for the movement path correction according to the tool diameter of the CNC.

2 is a conceptual diagram of correction in the left moving direction of the tool in the case of a rectangular workpiece.

3 is a conceptual diagram of correction in the direction of right movement of a tool in the case of a rectangular workpiece.

4 is a principle diagram showing a programmed path when the tool diameter is zero when machining a workpiece.

5 is a principle diagram showing a programmed path and an actual tool path when the tool diameter is d.

6 is a block diagram of an apparatus for implementing the present invention.

7 is a tool movement path correction method for the case where the intersection angle of the arc and the straight line of the present invention is 90 degrees or less.

8 is a flowchart showing the operation procedure of the present invention.

* Explanation of symbols for main parts of the drawings

10,30: microprocessor 20: RAM

40: D / A converter 50: Servo controller

60: servo motor

The present invention relates to a method for generating a tool movement path according to a tool diameter when machining a workpiece by a Computer Numerical Control (CNC), in particular, the first machining block is an arc, The first block is a straight line ) Has 0 It relates to a movement path compensation method according to the tool diameter that can generate the compensation of the tool movement path in the case of 90 °.

In general, the tool is controlled by the CNC to move to the commanded position, which is the center of the tool.

Accordingly, since the surface of the workpiece to be machined is a position away from the center of the tool by the radius of the tool, in order to process the workpiece to a desired shape when machining the workpiece, the movement path to which the tool should move must be changed according to the tool diameter (d) used therein. do.

In other words, the tool movement path must be corrected by the tool radius in order to obtain a workpiece having a desired shape.

As a specific example, as shown in FIG. 1, the radius of the tool from the movement path 2 originally programmed by the user to be machined using the tool 1 having the predetermined diameter d. The tool 4 can only be machined to the desired shape by moving the tool 1 along another travel path 3 apart.

In general, when machining a workpiece by a machine tool, the G-code (preparation function) used to correct the movement path according to the tool diameter is shown in FIG. 2, G40 for canceling the movement path correction according to the tool diameter. As shown in FIG. 3, G41 for commanding the movement path correction when the tool 1 moves to the left with respect to the work piece 4, the tool 1 moves to the right with respect to the work piece 4 as shown in FIG. There are G42 codes to command the movement path correction when moving and machining.

In calculating a new tool movement path by using such a function code, if the block shape to be moved (block surface) is a straight line and a straight line, a straight line and an arc, an arc and a straight line, an arc and a circular arc, two block forms. The new calibrated tool movement path must be calculated by finding the intersection point and connecting the two intersection points.

At this time, in order to obtain the tool movement path corrected by the tool radius, the intersection of these lines is obtained by moving a straight line or an arc by the tool radius from the tool movement path programmed with the original tool movement path for each block.

Nevertheless, in the related art, a precise tool movement path correction method according to such a workpiece type has not been proposed, and thus has a disadvantage in that it is unsuitable for machining a workpiece requiring high precision.

In other words, although it is a slight difference, the shape of the highly precise workpiece has not been formed, which has been a factor of degrading the overall product quality.

Accordingly, the present invention has been made in view of such a point, in which the first block is an arc, the second block is a straight line and its intersection angle is 0. The purpose of the present invention is to provide a movement path correction method according to a tool diameter that can generate a correct tool movement path by obtaining vertical and horizontal vectors of a tool radius in the case of 90˚.

In order to achieve the above object, the present invention provides a CNC machine tool for machining a workpiece in a desired shape while moving a tool movement path corrected according to a tool diameter, and sets a starting point of an arc, an intersection point of an arc and a straight line, and an end point of a straight line. In a state, in the state where the first path is ignored by the first microprocessor, the first step of reading the corresponding code to determine whether to correct the left or right of the tool movement direction, and the program of one block in the NC program A second step for determining whether the movement path correction is in progress after the processor reads, and a third step for obtaining an arc vertical vector V1 and a straight horizontal vector d2 having a tool radius size when the movement path correction is in progress. A fourth horizontal angle vector d1 and a straight line vertical vector V2 of a tool radius size according to the tool diameter calculated by the first microprocessor; A fifth step for obtaining the vectors V1 'and V2' perpendicular to each other at the intersection point between the arc and the straight line, the sixth step for obtaining the first intersection vector C1, and the intersection vector C2 for obtaining the second arc and the straight line; A seventh step, an eighth step for obtaining the intersection vector C3 between the third straight line and the arc, and a ninth step for connecting the points obtained in the respective steps to drive the servomotor according to the corrected tool movement path. It is done.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

4 is a principle diagram showing a programmed path when the tool diameter is zero when machining the workpiece, FIG. 5 is a principle diagram showing a programmed path and an actual tool path when the tool diameter is d, and FIG. Fig. 7 is a block diagram illustrating a tool movement path correction method when the intersection angle of the arc and the arc of the present invention is 90 degrees or less, and Fig. 8 is a flowchart showing the operation procedure of the present invention.

Assume that there is a G-code program for machining the following workpieces.

Here, the coordinates (X, Y) starting at the movement path compensation according to the tool diameter on the XY plane are (200,200), G90 is the absolute coordinate system, G17 is the XY plane, G41 is the left compensation in the tool direction, D10 is the tool diameter 10, G01 represents linear interpolation between two points.

In FIG. 4 showing the path of moving the tool on the X-Y plane by such a machining program, the case where D10 is not present, that is, the tool diameter is zero.

At this time, the angle of the intersection of the second block (G90, G17, G41, X100, Y100) and the third block (G01, X300, Y300) ) Is 0 Assume that it is 90 degrees.

Under this initial condition, the tool movement path correction operation for the tool diameter d is shown in FIG. 5, where the originally programmed tool movement path is S → E → T, and the corrected movement path is S → S1-> S2-> S3, and this operation proceeds according to the operating apparatus of FIG. In FIG. 6, reference numeral 10 denotes a first microprocessor that calculates a movement path correction according to a tool diameter, that is, a calculation on the correction path to move a path corrected according to the tool diameter, and reference numeral 20 denotes the first microprocessor. The RAM designates the correction path data calculated by the microprocessor 10, and 30 denotes a result of the calculation of the movement path correction according to the tool diameter by the first microprocessor 10, that is, the final target to which the tool should move. A second microprocessor that receives the position from the RAM 20 and performs overall control for position control of the servomotor 60. Reference numeral 40 denotes a D / A converter for converting the speed control digital data of the servo motor 60 output from the second microprocessor 30 into an analog signal, and reference numeral 50 denotes the D / A converter 40. A servo control unit for controlling the speed and current of the servo motor 60 by using the speed control input data of the servo motor 60 converted into an analog signal, and 80 denotes a servo motor detected by the encoder 70. By increasing or decreasing the pulse data with respect to the position of (60) and inputting it to the second microprocessor (30), the current position of the servomotor (60) is determined by the servomotor position discrimination program stored in the second microprocessor (30). It is an up / down counter.

Next, the overall operation of the present invention will be described with reference to FIGS.

When the present invention starts, in step S1, the first microprocessor 10 is set in the state where the starting point of the circular arc is set to (Xs, Ys), the intersection point of the circular arc and the straight line (Xc, Yc), and the end point of the straight line is set to (Xe, Ye). Reads a G-code program.

That is, any one of the codes G40, G41, G42 which means whether the left or right of the tool moving direction or the compensation can be ignored is read. In the present invention, the G42 code is read for convenience in the right direction. The tool movement path is corrected.

In step S2, the program of one block is read from the NC program. In step S3, the first microprocessor 10 determines whether the movement path correction according to the tool diameter is in progress, and the determination result of the movement path correction is determined. If it is in progress (yes), the circular arc vertical vector V1 and the straight horizontal vector d2 of the tool radius size are obtained using the following equations (3) (4) and (3 ') (4') in step S4.

In other words,

Where d is the tool radius, V1x and V1y are the X and Y components of the V1 vector and (Xcc, Ycc) is the center of the arc.

Where d is the tool radius and d2x, d2y are the X and Y components of the d2 vector.

Subsequently, in step S5, an arc horizontal vector d1 having a tool radius size from the movement path correction start point Xs, Ys and the end point Xe, Ye according to the tool diameter calculated by the first microprocessor 10 in step S4. And rotate the vertical vector V1 of the tool radius size by 90 ° counterclockwise, and rotate the horizontal vector d2 90 ° counterclockwise, respectively, to the following equation (5) (6) (5 ') (6 Obtained by ').

Next, in step S6, the vectors V1 'and V2' perpendicular to the intersection points Xc and Yc where the arc and the straight line are in contact with each other are obtained using the following equations (7) (8) (7 ') (8').

Next, the first intersection vector C1 (Xc1, Yc1) is obtained in step S7, and this first intersection vector C1 becomes the V1 'vector.

Next, in step S8, the intersection vector C2 (Xc2, Yc2) between the circular arc and the straight line, which is the form of the second block surface, is obtained by the following equation (11) (12).

Next, in step S9, the intersection vector C3 (Xc3, Yc3) of the third straight line and the arc, that is, the last intersection vector, is obtained by the following equation (13) (14).

As described above, when the intersection vectors between the arc and the straight line are obtained and the points are connected to each other, a new tool movement path corrected by the tool radius is generated.

That is, when digital data for speed control of the servo motor 60 is input to the D / A converter 40 from the second microprocessor 30, the digital data is converted into analog voltage by the D / A converter 40 and the servo is turned on. It is applied to the control unit 50 to control the moving speed of the servo motor 60.

On the other hand, when the determination result in step S3 is not in progress of the tool movement path correction in which the tool diameter is different, the process proceeds to step S11 so that the workpiece is processed while the tool moves along the tool movement path originally programmed by the user.

Thus, according to the movement path correction method according to the tool diameter of the present invention, the first block is an arc, the second block is a straight line, the intersection angle is 0 In case of 90˚, the vertical and horizontal vector of the radius of the tool is obtained for the tool movement direction, and the correct tool movement path is compensated and generated, and then the tool moves along the movement path to process the workpiece. Will have an excellent effect.

Claims (4)

In a CNC machine tool that processes a workpiece in a desired shape while moving a tool movement path corrected according to a tool diameter, the first microprocessor moves by setting the start point of the arc, the intersection of the arc and the straight line, and the end point of the straight line. In case of path compensation, the first step to read the code to judge the right or left side of the tool movement direction, and if the first micro processor reads one block program from NC program, and if the movement path is in progress A second step for determining whether or not to be determined; a third step for obtaining an arc vertical vector V1 and a straight line vertical vector d2 having a tool radius size when the movement path correction is in progress; and a tool calculated by the first microprocessor. In the fourth step to find the horizontal horizontal vector d1 and the vertical vertical vector V2 of the tool radius according to the diameter, and at the intersection of the circular arc and the straight line A fifth step for obtaining the vertical vectors V1 'and V2', a sixth step for obtaining the first intersection vector C1, a seventh step for obtaining the intersection vector C2 between the second arc and a straight line, and the third straight line and the arc The eighth step of obtaining the intersection vector C3 and the ninth step of driving the servo motor according to the tool movement path corrected by connecting the points obtained in each step with each other, the movement path correction method according to the tool diameter . The method of claim 1, wherein the arc horizontal vector d1 in the fourth step is obtained in a state where the vertical vector V1 is rotated 90 degrees counterclockwise. The method of claim 1, wherein the straight line vertical vector V2 in the fourth step is obtained by rotating the horizontal vector d2 in a counterclockwise direction by 90 degrees. 2. The movement path correction method according to the tool diameter according to claim 1, characterized in that the workpiece is processed while moving the movement path originally programmed by the user when the movement path correction is not in progress. .