JPH0780752A - Numerical control method and numerical control system - Google Patents

Abstract

PURPOSE:To provide a numerical control method and a numerical control system which can finely cope with local variation in shape, and even with the peripheral section of a work piece, and thereby can process the work piece accurately. CONSTITUTION:In the numerical control system where design value working shape data is inputted, a design value NC program is formed, and a work piece is then processed by a working machine 1 based on the program, errors in shape are measured by a shape measuring means 100, it is then judged by a NC program executing section 19 whether or not each error is in an allowable range, and when the error is found to have been out of an allowable range, the executing section 19 allows a message for an operator to expedite an input of correction data to be indicated. The correction data is inputted by the operator, correction working data is formed, a correction NC program is formed by a correction NC program forming section 13, the program is then stored in a memory section 17, it is analyzed by an analysis section 18, and the program is executed by the NC execution section, so that correction working is thereby performed by the working machine 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical control method and a numerical control system for a numerical control device (NC device).

[0002]

2. Description of the Related Art In numerical control machining with an NC device, the shape (actual shape) of a workpiece is measured after the machining is completed.
When an error occurs with respect to a desired shape, a process for correcting the error may be performed. The conventional correction method is
Error data is read from the input unit, corrected shape data for correction processing is created from the error data, and stored in the corrected shape data storage unit. Next, a polynomial that approximates the corrected shape is obtained based on the corrected shape data. Then, a desired program was achieved by creating a command program for the numerical control device (NC device) according to this formula and performing correction processing.

FIG. 3 shows the relationship among the actual shape, the error, the design value shape, the correction amount, and the correction shape. A curve 40 shows a design value shape, and a curve 41 shows an actual shape. The difference between the Z-coordinate values of the curves 40 and 41 at the points having the same X-coordinate value is the error 4
It is 3. A correction amount 44 is set on the opposite side in the Z-axis direction from the curve 40 showing the design value shape by an amount equal to the value of this error to determine a curve 42, and this curve 42 is set as the correction shape.

[0004]

In such a conventional correction method, when performing the polynomial approximation of the corrected shape data, it is not always possible to deal with all the shapes. For example, there is a case where a point (a singular point) that cannot be approximated by a polynomial and is largely deviated from the approximate expression because it is largely separated from the surrounding shape locally. In this case, it becomes difficult to perform the desired processing on the local portion.

Further, for example, as shown in FIG. 10, measurement cannot be performed at the edge portion of the workpiece,
Interpolation is performed based on the data of the shape error measured around the edge portion, and an approximate polynomial (or straight line) that is correction data is estimated and generated. However, if the shape error data measured around the edge is incorrect and it is a singular point in the straight line or curve indicated by the data, the edge correction data is also incorrect. Will be. Therefore, it takes time to perform the desired processing.

An object of the present invention is to provide a numerical control method for producing corrected shape data capable of finely dealing with local variations in shape and the edge of a work piece, and enabling accurate processing. And to provide a numerical control system.

[0007]

In order to solve the above problems, according to the present invention, a numerical control system for creating corrected shape data for performing correction processing from error data about an ideal shape of a workpiece. In the above, the output means for outputting the error data to the outside, and the first input means for externally inputting the correction data based on the error data output to the output means for making the workpiece to have an ideal shape A second input means for inputting design value data relating to the ideal shape of the workpiece, and a corrected shape data creation means for creating the corrected shape data based on the design value data and the correction data. Can be prepared.

[0008]

In the present invention, the shape error, which is the difference between the design value shape which is the ideal shape of the workpiece and the actual shape, is measured, and when this shape error is within the predetermined range, Finish processing (approx.
Correction processing may be performed). If the shape error is not within the predetermined range, the operator is prompted to input correction data, and a program for performing correction processing is created based on the input correction data. And
Correction processing is performed based on this program.

[0009]

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

FIG. 2 shows a block diagram of the configuration of an embodiment of a numerical control system to which the numerical control method of the present invention is applied. FIG. 8 shows an example of the hardware system configuration of the NC program creating device 40 used in this embodiment.

In FIG. 2, the present embodiment shows a workpiece 50.
Processing machine 1 for processing to N, and N connected to this
An NC machining program is created by referring to the C controller 30, the shape measuring device 100 provided in the processing machine 1 for measuring the shape of the workpiece 50, and the shape measurement result.
And a program creation device 40.

The shape measuring apparatus 100 is provided so as to be movable relative to the work piece 50, and the measurement terminal 70 for detecting the relative positional relationship of the work piece 50, and this measurement with reference to a predetermined origin. It is composed of a position measuring device 90 for measuring the position of the terminal 70, and an information processing device 10 for processing measurement data to obtain a shape measurement value.

Measuring terminal 70 and position measuring device (length measuring device 91)
90 is mounted on the processing machine 1 as shown in FIG.

The processing machine 1 includes a workpiece 50, a workpiece drive mechanism 87 for holding and holding the workpiece 50 and rotating the same, a stage 81 for mounting the drive mechanism 87, and a support base for movably supporting the stage 81. 82, a stage drive device 83 for moving the stage 81 by a necessary amount, and a stage 8 for supporting the tool base 51 and the measurement terminal 70.
4, a support base 85 for movably supporting the stage 84, and a stage drive device 86 for moving the stage 84 by a necessary amount.

The NC controller 30 operates the stage driving devices 83, 8 of the processing machine 1 according to the processing program.
6 and the work drive mechanism 87. Also,
When performing the shape measurement, the operations of the stage driving devices 83 and 86 are controlled according to the instruction from the NC program creating device 40.

The NC program creation device 40 creates a control program for the NC controller 30 and various parameters necessary for machining, measurement, etc., and outputs them to the shape measurement information from the information processing device 10. Import, create a correction program, parameters, etc.,
Send to the NC controller 30.

As shown in FIG. 8, the NC program creating device 40 includes a central processing unit (CPU) 401 and a CP.
A first memory (ROM) 402 for storing the program of U401 and each fixed data, and a second memory (RAM) 4 for storing data read from the outside, operation results, etc.
03, an interface 404 for exchanging data with the NC controller 30, and an NC program creating device interface 405 for connecting the information processing device 10.
And an input device 406 and a display device 407.

Although not shown, the information processing apparatus 10
A shape measuring means for receiving the measurement command sent from the NC program creating device 40 and taking in an output signal from the measuring terminal 70 to measure the shape of the workpiece, and a shape measured value for storing the measured value at each measuring point. It has a storage means and a shape measurement value output section for outputting the shape measurement value to the NC program creating device 40.

The measurement terminal 70 is composed of, for example, a differential transformer type measurement probe, and outputs a signal indicating a displacement amount of ± from a predetermined reference point, for example, the center position.
In this embodiment, the measuring terminal 70 is of a contact type, but
It may be a non-contact type.

As the position measuring device 90, an optical length measuring instrument 91 is used in this embodiment. That is, a mirror 94 is attached to the stage 81 and a mirror 96 is attached to the stage 84, and light rays are incident on the former via the mirrors 92 and 93 and on the latter via the mirror 95, respectively. The length measuring instrument 91 of this embodiment is provided with a mirror 94.
And 96 displacements are optically measured, and coordinate data based on a predetermined origin is output. In the present embodiment, the equipment provided in the processing machine 1 is shared, but it may be provided independently.

Next, FIG. 1 shows a functional block diagram of the NC program creating device 40 of the present invention.

In FIG. 1, the operation input display output unit 14
Inputs an operation instruction from the operator 20, and outputs an instruction such as a message to the operator 20. The design value machining shape data input unit 15 inputs and stores data regarding an ideal machining shape. This data is output to the operation input display output unit 14 as required by the operator. Further, it is used by the corrected machining shape data creation unit 12 described later. The design value NC program creating unit 16 creates an NC program based on the ideal machining shape input by the design value machining shape data input unit 15. The NC program storage unit 17 includes the design value NC program creation unit 16
Alternatively, the program created by the corrected NC program creating unit 13 is stored. The NC program analysis unit 18 analyzes the program stored in the NC program storage unit 17. The NC program execution unit 19
The program analyzed by the NC program analysis unit 18 is executed, and the workpiece is processed by the processing machine.

The shape measuring apparatus 100 measures the shape of the machined surface of the machined workpiece and transmits the measurement result to the NC program execution unit 19. NC program execution unit 1
Reference numeral 9 calculates an error in the shape of the machined surface based on the transmitted measurement result, compares the value of this error with a predetermined allowable error value, and determines whether the shape error is within the allowable error. To determine. If it is judged to be within the tolerance,
A graph showing this shape error and the fact that the processing is finished are transmitted to the operation input display output unit 14, and a message and a graph indicating this are displayed on the operation input display output unit 14. When it is determined that the difference is not within the allowable error, the graph showing the shape error and the message prompting the operator to input the correction data are transmitted to the operation input display output unit 14 and displayed.

Upon receipt of this message, the operator inputs correction data from the operation input display output unit 14. The correction data input unit 11 inputs the correction data input from the operation input display output unit 14. This data is output to the operation input display output unit 14 as required by the operator. Based on the correction data input by the correction data input unit 11 and the design value processed shape data input by the design value processed shape data input unit 15, the corrected processed shape data creation unit 12 creates the design value processed shape data. Compensation processing data including compensation data is created. The correction NC program creation unit 13 creates a correction NC program from the correction processed data and stores it in the NC program storage unit 17. This corrected NC program is analyzed by the NC program analysis unit 18 and executed by the NC program execution unit 19.

Next, the operation of the NC program creating device 40 according to the present invention will be described with reference to FIGS. 1 and 9.

First, the operator inputs the design value processed shape data from the operation input display output unit 14. This data is input to the design value machining shape data input unit (step 910). Next, the design value NC program creating unit 16 creates a design value NC program using the design value shape data (step 920). NC created
The program is stored in the NC program storage unit 17 and then analyzed by the NC program analysis unit 18,
This is executed by the C program execution unit 19 and the workpiece is processed by the processing machine (step 930).

After processing, the shape measuring device 10
With 0, the shape error, which is the difference between the design value shape (ideal shape) of the workpiece and the actual shape, is measured. This shape error is
Through the NC program execution unit, the operation input table output unit 14
(Step 940). A specific example of this display is shown in FIG.

Next, the NC program execution unit 19
It is determined whether the shape error is within the allowable range (step 950). If it is judged to be within the allowable range,
Finish processing. When it is determined that the value is not within the allowable range, the fact is notified to the operation input display output unit 14, and a message prompting the operator to input the correction data is displayed. The operator sees this message and inputs the correction data to the operation input display output unit 14. This correction data is input by the correction data input unit 11 (step 960). Specific examples of the correction data are shown in FIGS. 5 and 6. FIG. 5 shows an example of directly inputting a numerical value. Referring to FIG. 6, a broken line 51 obtained by reversing the shape error 50 with respect to the horizontal axis is used as a correction amount, a solid line 52 obtained by moving the broken line 51 in parallel with the horizontal axis by a movement amount 54 is used as a correction amount, and a cursor 53 is used. By specifying the position and the correction amount to be changed, the shape is changed to a free shape like the local portion 55. Figure 7
Displays the position of the cursor numerically. The correction position and correction amount change in conjunction with the correction input operation, and the graph display changes at the same time. Also, as shown in FIG.
The correction data may be added or changed while viewing the display of the correction data already input. For this, the correction data may be added or changed while observing the display of the correction data that has been input before, or the correction data may be added or changed while observing the display of the correction data calculated by the calculation formula.

Returning to FIG. 9, the corrected processed shape data creating unit 12 creates corrected processed shape data from the input corrected data and design value processed shape data (lens diameter, etc.) (step 970).

Here, a method of creating the corrected machining shape data from the input correction data will be described. For example, consider the case where the shape of the workpiece is approximated by the following polynomial.

[0031]

[Equation 1]

Three correction data are given, and these coordinate positions are

[0033]

[Equation 2]

If,

[0035]

[Equation 3]

Is satisfied. This simultaneous equation is Gauss
C1, C2, C3 are obtained by solving by the Jordan method or the like, and these are made a part of the corrected machining shape data. Also,
The size of the surface to be machined, the tool diameter, the machining origin, etc. based on the design value machining shape data are also part of the corrected machining shape data. The above-mentioned Gauss-Jordan method is described in detail in "Basic Numerical Analysis" (Mr. Matsuyama, Shokoido), pp. 23-29.

From the corrected machining shape data, the correction NC program creating section 13 creates a correction NC program (step 980). This correction NC program is N
The correction program is stored in the C program storage unit 17, analyzed by the NC program analysis unit 18, and executed by the NC program execution unit to perform the correction processing in the processing machine 1 (step 99).
0).

[0038]

According to the present invention, local variations in shape,
Also, it is possible to provide a numerical control method and a numerical control system having a function of creating corrected shape data capable of finely dealing with the edges of an object to be processed and performing accurate processing.

Further, according to the present invention, when the correction machining shape data necessary for the correction machining is changed, the correction machining shape data can be changed according to the complexity of the machining shape, the machining condition regarding the tool of the machining machine, and the shape error. Therefore, the calculation unit for calculating the corrected machining shape data does not become complicated. Further, it is possible to reduce the machining shape error.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an NC program creating device 40 according to the present invention.

FIG. 2 is a block diagram showing the configuration of a numerical control system to which an embodiment of the present invention is applied.

FIG. 3 is an explanatory diagram showing a relationship among an actual shape, an error, a design value shape, a correction amount, and a correction shape.

FIG. 4 is an explanatory diagram showing a specific example of display of a shape error.

FIG. 5 is an explanatory diagram showing a specific example of inputting correction data.

FIG. 6 is an explanatory diagram showing a specific example of inputting correction data.

FIG. 7 is an explanatory diagram of display of a cursor position.

FIG. 8 is a block diagram showing an example of a hardware system configuration of an NC program creating device 40 used in this embodiment.

FIG. 9 is a flowchart showing an operation procedure of the NC program creating device 40 of the present invention.

FIG. 10 is an explanatory diagram regarding measurement of an edge portion of a workpiece.

FIG. 11 is an explanatory diagram showing a specific example of inputting correction data.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing machine, 11 ... Correction data input part, 12 ... Correction processing shape data creation part, 13 ... Correction NC program creation part,
14 ... Operation input display output unit, 15 ... Design value machining shape data input unit, 16 ... Design value NC program creation unit, 17 ...
NC program storage unit, 18 ... NC program analysis unit,
19 ... NC program execution unit, 40 ... NC program creating device, 100 ... Shape measuring device.

Claims (3)

[Claims] 1. A numerical control system for creating corrected shape data for performing correction processing from error data about an ideal shape of a workpiece, wherein the error data is obtained, and the error data is within a predetermined range. It is determined whether the error data is within the allowable error range. If the error data is determined not to be within the allowable error range by the determination, the error data is presented to the operator, Correction data for creating the ideal shape of the workpiece based on the error data, and creating the corrected shape data based on the design value data and the correction data representing the ideal shape of the workpiece. A numerical control method characterized by: 2. A numerical control system for creating corrected shape data for performing correction processing from error data about an ideal shape of a work piece, the output means outputting the error data to the outside, and the output means. First input means for externally inputting correction data based on the output error data for making the workpiece an ideal shape, and second inputting design value data relating to the ideal shape of the workpiece. And a corrected shape data creating means for creating the corrected shape data based on the design value data and the correction data. 3. The determination device according to claim 2, further comprising: a determination unit that determines whether or not the error data is within an allowable error range that is a predetermined range. A numerical control system, wherein correction data is input from the outside by the first input means when it is determined that the correction data is not within the error range.