JPH06138921A - Measuring method and automatic correction method for linear interpolation feeding accuracy of numerically controlled machine tool - Google Patents

Abstract

PURPOSE:To automatically measure and correct the linear interpolation feeding accuracy through a machine tool by calculating the deviation data from the detection data obtained by measurement of the linear interpolation feeding accuracy and then calculating the linear interpolation feeding error and deciding the correction value based on the deviation data. CONSTITUTION:A master block 1 is set at a prescribed position on a table 9 of a numerically controlled machine tool 20, and a probe 2 is set at the position of an axial core 15 of a tool spindle 10. The probe tip 13 of the 2 is moved to a start point 16 of a reference linear part 14 of the block 1 and positioned there. Then the tip 13 moves up to an end point 17 from the point 16 based on a program. A processing computer 5 detects the detection data corresponding to the position calculated from the sampling times corresponding to both points 16 and 17 moved relatively and the sampling points between both points 16 and 17. Then the computer 5 calculates the deviation data against the shape data on the part 14 and then calculates a linear interpolation error to decide the correction value and to correct the linear interpolation feeding accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a linear interpolation feed error of a numerically controlled machine tool by a measuring device sensor and automatically corrects the error to improve the linear interpolation feed accuracy of the machine to be machined. The present invention relates to a method for measuring linear interpolation accuracy of a numerically controlled machine tool and an automatic correction method for improving the processing accuracy of an object and the measuring accuracy of a measuring device.

[0002]

2. Description of the Related Art Conventionally, there has been no method for automatically measuring and correcting the linear interpolation feed accuracy of a numerically controlled machine tool. For this reason, the linear interpolation feed accuracy of a numerically controlled machine tool is such that a work piece of a certain size is finished by an outer circumference with an end mill, and a straight line, a test indicator, or a three-dimensional measuring machine is used to linearly feed the machined surface. The straightness, parallelism and squareness, which are errors, were measured.

[0003]

However, the method of performing the outer peripheral finish cutting and measuring the linear interpolation feed error of the machined surface by using the three-dimensional measuring machine requires two steps of machining and measurement, which is a great problem. Man-hours and labor required: There was a problem that the accuracy of the measuring device had an effect. Also the conventional XY
Even if the linear interpolation feed error measurement of the machined surface is moved by an NC program such that the displacement is constant using a recorder, the error measurement is not possible because the displacement direction is one direction. It was possible. An object of the present invention is to provide a method for automatically measuring and compensating the linear interpolation feed accuracy of a numerical control type machine tool on a machine, without performing machining of a work piece, and by using less man-hours and labor. A method for measuring the linear interpolation feed accuracy of a controlled machine tool, and calculation of a linear interpolation feed error of a numerically controlled machine tool and determination of a correction amount from the detection data obtained by the measurement method, and the determined correction amount An object of the present invention is to provide a method of inputting to the NC device to correct each control parameter.

[0004]

Therefore, the present invention has solved the above-mentioned problems of the prior art by providing a method of measuring the linear interpolation accuracy of a numerically controlled machine tool as claimed in the claims and an automatic correction method.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the attached FIGS. FIG. 1 is a schematic block diagram of a numerically controlled machine tool and a measuring apparatus for carrying out a method of measuring linear interpolation accuracy and an automatic correction method of a numerically controlled machine tool according to an embodiment of the present invention, and FIG. 2 is a plan view of a master block of FIG. FIG. 3 shows a flow chart of a method of measuring linear interpolation accuracy and an automatic correction method of a numerically controlled machine tool according to an embodiment of the present invention, and FIG. 4 is an explanatory view of the measuring method shown in FIG.

At a predetermined position on the table 9 of the numerically controlled machine tool 20, linear portions 14, 14 having a shape as shown in FIG.
The master block 1 having A, 14B, and 14C is placed, and each position on the master block is positioned with respect to the axis 15 of the tool spindle 10 of the numerically controlled machine tool 20. Next, in the embodiment, the contact type probe 2 is fixedly attached to the position of the axis 15 of the tool spindle 10 (or may be in the vicinity thereof), whereby the tip 13 of the contact type probe 2 is attached to the master block 1 on the table 9. Reference straight line part 1
The position is fixed for each position including 4. Next, set the probe tip 13 to the starting point 16
To the starting point 16 of the straight line portion 14 and position it.

In the embodiment, the contact type probe 2 is a two-dimensional sensor, but it may be a non-contact type probe, and the table 9 is a ball screw 1 driven by a servo drive device 11.
2 is moved in the XY direction (only the servo drive device 11 and the ball screw 12 for driving in one direction are shown in FIG. 1), and the tip 13 of the contact type probe 2 is a master block on the table 9. Along the reference straight line portion 14 of the master block 1 on the XY plane parallel to the upper surface 18 of 1.
The linear portion 14 is moved from the starting point 16 to the ending point 17 in accordance with a program that is linearly moved between the starting point and the ending point of the linear portion of the master block. Contrary to the embodiment, the table 9 may be fixed and the tip 13 of the contact type probe 2 may be moved together with the tool spindle 10.

Next, the method of measuring the linear interpolation accuracy and the automatic correction method of the numerically controlled machine tool according to one embodiment of the present invention will be described with reference to the flow chart shown in FIG. In the block 21, the linear portion 1 is placed at a predetermined position on the table 9 of the numerically controlled machine tool 20.
Master block 1 with 4, 14A, 14B, 14C
Is mounted, and the tool spindle 1 of the numerically controlled machine tool 20
Each position on the master block 1 is positioned with respect to the 0 axis center 15. At block 22, the contact probe 2 is fixedly attached at or near the tool spindle axis 15 position. In block 23, the probe tip 13 is moved to the starting point 16 of the reference straight line portion 14 of the master block 1 and positioned with respect to the starting point 16 of the straight line portion 14.

Next, in block 24, the start point 16 and the end point 17 of the straight line portion 14 of the master block inputted in advance and the sampling points 41, 42. ． (FIG. 4) is executed to execute a program at a predetermined speed such that the displacement of the probe tip 13 is constant, and the probe tip 13 is moved to the master block 1.
Are relatively moved along the straight line portion 14 of. At the same time, the shape data of the straight line portion of the master block which is input in advance is output to the processing computer 5. Sampling points 41, 42. ．
In the embodiment, each position of (FIG. 4) is calculated from the input feed speed and the sampling period calculated from the number of sampling points between the start point and the end point of the straight line portion.

In block 25, the probe tip 13 is detected as detection data corresponding to a position determined from a sampling time corresponding to a start point and an end point where the probe tip 13 relatively moves along the linear portion 14 of the master block 1 and a sampling point between the two. The displaced displacement is sent to the amplifier 3 in block 26 and converted into an analog signal, and further in block 27 A /
The digital signal is converted by the D converter 4 and output to the processing computer 5. Here, if the probe 2 with a digital signal is used, the A / D converter 4 is not necessary and the signal is directly sent to the processing computer 5.

Then, in block 28, the digital signal of the A / D converter 4 input to the processing computer 5 is
Deviation data from the shape data of the master block output in the block 24 is calculated, and since the difference between the detected displacement and the predetermined displacement is the error at that position, the straightness is calculated, and the linear interpolation error Calculation and determination of correction amount are performed. If the error is outside the specified range in block 29, the process proceeds to block 30, and the straightness, which is the determined correction amount error, is sent to the NC device 6 to correct various control parameters, and drive servo is performed. It is fed back to the motor 11. The NC device corrected based on the error moves to block 24. If the error is within the specified range in block 29, the process proceeds to block 31 to execute the machining program. Then, the steps of blocks 21 to 31 are continuously performed on the other linear portions 14A, 14B, 14C of the master block 1 as well, and the linear portions 14 and 14A form a square
And 14B can measure and correct the parallelism.

The measuring method of FIG. 3 will be described in more detail with reference to FIG. As the NC program of the block 24, since each point on the master block 1 is located at the coordinate position with respect to the axial center 15 of the tool spindle 10 of the numerically controlled machine tool 20, the linear portion 14 has a starting point 16 and an ending point 17. Interpolation settings are input in advance, sampling points 41 between the two,
42. ． In the embodiment, (FIG. 4) is calculated and interpolated from the input feed speed and the sampling period calculated from the number of sampling points between the start point and the end point of the straight line portion. At the same time, the shape data of the straight line portion of the master block is also output to the processing computer 5 in the same manner. In the following description, the tool offset amount between the center of the probe tip 13 and the linear portion 14 of the master block 1 is shown as being corrected in advance.

Therefore, in block 28, P (X 0,
Let Y 0), P (X 1, Y 1) be the start and end points of the master block, and the points P (X 41, Y 41), P on the straight line of the master block calculated from the sampling points in between.
(X 42, Y 42). ． The displacement data corresponding to
From the displacement data, the displacement point P (X0 + DX + EXO, Y0 + DY + EY
O), P (X41 + DX + EX41, Y41 + DY + EY41). ． ． ． P (X
1 + DX + EX1, Y1 + DY + EY1) is calculated. DX, DY here
Is initial displacement, and EX and EY are displacements due to error. In the embodiment, the maximum is based on the line connecting the displacement point P (X0 + DX + EXO, Y0 + DY + EYO) at the start point and the displacement point P (X1 + DX + EX1, Y1 + DY + EY1) at the end point. The difference between the displacement point and the minimum displacement point is defined as the linearity error. Also, the initial displacement is removed and output so that the error can be easily determined.

Another embodiment of the present invention is a method for measuring the linear interpolation accuracy of a numerically controlled machine tool and an automatic correction method.
A linear scale (not shown) for measuring relative movement along the linear portion 14 of the master block 3 of FIG. 3 is provided, the measurement data of the linear scale is output, and the output measurement data of the linear scale and the output of the block 24 are output. Deviation data between the start point and the end point and the program data corresponding to the sampling points between them is calculated, and the deviation data is input to the processing computer to calculate the linear interpolation error of the numerically controlled machine tool and determine the correction amount. You can

[0015]

As described above, according to the present invention, the linear interpolation feed accuracy of the numerically controlled machine tool is measured without machining the workpiece, and with less man-hours and labor, the detection data obtained by the measurement is used. Linear interpolation feed of a numerically controlled machine tool capable of calculating a linear interpolation feed error of a numerically controlled machine tool and determining a correction amount and inputting the determined correction amount to an NC device to correct each control parameter. It will provide an error correction method, which automatically measures and corrects the linear interpolation feed accuracy of a numerically controlled machine tool on the machine, measuring it with less man-hours and labor without actual machining, and automatically making an error. It has become possible to provide a method for efficiently improving the processing accuracy by correcting the.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a numerically controlled machine tool and a measuring apparatus that implements a method of measuring linear interpolation accuracy and an automatic correction method of a numerically controlled machine tool according to an embodiment of the present invention.

FIG. 2 is a plan view of the master block shown in FIG.

FIG. 3 is a flowchart of a method of measuring linear interpolation accuracy and automatically correcting a numerically controlled machine tool according to an embodiment of the present invention.

FIG. 4 is an explanatory view of the measuring method of FIG.

[Explanation of symbols]

 1. ． Master block 2. ． Probe 5. ． Processing computer 6. ． NC device 9. ． Table 10. ． Tool spindle 11. ． Servo drive device 13. ． Probe tip 14. ． Straight part 15. ． Tool spindle axis 16. ． Starting point 17. ． End point 20. ． Numerical control machine tool

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yasuo Takami 20 Ishigane, Toyama City, Toyama Prefecture Fujikoshi Co., Ltd.

Claims (2)

[Claims] 1. A) A master block having a linear portion is placed at a predetermined position on a table of a numerically controlled machine tool, and each position on the master block is positioned with respect to a tool spindle axis of the numerically controlled machine tool. Step; b) Providing a probe at or near the tool spindle axis position; c) Positioning the probe tip with respect to the master block and then arranging it at the starting point of the linear portion of the master block; d) Pre-input Relatively moving the probe tip along a linear portion of the master block from a starting point to an end point according to the programmed program; e) the starting point and the endpoint of relative movement of the probe tip along the linear portion of the master block. And the detection data corresponding to the position calculated from the sampling time corresponding to the sampling point between F) Inputting the shape data of the master block previously input, and the detection data corresponding to the output start point and end point and the sampling points between them into a processing computer,
The process of calculating the deviation data, calculating the linear interpolation error of the numerically controlled machine tool and determining the correction amount from the deviation data; g) inputting the calculated correction amount into the NC device and correcting each control parameter. H) a step of machining using a numerically controlled machine tool corrected based on the error detection data; and i) a numerical value characterized by continuously performing steps a) to h) above. A method of measuring linear interpolation feed accuracy of a controlled machine tool and an automatic correction method. 2. A step of: a) placing a master block having a linear portion at a predetermined position on a table of a numerically controlled machine tool and positioning each position on the master block with respect to the tool spindle axis; b) the tool. Providing a probe at or near the spindle axis position; c) positioning the probe tip with respect to the master block and then arranging it at the starting point of the linear portion of the master block; d) the probe according to a program input in advance. Relative movement of the tip along a linear portion of the master block from a starting point to an end point; e) linear scale measurement data for measuring relative movement of the probe tip along the linear portion of the master block, The tip and the end point where the tip of the probe relatively moves along the straight line portion of the master block and the sample between them. Outputting the measurement data corresponding to the position calculated from the sampling time corresponding to the ring point; f) The shape data of the master block previously input and the output measurement data of the linear scale are input to a processing computer. Inputting the deviation data, calculating the linear interpolation error of the numerically controlled machine tool and determining the correction amount from the deviation data; g) inputting the calculated correction amount into the NC device A step of correcting control parameters; h) a step of machining using a numerically controlled machine tool corrected based on the error detection data; and i) continuously performing steps a) to h) above. And a method for automatically correcting the linear interpolation feed accuracy of a numerically controlled machine tool.