Measuring head calibration method for gear machine tool

Abstract

The invention discloses a measuring head calibration method for a gear machine tool, and relates to the technical field of gear machine tools. In order to solve the problems that a current domestic gear machine tool calibration method is complex, poor in precision stability and the like, the invention provides a measuring head calibration method for a gear machine tool, the measuring head calibration method is used for calibrating a gear machine tool measuring system, and the measuring head is adsorbed on a machine tool workbench / workpiece through a customized high-precision cylindrical magnetic device and is measured through a gear online measuring system. A plurality of points of a cylindrical surface are measured, a least square method is adopted to fit a circle, and the pre-stroke TY of a measuring head and X-axis and Y-axis parameters of a machine tool are calibrated through iterative calculation. The method has the advantages of being easy and convenient to operate, high in calibration speed, high in precision and the like, and therefore the problem that the gear machine tool is poor in precision stability is solved.

Description

Technical Field

[0001] The invention relates to the field of gear machine tool measurement technology, and in particular to a probe calibration method for a gear machine tool. Background Art

[0002] For high-precision gear machine tools, the accuracy of the on-machine measurement system often determines the machining accuracy of the gear machine tools. The accuracy of the measurement system is achieved by calibrating the probe of the measurement system, thereby improving the machining accuracy of the gear machine tools. Gears are key components of transmission. In order to improve the accuracy of gears, it is necessary to improve the machining accuracy of gear machine tools, and further improve the accuracy of the on-machine measurement system of gear machine tools. Ultimately, the accuracy of the probe calibration is required. At present, the probe calibration operation of the on-machine measurement system of domestic gear machine tools is complicated and has poor accuracy, which limits the stability of the machining accuracy of gear machine tools. Summary of the invention

[0003] The object of the present invention is to provide a probe calibration method for a gear machine tool, so as to solve the problems of complex probe calibration operation and poor accuracy that limit the machining accuracy of gear machine tools proposed in the above background technology.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for calibrating a probe for a gear machine tool comprises the following steps:

[0006] Step 1: Attach the customized high-precision standard cylinder to the turntable / workpiece by magnetic attraction to obtain the approximate distance RR0 between the measurement calibration cylinder and the center of the turntable.

[0007] Step 2: Measure data points P1…Pn, n≥3;

[0008] 1) First, manually open the probe to a position close to the top of the cylinder.

[0009] 2) Through the NC program, first measure the top of the cylinder, then rotate the C axis, according to the calibrated cylinder distance RR0 from the turntable center, measure the contact position between the probe and the cylinder surface at N groups of different X positions, and save the X, C measurement data;

[0010] 3) Based on the above measured X, C data, calculate the angle values ​​θ1…θn of the N groups of left and right sides relative to the center of the cylinder;

[0011] Step 3: According to the measurement in step 2, convert the X, C data in the polar coordinate system to the X, Y values ​​in the Cartesian coordinate system, calculate the radius value of the measuring point, and obtain the fitting straight lines of the left and right tooth surfaces through least squares fitting;

[0012] Step 4: According to the calculation in step 3, the slopes of the left and right tooth surface fitting lines are made equal through iterative calculation to obtain the dy value;

[0013] Step 5: Move the Y axis and the C axis of the turntable to determine whether dy meets the requirements, then proceed to the next step, otherwise return to step 2;

[0014] Step 6: Measure data points P1…Pn, n≥3;

[0015] Step 7: Calculate and fit the difference between the radius of the measuring point and the equivalent radius R2 of the calibration cylinder, R2 = RR1 + RR2, where RR1 is the radius of the calibration cylinder, RR2 is the radius of the probe, and the fitting straight line is iteratively calculated through the probe pre-travel TY and dx parameters. The fitting target sets the difference and slope to 0, and obtains the probe pre-travel TY and dx parameters;

[0016] In the step 1, the upper and lower surfaces of the high-precision standard cylinder are parallel to the turntable plane.

[0017] In the step 2, first measure n sets of data on one side, then measure the data at the same X coordinate on the other side, and record the values ​​when the X-axis and the C-axis are in contact;

[0018] In the step 7, the circle is fitted by iterative calculation of the probe pre-stroke TY and dx;

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention establishes a method for calibrating a probe for a gear machine tool by using a high-precision standard cylinder, adopts least squares fitting measurement data, iteratively calculates the probe pre-travel TY, X-axis parameter dx and Y-axis parameter dy, thereby calibrating the measurement system and improving the accuracy of the measurement system.

[0021] The probe calibration method of the present invention is easy to operate and has high calibration efficiency, and further improves the accuracy and stability of the gear machine tool measurement system, thereby improving the stability of the gear machine tool and the machining accuracy of the gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart for calibrating a probe for a gear machine tool according to the present invention;

[0023] Figure 2 This is the overall diagram of the probe calibration cylinder measurement of the present invention;

[0024] Figure 3 A schematic diagram of the probe calibration data point collection of the present invention;

[0025] Figure 4 This is a simplified diagram of the probe calibration coordinate system transformation of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] A probe calibration method for a gear machine tool comprises the following steps:

[0028] Step 1: Attach the customized high-precision standard cylinder to the turntable workpiece through magnetic attraction.

[0029] Step 2: Data point measurement, left data points PL1…PLn, right data points PR1…PRn.

[0030] 1) First, manually move the probe to a position close to the top of the cylinder, measure the tooth top P0, and obtain the X-axis and C-axis data.

[0031] 2) Based on the P0 point, the points are evenly distributed on the cylinder. By rotating the C axis, the left and right tooth surface points and the contact position between the probe and the cylinder are measured respectively, and the X-axis and C-axis measurement data are saved.

[0032] 3) Based on the above measured X, C data, the polar coordinate system is converted into a Cartesian coordinate system, and the X, C axis data is converted into X, Y data, such as Figure 4 shown.

[0033]

[0034] Step 3: Calculate the radius Ri, and fit the left and right tooth surface measurement points by the least squares method to obtain the left straight line, slope KL and intercept BL, and the right straight line, slope KR and intercept BR.

[0035] Ri 2 =xi 2 +yi 2 ;

[0036] Step 4: Through the condition KL=KR, iterative calculation obtains dy;

[0037] Step 4: Move the Y-axis and C-axis, and move the Y-axis dy.

[0038] Step 5: Determine whether dy meets the requirements. If so, proceed to the next step, otherwise return to step 2.

[0039] Step 6: Data point measurement, left data points PL1…PLn, right data points PR1…PRn.

[0040] Step 7: Calculate and fit the difference between the radius of the measurement point and the equivalent radius of the calibration cylinder (RR1+RR2), where RR1 is the radius of the calibration cylinder, RR2 is the probe radius, and the iteration conditions KL=KR=0, BL=BR=0. The fitting straight line is iteratively calculated through the probe pre-travel TY and dx parameters to obtain the probe pre-travel TY and dx parameters.

[0041] In the step 1, the upper and lower surfaces of the high-precision standard cylinder are parallel to the turntable plane.

[0042] In the step 2, firstly measure n groups of data on one side, then measure the data at the same X coordinate on the other side, and record the values ​​when the X-axis and the C-axis are in contact.

[0043] In step seven, the circle parameters are fitted by iterative calculation of the probe pre-stroke TY and dx, and the difference between the radius of each measuring point and the actual value is calculated.

[0044] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only preferred examples of the invention and are not intended to limit the present invention. Without departing from the novel spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A probe calibration method for a gear machine tool, characterized in that: The steps include: Step 1: Attach the customized high-precision standard cylinder to the turntable / workpiece by magnetic attraction to obtain the approximate distance RR0 between the measured calibration cylinder and the center of the turntable; Step 2: Measure data points P1…Pn, n≥3; 1) First, manually open the probe to a position close to the top of the cylinder; 2) Through the NC program, first measure the top of the cylinder, then rotate the C axis, according to the calibrated cylinder distance RR0 from the turntable center, measure the contact position between the probe and the cylinder surface at N groups of different X positions, and save the X, C measurement data; 3) Based on the above measured X, C data, calculate the angle values ​​θ1…θn of the n groups of left and right sides relative to the center of the cylinder; Step 3: According to the measurement in step 2, convert the X, C data in the polar coordinate system to the X, Y values ​​in the Cartesian coordinate system, calculate the radius value of the measuring point, and obtain the fitting straight lines of the left and right tooth surfaces through least squares fitting; Step 4: According to the calculation in step 3, the slopes of the left and right tooth surface fitting lines are made equal through iterative calculation to obtain the dy value; Step 5: Move the Y axis and the C axis of the turntable to determine whether dy meets the requirements, then proceed to the next step, otherwise return to step 2; Step 6: Measure data points P1…Pn, n≥3; Step 7: Calculate and fit the difference between the radius of the measurement point and the equivalent radius R2 of the calibration cylinder, R2 = RR1 + RR2, where RR1 is the radius of the calibration cylinder, RR2 is the probe radius, and iteratively calculate the fitting straight line through the probe pre-travel TY and dx parameters. The fitting target sets the difference and slope to 0, and obtains the probe pre-travel TY and dx parameters.

2. The method for calibrating a probe for a gear machine tool according to claim 1, characterized in that: In the step 2, the probe obtains X and C parameters by measuring the calibration cylinder, and in the step 3, the X and C parameters are converted into X and Y parameters.

3. The method for calibrating a probe for a gear machine tool according to claim 1, characterized in that: In the step 4, the slopes of the left and right tooth surface fitting lines are made equal to obtain the dy value through fitting and iterative calculation.

4. The method for calibrating a probe for a gear machine tool according to claim 1, characterized in that: In the step seven, the radius difference is fitted and calculated by using the probe pre-travel TY and dx parameters, and the slopes and differences of the left and right fitting lines are iteratively calculated to 0.

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