CN103278107B - The device and method of laser scanning grating compensating measure gear pattern - Google Patents

Abstract

A device and method for laser scanning grating compensation measurement of gear profile belong to the technical field of laser detection. The prior art has low measurement accuracy. The measuring device of the present invention refers to a displacement zero measurement system composed of a laser displacement sensor and a reflector; the angular displacement sensor, the z-direction grating ruler, the main adjustment grating ruler and the micro-adjustment grating ruler are respectively connected with a special microprocessor. In the measurement method of the present invention, the calibration measurement refers to placing the mandrel on the workpiece carrying turntable, the rotating pair of the turntable drives the mandrel to rotate, and adjusts the position of the mandrel on the workpiece carrying turntable until the mandrel rotates in a full circle. The displacement _D3 between the cylinder of the central axis and the laser displacement sensor is always indicated as 0, and the axis of the axis of the axis coincides with the auxiliary axis of the turntable rotation. The measurement positions of the main adjustment grating scale, z-direction grating scale, and micro-adjustment grating scale at this time are taken as the zero position ; The coordinates of the points to be measured on the measurement section of the gear to be measured are: z=D ₁ , θ=α; zero displacement measurement system refers to adjusting the main adjustment mechanism and the micro adjustment mechanism, so that the displacement D ₃ between the measuring surface of the gear to be measured and the laser displacement sensor is 0.

Description

Device and method for measuring gear shape with laser scanning grating compensation

technical field

The present invention relates to a device and method for laser scanning grating compensation measurement of gear shape. The gear shape is measured in the field of gear precision manufacturing. According to the angular displacement and linear displacement data obtained during the measurement process, the gear shape is reconstructed, and then combined with the The gear design shape comparison and the geometric error of the gear shape are given, which belongs to the technical field of laser detection.

Background technique

Gear shape is an important error index for evaluating gears. It can characterize the geometric error of the shape of a single tooth surface of a gear, reflect the stability of the transmission motion of the gear pair, and indirectly evaluate the contact accuracy of the gear pair. From this, the source of gear error can be analyzed and the control gear can be controlled. transmission quality.

A kind of gear topography laser measurement technique relevant to the present invention is as follows:

A document entitled "Laser Gear Measuring Instrument" (Dai Runsheng) published on page 13 of the first issue of "Foreign Metrology" in 1982 discloses a laser gear measuring instrument manufactured by Diffracto Corporation of Canada. The measuring instrument has a measuring head that can move in a fixed plane and a turntable on which the gear to be measured is placed, and the measuring head is a laser displacement sensor. The turntable can rotate in a plane parallel to the measurement reference plane. When the gear to be measured rotates with the turntable, the measuring head can measure the coordinates of the measured point of the gear to be measured by detecting the reflected beam, and the angle signal transmitted from the turntable and The signal output by the measuring head is sent to the special microprocessor in the same way, and the signal is used as the original data, and after data processing, the geometric error of the gear shape is obtained. Due to the nonlinear measurement characteristics of the laser displacement sensor itself, when the size difference of different gears to be measured is large, the measurement range is also large, resulting in an increase in the offset error between the actual measurement characteristic curve and the ideal linear characteristic curve. , which reduces the linearity of the laser displacement sensor, thereby reducing the gear shape measurement accuracy. In addition, this gauge can only measure external gears.

Contents of the invention

In order to adapt to the gear size and gear type of the gear to be tested, maintain a high linearity of the laser displacement sensor, and improve the measurement accuracy of the gear shape, we invented a laser scanning grating compensation device and method for measuring the gear shape.

The device for laser scanning grating compensation measurement gear shape of the present invention has a workpiece carrying turntable 9 supported by a turntable rotation pair 10, as shown in Figure 1, an angular displacement sensor 11 is installed at the lower end of the turntable rotation pair 10, and the axis of the turntable rotation pair 10 is The z-axis of the measurement system is characterized in that the displacement measurement light exit of the laser displacement sensor 7 faces the reflector 8, and the displacement measurement optical axis reflected by the reflector 8 is located above the workpiece carrying turntable 9 and is perpendicular to the z-axis; the micro-adjustment mechanism 5- The side is connected to the laser displacement sensor 7, and the other side is connected to the micro-adjustment grating scale 6; the side of the z-direction adjustment mechanism 3 is connected to the micro-adjustment mechanism 5 and the mirror 8, and the other side is connected to the z-direction grating scale 4; the side of the main adjustment mechanism 1 It is connected to the z-direction adjustment mechanism 3, and the other side is connected to the main adjustment grating ruler 2; the displacement zero position measurement system is composed of the laser displacement sensor 7 and the mirror 8; the angular displacement sensor 11, the z-direction grating ruler 4, the main adjustment grating ruler 2 and The fine-tuning grating ruler 6 is respectively connected with a dedicated microprocessor.

The measurement steps included in the laser scanning grating compensation method for measuring gear profile of the present invention include gear position alignment, section scanning and data processing. The measurement system is a cylindrical measurement system O-zρθ, where z is the axis direction of the rotary pair 10 of the turntable, ρ is the direction perpendicular to the axis of the rotary pair 10 of the turntable, and θ is the orientation of the point to be measured on the measurement section of the gear to be measured, which is characterized in that, as shown in Figure 1:

1. Calibrate the measurement system before the gear position is corrected, place the mandrel 12 on the workpiece carrying turntable 9, adjust the main adjustment mechanism 1 and the z-direction adjustment mechanism 3, so that the displacement measurement light emitted by the laser displacement sensor 7 can irradiate the core On the cylindrical surface of shaft 12; the turntable rotary pair 10 drags the mandrel 12 to rotate, observe the displacement D ₃ between the mandrel 12 cylinder displayed by the laser displacement sensor 7 and the laser displacement sensor 7, and adjust the mandrel 12 on the workpiece carrying turntable 9 at the same time until the displacement _D3 of the mandrel 12 is always indicated as 0 during the full-circle rotation, the axis of the mandrel 12 coincides with the axis of the turntable rotation pair 10, and the main adjustment grating scale 2 and the z-direction grating scale 4 at this time , Micro-adjust the measuring position of the grating ruler 6 as the zero position; the coordinates of the measuring point of the measuring section of the gear to be measured are:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula: D ₁ , D ₀ , and D ₂ are the displacements measured by the z-direction grating scale 4, the main adjustment grating scale 2, and the micro-adjustment grating scale 6 respectively, d ₀ is the diameter of the mandrel 12, and α is the displacement measured by the angular displacement sensor 11 angular displacement;

2. After the gear position is corrected and before the section scanning, reset the displacement zero position measurement system to zero, as shown in Figure 2 and Figure 3, adjust the main adjustment mechanism 1 and the micro adjustment mechanism 5, so that the measurement surface of the gear to be measured 13 is consistent with the The displacement _D3 of the laser displacement sensor 7 is 0.

Its technical effect of the present invention is, form a displacement zero position measurement system by laser displacement sensor 7 and reflector 8, although the zero position of zero displacement measurement system causes the zero position change because of the gear size of the gear to be measured like this, but, by adjusting the main adjustment Mechanism 1 and micro-adjustment mechanism 5 reset the displacement zero position measurement system to zero again. In the subsequent scanning process of the measurement section of the gear to be measured, the laser displacement sensor 7 no longer gives the ρ coordinate value of the point to be measured, but the master Adjust the grating ruler 2 and fine-tune the grating ruler 6 to measure the displacement D ₀ and displacement D ₂ measurement data, and then calculate the ρ coordinate value of the point to be measured by formula (1). The laser displacement sensor 7 is only a component of the displacement zero position measurement system, and is no longer used as a measurement component for the ρ coordinate value of the measurement section of the measurement section of the gear to be measured. The main adjustment grating ruler 2 and the micro-adjustment grating ruler 6 replace the laser displacement sensor 7 as the measurement components. From the perspective of the measurement device as a whole, or from the perspective of the whole process of the measurement method, the two grating rulers actually play a compensating role . During the measurement process, the laser displacement sensor 7 only works in a very small range, so the linearity is very high; in addition, since the measurement accuracy of the grating ruler is much greater than that of the laser displacement sensor, the final gear shape measurement accuracy Significantly improved. When the sizes of the gears to be measured are different, the displacement zero position measurement system is also reset to zero first, and then the measurement is completed by the grating ruler. Therefore, the invention enables the measurement range of the gear size to be expanded. The adoption of reflector 8, the one, makes the present invention can measure the topography of different types of gears including external gear, internal gear, as shown in Figure 2, Figure 3; , to avoid damage to expensive laser displacement sensors by accidental collisions.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the measuring device of the present invention and a schematic diagram of the calibration process of the measuring system of the measuring method, which is also used as a summary drawing. Figure 2 is a schematic diagram of the process of measuring external gears using the measuring method of the present invention. Fig. 3 is a schematic diagram of the process of measuring an internal gear using the measuring method of the present invention.

Detailed ways

The device for laser scanning grating compensation measurement gear shape of the present invention has a workpiece carrying turntable 9 supported by a turntable rotation pair 10, as shown in Figure 1, an angular displacement sensor 11 is installed at the lower end of the turntable rotation pair 10, and the axis of the turntable rotation pair 10 is The z-axis of the measurement system. The central part of the upper part of the workpiece carrying turntable 9 is provided with a swing space 14 for accommodating the mirror 8 when measuring the internal gear, as shown in FIG. 3 . The angular displacement sensor 11 is performed by an encoder. The displacement measurement light exit of the laser displacement sensor 7 faces the reflector 8, and the displacement measurement light axis reflected by the reflector 8 is located above the workpiece carrying turntable 9 and perpendicular to the z-axis. One side of the micro-adjustment mechanism 5 is connected to a laser displacement sensor 7 , and the other side is connected to a micro-adjustment grating ruler 6 . One side of the z-direction adjustment mechanism 3 is connected to the micro-adjustment mechanism 5 and the reflector 8, and the other side is connected to the z-direction grating scale 4. One side of the main adjustment mechanism 1 is connected to the z-direction adjustment mechanism 3 , and the other side is connected to the main adjustment grating ruler 2 . The main adjustment mechanism 1, the z-direction adjustment mechanism 3, and the micro adjustment mechanism 5 are all screw nut mechanisms. A displacement zero measurement system is composed of a laser displacement sensor 7 and a mirror 8 . The angular displacement sensor 11, the z-direction grating ruler 4, the main adjustment grating ruler 2 and the micro-adjustment grating ruler 6 are respectively connected with a special-purpose microprocessor. , z-direction grating ruler 4, main adjustment grating ruler 2 and micro-adjustment grating ruler 6 carry out data processing on the original coordinate data of the points to be measured in the measurement section of the gear to be measured to obtain the geometric error of the shape of the gear to be measured.

In the laser scanning grating compensation method for measuring gear topography of the present invention, the measurement system is a cylindrical measurement system O-zρθ, z is the axis direction of the rotary pair 10 of the turntable, ρ is the direction perpendicular to the axis of the rotary pair 10 of the turntable, and θ Measure the orientation of the test point on the section of the gear to be tested. The measurement method specifically includes the following steps:

1. Calibration measurement system

Place the mandrel 12 on the workpiece carrying turntable 9, the mandrel 12 is a reference member with a standard cylindrical surface, adjust the main adjustment mechanism 1 and the z-direction adjustment mechanism 3, so that the displacement measurement light emitted by the laser displacement sensor 7 It can be irradiated onto the cylindrical surface of the mandrel 12; the rotating table rotating pair 10 drags the mandrel 12 to rotate, observe the displacement D ₃ between the cylindrical surface of the mandrel 12 displayed by the laser displacement sensor 7 and the laser displacement sensor 7, and adjust the position of the mandrel 12 on the workpiece Carry the position on the turntable 9 until the displacement _D3 of the mandrel 12 is always indicated as 0 during the full-circle rotation, the axis of the mandrel 12 coincides with the axis of the turntable rotation pair 10, and the main adjustment grating ruler 2, z To the grating ruler 4, finely adjust the measuring position of the grating ruler 6 as the zero position; the coordinates of the measuring point of the measuring section of the gear to be measured are:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula: D ₁ , D ₀ , and D ₂ are the displacements measured by the z-direction grating scale 4, the main adjustment grating scale 2, and the micro-adjustment grating scale 6 respectively, d ₀ is the diameter of the mandrel 12, and α is the displacement measured by the angular displacement sensor 11 angular displacement.

2. Alignment of gear position

When the gear 13 to be tested is an external gear, the gear 13 to be tested is placed on the workpiece carrying turntable 9, and the z-direction adjustment mechanism 3 is adjusted so that the displacement measurement light is irradiated on a section of the gear 13 to be tested, as shown in FIG. 2 . When the gear 13 to be tested is an internal gear, place the gear 13 to be tested on the workpiece carrying turntable 9, adjust the z-direction adjustment mechanism 3, and move the reflector 8 to a position higher than the gear 13 to be tested, and then adjust the main adjustment Mechanism 2, to make the reflector 8 move in translation to above the swivel space 14 in the upper central part of the workpiece carrying turntable 9, and adjust the z-direction adjustment mechanism 3 again, so that the reflector 8 moves down and falls into the gear to be measured 13 and the swivel space 14 At the same time, the displacement measurement light is irradiated onto a section of the gear 13 to be tested, as shown in FIG. 3 . The turntable rotation pair 10 drags the gear to be tested 13 to rotate, if the outer diameter of the outer gear of the gear to be tested 13 or the inner diameter of the inner gear interferes with the reflector 8, adjust the position of the gear to be tested 13 on the workpiece carrying turntable 9 until no Interference, to complete the position alignment of the gear 13 to be tested.

3. Zero displacement measurement system

As shown in FIG. 2 and FIG. 3 , adjust the main adjustment mechanism 1 and the fine adjustment mechanism 5 so that the displacement D ₃ between the measurement surface of the gear to be measured 13 and the laser displacement sensor 7 is 0.

4. Section scanning

The turntable rotation pair 10 drags the gear to be measured 13 to rotate, and adjusts the micro-adjustment mechanism 5 so that the displacement _D3 of the gear to be measured 13 relative to the laser displacement sensor 7 is 0. At this time, the main adjustment grating ruler 2 and the fine adjustment grating ruler 6 display The displacements are respectively displacement D ₀ and displacement D ₂ , and the coordinate sequence (z ₁ (t), ρ ₁ (t), θ ₁ (t)) of a section of the gear to be measured 13 is recorded from the rotation of the gear to be measured 13, t is time. After scanning a measurement section, adjust the z-direction adjustment mechanism 3 again so that the displacement measurement light irradiates the next section of the gear to be measured 13, and record the coordinate sequence of the section (z ₂ (t), ρ ₂ (t), θ ₂ (t)), complete all section scans in turn, record the coordinate sequence of all sections (z _i (t), ρ _i (t), θ _i (t)) (i=1,2,3... n), wherein n is the number of scanning sections of the gear to be tested 13, and i is an ordinal number.

5. Data processing

The coordinate sequence (z _i (t), ρ _i (t), θ _i (t)) (i=1,2,3...n) of all sections is processed by the data acquisition and processing system to obtain the Measure the shape and geometric error of the gear 13.

Claims (6)

1. A device for laser scanning grating compensation and measurement of gear profile, its workpiece carrying turntable (9) is supported by the turntable rotation pair (10), an angular displacement sensor (11) is installed at the lower end of the turntable rotation pair (10), and the turntable rotation pair The axis of (10) is the z-axis of the measurement system, and it is characterized in that the displacement measurement light exit of the laser displacement sensor (7) faces the reflector (8), and the displacement measurement light axis reflected by the reflector (8) is located at the workpiece carrying turntable ( 9) Above and perpendicular to the z-axis; one side of the micro-adjustment mechanism (5) is connected to the laser displacement sensor (7), and the other side is connected to the micro-adjustment grating ruler (6); one side of the z-direction adjustment mechanism (3) is connected to the micro-adjustment mechanism (5) and mirror (8), the other side is connected to the z-direction grating ruler (4); one side of the main adjustment mechanism (1) is connected to the z-direction adjustment mechanism (3), and the other side is connected to the main adjustment grating ruler (2) ; A displacement zero measurement system is composed of a laser displacement sensor (7) and a reflector (8); an angular displacement sensor (11), a z-direction grating ruler (4), a main adjustment grating ruler (2) and a micro-adjustment grating ruler (6 ) are respectively connected with a dedicated microprocessor. 2. The device for laser scanning grating compensation measurement of gear profile according to claim 1, characterized in that the angular displacement sensor (11) is played by an encoder. 3. The device for laser scanning grating compensation measurement gear profile according to claim 1, characterized in that the main adjustment mechanism (1), the z-direction adjustment mechanism (3), and the micro adjustment mechanism (5) are all lead screw nuts mechanism. 4. The device for laser scanning grating compensation measurement of gear profile according to claim 1, characterized in that the dedicated microprocessor is a data acquisition and processing system. 5. A method for measuring the profile of a gear using laser scanning grating compensation for measuring the profile of a gear with laser scanning grating compensation according to claim 1, the measurement steps included include gear position alignment, cross-sectional scanning and data processing, measuring The system is a cylindrical measurement system O-zρθ, z is the axis direction of the rotary pair (10) of the turntable, ρ is the direction perpendicular to the axis of the rotary pair (10) of the turntable, and θ is the orientation of the point to be measured in the measurement section of the gear to be measured. in: A. Calibrate the measuring system before the gear position is corrected, place the mandrel (12) on the workpiece carrying turntable (9), adjust the main adjustment mechanism (1) and z-direction adjustment mechanism (3), so that the laser displacement sensor (7 ) can be irradiated onto the cylindrical surface of the mandrel (12); the rotary pair (10) of the turntable (10) drags the mandrel (12) to rotate, and observes the cylindrical surface of the mandrel (12) displayed by the laser displacement sensor (7) and Displacement D ₃ of the laser displacement sensor (7), and adjust the position of the mandrel (12) on the workpiece carrying turntable (9) at the same time, until the said displacement D ₃ of the mandrel (12) is always indicated as 0 during the full circle rotation , the axis of the mandrel (12) coincides with the axis of the rotary pair (10) of the turntable, and the measurement positions of the main adjustment grating ruler (2), the z-direction grating ruler (4), and the micro-adjustment grating ruler (6) at this time are taken as the zero position; The coordinates of the points to be measured on the measurement section of the gear to be measured are: $\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}\end{array}\right.<span\; class="notranslate">\; ,</span>$ In the formula: D ₁ , D ₀ , and D ₂ are the displacements measured by the z-direction grating ruler (4), the main adjustment grating ruler (2), and the micro-adjustment grating ruler (6), and d ₀ is the diameter of the core shaft (12), α is the angular displacement measured by the angular displacement sensor (11); B. After the gear position is corrected and before the section scanning, reset the displacement zero position measurement system to zero, adjust the main adjustment mechanism (1) and the micro adjustment mechanism (5), so that the measurement surface of the gear to be measured (13) is in line with the laser displacement sensor The displacement D ₃ of (7) is 0. 6. The method for measuring the profile of a gear with laser scanning grating compensation according to claim 5, characterized in that the mandrel (12) is a reference piece and has a standard cylindrical surface.