Spiral bevel gear tooth profile and pitch measurement method, device, equipment and storage medium

Abstract

The present application discloses a method, device, equipment, and storage medium for measuring the tooth profile and pitch of a spiral bevel gear. The method comprises: obtaining tooth profile data and pitch data of a spiral bevel gear to be measured, wherein the tooth profile data and pitch data are measured by a probe of a spiral bevel gear machine tool based on a pre-established measurement coordinate system; obtaining a tooth profile error of the spiral bevel gear to be measured based on the tooth profile data; and obtaining a pitch error of the spiral bevel gear to be measured based on the pitch data; wherein the measurement coordinate system is obtained by the following steps: obtaining multiple accurate sphere center position information corresponding to multiple sphere center points; obtaining axis position information of the axis of a workpiece spindle based on the multiple accurate sphere center position information; and establishing a measurement coordinate system of the spiral bevel gear machine tool based on the axis position information. The present application can improve the measurement accuracy of the tooth profile and pitch of spiral bevel gears.

Description

Technical Field

[0001] The present application relates to the field of mechanical processing technology, and in particular to a method, device, equipment and storage medium for measuring the tooth profile and pitch of a spiral bevel gear. Background Art

[0002] For high-precision spiral bevel gears, it is difficult to achieve the required accuracy through a single gear grinding process. It is often necessary to measure the tooth profile and pitch of the spiral bevel gear to obtain the tooth profile and pitch error of the gear. Then, based on the last measurement results, the processing parameters are adjusted and corrected one or more times before a product that meets the accuracy requirements can be processed. This process is called closed-loop processing of spiral bevel gears.

[0003] In the closed-loop processing of spiral bevel gears, offline measurement technology is mainly used. Gears generally need to go through processes such as grinding, disassembly, inspection, clamping, secondary grinding, disassembly, and re-inspection. The inspection and re-inspection measurement processes are operated by special measuring equipment. At the same time, the measurement process is based on a measurement coordinate system established based on the geometric characteristics of the gear blank. The grinding and secondary grinding processes are operated by electronically controlled machine tools. At the same time, the processing process is based on a machine tool coordinate system determined by the machine tool spindle. The lack of rigid connection between the two leads to inconsistency between the measurement coordinate system and the processing coordinate system, which affects the tooth profile and pitch measurement accuracy in the spiral bevel gear grinding process. Summary of the Invention

[0004] The present application aims to propose a method, device, equipment and storage medium for measuring the tooth profile and pitch of spiral bevel gears, which can improve the measurement accuracy of the tooth profile and pitch of spiral bevel gears.

[0005] According to the first aspect of the present application, a method for measuring the tooth profile and pitch of a spiral bevel gear includes:

[0006] Acquiring tooth profile data and tooth pitch data of a spiral bevel gear to be measured, wherein the spiral bevel gear to be measured is clamped on an end face of a workpiece spindle of a spiral bevel gear machine tool, and the tooth profile data and tooth pitch data are measured by a probe of the spiral bevel gear machine tool based on a pre-established measurement coordinate system;

[0007] Obtaining a tooth profile error of the spiral bevel gear to be measured according to the tooth profile data to be measured;

[0008] Obtaining a pitch error of the spiral bevel gear to be measured according to the pitch data to be measured;

[0009] The measurement coordinate system is obtained by the following steps:

[0010] Acquire multiple accurate sphere center position information corresponding to multiple sphere center points, where the multiple sphere center points are the centers of a standard sphere at different spatial positions, and the number of the sphere center points is greater than or equal to three. The standard sphere is set on the end face of a workpiece spindle of the spiral bevel gear machine tool, and the workpiece spindle is used to rotate to place the standard sphere at different spatial positions.

[0011] Obtaining axis position information of the axis of the workpiece spindle based on the multiple accurate sphere center position information;

[0012] Based on the axis position information, a measurement coordinate system of the spiral bevel gear machine tool is established, wherein the measurement coordinate system takes the plane parallel to the end face of the workpiece spindle as the XY plane and the axis of the workpiece spindle as the Z axis.

[0013] According to some embodiments of the present application, the obtaining of multiple accurate sphere center position information corresponding to multiple sphere center points, wherein the accurate sphere center position information corresponding to each sphere center point is obtained by the following steps:

[0014] Controlling the probe to randomly contact the surface of the standard sphere to obtain position information of a plurality of random touch points on the surface of the standard sphere, wherein the number of the random touch points is greater than or equal to three;

[0015] Based on the least square method, the rough center position information of the standard ball is obtained according to the position information of the plurality of random touch points;

[0016] A plurality of preset touch points are set on the surface of the standard sphere, and a preset movement path of the stylus contacting the plurality of preset touch points is planned, wherein the plurality of preset touch points include a plurality of first preset touch points and a second preset touch point, the number of the first preset touch points is greater than or equal to three, the plurality of first preset touch points are located in the same plane and the plane passes through the center of the standard sphere, and a line connecting the second preset touch point and the center of the standard sphere is perpendicular to the plane on which the plurality of first preset touch points are located;

[0017] According to the rough sphere center position information and the preset movement path, a movement constraint equation that the probe needs to satisfy when moving along the preset movement path is obtained;

[0018] Controlling the probe to move along the preset moving path and to contact the plurality of preset touch points to obtain position information of the plurality of preset touch points;

[0019] Based on the least square method, the accurate center position information of the standard ball is obtained according to the position information of the plurality of preset touch points and the movement constraint equation.

[0020] According to some embodiments of the present application, obtaining the axis position information of the axis of the workpiece spindle based on the multiple accurate sphere center position information includes:

[0021] Fitting the plurality of sphere center points according to the plurality of accurate sphere center position information to obtain a first fitting circle, and determining the first center position information of the first fitting circle;

[0022] Obtaining a deviation matrix based on the multiple accurate sphere center position information and the first center position information of the first fitting circle, wherein the deviation matrix represents positional deviations of the multiple accurate sphere center position information relative to the first center position information of the first fitting circle;

[0023] Calculating the covariance matrix of the deviation matrix and obtaining the eigenvector corresponding to the minimum eigenvalue of the covariance matrix;

[0024] Determining direction information of the axis of the workpiece spindle according to the feature vector;

[0025] Determine the plane where the fitting circle is located according to the eigenvector, and select two orthogonal basis vectors in the plane;

[0026] Projecting the plurality of sphere center points onto the plane where the fitting circle is located according to the two orthogonal basis vectors to obtain a plurality of two-dimensional coordinate information corresponding to the plurality of sphere center points;

[0027] Based on the least squares method, fitting the plurality of sphere center points according to the plurality of two-dimensional coordinate information corresponding to the plurality of sphere center points to obtain a second fitting circle, and determining the second center position information of the second fitting circle;

[0028] The axis position information of the axis of the workpiece spindle is obtained according to the second center position information of the second fitting circle and the direction information of the axis of the workpiece spindle.

[0029] According to some embodiments of the present application, establishing a measurement coordinate system of the spiral bevel gear machine tool based on the axis position information includes:

[0030] Determining the Z axis of the measurement coordinate system according to the axis position information;

[0031] Controlling the probe to randomly contact the end surface of the workpiece spindle to obtain position information of a plurality of random plane touch points located on the end surface of the workpiece spindle, wherein the number of the random plane touch points is greater than or equal to three;

[0032] Obtaining end plane position information of the end face of the workpiece spindle according to position information of the plurality of random plane touch points;

[0033] Determine the XY plane of the measurement coordinate system according to the end plane position information, the tooth blank height and the installation distance of the spiral bevel gear to be measured, and determine the origin O of the measurement coordinate system according to the determined Z axis and the XY plane;

[0034] Controlling the measuring head to contact the middle area of ​​the tooth surface of the spiral bevel gear to obtain position information of a rough measuring point of the tooth surface midpoint located in the middle area of ​​the tooth surface;

[0035] Determine, according to the position information of the tooth surface midpoint rough measurement point, a rough X-axis of the measurement coordinate system passing through the tooth surface midpoint rough measurement point and the origin O;

[0036] Obtaining a rough measurement coordinate system according to the determined Z axis, the origin O and the rough X axis;

[0037] Based on the tooth surface equation of the spiral bevel gear, obtaining the first theoretical tooth surface midpoint coordinates and unit normal vector corresponding to the midpoint of a tooth surface of the spiral bevel gear to be tested;

[0038] Based on the rough measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system. By comparing the rough tooth surface midpoint coordinates with the first theoretical tooth surface midpoint coordinates, the rough measurement coordinate system is continuously corrected to obtain the measurement coordinate system.

[0039] According to some embodiments of the present application, based on the rough measurement coordinate system, controlling the probe to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system, and continuously correcting the rough measurement coordinate system by comparing the rough tooth surface midpoint coordinates with the first theoretical tooth surface midpoint coordinates to obtain the measurement coordinate system, including:

[0040] Based on the rough measurement coordinate system, controlling the probe to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough midpoint coordinates of the tooth surface in the rough measurement coordinate system;

[0041] Determine a first radius according to the coordinates of the midpoint of the rough tooth surface, wherein the first radius is the distance between the midpoint of the rough tooth surface corresponding to the coordinates of the midpoint of the rough tooth surface and the main axis of the workpiece;

[0042] Obtaining an absolute value of a difference between the first radius and a theoretical radius, wherein the theoretical radius is the distance between the midpoint of the first theoretical tooth surface and the workpiece spindle, and the theoretical radius is determined according to the coordinates of the midpoint of the first theoretical tooth surface;

[0043] When the absolute value is greater than the preset accuracy value, the current rough measurement coordinate system is rotated around the workpiece spindle by an adjustment angle to obtain an updated rough measurement coordinate system, and the coordinate system is switched to the rough measurement coordinate system, and the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system;

[0044] When the absolute value is smaller than the preset accuracy value, the current rough measurement coordinate system is determined as the measurement coordinate system.

[0045] According to some embodiments of the present application, the tooth profile data to be measured includes measured tooth surface coordinates of multiple tooth surface points of the spiral bevel gear to be measured, and obtaining the tooth profile data to be measured of the spiral bevel gear to be measured includes:

[0046] Based on the measurement coordinate system, controlling the probe to contact the tooth surface of the spiral bevel gear to be measured, and measuring the measured tooth surface coordinates of the multiple tooth surface points;

[0047] Obtaining the tooth profile error of the spiral bevel gear to be measured based on the tooth profile data to be measured includes:

[0048] Based on the measurement coordinate system and according to the tooth surface equation of the spiral bevel gear, obtaining the theoretical tooth surface coordinates of the plurality of tooth surface points of the spiral bevel gear to be measured;

[0049] The tooth profile error is obtained according to the theoretical tooth surface coordinates and the measured tooth surface coordinates of the plurality of tooth surface points.

[0050] According to some embodiments of the present application, the tooth pitch data to be measured includes multiple single tooth pitches and cumulative tooth pitches of the spiral bevel gear to be measured, and the tooth pitch error includes a single tooth pitch error and a cumulative tooth pitch error;

[0051] The plurality of single tooth pitches include the single tooth pitches between all two adjacent tooth surfaces, and the step of obtaining the tooth pitch data of the spiral bevel gear to be tested includes:

[0052] Based on the measurement coordinate system and according to the tooth surface equation of the spiral bevel gear, a second theoretical tooth surface midpoint coordinate corresponding to a tooth surface midpoint of the spiral bevel gear to be measured is obtained;

[0053] Executing a tooth pitch measurement strategy according to the second theoretical tooth surface midpoint coordinate to obtain the plurality of single tooth pitches;

[0054] The tooth pitch measurement strategy includes:

[0055] The measuring head is positioned between two adjacent tooth surfaces of the Nth group of the spiral bevel gear to be measured;

[0056] Controlling the probe to be located at the coordinate of the second theoretical tooth surface midpoint;

[0057] Controlling the spiral bevel gear to be measured to rotate in a first direction so that the left tooth surface of the Nth group of two adjacent tooth surfaces contacts the measuring probe, so as to obtain the left rotation angle value between the Nth group of two adjacent tooth surfaces;

[0058] Controlling the spiral bevel gear to be measured to rotate in a second direction so that the right tooth surface of the Nth group of adjacent tooth surfaces contacts the measuring head, so as to obtain the right rotation angle value between the Nth group of adjacent tooth surfaces;

[0059] Obtain a single tooth pitch corresponding to two adjacent tooth surfaces of the Nth group according to the left rotation angle value and the right rotation angle value, and assign N+1 to N;

[0060] If the single pitch errors between all adjacent tooth surfaces are not obtained, the process jumps to the step of positioning the measuring probe between the Nth group of adjacent tooth surfaces of the spiral bevel gear to be measured;

[0061] Obtaining the pitch error of the spiral bevel gear to be measured based on the pitch data to be measured includes:

[0062] Obtaining a plurality of single tooth pitch errors corresponding to the plurality of single tooth pitches according to the theoretical tooth pitch of the spiral bevel gear to be tested and the plurality of single tooth pitches;

[0063] The cumulative tooth pitch error is obtained by summing a plurality of the single tooth pitch errors.

[0064] According to the spiral bevel gear tooth profile and pitch measuring device of the second embodiment of the present application, the device includes:

[0065] an acquisition module, configured to acquire tooth profile data and tooth pitch data of a spiral bevel gear to be measured, wherein the spiral bevel gear to be measured is clamped on an end face of a workpiece spindle of a spiral bevel gear machine tool, and the tooth profile data and tooth pitch data are measured by a probe of the spiral bevel gear machine tool based on a pre-established measurement coordinate system;

[0066] A first obtaining module is used to obtain the tooth profile error of the spiral bevel gear to be measured according to the tooth profile data to be measured;

[0067] A second obtaining module is used to obtain the pitch error of the spiral bevel gear to be measured according to the pitch data to be measured;

[0068] The measurement coordinate system is obtained by the following steps:

[0069] Acquire multiple accurate sphere center position information corresponding to multiple sphere center points, where the multiple sphere center points are the centers of a standard sphere at different spatial positions, and the number of the sphere center points is greater than or equal to three. The standard sphere is set on the end face of a workpiece spindle of the spiral bevel gear machine tool, and the workpiece spindle is used to rotate to place the standard sphere at different spatial positions.

[0070] Obtaining axis position information of the axis of the workpiece spindle based on the multiple accurate sphere center position information;

[0071] Based on the axis position information, a measurement coordinate system of the spiral bevel gear machine tool is established, wherein the measurement coordinate system takes the plane parallel to the end face of the workpiece spindle as the XY plane and the axis of the workpiece spindle as the Z axis.

[0072] An electronic device according to an embodiment of the third aspect of the present application includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the spiral bevel gear tooth profile and pitch measurement method as described in any one of the embodiments of the first aspect are implemented.

[0073] According to the computer-readable storage medium of the fourth embodiment of the present application, computer-executable instructions are stored, and the computer-executable instructions are used to execute the spiral bevel gear tooth profile and pitch measurement method as described in the first embodiment above.

[0074] In the embodiment of the present application, based on a pre-constructed measurement coordinate system, the tooth profile and pitch data of the spiral bevel gear to be measured are obtained by measuring the probe of the spiral bevel gear machine tool, and then the tooth profile and pitch error are obtained. The present application adopts a trigger probe on-machine measurement technology, which integrates measurement and processing. After the spiral bevel gear to be measured is measured and the error is obtained, if it needs to be processed, it does not need to be disassembled, which can effectively avoid the multiple installation errors caused by repeated clamping of the spiral bevel gear to be measured in the clamping link; at the same time, a unified coordinate system is established, that is, a measurement coordinate system with the end face of the workpiece spindle parallel to the spiral bevel gear machine tool as the XY plane and the axis of the workpiece spindle as the Z axis, which is used as the measurement reference and processing reference at the same time, so that the measurement and processing processes use a consistent coordinate system, which can effectively eliminate the tooth blank reference error caused by the low tooth blank reference accuracy, blank deformation or uneven heat treatment of the spiral bevel gear to be measured. In summary, the present application constructs a measurement-processing homologous reference system, which can obtain a tooth profile and pitch measurement result that separates the installation error and the tooth blank reference error, improves the measurement accuracy, and also helps to improve the subsequent processing accuracy.

[0075] Other features and advantages of the present application will be set forth in the following description, and in part will be apparent from the description, or may be learned by practicing the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0077] Figure 1 1 is a flow chart of an embodiment of a method for measuring the tooth profile and pitch of a spiral bevel gear of the present application;

[0078] Figure 2 Schematic diagram of the offline measurement process;

[0079] Figure 3 Schematic diagram of the on-machine measurement process;

[0080] Figure 4 Schematic diagram of the structure of the spiral bevel gear on-machine measurement system of the present application;

[0081] Figure 5 is a schematic diagram of a probe in a spiral bevel gear in-machine measurement system of the present application;

[0082] Figure 6 It is a schematic diagram of the coordinate system structure of the machine tool of this application;

[0083] Figure 7 is a schematic diagram of the machine tool kinematic chain for measuring gears of the present application;

[0084] Figure 8 This is a schematic diagram of the machine tool kinematic chain for measuring the standard ball of the present application;

[0085] Figure 9 is a schematic diagram of random touch points on the surface of the standard ball of this application;

[0086] Figure 10 is a schematic diagram of the preset touch points and preset movement paths of this application;

[0087] Figure 11 It is a schematic diagram of multiple accurate ball center position information of this application;

[0088] Figure 12 is a schematic diagram of the measurement coordinate system of this application;

[0089] Figure 13 This is a flow chart of the process of iteratively establishing a precise measurement coordinate system from a rough measurement coordinate system in this application;

[0090] Figure 14 is a schematic diagram of the tooth surface of the spiral bevel gear to be tested in the present application;

[0091] Figure 15 Schematic diagram of the tooth profile error measurement path of the present application;

[0092] Figure 161 is a schematic structural diagram of an embodiment of a spiral bevel gear tooth profile and pitch measuring device of the present application;

[0093] Figure 17 It is a hardware structure diagram of an embodiment of the electronic device of the present application. DETAILED DESCRIPTION

[0094] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0095] In the description of this application, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0096] In the description of this application, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0097] In the description of this application, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technical personnel in the relevant technical field can reasonably determine the specific meaning of the above terms in this application based on the specific content of the technical solution.

[0098] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the embodiments described below are only part of the embodiments of the present application, not all of the embodiments.

[0099] Figure 1 This is a flow chart of the method for measuring the tooth profile and pitch of spiral bevel gears according to the embodiment of the present application. Figure 1 , further elaborating on the embodiments of this application.

[0100] The present invention provides a method for measuring the tooth profile and pitch of a spiral bevel gear. The method comprises the following steps:

[0101] Step 101: Acquire tooth profile data and tooth pitch data of a spiral bevel gear to be measured, wherein the spiral bevel gear to be measured is clamped on the end face of a workpiece spindle of a spiral bevel gear machine tool, and the tooth profile data and tooth pitch data are measured by a probe of the spiral bevel gear machine tool based on a pre-established measurement coordinate system;

[0102] Step 102: Obtain the tooth profile error of the spiral bevel gear to be measured based on the tooth profile data to be measured;

[0103] Step 103: Obtaining the pitch error of the spiral bevel gear to be measured based on the pitch data to be measured;

[0104] The measurement coordinate system is obtained through the following steps:

[0105] Acquire multiple accurate sphere center position information corresponding to multiple sphere center points, where the multiple sphere center points are the sphere centers of the standard sphere at different spatial positions, and the number of sphere center points is greater than or equal to three. The standard sphere is set on the end face of the workpiece spindle of the spiral bevel gear machine tool, and the workpiece spindle is used to rotate the standard sphere to different spatial positions.

[0106] Obtaining axis position information of the workpiece spindle axis based on multiple accurate sphere center position information;

[0107] Based on the axis position information, a measurement coordinate system of the spiral bevel gear machine tool is established, wherein the measurement coordinate system takes the plane parallel to the end face of the workpiece spindle as the XY plane and the axis of the workpiece spindle as the Z axis.

[0108] In the embodiment of the present application, based on a pre-constructed measurement coordinate system, the tooth profile and pitch data of the spiral bevel gear to be measured are obtained by measuring the probe of the spiral bevel gear machine tool, and then the tooth profile and pitch error are obtained. The present application adopts a trigger probe on-machine measurement technology, which integrates measurement and processing. After the spiral bevel gear to be measured is measured and the error is obtained, if it needs to be processed, it does not need to be disassembled, which can effectively avoid the multiple installation errors caused by repeated clamping of the spiral bevel gear to be measured in the clamping link; at the same time, a unified coordinate system is established, that is, a measurement coordinate system with the end face of the workpiece spindle parallel to the spiral bevel gear machine tool as the XY plane and the axis of the workpiece spindle as the Z axis, which is used as the measurement reference and processing reference at the same time, so that the measurement and processing processes use a consistent coordinate system, which can effectively eliminate the tooth blank reference error caused by the low tooth blank reference accuracy, blank deformation or uneven heat treatment of the spiral bevel gear to be measured. In summary, the present application constructs a measurement-processing homologous reference system, which can obtain a tooth profile and pitch measurement result that separates the installation error and the tooth blank reference error, improves the measurement accuracy, and also helps to improve the subsequent processing accuracy.

[0109] In addition, the use of trigger probe on-machine measurement technology can achieve online compensation of processing errors, shorten the processing cycle by more than 60%, eliminate the need for expensive special measuring equipment such as three-coordinate measuring machines and gear measuring centers, and save processing costs. Figure 2 and Figure 3 As shown, Figure 2 Schematic diagram of the offline measurement process. Figure 3 Schematic diagram of the on-machine measurement process.

[0110] It should be noted that the present application is applied to the on-machine measurement system of the spiral bevel gear of the six-axis five-linkage spiral bevel gear machine tool. In order to facilitate the explanation of the spiral bevel gear tooth profile and pitch measurement method of the present application, the on-machine measurement system of the spiral bevel gear is briefly described here.

[0111] like Figure 4 As shown in the figure, the X-axis of the spiral bevel gear machine is the horizontal axis of the machine, the Y-axis is the vertical axis of the machine, the Z-axis is the machine bed axis, the A-axis is the workpiece spindle, the B-axis is the rotary table spindle, and the C-axis is the tool spindle. The A-axis and C-axis can achieve arbitrary rotation. The X-axis and Z-axis are located perpendicular to the same horizontal plane of the bed. The Y-axis is located on the column, perpendicular to the plane formed by the X and Z axes. The workpiece box is located on the rotary table and can rotate about the B-axis.

[0112] like Figure 4 As shown in the figure, the probe is an on-machine measurement probe and is a trigger-type probe installed next to the C-axis. During the measurement process, the relative position of the probe and the center of the C-axis remains unchanged. Figure 5 As shown, the probe center point O P With C-axis center point O C The position relationship in the XY plane of the machine tool coordinate system is as follows Figure 2 As shown, the offsets of the two center points in the X and Y directions are set to ΔPb_X 、 ΔPb_Y The probe is extended during measurement to avoid interference between the worm wheel and the gear.

[0113] like Figure 4 As shown in the figure, the spiral bevel gear to be measured is mounted on the A-axis. It should be noted that when a calibration ball is required, it can be attached to the edge of the A-axis end face (i.e., the edge of the gear turntable) via a magnetic base. The calibration ball rotates with the A-axis as it rotates. When measuring the gear on the machine, the A-axis serves as the rotation axis, similar to the turntable in a gear measurement center. The B-axis rotates to the pitch angle of the spiral bevel gear and remains stationary to prevent interference between the probe and the tooth surface during measurement.

[0114] The machine tool kinematic chain model established based on the above spiral bevel gear on-machine measurement system is as follows: Figure 6 and Figure 7 As shown, Figure 6 This is a schematic diagram of the coordinate system structure of the machine tool. Figure 7 This is a schematic diagram of the machine tool kinematic chain for measuring gears. The kinematic chains from the machine bed to the workpiece (the spiral bevel gear to be measured) and from the machine bed to the probe are two separate chains. The chain from the machine bed to the spiral bevel gear to be measured is the chain from the machine coordinate system (MCS) to the workpiece coordinate system (WCS). It should be noted that this workpiece coordinate system is also the measurement coordinate system in this application. The chain from the machine bed to the probe is the chain from the machine coordinate system to the tool / probe coordinate system (TCS). Figure 6 In, r m1 is the position vector from the A-axis coordinate system to the workpiece coordinate system, r m2 is the position vector from the Y-axis coordinate system to the probe coordinate system, r p is the position vector from the probe coordinate system to the workpiece coordinate system, S Y is the Y-axis coordinate system, S A is the A-axis coordinate system. P is the probe coordinate system, S W is the measurement coordinate system, S F is the machine tool coordinate system. Figure 7 In, o F is the origin of the machine tool coordinate system, S P is the probe coordinate system, S W is the measurement coordinate system, R2 is the distance between the center point of the B axis and the workpiece mounting end face in the same XZ plane, θ2 is the B axis phase, ω2 is the A axis phase, and Workpiece_H represents the workpiece height. DX Indicates the position of the center point of the machine tool B axis on the X axis in the machine tool coordinate system. DY Indicates the distance from the end face of the A-axis to the XZ plane of the machine coordinate system. DZ Indicates the distance from the probe installation surface to the XY plane of the machine coordinate system. Pb_long indicates the distance from the probe center point to the probe installation surface. ΔPb_X 、 ΔPb_Y They are the offset of the probe and the tool center point in the X and Y directions respectively.

[0115] The above-mentioned measurement coordinate system needs to be pre-constructed first, and then the tooth profile and pitch measurements of the spiral bevel gear to be measured are based on this measurement coordinate system, and if the gear needs to be processed later, this unified coordinate system will still be used. This is because during offline measurement, the processing coordinate system is based on the machine tool rotary axis, and the measurement coordinate system depends on the geometric characteristics of the gear blank. There is a lack of rigid connection between the two, and the tooth blank reference error, including reference accuracy, blank deformation, uneven heat treatment, etc., will also cause the measurement coordinate system and the processing coordinate system to be inconsistent, thereby affecting the tooth profile and pitch measurement accuracy in the spiral bevel gear grinding process. The present application uses the workpiece spindle A-axis of the spiral bevel gear machine tool as a reference to establish a measurement coordinate system, thereby separating the tooth blank reference error.

[0116] The above-mentioned spiral bevel gear machine tool is a CNC machine tool.

[0117] In some embodiments, the machine tool kinematic chain of the measuring standard ball is as follows Figure 8 As shown, where S B is the standard spherical coordinate system, which takes the center of the standard sphere as the coordinate origin. d wx , d wy , d wz They respectively represent the distances between the center of the standard ball and the center point of the A-axis end face of the machine tool in the X-axis, Y-axis, and Z-axis directions of the machine tool coordinate system.

[0118] From the machine tool coordinate system S F To the probe coordinate system S P The homogeneous coordinate transformation matrix can be expressed as:

[0119] (1);

[0120] in, is the coordinate transformation matrix from the probe head to the stylus tip, is the coordinate transformation matrix from the C axis to the measuring head, is the coordinate transformation matrix from the Y axis to the C axis, is the coordinate transformation matrix from X axis to Y axis, is the coordinate transformation matrix from the machine tool body to the X-axis, X is the X-axis coordinate of the machine tool, Y is the Y-axis coordinate of the machine tool, DZ Indicates the distance from the probe installation surface to the XY plane of the machine coordinate system. Pb_long indicates the distance from the probe center point to the probe installation surface. ΔPb_X 、 ΔPb_Y They are the offsets of the probe and tool center point in the X and Y axis directions respectively.

[0121] From the machine tool coordinate system S F To the standard spherical coordinate system SB The transformation matrix can be expressed as:

[0122] (2);

[0123] in, is the coordinate transformation matrix from the A axis to the standard spherical coordinate system, is the coordinate transformation matrix from the Y-axis to the A-axis coordinate system, is the coordinate transformation matrix from the Z axis to the Y axis coordinate system, is the coordinate transformation matrix from the X-axis to the Z-axis coordinate system, is the coordinate transformation matrix from the Y-axis to the X-axis coordinate system, DX Indicates the position of the center point of the machine tool B axis on the X axis in the machine tool coordinate system. DY Indicates the position of the center point of the machine tool A axis on the Y axis in the machine tool coordinate system. Z represents the Z-axis coordinate of the machine tool, B represents the B-axis coordinate of the machine tool, and R2 represents the distance between the center point of the B-axis and the mounting end face of the workpiece in the same XZ plane.

[0124] In some embodiments, multiple accurate sphere center position information corresponding to multiple sphere center points is obtained, wherein the accurate sphere center position information corresponding to each sphere center point is obtained by the following steps:

[0125] Controlling the probe to randomly contact the surface of the standard sphere to obtain position information of a plurality of random touch points on the surface of the standard sphere, wherein the number of the random touch points is greater than or equal to three;

[0126] Based on the least squares method, the rough center position information of the standard ball is obtained according to the position information of multiple random touch points;

[0127] A plurality of preset touch points are set on the surface of a standard sphere, and a preset movement path for the probe to contact the plurality of preset touch points is planned, wherein the plurality of preset touch points include a plurality of first preset touch points and one second preset touch point, the number of the first preset touch points is greater than or equal to three, the plurality of first preset touch points are located in the same plane and the plane passes through the center of the standard sphere, and a line connecting the second preset touch point and the center of the standard sphere is perpendicular to the plane in which the plurality of first preset touch points are located;

[0128] According to the rough sphere center position information and the preset movement path, a movement constraint equation that the probe needs to satisfy when moving along the preset movement path is obtained;

[0129] Controlling the probe to move along a preset moving path and contact a plurality of preset touch points to obtain position information of the plurality of preset touch points;

[0130] Based on the least squares method, the accurate center position information of the standard ball is obtained according to the position information of multiple preset touch points and the movement constraint equation.

[0131] In this embodiment, by recalculating accurate sphere center position information based on the rough sphere center position information of the standard sphere, a more accurate sphere center position can be obtained.

[0132] The above-mentioned control probe randomly contacts the surface of the standard ball to obtain the position information of multiple random touch points on the surface of the standard ball. The probe can be controlled to move so that the probe contacts the random surface of the standard ball. In some cases, the probe can also be moved by a handwheel so that the probe contacts the random surface of the standard ball, and then the position of each axis of the machine tool is recorded after each contact. , ( i =1,2,…, n , n >3), i.e. n The coordinates of a random touch point in the machine tool coordinate system, such as Figure 9 shown.

[0133] The rough coordinates of the midpoint of the A-axis end face of the machine tool are given in the machine tool factory inspection report, or you can move the probe to the midpoint of the A-axis end face of the machine tool and write down the machine tool reading, that is, the coordinate point in the machine tool coordinate system is (X AM ,Y AM ,Z AM ). Through coordinate transformation, calculate each random touch point P i In the standard spherical coordinate system S B (x B ,y B ,z B ) under the corresponding coordinates, which are the position information of the above-mentioned multiple random touch points. The coordinate transformation process is restricted by the following expression:

[0134] (3);

[0135] in, According to formula (2), According to formula (1) The inverse transformation yields, d wx , d wy , d wz are unknown numbers, representing the distances of the center point of the standard ball relative to the center point of the end face of the A-axis of the machine tool in the X-axis, Y-axis, and Z-axis directions of the machine tool coordinate system, respectively. Figure 8 shown.

[0136] The process of obtaining the rough center position information of the standard ball based on the least squares method and the position information of multiple random touch points can be as follows.

[0137] Known P i In the standard spherical coordinate system S B (x B ,y B ,z B ) under the corresponding coordinates, since P i It is a point on the standard spherical isometric surface, so it satisfies the spherical equation and contains unknown position parameters d wx , d wy , d wz , that is, the position of the center of the standard ball relative to the center point of the end face of the machine tool A axis. Therefore, the least square method can be used to establish an optimization model to preliminarily calculate the position of the center of the standard ball, that is, the rough center position information of the standard ball ( ), the optimization model is constrained by the following expression:

[0138] (4);

[0139] Among them, R b is the radius of the standard sphere, r m is the probe radius, P ix 、P iy 、P iz According to formula (3), P i The corresponding coordinate values ​​in the standard spherical coordinate system.

[0140] The above-mentioned setting includes a plurality of preset touch points on the surface of the standard sphere, and a preset moving path for the probe to contact the plurality of preset touch points is planned.

[0141] Specifically, as shown in Figure 10, five preset touch points to be measured are planned and set on the standard sphere. Specifically, the four intersection points a, b, c, and d of the standard sphere and the X-axis and Y-axis of the standard sphere coordinate system are set as the first preset touch points. These four first preset touch points are all in the XY plane of the standard sphere coordinate system. The intersection point e of the standard sphere and the positive half axis of the Z axis is set as the second preset touch point. The preset moving path is as follows: Figure 10 As shown in the figure, the five preset touch points a, b, c, d, and e are measured in sequence.

[0142] Based on the rough sphere center position information and the preset movement path, a movement constraint equation that the probe needs to satisfy when moving along the preset movement path is obtained;

[0143] The probe is controlled to move along a preset moving path and contact a plurality of preset touch points to obtain position information of the plurality of preset touch points.

[0144] Specifically, since the multiple preset touch points are preset, the theoretical position coordinates corresponding to the multiple preset touch points in the machine tool coordinate system can be obtained. It should be noted that when the multiple preset touch points are located on the X-axis, Y-axis, and Z-axis of the standard spherical coordinate system, it is easier to determine the theoretical position coordinates.

[0145] Assume that in the standard spherical coordinate system, the corresponding coordinates of the preparation positions of multiple preset touch points are P bi , (i=1,2,3,4,5), the normal vector corresponding to each point is n bi When measuring the standard ball, the position of each axis of the machine tool can be calculated by the following motion constraint equation:

[0146] (5);

[0147] in, d off_set is the offset distance, which is used to avoid the rough center position calculated previously ( ) is inaccurate, resulting in interference during the measurement process and not measuring the ideal test point. Therefore, the preparation position of the preset touch point still needs to be offset inward by a certain distance along its normal vector. d off_set , o m =[0,0,0,1] T Indicates that the probe center point is at S p (x p ,y p ,z p ) coordinates in the coordinate system.

[0148] Substitute the coordinates of the point to be measured P into equation (5) bi and its unit normal vector n bi and the probe radius r m and the determined offset distance d off_set , combined with formula (3), the positions of the various axes of the machine tool when the probe is in the preparation position of multiple preset touch points can be calculated, that is, the corresponding coordinates of the preparation positions of multiple preset touch points in the machine tool coordinate system can be obtained, and then the positions of the various axes of the machine tool can be controlled to control the probe to move to the corresponding preparation position.

[0149] According to the principle of on-machine measurement: in the machine tool coordinate system, the coordinates of a certain point on the probe are the same as those of the measured point, that is, the center point of the probe is located at the measured point offset by the probe radius from its normal vector.

[0150] After calculating the coordinates corresponding to the theoretical position and the preparation position of the center point of the probe for measuring multiple preset touch points in the machine tool coordinate system, for each preset touch point, the probe is controlled to move from the preparation position corresponding coordinates along the normal direction of the point to be measured to the coordinates corresponding to the theoretical position, and the measurement operation is performed on the preset touch point to be measured. That is, when the probe touches the standard sphere during the approach process, the actual measurement coordinates of the preset touch point are recorded, that is, the position information of the above-mentioned multiple preset touch points.

[0151] The above method is based on the least square method, and the accurate center position information of the standard ball is obtained according to the position information of multiple preset touch points and the movement constraint equation.

[0152] Specifically, after the actual measurement coordinates of the plurality of preset touch points, i.e., the position information of the plurality of preset touch points are measured, the measurement data are substituted into the above-mentioned motion constraint equation, i.e., equation (5), to obtain the unknown position parameters of the plurality of preset touch points in the standard spherical coordinate system. d wx , d wy , d wz The corresponding coordinates of the coordinates are obtained by the least square method to establish an optimization model. The optimization model is constrained by formula (4) and the unknown position parameters are calculated. d wx , d wy , d wz The value of is used to represent the position of the center of the standard ball, so the position of the center of the standard ball can be expressed as (d wx ,d wy ,d wz ) , that is, the accurate center position information of the above-mentioned standard ball.

[0153] In some embodiments, obtaining the axis position information of the workpiece spindle axis based on the multiple accurate sphere center position information includes:

[0154] Fitting multiple sphere center points according to multiple accurate sphere center position information to obtain a first fitting circle, and determining first circle center position information of the first fitting circle;

[0155] Obtaining a deviation matrix based on the multiple accurate sphere center position information and the first center position information of the first fitting circle, wherein the deviation matrix represents positional deviations of the multiple accurate sphere center position information relative to the first center position information of the first fitting circle;

[0156] Calculate the covariance matrix of the deviation matrix and obtain the eigenvector corresponding to the minimum eigenvalue of the covariance matrix;

[0157] Determine the direction information of the axis of the workpiece spindle according to the characteristic vector;

[0158] According to the eigenvector, determine the plane where the fitting circle is located, and select two orthogonal basis vectors in the plane;

[0159] According to two orthogonal basis vectors, multiple sphere center points are projected onto the plane where the fitting circle is located to obtain multiple two-dimensional coordinate information corresponding to the multiple sphere center points;

[0160] Based on the least squares method, the multiple sphere center points are fitted according to the multiple two-dimensional coordinate information corresponding to the multiple sphere center points to obtain a second fitting circle, and the second center position information of the second fitting circle is determined;

[0161] The axis position information of the axis of the workpiece spindle is obtained according to the second center position information of the second fitting circle and the direction information of the axis of the workpiece spindle.

[0162] In this embodiment, the axis position information of the axis of the workpiece spindle A-axis can be accurately determined.

[0163] In the above method, multiple sphere center points are fitted based on multiple accurate sphere center position information to obtain a first fitting circle, and the first center position information of the first fitting circle is determined.

[0164] Specifically, the precise coordinates of the center of the standard sphere are obtained in the previous step. (d wx ,d wy ,d wz ) Then, rotate α° around the A axis and repeat the measurement steps to obtain the second accurate spherical center coordinates. (d wx2 ,d wy2 ,d wz2 ) , and so on to get (d wxi ,d wyi ,d wzi ) , ( i =1,2,…, n , n >3), that is, the above-mentioned multiple accurate sphere center position information is obtained, such as Figure 11 shown.

[0165] Assume that the accurate center coordinates of multiple standard spheres measured in the previous step when the A axis is at n different angles are:

[0166] (6);

[0167] Then the coordinates of the first center O1 of the first fitting circle formed by these points are

[0168] (7);

[0169] The deviation matrix is ​​obtained based on the multiple accurate sphere center position information and the first center position information of the first fitting circle.

[0170] Specifically, the deviation matrix B of the coordinates of each accurate sphere center coordinate point relative to the first circle center O1 is calculated as:

[0171] (8);

[0172] The covariance matrix of the deviation matrix is ​​calculated above, and the eigenvector corresponding to the minimum eigenvalue of the covariance matrix is ​​obtained; and the direction information of the axis of the workpiece spindle is determined according to the eigenvector.

[0173] Specifically, the covariance matrix M is:

[0174] (9);

[0175] When the A-axis rotates, the standard sphere center trajectory is approximately a circle in the plane, and the variance of the data point along the plane normal direction (i.e. the axis direction of the A-axis) is the smallest, so the eigenvalue of the covariance matrix M is solved. λ 1 ,λ 2 ,λ 3 and the corresponding unit eigenvector ν 1 ,ν 2 , ν 3. Eigenvector corresponding to the minimum eigenvalue ν=(a,b,c) The axis direction.

[0176] According to the eigenvector, the plane where the fitting circle is located is determined, and two orthogonal basis vectors in the plane are selected; according to the two orthogonal basis vectors, multiple sphere center points are projected onto the plane where the fitting circle is located to obtain multiple two-dimensional coordinate information corresponding to the multiple sphere center points.

[0177] Specifically, the equation of the plane where the standard sphere center trajectory is located is:

[0178] (10);

[0179] Choose two orthogonal basis vectors in the plane , Each point Projected onto the plane, we get the two-dimensional coordinates ( , ):

[0180] ;

[0181] The above is based on the least squares method, and according to the multiple two-dimensional coordinate information corresponding to the multiple sphere center points, the multiple sphere center points are fitted to obtain the second fitting circle, and the second center position information of the second fitting circle is determined; according to the second center position information of the second fitting circle and the direction information of the axis of the workpiece spindle, the axis position information of the axis of the workpiece spindle is obtained.

[0182] Specifically, the least squares method is used to fit the two-dimensional circle and the center O2(u c ,v c ), radius r.

[0183] (11);

[0184] Finally, the actual position of the A axis is obtained, that is, the straight line passing through the center O2 and with direction v, which is expressed as:

[0185] (12);

[0186] That is, the axis position information of the workpiece spindle axis is obtained.

[0187] In some embodiments, establishing a measurement coordinate system of a spiral bevel gear machine tool based on axis position information includes:

[0188] Determine the Z axis of the measurement coordinate system based on the axis position information;

[0189] Controlling the probe to randomly contact the end face of the workpiece spindle to obtain position information of a plurality of random plane touch points located on the end face of the workpiece spindle, wherein the number of the random plane touch points is greater than or equal to three;

[0190] According to the position information of multiple random plane touch points, the end plane position information of the end face of the workpiece spindle is obtained;

[0191] Determine the XY plane of the measurement coordinate system based on the end plane position information, the tooth blank height and the installation distance of the spiral bevel gear to be measured, and determine the origin O of the measurement coordinate system based on the determined Z axis and XY plane;

[0192] Controlling the probe to contact the middle area of ​​the tooth surface of the spiral bevel gear to obtain position information of a rough measuring point of the tooth surface midpoint located in the middle area of ​​the tooth surface;

[0193] According to the position information of the rough measuring point at the midpoint of the tooth surface, the rough X axis of the measuring coordinate system passing through the rough measuring point at the midpoint of the tooth surface and the origin O is determined;

[0194] According to the determined Z axis, origin O and rough X axis, a rough measurement coordinate system is obtained;

[0195] Based on the tooth surface equation of the spiral bevel gear, the first theoretical tooth surface midpoint coordinates and unit normal vector corresponding to the midpoint of a tooth surface of the spiral bevel gear to be tested are obtained;

[0196] Based on the rough measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system. By comparing the rough tooth surface midpoint coordinates with the first theoretical tooth surface midpoint coordinates, the rough measurement coordinate system is continuously corrected to obtain the measurement coordinate system.

[0197] In this embodiment, a measurement coordinate system is established based on the axis position information of the A axis, which can realize the use of coordinate system 1 in the measurement and processing process. At the same time, by first establishing a rough coordinate system and then continuously correcting it, a more accurate measurement coordinate system can be obtained. The established measurement coordinate system is as follows: Figure 12 shown.

[0198] In some embodiments, establishing a measurement coordinate system of a spiral bevel gear machine tool includes the following steps.

[0199] The first step is to determine the actual position of the A-axis axis as the gear measurement coordinate system Z WCS Axis. At this time, the coordinate origin O of the measurement coordinate system WCS is obtained. w The x coordinate O in the machine tool wx and y coordinate O wy , and Z WCS direction, but further confirmation is needed wz , and X WCS and Y WCS direction.

[0200] The second step is to determine the coordinates of the origin of the measurement coordinate system O wz . Z WCS After the axis direction is determined, control the probe to measure at least 3 points on the end face of the workpiece spindle, take the average value of the z coordinates of these points and add the height of the gear blank and the installation distance h caused by the spiral bevel gear clamping to obtain the position O of the measurement coordinate system XY plane in the machine tool coordinate system. wz , combined with the measurement coordinate system Z determined in the previous step WCS The axis direction and position can determine the origin of the measurement coordinate system O w In addition, the probe can be directly controlled to measure at least three points on the tooth top plane of the spiral bevel gear to be measured, and the z coordinates of these points are averaged to obtain the position of the XY plane of the measurement coordinate system in the machine tool coordinate system. wz .

[0201] The third step is to measure the coordinate system X WCS The axis is initially established. The tooth surface midpoint is captured by controlling the probe to touch the tooth surface midpoint area. P 5,3 The spatial coordinates of x p5,3 , y p5,3 , z p5,3 ), the position of the machine tool A axis and the position of the reference surface have been determined before. Here, the coordinates of the feature point relative to the axis of the machine tool A axis are the same as those in the machine tool coordinate system. The X, Y, and Z axis directions are still the X, Y, and Z axis directions in the machine tool coordinate system, but the coordinate origin becomes the intersection of the machine tool A axis and the reference surface. WCS The axis should pass through the midpoint of the tooth surface and the origin of the coordinate system O at the same time WCS , so X can be calculated based on the coordinates of the measuring point WCS The angle β between the axis and the X axis of the machine tool:

[0202] (13);

[0203] Therefore, the X-axis rotation angle β in the machine tool coordinate system can determine the X-axis of the measurement coordinate system. WCS Axis, and then use the right hand to determine the Y axis of the measurement coordinate system WCS Axis direction. Determine the origin of the measurement coordinate system O WCS Position, X WCS Axis direction, Y WCS Axis direction and Z WCS After the direction of the axis is determined, the measurement coordinate system is initially aligned. It should be noted that since the accuracy of the midpoint coordinates of the tooth surface captured in this step is relatively general, only a rough X coordinate can be preliminarily determined. WCS axis.

[0204] It should be noted that 5×9 tooth surface points are generally evenly discretized in the working area of ​​the spiral bevel gear tooth surface, resulting in 5 rows and 9 columns with a total of 45 tooth surface points, such as Figure 14 As shown, (5,3) is the midpoint of the tooth surface.

[0205] The fourth step is X WCS The axis is accurately established. For the system error in the initial positioning, an iterative optimization algorithm is used to compensate and correct it. This process gradually reduces the coordinate system deviation by repeatedly comparing the measured coordinates of the center point of the tooth surface with the theoretical coordinate data. The specific iterative process is as follows Figure 13 As shown, X is achieved through multiple rounds of data collection and parameter correction. WCS The axis is aligned with high precision, and the measurement coordinate system is finally established accurately.

[0206] In some embodiments, as Figure 13As shown, based on the rough measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system. By comparing the rough tooth surface midpoint coordinates with the first theoretical tooth surface midpoint coordinates, the rough measurement coordinate system is continuously corrected to obtain the measurement coordinate system, including:

[0207] Based on the rough measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough coordinates of the midpoint of the tooth surface in the rough measurement coordinate system;

[0208] Determine a first radius according to the coordinates of the midpoint of the rough tooth surface, wherein the first radius is the distance between the midpoint of the rough tooth surface corresponding to the coordinates of the midpoint of the rough tooth surface and the main axis of the workpiece;

[0209] Obtaining an absolute value of a difference between a first radius and a theoretical radius, wherein the theoretical radius is the distance between a midpoint of the first theoretical tooth surface and a spindle of the workpiece, and the theoretical radius is determined based on the coordinates of the midpoint of the first theoretical tooth surface;

[0210] When the absolute value is greater than the preset accuracy value, the current rough measurement coordinate system is rotated around the workpiece spindle by an adjustment angle to obtain an updated rough measurement coordinate system. The system then jumps to the rough measurement coordinate system and controls the probe to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system.

[0211] When the absolute value is less than the preset accuracy value, the current rough measurement coordinate system is determined as the measurement coordinate system.

[0212] In this embodiment, a higher precision measurement coordinate system can be obtained by repeatedly adjusting the rotation adjustment angle of the current rough measurement coordinate system around the workpiece main axis until the precision requirement is met.

[0213] Since the spiral bevel gear tooth surface equation is known, the center point of the tooth surface can be calculated based on it P 5,3 The theoretical coordinates in the ideal measurement coordinate system, and the unit normal vector of the point n 5,3 , at the bottom of the roughly constructed measurement coordinate system n 5,3 Touch point P 5,3 , output the measurement results PM 5,3 =( x m5,3 , y m5,3 , z m5,3 ), at this point the radius is:

[0214] (14);

[0215] With X WCS Axis angle β k It is obtained from the following formula:

[0216] (15);

[0217] The radius of the measuring point is then R M5,3 With theoretical radius R 5,3 If the set accuracy ε is not met, the current coordinate system will be rotated around Z WCS Axis rotation β k After that, re-measure the midpoint of the tooth surface in the rotated measurement coordinate system. Repeat the above process until | R M5,3 - R 5,3 If the accuracy requirements are met, the current coordinate system is used as the final measurement coordinate system, and subsequent on-machine measurements are based on the data of this measurement coordinate system.

[0218] In some embodiments, the tooth profile data to be measured includes measured tooth surface coordinates of multiple tooth surface points of the spiral bevel gear to be measured, and obtaining the tooth profile data to be measured of the spiral bevel gear to be measured includes:

[0219] Based on the measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured, and the measured tooth surface coordinates of multiple tooth surface points are obtained;

[0220] According to the tooth profile data to be measured, the tooth profile error of the spiral bevel gear to be measured is obtained, including:

[0221] Based on the measurement coordinate system and the tooth surface equation of the spiral bevel gear, the theoretical tooth surface coordinates of multiple tooth surface points of the spiral bevel gear to be measured are obtained;

[0222] The tooth profile error is obtained based on the theoretical tooth surface coordinates and measured tooth surface coordinates of multiple tooth surface points.

[0223] In this embodiment, tooth profile data is measured based on the established measurement coordinate system, and tooth profile errors are obtained, so that accurate processing can be achieved based on the unified coordinate system based on the data.

[0224] The above-mentioned multiple tooth surface points can be obtained by projection method to obtain uniformly discrete 9×5 tooth surface points in the working area of ​​the spiral bevel gear tooth surface, a total of 45 tooth surface points, of which (5,3) is the midpoint of the tooth surface, such as Figure 14 As shown in the figure, for these 45 tooth surface points, the theoretical tooth surface coordinates of each tooth surface point can be calculated according to the tooth surface equation of the spiral bevel gear, and then the probe can be controlled as follows Figure 15 The tooth profile error measurement path shown in the figure measures the 45 tooth surface points in sequence to obtain the measured tooth surface coordinates of each tooth surface point. The tooth surface error of each tooth surface point can be obtained by subtracting the theoretical tooth surface point from the measured tooth surface point.

[0225] The tooth profile error of spiral bevel gears is reflected by the difference surface. The midpoint (5,3) of the tooth surface is selected as the reference point, and the tooth surface error at this point is considered to be 0. The tooth surface error of each tooth surface point is subtracted from the error of the remaining points to obtain the relative tooth surface error. The difference surface can be generated from the relative tooth surface error, as shown in the following formula:

[0226] (16);

[0227] It should be noted that during tooth profile measurement, multiple tooth surfaces at equal intervals can generally be selected, and the tooth profile error can be obtained based on the 45 tooth surface points on each tooth surface. Specifically, four tooth surfaces can be selected for tooth profile measurement.

[0228] In some embodiments, the tooth pitch data to be measured includes multiple single tooth pitches and cumulative tooth pitches of the spiral bevel gear to be measured, and the tooth pitch error includes a single tooth pitch error and a cumulative tooth pitch error;

[0229] Multiple single tooth pitches include all single tooth pitches between two adjacent tooth surfaces. The obtained tooth pitch data of the spiral bevel gear to be tested include:

[0230] Based on the measurement coordinate system and the tooth surface equation of the spiral bevel gear, the coordinates of the second theoretical tooth surface midpoint corresponding to the midpoint of one tooth surface of the spiral bevel gear to be measured are obtained;

[0231] Execute the tooth pitch measurement strategy according to the second theoretical tooth surface midpoint coordinates to obtain multiple single tooth pitches;

[0232] Among them, the pitch measurement strategy includes:

[0233] Place the probe between two adjacent tooth surfaces of the Nth group of spiral bevel gear to be measured;

[0234] The control probe is located at the coordinate of the middle point of the second theoretical tooth surface;

[0235] Controlling the spiral bevel gear to be measured to rotate in a first direction so that the left tooth surface of the Nth group of adjacent tooth surfaces contacts the measuring probe to obtain the left rotation angle value between the Nth group of adjacent tooth surfaces;

[0236] Controlling the spiral bevel gear to be measured to rotate in a second direction so that the right tooth surface of the Nth group of adjacent tooth surfaces contacts the measuring probe, so as to obtain the right rotation angle value between the Nth group of adjacent tooth surfaces;

[0237] Obtain the single tooth pitch corresponding to the Nth group of two adjacent tooth surfaces according to the left rotation angle value and the right rotation angle value, and assign N+1 to N;

[0238] If the single pitch error between all adjacent tooth surfaces is not obtained, the process jumps to placing the probe between the Nth group of adjacent tooth surfaces of the spiral bevel gear to be measured;

[0239] According to the pitch data to be measured, the pitch error of the spiral bevel gear to be measured is obtained, including:

[0240] According to the theoretical tooth pitch of the spiral bevel gear to be measured and the multiple single tooth pitches, multiple single tooth pitch errors corresponding to the multiple single tooth pitches are obtained;

[0241] The cumulative pitch error is obtained by summing up multiple individual pitch errors.

[0242] In this embodiment, the pitch data is measured based on the established measurement coordinate system, and the pitch error is obtained, so that accurate processing can be achieved based on the unified coordinate system based on the data.

[0243] The first direction and the second direction are opposite to each other. Specifically, the rotation around the first direction may be counterclockwise, and the rotation around the second direction may be clockwise.

[0244] The difference between the measured value and the theoretical value reflects the actual pitch error. The single pitch deviation can be expressed as:

[0245] (17);

[0246] in, A sta It represents the theoretical rotation angle difference between two adjacent tooth surfaces, which is equal to the central angle of a single tooth. A N1 and A N2 Indicates the left and right rotation angle values ​​between two adjacent tooth surfaces in the Nth group. R p represents the pitch radius at the measuring point, N is less than or equal to Z, and Z is the number of teeth on the spiral bevel gear to be measured. The cumulative pitch error can be obtained by summing the individual pitch errors, as shown below:

[0247] (18);

[0248] The pitch error of the spiral bevel gear to be tested can be obtained.

[0249] In some embodiments, for a spiral bevel gear that has completed one gear grinding process, the tooth profile and pitch data are measured based on the measurement coordinate system, and then the tooth surface error and the tooth pitch error are obtained. Then, the spiral bevel gear is subjected to a secondary gear grinding process based on this measurement coordinate system. Therefore, the entire processing process of the spiral bevel gear does not require repeated disassembly and assembly, and the installation error is separated. In addition, the measurement and processing processes use a consistent coordinate system, which separates the tooth blank reference error. Ultimately, the required high-precision spiral bevel gear can be processed to meet the processing accuracy requirements.

[0250] The spiral bevel gear tooth profile and pitch measurement method provided in the embodiment of the present application can be performed by a spiral bevel gear tooth profile and pitch measurement device 200. In the embodiment of the present application, the spiral bevel gear tooth profile and pitch measurement device 200 is used as an example to illustrate the spiral bevel gear tooth profile and pitch measurement method provided in the embodiment of the present application.

[0251] See Figure 16 , is a structural diagram of a spiral bevel gear tooth profile and pitch measuring device 200 provided in an embodiment of the present application. Figure 16 As shown, the spiral bevel gear tooth profile and pitch measuring device 200 includes:

[0252] An acquisition module 201 is configured to acquire tooth profile data and tooth pitch data of a spiral bevel gear to be measured, wherein the spiral bevel gear to be measured is clamped on the end face of a workpiece spindle of a spiral bevel gear machine tool, and the tooth profile data and tooth pitch data are measured by a probe of the spiral bevel gear machine tool based on a pre-established measurement coordinate system;

[0253] A first obtaining module 202 is used to obtain the tooth profile error of the spiral bevel gear to be measured based on the tooth profile data to be measured;

[0254] The second obtaining module 203 is used to obtain the pitch error of the spiral bevel gear to be measured according to the pitch data to be measured;

[0255] The measurement coordinate system is obtained through the following steps:

[0256] Acquire multiple accurate sphere center position information corresponding to multiple sphere center points, where the multiple sphere center points are the sphere centers of the standard sphere at different spatial positions, and the number of sphere center points is greater than or equal to three. The standard sphere is set on the end face of the workpiece spindle of the spiral bevel gear machine tool, and the workpiece spindle is used to rotate the standard sphere to different spatial positions.

[0257] Obtaining axis position information of the workpiece spindle axis based on multiple accurate sphere center position information;

[0258] Based on the axis position information, a measurement coordinate system of the spiral bevel gear machine tool is established, wherein the measurement coordinate system takes the plane parallel to the end face of the workpiece spindle as the XY plane and the axis of the workpiece spindle as the Z axis.

[0259] In some implementations, the acquisition module 201 may be configured to:

[0260] Controlling the probe to randomly contact the surface of the standard sphere to obtain position information of a plurality of random touch points on the surface of the standard sphere, wherein the number of the random touch points is greater than or equal to three;

[0261] Based on the least squares method, the rough center position information of the standard ball is obtained according to the position information of multiple random touch points;

[0262] A plurality of preset touch points are set on the surface of a standard sphere, and a preset movement path for the probe to contact the plurality of preset touch points is planned, wherein the plurality of preset touch points include a plurality of first preset touch points and one second preset touch point, the number of the first preset touch points is greater than or equal to three, the plurality of first preset touch points are located in the same plane and the plane passes through the center of the standard sphere, and a line connecting the second preset touch point and the center of the standard sphere is perpendicular to the plane in which the plurality of first preset touch points are located;

[0263] According to the rough sphere center position information and the preset movement path, a movement constraint equation that the probe needs to satisfy when moving along the preset movement path is obtained;

[0264] Controlling the probe to move along a preset moving path and contact a plurality of preset touch points to obtain position information of the plurality of preset touch points;

[0265] Based on the least squares method, the accurate center position information of the standard ball is obtained according to the position information of multiple preset touch points and the movement constraint equation.

[0266] In some implementations, the acquisition module 201 may be configured to:

[0267] Fitting multiple sphere center points according to multiple accurate sphere center position information to obtain a first fitting circle, and determining first circle center position information of the first fitting circle;

[0268] Obtaining a deviation matrix based on the multiple accurate sphere center position information and the first center position information of the first fitting circle, wherein the deviation matrix represents positional deviations of the multiple accurate sphere center position information relative to the first center position information of the first fitting circle;

[0269] Calculate the covariance matrix of the deviation matrix and obtain the eigenvector corresponding to the minimum eigenvalue of the covariance matrix;

[0270] Determine the direction information of the axis of the workpiece spindle according to the characteristic vector;

[0271] According to the eigenvector, determine the plane where the fitting circle is located, and select two orthogonal basis vectors in the plane;

[0272] According to two orthogonal basis vectors, multiple sphere center points are projected onto the plane where the fitting circle is located to obtain multiple two-dimensional coordinate information corresponding to the multiple sphere center points;

[0273] Based on the least squares method, the multiple sphere center points are fitted according to the multiple two-dimensional coordinate information corresponding to the multiple sphere center points to obtain a second fitting circle, and the second center position information of the second fitting circle is determined;

[0274] The axis position information of the axis of the workpiece spindle is obtained according to the second center position information of the second fitting circle and the direction information of the axis of the workpiece spindle.

[0275] In some implementations, the acquisition module 201 may be configured to:

[0276] Determine the Z axis of the measurement coordinate system based on the axis position information;

[0277] Controlling the probe to randomly contact the end face of the workpiece spindle to obtain position information of a plurality of random plane touch points located on the end face of the workpiece spindle, wherein the number of the random plane touch points is greater than or equal to three;

[0278] According to the position information of multiple random plane touch points, the end plane position information of the end face of the workpiece spindle is obtained;

[0279] Determine the XY plane of the measurement coordinate system based on the end plane position information, the tooth blank height and the installation distance of the spiral bevel gear to be measured, and determine the origin O of the measurement coordinate system based on the determined Z axis and XY plane;

[0280] Controlling the probe to contact the middle area of ​​the tooth surface of the spiral bevel gear to obtain position information of a rough measuring point of the tooth surface midpoint located in the middle area of ​​the tooth surface;

[0281] According to the position information of the rough measuring point at the midpoint of the tooth surface, the rough X axis of the measuring coordinate system passing through the rough measuring point at the midpoint of the tooth surface and the origin O is determined;

[0282] According to the determined Z axis, origin O and rough X axis, a rough measurement coordinate system is obtained;

[0283] Based on the tooth surface equation of the spiral bevel gear, the first theoretical tooth surface midpoint coordinates and unit normal vector corresponding to the midpoint of a tooth surface of the spiral bevel gear to be tested are obtained;

[0284] Based on the rough measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system. By comparing the rough tooth surface midpoint coordinates with the first theoretical tooth surface midpoint coordinates, the rough measurement coordinate system is continuously corrected to obtain the measurement coordinate system.

[0285] In some implementations, the acquisition module 201 may be configured to:

[0286] Based on the rough measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough coordinates of the midpoint of the tooth surface in the rough measurement coordinate system;

[0287] Determine a first radius according to the coordinates of the midpoint of the rough tooth surface, wherein the first radius is the distance between the midpoint of the rough tooth surface corresponding to the coordinates of the midpoint of the rough tooth surface and the main axis of the workpiece;

[0288] Obtaining an absolute value of a difference between a first radius and a theoretical radius, wherein the theoretical radius is the distance between a midpoint of the first theoretical tooth surface and a spindle of the workpiece, and the theoretical radius is determined based on the coordinates of the midpoint of the first theoretical tooth surface;

[0289] When the absolute value is greater than the preset accuracy value, the current rough measurement coordinate system is rotated around the workpiece spindle by an adjustment angle to obtain an updated rough measurement coordinate system. The system then jumps to the rough measurement coordinate system and controls the probe to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system.

[0290] When the absolute value is less than the preset accuracy value, the current rough measurement coordinate system is determined as the measurement coordinate system.

[0291] In some embodiments, the tooth profile data to be measured includes the measured tooth surface coordinates of multiple tooth surface points of the spiral bevel gear to be measured. The acquisition module 201 can be used to:

[0292] Based on the measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured, and the measured tooth surface coordinates of multiple tooth surface points are obtained;

[0293] The first obtaining module 202 can be used to:

[0294] Based on the measurement coordinate system and the tooth surface equation of the spiral bevel gear, the theoretical tooth surface coordinates of multiple tooth surface points of the spiral bevel gear to be measured are obtained;

[0295] The tooth profile error is obtained based on the theoretical tooth surface coordinates and measured tooth surface coordinates of multiple tooth surface points.

[0296] In some embodiments, the tooth pitch data to be measured includes multiple single tooth pitches and cumulative tooth pitches of the spiral bevel gear to be measured, and the tooth pitch error includes a single tooth pitch error and a cumulative tooth pitch error;

[0297] The acquisition module 201 can be used to:

[0298] Based on the measurement coordinate system and the tooth surface equation of the spiral bevel gear, the coordinates of the second theoretical tooth surface midpoint corresponding to the midpoint of one tooth surface of the spiral bevel gear to be measured are obtained;

[0299] Execute the tooth pitch measurement strategy according to the second theoretical tooth surface midpoint coordinates to obtain multiple single tooth pitches;

[0300] Among them, the pitch measurement strategy includes:

[0301] Place the probe between two adjacent tooth surfaces of the Nth group of spiral bevel gear to be measured;

[0302] The control probe is located at the coordinate of the middle point of the second theoretical tooth surface;

[0303] Controlling the spiral bevel gear to be measured to rotate in a first direction so that the left tooth surface of the Nth group of adjacent tooth surfaces contacts the measuring probe to obtain the left rotation angle value between the Nth group of adjacent tooth surfaces;

[0304] Controlling the spiral bevel gear to be measured to rotate in a second direction so that the right tooth surface of the Nth group of adjacent tooth surfaces contacts the measuring probe, so as to obtain the right rotation angle value between the Nth group of adjacent tooth surfaces;

[0305] Obtain the single tooth pitch corresponding to the Nth group of two adjacent tooth surfaces according to the left rotation angle value and the right rotation angle value, and assign N+1 to N;

[0306] If the single pitch error between all adjacent tooth surfaces is not obtained, the process jumps to placing the probe between the Nth group of adjacent tooth surfaces of the spiral bevel gear to be measured;

[0307] The second obtaining module 203 can be used to:

[0308] According to the theoretical tooth pitch of the spiral bevel gear to be measured and the multiple single tooth pitches, multiple single tooth pitch errors corresponding to the multiple single tooth pitches are obtained;

[0309] The cumulative pitch error is obtained by summing up multiple individual pitch errors.

[0310] Since the spiral bevel gear tooth profile and pitch measuring device 200 adopts all the technical solutions of the spiral bevel gear tooth profile and pitch measuring method of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described in detail here.

[0311] Figure 17 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application.

[0312] The electronic device may include a processor 301 and a memory 302 storing computer program instructions.

[0313] Specifically, the processor 301 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0314] Memory 302 may include a large-capacity memory for data or instructions. By way of example, and not limitation, memory 302 may include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disk, a magneto-optical disk, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 302 may include removable or non-removable (or fixed) media. Where appropriate, memory 302 may be internal or external to the integrated gateway disaster recovery device. In certain embodiments, memory 302 is non-volatile solid-state memory.

[0315] In some embodiments, the memory 302 may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0316] The processor 301 reads and executes computer program instructions stored in the memory 302 to implement any one of the spiral bevel gear tooth profile and pitch measurement methods in the above embodiments.

[0317] In one example, the electronic device may further include a communication interface 303 and a bus 310. Figure 17 As shown, the processor 301 , the memory 302 , and the communication interface 303 are connected via a bus 310 and communicate with each other.

[0318] The communication interface 303 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0319] Bus 310 includes hardware, software, or both, and couples the components of the online data traffic metering device to each other. By way of example, and not limitation, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industrial Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industrial Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Area Network (VLB) bus, or other suitable buses, or a combination of two or more of these. Where appropriate, bus 310 may include one or more buses. Although the embodiments of the present application describe and illustrate specific buses, the present application contemplates any suitable bus or interconnect.

[0320] The electronic device can execute the spiral bevel gear tooth profile and pitch measurement method in the embodiment of the present application, thereby realizing the combination Figure 1 and Figure 16 The invention describes a method and device for measuring the tooth profile and pitch of spiral bevel gears.

[0321] In addition, in conjunction with the spiral bevel gear tooth profile and pitch measurement methods in the above embodiments, embodiments of the present application may provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any of the spiral bevel gear tooth profile and pitch measurement methods in the above embodiments is implemented.

[0322] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.

[0323] The functional blocks shown in the block diagrams described above can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, and the like. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored in a machine-readable medium or transmitted via a data signal carried in a carrier wave over a transmission medium or communication link. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memory, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, and the like. Code segments can be downloaded via computer networks such as the Internet or an intranet.

[0324] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0325] Aspects of the present disclosure have been described above with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each block in the flowcharts and / or block diagrams, as well as combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine such that execution of these instructions by the processor of the computer or other programmable data processing device enables the implementation of the functions / actions specified in one or more blocks in the flowcharts and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It should also be understood that each block in the block diagrams and / or flowcharts, as well as combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by dedicated hardware that performs the specified functions or actions, or by a combination of dedicated hardware and computer instructions.

[0326] The above description is only a specific embodiment of the present application. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the scope of protection of the present application.

Claims

1. A method for measuring the tooth profile and pitch of a spiral bevel gear, characterized in that: include: Acquiring tooth profile data and tooth pitch data of a spiral bevel gear to be measured, wherein the spiral bevel gear to be measured is clamped on an end face of a workpiece spindle of a spiral bevel gear machine tool, and the tooth profile data and tooth pitch data are measured by a probe of the spiral bevel gear machine tool based on a pre-established measurement coordinate system; Obtaining a tooth profile error of the spiral bevel gear to be measured according to the tooth profile data to be measured; Obtaining a pitch error of the spiral bevel gear to be measured according to the pitch data to be measured; The measurement coordinate system is obtained by the following steps: Acquiring multiple accurate sphere center position information corresponding to multiple sphere center points, where the multiple sphere center points are the centers of a standard sphere at different spatial positions, and the number of the sphere center points is greater than or equal to three. The standard sphere is set on the end face of the workpiece spindle, and the workpiece spindle is used to rotate the standard sphere to different spatial positions. Obtaining axis position information of the axis of the workpiece spindle based on the multiple accurate sphere center position information; Based on the axis position information, a measurement coordinate system of the spiral bevel gear machine tool is established, wherein the measurement coordinate system takes a plane parallel to the end face of the workpiece spindle as an XY plane and the axis of the workpiece spindle as a Z axis; The accurate sphere center position information corresponding to each sphere center point is obtained by the following steps: Controlling the probe to randomly contact the surface of the standard sphere to obtain position information of a plurality of random touch points on the surface of the standard sphere, wherein the number of the random touch points is greater than or equal to three; Based on the least square method, the rough center position information of the standard ball is obtained according to the position information of the plurality of random touch points; A plurality of preset touch points are set on the surface of the standard sphere, and a preset movement path of the stylus contacting the plurality of preset touch points is planned, wherein the plurality of preset touch points include a plurality of first preset touch points and a second preset touch point, the number of the first preset touch points is greater than or equal to three, the plurality of first preset touch points are located in the same plane and the plane passes through the center of the standard sphere, and a line connecting the second preset touch point and the center of the standard sphere is perpendicular to the plane on which the plurality of first preset touch points are located; According to the rough sphere center position information and the preset movement path, a movement constraint equation that the probe needs to satisfy when moving along the preset movement path is obtained; Controlling the probe to move along the preset moving path and to contact the plurality of preset touch points to obtain position information of the plurality of preset touch points; Based on the least square method, the accurate center position information of the standard ball is obtained according to the position information of the plurality of preset touch points and the movement constraint equation.

2. The method for measuring the tooth profile and pitch of a spiral bevel gear according to claim 1, wherein: The step of obtaining the axis position information of the workpiece spindle according to the plurality of accurate sphere center position information includes: Fitting the plurality of sphere center points according to the plurality of accurate sphere center position information to obtain a first fitting circle, and determining the first center position information of the first fitting circle; Obtaining a deviation matrix based on the multiple accurate sphere center position information and the first center position information of the first fitting circle, wherein the deviation matrix represents positional deviations of the multiple accurate sphere center position information relative to the first center position information of the first fitting circle; Calculating the covariance matrix of the deviation matrix and obtaining the eigenvector corresponding to the minimum eigenvalue of the covariance matrix; Determining direction information of the axis of the workpiece spindle according to the feature vector; Determine the plane where the fitting circle is located according to the eigenvector, and select two orthogonal basis vectors in the plane; Projecting the plurality of sphere center points onto the plane where the fitting circle is located according to the two orthogonal basis vectors to obtain a plurality of two-dimensional coordinate information corresponding to the plurality of sphere center points; Based on the least squares method, fitting the plurality of sphere center points according to the plurality of two-dimensional coordinate information corresponding to the plurality of sphere center points to obtain a second fitting circle, and determining the second center position information of the second fitting circle; The axis position information of the axis of the workpiece spindle is obtained according to the second center position information of the second fitting circle and the direction information of the axis of the workpiece spindle.

3. The method for measuring the tooth profile and pitch of spiral bevel gears according to claim 1, wherein: The method of establishing a measurement coordinate system of the spiral bevel gear machine tool based on the axis position information includes: Determining the Z axis of the measurement coordinate system according to the axis position information; Controlling the probe to randomly contact the end surface of the workpiece spindle to obtain position information of a plurality of random plane touch points located on the end surface of the workpiece spindle, wherein the number of the random plane touch points is greater than or equal to three; Obtaining end plane position information of the end face of the workpiece spindle according to position information of the plurality of random plane touch points; Determine the XY plane of the measurement coordinate system according to the end plane position information, the tooth blank height and the installation distance of the spiral bevel gear to be measured, and determine the origin O of the measurement coordinate system according to the determined Z axis and the XY plane; Controlling the measuring head to contact the middle area of ​​the tooth surface of the spiral bevel gear to obtain position information of a rough measuring point of the tooth surface midpoint located in the middle area of ​​the tooth surface; Determine, according to the position information of the tooth surface midpoint rough measurement point, a rough X-axis of the measurement coordinate system passing through the tooth surface midpoint rough measurement point and the origin O; Obtaining a rough measurement coordinate system according to the determined Z axis, the origin O and the rough X axis; Based on the tooth surface equation of the spiral bevel gear, obtaining the first theoretical tooth surface midpoint coordinates and unit normal vector corresponding to the midpoint of a tooth surface of the spiral bevel gear to be tested; Based on the rough measurement coordinate system, the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system. By comparing the rough tooth surface midpoint coordinates with the first theoretical tooth surface midpoint coordinates, the rough measurement coordinate system is continuously corrected to obtain the measurement coordinate system.

4. The method for measuring the tooth profile and pitch of a spiral bevel gear according to claim 3, wherein: The method comprises: controlling the probe to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector based on the rough measurement coordinate system to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system; and continuously correcting the rough measurement coordinate system by comparing the rough tooth surface midpoint coordinates with the first theoretical tooth surface midpoint coordinates to obtain the measurement coordinate system. Based on the rough measurement coordinate system, controlling the probe to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough midpoint coordinates of the tooth surface in the rough measurement coordinate system; Determine a first radius according to the coordinates of the midpoint of the rough tooth surface, wherein the first radius is the distance between the midpoint of the rough tooth surface corresponding to the coordinates of the midpoint of the rough tooth surface and the main axis of the workpiece; Obtaining an absolute value of a difference between the first radius and a theoretical radius, wherein the theoretical radius is the distance between the midpoint of the first theoretical tooth surface and the workpiece spindle, and the theoretical radius is determined according to the coordinates of the midpoint of the first theoretical tooth surface; When the absolute value is greater than the preset accuracy value, the current rough measurement coordinate system is rotated around the workpiece spindle by an adjustment angle to obtain an updated rough measurement coordinate system, and the coordinate system is switched to the rough measurement coordinate system, and the probe is controlled to contact the tooth surface of the spiral bevel gear to be measured along the direction of the unit normal vector to obtain the rough tooth surface midpoint coordinates in the rough measurement coordinate system; When the absolute value is smaller than the preset accuracy value, the current rough measurement coordinate system is determined as the measurement coordinate system.

5. The method for measuring the tooth profile and pitch of a spiral bevel gear according to claim 1, wherein: The tooth profile data to be measured includes the measured tooth surface coordinates of a plurality of tooth surface points of the spiral bevel gear to be measured, and obtaining the tooth profile data to be measured of the spiral bevel gear to be measured includes: Based on the measurement coordinate system, controlling the probe to contact the tooth surface of the spiral bevel gear to be measured, and measuring the measured tooth surface coordinates of the multiple tooth surface points; Obtaining the tooth profile error of the spiral bevel gear to be measured based on the tooth profile data to be measured includes: Based on the measurement coordinate system and according to the tooth surface equation of the spiral bevel gear, obtaining the theoretical tooth surface coordinates of the plurality of tooth surface points of the spiral bevel gear to be measured; The tooth profile error is obtained according to the theoretical tooth surface coordinates and the measured tooth surface coordinates of the plurality of tooth surface points.

6. The method for measuring the tooth profile and pitch of a spiral bevel gear according to claim 1, wherein: The tooth pitch data to be measured includes multiple single tooth pitches and cumulative tooth pitches of the spiral bevel gear to be measured, and the tooth pitch error includes a single tooth pitch error and a cumulative tooth pitch error; The plurality of single tooth pitches include the single tooth pitches between all two adjacent tooth surfaces, and the step of obtaining the tooth pitch data of the spiral bevel gear to be tested includes: Based on the measurement coordinate system and according to the tooth surface equation of the spiral bevel gear, a second theoretical tooth surface midpoint coordinate corresponding to a tooth surface midpoint of the spiral bevel gear to be measured is obtained; Executing a tooth pitch measurement strategy according to the second theoretical tooth surface midpoint coordinate to obtain the plurality of single tooth pitches; The tooth pitch measurement strategy includes: The measuring head is positioned between two adjacent tooth surfaces of the Nth group of the spiral bevel gear to be measured; Controlling the probe to be located at the coordinate of the second theoretical tooth surface midpoint; Controlling the spiral bevel gear to be measured to rotate in a first direction so that the left tooth surface of the Nth group of two adjacent tooth surfaces contacts the measuring probe, so as to obtain the left rotation angle value between the Nth group of two adjacent tooth surfaces; Controlling the spiral bevel gear to be measured to rotate in a second direction so that the right tooth surface of the Nth group of adjacent tooth surfaces contacts the measuring head, so as to obtain the right rotation angle value between the Nth group of adjacent tooth surfaces; Obtain a single tooth pitch corresponding to two adjacent tooth surfaces of the Nth group according to the left rotation angle value and the right rotation angle value, and assign N+1 to N; If the single pitch errors between all adjacent tooth surfaces are not obtained, the process jumps to the step of positioning the measuring probe between the Nth group of adjacent tooth surfaces of the spiral bevel gear to be measured; Obtaining the pitch error of the spiral bevel gear to be measured based on the pitch data to be measured includes: Obtaining a plurality of single tooth pitch errors corresponding to the plurality of single tooth pitches according to the theoretical tooth pitch of the spiral bevel gear to be tested and the plurality of single tooth pitches; The cumulative tooth pitch error is obtained by summing a plurality of the single tooth pitch errors.

7. A spiral bevel gear tooth profile and pitch measuring device, characterized in that: The method for measuring the tooth profile and pitch of a spiral bevel gear as claimed in any one of claims 1 to 6 comprises: an acquisition module, configured to acquire tooth profile data and tooth pitch data of a spiral bevel gear to be measured, wherein the spiral bevel gear to be measured is clamped on an end face of a workpiece spindle of a spiral bevel gear machine tool, and the tooth profile data and tooth pitch data are measured by a probe of the spiral bevel gear machine tool based on a pre-established measurement coordinate system; A first obtaining module is used to obtain the tooth profile error of the spiral bevel gear to be measured according to the tooth profile data to be measured; A second obtaining module is used to obtain the pitch error of the spiral bevel gear to be measured according to the pitch data to be measured; The measurement coordinate system is obtained by the following steps: Acquire multiple accurate sphere center position information corresponding to multiple sphere center points, where the multiple sphere center points are the centers of a standard sphere at different spatial positions, and the number of the sphere center points is greater than or equal to three. The standard sphere is set on the end face of a workpiece spindle of the spiral bevel gear machine tool, and the workpiece spindle is used to rotate to place the standard sphere at different spatial positions. Obtaining axis position information of the axis of the workpiece spindle based on the multiple accurate sphere center position information; Based on the axis position information, a measurement coordinate system of the spiral bevel gear machine tool is established, wherein the measurement coordinate system takes the plane parallel to the end face of the workpiece spindle as the XY plane and the axis of the workpiece spindle as the Z axis.

8. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the method for measuring the tooth profile and pitch of a spiral bevel gear according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the spiral bevel gear tooth profile and pitch measurement method according to any one of claims 1 to 6.

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