An inner spline pair online rapid detection device and method

Abstract

This invention discloses an online rapid inspection device and method for internal spline pairs. The device includes: a positioning fixture for fixing the internal spline workpiece at the inspection station, ensuring that the workpiece's axis coincides with the inspection reference axis; a rotary drive mechanism connected to a high-precision displacement sensor for driving the high-precision displacement sensor to perform scanning motion along the circumference of the internal spline workpiece; a high-precision displacement sensor for acquiring radial displacement signals from each tooth surface of the internal spline; and a data processing module communicatively connected to the high-precision displacement sensor for receiving the radial displacement signals and performing processing such as tooth profile feature data extraction, tooth pitch parameter calculation, tooth shape error parameter calculation, symmetry parameter calculation, and comparison with tolerance ranges to generate real-time inspection results. This invention enables the direct inspection of key geometric parameters of internal splines on the machining line, reducing positioning errors caused by workpiece transfer and reclamping, and improving inspection efficiency and repeatability.

Description

Technical Field

[0001] This invention relates to the field of geometric measurement technology for mechanical parts, and more specifically, to an online rapid detection device and method for internal spline pairs. Background Technology

[0002] During the machining and assembly of internal splines, key geometric parameters such as tooth pitch, tooth profile error, and symmetry need to be inspected to ensure the assembly quality of the internal spline pair. In existing technologies, internal spline inspection typically employs offline methods, where the workpiece is removed from the machining line and transferred to a dedicated metrology room or inspection table for measurement. This offline inspection method has the following drawbacks: First, the inspection process requires interrupting the production flow, resulting in low inspection efficiency and impacting the overall production cycle time; second, offline inspection cannot reflect changes in the machining status in real time, making it difficult to monitor and adjust the machining process promptly; third, positioning errors caused by multiple clamping operations affect the repeatability of the inspection results. These drawbacks make it difficult for existing offline inspection methods to meet the requirements of online real-time monitoring during internal spline machining. Summary of the Invention

[0003] This invention provides an online rapid detection device and method for internal spline pairs, solving the technical problems of low detection efficiency, inability to achieve online real-time detection and multi-parameter comprehensive evaluation in related technologies.

[0004] In a first aspect, the present invention discloses an online rapid detection device for internal spline pairs, comprising: a positioning fixture for fixing the internal spline workpiece at the detection station, so that the axis of the workpiece coincides with the detection reference axis; a rotary drive mechanism connected to a high-precision displacement sensor for driving the high-precision displacement sensor to perform scanning motion along the circumference of the internal spline workpiece; a high-precision displacement sensor for acquiring radial displacement signals of each tooth surface of the internal spline; and a data processing module communicatively connected to the high-precision displacement sensor for receiving the radial displacement signals and performing processing such as tooth profile feature data extraction, tooth pitch parameter calculation, tooth shape error parameter calculation, symmetry parameter calculation, and comparison with tolerance range to generate real-time detection results.

[0005] Furthermore, the positioning fixture includes a positioning component, a moving base, a fixed base, a shifting drive, a shifting seat, and a support column. At the detection position, the moving base is located directly below the fixed base, and the fixed base and the moving base are respectively provided with positioning components at their opposite ends. The shifting seat is located on the side of the fixed base away from the moving base, and the shifting seat is connected to the moving base through the support column. The moving base is hooked onto the lower end of the support column, and the output end of the shifting drive is drivenly connected to the shifting seat. The positioning component includes a boss and a positioning mold. The fixed base and the moving base are respectively fixedly provided with the boss at their opposite ends. The positioning mold is fixedly installed on the boss, so that the two positioning molds are arranged facing each other. The mold groove of the positioning mold is used to place the internal spline workpiece. When the lower positioning mold moves up to abut against the upper positioning mold under the drive of the displacement drive, the internal spline workpiece is fixed at the detection station.

[0006] Secondly, this invention also discloses an online rapid detection method for internal spline pairs, comprising the following steps: driving a high-precision displacement sensor to scan along the circumference of the internal spline workpiece using a rotary drive mechanism, acquiring radial displacement signals of each tooth surface, and obtaining radial displacement scanning data arranged according to the scanning angle; periodically dividing the radial displacement scanning data according to the scanning angle, dividing the continuous radial displacement signals into tooth profile signal segments corresponding to each tooth groove, identifying the tooth surface start position, tooth surface end position, and tooth profile center position in each tooth profile signal segment, and obtaining tooth profile feature data, wherein the tooth profile feature data includes the tooth surface start angle value, tooth surface end angle value, tooth profile center angle value, and radial displacement value at each sampling point for each tooth; calculating the actual tooth pitch angle value between adjacent teeth based on the tooth profile center angle values ​​of adjacent teeth in the tooth profile feature data, and dividing the actual tooth pitch... The angle value is compared with the theoretical tooth pitch angle value to obtain the individual tooth pitch deviation value and the cumulative tooth pitch deviation value of each tooth; the radial displacement value of each tooth sampling point is compared with the theoretical tooth profile curve point by point, and the difference between the maximum and minimum values ​​of the differences of all sampling points in each tooth is taken to obtain the total tooth profile deviation value; based on the tooth profile center angle value of symmetrically distributed tooth pairs, the deviation between the angle value of the line connecting the two tooth profile centers of each symmetrical tooth pair and the theoretical symmetry axis angle value is calculated to obtain the symmetry parameter; the individual tooth pitch deviation value, the cumulative tooth pitch deviation value, the total tooth profile deviation value, and the symmetry parameter are compared with the preset tolerance range respectively. When all parameter values ​​are within the corresponding tolerance range, a qualified test result is generated; when any parameter value exceeds the corresponding tolerance range, a non-qualified test result is generated, the out-of-tolerance parameter item and its out-of-tolerance value are marked, and the result is output in real time through the data processing module.

[0007] Furthermore, after acquiring the radial displacement scanning data arranged according to the scanning angle, the process further includes: performing low-pass filtering on the radial displacement scanning data to remove high-frequency noise components, and acquiring filtered radial displacement scanning data, which is then used in subsequent steps.

[0008] Furthermore, the rotary drive mechanism performs multiple repeated scans on the same internal spline workpiece, and the data processing module takes the arithmetic mean of the radial displacement data obtained from the multiple scans according to the corresponding angular positions to obtain the averaged radial displacement scan data.

[0009] Furthermore, the rotary drive mechanism drives the high-precision displacement sensor to perform circumferential scanning according to a preset angular step. The angular step is determined based on the number of teeth in the internal spline, ensuring that the number of sampling points contained in each tooth groove is not less than the preset number. Specifically, for an internal spline with a number of teeth z, the circumferential angle range corresponding to a single tooth groove is 360° divided by z, and the angular step is less than the circumferential angle range of a single tooth groove divided by the minimum number of sampling points required in each tooth groove.

[0010] Furthermore, when periodically segmenting the radial displacement scanning data, the process also includes: calculating a first-order difference sequence for the radial displacement scanning data along the scanning angle direction; marking the positions where the absolute value of the difference value in the first-order difference sequence exceeds a preset boundary threshold as candidate boundary points; pairing and filtering the candidate boundary points according to their adjacency relationship; removing isolated pseudo-boundary points; and obtaining the accurate start and end positions of each tooth surface.

[0011] Furthermore, after acquiring the tooth profile feature data, the process also includes an eccentricity compensation correction step: based on the tooth profile center angle values ​​of all teeth, the actual rotation center coordinates of the workpiece are fitted according to the least squares criterion, and the eccentricity and eccentricity direction angle of the actual rotation center relative to the theoretical rotation center are calculated; the radial displacement measurement value at each sampling point is subtracted from the projection component of the eccentricity in the radial direction of that sampling point to obtain the corrected radial displacement value, where the projection component is the product of the eccentricity and the cosine of the difference between the scanning angle and the eccentricity direction angle of that sampling point.

[0012] Furthermore, when calculating the tooth profile error parameters, the total tooth profile deviation is also decomposed into two components: tooth profile shape deviation and tooth profile slope deviation. For the deviation sequence formed by the difference between the actual radial displacement value and the theoretical radial displacement value of each sampling point, a reference line is fitted according to the least squares criterion. The tooth profile shape deviation is the difference between the maximum and minimum values ​​of the residuals at each sampling point. The tooth profile slope deviation is the arctangent angle value corresponding to the slope of the fitted reference line, which characterizes the overall tilt angle of the actual tooth profile curve relative to the theoretical tooth profile curve.

[0013] Furthermore, after generating the test results, the process also includes: the data processing module storing the test parameters of each internal spline workpiece according to the test time to form time series data; calculating the mean and standard deviation of the same test parameter for multiple consecutive workpieces within a preset time window; and generating and outputting a processing warning signal when the mean of the parameter shows a continuous deviation trend or the standard deviation exceeds the preset process control threshold. After generating the detection results, the process also includes: when the detection result is unqualified, the data processing module sends a sorting control command to the control system of the processing line through the communication interface to remove the unqualified workpiece from the processing line; when the number of unqualified workpieces detected exceeds the preset alarm threshold within the preset continuous workpiece counting range, the data processing module sends a shutdown control command to the control system of the processing line.

[0014] This invention employs a high-precision displacement sensor in conjunction with a rotary drive mechanism to acquire radial displacement data by circumferentially scanning the internal spline. Data acquisition can be completed directly on the machining line without transferring the workpiece to offline inspection equipment. This solves the technical problems of low inspection efficiency and accumulated positioning errors caused by workpiece transfer and reclamping in offline inspection methods, achieving the technical effects of improved inspection efficiency and reduced impact of clamping and positioning errors on inspection repeatability. The invention uses a data processing module to process the radial displacement scan data in real time, sequentially extracting tooth profile feature data, calculating tooth pitch parameters, tooth shape error parameters, and symmetry parameters, and comparing them with tolerance ranges. Inspection conclusions can be output immediately after the workpiece scan is completed, achieving the technical effect of reducing the impact of the inspection process on production cycle time. Furthermore, this invention performs time-series statistical analysis of the inspection parameters of continuous workpieces and outputs early warning signals for the machining process, achieving the technical effect of alerting operators at an early stage of machining deviation and reducing batch quality risks. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the online rapid detection device for internal spline pairs provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the positioning fixture of the online rapid detection device for internal spline pairs provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the positioning component and moving base of the online rapid detection device for internal spline pairs provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the rotary drive mechanism of the online rapid detection device for internal spline pairs provided in an embodiment of the present invention; Figure 5 This is a flowchart of the online rapid detection method for internal spline pairs provided in the embodiments of the present invention; Figure 6 This is a sub-flowchart of the online rapid detection method for internal spline pairs provided in this embodiment of the invention to eliminate the influence of eccentricity in the positioning fixture clamping.

[0016] In the diagram: 1. Positioning fixture; 11. Positioning assembly; 101. Boss; 102. Positioning mold; 103. Docking plate; 104. Slot; 12. Moving base; 121. Support column; 13. Fixed base; 14. Shifting seat; 15. Shifting drive component; 16. Mounting base; 17. Guide column; 2. Rotary drive mechanism; 21. Rotary drive component; 22. Worm gear component; 23. Worm wheel component; 231. Limiting shaft; 232. Limiting seat; 24. Suspension shaft; 3. High-precision displacement sensor; 4. Frame. Detailed Implementation

[0017] During the machining and assembly of internal splines, key geometric parameters such as tooth pitch, tooth profile error, and symmetry need to be inspected to ensure the assembly quality of the internal spline pair. In existing technologies, internal spline inspection typically employs offline methods, where the workpiece is removed from the machining line and transferred to a dedicated metrology chamber for measurement. This offline inspection method has the following technical problems: First, the inspection process requires interrupting the production flow, resulting in low inspection efficiency and affecting the overall production cycle time; second, offline inspection cannot reflect changes in the machining status in real time, making it difficult to monitor and adjust the machining process in real time; third, positioning errors caused by multiple clamping operations affect the repeatability of the inspection results. Therefore, a method is needed that allows for rapid, real-time inspection of internal splines directly on the machining line to improve inspection efficiency and repeatability, and to meet the requirements of online real-time monitoring.

[0018] According to an embodiment of this invention, this embodiment provides an online rapid detection method for internal spline pairs. The execution of this online rapid detection method for internal spline pairs depends on the following hardware environment: an online rapid detection device for internal spline pairs, specifically, such as... Figure 1 As shown, the online rapid inspection device for internal spline pairs includes a positioning fixture 1, a rotary drive mechanism 2, a high-precision displacement sensor 3, and a data processing module. The positioning fixture 1 is used to fix the internal spline workpiece to be inspected at the inspection station, ensuring that the workpiece's axis coincides with the inspection reference axis. The rotary drive mechanism 2 is connected to the high-precision displacement sensor 3 and drives the high-precision displacement sensor 3 to perform scanning motion along the circumferential direction of the internal spline. The high-precision displacement sensor 3 is used to collect radial displacement signals from the internal spline tooth surface. The data processing module is communicatively connected to the high-precision displacement sensor 3 and is used to receive and process the radial displacement signal data and output the inspection results.

[0019] Continue reading Figure 1 The positioning fixture 1 includes a positioning component 11, a moving base 12, a fixed base 13, a shifting drive 15, a shifting seat 14, and a support column 121. At the detection position, the moving base 12 is located directly below the fixed base 13, and the positioning component 11 is respectively provided at the opposite ends of the fixed base 13 and the moving base 12. The shifting seat 14 is located on the side of the fixed base 13 away from the moving base 12, and the shifting seat 14 is connected to the moving base 12 through the support column 121. The moving base 12 is hooked to the lower end of the support column 121 through the slot 104. The output end of the shifting drive 15 is connected to the shifting seat 14. The positioning component 11 includes a boss 101 and a positioning mold 102. The boss 101 is fixedly installed at one end of the fixed base 13 and the moving base 12 facing each other. The positioning mold 102 is fixedly installed on the boss 101, so that the two positioning molds 102 are set facing each other. The mold groove of the positioning mold 102 is used to place the internal spline workpiece, and the size of the mold groove of the positioning mold 102 is selected according to the size of the internal spline workpiece to ensure that the internal spline workpiece placed in the mold groove is embedded and clamped to avoid loosening. When the lower positioning mold 102 moves up to abut against the upper positioning mold 102 under the drive of the shifting drive 15, the internal spline workpiece is fixed at the inspection station.

[0020] For example, the shifting drive 15 is a hydraulic telescopic cylinder. The lower positioning mold 102 pre-positions the axis of the internal spline workpiece. At this time, the state of the internal spline workpiece in the positioning mold 102 is the same as the state of the internal spline workpiece when it is in the processing station. Initially, the moving base 12 is located in the processing station of the production line. When inspection is required, there is no need to disassemble the workpiece again. The moving base 12 is simply moved horizontally to below the fixed base 13 by means of a robot (not shown in the figure). At this time, the support column 121 is located in the slot 104 on the moving base 12, and the supporting part at the lower end of the support column 121 supports the moving base 12 to ensure that the upper positioning mold 102 and the lower positioning mold 13 are in good condition. 02 is positioned facing each other. The output end of the hydraulic telescopic cylinder drives the shifting seat 14 to move upward. The shifting seat 14 drives the moving base 12 to move upward synchronously through the support column 121 until the lower positioning mold 102 abuts against the upper positioning mold 102, thereby clamping and positioning the internal spline workpiece between the two positioning molds 102. That is, the internal spline workpiece is fixed at the inspection station. After the inspection is completed, the moving base 12 is moved to the processing station as a whole with the help of the robot arm. The entire process does not require the workpiece to be transferred separately. That is, this device is part of the workpiece production line. After the inspection, the processing conditions of the workpiece can be adjusted in time according to the inspection results to ensure that the inspection process does not interrupt the production process.

[0021] It should be noted that, as Figure 2 As shown, the support column 121 passes through the fixed base 13 and slides with the fixed base 13, and the fixed base 13 is fixedly installed on the guide column 17. The guide column 17 passes through the shift seat 14 and the fixed base 13 in sequence and slides with them to ultimately ensure the accuracy of the two positioning modules 102 moving towards each other.

[0022] Continue to refer to Figure 2 A mounting base 16 is fixedly installed on the upper part of the guide post 17, and the shifting drive component 15 is set on the mounting base 16, and the mounting base 16 is fixedly installed on the frame 4.

[0023] For example, such as Figure 3As shown, the side of the positioning mold 102 is provided with a material taking groove. After the production of the internal spline workpiece placed in the mold groove of the positioning mold 102 is completed, the workpiece that is radially clamped and fixed can be easily taken out axially through the side of the material taking groove. There are multiple material taking grooves. A docking plate 103 is fixedly installed in one of the material taking grooves of the lower positioning mold 102. The upper end of the docking plate 103 protrudes outside the positioning mold 102. When the lower positioning mold 102 moves up to abut against the upper positioning mold 102, the protrusion of the docking plate 103 engages with the corresponding material taking groove position of the upper positioning mold 102 to further prevent the two positioning molds 102 from circumferentially rotating and misaligning.

[0024] For example, see [link to relevant documentation]. Figure 2 and Figure 4 The rotary drive mechanism 2 includes a rotary drive component 21, a worm gear component 22, a worm wheel component 23, and a suspension shaft 24. The rotary drive component 21 is mounted on the frame 4. For example, the rotary drive component 21 is a drive motor. The output end of the rotary drive component 21 is connected to the worm gear component 22, which meshes with the worm wheel component 23. The worm wheel component 23 is coaxially mounted with the limiting shaft 231. The upper end of the limiting shaft 231 is rotatably mounted on the limiting seat 232, which is fixedly mounted on the upper end of the guide post 17. The lower end of the limiting shaft 231 is fixedly connected to the suspension shaft 24, and a high-precision displacement sensor 3 is mounted on the lower end of the suspension shaft 24. Figure 2 The layout of the positioning mold 102 is such that the detection end of the high-precision displacement sensor 3 is located in the mold groove of the positioning mold 102. After the two positioning molds 102 come together, the detection end of the high-precision displacement sensor 3 is located in the toothed area of ​​the internal spline workpiece, so that the high-precision displacement sensor 3 can perform scanning motion along the circumference of the internal spline.

[0025] Based on the above detection device, please refer to [further details]. Figure 5 and Figure 6 The method includes the following steps: Step 1: Obtain radial displacement scanning data of the internal spline workpiece.

[0026] A high-precision displacement sensor 3 is driven by a rotary drive mechanism 2 to scan along the circumference of the internal spline workpiece. The high-precision displacement sensor 3 acquires the radial displacement signals of each tooth surface of the internal spline in a non-contact or micro-contact manner. The data processing module receives the radial displacement signals output by the high-precision displacement sensor 3 and obtains the original radial displacement scanning data arranged according to the scanning angle.

[0027] It should be noted that the aforementioned non-contact method refers to the high-precision displacement sensor 3 employing an eddy current sensor or a laser displacement sensor to acquire radial displacement signals through electromagnetic induction or optical reflection without physical contact with the tooth surface. The aforementioned micro-contact method refers to the high-precision displacement sensor 3 employing a contact-type inductive sensor, where the sensor probe contacts the tooth surface with an extremely small measuring force, acquiring radial displacement signals through minute changes in the probe's displacement. The choice between the two methods depends on the material hardness and tooth surface roughness requirements of the internal spline being measured.

[0028] It should be noted that during the scanning process described above, the rotary drive mechanism 2 drives the high-precision displacement sensor 3 to perform circumferential scanning according to a preset angular step. This angular step is determined based on the number of teeth in the internal spline, ensuring that each tooth groove contains at least a preset number of sampling points. For a number of teeth... The internal spline, the circumferential angle range corresponding to a single tooth groove is The angle step should be less than ,in This represents the number of internal spline teeth. The minimum number of sampling points required within each tooth groove.

[0029] In this embodiment of the application, in order to reduce random noise interference in the original radial displacement scan data, after obtaining the original radial displacement scan data, the following step is further included: performing low-pass filtering on the original radial displacement scan data to remove high-frequency noise components, thereby obtaining filtered radial displacement scan data. The radial displacement scan data used in subsequent steps is the filtered radial displacement scan data.

[0030] In this embodiment of the application, in order to further improve the reliability of the scanning data, based on step 1, the rotary drive mechanism 2 performs multiple repeated scans on the same internal spline workpiece. The data processing module takes the arithmetic mean of the radial displacement data obtained from multiple scans according to the corresponding angular positions to obtain the averaged radial displacement scanning data, so as to suppress random sampling errors in a single scan.

[0031] Step 2: Extract the tooth profile feature data of the internal spline based on the radial displacement scan data.

[0032] The radial displacement scan data is periodically segmented according to the scanning angle, dividing the continuous radial displacement signal into tooth profile signal segments corresponding to each tooth groove. Each tooth profile signal segment is analyzed to identify the tooth surface start position, tooth surface end position, and tooth profile center position, thus obtaining tooth profile feature data. The tooth profile feature data includes the tooth surface start angle value, tooth surface end angle value, tooth profile center angle value, and radial displacement value at each sampling point for each tooth.

[0033] It should be noted that the segmentation of the tooth profile signal segment mentioned above refers to determining the boundary position between the tooth surface and the tooth groove based on the abrupt change characteristics of the displacement value in the radial displacement scan data. Specifically, in the curve of the radial displacement scan data changing along the scanning angle direction, the position where the displacement value changes abruptly corresponds to the transition region between the tooth surface and the tooth groove, and the signal segment between two adjacent transition regions is taken as a tooth profile signal segment.

[0034] It should be noted that the identification of the tooth profile center position mentioned above refers to taking the arithmetic mean of the starting angle value and the ending angle value of the tooth surface in each tooth profile signal segment, and using the resulting angle value as the tooth profile center angle value.

[0035] In this embodiment of the application, in order to improve the accuracy of tooth surface boundary recognition, when periodically segmenting the radial displacement scanning data, the following steps are also included: calculating a first-order difference sequence for the radial displacement scanning data along the scanning angle direction, marking the positions in the first-order difference sequence where the absolute value of the difference value exceeds a preset boundary threshold as candidate boundary points, pairing and filtering the candidate boundary points according to their adjacent relationships, removing isolated pseudo boundary points, and obtaining the accurate start and end positions of each tooth surface.

[0036] In this embodiment of the application, in order to eliminate the influence of the clamping eccentricity of the positioning fixture 1 on the tooth profile feature data, the following steps are also included in step 2: fitting the actual rotation center of the workpiece according to the tooth profile center angle value of all teeth, calculating the eccentricity and eccentricity direction angle of the actual rotation center relative to the theoretical rotation center, and performing eccentricity compensation correction on the radial displacement value of each sampling point based on the eccentricity and eccentricity direction angle to obtain the corrected tooth profile feature data.

[0037] Furthermore, the steps for the above-mentioned eccentricity compensation correction are as follows: Step 2-1: Fit the actual rotation center coordinates of the workpiece: Let all The center angle values ​​of the tooth profiles of each tooth constitute an angle set. , ,in For the first The center angle value of the tooth profile of each tooth, for the angle set Fit the actual rotation center coordinates of the workpiece using the least squares criterion. ,in , These are the horizontal and vertical coordinate components of the actual rotation center in the detection coordinate system.

[0038] Step 2-2: Calculate the eccentricity and eccentricity direction angle :

[0039]

[0040] in, The actual radial distance between the actual center of rotation and the theoretical center of rotation. The angle of the eccentric direction relative to the horizontal axis of the detection coordinate system.

[0041] Steps 2-3: Perform eccentricity compensation correction on the radial displacement measurement values: For the first Radial displacement measurements at each sampling point Calculate the correction value after eccentricity compensation using the following formula. :

[0042] in, For the first The scanning angle corresponding to each sampling point This is the projection component of the eccentricity in the radial direction at the sampling point.

[0043] Step 3: Based on the tooth profile feature data, calculate the tooth pitch parameter, tooth profile error parameter, and symmetry parameter of the internal spline.

[0044] Based on the center angle values ​​of adjacent teeth in the tooth profile feature data, the actual tooth pitch angle values ​​between adjacent teeth are calculated. Each actual tooth pitch angle value is compared with the theoretical tooth pitch angle value to calculate the individual tooth pitch deviation value and the cumulative tooth pitch deviation value, thus obtaining the tooth pitch parameters.

[0045] Based on the radial displacement values ​​of the sampling points of each tooth in the tooth profile feature data, the actual tooth profile curve of each tooth is compared with the theoretical tooth profile curve point by point. The difference between the actual radial displacement value and the theoretical radial displacement value at each sampling point is calculated. The difference between the maximum and minimum values ​​of the differences at all sampling points within each tooth is taken to obtain the tooth profile error parameter. The tooth profile error parameter includes the total tooth profile deviation value of each tooth.

[0046] Based on the center angle values ​​of the tooth profiles of symmetrically distributed tooth pairs in the tooth profile feature data, the deviation between the angle value of the line connecting the centers of the two tooth profiles of each symmetrical tooth pair and the theoretical axis of symmetry is calculated to obtain the symmetry parameter.

[0047] It should be noted that the theoretical tooth pitch angle values ​​mentioned above refer to the standard angular distance between adjacent teeth determined based on the number of teeth in the internal spline. For a number of teeth... The internal spline, theoretical tooth pitch angle value for:

[0048] in, This represents the number of internal spline teeth. This is the theoretical tooth pitch angle value.

[0049] It should be noted that the above-mentioned single tooth pitch deviation values and cumulative tooth pitch deviation value The calculation method is as follows:

[0050]

[0051] in, For the first The actual tooth pitch angle value between adjacent tooth pairs This is the theoretical tooth pitch angle value. For the first Individual tooth pitch deviation value of each tooth For the front The cumulative tooth pitch deviation value of each tooth. This is the cutoff tooth number for calculating the cumulative tooth pitch deviation value.

[0052] It should be noted that the theoretical tooth profile curve mentioned above refers to the standard tooth profile curve generated based on the design parameters of the internal spline. These design parameters include the module, pressure angle, and root circle diameter, etc., and the theoretical tooth profile is determined according to the involute equation.

[0053] It should be noted that the aforementioned symmetrical tooth pair refers to two teeth that are mirror-symmetrical about a certain radial axis of symmetry in the cross-section of an internal spline. For internal splines with an even number of teeth, the theoretical difference in the center angle of the tooth profile of each pair of symmetrical teeth is... .

[0054] In this embodiment of the application, to provide a more detailed evaluation of tooth profile error, the calculation of tooth profile error parameters further includes the following steps: decomposing the total tooth profile deviation into two components: tooth profile shape deviation and tooth profile slope deviation. The tooth profile shape deviation is obtained by calculating the residual between the actual tooth profile curve and the fitted reference line, representing the degree of shape deviation of the actual tooth profile curve relative to the linear reference; the tooth profile slope deviation is obtained by calculating the angle difference between the fitted reference line and the theoretical tooth profile curve, representing the overall inclination of the actual tooth profile curve relative to the theoretical tooth profile curve.

[0055] Furthermore, the aforementioned tooth shape deviation and tooth profile slope deviation The calculation method is as follows: For the first Let each tooth contain [a number of teeth]. One sampling point, ,in For the first The total number of sampling points per tooth. Here are the sampling point indices; the actual radial displacement value at each sampling point is... The corresponding theoretical radial displacement value is The deviation value of each sampling point is For the bias sequence A reference line is fitted using the least squares criterion. Let the value of the fitted reference line at each sampling point be... Then the tooth shape deviation The residuals at each sampling point The difference between the maximum and minimum values:

[0056] Tooth profile slope deviation The angle value corresponding to the slope of the fitted reference line:

[0057] in, For deviation sequence The slope of the least squares fitted line. Characterizes the overall tilt angle of the actual tooth profile curve relative to the theoretical tooth profile curve.

[0058] Step 4: Based on the tooth pitch parameter, tooth profile error parameter, and symmetry parameter, generate real-time detection results for the internal spline workpiece.

[0059] The individual and cumulative pitch deviation values ​​in the pitch parameter, the total tooth profile deviation value in the tooth profile error parameter, and the symmetry deviation value in the symmetry parameter are compared with preset tolerance ranges. When all the above parameter values ​​are within their respective tolerance ranges, a qualified inspection result is generated; when any parameter value exceeds its corresponding tolerance range, a unqualified inspection result is generated, and the out-of-tolerance parameter item and its corresponding out-of-tolerance value are marked. The inspection results are output in real time through the display interface or communication interface of the data processing module.

[0060] It should be noted that the preset tolerance ranges mentioned above are allowable deviation ranges determined based on the precision grade of the internal spline and the corresponding national or industry standards. Different precision grades correspond to different tolerance values. The data processing module pre-stores tolerance data tables corresponding to each precision grade and retrieves the corresponding tolerance range according to the precision grade set for the current inspection task.

[0061] It should be noted that the out-of-tolerance parameters marked in the above-mentioned non-conforming test results include the name of the out-of-tolerance parameter, the out-of-tolerance value, and the position of the out-of-tolerance tooth number, so as to facilitate the location of specific machining defects.

[0062] In this embodiment of the application, to facilitate trend analysis of the processing process, in addition to step 4, the following steps are also included: The data processing module stores the detection parameters of each internal spline workpiece according to the detection time, forming time series data. Statistical analysis is performed on the same detection parameter of multiple consecutive workpieces to calculate the mean and standard deviation of the parameter within a preset time window. When the mean of the parameter shows a continuous deviation trend or the standard deviation exceeds the preset process control threshold, a processing process warning signal is generated and output to indicate that the processing equipment may have changes in state such as tool wear or decreased positioning accuracy.

[0063] In this embodiment, to link the detection results with the operation control of the processing line, after generating the detection results, the following steps are included: When the detection result is unqualified, the data processing module sends a sorting control command to the processing line control system through the communication interface, and the sorting mechanism removes the unqualified workpieces from the processing line. When the number of detected unqualified workpieces exceeds a preset alarm threshold within a preset continuous workpiece counting range, the data processing module sends a stop control command to the processing line control system to prevent the generation of a batch of unqualified workpieces.

[0064] This invention uses a high-precision displacement sensor 3 in conjunction with a rotary drive mechanism 2 to perform circumferential scanning of the internal spline to obtain radial displacement data. Therefore, data acquisition can be completed directly on the processing line without transferring the workpiece to an offline inspection device, thus avoiding the problems of reduced inspection efficiency and accumulated positioning errors caused by workpiece transfer and reclamping in offline inspection methods.

[0065] In this embodiment, the workpiece is fixed by the positioning fixture 1, so that the position reference of the workpiece remains consistent during the detection process. Therefore, the positioning state between each detection is consistent, thereby improving the repeatability of the detection results.

[0066] This implementation uses a data processing module to process radial displacement scanning data in real time, sequentially extracting tooth profile feature data, calculating tooth pitch parameters, tooth shape error parameters, and symmetry parameters, and comparing them with tolerance ranges. Therefore, it can obtain and output the detection conclusion immediately after the workpiece is scanned, thereby meeting the need for real-time monitoring of the internal spline detection process and reducing the occupation of the detection process on the production cycle.

[0067] Furthermore, by performing time-series statistical analysis on the detection parameters of continuous workpieces and outputting early warning signals for the processing process, it is possible to provide alerts at an early stage when the processing state deviates, thereby helping to adjust the processing equipment status in a timely manner and reduce batch quality risks.

[0068] The embodiments of the present invention have been described above. However, the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make more equivalent embodiments under the guidance of the present embodiments, and all of them are within the protection scope of the present embodiments.

Claims

1. An inner spline pair online quick detection device, characterized in that, include: Positioning fixtures are used to fix internal spline workpieces at the inspection station, so that the axis of the workpiece coincides with the inspection reference axis; A rotary drive mechanism, connected to a high-precision displacement sensor, is used to drive the high-precision displacement sensor to perform scanning motion along the circumference of the internal spline workpiece. A high-precision displacement sensor is used to acquire radial displacement signals from each tooth surface of the internal spline. A data processing module, communicating with the high-precision displacement sensor, periodically segments the radial displacement scan data according to the scanning angle, dividing the continuous radial displacement signal into tooth profile signal segments corresponding to each tooth groove. It identifies the tooth surface start position, tooth surface end position, and tooth profile center position in each tooth profile signal segment, acquiring tooth profile feature data. This feature data includes the tooth surface start angle value, tooth surface end angle value, tooth profile center angle value, and radial displacement value at each sampling point. Based on the tooth profile center angle values ​​of adjacent teeth in the feature data, the actual tooth pitch angle value between adjacent teeth is calculated, and the actual tooth pitch angle value is compared with the theoretical tooth pitch angle value. Obtain the individual tooth pitch deviation value and cumulative tooth pitch deviation value for each tooth; compare the radial displacement value of each tooth's sampling point with the theoretical tooth profile curve point by point, and take the difference between the maximum and minimum values ​​of the differences of all sampling points within each tooth to obtain the total tooth profile deviation value; calculate the deviation between the angle value of the line connecting the centers of the two tooth profiles of each symmetrical tooth pair and the angle value of the theoretical axis of symmetry based on the center angle values ​​of the tooth profiles of the symmetrical tooth pairs to obtain the symmetry parameter; compare the individual tooth pitch deviation value, cumulative tooth pitch deviation value, total tooth profile deviation value, and symmetry parameter with the preset tolerance range respectively. When all parameter values ​​are within the corresponding tolerance range, a qualified test result is generated; when any parameter value exceeds the corresponding tolerance range, a non-qualified test result is generated, and the out-of-tolerance parameter item and its out-of-tolerance value are marked. The positioning fixture includes a positioning component, a moving base, a fixed base, a shifting drive, a shifting seat, and a support column. At the detection position, the moving base is located directly below the fixed base, and the positioning component is respectively provided at one end of the fixed base and the moving base facing each other. The shifting seat is located on the side of the fixed base away from the moving base, and the shifting seat is connected to the moving base through the support column. The moving base is hooked onto the lower end of the support column, and the output end of the shifting drive is drivenly connected to the shifting seat.

2. The inner spline pair online quick detection device according to claim 1, characterized in that, The positioning assembly includes a boss and a positioning mold. The fixed base and the moving base are respectively fixedly provided with the boss at their opposite ends. The positioning mold is fixedly installed on the boss, so that the two positioning molds are arranged facing each other. The mold groove of the positioning mold is used to place the internal spline workpiece. When the lower positioning mold moves up to abut against the upper positioning mold under the drive of the displacement drive, the internal spline workpiece is fixed at the detection station.

3. The method for on-line rapid detection of an internal spline pair, applied to the on-line rapid detection device of the internal spline pair according to claim 1, characterized in that, Includes the following steps: A high-precision displacement sensor is driven by a rotary drive mechanism to scan along the circumference of the internal spline workpiece, collect radial displacement signals of each tooth surface, and obtain radial displacement scanning data arranged according to the scanning angle. The radial displacement scanning data is periodically segmented according to the scanning angle, and the continuous radial displacement signal is divided into tooth profile signal segments corresponding to each tooth groove. The tooth surface start position, tooth surface end position and tooth profile center position in each tooth profile signal segment are identified to obtain tooth profile feature data. The tooth profile feature data includes the tooth surface start angle value, tooth surface end angle value, tooth profile center angle value and radial displacement value at each sampling point for each tooth. Based on the tooth profile center angle values ​​of adjacent teeth in the tooth profile feature data, calculate the actual tooth pitch angle value between each adjacent tooth, compare the actual tooth pitch angle value with the theoretical tooth pitch angle value, and obtain the individual tooth pitch deviation value and cumulative tooth pitch deviation value of each tooth; based on the radial displacement value of each tooth's sampling point and the theoretical tooth profile curve, compare point by point, and take the difference between the maximum and minimum values ​​of the differences of all sampling points within each tooth to obtain the total tooth profile deviation value; based on the tooth profile center angle values ​​of symmetrically distributed tooth pairs, calculate the deviation between the angle value of the line connecting the two tooth profile centers of each symmetrical tooth pair and the theoretical symmetry axis angle value to obtain the symmetry parameter. The individual tooth pitch deviation value, cumulative tooth pitch deviation value, total tooth profile deviation value, and symmetry parameter are compared with the preset tolerance range. When all parameter values ​​are within the corresponding tolerance range, a qualified test result is generated. When any parameter value exceeds the corresponding tolerance range, a non-qualified test result is generated, the out-of-tolerance parameter item and its out-of-tolerance value are marked, and the result is output in real time through the data processing module.

4. The inner spline pair online quick detection method according to claim 3, characterized in that, After obtaining the radial displacement scan data arranged according to the scanning angle, the process further includes: performing low-pass filtering on the radial displacement scan data to remove high-frequency noise components, obtaining filtered radial displacement scan data, and using the filtered radial displacement scan data in subsequent steps.

5. The inner spline pair online quick detection method according to claim 3, characterized in that, The rotary drive mechanism performs multiple repeated scans on the same internal spline workpiece. The data processing module takes the arithmetic mean of the radial displacement data obtained from the multiple scans according to the corresponding angular positions to obtain the averaged radial displacement scan data.

6. The inner spline pair online quick detection method according to claim 3, characterized in that, The rotary drive mechanism drives the high-precision displacement sensor to perform circumferential scanning according to a preset angle step. The angle step is determined based on the number of teeth in the internal spline, ensuring that the number of sampling points in each tooth groove is not less than the preset number. Specifically, for an internal spline with a number of teeth z, the circumferential angle range corresponding to a single tooth groove is 360° divided by z, and the angle step is less than the circumferential angle range of a single tooth groove divided by the minimum number of sampling points required in each tooth groove.

7. The inner spline pair online quick detection method according to claim 3, characterized in that, When periodically segmenting the radial displacement scanning data, the process also includes: calculating a first-order difference sequence for the radial displacement scanning data along the scanning angle direction; marking the positions where the absolute value of the difference value in the first-order difference sequence exceeds a preset boundary threshold as candidate boundary points; pairing and filtering the candidate boundary points according to their adjacency relationship; removing isolated pseudo-boundary points; and obtaining the accurate start and end positions of each tooth surface.

8. The inner spline pair online quick detection method according to claim 3, characterized in that, After acquiring the tooth profile feature data, the process also includes an eccentricity compensation correction step: based on the tooth profile center angle values ​​of all teeth, the actual rotation center coordinates of the workpiece are fitted according to the least squares criterion, and the eccentricity and eccentricity direction angle of the actual rotation center relative to the theoretical rotation center are calculated; the radial displacement measurement value at each sampling point is subtracted from the projection component of the eccentricity in the radial direction of that sampling point to obtain the corrected radial displacement value, where the projection component is the product of the eccentricity and the cosine of the difference between the scanning angle and the eccentricity direction angle of that sampling point.

9. The inner spline pair online quick detection method according to claim 3, characterized in that, When calculating the tooth profile error parameters, the total tooth profile deviation is also decomposed into two components: tooth profile shape deviation and tooth profile slope deviation. For the deviation sequence formed by the difference between the actual radial displacement value and the theoretical radial displacement value of each sampling point, a reference line is fitted according to the least squares criterion. The tooth profile shape deviation is the difference between the maximum and minimum values ​​of the residuals at each sampling point. The tooth profile slope deviation is the arctangent angle value corresponding to the slope of the fitted reference line, which characterizes the overall tilt angle of the actual tooth profile curve relative to the theoretical tooth profile curve.

10. The inner spline pair online quick detection method according to claim 3, characterized in that, After generating the test results, the process also includes: the data processing module stores the test parameters of each internal spline workpiece according to the test time to form time series data; calculates the mean and standard deviation of the same test parameter for multiple consecutive workpieces within a preset time window; when the mean of the parameter shows a continuous deviation trend or the standard deviation exceeds the preset process control threshold, a processing warning signal is generated and output. After generating the detection results, the process also includes: when the detection result is unqualified, the data processing module sends a sorting control command to the control system of the processing line through the communication interface to remove the unqualified workpiece from the processing line; when the number of unqualified workpieces detected exceeds the preset alarm threshold within the preset continuous workpiece counting range, the data processing module sends a shutdown control command to the control system of the processing line.

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