Self-adaptive rotating speed sensor, electric driving box and impact test method of electric driving box

Abstract

The invention provides a self-adaptive rotating speed sensor, an electric driving box and an impact testing method thereof, and belongs to the technical field of new energy automobile transmission system testing. The sensor comprises a sensor main body, an external thread positioning structure, an internal thread adjusting structure, a rotating speed detection probe and an ultrasonic sensor probe, the external thread positioning structure is used for fixing and positioning the sensor main body on the to-be-tested electric drive box shell; the internal thread adjusting structure is arranged in the sensor main body and is connected with the rotating speed detection probe and the ultrasonic sensor probe; the ultrasonic sensor probe is used for detecting the distance between the rotating speed detection probe and the detected gear in real time; the rotating speed detection probe is used for collecting a rotating speed signal of a shaft system in the to-be-detected electric driving box. The internal thread adjusting structure drives the rotating speed detection probe to axially move to adjust the test gap, and the ultrasonic sensor is combined to detect the gap change in real time and adjust the detection gap in real time, so that the dynamic gap can be accurately measured, and the measurement error is effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of testing technology for new energy vehicle transmission systems, specifically relating to an adaptive speed sensor, an electric drive box, and its impact testing method. Background Technology

[0002] With the rapid development of new energy vehicle technology, users have increasingly higher requirements for vehicle noise, vibration, and comfort (NVH). Therefore, major OEMs are increasing their investment to improve the overall NVH performance of vehicles and enhance brand competitiveness. Tip-in / Tip-out clunk (hereinafter referred to as TITO) is a type of NVH that requires special attention. This condition is mainly manifested when releasing or pressing the accelerator pedal, causing torque to change from positive to negative or vice versa. This results in a momentary impact on the vehicle's transmission system, and the sound is directly transmitted to the driver's ears, causing discomfort.

[0003] To address these issues, major manufacturers primarily focus on optimizing gear backlash and torque zero-crossing strategies. Gear backlash optimization often relies on tightening critical dimensional tolerances based on gear backlash parameters determined during the initial design phase. However, the backlash adjustments considered at the design stage cannot adapt to dynamic factors during operation, such as load fluctuations (e.g., shaft deformation due to impact loads), temperature changes (thermal expansion of gears due to high-speed operation), and wear (tooth surface wear due to long-term meshing). This easily leads to deviations between actual and design values, resulting in a lack of precise basis for pinpointing the root cause of tip-in / tip-out clunk impacts and optimizing gear backlash. Existing speed sensors generally use fixed installation methods, making it impossible to adjust the distance between the detection probe and the measured gear in real time. The acquired signals are susceptible to environmental interference, making it difficult to accurately capture dynamic backlash changes.

[0004] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and provide an adaptive speed sensor, an electric drive box and its impact testing method, which can realize dynamic gap measurement and adjust the detection gap in real time, thereby reducing measurement error and improving the accuracy of dynamic gap measurement.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides an adaptive speed sensor, comprising a sensor body, an external thread positioning structure, an internal thread adjustment structure, a speed detection probe, and an ultrasonic sensor probe;

[0008] The external thread positioning structure is provided on the outer side wall of the sensor body and is used to engage with the threaded hole of the preset internal thread opening on the electric drive housing under test to realize the fixation and positioning of the sensor body on the electric drive housing under test.

[0009] The internal thread adjustment structure is located inside the sensor body and is connected to the speed detection probe and the ultrasonic sensor probe. By rotating the internal thread adjustment structure, the speed detection probe and the ultrasonic sensor probe can be driven to move along the axial direction of the sensor body to adjust the test gap between the speed detection probe and the gear under test in the electric drive box under test.

[0010] The ultrasonic sensor probe and the speed detection probe are arranged side by side along the axial direction of the sensor body, and the detection end of the ultrasonic sensor probe and the detection end of the speed detection probe are facing the same direction. The ultrasonic sensor probe is used to detect the distance between the speed detection probe and the gear under test in real time and output a distance detection signal.

[0011] The speed detection probe is used to collect the speed signal of the shaft system inside the electric drive box under test.

[0012] A further improvement of the present invention is that:

[0013] The adaptive speed test sensor also includes a signal transmission line, which extends from the end of the sensor body away from the gear being tested. One end of the signal transmission line is connected to the speed detection probe and the ultrasonic sensor probe, respectively, and the other end is used to connect to an external test system to transmit the speed detection signal and the distance detection signal.

[0014] A second aspect of the present invention provides an electric drive box for impact testing, comprising an electric drive box body and a plurality of the above-described adaptive speed sensors;

[0015] The electric drive box body includes a housing and a drive motor, an input shaft system, an intermediate shaft system, and a differential shaft system assembled in the housing. The power output end of the drive motor is connected to the input shaft system. The input shaft system, the intermediate shaft system, and the differential shaft system are connected in sequence. The housing has multiple openings with internal threads, and the internal thread of each opening matches the external thread of the corresponding adaptive speed sensor.

[0016] Each adaptive speed sensor is connected to the internal thread of the corresponding opening via an external thread. The detection ends of the multiple adaptive speed sensors face the gear under test in each shaft system to collect the speed signals of the input shaft system, the intermediate shaft system, and the differential shaft system.

[0017] A further improvement of the present invention is that:

[0018] The housing has at least one opening corresponding to the position of the gear being tested in the input shaft system, the intermediate shaft system, and the differential shaft system. The distance between the detection end of the adaptive speed sensor in each opening and the gear being tested is equal.

[0019] A third aspect of the present invention provides an impact testing method for an electric drive housing, applied to the aforementioned electric drive housing, the impact testing method comprising:

[0020] The plurality of adaptive speed sensors are arranged on the housing of the electric drive box under test, such that the distance between the speed detection probe of the plurality of adaptive speed sensors and the gear under test is equal.

[0021] A torque sensor is arranged on the drive half-shaft of the differential shaft system;

[0022] The vehicle was tested under a preset impact condition. The speed signal was collected by the adaptive speed sensor and the torque signal was collected by the torque sensor.

[0023] Based on the rotational speed signal and the torque signal, the dynamic clearance of the gear under test under the preset impact condition is obtained.

[0024] A further improvement of the present invention is that:

[0025] Based on the speed signal and the torque signal, the dynamic clearance of the gear under test under the preset impact condition is obtained, including:

[0026] The rotational speed signal is integrated to obtain the angular displacement of each measured shaft system;

[0027] The moment when the half-shaft torque crosses zero is determined based on the torque signal;

[0028] Calculate the angular displacement difference between any two meshing shaft systems at the moment when the half-shaft torque crosses zero;

[0029] The dynamic clearance value of the gear under test is obtained based on the angular displacement difference.

[0030] A further improvement of the present invention is that:

[0031] The input shaft system, the intermediate shaft system, and the differential shaft system are assembled to the housing via support bearings; the impact testing method further includes:

[0032] A vibration sensor is arranged on the surface of the housing at the support bearing.

[0033] A whole vehicle test was conducted under a preset impact condition, and the three-dimensional vibration signal was collected by the vibration sensor.

[0034] Based on the aforementioned triaxial vibration signals, an objective evaluation result of the impact strength is obtained;

[0035] The objective evaluation results are fitted with the pre-obtained subjective evaluation results to obtain a comprehensive subjective and objective evaluation result of the impact strength of the electric drive box under test.

[0036] A further improvement of the present invention is that:

[0037] Based on the aforementioned triaxial vibration signals, an objective evaluation result of the impact strength is obtained, including:

[0038] The peak-to-peak value of the triaxial vibration acceleration at the moment the torque crosses zero is extracted from the triaxial vibration signal, and the objective evaluation index value is calculated using the following formula as the objective evaluation result of the impact strength:

[0039]

[0040] Among them, X P-P The peak-to-peak value of the vibration acceleration in the X direction of the adaptive speed sensor, and the peak-to-peak value of the Y direction. P-P The peak-to-peak value of the vibration acceleration in the Y direction of the adaptive speed sensor, Z P-P The peak-to-peak value of the vibration acceleration in the Z direction of the adaptive speed sensor is given, and RSS is an objective evaluation index value.

[0041] A further improvement of the present invention is that:

[0042] The vibration sensor is arranged on a high-speed, low-inertia shaft system.

[0043] A further improvement of the present invention is that:

[0044] Before arranging the plurality of adaptive speed sensors on the housing of the electric drive unit under test, the impact testing method further includes: calibrating the linear relationship between the measured torque and the output voltage of the torque sensor using a static torsion test bench, wherein the linear relationship is expressed as:

[0045] T=kU+b

[0046] Where T is torque, U is voltage, k is linear slope, and b is initial torque value.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides an adaptive speed sensor, an electric drive box for impact testing, and an impact testing method thereof, including a sensor body, an external thread positioning structure, an internal thread adjustment structure, a speed detection probe, and an ultrasonic sensor probe. The speed detection probe is driven to move axially through the internal thread adjustment structure to adjust the test gap. Combined with the real-time detection of gap changes by the ultrasonic sensor, the accurate measurement of the dynamic gap is realized. It has the advantages of real-time adjustment of the detection gap, reducing measurement errors, and improving the accuracy of dynamic gap measurement. Attached Figure Description

[0048] The above and other objects, features, and advantages of the present invention will become more apparent from the more detailed description of the embodiments of the invention in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0049] Figure 1 This is a front view of an adaptive speed sensor according to some embodiments of the present invention;

[0050] Figure 2 This is a cross-sectional view of an adaptive speed sensor according to some embodiments of the present invention;

[0051] Figure 3 This is a schematic diagram of the structure of an electric drive box for impact testing according to some embodiments of the present invention;

[0052] Figure 4a These are external views of an electric drive box for impact testing according to some embodiments of the present invention;

[0053] Figure 4b This is a partial cross-sectional view of an electric drive box for impact testing according to some embodiments of the present invention;

[0054] Figure 5 This is a flowchart illustrating the impact testing method for an electric drive box according to some embodiments of the present invention;

[0055] Figure 6 This is a schematic diagram of the vehicle sensor arrangement according to some embodiments of the present invention;

[0056] Figure 7 This is a structural diagram of the shaft system layout of a certain electric drive assembly;

[0057] Figure 8a These are graphs showing the rotational speed and torque data of some embodiments of the present invention;

[0058] Figure 8b These are dynamic gap simulation curves of some embodiments of the present invention;

[0059] Figure 9This is a schematic diagram of a static torsion test bench structure according to some embodiments of the present invention.

[0060] Explanation of reference numerals in the attached figures:

[0061] 10-Adaptive speed sensor, 11-Sensor body, 12-External thread positioning structure, 13-Internal thread adjustment structure, 14-Speed ​​detection probe, 15-Ultrasonic sensor probe, 16-Signal transmission line;

[0062] 20-Electric drive box body, 21-Drive motor, 22-Input shaft system, 23-Intermediate shaft system, 24-Differential shaft system, 25-Housing, 26-Opening, 27-Gear under test, 28-Clearance;

[0063] 61a - Left drive half-shaft, 61b - Right drive half-shaft, 62a - Left wheel, 62b - Right wheel, 63 - Torque measuring point, 64 - Speed ​​measuring point;

[0064] 71 - First shaft system, 72 - Second shaft system;

[0065] 91-Fixed end, 92a-First spline tooling plate, 92b-Second spline tooling plate, 93-Transmission half shaft, 94-Torque output end, 95-Motor end tooling, 96-Strain gauge position, 97a and 97b-Strain gauge. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0067] To address the problems of existing gear backlash optimization methods lacking precise data and existing speed sensors being unable to adjust the distance between the detection probe and the gear under test in real time, and the acquisition signal being susceptible to environmental interference, making it difficult to accurately capture dynamic backlash changes, this invention first proposes an adaptive speed sensor. The adaptive speed sensor of this invention will be further described in detail below with reference to the accompanying drawings.

[0068] First, refer to Figure 1 and Figure 2 The adaptive speed sensor 10 of some embodiments of the present invention will be described below.

[0069] like Figure 1 and Figure 2As shown, the adaptive speed sensor 10 of the present invention includes a sensor body 11, an external thread positioning structure 12, an internal thread adjustment structure 13, a speed detection probe 14, and an ultrasonic sensor probe 15.

[0070] The external thread positioning structure 12 is disposed on the outer side wall of the sensor body 11 and is used to engage with the threaded hole of the preset internal thread opening on the electric drive housing under test, so as to fix and position the sensor body 11 on the electric drive housing under test.

[0071] The internal thread adjustment structure 13 is disposed inside the sensor body 11 and is connected to the speed detection probe 14 and the ultrasonic sensor probe 15. By rotating the internal thread adjustment structure 13, the speed detection probe 14 and the ultrasonic sensor probe 15 can be driven to move along the axial direction of the sensor body 11 to adjust the test gap between the speed detection probe 13 and the gear under test in the electric drive box under test.

[0072] The speed detection probe 14 is used to collect the speed signal of the shaft system inside the electric drive box under test. The ultrasonic sensor probe 15 is arranged in parallel with the speed detection probe 14 along the axial direction of the sensor body 11, and the detection end of the ultrasonic sensor probe and the detection end of the speed detection probe are aligned. The ultrasonic sensor probe is used to detect the distance between the speed detection probe 14 and the gear under test in real time and output a distance detection signal.

[0073] The external thread positioning structure refers to a mechanical connection component with standard thread parameters, specifically implemented using metric or pipe threads. Its thread lead forms an interference fit with the housing opening, achieving coarse positioning. The internal thread adjustment structure refers to a hollow sleeve with internal threads, specifically implemented using a trapezoidal thread pair. Rotation of the thread is converted into linear displacement, achieving precise positioning and control of the detection probe. The ultrasonic sensor probe is a ranging element based on the pulse-echo principle, specifically implemented using a 40kHz piezoelectric ceramic transducer. It calculates the distance between the probe and the gear surface by transmitting and receiving ultrasonic signals.

[0074] Specifically, the sensor body is rigidly connected to the housing via external threads, establishing a stable detection reference surface. During use, the ultrasonic sensor outputs a gap signal in real time, triggering an internal thread adjustment action when the detected gap exceeds a threshold. The speed detection probe collects the gear speed under the optimized gap, and its signal, along with the ultrasonic ranging data, is synchronously transmitted to the processing unit of the external testing system for subsequent calculation of parameters such as dynamic gap.

[0075] Compared to existing technologies, traditional sensors are fixed in place using bolts, which cannot dynamically adjust the detection position. This solution integrates mechanical positioning and dynamic adjustment through a double-threaded structure, overcoming positional limitations while maintaining installation stability. Furthermore, the ultrasonic sensor probe 15 identifies the position of the measured point and provides timely feedback to the tester, thereby improving the operability of blind installation and ensuring consistency between the test probe and the measured position.

[0076] The aforementioned adaptive speed sensor has advantages such as automatic distance adjustment, visualization, and ease of operation, which can save testing time and improve testing accuracy. The collected speed data can provide direct basis for the analysis of gear pair meshing state, help accurately identify the root cause of impact noise, and guide the precise optimization of gear clearance parameters.

[0077] In some embodiments of the present invention, please continue to refer to Figure 1 and Figure 2 The adaptive speed test sensor also includes a signal transmission line 16, which extends from the end of the sensor body 11 away from the gear being tested. One end of the signal transmission line 16 is connected to the speed detection probe 14 and the ultrasonic sensor probe 15, respectively, and the other end is used to connect to an external test system to transmit the speed detection signal and the distance detection signal.

[0078] The signal transmission line 16 is a wire bundle carrying electrical signals, which can be implemented using a multi-core shielded cable. Internally, it contains independent channels for transmitting rotational speed pulse signals and ultrasonic ranging signals respectively, to suppress the impact of electromagnetic interference on signal transmission quality. The external testing system refers to equipment with signal acquisition and analysis functions, which can be implemented using a combination of a multi-channel data acquisition instrument and host computer software, used to synchronously receive rotational speed signals and distance signals and perform correlation calculations.

[0079] A second aspect of the invention provides an electrically driven housing for impact testing.

[0080] Next, refer to Figure 3 This invention describes an electrically driven box for impact testing, based on some embodiments of the present invention.

[0081] like Figure 3 As shown, the electric drive box for impact testing includes: an electric drive box body 20 and multiple adaptive speed sensors 10 as described in the above embodiments.

[0082] The electric drive housing body 20 includes a housing 25 and a drive motor 21, an input shaft system 22, an intermediate shaft system 23, and a differential shaft system 24 assembled within the housing 25. The power output end of the drive motor 21 is connected to the input shaft system 22. The input shaft system 22, the intermediate shaft system 23, and the differential shaft system 24 are sequentially connected. The housing 25 has multiple openings 26 with internal threads. Figure 2 Only one is shown in the image), and the internal thread of each opening 26 is respectively connected to the corresponding adaptive speed sensor 10. Figure 2 Only one is shown in the image. The external thread is matched.

[0083] Each adaptive speed sensor 10 is connected to the internal thread of the corresponding opening 26 via an external thread. The detection ends of the plurality of adaptive speed sensors 10 face the gear under test in each shaft system to collect the speed signals of the input shaft system 22, the intermediate shaft system 23 and the differential shaft system 24.

[0084] The electric drive housing 20 can be assembled with an aluminum alloy cast shell and an internal transmission shaft system to simulate the power transmission path under real working conditions. The drive motor 21 is the power output device, providing controllable torque input to the transmission chain. The input shaft system 22 is the power input transmission component, used to transmit motor power to the intermediate shaft system 22. The intermediate shaft system 22 is a speed-changing transition transmission component, used to change the transmission ratio and distribute torque. The differential shaft system 23 is a torque distribution transmission component, used to achieve differential movement between the half-shafts.

[0085] Multiple adaptive speed sensors 10 are respectively arranged at the positions of the gears being measured on each shaft system in the housing, with the detection end aligned with the gear rotation surface through the pre-drilled mounting holes in the housing. A rotary transformer is installed at the motor shaft to collect the actual speed signal of the motor shaft. When the electric drive unit operates under impact conditions, the speed of each shaft system in the transmission chain fluctuates due to changes in dynamic clearance. The adaptive speed sensors simultaneously collect the speed signals of the input shaft system, intermediate shaft system, and differential shaft system. By comparing the phase difference and fluctuation amplitude of the speed signals of different shaft systems, transmission nodes with abnormal dynamic clearance can be identified.

[0086] This solution establishes a multi-axis synchronous monitoring mechanism by arranging sensors at key nodes of the complete transmission chain. By collecting speed fluctuation signals in real time, it can capture the dynamic meshing state of the gear pair when torque changes suddenly, accurately locate the specific transmission link with abnormal dynamic clearance of the gear pair, and provide data support for optimizing gear clearance parameters. This avoids the problem of blindly adjusting the clearance due to the inability to distinguish the effects of multi-stage transmission in traditional methods.

[0087] In some embodiments of the present invention, the number of openings on the housing corresponding to the positions of the gears under test of the input shaft system, the intermediate shaft system, and the differential shaft system is at least one, and the distance between the detection end of the adaptive speed sensor in each opening and the gear under test is equal.

[0088] The position of the gear being measured refers to the position of the corresponding housing surface of the gear meshing area in the input shaft system, intermediate shaft system, and differential shaft system. The specific position can be determined according to the gear transmission path, ensuring that the sensor detection end is directly facing the gear detection surface.

[0089] See below Figure 4a and Figure 4b Please provide a detailed explanation.

[0090] like Figure 4a As shown, internally threaded holes are made at the corresponding positions of the gears being measured on each shaft system of the housing, so that at least one adaptive speed sensor 10 is arranged on each shaft system. The adaptive speed sensor 10 is screwed into the opening 26 of the housing through an external thread, so as to achieve axial alignment between the sensor detection end and the gear detection surface. Figure 4b As shown, during the threaded engagement process, the sensor is screwed into the housing along the thread lead, and its axial movement is controlled by the thread pitch. The gap 28 formed between the adaptive speed test sensor 10 and the gear 27 under test refers to the minimum distance between the ultrasonic sensor probe of the adaptive speed test sensor and the tip circle of the gear 27 under test. When arranging the adaptive speed sensors 10, the gap between each adaptive speed test sensor 10 and the gear 27 under test is consistent to ensure the consistency of subsequent data results.

[0091] Through the above technical solution, this embodiment solves the problems of insufficient sensor positioning accuracy and poor installation reliability under dynamic working conditions, and ensures that the sensor detection end and the gear detection surface maintain a stable alignment relationship, avoiding measurement errors caused by installation offset or vibration displacement, and providing a reliable guarantee for accurate measurement of gear dynamic clearance under impact conditions.

[0092] A third aspect of the present invention provides an impact testing method for an electric drive box, applied to the electric drive box described in the above embodiments.

[0093] Next, refer to Figure 5 This invention describes the impact testing method for an electric drive box according to some embodiments of the present invention.

[0094] like Figure 5 As shown, the method includes the following steps S510-S540.

[0095] Step S510: Arrange the plurality of adaptive speed sensors on the housing of the electric drive box to be tested, so that the distance between the speed detection probe of the adaptive speed sensor and the gear under test is equal.

[0096] Step S520: Arrange a torque sensor on the drive half-shaft of the differential shaft system;

[0097] Step S530: Conduct a full vehicle test under a preset impact condition, and collect the speed signal through the adaptive speed sensor and the torque signal through the torque sensor.

[0098] Step S540: Based on the rotational speed signal and the torque signal, obtain the dynamic clearance of the gear under test under the preset impact condition.

[0099] Among them, a torque sensor is a device that can measure changes in the torque of a rotating shaft. Specifically, it can be implemented using strain gauge or magnetoelastic sensors to capture transient characteristics at the moment the torque crosses zero. Dynamic clearance refers to the instantaneous change in meshing clearance of a gear pair under impact load. It can be calculated from the angular displacement difference and is used to characterize the elastic deformation and thermal expansion effects of gears during actual operation.

[0100] Specifically, by equidistantly arranging adaptive speed sensors, the consistency of speed detection benchmarks for each shaft system is ensured, eliminating measurement errors caused by installation deviations. Torque sensors are positioned at the differential half-shaft to accurately capture load characteristics at moments of sudden torque changes. During vehicle testing, speed and torque signals are simultaneously acquired, and the angular displacement of each shaft system is obtained through integration processing. Combined with the timing nodes at the torque zero-crossing point, the angular displacement difference between meshing shafts is calculated. This difference directly reflects the dynamic clearance change of the gear pair under impact loads, encompassing the combined effects of elastic deformation, thermal expansion, and wear accumulation.

[0101] Compared to existing technologies, traditional methods rely solely on gear clearance parameters determined at the initial design stage, failing to reflect clearance changes caused by shaft deformation and thermal expansion under dynamic operating conditions. This solution utilizes multi-sensor collaborative detection to dynamically correlate the moment of torque mutation with angular displacement changes, accurately separating instantaneous clearance fluctuations under impact loads. This provides real-world data support for gear clearance optimization, effectively improving the diagnostic accuracy of impact noise problems.

[0102] In some embodiments of the present invention, the dynamic clearance of the gear under test under the preset impact condition is obtained based on the rotational speed signal and the torque signal, including:

[0103] The rotational speed signal is integrated to obtain the angular displacement of each measured shaft system;

[0104] The moment when the half-shaft torque crosses zero is determined based on the torque signal;

[0105] Calculate the angular displacement difference between any two meshing shaft systems at the moment when the half-shaft torque crosses zero;

[0106] The dynamic clearance value of the gear under test is obtained based on the angular displacement difference.

[0107] The moment when the half-shaft torque crosses zero refers to the critical state of the transmission system's positive and negative torque switching. This can be achieved by detecting the zero point position of the torque signal when it changes from positive to negative or from negative to positive, at which point the contact direction of the gear meshing surface changes abruptly. The dynamic clearance value can be derived from the conversion relationship between angular displacement difference and gear transmission ratio.

[0108] Next, combined Figure 6 The impact testing methods for the electric drive box of some embodiments of the present invention will be described in detail.

[0109] Vehicle sensor layout diagram reference Figure 6 In the diagram, the green dot represents speed measurement point 64, and the blue rectangular dot represents torque measurement point 63. Drive motor 21, intermediate shaft system 23, differential shaft system 24, left wheel 62a, and right wheel 62b are selected as speed measurement points 64, and adaptive speed sensors are arranged at the corresponding positions.

[0110] Torque measuring points 63 are set on the left drive half-shaft 61a and right drive half-shaft 61b of the differential shaft system 24, and torque sensors are arranged thereon.

[0111] After the sensor setup and equipment debugging are completed, set the sampling frequency parameters. Preferably, collect at least 5 sets of data to improve the speed of subsequent data analysis.

[0112] The vehicle was tested, and signal acquisition was carried out under test conditions of forward speed of 8kph, 10kph, 15kph, 20kph, and 30kph, as well as test conditions of reverse speed of 7-8kph. The moment or test condition range with the most obvious impact was selected for signal acquisition.

[0113] The following combination Figure 7 The calculation method and principle of dynamic time slots are explained. Figure 7 The motor shaft system is an integrated shaft design. According to data analysis, impact problems are prone to occur at high-speed spline or gear joints. Therefore, it is only necessary to measure the relevant information of the two shaft systems shown in the figure, specifically including the torque signal T (time) of the transmission half shaft, the speed (angular velocity) signal ω1 (time) of the first shaft system 71, and the angular velocity and torque data of the speed (angular velocity) signal ω2 (time) of the second shaft system 72.

[0114] Integrating the rotational speed (angular velocity) signals ω1(time) and ω2(time) respectively, and integrating over ω1(time), yields the angular displacement curve of the first shaft system. in:

[0115]

[0116] Integrating over ω²(time) yields the angular displacement curve of the second axis system. in:

[0117]

[0118] The difference in angular displacement between the two shaft systems can be obtained based on the angular displacements of the first and second shaft systems, using the following formula:

[0119]

[0120] in, This represents the difference in angular displacement.

[0121] When gears mesh, if there is no clearance, the angular displacement of the two shafts should be in a fixed proportion according to the transmission ratio; if there is dynamic clearance, when the torque changes (such as crossing zero), the rotation of the two shafts will be asynchronous, and the difference in angular displacement will fluctuate significantly. This difference directly reflects the difference in relative motion between the gears.

[0122] The angular displacement difference signal and the torque signal are transformed using coordinates to ultimately extract the dynamic clearance.

[0123] Angular displacement difference in the time domain Related to torque T (time), it is transformed into a relationship in the torque domain.

[0124] For the Tip in / Tip out condition corresponding to the moment when the torque crosses zero, the gear will cross the dynamic clearance due to the sudden change in torque direction. The angular displacement difference at this moment is the gear dynamic clearance.

[0125] Figure 8a The collected speed and torque data are shown. Figure 8b The simulation results of the dynamic gap are shown. Figure 8a The horizontal axis represents time, the vertical axis represents speed on the left and torque on the right, and the red, green and blue curves represent the middle shaft, differential shaft and left half shaft, respectively; Figure 8b The horizontal axis represents the drive motor angle, and the vertical axis represents torque, measured in Newton-meters (N·m). The red curve represents the output torque, also measured in N·m. The difference in drive motor angle at the moment the torque crosses zero is the dynamic backlash. This dynamic backlash, together with the designed static backlash, determines the variability of the clunk problem.

[0126] This solution integrates the dynamic characteristics of speed and torque signals, extracts the angular displacement difference at the critical moment when the torque crosses zero, and directly quantifies the dynamic meshing clearance of the gear pair under real working conditions. This overcomes the defect of deviation between static parameters and actual dynamic values, and can provide a direct basis for subsequent gear design. It has strong guiding significance for the precise optimization of gear clearance parameters.

[0127] In some embodiments of the present invention, the input shaft system, the intermediate shaft system, and the differential shaft system are assembled with the housing via support bearings; the impact testing method further includes:

[0128] A vibration sensor is arranged on the surface of the housing at the support bearing.

[0129] A whole vehicle test was conducted under a preset impact condition, and the three-dimensional vibration signal was collected by the vibration sensor.

[0130] Based on the aforementioned triaxial vibration signals, an objective evaluation result of the impact strength is obtained;

[0131] The objective evaluation results are fitted with the pre-obtained subjective evaluation results to obtain a comprehensive subjective and objective evaluation result of the impact strength of the electric drive box under test.

[0132] Specifically, the bearing support area on the housing surface is a specific area on the electric drive housing used for mounting and fixing the shaft support bearings. It is a key connection point for achieving rotational support between the shaft system and the housing. The input shaft system, intermediate shaft system, and differential shaft system within the electric drive housing need to be assembled with the housing through the support bearings. Vibration sensors can be implemented using triaxial accelerometers. This arrangement can directly capture the vibration energy transmitted from the shaft system's dynamic load to the housing. The triaxial vibration signal refers to vibration acceleration data in the three orthogonal directions (X, Y, and Z), which can be achieved by simultaneously acquiring time-domain waveforms along the three axes, fully reflecting the spatial propagation characteristics of the impact load.

[0133] Objective evaluation results refer to impact strength indices calculated based on the quantification of vibration signals. Specifically, peak-to-peak value, RMS value, or energy integral algorithms can be used to establish repeatable and verifiable engineering evaluation standards. Subjective evaluation results can be obtained using existing methods, which will not be elaborated upon here. Comprehensive subjective and objective evaluation results refer to joint evaluation results that integrate experimental data and human perception. They are based on measured data and the subjective evaluation of on-site testers. The evaluation indicators are generated based on measured data and will not change with the engineer's subjective interpretation.

[0134] In existing technologies, the objective evaluation index for test data typically uses the impact intensity evaluation index at the TITO moment (torque zero crossing). Generally, the root mean square (RMS) value of the three-dimensional vibration of the reducer housing (intermediate shaft) is taken as the evaluation index. However, based on the combined assessment of current test data and subjective evaluation, it has been found that data processed using the RMS method tends to be undervalued, failing to accurately reflect the true state of vibration. This solution acquires the complete three-dimensional distribution characteristics of impact energy through three-dimensional vibration signal acquisition, thus accurately reflecting the vibration state. Combined with a subjective and objective data fusion algorithm, the evaluation results can accurately identify abnormal vibration characteristics in the bearing support area and accurately predict the intensity of impact perceived by the human body, providing bidirectional data support for gear clearance optimization.

[0135] The following examples illustrate the testing and calculation process for objective evaluation results.

[0136] Vibration sensors are placed on the housing surface at the support bearing of the high-speed, low-inertia shaft system. For an integrated shaft electric drive system, the high-speed, low-inertia shaft system mainly consists of the motor shaft gear and its mating gear. For a splined motor-electric drive assembly, the high-speed, low-inertia shaft system mainly consists of the spline of the motor and the internal spline of the mating gear.

[0137] The vehicle was tested under TITO conditions, and three-dimensional vibration signals were collected by vibration sensors.

[0138] The peak-to-peak value of the triaxial vibration acceleration at the moment when the torque crosses zero (i.e., when the torque changes from positive to negative or from negative to positive) is extracted from the triaxial vibration signal. An objective evaluation index value is then calculated using the following formula, which serves as the objective evaluation result of the impact strength:

[0139]

[0140] Among them, X P-P The peak-to-peak value of the vibration acceleration in the X direction of the adaptive speed sensor, and the peak-to-peak value of the Y direction. P-P The peak-to-peak value of the vibration acceleration in the Y direction of the adaptive speed sensor, Z P-P The peak-to-peak value of the vibration acceleration in the Z direction of the adaptive speed sensor is given, and RSS is an objective evaluation index value.

[0141] Here, the peak-to-peak value of vibration acceleration refers to the maximum difference between the positive and negative peak values ​​in the vibration signal waveform. It can be extracted through time-domain signal processing algorithms and is used to characterize the maximum instantaneous energy of an impact event.

[0142] Through the above technical solution, this embodiment achieves multi-dimensional objective quantification of impact intensity, truly reflects the actual state of vibration, and has consistency between subjective and objective factors; it provides accurate vibration energy data for dynamic deviation analysis of gear clearance, so that the correlation analysis of subjective and objective evaluation results has a quantifiable physical basis, thereby effectively supporting the accurate formulation of gear clearance optimization strategies.

[0143] In some embodiments of the present invention, before arranging the plurality of adaptive speed sensors on the housing of the electric drive box under test, the impact testing method further includes: calibrating the linear relationship between the measured torque and the output voltage of the torque sensor using a static torsion test bench. This will be explained in detail below with reference to Figure 8.

[0144] Figure 9 These are schematic diagrams of the static torsion test bench structure according to some embodiments of the present invention. Please refer to them. Figure 9 The static torsion test bench provides a stable loading environment free from dynamic disturbances during the calibration process. It includes: a fixed end 91, a first splined fixture 92a, a second splined fixture 92b, a drive half-shaft 93, a torque output end 94, and a motor end fixture 95. The torque output end 96 applies a preset standard torque to the drive half-shaft, simulating the torque load on the half-shaft during electric drive unit operation. The motor end fixture 95 connects and fixes one end of the drive half-shaft to the torque output end of the static torsion test bench, ensuring stable torque transmission to the drive half-shaft 93.

[0145] Before calibration, strain gauges 97a and 97b (highlighted in red in the enlarged image) are symmetrically attached to strain gauge positions 96 on the transmission half-shaft 93 as strain measurement point pairs. The transmission half-shaft 93 is connected to the motor end fixture 95 via the first splined fixture plate 92a, and finally fixed to the fixed end 91 via the second splined fixture plate 92b. The motor end fixture 95 is then fixed to the torque output end of the static torsion tester, causing the transmission half-shaft 93 to undergo torsional deformation when torque is applied to the static torsion tester. When the half-shaft undergoes a small torsional deformation, the resistance of the strain gauges changes synchronously with the deformation, thus outputting a corresponding voltage signal. Through calibration, the change in voltage signal can be converted into the magnitude of the torque value.

[0146] By continuously adjusting the voltage, a linear relationship between torque and voltage is fitted.

[0147] T=kU+b

[0148] Where T is torque, U is voltage, k is linear slope, and b is initial torque value.

[0149] By calibrating this invention, the output signal of the torque sensor is accurately matched with the actual torque value, avoiding the calculation error of gear dynamic clearance caused by sensor nonlinearity or zero-point drift, and providing a reliable torque data basis for accurate analysis of gear meshing state under impact conditions.

[0150] The method of this invention can be applied to iterative verification and simulation parameter optimization processes for different vehicle models, providing guidance for new vehicle development. The speed sensor used in this invention has a simple structure and provides clear test results, making it suitable for promotion as a group standard.

[0151] Finally, it should be noted that the above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the application methods and principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the methods described in the above specific embodiments of the present invention. Therefore, the methods described above are only preferred and have no limiting significance.

Claims

1. An adaptive speed sensor, characterized in that: Includes the sensor body, external thread positioning structure, internal thread adjustment structure, speed detection probe, and ultrasonic sensor probe; The external thread positioning structure is provided on the outer side wall of the sensor body and is used to engage with the threaded hole of the preset internal thread opening on the electric drive housing under test to realize the fixation and positioning of the sensor body on the electric drive housing under test. The internal thread adjustment structure is located inside the sensor body and is connected to the speed detection probe and the ultrasonic sensor probe. By rotating the internal thread adjustment structure, the speed detection probe and the ultrasonic sensor probe can be driven to move along the axial direction of the sensor body to adjust the test gap between the speed detection probe and the gear under test in the electric drive box under test. The ultrasonic sensor probe and the speed detection probe are arranged side by side along the axial direction of the sensor body, and the detection end of the ultrasonic sensor probe and the detection end of the speed detection probe are facing the same direction. The ultrasonic sensor probe is used to detect the distance between the speed detection probe and the gear under test in real time and output a distance detection signal. The speed detection probe is used to collect the speed signal of the shaft system inside the electric drive box under test.

2. The adaptive speed sensor according to claim 1, characterized in that: The adaptive speed test sensor also includes a signal transmission line, which extends from the end of the sensor body away from the gear being tested. One end of the signal transmission line is connected to the speed detection probe and the ultrasonic sensor probe, respectively, and the other end is used to connect to an external test system to transmit the speed detection signal and the distance detection signal.

3. An electric drive box for impact testing, characterized in that, Includes an electric drive housing and a plurality of adaptive speed sensors as described in any one of claims 1 to 2; The electric drive box body includes a housing and a drive motor, an input shaft system, an intermediate shaft system, and a differential shaft system assembled in the housing. The power output end of the drive motor is connected to the input shaft system. The input shaft system, the intermediate shaft system, and the differential shaft system are connected in sequence. The housing has multiple openings with internal threads, and the internal thread of each opening matches the external thread of the corresponding adaptive speed sensor. Each adaptive speed sensor is connected to the internal thread of the corresponding opening via an external thread. The detection ends of the multiple adaptive speed sensors face the gear under test in each shaft system to collect the speed signals of the input shaft system, the intermediate shaft system, and the differential shaft system.

4. The electric drive box for impact testing according to claim 3, characterized in that: The housing has at least one opening corresponding to the position of the gear being tested in the input shaft system, the intermediate shaft system, and the differential shaft system. The distance between the detection end of the adaptive speed sensor in each opening and the gear being tested is equal.

5. An impact testing method for an electric drive box, applied to the electric drive box according to any one of claims 3 to 4, characterized in that: The impact testing method includes: The plurality of adaptive speed sensors are arranged on the housing of the electric drive box under test, such that the distance between the speed detection probe of the plurality of adaptive speed sensors and the gear under test is equal. A torque sensor is arranged on the drive half-shaft of the differential shaft system; The vehicle was tested under a preset impact condition. The speed signal was collected by the adaptive speed sensor and the torque signal was collected by the torque sensor. Based on the rotational speed signal and the torque signal, the dynamic clearance of the gear under test under the preset impact condition is obtained.

6. The impact testing method for the electric drive box according to claim 5, characterized in that: Based on the speed signal and the torque signal, the dynamic clearance of the gear under test under the preset impact condition is obtained, including: The rotational speed signal is integrated to obtain the angular displacement of each measured shaft system; The moment when the half-shaft torque crosses zero is determined based on the torque signal; Calculate the angular displacement difference between any two meshing shaft systems at the moment when the half-shaft torque crosses zero; The dynamic clearance value of the gear under test is obtained based on the angular displacement difference.

7. The impact testing method for the electric drive box according to claim 5, characterized in that: The input shaft system, the intermediate shaft system, and the differential shaft system are assembled with the housing via support bearings; The impact testing method also includes: A vibration sensor is arranged on the surface of the housing at the support bearing. A whole vehicle test was conducted under a preset impact condition, and the three-dimensional vibration signal was collected by the vibration sensor. Based on the aforementioned triaxial vibration signals, an objective evaluation result of the impact strength is obtained; The objective evaluation results are fitted with the pre-obtained subjective evaluation results to obtain a comprehensive subjective and objective evaluation result of the impact strength of the electric drive box under test.

8. The impact testing method for the electric drive box according to claim 7, characterized in that: Based on the aforementioned triaxial vibration signals, an objective evaluation result of the impact strength is obtained, including: The peak-to-peak value of the triaxial vibration acceleration at the moment the torque crosses zero is extracted from the triaxial vibration signal, and the objective evaluation index value is calculated using the following formula as the objective evaluation result of the impact strength: Among them, X P-P The peak-to-peak value of the vibration acceleration in the X direction of the adaptive speed sensor, and the peak-to-peak value of the Y direction. P-P The peak-to-peak value of the vibration acceleration in the Y direction of the adaptive speed sensor, Z P-P The peak-to-peak value of the vibration acceleration in the Z direction of the adaptive speed sensor is given, and RSS is an objective evaluation index value.

9. The impact testing method for an electric drive box according to claim 7, characterized in that: The vibration sensor is arranged on a high-speed, low-inertia shaft system.

10. The impact test method for an electric drive box according to any one of claims 6 to 8, characterized in that: Before arranging the plurality of adaptive speed sensors on the housing of the electric drive unit under test, the impact testing method further includes: calibrating the linear relationship between the measured torque and the output voltage of the torque sensor using a static torsion test bench, wherein the linear relationship is expressed as: T=kU+b Where T is torque, U is voltage, k is linear slope, and b is initial torque value.

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