A method and device for detecting abnormal noise of a differential

Abstract

The embodiment of the application discloses a differential mechanism abnormal sound detection method and device, the differential mechanism abnormal sound detection method comprises the following steps: judging the sound intensity of the differential mechanism, and obtaining a sound intensity judgment result; determining that the differential mechanism is in a normal state according to the sound intensity judgment result, judging the vibration of the differential mechanism, and obtaining a vibration judgment result. The differential mechanism abnormal sound detection method provided by the embodiment of the application can directly and conveniently judge whether the differential mechanism generates abnormal sound through sound intensity judgment, so as to save the time and cost required for detection; through vibration judgment, whether the differential mechanism generates abnormal sound can be judged by comparing objective vibration data, so that the accuracy of the differential mechanism abnormal sound detection is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method and device for detecting abnormal noises in a differential. Background Technology

[0002] As a key component of vehicle steering, the differential achieves differential turning of the left and right wheels through internal friction torque. However, if the friction torque is too large, it will cause stick-slip noise, leading to NVH (Noise, Vibration, Harshness) problems for the entire vehicle and affecting the user experience.

[0003] The relevant technologies for identifying abnormal noises during turns generally involve testing and identification after the entire vehicle has been taken off the production line, and then evaluated by evaluators. However, since different evaluators have different levels of sound recognition ability, relying solely on human hearing may result in misjudgments or omissions. Summary of the Invention

[0004] In view of this, the embodiments of this application aim to provide a method and device for detecting abnormal noise in a differential, which can improve the accuracy of detecting abnormal noise in a differential.

[0005] To achieve the above objectives, embodiments of this application provide a method for detecting abnormal noise in a differential, comprising: The differential is subjected to sound intensity judgment, and the sound intensity judgment result is obtained; Based on the sound intensity judgment result, it is determined that the differential is in a normal state. Vibration judgment is then performed on the differential to obtain the vibration judgment result.

[0006] In some embodiments, the step of judging the sound intensity of the differential and obtaining the sound intensity judgment result specifically includes: Obtain the preset sound intensity value and the actual sound intensity value of the differential; Compare the actual sound intensity value with the preset sound intensity value; If the actual sound intensity value is not greater than the preset sound intensity value, the differential is in a normal state; if the actual sound intensity value is greater than the preset sound intensity value, the differential is in an abnormal noise state.

[0007] In some embodiments, the abnormal noise detection method includes: Based on the sound intensity judgment result, it is determined that the differential is in an abnormal noise state, and the differential is subjected to break-in treatment.

[0008] In some embodiments, the step of performing vibration judgment on the differential and obtaining the vibration judgment result specifically includes: Obtain the preset vibration limit and actual vibration value of the differential; Compare the actual vibration value with the preset vibration limit value; If the actual vibration value is determined to be no greater than the preset vibration limit, the differential is in a normal state; if the actual vibration value is determined to be greater than the preset vibration limit, the differential is in an abnormal noise state.

[0009] In some embodiments, the abnormal noise detection method includes: Based on the vibration assessment results, it was determined that the differential was in an abnormal noise state, and the differential underwent a break-in process.

[0010] In some embodiments, the abnormal noise detection method includes: Based on the vibration judgment result, it is determined that the differential is in a normal state. The torque distribution coefficient of the differential is judged, and the torque distribution coefficient judgment result is obtained.

[0011] In some embodiments, the step of determining the torque distribution coefficient of the differential and obtaining the torque distribution coefficient determination result specifically includes: Obtain the theoretical torque distribution coefficient and the actual torque distribution coefficient of the differential; If the difference between the actual torque distribution coefficient and the theoretical torque distribution coefficient is not greater than a preset difference range, the differential is in a normal state; if the difference between the actual torque distribution coefficient and the theoretical torque distribution coefficient is greater than a preset difference range, the differential is in an abnormal noise state.

[0012] In some embodiments, the abnormal noise detection method includes: Based on the torque distribution coefficient, it is determined that the differential is in an abnormal noise state, and the differential is subjected to a break-in process.

[0013] In some embodiments, after a preset number of break-in cycles, if the differential is found to be in an abnormal noise state after break-in, the torque distribution coefficient of the differential is adjusted.

[0014] In some embodiments, before determining the acoustic intensity of the differential, the following steps are also included: Under preset operating conditions, the torque distribution coefficient of the differential is tested for a first preset number of test cycles to obtain multiple test torque distribution coefficients corresponding to the first preset number of test cycles. The test torque distribution coefficient of the last test cycle of the first preset test cycle is taken as the actual torque distribution coefficient.

[0015] This application also provides a differential noise detection device, comprising: A test bench is used to mount the differential for detecting abnormal noises from the differential. A vibration sensor is used to obtain the actual vibration value of the differential.

[0016] The differential noise detection method provided in this application embodiment can intuitively and conveniently determine whether the differential is making abnormal noise by judging the sound intensity, thus saving the time and cost required for detection; by judging the vibration, it can determine whether the differential is making abnormal noise by comparing objective vibration data, thereby improving the accuracy of differential noise detection. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a method for detecting abnormal noise from a differential provided in one embodiment of this application. Figure 2 This is a flowchart illustrating a method for detecting abnormal noise from a differential provided in another embodiment of this application. Figure 3 This is a flowchart illustrating a method for detecting abnormal noise from a differential provided in another embodiment of this application. Detailed Implementation

[0018] It should be noted that, unless otherwise specified, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed descriptions in the specific implementation should be understood as explanations of the purpose of this application and should not be regarded as undue limitations on this application.

[0019] This application provides a method for detecting abnormal noise in a differential, the method comprising: S1: Determine the sound intensity of the differential and obtain the sound intensity determination result; S2: Based on the sound intensity judgment result, determine that the differential is in a normal state, perform vibration judgment on the differential, and obtain the vibration judgment result.

[0020] The specific implementation method of the above steps in the differential noise handling method is described below.

[0021] S1: Determine the sound intensity of the differential and obtain the sound intensity determination result.

[0022] Understandably, during vehicle skidding or cornering, the differential will produce stick-slip noise, i.e., abnormal noise from the differential, leading to NVH (Noise, Vibration, and Harshness) issues for the entire vehicle. The abnormal noise emitted by the differential has a certain acoustic intensity, which can be easily detected by instruments for measuring acoustic intensity, or, when the intensity is sufficiently high, can be directly perceived by the human ear, thus determining whether an abnormal noise is occurring from the differential. Therefore, judging acoustic intensity is relatively intuitive and convenient, saving time and costs associated with testing.

[0023] S2: Based on the sound intensity judgment result, determine that the differential is in a normal state, perform vibration judgment on the differential, and obtain the vibration judgment result.

[0024] Understandably, differentials have certain preset vibration limits. When a differential makes abnormal noise, it is accompanied by vibration exceeding the limit, meaning the actual vibration value of the differential when abnormal noise occurs is greater than the preset vibration limit. Therefore, vibration assessment of the differential allows for comparison with objective vibration data to determine whether abnormal noise is occurring, thereby improving the accuracy of differential noise detection.

[0025] In some embodiments, the step of determining the sound intensity of the differential and obtaining the sound intensity determination result specifically includes: Obtain the preset and actual sound intensity values ​​of the differential; Compare the actual sound intensity value with the preset sound intensity value; If the actual sound intensity value is not greater than the preset sound intensity value, the differential is in normal condition; if the actual sound intensity value is greater than the preset sound intensity value, the differential is in abnormal noise condition.

[0026] Under normal circumstances, the noise emitted by the differential exceeds the preset noise level and will be quite loud. Therefore, by comparing the actual noise level with the preset noise level, it is possible to determine whether the differential is in an abnormal noise state or in a normal state, and to perform subsequent processing steps according to the state of the differential.

[0027] The actual sound intensity value can be detected by instruments that measure sound intensity. The specific type of instrument used to measure sound intensity is not limited, such as a decibel meter.

[0028] The specific value of the preset sound intensity is not limited. For example, the preset sound intensity value can be in the range of 70 dB to 80 dB, such as 70 dB, 72 dB, 75 dB, 77 dB and 80 dB.

[0029] It should be noted that the preset acoustic intensity value was obtained through bench steady-state testing. The specific control variables and test procedures involved in the bench steady-state testing of the preset acoustic intensity value are widely and maturely applied in related technologies, and will not be elaborated here.

[0030] In related technologies, the differential is a key component for vehicle steering. The internal friction torque of the differential is an inherent characteristic, and differential turning of the left and right wheels is achieved through this internal friction torque during steering. Simultaneously, friction torque is a key cause of abnormal noises during steering. The friction torque mainly originates from the friction torque of various structural components within the differential, such as the friction torque at the half-shaft gear shims, the friction torque between the planetary gears and the half-shaft gears, the friction torque at the planetary gear shims, and the friction torque at the planetary shaft. Furthermore, the magnitude of the friction torque of each structural component within the differential is primarily influenced by factors such as the coefficient of friction of the friction surfaces of these components.

[0031] In some embodiments, the method for detecting abnormal noise from the differential includes: Based on the sound intensity assessment, it was determined that the differential was in an abnormal noise state, and the differential underwent a break-in process.

[0032] It is understandable that burrs may exist between the mating surfaces of the internal structural components of a differential, leading to excessive frictional torque and thus abnormal noise. Therefore, by performing a break-in process on the differential, burrs between the mating surfaces can be eliminated, thereby reducing the frictional torque between the structural components. If the differential is found to be making abnormal noise by judging the sound intensity, it means that the internal friction torque of the differential is too large. In this case, the differential needs to be broken in to eliminate burrs between the mating surfaces. The surface of each structural component in the differential becomes smooth through the break-in process, thereby reducing the friction coefficient of the friction surfaces of each structural component and further reducing the friction torque between the structural components, thus reducing the probability of abnormal noise from the differential.

[0033] In some embodiments, the step of performing vibration assessment on the differential and obtaining the vibration assessment result specifically includes: Obtain the preset vibration limit and actual vibration value of the differential; Compare the actual vibration value with the preset vibration limit; If the actual vibration value is not greater than the preset vibration limit, the differential is in normal condition; if the actual vibration value is greater than the preset vibration limit, the differential is in abnormal noise condition.

[0034] Under normal circumstances, if the actual vibration value of the differential exceeds the preset vibration limit, abnormal noise will occur. Therefore, by comparing the actual vibration value with the preset vibration limit, it is possible to determine whether the differential is in an abnormal noise state or in a normal state, and to perform subsequent processing steps according to the state of the differential.

[0035] The actual vibration value of the differential can be detected by instruments that measure differential vibration. The specific type of instrument used to measure differential vibration is not limited, such as vibration sensors.

[0036] It should be noted that the preset vibration limit is obtained through bench steady-state testing. The specific control variables and test procedures involved in the bench steady-state testing of the preset vibration limit are widely and maturely applied in related technologies, and will not be elaborated here.

[0037] In some embodiments, the method for detecting abnormal noise from the differential includes: Based on the vibration assessment results, it was determined that the differential was in an abnormal noise state, and the differential underwent a break-in process.

[0038] Understandably, if vibration analysis determines that the differential is making abnormal noise, it indicates that the internal friction torque of the differential is too high. In this case, the differential needs to be broken in to eliminate burrs between the mating surfaces. This process makes the surfaces of the various structural components within the differential smooth, thereby reducing the friction coefficient of the friction surfaces of each component and further reducing the friction torque between the components, thus reducing the probability of abnormal noise from the differential.

[0039] In some embodiments, the break-in process for the differential during the first run-in period includes the following steps: The first break-in condition is cycled a first preset number of times, and the second break-in condition is cycled a second preset number of times; the break-in intensity of the first break-in condition is less than the break-in intensity of the second break-in condition.

[0040] It is understandable that the presence of burrs between the mating surfaces of the internal structural components of a newly installed differential can lead to excessive frictional torque between these components, resulting in abnormal noise. Therefore, by performing a first and second break-in cycle on the differential, the burrs between the mating surfaces can be eliminated, thereby reducing the frictional torque between the structural components.

[0041] The first break-in condition refers to a test bench simulating a vehicle speed of 60 km / h (Kilometer Per Hour) and a speed difference of 20 rpm (Revolutions Per Minute) between the left and right wheels. Under this condition, the break-in effect on the internal structural components of the differential is relatively weak, but it still ensures effective break-in between the mating surfaces of the components, eliminating burrs between them.

[0042] The second break-in condition refers to a scenario where the break-in speed difference of the differential is 50% of the preset speed difference required by the differential, and the break-in friction torque of the differential is 50% of the preset friction torque required by the differential. Under this second break-in condition, damage caused by excessive friction between structural components can be avoided, while ensuring a strong break-in effect between the internal structural components of the differential.

[0043] It should be noted that the required preset speed difference and preset friction torque of the differential can be obtained through bench steady-state testing or theoretical calculation. The specific control variables involved in the bench steady-state testing or theoretical calculation of the preset speed difference and preset friction torque are widely and maturely applied in related technologies and will not be elaborated upon here.

[0044] The specific number of the first preset number of times is not limited, such as 1 time, 2 times, 3 times, 4 times, etc.

[0045] The specific number of the second preset number of times is not limited, such as 4 times, 5 times, 6 times, 7 times, etc.

[0046] In some embodiments, the first preset number of runs is less than the second preset number of runs; for example, the first preset number of runs is 3 times and the second preset number of runs is 6 times. That is to say, after the differential undergoes 3 cycles of the first break-in condition and 6 cycles of the second break-in condition, the influence of burrs between the mating surfaces on the frictional torque between the structural components can be effectively eliminated. This makes the surfaces of each structural component in the differential smooth through break-in, thereby reducing the friction coefficient of the friction surfaces of each structural component. In this way, the frictional torque of the differential can be reduced, and the probability of abnormal noise from the differential can be reduced.

[0047] In some embodiments, after the first break-in cycle of the differential is performed 3 times under the first break-in condition and 6 times under the second break-in condition, it is necessary to perform abnormal noise detection on the differential after break-in.

[0048] If the differential is judged to be in normal condition after break-in, it means that the NVH problem caused by abnormal noise has been solved through the break-in process. The broken-in differential can be shipped out of the production line, thereby realizing risk identification before the differential leaves the factory for use, improving the product quality of the differential, greatly saving the later maintenance cost of the differential, and helping to improve the user experience.

[0049] If the differential is found to be making abnormal noises after the break-in period, it needs to undergo another round of break-in treatment. Specifically, the break-in process for the differential includes: cycling through a second preset number of times under a second break-in condition, wherein the cumulative value of the second preset number of break-in cycles is less than or equal to a preset number of break-in cycles.

[0050] Understandably, if a differential exhibits abnormal noise after break-in, it indicates that burrs between internal structural components have not been completely eliminated, or that the surfaces of these components are not smooth enough, resulting in a relatively high coefficient of friction between the friction surfaces of each component. Therefore, only a second break-in condition is applied to the differential to achieve the break-in goal more quickly under conditions with stronger break-in effects, saving time and costs.

[0051] It is understood that the second break-in condition and the second preset number of cycles can be equivalent to those in the aforementioned embodiments. This avoids damage to structural components due to excessive friction, and effectively eliminates the influence of burrs between mating surfaces on the frictional torque between structural components. This makes the surfaces of each structural component within the differential smooth through break-in, thereby reducing the friction coefficient of the friction surfaces of each component, further reducing the frictional torque of the differential, and lowering the probability of abnormal noise from the differential.

[0052] It should be noted that after each round of break-in for the differential, such as after each round of break-in treatment with 6 cycles of the second break-in condition, the differential after break-in should be tested for abnormal noise, and the sum of the second preset number of break-in treatments of the differential should be compared with the preset number of break-in cycles.

[0053] Specifically, if the differential is determined to be in a normal state after break-in, it can be shipped out. If the differential is determined to be in an abnormal noise state after break-in, and the cumulative value of the second preset number of break-in cycles is less than the preset number of break-in cycles, the differential needs to be broken in again, for example, 6 cycles under the second break-in condition, until the differential is determined to be in a normal state after break-in, then the break-in process ends, and the differential can be shipped out. Alternatively, if the differential is determined to be in an abnormal noise state after break-in, and the cumulative value of the second preset number of break-in cycles is equal to the preset number of break-in cycles, then the break-in process ends, and the torque distribution coefficient of the differential is adjusted.

[0054] The specific number of preset break-in cycles is not limited, such as 18, 24, 30, 36, etc.

[0055] In some embodiments, the preset number of break-in cycles is 30, and the break-in process is performed multiple times under the second break-in condition for the second preset number of cycles to achieve a better break-in effect.

[0056] Understandably, the second preset number of times can be a fixed value, such as 6 times. The preset number of break-in cycles is the sum of the second preset number of times. When the second preset number of times is a fixed value, that is, the preset number of break-in cycles is an integer multiple of the second preset number of times.

[0057] In related technologies, differentials are initially designed based on a specific theoretical torque distribution coefficient, and this coefficient is positively correlated with the differential's friction torque. Understandably, when the differential reaches the theoretical torque distribution coefficient during initial design, its performance is optimal and there are no abnormal noises. However, the torque distribution coefficient of the initially assembled differential can be affected by factors such as assembly precision or the quality of structural components, resulting in an error between the final torque distribution coefficient and the preset coefficient during initial design. In other words, the torque distribution coefficient of the assembled differential may be greater than the preset coefficient, leading to excessive friction torque and abnormal noises.

[0058] In some embodiments, the method for detecting abnormal noise from the differential includes: S3: Based on the vibration judgment results, determine that the differential is in a normal state, judge the torque distribution coefficient of the differential, and obtain the torque distribution coefficient judgment result.

[0059] Understandably, determining the torque distribution coefficient of a differential involves comparing its actual torque distribution coefficient upon initial installation with the theoretical torque distribution coefficient of the designed differential. If the actual torque distribution coefficient is greater than the theoretical torque distribution coefficient, and the error is significant, it will cause excessive frictional torque between structural components, resulting in abnormal noise. Therefore, comparing the actual torque distribution coefficient with the theoretical torque distribution coefficient to determine whether the differential is making abnormal noise can improve the accuracy of differential noise detection.

[0060] In some embodiments, the step of determining the torque distribution coefficient of the differential and obtaining the torque distribution coefficient determination result specifically includes: Obtain the theoretical torque distribution coefficient and the actual torque distribution coefficient of the differential; Compare the actual torque distribution coefficient with the theoretical torque distribution coefficient; If the difference between the actual torque distribution coefficient and the theoretical torque distribution coefficient is not greater than the preset difference range, the differential is in normal condition; if the difference between the actual torque distribution coefficient and the theoretical torque distribution coefficient is greater than the preset difference range, the differential is in abnormal noise condition.

[0061] Generally, if the actual torque distribution coefficient of the differential exceeds the theoretical torque distribution coefficient, it will cause excessive friction torque between structural components, resulting in abnormal noise. Therefore, by comparing the actual torque distribution coefficient with the theoretical torque distribution coefficient, it is possible to determine whether the differential is in an abnormal noise state or in a normal state, and to perform subsequent processing steps according to the state of the differential.

[0062] The specific value of the preset difference range is not limited. For example, the preset difference range is 10% of the theoretical torque distribution coefficient. That is, when the difference between the actual torque distribution coefficient and the theoretical torque distribution coefficient is greater than 10% of the theoretical torque distribution coefficient, the differential is in an abnormal noise state.

[0063] It should be noted that the preset difference range is obtained through bench steady-state testing. The specific control variables and test procedures involved in the bench steady-state testing of the preset difference range are widely and maturely applied in related technologies, and will not be elaborated here.

[0064] In some embodiments, the method for detecting abnormal noise from the differential includes: S4: Based on the torque distribution coefficient, it is determined that the differential is in an abnormal noise state, and the differential is subjected to break-in treatment.

[0065] Understandably, if the torque distribution coefficient indicates that the differential is making abnormal noise, it means that the internal friction torque of the differential is too high. In this case, the differential needs to be broken in to eliminate burrs between the mating surfaces. This process makes the surfaces of the various structural components in the differential smooth, thereby reducing the friction coefficient of the friction surfaces of each structural component and further reducing the friction torque between the structural components, thus reducing the probability of abnormal noise from the differential.

[0066] In some embodiments, see Figure 1 Methods for detecting abnormal noises in differentials include: S1: Determine the sound intensity of the differential and obtain the sound intensity determination result; S2: Based on the sound intensity judgment result, determine that the differential is in a normal state, perform vibration judgment on the differential, and obtain the vibration judgment result.

[0067] In some embodiments, see Figure 2 Methods for detecting abnormal noises in differentials include: S1: Determine the sound intensity of the differential and obtain the sound intensity determination result; S2: Based on the sound intensity judgment result, determine that the differential is in a normal state, perform vibration judgment on the differential, and obtain the vibration judgment result; S3: Based on the vibration judgment results, determine that the differential is in a normal state, judge the torque distribution coefficient of the differential, and obtain the torque distribution coefficient judgment result; S4: Based on the torque distribution coefficient, it is determined that the differential is in an abnormal noise state, and the differential is subjected to break-in treatment.

[0068] In other words, to determine if a differential is in a normal state, it must simultaneously meet the criteria for sound intensity, vibration, and torque distribution coefficient. If any one of these criteria indicates that the differential is making abnormal noise, the process proceeds directly to the next step: breaking in the differential. Thus, by using multiple diagnostic procedures to detect abnormal noise in the differential, the accuracy of noise detection can be greatly improved.

[0069] It should be noted that among the three judgments included in abnormal noise detection, the sound intensity judgment is the most intuitive and convenient method. Therefore, the sound intensity judgment should be performed first to save time and cost. However, the specific order of the vibration judgment and torque distribution coefficient judgment is not limited.

[0070] In some embodiments, before the step of detecting abnormal noise in the differential, the method further includes: detecting the actual torque distribution coefficient of the differential under preset operating conditions.

[0071] The preset operating condition refers to the extreme turning condition where the test bench simulates the vehicle speed at 15~20 km / h, with sudden acceleration, relaxed acceleration, and alternating left and right full steering wheel control. At the same time, in this operating condition, the torque of the differential is controlled within the preset range of the theoretical torque.

[0072] Under preset operating conditions, the torque of the left half-shaft and the torque of the right half-shaft of the differential can reach the maximum difference. By measuring the torque of the differential, the torque of the left half-shaft and the torque of the right half-shaft of the differential can be obtained, and the test torque distribution coefficient can be obtained by further calculation based on the two.

[0073] The specific type of instrument used to measure differential torque is not limited, such as a torque sensor.

[0074] The actual torque distribution coefficient can be obtained through multiple test torque distribution coefficients. Specifically, this means testing the differential under preset operating conditions for a first preset number of test cycles. The specific value of the first preset number of test cycles is not limited, such as 4, 5, 6, 7, etc. For example, the first preset number of test cycles is 5. In this way, multiple test torque distribution coefficients can be obtained through multiple tests, thereby reducing the error of the test torque distribution coefficient. The number of test torque distribution coefficients is 5.

[0075] The actual torque distribution coefficient is obtained by testing multiple torque distribution coefficients. The coefficient obtained from the last torque distribution coefficient test performed on the differential under preset operating conditions can be selected as the actual torque distribution coefficient. It is understandable that when the differential undergoes torque distribution coefficient testing under preset operating conditions, the internal structural components of the differential will undergo a break-in process. After multiple torque distribution coefficient tests, the differential tends to stabilize under preset operating conditions. Therefore, using the last torque distribution coefficient obtained from the preset operating conditions test as the actual torque distribution coefficient is more stable.

[0076] The specific value of the preset range of theoretical torque is not limited. For example, the preset range of theoretical torque is 15% to 20% of the theoretical torque. Controlling the torque of the differential to be within 15% to 20% of the theoretical torque can prevent damage to the differential.

[0077] It should be noted that the theoretical torque is obtained through bench steady-state testing. The specific control variables and testing procedures involved in the bench steady-state testing for the preset theoretical torque are widely and maturely applied in related technologies and will not be elaborated upon here.

[0078] In some embodiments, the differential is subjected to abnormal noise detection under preset operating conditions and a second preset number of test cycles.

[0079] The preset operating condition refers to a test bench simulating extreme cornering conditions with a vehicle speed of 15-20 km / h, sudden acceleration, relaxed acceleration, and alternating full steering wheel turns. Simultaneously, under these conditions, the torque of the differential is controlled within a preset range of its theoretical torque. Under these preset conditions, the likelihood of abnormal noise from the differential is significantly increased.

[0080] The specific number of the second preset test cycles is not limited. For example, under normal circumstances, the second preset test cycle is 1 time, that is, the differential is tested for abnormal noise once under preset operating conditions. This completes the three judgments included in the abnormal noise detection and determines whether the differential is in an abnormal noise state or in a normal state.

[0081] It should be noted that the abnormal noise treatment method in any of the above embodiments can be performed on the whole vehicle, or on the abnormal noise treatment device, or the abnormal noise treatment method can be divided into different steps and performed on the whole vehicle and the abnormal noise treatment device respectively.

[0082] In some embodiments, after a preset number of break-in cycles, if the differential is found to be in an abnormal noise state after break-in, the torque distribution coefficient of the differential is adjusted.

[0083] Understandably, after determining that the differential is in an abnormal noise state, in order to ensure that the burrs between the internal structural components of the differential are completely eliminated and that the surfaces of the internal structural components of the differential are sufficiently smooth, the differential needs to undergo a set number of break-in cycles.

[0084] After the break-in period is completed, the differential is determined to be in an abnormal noise state or a normal state by judging the sound intensity, vibration and torque distribution coefficients as described in the above embodiments.

[0085] If the differential is making abnormal noises, further improvement of the internal friction torque is needed. This can be achieved by adjusting the torque distribution coefficient of the differential, primarily by reducing the preset torque distribution coefficient required by the initial design of the differential, thereby reducing the friction torque and lowering the probability of abnormal noises from the differential.

[0086] If the differential is in normal condition, it means that the NVH problem caused by abnormal noise has been solved through the break-in process. The broken-in differential can be shipped out of the production line, thus realizing risk identification before the differential leaves the factory for use, improving the product quality of the differential, greatly saving later maintenance costs, and helping to improve the user experience.

[0087] In some embodiments, after adjusting the torque distribution coefficient of the differential, abnormal noise detection is performed on the adjusted differential to determine whether the adjusted differential is in an abnormal noise state.

[0088] If the adjusted differential is determined to be in a normal state, it means that by adjusting the torque distribution coefficient of the differential, the NVH problem caused by abnormal noise in the differential has been solved. The differential after break-in can be shipped out, thereby realizing risk identification before the differential leaves the factory for use, improving the product quality of the differential, greatly saving the later maintenance cost of the differential, and helping to improve the user experience.

[0089] If the adjusted differential is found to be in an abnormal noise state, the torque distribution coefficient of the differential needs to be readjusted, and subsequent abnormal noise treatment methods need to be implemented to ensure that the abnormal noise treatment method of this application can solve the NVH problem caused by the abnormal noise of the differential. That is, if the adjusted differential is found to be in an abnormal noise state, the torque distribution coefficient of the differential needs to be readjusted again until the abnormal noise test is passed.

[0090] In some embodiments, the step of adjusting the torque distribution coefficient of the differential includes: Obtain the adjustment torque distribution coefficient of the differential, where the adjustment torque distribution coefficient is less than the theoretical torque distribution coefficient; The surface treatment of the friction pairs of the differential is performed according to the torque distribution coefficient, or the size of the friction pairs of the differential is adjusted.

[0091] It's understandable that when a differential reaches its theoretical torque distribution coefficient during initial assembly, its performance is optimal and there are no abnormal noises. However, during the manufacturing and assembly process, factors such as assembly precision and the quality of structural components can cause discrepancies between the actual and theoretical torque distribution coefficients of the assembled differential. In other words, the actual torque distribution coefficient of the assembled differential may be greater than the theoretical torque distribution coefficient during initial design, resulting in excessive friction torque and abnormal noise.

[0092] Therefore, adjusting the torque distribution coefficient of a differential mainly involves redesigning the differential by obtaining a new torque distribution coefficient, which is called the adjustment torque distribution coefficient. The adjustment torque distribution coefficient should be less than the theoretical torque distribution coefficient to improve the tolerance of differential production and assembly. This reduces the probability that the adjusted differential's torque distribution coefficient will exceed the theoretical torque distribution coefficient, thereby reducing the likelihood of excessive friction torque in the differential causing abnormal noise.

[0093] Adjusting the torque distribution coefficient of a differential can be achieved by surface treatment of the differential's friction pairs. This mainly involves treating the surfaces of the structural components within the differential, such as phosphating, nickel plating, QPQ (Quench-Polish-Quench), and other plating processes. This makes the surfaces of the structural components within the differential smoother, reducing the friction coefficient of the friction surfaces of each component, thereby reducing the friction torque between the components and thus reducing the likelihood of abnormal noises from the differential.

[0094] Adjusting the torque distribution coefficient of the differential can be achieved by adjusting the dimensions of the friction pairs within the differential, primarily by adjusting the major and minor diameters of the structural components inside the differential. This improves the meshing relationship between the structural components, reduces the frictional torque between them, and thus lowers the likelihood of abnormal noises from the differential.

[0095] It should be noted that the adjustment torque distribution coefficient should be less than the theoretical torque distribution coefficient. Specifically, the difference between the adjustment torque distribution coefficient and the theoretical torque distribution coefficient should be within a preset difference range, which is 10% to 20% of the theoretical torque distribution coefficient, such as 10%, 12%, 14%, 16%, 18%, and 20%.

[0096] It should be noted that the abnormal noise detection of the differential after break-in and the abnormal noise detection of the differential after adjustment in the aforementioned embodiments are both abnormal noise detection of the differential, that is, the abnormal noise detection in both is carried out under preset operating conditions and a second preset number of test cycles.

[0097] It should be noted that, in the aforementioned embodiments, before performing abnormal noise detection on the differential after break-in and before performing abnormal noise detection on the differential after adjustment, it is necessary to detect the actual torque distribution coefficient of the differential under preset operating conditions. It is understood that since both the broken-in and adjusted differentials cause changes in their actual torque distribution coefficients, detecting the actual torque distribution coefficients of the broken-in and adjusted differentials under preset operating conditions can obtain the corresponding actual torque distribution coefficients for use in determining the torque distribution coefficient included in abnormal noise detection. This application also provides an abnormal noise detection device for a differential, which includes a testing bench and a vibration sensor. The testing bench is used to arrange the differential for abnormal noise detection and can also be used for break-in treatment of the differential; the vibration sensor is used to obtain the actual vibration value of the differential.

[0098] If abnormal noise testing and break-in are performed on the entire vehicle, and a cornering noise is discovered during the overall vehicle evaluation, the only solution is to replace the entire assembly. This is not only time-consuming but also disrupts the overall system's operation, resulting in significant losses. In contrast, testing on a noise control device allows for noise detection and break-in of the newly installed differential, simplifying the process. If the break-in differential is confirmed to be in normal condition, the NVH (noise, vibration, and harshness) issues caused by the noise are resolved. The broken-in differential can then be shipped out, enabling risk identification before the differential leaves the factory, improving product quality, significantly reducing future maintenance costs, and ultimately enhancing the user experience.

[0099] See below. Figure 3 This application provides a detailed description of the methods for handling abnormal noise from differentials in some embodiments.

[0100] S10: Input the friction torque parameters of the differential and calculate the theoretical torque distribution coefficient of the differential; S20: Test the torque distribution coefficient of the newly installed differential; S30: Perform an audio intensity test on the newly installed differential to determine whether the newly installed differential is in an abnormal noise state. If yes, proceed to step S60; otherwise, proceed to step S40. S40: Perform vibration judgment on the newly installed differential to determine whether the newly installed differential is in an abnormal noise state. If yes, proceed to step S60; otherwise, proceed to step S50. S50: Determine the torque distribution coefficient of the newly installed differential and determine whether the newly installed differential is in an abnormal noise state. If yes, proceed to step S60; otherwise, end the abnormal noise handling method. S60: Determine whether the number of times the differential has been broken in is greater than the preset number of break-in cycles. If yes, proceed to step S110; otherwise, proceed to step S70. S70: Run-in process for the differential; S80: Perform an audio intensity test on the differential after break-in. If the differential is found to be in an abnormal noise state after break-in, proceed to step S110. If the differential is found to be in a normal state after break-in, proceed to step S90. S90: Perform vibration judgment on the differential after break-in. If the differential is found to be in an abnormal noise state after break-in, proceed to step S110. If the differential is found to be in a normal state after break-in, proceed to step S100. S100: Determine the torque distribution coefficient of the differential after break-in. If the differential is found to be in an abnormal noise state after break-in, proceed to step S110. If the differential is found to be in a normal state after break-in, end the abnormal noise handling method. S110: Adjusts the torque distribution coefficient of the differential; S120: Judge the sound intensity of the adjusted differential. If the adjusted differential is in an abnormal noise state, execute step S110. If the adjusted differential is in a normal state, execute step S130. S130: Perform vibration judgment on the adjusted differential. If the adjusted differential is found to be in an abnormal noise state, proceed to step S110. If the adjusted differential is found to be in a normal state, proceed to step S140. S140: Determine the torque distribution coefficient of the adjusted differential. If the adjusted differential is found to be in an abnormal noise state, proceed to step S110. If the adjusted differential is found to be in a normal state, end the abnormal noise handling method.

[0101] The various embodiments / implementations provided in this application can be combined with each other without creating contradictions.

[0102] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for detecting abnormal noise in a differential, characterized in that, An abnormal noise detection device for the differential is used for detection. The abnormal noise detection device includes a test bench and a vibration sensor. The test bench is used to arrange the differential for abnormal noise detection. The vibration sensor is used to obtain the actual vibration value of the differential. The abnormal noise detection method includes: The differential is subjected to sound intensity judgment, and the sound intensity judgment result is obtained; Based on the sound intensity judgment result, it is determined that the differential is in a normal state. Vibration judgment is performed on the differential to obtain the vibration judgment result. Based on the sound intensity judgment result, it is determined that the differential is in an abnormal noise state. The differential is then subjected to break-in treatment. After a preset number of break-in cycles, it is determined that the differential is in an abnormal noise state after break-in. The torque distribution coefficient of the differential is then adjusted. Based on the vibration judgment result, it is determined that the differential is in a normal state. The torque distribution coefficient of the differential is judged, and the torque distribution coefficient judgment result is obtained. Based on the vibration judgment result, it is determined that the differential is in an abnormal noise state, and the differential is subjected to a break-in process. After a preset number of break-in cycles, it is determined that the differential is in an abnormal noise state after break-in, and the torque distribution coefficient of the differential is adjusted. Based on the torque distribution coefficient determination result, if the differential is found to be in an abnormal noise state, the torque distribution coefficient of the differential is adjusted until the abnormal noise test is passed.

2. The abnormal noise detection method according to claim 1, characterized in that, The steps of determining the sound intensity of the differential and obtaining the sound intensity determination result specifically include: Obtain the preset sound intensity value and the actual sound intensity value of the differential; Compare the actual sound intensity value with the preset sound intensity value; If the actual sound intensity value is not greater than the preset sound intensity value, the differential is in a normal state; if the actual sound intensity value is greater than the preset sound intensity value, the differential is in an abnormal noise state.

3. The abnormal noise detection method according to claim 1, characterized in that, The steps of performing vibration assessment on the differential and obtaining the vibration assessment results specifically include: Obtain the preset vibration limit and actual vibration value of the differential; Compare the actual vibration value with the preset vibration limit value; If the actual vibration value is determined to be no greater than the preset vibration limit, the differential is in a normal state; if the actual vibration value is determined to be greater than the preset vibration limit, the differential is in an abnormal noise state.

4. The abnormal noise detection method according to claim 1, characterized in that, The steps of determining the torque distribution coefficient of the differential and obtaining the torque distribution coefficient determination result specifically include: Obtain the theoretical torque distribution coefficient and the actual torque distribution coefficient of the differential; If the difference between the actual torque distribution coefficient and the theoretical torque distribution coefficient is not greater than a preset difference range, the differential is in a normal state; if the difference between the actual torque distribution coefficient and the theoretical torque distribution coefficient is greater than a preset difference range, the differential is in an abnormal noise state.

5. The abnormal noise detection method according to claim 1, characterized in that, Before judging the sound intensity of the differential, the following steps are also included: Under preset operating conditions, the torque distribution coefficient of the differential is tested for a first preset number of test cycles to obtain multiple test torque distribution coefficients corresponding to the first preset number of test cycles. The test torque distribution coefficient of the last test cycle of the first preset test cycle is taken as the actual torque distribution coefficient.

6. A device for detecting abnormal noise in a differential, characterized in that, The abnormal noise detection method according to any one of claims 1 to 5 is used for detection, including: A test bench is used to mount the differential for detecting abnormal noises from the differential. A vibration sensor is used to obtain the actual vibration value of the differential.

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