Automobile abnormal sound diagnosis and processing method

Abstract

The invention provides an automobile abnormal sound diagnosis and processing method, which relates to the technical field of automobiles, and comprises the following steps of: when an automobile turns at an accelerated speed or runs in a straight line, acquiring noise information in the automobile and vibration information of a differential shell; according to the noise information and the vibration information, whether the automobile has the abnormal sound problem or not is judged; if yes, the automobile is adjusted through a set adjustment scheme until the abnormal sound problem disappears; and if not, automobile abnormal sound processing is completed. According to the technical scheme, the abnormal sound in the vehicle and the vibration of the differential mechanism shell are tested during accelerated turning and linear driving in the vehicle, the situation that the abnormal sound in the vehicle corresponds to the vibration of the differential mechanism is confirmed, the source and the path of the abnormal sound of the differential mechanism are analyzed and optimized, a complete solution is provided for solving the abnormal sound of the differential mechanism, and the problem solving efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a method for diagnosing and processing abnormal noise of an automobile. Background Art

[0002] The differential is a key component in vehicle steering. It achieves differential turning of the left and right wheels through internal friction torque during steering. However, if the friction torque is too large, it will cause stick-slip noise. The abnormal noise of the differential under turning conditions will reduce the comfort and reputation of the vehicle. Solving the abnormal noise of the differential is of great significance to improving the quality of the vehicle.

[0003] The existing technology for identifying the working conditions of abnormal noise during cornering generally uses the whole vehicle off-line for detection and identification, and evaluation by evaluators. If it is found that the differential has abnormal noise during cornering during the whole vehicle evaluation, the abnormal noise problem can only be solved by replacing the differential assembly, which is extremely costly. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for diagnosing and processing abnormal noise of an automobile, aiming to solve the problem of high cost in the existing processing of abnormal noise of an automobile.

[0005] To achieve the above object, the present invention provides a method for diagnosing and processing abnormal noise of an automobile, comprising the following steps:

[0006] When the car accelerates, turns or drives straight, obtain the noise information inside the car and the vibration information of the differential housing;

[0007] Determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information;

[0008] If so, adjust the car through the set adjustment plan until the abnormal noise problem disappears;

[0009] If not, the abnormal noise treatment of the car is completed.

[0010] In one embodiment, in the step of adjusting the automobile by a set adjustment scheme until the abnormal noise problem disappears, the set adjustment scheme is set to at least one, and the set adjustment scheme includes at least one of the following:

[0011] Reduce the friction torque inside the differential;

[0012] Replace the differential lubricant with one with better lubrication effect;

[0013] Improve the working surface roughness of the differential;

[0014] Reduce the friction coefficient of the side gear gasket surface;

[0015] Reduce the structural transmission of friction excitation on the vehicle;

[0016] Improve the sound insulation and absorption performance level of the entire vehicle.

[0017] In one embodiment, if so, the car is adjusted through a set adjustment scheme until the abnormal noise problem disappears: the set adjustment scheme is set to multiple, and after each set adjustment scheme, the step returns to the step of obtaining the noise information inside the car and the vibration information of the differential case when the car accelerates to turn or drives in a straight line.

[0018] In one embodiment, if yes, the step of adjusting the car by a set adjustment scheme until the abnormal noise problem disappears includes:

[0019] If yes, reduce the friction torque in the differential, and return to the step of "determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information";

[0020] When the friction torque in the differential is reduced and the vehicle still has the abnormal noise problem, replace the differential lubricant with a better lubricating effect, and return to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information";

[0021] When the friction torque in the differential is reduced and the vehicle does not have abnormal noise, return to step "the abnormal noise treatment of the vehicle is completed";

[0022] When the vehicle still has the abnormal noise problem after replacing the differential lubricant with a better lubricating effect, the working surface roughness of the differential is increased, and the process returns to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information";

[0023] When the differential lubricant with better lubrication effect is replaced and the vehicle does not have abnormal noise problem, return to step "Complete the abnormal noise treatment of the vehicle";

[0024] When the working surface roughness of the differential is increased and the vehicle still has the abnormal noise problem, the friction coefficient of the side gear gasket surface is reduced, and the process returns to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information";

[0025] When the working surface roughness of the differential is improved and the vehicle does not have abnormal noise problem, return to step "the abnormal noise treatment of the vehicle is completed";

[0026] When the friction coefficient of the side gear gasket surface is reduced, the structural transmission of the friction excitation on the whole vehicle is reduced, and the process returns to the step of "determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information";

[0027] When the friction coefficient of the side gear gasket surface is reduced and the vehicle does not have abnormal noise problem, return to step "Complete the abnormal noise treatment of the vehicle";

[0028] When the vehicle still has an abnormal noise problem after reducing the transmission of friction excitation to the structure of the vehicle, the sound insulation and absorption performance level of the vehicle is improved, and the process returns to the step of "determining whether the vehicle has an abnormal noise problem based on the noise information and the vibration information";

[0029] When the friction excitation is reduced and the vehicle does not have abnormal noise, the process returns to step "the abnormal noise treatment of the vehicle is completed";

[0030] When the vehicle still has abnormal noise problem after improving the sound insulation and absorption performance level of the whole vehicle, reduce the friction torque in the differential, and return to the step of "determining whether the vehicle has abnormal noise problem according to the noise information and the vibration information";

[0031] When the sound insulation and absorption performance level of the entire vehicle is improved and there is no abnormal noise problem in the vehicle, return to step "Complete the abnormal noise treatment of the vehicle".

[0032] In one embodiment, the step of improving the working surface roughness of the differential comprises:

[0033] Improve the working surface roughness of the differential's half-shaft gears, gaskets and differential positioning surfaces.

[0034] In one embodiment, the step of reducing the friction coefficient of the side gear washer surface comprises:

[0035] Phosphating treatment of the side shaft gear gasket surface; or,

[0036] A molybdenum disulfide coating is applied on the surface of the side shaft gear gasket.

[0037] In one embodiment, in the step of determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information:

[0038] The noise information includes a noise spectrum inside the vehicle; and / or,

[0039] The vibration information includes a vibration spectrum of the differential case.

[0040] In one embodiment, the step of determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information includes:

[0041] According to the in-car noise spectrum when the car accelerates and turns and the in-car noise spectrum when the car is driving straight, it is judged whether there is noise in the in-car noise spectrum when the car accelerates and turns;

[0042] According to the vibration spectrum of the differential case when the car is accelerating and turning and the vibration spectrum of the differential case when the car is driving straight, it is judged whether there is noise in the vibration spectrum of the differential case when the car is accelerating and turning;

[0043] If there is noise in the vehicle interior noise spectrum when the vehicle accelerates and turns, and there is noise in the differential housing vibration spectrum when the vehicle accelerates and turns, it is determined that the vehicle has an abnormal noise problem.

[0044] In one embodiment, when the car accelerates to turn, the speed of the car accelerates from 0 to 20 km / h.

[0045] The technical solution of the present invention tests abnormal noise inside the vehicle and vibration of the differential housing when the vehicle is accelerating, turning and driving in a straight line, confirms that the abnormal noise inside the vehicle corresponds to the vibration of the differential, and provides a complete solution for solving the abnormal noise of the differential by analyzing and optimizing the source and path of the abnormal noise of the differential, thereby improving the efficiency of solving the problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 This is a flow chart of an embodiment of a method for diagnosing and treating abnormal noise of an automobile proposed by the present invention;

[0048] Figure 2 A schematic diagram of a flow chart of another embodiment of the method for diagnosing and treating abnormal noise of an automobile provided by the present invention;

[0049] Figure 3 This is a spectrum diagram of the in-car noise before the abnormal noise of the car is processed in Example 1 of the present invention;

[0050] Figure 4 This is a vibration spectrum diagram of the differential housing before the abnormal noise of the automobile is processed in Example 1 of the present invention;

[0051] Figure 5 The spectrum diagram of the noise inside the car after the abnormal noise processing of the car is completed in the embodiment 1 of the present invention;

[0052] Figure 6 This is a vibration spectrum diagram of the differential case after the abnormal noise treatment of the automobile is completed in Example 1 of the present invention.

[0053] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0054] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0055] It should be noted that, in the embodiments, those without specifying specific conditions are carried out according to normal conditions or conditions recommended by the manufacturer. Those without specifying the manufacturer of reagents or instruments used are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, and "A and / or B" is taken as an example, including schemes A, B, or A and B that meet the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of the technical schemes is contradictory or cannot be achieved, it should be considered that the combination of such technical schemes does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work, all belong to the scope of protection of the present invention.

[0056] The differential is a key component in vehicle steering. It achieves differential turning of the left and right wheels through internal friction torque during steering. However, if the friction torque is too large, it will cause stick-slip noise. The abnormal noise of the differential under turning conditions will reduce the comfort and reputation of the vehicle. Solving the abnormal noise of the differential is of great significance to improving the quality of the vehicle.

[0057] The existing technology for identifying the working conditions of abnormal noise during cornering generally uses the whole vehicle off-line for detection and identification, and evaluation by evaluators. If it is found that the differential has abnormal noise during cornering during the whole vehicle evaluation, the abnormal noise problem can only be solved by replacing the differential assembly, which is extremely costly.

[0058] In view of this, see Figure 1 The present invention proposes a method for diagnosing and processing abnormal noise of an automobile, comprising the following steps:

[0059] When the car accelerates, turns or drives straight, obtain the noise information inside the car and the vibration information of the differential housing;

[0060] Determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information;

[0061] If so, adjust the car through the set adjustment plan until the abnormal noise problem disappears;

[0062] If not, the abnormal noise treatment of the car is completed.

[0063] The technical solution of the present invention tests abnormal noise inside the vehicle and vibration of the differential housing when the vehicle is accelerating, turning and driving in a straight line, confirms that the abnormal noise inside the vehicle corresponds to the vibration of the differential, and provides a complete solution for solving the abnormal noise of the differential by analyzing and optimizing the source and path of the abnormal noise of the differential, thereby improving the efficiency of solving the problem.

[0064] It should be noted that when a pure electric vehicle accelerates to the left or right and turns at a constant speed at a certain speed, a humming sound is heard in the car, but when driving in a straight line, there is no abnormal sound; in the noise spectrum diagram where the abnormal sound exists, it is shown as one or more narrow-band noises, and the noise spectrum characteristics are consistent with the vibration of the differential housing. According to the working conditions of the problem and the disassembly analysis of the differential, it can be determined that the abnormal sound is caused by the stick-slip friction between the differential housing and the half-shaft gear. The abnormal sound of the differential under turning conditions will reduce the comfort and reputation of the entire vehicle. Solving the abnormal sound of the differential is of great significance to improving the quality of the entire vehicle.

[0065] In one embodiment, in the step of adjusting the automobile by a set adjustment scheme until the abnormal noise problem disappears, the set adjustment scheme is set to at least one, and the set adjustment scheme includes at least one of the following:

[0066] Reduce the friction torque inside the differential;

[0067] Replace the differential lubricant with one with better lubrication effect;

[0068] Improve the working surface roughness of the differential;

[0069] Reduce the friction coefficient of the side gear gasket surface;

[0070] Reduce the structural transmission of friction excitation on the entire vehicle;

[0071] Improve the sound insulation and absorption performance level of the entire vehicle.

[0072] The technical solution of the present invention can adjust the differential working conditions of the automobile from multiple aspects and reduce the generation and transmission of friction noise from multiple aspects by adopting a variety of different adjustment schemes, without replacing the differential assembly, thereby reducing the cost of the adjustment scheme.

[0073] In one embodiment, if so, the car is adjusted through a set adjustment scheme until the abnormal noise problem disappears: the set adjustment scheme is set to multiple, and after each set adjustment scheme, the step returns to the step of obtaining the noise information inside the car and the vibration information of the differential case when the car accelerates to turn or drives in a straight line.

[0074] The technical solution of the present invention reacquires the noise information inside the vehicle and the vibration information of the differential housing after an alternating adjustment scheme, and determines whether the vehicle has an abnormal noise problem based on the noise information and the vibration information; if the abnormal noise problem still exists, the adjustment scheme is continued in a cycle; if there is no abnormal noise problem, the adjustment of the vehicle is completed.

[0075] In one embodiment, if yes, the step of adjusting the car by a set adjustment scheme until the abnormal noise problem disappears includes:

[0076] If yes, reduce the friction torque in the differential, and return to the step of "determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information";

[0077] When the friction torque in the differential is reduced and the vehicle still has the abnormal noise problem, replace the differential lubricant with a better lubricating effect, and return to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information";

[0078] When the friction torque in the differential is reduced and the vehicle does not have abnormal noise, return to step "the abnormal noise treatment of the vehicle is completed";

[0079] When the vehicle still has the abnormal noise problem after replacing the differential lubricant with a better lubricating effect, the working surface roughness of the differential is increased, and the process returns to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information";

[0080] When the differential lubricant with better lubrication effect is replaced and the vehicle does not have abnormal noise problem, return to step "Complete the abnormal noise treatment of the vehicle";

[0081] When the working surface roughness of the differential is increased and the vehicle still has the abnormal noise problem, the friction coefficient of the side gear gasket surface is reduced, and the process returns to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information";

[0082] When the working surface roughness of the differential is improved and the vehicle does not have abnormal noise problem, return to step "the abnormal noise treatment of the vehicle is completed";

[0083] When the friction coefficient of the side gear gasket surface is reduced, the structural transmission of the friction excitation on the whole vehicle is reduced, and the process returns to the step of "determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information";

[0084] When the friction coefficient of the side gear gasket surface is reduced and the vehicle does not have abnormal noise problem, return to step "Complete the abnormal noise treatment of the vehicle";

[0085] When the vehicle still has an abnormal noise problem after reducing the transmission of friction excitation to the structure of the vehicle, the sound insulation and absorption performance level of the vehicle is improved, and the process returns to the step of "determining whether the vehicle has an abnormal noise problem based on the noise information and the vibration information";

[0086] When the friction excitation is reduced and the vehicle does not have abnormal noise, the process returns to step "the abnormal noise treatment of the vehicle is completed";

[0087] When the vehicle still has abnormal noise problem after improving the sound insulation and absorption performance level of the whole vehicle, reduce the friction torque in the differential, and return to the step of "determining whether the vehicle has abnormal noise problem according to the noise information and the vibration information";

[0088] When the sound insulation and absorption performance level of the entire vehicle is improved and there is no abnormal noise problem in the vehicle, return to step "Complete the abnormal noise treatment of the vehicle".

[0089] In one embodiment, the step of improving the working surface roughness of the differential comprises:

[0090] Improve the working surface roughness of the differential's half-shaft gears, gaskets and differential positioning surfaces.

[0091] The technical solution of the present invention improves the working surface roughness of the differential by improving the working surface roughness of the differential half-shaft gears, gaskets and differential positioning surfaces; thereby reducing the slippage between the components and reducing the noise generated by the relative movement of the internal parts of the differential.

[0092] In one embodiment, the step of reducing the friction coefficient of the side gear washer surface comprises:

[0093] Phosphating treatment of the side shaft gear gasket surface; or,

[0094] A molybdenum disulfide coating is applied on the surface of the side shaft gear gasket.

[0095] The technical solution of the present invention can further reduce the friction coefficient of the side gear gasket surface by phosphating or coating with a molybdenum disulfide coating, and reduce the friction noise generated on the gasket surface during the movement of the differential.

[0096] In one embodiment, in the step of determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information:

[0097] The noise information includes a noise spectrum inside the vehicle; and / or,

[0098] The vibration information includes a vibration spectrum of the differential case.

[0099] The technical solution of the present invention can accurately determine the frequency band of the noise by using the in-vehicle noise spectrum as noise information and / or the differential case vibration spectrum as vibration information, and observe whether the noise in the corresponding frequency band is weakened during the subsequent adjustment process, thereby accelerating the diagnosis speed.

[0100] In one embodiment, the step of determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information includes:

[0101] According to the in-car noise spectrum when the car accelerates and turns and the in-car noise spectrum when the car is driving straight, it is judged whether there is noise in the in-car noise spectrum when the car accelerates and turns;

[0102] According to the vibration spectrum of the differential case when the car is accelerating and turning and the vibration spectrum of the differential case when the car is driving straight, it is judged whether there is noise in the vibration spectrum of the differential case when the car is accelerating and turning;

[0103] If there is noise in the vehicle interior noise spectrum when the vehicle accelerates and turns, and there is noise in the differential housing vibration spectrum when the vehicle accelerates and turns, it is determined that the vehicle has an abnormal noise problem.

[0104] The technical solution of the present invention combines the noise performance during acceleration and turning with the noise performance during straight-line driving to determine whether the noise source is continuous or only occurs during turning. After determining that the noise is only generated during turning, the in-vehicle noise spectrum and the differential housing vibration spectrum are used to determine whether the noise source is the differential, thereby improving the diagnostic accuracy and facilitating subsequent adjustments to the differential.

[0105] In one embodiment, when the car accelerates to turn, the speed of the car accelerates from 0 to 20 km / h.

[0106] The technical solution of the present invention can detect the in-vehicle noise spectrum and the differential housing vibration spectrum of the vehicle at low speed by accelerating the vehicle speed from 0 to 20 km / h, thereby avoiding the influence of wind noise at high speed.

[0107] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0108] Example 1

[0109] This embodiment provides a method for diagnosing and processing abnormal noise of an automobile, comprising the following steps:

[0110] S1: The problem vehicle is tested for left and right turning conditions (maximum steering wheel angle) and straight driving conditions, with the vehicle speed accelerated from 0 to 20 km / h, the interior noise and differential housing vibration, and spectrum analysis, such as Figure 3 and Figure 4. Adjust the coordinates to a suitable range until all the characteristics of the problem phenomenon can be clearly seen in the spectrum diagram. In the noise spectrum with abnormal turning noise, an obvious narrow-band noise can be seen with a frequency between 550-570Hz. At the same time, there is also a narrow-band noise of the same frequency band in the differential and steering knuckle vibration spectrum. There is no abnormal noise in the straight-line driving condition, and there is no abnormal narrow-band frequency component in the vehicle noise and differential vibration.

[0111] S2: Reduce the friction torque in the differential. After the implementation plan is implemented, the cornering condition test and evaluation are carried out. If there is no abnormal noise subjectively and there is no abnormal narrow-band noise in the noise spectrum data inside the vehicle, the optimization is completed; if there is still abnormal noise subjectively, execute step S3.

[0112] S3: Use differential lubricants with better lubrication effects to improve the friction performance of lubricants at low temperatures and high loads and reduce oil viscosity. After the implementation plan, conduct cornering test and evaluation. If there is no abnormal noise subjectively and no abnormal narrow-band noise in the noise spectrum data inside the vehicle, the optimization is completed; if there is still abnormal noise subjectively, execute step S4.

[0113] S4: Improve the working surface roughness of the differential half-shaft gear, gasket and differential positioning surface. After the implementation plan, conduct a turning condition test and evaluation. If there is no abnormal noise subjectively and there is no abnormal narrow-band noise in the vehicle noise spectrum data, the optimization is completed; if there is still abnormal noise subjectively, execute step S5.

[0114] S5: Reduce the friction coefficient of the side gear gasket surface by phosphating or molybdenum disulfide coating. After the implementation plan, conduct cornering test and evaluation. If there is no abnormal noise subjectively and no abnormal narrow-band noise in the vehicle noise spectrum data, the optimization is completed; if there is still abnormal noise subjectively, execute step S6.

[0115] S6: Add a counterweight or vibration absorber to the drive axle to reduce the structural transmission of friction excitation on the vehicle. After the implementation plan, conduct a cornering test and evaluation. If there is no abnormal noise subjectively and no abnormal narrow-band noise in the vehicle noise spectrum data, the optimization is completed; if there is still abnormal noise subjectively, execute step S7.

[0116] S7: Improve the sound insulation and absorption performance of the whole vehicle. After the implementation plan is implemented, the turning condition test and evaluation are carried out. If there is no abnormal sound subjectively and there is no abnormal narrow-band noise in the noise spectrum data inside the vehicle, the optimization is completed; if there is still abnormal sound subjectively, execute step S2.

[0117] After the abnormal noise of the car is processed, the optimized in-car noise spectrum and differential housing vibration spectrum are as follows: Figure 5 and Figure 6 shown.

[0118] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for diagnosing and treating abnormal noise of a car, characterized in that: The following steps are involved: When the car accelerates, turns or drives straight, obtain the noise information inside the car and the vibration information of the differential housing; Determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information; If so, adjust the car using the set adjustment plan until the abnormal noise problem disappears; If not, the abnormal noise treatment of the car is completed.

2. The method for diagnosing and treating abnormal noise of a vehicle according to claim 1, characterized in that: In the step of adjusting the automobile by a set adjustment scheme until the abnormal noise problem disappears, the set adjustment scheme is set to at least one, and the set adjustment scheme includes at least one of the following: Reduce the friction torque inside the differential; Replace the differential lubricant with one with better lubrication effect; Improve the working surface roughness of the differential; Reduce the friction coefficient of the side gear gasket surface; Reduce the structural transmission of friction excitation on the vehicle; Improve the sound insulation and absorption performance level of the entire vehicle.

3. The method for diagnosing and treating abnormal noise of a vehicle according to claim 2, characterized in that: If so, the car is adjusted through the set adjustment plan until the abnormal noise problem disappears: the set adjustment plan is set to multiple, and after each set adjustment plan, the process returns to the step of obtaining the noise information inside the car and the vibration information of the differential case when the car accelerates, turns or drives in a straight line.

4. The method for diagnosing and treating abnormal noise of a vehicle according to claim 3, characterized in that: If yes, adjust the car through the set adjustment plan until the abnormal noise problem disappears, including: If yes, reduce the friction torque in the differential, and return to step "determine whether the vehicle has an abnormal noise problem based on the noise information and the vibration information"; When the friction torque in the differential is reduced and the vehicle still has the abnormal noise problem, replace the differential lubricating oil with a better lubricating effect, and return to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information"; When the friction torque in the differential is reduced and the vehicle does not have abnormal noise, return to step "the abnormal noise treatment of the vehicle is completed"; When the vehicle still has the abnormal noise problem after replacing the differential lubricant with a better lubricating effect, the working surface roughness of the differential is increased, and the process returns to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information"; When the differential lubricant with better lubrication effect is replaced and the vehicle does not have abnormal noise problem, return to step "then the abnormal noise treatment of the vehicle is completed"; When the working surface roughness of the differential is increased and the vehicle still has the abnormal noise problem, the friction coefficient of the side gear gasket surface is reduced, and the process returns to the step of "determining whether the vehicle has the abnormal noise problem according to the noise information and the vibration information"; When the working surface roughness of the differential is improved and the vehicle does not have abnormal noise problem, return to step "the abnormal noise treatment of the vehicle is completed"; When the friction coefficient of the side gear gasket surface is reduced, the structural transmission of the friction excitation on the whole vehicle is reduced, and the process returns to the step of "determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information"; When the friction coefficient of the side gear gasket surface is reduced and the vehicle does not have abnormal noise problem, return to step "the abnormal noise treatment of the vehicle is completed"; When the vehicle still has an abnormal noise problem after reducing the transmission of friction excitation to the structure of the vehicle, the sound insulation and absorption performance level of the vehicle is improved, and the process returns to the step of "determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information"; When the friction excitation is reduced and the structure transmission on the whole vehicle is completed and there is no abnormal noise problem in the vehicle, return to step "then the abnormal noise treatment of the vehicle is completed"; When the vehicle still has abnormal noise problem after improving the sound insulation and absorption performance level of the whole vehicle, reduce the friction torque in the differential, and return to the step of "determining whether the vehicle has abnormal noise problem according to the noise information and the vibration information"; When the sound insulation and absorption performance level of the entire vehicle is improved and there is no abnormal noise problem in the vehicle, return to step "Complete the abnormal noise treatment of the vehicle".

5. The method for diagnosing and treating abnormal noise of a vehicle according to claim 2, characterized in that: The step of improving the working surface roughness of the differential comprises: Improve the working surface roughness of the differential's half-shaft gears, gaskets and differential positioning surfaces.

6. The method for diagnosing and treating abnormal noise of a vehicle according to claim 2, characterized in that: The step of reducing the friction coefficient of the side gear gasket surface comprises: Phosphating treatment of the side shaft gear gasket surface; or, A molybdenum disulfide coating is applied on the surface of the side shaft gear gasket.

7. The method for diagnosing and treating abnormal noise of a vehicle according to claim 1, characterized in that: In the step of determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information: The noise information includes a noise spectrum inside the vehicle; and / or, The vibration information includes a vibration spectrum of the differential case.

8. The method for diagnosing and treating abnormal noise of a vehicle according to claim 7, characterized in that: The step of determining whether the vehicle has an abnormal noise problem according to the noise information and the vibration information comprises: According to the in-car noise spectrum when the car accelerates and turns and the in-car noise spectrum when the car is driving straight, it is judged whether there is noise in the in-car noise spectrum when the car accelerates and turns; According to the vibration spectrum of the differential case when the car is accelerating and turning and the vibration spectrum of the differential case when the car is driving straight, it is judged whether there is noise in the vibration spectrum of the differential case when the car is accelerating and turning; If there is noise in the vehicle interior noise spectrum when the vehicle accelerates and turns, and there is noise in the differential housing vibration spectrum when the vehicle accelerates and turns, it is determined that the vehicle has an abnormal noise problem.

9. The method for diagnosing and treating abnormal noise of a vehicle according to claim 8, characterized in that: When a car accelerates to turn, its speed increases from 0 to 20 km / h.

Images