A method and tool for evaluating wind noise performance of automobile wipers

Abstract

The present invention provides a method and tool for evaluating the performance of wind noise of automobile wipers, wherein the evaluation method comprises: step S1, establishing a CFD wind tunnel model and performing simulation calculation; step S2, performing wiper flow field analysis; step S3, analyzing the distribution of radiated noise of wipers; step S4, adjusting the height of wipers, repeating steps S1-S3, and statistically analyzing the distribution of radiated noise of wipers at different heights; step S5, extracting the surface contour of the engine hood and the trend line of the front windshield; step S6, extracting indicators related to the actual vehicle measurement operation, and formulating wiper wind noise evaluation indicators related to the wiper height; step S7, performing actual vehicle wind tunnel testing; step S8, using tools to detect the height of the actual vehicle wipers, and qualitatively judging the radiated noise of wipers. The present invention can correspond the radiated noise of wipers to the height of wipers, and directly evaluate the radiated noise of wipers by detecting the height of wipers.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle wind noise control, and in particular relates to a method and an evaluation tool for automobile wind noise performance of windshield wipers. Background Art

[0002] As the vehicle speed increases, wind noise gradually covers engine noise and road noise and becomes the main noise source of the car. When the wind noise is loud, it will affect the communication between people in the car, destroy the quietness of the passenger compartment, and easily cause dissatisfaction among drivers and passengers. Moreover, with the development of new energy vehicles, in mid-to-high-end pure electric passenger cars without engines, the impact of wind noise on the passenger experience is more prominent. Therefore, the wind noise performance of a car has become one of the important indicators for evaluating the quality of a car.

[0003] As a protruding accessory outside the car body, the wiper is an important source of wind noise. The airflow blows directly onto the wiper, generating vortices at the rear, forming strong pulsating noise. Therefore, it is generally required that the wiper be hidden under the extension line of the engine hood to avoid noise caused by the impact of the airflow. However, the layout of the wiper also needs to take into account the requirements of field of view, pedestrian collision safety, and sweeping area. It is not always possible to completely hide the wiper under the extension line of the engine hood. In this case, it is necessary to evaluate the height of the wiper to determine whether it meets the wind noise requirements. Therefore, how to design a method and evaluation tool for evaluating the wind noise performance of automobile wipers, so as to determine whether the height of the wiper meets the wind noise requirements, has become a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0004] The purpose of the present invention is to provide a method and tool for evaluating the wind noise performance of automobile wipers, so as to solve the above-mentioned technical problems in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for evaluating wind noise performance of automobile wipers comprises the following steps:

[0007] Step S1, establishing a CFD wind tunnel model in a three-dimensional software, and then importing the wind tunnel model into a wind noise analysis software for simulation calculation;

[0008] Step S2, post-processing the simulation calculation results to perform wiper flow field analysis;

[0009] Step S3, continue to post-process the simulation calculation results to analyze the distribution of the radiated noise of the wiper;

[0010] Step S4, adjusting the height of the wiper on the vehicle in the wind tunnel model, repeating steps S1-S3, and counting the distribution of radiation noise of wipers at different heights;

[0011] Step S5, extracting the trend line of the engine hood surface contour and the trend line of the front windshield that pass through the wiper high point;

[0012] Step S6, comprehensively extracting indicators related to the actual vehicle measurement operation, and formulating a wiper wind noise evaluation index related to the wiper height;

[0013] Step S7, conducting a wind tunnel test on a real vehicle to verify the in-vehicle noise performance corresponding to wipers at different heights in the evaluation index formulated in step S6;

[0014] Step S8: Use the automobile wiper wind noise evaluation tool to detect the height of the actual vehicle wiper, and make a qualitative assessment of the wiper radiation noise according to the above evaluation index.

[0015] Preferably, in step S7, the evaluation index formulated in step S6 is corrected according to the sound pressure level performance of the main characteristic frequency band of the wiper noise contributing to the vehicle interior noise.

[0016] A wind noise evaluation tool for automobile wipers, comprising a positioning hook, a positioning seat, a tangent ruler, and a height measuring device, wherein the hook-shaped portion of the positioning hook is hooked on the rear end edge of the engine hood, the positioning seat is connected to a fixing plate of the positioning hook, and the tangent ruler is connected to one side of the positioning seat; the height measuring device is arranged on an end of the tangent ruler away from the positioning seat, and the height measuring device is used to measure the height of the vehicle's wiper in the vertical direction.

[0017] Preferably, the positioning seat includes a knob switch, a base, a magnetic isolation sleeve, a permanent magnet, and a brass plug. One side of the base is connected to the fixed plate, and the base is provided with a receiving hole perpendicular to the fixed plate, the magnetic isolation sleeve is arranged in the receiving hole, and the permanent magnet is horizontally arranged in the center hole of the magnetic isolation sleeve; the knob switch includes a rotating block and a connecting rod connected to one side of the rotating block, the rotating block is located on the side of the base away from the fixed plate, and one end of the connecting rod away from the rotating block passes through the center hole and is connected to the middle position of the permanent magnet; the magnetic isolation sleeve is relatively provided with two first through holes communicating with the center hole, and the base is provided with a second through hole opposite to the two first through holes, and the axis of the first through hole is perpendicular to the engine hood; the brass plug is arranged in the first through hole and the second through hole.

[0018] Preferably, a mounting groove is provided on the base, and the mounting groove is a U-shaped groove opening vertically downward. The tangent ruler has a mounting plate matching the mounting groove, and the base is also provided with a locking assembly for locking the mounting plate.

[0019] Preferably, the locking assembly includes a locking screw, and a screw hole communicating with the upper end of the mounting groove is provided on the base, the threaded section of the locking screw is threadably matched with the screw hole, and the locking screw is used to press the mounting plate onto the engine hood.

[0020] Preferably, the locking assembly also includes a limit pin and a fastening pad. A pin hole vertically connected to the mounting groove is provided on the right side of the base, and a screw hole opposite to the pin hole is provided on the left inner wall of the mounting groove. The left end of the limit pin passes through the pin hole and the mounting groove and then cooperates with the screw hole; the fastening pad is located in the mounting groove and is mounted on the limit pin, and the upper end of the mounting plate is in contact with the lower side of the fastening pad.

[0021] Preferably, the height measuring device includes a leveling screw, a height gauge, a spirit level, a height probe, and a mounting seat, wherein the mounting seat is a U-shaped seat with an opening facing vertically downward, a protruding block is provided at the left end of the tangent ruler, the upper end of the protruding block is rotatably connected to the upper left end of the mounting seat, and the left end of the tangent ruler is accommodated in the opening of the mounting seat; the spirit level is provided on the mounting seat, and the lower end of the threaded section of the leveling screw passes through the threaded hole provided at the right end of the mounting seat and abuts against the tangent ruler; the height gauge is vertically provided on the top surface of the mounting seat, the lower end of the height probe is used to contact the wiper, and the upper end of the height probe is provided with a sleeve for being mounted on the height gauge.

[0022] Preferably, a compensating measuring ruler is provided at the lower part of the left end of the tangent ruler.

[0023] Preferably, the left end surface of the tangent ruler is an inclined surface.

[0024] The beneficial effects of the present invention are:

[0025] The automobile wiper wind noise performance evaluation method and evaluation tool of the present invention directly correspond the wiper radiation noise to the height of the wiper relative to the extension line of the engine hood through CFD flow field simulation calculation analysis and post-processing of the simulation results, and directly evaluate the wiper radiation noise through the detected wiper height in the actual vehicle stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0027] Figure 1 A flow chart of a method for evaluating wind noise performance of automobile wipers provided by an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of a tangent ruler provided by an embodiment of the present invention being connected to a height measuring device;

[0029] Figure 3 A schematic diagram of a vehicle windshield wiper noise evaluation tool provided by an embodiment of the present invention when in use;

[0030] Figure 4 for Figure 3 Middle AA section view;

[0031] Figure 5 for Figure 3 The enlarged view of point B in the middle;

[0032] Figure 6 A schematic diagram of the connection between the positioning seat and the positioning hook provided in an embodiment of the present invention;

[0033] Figure 7 A schematic diagram of a tangent ruler provided in an embodiment of the present invention.

[0034] Markings in the accompanying drawings:

[0035] 001, engine hood, 002, front windshield, 003, wiper, 004, drain gutter;

[0036] 100. Positioning seat, 101. Knob switch, 102. Locking screw, 103. Fastening pad, 104. Limit pin, 105. Base, 106. Magnetic isolation sleeve, 107. Permanent magnet, 108. Brass plug;

[0037] 200, tangent ruler, 201, mounting plate, 202, avoidance notch, 203, protruding block;

[0038] 300. Height measuring device; 301. Leveling screw; 302. Height measuring ruler; 303. Level; 304. Rotating shaft; 305. Height measuring head; 306. Mounting seat; 307. Sleeve; 308. Compensation measuring ruler; 400. Positioning hook; 401. Hook-shaped portion; 402. Fixing plate. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the solution will be further described in detail below in conjunction with specific embodiments.

[0040] like Figure 1 As shown, an embodiment of the present invention provides a method for evaluating wind noise performance of automobile wipers, which comprises the following steps:

[0041] Step S1, establishing a CFD wind tunnel model in a three-dimensional software, and then importing the wind tunnel model into a wind noise analysis software for simulation calculation;

[0042] Step S2, post-processing the simulation calculation results to perform wiper flow field analysis;

[0043] Step S3, continue to post-process the simulation calculation results to analyze the distribution of the radiated noise of the wiper;

[0044] Step S4, adjusting the height of the wiper on the vehicle in the wind tunnel model, repeating steps S1-S3, and counting the distribution of radiation noise of wipers at different heights;

[0045] Step S5, extracting the trend line of the engine hood surface contour and the trend line of the front windshield that pass through the wiper high point;

[0046] Step S6, comprehensively extracting indicators related to the actual vehicle measurement operation, and formulating a wiper wind noise evaluation index related to the wiper height;

[0047] Step S7, conducting a wind tunnel test on a real vehicle to verify the in-vehicle noise performance corresponding to wipers at different heights in the evaluation index formulated in step S6;

[0048] Step S8: Use the automobile wiper wind noise evaluation tool to detect the height of the actual vehicle wiper, and make a qualitative assessment of the wiper radiation noise according to the above evaluation index.

[0049] Furthermore, in step S7, the evaluation index established in step S6 is corrected according to the sound pressure level performance of the main characteristic frequency band of the wiper noise contributing to the vehicle interior noise.

[0050] In a specific embodiment, the automobile windshield wiper noise evaluation method may include the following steps:

[0051] Step 1: Import the vehicle's 3D CAS data into ANSA software, build a CFD wind tunnel model, place the vehicle in the wind tunnel model, and use the software to grid its data; then use Star CCM+ software to perform wind tunnel CFD simulation calculation and analysis.

[0052] Step 2: Perform wiper flow field analysis: that is, perform post-analysis on the simulation calculation result data, output the wiper velocity field cross-section diagram, analyze the scouring, separation and reattachment of the wiper by the high-speed wall-attached airflow coming from the engine hood directly in front of the car, and observe the airflow disturbance and flow field boundary.

[0053] Step 3: Continue to analyze and post-process the result data of the simulation calculation, and output the distribution of the radiated noise of the wiper, that is, the distribution of the sound pressure level of the wiper or the distribution of the radiated noise (sound pressure level) of the front windshield.

[0054] Step 4: Adjust the height of the wiper, repeat steps 1-3, and count the changes in sound pressure levels of wipers at different heights.

[0055] Step 5: Import the 3D CAS data of the vehicle into the 3D software, and extract the contour lines of the wipers, the contour trend lines of the front windshield, the contour trend lines of the gutter, and the contour trend lines of the engine hood surface.

[0056] Step 6, on the trend line of the engine hood contour extracted in step 5, select an arc, the starting point a of the arc can be selected on the rear end edge of the engine hood contour, and then the arc extends along the engine compartment contour trend line toward the front of the vehicle to its end point b, the length L of the arc, that is, the distance between the starting point a and the end point b, can be preferably 100 mm (or an integer multiple of 10 mm between 100-200 mm), and then the arc is fitted into a ray, the ray starts from the end point b of the arc, passes through the starting point a of the arc, and extends to the contour trend line of the front windshield;

[0057] Then, combined with the analysis data of steps 1-4, the first height critical value X1 when the wiper noise is qualified and the second height critical value X2 when the wiper noise is unqualified are set, and then the wiper wind noise evaluation index is formulated as follows: let the distance between the high point of the wiper and the ray in the vertical direction (that is, the height of the wiper) be Z, if Z≤X1, the wiper noise is qualified; if X1<Z<X2, the wiper noise is basically qualified; if Z≥X2, the wiper noise is unqualified. It can be understood that X1<X2.

[0058] Step 7, actual vehicle wind tunnel test: place sensors in the vehicle to test the performance of vehicle interior noise at four wiper heights: Z = X1, Z = (X1 + X2) / 2, Z = X2, and Z = X2 + △X (△X = 5 to 10 mm can be preferred); at the same time, adjust the specific values ​​of X1 and X2 according to the sound pressure level performance of the main characteristic frequency band (generally 2000 to 5000 Hz) of the wiper wind noise contribution to the vehicle interior noise, and record them as X1' and X2' after correction. The number of cycles of this test and correction process can be multiple times, so that the final X1' and X2' are more accurate, thereby further improving the accuracy of the evaluation results; the number of times can also be 1 to 2 times.

[0059] Step 8, real vehicle testing: Use the car wiper wind noise evaluation tool to test the height of the real vehicle wiper to obtain the wiper height, and then make a qualitative judgment on the wiper radiated noise based on the wiper wind noise evaluation index.

[0060] It can be understood that in step 6, if X1<Z<X2, the wiper noise is basically qualified, because in mass production, the data in the critical bandwidth is usually not directly judged positively (negative or positive), but is probabilistically affirmed or denied in combination with the statistical results of the data of this batch of vehicles; in step 6, the extracted arc is an arc that is extremely close to a straight line. By generating the above-mentioned ray from this arc, a coordinate reference is established from simulation calculation to actual vehicle measurement (the ray is equivalent to the reference line, and when measuring, the height of the wiper relative to the ray in the vertical direction is measured), but this establishment from simulation There is a certain error in the calculated benchmark relationship of the actual vehicle measurement, and multiple rounds of comparison and correction can reduce the error; it is necessary to determine X1 and X2 according to the shape of the wall airflow of the engine hood in the external flow field, and simulate the different positions of the wiper in the airflow, and correct X1 and X2. This is mainly because there is a certain uncertainty in the mass production of each car, such as the wiper installation position tolerance, the engine hood position tolerance, etc., which will cause judgment errors in the results. Only through multiple rounds of wind tunnel test data can the corrected values ​​of the two critical values ​​of X1 and X2 be found; the present invention evaluates the wind noise performance of static wipers.

[0061] The automobile wiper wind noise performance evaluation method provided in an embodiment of the present invention directly corresponds the wiper radiation noise to the wiper's height in the vertical direction relative to the engine hood extension line (i.e., the above-mentioned ray) through CFD flow field simulation calculation analysis and post-processing of the simulation results, and directly evaluates the wiper radiation noise through the detected wiper height in the actual vehicle stage.

[0062] like Figures 2 to 7 As shown, the embodiment of the present invention also provides a wind noise evaluation tool for automobile wipers used in the above evaluation method, which includes a positioning hook 400, a positioning seat 100, a tangent ruler 200, and a height measuring device 300. The hook-shaped portion 401 of the positioning hook is hooked on the rear edge of the engine hood, the positioning seat is connected to the fixing plate 402 of the positioning hook, and the tangent ruler 200 is connected to one side of the positioning seat; the lower end surface of the positioning seat and the lower side surface of the tangent ruler are respectively in contact with the outer surface of the engine hood, and the height measuring device 300 is arranged on the tangent ruler 200 at one end away from the positioning seat, and the height measuring device is used to measure the height of the vehicle's wiper in the vertical direction. With this solution, the positioning hook is used to fix the evaluation tool on the engine hood, and the height measuring device is used to measure the height of the wiper.

[0063] like Figure 4As shown, the positioning seat 100 includes a knob switch 101, a base 105, a magnetic shielding sleeve 106, a permanent magnet 107, and a brass plug 108. One side of the base 105 is connected to the fixed plate, and the base is provided with a receiving hole perpendicular to the fixed plate. The magnetic shielding sleeve 106 is arranged in the receiving hole, and the permanent magnet 107 is horizontally arranged in the center hole of the magnetic shielding sleeve; the knob switch includes a rotating block and a connecting rod connected to one side of the rotating block, the rotating block is located on the side of the base away from the fixed plate, and one end of the connecting rod away from the rotating block passes through the center hole and is connected to the middle position of the permanent magnet; the magnetic shielding sleeve is relatively provided with two first through holes communicating with the center hole, and the base is provided with a second through hole opposite to the two first through holes, and the axis of the first through hole is perpendicular to the engine hood; the brass plug 108 is arranged in the first through hole and the second through hole. With this solution, you only need to turn the knob switch to drive the permanent magnet to rotate to a vertical state through the connecting rod, so that the N pole and S pole of the permanent magnet are aligned with the brass plugs at the top and bottom of the base respectively, and the magnetic lines of the permanent magnet penetrate the brass plugs to make the base adsorbed on the engine hood 001, thereby achieving the fixation of the base and the engine hood. It can be understood that the second through hole is coaxial with the first through hole.

[0064] Specifically, the base is provided with a mounting groove, which is a U-shaped groove with an opening vertically downward, and the tangent ruler 200 is provided with a mounting plate 201 that matches the mounting groove, and the base is also provided with a locking assembly for locking the mounting plate. With this solution, the mounting plate can be effectively prevented from moving in the mounting groove by simply placing the mounting plate in the mounting groove and locking the mounting plate with the locking assembly. It can be understood that the mounting plate is vertically connected to the left side of the top surface of the tangent ruler; the lower part of the mounting groove has an avoidance notch 202 to avoid the tangent ruler.

[0065] Furthermore, the locking assembly includes a locking screw 102, and a screw hole communicating with the upper end of the mounting groove is provided on the base, and the threaded section of the locking screw 102 is threadedly matched with the screw hole. The locking screw 102 is used to press the mounting plate onto the engine hood, thereby utilizing the locking screw 102 to press the mounting plate onto the engine hood to achieve locking of the mounting plate 201.

[0066] Preferably, the locking assembly further includes a limit pin 104 and a fastening pad 103. A pin hole vertically connected to the mounting groove is provided on the right side of the base, and a screw hole opposite to the pin hole is provided on the left inner wall of the mounting groove. The left end of the limit pin passes through the pin hole and the mounting groove and then matches with the screw hole. The fastening pad is located in the mounting groove and is sleeved on the limit pin, and the upper end of the mounting plate contacts the lower side of the fastening pad. With this solution, after the lower end of the locking screw passes through the screw hole, the fastening pad 103 is pressed down, so that the fastening pad 103 moves down to press the mounting plate against the engine hood, thereby locking the mounting plate. It can be understood that the limit pin serves to pre-install the fastening pad on the base and keep the fastening pad 103 in a certain floating state, and the center hole of the fastening pad is matched with the limit pin clearance; the function of the fastening pad is to convert the "point" force of the locking screw into a "surface" force, and then apply it to the mounting plate of the tangent ruler, in order to protect the tangent ruler.

[0067] Furthermore, the height measuring device 300 includes a leveling screw 301, a height measuring ruler 302, a spirit level 303, a height measuring head 305, and a mounting seat 306. The mounting seat 306 is a U-shaped seat with an opening facing vertically downward. A protruding block 203 is provided at the left end of the tangent ruler, and the upper end of the protruding block is rotatably connected to the upper left end of the mounting seat, and the left end of the tangent ruler is accommodated in the opening of the mounting seat; the spirit level is provided on the top surface of the mounting seat, and the lower end of the threaded section of the leveling screw passes through the threaded hole provided at the right end of the mounting seat and abuts against the tangent ruler; the height measuring ruler is vertically provided on the top surface of the mounting seat, the lower end of the height measuring head is used to contact with the wiper, and the upper end of the height measuring head is provided with a sleeve 307 for being mounted on the height measuring ruler. With this solution, after the left end face of the tangent ruler contacts the wiper and the lower end of the height probe contacts the wiper, observe the level meter, rotate the leveling screw according to the level meter, and drive the mounting seat to move through the leveling screw, so that the mounting seat is in a horizontal state, that is, the level meter indicates a horizontal state, and then observe the corresponding scale of the sleeve on the height measuring ruler to obtain the height of the wiper. Preferably, the upper end of the protruding block is rotatably connected to the upper left end of the mounting seat 306 through the rotating shaft 304.

[0068] like Figure 7 As shown, a compensating measuring ruler 308 is provided at the lower part of the left end of the tangent ruler 200. After the mounting base is leveled, the position of the lower left corner of the mounting base on the compensating measuring ruler is observed, and the height of the wiper obtained is corrected to obtain the final measurement value of the wiper height, so that the height of the wiper obtained by the height measuring device is more accurate. It can be understood that, if Figure 5As shown, the compensating measuring ruler has a plurality of compensating scale lines, each of which starts from the lower left end of the tangent ruler, extends to the upper right in sequence and is distributed in a fan shape.

[0069] Preferably, the left end face of the tangent ruler 200 is an inclined face. Preferably, the center of the rotating shaft is located directly above the lower left end of the tangent ruler, so that the obtained height compensation value is more accurate, and thus the obtained wiper height is more accurate. It is understandable that Figure 3 The left end is in the direction of the rear of the vehicle, and the right end is in the direction of the front of the vehicle; the sleeve can slide freely up and down on the height ruler, and cooperate with the scale on the height ruler to perform measurement; the role of the tangent ruler is equivalent to that of the ray; the positioning seat can be a rectangular structure, and the fixing plate can be a rectangular plate; the length of the positioning hook is equal to the above-mentioned length L.

[0070] Figure 3 The engine hood 001 indicated by the center line may be equivalent to the trend line of the engine hood surface contour extracted from the above-mentioned three-dimensional software, the front windshield 002 may be equivalent to the contour trend line of the front windshield extracted from the above-mentioned three-dimensional software, the wiper 003 may be equivalent to the contour line of the wiper extracted from the above-mentioned three-dimensional software, and the gutter 004 may be equivalent to the contour trend line of the gutter extracted from the above-mentioned three-dimensional software.

[0071] The use process of the automobile wiper wind noise evaluation tool provided by the embodiment of the present invention is as follows:

[0072] like Figure 3 As shown, the hook-shaped portion of the positioning hook 400 is hooked on the rear edge of the engine hood 001, and the positioning seat is fitted and aligned with the right side of the fixing plate of the positioning hook, and the positioning seat 100 is fixed to the fixing plate with bolts;

[0073] Insert the mounting plate 201 of the tangent ruler 200 into the mounting groove, and then press Figure 3 Adjust the position of the tangent ruler 200 in the left and right directions so that the left end face of the tangent ruler is against the wiper, and the positioning seat, the positioning hook and the lower side of the tangent ruler are in contact with the outer surface of the engine hood, and then rotate the rotating block so that the permanent magnet is in a vertical state to adsorb the positioning seat on the engine hood 001, and tighten the locking screw so that the lower end of the locking screw presses down the fastening pad, and the fastening pad moves downward to press the mounting plate against the engine hood, thereby fixing the tangent ruler;

[0074] According to the indication of the level gauge 303, rotate the leveling screw until the mounting base 306 is in a horizontal state; turn the height probe so that the lower end of the height probe is pressed on the high point of the wiper 003, and then read the value corresponding to the scale line corresponding to the sleeve from the height ruler, which is recorded as Z1;

[0075] like Figure 5As shown, according to the position of the lower left edge of the mounting seat 306 on the compensation measuring ruler, the value is read and recorded as Z2, and Z1-Z2 is the final measured value of the wiper height. In a specific embodiment, if the lower left edge of the mounting seat (i.e., the lower left corner) is between the 0.5 scale line and the 1 scale line, the initial reading is 0.5mm, and an estimated reading is appropriately made between 0.5-1mm, such as an estimated reading of 0.6, thereby obtaining Z2.

[0076] When using this evaluation tool to evaluate the wind noise performance of wipers on a batch of actual vehicles:

[0077] If Z1-Z2≤X1', the windshield wiper noise is judged as qualified;

[0078] If there are not three consecutive vehicles with X1'<Z1-Z2<X2', then the windshield wiper noise performance of the vehicles with X1'<Z1-Z2<X2' in this batch of vehicles shall be judged as qualified;

[0079] If X1'<Z1-Z2<X2' for three consecutive vehicles, and after retesting, Z1-Z2 of the three vehicles still remains X1'<Z1-Z2<X2', then the windshield wiper noise performance of the vehicles in this batch with X1'<Z1-Z2<X2' shall be judged as unqualified;

[0080] If Z1-Z2≥X2', the wiper wind noise performance is judged to be unqualified.

[0081] The windshield wiper noise performance evaluation method and tool of the present invention can reflect the CFD analysis results of the data stage in the actual vehicle stage, and use them in the mass production stage of the whole vehicle to perform batch testing and ultimately qualitative evaluation of the windshield wiper noise performance, thereby improving the stability of product quality.

[0082] The above are only preferred embodiments of the present invention. It should be pointed out that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, after reading the contents of the present invention, relevant technical personnel in the field may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A method for evaluating wind noise performance of automobile wipers, characterized in that: It includes the following steps: Step S1, establishing a CFD wind tunnel model in a three-dimensional software, and then importing the wind tunnel model into a wind noise analysis software for simulation calculation; Step S2, post-processing the simulation calculation results to perform wiper flow field analysis; Step S3, continue to post-process the simulation calculation results to analyze the distribution of the wiper radiation noise; Step S4, adjusting the height of the wiper on the vehicle in the wind tunnel model, repeating steps S1-S3, and counting the distribution of radiation noise of wipers at different heights; Step S5, extracting the trend line of the engine hood surface contour and the trend line of the front windshield that pass through the wiper high point; Step S6, comprehensively extracting indicators related to the actual vehicle measurement operation, and formulating a wiper wind noise evaluation index related to the wiper height; combining the analysis data of steps S1-S4, setting a first height critical value X1 when the wiper noise is qualified, and a second height critical value X2 when the wiper noise is unqualified, and then formulating the wiper wind noise evaluation index as follows: assuming that the distance between the high point of the wiper and the ray in the vertical direction is Z, if Z≤X1, the wiper noise is qualified; if X1<Z<X2, the wiper noise is basically qualified; if Z≥X2, the wiper noise is unqualified; Step S7, conducting a wind tunnel test on a real vehicle to verify the in-vehicle noise performance corresponding to wipers at different heights in the evaluation index formulated in step S6; Step S8: Use the automobile wiper wind noise evaluation tool to detect the height of the actual vehicle wiper, and make a qualitative assessment of the wiper radiation noise according to the above evaluation index.

2. The method for evaluating wind noise performance of automobile wipers according to claim 1, characterized in that: In step S7, the evaluation index established in step S6 is corrected according to the sound pressure level performance of the main characteristic frequency band of the wiper noise contributing to the vehicle interior noise.

3. A vehicle windshield wiper noise evaluation tool, characterized in that: It comprises a positioning hook, a positioning seat, a tangent ruler, and a height measuring device. The hook-shaped portion of the positioning hook is hooked on the rear end edge of the engine hood, the positioning seat is connected to a fixing plate of the positioning hook, and the tangent ruler is connected to one side of the positioning seat; the height measuring device is arranged on an end of the tangent ruler away from the positioning seat, and the height measuring device is used to measure the height of the vehicle's windshield wiper in the vertical direction; The positioning seat includes a knob switch, a base, a magnetic isolation sleeve, a permanent magnet, and a brass plug. One side of the base is connected to the fixed plate, and the base is provided with a receiving hole perpendicular to the fixed plate. The magnetic isolation sleeve is arranged in the receiving hole, and the permanent magnet is horizontally arranged in the center hole of the magnetic isolation sleeve; the knob switch includes a rotating block and a connecting rod connected to one side of the rotating block, the rotating block is located on the side of the base away from the fixed plate, and one end of the connecting rod away from the rotating block passes through the center hole and is connected to the middle position of the permanent magnet; the magnetic isolation sleeve is relatively provided with two first through holes communicating with the center hole, and the base is provided with a second through hole opposite to the two first through holes, and the axis of the first through hole is perpendicular to the engine hood; the brass plug is arranged in the first through hole and the second through hole.

4. The vehicle wiper wind noise evaluation tool according to claim 3, characterized in that: The base is provided with a mounting groove, which is a U-shaped groove opening vertically downward. The tangent ruler has a mounting plate matching the mounting groove. The base is also provided with a locking assembly for locking the mounting plate.

5. The vehicle windshield wiper noise evaluation tool according to claim 4, characterized in that: The locking assembly includes a locking screw, and a screw hole communicating with the upper end of the mounting groove is provided on the base. The threaded section of the locking screw is threadably matched with the screw hole, and the locking screw is used to press the mounting plate onto the engine hood.

6. The vehicle windshield wiper noise evaluation tool according to claim 5, characterized in that: The locking assembly also includes a limit pin and a fastening pad. A pin hole vertically connected to the mounting groove is provided on the right side of the base, and a screw hole opposite to the pin hole is provided on the left inner wall of the mounting groove. The left end of the limit pin passes through the pin hole and the mounting groove and then cooperates with the screw hole. The fastening pad is located in the mounting groove and is sleeved on the limit pin, and the upper end of the mounting plate contacts the lower side of the fastening pad.

7. The vehicle windshield wiper noise evaluation tool according to claim 3, characterized in that: The height measuring device includes a leveling screw, a height measuring ruler, a spirit level, a height measuring head, and a mounting seat. The mounting seat is a U-shaped seat with an opening vertically downward. A protruding block is provided at the left end of the tangent ruler. The upper end of the protruding block is rotatably connected to the upper left end of the mounting seat, and the left end of the tangent ruler is accommodated in the opening of the mounting seat; the spirit level is provided on the mounting seat, and the lower end of the threaded section of the leveling screw passes through the threaded hole provided at the right end of the mounting seat and abuts against the tangent ruler; the height measuring ruler is vertically provided on the top surface of the mounting seat, the lower end of the height measuring head is used to contact with the wiper, and the upper end of the height measuring head is provided with a sleeve for being mounted on the height measuring ruler.

8. The vehicle windshield wiper noise evaluation tool according to claim 7, characterized in that: A compensating measuring ruler is arranged at the lower part of the left end of the tangent ruler.

9. The vehicle windshield wiper noise evaluation tool according to claim 7, characterized in that: The left end surface of the tangent ruler is an inclined surface.

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