Method for designing vehicle adjustment based on tire rigidity

Abstract

The invention provides a method for designing vehicle adjustment based on tire rigidity, belongs to the technical field of vehicle adjustment, and can solve the problems that in an existing vehicle adjustment process, tire rigidity parameters need to be continuously adjusted during real vehicle testing, the testing process is complicated, the debugging period of vehicle and tire matching is long, and the testing efficiency is high. And the technical problems of vehicle deviation, noise and abnormal sound and tire abnormal wear are solved. According to the method for designing the vehicle adjustment and calibration based on the tire rigidity, the static rigidity and the dynamic rigidity of the tire under the conditions of different bearing loads and different inflation pressures are tested indoors, the working condition of the tire during actual use of the vehicle is simulated, tire rigidity data needed by vehicle adjustment and calibration are obtained, matching of the vehicle and the tire is achieved, and vehicle adjustment and calibration are completed. The method can be applied to the aspect of vehicle adjustment, the matching of the tire test condition and the real vehicle test condition is realized, and the debugging period of the matching of the vehicle and the tire is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle calibration, and in particular relates to a method for designing vehicle calibration based on tire stiffness. Background Art

[0002] The static stiffness of a tire includes lateral stiffness, longitudinal stiffness, radial stiffness, torsional stiffness and envelope stiffness, while the dynamic stiffness of a tire is mainly the cornering stiffness. The static stiffness of a tire refers to the ratio of the change in pressure (or tensile force) on the tire to the change in its displacement within a certain displacement range; the cornering stiffness is the ratio of the tire cornering force to the slip angle. The stiffness of a tire directly affects the handling and grip of the vehicle, as well as the noise level, comfort and wear resistance of the vehicle. However, inappropriate tire stiffness will affect tire wear. Therefore, OEMs attach great importance to the stiffness parameters of tires when adjusting vehicle wheels.

[0003] At present, since the OEMs and tire manufacturers have not yet established the matching relationship between tire stiffness and vehicle under different tire inflation pressures and load conditions, the stiffness parameter conditions used in vehicle tuning are not the actual conditions during actual vehicle testing. Therefore, parameters need to be constantly adjusted during actual vehicle testing. The test process is too complicated, the debugging cycle for vehicle and tire matching is long, and problems such as vehicle deviation, abnormal noise and abnormal tire wear may occur.

[0004] Based on this, the present invention proposes a method for designing vehicle tuning based on tire stiffness. Summary of the invention

[0005] The present invention aims at the technical problems that in the above-mentioned existing vehicle calibration process, the tire stiffness parameters need to be continuously adjusted during the actual vehicle test, the test process is complicated, the debugging cycle of the vehicle and tire matching is long, and the vehicle may run off the track, make abnormal noise and abnormal tire wear may occur. A method for vehicle calibration based on tire stiffness design is proposed, and indoor test experiments are carried out based on the inflation pressure of the tire, the load-bearing load and the sideslip angle of the tire and the simulated road surface under the actual vehicle test conditions to simulate the working conditions of the tire when actually used in the vehicle, thereby achieving the matching of the tire test conditions with the actual vehicle test conditions, optimizing the matching of the vehicle and the tire, shortening the debugging cycle of the vehicle and tire matching, improving the vehicle's handling stability, straight-line driving performance and comfort, and being able to avoid the problem of abnormal tire wear caused by the matching problem between the vehicle and the wheel, as well as the abnormal vibration or noise problem caused further.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: a method for designing vehicle calibration based on tire stiffness, through indoor testing of the static stiffness and dynamic stiffness of tires under different loads and different inflation pressures, simulating the working conditions of tires in actual vehicle use, obtaining the tire stiffness data required for vehicle calibration, achieving the matching of vehicles and tires, and completing vehicle calibration. Among them, the load is 40% to 120% of the load marked on the tire sidewall, and the inflation pressure is 180-290kpa.

[0007] In some embodiments, the static stiffness includes lateral stiffness, longitudinal stiffness, radial stiffness, envelope stiffness and torsional stiffness, and the static stiffness is calculated according to the formula S=(F1-F2) / (δ1-δ2), where F1 represents the first test load in N, F1=Fc+500N, F2 represents the second test load in N, F2=Fc-500N,

[0008] Fc represents the test radial load, which is 40%, 80%, 100% and 120% of the standard load marked on the tire sidewall.

[0009] δ1 represents the displacement corresponding to the first test load, and δ2 represents the displacement corresponding to the second test load.

[0010] In some embodiments, in the step of testing the lateral stiffness of the tire, based on the effective value of the lateral force and the lateral displacement obtained by the static stiffness testing machine, according to the formula S 横 =(F1 横 - F2 横 ) / (δ1 横 -δ2 横 ), the lateral stiffness of the tire is calculated, where the lateral displacement ranges from 5 to 15 mm.

[0011] In some embodiments, in the step of testing the longitudinal stiffness of the tire, based on the effective value of the longitudinal force and the longitudinal displacement obtained by the static stiffness testing machine, according to the formula S 纵 =(F1 纵 - F2 纵 ) / (δ1 纵 -δ2 纵 ), the longitudinal stiffness of the tire is calculated, where the longitudinal displacement ranges from 5 to 10 mm.

[0012] In some embodiments, in the step of testing the radial stiffness of the tire, based on the effective value of the radial force and the radial displacement obtained by the static stiffness testing machine, according to the formula S 径 =(F1 径 - F2 径 ) / (δ1 径 -δ2径 ), the radial stiffness of the tire is calculated, where the radial displacement ranges from 10 to 25 mm.

[0013] In some embodiments, in the step of testing the envelope stiffness of the tire, based on the effective value of the envelope radial force and the envelope displacement obtained by the static stiffness testing machine, according to the formula S 包 =(F1 包 - F2 包 ) / (δ1 包 -δ2 包 ), and calculate the tire envelope stiffness.

[0014] In some embodiments, in the step of testing the torsional stiffness of the tire, based on the effective value of the torsional moment and the angular displacement obtained by the static stiffness testing machine, according to the formula S 扭 =(F1 扭 - F2 扭 ) / (δ1 扭 -δ2 扭 ), the torsional stiffness of the tire is calculated, where the angular displacement ranges from 0 to 6°.

[0015] In some embodiments, in the step of testing the dynamic cornering stiffness of the tire, a pure cornering scan of the tire under different radial loads and different inflation pressures is performed on a six-component force testing machine when the tire is traveling at a speed of 60 km / h, and the lateral force and the side slip angle are recorded. Based on the obtained lateral force and side slip angle, according to formula C λ =ΔFy / Δλ, the dynamic cornering stiffness is calculated, where ΔFy represents the change in cornering force, Δλ represents the change in slip angle, and the slip angle λ takes values ​​of 2°, 4° or 8°, that is, the changes in slip angle are the difference between slip angles of 2° and 4°, the difference between slip angles of 2° and 8°, and the difference between slip angles of 4° and 8°.

[0016] In some of the embodiments, the pure sideslip sweep speed is 2 deg / s, the sideslip angle is -15° to +15°, and the inclination angle is -5° to +5°.

[0017] In some of the embodiments, the camber angle of the vehicle tire ranges from 0.5° to 1.5°.

[0018] Compared with the prior art, the advantages and positive effects of the present invention are:

[0019] (1) The present invention provides a method for designing vehicle calibration based on tire stiffness, thereby achieving matching between tire test conditions and actual vehicle test conditions, optimizing the matching between vehicle and tire, improving the vehicle's handling stability, straight-line driving performance, and comfort, shortening the vehicle and tire matching debugging period, and being able to avoid abnormal tire wear caused by vehicle and wheel matching problems, as well as further resulting abnormal vibration or noise problems.

[0020] (2) The present invention is a method for designing vehicle calibration based on tire stiffness. In the static stiffness test step, the test air pressure is based on the actual inflation pressure used, and the test load is based on the actual load used. The test result is closest to the actual use condition and can meet the optimal driving state under the actual vehicle test condition.

[0021] (3) The present invention is a method for designing vehicle calibration based on tire stiffness. In the test step of dynamic cornering stiffness, the test air pressure is based on the actual inflation pressure used, and the test load is based on the actual load used. The test result is closest to the actual use condition and can meet the data application under the actual vehicle test condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the camber structure of a vehicle tire;

[0023] Figure 2 It is a structural schematic diagram of the camber angle of a vehicle tire;

[0024] Figure 3 is a schematic diagram of lateral force and sideslip angle;

[0025] Figure 4 It is a schematic diagram of the cornering stiffness curve;

[0026] Figure 5 This is the curve fitted after the pure sideways sweep test at an inclination angle of 0 degrees in Example 1;

[0027] Figure 6 This is the curve fitted after the pure sideways sweep test at an inclination angle of 5 degrees in Example 1;

[0028] Figure 7 This is the fitted curve after the pure sideways scanning test at an inclination angle of -5 degrees in Example 1. DETAILED DESCRIPTION

[0029] In order to be able to understand the characteristics and technical contents of the embodiments of the present invention in more detail, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described below are only part of the embodiments of the present invention, rather than all the embodiments of the present invention. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection requested by the present invention.

[0030] The embodiment of the present invention provides a method for designing vehicle calibration based on tire stiffness, which simulates the working conditions of tires in actual vehicle use by testing the static stiffness and dynamic stiffness of tires under different loads and different inflation pressures indoors, obtains tire stiffness data required for vehicle calibration, achieves matching between vehicle and tire, and completes vehicle calibration. The present invention achieves the matching of tire test conditions and actual vehicle test conditions, optimizes the matching between vehicle and tire, shortens the debugging cycle of vehicle and tire matching, improves the vehicle's handling stability, straight-line driving performance, and comfort performance, and can avoid abnormal tire wear caused by vehicle and tire matching problems, as well as further abnormal tire vibration or noise problems.

[0031] The method for designing vehicle calibration based on tire stiffness in an embodiment of the present invention uses a static stiffness testing machine, a six-component force testing machine, a front axle independent suspension vehicle and / or a front and rear axle independent suspension vehicle, and specifically includes the following steps:

[0032] Test the lateral stiffness, longitudinal stiffness, radial stiffness, envelope stiffness and torsional stiffness of the tire under different radial loads and different inflation pressures, and calculate according to the formula S = (F1-F2) / (δ1-δ2), where F1 represents the first test load, in N, F1 = Fc+500N, F2 represents the second test load, in N, F2 = Fc-500N, Fc represents the test radial load, and the values ​​are 40%, 80%, 100%, and 120% of the standard load marked on the tire sidewall, δ1 represents the displacement corresponding to the first test load, and δ2 represents the displacement corresponding to the second test load;

[0033] The effective rolling radius and pure side slip sweep SA SWEEP of the tire under different radial loads and different inflation pressures were tested by a six-component force testing machine at a speed of 60 km / h. The lateral force and side slip angle were recorded. Based on the measured lateral force and side slip angle, the formula C was used to calculate the side slip angle. λ=ΔFy / Δλ to calculate the dynamic cornering stiffness and generate a cornering curve to evaluate the stability of the vehicle when turning, where ΔFy represents the change in cornering force, Δλ represents the change in slip angle, and the slip angle λ is 2°, 4° or 8°, that is, the value of Δλ is the difference between 4° and 2°, the difference between 8° and 4°, and the difference between 8° and 2° respectively; the effective rolling radius can reflect the amount of tire sinking when dynamic, and indirectly reflect the radial rigidity of the tire when driving at a constant speed; the sweep speed is 2deg / s, the slip angle is -15°~+15°, and the inclination angle is -5°~+5°; the cornering stiffness curve is used to reflect the relationship between cornering force and slip angle, and is mainly used to evaluate the stability of the vehicle when turning. When the slip angle reaches a certain value, the cornering force no longer increases significantly and tends to be stable;

[0034] Collect and integrate the above test data to obtain the tire stiffness data required for vehicle calibration, and compare the static stiffness and dynamic stiffness data of the indoor test with the stiffness data of the vehicle's reference tire. When the two are close, the vehicle can be installed for testing, thereby shortening the vehicle calibration time and improving the calibration efficiency;

[0035] Assemble the matching tires to the vehicle, perform four-wheel alignment parameter verification if necessary, conduct vehicle field testing, and verify the matching of laboratory test data with the tire performance requirements during vehicle design.

[0036] In the test conditions of the static stiffness of the present invention, the test air pressure is based on the actual inflation pressure, and the test load is based on the actual load. The test result is closest to the actual use condition and can meet the optimal driving state under the actual vehicle test condition. In the step of testing the lateral stiffness of the tire, based on the effective value of the lateral force and the lateral displacement obtained by the static stiffness test machine test, according to the formula S 横 =(F1 横 - F2 横 ) / (δ1 横 -δ2 横 ), the lateral stiffness of the tire is calculated, where the lateral displacement ranges from 5 to 15 mm. When the lateral displacement is less than 5 mm, the lateral deformation of the tire is too large and the vehicle rolls severely; when the lateral displacement is greater than 15 mm, the tire will slip laterally and have poor adhesion to the ground;

[0037] In the step of testing the longitudinal stiffness of the tire, based on the effective value of the longitudinal force and the longitudinal displacement obtained by the static stiffness testing machine, according to the formula S 纵 =(F1 纵 - F2 纵 ) / (δ1 纵 -δ2 纵), the longitudinal stiffness of the tire is calculated, wherein the longitudinal displacement has a value range of 5-10mm. When the longitudinal displacement is less than 5mm, the tire is too sensitive when the vehicle starts or brakes, and the passengers in the car lean back or nod their heads violently, causing discomfort to the passengers; when the longitudinal displacement is greater than 10mm, the tire has a large delay when the vehicle starts or brakes, and the driver's driving feeling is not good;

[0038] In the step of testing the radial stiffness of the tire, based on the effective value of the radial force and radial displacement obtained by the static stiffness testing machine, according to the formula S 径 =(F1 径 - F2 径 ) / (δ1 径 -δ2 径 ), the radial stiffness of the tire is calculated, wherein the radial displacement has a value range of 10-25mm. When the radial displacement is less than 10mm, the radial sinking of the tire is small, and the impact between the tire and the road surface is too strong during the vehicle driving, resulting in a bumpy feeling and causing discomfort to passengers; when the radial displacement is greater than 25mm, the radial sinking of the tire is large, and the tire has a significant lag response when the vehicle changes lanes or turns, affecting the vehicle handling performance;

[0039] In the step of testing the tire envelope stiffness, based on the effective value of the envelope radial force and envelope displacement obtained by the static stiffness testing machine, according to the formula S 包 =(F1 包 - F2 包 ) / (δ1 包 -δ2 包 ), calculate the envelope stiffness of the tire;

[0040] In the step of testing the torsional stiffness of the tire, based on the effective value of the torsional moment and the angular displacement obtained by the static stiffness testing machine, according to the formula S 扭 =(F1 扭 - F2 扭 ) / (δ1 扭 -δ2 扭 ), the torsional stiffness of the tire is calculated, where the angular displacement ranges from 0 to 6°.

[0041] In the above test conditions of the dynamic cornering stiffness of the present invention, the test air pressure is based on the actual inflation pressure, and the test load is based on the actual load. The test results are closest to the actual use conditions and can meet the data application under the actual vehicle test conditions. Figure 1 As shown in the figure, the vehicle tires have camber when driving. Figure 2 The figure shows the schematic diagram of tire camber angle. When designing vehicle positioning parameters, the range of tire camber angle β is 0.5°-1.5°. Figure 3As shown in FIG. 1 , it is a schematic diagram of lateral force and side slip angle. Since the positive camber angle of the front wheel will provide a small amount of understeering characteristics to the car, and the understeering of the car is conducive to the stability of the car's driving, in a preferred embodiment, the tire camber angle β is 1°. The required test conditions are input into the six-component force test program, and the side slip stiffness C under the above conditions is obtained through the six-component force test equipment. λ , draw the schematic diagram of the cornering stiffness curve as shown in the attached Figure 4 shown.

[0042] In the above test conditions of the present invention, the inflation pressure and the test radial load can be changed according to the requirements of the actual vehicle. For passenger car PCR tires, the inflation pressure of standard tires is 180-250kpa, the inflation pressure of reinforced tires is 180-290kpa, and the test radial load is preferably 40%, 80%, 100%, 120% or other percentages of the load marked on the tire sidewall; for light truck UTR / LTR tires, the inflation pressure of 6PR tires is 300-350kpa, the inflation pressure of 8PR tires is 400-450kpa, the inflation pressure of 10PR tires is 500-550kpa, and the inflation pressure of 12PR tires is 600-650kpa; the test radial load is preferably 40%, 80%, 100%, 120% or other percentages of the load marked on the tire sidewall.

[0043] The stiffness test conditions of the present invention are based on the design objectives and actual working conditions of the vehicle, which enables the acquisition of dynamic test data, and the matching of tire test conditions with actual vehicle test conditions. The vehicle and tire matching parameters can be accurately designed to complete vehicle calibration.

[0044] In order to more clearly and in detail introduce the method for designing vehicle calibration based on tire stiffness provided by an embodiment of the present invention, it will be described below in conjunction with a specific embodiment.

[0045] Example 1

[0046] Experimental equipment: static stiffness testing machine, six-component force testing machine, vehicles with independent suspensions on both front and rear axles, and PCR standard tires for passenger cars;

[0047] Tire specifications: 225 / 65R17 102H, standard load 850kg marked on the sidewall;

[0048] Test load: 40% of the standard load marked on the tire sidewall (1 person in the vehicle), 80% of the standard load marked on the tire sidewall (at least 2 people in the vehicle but not fully loaded); 100% of the standard load marked on the tire sidewall (fully loaded with people); 120% of the standard load marked on the tire sidewall (fully loaded with people + luggage or cargo);

[0049] Test air pressure: The inflation pressure of PCR standard passenger car tires is 230kpa for the front wheels and 250kpa for the rear wheels;

[0050] Lateral stiffness test: A static stiffness test machine is used to obtain the lateral force and corresponding lateral displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall). Based on the effective value of the lateral force and lateral displacement obtained, according to the formula S 横 =(F1 横 - F2 横 ) / (δ1 横 -δ2 横 ), the lateral stiffness of the tire is calculated, wherein the value range of the lateral displacement is 5-15mm, and the lateral stiffness test results are shown in Tables 1 and 2;

[0051] Table 1 Test results of the lateral stiffness of the front wheels of the vehicle in Example 1

[0052]

[0053] Table 2 Test results of rear wheel lateral stiffness of vehicle in Example 1

[0054]

[0055] Longitudinal stiffness test: Static stiffness test machine is used to obtain longitudinal force and corresponding longitudinal displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall). Based on the effective value of the longitudinal force and longitudinal displacement obtained, according to the formula S 纵 =(F1 纵 - F2 纵 ) / (δ1 纵 -δ2 纵 ), the longitudinal stiffness of the tire is calculated, wherein the value range of the longitudinal displacement is 5-10mm, and the longitudinal stiffness test results are shown in Tables 3 and 4;

[0056] Table 3 Test results of the longitudinal stiffness of the front wheels of the vehicle in Example 1

[0057]

[0058]

[0059] Table 4 Test results of longitudinal stiffness of rear wheels of vehicle in Example 1

[0060]

[0061] Radial stiffness test: A static stiffness test machine is used to obtain radial force and corresponding radial displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall). Based on the effective value of the radial force and radial displacement obtained, according to the formula S 径 =(F1 径 - F2 径 ) / (δ1 径 -δ2 径 ), the radial stiffness of the tire is calculated, wherein the radial displacement value range is 10-25mm, and the radial stiffness test results are shown in Table 5 and Table 6;

[0062] Table 5 Test results of radial stiffness of the front wheels of vehicles in Example 1

[0063]

[0064]

[0065] Table 6 Test results of radial stiffness of rear wheels of vehicle in Example 1

[0066]

[0067] Envelope stiffness test: Using a static stiffness test machine, the effective value of the envelope radial force and envelope displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall) are obtained. According to the formula S 包 =(F1 包 - F2 包 ) / (δ1 包 -δ2 包 ), the envelope stiffness of the tire is calculated, wherein the envelope displacement value range is 5-10mm, and the envelope stiffness test results are shown in Table 7 and Table 8;

[0068] Table 7 Test results of the front wheel envelope stiffness of the vehicle in Example 1

[0069]

[0070] Table 8 Test results of rear wheel envelope stiffness of vehicle in Example 1

[0071]

[0072] Torsional stiffness test: A static stiffness test machine is used to obtain the torsional force and corresponding angular displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall). Based on the effective value of the torsional moment and the angular displacement obtained, according to the formula S 扭 =(F1 扭 - F2 扭) / (δ1 扭 -δ2 扭 ), the torsional stiffness of the tire is calculated, wherein the value range of the angular displacement is 0-6°, and the torsional stiffness test results are shown in Tables 9 and 10;

[0073] Table 9 Test results of the front wheel torsional stiffness of the vehicle in Example 1

[0074]

[0075] Table 10 Test results of rear wheel torsional stiffness of vehicle in Example 1

[0076]

[0077] Effective rolling radius test: When the tire is tested at a speed of 60 km / h, the effective rolling radius of the tire under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall) is obtained, and the effective rolling radius is recorded as the test result: 352 mm;

[0078] Pure side slip sweep SASWEEP: The test sweep speed is 2deg / s, the side slip angle is -15°~+15°, the inclination angle is -5°~+5°, and the tire speed is 60km / h. Pure side slip sweep under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall) is obtained as follows Figure 5-Figure 7 The following are the curves fitted after the tests of 0 degree inclination (SA-SWEEP-0IA), 5 degree inclination (SA-SWEEP-5IA) and -5 degree inclination (SA-SWEEP-ne5IA), which illustrate the process of obtaining the cornering stiffness. The horizontal axis is the cornering angle [SA Filtered (degrees)], and the vertical axis is the lateral force [FYw Filtered (N)]. The blue, red, gray and yellow colors represent the standard loads marked on the tire sidewalls, 40%, 80%, 100% and 120% respectively. The lateral force and cornering angle are recorded according to the formula C. λ =ΔFy / Δλ to calculate the dynamic cornering stiffness of the cornering force corresponding to the slip angle λ of 2°, 4°, and 8°. The dynamic cornering stiffness test results are shown in Tables 11 and 12;

[0079] Table 11 Test results of dynamic cornering stiffness of the front wheel of the vehicle in Example 1

[0080]

[0081] Table 12 Test results of dynamic cornering stiffness of rear wheels of vehicle in Example 1

[0082]

[0083] The above test data are collected and integrated to obtain the tire stiffness data required for vehicle tuning. The stiffness data obtained from the above experiment is close to the reference tire stiffness of the tuned vehicle.

[0084] The matching tires are assembled with the vehicle, and the driving dynamics performance related to static stiffness and dynamic cornering stiffness is subjectively evaluated and debugged. The subjective evaluation scoring criteria are shown in Table 13:

[0085] Table 13 Subjective evaluation criteria

[0086]

[0087] The subjective evaluation results are as follows:

[0088] 1. Results of subjective evaluation items corresponding to lateral stiffness: 7 points for yaw response characteristics, 7 points for lateral force establishment process, 7 points for yaw motion establishment process, 7 points for lateral limit performance, 7 points for roll characteristics, and 7 points for lane change driving characteristics;

[0089] 2. Results of subjective evaluation items corresponding to longitudinal stiffness: acceleration pitch 6.75 points, traction capacity 7 points, braking pitch 7 points, longitudinal gap sensitivity 6.75 points, longitudinal groove sensitivity 6.75 points;

[0090] 3. Results of subjective evaluation items corresponding to radial stiffness: 7 points for low-speed driving vibration reduction comfort, 6.75 points for high-speed driving vibration reduction comfort, and 7 points for wheel rolling comfort;

[0091] 4. Results of subjective evaluation items corresponding to envelope stiffness: vibration absorption capacity 7 points, rebound characteristics 7 points, load change impact 6.75 points, road obstacle impact 6.75 points;

[0092] 5. Results of subjective evaluation items corresponding to torsional stiffness: steering controllability 7 points, steering transient response 7 points, steering return oscillation 7 points, inherent steering characteristics 7 points, steering shimmy 6.75 points;

[0093] 6. Results of subjective evaluation items corresponding to cornering stiffness: center area response 7 points, center area self-centering ability 7 points, center area steering wheel torque level 6.75 points.

[0094] After the above evaluation and debugging, the vehicle calibration is completed.

[0095] Example 2

[0096] Experimental equipment: static stiffness testing machine, six-component force testing machine, light truck with independent front suspension and torsion beam rear axle, light truck tire LTR tire;

[0097] Tire specifications: 185R15LT 6PR 98 / 97R, standard load marked on the sidewall: 750kg (single tire) / 730kg (dual tire);

[0098] Test load (single tire load): 40% of the standard load marked on the tire sidewall (1 person in the vehicle); 80% of the standard load marked on the tire sidewall (at least 1 person in the vehicle but not fully loaded); 100% of the standard load marked on the tire sidewall (full load of people and cargo in the vehicle); 120% of the standard load marked on the tire sidewall (overloaded with people and cargo in the vehicle);

[0099] Test air pressure: The inflation pressure of the light load tire LTR 6PR tire is 350kpa;

[0100] Lateral stiffness test: A static stiffness test machine is used to obtain the lateral force and corresponding lateral displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall). Based on the effective value of the lateral force and lateral displacement obtained, according to the formula S 横 =(F1 横 - F2 横 ) / (δ1 横 -δ2 横 ), the lateral stiffness of the tire is calculated, wherein the value range of the lateral displacement is 5-15mm, and the lateral stiffness test results are shown in Table 14;

[0101] Table 14 Test results of lateral stiffness of vehicle tires in Example 2

[0102]

[0103] Longitudinal stiffness test: Static stiffness test machine is used to obtain longitudinal force and corresponding longitudinal displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall). Based on the effective value of the longitudinal force and longitudinal displacement obtained, according to the formula S 纵 =(F1 纵 - F2 纵 ) / (δ1 纵 -δ2 纵 ), the longitudinal stiffness of the tire is calculated, wherein the value range of the longitudinal displacement is 5-10mm, and the longitudinal stiffness test results are shown in Table 15;

[0104] Table 15 Test results of longitudinal stiffness of vehicle tires in Example 2

[0105]

[0106] Radial stiffness test: A static stiffness test machine is used to obtain radial force and corresponding radial displacement under different radial loads (40%, 80%, 100%, 120% of the standard load marked on the tire sidewall). Based on the effective value of the radial force and radial displacement obtained, according to the formula S 径 =(F1 径 - F2 径 ) / (δ1 径 -δ2 径 ), the radial stiffness of the tire is calculated, wherein the radial displacement value range is 10-25mm, and the radial stiffness test results are shown in Table 16;

[0107] Table 16 Test results of radial stiffness of vehicle tires in Example 2

[0108]

[0109] The above test data are collected and integrated to obtain the tire stiffness data required for vehicle tuning. The stiffness data obtained from the above experiment is close to the reference tire stiffness of the tuned vehicle;

[0110] The matching tires were assembled on the vehicle. Since light trucks have relatively few requirements, only the subjective evaluation and debugging of the driving dynamics performance related to the lateral stiffness, longitudinal stiffness and radial stiffness in the static stiffness were carried out. The results are as follows:

[0111] 1. Results of subjective evaluation items corresponding to lateral stiffness: 7 points for yaw response characteristics, 7 points for lateral force establishment process, 7 points for yaw motion establishment process, 7 points for lateral limit performance, 7 points for roll characteristics, and 7 points for lane change driving characteristics;

[0112] 2. Results of subjective evaluation items corresponding to longitudinal stiffness: acceleration pitch 7 points, traction capacity 6.75 points, braking pitch 7 points, longitudinal gap sensitivity 6.75 points, longitudinal groove sensitivity 7 points;

[0113] 3. Results of subjective evaluation items corresponding to radial stiffness: 7 points for low-speed driving vibration reduction comfort, 7 points for high-speed driving vibration reduction comfort, and 7 points for wheel rolling comfort;

[0114] After the above evaluation and debugging, the vehicle calibration is completed.

[0115] Finally, it should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only the preferred feasible embodiments of the present invention, and the above-mentioned embodiments are only used to illustrate the technical scheme of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, modifications, evolutions and improvements made by ordinary technicians in this field to the technical scheme of the present invention should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for designing vehicle tuning based on tire stiffness, characterized in that: By testing the static and dynamic stiffness of tires under different loads and inflation pressures indoors, the working conditions of the tires in actual vehicle use are simulated, the tire stiffness data required for vehicle tuning is obtained, the vehicle and tire are matched, and the vehicle tuning is completed.

2. The method for designing vehicle tuning based on tire stiffness according to claim 1, characterized in that: Static stiffness includes lateral stiffness, longitudinal stiffness, radial stiffness, envelope stiffness and torsional stiffness. Static stiffness is calculated according to the formula S = (F1-F2) / (δ1-δ2). Where, F1 represents the first test load, the unit is N, F1 = Fc + 500N, F2 represents the second test load, the unit is N, F2 = Fc - 500N, Fc represents the test radial load, which is 40%, 80%, 100% and 120% of the standard load marked on the tire sidewall. δ1 represents the displacement corresponding to the first test load, and δ2 represents the displacement corresponding to the second test load.

3. The method for designing vehicle tuning based on tire stiffness according to claim 2, characterized in that: In the lateral stiffness test step, based on the effective value of the lateral force and the lateral displacement obtained, according to the formula S 横 =(F1 横 - F2 横 ) / (δ1 横 -δ2 横 ), the lateral stiffness of the tire is calculated, where the lateral displacement ranges from 5 to 15 mm.

4. The method for designing vehicle tuning based on tire stiffness according to claim 2, characterized in that: In the step of testing longitudinal stiffness, based on the effective value of longitudinal force and longitudinal displacement, according to formula S 纵 =(F1 纵 - F2 纵 ) / (δ1 纵 -δ2 纵 ), the longitudinal stiffness of the tire is calculated, where the longitudinal displacement ranges from 5 to 10 mm.

5. The method for designing vehicle tuning based on tire stiffness according to claim 2, characterized in that: In the radial stiffness test step, based on the effective value of the radial force and radial displacement, according to the formula S 径 =(F1 径 - F2 径 ) / (δ1 径 -δ2 径 ), the radial stiffness of the tire is calculated, where the radial displacement ranges from 10 to 25 mm.

6. The method for designing vehicle tuning based on tire stiffness according to claim 2, characterized in that: In the envelope stiffness test step, based on the effective value of the radial force and envelope displacement of the envelope, according to the formula S 包 =(F1 包 - F2 包 ) / (δ1 包 -δ2 包 ), the envelope stiffness of the tire is calculated, where the envelope displacement ranges from 5 to 10 mm.

7. The method for designing vehicle calibration based on tire stiffness according to claim 2, characterized in that: In the step of testing torsional stiffness, based on the effective value of the torsional moment and the angular displacement, according to the formula S 扭 =(F1 扭 - F2 扭 ) / (δ1 扭 -δ2 扭 ), the torsional stiffness of the tire is calculated, where the angular displacement ranges from 0 to 6°.

8. The method for designing vehicle tuning based on tire stiffness according to claim 1, characterized in that: In the dynamic stiffness test step, the pure side slip sweep of the tire under different radial loads and different inflation pressures at a speed of 60 km / h is tested. Based on the obtained lateral force and side slip angle, according to formula C λ =ΔFy / Δλ, the dynamic cornering stiffness is calculated, where ΔFy represents the change in cornering force, Δλ represents the change in slip angle, and the slip angle λ is 2°, 4° or 8°.

9. The method for designing vehicle tuning based on tire stiffness according to claim 8, characterized in that: The pure sideways sweep speed is 2deg / s, the sideways angle is -15°~+15°, and the inclination angle is -5°~+5°.

10. The method for designing vehicle tuning based on tire stiffness according to claim 9, characterized in that: The camber angle of vehicle tires ranges from 0.5° to 1.5°.

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