Whole vehicle road load bench test device and method

Abstract

The invention relates to a whole vehicle road load bench test device and method. A drive axle fixing tool and a control system are additionally arranged on a tire drum test machine; the drive axle fixing tool is provided with a vertical loading system for applying an actual load during a whole vehicle test, a drive axle body with wheels, a power system, a transmission, a transmission shaft, a temperature adjusting system and a transmission control system are assembled to form a to-be-tested sample piece during use, and the drive axle body of the to-be-tested sample piece is connected with the drive axle fixing tool. The wheel is in contact with the dynamometer roller; the control system controls the to-be-tested sample piece and the vertical loading system to operate by using input sample piece parameters and road spectrum information; a loading device of the tire drum testing machine is controlled according to the rotating speed of the dynamometer roller and the compensated rack driving resistance curve, and the driving resistance is adjusted, so that the rack test fits the actual condition, and the test result is ensured to be accurate; the test can be carried out only by providing key vehicle parts, the vehicle model development period is shortened, and the cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of bench simulation experiments, and in particular to a whole vehicle road load bench test device and method. Background Art

[0002] At present, the whole vehicle road durability test is a necessary test for the whole vehicle development and verification. The whole vehicle road load durability test cycle is long and is greatly affected by the weather. The fixed expenses such as site fees, driver fees, fuel costs and travel expenses are very high, resulting in high test costs. Therefore, various automobile companies are currently exploring how to carry out virtual verification and bench verification to minimize road verification and reduce development costs.

[0003] In some related technologies, a component bench is used to simulate load endurance tests, but the test results are not credible enough. The reasons are:

[0004] (1) During the test, the tires were directly removed and the axles were connected to the dynamometer. This did not take into account the impact of the driving resistance of the tires in the actual vehicle road load test.

[0005] (2) During the actual vehicle test, the road load fluctuates with the vehicle load and speed, and the driving resistance of the tires at different speeds at each moment is also different. When the component bench is used for simulation, the vehicle is in a fixed state, and the impact of transient driving resistance caused by frequently changing working conditions is not taken into account, which ultimately leads to insufficient credibility of the test results. Summary of the invention

[0006] The embodiments of the present application provide a whole vehicle road load bench test device and method to solve the problem that the bench simulation test for the whole vehicle road load in the related technology does not take into account the influence of the driving resistance of the tires in the actual whole vehicle road load test, resulting in insufficient credibility of the test results.

[0007] In a first aspect, a whole vehicle road load bench test device is provided, which includes a tire drum tester, the tire drum tester is connected to a drive axle fixing tool and a control system; the drive axle fixing tool is provided with a vertical loading system;

[0008] The control system is used to control the vertical loading system to simulate the actual load during the whole vehicle test; the control system is also used to detect the rotation speed of the dynamometer drum of the tire drum tester, and control the loading device of the tire drum tester to adjust the driving resistance in time according to the compensated bench driving resistance curve and the rotation speed.

[0009] In some embodiments, the drive axle fixing tool comprises a connecting seat, in which a mounting channel for the drive axle body to pass is provided; and a support arm connected to the tire drum tester is provided on the outer side of the connecting seat;

[0010] The vertical loading system comprises a hydraulic cylinder, the telescopic end of which extends into the installation channel and abuts against the drive axle body.

[0011] A second aspect provides a vehicle road load bench test method, which comprises the following steps:

[0012] Provide vehicle road load bench test equipment;

[0013] Assemble the drive axle body with wheels at both ends of the vehicle, the power system, the transmission, the transmission shaft, the temperature adjustment system and the transmission control system to form a sample to be tested; then connect the drive axle body of the sample to be tested with the drive axle fixing fixture so that the wheels are in contact with the dynamometer roller;

[0014] The sample parameters and road spectrum information collected from the actual vehicle road load test are used as control data; the control data and control system are used to control the operation of the sample to be tested and the vertical loading system; then, the loading device of the tire drum tester is controlled to adjust the driving resistance in a timely manner according to the rotation speed of the dynamometer drum and the compensated bench driving resistance curve.

[0015] In some embodiments, the sample parameters include engine inertia, engine idle speed, engine universal characteristic MAP, vehicle test mass, main reduction ratio, gearbox ratio, wheel rolling radius, and braking torque;

[0016] The road spectrum information includes the vehicle speed, gear position and driving distance, engine speed, throttle, output torque, transmission shaft output torque, actual load, and actual road driving resistance curve of the vehicle during the vehicle driving process of the actual vehicle road load test.

[0017] In some embodiments, obtaining the compensated test bench running resistance curve specifically includes the following steps:

[0018] The actual road driving resistance curve of the vehicle obtained through the road sliding test is used as the reference driving resistance curve;

[0019] Conduct internal resistance coasting test on the vehicle road load bench test device to obtain the bench internal resistance curve;

[0020] The sample to be tested is mounted on a vehicle road load bench test device to perform a sliding test to obtain a bench driving resistance curve of the sample to be tested;

[0021] According to the reference running resistance curve, the test bench running resistance curve and the test bench internal resistance curve, the test bench running resistance corresponding to each vehicle speed is compensated to obtain a compensated test bench running resistance curve.

[0022] In some embodiments, performing an internal resistance coasting test on a vehicle road load bench test device to obtain a bench internal resistance curve includes the following steps:

[0023] Use the motor of the tire drum tester to drive the dynamometer drum to run to the set speed;

[0024] Cut off the power input of the dynamometer motor so that the dynamometer roller can use its own inertia to overcome the internal resistance and slide;

[0025] Record the time from the start of deceleration to zero speed and the total sliding distance;

[0026] Obtaining an upper error limit value and a lower error limit value of a certain vehicle speed during the process of decelerating from a set speed to zero, and a time corresponding to the upper error limit value of the certain vehicle speed sliding to the lower error limit value of the certain vehicle speed; calculating a corresponding sliding distance according to the upper error limit value, the lower error limit value and the time;

[0027] Then, according to the kinetic energy theorem and the upper error limit, the lower error limit and the sliding distance, the internal resistance value of the test bench corresponding to a certain vehicle speed is calculated;

[0028] Repeat the above steps to obtain the test bench internal resistance values ​​corresponding to multiple vehicle speeds to fit the test bench internal resistance curve.

[0029] In some embodiments, the test sample is mounted on a vehicle road load bench test device to perform a sliding test to obtain a bench driving resistance curve of the test sample, including the following steps:

[0030] Use the control system to control the power system and transmission of the sample to be tested so that the transmission shaft drives the wheels to rotate to the set maximum speed;

[0031] Cut off the power input from the transmission to the drive shaft to allow the wheels to coast;

[0032] Record the time taken by the wheel from the start of deceleration to zero speed and the speed at each moment;

[0033] Calculate the time difference and speed difference corresponding to the time when the upper error limit of a certain vehicle speed slides to the lower error limit of the certain vehicle speed during the process of decelerating the set speed to zero; then calculate the test bench driving resistance corresponding to a certain vehicle speed in combination with Newton's second law;

[0034] Repeat the above steps to obtain the bench running resistance corresponding to multiple vehicle speeds, so as to fit the bench running resistance curve.

[0035] In some embodiments, the bench running resistance corresponding to each vehicle speed is compensated according to the reference running resistance curve, the bench running resistance curve and the bench internal resistance curve to obtain the compensated bench running resistance curve, including the following steps:

[0036] Obtaining the standard resistance corresponding to the reference running resistance curve, the bench running resistance corresponding to the bench running resistance curve, and the bench internal resistance values ​​corresponding to the bench internal resistance curve at the same vehicle speed;

[0037] The middle value is obtained by subtracting the bench running resistance corresponding to the bench running resistance curve and the bench internal resistance value corresponding to the bench internal resistance curve at the same vehicle speed; then the middle value is compared with the standard resistance value corresponding to the reference running resistance curve for judgment;

[0038] If the error between the intermediate value and the standard resistance value corresponding to the reference running resistance curve is less than the design error range, the running resistance corresponding to the running resistance curve of the vehicle speed meets the requirement; otherwise, the running resistance corresponding to the running resistance curve of the vehicle speed meets the requirement;

[0039] Repeat the above steps to optimize the bench running resistance corresponding to each vehicle speed of the bench running resistance curve to obtain a compensation curve.

[0040] In some embodiments, compensating the bench running resistance corresponding to the vehicle speed in the bench running resistance curve comprises the following steps:

[0041] The compensation value is obtained by subtracting the intermediate value from the standard resistance value corresponding to the reference driving resistance curve;

[0042] The bench running resistance corresponding to the vehicle speed is added with the compensation value to obtain a new bench running resistance corresponding to the vehicle speed.

[0043] In some embodiments, after the control data and the control system are used to control the operation of the test sample and the vertical loading system; the loading device of the tire drum tester is controlled to adjust the running resistance in time according to the compensated bench running resistance and the rotation speed of the dynamometer drum, and the following steps are also included:

[0044] Determine whether the power system and temperature control system have been preheated and have reached the same temperature and pressure as the actual vehicle road load test;

[0045] If it is reached, the step of controlling the loading device of the tire drum tester to timely adjust the running resistance according to the compensated bench running resistance curve and the speed is performed;

[0046] No, continue preheating.

[0047] The beneficial effects of the technical solution provided by this application include:

[0048] The embodiment of the present application provides a whole vehicle road load bench test device and method. Since a drive axle fixing tool and a control system are added to a tire drum tester; the drive axle fixing tool is provided with a vertical loading system for applying the actual load during the whole vehicle test, when in use, the drive axle body with wheels, the power system, the transmission, the drive shaft, the temperature adjustment system and the transmission control system are assembled to form a sample to be tested, and then the drive axle body of the sample to be tested is connected to the drive axle fixing tool so that the wheel contacts the dynamometer drum; the control system uses control data to control the operation of the sample to be tested and the vertical loading system; then the loading device of the tire drum tester is controlled to transiently adjust the driving resistance according to the rotation speed of the dynamometer drum and the compensated bench driving resistance curve, so that the bench test fits the actual transient changes at different vehicle speeds to ensure the accuracy of the test results; in addition, there is no need to test the whole vehicle, only key vehicle components need to be provided, and testing can be carried out without a sample vehicle before the design plan is finalized and after the sample trial production is completed, and then the vehicle model design plan is adjusted in time according to the test results to optimize the performance of the whole vehicle, shorten the vehicle model development cycle, and reduce development costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 A schematic diagram of a state in which a sample to be tested is installed on a vehicle road load bench test device provided in an embodiment of the present application;

[0051] Figure 2 A flow chart of a vehicle road load bench test method provided in an embodiment of the present application.

[0052] In the figure: 1. Tire drum testing machine; 2. Drive axle fixing tool; 200. Connecting seat; 201. Support arm; 3. Vertical loading system; 4. Dynamometer roller; 5. Wheel; 6. Drive axle body; 7. Power system; 8. Transmission; 9. Drive shaft; 10. Temperature regulation system; 11. Transmission control system. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0054] The main components of a general tire drum tester include:

[0055] Frame: It is welded from steel sections and plays a supporting role. All components are installed on the frame. Roller: It is rolled from steel plates and is placed on the bracket through the supporting half shafts at both ends and with vertical seat bearings to form a freely rotating cylinder. There is a material port on the cylinder that can be opened, locked and sealed, and a lifting plate is welded inside the cylinder. Driving device: It is composed of a reducer motor, a coupling, etc., which drives the roller to operate at a constant speed that meets the requirements. The reduction system is also equipped with a manual adjustment device for easy unloading. Counting device: It is connected to the supporting half shaft at one end of the roller, and can feedback the speed and record the number of rotations. After reaching the required number of revolutions, the control equipment automatically stops. Loading device: It provides resistance torque to simulate driving resistance. Measuring device: It measures torque and speed, usually including force lever type and flywheel mechanism.

[0056] For this application, the greater the road load, the more fuel is consumed. The road load diagram focuses on the power demand of a stable operating state within a certain driving speed range. The load endurance test is simulated using a component bench, but there is a problem of insufficient credibility of the test results. The reasons are:

[0057] (1) During the test, the tires were directly removed and the axles were connected to the dynamometer. This did not take into account the impact of the driving resistance of the tires in the actual vehicle road load test.

[0058] (2) During the actual vehicle test, the road load fluctuates with the vehicle load and speed, and the driving resistance of the tires at different speeds at each moment is also different. When the component bench is used for simulation, the vehicle is in a fixed state, and the impact of transient driving resistance caused by frequently changing working conditions is not taken into account, which ultimately leads to insufficient credibility of the test results.

[0059] The embodiments of the present application provide a whole vehicle road load bench test device and method to solve the problem that the bench simulation test for the whole vehicle road load in the related technology does not take into account the influence of the driving resistance of the tires in the actual whole vehicle road load test, resulting in insufficient credibility of the test results.

[0060] First, see Figure 1-Figure 2Firstly, a whole vehicle road load bench test device is proposed, including a tire drum tester 1; the tire drum tester 1 is connected with a drive axle fixing tool 2 and a control system; the drive axle fixing tool 2 is provided with a vertical loading system 3; the control system is used to simulate the actual load applied by the vertical loading system 3 during the whole vehicle test; the control system is also used to detect the rotation speed of a dynamometer drum 4 of the tire drum tester 1, the dynamometer drum 4 is pressed against a wheel 5, and then the loading device of the tire drum tester 1 is controlled to transiently (timely) adjust the driving resistance according to the rotation speed and the compensated bench driving resistance curve.

[0061] The drive axle fixing fixture 2 includes a connection seat 200, in which a mounting channel for the drive axle body 6 is provided; a support arm 201 connected to the tire drum tester 1 is provided on the outside of the connection seat 200; and a vertical loading system 3 includes a hydraulic cylinder, the telescopic end of which extends into the mounting channel and abuts against the drive axle body 6. The above is only a specific structure of the vertical loading system 3 of the drive axle fixing fixture 2, including but not limited to other forms, as long as the linear connection fixes the drive axle body 6 and can apply the actual load during the vehicle test.

[0062] The above is based on the tire drum tester 1, which can simulate the actual load during the vehicle test, and simulate the driving resistance of the vehicle in the actual vehicle road load test through the compensated bench driving resistance curve and the wheel 5 rotation speed.

[0063] When in use, the drive axle body 6 with wheels 5, the power system 7, the transmission 8, the transmission shaft 9, the temperature adjustment system 10 and the transmission control system 11 are assembled to form a sample to be tested, and then the drive axle body 6 of the sample to be tested is connected to the drive axle fixing tool 2 so that the wheel 5 contacts the dynamometer drum 4; the control system uses the control data to control the operation of the sample to be tested and the vertical loading system 3; then the loading device of the tire drum tester 1 is controlled to timely transiently adjust the driving resistance according to the rotation speed of the dynamometer drum 4 and the compensated bench driving resistance curve, so that the bench test fits the transient changes at different vehicle speeds in accordance with the actual situation, so as to ensure the accuracy of the test results; in addition, there is no need to test the whole vehicle, only key vehicle components need to be provided, and the test can be carried out without a sample vehicle before the design plan is finalized and after the sample trial production is completed, and then the vehicle design plan is adjusted in time according to the test results to optimize the performance of the whole vehicle, shorten the vehicle development cycle, and reduce the development cost.

[0064] In a second aspect, a vehicle road load bench test method comprises the following steps:

[0065] Step 100: providing a vehicle road load bench test device;

[0066] Step 200: Assemble the drive axle body 6 with wheels 5 at both ends of the vehicle, the power system 7, the transmission 8, the transmission shaft 9, the temperature adjustment system 10 and the transmission control system 11 to form a sample to be tested; then connect the drive axle body 6 of the sample to be tested to the drive axle fixing tool 2 so that the wheels 5 are in contact with the dynamometer roller 4;

[0067] Step 300: Use the sample parameters and road spectrum information collected from the actual vehicle road load test as control data; use the control data and control system to control the operation of the sample to be tested and the vertical loading system 3; then control the loading device of the tire drum tester 1 to transiently adjust the driving resistance according to the rotation speed of the dynamometer drum 4 and the compensated bench driving resistance curve.

[0068] The control system controls the loading device of the tire drum tester 1, and converts the vehicle speed and acceleration according to the collected rotation speed, combines the control data previously input into the control system and the compensated bench driving resistance curve, thereby obtaining the total driving resistance at this moment, which is then converted into torque and applied to the wheel by the loading device. Since the tire rotation speed and torque are changing in real time, this action is continuously repeated, so that the whole vehicle road load bench test device dynamically simulates the driving resistance to the wheel 5.

[0069] The control system is responsible for collecting signals such as vehicle speed, rotation speed, throttle, torque, temperature, pressure, opening, position coordinates, displacement, stress and force of each system, and storing them in real time. The control system integrates automobile driving simulation software, which can control the system to be tested to run according to instructions according to the programmed automatic sequence, and can take measures to protect the test equipment and samples according to the pre-set parameter limits and instructions when the value of a certain parameter collected exceeds the limit. In order to ensure that the transmission efficiency is consistent with the actual vehicle, the installation position and angle of each part of the sample to be tested need to be adjusted to be consistent with the actual vehicle; the transmission control system 11 is a fast-response shifting robot; its shifting logic is a control logic that confirms the timing of entering different gears according to the real-time vehicle speed, and the shifting logic is used to determine under what circumstances upshifting or downshifting can be started; for downshifting, in addition to the conventional gear-by-gear shifting logic, it is also necessary to ensure consistency with the actual driver's operating habits in special scenarios, that is, if the vehicle needs to stop at a higher speed at the end of the cycle, the driver in reality generally uses the method of directly stepping on the clutch and combining the brakes to achieve the goal, so the shifting strategy in this scenario also needs to be consistent with the driver's habits, otherwise the damage calculated in the final braking stage will differ by thousands of times. Therefore, the selection of multiple shifting strategies should not only be judged based on the vehicle speed, but also combined with the automatic sequence that simulates the driver's operating habits.

[0070] The above sample parameters include engine inertia, engine idle speed, engine universal characteristic MAP, vehicle test mass, final reduction ratio, gearbox ratio, wheel rolling radius, and braking torque;

[0071] The road spectrum information includes the vehicle speed, gear position and driving distance, engine speed, throttle, output torque, drive shaft output torque, actual load, and actual road driving resistance curve of the vehicle during the actual vehicle road load test.

[0072] In some preferred embodiments, a detailed description is given on how to obtain the compensated test bench running resistance curve, which specifically includes the following steps:

[0073] Step 300-1, using the actual road driving resistance curve of the whole vehicle obtained through the road coasting test as the reference driving resistance curve; wherein obtaining the reference driving resistance curve comprises the following steps: preparing the vehicle and conducting an actual road coasting test in accordance with the requirements of Appendix CD of GB 18352.6-2016 Light-duty Vehicle Pollutant Emission Limits and Measurement Methods (China Phase VI) to obtain the coasting data of the test vehicle on the actual road, and calculating the road driving resistance at each vehicle speed, that is, the standard resistance value F 道路i , and the road sliding curve F0=A0+B0*V+C0*V 2 .

[0074] Step 300-2: Perform an internal resistance coasting test on the vehicle road load bench test device to obtain a bench internal resistance curve; Step 300-2 specifically includes:

[0075] The motor of the dynamometer of the tire drum tester 1 is used to drive the dynamometer drum 4 to run to a set maximum speed;

[0076] Cut off the power input of the motor of the dynamometer so that the dynamometer roller 4 can slide by using its own inertia to overcome the internal resistance;

[0077] Record the time from the start of deceleration to zero speed and the total sliding distance;

[0078] In the process of decelerating from the set speed to zero, obtain the upper and lower error limits of a certain speed, as well as the time corresponding to the upper error limit of the certain speed sliding to the lower error limit of the certain speed; calculate the corresponding sliding distance L according to the upper error limit, the lower error limit and the time; then calculate the internal resistance value of the test bench corresponding to the certain speed according to the kinetic energy theorem; the lower error limit of a certain speed is V i -5km, that is, v 1 ; The upper limit of the error of a certain speed is V i +5km, that is, v 2 ; m is the mass of the vehicle; according to the kinetic energy theorem FL = 1 / 2mv 2 2 -1 / 2mv 1 2 , calculate a certain vehicle speed V iResistance F ri。

[0079] Repeat the above steps to obtain the internal resistance values ​​of the test bench corresponding to multiple vehicle speeds to fit the internal resistance curve of the test bench; that is, F r =A r +B r *V+C r *V 2 .

[0080] Step 300-3, installing the sample to be tested on a vehicle road load bench test device to perform a sliding test to obtain a bench driving resistance curve of the sample to be tested; Step 300-3 specifically includes:

[0081] The control system is used to control the power system 7 and the transmission 8 of the sample to be tested, so that the transmission shaft 9 drives the wheel 5 to rotate to a set maximum speed;

[0082] Cut off the power input from the transmission 8 to the transmission shaft 9, so that the wheel 5 slides;

[0083] Record the time taken by the wheel 5 from the start of deceleration to the speed reaching zero and the speed at each moment;

[0084] Calculate the time difference Δt and speed difference ΔV corresponding to the sliding from the error upper limit value Vi+5km / h of a certain speed to the error lower limit value Vi-5km / h of a certain speed during the process of decelerating from the maximum speed to zero; then calculate the bench driving resistance corresponding to a certain speed in combination with Newton's second law; Newton's second law F=ma=m*ΔV / Δt, where m is the mass of the vehicle, calculate the bench driving resistance F corresponding to the speed Vi 实际i .

[0085] Repeat the above steps to obtain the bench running resistance corresponding to multiple vehicle speeds to form a bench running resistance curve.

[0086] Step 300-4, compensating the bench driving resistance corresponding to each vehicle speed according to the reference driving resistance curve, the bench driving resistance curve and the bench internal resistance curve, so as to obtain a compensated bench driving resistance curve; Step 300-4 specifically includes: obtaining the standard resistance corresponding to the reference driving resistance curve, the bench driving resistance corresponding to the bench driving resistance curve and the bench internal resistance value corresponding to the bench internal resistance curve at the same vehicle speed;

[0087] The middle value is obtained by subtracting the bench running resistance corresponding to the bench running resistance curve and the bench internal resistance value corresponding to the bench internal resistance curve at the same vehicle speed; then the middle value is compared with the standard resistance value corresponding to the reference running resistance curve for judgment;

[0088] If the error between the intermediate value and the standard resistance value corresponding to the reference running resistance curve is less than the design error range, the running resistance corresponding to the running resistance curve of the vehicle speed meets the requirement; otherwise, the running resistance corresponding to the running resistance curve of the vehicle speed meets the requirement;

[0089] Repeat the above steps to optimize the bench running resistance corresponding to each vehicle speed of the bench running resistance curve to obtain a compensation curve.

[0090] Since the test bench has an internal resistance F ri Although theoretically F 实际i -F ri =F 道路i In fact, due to the large difference between the test bench and the road, F 实际i -F ri ≠F 道路i .

[0091] F 实际i is the running resistance of the test bench, F 道路i is the standard resistance value, F ri is the internal resistance of the test bench.

[0092] Compare the driving resistance (F 实际i -F ri ) and standard resistance value F 道路i If the deviation between the two is within ±10N, it is considered that the test bench sliding resistance meets the requirements; if the deviation between the two is greater than ±10N, the test bench sliding resistance needs to be compensated. The resistance F that needs to be compensated for each vehicle speed is 补偿i =F 实际i -F ri -F 道路i , then the new test bench travel resistance F ri '=F ri +F 补偿i , fit the updated rear frame driving resistance and the corresponding vehicle speed to obtain the new frame driving resistance curve and coefficient

[0093] Repeat the above steps to optimize the bench running resistance corresponding to each vehicle speed of the bench running resistance curve to obtain a compensation curve.

[0094] In some preferred embodiments, after the control data and the control system are used to control the test sample and the vertical loading system 3 to operate; the loading device of the tire drum tester 1 is controlled to transiently adjust the running resistance according to the compensated bench running resistance curve and the rotation speed of the wheel 5, and the following steps are also included:

[0095] Determine whether the power system 7 and the temperature control system 10 are preheated and have reached the same temperature and pressure as the actual vehicle road load test;

[0096] If it is reached, the step of controlling the loading device of the tire drum tester 1 to timely adjust the running resistance according to the compensated bench running resistance curve and the speed is performed;

[0097] No, continue preheating.

[0098] In some preferred embodiments, the above describes how to meet the test state of accurately fitting the actual vehicle road. The following describes the subsequent process of the test:

[0099] During the test using the vehicle road load bench test device to simulate the test, the automatic sequence is run continuously for no less than 3 cycles, and relevant information during operation is collected; fatigue analysis software is used to calculate the degree of damage to the system in each cycle, invalid data is eliminated, and the average value D1 of multiple results is taken, and the bench parameters and automatic sequence are repeatedly debugged until D1≈D0; if the assessment needs to be accelerated, the strengthening coefficient n needs to be calculated, and the relevant parameters need to be optimized until D1≈n*D0; based on the given strengthening coefficient n, the number of test cycles or test time is calculated according to the debugged automatic sequence and assessment mileage, the total damage Dt1 of the bench test is calculated, and the bench test is carried out; if the main assessment parts are damaged during the test, the test is stopped, Record the number of test cycles and test mileage at this time, and analyze the reasons for sample failure; if some non-main test parts fail or are damaged during the test, stop the test bench and record the relevant circumstances of the failure. Only after investigating and analyzing the cause of the failure and solving it, can the test continue until the test is completed; check the collected data every day to ensure the consistency and accuracy of the test data; after the bench test, conduct appearance inspection, function inspection, disassembly analysis, etc. on the test samples; organize and analyze the data recorded by the control system, combine the post-test sample inspection and analysis, problems and faulty parts analysis during the test, and analyze the performance of each component of the transmission system with the data recorded by the control system to prepare a test report.

[0100] Beneficial effects of the present invention:

[0101] First, the present invention uses an engine or a drive motor to drive the wheels, and the vertical loading system and the loading device of the tire drum tester 1 provide resistance. The dynamometer drum 4 of the tire drum tester 1 simulates the transmission pair between the wheels of the whole vehicle and the ground, thereby simulating different working conditions on the whole vehicle on the test bench. This test method can be used before the design plan is finalized and after the prototype is trial-produced, without the need for a prototype vehicle or even a drive system, and the vehicle model design plan can be adjusted in time according to the test results, the performance of the whole vehicle can be optimized, the vehicle model development cycle can be shortened, and the development cost can be reduced.

[0102] Second, the present invention, combined with the above-mentioned test system, solves the problem that the traditional component test bench cannot slide, ensures the consistency between the test bench running resistance and the actual road running resistance of the vehicle, and improves the accuracy of variable working condition and uniform speed working condition tests;

[0103] Third, the present invention can adjust specific test conditions for testing. Compared with uncontrollable factors such as changes in the vehicle road test environment and human operation, the bench test consistency is better and the test results are more accurate.

[0104] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0105] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0106] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A vehicle road load bench test device, comprising a tire drum tester (1), characterized in that: The tire drum testing machine (1) is connected to a drive axle fixing fixture (2) and a control system; the drive axle fixing fixture (2) is provided with a vertical loading system (3); The control system is used to control the vertical loading system (3) to simulate the actual load during the whole vehicle test; the control system is also used to detect the rotation speed of the dynamometer roller (4) of the tire drum tester (1), and to control the loading device of the tire drum tester (1) to adjust the running resistance in a timely manner according to the compensated bench running resistance curve and the rotation speed.

2. The vehicle road load bench test device according to claim 1, characterized in that: The drive axle fixing tool (2) comprises a connecting seat (200), wherein a mounting passage for the drive axle body (6) to pass through is provided inside the connecting seat (200); and a supporting arm (201) connected to the tire drum testing machine (1) is provided outside the connecting seat (200); The vertical loading system (3) comprises a hydraulic cylinder, the telescopic end of which extends into the installation channel to abut against the drive axle body (6).

3. A vehicle road load bench test method, characterized in that: It includes the following steps: Providing a vehicle road load bench test device as described in any one of claims 1-2; Assembling a drive axle body (6) with wheels (5) at both ends of a vehicle, a power system (7), a transmission (8), a transmission shaft (9), a temperature adjustment system (10) and a transmission control system (11) to form a sample to be tested; then connecting the drive axle body (6) of the sample to be tested to the drive axle fixing fixture (2) so that the wheels (5) are in contact with the dynamometer roller (4); The sample parameters and road spectrum information collected from the actual vehicle road load test are used as control data; the control data and the control system are used to control the operation of the sample to be tested and the vertical loading system (3); and then the loading device of the tire drum tester (1) is controlled to adjust the driving resistance in a timely manner according to the rotation speed of the dynamometer roller (4) and the compensated bench driving resistance curve.

4. The vehicle road load bench test method according to claim 3, characterized in that: The sample parameters include engine inertia, engine idle speed, engine universal characteristic MAP, vehicle test mass, final reduction ratio, gearbox ratio, wheel rolling radius, and braking torque; The road spectrum information includes the vehicle speed, gear position and driving distance, engine speed, throttle, output torque, transmission shaft output torque, actual load, and actual road driving resistance curve of the vehicle during the vehicle driving process of the actual vehicle road load test.

5. The vehicle road load bench test method according to claim 4, characterized in that: Obtaining the compensated test bench running resistance curve specifically includes the following steps: The actual road driving resistance curve of the vehicle obtained through the road sliding test is used as the reference driving resistance curve; Conduct internal resistance coasting test on the vehicle road load bench test device to obtain the bench internal resistance curve; The sample to be tested is mounted on a vehicle road load bench test device to perform a sliding test to obtain a bench driving resistance curve of the sample to be tested; According to the reference running resistance curve, the test bench running resistance curve and the test bench internal resistance curve, the test bench running resistance corresponding to each vehicle speed is compensated to obtain a compensated test bench running resistance curve.

6. The vehicle road load bench test method according to claim 5, characterized in that: Conducting an internal resistance coasting test on a vehicle road load bench test device to obtain a bench internal resistance curve includes the following steps: Using the motor of the tire drum tester (1) to drive the dynamometer drum (4) to run to a set speed; Cutting off the power input of the motor of the dynamometer so that the dynamometer roller (4) utilizes its own inertia to overcome the internal resistance and slide; Record the time from the start of deceleration to zero speed and the total sliding distance; Obtaining an upper error limit value and a lower error limit value of a certain vehicle speed during the process of decelerating from a set speed to zero, and a time corresponding to the upper error limit value of the certain vehicle speed sliding to the lower error limit value of the certain vehicle speed; calculating a corresponding sliding distance according to the upper error limit value, the lower error limit value and the time; Then, according to the kinetic energy theorem and the upper error limit, the lower error limit and the sliding distance, the internal resistance value of the test bench corresponding to a certain vehicle speed is calculated; Repeat the above steps to obtain the test bench internal resistance values ​​corresponding to multiple vehicle speeds to fit the test bench internal resistance curve.

7. The vehicle road load bench test method according to claim 6, characterized in that: The test sample is mounted on a vehicle road load bench test device to perform a sliding test to obtain a bench driving resistance curve of the test sample, including the following steps: The control system is used to control the power system (7) and the transmission (8) of the sample to be tested, so that the transmission shaft (9) drives the wheel (5) to rotate to a set maximum speed; Cutting off the power input from the transmission (8) to the transmission shaft (9) so that the wheel (5) slides; Recording the time taken for the wheel (5) to slow down and reach zero speed at each moment; Calculate the time difference and speed difference corresponding to the time when the upper error limit of a certain vehicle speed slides to the lower error limit of the certain vehicle speed during the process of decelerating the set speed to zero; then calculate the test bench driving resistance corresponding to a certain vehicle speed in combination with Newton's second law; Repeat the above steps to obtain the bench running resistance corresponding to multiple vehicle speeds, so as to fit the bench running resistance curve.

8. The vehicle road load bench test method according to claim 7, characterized in that: According to the reference running resistance curve, the test bench running resistance curve and the test bench internal resistance curve, the test bench running resistance corresponding to each vehicle speed is compensated to obtain the compensated test bench running resistance curve, including the following steps: Obtaining the standard resistance corresponding to the reference running resistance curve, the bench running resistance corresponding to the bench running resistance curve, and the bench internal resistance values ​​corresponding to the bench internal resistance curve at the same vehicle speed; The middle value is obtained by subtracting the bench running resistance corresponding to the bench running resistance curve and the bench internal resistance value corresponding to the bench internal resistance curve at the same vehicle speed; then the middle value is compared with the standard resistance value corresponding to the reference running resistance curve for judgment; If the error between the intermediate value and the standard resistance value corresponding to the reference running resistance curve is less than the design error range, the running resistance corresponding to the running resistance curve of the vehicle speed meets the requirement; otherwise, the running resistance corresponding to the running resistance curve of the vehicle speed meets the requirement; Repeat the above steps to optimize the bench running resistance corresponding to each vehicle speed of the bench running resistance curve to obtain a compensation curve.

9. The vehicle road load bench test method according to claim 8, characterized in that: Compensating the bench running resistance corresponding to the vehicle speed in the bench running resistance curve includes the following steps: The compensation value is obtained by subtracting the intermediate value from the standard resistance value corresponding to the reference driving resistance curve; The bench running resistance corresponding to the vehicle speed is added with the compensation value to obtain a new bench running resistance corresponding to the vehicle speed.

10. The vehicle road load bench test method according to claim 3, characterized in that: After the test sample and the vertical loading system (3) are controlled to run by using the control data and the control system; the loading device of the tire drum tester (1) is controlled to adjust the running resistance in time according to the compensated bench running resistance and the rotation speed of the dynamometer drum (4), and the following steps are also included: Determine whether the power system (7) and the temperature control system (10) have been preheated and have reached the same temperature and pressure as in an actual vehicle road load test; If it is reached, the step of timely adjusting the running resistance of the tire drum tester (1) is performed according to the compensated bench running resistance curve and the rotation speed; No, continue preheating.

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