Method for testing cooling performance of vehicle retarder

Abstract

The invention provides a method for testing the cooling performance of a vehicle retarder, and the method comprises the steps: placing a vehicle on a chassis dynamometer in an environment cabin, and adjusting the temperature parameter and humidity parameter of the environment cabin to simulate an outdoor environment; setting a gear of a retarder of the vehicle as a constant speed gear, adjusting a gradient parameter of a chassis dynamometer to a first preset gradient so as to simulate a driving gradient of the vehicle, and controlling the vehicle to run at a first preset vehicle speed; in the process that the vehicle runs at the first preset vehicle speed, the vehicle speed, the vehicle running time, the vehicle running mileage and the inlet and outlet temperature difference of retarder cooling liquid are recorded; an analysis result is generated according to the speed of the vehicle, the driving time of the vehicle, the driving mileage of the vehicle and the inlet and outlet temperature difference of the retarder, and the analysis result is used for representing whether the cooling performance of the retarder meets the design index or not. The environment working condition and the road working condition are adjusted according to test requirements, test variables are accurately controlled, and the test result is prevented from being influenced by the external environment and the road working condition.

Description

Technical Field

[0001] The present invention relates to the technical field of retarder testing, and in particular to a method for testing the cooling performance of a vehicle retarder. Background Art

[0002] With the development of the automobile industry, the use of retarders plays an increasingly important role in vehicle safe driving. Retarder can effectively assist vehicle braking and reduce wear on the brake system.

[0003] Existing retarder cooling performance testing methods have many shortcomings. For example, traditional road tests are greatly affected by environmental factors such as weather and road conditions, making it difficult to ensure the consistency of test conditions. In addition, during road tests, it is difficult to accurately control test variables, which affects the accuracy and reliability of test data.

[0004] Currently, no effective solution has been proposed to the above-mentioned technical problem of inaccurate retarder cooling performance testing. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for testing the cooling performance of a vehicle retarder, so as to solve the technical problem of inaccurate retarder cooling performance testing.

[0006] To achieve the above-mentioned object, according to one aspect of the present invention, a method for testing the cooling performance of a vehicle retarder is provided, comprising: placing a vehicle on a chassis dynamometer in an environmental chamber, adjusting the temperature parameters and humidity parameters of the environmental chamber to simulate an outdoor environment; setting the gear position of the vehicle's retarder to a constant speed gear, adjusting the slope parameter of the chassis dynamometer to a first preset slope to simulate the vehicle's driving slope, and controlling the vehicle to travel at a first preset speed; while the vehicle is traveling at the first preset speed, recording the vehicle's speed, the vehicle's driving time, the vehicle's mileage, and the inlet and outlet temperature difference of the retarder coolant; generating an analysis result based on the vehicle's speed, the vehicle's driving time, the vehicle's mileage, and the inlet and outlet temperature difference of the retarder, the analysis result being used to characterize whether the cooling performance of the retarder meets the design specifications.

[0007] Furthermore, when the vehicle is traveling at a first preset speed, auxiliary braking of the vehicle is turned on, wherein the auxiliary braking includes at least engine braking and exhaust braking.

[0008] Furthermore, when the vehicle is traveling at a first preset speed, the cooling system of the vehicle engine is turned on.

[0009] Furthermore, when the vehicle is traveling at the first preset speed, the vehicle is in a fully loaded state.

[0010] Furthermore, before controlling the vehicle to travel at a first preset speed, the method includes: controlling the vehicle to travel a first preset mileage at a second preset speed to preheat the vehicle, wherein the second preset speed is greater than the first preset speed; after the vehicle travels the first preset mileage, adjusting the vehicle's driving gear step by step until the vehicle's speed is adjusted to the first preset speed, wherein, at the first preset speed, the speed of the vehicle's engine is greater than or equal to the speed corresponding to the engine's upper torque point, and less than or equal to the speed corresponding to the engine's power point.

[0011] Furthermore, an analysis result is generated based on the vehicle speed, the vehicle driving time, the vehicle mileage, and the inlet and outlet temperature difference of the retarder coolant, including: comparing the first real-time speed of the vehicle within a second preset mileage with the first preset speed; when the first real-time speed is equal to the first preset speed, generating a first analysis result, the first analysis result being used to characterize that the cooling performance of the retarder meets the design indicators.

[0012] Furthermore, an analysis result is generated based on the vehicle speed, the vehicle driving time, the vehicle mileage, and the inlet and outlet temperature difference of the retarder, including: comparing the inlet temperature of the retarder coolant with the outlet temperature of the retarder coolant within a preset driving time of the vehicle; when the inlet temperature difference of the retarder coolant is less than a temperature difference threshold, generating a second analysis result, the second analysis result being used to characterize that the cooling performance of the retarder meets the design indicators.

[0013] Furthermore, the testing method also includes: when the vehicle is traveling at a first preset speed, comparing the vehicle's second real-time speed with a third preset speed, wherein the third preset speed is greater than the first preset speed; when the second real-time speed is greater than the third preset speed, controlling the chassis dynamometer to adjust the driving slope to 0°.

[0014] Furthermore, the testing method also includes: when the vehicle is traveling at a first preset speed, comparing the real-time temperature of the retarder coolant with the maximum allowable water temperature of the retarder; when the real-time temperature is greater than the maximum allowable water temperature, controlling the chassis dynamometer to adjust the driving slope to 0°.

[0015] Furthermore, the testing method also includes: after the retarder coolant is cooled to a safe water temperature, adjusting the slope parameter of the chassis dynamometer to a second preset slope, wherein the second preset slope is smaller than the first preset slope.

[0016] Using the technical solution of the present invention, a vehicle is placed on a chassis dynamometer within an environmental chamber. The chassis dynamometer's slope parameters are adjusted to simulate the vehicle's road slope. The chamber's temperature and humidity parameters are adjusted to simulate a realistic outdoor environment. The vehicle is then controlled to travel at a first preset speed. The retarder's cooling performance is measured using the vehicle's speed, driving time, mileage, and the inlet and outlet temperature difference of the retarder coolant. This solution allows for adjustments to environmental and road conditions based on test requirements, precisely controlling test variables and ensuring consistent test conditions. This prevents test results from being affected by the external environment and road conditions, resulting in accurate and reliable test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 A schematic flow chart showing a first embodiment of a method for testing retarder cooling performance according to the present invention;

[0019] Figure 2 A flow chart showing a second embodiment of a method for testing retarder cooling performance according to the present invention is shown. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of this application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0024] Existing retarder cooling performance testing methods have many shortcomings. For example, traditional road tests are greatly affected by environmental factors such as weather and road conditions, making it difficult to ensure the consistency of test conditions. In addition, during road tests, it is difficult to accurately control test variables, which affects the accuracy and reliability of test data.

[0025] In order to solve the above problems, the embodiments of the present application provide the following testing methods.

[0026] Combine Figure 1 As shown, according to a specific embodiment of the present application, a method for testing the cooling performance of a vehicle retarder is provided.

[0027] Specifically, the test method includes the following steps:

[0028] Step S1: placing the vehicle on a chassis dynamometer in an environmental chamber, and adjusting the temperature and humidity parameters of the environmental chamber to simulate an outdoor environment.

[0029] Step S2: setting the gear of the vehicle's retarder to a constant speed gear, adjusting the slope parameter of the chassis dynamometer to a first preset slope to simulate the vehicle's driving slope, and controlling the vehicle to travel at a first preset speed.

[0030] Step S3: When the vehicle is traveling at the first preset speed, the vehicle speed, the vehicle driving time, the vehicle mileage, and the inlet and outlet temperature difference of the retarder coolant are recorded.

[0031] Step S4: generating an analysis result based on the vehicle speed, the vehicle driving time, the vehicle mileage and the inlet and outlet temperature difference of the retarder. The analysis result is used to indicate whether the cooling performance of the retarder meets the design index.

[0032] In an embodiment of the present application, a vehicle is placed on a chassis dynamometer within an environmental chamber. The chassis dynamometer's slope parameters are adjusted to simulate the vehicle's road slope. The chamber's temperature and humidity parameters are adjusted to simulate a realistic outdoor environment. The vehicle is then controlled to travel at a first preset speed. The retarder's cooling performance is measured using the vehicle's speed, travel time, mileage, and the inlet and outlet temperature difference of the retarder coolant. In this approach, environmental and road conditions can be adjusted based on test requirements, precisely controlling test variables to ensure consistency in test conditions and preventing test results from being affected by the external environment and road conditions, thereby ensuring accurate and reliable test results.

[0033] It should be noted that the environmental chamber is used to simulate a high-temperature outdoor environment. For example, the temperature and humidity parameters of the environmental chamber are adjusted so that the temperature of the environmental chamber is controlled between 32°C and 38°C. In addition, a fan is provided in the environmental chamber, and the fan outlet is set toward the front of the vehicle. The wind speed of the fan is controlled according to the driving speed of the vehicle to simulate the headwind of the vehicle, which is used to cool the engine and the entire vehicle.

[0034] It should be further explained that the chassis dynamometer is set to a road resistance simulation state, and the actual road driving resistance of the vehicle is determined according to the GB / T27840-2011 standard. The driving resistance is applied to the vehicle through the chassis dynamometer to simulate the vehicle's driving slope, where the actual road slope is -5%.

[0035] Furthermore, before testing the retarder cooling performance, the vehicle's engine needs to be tested to ensure proper engine operation. Specifically, the test method involves recording the actual engine output power (P1), where the rated engine output power is P2. If P1 > 0.8P2, the engine is considered normal and the retarder test proceeds. Testing the engine's external characteristic power prevents engine failure from affecting the retarder test results, thus ensuring more accurate retarder testing.

[0036] In an exemplary embodiment of the present application, when the vehicle is traveling at a first preset speed, auxiliary braking of the vehicle is turned on, wherein the auxiliary braking includes at least engine braking and exhaust braking.

[0037] During the test, while the retarder is braking, other auxiliary brakes are activated to simulate the retarder's extreme braking conditions, meaning that only the retarder is required to partially brake the vehicle. If the retarder's cooling performance still does not meet the design specifications with other auxiliary brakes activated, the retarder's cooling performance is considered substandard.

[0038] In an exemplary embodiment of the present application, when the vehicle is traveling at a first preset speed, a cooling system of the vehicle engine is turned on.

[0039] During the test, the vehicle's thermostat was kept in the open position to allow the coolant to circulate freely through the radiator, dissipating heat from the engine. The two external vehicle fans were always on, effectively dissipating heat from the engine. By activating the vehicle's engine cooling system, engine heat generation was prevented from affecting the retarder's cooling performance, making the retarder cooling performance test more accurate and reliable.

[0040] In an exemplary embodiment of the present application, when the vehicle is traveling at a first preset speed, the vehicle is in a fully loaded state.

[0041] During the test, the vehicle is fully loaded to simulate the extreme load condition of the retarder, making the cooling performance test of the retarder more realistic and having practical reference value, so as to avoid speed imbalance or retarder temperature imbalance caused by the retarder load after the vehicle is installed.

[0042] In an embodiment of the present application, before controlling the vehicle to travel at the first preset speed, the following steps are included:

[0043] Step S01: controlling the vehicle to travel a first preset mileage at a second preset speed to preheat the vehicle, wherein the second preset speed is greater than the first preset speed.

[0044] It should be noted that the vehicle's maximum speed is V1. The second preset speed and first preset mileage can be set based on actual needs. Generally, the second preset speed is 0.8V1, and the first preset mileage is no less than 20km. The vehicle is driven at a higher speed for a certain distance to allow the engine water and oil temperatures to reach normal operating temperatures. This highly simulates the real-world scenario during the test, making the retarder cooling performance test more realistic and valuable for practical reference.

[0045] Step S02: After the vehicle has traveled a first preset mileage, the vehicle's driving gear is adjusted step by step until the vehicle's speed is adjusted to a first preset speed, wherein, at the first preset speed, the vehicle's engine speed is greater than or equal to the speed corresponding to the engine's upper torque point, and less than or equal to the speed corresponding to the engine's power point.

[0046] It should be noted that when the vehicle is running at the second preset speed, the retarder is not engaged. After the retarder is engaged, the vehicle's driving gear needs to be lowered to fully utilize engine braking. Specifically, the gear shifting process is as follows: after downshifting one gear, determine whether the engine speed after the downshift is greater than or equal to the speed corresponding to the engine's upper torque point. If it is less than the speed corresponding to the engine's upper torque point, continue downshifting; if it is greater than the speed corresponding to the engine's upper torque point, continue to determine whether the engine speed after the downshift is less than or equal to the speed corresponding to the engine's power point. If the engine speed after the downshift is greater than or equal to the speed corresponding to the engine's upper torque point and less than or equal to the speed corresponding to the engine's power point, then continue driving normally in that driving gear.

[0047] In the above steps, the real vehicle condition is restored by preheating the vehicle, making the cooling performance test of the retarder more realistic and reliable; the vehicle speed after the retarder is turned on is adjusted by downshifting step by step, so that the vehicle engine speed is greater than or equal to the speed corresponding to the upper torque point of the engine, and less than or equal to the speed corresponding to the power point of the engine, so as to make full use of engine braking and engine-assisted braking, so as to truly test the braking capacity of the retarder.

[0048] In an exemplary embodiment of the present application, step S4 generates an analysis result based on the vehicle speed, the vehicle driving time, the vehicle mileage, and the inlet and outlet temperature difference of the retarder coolant, including the following steps:

[0049] The first real-time speed of the vehicle within the second preset mileage is compared with the first preset speed; when the first real-time speed is equal to the first preset speed, a first analysis result is generated, and the first analysis result is used to indicate that the cooling performance of the retarder meets the design indicators.

[0050] It should be noted that the retarder's cooling performance affects its braking performance. That is, when the retarder's temperature is too high, its braking performance will decrease. The second preset mileage is calibrated based on test requirements and is generally set to 30km. If the vehicle can maintain a constant speed at the first preset speed within the second preset mileage, it indicates that the retarder's braking performance is good, meaning that the retarder's temperature is in equilibrium during this period, indicating that the retarder's cooling performance meets the design specifications.

[0051] Furthermore, within the second preset mileage of the vehicle, if the first real-time vehicle speed is greater than the first preset vehicle speed, the braking performance of the retarder is unstable and the braking performance is affected by the temperature of the retarder, that is, the temperature of the retarder is in an unbalanced state during this period, that is, the cooling performance of the retarder meets the design indicators.

[0052] In an exemplary embodiment of the present application, step S4 generates an analysis result based on the vehicle speed, the vehicle driving time, the vehicle mileage, and the inlet and outlet temperature difference of the retarder coolant, including the following steps:

[0053] During a preset driving time of the vehicle, the inlet temperature of the retarder coolant is compared with the outlet temperature of the retarder coolant; when the inlet temperature difference of the retarder coolant is less than a temperature difference threshold, a second analysis result is generated, and the second analysis result is used to indicate that the cooling performance of the retarder meets the design indicators.

[0054] It should be noted that during operation, the retarder coolant temperature is allowed to fluctuate slightly, but within the preset driving duration, the coolant temperature will be in dynamic equilibrium. Specifically, the preset driving duration can be calibrated according to test requirements. Generally, the preset driving duration does not exceed 15 minutes, and the temperature difference threshold is generally less than or equal to 1°C. That is, if the retarder coolant inlet and outlet temperature difference is less than or equal to 1°C within the preset driving duration, it indicates that the coolant temperature is balanced, and the retarder cooling performance meets the design specifications.

[0055] In an exemplary embodiment of the present application, the testing method further includes: while the vehicle is traveling at a first preset speed, comparing the vehicle's second real-time speed with a third preset speed, wherein the third preset speed is greater than the first preset speed; and when the second real-time speed is greater than the third preset speed, controlling the chassis dynamometer to adjust the driving slope to 0°.

[0056] It should be noted that while the vehicle is traveling at the first preset speed, if the second real-time speed exceeds the first preset speed, the retarder's braking performance becomes unstable and is affected by the retarder's temperature, meaning the retarder's temperature is unbalanced during this period. Furthermore, the third preset speed is greater than the first preset speed and is calibrated based on test requirements. If the second real-time speed remains continuously greater than the third preset speed, indicating a severe speed imbalance that cannot be restored to equilibrium, the chassis dynamometer adjusts the driving gradient to 0°, terminating the test.

[0057] Furthermore, the test method includes: after the retarder coolant is cooled to a safe water temperature, adjusting the slope parameter of the chassis dynamometer to a second preset slope, wherein the second preset slope is smaller than the first preset slope.

[0058] It should be noted that unstable retarder braking performance indicates that the retarder coolant temperature is too high. After the retarder coolant cools to a safe temperature, the retarder is retested. This time, the driving slope is lowered and the test is repeated according to steps S1 to S4 in the above embodiment. The driving slope is gradually reduced in steps of 0.3% until the second real-time speed of the vehicle equals the first preset speed while the vehicle is traveling at the first preset speed.

[0059] In an exemplary embodiment of the present application, the testing method further includes: while the vehicle is traveling at a first preset speed, comparing the real-time temperature of the retarder coolant with the maximum allowable water temperature of the retarder; when the real-time temperature is greater than the maximum allowable water temperature, controlling the chassis dynamometer to adjust the driving slope to 0°.

[0060] It should be noted that during operation, the retarder coolant temperature is allowed to fluctuate slightly, but within the preset driving time, the coolant temperature will be in dynamic equilibrium. If the real-time retarder coolant temperature exceeds the retarder's maximum allowable water temperature, it indicates that the retarder is not operating properly. At this time, the chassis dynamometer adjusts the driving slope to 0°, ending the test.

[0061] Furthermore, the test method also includes: after the retarder coolant is cooled to a safe water temperature, adjusting the slope parameter of the chassis dynamometer to a second preset slope, wherein the second preset slope is smaller than the first preset slope.

[0062] Specifically, after the retarder coolant cools to a safe temperature, the retarder is retested, this time with the driving slope lowered, and the test is repeated according to steps S1 to S4 of the above embodiment. The driving slope is gradually reduced in steps of 0.3% until the retarder coolant temperature reaches dynamic equilibrium.

[0063] In a specific embodiment of the present application, Figure 2 As shown, the test method for vehicle retarder cooling performance includes the following steps:

[0064] S100: Vehicle preparation and inspection.

[0065] Specifically, it is necessary to check whether the actual output power of the engine is greater than 80% of the rated power.

[0066] S200: Set the environmental chamber status.

[0067] Specifically, the temperature of the environmental chamber was set to 35°C, and the speed of the fan in the chamber was adjusted according to the vehicle speed to simulate the headwind of the vehicle.

[0068] S300: Vehicle warm-up preparation.

[0069] The chassis dynamometer was set to a road resistance simulation state. The vehicle's actual road driving resistance was determined according to GB / T 27840-2011. This driving resistance was applied to the vehicle through the chassis dynamometer to simulate the vehicle's driving slope. The actual road slope was -5%. The vehicle traveled continuously for 20 km at 80% of its maximum speed, at which time the driving gear was 11.

[0070] S400: The vehicle enters the predetermined speed and gear.

[0071] Specifically, the driver drives the vehicle to the 10th gear at a speed of 70 km / h.

[0072] S500: Determine whether the engine speed reaches a predetermined speed.

[0073] When the vehicle speed is 70 km / h, it is determined whether the corresponding engine speed is within the range of 1400-1800 r / min. If so, the process proceeds to S600. If not, the process returns to S400, wherein the driving gear is adjusted step by step, illustratively, from 10th gear to 9th gear.

[0074] S600: Enter the set working condition to perform retarder test.

[0075] The slope parameter of the chassis dynamometer was adjusted to -5%, the gear of the retarder was set to the constant speed gear, the air conditioning and auxiliary braking were turned on, the vehicle thermostat was turned on, the electronic control setting of the vehicle fan was released, and the vehicle fan was always in the on state; wherein, the vehicle's driving speed was 70 km / h.

[0076] S700: Whether to trigger the zeroing condition.

[0077] In the retarder constant speed state, the vehicle speed increases from 70km / h to 75km / h and enters S800.

[0078] S800: The slope parameter of the chassis dynamometer is reset to zero.

[0079] S900: Reduced the chassis dynamometer slope parameter by 0.3%.

[0080] The vehicle decelerates to a stop under the action of resistance. After the vehicle retarder coolant cools down, the test is restarted. Other conditions remain unchanged. The downhill slope is reduced by 0.3% to -4.7% and the test is restarted.

[0081] S1000: Complete the test and record the data analysis results.

[0082] Finally, the vehicle ran steadily at a speed of 70km / h, and the retarder coolant temperature finally stabilized at 104.2℃.

[0083] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0084] 1. Place the vehicle on a chassis dynamometer within an environmental chamber. Adjust the chassis dynamometer's slope parameters to simulate the vehicle's road slope. Adjust the chamber's temperature and humidity parameters to simulate a realistic outdoor environment. The vehicle is controlled to travel at a preset speed. The retarder's cooling performance is measured by measuring vehicle speed, driving time, mileage, and the temperature difference between the retarder coolant inlet and outlet. Adjustments to environmental and road conditions are made based on test requirements, precisely controlling test variables to ensure consistent test conditions and prevent test results from being affected by the external environment and road conditions, resulting in accurate and reliable test results.

[0085] 2. During the test, while the retarder is braking, other auxiliary brakes are activated to simulate the retarder's extreme braking conditions, meaning that only the retarder is required to partially brake the vehicle. If the retarder's cooling performance still does not meet the design specifications with other auxiliary brakes activated, the retarder's cooling performance is deemed to be substandard.

[0086] 3. During the test, the vehicle's thermostat is kept in the open position to allow the coolant to circulate through the radiator and dissipate heat from the engine. The two external vehicle fans are always on, which means that the vehicle control system's electronic control settings for the vehicle fans are deactivated to fully dissipate heat from the engine. By activating the vehicle's engine cooling system, engine heat generation is prevented from affecting the retarder's cooling performance, making the retarder cooling performance test more accurate and reliable.

[0087] 4. During the test, the vehicle is fully loaded to simulate the extreme load condition of the retarder, making the cooling performance test of the retarder more realistic and having practical reference value, so as to avoid speed imbalance or retarder temperature imbalance caused by the retarder load after the vehicle is installed.

[0088] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0089] In addition to the above, it should be noted that references to "one embodiment," "another embodiment," "an embodiment," and the like in this specification refer to specific features, structures, or characteristics described in conjunction with that embodiment as included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also falls within the scope of the present invention.

[0090] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0091] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for testing the cooling performance of a vehicle retarder, characterized in that: include: Placing the vehicle on a chassis dynamometer in an environmental chamber, and adjusting the temperature and humidity parameters of the environmental chamber to simulate an outdoor environment; Setting the gear position of the retarder of the vehicle to a constant speed gear, adjusting the slope parameter of the chassis dynamometer to a first preset slope to simulate the driving slope of the vehicle, and controlling the vehicle to travel at a first preset vehicle speed; When the vehicle is traveling at a first preset speed, the speed of the vehicle, the driving time of the vehicle, the mileage of the vehicle, and the inlet and outlet temperature difference of the retarder coolant are recorded; An analysis result is generated according to the vehicle speed, the vehicle driving time, the vehicle mileage and the inlet and outlet temperature difference of the retarder, and the analysis result is used to indicate whether the cooling performance of the retarder meets the design index.

2. The testing method according to claim 1, characterized in that: When the vehicle is traveling at the first preset speed, auxiliary braking of the vehicle is turned on, wherein the auxiliary braking includes at least engine braking and exhaust braking.

3. The testing method according to claim 1, characterized in that: When the vehicle is traveling at the first preset speed, the cooling system of the vehicle engine is turned on.

4. The testing method according to claim 1, characterized in that: When the vehicle is traveling at the first preset vehicle speed, the vehicle is in a fully loaded state.

5. The testing method according to any one of claims 1 to 4, characterized in that: Before controlling the vehicle to travel at a first preset speed, the method includes: Controlling the vehicle to travel a first preset mileage at a second preset vehicle speed to preheat the vehicle, wherein the second preset vehicle speed is greater than the first preset vehicle speed; After the vehicle travels the first preset mileage, the driving gear of the vehicle is adjusted step by step until the speed of the vehicle is adjusted to the first preset speed, wherein, at the first preset speed, the speed of the vehicle engine is greater than or equal to the speed corresponding to the upper torque point of the engine, and is less than or equal to the speed corresponding to the power point of the engine.

6. The testing method according to claim 1, characterized in that: Generate analysis results based on the vehicle speed, the vehicle travel time, the vehicle travel mileage, and the inlet and outlet temperature difference of the retarder coolant, including: comparing a first real-time vehicle speed of the vehicle within a second preset mileage with the first preset vehicle speed; When the first real-time vehicle speed is equal to the first preset vehicle speed, a first analysis result is generated, and the first analysis result is used to indicate that the cooling performance of the retarder meets the design index.

7. The testing method according to claim 1, characterized in that: Generate analysis results according to the vehicle speed, the vehicle travel time, the vehicle mileage and the inlet and outlet temperature difference of the retarder, including: During a preset driving time of the vehicle, comparing an inlet temperature of the retarder coolant with an outlet temperature of the retarder coolant; When the inlet temperature difference of the retarder coolant is less than the temperature difference threshold, a second analysis result is generated, and the second analysis result is used to indicate that the cooling performance of the retarder meets the design index.

8. The testing method according to claim 1, characterized in that: The test method also includes: When the vehicle is traveling at a first preset speed, comparing the second real-time speed of the vehicle with a third preset speed, wherein the third preset speed is greater than the first preset speed; When the second real-time vehicle speed is greater than the third preset vehicle speed, the chassis dynamometer is controlled to adjust the driving slope to 0°.

9. The testing method according to claim 1, characterized in that: The test method also includes: When the vehicle is traveling at a first preset speed, comparing the real-time temperature of the retarder coolant with the maximum allowable water temperature of the retarder; When the real-time temperature is greater than the maximum allowable water temperature, the chassis dynamometer is controlled to adjust the driving slope to 0°.

10. The testing method according to claim 8 or 9, characterized in that: The test method also includes: After the retarder coolant is cooled to a safe water temperature, the slope parameter of the chassis dynamometer is adjusted to a second preset slope, wherein the second preset slope is smaller than the first preset slope.

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