A method for hill-start endurance testing of dual-clutch automatic transmissions based on a whole vehicle

Abstract

This invention relates to a method for hill-climb durability testing of a dual-clutch automatic transmission based on a whole vehicle. The steps are as follows: Accurately locate the vehicle; conduct a whole-vehicle hill-climb test, specifically: place the vehicle on a slope, apply the brakes, release the brakes to confirm normal braking; engage D gear, control the throttle opening to apply oil, automatically disengage the electronic parking brake or hill-start assist system, starting at a speed not exceeding a first preset speed threshold, maintaining throttle until reaching the top of the slope, and returning from another slope; repeat the operation, completing n hill climbs within a first preset time constitutes one cycle. After one cycle, engage D gear and drive on a flat road at a first preset speed for a second preset time, then begin the next cycle. The electronic parking brake and hill-start assist system are alternated every seven cycles until the cycle ends; determine the durability of the dual-clutch automatic transmission based on the wear condition of the clutches. This invention can accurately evaluate the reliability and durability of a vehicle's dual-clutch automatic transmission under hill-start and driving conditions.

Description

Technical Field

[0001] This invention relates to the field of automotive powertrain technology, specifically to a method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle. Background Technology

[0002] In dual-clutch automatic transmissions, the dual clutch is a crucial component, generally categorized as dry or wet. Besides shifting gears, a primary function of the dual clutch is as a starting element. Compared to dry clutches, wet clutches, due to their designed lubrication and cooling oil circuits, allow for higher energy input and are therefore suitable for vehicles with higher torque. Vehicles often use a partial clutch engagement when starting to ensure smooth engine power delivery and meet user requirements for a comfortable start. However, with increasingly severe traffic congestion, frequent use of a partial clutch engagement for short periods in conditions such as inclines or traffic jams can cause a rapid increase in clutch operating temperature, and in severe cases, even clutch slippage and vehicle malfunction.

[0003] Current clutch bench testing methods only assess the reliability and durability of the clutch unit itself, without interaction with other systems. Furthermore, there is no rapid verification test method for the reliability and durability of dual-clutch automatic transmissions on a vehicle. Therefore, there is an urgent need to design a reliability and durability testing method for dual-clutch automatic transmissions in vehicles to accurately determine their reliability and durability under slope conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a method for hill-start durability testing of a dual-clutch automatic transmission based on a vehicle, so as to accurately evaluate the reliability and durability of the dual-clutch automatic transmission in a vehicle under hill start and driving conditions.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle includes the following steps:

[0007] S1, Accurate vehicle;

[0008] S2. Conduct a full vehicle hill-climbing test, specifically:

[0009] S21. Position both the front and rear wheels of the vehicle on a slope with a gradient of the first preset gradient threshold, apply the brakes to keep the vehicle stationary, and release the brakes to confirm that the electronic parking brake (EPB) is functioning properly.

[0010] S22, shift to D gear, apply throttle at the first preset throttle opening, so that the electronic parking brake EPB or hill start assist system HHC is automatically released, the starting speed does not exceed the first preset speed threshold, stabilize the throttle until the top of the hill is reached, and return from the hill with a slope of the second preset slope threshold.

[0011] S23. Repeat S21 and S22. Complete n hill climbs within the first preset time to complete one cycle. After one cycle, shift to D gear and drive on a flat road at the first preset speed for a second preset time. Then start the next cycle. Every seven cycles, alternate between the electronic parking brake EPB and the hill start assist system HHC until the number of cycles is m.

[0012] S24. Determine the reliability and durability of the dual-clutch automatic transmission under hill start and driving conditions based on the wear condition of the clutch assembly.

[0013] Preferably, in step S1, the specific steps for determining the vehicle are as follows:

[0014] S11. Confirm the ambient temperature is above 25℃, check the vehicle's condition, turn on the headlights and air conditioning at full load, perform full load weight distribution on the vehicle according to the curb weight and front and rear wheel load requirements declared in vehicle regulations, and confirm that the tire pressure is normal. Test the computer and vehicle...

[0015] It connects to the vehicle's body controller to obtain the vehicle's speed signal and throttle opening signal;

[0016] S12. Confirm that the vehicle's electronic parking brake (EPB) and hill start assist (HHC) can be automatically released, and confirm that the recorded ECU and TCU data are normal.

[0017] Preferably, in S21, the ramp is a dry asphalt or concrete pavement, and the ramp length is at least 15m.

[0018] Preferably, in step S2, the first preset slope threshold is any slope within the range of 17% to 23%, the second preset slope threshold is 30%, and the first preset throttle opening is any throttle opening within the range of 20% to 29%.

[0019] Preferably, in S22, the first preset speed threshold is 2500 rpm; if the starting speed exceeds the first preset speed threshold, then shift to N or R gear and reverse down the slope, so that the front and rear wheels of the vehicle are on the slope with the first preset slope threshold; if the accelerator is pressed and the vehicle stops or reverses, then idle at the first preset speed threshold for 10 minutes or more before performing the hill climbing test.

[0020] Preferably, in step S23, the first preset time is 130 seconds, n is 3; the first preset vehicle speed is 20 km / h, and the second preset time is 1 minute.

[0021] Preferably, in S23, m ≥ 80.

[0022] Preferably, in S24, the specific steps are as follows: disassemble the clutch and inspect each part of the clutch. If the damage level of each part is level 2 or below, the reliability and durability of the clutch are deemed to be qualified.

[0023] The damage levels of the parts are as follows: Level 1 indicates no discoloration on the surface of the part; Level 2 indicates that the discoloration rate of the surface of the part is less than 20% and the function is normal; Level 3 indicates that the discoloration rate of the surface of the part is between 20% and 50% and the function is normal; Level 4 indicates that the discoloration rate of the surface of the part is between 50% and 80% and the function is normal; Level 5 indicates that the discoloration rate of the surface of the part is greater than or equal to 80% and the function is abnormal.

[0024] The beneficial effects of this invention are:

[0025] This invention provides a vehicle-based method for hill-start durability testing of dual-clutch automatic transmissions. It simulates actual hill-start and cyclic climbing tests on a real slope, evaluating the durability and reliability of the dual-clutch automatic transmission under hill-start and climbing conditions. By integrating the transmission TCU, hill-start assist system (HHC), and electronic parking brake system, it provides an objective and realistic assessment of the durability and reliability of the dual-clutch automatic transmission during hill-start and driving, filling a gap in hill-start durability and reliability testing for dual-clutch automatic transmissions. This method is applicable to both wet and dry dual-clutch automatic transmissions and offers advantages such as simple operation, ease of implementation, and high accuracy, making it valuable for widespread application in the field of automotive powertrain technology. Attached Figure Description

[0026] Figure 1 This is a flowchart of the slope durability test method for a dual-clutch automatic transmission based on a whole vehicle according to the present invention. Detailed Implementation

[0027] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex. Example

[0029] like Figure 1 As shown, a method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle includes the following steps:

[0030] S1. Accurate vehicle identification; specific steps are as follows:

[0031] S11. Confirm that the ambient temperature is above 25℃, check the vehicle status, turn on the headlights and air conditioning load to the full load (in this embodiment, the air conditioning mode is internal circulation, cooling), and perform full load weighting on the vehicle according to the curb weight and front and rear wheel load requirements declared in the vehicle regulations (in this embodiment, each person is weighed 75Kg, the trunk is weighed 25Kg, and the total weight is 400Kg), and confirm that the tire pressure is normal.

[0032] S12. Confirm that the vehicle's electronic parking brake (EPB) and hill start assist (HHC) can be automatically released, and confirm that the recorded ECU and TCU data are normal.

[0033] S2. Conduct a full vehicle hill-climbing test, specifically:

[0034] S21. With both the front and rear wheels of the vehicle on a 20% slope, apply the brakes to keep the vehicle stationary, and release the brakes to confirm that the electronic parking brake (EPB) is working properly (no rolling back).

[0035] The ramps are made of dry asphalt or concrete and are at least 15m long.

[0036] S22. Shift the gear lever to D. When the instrument panel displays D, quickly press the accelerator and apply the accelerator at about 25% throttle opening to automatically disengage the electronic parking brake (EPB) or hill start assist (HHC). Control the throttle to prevent the drive wheels from slipping. The starting speed should not exceed 2500 rpm. Maintain the throttle until you reach the top of a 20% slope. Then return via a 30% slope or other slopes (depending on the conditions of the test track).

[0037] If the starting speed exceeds 2500 rpm, shift to N or R gear and reverse down the slope to ensure that both the front and rear wheels of the vehicle are on a 20% slope. If the vehicle stops or reverses when the accelerator is pressed, then idle at 2500 rpm for 10 minutes or more before performing the hill climb test.

[0038] S23. Repeat S21 and S22. Complete 3 hill climbs within 130 seconds to complete one cycle. Do not shift gears on the hill during each cycle. After one cycle, put the car in D gear and drive on a flat road at a speed of 20 km / h for 1 minute to cool down. Then start the next cycle. Alternate between the electronic parking brake EPB and the hill start assist system HHC every 7 cycles until the number of cycles is 85.

[0039] The system alternates between the electronic parking brake (EPB) and the hill start assist (HHC) every seven cycles. The first cycle uses the EPB to stop, the second cycle uses the HHC, the third cycle uses the EPB, the fourth cycle uses the HHC, and so on.

[0040] S24. Determine the reliability and durability of the dual-clutch automatic transmission under hill start and driving conditions based on the wear condition of the clutch assembly; specifically:

[0041] Disassemble the clutch and inspect each part of the clutch. If the damage level of each part is level 2 or below, the reliability and durability of the clutch are deemed to be qualified.

[0042] The damage levels of the parts are as follows: Level 1 indicates no discoloration on the part surface; Level 2 indicates a discoloration rate of less than 20% (excluding endpoint values) and normal function; Level 3 indicates a discoloration rate between 20% and 50% (including endpoint values) and normal function; Level 4 indicates a discoloration rate between 50% and 80% (excluding endpoint values) and normal function; Level 5 indicates a discoloration rate of 80% or higher and abnormal function.

[0043] In summary, the dual-clutch automatic transmission hill-start durability test method of the present invention simulates the actual driving conditions of a vehicle on an incline by performing hill start and cyclic climbing tests on a real incline. This allows for the evaluation of the durability and reliability of the dual-clutch automatic transmission under hill start and climbing conditions. Furthermore, by combining the interaction of the transmission TCU, hill start assist system (HHC), and electronic parking brake system, it achieves an objective and realistic evaluation of the durability and reliability performance of the dual-clutch automatic transmission during hill start and driving when the user is using the vehicle. This fills the gap in hill-start durability and reliability testing for dual-clutch automatic transmissions, is applicable to both wet and dry dual-clutch automatic transmissions, and has the advantages of simple operation, ease of implementation, and high accuracy. It has significant application value in the field of automotive powertrain technology.

[0044] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle, characterized in that, Includes the following steps: S1, Accurate vehicle; S2. Conduct a full vehicle hill-climbing test, specifically: S21. Position both the front and rear wheels of the vehicle on a slope with a gradient of the first preset gradient threshold, apply the brakes to keep the vehicle stationary, and release the brakes to confirm that the electronic parking brake (EPB) is functioning properly. The first preset slope threshold is any slope within the range of 17% to 23%; S22. Engage D gear, apply throttle at the first preset throttle opening to automatically disengage the electronic parking brake (EPB) or hill start assist (HHC) system. The starting speed should not exceed the first preset speed threshold. Maintain throttle until the top of the hill is reached, and return from the hill with a slope of the second preset slope threshold. The second preset slope threshold is 30%, and the first preset throttle opening is any throttle opening within the range of 20% to 29%. S23. Repeat S21 and S22. Complete n hill climbs within the first preset time to complete one cycle. After one cycle, shift to D gear and drive on a flat road at the first preset speed for a second preset time. Then start the next cycle. Every seven cycles, alternate between the electronic parking brake EPB and the hill start assist system HHC until the number of cycles is m. S24. Determine the reliability and durability of the dual-clutch automatic transmission under hill start and driving conditions based on the wear condition of the clutch assembly.

2. The method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle as described in claim 1, characterized in that, In S1, the specific steps for locating the vehicle are as follows: S11. Confirm that the ambient temperature is above 25℃, check the vehicle condition, turn on the headlights and air conditioning at full load, perform full load weight distribution on the vehicle according to the curb weight and front and rear wheel load requirements declared in the vehicle regulations, and confirm that the tire pressure is normal. S12. Confirm that the vehicle's electronic parking brake (EPB) and hill start assist (HHC) can be automatically released, and confirm that the recorded ECU and TCU data are normal.

3. The method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle as described in claim 1, characterized in that, In S21, the ramp is a dry asphalt or concrete pavement, and the ramp length is at least 15m.

4. The method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle as described in claim 1, characterized in that, In S22, the first preset speed threshold is 2500 rpm; if the starting speed exceeds the first preset speed threshold, then shift to N or R gear and reverse down the slope, so that the front and rear wheels of the vehicle are on the slope with the first preset slope threshold; if the accelerator is pressed and the vehicle stops or reverses, then idle at the first preset speed threshold for 10 minutes or more before performing the hill climbing test.

5. The method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle according to claim 1, characterized in that, In S23, the first preset time is 130 seconds, n is 3; the first preset vehicle speed is 20 km / h, and the second preset time is 1 minute.

6. The method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle according to claim 1, characterized in that, In S23, m ≥ 80.

7. The method for hill-start endurance testing of a dual-clutch automatic transmission based on a whole vehicle according to claim 1, characterized in that, In S24, the specific steps are as follows: disassemble the clutch and inspect each part of the clutch. If the damage level of each part is level 2 or below, the reliability and durability of the clutch are deemed to be qualified. The damage levels of the parts are as follows: Level 1 indicates no discoloration on the surface of the part; Level 2 indicates that the discoloration rate of the surface of the part is less than 20% and the function is normal; Level 3 indicates that the discoloration rate of the surface of the part is between 20% and 50% and the function is normal; Level 4 indicates that the discoloration rate of the surface of the part is between 50% and 80% and the function is normal; Level 5 indicates that the discoloration rate of the surface of the part is greater than or equal to 80% and the function is abnormal.

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