A fast verification method for durability of clutch buffer valve

Abstract

The present invention proposes a method for rapid durability verification of a clutch buffer valve. According to the design data of the clutch of the target vehicle model and combined with customer survey data, two most effective clutch buffer valve durability test conditions are selected: shifting condition and ramp start condition. Based on the cyclic test results of these two conditions, it is judged whether the target clutch buffer valve meets the design requirements, so as to achieve rapid and efficient durability verification of the buffer valve. The method of the present invention uses shifting conditions and ramp start conditions to cover other conditions to perform durability verification of the clutch buffer valve. Compared with the traditional full-condition detection method, while ensuring the accuracy and reliability of the verification results, it improves the verification efficiency, shortens the verification cycle of the clutch buffer valve, and greatly saves the durability test cost.

Description

Technical Field

[0001] The invention relates to the technical field of clutch buffer valve durability verification, and in particular to a clutch buffer valve durability rapid verification method. Background Art

[0002] The clutch buffer valve is a hydraulic buffer valve installed in the pipeline of the automobile clutch hydraulic system. Its function is to absorb the hydraulic pulse and vibration from the pipeline, maintain the stability of the system, prevent the automobile clutch control system from shaking and making abnormal noises when starting, and increase the stability and comfort of the clutch system. Many OEMs solve the problem of clutch pedal shaking and abnormal noises by adding / changing clutch buffer valves. How to quickly and effectively verify the durability of added / changed clutch buffer valves is a technical problem that needs to be solved urgently. At present, there are the following problems in the durability verification of clutch buffer valves in China:

[0003] 1. If the verification is carried out by conventional vehicle durability and vehicle shift cycle tests, the test mileage is long, the test cycle is long, and the test cost is high, which cannot meet the rapid and efficient verification requirements of the buffer valve;

[0004] Second, if the verification is carried out by bench test, there will be differences with the actual working conditions of customers, and it is impossible to reasonably verify the matching and durability of the clutch system;

[0005] 3. There is no rapid durability verification method for the clutch hydraulic system, and it is urgent to develop a rapid durability verification method suitable for the clutch hydraulic system. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention designs an efficient and reliable durability rapid verification method for a clutch buffer valve, so as to shorten the verification cycle of the clutch buffer valve and save test costs.

[0007] In order to achieve the above object, the present invention proposes a clutch buffer valve durability rapid verification method, comprising the following steps:

[0008] Step 1: According to the design data of the clutch of the target vehicle model and the customer survey data, the shift frequency ratio of each gear during the shift durability test is selected to verify the shift durability of the clutch buffer valve. If the verification result is qualified, step 2 is executed; otherwise, step S5 is executed;

[0009] Step 2, performing a temperature durability test on the clutch buffer valve that has passed the gear shift durability test. If the verification result is qualified, proceed to step 3; otherwise, proceed to step S5;

[0010] Step 3, repeat step 1 and step 2 for a total of 100 cycles. If the verification results are all qualified, proceed to step 4; otherwise, after recording the working conditions when the fault occurs, proceed to step S5;

[0011] Step 4: The clutch buffer valve durability test is qualified;

[0012] Step 5: According to the specific fault conditions of the clutch buffer valve durability test, optimize the design data of the clutch and its buffer valve, and return to step 1 for re-verification.

[0013] Preferably, in step 1, the ratio of the number of gear shifts in each gear during the gear shifting endurance test is selected based on the design data of the clutch of the target vehicle model and combined with the customer survey data, the design data of the clutch includes the designed number of gear shifts and the maximum operating temperature of the clutch; the customer survey data is the ratio of the number of gear shifts in each gear during actual use by the customer; the ratio of the number of gear shifts in each gear during the gear shifting endurance test, the ratio of the number of gear shifts in gears 1 to 6 are: 6:6:5:3:2:1 respectively.

[0014] Preferably, in step 2, a temperature endurance test is performed on the clutch buffer valve that has passed the gear shift endurance test. The verification condition selected for the temperature endurance test is a hill start condition. The maximum test temperature of the clutch buffer valve does not exceed 120°C. When the clutch buffer valve is subjected to the temperature endurance test, a thermocouple is installed in the clutch inner cavity for constantly detecting the working temperature of the clutch buffer valve.

[0015] Preferably, the operating conditions recorded when the fault occurs in step 3 include gear shifting conditions and hill start conditions.

[0016] Preferably, in step 5, the design data of the clutch buffer valve is optimized according to the specific fault conditions of the clutch buffer valve durability test, and the design data of the clutch buffer valve includes buffer valve pipeline design data, buffer valve oil inlet design data, buffer valve oil outlet design data and buffer pad design data.

[0017] Beneficial Effects of the Invention

[0018] The present invention provides a method for quickly verifying the durability of a clutch buffer valve. First, according to the working principle of the clutch buffer valve and the actual measurement results of the buffer valve hydraulic pipeline pressure, an effective verification method for the buffer valve is determined, and a shifting condition verification method is formulated in combination with customer survey data. At the same time, a ramp start condition is used to cover other conditions to accelerate the matching verification of the clutch buffer valve. Compared with the traditional full-condition detection method, the method of the present invention improves the verification efficiency, shortens the verification cycle of the clutch buffer valve, and saves the test cost while ensuring the accuracy and reliability of the verification results. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flowchart of a method for rapid durability verification of a clutch buffer valve according to the present invention;

[0020] Figure 2 A comparison chart of buffer valve pipe pressure test results in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the gear shifting operation in an embodiment of the present invention;

[0022] Figure 4 : is a graph showing the proportion of the number of gear shifts in each gear in an embodiment of the present invention;

[0023] Figure 5 It is a temperature monitoring curve diagram of the clutch during the temperature endurance test in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example: See Figure 1-5 .

[0026] like Figure 1 As shown, a method for quickly verifying the durability of a clutch buffer valve of the present invention comprises the following steps:

[0027] Step 1: According to the design data of the clutch of the target vehicle model and the customer survey data, the shift frequency ratio of each gear during the shift durability test is selected to verify the shift durability of the clutch buffer valve. If the verification result is qualified, step 2 is executed; otherwise, step S5 is executed;

[0028] Step 2, performing a temperature durability test on the clutch buffer valve that has passed the gear shift durability test. If the verification result is qualified, proceed to step 3; otherwise, proceed to step S5;

[0029] Step 3, repeat step 1 and step 2 for a total of 100 cycles. If the verification results are all qualified, proceed to step 4; otherwise, after recording the working conditions when the fault occurs, proceed to step S5;

[0030] Step 4: The clutch buffer valve durability test is qualified;

[0031] Step 5: According to the specific fault conditions of the clutch buffer valve durability test, optimize the design data of the clutch and its buffer valve, and return to step 1 for re-verification.

[0032] 1. Please refer to Figure 2-5The design process and principle of a clutch buffer valve durability rapid verification method of the present invention are further explained below.

[0033] The structure and working principle of the clutch buffer valve: There is a pipeline inside the clutch buffer valve, with an oil inlet and an oil outlet respectively at the front and back of the pipeline, and a buffer pad assembly (elastic steel sheet + sealing ring) is provided on the back of the pipeline. When the hydraulic oil enters from the oil inlet of the valve body, the elastic steel sheet can play a good buffering role, absorbing the hydraulic pulse and vibration from the pipeline, so that the oil can flow out smoothly from the oil outlet, maintaining the stability of the hydraulic system, and preventing the automobile clutch control system from shaking and making abnormal noises when working.

[0034] Specifically, the basis for selecting the clutch buffer valve shift durability test in step 1 is as follows:

[0035] Conduct hydraulic test on clutch buffer valve: start accelerating from 0, test the buffer valve hydraulic system pipe pressure, the test results are as follows: Figure 2 As shown, from the measured results, it can be seen that the hydraulic pipeline of the buffer valve only has pulse fluctuations (with pipe pressure) when the gear shifting operation is performed. After the gear shifting is completed, the pipe pressure is 0. Therefore, it is determined that the most effective verification condition for the durability verification of the buffer valve is the gear shifting condition.

[0036] Furthermore, in step 1, combined with the customer survey data, the proportion of the number of shifts of each gear during the gear shift durability test is selected, and the specific content is as follows:

[0037] Common clutch system verification methods include vehicle conventional endurance test and gear shift cycle test. Vehicle conventional endurance test focuses on vehicle matching verification (power system matching), while vehicle gear shift cycle test focuses on gear shift verification (such as verifying the transmission synchronizer and clutch system). The comparison of the number of gear shifts is shown in Table 1 below:

[0038] Table 1. Comparison of conventional endurance and shift cycle times

[0039] project Conventional durability Gear Shift Cycle Total number of gear shifts (times) 100000 230000

[0040] Since the gear shift cycle test involves a high number of gear shifts, it is more effective in verifying gear shift durability.

[0041] Further research was conducted on the number of gear shifts per gear of customers, and the proportion of gear shifts per gear was counted. The number of gear shifts per gear was set based on the proportion, as shown in Table 2 below. The gear shifting operation was designed by simulating the driving habits of customers. The gear shifting operation is as follows: Figure 3 shown.

[0042] Table 2. Survey data and proportion of customers’ gear shifting frequency in each gear

[0043]

[0044] like Figure 4 The figure shows a comparison diagram of the ratio of the design shift times for quick verification and the actual shift times of customers in the above table. From the comparison results in the figure, it can be seen that when the ratio of the shift times of each gear is: 1 to 6 gears: 6: 6: 5: 3: 2: 1, it is close to the ratio of the actual shift times of customers. Therefore, this ratio of the shift times is used as the ratio of the shift times of each gear in the gear shift durability test.

[0045] Specifically, in step 2, a temperature durability test is performed on the clutch buffer valve that has passed the gear shift durability test. To prevent the clutch from having a matching failure, the clutch temperature is tested under different working conditions. The measurement results are shown in Table 3 below:

[0046] Table 3. Average clutch temperature under different working conditions

[0047]

[0048] From the test results, it can be seen that the clutch works most severely in the hill start condition, so the hill start condition is selected to cover other conditions for clutch matching verification.

[0049] Furthermore, the clutch buffer valve temperature durability test requires the installation of a thermocouple in the clutch cavity to monitor the clutch operating temperature at all times. During the actual measurement, the clutch operating temperature must not exceed 120 degrees. Note: If the clutch temperature exceeds 120 degrees, it will cause abnormal wear of the clutch friction plate. In this case, the clutch needs to be cooled before continuing the test, which will affect the reliability of the test.

[0050] In summary, the specific clutch buffer valve durability rapid verification scheme is as shown in Table 4 below:

[0051] Table 4. Clutch cushion valve durability rapid verification program

[0052]

[0053] According to the above scheme and steps, the clutch buffer valve is subjected to a durability test, and the test data of 100 cycles in step 3 are recorded in the form shown in Table 5 below:

[0054] Table 5. Test cycle record

[0055]

[0056] 2. Verify the reliability of the rapid verification method of the present invention

[0057] A routine durability test was conducted on the clutch buffer valve that passed the above-mentioned quick verification test. The specific process and comparative results are as follows.

[0058] ① Clutch friction plate wear measurement

[0059] The qualified clutch buffer valve was installed in the clutch for conventional endurance test, and the thickness of the clutch friction plate was measured. The measurement results were compared with the conventional endurance and shift cycle tests as follows:

[0060] Table 6. Comparison of clutch friction plate wear

[0061] project Conventional durability Gear Shift Cycle Rapid Verification Solution Initial friction plate (mm) 3.50mm 3.49mm 3.50mm Friction plate residue (mm) 1.50mm 1.49mm 1.50mm Total wear (mm) 2.01mm 2mm 2mm

[0062] Based on the measured wear of the clutch friction plate, it can be seen that the overall intensity of clutch wear is quickly verified to be equivalent to conventional endurance and shift cycles, which is in line with expectations.

[0063] ② Vehicle durability test

[0064] The clutch buffer valve that has passed the quick verification is subjected to subsequent vehicle durability test. The temperature monitoring curve of the entire test process is as follows: Figure 5 The specific test results are shown in Table 7 below:

[0065] Table 7. Performance of the quick-tested cushion valve in the vehicle durability test

[0066]

[0067] The performance of the buffer valve in the vehicle durability verification proves that the clutch buffer valve verified by the rapid verification method of the present invention has passed the durability verification in the vehicle durability tests conducted in subsequent projects, and there is no related fault feedback for the clutch buffer valve after sales, proving that the rapid verification method of the present invention is effective.

[0068] 3. Comparison between rapid verification method and conventional durability verification method

[0069] The following table shows the comparison results between the rapid verification method of the present invention and the conventional durable verification method.

[0070] Table 8. Comparison of fast verification scheme and vehicle endurance mileage and cycle

[0071]

[0072] From the above, it can be seen that compared with conventional durability and shift cycle durability test methods, the clutch buffer valve durability rapid verification scheme of the present invention greatly shortens the test cycle and test mileage while ensuring the accuracy and reliability of the durability test results. The test cycle is reduced by 72% and the test mileage (cost) is reduced by 67%.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapid durability verification of a clutch buffer valve, characterized in that: The following steps are involved: Step 1. According to the design data of the clutch of the target vehicle model and the customer survey data, the shift frequency ratio of each gear during the shift durability test is selected to verify the shift durability of the clutch buffer valve. If the verification result is qualified, go to step 2; otherwise, go to step 5. The design data of the clutch includes the designed shift times and the maximum operating temperature of the clutch; the customer survey data is the ratio of the shift times of each gear during actual use by customers; the ratio of the shift times of each gear during the shift endurance test, the ratio of the shift times of 1 to 6 gears are: 6:6:5:3:2:1 respectively; Step 2: Perform a temperature durability test on the clutch buffer valve that has passed the gear shift durability test. If the verification result is qualified, proceed to step 3; otherwise, proceed to step 5; The verification condition selected for the temperature durability test is the ramp start condition, and the maximum test temperature of the clutch buffer valve does not exceed 120°C; when the clutch buffer valve is subjected to the temperature durability test, a thermocouple is installed in the clutch inner cavity to detect the working temperature of the clutch buffer valve at all times; Step 3: Repeat steps 1 and 2 for a total of 100 cycles. If the verification results are all qualified, proceed to step 4; otherwise, after recording the working conditions when the fault occurs, proceed to step 5; Step 4: The clutch buffer valve durability test is qualified; Step 5: According to the specific fault conditions of the clutch buffer valve durability test, optimize the design data of the clutch and its buffer valve, and return to step 1 for re-verification.

2. A clutch buffer valve durability rapid verification method according to claim 1, characterized in that: The operating conditions when the fault occurs are recorded in step 3, and the operating conditions include gear shifting conditions and hill start conditions.

3. A clutch buffer valve durability rapid verification method according to claim 1, characterized in that: As described in step 5, according to the specific fault conditions of the clutch buffer valve durability test, the design data of the clutch buffer valve is optimized, and the design data of the clutch buffer valve includes buffer valve pipeline design data, buffer valve oil inlet design data, buffer valve oil outlet design data and buffer pad design data.

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