An engine reliability test method associated with user usage

Abstract

This invention discloses a user-related engine reliability testing method. Based on the failure mechanisms of key components, the method uses damage values ​​to measure the service life of components. By comparing the damage values ​​of components in test scenarios with those in user scenarios, the acceleration factor for bench testing is derived. Combined with the test duration, the mileage of the equivalent user scenario for the bench test is determined. The reliability of key components is predicted using a reliability growth model, and the test plan is evaluated. Tests are then conducted to assess whether component lifespans meet user B10 lifespan requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of engine reliability testing, and in particular to an engine reliability testing method associated with user use. Background Art

[0002] An engine reliability test involves using a dynamometer to control the engine to run for a certain cumulative time under set operating conditions on an engine test bench. The engine's performance is confirmed before and after the reliability test. After the test, the engine is disassembled and analyzed to determine whether the engine meets reliability requirements based on component failures. Currently, engine reliability tests typically refer to GB / T 19055, "Automotive Engine Reliability Test Methods," or company-standard operating conditions, to conduct reliability tests for a fixed time. However, vehicle operating conditions are complex and varied, and the operating conditions recommended by national or company-standard reliability test specifications cannot cover the actual engine operating conditions. Furthermore, the test duration does not correspond to user mileage. Therefore, even if reliability assessments are conducted strictly in accordance with the test specifications, many reliability failures may still occur after the engine is released to the market. Therefore, there is a need for an engine reliability test method that can correlate user operating conditions and mileage to expose and resolve reliability defects during the engine development phase, thereby improving product reliability.

[0003] The most widely accepted reliability metric for products is the engine's B10 lifespan. B10 represents the operating mileage from the start of operation until 10% of units experience a critical failure, requiring the engine to be removed from the chassis for repair or complete replacement. For heavy-duty engines, various companies have proposed B10 requirements of 1.8 million kilometers or even 2 million kilometers. Quantifying the B10 lifespan of engines in relation to user experience during the development phase is a pressing issue for the industry.

[0004] The disclosure of the above background technology content is only used to assist in understanding the concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of this application. Summary of the Invention

[0005] The purpose of the present invention is to propose an engine reliability test method for verifying the B10 life based on equivalent component damage in vehicle operation scenarios. The method is applicable to all engines and can be used to conduct reliability tests on engine benches to evaluate whether engines for different purposes meet the user's B10 target life requirements.

[0006] To this end, the present invention proposes an engine reliability test method associated with user use.

[0007] Preferably, the present invention may also have the following technical features:

[0008] A user-related engine reliability test method includes the following steps:

[0009] Step 1: Determine the main test parts;

[0010] Step 2: Determine the failure mechanism of key components;

[0011] Step 3: Collect typical user route profiles;

[0012] Step 4: Design the test conditions and duration;

[0013] Step 5: Calculate the equivalent mileage of the test-associated user. Based on the typical user road spectrum obtained in step 3, the damage model of key components is combined to calculate the road spectrum unit mileage damage D. ref ; Then calculate the damage per hour D of the test condition based on the final test condition obtained in step 4 and the damage model of the component test , damage per hour under test conditions D test Helu spectrum unit mileage damage D ref The test condition acceleration factor AF is obtained by the ratio of

[0014] Combined with the typical user road spectrum and the expected time of the test condition, calculate the equivalent mileage M of the test condition equ =AF·T, T is the test duration;

[0015] Step 6: Predict component reliability;

[0016] Step 7: Determine whether the reliability meets the requirements;

[0017] Step 8: Conduct reliability test;

[0018] Step 9: Engine disassembly and evaluation;

[0019] Step 10: Determine whether the test part meets the B10 verification target. Based on the failure condition recorded in step 8 and the disassembly and evaluation results in step 9, determine whether the test part meets the B10 life requirement. If not, repeat steps 8 to 10 after optimization and rectification.

[0020] Furthermore, in step one, the key components include one or more of a piston, a bearing, a valve, and a cylinder head.

[0021] Furthermore, in step 4, based on the performance of typical user road spectra, relevant parameters are adjusted or cyclic conditions are changed on the existing reliability working conditions to form a basic prototype of the accelerated test conditions; the test duration is selected according to the bench test requirements.

[0022] Furthermore, in step 4, the working conditions corresponding to the typical failure fragments are classified through cluster analysis, and then one working condition is selected from each type of working condition as a representative. The representative working conditions of each type of working condition selected form the basic prototype of the accelerated test working condition.

[0023] Furthermore, in step 5, the road spectrum unit mileage damage D ref , D ref =D rel / M load , damage per hour under test conditions D test , D test =D rel / T, where M load Indicates the total mileage of vehicles in the calculated road spectrum, D rel is the total pseudo impairment value of the test or path spectrum.

[0024] Furthermore, in step six, the part reliability R(t) is obtained based on the analysis of historical model market quality data and the combination of the two-parameter Weibull distribution of part life mileage.

[0025] Furthermore, in step 7, if the reliability of the main component R(t) is ≥ 0.90, the requirement is met and the next step is performed; if the reliability requirement is not met, the test conditions or test duration need to be adjusted and steps 5 and 6 are repeated;

[0026] Furthermore, after the engine completes the bench test, confirm the validity of the data and arrange for the bench to be disassembled for inspection; according to the main assessment parts determined in step one, measure and record the disassembly data; after completing the engine disassembly, organize the test data and disassembly data, organize the disassembly review, and score each key part and evaluate the remaining life (RL).

[0027] Furthermore, the remaining life RL = AL - M equ , AL is the total life of the parts, AL=LF·M equ , LF is the life coefficient.

[0028] The beneficial effects of the present invention compared with the prior art include: based on the failure mechanism of key parts, measuring the service life of parts with damage values, comparing the damage values ​​of parts in test scenarios and user usage scenarios, obtaining the acceleration factor of the bench test, and combining the test duration to determine the mileage of the bench test under the equivalent user usage scenario. The reliability of key parts is predicted by the reliability growth model, the test plan is evaluated, and the test is carried out to evaluate whether the life of parts meets the user's B10 life requirements. The T-BOX big data of user-operated vehicles is used to obtain the main failure loads of key parts, and quantified through the damage model to evaluate the life of key parts. The quantitative failure load index is used to associate the user usage scenario with the part life of the test condition scenario, so as to achieve the purpose of evaluating whether the test plan is equivalent to the user's B10 life target. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a control flow chart of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be emphasized that the following description is merely illustrative and is not intended to limit the scope of the present invention and its application.

[0031] Non-limiting and non-exclusive embodiments will be described with reference to the following figures, wherein like reference numerals refer to like parts unless otherwise specifically specified.

[0032] like Figure 1 The engine reliability test method shown in the figure includes the following steps:

[0033] Step 1: Determine the main parts to be evaluated: Based on the verification requirements of the project structural parts change points and the prototype machine’s external market feedback failures, conduct tests to verify the determination of key components and specific failure modes.

[0034] In step 1, the key components include one or more of a piston, a bearing, a valve, and a cylinder head.

[0035] Step 2: Determine the failure mechanism of key components: Theoretically analyze and determine the failure mechanism of key component failure modes.

[0036] Step 3: Collect typical user road spectra: Determine key engine-related damage influencing parameters based on the failure mechanism of key components, collect fault-related parameters on typical user vehicles, and summarize and analyze data from more than six months.

[0037] Step 4: Design test conditions and duration: Design test conditions on the test bench. These conditions are generally based on the performance of typical user road spectra. Adjustments to relevant parameters or changes to the cyclic conditions are made to the existing reliability conditions to form a basic prototype of the accelerated test conditions. The final test conditions are then calculated and revised based on actual condition data. Test duration is an optional variable. Generally, a preliminary test duration is determined based on test experience, and then revised based on the B10 lifespan target and equivalent mileage calculations.

[0038] In step 4, when designing the test bench conditions, you can also use typical failure segments from typical user profiles for cluster analysis to form a basic prototype for the accelerated test conditions. Cluster analysis categorizes the conditions corresponding to these typical failure segments, then selects a representative condition from each category. These representative conditions from each category form the basic prototype for the accelerated test conditions.

[0039] The bench test based on the basic prototype of the accelerated test condition determined by the typical user loop is closer to reality and improves the accuracy of the test results.

[0040] Step 5: Calculate the equivalent mileage of the test-associated user: Based on the typical user road spectrum obtained in step 3, the damage model of key components is combined to calculate the road spectrum unit mileage damage D ref ; Then calculate the damage per hour D of the test condition based on the final test condition obtained in step 4 and the damage model of the component test , damage per hour under test conditions D test Helu spectrum unit mileage damage D ref The test condition acceleration factor AF is obtained by the ratio of

[0041] Combined with the typical user road spectrum and the expected time of the test condition, calculate the equivalent mileage M of the test condition equ =AF·T. The acceleration factor AF is used to determine the number of kilometers per hour on the bench test. The product of the acceleration factor AF and the test duration T is the bench test T hours, and the corresponding number of kilometers is M. equ In this way, by linking the test duration with the user's mileage through the acceleration factor, reliability defects can be exposed and resolved during the engine development phase, thereby improving product reliability and market competitiveness.

[0042] In step 5, the road spectrum unit mileage damage D ref , D ref =D rel / M load , where the damage per hour under test condition is D test , D test =D rel / T.

[0043] In the above, M load Indicates the total mileage of vehicles in the calculated road spectrum, D rel is the total pseudo damage value of the test or road spectrum, T is the test duration, for example, the damage model of the piston Where K is the failure factor, is the temperature variation of the part.

[0044] Step 6: Predicting the reliability of parts: The life of most mechanical products conforms to the Weibull distribution. According to the analysis of historical machine model market quality data, the life mileage of parts conforms to the two-parameter Weibull distribution. Therefore, the reliability of parts R(t) is Where is the shape parameter (the shape parameter obtained by fitting the Weibull distribution of the market average failure mileage), η is the scale parameter, α is the confidence level, and t is the target life mileage.

[0045] Step 7: Determine whether reliability meets requirements: If the reliability of the primary component, R(t), is ≥ 0.90, the requirement is met (the target reliability can be defined based on the product's maturity and the company's historical data), and proceed to the next step. If the reliability requirements are not met, adjust the test conditions or test duration, and repeat steps 5 and 6.

[0046] Step 8: Conduct reliability testing: Prepare the new engine, arrange the relevant test points, and place it on the test bench. Conduct reliability testing according to the test plan determined in Step 4. Measure engine performance and oil consumption before and after the test, and record relevant parameters and fault conditions during the test.

[0047] Step 9. Engine disassembly and evaluation: After the engine completes the bench test, confirm the validity of the data and arrange for the next bench disassembly and inspection. According to the main assessment parts determined in step 1, the disassembly and inspection process needs to focus on these key parts, and do a good job of measuring and recording the disassembly and inspection data; after completing the engine disassembly and inspection, organize the test data and disassembly and inspection data and organize a disassembly and inspection review, score each key part and evaluate the remaining life RL (hereinafter referred to as RL) (if there is no failure of the parts). RL is scored according to the experience of the review team. Generally, the RL evaluation is not allowed to exceed 50% of the equivalent life of this verification test, where RL = AL-M equ , AL is the total life of the parts, AL=LF·M equ LF is the life factor. The life factor value is designed based on the degree of damage to the component after disassembly and inspection. The higher the degree of damage to the component, the smaller the corresponding life factor. For example, the damage level of the disassembled component is divided into four grades: excellent, good, qualified, and unqualified. An excellent rating corresponds to a life factor of 1.3-1.5; a good rating corresponds to a life factor of 1.1-1.3; a qualified rating corresponds to a life factor of 1.0-1.1; and components rated unqualified will be rectified and no life factor will be assigned.

[0048] Step 10: Determine whether the part meets the B10 verification target: Based on the failure recorded in Step 8 and the disassembly and evaluation results in Step 9, determine whether the part meets the B10 lifespan requirement. If not, repeat Steps 8-10 after optimizing and rectifying the problem.

[0049] Those skilled in the art will recognize that numerous variations to the foregoing description are possible, and that the examples and figures are intended only to describe one or more specific implementations.

[0050] Although what is considered to be exemplary embodiments of the present invention has been described and illustrated, it will be understood by those skilled in the art that various changes and substitutions may be made thereto without departing from the spirit of the present invention. In addition, many modifications may be made to adapt a particular situation to the teachings of the present invention without departing from the central concept of the invention described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but rather encompasses all embodiments and their equivalents falling within the scope of the present invention.

Claims

1. An engine reliability test method associated with user use, characterized in that: The steps include: Step 1: Determine the main test parts; Step 2: Determine the failure mechanism of key components; Step 3: Collect typical user route profiles; Step 4: Design the test conditions and duration; Step 5: Calculate the equivalent mileage of the test-associated user. Based on the typical user road spectrum obtained in step 3, the damage model of key components is combined to calculate the road spectrum unit mileage damage D. ref ; Then calculate the damage per hour D of the test condition based on the final test condition obtained in step 4 and the damage model of the component test , damage per hour under test conditions D test Helu spectrum unit mileage damage D ref The test condition acceleration factor AF is obtained by the ratio of Combined with the typical user road spectrum and the expected time of the test condition, calculate the equivalent mileage M of the test condition equ =AF·T, T is the test duration; Step 6: Predict component reliability; Step 7: Determine whether the reliability meets the requirements; Step 8: Conduct reliability test; Step 9: Engine disassembly and evaluation; Step 10: Determine whether the test part meets the B10 verification target. Based on the failure condition recorded in step 8 and the disassembly and evaluation results in step 9, determine whether the test part meets the B10 life requirement. If not, repeat steps 8 to 10 after optimization and rectification.

2. The user-related engine reliability test method according to claim 1, characterized in that: In step 1, the key components include one or more of a piston, a bearing, a valve, and a cylinder head.

3. The user-related engine reliability test method according to claim 1, characterized in that: In step 4, based on the performance of typical user road spectra, relevant parameters are adjusted or cyclic conditions are changed in the existing reliability conditions to form a basic prototype of the accelerated test conditions; the test duration is selected according to the bench test requirements.

4. The user-related engine reliability test method according to claim 1, characterized in that: In step 4, the working conditions corresponding to the typical failure fragments are classified through cluster analysis, and then one working condition is selected from each type of working condition as a representative. The representative working conditions of each type of working condition selected form the basic prototype of the accelerated test condition.

5. The user-related engine reliability test method according to claim 1, characterized in that: In step 5, the road spectrum unit mileage damage D ref , D ref =D rel / M load , damage per hour under test conditions D test , D test =D rel / T, where M load Indicates the total mileage of vehicles in the calculated road spectrum, D rel is the total pseudo impairment value of the test or path spectrum.

6. The user-related engine reliability test method according to claim 1, characterized in that: In step six, the part reliability R(t) is obtained based on the analysis of historical model market quality data and the two-parameter Weibull distribution of part life mileage.

7. The user-related engine reliability test method according to claim 1, characterized in that: In step 7, if the reliability of the main component under assessment R(t) ≥ 0.90, the requirement is met and the next step is carried out; if the reliability requirement is not met, the test conditions or test duration need to be adjusted and steps 5 and 6 need to be repeated.

8. The user-related engine reliability test method according to claim 1, characterized in that: After the engine completes bench testing, confirm the validity of the data and arrange for disassembly and inspection of the engine. According to the main assessment parts determined in step one, measure and record the disassembly and inspection data. After the engine disassembly and inspection is completed, organize the test data and disassembly and inspection data, organize a disassembly and inspection review, and score each key part and evaluate the remaining life (RL).

9. The user-related engine reliability test method according to claim 8, characterized in that: Remaining life RL = AL - M equ , AL is the total life of the parts, AL=LF·M equ , LF is the life coefficient.

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