Method and device for predicting engine oil life of engine

Abstract

The invention relates to the technical field of vehicles, in particular to an engine oil life prediction method and device for an engine, and aims to solve the problem that the engine oil life cannot be accurately predicted in the prior art. According to the method, the oxidation life of the engine oil is determined according to the difference between each temperature value of the engine oil and a set temperature value and the proportion of the maintaining duration of each temperature value of the engine oil in the actual operation time of an engine; determining the acid containing life of the engine oil according to the degradation rate of the engine oil caused by the increase of acidic substances in the engine oil under each working condition of the engine and the proportion of the operation duration of each working condition of the engine in the actual operation time of the engine; based on the engine oil oxidation life, the engine oil acid-tolerant life and the engine oil carbon-tolerant life, whether the engine oil needs to be replaced or not is determined, and the engine oil carbon-tolerant life represents the engine oil carbon-tolerant life value obtained after the engine oil carbon-tolerant life limit value is reduced along with increase of the carbon content in the engine oil within the actual operation time of the engine. The service life of the engine oil can be accurately predicted, and the engine oil is prevented from being replaced too early or too late.

Description

Technical Field

[0001] The present application belongs to the field of vehicle technology, and in particular, relates to a method and device for predicting the oil life of an engine. Background Art

[0002] The role of engine oil is to protect the engine from wear and tear. The performance of engine oil will gradually deteriorate as the use time increases. Therefore, it is necessary to replace the engine oil in time to ensure the normal operation of the engine. The life of the engine oil will be affected by many factors, such as the working conditions of the engine, the quality of the engine oil itself, the engine operating environment, and the combustion products in the crankcase blowby, which will affect the life of the engine oil and cause the performance of the engine oil to gradually deteriorate during use. Among them, crankcase blowby refers to the fact that when the engine is working, part of the combustible mixture and combustion products (including acidic substances and soot) in the cylinder are blown into the crankcase through the piston ring. Soot will increase the carbon content in the engine oil, thereby increasing the viscosity of the engine oil and shortening the life of the engine oil. The increase in acidic substances will also reduce the performance of the engine oil, resulting in a shortened life of the engine oil. Therefore, it is necessary to accurately predict the life of the engine oil so as to choose a reasonable time to change the engine oil. If it is changed too early, it will cause a waste of resources; if it is changed too late, it will damage the engine and affect the normal operation of the engine.

[0003] In the prior art, predictions of engine oil life are mostly based on pre-setting mileage thresholds or oil change time cycles based on empirical values, or only considering the impact of soot on engine oil life. Such prediction methods lack in-depth analysis of the engine oil failure mechanism and cannot accurately predict the actual life of the engine oil, especially under different operating conditions when the performance changes of the engine oil are more complex. Summary of the invention

[0004] In response to the above problems, the present application provides an engine oil life prediction method and device, which can accurately predict the life of the engine oil and avoid changing the oil too early or too late.

[0005] In a first aspect, the present application provides a method for predicting engine oil life, the method comprising:

[0006] The oil oxidation life is determined according to the difference between each temperature value of the oil and the set temperature value and the proportion of the time when each temperature value of the oil is maintained during the actual operation time of the engine; wherein the actual operation time of the engine is the actual operation time of the engine during the oil replacement cycle of the engine;

[0007] Determine the acid capacity life of the engine oil according to the rate of engine oil deterioration caused by the increase of acidic substances in the engine oil under various operating conditions of the engine and the proportion of the engine operation time under various operating conditions during the actual operation time of the engine;

[0008] Based on the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life, determine whether the engine oil needs to be replaced, wherein the engine oil carbon capacity life represents the engine oil carbon capacity life value after the engine oil carbon capacity life limit value decreases with the increase of carbon content in the random oil during the actual engine operation time.

[0009] In a possible implementation manner, determining the oil oxidation life according to the difference between each temperature value of the oil and the set temperature value and the proportion of the time for which each temperature value of the oil is maintained during the actual operation time of the engine includes:

[0010] Determine the single-point oil oxidation life at each temperature value of the oil according to the difference between each temperature value of the oil and the set temperature value and the initial oxidation life of the oil at the set temperature;

[0011] The oil oxidation life is determined based on the single-point oil oxidation life of each temperature value of the oil and the proportion of the time when each temperature value of the oil is maintained during the actual operation time of the engine.

[0012] In a possible implementation manner, the single-point oil oxidation life at each temperature value of the oil satisfies the following formula:

[0013]

[0014] Among them, Ai is the single-point oil oxidation life of the oil at the i-th temperature value; a is the initial oxidation life of the oil at the set temperature; t is the difference between the i-th temperature value of the oil and the set temperature value.

[0015] In a possible implementation manner, the engine oil oxidation life satisfies the following formula:

[0016]

[0017] Among them, A is the oil oxidation life; Ai is the single-point oil oxidation life of the i-th temperature value of the oil, and the oil has m temperature values ​​during the actual operation time of the engine; Qi is the proportion of the maintenance time of the i-th temperature value of the oil during the actual operation time of the engine.

[0018] In a possible implementation, determining the oil acid capacity life according to the rate of oil deterioration caused by the increase of acidic substances in the oil under various operating conditions of the engine and the proportion of the engine operating time under various operating conditions during the actual operating time of the engine includes:

[0019] According to the corresponding relationship between each working condition of the engine and the oil acid failure slope, determine the oil acid failure slope of each working condition of the engine during the actual operation time of the engine; wherein the oil acid failure slope is used to characterize the rate of oil deterioration caused by the increase of acidic substances in the oil under each working condition of the engine;

[0020] Determining the single-point engine oil acid capacity life of each operating condition of the engine according to the engine oil acid capacity life limit value and the engine oil acid capacity failure slope of each operating condition of the engine during the actual operation time of the engine;

[0021] The oil acid capacity life is determined based on the single-point oil acid capacity life of each operating condition of the engine and the proportion of the engine operating time of each operating condition during the actual operating time of the engine.

[0022] In a possible implementation, the correspondence between various operating conditions of the engine and the oil acid failure slope is obtained based on the combustion temperature and fuel consumption of the engine under different operating conditions.

[0023] In a possible implementation manner, the single-point oil acid capacity life of the engine under various operating conditions satisfies the following formula:

[0024] Bj=b / Xj

[0025] Among them, Bj is the single-point oil acid capacity life of the engine in the jth operating condition; b is the oil acid capacity life limit value; Xj is the oil acid capacity failure slope of the engine in the jth operating condition.

[0026] In a possible implementation manner, the engine oil acid capacity life satisfies the following formula:

[0027]

[0028] Among them, B is the oil acid life; Bj is the single-point oil acid life of the engine in the jth operating condition, and the engine has n operating conditions during the actual operating time of the engine; Pj is the proportion of the operating time of the engine in the jth operating condition during the actual operating time of the engine.

[0029] In a possible implementation manner, determining whether the engine oil needs to be replaced based on the engine oil oxidation life, the engine oil acid capacity life, the engine oil carbon capacity life and the actual engine running time includes:

[0030] Selecting the minimum value among the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life as the engine oil life value;

[0031] Determine whether the actual running time of the engine exceeds the engine oil life value, if so, the engine oil needs to be replaced, if not, the engine oil does not need to be replaced; or

[0032] Determine whether the mileage of the vehicle since the last oil change exceeds the predicted mileage. If so, the oil needs to be changed; if not, the oil does not need to be changed, wherein the predicted mileage is determined based on the average vehicle speed during the actual operating time of the engine and the oil life value.

[0033] In a second aspect, the present application provides an engine oil life prediction device, the device comprising:

[0034] The first life prediction module is used to determine the oxidation life of the engine oil according to the difference between each temperature value of the engine oil and the set temperature value and the proportion of the maintenance time of each temperature value of the engine oil during the actual operation time of the engine; wherein the actual operation time of the engine is the actual operation time of the engine during the oil replacement cycle of the engine;

[0035] A second life prediction module is used to determine the acid capacity life of the engine oil according to the rate of engine oil deterioration caused by the increase of acidic substances in the engine oil under various working conditions of the engine and the proportion of the engine running time under various working conditions during the actual running time of the engine;

[0036] The engine oil replacement strategy module is used to determine whether the engine oil needs to be replaced based on the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life, wherein the engine oil carbon capacity life represents the engine oil carbon capacity life value after the engine oil carbon capacity life limit value decreases as the carbon content in the random oil increases during the actual operation time of the engine.

[0037] In a possible implementation manner, the first life prediction module is specifically used to:

[0038] Determine the single-point oil oxidation life at each temperature value of the oil according to the difference between each temperature value of the oil and the set temperature value and the initial oxidation life of the oil at the set temperature;

[0039] The oil oxidation life is determined based on the single-point oil oxidation life of each temperature value of the oil and the proportion of the time when each temperature value of the oil is maintained during the actual operation time of the engine.

[0040] In a possible implementation, the single-point oil oxidation life at each temperature value of the oil satisfies the following formula:

[0041]

[0042] Among them, Ai is the single-point oil oxidation life of the oil at the i-th temperature value; a is the initial oxidation life of the oil at the set temperature; t is the difference between the i-th temperature value of the oil and the set temperature value.

[0043] In a possible implementation manner, the engine oil oxidation life satisfies the following formula:

[0044]

[0045] Among them, A is the oil oxidation life; Ai is the single-point oil oxidation life of the i-th temperature value of the oil, and the oil has m temperature values ​​during the actual operation time of the engine; Qi is the proportion of the maintenance time of the i-th temperature value of the oil during the actual operation time of the engine.

[0046] In a possible implementation manner, the second life prediction module is specifically used to:

[0047] According to the corresponding relationship between each working condition of the engine and the oil acid failure slope, determine the oil acid failure slope of each working condition of the engine during the actual operation time of the engine; wherein the oil acid failure slope is used to characterize the rate of oil deterioration caused by the increase of acidic substances in the oil under each working condition of the engine;

[0048] Determining the single-point engine oil acid capacity life of each operating condition of the engine according to the engine oil acid capacity life limit value and the engine oil acid capacity failure slope of each operating condition of the engine during the actual operation time of the engine;

[0049] The oil acid capacity life is determined based on the single-point oil acid capacity life of each operating condition of the engine and the proportion of the engine operating time of each operating condition during the actual operating time of the engine.

[0050] In a possible implementation, the correspondence between various operating conditions of the engine and the oil acid failure slope is obtained based on the combustion temperature and fuel consumption of the engine under different operating conditions.

[0051] In a possible implementation manner, the single-point oil acid capacity life of the engine under various operating conditions satisfies the following formula:

[0052] Bj=b / Xj

[0053] Among them, Bj is the single-point oil acid capacity life of the engine in the jth operating condition; b is the oil acid capacity life limit value; Xj is the oil acid capacity failure slope of the engine in the jth operating condition.

[0054] In a possible implementation manner, the engine oil acid capacity life satisfies the following formula:

[0055]

[0056] Among them, B is the oil acid life; Bj is the single-point oil acid life of the engine in the jth operating condition, and the engine has n operating conditions during the actual operating time of the engine; Pj is the proportion of the operating time of the engine in the jth operating condition during the actual operating time of the engine.

[0057] In a possible implementation manner, the oil replacement strategy module is specifically used to:

[0058] Selecting the minimum value among the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life as the engine oil life value;

[0059] Determine whether the actual running time of the engine exceeds the engine oil life value, if so, the engine oil needs to be replaced, if not, the engine oil does not need to be replaced; or

[0060] Determine whether the mileage of the vehicle since the last oil change exceeds the predicted mileage. If so, the oil needs to be changed; if not, the oil does not need to be changed, wherein the predicted mileage is determined based on the average vehicle speed during the actual operating time of the engine and the oil life value.

[0061] The beneficial effects of this application are as follows:

[0062] The present application provides a method and device for predicting the oil life of an engine, which comprehensively considers the oxidation of the oil at different temperatures and the deterioration of the oil due to the increase of acidic substances and the increase of carbon content under different operating conditions of the engine, quantifies the three key parameters of the oil oxidation life, the oil acid capacity life and the oil carbon capacity life, and combines the actual operating time and operating condition distribution information of the engine to achieve a more scientific and reasonable prediction of the oil life. The present application not only helps to reduce unnecessary oil changes, but also reduces the risk of engine failure caused by oil deterioration, thereby improving the reliability and service life of the engine. Moreover, the prediction method of the present application will not be significantly adjusted and revised due to changes in the model or performance calibration data, and can provide reliable oil life prediction results in a variety of situations.

[0063] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings introduced below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0065] Figure 1 A schematic flow chart of a method for predicting engine oil life provided in an embodiment of the present application;

[0066] Figure 2 A schematic diagram of an engine oil life prediction device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other. In addition, although the logical order is shown in the flow chart, in some cases, the steps shown or described can be performed in an order different from that here.

[0068] The terms "first" and "second" in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive protection. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices. "Multiple" in the present application can mean at least two, for example, two, three or more, and the embodiments of the present application are not limited.

[0069] The following is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description. It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned, which should be considered as exemplary, and their purpose is only to illustrate the feasibility of the implementation of the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0070] Before introducing the engine oil life prediction method provided in the embodiment of the present application, in order to facilitate understanding, the technical background of the embodiment of the present application is first introduced in detail below.

[0071] The role of engine oil is to protect the engine from wear and tear. The performance of engine oil will gradually deteriorate as the use time increases. Therefore, it is necessary to replace the engine oil in time to ensure the normal operation of the engine. The life of the engine oil will be affected by many factors, such as the working conditions of the engine, the quality of the engine oil itself, the engine operating environment, and the combustion products in the crankcase blowby, which will affect the life of the engine oil and cause the performance of the engine oil to gradually deteriorate during use. Among them, crankcase blowby refers to the fact that when the engine is working, part of the combustible mixture and combustion products (including acidic substances and soot) in the cylinder are blown into the crankcase through the piston ring. Soot will increase the carbon content in the engine oil, thereby increasing the viscosity of the engine oil and shortening the life of the engine oil. The increase in acidic substances will also reduce the performance of the engine oil, resulting in a shortened life of the engine oil. Therefore, it is necessary to accurately predict the life of the engine oil so as to choose a reasonable time to change the engine oil. If it is changed too early, it will cause a waste of resources; if it is changed too late, it will damage the engine and affect the normal operation of the engine.

[0072] In the prior art, predictions of engine oil life are mostly based on pre-setting mileage thresholds or oil change time cycles based on empirical values, or only considering the impact of soot on engine oil life. Such prediction methods lack in-depth analysis of the engine oil failure mechanism and cannot accurately predict the actual life of the engine oil, especially under different operating conditions when the performance changes of the engine oil are more complex.

[0073] In view of this, in order to accurately predict the life of engine oil and avoid changing the oil too early or too late, the embodiment of the present application provides a method and device for predicting the life of engine oil. Some preferred embodiments of the present application are described below in conjunction with the drawings of the specification.

[0074] Embodiment 1:

[0075] Figure 1 A flow chart of a method for predicting engine oil life provided in some embodiments of the present application is as follows: Figure 1 As shown, the process includes the following steps:

[0076] S101: Determine the oxidation life of the engine oil according to the difference between each temperature value of the engine oil and the set temperature value and the proportion of the time when each temperature value of the engine oil is maintained during the actual operation time of the engine.

[0077] The actual engine running time is the actual engine running time during the oil change cycle of this engine.

[0078] In the embodiment of the present application, each oil change cycle starts from the last oil change or from the first time the engine is used. Correspondingly, if the current oil change cycle starts from the last oil change, the actual engine running time is from the last oil change to the current moment; if the current oil change cycle starts from the first time the engine is used, the actual engine running time is from the first time the engine is used to the current moment.

[0079] Optionally, the oil life prediction method of the present application is executed at set intervals within each oil change cycle until it is determined that the oil needs to be changed within the current oil change cycle.

[0080] In the embodiment of the present application, each temperature value of the engine oil is different temperature values ​​of the engine oil detected during the actual operation time of the engine. Specifically, it can be the temperature value of the engine oil obtained by a temperature sensor.

[0081] The set temperature value is a reference benchmark defined in this application, and the set temperature value can be set according to the recommended operating temperature range provided by the engine oil manufacturer. For example, the set temperature value can be the ideal operating temperature value of the engine under standard operating conditions. At the set temperature, the length of time required for the engine oil newly added to the engine from the beginning of use until its oxidation degree reaches a predetermined unacceptable level is the initial oxidation life of the engine oil at the set temperature. It can be understood that the oxidation rate of engine oil is different at different temperatures. The higher the temperature, the faster the oxidation reaction of the engine oil occurs, resulting in a faster reduction in the life of the engine oil. Therefore, the present application can estimate the oxidation rate of the engine oil at various temperature values ​​of the engine oil by detecting the engine oil temperature during the actual operating time of the engine and comparing it with the set temperature value.

[0082] At the same time, the present application takes into account that the oxidation rate of the engine oil at different temperatures is different. The longer the engine oil is maintained at a certain temperature, the more serious the oxidation degree caused by the temperature. Therefore, it is necessary to consider not only the temperature value itself, but also the duration of the temperature value.

[0083] Therefore, when determining the oxidation life of the engine oil, the present application also needs to consider the proportion of the maintenance time of each temperature value of the engine oil in the actual running time of the engine. In this way, by combining the temperature difference between the actual engine oil temperature and the set temperature value and the maintenance time of each temperature value, the oxidation life of the engine oil is determined. Not only the influence of temperature on the oxidation of the engine oil is considered, but also the cumulative effect of this influence over time is considered. The present application can more accurately estimate the life lost by the engine oil due to oxidation during the actual running time of the engine, thereby improving the accuracy of the prediction of the engine oil life.

[0084] As a feasible implementation manner, the specific steps of determining the oxidation life of the engine oil according to the difference between each temperature value of the engine oil and the set temperature value and the proportion of the time for which each temperature value of the engine oil is maintained during the actual operation time of the engine include the following S101a-S101b:

[0085] S101a, determining the single-point oxidation life of the engine oil at each temperature value of the engine oil according to the difference between each temperature value of the engine oil and the set temperature value and the initial oxidation life of the engine oil at the set temperature;

[0086] Specifically, the single-point oil oxidation life at each temperature value of the oil is determined using the following formula:

[0087]

[0088] Among them, Ai is the single-point oil oxidation life of the oil at the i-th temperature value; a is the initial oxidation life of the oil at the set temperature; t is the difference between the i-th temperature value of the oil and the set temperature value.

[0089] It should be noted that in the embodiments of the present application, "single-point oil life" refers to the oil life under a certain condition. For example, when the condition is a certain temperature value of the oil, "single-point oil oxidation life" refers to the expected oxidation life of the oil at the specific temperature value, that is, the expected time for the oil to work normally as the oil oxidation substances increase at the specific temperature value; for another example, when the condition is a certain engine operating condition, "single-point oil acid capacity life" refers to the expected acid capacity life of the oil under the operating condition, that is, the expected time for the oil to work normally as the acid substances in the oil increase under the operating condition.

[0090] S101b, determining the oil oxidation life according to the single-point oil oxidation life of each temperature value of the oil and the proportion of the time when each temperature value of the oil is maintained during the actual operation time of the engine,

[0091]

[0092] Among them, A is the oil oxidation life; Ai is the single-point oil oxidation life of the i-th temperature value of the oil, and the oil has m temperature values ​​during the actual operation time of the engine; Qi is the proportion of the maintenance time of the i-th temperature value of the oil during the actual operation time of the engine.

[0093] It can be seen that Formula 2 first multiplies the proportion corresponding to each temperature value by the single-point oil oxidation life of the temperature value to obtain the contribution value of the temperature value to the oxidation life. The contribution values ​​of all temperature values ​​are added together to obtain the comprehensive oxidation life during the actual operating time of the entire engine, that is, the oil oxidation life.

[0094] In the embodiment of the present application, the various temperature values ​​experienced by the oil during the actual operation time of the engine and the length of time they are maintained are first recorded. Then, these temperature values ​​are substituted into Formula 1, and the single-point oil oxidation life corresponding to each temperature value is obtained. Since the oxidation rate of the oil at different temperatures is different, the length of time the oil is maintained at each temperature value is also considered. In this way, by combining the temperature difference and the maintenance time, the life lost by the oil due to oxidation during the entire oil change cycle can be more accurately estimated, and the oil oxidation life can be finally determined.

[0095] S102: Determine the acid capacity life of the engine oil according to the rate of engine oil deterioration caused by the increase of acidic substances in the engine oil under various engine operating conditions and the proportion of the engine operating time under various engine operating conditions within the actual engine operating time.

[0096] As a feasible implementation manner, according to the rate of oil deterioration caused by the increase of acidic substances in the oil under various working conditions of the engine and the proportion of the operating time of each working condition of the engine during the actual operating time of the engine, the specific steps of determining the acid capacity life of the oil include the following S102a-S102c:

[0097] S102a, determining the oil acid failure slope of each operating condition of the engine during the actual engine operation time according to the corresponding relationship between each operating condition of the engine and the oil acid failure slope.

[0098] Among them, the oil acid capacity failure slope is used to characterize the rate of oil deterioration caused by the increase of acidic substances in the oil under various operating conditions of the engine. The corresponding relationship between various operating conditions of the engine and the oil acid capacity failure slope is based on the combustion temperature and fuel consumption of the engine under different operating conditions.

[0099] Specifically, the combustion temperature and fuel consumption of the engine will affect the acid content in the crankcase blowby gas, which in turn affects the acid content in the engine oil, thereby affecting the oil acid capacity life. Since the corresponding engine combustion temperature and fuel consumption under different engine operating conditions are different, the rate of increase of acid substances under different engine operating conditions is also different, and thus different oil acid capacity failure slopes will be obtained under different engine operating conditions.

[0100] Optionally, the corresponding relationship between each operating condition of the engine and the oil acid failure slope in the present application can be stored in a "combustion temperature and fuel consumption-oil acid failure slope relationship diagram", which is obtained by summarizing and analyzing a large amount of test data, and the corresponding oil acid failure slope can be found in the diagram according to the combustion temperature and fuel consumption. Due to different operating conditions of the engine, different combustion temperatures and fuel consumption, different oil acid failure slopes can be obtained under different engine conditions. The oil acid failure slope corresponding to a condition can be used to estimate the acidification rate of the oil under that condition.

[0101] S102b, determining the single-point engine oil acid capacity life of each operating condition of the engine according to the engine oil acid capacity life limit value and the engine oil acid capacity failure slope of each operating condition of the engine during the actual engine operation time.

[0102] Specifically, the following formula is used to determine the single-point oil acid capacity life of the engine under various operating conditions:

[0103] Bj=b / Xj Formula 3

[0104] Among them, Bj is the single-point oil acid capacity life of the engine in the jth operating condition; b is the oil acid capacity life limit value; Xj is the oil acid capacity failure slope of the engine in the jth operating condition.

[0105] It should be noted that the oil acid capacity limit value b depends on the quality of the oil itself. The oil acid capacity limit value b is divided by the oil acid capacity failure slope of each engine operating condition to obtain the single-point oil acid capacity life under each engine operating condition.

[0106] S102c, determining the acid capacity life of the engine oil according to the single-point acid capacity life of the engine oil in each operating condition of the engine and the proportion of the operating time of the engine in each operating condition within the actual operating time of the engine.

[0107] Specifically, the following formula is used to determine the oil acid capacity life:

[0108]

[0109] Among them, B is the oil acid life; Bj is the single-point oil acid life of the engine in the jth operating condition, and the engine has n operating conditions during the actual operating time of the engine; Pj is the proportion of the operating time of the engine in the jth operating condition during the actual operating time of the engine.

[0110] It can be seen that Formula 4 first multiplies the proportion corresponding to each operating condition by the single-point oil acid life of the operating condition to obtain the contribution value of the operating condition to the acid life. The contribution values ​​of all operating conditions are added together to obtain the comprehensive acid life during the actual operating time of the entire engine, that is, the oil acid life.

[0111] In the embodiment of the present application, the various operating conditions that the engine oil experiences during the actual operation time of the engine and the length of time they are maintained are first recorded. Next, the engine oil acid capacity life limit value is compared with the engine oil acid capacity failure slope corresponding to these operating conditions to obtain the single-point engine oil acid capacity life of the engine oil. Since the acidification rate of the engine oil under different operating conditions varies, the length of time maintained under each operating condition is also considered. In this way, by combining the difference in the acidification rate of different operating conditions and the maintenance time of different operating conditions, the life lost by the engine oil due to acidification during the entire oil change cycle can be more accurately estimated, and the engine oil acid capacity life can be ultimately determined.

[0112] S103: Determine whether the engine oil needs to be replaced based on the engine oil oxidation life, the engine oil acid capacity life, and the engine oil carbon capacity life.

[0113] Among them, the carbon capacity life of the engine oil represents the carbon capacity life value of the engine oil after the carbon content in the oil increases and the carbon capacity life limit of the engine oil decreases during the actual operation time of the engine. The carbon capacity life limit of the engine oil depends on the quality of the engine oil.

[0114] In the embodiment of the present application, the oil carbon capacity life is determined according to the oil carbon capacity failure slope, the oil carbon capacity life limit value and the proportion of each operating condition of the engine under various operating conditions of the engine. Specifically, the oil carbon capacity life is determined according to the oil carbon capacity failure slope, the oil carbon capacity life limit value and the proportion of each operating condition of the engine under various operating conditions of the engine, including the following steps:

[0115] According to the corresponding relationship between each working condition of the engine and the oil carbon capacity failure slope, the oil carbon capacity failure slope of each working condition of the engine is determined;

[0116] Determine the single-point oil carbon capacity life of each engine operating condition according to the oil carbon capacity life limit value and the oil carbon capacity failure slope of each engine operating condition;

[0117] The oil carbon capacity life is determined based on the single-point oil carbon capacity life under various engine operating conditions and the proportion of the engine's operating time under various engine operating conditions during the actual engine operating time.

[0118] Among them, the corresponding relationship between each engine working condition and the oil carbon capacity failure slope is determined based on the combustion calibration data of the engine under different working conditions, and the combustion calibration data includes injection advance angle, injection end time, limit injection end time, rail pressure and injection duration. Since the combustion calibration data of the engine corresponding to different engine working conditions are different, the rate of increase of carbon content in different engine working conditions is also different, and thus different oil carbon capacity failure slopes will be obtained under different engine working conditions.

[0119] Optionally, the corresponding relationship between each operating condition of the engine and the oil carbon capacity failure slope in the present application can be stored in a "combustion calibration data-oil carbon capacity failure slope relationship diagram", which is obtained by summarizing and analyzing a large amount of test data, and the corresponding oil carbon capacity failure slope can be found in the diagram according to the combustion calibration data. Since the operating conditions of the engine are different, the combustion calibration data is different, and therefore different oil carbon capacity failure slopes can be obtained under different engine conditions. The oil carbon capacity failure slope corresponding to a condition can be used to estimate the rate of increase of the carbon content of the oil under that condition.

[0120] Use the following formula to determine the single point oil carbon capacity life:

[0121] Cj=c / Yj Formula 5

[0122] Among them, Cj is the single-point oil carbon capacity life of the j-th operating condition of the engine; c is the oil carbon capacity life limit value; Yj is the oil carbon capacity failure slope of the j-th operating condition of the engine.

[0123] Use the following formula to determine the oil carbon capacity life:

[0124]

[0125] Among them, C is the oil acid life; Cj is the single-point oil acid life of the engine's j-th operating condition, and the engine has n operating conditions during the actual operating time of the engine; Pj is the proportion of the maintenance time of the engine's j-th operating condition during the actual operating time of the engine.

[0126] As a feasible implementation, determining whether the engine oil needs to be replaced based on the engine oil oxidation life, the engine oil acid capacity life, the engine oil carbon capacity life and the actual engine running time includes the following steps S103a-S103c:

[0127] S103a, selecting the minimum value among the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life as the engine oil life value;

[0128] S103b, determining whether the actual engine running time exceeds the engine oil life value, if so, the engine oil needs to be replaced, if not, the engine oil does not need to be replaced; or

[0129] S103c, determining whether the vehicle's mileage since the last oil change exceeds the predicted mileage, if so, the oil needs to be changed, if not, the oil does not need to be changed, wherein the predicted mileage is determined based on the average vehicle speed and the oil life value during the actual engine operation time.

[0130] Specifically, the predicted mileage is the product of the average vehicle speed during the actual running time of the engine and the oil life value.

[0131] The engine oil life prediction method provided in the embodiment of the present application comprehensively considers the oxidation of the oil at different temperatures and the deterioration of the oil due to the increase of acidic substances and the increase of carbon content in the engine under different operating conditions, quantifies the three key parameters of the oil oxidation life, the oil acid capacity life and the oil carbon capacity life, and combines the actual operating time and operating condition distribution information of the engine to achieve a more scientific and reasonable prediction of the oil life. The present application not only helps to reduce unnecessary oil changes, but also reduces the risk of engine failure caused by oil degradation, thereby improving the reliability and service life of the engine. Moreover, the prediction method of the present application will not be significantly adjusted and revised due to changes in the model or performance calibration data, and can provide reliable oil life prediction results in a variety of situations.

[0132] Embodiment 2:

[0133] Based on the same technical concept, on the basis of the above embodiments, in an embodiment of the present application, there is provided a method for predicting the oil life of the engine of the vehicle using the above embodiments.

[0134] Embodiment 3:

[0135] Based on the same technical concept, on the basis of the above embodiments, in an embodiment of the present application, a device for predicting the oil life of an engine is provided. Figure 2 This is a schematic diagram of the structure of an engine oil life prediction device provided in an embodiment of the present application. Figure 2 As shown, the device comprises:

[0136] The first life prediction module 201 is used to determine the oxidation life of the engine oil according to the difference between each temperature value of the engine oil and the set temperature value and the proportion of the maintenance time of each temperature value of the engine oil during the actual operation time of the engine; wherein the actual operation time of the engine is the actual operation time of the engine during the oil replacement cycle of the engine;

[0137] The second life prediction module 202 is used to determine the acid capacity life of the engine oil according to the rate of engine oil deterioration caused by the increase of acidic substances in the engine oil under various working conditions of the engine and the proportion of the engine operating time under various working conditions of the engine during the actual operating time of the engine;

[0138] The engine oil change strategy module 203 is used to determine whether the engine oil needs to be changed based on the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life, wherein the engine oil carbon capacity life represents the engine oil carbon capacity life value after the engine oil carbon capacity life limit value decreases as the carbon content in the random oil increases during the actual engine operation time.

[0139] In a possible implementation manner, the first life prediction module 201 is specifically configured to:

[0140] Determine the single-point oil oxidation life at each temperature value of the oil according to the difference between each temperature value of the oil and the set temperature value and the initial oxidation life of the oil at the set temperature;

[0141] The oil oxidation life is determined based on the single-point oil oxidation life of each temperature value of the oil and the proportion of the time when each temperature value of the oil is maintained during the actual operation time of the engine.

[0142] In a possible implementation, the single-point oil oxidation life at each temperature value of the oil satisfies the following formula:

[0143]

[0144] Among them, Ai is the single-point oil oxidation life of the oil at the i-th temperature value; a is the initial oxidation life of the oil at the set temperature; t is the difference between the i-th temperature value of the oil and the set temperature value.

[0145] In a possible implementation manner, the engine oil oxidation life satisfies the following formula:

[0146]

[0147] Among them, A is the oil oxidation life; Ai is the single-point oil oxidation life of the i-th temperature value of the oil, and the oil has m temperature values ​​during the actual operation time of the engine; Qi is the proportion of the maintenance time of the i-th temperature value of the oil during the actual operation time of the engine.

[0148] In a possible implementation manner, the second life prediction module 202 is specifically configured to:

[0149] According to the corresponding relationship between each working condition of the engine and the oil acid failure slope, determine the oil acid failure slope of each working condition of the engine during the actual operation time of the engine; wherein the oil acid failure slope is used to characterize the rate of oil deterioration caused by the increase of acidic substances in the oil under each working condition of the engine;

[0150] Determining the single-point engine oil acid capacity life of each operating condition of the engine according to the engine oil acid capacity life limit value and the engine oil acid capacity failure slope of each operating condition of the engine during the actual operation time of the engine;

[0151] The oil acid capacity life is determined based on the single-point oil acid capacity life of each operating condition of the engine and the proportion of the engine operating time of each operating condition during the actual operating time of the engine.

[0152] In a possible implementation, the correspondence between various operating conditions of the engine and the oil acid failure slope is obtained based on the combustion temperature and fuel consumption of the engine under different operating conditions.

[0153] In a possible implementation manner, the single-point oil acid capacity life of the engine under various operating conditions satisfies the following formula:

[0154] Bj=b / Xj

[0155] Among them, Bj is the single-point oil acid capacity life of the engine in the jth operating condition; b is the oil acid capacity life limit value; Xj is the oil acid capacity failure slope of the engine in the jth operating condition.

[0156] In a possible implementation manner, the engine oil acid capacity life satisfies the following formula:

[0157]

[0158] Among them, B is the oil acid life; Bj is the single-point oil acid life of the engine in the jth operating condition, and the engine has n operating conditions during the actual operating time of the engine; Pj is the proportion of the operating time of the engine in the jth operating condition during the actual operating time of the engine.

[0159] In a possible implementation manner, the oil replacement strategy module 203 is specifically configured to:

[0160] Selecting the minimum value among the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life as the engine oil life value;

[0161] Determine whether the actual running time of the engine exceeds the engine oil life value, if so, the engine oil needs to be replaced, if not, the engine oil does not need to be replaced; or

[0162] Determine whether the mileage of the vehicle since the last oil change exceeds the predicted mileage. If so, the oil needs to be changed; if not, the oil does not need to be changed, wherein the predicted mileage is determined based on the average vehicle speed during the actual operating time of the engine and the oil life value.

[0163] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and modules can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0164] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0165] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0166] In addition, each functional module in each embodiment of the present application can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0167] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0168] The technical solution provided by the present application is introduced in detail above. The principles and implementation methods of the present application are explained by using specific examples in the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0169] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0170] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for predicting engine oil life, characterized in that: include: The oil oxidation life is determined according to the difference between each temperature value of the oil and the set temperature value and the proportion of the time when each temperature value of the oil is maintained during the actual operation time of the engine; wherein the actual operation time of the engine is the actual operation time of the engine during the oil replacement cycle of the engine; Determine the acid capacity life of the engine oil according to the rate of engine oil deterioration caused by the increase of acidic substances in the engine oil under various operating conditions of the engine and the proportion of the engine operation time under various operating conditions during the actual operation time of the engine; Based on the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life, determine whether the engine oil needs to be replaced, wherein the engine oil carbon capacity life represents the engine oil carbon capacity life value after the engine oil carbon capacity life limit value decreases with the increase of carbon content in the random oil during the actual engine operation time.

2. The method according to claim 1, characterized in that Determining the oxidation life of the engine oil according to the difference between each temperature value of the engine oil and the set temperature value and the proportion of the time for which each temperature value of the engine oil is maintained during the actual operation time of the engine includes: Determine the single-point oil oxidation life at each temperature value of the oil according to the difference between each temperature value of the oil and the set temperature value and the initial oxidation life of the oil at the set temperature; The oil oxidation life is determined based on the single-point oil oxidation life of each temperature value of the oil and the proportion of the time when each temperature value of the oil is maintained during the actual operation time of the engine.

3. The method according to claim 2, characterized in that The single-point oil oxidation life of each temperature value of the oil satisfies the following formula: Among them, Ai is the single-point oil oxidation life of the oil at the i-th temperature value; a is the initial oxidation life of the oil at the set temperature; t is the difference between the i-th temperature value of the oil and the set temperature value.

4. The method according to claim 2, characterized in that The oil oxidation life satisfies the following formula: Among them, A is the oil oxidation life; Ai is the single-point oil oxidation life of the i-th temperature value of the oil, and the oil has m temperature values ​​during the actual operation time of the engine; Qi is the proportion of the maintenance time of the i-th temperature value of the oil during the actual operation time of the engine.

5. The method according to claim 1, characterized in that The determining of the oil acid capacity life according to the rate of oil deterioration caused by the increase of acidic substances in the oil under various working conditions of the engine and the proportion of the engine running time under various working conditions during the actual running time of the engine includes: According to the corresponding relationship between each working condition of the engine and the oil acid failure slope, determine the oil acid failure slope of each working condition of the engine during the actual operation time of the engine; wherein the oil acid failure slope is used to characterize the rate of oil deterioration caused by the increase of acidic substances in the oil under each working condition of the engine; Determining the single-point engine oil acid capacity life of each operating condition of the engine according to the engine oil acid capacity life limit value and the engine oil acid capacity failure slope of each operating condition of the engine during the actual operation time of the engine; The oil acid capacity life is determined based on the single-point oil acid capacity life of each operating condition of the engine and the proportion of the engine operating time of each operating condition during the actual operating time of the engine.

6. The method according to claim 5, characterized in that The corresponding relationship between each operating condition of the engine and the oil acid failure slope is obtained based on the combustion temperature and fuel consumption of the engine under different operating conditions.

7. The method according to claim 5, characterized in that The single-point oil acid capacity life of the engine under various operating conditions satisfies the following formula: Bj=b / Xj Among them, Bj is the single-point oil acid capacity life of the engine in the jth operating condition; b is the oil acid capacity life limit value; Xj is the oil acid capacity failure slope of the engine in the jth operating condition.

8. The method according to claim 5, characterized in that The oil acid capacity life satisfies the following formula: Among them, B is the oil acid life; Bj is the single-point oil acid life of the engine in the jth operating condition, and the engine has n operating conditions during the actual operating time of the engine; Pj is the proportion of the operating time of the engine in the jth operating condition during the actual operating time of the engine.

9. The method according to any one of claims 1 to 8, characterized in that: The determining whether the engine oil needs to be replaced based on the engine oil oxidation life, the engine oil acid capacity life, the engine oil carbon capacity life and the actual engine running time includes: Selecting the minimum value among the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life as the engine oil life value; Determine whether the actual running time of the engine exceeds the oil life value, if so, the oil needs to be replaced, if not, the oil does not need to be replaced; or Determine whether the mileage of the vehicle since the last oil change exceeds the predicted mileage. If so, the oil needs to be changed; if not, the oil does not need to be changed, wherein the predicted mileage is determined based on the average vehicle speed during the actual operating time of the engine and the oil life value.

10. An engine oil life prediction device, characterized in that: include: The first life prediction module is used to determine the oxidation life of the engine oil according to the difference between each temperature value of the engine oil and the set temperature value and the proportion of the maintenance time of each temperature value of the engine oil during the actual operation time of the engine; wherein the actual operation time of the engine is the actual operation time of the engine during the oil replacement cycle of the engine; A second life prediction module is used to determine the acid capacity life of the engine oil according to the rate of engine oil deterioration caused by the increase of acidic substances in the engine oil under various working conditions of the engine and the proportion of the engine running time under various working conditions during the actual running time of the engine; The engine oil replacement strategy module is used to determine whether the engine oil needs to be replaced based on the engine oil oxidation life, the engine oil acid capacity life and the engine oil carbon capacity life, wherein the engine oil carbon capacity life represents the engine oil carbon capacity life value after the engine oil carbon capacity life limit value decreases as the carbon content in the random oil increases during the actual operation time of the engine.

Images