EP2653676B1 - Method for monitoring the quality of a lubricant in an internal combustion engine - Google Patents

Description

The invention relates to the field of indicating devices for a lubrication of an internal combustion engine fitted to a motor vehicle. It relates to a method for controlling a quality of a lubricant of an internal combustion engine. It also relates to a device for implementing such a method.

The document FR 2,935,431 (Peugeot Citroën Automobiles SA) describes a method of controlling a quality of a lubricant of an internal combustion engine fitted to a motor vehicle. The internal combustion engine is the seat of a combustion of a fuel that moves parts of the internal combustion engine. The internal combustion engine is equipped with a circuit inside which circulates a lubricant which is applied to the parts for their oiling. The lubricant is contained in particular within a reserve equipping the motor vehicle. The combustion process tends to degrade the quality of the lubricant. Indeed, as and when the use of the internal combustion engine, carbonaceous particles and / or fuel tend to pollute the lubricant, which reduces the oiling properties of the latter. The life of the internal combustion engine is particularly related to the quality of the lubricant and more particularly related to a period of time separating two successive lubricant changes. The lubricant quality control method described by the document FR 2,935,431 has a plurality of steps. The document DE 196 54 450 discloses a further method of controlling a quality of a lubricant of an engine.

The method comprises a step of determining a first and a second operating zone of the internal combustion engine respectively corresponding to a first high risk of dilution of the fuel in the lubricant and a second high risk of presence of carbon particles in the lubricant.

Then, the method comprises a step of selecting a reference distance.

Then, the method comprises a step of calculating the reference distance, adjusted in sliding value, of a percentage of distance traveled in the first and / or second zone, such percentage being associated with the first and / or second risk. .

Finally, the method comprises a step of triggering an alert when at least one of the first level and / or the second level of criticality exceeds a threshold specific to the risk considered.

The control process described by the document FR 2,935,431 deserves to be improved to take into account a certain number of parameters, and to avoid oversizing of a volume of the reserve, such oversizing inducing multiple disadvantages, including an excessive cost price of the internal combustion engine and the motor vehicle , too much mass of the internal combustion engine and the motor vehicle, excessive space generated by the reserve, a prohibitive cost of production of the internal combustion engine and the motor vehicle, an increased maintenance cost for the customer, in particular in terms of emptying, as well as a loss of time related to a filling of the reserve lubricant.

In addition, such a method does not take into account a driving mode of the motor vehicle, but such a driving mode influences the quality of the lubricant over time. It is therefore usual to provide a volume of the reserve which is large enough to try to ensure a satisfactory quality of the lubricant, regardless of the driving mode of the motor vehicle.

The object of the present invention is to provide a method for controlling a quality of a lubricant of an internal combustion engine fitted to a motor vehicle, the method for optimizing a volume of a lubricant reserve, while operating a satisfactory lubrication of the internal combustion engine, regardless of a running mode of the motor vehicle.

A method of the present invention is a method of controlling a quality of a lubricant of an internal combustion engine equipping a motor vehicle.

• une étape de caractérisation pendant une phase préalable d'une pluralité de taux théorique de polluants compris à l'intérieur du lubrifiant en fonction d'une pluralité de mode de roulage du véhicule automobile pour déterminer des cartographies-types,
• une étape de déduction pendant la phase préalable d'une distance optimisée de roulage du véhicule automobile pour chaque cartographie-type,
• une étape de comparaison d'une cartographie réelle de roulage pendant une phase de roulage du véhicule automobile pour en déduire la cartographie-type adaptée parmi les cartographies-types, et
• une étape d'alerte pendant la phase de roulage du véhicule automobile si une distance réelle parcourue excède une distance optimisée adaptée correspondante à la cartographie-type adaptée.

According to the present invention, the method comprises

• a characterization step during a preceding phase of a plurality of theoretical pollutant levels included inside the lubricant as a function of a plurality of running modes of the motor vehicle to determine standard maps,
• a deduction step during the preliminary phase of an optimized distance of rolling of the motor vehicle for each standard mapping,
• a step of comparing a real rolling map during a driving phase of the motor vehicle to deduce the adapted standard mapping from the standard maps, and
• an alerting step during the driving phase of the motor vehicle if a real distance traveled exceeds an adapted optimized distance corresponding to the adapted standard map.

Preferably, each theoretical rate of a corresponding standard map is a function of at least one of a combustion mode of the internal combustion engine, of an engine of the internal combustion engine and of an engine load. internal combustion.

Preferably, the comparison step comprises a step of calculating a real pollutant rate inside the lubricant.

Preferably, the calculation step takes into account at least one of a running mode, a drain interval, a lubricant consumption and a lubricant volume.

A device for implementing such a method is mainly recognizable in that the device comprises characterization means for determining the standard maps and deduction means for determining each optimized distance.

The device advantageously comprises comparison means for selecting the adapted standard mapping from the standard maps.

The device advantageously comprises warning means which are provided with a maintenance indicator.

The device advantageously comprises means for calculating the real rate.

Other features and advantages of the present invention will appear on reading the description which will be made of exemplary embodiments, in relation to the figures of the attached plate, in which

The figure 1 is a schematic view of a device equipping a motor vehicle for carrying out the method of the present invention.

The figure 2 is a schematic view of a sequence of successive emptying operations according to a distance traveled by the motor vehicle equipped with the device shown in FIG. figure 1 .

The figure 3 is a schematic view of the process of the present invention.

On the figure 1 , a motor vehicle is equipped with an internal combustion engine 1 to provide for its movement. The internal combustion engine 1 is in connection with a circuit 2 inside which a lubricant 3, such as an oil or the like, circulates for the lubrication of moving parts of the internal combustion engine 1. The circuit 2 comprises a tank 4 of a volume 5 to contain the lubricant 3.

As the lubricant 3 circulates inside the circuit 2, the lubricant 3 tends to be charged with pollutants 6, such as fuel, carbonaceous particles or the like. On the figure 2 , such a pollutant load 6 requires regular emptying V ₁ , V ₂ , V ₃ ..., V _n lubricant 3 to at least partially change the lubricant 3 to extract the pollutants 6 of the circuit 2. Thus, two successive empties V _i , V _{i + 1} are separated from each other by a nominal distance D _{i + 1} which is traveled by the motor vehicle. The nominal distance D _{i + 1} corresponds to an emptying interval IV.

In its generality, the present invention proposes to discern among users of the motor vehicle, for example those of a first group who have a use of the motor vehicle of the first type and those of a second group who have a use of a second type. A first type of use is for example a so-called severe use of the motor vehicle, during which a driving mode, and / or speeds of the motor vehicle are higher than a defined standard, or excessive. A use of the second type is for example a so-called normal use of the motor vehicle which is homogeneous and in the defined standard, in other words without dispersion of operating parameters. Each type of use is characterized by a map-type Y _i (i being equal to 1 to n), visible schematically on the figure 3 . The use of first-type is characterized by a first type-mapping Y ₁ while a second-type use is characterized by a second type-mapping Y ₂ . At each type mapping Y _i corresponds a change in a pollutant level 6 inside the lubricant 3 as a function of a distance traveled by the motor vehicle.

Also, and also referring to the figure 2 , the present invention proposes to compare a real rolling map Y _r of the motor vehicle with Yi-type maps to indicate to a user a suitable optimized distance Dopt _has between two successive oil changes V _i , V _{i + 1} depending on the type of use of the motor vehicle, this in the case where the actual rolling chart Y _r requires it. . In other words, a service indicator 7 lubricant 3 shows the user the optimized distance D opt adapted _to that depends on the type of use of the motor vehicle. In other words again, the service indicator 7 indicates the optimized distance D opt _has adapted that is customized to the type of use of the motor vehicle. It finally results that, due to a cumulative nature of the presence of pollutants 6 inside the lubricant 3 between two successive discharges V _i , V _{i + 1} , it is possible to reduce the volume 5 of the reserve These provisions are such that a user of the first type uses a drain after a distance traveled by the motor vehicle which is equal to the optimized optimized distance Dopt _a , which is strictly lower than the nominal distance D _{i +1} , while a user of the second type uses a drain after a distance traveled which is equal to the nominal distance D _{i + 1} .

More particularly, the method of the present invention comprises a plurality of successive steps A, B, C, D.

Among the successive steps A, B, C, D, the first two steps A, B are performed during a preliminary phase P1 which is in particular carried out in the workshop. The preliminary phase P1 comprises a characterization step A and a deduction step B.

The characterization phase A is intended to establish a plurality of standard maps Y _i . Each type mapping Y _i describes an evolution of a theoretical T _thi rate of pollutants 6 included inside the lubricant 3 according to a rolling mode Z _i . In other words, for a first rolling mode Z ₁ , for example described as severe, a first type mapping Y ₁ gives a first theoretical T _th1 rate of pollutants 6 included inside the lubricant 3. In other words, for a second running mode Z ₂ , for example described as normal, a second type map Y ₂ gives a second theoretical rate T _th2 pollutants 6 included inside the lubricant 3. It follows that for each running mode Z _i the corresponding standard map Y _{i is available,} which gives, as a function of time, the evolution of the corresponding theoretical T _thi rate of pollutants 6 inside the lubricant 3.

More particularly, each theoretical T _thi rate of the corresponding standard mapping Y _i is a function of a combustion mode of the internal combustion engine 1, a speed of the internal combustion engine 1 and a load of the internal combustion engine 1.

The deduction phase B is intended to determine a corresponding optimized distance D _opti to each of the standard maps Y _i . The optimized distance D _opti is the distance traveled by the motor vehicle beyond which a drain V _i is desired, given the corresponding driving mode Z _i . In other words, the optimized distance D _opti is the distance traveled since the last drain V _i and which involves a new drain V _{i + 1} .

Among the successive steps A, B, C, D, the last two steps C, D are performed during a rolling phase P ₂ of the motor vehicle. The driving phase P ₂ comprises a comparison step C and a warning step D.

The comparison step C comprises a comparison between a real rolling map Y _r and the set of standard maps Y _i to deduce a suitable standard map Y _a . In other words, the comparison step C aims to choose among the standard maps Y _i the closest standard map of the actual rolling map Y _r to deduce an optimized optimized distance Dopt _a corresponding to the adapted standard map. There _is . In other words, the comparison step C is a step of comparing the actual rolling map Y _r with a statistical population established during the characterization step A.

The comparison step C comprises a calculation step C 'of a real rate T _r of pollutants 6 inside the lubricant 3. The calculation step C' takes into account a real rolling mode Z _r , l emptying interval IV, a CO consumption of lubricant 3 and the volume 5 of lubricant 3.

The D warning step comprises a display of an alert message to the user of the motor vehicle due to the fact that an actual distance D _r is greater than the optimized distance D opt _is adapted corresponding to the cartographie- adapted type Y _a .

A device 100 for implementing such a method comprises characterization means 101 for determining the standard maps Y _i and deduction means 102 for determining each optimized distance Dopt _i . The means of characterization 101 and the deduction means 102 are preferably means installed in the workshop.

The device 100 also comprises comparison means 103 for selecting the adapted standard mapping Y _a among the standard maps Y _i . The device 100 also comprises warning means 104 which are provided with the maintenance indicator 7. The device 100 finally comprises means 105 for calculating the actual rate T _r . The comparison means 103, the warning means 104 and the calculation means 105 are loaded on board a motor vehicle.

Claims (8)

1. A method for monitoring the quality of a lubricant (3) in an internal combustion engine (1) equipping a motor vehicle, characterized in that the method includes:

   - a characterization step (A) during a prior phase (P₁) of a plurality of theoretical rate (T_thi) of pollutants (6) comprised in the interior of the lubricant (3) from mapping types (Y_i) describing a development of the theoretical rate (T_thi) of pollutants (6) comprised in the interior of the lubricant (3) according to a running mode (Z_i),

   - a deduction step (B) during the prior phase (P₁) of an optimized distance (Dopt_i) of running of the motor vehicle for each mapping type (Y_i),

   - a comparison step (C) of an actual running mapping (Y_r) during a running phase (P₂) of the motor vehicle to deduce therefrom the adapted mapping type (Y_a) from the mapping types (Y_i), and

   - a warning step (D) during the running phase (P₂) of the motor vehicle if an actual distance covered (D_r) exceeds an adapted optimized distance (Dopt_a) corresponding to the adapted mapping type (Y_a).
2. The method according to the preceding claim, characterized in that each theoretical rate (T_thi) of a corresponding mapping type (Y_i) is a function of any one at least of a combustion mode of the internal combustion engine (1), of an engine speed of the internal combustion engine (1) and of a load of the internal combustion engine (1).
3. The method according to any one of the preceding claims, characterized in that the comparison step (C) includes a calculation step (C') of an actual rate (T_r) of pollutants (6) in the interior of the lubricant (3).
4. The method according to Claim 3, characterized in that the calculation step (C') takes into account any one at least of a running mode (Zi), of a change interval (IV), of a consumption (CO) of lubricant (3) and of a volume (5) of lubricant (3).
5. A device (100) for the implementation of a method according to any one of the preceding claims, characterized in that the device (100) includes characterization means (101) to determine the mapping types (Y_i) and deduction means (102) for determining each optimized distance (Dopt_i).
6. The device (100) according to Claim 5, characterized in that the device (100) includes comparison means (103) for selecting the adapted mapping type (Y_a) from the mapping types (Y_i) .
7. The device (100) according to any one of Claims 5 and 6, characterized in that the device (100) includes warning means (104) which are provided with a maintenance indicator (7).
8. The device according to any one of Claims 5 to 7, characterized in that the device (100) includes calculation means (105) of the actual rate (T_r).

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