JP2008050972A - Device for determining degradation of engine oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for determining the degradation of engine oil that can accurately determine the degradation of the engine oil, and appropriately gives a driver or the like the exchange timing of the engine oil. <P>SOLUTION: An integrated value of a pentane insoluble portion is obtained to determine oil degradation (steps ST3 to ST6) based on a pentane insoluble portion map in view of mutual action between respective parameters of engine rotation speed Ne, a load Tq, an oil temperature Temp. In this manner, it becomes possible to determine accurately oil degradation by using the pentane insoluble portion map with consideration given to the mutual action of a plurality of parameters including the engine rotation speed Ne, the load Tq, the oil temperature Temp, rather than calculating a degradation index for each parameter of the engine rotation speed Ne, the load Tq, the oil temperature Temp, and to properly inform a driver or the like of the exchange timing of engine oil. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an engine oil deterioration determination device for determining deterioration of engine oil for lubricating an internal combustion engine.

  In an internal combustion engine (hereinafter also referred to as an engine) mounted in an automobile or the like, sliding parts such as a piston, a crankshaft, and a connecting rod are lubricated with engine oil. Such engine oil for lubrication deteriorates as the engine is used.

  Engine oil deterioration is caused by, for example, oxidation of base oil, increase in viscosity, consumption of additives such as antiwear and detergent dispersants, and external mixing of combustion products such as soot. In any of these cases, engine oil needs to be changed to maintain engine performance.

As a method for determining the engine oil replacement time, there is a technique described in Patent Document 1 below. In the technique described in Patent Document 1, oil temperature, load, and engine speed are detected as parameters related to engine oil deterioration, and the detected oil temperature, load, and engine speed are used for deterioration based on a characteristic curve. Is obtained for each parameter, and the evaluation coefficients B _T , B _L , B _N are multiplied by the engine speed. Then, the engine speed after multiplying each evaluation coefficient is converted into a travel distance to determine the remaining travel distance (remaining travel distance until the next oil change time).

Further, as this type of engine oil deterioration determination device, an oil deterioration index (for example, viscosity, total base number, pentane insoluble amount, etc.) is obtained based on the operating state of the engine, and an integrated value obtained by integrating the oil deterioration index is obtained. There is a device that issues a warning to a driver or the like when a predetermined determination value is exceeded.
Japanese Patent No. 3493583

By the way, in the method described in Patent Document 1 described above, the evaluation coefficients B _T , B _L , and B _N corresponding to the oil temperature, load, and engine speed parameters are calculated individually. This is not reflected in the remaining travel distance (engine oil replacement time), and the accuracy of engine oil deterioration determination is poor. Moreover, since it is converted into the travel distance, the deterioration determination reflecting the oil deterioration at the time of idling stop cannot be performed.

  The present invention has been made in consideration of such circumstances, and can be used to accurately determine deterioration of engine oil and to accurately notify the driver of the timing of engine oil replacement. An object is to provide a determination device.

  In the present invention, instead of calculating the deterioration index for each parameter of the engine speed, load, and oil temperature, the deterioration index is calculated in consideration of the interaction of a plurality of parameters including the engine speed, load, and oil temperature. One characteristic is that the accuracy of deterioration determination is improved by calculating and integrating one insoluble portion of pentane.

  Specifically, in an engine oil deterioration determination device for determining deterioration of engine oil that lubricates an internal combustion engine, detection means for detecting an operating state of the internal combustion engine including engine speed, load, and oil temperature, and the internal combustion engine Determination processing means for determining deterioration of engine oil based on the detected value of the operating state of the engine, wherein the determination processing means uses the operating state of the internal combustion engine including the engine speed, load, and oil temperature as parameters. A map for obtaining an increase amount of insoluble content of pentane per unit, the map having an insoluble content of pentane in consideration of the interaction of a plurality of parameters including the engine speed, load, and oil temperature Based on the detected value of the operating state of the internal combustion engine including the number, load, and oil temperature, referring to the pentane insoluble component map and calculating the increase amount of the pentane insoluble component Out results over time by integrating, the integrated value is characterized by issuing a warning when exceeding a predetermined value.

  According to the present invention, based on a pentane insoluble matter map that takes into account the interaction between a plurality of parameters including engine speed, load, and oil temperature, an integrated value of pentane insoluble matter is obtained to determine oil deterioration. Therefore, it is possible to accurately determine the deterioration of the engine oil and appropriately notify the driver or the like of the timing for replacing the engine oil. Moreover, since the insoluble content of pentane is used as an oil deterioration index, oil deterioration due to increase in viscosity, soot, and oxidation can be determined with one index.

  As described above, according to the present invention, the increase in pentane insoluble matter is calculated using the pentane insoluble matter map that takes into account the interaction of a plurality of parameters including engine speed, load, and oil temperature. At the same time, the calculation results are integrated over time, and a warning is issued when the integrated value exceeds a predetermined value. It is possible to appropriately inform the driver of the replacement time. In addition, since oil deterioration is determined based on an integrated value obtained by integrating the increase in the amount of insoluble pentane over time, more accurate oil deterioration determination that reflects oil deterioration when idling is stopped can be performed. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, an engine (internal combustion engine) to which the engine oil deterioration determination device of the present invention is applied will be described.

-Engine-
FIG. 1 is a diagram showing a schematic configuration of an engine to which the present invention is applied. FIG. 1 shows only the configuration of one cylinder of the engine.

  The engine 1 is a multi-cylinder gasoline engine, and includes a piston 1b that forms a combustion chamber 1a and a crankshaft 15 that is an output shaft. The piston 1b is connected to the crankshaft 15 via the connecting rod 16, and the reciprocating motion of the piston 1b is converted into rotation of the crankshaft 15 by the connecting rod 16.

  A signal rotor 17 having a plurality of protrusions (teeth) 17 a... 17 a on the outer peripheral surface is attached to the crankshaft 15. A crank position sensor 27 is disposed near the side of the signal rotor 17. The crank position sensor 27 is, for example, an electromagnetic pickup, and generates a pulsed signal (output pulse) corresponding to the protrusion 17a of the signal rotor 17 when the crankshaft 15 rotates.

  An oil pan 18 for storing engine oil is provided below the cylinder block 1c of the engine 1. The engine oil stored in the oil pan 18 is pumped up by an oil pump through an oil strainer that removes foreign matters when the engine 1 is operated, and further purified by an oil filter, and then the piston 1b, the crankshaft 15, and the connecting oil. It is supplied to the rod 16 and used for lubrication and cooling of each part. The engine oil supplied in this way is used for lubrication and cooling of each part of the engine 1 and then returned to the oil pan 18 and stored in the oil pan 18 until it is pumped up again by the oil pump. Is done. An oil temperature sensor 22 that detects the temperature of the engine oil is disposed in the oil pan 18. Further, a water temperature sensor 21 that detects an engine water temperature (cooling water temperature) is disposed in the cylinder block 1 c of the engine 1.

  A spark plug 3 is disposed in the combustion chamber 1 a of the engine 1. The ignition timing of the spark plug 3 is adjusted by the igniter 4. The igniter 4 is controlled by an ECU (electronic control unit) 100 described later.

  An intake passage 11 and an exhaust passage 12 are connected to the combustion chamber 1 a of the engine 1. An intake valve 13 is provided between the intake passage 11 and the combustion chamber 1a. By opening and closing the intake valve 13, the intake passage 11 and the combustion chamber 1a are communicated or blocked. Further, an exhaust valve 14 is provided between the exhaust passage 12 and the combustion chamber 1a. By opening and closing the exhaust valve 14, the exhaust passage 12 and the combustion chamber 1a are communicated or blocked. The opening / closing drive of the intake valve 13 and the exhaust valve 14 is performed by each rotation of the intake camshaft and the exhaust camshaft to which the rotation of the crankshaft 15 is transmitted.

On the other hand, in the intake passage 11, an air cleaner 7, a hot-wire air flow meter 23, an intake air temperature sensor 24 (built in the air flow meter 23), and an electronically controlled throttle valve 5 for adjusting the intake air amount of the engine 1. Is arranged. The throttle valve 5 is driven by a throttle motor 6. The opening degree of the throttle valve 5 is detected by a throttle position sensor 26. In the exhaust passage 12 of the engine 1, an O ₂ sensor 25 for detecting the oxygen concentration in the exhaust gas and the three-way catalyst 8 are arranged.

  A fuel injection injector (fuel injection valve) 2 is arranged in the intake passage 11. Fuel of a predetermined pressure is supplied from the fuel tank to the injector 2 by a fuel pump, and the fuel is injected into the intake passage 11. This injected fuel is mixed with intake air to form an air-fuel mixture and introduced into the combustion chamber 1a of the engine 1. The air-fuel mixture (fuel + air) introduced into the combustion chamber 1a is ignited by the spark plug 3 and burns and explodes. The piston 1b reciprocates due to combustion / explosion of the air-fuel mixture in the combustion chamber 1a, and the crankshaft 15 rotates. The operating state of the engine 1 is controlled by the ECU 100.

-ECU-
As shown in FIG. 2, the ECU 100 includes a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like.

  The ROM 102 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 101 executes arithmetic processing based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results of the CPU 101, data input from each sensor, and the like. The backup RAM 104 is a non-volatile memory that stores data to be saved when the engine 1 is stopped. is there.

  The CPU 101, ROM 102, RAM 103, and backup RAM 104 are connected to each other via a bus 107, and are connected to an input interface 105 and an output interface 106.

Connected to the input interface 105 are a water temperature sensor 21, an oil temperature sensor 22, an air flow meter 23, an intake air temperature sensor 24, an O ₂ sensor 25, a throttle position sensor 26, a crank position sensor 27, an ignition switch 28, and the like. . The output interface 106 includes an injector 2, an igniter 4 for the spark plug 3, a throttle motor 6 for the throttle valve 5, and a warning lamp 9 for notifying (warning) the driver that the oil change time has come. It is connected.

  The ECU 100 executes various controls of the engine 1 based on the output signals of the various sensors described above. Furthermore, the ECU 100 executes the following engine oil deterioration determination process.

-Engine oil deterioration judgment process-
First, the pentane insoluble component map used for the engine oil deterioration determination process will be described.

  As shown in FIG. 4, the pentane insoluble component map includes the increase amount dPr of the pentane insoluble component per unit time using the engine speed Ne, the load Tq, and the oil temperature Temp among the operating conditions of the engine 1 as parameters. It is a map for seeking.

  The pentane insoluble component map used in this example reflects the interaction between the engine speed Ne, load Tq, and oil temperature Temp, and reflects the interaction between the engine speed Ne, load Tq, and oil temperature Temp. As shown, the increase amount dPr of the insoluble pentane per unit time is obtained in advance by experiments and calculations and mapped. Specifically, in the bench test of the engine 1, for example, the engine speed Ne and the load Tq are changed under the condition that the oil temperature Temp is constant, and pentane insoluble per unit time under various conditions in the engine operation region. The process of measuring the amount of increase in the minute is performed for each condition of the oil temperature, and the measured values obtained by this measurement are mapped and stored in the ROM 102 of the ECU 100.

  In the pentane insoluble component map of this example, the increase amount dPr of the pentane insoluble component per unit time increases as the engine speed Ne increases, and the increase amount dPr of the pentane insoluble component per unit time increases as the load Tq increases. Is set to be high. Furthermore, the increase amount dPr of the insoluble portion of pentane per unit time is set higher as the oil temperature Temp becomes higher.

  Next, the engine oil deterioration determination process will be described with reference to the flowchart of FIG.

  In step ST1, it is determined whether or not the engine 1 has been started. When the engine 1 has not been started, this routine is temporarily terminated. If the engine 1 has been started, the process proceeds to step ST2.

  In step ST2, it is determined whether or not the next start warning flag is ON. Now, at the initial stage of engine oil replacement (engine oil is new), the integrated value Pr for the insoluble pentane is the initial value “0”, and the next start warning flag is OFF, so the process proceeds to step ST3.

  In step ST3, engine operating conditions including the engine speed Ne, the load Tq, and the oil temperature Temp are detected. The engine speed Ne is read from the output signal of the crank position sensor 27. The load Tq is detected based on the intake air amount obtained from the detection signal of the air flow meter 23. The oil temperature Temp is read from the output signal of the oil temperature sensor 22 arranged in the oil pan 18.

  In step ST4, based on the engine speed Ne, load Tq, and oil temperature Temp detected in step ST3, an increase amount dPr of pentane insoluble matter is calculated with reference to the pentane insoluble matter map of FIG. The calculated pentane insoluble component increment is integrated to determine the pentane insoluble component integrated value Pr. The initial value of the pentane insoluble integrated value Pr is “0”.

  Next, in step ST5, it is determined whether or not the ignition switch 28 is OFF (IG OFF). If the determination result is negative (if the ignition switch 28 is ON), the process returns to step ST3. The engine speed Ne, the load Tq, and the oil temperature Temp are detected, and the increase amount of the pentane insoluble matter obtained from the pentane insoluble matter map shown in FIG. 4 based on the engine speed Ne, the load Tq, and the oil temperature Temp. dPr is integrated to determine the pentane-insoluble integrated value Pr (step ST4). The detection of the engine speed Ne, the load Tq, the oil temperature Temp (step ST3), and the calculation of the pentane insoluble integrated value Pr (step ST4) are performed when the ignition switch 28 is OFF (the determination result of step ST5 is The process is repeatedly executed every predetermined time (for example, every several ms) until a positive determination is made.

  Next, when the ignition switch 28 is turned OFF (the determination result of step ST5 is affirmative), in step ST6, it is determined whether or not the current pentane insoluble integrated value Pr exceeds the deterioration limit value Pr0. If the determination result is negative, after the engine 1 has been stopped (step ST7 is positive), this routine is once terminated.

  The processes from step ST1 to step ST7 are sequentially performed every time the engine 1 is started. As shown in FIG. 5, the pentane insoluble integrated value Pr increases as the operation time of the engine 1 increases. To go. When the operating time of the engine 1 becomes longer and the pentane insoluble integrated value Pr exceeds the deterioration limit value Pr0 (the determination result of step ST6 is affirmative determination: Pr> Pr0), a warning flag at the next start at step ST8 Set to ON. Note that the deterioration limit value Pr0 used in step ST6 is set to a value empirically obtained in advance through experiments and calculations in consideration of the relationship between the integrated value Pr of the pentane insoluble matter and the oil change time.

  As described above, since the determination result in step ST2 is affirmative when the engine is started next time after the next start warning flag is turned on, the warning lamp 9 is turned on in step ST9, and the driver or the like. Warning that it is time to change oil.

  Here, even after the warning lamp 9 is turned on, the detection of the engine speed Ne, the load Tq, and the oil temperature Temp (step ST3) and the calculation of the pentane insoluble integrated value Pr (step ST4) are started next time. Until the hour warning flag is turned off, it is repeatedly executed every time the engine is started. Further, after the warning lamp 9 is turned on, the next start warning flag is kept ON until the engine oil is changed. Then, when the oil is changed and, for example, a reset switch (not shown) is operated, the next start warning flag is turned OFF, and the pentane insoluble integrated value Pr is returned to the initial value “0”.

  After such initialization is performed, the processing of step ST1 to step ST7 is performed again every time the engine is started, and the pentane-insoluble integrated value Pr calculated in step ST4 increases as the operation time increases. (See FIG. 5), when the pentane insoluble integrated value Pr exceeds the deterioration limit value Pr0, the warning flag at the next start is turned on, and the warning lamp 28 is turned on at the next engine start. These processes are sequentially repeated.

  According to the engine oil deterioration determination process described above, the integrated value of the pentane insoluble matter is obtained based on the pentane insoluble matter map that takes into account the interaction among the parameters of the engine speed Ne, the load Tq, and the oil temperature Temp. Therefore, it is possible to accurately determine the deterioration of the engine oil and appropriately notify the driver or the like of the replacement timing of the engine oil. In addition, since the insoluble content of pentane is used as an oil deterioration index, oil deterioration due to increase in viscosity, soot, and oxidation can be determined with one index. Furthermore, since oil deterioration is determined based on the integrated value obtained by integrating the increase in pentane insoluble matter over time, it is possible to perform more accurate oil deterioration determination that reflects oil deterioration when idling is stopped. it can.

-Other embodiments-
In the above example, the engine speed, load, and oil temperature are detected from the engine operating state, and the pentane insoluble component map is referred to based on the detected values of the engine speed, load, and oil temperature. The integrated value of insoluble matter is calculated, but this is not a limitation. In addition to the engine speed, load, and oil temperature, other engine operating conditions such as the engine coolant temperature are detected, and the engine rotation is detected. The integrated value of the pentane insoluble matter may be calculated based on the detected value of the engine operating state including the number, load, oil temperature, and cooling water temperature. In this case, the integrated value of pentane insoluble matter is calculated using a pentane insoluble matter map that takes into account the interaction between other parameters such as water temperature and engine speed, load, and oil temperature.

  In the above example, the warning lamp is turned on as a means for warning the driver that it is time to change the oil. However, the present invention is not limited to this, and blinking of the warning lamp or using an LED or a liquid crystal You may make it issue a warning to a driver | operator etc. by other means, such as displaying a message.

  Further, the remaining travel distance (remaining travel distance until the next oil change timing) is obtained from the pentane insoluble component integrated value Pr, and the remaining travel distance is obtained by analog method or digital method at all times or according to the user's request. May be displayed on the display device.

  In the above example, the example in which the present invention is applied to the determination of deterioration of engine oil of a gasoline engine is shown. However, the present invention is not limited to this, and for example, LPG (liquefied petroleum gas), LNG (liquefied natural gas), etc. The present invention can also be applied to the determination of engine oil deterioration of an ignition type engine that uses other fuel, and can also be applied to the determination of engine oil deterioration of a direct injection type engine. Further, the present invention is not limited to an ignition type engine, and the present invention can be applied to determination of deterioration of engine oil such as a diesel engine.

It is a schematic block diagram which shows an example of the engine to which the determination apparatus of the engine oil of this invention is applied. It is a block diagram which shows the structure of control systems, such as ECU. It is a flowchart which shows the content of the engine oil deterioration determination process which ECU performs. It is a figure which shows the pentane insoluble content map used by the engine oil degradation determination process of FIG. It is a graph which shows the time change of a pentane insoluble part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Injector 3 Spark plug 5 Throttle valve 6 Throttle motor 9 Warning lamp 18 Oil pan 22 Oil temperature sensor 23 Air flow meter 27 Crank position sensor 100 ECU (determination device)

Claims (1)

An engine oil deterioration determination apparatus for determining deterioration of engine oil for lubricating an internal combustion engine, the detection means for detecting an operation state of the internal combustion engine including an engine speed, a load, and an oil temperature, and an operation state of the internal combustion engine Determination processing means for determining deterioration of the engine oil based on the detected value of
The determination processing means is a map for obtaining an increase amount of insoluble pentane per unit time using the operating state of the internal combustion engine including the engine speed, load, and oil temperature as parameters, and the engine speed, It has a pentane insoluble component map that takes into account the interaction of multiple parameters including load and oil temperature, and the pentane insoluble based on the detected value of the operating state of the internal combustion engine including the engine speed, load, and oil temperature The amount of increase in pentane insoluble matter is calculated with reference to the minute map, and the calculated results are integrated over time, and a warning is issued when the integrated value exceeds a predetermined value. Degradation judgment device.

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