JP2021032188A - Deterioration determination device and deterioration determination method for engine oil - Google Patents

Abstract

To accurately determine a deterioration state of engine oil of a diesel engine with a DPF by comprehensively considering use frequency of the engine, an engine oil temperature, a concentration of nitrogen oxide in exhaust gas and a dilution degree due to dilution with mixed fuel during DPF regeneration.SOLUTION: A deterioration determination device for engine oil includes: an initial value setting section setting an initial value indicating an initial state of the engine oil; a deterioration value calculation section calculating a deterioration value indicating a deterioration state of the engine oil; and a deterioration determination section determining a deterioration state by using the initial value and the deterioration value. The deterioration value calculation section uses engine start frequency, an engine oil temperature, NOx gas generation amount and fuel dilution amount during regeneration of a DPF as deterioration parameters, and calculates an integrated value of the deterioration value on the basis of each of the deterioration parameters. The deterioration determination section determines the deterioration state by comparing a subtraction value obtained by subtracting the integrated value from the initial value with a threshold value.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an engine oil deterioration determination device and a deterioration determination method for determining a deterioration state of engine oil that lubricates an engine.

In an internal combustion engine (engine) mounted on an automobile or the like, sliding parts such as a piston, a crankshaft, and a connecting rod are lubricated with engine oil. However, with use of such engine oil, physical deterioration, deterioration due to oxidation, deterioration due to heat, etc. occur, causing problems such as increased viscosity, poor lubrication, seizure and wear of sliding parts, and the like. This will reduce the life of the engine. Therefore, it is necessary to change the engine oil in order to maintain the engine performance.

Engine oil has a different deterioration tendency depending on how often the engine is used and how it is used. Accurately determining the deterioration state of engine oil saves resources (replaces it even though it has a remaining life to prevent it from using a lot of oil) and protects the engine for a long period of time (does not use deteriorated oil). ) Is important for both.

Various proposals have been made regarding the method for determining the deterioration of engine oil. For example, Patent Document 1 describes an internal combustion engine lubricating oil deterioration degree determination system for determining the deterioration degree of the lubricating oil of an internal combustion engine, which is a temperature detecting means for detecting the temperature of the lubricating oil and a gas discharged from the internal combustion engine. It is shown to have a nitrogen oxide amount detecting means for detecting the amount of nitrogen oxide in the medium, and a determining means for determining the degree of deterioration of the lubricating oil based on the detected lubricating oil temperature and the detected nitrogen oxide amount. ing.

On the other hand, in an engine equipped with an exhaust purification device such as a DPF (Diesel Particulate Filter) in order to reduce particulate matter (PM) contained in the exhaust gas of a diesel engine, there is a concern that the DPF may be clogged with PM. Therefore, the collected PM is burned to regenerate the DPF.

In order to regenerate this DPF, after the main injection into the combustion chamber of the diesel engine, the post-injection (post-injection) is performed at a timing that does not directly contribute to combustion, and the fuel injected by the post-injection is unburned. It is discharged to the outside of the combustion chamber as fuel and ignited in the exhaust passage to raise the exhaust gas temperature. When the high-temperature exhaust gas burned in the exhaust passage in this way passes through the DPF, the PM in the DPF is burned off, so that the PM in the DPF is reduced and the DPF is regenerated.

Lubricating oil such as sliding parts between a piston and a cylinder in an engine has deterioration due to dilution of oil by fuel in addition to deterioration of the oil itself. This occurs when the fuel injected into the combustion chamber is mixed with the oil that lubricates the sliding portion between the piston and the cylinder. Therefore, when the DPF is regenerated, the post-injection fuel adheres to the cylinder wall surface and is often mixed with the oil that lubricates the sliding portion between the piston and the cylinder. , Oil deterioration is promoted.

Therefore, in a diesel engine with a DPF, when predicting deterioration of engine oil, the prediction may change significantly unless the parameters related to the amount of fuel dilution due to post-injection are taken into consideration.

As patent documents regarding deterioration of engine oil due to mixing of fuel, for example, Patent Document 2 describes the degree of dilution of oil diluted by mixing of fuel in a diesel engine control device for detecting the presence or absence of abnormality in engine oil. Based on the dilution degree estimation means for estimating the degree of dilution, the parameter value detection means for detecting the parameter value related to the temperature of the oil, the dilution degree estimated by the dilution degree estimation means, and the parameter value detected by the parameter value detection means. The kinematic viscosity calculating means for calculating the kinematic viscosity of the oil, the oil abnormality determining means for determining the oil as abnormal when the kinematic viscosity calculated by the kinematic viscosity calculating means is larger than a predetermined value, and the oil abnormality determining means for determining the abnormality. It is sometimes shown to have a rotation control means that suppresses the high speed rotation of the engine rotation speed.

Further, Patent Document 3 describes a DPF that removes PM contained in engine exhaust gas, a manual switch for regenerating the DPF, an automatic regeneration function for regenerating the DPF, and a manual regeneration function for regenerating the DPF by the manual switch. Control with an automatic regeneration function and a warning function that prompts the oil change when the total number of regenerations by the manual regeneration function reaches the specified number, and an engine output reduction function that reduces the engine output when the oil is not changed even if the specified number is exceeded. It is shown to be equipped with a device.

Japanese Unexamined Patent Publication No. 2005-337906 Japanese Unexamined Patent Publication No. 2010-185282 Japanese Unexamined Patent Publication No. 2014-129733

As described above, Patent Document 1 indicates that the degree of deterioration of the lubricating oil is determined based on the temperature of the lubricating oil and the amount of nitrogen oxides in the exhaust gas, but for a diesel engine with a DPF, the degree of deterioration of the lubricating oil is determined. Not shown and no consideration is given to dilution due to fuel contamination in DPF regeneration.

Further, in Patent Document 2, the degree of dilution diluted by the mixing of fuel in DPF regeneration is estimated based on the kinematic viscosity to determine the oil abnormality, and the frequency of use of the engine and nitrogen oxidation in the exhaust gas are determined. The concentration of substances is not taken into consideration.

Further, in Patent Document 3, the degree of dilution diluted by the mixing of fuel in DPF regeneration is estimated based on the total number of regenerations to determine the oil deterioration, and the frequency of use of the engine and the frequency of use of the engine are determined. The concentration of nitrogen oxides in the exhaust gas is not taken into consideration.

As described above, in the method for determining the deterioration of engine oil disclosed in Patent Documents 1 to 3, the engine oil of a diesel engine with a DPF is used, the frequency of use of the engine, the temperature of the engine oil, and the concentration of nitrogen oxide in the exhaust gas. , And the degree of dilution diluted by the mixing of fuel in DPF regeneration is comprehensively considered, and it cannot be said that the deteriorated state of the engine oil is determined with higher accuracy.

Therefore, in view of the above problems, at least one embodiment of the present invention describes the deterioration state of the engine oil of a diesel engine with a DPF, the frequency of use of the engine, the engine oil temperature, the concentration of nitrogen oxides in the exhaust gas, and the DPF. It is an object of the present invention to provide an engine oil deterioration determination device and a deterioration determination method for accurately determining the degree of dilution due to the mixing of fuel in regeneration.

(1) It was invented to achieve the above-mentioned object, and at least one embodiment of the present invention is a diesel engine engine oil deterioration determination device in which a DPF is provided in an exhaust system, and is described above. The initial value setting unit for setting the initial value for indexing the initial state of the engine oil, the deterioration value calculation unit for calculating the deterioration value for indexing the deterioration state of the engine oil, and the initial value and the deterioration value are used. The deterioration determination unit for determining the deterioration state of the engine oil is provided, and the deterioration value calculation unit includes the number of engine starts, the engine oil temperature, the amount of NOx gas generated, and the engine oil due to the mixing of fuel in the regeneration of the DPF. The integrated value is calculated by summing up the deterioration values calculated based on the respective deterioration parameters with the fuel dilution amount to be diluted and the deterioration parameter, and the deterioration determination unit calculates the integrated value from the initial value. It is characterized in that the deteriorated state of the engine oil is determined by comparing the subtracted subtraction value with a predetermined threshold value.

According to such a configuration, the engine oil of a diesel engine with DPF is diluted by the number of engine starts, that is, the frequency of use, the engine oil temperature, the amount of NOx gas generated in the exhaust gas, and the mixing of fuel in DPF regeneration. It is possible to accurately determine the deterioration state of engine oil by comprehensively considering the amount of fuel diluted.

(2) In some embodiments, the initial value setting unit sets the initial value based on information on the specifications and grades of the engine oil to be used.

According to such a configuration, the deteriorated state can be determined by reflecting the performance of the engine oil used, so that the deteriorated state can be determined with high accuracy.

(3) In some embodiments, the deterioration value of the deterioration parameter is calculated as a dimensionless numerical value using a preset deterioration value conversion map.

According to such a configuration, the deterioration value of each deterioration parameter is calculated as a dimensionless numerical value using the deterioration value conversion map, so that the deterioration determination can be easily performed by using this quantified deterioration value. It will be possible to do.

(4) In some embodiments, in the calculation of the integrated value, the deterioration value of each of the deterioration parameters is weighted according to the degree of influence of the deterioration parameter on the deterioration of the engine oil. ..

According to such a configuration, the deterioration value of each deterioration parameter is weighted according to the degree of influence of the deterioration parameter on the deterioration of the engine oil, and the integrated value is calculated. Therefore, the number of engine starts, that is, the frequency of use, It is possible to make a more accurate judgment by comprehensively considering the engine oil temperature, the amount of NOx gas generated in the exhaust gas, and the amount of fuel diluted due to the mixing of fuel in DPF regeneration.

(5) In some embodiments, the weighting has a large deterioration value with the engine oil temperature and the NOx gas generation amount as deterioration parameters, and the deterioration value with the fuel dilution amount as the deterioration parameter is medium. It is characterized in that the deterioration value with the number of engine starts as a deterioration parameter is small.

According to such a configuration, the engine oil deterioration of each deterioration parameter of the number of engine starts, the engine oil temperature, the amount of NOx gas generated in the exhaust gas, and the amount of fuel diluted by the mixing of fuel in DPF regeneration Since the degree of influence of the engine oil is taken into consideration, the deterioration state of the engine oil can be determined more accurately.

(6) In some embodiments, the relationship between the engine speed, the engine load, and the deterioration value is set in the NOx gas amount deterioration value conversion map for calculating the deterioration value using the NOx gas generation amount as the deterioration parameter. It is characterized by that.

According to such a configuration, since the amount of NOx gas generated is determined from the engine speed and the engine load, it is not necessary to install a NOx gas sensor, so that the engine oil deterioration determination device can be simplified.

(7) In some embodiments, a display device for displaying the deterioration state of the engine oil is provided, and the deterioration state determined by the deterioration determination unit is displayed on the display device.

According to such a configuration, the deterioration state determined by the deterioration determination unit is displayed on the display device, so that the operator can recognize the deterioration state of the engine oil, and resource saving (replacement even though there is a remaining life). This helps prevent the use of a large amount of oil) and protects the engine for a long period of time (does not use deteriorated oil).

(8) At least one embodiment of the present invention is a method for determining deterioration of engine oil of a diesel engine in which a DPF is provided in an exhaust system, and is an initial value for indexing an initial state based on information on the engine oil used. The steps for setting, the number of engine starts, the engine oil temperature, the amount of NOx gas generated, and the amount of fuel dilution in which the engine oil is diluted by the mixing of fuel in the regeneration of the DPF are used as deterioration parameters. A step of calculating a deterioration value based on a deterioration parameter, a step of summing up the deterioration values of the respective deterioration parameters to calculate an integrated value, and a step of subtracting the integrated value from the initial value to calculate a subtracted value. The engine oil is characterized by comprising a step of comparing the subtracted value with a predetermined threshold value set in advance to determine a deteriorated state of the engine oil.

According to such a configuration, the engine oil of a diesel engine with a DPF is diluted by the number of engine starts, that is, the frequency of use, the engine oil temperature, the amount of NOx gas generated in the exhaust gas, and the mixing of fuel in the DPF regeneration. The deterioration state of the engine oil can be accurately determined by comprehensively considering the dilution amount.

(9) In some embodiments, the step of calculating the deterioration value based on the deterioration parameter is to calculate the deterioration value as a dimensionless numerical value using a preset deterioration value conversion map, and deteriorate the number of engine starts. The deterioration value as a parameter is calculated using the start count deterioration value conversion map in which the relationship between the cumulative count value of the engine start count and the deterioration value is set, and the deterioration value with the engine oil temperature as the deterioration parameter is the engine. The deterioration value calculated using the oil temperature deterioration value conversion map in which the relationship between the oil temperature and the operating time and the deterioration value at the engine oil temperature is set, and the NOx gas generation amount is used as the deterioration parameter is the engine rotation speed. The relationship between the fuel dilution rate and the deterioration value is set for the deterioration value calculated using the NOx gas amount deterioration value conversion map in which the relationship between the engine load and the deterioration value is set and the fuel dilution amount is used as the deterioration parameter. It is characterized in that it is calculated using the fuel dilution amount deterioration value conversion map.

According to such a configuration, the deterioration value of each deterioration parameter is calculated as a dimensionless numerical value using the deterioration value conversion map, and therefore the deterioration determination can be easily performed by using this quantified deterioration value. Will be possible.

According to at least one embodiment of the present invention, the engine oil of a diesel engine with a DPF is determined by the number of engine starts, that is, the frequency of use, the engine oil temperature, the amount of NOx gas generated in the exhaust gas, and the mixing of fuel in the DPF regeneration. The deterioration state of the engine oil can be accurately determined by comprehensively considering the amount of fuel diluted.

It is an overall block diagram of the deterioration determination apparatus of the engine oil which concerns on one Embodiment of this invention. It is a block diagram of the deterioration value calculation part. The outline of the deterioration value conversion map for calculating the deterioration value of each deterioration parameter is shown, (A) is the start count deterioration value conversion map, (B) is the oil temperature deterioration value conversion map, and (C) is the NOx gas amount deterioration value conversion. The map, (D), shows the fuel dilution amount deterioration value conversion map. It is a flowchart which shows the flow of the deterioration determination method of the engine oil in a deterioration control device. It is a flowchart which shows the subroutine of steps S5 and S6 of the flowchart of FIG. 5 is a flowchart showing another embodiment of step S30 of the flowchart of FIG. It is a characteristic diagram showing the degree of influence of each deterioration parameter on engine oil deterioration. (A) is the number of engine starts, (B) is the engine oil temperature, (C) is the amount of NOx gas generated, and (D) is the regeneration of DPF. Indicates the fuel dilution amount due to fuel contamination at the time. A display example of the initial value input screen is shown. It is a characteristic figure which shows the judgment image of the deterioration state in the deterioration determination part, and shows the relationship between the oil deterioration life line and the deterioration threshold value. A display example of the deterioration status display screen is shown.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the relative arrangement of the components described as the embodiment or shown in the drawings is not intended to limit the scope of the present invention to these, and is merely an explanatory example.

FIGS. 1 to 5 show an engine oil deterioration determination device and a deterioration determination method according to an embodiment of the present invention. FIG. 1 schematically shows the overall configuration of the engine oil deterioration determination device 1. The engine 2 shown in FIG. 1 is an in-vehicle direct-injection diesel engine, in which a cylinder head 5 is provided above a cylinder block 3, and an intake pipe 7 in which intake air is sucked and exhaust e are discharged to the cylinder head 5. The exhaust pipe 9 is connected. The cylinder head 5 is provided with a glove lug 13 having an exposed head in the combustion chamber 11 for ignition in a low temperature period, and is located in the center of the combustion chamber 11 and is a common rail type fuel injection device 15. A fuel injection nozzle 17 is provided.

The exhaust turbine 19a of the supercharger 19 is connected to the exhaust pipe 9, and the exhaust pipe 9 on the downstream side of the exhaust turbine 19a is connected to the catalyst 21 and its downstream side to the outside of the exhaust particulate matter (PM). A DPF (Diesel Particulate Filter) 23 that captures the exhaust particulate matter is provided in order to suppress the emission.

Further, on the upstream side of the DPF 23, a filter upstream pressure sensor 25 for detecting the pressure on the upstream side is provided, and on the downstream side of the DPF 23, a filter downstream pressure sensor 27 for detecting the pressure on the downstream side is provided. Further, an oil pan 35 for storing the engine oil 33 that lubricates the lubricating portion such as the sliding portion between the piston 29 of the engine 2 and the cylinder 31 is formed in the lower part of the cylinder block 3, and the engine oil is provided in the oil pan 35. An oil temperature sensor 37 that detects the temperature of 33 is provided.

Further, as shown in FIG. 1, an engine start number sensor 39 for counting the start number of the engine 2, an engine speed sensor 41 for detecting the engine speed, and an engine load sensor 43 for detecting the engine load are provided. The engine load sensor 43 is detected based on the amount of depression of the accelerator pedal and the amount of fuel injected into the combustion 11 chamber during the combustion stroke of the engine 2.

Further, as shown in FIG. 1, a deterioration control device 45 is provided that monitors the deterioration state of the engine oil 33, determines whether it has reached the end of its life, and prompts the replacement of the engine oil 33. The deterioration control device 45 includes an oil temperature sensor 37, an engine start count sensor 39, an engine rotation speed sensor 41, an engine load sensor 43, a filter upstream pressure sensor 25, a filter downstream pressure sensor 27, and other vehicles (not shown). Signals are input from a mileage sensor that detects the distance, a timer that detects the operating time of the engine 2, and the like.

As shown in FIG. 1, the deterioration control device 45 includes an initial value setting unit 47 for setting an initial value for indexing the initial state of the engine oil, and a deterioration value calculation for calculating the deterioration value for indexing the deterioration state of the engine oil. A unit 49, a deterioration determination unit 51 that determines the deterioration state of the engine oil using the initial value and the deterioration value, and further, a PM collected when the PM collected in the DPF 23 reaches a predetermined amount. It includes a DPF regeneration control unit 53 that burns and regenerates the DPF 23, and a display control unit 57 that controls the display device 55.

Further, the deterioration control device 45 is provided with a storage unit (not shown), and the storage unit includes an oil temperature sensor 37, an engine rotation speed sensor 41, an engine load sensor 43, a filter upstream pressure sensor 25, and a filter downstream pressure sensor 27. The detection data from, is stored every unit time or every predetermined time. In addition, the cumulative count value of the number of times the engine 2 has been started from the engine start number sensor 39 up to the present, the data of the mileage from the mileage sensor (not shown), the data of the operating time of the engine 2 from the timer (not shown), and the DPF23 Data on the number of times of reproduction, data on the number of post-injections during reproduction, and the like are stored.

The deterioration control device 45 executes DPF23 regeneration control, deterioration determination control of the engine oil 33, and display control of the display device 55 by using the various data stored in the storage unit.

In the DPF regeneration control unit 53, for example, when the mileage reaches a certain value after oil change or oil supply at the time of a new vehicle, or the difference between the detection values of the filter upstream pressure sensor 25 and the filter downstream pressure sensor 27. When the pressure reaches a certain value or more, it is determined that PM is collected in a predetermined amount or more, and the regeneration control of the DPF 23 is started.

This regeneration control controls the fuel injection nozzle 17 to post-inject (post-inject) a predetermined amount of fuel into the combustion chamber 11 during the expansion stroke of the engine 2 after the main injected fuel has burned. The unburned fuel discharged from the combustion chamber 11 into the exhaust pipe 9 in the exhaust stroke of the above is heated by the catalyst 21 and burned to generate high-temperature exhaust gas, which is used to generate high-temperature exhaust gas on the downstream side of the catalyst 21. Regeneration of DPF23 is performed by burning PM captured by DPF23. After this, the injection is repeatedly executed until the amount of PM captured by the DPF 23 becomes substantially zero (until the pressure difference between the upstream side and the downstream side becomes substantially zero).

The initial value setting unit 47 of the deterioration control device 45 sets an initial value that indexes the initial state of the engine oil 33. The initial value for indexing the initial state of the engine oil is set by the operator inputting the standard and grade information of the engine oil 33 to be used via the initial value input means 48.

Examples of the engine oil 33 for diesel engines include API standards (American Petroleum Institute standards) grades CF and CF-4, ACEA standards (European Automobile Manufacturers Association standards) grades A / B and C, and JASO standards (JASO standards). The grade DL-1 of the Japanese Automotive Standards Organization) is used.

Depending on the difference between the additive contained in the engine oil and the base oil, there are high-performance engine oil and medium- and low-performance engine oil. Therefore, depending on the engine oil used, for example, high-performance engine oil Differences are provided in the initial value settings such as 100 points, 70 points and 80 points for medium-performance engine oil, and 60 points for low-performance engine oil.

For example, 70 points for API standard CF grade engine oil, 70 points for CF-4 grade engine oil, 100 points for ACEA standard A / B grade, 80 points for C grade, JASO. In DL-1 grade, an initial value is set such as 60 points.

These initial values are examples, and depending on the deterioration value score of the deterioration parameter described later and the threshold score, the high-performance engine oil has 50 points or 10 points instead of 100 points, and the medium-performance engine oil has 50 points or 10 points. , 70 points, 40 points instead of 70 points, 40 points, or 7 points, 8 points, and 30 points or 6 points instead of 60 points for low-performance engine oil. In short, it is an arbitrary value as long as the performance difference of the engine oil 33 used is reflected in the initial value score.

The deterioration value calculation unit 49 of the deterioration control device 45 calculates a deterioration value that indicates a deterioration state of the engine oil 33. The deterioration values that indicate the deterioration state of the engine oil 33 are the number of engine starts, the engine oil temperature, the amount of NOx gas generated, the amount of fuel dilution in which the engine oil 33 is diluted by the mixing of fuel in the regeneration of DPF23, and the amount of fuel dilution. Is a deterioration value calculated based on each deterioration parameter.

Further, the deterioration value calculation unit 49 calculates the integrated value by summing the deterioration values calculated based on the respective deterioration parameters. Therefore, it can be said that the integrated value is also a deterioration value that indicates a deterioration state.

The deterioration value based on each deterioration parameter is calculated as a dimensionless numerical value using a preset deterioration value conversion map. As shown in FIG. 2, the deterioration value calculation unit 49 includes a start count deterioration value conversion map 59 when the engine start count is used as a deterioration parameter, and an oil temperature deterioration value conversion map when the engine oil temperature is used as a deterioration parameter. It has 61, a NOx gas amount deterioration value conversion map 63 when the NOx gas generation amount is used as a deterioration parameter, and a fuel dilution amount deterioration value conversion map 65 when the fuel dilution amount is used as a deterioration parameter.

In the start count deterioration value conversion map 59, as shown in FIG. 3A, the relationship between the cumulative count value of the engine start count and the deterioration value is set. That is, the deterioration value Fa with the number of engine starts as a deterioration parameter is a zero point until the cumulative count value of the number of engine starts is a1 (for example, 1000 times), and 3 points for a1 or more and up to 4000 times. Is set and calculated based on the score. The data of the cumulative count value of the number of starts up to the present after the engine oil is replaced or the oil is supplied at the time of a new vehicle, which is stored in the storage unit of the deterioration control device 45, is acquired, and the start number deterioration value conversion map 59 is used. And the deterioration value Fa is calculated.

As shown in FIG. 3B, the oil temperature deterioration value conversion map 61 sets the relationship between the engine oil temperature, the operating time at the engine oil temperature, and the deterioration value. That is, the oil temperature (° C.) on the vertical axis is set to a temperature range obtained by dividing the normal use range (0 ° C. to 150 ° C.) into four, and the time (h) on the horizontal axis is exposed during actual operation. It is the integrated time of the temperature region, and the operating time is set by dividing it into three parts such as 1 hour, 2 hours, and 3 hours. A score of 1 to 3 is set for each region divided within the range of the divided temperature (° C.) and time (h), and the deterioration value Fb with the engine oil temperature as the deterioration parameter is calculated based on the score. To do.

Oil is acquired by acquiring the oil temperature data and the operating time (cumulative operating time) data at that temperature after the engine oil is replaced or the oil is supplied at the time of a new vehicle, which is stored in the storage unit of the deterioration control device 45. The deterioration value Fb is calculated using the temperature deterioration value conversion map 61. At that time, some deterioration values Fb are calculated from the combination of the oil temperature and the operation time, and the highest deterioration value Fb among them is adopted.

In the NOx gas amount deterioration value conversion map 63, as shown in FIG. 3C, the relationship between the engine speed, the engine load, and the deterioration value is set. That is, the engine load on the vertical axis is set as a load range obtained by dividing the engine load in the normal use range into four, and the engine speed (rpm) on the horizontal axis is 3 in the normal use range (for example, 0 to 5000 rpm). The divided engine speed range is set, and 1 to 4 points are set for each area divided by the divided engine load and engine speed range, and the NOx gas generation amount is deteriorated based on the points. The deterioration value Fc as a parameter is set.

NOx is acquired by acquiring the combination data of the engine speed and the engine load for each unit time or predetermined time after the engine oil is replaced or the oil is supplied at the time of a new vehicle, which is stored in the storage unit of the deterioration control device 45. The deterioration value Fc is calculated using the gas amount deterioration value conversion map 63.

The calculation of the deterioration value Fc is performed, for example, when the combination relationship between the engine speed and the engine load stored in the storage unit for each unit time or for each predetermined time is repeated a predetermined number of times or more or a predetermined time or more in the same state. Based on the distribution of the combination relationship between the adopted engine speed and the engine load, the deterioration value Fc of the most distributed section region is calculated, or the highest deterioration value Fc is calculated by adopting the data of. Further, the deterioration value Fc of the partition area is calculated based on the longest continuous relationship between the engine speed and the engine load in each unit time or predetermined time stored in the storage unit in the same state. You may.

Since the NOx gas generation amount is determined from the engine speed and the engine load to calculate the deterioration value, it is not necessary to install the NOx gas sensor as compared with the case where the NOx gas sensor is installed to detect the NOx gas generation amount. The deterioration judgment device for engine oil can be simplified.

In the fuel dilution amount deterioration value conversion map 65, as shown in FIG. 3D, the relationship between the fuel dilution rate and the deterioration value is set. That is, the deterioration value Fd with the fuel dilution amount as the deterioration parameter is such that the dilution rate (the ratio of the amount of fuel injected by the post-injection to the amount of engine oil 33 in the oil pan 35) is d1% (for example, 5%). At zero point, 1 point up to d2% (eg 10%), 2 points up to d3% (eg 20%), 3 points up to d4% (eg 30%), d5% (eg 40%) Up to 4 points are set.

By acquiring the latest data on the number of times of regeneration after changing the engine oil or after supplying oil at the time of a new vehicle and the data on the number of times of post-injection at the time of regeneration stored in the storage unit of the deterioration control device 45, the DPF23 has been obtained so far. The amount of fuel injected afterwards during the regeneration of is calculated.

Most of the fuel post-injected into the combustion chamber 11 is discharged into the exhaust pipe 9 by the subsequent exhaust stroke, but a part of the fuel adheres to the wall surface of the cylinder 31 and remains in the combustion chamber 11. The adhering fuel is mixed with the oil that lubricates the sliding portion between the piston 29 and the cylinder 31 due to the sliding of the piston 29, and falls into the oil pan 35. As a result, the engine oil 33 in the oil pan 35 is diluted.

Since the amount of fuel mixed in the engine oil 33 by one post-injection is a substantially constant amount, the diluted fuel amount to be diluted is estimated from the total post-injection amount, and the diluted fuel amount and the engine oil in the oil pan 35 are estimated. The dilution rate is calculated from the amount of 33. Then, the deterioration value Fd is calculated using the fuel dilution amount deterioration value conversion map 65 based on the dilution rate.

In the deterioration value calculation unit 49, the deterioration values Fa, Fb, Fc, and Fd of each deterioration parameter are converted into the above-mentioned start number deterioration value conversion map 59, the oil temperature deterioration value conversion map 61, and the NOx gas amount deterioration value conversion map 63. And the fuel dilution amount deterioration value conversion map 65 are used for each calculation, and the deterioration values Fa, Fb, Fc, and Fd of each deterioration parameter are summed to calculate the integrated value B = (Fa + Fb + Fc + Fd).

The deterioration determination unit 51 of the deterioration control device 45 determines the deterioration state of the engine oil 33 calculated by the deterioration value calculation unit 49 from the initial value A that indexes the initial state of the engine oil 33 set by the initial value setting unit 47. The indexed integrated value B = (Fa + Fb + Fc + Fd) is subtracted to calculate the subtraction value C = (AB), and the subtraction value C = (AB) is compared with the predetermined threshold values P1 to P4 to compare the engine oil. The deterioration state of 33 is determined.

When the subtraction value C becomes equal to or less than the life threshold value P4, it is determined that the engine oil 33 has reached the end of its life, and the operator is urged to replace the engine oil 33.

The flow of the deterioration determination method of the engine oil 33 in the deterioration control device 45 having the above configuration will be described with reference to the flowcharts of FIGS. 4 and 5.

First, in step S1, the engine oil 33 is replaced or the engine oil 33 is supplied at the time of a new vehicle. Or, check that the oil has already been changed or that the oil is in the state of the new car. In step S2, the standard and grade of the engine oil 33 to be used are input via the initial value input means 48, and the initial value A is set. As described above, when the standard and grade information of the engine oil 33 to be used is input, the score of the initial value A is automatically set.

In step S3, the engine 2 is operated and the use of the engine oil 33 is started. In step S4, the deterioration state of the engine oil 33 is displayed on the display. As shown in FIG. 1, it is displayed on the deterioration state display screen 67 of the display device 55.

In step S5, the deterioration values Fa, Fb, Fc, and Fd of each deterioration parameter are calculated. The deterioration values Fa, Fb, Fc, and Fd of each deterioration parameter are calculated by the deterioration value calculation unit 49 as described above.

In step S6, the integrated value B = (Fa + Fb + Fc + Fd) of the deterioration value of each deterioration parameter is calculated. In step S7, the subtraction value C = (initial value A-integrated value B) is calculated. In the next step S8, it is determined whether the calculated subtraction value C is equal to or less than the life threshold value P4.

If the determination result in step S8 is No, the process returns to step S4 and repeats from step S4. In step S4, since it is not equal to or less than the life threshold value P4, the deterioration state of the engine oil 33 is displayed on the deterioration state display screen 67 of the display device 55 based on the relationship with the threshold values P1 to P3.

If the determination result in step S8 is Yes, the process proceeds to step S9, and in step S9, a notification prompting the replacement of the engine oil 33 is performed.

After that, in step S10, it is determined whether the engine oil 33 has been replaced. If the determination result in step S10 is No, the process returns to step S4 and repeats from step S4. If the determination result in step S10 is Yes, the process proceeds to step S11, and in step S11, the integrated value B is reset. Then, it returns and is repeatedly executed from step S1 again.

Next, with reference to FIG. 5, the subroutine describes the calculation of the deterioration values Fa, Fb, Fc, and Fd of each deterioration parameter in step S5, and the calculation of the integrated value B = (Fa + Fb + Fc + Fd) of the deterioration values of each deterioration parameter in S6. The flowchart of the above will be described.

First, in step S21, the operating state of the engine 2 is detected. That is, data such as engine speed, engine load, engine oil temperature, number of engine starts, operating time, and fuel dilution amount are detected.

In step S22, data on the number of engine starts is acquired. That is, the cumulative count value of the latest number of starts after the engine oil is replaced or the oil is supplied at the time of a new vehicle, which is stored in the storage unit of the deterioration control device 45, is acquired. Then, in step S23, the deterioration value Fa is calculated using the start number deterioration value conversion map 59 based on the acquired cumulative count value of the latest start times.

In step S24, the engine oil temperature and time data are acquired. That is, the data of the oil temperature and the data of the operating time at that temperature are acquired after the engine oil is replaced or the oil is supplied at the time of a new vehicle, which is stored in the storage unit of the deterioration control device 45. Then, in step S25, the deterioration value Fb is calculated using the oil temperature deterioration value conversion map 61 based on the acquired oil temperature data and the operation time data at that temperature.

In step S26, data on the engine speed and the engine load are acquired. That is, the combination data of the engine speed and the engine load for each unit time or a predetermined time after the engine oil is replaced or the oil is supplied at the time of a new vehicle, which is stored in the storage unit of the deterioration control device 45, is acquired. Then, in step S27, the deterioration value Fc is calculated using the NOx gas amount deterioration value conversion map 63 based on the acquired combination data of the engine speed and the engine load.

In step S28, fuel dilution data is acquired. That is, the latest data on the number of times of regeneration after the engine oil is replaced or after the oil is supplied at the time of a new vehicle stored in the storage unit of the deterioration control device 45, and the data on the number of post-injections at the time of regeneration are acquired. Then, in step S29, the amount of fuel that has been post-injected so far is calculated from the acquired data, the amount of diluted fuel is estimated from the amount of post-injected fuel, and the amount of diluted fuel and the amount of engine oil 33 in the oil pan 35 are 33. The fuel dilution rate is calculated from and. Then, the deterioration value Fd is calculated using the fuel dilution amount deterioration value conversion map 65 based on the calculated fuel dilution rate.

In the next step S30, the integrated value B = (Fa + Fb + Fc + Fd) of the total sum is calculated from the deterioration values of the respective deterioration parameters calculated in steps S23, S25, S27, and S29.

According to one embodiment shown in FIGS. 1 to 5 above, the deterioration state of the engine oil 33 of the engine 2 to which the DPF 23 is mounted is determined by the frequency of use of the engine, that is, the number of starts, the engine oil temperature, and the oxidation of nitrogen in the exhaust gas. Since the determination can be made by comprehensively considering the substance (NOx gas generation amount) and the fuel dilution amount diluted by the mixing of fuel in the regeneration of the DPF 23, the deterioration state of the engine oil 33 can be accurately determined. As a result, it is useful for both resource saving (preventing the use of a large amount of oil by replacing it even though it has a remaining life) and long-term engine protection (without using deteriorated oil).

Further, according to one embodiment, the deterioration value of each deterioration parameter is calculated as a dimensionless numerical value using a preset deterioration value conversion map, and therefore deterioration is performed by using this quantified deterioration value. The determination can be easily performed. Therefore, even if other deterioration parameters are additionally considered in addition to the deterioration parameters of the number of engine starts, engine oil temperature, NOx gas generation amount, and fuel dilution amount, it is possible to add a deterioration value conversion map of other deterioration parameters. , It becomes possible to easily determine the deterioration of engine oil.

Further, according to one embodiment, the initial value setting unit 47 sets the initial value A, which indicates the initial state of the engine oil 33, based on the information of the standard and grade of the engine oil to be used. The deterioration state is judged by reflecting the performance of the engine oil. Therefore, it is possible to make a highly accurate determination.

In some embodiments, as shown in FIGS. 6 and 7, in the calculation of the integrated value of the deterioration values Fa, Fb, Fc, and Fd of each deterioration parameter, the deterioration value of each deterioration parameter is added to the engine oil of each deterioration parameter. Weighting is performed according to the degree of influence on deterioration.

That is, as in step S31 shown in FIG. 6, weighting is distributed to the deterioration values of each deterioration parameter, and the coefficients α ₁ , α ₂ , α ₃ , and α ₄ are multiplied, and the weighted integrated value B'= ( α ₁ Fa + α ₂ Fb + α ₃ Fc + α ₄ Fd) is calculated.

The weighting of the deterioration value of each deterioration parameter is large, the deterioration value Fb with the engine oil temperature as the deterioration parameter and the deterioration value Fc with the NOx gas generation amount as the deterioration parameter, and the deterioration value with the fuel dilution amount as the deterioration parameter. Fd is medium, and the deterioration value Fa with the number of engine starts as a deterioration parameter is small. For example, the coefficient _{α 1, α 2, α 3} , when indicated by the numerical ratio of _{α 4, α 1: 10,} α 2: 35, α 3: 35, α 4: a weight factor of 20 (α ₁ + α ₂ + Α ₃ + α ₄ = 100). The numerical ratio of this weighting coefficient is an example, and can be changed as appropriate based on a test or the like.

FIG. 7 (A) shows the deterioration tendency of the engine oil with respect to the number of engine starts, that is, the period of use, FIG. 7 (B) shows the deterioration tendency of the engine oil with respect to the oil temperature, and FIG. 7 (C) shows the amount of NOx gas. FIG. 7 (D) shows the deterioration tendency of the engine oil with respect to the fuel dilution amount.

When the weighting of the deterioration value of each deterioration parameter is set in consideration of the influence of the number of starts, the influence of the oil temperature, the influence of the NOx gas amount, and the influence of the fuel dilution amount, the NOx gas generation amount is regarded as the deterioration parameter. The deterioration value Fc is the maximum, the deterioration value Fb with the engine oil temperature as the deterioration parameter is large, the deterioration value Fd with the fuel dilution amount as the deterioration parameter is medium, and the deterioration value Fa with the number of engine starts as the deterioration parameter is small. It is preferable to set it in stages. That is, the coefficients α ₁ , α ₂ , α ₃ , and α ₄ are preferably set in the relationship of α ₃ > α ₂ > α ₄ > α _1.

According to the embodiment shown in FIGS. 6 and 7 above, in the calculation of the integrated value of the deterioration values Fa, Fb, Fc, and Fd of each deterioration parameter, the deterioration value of each deterioration parameter is added to the engine oil deterioration of each deterioration parameter. Weighting is performed according to the degree of influence of, and the deterioration values of each deterioration parameter are summed up, so that the fuel is diluted by the number of engine starts, the engine oil temperature, the amount of NOx gas generated, and the mixture of fuel in DPF regeneration. The determination that comprehensively considers the dilution amount can be performed more accurately.

In addition, by setting the weighting so that the deterioration value of the deterioration parameter of the engine oil temperature and the amount of NOx gas generated is large, the deterioration value of the deterioration parameter of the fuel dilution amount is medium, and the deterioration value of the deterioration parameter of the number of starts is small. , It is possible to judge the deterioration state of engine oil more accurately.

In addition, even when other deterioration parameters are additionally considered in addition to the deterioration parameters of the number of engine starts, engine oil temperature, NOx gas generation amount, and fuel dilution amount, the deterioration values of other deterioration parameters added in the calculation of the integrated value By considering the weighting, it becomes possible to easily make a deterioration determination in consideration of various deterioration parameters.

In some embodiments, as shown in FIGS. 1 and 8, the deterioration determination device 1 of the engine oil 33 includes a display device 55, and the screen (display) of the display device 55 has initial value input means. The initial value input screen 69, which is 48, is displayed. The display form of the initial value input screen 69 and the acquisition of the information input to the initial value input screen 69 are controlled by the display control unit 57 of the deterioration control device 45.

FIG. 8 shows an example of the initial value input screen 69. The oil standard selection unit 71 contains standard names such as API standard (American Automobile Manufacturers Association standard), ACEA standard (European Automobile Manufacturers Association standard), and JASO standard (Japanese Automotive Standards Organization standard) used as engine oil 33 for diesel engines. Is listed and displayed. It is input by selecting the standard name of the engine oil 33 used by the operator from the displayed standard name.

The screen of the grade selection unit 73 is displayed adjacent to the right side of the screen of the oil standard selection unit 71. Here, the grade names in the selected oil standard are listed and displayed. It is input by selecting the grade name of the engine oil 33 used by the operator from the displayed grade name.

Then, the screen of the selection oil unit 75 is displayed on the right side of the screen of the grade selection unit 73. The final selected standard and grade are displayed here. As an example of setting the initial value, as described above, the case where the CF of the API standard is selected is shown, and the example in which 70 points are set as the initial value A of the engine oil 33 is shown.

According to the above embodiments shown in FIGS. 1 and 8, the input operation of the engine oil 33 used by the operator is facilitated, and the engine oil information to be used can be easily set.

In some embodiments, as shown in FIGS. 1, 9 and 10, the deterioration determination device 1 of the engine oil 33 is provided with a display device 55, and the screen (display) of the display device 55 is provided with engine oil. The deterioration state display screen 67 displaying the deterioration state of 33 is displayed. The display form of the deterioration state display screen 67 is controlled by the display control unit 57 of the deterioration control device 45.

FIG. 10 shows an example of the deterioration state display screen 67. The oil used display 77 at the top of the screen shows the standard and grade of the selected oil. Deterioration status display units 79 to 83 are displayed side by side in the center of the screen. The deterioration state display unit 79 is lit in four stages as the deterioration state (1) (lights in blue), the deterioration state display unit 80 is lit in three stages as the deterioration state (2) (lights in blue), and the deterioration state display unit 81 is lit in three stages. Is lit in two stages as a deteriorated state (3) (lighted in blue), the deteriorated state display unit 82 is lit in one stage as a deteriorated state (4) (lit in red), and the deteriorated state display unit 83 is lit in a deteriorated state (5). It lights up in one step (lights up in red).

The deterioration state (5) of the deterioration state display unit 83 may be one-step blinking (red blinking). Further, the deteriorated state display unit 82 may be lit in one step (yellow lit) as the deteriorated state (4), and the deteriorated state display unit 83 may be lit in one step (red lit) as the deteriorated state (5).

Further, the deterioration state display screen 67 of FIG. 10 shows an example in which five deterioration state display units 79 to 83 are arranged adjacent to each other, but the present invention is not limited to this, and the deterioration state display unit is lit by one. Even if the height of the part changes from 4 steps (lights blue) → 3 steps (lights blue) → 2 steps (lights blue) → 1 step (lights red) → 1 step (blinks red), other deterioration states (lighting red) The display screen may be used so that the changes in 1) to (5) can be seen.

The deterioration states (1) to (5) are determined based on the comparison result between the threshold values P1 to P4 in the deterioration determination unit 51 and the threshold values P1 to P4 in the deterioration determination unit 51, as shown in the relationship between the threshold values P1 to P4 and the oil deterioration life line in FIG. .. That is, when the subtraction value C = (initial value A-integrated value B) exceeds the threshold value P1, the state is the state (1), and the state (1) is the state after the oil change or the oil supply at the time of a new car. is there.

When the subtraction value C drops below the threshold value P1, it is the state (2), and when the subtraction value C drops below the threshold value P2, it is the state (3). The states (2) and (3) are states in which there is a margin for oil deterioration.

When the subtraction value C drops below the threshold value P3, it is a state (4), and the state (4) is a level close to the threshold value P4 (lifetime threshold value P4). It is a level that may reach P4.

When the subtraction value C drops below the threshold value P4, it is the state (5). The threshold value P4 is called a life threshold because it is a threshold for determining that the engine oil 33 has reached the end of its life and needs to be replaced.

According to the embodiments shown in FIGS. 1, 9 and 10, the deterioration state determined by the deterioration determination unit 51 is displayed on the deterioration state display screen 67 of the display device 55, so that the operator is notified of the deterioration state of the engine oil 33. Since it can be recognized, it is useful for both resource saving (replace it even though it has a remaining life to prevent it from using a lot of oil) and protect the engine for a long period of time (do not use deteriorated oil).

According to at least one embodiment of the present invention, the engine oil of a diesel engine with a DPF is subjected to the number of engine starts, that is, the frequency of use, the engine oil temperature, the amount of NOx gas generated in the exhaust gas, and the contamination of fuel in the DPF regeneration. Since the deterioration state of the engine oil can be accurately determined by comprehensively considering the amount of fuel diluted to be diluted, it is suitable for use in the engine oil deterioration determination device and deterioration determination method of a diesel engine with a DPF.

1 Deterioration judgment device 2 Engine (diesel engine)
21 catalyst 23 DPF
25 Filter upstream pressure sensor 27 Filter downstream pressure sensor 33 Engine oil 37 Oil temperature sensor 39 Engine start count sensor 41 Engine rotation speed sensor 43 Engine load sensor 45 Deterioration control device 47 Initial value setting unit 48 Initial value input means 49 Deterioration value Calculation unit 51 Deterioration judgment unit 53 DPF regeneration control unit 55 Display device 57 Display control unit 59 Number of starts Deterioration value conversion map 61 Oil temperature deterioration value conversion map 63 NOx gas amount deterioration value conversion map 65 Fuel dilution amount deterioration value conversion map 67 Deterioration Status display screen 69 Initial value input screen

Claims (9)

The DPF is a device for determining the deterioration of engine oil of a diesel engine provided in the exhaust system.
Using the initial value setting unit for setting the initial value for indexing the initial state of the engine oil, the deterioration value calculation unit for calculating the deterioration value for indexing the deterioration state of the engine oil, and the initial value and the deterioration value. A deterioration determination unit for determining a deterioration state of the engine oil is provided.
The deterioration value calculation unit uses the number of engine starts, the engine oil temperature, the amount of NOx gas generated, and the fuel dilution amount at which the engine oil is diluted by the mixing of fuel in the regeneration of the DPF as deterioration parameters, respectively. The integrated value is calculated by summing the deterioration values calculated based on the deterioration parameters.
The deterioration determination unit is an engine oil deterioration determination device, which determines a deterioration state of the engine oil by comparing a subtraction value obtained by subtracting the integrated value from the initial value with a predetermined threshold value. The engine oil deterioration determination device according to claim 1, wherein the initial value setting unit sets the initial value based on information on a standard and a grade of the engine oil to be used. The engine oil deterioration determination device according to claim 1 or 2, wherein the deterioration value of the deterioration parameter is calculated as a dimensionless numerical value using a preset deterioration value conversion map. Any one of claims 1 to 3, wherein in the calculation of the integrated value, the deterioration value of each of the deterioration parameters is weighted according to the degree of influence of the deterioration parameter on the deterioration of the engine oil. The engine oil deterioration determination device described in 1. The weighting has a large deterioration value with the engine oil temperature and the NOx gas generation amount as deterioration parameters, a deterioration value with the fuel dilution amount as a deterioration parameter, and the number of engine starts as a deterioration parameter. The engine oil deterioration determination device according to claim 4, wherein the deterioration value is small. The NOx gas amount deterioration value conversion map for calculating a deterioration value using the NOx gas generation amount as a deterioration parameter is according to claim 3, wherein the relationship between the engine speed, the engine load, and the deterioration value is set. Engine oil deterioration judgment device. The engine according to any one of claims 1 to 6, further comprising a display device for displaying the deterioration state of the engine oil, and displaying the deterioration state determined by the deterioration determination unit on the display device. Oil deterioration judgment device. The DPF is a method for determining the deterioration of engine oil of a diesel engine provided in the exhaust system.
The step of setting the initial value that indicates the initial state based on the information of the engine oil used, and
Deterioration values based on the deterioration parameters, with the number of engine starts, the engine oil temperature, the amount of NOx gas generated, and the fuel dilution amount at which the engine oil is diluted by the mixing of fuel in the regeneration of the DPF as deterioration parameters. And the steps to calculate
The step of summing the deterioration values of the deterioration parameters to calculate the integrated value, and
A step of subtracting the integrated value from the initial value to calculate the subtracted value, and
A step of determining the deterioration state of the engine oil by comparing the subtraction value with a predetermined threshold value set in advance, and
A method for determining deterioration of engine oil, which comprises. In the step of calculating the deterioration value based on the deterioration parameter, the deterioration value is calculated as a dimensionless numerical value using a preset deterioration value conversion map.
The deterioration value with the engine start count as the deterioration parameter is calculated using the start count deterioration value conversion map in which the relationship between the cumulative count value of the engine start count and the deterioration value is set.
The deterioration value with the engine oil temperature as the deterioration parameter is calculated using an oil temperature deterioration value conversion map in which the relationship between the engine oil temperature and the operating time and the deterioration value at the engine oil temperature is set.
The deterioration value using the NOx gas generation amount as the deterioration parameter is calculated using the NOx gas amount deterioration value conversion map in which the relationship between the engine speed, the engine load, and the deterioration value is set.
The deterioration value using the fuel dilution amount as the deterioration parameter is calculated using the fuel dilution amount deterioration value conversion map in which the relationship between the fuel dilution rate and the deterioration value is set.
The method for determining deterioration of engine oil according to claim 8.