Deterioration detection device

Abstract

To provide a deterioration determination device capable of improving accuracy of determining deterioration of oil circulating in an internal combustion engine.SOLUTION: A deterioration determination device has: an acquisition unit that acquires a temperature of an internal combustion engine from a detection device that detects the temperature of the internal combustion engine; an integration unit that, when the detection device is normal, associates and integrates a fuel injection amount of the internal combustion engine with a temperature range including the temperature among a plurality of temperature ranges, and, when the detection device is abnormal, associates and integrates the fuel injection amount with one or more temperature ranges among the plurality of temperature ranges; and a determination unit that determines a deterioration state of oil circulating through the internal combustion engine from a first integrated value of the fuel injection amount associated with each of the plurality of temperature ranges.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a deterioration determination device.

Background Art

[0002] For example, Patent Document 1 describes an oil deterioration determination device that determines the deterioration of oil circulating in an internal combustion engine based on the temperature of the internal combustion engine and the fuel injection amount. This deterioration determination device estimates the accumulation amount of sludge precursors in the oil pan by multiplying a coefficient corresponding to the temperature of the internal combustion engine by the fuel injection amount within a predetermined period, and determines the deterioration of the oil when the accumulation amount is equal to or greater than a certain value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the sensor for detecting the temperature of the internal combustion engine fails, the above coefficient cannot be calculated, and it becomes impossible to estimate the accumulation amount of sludge precursors, so the accuracy of oil deterioration determination decreases.

[0005] Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a deterioration determination device capable of improving the accuracy of deterioration determination of oil circulating in an internal combustion engine.

Means for Solving the Problems

[0006] The deterioration determination device of the present invention includes an acquisition unit that acquires the temperature from a detection device that detects the temperature of an internal combustion engine, and when the detection device is normal, it associates the fuel injection amount of the internal combustion engine with the temperature range that includes the temperature among a plurality of temperature ranges and integrates them, and when the detection device is abnormal, among the plurality of temperature ranges, Lowest temperature side An integration unit that associates the fuel injection amount with the temperature range and integrates it, and the fuel injection amount associated with each of the plurality of temperature ranges product It includes a determination unit that determines the deterioration state of the oil circulating in the internal combustion engine from the calculated value.

[0008] other Deterioration determination device This includes an acquisition unit that acquires the temperature from a detection device that detects the temperature of an internal combustion engine, and, if the detection device is functioning correctly, it associates the fuel injection amount of the internal combustion engine with the temperature range that includes the temperature among a plurality of temperature ranges and integrates them. If the detection device is malfunctioning, the fuel injection amount corresponding to each of the plurality of temperature ranges product Based on the ratio of the calculated values, the fuel injection amount is divided and integrated, corresponding to each of the multiple temperature ranges. It comprises an integration unit and a determination unit that determines the deterioration state of the oil circulating in the internal combustion engine from the integrated values ​​of the fuel injection amounts associated with each of the plurality of temperature ranges. do.

[0009] Furthermore, other Deterioration determination device The system includes: an acquisition unit that acquires the temperature from a detection device that detects the temperature of an internal combustion engine; an integration unit that, if the detection device is functioning correctly, associates the fuel injection amount of the internal combustion engine with the temperature range that includes the temperature among a plurality of temperature ranges and integrates the results; and a determination unit that determines the deterioration state of the oil circulating in the internal combustion engine from a first integrated value of the fuel injection amount associated with each of the plurality of temperature ranges. For each of the aforementioned multiple temperature ranges, the fuel injection amounts within multiple past cumulative periods of different lengths are accumulated, and a larger coefficient is applied to the fuel injection amount within the cumulative period for shorter cumulative periods. product A calculation unit that multiplies the calculated value and calculates the sum of the second accumulated value and the multiplied coefficient for each of the plurality of accumulation periods. and The system has a mechanism, and if the detection device is abnormal, the integrating unit divides the fuel injection amount based on the ratio of the sum of each of the multiple temperature ranges and integrates it in correspondence to each of the multiple temperature ranges. do .

[0010] In the above-described deterioration determination device, the calculation unit determines, for each of the plurality of cumulative periods, the period corresponding to the length of the cumulative period. Accumulation The arithmetic values ​​are averaged, and the averaged values ​​are before Accumulation The calculated value may be multiplied by the aforementioned coefficient.

Advantages of the Invention

[0011] According to the present invention, the accuracy of deterioration determination of oil circulating in an internal combustion engine can be improved.

Brief Description of the Drawings

[0012] [Figure 1] FIG. 1 is a configuration diagram showing an example of a vehicle management system. [Figure 2] FIG. 2 is a diagram showing an example of injection amount statistical information and a deterioration coefficient table. [Figure 3] FIG. 3 is a time chart showing an example of the integration process of the fuel injection amount when the water temperature sensor is normal. [Figure 4] FIG. 4 is a time chart showing an example of the integration process of the fuel injection amount when an abnormality occurs in the water temperature sensor. [Figure 5] FIG. 5 is a flowchart showing an example of the integration process of the fuel injection amount. [Figure 6] FIG. 6 shows an operation example of distributing the fuel injection amount to each temperature range based on the distribution ratio. [Figure 7] FIG. 7 is a flowchart showing another example of the integration process of the fuel injection amount. [Figure 8] FIG. 8 is a configuration diagram showing another example of the vehicle management system.

Modes for Carrying Out the Invention

[0013] (Vehicle Management System) FIG. 1 is a configuration diagram showing an example of a vehicle management system S. The vehicle management system S includes, for example, a vehicle system 9 mounted on a vehicle not shown and a management server 5. The vehicle system 9 includes an ECU (Electronic Control Unit) 1, an engine 2, a communication module 3, and an ignition switch (IG-SW) 4.

[0014] The engine 2 is a driving source of the vehicle and is an example of an internal combustion engine. An oil pan 20 is provided at the lower part in the vertical direction of the engine 2. Oil L is stored in the oil pan 20. The oil L is sent from the oil pan 20 to the engine 2 by a pump mechanism (not shown) as indicated by the arrow, circulates through the engine 2, and is discharged into the oil pan 20.

[0015] In addition, an intake air sensor 21, a crank position sensor 22, and a water temperature sensor 23 are provided in the engine 2. The intake air sensor 21 detects the intake air amount of the engine 2. The crank position sensor 22 detects the rotational speed (rpm) of the engine 2. The water temperature sensor 23 is an example of a detection device and detects the temperature from the cooling water of the engine 2.

[0016] When the IG-SW4 is on, it starts the engine 2 to make the vehicle in a drivable state, and when it is off, it stops the engine 2 to make the vehicle in a non-drivable state. The communication module 3 accesses a communication network such as the Internet by a technology such as Wi-Fi or 4G (Generation). The ECU 1 communicates with the management server 5 via the communication module 3.

[0017] The ECU 1 is an example of a deterioration determination device. The ECU 1 is, for example, a computer that controls the engine 2, but is not limited thereto.

[0018] The ECU 1 includes a CPU (Central Processing Unit) 10, a ROM (Read Only Memory) 11, a RAM (Random Access Memory) 12, a storage memory 13, and an input / output port 14. The CPU 10 is electrically connected to the ROM 11, the RAM 12, the storage memory 13, and the input / output port 14 via a bus 19 so that signals can be input and output to each other.

[0019] ROM11 stores the program that drives the CPU10. RAM12 functions as the working memory for the CPU10. The input / output port 14 is a circuit that processes the input and output of data signals between the CPU10 and the IG-SW4, communication module 3, intake sensor 21, crank position sensor 22, and water temperature sensor 23.

[0020] When the CPU 10 reads a program from the ROM 11, it forms the following functions: an operation control unit 100, a sensor value acquisition unit 101, a sensor state monitoring unit 102, a statistical information generation unit 103, and a degradation determination unit 104. In addition, injection amount statistical information 130 is stored in the storage memory 13.

[0021] The operation control unit 100 instructs the sensor value acquisition unit 101, the sensor state monitoring unit 102, the statistical information generation unit 103, and the degradation determination unit 104 to perform operations according to a predetermined sequence defined in the program. Various types of information are input and output between the operation control unit 100, the sensor value acquisition unit 101, the sensor state monitoring unit 102, the statistical information generation unit 103, and the degradation determination unit 104 according to the operation.

[0022] The sensor value acquisition unit 101 is an example of an acquisition unit. The sensor value acquisition unit 101 acquires the respective sensor values ​​from the intake sensor 21, the crank position sensor 22, and the water temperature sensor 23 via the input / output port 14. The sensor status monitoring unit 102 monitors the status of the water temperature sensor 23. For example, if the sensor value of the water temperature sensor 23 is above or below a predetermined threshold for a certain period of time or longer, the sensor status monitoring unit 102 determines that the water temperature sensor 23 is in an abnormal state, and if the sensor value does not meet the above conditions, it determines that the water temperature sensor 23 is in a normal state.

[0023] The statistical information generation unit 103 is an example of an integration unit. The statistical information generation unit 103 generates injection amount statistical information 130 by integrating the fuel injection amount of the engine 2. The statistical information generation unit 103 integrates the fuel injection amount for each temperature range of the engine 2. The injection amount statistical information 130 shows the integrated value of the fuel injection amount for all trips for each temperature range.

[0024] The statistical information generation unit 103 calculates the fuel injection amount from the sensor values ​​of the intake sensor 21 and the crank position sensor 22, for example, but there are no limitations on the calculation method. When the IG-SW4 is ON, the statistical information generation unit 103 calculates and accumulates the fuel injection amount periodically, for example, and when the IG-SW4 is turned OFF, it reflects the accumulated value in the injection amount statistics information 130. In other words, the fuel injection amount is accumulated for each vehicle trip and the injection amount statistics information 130 is updated.

[0025] The deterioration determination unit 104 is an example of a determination unit. The deterioration determination unit 104 determines the deterioration state of the oil L from the cumulative value of the injection amount statistics information 130. The deterioration determination unit 104 transmits the injection amount statistics information 130 to the management server 5 via the communication module 3.

[0026] The management server 5 manages the status of the vehicle. The management server 5 has a communication port 50, a deterioration degree calculation unit 51, a remaining lifespan calculation unit 52, and a deterioration coefficient table 53. The communication port 50 communicates with the communication module 3 of the vehicle management system S via a communication network. The deterioration degree calculation unit 51 and the remaining lifespan calculation unit 52 are formed, for example, as functions of a program that drives the CPU. The deterioration coefficient table 53 is stored in memory or elsewhere beforehand.

[0027] The degradation level calculation unit 51 calculates the degree of degradation of the oil L. The degradation level calculation unit 51 receives injection amount statistics 130 from the degradation determination unit 104 via the communication port 50.

[0028] The degradation degree calculation unit 51 estimates the amount of sludge precursors mixed in the oil L as the degree of degradation. Sludge precursors are generated when fuel burns in the combustion chamber (not shown) of the engine 2 and are captured by the oil L. However, as the amount of sludge precursors in the oil L increases, they aggregate or precipitate as sludge, which is an insoluble component.

[0029] The degradation level calculation unit 51 calculates the degradation level from the degradation coefficient table 53 and the injection amount statistics information 130. The degradation level calculation unit 51 transmits the degradation level to the communication module 3 via the communication port 50. The communication module 3 receives the degradation level and outputs it to the degradation determination unit 104. The degradation determination unit 104 determines that the oil L has deteriorated, for example, if the degradation level exceeds a threshold.

[0030] The remaining lifespan calculation unit 52 calculates the remaining lifespan of the oil L. The remaining lifespan calculation unit 52 calculates the rate of increase from the degree of deterioration for each predetermined mileage of the vehicle, and estimates the remaining lifespan based on the rate of increase. The degree of deterioration calculation unit 51, the remaining lifespan calculation unit 52, and the deterioration coefficient table 53 may be provided in the ECU1.

[0031] (Calculation of degree of deterioration) Figure 2 shows an example of injection quantity statistics 130 and degradation coefficient table 53. The injection quantity statistics 130 shows the total fuel injection amount for each of the multiple temperature ranges #1 to #10. The temperature ranges #1 to #10 are, as an example, divided into ranges below 150°C as shown in the figure.

[0032] The statistical information generation unit 103 associates the fuel injection amount with the temperature range that includes the temperature detected by the water temperature sensor 23 from the temperature range #1 to #10 and integrates the fuel injection amount. In other words, the statistical information generation unit 103 integrates the fuel injection amount for each temperature range #1 to #10. At the end of the trip, the statistical information generation unit 103 adds the integrated value during the trip to the fuel injection amount for the corresponding temperature range #1 to #10 in the injection amount statistical information 130. Therefore, the injection amount statistical information 130 shows the integrated value of the fuel injection amount for all trips for each temperature range #1 to #10. Note that the integrated value calculated by the statistical information generation unit 103 is an example of the first integrated value.

[0033] Table 53 of the degradation coefficients shows the degradation coefficients for each temperature range #1 to #10. The degradation coefficient is the amount of sludge precursor accumulated per unit amount of fuel injection for each temperature range #1 to #10. The lower the coolant temperature, the lower the combustion temperature in the combustion chamber of engine 2, which increases the amount of unburned fuel and thus the amount of sludge precursor generated. For this reason, the degradation coefficient is larger in the lower temperature ranges #1 to #10.

[0034] The degradation calculation unit 51 multiplies the fuel injection amount by a degradation coefficient for each temperature range #1 to #10, as indicated by the arrows. For example, the fuel injection amount for temperature range #10 in the injection amount statistics information 130 is multiplied by the degradation coefficient for temperature range #10 in the degradation coefficient table 53.

[0035] Degradation level = Σ(fuel injection amount × degradation coefficient) ... (1)

[0036] The degradation degree calculation unit 51 calculates the degradation degree by summing the multiplicative values ​​of the fuel injection amount and degradation coefficient for each temperature range #1 to #10, as shown in equation (1). Here, Σ in equation (1) is an operator that represents the sum for the temperature ranges #1 to #10.

[0037] The deterioration determination unit 104 determines that the oil L is in a deteriorated state if the degree of deterioration is greater than a threshold, and determines that the oil L is in an undeteriorated state if the degree of deterioration is less than or equal to the threshold. The deterioration determination unit 104 may also notify the vehicle occupant of the determination result of the oil L by a notification means (not shown) such as a lamp.

[0038] However, if the water temperature sensor 23 malfunctions during the calculation of the degree of deterioration, and the statistical information generation unit 103 stops accumulating the fuel injection amount, the fuel injection amount during that period will not be reflected in the degree of deterioration, thus reducing the accuracy of the oil L deterioration determination.

[0039] Therefore, if the water temperature sensor 23 is abnormal, the statistical information generation unit 103 associates the fuel injection amount with at least one temperature range from temperature range #1 to #10 and integrates it. This makes it possible to reflect the fuel injection amount during the period when the water temperature sensor 23 is abnormal in the degree of deterioration, thereby improving the accuracy of oil L deterioration determination. An example of operation is described below.

[0040] (Example of operation) Figure 3 is a time chart showing an example of the fuel injection amount integration process when the water temperature sensor 23 is functioning correctly. Figure 3 also shows the injection amount statistics 130 after the integration process.

[0041] The time chart shows the time changes of the on / off state of IG-SW4 (IG-SW), the cumulative value of fuel injection amount per trip unit for temperature ranges #1 and #10 (cumulative fuel injection amount), injection amount statistics 130 for temperature ranges #1 and #10, and the state of the water temperature sensor 23 (sensor state). In this example, it is assumed that the sensor state is always normal and the temperature of the water temperature sensor 23 is within temperature range #10. Therefore, the cumulative value for temperature range #1 and the injection amount statistics 130 are always 0.

[0042] IG-SW4 is ON at times t1-t2 and t3-t4. The cumulative value of fuel injection amount in temperature range #10 increases at times t1-t2 and t3-t4 of the trip period. Assume that the cumulative value at time t2 is A1 and the cumulative value at time t4 is A2. The injection amount statistics 130 for temperature range #10 will have a cumulative value of A1 at time t2 after the end of the first trip period, and a cumulative value of (A1+A2) at time t4 after the end of the next trip period. Thus, the injection amount statistics 130 shows the sum of the cumulative values ​​for each trip period.

[0043] Figure 4 is a time chart showing an example of the fuel injection amount integration process when an abnormality occurs in the water temperature sensor 23. Figure 4 also shows the injection amount statistics 130 after the integration process. In Figure 4, the processing at times t1 to t2 is the same as in Figure 3, so its explanation is omitted.

[0044] The sensor status becomes abnormal between times t3a and t4, after time t3. At time t3a, the accumulation of fuel injection amounts in temperature range #10 is interrupted, and instead, the accumulation of fuel injection amounts in temperature range #1 begins. In other words, when the water temperature sensor 23 malfunctions, the temperature range associated with the accumulated value changes from temperature range #10 to the coldest temperature range, #1. Therefore, the accumulated value in temperature range #1 increases between times t3a and t4. Assume that the accumulated value at time t4 is A3.

[0045] The injection volume statistics 130 for temperature range #10 will have an integrated value of A1 at time t2 after the end of the first trip period. Similarly, the injection volume statistics 130 for temperature range #1 will have an integrated value of A3 at time t4 after the end of the next trip period.

[0046] Thus, when the water temperature sensor 23 is functioning normally, the statistical information generation unit 103 associates the fuel injection amount with the temperature range #10, which includes the engine temperature 2, and integrates it with the lowest temperature range #1 when the water temperature sensor 23 is malfunctioning. This allows the fuel injection amount during the period when the water temperature sensor 23 is malfunctioning to be reflected in the degree of deterioration, thereby improving the accuracy of the oil L deterioration determination.

[0047] Furthermore, temperature range #1 is the lowest temperature range among temperature ranges #1 to #10. Therefore, the cumulative value in temperature range #1 has a greater impact on oil degradation than the other temperature ranges #2 to #10. Consequently, the degradation degree calculation unit 51 is prevented from calculating a degradation degree lower than the actual one. As a result, the degradation determination unit 104 is prevented from determining the degradation state based on a degradation degree lower than the actual one, and the remaining life calculation unit 52 is prevented from calculating a remaining life shorter than the actual one.

[0048] Figure 5 is a flowchart showing an example of the fuel injection amount integration process. This process is executed, for example, at regular intervals. First, the statistical information generation unit 103 determines whether or not the IG-SW4 is in the ON state (step St1). If the IG-SW4 is in the ON state (Yes in step St1), the sensor value acquisition unit 101 acquires the respective sensor values ​​from the intake sensor 21, the crank position sensor 22, and the water temperature sensor 23 (step St2).

[0049] Next, the sensor status monitoring unit 102 determines whether the water temperature sensor 23 is abnormal or not (step St3). If the water temperature sensor 23 is normal (No in step St3), the statistical information generation unit 103 determines and selects a temperature range from temperature ranges #1 to #10 that corresponds to the temperature detected by the water temperature sensor 23 (step St4). If the water temperature sensor 23 is abnormal (Yes in step St3), the statistical information generation unit 103 selects the lowest temperature range, #1 (step St5).

[0050] Next, the statistical information generation unit 103 calculates the fuel injection amount from the sensor values ​​of the intake sensor 21 and the crank position sensor 22 (step St6). Next, the statistical information generation unit 103 integrates the fuel injection amounts (step St7).

[0051] Furthermore, if IG-SW4 is in the off state (No. in step St1), the statistical information generation unit 103 is updated with the accumulated value (step St8). Next, the statistical information generation unit 103 resets the accumulated value to 0 (step St9). The accumulation process is performed in this manner.

[0052] (Other examples) When the water temperature sensor 23 malfunctions, the statistical information generation unit 103 may, instead of being limited to the lowest temperature range #1, divide the fuel injection amount based on the ratio of the cumulative values ​​of temperature ranges #1 to #10 of the injection amount statistical information 130 (hereinafter referred to as the distribution ratio), and integrate them in correspondence to each temperature range #1 to #10.

[0053] Figure 6 shows an example of operation in which the fuel injection amount is distributed to each temperature range #1 to #10 based on the distribution ratio. Figure 6 shows an example of injection amount statistics 130, distribution ratio, and injection amount statistics 130 after fuel injection amount distribution when an abnormality occurs in the water temperature sensor 23 (sensor abnormality occurrence).

[0054] When the water temperature sensor 23 malfunctions, the statistical information generation unit 103 calculates the distribution ratio from the cumulative values ​​of the fuel injection amounts for each temperature range #1 to #10 of the injection amount statistical information 130. In this example, it is assumed that the distribution ratio is 0:0:0:0:1:4:4:6:7:8.

[0055] Subsequently, the statistical information generation unit 103 associates the fuel injection amount with each temperature range #1 to #10 based on the distribution ratio. In the injection amount statistical information 130 after distribution, the area indicated by the diagonal lines represents the distributed portion of the fuel injection amount. For example, if the fuel injection amount during a certain trip period is 300 ml, the statistical information generation unit 103 distributes 10 ml, 40 ml, 40 ml, 60 ml, 70 ml, and 80 ml to temperature ranges #5 to #10 according to the distribution ratio in the example above.

[0056] In this way, when the water temperature sensor 23 is abnormal, the statistical information generation unit 103 divides the fuel injection amount based on the distribution ratio of the cumulative values ​​of the fuel injection amounts associated with each temperature range #1 to #10, and integrates them in association with each temperature range #1 to #10. This makes it possible to reflect the fuel injection amount during the period when the water temperature sensor 23 is abnormal in the degree of deterioration, thereby improving the accuracy of oil L deterioration determination.

[0057] Furthermore, the statistical information generation unit 103 distributes the fuel injection amount to each temperature range #1 to #10 based on the distribution ratio obtained from the cumulative value of the injection amount statistical information 130 associated with each temperature range #1 to #10. Therefore, the vehicle driver's driving history can be reflected in the degree of deterioration from the distribution of past fuel injection amounts in temperature ranges #1 to #10. This improves the accuracy of oil deterioration determination.

[0058] Figure 7 is a flowchart showing another example of the fuel injection amount integration process. In Figure 7, components common to Figure 5 are denoted by the same reference numerals, and their explanations are omitted.

[0059] If the water temperature sensor 23 is abnormal (Yes in step St3), the statistical information generation unit 103 selects the entire temperature range #1 to #10 (step St11). Next, the statistical information generation unit 103 calculates the fuel injection amount (step St12). Next, the statistical information generation unit 103 calculates the distribution ratio from the integrated values ​​of each temperature range #1 to #10 in the injection amount statistical information 130 (step St13). Next, the statistical information generation unit 103 distributes the fuel injection amount calculated in step St12 to the temperature ranges #1 to #10 based on the distribution ratio and integrates them (step St14).

[0060] In this example, the distribution ratio is calculated from the injection amount statistics 130, but is not limited to this. For example, for each temperature range #1 to #10, the distribution ratio may be calculated from the cumulative values ​​of fuel injection amounts over multiple past cumulative periods of different lengths.

[0061] Figure 8 is a configuration diagram showing another example of the vehicle management system S. In Figure 8, components common to Figure 1 are denoted by the same reference numerals, and their explanations are omitted.

[0062] When the CPU 10 reads a program from the ROM 11, it forms the following functions: an operation control unit 100, a sensor value acquisition unit 101, a sensor state monitoring unit 102, a statistical information generation unit 103a, a degradation determination unit 104, and a period average calculation unit 105. The storage memory 13 stores injection amount statistical information 130 and a period average table 131.

[0063] The period average calculation unit 105 is an example of a calculation unit. The period average calculation unit 105 integrates the fuel injection amounts within multiple past cumulative periods of different lengths. Specifically, the period average calculation unit 105 calculates the average value of the fuel injection amounts within each cumulative period (hereinafter referred to as the period average value) for each temperature range #1 to #10 from the cumulative values ​​accumulated by the statistical information generation unit 103a. The period average calculation unit 105 stores the period average values ​​as a period average table 131 in the storage memory 13. The statistical information generation unit 103a calculates the distribution ratio based on the period average table 131 and distributes the cumulative values ​​within the trip period based on the distribution ratio, as described above. Note that the cumulative values ​​within each cumulative period accumulated by the period average calculation unit 105 are examples of the second cumulative values.

[0064] Table 131 stores the period-averaged cumulative values ​​of fuel injection amounts for one day, one week, one month, and three months. Here, one day, one week, one month, and three months are examples of cumulative periods. The calculation method for each period average is described below.

[0065] AV_1D=(current AV_1D×7+V_1D) / 8 ···(2)

[0066] The period average calculation unit 105 calculates the period average value AV_1D of the cumulative fuel injection amount for one day according to the above formula (2). The period average calculation unit 105 updates the period average value AV_1D daily from the current period average value AV_1D in the period average table 131 and the latest cumulative value V_1D for one day. Here, the period average calculation unit 105 sums the cumulative values ​​for each trip period calculated by the statistical information generation unit 103a for the latest day to obtain the cumulative value V_1D. The period average calculation unit 105 then averages the cumulative value V_1D over a period of 8 days using formula (2).

[0067] AV_1W = (Current AV_1W × 7 + V_1W) / 5 ... (3)

[0068] Furthermore, the period average calculation unit 105 calculates the period average value AV_1W of the cumulative fuel injection amount for one week according to the above formula (3). The period average calculation unit 105 updates the period average value AV_1W every week from the current period average value AV_1W in the period average table 131 and the cumulative value V_1W for the latest week. Here, the period average calculation unit 105 sums the cumulative values ​​for each trip period calculated by the statistical information generation unit 103a for the latest week to obtain the cumulative value V_1W. The period average calculation unit 105 then averages the cumulative value V_1W over a period of five weeks using formula (3).

[0069] AV_1M=(current AV_1M×3+V_1M) / 4 ···(4)

[0070] Furthermore, the period average calculation unit 105 calculates the period average value AV_1M of the cumulative fuel injection amount for one month according to the above formula (4). The period average calculation unit 105 updates the period average value AV_1M every month from the current period average value AV_1M in the period average table 131 and the cumulative value V_1M for the latest month. Here, the period average calculation unit 105 sums the cumulative values ​​for each trip period calculated by the statistical information generation unit 103a for the latest month only to obtain the cumulative value V_1M. The period average calculation unit 105 then averages the cumulative value V_1M over a period of four months using formula (4).

[0071] AV_3M=(current AV_3M×4+V_3M) / 4 ···(5)

[0072] Furthermore, the period average calculation unit 105 calculates the period average value AV_3M of the cumulative fuel injection amount for three months according to the above formula (5). The period average calculation unit 105 updates the period average value AV_3M every three months using the current period average value AV_3M in the period average table 131 and the cumulative value V_3M for the most recent three months. Here, the period average calculation unit 105 sums the cumulative values ​​for each trip period calculated by the statistical information generation unit 103a for the most recent three months to obtain the cumulative value V_3M. The period average calculation unit 105 then averages the cumulative value V_3M over a period of 15 months using formula (5).

[0073] The period average table 131 stores the distribution values ​​for each temperature range #1 to #10. The statistical information generation unit 103a calculates the ratio of the distribution values ​​for each temperature range #1 to #10 as the distribution ratio.

[0074] R=K1×AV_1D+K2×AV_1W+K3×AV_1M+K4×AV_3M ...(6) K1>K2>K3>K4 ···(7)

[0075] The period average calculation unit 105 calculates the distribution value R for each temperature range #1 to #10, for example, according to equation (6) above. The distribution value R is calculated as the sum of the products of each period average value AV_1D, AV_1W, AV_1M, AV_3M and the weight coefficients K1 to K4. That is, for each temperature range #1 to #10, the period average calculation unit 105 multiplies the period average values ​​AV_D, AV_1W, AV_1M, AV_3M within one day, one week, one month, and three months by the weight coefficients K1 to K4, and calculates the sum of these multiplied values ​​as the distribution value R. Here, the weight coefficients K1 to K4 are set to satisfy the relationship in equation (7) above.

[0076] The weight coefficient K1, multiplied by the period average value AV_1D of the cumulative fuel injection amount for one day, is the largest, followed by the weight coefficient K2, multiplied by the period average value AV_1W of the cumulative fuel injection amount for one week, which is the second largest. The weight coefficient K3, multiplied by the period average value AV_1M of the cumulative fuel injection amount for one month, is the third largest, and the weight coefficient K4, multiplied by the period average value AV_3M of the cumulative fuel injection amount for three months, is the smallest. In other words, the period average calculation unit 105 multiplies the cumulative value by larger weight coefficients K1 to K4 the shorter the cumulative period.

[0077] For example, K1=0.55, K2=0.2, K3=0.15, and K4=0.1 are set, but the weight coefficients K1 to K4 are changed as appropriate depending on the accuracy of the degradation level. Note that coefficients K1 to K4 are just examples.

[0078] The statistical information generation unit 103a calculates the distribution ratio from the distribution values ​​of each temperature range #1 to #10 in the period average table 131. For example, if the distribution values ​​R for each temperature range #1 to #10 are 0, 0, 0, 0, 0, 10, 30, 50, 60, and 80 respectively, the distribution ratio will be 0:0:0:0:0:1:3:5:6:8.

[0079] The statistical information generation unit 103a, in the same manner as described above, distributes the fuel injection amount for each trip period to temperature ranges #1 to #10 based on the distribution ratio and associates them accordingly. For example, if the cumulative value for a certain trip period is 230 (ml), the fuel injection amounts for each temperature range #1 to #10 will be 0, 0 (ml), 0 (ml), 0 (ml), 0 (ml), 10 (ml), 30 (ml), 50 (ml), 60 (ml), and 80 (ml), respectively.

[0080] In this example, when calculating the distribution value R, the shorter the cumulative period, the larger the weighting coefficients K1 to K4. Therefore, cumulative values ​​closer to the present are reflected more strongly in the distribution value R and also have a greater impact on the distribution ratio. Specifically, the average value AV_1D over one day has the greatest impact, followed by the average value AV_1W over one week. The average value AV_1M over one month has the third greatest impact, while the average value AV_3M over three months has the least impact.

[0081] Therefore, it becomes possible to reflect the latest fuel injection amount in the calculation of oil degradation, depending on the vehicle's seasonal fuel consumption and the driver's driving style. This improves the accuracy of degradation assessment.

[0082] Furthermore, the period average calculation unit 105 multiplies the period average values ​​AV_D, AV_1W, AV_1M, AV_3M, which are obtained by averaging the accumulated values ​​over a period corresponding to the length of each accumulation period, by weight coefficients K1 to K4. Therefore, compared to the case where averaging is not performed, it becomes possible to reflect the fuel injection amount over a longer period in the calculation of the degree of oil deterioration. Note that the period average calculation unit 105 is not limited to the above, and it is not necessary to average the accumulated values ​​of each accumulation period.

[0083] In this example, the period average calculation unit 105 and the period average table 131 are located in the ECU 1, but they may also be located in the management server 5. In this case, when the water temperature sensor 23 malfunctions, the statistical information generation unit 103a sends and receives various numerical values ​​to and from the period average calculation unit 105 and the period average table 131 via the communication module 3 to generate injection amount statistical information 130.

[0084] The embodiments described above are preferred examples of the present invention. However, the invention is not limited thereto, and various modifications are possible without departing from the spirit of the invention. [Explanation of symbols]

[0085] 1 ECU (Degradation Detection Device), 2 Engine (Internal Combustion Engine), 23 Water Temperature Sensor (Detection Device), 101 Sensor Value Acquisition Unit (Acquisition Unit), 103 Statistical Information Generation Unit (Accumulation Unit), 104 Degradation Detection Unit (Determination Unit), 105 Period Average Calculation Unit (Calculation Unit), 130 Injection Amount Statistical Information, 131 Period Average Table, L Oil

Claims

1. An acquisition unit that acquires the temperature from a detection device that detects the temperature of an internal combustion engine, When the detection device is functioning correctly, the integrating unit associates the fuel injection amount of the internal combustion engine with the temperature range that includes the temperature among a plurality of temperature ranges and integrates it; when the detection device is malfunctioning, the integrating unit associates the fuel injection amount with the lowest temperature range among the plurality of temperature ranges and integrates it; The system includes a determination unit that determines the deterioration state of the oil circulating in the internal combustion engine from the integrated value of the fuel injection amount associated with each of the aforementioned plurality of temperature ranges. Deterioration determination device.

2. An acquisition unit that acquires the temperature from a detection device that detects the temperature of an internal combustion engine, When the detection device is functioning correctly, the fuel injection amount of the internal combustion engine is associated with the temperature range that includes the temperature among a plurality of temperature ranges and integrated; when the detection device is malfunctioning, the fuel injection amount is divided based on the ratio of the integrated values ​​of the fuel injection amount associated with each of the plurality of temperature ranges and integrated according to each of the plurality of temperature ranges; The system includes a determination unit that determines the deterioration state of the oil circulating in the internal combustion engine from the integrated value of the fuel injection amount associated with each of the plurality of temperature ranges. Deterioration determination device.

3. An acquisition unit that acquires the temperature from a detection device that detects the temperature of an internal combustion engine, If the detection device is functioning correctly, the integrating unit associates the fuel injection amount of the internal combustion engine with the temperature range that includes the temperature among a plurality of temperature ranges and integrates them, A determination unit that determines the deterioration state of the oil circulating in the internal combustion engine from the integrated value of the fuel injection amount associated with each of the plurality of temperature ranges, The system includes a calculation unit that, for each of the multiple temperature ranges, accumulates the fuel injection amounts over multiple past accumulation periods of different lengths, multiplies the accumulated value of the fuel injection amount within the accumulation period by a larger coefficient for shorter accumulation periods, and calculates the sum of the accumulated value and the multiplied value of the coefficient for each of the multiple accumulation periods. If the detection device is malfunctioning, the integrating unit divides the fuel injection amount based on the ratio of the sum of each of the multiple temperature ranges and integrates it in correspondence with each of the multiple temperature ranges. Deterioration determination device.

4. The calculation unit averages the accumulated value over a period corresponding to the length of each of the plurality of accumulation periods, and multiplies the averaged accumulated value by the coefficient. The deterioration determination device according to claim 3.

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