Vehicle control device

Abstract

To provide a vehicle control device which prevents an engine from damage due to deterioration of engine oil.SOLUTION: A vehicle control device executes: a process to sequentially acquire an engine load KL and a rotation speed NE from engine sensors; a process to acquire a current oil deterioration rate DS, every time when the engine load KL and the rotation speed NE are acquired, by referring to a database DB representing a relation of the load KL and the rotation speed NE with an oil deterioration rate DS, a progress rate of engine oil deterioration; a process to acquire an oil deterioration degree OD by accumulating the oil deterioration rate DS; and a deterioration suppression process which controls a transmission and / or an engine so that the oil deterioration degree DS becomes equal to or lower than a predetermined value when the oil deterioration degree OD exceeds a threshold ODth and includes a process related to at least either one of a shift position, engine valve opening / closing timing, engine ignition timing and a speed of an own vehicle.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a vehicle control device that suppresses deterioration of engine oil. [Background technology]

[0002] A device has been proposed that acquires the degree of deterioration of a vehicle's engine oil (oil deterioration level) (see, for example, Patent Document 1 below). This device (hereinafter referred to as the "conventional device") acquires the oil deterioration level based on the total amount of fuel supplied to the engine (total flow rate) and the time elapsed since the engine oil was changed. When the oil deterioration level exceeds a threshold value, the conventional device provides the driver with information (for example, an image) to encourage the driver to change the engine oil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-139347 A Summary of the Invention

[0004] Even if the conventional device provides the driver with information to prompt the driver to change the engine oil, there is a risk that the driver will continue to use the vehicle without changing the engine oil. In this case, it is necessary to suppress the deterioration of the engine oil.

[0005] An object of the present invention is to provide a vehicle control device that can suppress deterioration of engine oil.

[0006] In order to solve the above problems, a vehicle control device (1) of the present invention comprises: A process of sequentially acquiring a load (KL) and a rotation speed (NE) of an engine (20) from an engine sensor (22); A process of acquiring the oil deterioration rate (DS) corresponding to the current load and rotation speed by referring to a database (DB) showing the relationship between the load and rotation speed and an oil deterioration rate (DS) which is the progression rate of deterioration of engine oil, each time the load and rotation speed are acquired; A process of acquiring an oil deterioration degree (OD) which is a degree of deterioration of the engine oil by integrating the oil deterioration rate; a deterioration suppression process for controlling a transmission and / or an engine of the vehicle when the degree of oil deterioration exceeds a threshold value (ODth) so that the oil deterioration rate becomes equal to or less than a predetermined value, the deterioration suppression process including a process related to at least one of a shift position of the transmission, a valve opening / closing timing of the engine, an ignition timing of the engine, and a speed of the vehicle; The apparatus is configured to execute the following steps:

[0007] According to the vehicle control device of the present invention, when the degree of deterioration of the engine oil becomes relatively large, the vehicle is controlled so as to slow down the rate at which the deterioration of the engine oil progresses, thereby making it possible to suppress the deterioration of the engine oil. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a vehicle control device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a database showing the relationship between load, rotation speed, and oil deterioration rate. [Diagram 3] FIG. 3 is a graph showing the degree of oil deterioration. [Figure 4] FIG. 4 is a flowchart of a program for implementing the engine protection function. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Summary) 1, a vehicle control device 10 according to an embodiment of the present invention is applied to a vehicle V1 (host vehicle) equipped with an engine 20 and a transmission 30, and controls the engine 20 and the transmission 30. The vehicle control device 10 calculates the degree of progression of engine oil deterioration (oil deterioration level) based on the load KL and rotation speed NE of the engine 20. The vehicle control device 10 has a function of controlling the engine 20 and / or the transmission 30 so as to slow down the rate of progression of engine oil deterioration (oil deterioration rate) when the oil deterioration level exceeds a threshold value.

[0010] (Specific configuration) The vehicle control device 10 includes an ECU 11 .

[0011] The ECU 11 includes a microcomputer equipped with a CPU 11a, a ROM 11b (flash ROM), a RAM 11c, a timer 11d, etc. The ECU 11 is connected to other control units (an engine ECU 21 and a transmission ECU 31, which will be described later) provided in the host vehicle via a CAN (Controller Area Network).

[0012] The engine 20 includes a cylinder head, a cylinder block, a crankcase, pistons, connecting rods, a crankshaft, various valves, spark plugs, etc. (not shown). The engine 20 also includes an engine ECU 21 and an engine sensor 22. The engine ECU 21 controls the various valves, spark plugs, etc. of the engine 20 based on commands obtained from other ECUs and information obtained from the engine sensor 22 (described later). The engine ECU 21 also provides the information obtained from the engine sensor 22 to the other ECUs.

[0013] The engine sensors 22 include a load sensor 22a and an engine speed sensor 22b.

[0014] The load sensor 22a acquires a load KL of the engine 20. The load sensor 22a acquires (calculates) the filling rate of air in a cylinder as the load KL, for example, based on the flow rate of air flowing through an intake path of the engine 20. The load sensor 22a also acquires (calculates) the filling rate of air in a cylinder as the load KL, for example, based on the temperature and pressure of air in a surge tank provided in the intake path.

[0015] The rotation speed sensor 22b includes a magnetic sensor that acquires the rotation speed NE of the crankshaft.

[0016] The transmission 30 includes an actuator for changing a combination (shift position) of a plurality of gears and meshing gears (not shown). The transmission 30 also includes a transmission ECU 31. The transmission ECU 31 controls the actuator according to commands obtained from other ECUs to change the shift position.

[0017] (Oil deterioration prevention function) When the ignition switch is in an ON state, the ECU 11 sequentially acquires the load KL and the rotation speed NE from the engine sensor 22 via the engine ECU 21.

[0018] Incidentally, the rate at which engine oil deterioration progresses (oil deterioration rate DS) is proportional to the concentration of nitrogen oxides (NOx) in the engine. The concentration of nitrogen oxides in the engine is correlated with the load KL and the engine speed NE. The relationship between the load KL and the engine speed NE and the concentration of nitrogen oxides is experimentally obtained. Based on the results, a database DB (see FIG. 2) showing the relationship between the load KL and the engine speed NE and the oil deterioration rate DS (∝NOx concentration) is created in advance. This database DB is stored in the ROM 11b. For the sake of simplicity, the database DB shown in FIG. 2 is composed of a region (L) where the oil deterioration rate is low, a region (M) where the oil deterioration rate is medium, and a region (H) where the oil deterioration rate is high, but the database DB may be further subdivided.

[0019] Each time the ECU 11 acquires the load KL and the rotation speed NE from the engine sensor 22, the ECU 11 refers to the database DB to acquire the oil deterioration rate DS (instantaneous value). Each time the ECU 11 acquires the oil deterioration rate DS, the ECU 11 accumulates the oil deterioration rate DS and acquires the accumulated value as the oil deterioration degree OD (degree of progress of deterioration of the engine oil). In other words, the oil deterioration degree OD corresponds to the area of ​​the shaded portion in the graph shown in FIG. 3. When the oil deterioration degree OD exceeds the threshold value ODth, the ECU 11 starts a deterioration suppression process for controlling the engine 20 and / or the transmission 30 so that the oil deterioration rate DS slows down (for example, becomes equal to or lower than the speed L).

[0020] For example, the deterioration suppression process includes processes related to at least one of the shift position, the opening and closing timing of the intake valve and the exhaust valve, and the operation timing of the spark plug.

[0021] Specifically, when the ignition switch is in an on state, the ECU 11 sequentially acquires the traveling speed and traveling distance of the vehicle from a sensor (not shown) and stores them. Then, based on these pieces of information, the ECU 11 calculates a ratio DRA (=DA / D0) of a distance DA traveled at a relatively high speed (for example, 100 km / h or more) to a total traveling distance D0. When the ratio DRA exceeds a threshold value DRAth, the ECU 11 transmits a command to the transmission ECU 31 to permit a shift position change within a predetermined range among all the shift positions of the transmission 30 and prohibit a change to other positions (shift position restriction process). Specifically, when the ratio DRA exceeds the threshold value DRAth, the ECU 11 transmits a command to the transmission ECU 31 to permit a position change within a low speed range among all the shift positions of the transmission 30 and prohibit a position change within a high speed range. For example, a change to the highest speed position among all the shift positions is prohibited.

[0022] Furthermore, when the ignition switch of the vehicle is in an on state, the ECU 11 sequentially obtains the temperature of a catalyst provided in an exhaust pipe of the vehicle and the travel distance from a sensor (not shown) and stores them. Then, based on this information, the ECU 11 calculates a ratio DRB (=DB / D0) of the distance DB traveled when the catalyst temperature is relatively low to the total travel distance D0. If the ratio DRB exceeds a threshold DRBth, the ECU 11 transmits a command to the engine ECU 21 to set the opening timing (and / or closing timing) of the intake valve to a predetermined timing. As a result, the duration θin of the intake valve is changed (advanced) from, for example, a reference value (the angular position of the crankshaft when the piston reaches the top dead center ("0°")) to a predetermined value α (the value at which the oil deterioration speed DS is smallest). The predetermined value α is experimentally determined. Instead of or in addition to controlling the intake valve, the ECU 11 may send a command to the engine ECU 21 to set the opening timing (and / or closing timing) of the exhaust valve to a predetermined timing. As a result, the duration θex of the exhaust valve is changed (advanced) from, for example, a reference value (the angular position of the crankshaft when the piston reaches top dead center ("0°")) to a predetermined value β. Note that the durations θin and θex may be changed from current values ​​determined based on other conditions to values ​​obtained by adding predetermined values ​​Δα and Δβ to the current values.

[0023] Furthermore, when the ignition switch of the vehicle is in an on state, the ECU 11 sequentially acquires the temperature and the mileage from a sensor (not shown) and stores them. Based on this information, the ECU 11 calculates the ratio DRC (=DC / D0) of the distance DC traveled in a low temperature environment (when the temperature is lower than a threshold) to the total mileage D0. If the ratio DRC exceeds the threshold DRCth, the ECU 11 transmits a command to the engine ECU 21 to set the ignition timing of the spark plug to a predetermined timing. As a result, the duration θig of the spark plug is changed (advanced) from, for example, a reference value (for example, an angular position at which the crankshaft rotates by "10°" after the piston reaches the top dead center) to a predetermined value γ (a value at which the oil deterioration speed DS is minimized). The predetermined value γ is experimentally determined.

[0024] The ECU 11 starts the deterioration suppression process and also starts a monitoring process for successively determining whether the engine oil has been replaced. For example, the ECU 11 displays an oil change completion button (icon) on a display device such as a navigation system or an instrument panel of the vehicle, and determines that the oil change has been completed when the driver presses the oil change completion button using a predetermined operating device. The ECU 11 may also successively obtain engine oil pressure and temperature from a sensor (not shown) and determine whether the engine oil has been replaced based on the changes in the pressure and temperature. Two electric signal lines may be connected via an oil pan drain bolt (or an oil filler cap) made of a conductor, and the ECU 11 may determine that the engine oil has been replaced when it detects that the drain bolt (or the oil filler) is removed and then reinstalled, causing the signal line to transition from a non-conductive state to a conductive state. When the ECU 11 determines that the engine oil has been changed, it ends the deterioration suppression process and sets (initializes) the oil deterioration degree OD (that is, the integrated value of the oil deterioration speed DS) to "0".

[0025] Next, with reference to FIG. 4, a program PR1 executed by the CPU 11a (hereinafter simply referred to as "CPU") of the ECU 11 to realize the above-mentioned oil deterioration suppression function will be described.

[0026] (Program PR1) When the CPU detects that the ignition switch of the vehicle V1 has transitioned from the OFF state to the ON state, the CPU starts the execution of the program PR1. The CPU starts the execution of the program PR1 from step 100 and proceeds to step 101.

[0027] In step 101, the CPU acquires the load KL from the engine sensor 22. Next, the CPU proceeds to step .

[0028] In step 102, the CPU acquires the rotation speed NE from the engine sensor 22. Next, the CPU proceeds to the process of step 103.

[0029] In step 103, the CPU refers to the database DB (FIG. 2) to obtain the oil deterioration rate DS(L / M / H) corresponding to the current load KL and rotation speed NE.

[0030] In step 104, the CPU accumulates the oil deterioration rate DS to obtain (update) the oil deterioration degree OD (OD=OD+DS). The CPU writes the obtained (updated) oil deterioration degree OD to the ROM 11b. That is, even if power is no longer supplied to the engine protection ECU 11, the oil deterioration degree OD is held. Next, the CPU proceeds to step 105.

[0031] In step 105, the CPU determines whether the oil degradation level OD exceeds the threshold value ODth. If the CPU determines that the oil degradation level OD exceeds the threshold value ODth (105: Yes), the CPU proceeds to step 106. That is, the CPU starts degradation suppression processing. On the other hand, if the CPU does not determine that the oil degradation level OD exceeds the threshold value ODth (105: No), the CPU returns the processing to step 101.

[0032] In step 106, the CPU determines whether or not the ratio DRA exceeds the threshold DRAth. If the CPU determines that the ratio DRA exceeds the threshold DRAth (106: Yes), the CPU proceeds to step 107. On the other hand, if the CPU does not determine that the ratio DRA exceeds the threshold DRAth (106: No), the CPU skips step 107 and proceeds to step 108.

[0033] In step 107, the CPU transmits a command to the transmission ECU 31 to prohibit a position change to the highest speed position. Next, the CPU advances the process to step .

[0034] In step 108, the CPU determines whether the rate DRB exceeds the threshold DRBth. If the CPU determines that the rate DRB exceeds the threshold DRBth (108: Yes), the CPU proceeds to step 109. On the other hand, if the CPU does not determine that the rate DRB exceeds the threshold DRBth (108: No), the CPU skips step 109 and proceeds to step 110.

[0035] In step 109, the CPU transmits a command to the engine ECU 21 to set the opening timing (and / or closing timing) of the intake valve (and / or the exhaust valve) to a predetermined timing. Next, the CPU proceeds to step 110.

[0036] The CPU determines whether or not the ratio DRC exceeds the threshold DRCth in step 110. If the CPU determines that the ratio DRC exceeds the threshold DRCth (110: Yes), the CPU proceeds to step 111. On the other hand, if the CPU does not determine that the ratio DRC exceeds the threshold DRCth (110: No), the CPU skips step 111 and proceeds to step 112.

[0037] In step 111, the CPU transmits a command to the engine ECU 21 to set the ignition timing of the spark plug to a predetermined timing. Next, the CPU proceeds to step 112.

[0038] The CPU determines whether or not the oil change has been completed in step 112. If the CPU determines that the oil change has been completed (112: Yes), the CPU proceeds to step 113. On the other hand, if the CPU does not determine that the oil change has been completed (112: No), the CPU returns to step 112.

[0039] The CPU ends the deterioration suppression process in step 113. That is, the CPU transmits a command to the transmission ECU 31 to permit position changes to all shift positions. The CPU also transmits a command to the engine ECU 21 to return the operating angles θin, θex, and θig to reference values ​​("0°" (or values ​​determined based on other conditions)). Next, the CPU proceeds to step 114.

[0040] In step 114, the CPU initializes the oil deterioration degree OD to “0.” Next, the CPU returns the process to step 101.

[0041] (effect) According to the vehicle control device 10 of this embodiment, when the oil deterioration degree OD becomes relatively large (OD>ODth), the vehicle is controlled so that the rate of deterioration of the engine oil slows down (DS≦L). This makes it possible to suppress the deterioration of the engine oil.

[0042] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention.

[0043] For example, the deterioration suppression process may include a process of reducing the number of revolutions NE. Specifically, when the oil deterioration degree OD exceeds a threshold value ODth, the ECU 11 may transmit a command to the engine ECU 21 to specify an upper limit value (e.g., 100 km / h) of the traveling speed of the host vehicle.

[0044] Also, the ECU 11 may execute the deterioration suppression process regardless of the ratios DRA, DRB, and DRC, that is, steps 106, 108, and 110 in FIG. [Explanation of symbols]

[0045] 1...vehicle control device, 11...engine protection ECU, KL...load, NE...rotation speed

Claims

[Claim 1] A process of sequentially acquiring an engine load and an engine speed from an engine sensor; A process of acquiring the oil deterioration rate corresponding to the current load and rotation speed by referring to a database showing a relationship between the load and rotation speed and an oil deterioration rate which is a progression rate of deterioration of engine oil, each time the load and rotation speed are acquired; A process of acquiring an oil deterioration degree, which is a degree of deterioration of the engine oil, by integrating the oil deterioration rate; a deterioration suppression process for controlling a transmission and / or an engine of the vehicle when the degree of oil deterioration exceeds a threshold value so that the oil deterioration rate becomes equal to or less than a predetermined value, the deterioration suppression process including a process related to at least one of a shift position, a valve opening / closing timing of the engine, an ignition timing of the engine, and a speed of the vehicle; A vehicle control device configured to execute the above.

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