JP6475098B2 - Engine oil level detector - Google Patents

Description

  The present invention relates to a technical field of an engine oil level detection device that detects an oil level position of engine oil in an oil reservoir such as an oil pan provided in a vehicle.

Japanese Patent Laid-Open No. 5-332120 JP-A-57-84316 Japanese Patent No. 5065068

  An engine oil level detection device that detects the oil level of an engine oil in an oil storage tank that stores engine oil (lubricating oil) in a circulating manner with the engine, such as an oil pan provided below a vehicle engine, is known. (See, for example, Patent Documents 1 and 2 above).

  Patent Document 1 discloses a technique capable of detecting the oil level position of engine oil not by binary values of Full / Low but by multivalues of three or more values. Specifically, Patent Document 1 discloses a float that floats on an oil surface in an oil tank, and a plurality of reed switches (hereinafter referred to as “oil level switches”) that are arranged in the vertical direction and are turned on when the floats are close to each other. A technique is disclosed that multi-values the oil level position based on the number of oil level switches that are provided and turned on.

  Patent Document 3 discloses a technique for determining that an oil level switch is out of order or has an excessive oil level when the oil level switch does not operate within a predetermined time from the start of the engine.

  However, providing a plurality of oil level switches is undesirable because it leads to an increase in cost.

  Therefore, the present invention aims to overcome the above-described problems and to reduce the cost of an engine oil level detection device that multi-values the oil level position of the engine oil in the oil storage tank.

  The engine oil level detection device according to the present invention is an engine oil level detection device that detects an oil level position of the engine oil in an oil storage tank that stores the engine oil so as to be circulated with the engine, An oil level switch that is turned on in response to the oil level position reaching a predetermined level, and a time from the reference time point when the engine is started as a reference until the oil level switch is turned on, is measured. And an oil level estimation unit that estimates the oil level position based on the time.

  Thereby, it is not necessary to provide a plurality of oil level switches for multi-value detection of the engine oil oil level position.

In the engine oil level detection device according to the present invention described above, the oil level estimation unit is a time / oil level representing a correspondence relationship between a time from the reference time point until the oil level switch is turned on and the oil level position. It is desirable to estimate the oil level position based on position correspondence information.
By using the time / oil surface position correspondence information representing the correspondence between the time and the oil surface position as described above, it is possible to estimate the engine oil oil surface position relatively easily.

In the engine oil level detection device according to the present invention described above, the oil level estimation unit is configured to provide information on the oil level position at each time assumed as a time from the reference time point until the oil level switch is turned on. It is desirable to estimate the oil level position based on the time / oil level position correspondence information as table information associated with.
Thereby, the estimation of the engine oil oil level position is realized only by acquiring the oil level position information of the engine oil corresponding to the measurement time from the table information.

In the engine oil level detection device according to the present invention described above, the oil level estimation unit is provided with a stop time until the start of the engine, a rotation speed of the engine when the engine is started, and the oil storage tank. It is determined whether at least one of acceleration acting on a given vehicle or the temperature of the engine oil deviates from a predetermined assumed value, and if it deviates from the assumed value, the oil It is desirable not to estimate the surface position.
The time until the oil level switch is turned on from the reference time is the stop time until the engine starts, the number of revolutions at the time of starting, the acceleration acting on the vehicle provided with the oil storage tank, or the temperature of the engine oil The engine oil level position detection accuracy is improved by not estimating the oil level position when these factors deviate from the assumed values. Reduction can be prevented.

In the engine oil level detection device according to the present invention described above, the oil level estimation unit includes a time from the reference time until the oil level switch is turned on, a stop time until the engine is started, and the start The oil level position corresponding to a combination with at least one of the rotational speed of the engine, the acceleration acting on the vehicle provided with the oil storage tank, and the temperature of the engine oil It is desirable to estimate the oil level position based on time / oil level position correspondence information.
As a result, the estimation of the engine oil oil level position based on the time from the reference time point until the oil level switch is turned on indicates the correspondence between the time from the reference time point until the oil level switch is turned on and the engine oil oil level position. It is done in a form that takes into account the changing elements.

  According to the present invention, it is not necessary to provide a plurality of oil level switches in the engine oil level detection device that multi-values the oil level position of the engine oil in the oil storage tank, and the cost can be reduced.

It is the block diagram which showed the structure outline | summary of the vehicle control apparatus provided with the engine oil level detection apparatus as embodiment. It is explanatory drawing of an oil level switch. It is explanatory drawing about the oil level detection method of embodiment. It is the figure which showed the example of time and oil level position corresponding | compatible information. It is a flowchart of an oil level detection process. It is the figure which showed the other example of time and oil level position corresponding information. It is a flowchart of the oil level detection process in another example of the detection method.

<1. Overall Configuration of Vehicle Control Device>
FIG. 1 is a block diagram showing an outline of the configuration of a vehicle control device 1 including an engine oil level detection device according to an embodiment of the present invention. In FIG. 1, only the configuration of the main part according to the present invention is extracted and shown from the configuration of the vehicle control device 1.
The engine oil level detection device includes at least the engine control unit 3 and the oil level switch 10d among the components shown in FIG.

  The vehicle control apparatus 1 includes a display control unit 2, an engine control unit 3, a transmission control unit 4, a brake control unit 5, a display unit 6, an engine-related actuator 7, a transmission-related actuator 8, a brake-related actuator 9, and sensors / operators. 10 and a bus 11.

The sensors / operators 10 comprehensively represent various sensors and operators provided on the vehicle. The sensor / operator 10 has a speed sensor 10a that detects the speed of the host vehicle as a vehicle speed, an engine speed sensor 10b that detects the engine speed, and an accelerator opening degree that is detected from the amount of depression of the accelerator pedal. There is an accelerator opening sensor 10c. Also, an oil level switch 10d that is turned on when the level of engine oil Eo that functions as engine lubricating oil reaches a predetermined level, an oil temperature sensor 10e that detects the temperature of engine oil Eo as an oil temperature, and engine cooling There is a water temperature sensor 10f that detects the temperature of water as a water temperature, a G sensor 10g that detects acceleration acting on the host vehicle, and a brake switch 10h that is turned ON / OFF according to operation / non-operation of the brake pedal.
Although not shown, the sensor / operator 10 is provided as another sensor, for example, an intake air amount sensor for detecting the intake air amount to the engine, and is provided in each intake passage and supplied to each cylinder of the engine. A throttle opening sensor that detects the opening of a throttle valve that adjusts the intake air amount, an outside air temperature sensor that detects the temperature outside the vehicle, and the like are also provided.
Further, as an operator, an ignition switch for instructing start / stop of the engine, an automatic transmission mode / manual transmission mode selection in the automatic transmission, and an up / down instruction in the manual transmission mode are given. There are a select lever, a display changeover switch for switching display information in an MFD (Multi Function Display) provided in the display unit 11 described later, and the like.

The oil level switch 10d provided as the sensor / operator 10 will be described with reference to FIG.
The oil level switch 10 d is provided for the oil pan 101 disposed below the engine block 100. The oil pan 101 is an oil storage tank that stores the engine oil Eo so that it can circulate with the engine.
In the oil pan 101, there are provided a rod-shaped guide 101a extending in the vertical direction (height direction) and a float 101b having a ring-shaped outer shape and having the rod-shaped guide 101a inserted through a central cavity. . The float 101b has buoyancy with respect to the engine oil Eo, and is guided by the rod-shaped guide 101a according to the vertical displacement of the oil level Seo of the engine oil Eo stored in the oil pan 101. Displaces vertically.
The oil level switch 10d is a switch that is turned on when the float 101b approaches. That is, the oil level switch 10d is turned on when the level of the engine oil Eo (height of the oil level Seo) reaches a predetermined level (predetermined height).

Returning to FIG.
The display control unit 2, the engine control unit 3, the transmission control unit 4, and the brake control unit 5 are each a micro that includes, for example, a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM). The computers are connected to each other via a bus 11 so that data communication is possible. The display unit 6, the engine-related actuator 7, the transmission-related actuator 8, and the brake-related actuator 9 are provided as control targets of these control units.

  The display unit 6 comprehensively represents various meters and MFDs such as a speedometer and a tachometer provided in a meter panel installed in front of the driver, and other display devices for presenting information to the driver. ing. Various information such as the total travel distance of the host vehicle, the outside air temperature, and instantaneous fuel consumption can be displayed on the MFD simultaneously or by switching.

  The display control unit 2 displays a display based on a detection signal from a predetermined sensor such as the vehicle speed sensor 10a, the engine speed sensor 10b, or the above-described outside air temperature sensor in the sensor / operator 10 or operation input information by the operator. The display operation by the unit 6 is controlled.

The engine control unit 3 controls various actuators provided as the engine-related actuator 7 based on a detection signal from a predetermined sensor in the sensor / operator 10 or operation input information by the operator. As the engine-related actuator 7, for example, various actuators related to engine driving such as a throttle actuator for driving a throttle valve and an injector for performing fuel injection are provided.
For example, the engine control unit 3 performs engine start / stop control according to the operation of the ignition switch described above. The engine control unit 3 also controls the fuel injection timing, the fuel injection pulse width, the throttle opening, and the like based on detection signals from predetermined sensors such as the engine speed sensor 10b and the accelerator opening sensor 10c.

In addition, the engine control unit 3 in this example performs a process of detecting the level (oil level Seo height) of the engine oil Eo in the oil pan 101 based on the detection information by the oil level switch 10d. Further, the engine control unit 3 transmits the detected level information of the engine oil Eo to the display control unit 2 and causes the display unit 6 to display it.
The oil level detection method will be described later.

The transmission control unit 4 controls various actuators provided as the transmission-related actuator 8 based on a detection signal from a predetermined sensor in the sensor / operator 10 or operation input information by the operator. As the transmission-related actuator 8, for example, an actuator for performing shift control of the automatic transmission is provided.
For example, when the automatic shift mode is selected by the above-described select lever, the transmission control unit 4 performs a shift control by outputting a shift signal to the actuator according to a predetermined shift pattern. Further, when the manual shift mode is set, the transmission control unit 4 performs a shift control by outputting a shift signal according to a shift up / down instruction from the select lever to the actuator.

  The brake control unit 5 controls various actuators provided as the brake-related actuator 9 based on a detection signal from a predetermined sensor in the sensor / operator 10 or operation input information by the operator. As the brake-related actuator 9, for example, various brake-related actuators such as a hydraulic pressure control actuator for controlling the hydraulic pressure output from the brake booster to the master cylinder and the hydraulic pressure in the brake fluid piping are provided. For example, the brake control unit 5 calculates the slip ratio of the wheel from detection information of a predetermined sensor (for example, an axle rotation speed sensor or the vehicle speed sensor 10a), and the hydraulic pressure is controlled by the hydraulic control actuator according to the slip ratio. By so doing, so-called ABS (Antilock Brake System) control is realized.

<2. Overview of oil level detection method>
FIG. 3 is an explanatory diagram of the oil level detection method of the embodiment, and illustrates the relationship between the elapsed time before and after the engine start and the height of the oil level Seo. Specifically, in FIG. 3, five values of “Full”, “Mid + α”, “Mid”, “Low + α”, and “Low” are assumed as the oil level when the engine is stopped, and these “Full”, “Mid + α”, “Mid” are assumed. In each case of “Low + α” and “Low”, the transition of the height of the oil level Seo according to the elapsed time from the start of the engine is shown.

The height of the oil level Seo in the oil pan 101 is lowered when the engine oil Eo is taken out to the engine side when the engine is started. When the engine is stopped during operation, the engine oil Eo begins to gradually return to the oil pan 101, and after a certain period of time has elapsed from when the engine stopped (when the engine oil Eo has almost returned from the engine side), the oil level Seo. The height of is stable.
In the detection of the level of the engine oil Eo in this example, the oil levels of “Full”, “Mid + α”, “Mid”, “Low + α”, and “Low” to be detected (estimated) have passed a certain period of time since the engine stop time. The oil level Seo is at a stable level. That is, in the oil level detection of this example, the oil of “Full”, “Mid + α”, “Mid”, “Low + α”, and “Low” in the stable state after the stop based on the change in the oil level Seo after the engine is started. Guess the level.

  Immediately after the engine is started, the oil surface Seo height changes at a relatively high speed, and when a certain amount of engine oil Eo is subsequently taken out to the engine side, the oil surface Seo height is relatively stable (however, , If the engine speed is stable). In the drawing, the height of the oil level Seo in the stable state after engine start corresponding to each of “Full”, “Mid + α”, “Mid”, “Low + α”, and “Low” is expressed as Sb1, Sb2, Sb3, Sb4, and Sb5. (Sb1> Sb2> Sb3> Sb4> Sb5).

  Here, the oil level switch 10d is provided to turn on in response to the level of the engine oil Eo reaching the level represented by “x” in the drawing. In this example, the level x is set to a level that satisfies the condition that it is lower than the “Low” level and higher than the “Sb1” level. In other words, it is set to a level lower than the lowest level of the detectable oil level and higher than the oil level during engine operation corresponding to the highest level (“Full”) of the detectable oil levels. doing.

  When the amount of oil is “Low”, the time from when the engine oil Eo starts to be taken out from the oil pan 101 to the engine side after the engine is started until the level of the engine oil Eo reaches the level x is minimized (for example, “A seconds”). For the other “Low + α” to “Full”, the time until the level of the engine oil Eo reaches the level x after the engine start is shorter in the order of “Low + α”, “Mid”, “Mid + α”, and “Full” where the oil amount is smaller. (In order, “b second”, “c second”, “d second”, and “e second”).

In the detection method of this example, for each level of “Full”, “Mid + α”, “Mid”, “Low + α”, and “Low” to be obtained as detection results, the time from when the engine starts until the level of the engine oil Eo reaches level x That is, the time from when the engine is started until the oil level switch 10d is turned on is determined. Specifically, for example, “˜a seconds” for the “Low” level, “a + 1 to b seconds” for the “Low + α” level, “b + 1 to c seconds” for the “Mid” level, and “Mid + α” levels for the “Mid + α” level. For the “c + 1 to d seconds” and “Full” levels, the time of “d + 1 seconds to” is determined in advance through experiments or the like.
In addition, in the detection method of the present example, the time until the oil level switch 10d is turned on is measured with reference to the engine starting time, and the “Full” is determined depending on which of the above grasped times the measurement time corresponds to. ”“ Mid + α ”,“ Mid ”,“ Low + α ”, or“ Low ”, an oil level detection result is obtained.

  As described above, in this example, the level x (the level at which the oil level switch 10d is turned on) is set lower than the “Low” level, but according to this, the measurement time is redundant in the detection method described above. Is prevented.

In order to realize the detection method as described above, the vehicle control apparatus 1 uses the engine oil from the engine start time for each level of “Full”, “Mid + α”, “Mid”, “Low + α”, and “Low” to be obtained as a detection result. Time / level correspondence information (time / oil surface position correspondence information) I1 in which information on time until the level of Eo reaches level x is associated is stored (see FIG. 4).
The time / level correspondence information I1 is stored in a storage device that can be read by the engine control unit 3, such as the ROM provided in the engine control unit 3, for example.

<3. Processing procedure>
Hereinafter, a specific processing procedure for realizing the oil level detection method as the embodiment whose outline has been described above will be described with reference to the flowchart of FIG. 5.
The process shown in FIG. 5 is executed by the CPU in the engine control unit 3 based on a program stored in a predetermined storage device such as the ROM described above.

  First, the engine control unit 3 waits until engine start is detected in step S101, and when engine start is detected, starts time measurement in step S102. The detection of engine start may be detection of an engine start operation, or may be detection of execution of engine start control according to the start operation.

  The subsequent steps S103 to S106 are processes for determining whether or not a “detection exclusion condition” that is determined in advance as the oil level detection process should not be executed.

First, in step S103, it is determined whether or not the engine stop time (stop time until start detected in step S101) is equal to or less than a certain time, and an affirmative result is obtained that the engine stop time is equal to or less than a certain time. If YES in step S111, the flow advances to step S111 to reset the time measurement value to 0, and the processing shown in FIG.
When the engine stop time is an extremely short time such as 10 seconds, for example, the height of the oil level Seo at the time of engine start is affected by the operation time of the engine before the stop, the oil temperature state, and the like. Will be mixed. That is, the height of the oil level Seo is not stable depending on the situation before the stop (hereinafter referred to as “previous situation”). Therefore, regardless of the previous situation, the time until the oil level Seo is stabilized is grasped, and when the engine stop time is less than the grasped time, the time measurement is stopped as described above. The oil level detection process is not performed. This prevents the oil level detection accuracy from being lowered.
The engine stop time is measured by, for example, the engine control unit 3.

If a negative result is obtained in step S103 that the engine stop time is not less than the predetermined time, the engine control unit 3 proceeds to step S104, and determines whether or not the engine speed at the time of engine start is out of the predetermined range. To do. If an affirmative result is obtained that the engine speed at the start of the engine is outside a certain range, the process proceeds to step S111, the time measurement value is reset to 0, and the process shown in this figure is terminated.
The higher the engine speed at the start of the engine, the sooner the oil level Seo becomes lower (because the amount of oil taken out by the oil pump for supplying the engine oil Eo from the oil pan 101 side to the engine side becomes larger). . That is, the time from when the engine is started until the oil level switch 10d is turned on is shortened.
Thus, whether or not the engine speed at the time of starting the engine is high is an element that affects the accuracy of oil level detection. Therefore, as described above, it is determined whether or not the engine speed at the time of starting the engine is out of a certain range (for example, whether or not the engine speed is equal to or higher than a predetermined speed). If a positive result is obtained, time measurement is performed. Stop and do not perform the oil level detection process. This prevents the oil level detection accuracy from being lowered.

  As the engine speed at the time of starting the engine, for example, sampling performed by the engine control unit 3 in a predetermined cycle with respect to a detection signal from the engine speed sensor 10b is set to a sampling timing corresponding to the time when the engine start is detected. A sampled value may be used. Or it is good also as an average value etc. of the value sampled at the multiple sampling timing nearest to the time of engine starting being detected.

If a negative result is obtained in step S104 that the engine speed at the start of the engine is not outside the certain range, the engine control unit 3 proceeds to step S105 and determines whether or not the acceleration is outside the certain range. Specifically, it is determined whether or not the value of acceleration detected by the G sensor 10g (respective acceleration acting in the longitudinal direction and lateral direction of the vehicle) is outside a certain range. If an affirmative result is obtained that the acceleration is outside the certain range, the process proceeds to step S111, the time measurement value is reset to 0, and the process shown in this figure is terminated.
For example, the oil level Seo is inclined from the horizontal state depending on the condition of the road surface where the host vehicle is stopped when the engine is started (for example, the gradient). That is, the oil level switch 10d is turned on even though the oil level in the horizontal state is lower than the level x, or conversely, the oil level in the horizontal state is higher than the level x. The level switch 10d is not turned on, and the oil level detection accuracy is lowered.
For this reason, as described above, it was determined whether or not the acceleration was out of a certain range (for example, whether or not both the longitudinal and lateral accelerations were ± 0.1 m / s ² ), and a positive result was obtained. In this case, the time measurement is stopped and the oil level detection process is not performed. This prevents the oil level detection accuracy from being lowered.

If a negative result is obtained in step S105 that the acceleration is not outside the certain range, the engine control unit 3 proceeds to step S106, and whether the oil temperature value detected by the oil temperature sensor 10e is outside the certain range. Determine whether or not. If an affirmative result is obtained that the oil temperature is outside the certain range, the process proceeds to step S111, the time measurement value is reset to 0, and the process shown in FIG.
Since the engine oil Eo expands thermally, the higher the oil temperature, the higher the oil level Seo, and the shorter the time until the oil level switch 10d is turned on. When the oil temperature is low, the kinematic viscosity of the engine oil Eo is high, the speed at which the engine oil Eo is supplied to each part in the engine is slow, and the time until the oil level switch 10d is turned on tends to be long. The
If the oil temperature is excessively high and excessively low, it should be set for each level of “Full” to “Low” to be detected (time until the oil level switch 10d is turned on). ) Is wide and accurate detection may not be possible. For this reason, as described above, it is determined whether or not the value of the oil temperature is out of a certain range. If a positive result is obtained, the time measurement is stopped and the oil level detection process is not performed. This prevents the oil level detection accuracy from being lowered.

If a negative result is obtained in step S106, that is, if it is determined that all the “detection exclusion conditions” in steps S103 to S106 are not satisfied, the engine control unit 3 proceeds to step S107, and the oil level switch 10d is turned on. Wait until
If the oil level switch 10d is turned on, the time measurement is stopped in step S108, and the process proceeds to step S109. The oil level corresponding to the measurement time is acquired based on the time / level correspondence information I1. Specifically, if the measurement time corresponds to “˜a seconds”, the “Low” level is set. If the measurement time corresponds to “a + 1 to b seconds”, the “Low + α” level is set. If the measurement time corresponds to “b + 1 to c seconds”, “ If the “Mid” level corresponds to “c + 1 to d seconds”, the “Mid + α” level is acquired, and if it corresponds to “d + 1 seconds to”, the “Full” level is acquired.
In other words, the corresponding oil level (oil surface position) is estimated based on the measurement time, and the estimated oil level is obtained as a detection result.

  When the corresponding oil level is acquired in step S109, the engine control unit 3 stores the acquired oil level information in step S110. That is, in order to be able to present the detected oil level information to the driver, the oil level information is stored in a storage device that can be read by the engine control unit 3. Note that the storage device that stores information in step S110 may be either a nonvolatile storage device or a volatile storage device.

  When the oil level information is stored in step S110, the engine control unit 3 resets the time measurement value to 0 in step S111 and ends the processing shown in this figure.

  In the above, an example is given in which the time measurement until the oil level switch 10d is turned on by the time measurement start process in step S102 is immediately started according to the engine start. However, the time measurement start process in step S102 is For example, the determination processing in steps S103 to S106 may be performed (that is, in response to a negative result obtained in step S106). In this case, the reference time point for time measurement does not exactly coincide with the engine start time point, but the time until the oil level switch 10d is turned on is based on the time point when the engine is started. It is only necessary to start from a predetermined reference time, and it is not always necessary to exactly match the engine start time.

  In the above description, the oil temperature condition is cited as one of the “detection exclusion conditions” (S106). However, since the oil temperature and the water temperature have a correlation, the water temperature can be used instead of the oil temperature. At this time, in order to ensure detection accuracy of the oil level, the relationship between the water temperature and the oil temperature may be grasped, and the “constant range” corresponding to the water temperature may be set as the “constant range” in step S106.

  Furthermore, in the above description, it is assumed that the oil level is detected while the host vehicle is stopped. However, in the case of a hybrid vehicle, the engine may stop and start even during traveling. It is also conceivable to perform time measurement based on the engine start time in, and estimate the oil level based on the measurement time. During traveling, acceleration of the vehicle, front / rear and left / right acceleration may occur due to the occurrence of rolls during acceleration / deceleration of the vehicle, traveling on a curve, and the like, which may cause a decrease in detection accuracy. Therefore, it is effective to provide a detection exclusion condition determination process based on acceleration as in step S103.

<4. Another example of detection method>
In the above, an example in which the oil level is not detected when the “detection exclusion condition” is satisfied has been described. Hereinafter, as another example of the detection method, a method that enables oil level detection even in a case that satisfies the “detection exclusion condition” will be described.
Hereinafter, as an example, a method that enables oil level detection even when the oil temperature satisfies the “detection exclusion condition” will be described.

FIG. 6 shows an example of the time / level correspondence information I2 used in another example of the detection method.
As shown in the figure, the time / level correspondence information I2 includes the “Full”, “Mid + α”, “Mid”, “Low + α”, and “Low” levels to be obtained as detection results, and the time from when the engine is started until the oil level switch 10d is turned on. The correspondence with time information is defined as information defined for each oil temperature. Such time / level correspondence information I2 can be regarded as information prepared for each oil temperature with the time / level correspondence information I1 shown in FIG. In creating the time / level correspondence information I2, the correspondence between each level and time for each oil temperature is obtained in advance through experiments or the like.
FIG. 6 shows an example in which the correspondence between each level and time is defined every 20 ° C. In this case, the oil level at the oil temperature that is not defined in the time / level correspondence information I2 may be estimated using information defined in the time / level correspondence information I2. As an example, when detecting the oil level when the oil temperature not defined in the time / level correspondence information I2 = 15 ° C., the oil temperature defined in the time / level correspondence information I2 = The time information is corrected according to the temperature difference between 15 ° C. and 20 ° C., and the oil level information corresponding to the measurement time is acquired based on the corrected time information.
Of course, as the time / level correspondence information I2, information on correspondence between time and level may be prepared for each 1 ° C. of the oil temperature, and in that case, estimation from the definition information as described above is unnecessary. it can.

  In addition, it can be said that the time / level correspondence information I2 as described above is the following information. That is, the information represents the correspondence relationship between the oil level (oil level position) of the engine oil Eo with respect to the combination of the time from when the engine is started to when the oil level switch 10d is turned on and the oil temperature.

The flowchart in FIG. 7 shows a specific processing procedure to be executed in another example of the detection method. In FIG. 7, processes similar to those already described so far are denoted by the same step numbers and description thereof is omitted.
In this case, the process of step S106 is omitted, and the engine controller 3 detects the oil temperature detected by the oil temperature sensor 10e as the oil temperature acquisition process of step S201 in response to stopping the time measurement in step S108. Process to acquire the information of.
Then, in step S202, the engine control unit 3 acquires an oil level corresponding to the measurement time based on the time / level correspondence information I1 selected according to the oil temperature.

  Also in this case, after acquiring the oil level, the engine control unit 3 executes the oil level storing process in step S110, and then performs the time measurement value 0 reset process in step S111, and ends the oil level detection process.

  The same processing can be performed for the “detection exclusion condition” elements other than the oil temperature. Specifically, for each element of the engine stop time until the engine start, the engine speed at the time of engine start, and the acceleration, time / level correspondence information I1 is prepared for each element value in the same manner, When detecting the oil level, the time / level correspondence information I1 matching the value of the corresponding element is selected, and the oil level corresponding to the measurement time may be acquired based on the selected time / level correspondence information I1.

In addition, the oil level can be detected in consideration of all the factors of the engine stop time until the engine start, the engine speed at the time of engine start, the acceleration, and the oil temperature. In that case, for each combination of the values of these elements (that is, for each combination of engine stop time = xx seconds, engine speed = ΔΔ rpm, acceleration = OO m / s ² , oil temperature = □□ ° C. B), the correspondence between the oil level and the time from when the engine is started until the oil level switch 10d is turned on, and the oil level based on the measurement time using the time / level correspondence information that defines the correspondence May be estimated (detected).

Here, including the above “another example of the detection method”, the description so far has exemplified the case where table information is used as the “time / level correspondence information” used for estimating the oil level based on the measurement time. The estimation of the level can also be performed based on a function that represents the correspondence between the oil level and the time from the reference time point when the engine is started as a reference until the oil level switch is turned on.
By using the time / level correspondence information as such a function, the detected value of the oil level can be obtained as a linear value instead of a stepwise value such as “Full” to “Low”.

In the above-mentioned “another example of the detection method”, such functions include the engine stop time until the engine start exemplified as the “detection exclusion condition” element, the engine speed at the start of the engine, the acceleration, or the oil A function is prepared in consideration of at least one element of the temperature, in other words, at least one element among the elements that change the correspondence relationship between the oil level and the time until the oil level switch 10d is turned on. That is, for example, in the case of an oil temperature element, a function is prepared that represents the correspondence relationship between the oil level of the engine oil Eo and the combination of the time until the oil level switch 10d is turned on and the oil temperature. Specifically, it is a function that is generated so that the oil level is obtained using, for example, the time until the oil level switch 10d is turned on and the oil temperature as variables.
The function (and the table information exemplified as the time / level correspondence information I2) used in such “another example of the detection method” can be expressed as the following information. That is, the engine oil Eo with respect to a combination of the time from when the engine is started until the oil level switch 10d is turned on and at least one of the engine stop time until the engine is started, the engine speed at the time of starting the engine, the acceleration, or the oil temperature. This is information that shows the correspondence between oil levels.

<5. Summary of Embodiment>
As described above, the engine oil level detection device of the embodiment detects the oil level position of the engine oil in the oil storage tank (oil pan 101) that stores the engine oil (Eo) so as to be able to circulate with the engine. An engine oil level detection device, an oil level switch (10d) that is turned on in response to the oil level position reaching a predetermined level (level x), and a reference time point based on when the engine is started And an oil level estimation unit (engine control unit 3) for measuring the time from when the oil level switch is turned on to estimating the oil level position based on the measured time.

Thereby, it is not necessary to provide a plurality of oil level switches for multi-value detection of the engine oil oil level position.
Therefore, it is possible to reduce the cost of the engine oil level detection device that multi-detects the oil level of the engine oil in the oil storage tank.

Further, in the engine oil level detection device according to the embodiment, the oil level estimation unit includes time / oil level position correspondence information representing a correspondence relationship between the time from the reference time point until the oil level switch is turned on and the oil level position. The oil level position is estimated based on (time / level correspondence information I1 or I2).
By using the time / oil surface position correspondence information representing the correspondence between the time and the oil surface position as described above, it is possible to estimate the engine oil oil surface position relatively easily. Specifically, for example, if the table information as described above is used as the time / oil level position correspondence information, it is possible to eliminate the calculation process in estimating the oil level position. The oil level position can be easily estimated by substituting the measurement time into the function.
Therefore, it is possible to reduce the processing load required for detecting the oil level of the engine oil.

Further, in the engine oil level detection device according to the embodiment, the oil level estimation unit associates the oil level position information with each time assumed as the time from the reference time point until the oil level switch is turned on. The oil level position is estimated based on time / oil level position correspondence information as table information.
Thereby, the estimation of the engine oil oil level position is realized only by acquiring the oil level position information of the engine oil corresponding to the measurement time from the table information.
Therefore, it is possible to reduce the processing load required for detecting the oil level of the engine oil.

Further, in the engine oil level detection device of the embodiment, the oil level estimation unit acts on a vehicle provided with a stop time until the engine is started, an engine speed when the engine is started, and an oil storage tank. It is determined whether at least one of the acceleration and the temperature of the engine oil deviates from a predetermined assumed value, and if it deviates from the assumed value, the oil level position is not estimated. ing.
The engine stop time, the engine speed when the engine is started, the acceleration acting on the vehicle equipped with the oil storage tank, or the temperature of the engine oil is from the reference time until the oil level switch is turned on. This is a factor that changes the correspondence between the engine oil level and the engine oil level, and if these factors deviate from the expected values, the oil level position is not estimated, so the engine oil level can be detected. It is possible to prevent a decrease in accuracy.

Furthermore, in the engine oil level detection device according to the embodiment, the oil level estimation unit includes the time from the reference time until the oil level switch is turned on, the stop time until the engine is started, and the engine level when the engine is started. Based on the time and oil level position correspondence information indicating the correspondence relationship of the oil level position to the combination of at least one of the rotational speed, the acceleration acting on the vehicle provided with the oil storage tank, or the temperature of the engine oil The surface position is estimated.
As a result, the estimation of the engine oil oil level position based on the time from the reference time point until the oil level switch is turned on indicates the correspondence between the time from the reference time point until the oil level switch is turned on and the engine oil oil level position. It is done in a form that takes into account the changing elements.
Therefore, it is possible to improve the detection accuracy of the engine oil oil level position.

<6. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the specific examples described above, and various modifications can be considered.
For example, in the above, the case where the execution subject of the process according to the present invention is the engine control unit 3 is illustrated, but at least a part of the process according to the present invention is a control unit (ECU) other than the engine control unit 3 : The Electronic Control Unit) is not limited to the above example.

  Moreover, although the case where this invention was applied to the vehicle was illustrated above, this invention is widely applicable to objects, such as a vehicle mounted with an engine.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus, 3 ... Engine control part, 10b ... Engine speed sensor, 10d ... Oil level switch, 10e ... Oil temperature sensor, 10f ... Water temperature sensor, 101 ... Oil pan, Eo ... Engine oil, Seo ... Oil level

Claims (5)

An engine oil level detection device that detects an oil level position of the engine oil in an oil storage tank that circulates engine oil between the engine oil,
An oil level switch that is turned on in response to the oil level position reaching a predetermined level;
An oil level estimating unit that measures a time from a reference time point when the engine is started to a time when the oil level switch is turned on, and estimates the oil level position based on the measured time. Oil level detection device. The oil level estimator is
2. The engine oil level according to claim 1, wherein the oil level position is estimated based on time / oil level position correspondence information representing a correspondence relationship between a time from the reference time point until the oil level switch is turned on and the oil level position. Detection device. The oil level estimator is
The oil level based on the time-oil level position correspondence information as table information in which the information on the oil level position is associated with each time assumed as the time from the reference time point until the oil level switch is turned on. The engine oil level detection device according to claim 2, wherein the position is estimated. The oil level estimator is
At least one of a stop time until the start of the engine, an engine speed when the engine is started, an acceleration acting on a vehicle provided with the oil storage tank, and a temperature of the engine oil is preset. 4. The engine oil according to claim 1, wherein it is determined whether or not a predetermined assumed value is deviated, and the oil level position is not estimated when deviating from the assumed value. Level detection device. The oil level estimator is
It affects the time from the reference time until the oil level switch is turned on, the stop time until the engine starts, the rotational speed of the engine when the engine is started, and the vehicle provided with the oil reservoir. The oil level position is estimated based on the time / oil level position correspondence information representing a correspondence relationship of the oil level position to a combination of at least one of acceleration and / or the temperature of the engine oil. Item 4. The engine oil level detection device according to any one of Items 3 to 4.

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