JP2007231832A - Engine oil remaining quantity detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine oil remaining quantity detecting device capable of accurately measuring and indicating a remaining quantity of engine oil of a vehicle. <P>SOLUTION: The device detects the remaining quantity in an engine oil storage part by an oil level sensor 12 and obtains the remaining quantity by a microcomputer 4 on the basis of output from the oil level sensor 12. The obtained remaining quantity is indicated by a display device 13. In the microcomputer 4, if a door lock control system 14 detects the opening of a door of a vehicle after elapse of a prescribed period from stop of the engine, the previous remaining quantity of engine oil measured by the oil level sensor 12 is indicated by the display device 13 when the inclined angle of the vehicle is a prescribed angle or more, and when the inclined angle of the vehicle is smaller than the prescribed angle on the basis of a detection signal from vehicle inclination detecting means (the microcomputer 4, fuel sensor 8 and sensor signal input/output circuit 7), the remaining quantity of engine oil is detected by the oil level sensor 12 and indicated by the display device 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an engine oil remaining amount detecting device for detecting the remaining amount of engine oil (lubricating oil) of a vehicle.

In various types of vehicles such as automobiles and construction machinery vehicles, if engine oil is insufficient, the engine will be significantly damaged. For this reason, the oil level (oil remaining amount) of engine oil is detected and displayed according to the oil level remaining amount (for example, see Patent Document 1). As such an oil level sensor for detecting the oil level, for example, a float type sensor is known in the same manner as the fuel detection sensor for detecting the remaining amount of fuel.
Utility Model Registration No. 2515940

  By the way, in general, in order to accurately detect the level of engine oil (oil level, that is, the remaining amount of oil), it is necessary to stop the engine and return all oil to the oil tank or oil pan. This is because it takes a certain time for the engine oil to fall from the upper part of the engine and stabilize the oil level after the engine is stopped. Therefore, the accuracy of the oil level detected by the oil level sensor is considerably different before and after a certain time when the oil level is stabilized.

  On the other hand, even if a certain period of time has elapsed after the engine has stopped and the oil level has stabilized, if the vehicle stops or parks on a slope such as a slope, the position of the oil level of the engine oil relative to the oil level sensor shifts. The oil level cannot be detected accurately.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine oil remaining amount detection device that can accurately measure and display the remaining amount of engine oil in a vehicle.

  In order to achieve this object, the present invention detects the remaining amount of engine oil in the engine oil reservoir by means of an oil level sensor operated by a sensor power supply, and based on the output from the oil level sensor, An amount of remaining engine oil is obtained by a calculation control circuit and the calculated remaining amount of engine oil is displayed on a display means, wherein the calculation control circuit is configured so that a predetermined time elapses after the engine is stopped. When the door opening / closing detection means detects that the vehicle door is opened, based on the detection signal from the inclination detection means for detecting the inclination of the vehicle, it is determined whether or not the vehicle is inclined more than a predetermined angle, When the inclination angle of the vehicle is equal to or greater than a predetermined angle, the previous engine oil remaining amount measured by the oil level sensor is displayed. When the vehicle tilt angle is smaller than a predetermined angle, the sensor power supply is turned on and the remaining amount of engine oil is detected by the oil level sensor, and the detected remaining amount of engine oil is displayed on the display means. An engine oil remaining amount detecting device is provided.

  According to this configuration, even when the vehicle is parked or parked on a slope such as a slope or a parking lot where the vehicle is inclined, if the vehicle tilt angle is smaller than a predetermined value, the oil level sensor can accurately determine the remaining amount of engine oil. When the vehicle tilt angle is greater than or equal to a predetermined value, the remaining amount of engine oil of the vehicle can be displayed on the display means based on the previous measurement result. As a result, the remaining amount of engine oil in the vehicle can be accurately displayed regardless of the inclination angle of the vehicle.

  Moreover, according to this configuration, it is possible to determine that there is no person in the vehicle interior by determining whether the door is opened or closed, and it is possible to accurately measure the amount of oil without the vehicle being tilted or finely moved. In addition, the variation in the oil amount measurement due to the inclination of the vehicle is not displayed, and the troublesome judgment due to the change in the oil amount for each display can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Constitution]
In FIG. 1, reference numeral 1 denotes a control circuit for displaying an oil level mounted on a vehicle (not shown). The control circuit 1 has a power supply circuit 2, and the power supply circuit 2 has a battery terminal 2a and a battery terminal 2b. The battery terminal 2a is connected to the plus side of the battery B, the minus side of which is connected to the earth E via the wiring 3, and the earth terminal 2b is connected to the earth E.

  The control circuit 1 has a microcomputer (arithmetic control circuit) 4 operated by the power supply circuit 2, an oscillation circuit 5, a constant current circuit 6a of the oil remaining amount input circuit 6, and a sensor signal input / output circuit 7 for the fuel sensor. .

  The microcomputer 4 includes a storage device 4a and a timer 4b, and is controlled in operation based on a clock signal from the oscillation circuit 5. The storage device 4a has a ROM and a RAM (not shown). The ROM stores an oil remaining amount detection program (oil level detection program), and the RAM stores the detected oil remaining amount and fuel remaining amount. It has become.

  The oil remaining amount input circuit 6 has a sensor signal input / output circuit 6b operated by a constant current circuit 6a.

  Between the fuel terminal 8a connected to the input side of the sensor signal input / output circuit 7 and the fuel terminal 8b connected to the ground E, a float type fuel sensor 8 for detecting fuel in a fuel tank (not shown) is connected. Has been. The sensor signal input / output circuit 7 includes a delay filter (not shown), and outputs a fuel remaining amount signal (measurement signal) from the fuel sensor 8 via a delay filter (not shown) and inputs it to the microcomputer 4. It is like that.

  The microcomputer 4 drives and controls a stepping motor (not shown) that controls the rotation of the pointer 9a of the fuel gauge 9 based on the oil remaining amount signal from the fuel sensor 8 input through the delay filter. The remaining amount of fuel in the fuel tank (not shown) is indicated by the pointer 9a.

  Note that the measurement signal from the fuel sensor 8 fluctuates or greatly fluctuates in small increments due to vehicle running vibration or vibration associated with engine operation, etc., but this measurement signal is delayed by a delay filter (not shown) and transmitted to the pointer 9a. Therefore, the pointer 9a instructs the remaining amount of fuel in a stable state without small fluctuations or large fluctuations. Since a well-known technique can be adopted for such a fuel sensor 8 and a delay filter, the detailed description of the configuration is omitted.

  A key cylinder (not shown) of the vehicle is provided with a lock position “LOCK”, an accessory switch ON position “ACC”, an ignition switch ON position “IGN”, a start position “START”, and the like. Switching to these positions is performed by an ignition key (not shown). Since these structures are also well-known techniques, a detailed description of the structure is omitted.

  When the ignition key (not shown) is moved from the accessory switch position to the lock position “LOCK” and the accessory switch (not shown) is turned off, the main power supply of the power supply circuit 2 is turned off. It is supposed to be. In the state where the main power supply of the power supply circuit 2 is turned off, dark current is supplied from the power supply circuit 2 to the microcomputer 4 so that the stored contents stored in the storage device 4a are not erased.

  An ignition switch 10 of a key cylinder (not shown) is connected to the wiring 3 to the input terminal 11 a of the IGN signal input circuit 11. The IGN signal input circuit 11 outputs an ON / OFF signal of the ignition switch 10 and inputs it to the microcomputer 4.

  Further, a float type oil level sensor 12 for detecting the remaining amount of engine oil is disposed in an engine oil pan (engine oil reservoir) (not shown). The oil level sensor 12 is connected to the input side of the sensor signal input / output circuit 6b through a plus terminal 12a, and is connected to the ground E through a minus terminal 12b. This sensor signal input / output circuit 6b is operated by the constant current circuit 6a when the constant current circuit 6a is operating, and the oil remaining amount signal (measurement signal) output from the oil level sensor 12 is operated. Is input to the microcomputer 4. The microcomputer 4 displays the remaining amount of oil (oil level) on a display device (display means) 13 such as a liquid crystal display (LCD) based on the oil remaining amount signal output from the oil level sensor 12. ing.

  The vehicle (not shown) is provided with a door lock control system 14 using CAN [Controller Area Network]. The door opening / closing signal from the door lock control system 14 is input to the microcomputer 4.

The microcomputer 4 is connected to an EEPROM (memory) 15 which is a storage means. The EEPROM 15 stores data for turning on the constant current circuit 6a by the microcomputer 4 a predetermined time after the ignition switch 10 is turned off (engine is stopped). Further, the microcomputer 4 operates the timer 4b when the ignition switch 10 is turned off, and measures the time from when the ignition switch 10 is turned off by the timer 4b.
[Action]
Next, control by the microcomputer 4 of the engine oil remaining amount detection device having the above configuration will be described with reference to the flowchart of FIG.

When the ignition switch 10 is turned on and an engine (not shown) is operated, a fuel remaining amount signal from the fuel sensor 8 is input to the microcomputer 4 via the sensor signal input / output circuit 7. Then, the microcomputer 4 controls the stepping motor (rotating control of the pointer 9a of the fuel gauge 9 based on the oil remaining amount signal from the fuel sensor 8 inputted through a delay filter (not shown) of the sensor signal input / output circuit 7). (Not shown) is driven and the remaining amount of fuel in the fuel tank (not shown) is indicated by the pointer 9a.
Step S1
When the ignition switch 10 is turned off from this state to stop the engine (not shown), the microcomputer 4 detects the oil level sensor in the flowchart of FIG. 2 based on the oil remaining amount detection program in the ROM (not shown) of the storage device 4a. 12 (oil remaining amount detection control) is started, and it is determined in step S1 whether or not the previous measured value of the remaining amount of oil is unconfirmed.

In step S1, if the previous measured value of the remaining amount of oil is not determined, the process proceeds to step S8 with YES, and if the previous measured value of the remaining amount of oil is stored in the RAM of the storage device 4a. If NO, the process proceeds to step S2.
Step S2
In this step S2, the ON / OFF state (IGN state) of the ignition switch (IGN switch) 10 is determined, and if it is ON, it is ended, and if it is OFF, the timer 4b is activated to execute step S3. Migrate to
Step S3
In step S3, it is determined whether or not the ignition switch 10 is turned off for the first time. If it is the first time, the process proceeds to step S4. If not, the process proceeds to step S5.
Step S4
In step S4, the microcomputer 4 inputs the fuel remaining amount signal from the fuel sensor 8 through a delay filter (not shown) of the sensor signal input / output circuit 7, measures the remaining amount of fuel, and determines the measured remaining fuel amount. The first fuel remaining amount data immediately after the vehicle stops is stored in the RAM of the storage device 4a, and the process proceeds to step S5.
Step S5
In this step S5, it is determined from the time measured by the timer 4b whether or not a predetermined time (for example, 5 minutes) has elapsed since the ignition switch 10 was turned off. If the predetermined time has not elapsed, NO is determined. If the predetermined time has elapsed, the process proceeds to step S6 with YES.
Step S6
In this step S6, DR open detection (door open detection), that is, whether the door (DR) of the vehicle (not shown) is detected based on a signal from the door lock control system 14 (opened). Whether or not) is determined. If it is not detected that the door is opened, the process proceeds to step S14 with NO, and if it is detected that the door is opened, the process proceeds to step S7 with YES.
Step S7
In this step S7, it is determined whether or not the measurement of the remaining amount of oil has been carried out after detecting the DR open. If the remaining amount of oil has been measured, the process ends with YES and the remaining amount of oil has not been measured. If NO, the process proceeds to step S8.
Step S8
In step S8, the constant current circuit 6a is turned on to operate the sensor signal input / output circuit 6b, and the process proceeds to step S9.
Step S9
In step S9, an oil level measurement process is executed, and the process proceeds to step S10. That is, in this step S9, when the oil level signal from the oil level sensor 12 is inputted via the sensor signal input / output circuit 6b, the microcomputer 4 measures the engine oil level from the oil level signal, The measurement data of the remaining amount of oil is stored in the RAM of the storage device 4a, and the process proceeds to step S10.
Step S10
In step S10, the constant current circuit 6a is turned off, the sensor signal input / output circuit 6b is turned off, and the process proceeds to step S11.
Step S11
In this step S11, the remaining fuel signal from the fuel sensor 8 is inputted through a delay filter (not shown) of the sensor signal input / output circuit 7, the remaining fuel is measured, and the measured remaining fuel is measured after the vehicle is stopped. The second fuel remaining amount data after elapse of a predetermined time is stored in the RAM of the storage device 4a, and the process proceeds to step S12.
Step S12
In this step S12, the first fuel remaining amount data immediately after the vehicle stop measured in step S4 is compared with the second fuel remaining amount data after a predetermined time has elapsed since the vehicle stop measured in step S11. If the difference in the second fuel data is less than + −1 liter, it is determined that the vehicle is stopped on a flat ground, and the process proceeds to step S13. If the difference between the first and second fuel data is greater than or equal to + −1 liter and less than + −10 liter, it is determined that the vehicle has stopped on the slope and the remaining oil amount detection process is terminated.

  In addition, it can be judged from the following reasons whether the vehicle is stopped on a flat ground or an inclined ground. That is, while the vehicle is running, the fuel remaining amount signal from the fuel sensor 8 is input to the microcomputer 4 via the sensor signal input / output circuit 7, but the fuel level in the fuel tank (not shown) , The fuel remaining signal output from the fuel sensor 8 fluctuates or increases in small increments because of the centrifugal force when turning the curve, the inertial force at the time of stopping or starting the vehicle, etc. Or fluctuate.

  When the stepping motor (not shown) of the fuel gauge 9 is directly controlled by the fluctuating fuel remaining amount signal and the remaining amount of fuel is indicated by the pointer 9a driven by the stepping motor, the pointer 9a fluctuates little or greatly. Or the remaining amount of fuel is unknown.

  However, the fluctuating fuel remaining amount signal from the fuel sensor 8 is delayed through a delay filter (not shown) of the sensor signal input / output circuit 7 and input to the microcomputer 4 so that the microcomputer 4 can delay the fuel remaining amount. The driving of the stepping motor is controlled based on the signal, and the remaining amount of fuel is indicated by the pointer 9a that is rotationally driven by the stepping motor. At this time, the turning operation of the pointer 9a by the stepping motor is delayed by a delay filter so that it takes about 25 minutes to move 3/4 of the full scale in the turning direction. As a result, even if a fluctuating fuel remaining amount signal is output from the fuel sensor 8, the fuel remaining amount can be surely known by the fuel gauge 9.

  In general, the vehicle often travels on flat ground, and during traveling, the microcomputer 4 often measures the remaining amount of fuel while traveling on the flat ground. As a result, it is normal for the microcomputer 4 to instruct the remaining fuel amount measured on a flat ground during traveling with the pointer 9 a of the fuel gauge 9.

  As a result, when the vehicle stops in most cases, the microcomputer 4 detects the remaining amount of fuel measured when traveling on a flat ground.

  Therefore, even when the stop state of the vehicle of FIG. 3A is flat or substantially flat, or even when the stop state of the vehicle of FIG. It is normal to indicate the remaining amount of fuel.

  And the fuel instruction | indication (fuel instruction | indication at the time of oil measurement) by the pointer | guide 9a when predetermined time (for example, 5 minutes) has passed since the time of a stop will be changed like A and B of FIG. By detecting this change, it is possible to determine whether or not the vehicle is stopped on a flat ground or an inclined ground having a predetermined angle or more (for example, a slope inclined more than a predetermined angle).

In addition, as shown in FIG. 3C, when the fuel instruction at the time of stopping the oil is + −10 liters or more, it can be determined that the fuel is supplied, and in the case of refueling, the vehicle stops on the flat area of the filling station. Oil measurement is performed.
Step S13
In step S13, the microcomputer 4 executes an oil level display determination process and ends. That is, the microcomputer 4 displays the remaining amount of oil on the display device 13 based on the measurement data of the remaining amount of oil measured in step S9 and stored in the RAM of the storage device 4a, and the process ends. In the oil level display determination process, the process is terminated when the vehicle is stopped on an inclined ground having a predetermined angle or more. However, in actuality, the remaining amount of oil based on the previous measurement is displayed on the display device 13 by the end of this processing.
Step S14
In step S14, DR open detection (door open detection), that is, whether the door (DR) of the vehicle (not shown) has been opened based on a signal from the door lock control system 14 (opened). Whether or not) is judged again. If it is not detected that the door has been opened, the process ends with NO. If it is detected that the door has been opened, the process proceeds to YES in step S7.

  As described above, the engine oil remaining amount detection device according to the embodiment of the present invention detects the remaining amount of engine oil in the engine oil reservoir by the oil level sensor 12 operated by the sensor power supply (constant current circuit 6a). Then, based on the output from the oil level sensor 12, the remaining amount of the engine oil is obtained by the arithmetic control circuit (microcomputer 4), and the obtained remaining amount of engine oil is displayed on the display means (display device 13). I am doing so. In addition, the arithmetic control circuit (microcomputer 4) detects the inclination of the vehicle when the door open / close detection means (door lock control system 14) detects that the vehicle door has been opened after a lapse of a predetermined time from the stop of the engine. Based on the detection signals from the inclination detection means (the microcomputer 4, the fuel sensor 8, and the sensor signal input / output circuit 7) to detect, it is determined whether or not the vehicle is inclined more than a predetermined angle, and the inclination angle of the vehicle is predetermined. If the angle is equal to or greater than the angle, the previous engine oil level measured by the oil level sensor 12 is displayed on the display means (display device 13). The current circuit 6a) is turned on, the remaining amount of engine oil is detected by the oil level sensor 12, and the detected remaining amount of engine oil is displayed on the display means (table And it is adapted to display on the device 13).

  According to this configuration, even if the vehicle is parked or parked on a slope such as a slope or a parking lot that is inclined, if the vehicle tilt angle is smaller than a predetermined value, the oil level sensor 12 can reduce the remaining amount of engine oil. Accurately measured and displayed on the display means, and when the vehicle inclination angle is greater than or equal to a predetermined value, the remaining amount of engine oil of the vehicle can be displayed on the display means based on the previous measurement result. As a result, the remaining amount of engine oil in the vehicle can be accurately displayed regardless of the inclination angle of the vehicle.

  Moreover, according to this configuration, it is possible to determine that there is no person in the vehicle interior by determining whether the door is opened or closed, and it is possible to accurately measure the amount of oil without the vehicle being tilted or finely moved. In addition, the variation in the oil amount measurement due to the inclination of the vehicle is not represented, and the troublesome judgment due to the change in the oil amount for each display can be prevented.

  In the embodiment described above, the door lock control system 14 using CAN [Controller Area Network] is used as the door opening / closing detection means. However, the present invention is not necessarily limited to this. For example, a micro switch that directly detects the opening / closing of the door may be used as the door opening / closing detection means, a door lock detection switch that detects whether the door lock device is locked or unlocked may be used as the door opening / closing detection means, and the door opening of the immobilizer may be opened. The transmission means for transmitting a signal may be a door opening / closing detection means.

  In the embodiment described above, the fuel sensor 8 is used as a part of the inclination detection means to detect the inclination of the vehicle when the vehicle is stopped. However, the present invention is not necessarily limited to this. For example, when the vehicle has an inclinometer used for correction of the remaining fuel amount detection, the inclinometer may be used as the inclination detecting means.

It is a block diagram of the engine oil residual amount detection apparatus which concerns on this invention. 3 is a flowchart for explaining engine oil detection by the microcomputer of FIG. 1; It is explanatory drawing of vehicle stop conditions and engine oil measurement availability.

Explanation of symbols

4 ... Microcomputer (arithmetic control circuit, part of tilt detection means)
6a ... Constant current circuit (sensor power supply)
7. Sensor signal input / output circuit (part of tilt detection means)
8 ... Fuel sensor (part of tilt detection means)
13. Display device (display means)
12 ... Oil level sensor 14 ... Door lock control system (door open / close detection means)

Claims (1)

An arithmetic control circuit that detects the remaining amount of engine oil in the engine oil reservoir detected by the oil level sensor when the vehicle is stopped and detects the remaining amount of engine oil based on the output from the oil level sensor The engine oil remaining amount detection device is configured to display the obtained engine oil remaining amount on the display means,
When the door opening / closing detection means detects that the door of the vehicle has been opened after a lapse of a predetermined time from the stop of the engine, the arithmetic control circuit is based on a detection signal from the inclination detection means for detecting the inclination of the vehicle, It is determined whether or not the vehicle is inclined at a predetermined angle or more, and when the vehicle inclination angle is equal to or larger than a predetermined angle, the last remaining amount of engine oil measured by the oil level sensor is displayed on the display means, When the vehicle inclination angle is smaller than a predetermined angle, the sensor power supply is turned on, the remaining amount of engine oil is detected by the oil level sensor, and the detected remaining amount of engine oil is displayed on the display means. An engine oil remaining amount detection device.

Images