JP2014227942A - Engine oil level detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely determine whether or not an oil level in an oil pan is proper.SOLUTION: An oil level detection device comprises: an ultrasonic oil level sensor SW9; a calculation part 10a for calculating an average value of an oil level in an oil pan 13 on the basis of a detection value of the oil level sensor SW9; a determination part 10c for determining whether or not the oil level average value calculated by the calculation part 10a is not less than a predetermined upper limit or not more than a predetermined lower limit; and a lateral G-sensor SW13. The calculation part 10a has an extraction part 10d for making influences of the detection value of the oil level sensor SW9 detected for at least 7 seconds from when the detection value of the lateral G-sensor SW13 becomes less than 0.2 G after it exceeds 0.2 G onto calculation of the oil level average value smaller than those when the detection value of the lateral G-sensor SW13 is less than 0.2 G.

Description

  The present invention relates to an engine oil level detection device that detects an oil level stored in an oil pan of an engine mounted on a vehicle.

  An oil level detection device for an engine that detects an oil level stored in an oil pan of an engine mounted on a vehicle is known as a conventional technique.

  For example, the lubricating oil amount detection device disclosed in Patent Document 1 includes an oil amount detection sensor that outputs an electrical signal corresponding to the lubricating oil amount in an engine oil pan, and a pulsation component included in an output signal from the oil amount detection sensor. An averaging circuit that averages the engine speed, a rotation speed sensor that detects the engine rotation speed, a reference value setting circuit that sets a reference value for the amount of oil in the oil pan, a vehicle body inclination sensor that detects the inclination of the vehicle body, and the vehicle body Corrects the oil level fluctuation error due to the tilt of the vehicle body according to the output from the tilt sensor and corrects either the output of the averaging circuit or the reference value according to the output from the rotation speed sensor, then averaging And a determination circuit for determining whether or not the output of the circuit is equal to or lower than a reference value. According to this configuration, a relatively stable and accurate value can be obtained without measuring the oil level with large fluctuations, and malfunction also occurs when the oil level decreases due to the high-speed rotation of the engine or the inclination of the vehicle body. This can be reliably detected when the oil drops below a predetermined amount.

Japanese Utility Model Publication No. 4-24088

  By the way, there is an oil level sensor provided in the oil pan other than the oil amount detection sensor for detecting the oil level in the oil pan. As the oil level sensor, an opening through which oil in and out of the oil pan is formed is formed. An oil storage portion that stores oil flowing in from the opening, and an oil storage portion that is provided in the oil storage portion and has an oil level in the oil storage portion. Some have damping means that suppresses fluctuations, and a detection unit that detects the oil level in the oil pan by detecting the oil level in the oil storage unit using, for example, ultrasonic waves.

  However, the oil level sensor cannot detect the oil level with high accuracy because the oil level in the oil container fluctuates when the vehicle turns or accelerates / decelerates. Therefore, is the oil level appropriate? There is a problem that it cannot be determined accurately.

  The present invention has been made in view of such a point, and the problem is to accurately determine whether the oil level in the oil pan is an appropriate level.

  In order to solve the above-described problems, the present invention provides an oil level sensor that is detected during at least a predetermined period from when the acceleration sensor detection value becomes equal to or greater than a predetermined value. The influence of the detection value on the calculation of the average value of the oil level is made smaller than when the detection value of the acceleration sensor is less than a predetermined value.

  Specifically, the present invention is directed to an engine oil level detection device that detects an oil level stored in an oil pan of an engine mounted on a vehicle, and has taken the following solution.

  That is, the first invention is provided in the oil pan, an opening through which the oil in the oil pan can flow in and out is formed, and an oil storage portion that stores oil flowing in from the opening; Damping means that is provided in the oil container and suppresses fluctuations in the oil level in the oil container, and a detector that detects the oil level in the oil pan by detecting the oil level in the oil container. An oil level sensor; a calculating means for calculating an average value of the oil level in the oil pan based on a detection value of the oil level sensor; and an average value of the oil level calculated by the calculating means is a predetermined upper limit. Determining means for determining whether or not the value is greater than or equal to a predetermined lower limit value and an acceleration sensor for detecting the acceleration of the vehicle When the detected value of the acceleration sensor becomes equal to or greater than a predetermined value, the calculating means includes the oil level sensor detected for at least a predetermined period from when it becomes less than the predetermined value again. The present invention is characterized in that there is an influence suppression means for making the influence of the detected value on the calculation of the average value of the oil level smaller than when the detected value of the acceleration sensor is less than the predetermined value.

  According to this, when the detection value of the acceleration sensor becomes equal to or greater than the predetermined value, the influence suppression means detects the oil level detected between the time when the value is again less than the predetermined value and the oil level is substantially stabilized. Since the influence of the detection value of the sensor on the calculation of the average value of the oil level is made smaller than when the detection value of the acceleration sensor is less than a predetermined value, the oil level in the oil pan can be detected with high accuracy. For this reason, it is possible to accurately determine whether the oil level in the oil pan is an appropriate level.

  According to a second invention, in the first invention, the influence suppression means has an extraction means for extracting a value other than the one detected during the predetermined period from the detection value of the oil level sensor. The calculating means is configured to calculate an average value of the oil level based on the detection value of the oil level sensor extracted by the extracting means.

  According to this, when the state in which the detection value of the acceleration sensor is equal to or higher than the predetermined value from the detection value of the oil level sensor continues for a predetermined time or longer, the extraction means again falls below the predetermined value for a predetermined period. Extract anything other than those detected during In other words, when the detection value of the acceleration sensor becomes equal to or higher than the predetermined value, the extracting means detects the detection value of the oil level sensor that is detected from when the acceleration level again becomes less than the predetermined value until the oil level is almost stabilized. Do not extract. For this reason, the oil level in the oil pan can be detected with high accuracy. Therefore, it can be accurately determined whether the oil level in the oil pan is an appropriate level.

  In a third aspect based on the second aspect, the predetermined period is longer as the time from when the detected value of the acceleration sensor becomes equal to or higher than the predetermined value until it becomes lower than the predetermined value again is longer. It is characterized by being set.

  According to this, the predetermined period is set to be longer as the time from when the detected value of the acceleration sensor becomes equal to or greater than the predetermined value until it becomes less than the predetermined value again. That is, the predetermined period is set according to the turning time and acceleration / deceleration time of the vehicle. For this reason, the oil level in the oil pan can be detected with higher accuracy. Therefore, it can be determined more accurately whether the oil level in the oil pan is an appropriate level.

  According to a fourth invention, in any one of the first to third inventions, the influence suppression means is a state in which the detected value of the acceleration sensor is equal to or higher than the predetermined value from the detected value of the oil level sensor. Has an extraction means for extracting other than those detected during a second predetermined period longer than the predetermined period from when it has again become less than the predetermined value when it continues for a predetermined time, The calculating means is configured to calculate an average value of the oil level based on the detection value of the oil level sensor extracted by the extracting means.

  According to this, when the state in which the detection value of the acceleration sensor is equal to or higher than the predetermined value from the detection value of the oil level sensor continues for a predetermined time or longer, the extraction means again falls below the predetermined value for a predetermined period. Those other than those detected during the second predetermined period longer than the second predetermined period are extracted. In other words, the extraction means detects when the oil sensor in the oil level sensor has been in a state where the detected value of the acceleration sensor has exceeded the predetermined value for a predetermined time or longer and the oil level sensor is less than the predetermined value. Will not flow out again into the oil level sensor and will not be extracted until the oil level is almost stabilized. For this reason, the oil level in the oil pan can be detected with high accuracy. Therefore, it can be accurately determined whether the oil level in the oil pan is an appropriate level.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the oil pump further includes an oil pump that supplies the oil stored in the oil pan to the lubricating portion of the engine. The extraction is performed when the oil supply pressure by the oil pump is a predetermined pressure or less, or when the oil supply amount by the oil pump is a predetermined amount or less. Is.

  According to this, the extraction means extracts the detection value of the oil level sensor when the oil supply pressure by the oil pump is less than a predetermined pressure or when the oil supply amount by the oil pump is less than a predetermined amount. Do. That is, the extraction means performs the extraction when the oil level fluctuation is relatively small. For this reason, the oil level in the oil pan can be detected with high accuracy. Therefore, it can be accurately determined whether the oil level in the oil pan is an appropriate level.

  According to the present invention, when the detected value of the acceleration sensor becomes equal to or higher than the predetermined value, the influence suppression means detects the oil detected between the time when it becomes less than the predetermined value again and the time when the oil level is almost stabilized. Since the detection value of the level sensor has less influence on the calculation of the average value of the oil level than when the detection value of the acceleration sensor is less than the predetermined value, the oil level in the oil pan can be detected with high accuracy. It is possible to accurately determine whether the oil level in the oil pan is an appropriate level.

It is a figure showing a schematic structure of an engine concerning an embodiment of the present invention. It is a block diagram which shows an oil level detection apparatus. It is a fragmentary sectional view which shows a mode that the oil level sensor was provided in the oil pan. It is a longitudinal cross-sectional view which shows schematic structure of an oil level sensor. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. It is a flowchart which shows the oil level determination procedure by the side of the X level of an electronic control unit. It is a flowchart which shows the oil level determination procedure by the side of the L level of an electronic control unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its use.

  FIG. 1 shows a schematic configuration of an engine (engine body) 1 according to the embodiment. The engine 1 is a diesel engine that is mounted horizontally at the front of a vehicle and is supplied with fuel mainly composed of light oil, and a cylinder block provided with a plurality of cylinders 11a (only one is shown). 11, a cylinder head 12 disposed on the cylinder block 11, and an oil pan 13 disposed below the cylinder block 11 and storing lubricating oil (hereinafter referred to as oil). . In each cylinder 11a of the engine 1, a piston 14 is fitted and removably fitted. A top surface of the piston 14 is formed with a cavity defining a reentrant combustion chamber 14a. The piston 14 is connected to the crankshaft 15 via a connecting rod 14b.

  The cylinder head 12 is provided with an injector 18 (fuel injection valve) that injects fuel and a glow plug 19 that warms intake air and improves fuel ignitability when the engine 1 is cold. The injector 18 is disposed such that its fuel injection port faces the combustion chamber 14a from the ceiling surface of the combustion chamber 14a. Basically, fuel is directly supplied to the combustion chamber 14a near the top dead center of the compression stroke. The injection is supplied. This injector 18 constitutes a combustion injection valve.

  An intake passage 30 is connected to one side of the engine 1 so as to communicate with the intake port 16 of each cylinder 11a. On the other hand, an exhaust passage 40 for discharging burned gas (exhaust gas) from the combustion chamber 14a of each cylinder 11a is connected to the other side of the engine 1. In the intake passage 30 and the exhaust passage 40, as will be described in detail later, a large turbocharger 61 and a small turbocharger 62 for supercharging intake air are disposed.

  An air cleaner 31 that filters intake air is disposed at the upstream end of the intake passage 30. On the other hand, a surge tank 33 is disposed near the downstream end of the intake passage 30. The intake passage 30 downstream of the surge tank 33 is an independent passage branched for each cylinder 11a, and the downstream end of each independent passage is connected to the intake port 16 of each cylinder 11a.

  Between the air cleaner 31 and the surge tank 33 in the intake passage 30, compressors 61a and 62a of the large and small turbochargers 61 and 62, and an intercooler 35 for cooling the air compressed by the compressors 61a and 62a, A throttle valve 36 for adjusting the amount of intake air into the combustion chamber 14a of each cylinder 11a is provided. The throttle valve 36 is basically fully opened, but is fully closed to prevent shock when the engine is stopped.

  The upstream portion of the exhaust passage 40 is constituted by an exhaust manifold having an independent passage branched for each cylinder 11a and connected to the outer end of the exhaust port 17 and a collecting portion where the independent passages gather. Yes.

  On the downstream side of the exhaust manifold in the exhaust passage 40, the turbine 62b of the small turbocharger 62, the turbine 61b of the large turbocharger 61, and exhaust for purifying harmful components in the exhaust gas in order from the upstream side. A purification device 41 and a silencer 42 are provided.

The exhaust purification device 41 includes an oxidation catalyst 41a and a DPF 41b, which are arranged in this order from the upstream side. The oxidation catalyst 41a and the DPF 41b are accommodated in one case. The oxidation catalyst 41a has an oxidation catalyst supporting platinum or platinum added with palladium or the like, and promotes a reaction in which CO and HC in the exhaust gas are oxidized to produce CO ₂ and H ₂ O. Is. The oxidation catalyst 41a constitutes a catalyst having an oxidation function. The DPF 41b collects PM such as soot contained in the exhaust gas of the engine 1 and is formed of a heat-resistant ceramic material such as silicon carbide (SiC) or cordierite. It is a three-dimensional mesh filter formed of a flow type filter or a heat resistant ceramic fiber. The DPF 41b may be coated with an oxidation catalyst.

  A portion of the intake passage 30 between the surge tank 33 and the throttle valve 36 (that is, a portion downstream of the small compressor 62a of the small turbocharger 62), the exhaust manifold and the small turbocharger in the exhaust passage 40. A portion between the small turbine 62b of the feeder 62 (that is, a portion upstream of the small turbine 62b of the small turbocharger 62) is an EGR passage 51 for returning a part of the exhaust gas to the intake passage 30. Connected by. The EGR passage 51 is provided with an EGR valve 51a for adjusting the recirculation amount of the exhaust gas to the intake passage 30 and an EGR cooler 52 for cooling the exhaust gas with engine coolant.

  The large turbocharger 61 has a large compressor 61 a disposed in the intake passage 30 and a large turbine 61 b disposed in the exhaust passage 40. The large compressor 61 a is disposed between the air cleaner 31 and the intercooler 35 in the intake passage 30. On the other hand, the large turbine 61b is disposed between the exhaust manifold and the oxidation catalyst 41a in the exhaust passage 40.

  The small turbocharger 62 has a small compressor 62 a disposed in the intake passage 30 and a small turbine 62 b disposed in the exhaust passage 40. The small compressor 62 a is disposed on the downstream side of the large compressor 61 a in the intake passage 30. On the other hand, the small turbine 62 b is disposed on the upstream side of the large turbine 61 b in the exhaust passage 40.

  That is, in the intake passage 30, a large compressor 61a and a small compressor 62a are arranged in series from the upstream side, and in the exhaust passage 40, a small turbine 62b and a large turbine 61b are arranged in series from the upstream side. Has been. The large and small turbines 61b and 62b are rotated by the exhaust gas flow, and the large and small compressors 61a and 62a connected to the large and small turbines 61b and 62b are rotated by the rotation of the large and small turbines 61b and 62b, respectively. Each operates.

  The small turbocharger 62 is relatively small, and the large turbocharger 61 is relatively large. That is, the large turbine 61 b of the large turbocharger 61 has a larger inertia than the small turbine 62 b of the small turbocharger 62.

  The intake passage 30 is connected to a small intake bypass passage 63 that bypasses the small compressor 62a. The small intake bypass passage 63 is provided with a small intake bypass valve 63 a for adjusting the amount of air flowing to the small intake bypass passage 63. The small intake bypass valve 63a is configured to be in a fully closed state (normally closed) when no power is supplied.

  On the other hand, the exhaust passage 40 is connected to a small exhaust bypass passage 64 that bypasses the small turbine 62b and a large exhaust bypass passage 65 that bypasses the large turbine 61b. The small exhaust bypass passage 64 is provided with a regulating valve 64a for adjusting the exhaust amount flowing to the small exhaust bypass passage 64, and the large exhaust bypass passage 65 has an exhaust amount flowing to the large exhaust bypass passage 65. A wastegate valve 65a for adjusting the pressure is provided. Both the regulating valve 64a and the waste gate valve 65a are configured to be in a fully open state (normally open) when no power is supplied.

  The diesel engine 1 configured as described above is controlled by an electronic control unit (hereinafter referred to as ECU) 10. The ECU 10 is composed of a microprocessor having a CPU, a memory, a counter timer group, an interface, and a path connecting these units. As shown in FIG. 2, the ECU 10 includes a water temperature sensor SW1 that detects the temperature of engine cooling water, a supercharging pressure sensor SW2 that is attached to the surge tank 33 and detects the pressure of air supplied to the combustion chamber 14a, An intake air temperature sensor SW3 that detects the temperature of the intake air, a crank angle sensor SW4 that detects the rotation angle of the crankshaft 15, and an accelerator opening sensor that detects an accelerator opening corresponding to an operation amount of an accelerator pedal (not shown) of the vehicle. SW5, upstream exhaust pressure sensor SW6 that detects the exhaust pressure upstream of the DPF 41b, downstream exhaust pressure sensor SW7 that detects the exhaust pressure downstream of the DPF 41b, and catalyst temperature for detecting the temperature of the oxidation catalyst 41a The detection signals of the sensor SW8 are input, and various operations are performed based on these detection signals, whereby the engine 1 and the vehicle Determine the state, the injector 18 in response to this, the glow plugs 19, VVM71 of the valve operating system, various valves 36,51a, 63a, 64a, and outputs a control signal to 65a actuator.

  Thus, the engine 1 is configured to have a relatively low compression ratio with a geometric compression ratio of 12 or more and 15 or less, thereby improving exhaust emission performance and thermal efficiency. I am doing so. On the other hand, in the engine 1, torque is increased by the large and small turbochargers 61 and 62 described above to compensate for a low compression ratio of the geometric compression ratio.

  The ECU 10 determines the target torque (target load) mainly based on the engine speed and the accelerator opening as the basic control of the engine 1, and compresses the top dead center so as to generate this target torque. Fuel injection (main injection) by the injector 18 is executed in the vicinity. However, when the engine 1 is in a decelerating state, the ECU 10 stops (prohibits) main fuel injection near the compression top dead center by executing fuel cut control.

  Further, when the DPF regeneration condition is satisfied, the ECU 10 executes post injection that does not contribute to combustion (no torque is generated) by the injector 18 in the expansion stroke of the cylinder 11a in order to regenerate the DPF 41b. The post-injected fuel is supplied to the oxidation catalyst 41a together with the exhaust gas to cause an oxidation reaction. The exhaust gas supplied to the DPF 41b is heated by the oxidation reaction heat generated at this time, and the DPF 41b is heated by the heated exhaust gas. The PM deposited on is burned and removed (DPF 41b is regenerated).

  Here, the DPF regeneration condition is a predetermined condition that can determine that the regeneration of the DPF 41b is necessary. In the present embodiment, the PM accumulation amount of the DPF 41b is evaluated (estimated) by the differential pressure ΔP between the upstream exhaust pressure and the downstream exhaust pressure of the DPF 41b, and when the differential pressure ΔP becomes a predetermined value X or more, The regeneration condition of the DPF 41b is established. This DPF regeneration ends when the differential pressure ΔP falls below a predetermined lower limit value Y (<X) that is smaller than a predetermined value X as a regeneration condition. Therefore, when the PM accumulation amount M of the DPF 41b is equal to or greater than the predetermined value X and the DPF regeneration control is started, the DPF regeneration condition is satisfied as long as the PM accumulation amount is less than the predetermined value X, as long as the PM accumulation amount is not less than the lower limit value Y. The control is continued assuming that is established.

  Next, an oil level detection device for the engine 1 that detects the oil level (oil level height) stored in the oil pan 13 of the engine 1 will be described.

  In the oil pan 13, an ultrasonic oil level sensor (hereinafter simply referred to as an oil level sensor) SW9 (not shown in FIG. 1) and an oil pump 72 (only shown in FIG. 2) are provided. The oil level sensor SW9 detects the oil level in the oil pan 13 by detecting the oil level in the detection tube 86 described later with ultrasonic waves. This detection is performed every second, for example.

  As shown in FIG. 3, the oil level sensor SW <b> 9 is arranged in the vehicle front-rear direction center portion in the oil pan 13 and closer to one side of the vehicle lateral direction (left-right direction). As shown in FIGS. 3 to 5, the oil level sensor SW <b> 9 includes an oil storage portion 81 and a base portion 82.

  The oil storage part 81 stores oil that flows in from a first oil opening 83a described later. The oil storage unit 81 includes a first labyrinth chamber partition 83, a second labyrinth chamber partition 84, a transmitter / receiver storage 85, a detection tube 86, and an air vent tube 87.

  The first labyrinth chamber partition 83 and the second labyrinth chamber partition 84 are formed in a covered cylindrical shape. The second labyrinth chamber partition portion 84 has a larger diameter than the first labyrinth chamber partition portion 83. The transceiver housing portion 85 is formed in a covered cylindrical shape. The transceiver housing 85 has a larger diameter than the second labyrinth chamber partition 84. And the 1st labyrinth chamber partition part 83, the 2nd labyrinth chamber partition part 84, and the transmitter / receiver accommodating part 85 are arrange | positioned in this order from the upper side so that the axis | shaft may mutually correspond.

  The transceiver housing unit 85 houses the transceiver 88. The transmitter / receiver 88 is arranged so as to correspond to the detection tube 86. The transmitter / receiver 88 transmits the ultrasonic pulse toward the oil surface of the oil in the detection tube 86 and receives the reflected wave reflected from the oil surface, thereby detecting the ultrasonic pulse from the transmitter / receiver 88. The time from when transmitting toward the oil level in 86 to when the reflected wave reflected from the oil level is received by the transmitter / receiver 88 (detector) is measured.

  The detection tube 86 is formed in an elongated cylindrical shape. The detection tube 86 is slightly shifted from the center of the ceiling wall of the transceiver housing portion 85 (also referred to as “the bottom wall of the second labyrinth chamber partition portion 84”) so that the lower end opening faces the inside of the transceiver housing portion 85. Projected to the upper side of the part. The detection tube 86 passes through the ceiling wall of the first labyrinth chamber partition 83 and the ceiling wall of the second labyrinth chamber partition 84 (also referred to as “the bottom wall of the first labyrinth chamber partition 83”).

  The space defined by the ceiling wall of the first labyrinth chamber partition 83 and the second labyrinth chamber partition 84 and the detection tube 86 is the first labyrinth chamber 89, the second labyrinth chamber partition 84, and the ceiling of the transceiver housing portion 85. The spaces defined by the walls and the detection tube 86 constitute second labyrinth chambers 90, respectively. In addition, the 1st labyrinth chamber 89 and the 2nd labyrinth chamber 90 comprise the damping means which concerns on this invention which suppresses the fluctuation | variation of the oil level in oil level sensor SW9.

  A first oil opening 83 a is formed near the lower end of the portion of the peripheral wall of the first labyrinth chamber partition 83 that is opposite to the detection tube 86. The oil in the oil pan 13 can flow into and out of the first labyrinth chamber 89 from the first oil opening 83a.

  A partition plate 91 that partitions the inside of the first labyrinth chamber 89 together with the first labyrinth chamber partition portion 83 and the detection tube 86 is provided in the vicinity of the first oil opening 83 a between the first labyrinth chamber partition portion 83 and the detection tube 86. It has been. The partition plate 91 is in contact with the ceiling wall of the first labyrinth chamber partition 83 and the ceiling wall of the second labyrinth chamber partition 84.

  A second oil opening 84a is formed in the vicinity of the partition plate 91 on the ceiling wall of the second labyrinth chamber partitioning portion 84 and on the opposite side of the partition plate 91 from the first oil opening 83a. Yes. Oil in the first labyrinth chamber 89 can flow into and out of the second labyrinth chamber 90 from the second oil opening 84a.

  On the inner peripheral surface of the peripheral wall of the first labyrinth chamber partition 83, a plurality of first resistance plates 92 extending radially inward are disposed with a space therebetween. Each first resistance plate 92 is in contact with the ceiling wall of the first labyrinth chamber partition 83 and the ceiling wall of the second labyrinth chamber partition 84. A gap is formed between each first resistance plate 92 and the detection tube 86.

  On the outer peripheral surface of the detection tube 86, a plurality of second resistance plates 93 extending outward in the radial direction are arranged at intervals. Each second resistance plate 93 is disposed between the first resistance plates 92 adjacent in the circumferential direction. Each second resistance plate 93 is in contact with the ceiling wall of the first labyrinth chamber partition 83 and the ceiling wall of the second labyrinth chamber partition 84. A gap is formed between each second resistance plate 93 and the peripheral wall of the first labyrinth chamber partition 83.

  The oil that has flowed into the first labyrinth chamber 89 from the first oil opening 83 a passes through a labyrinth formed by the first resistance plate 92 and the second resistance plate 93 in the first labyrinth chamber 89. It flows meandering toward the opening 84a and flows into the second labyrinth chamber 90 from the second oil opening 84a. At this time, the flow of the oil flowing into the first labyrinth chamber 89 is given resistance by the first resistance plate 92 and the second resistance plate 93. Thereby, the high frequency fluctuation | variation of the oil level in the detection tube 86 is suppressed, and the fluctuation | variation of the oil level in the detection tube 86 is suppressed.

  The configuration and operation of the second labyrinth chamber 90 are substantially the same as the configuration and operation of the first labyrinth chamber 89. That is, the oil that has flowed into the second labyrinth chamber 90 from the second oil opening 84a flows in a meandering manner through a labyrinth formed by a resistor plate (not shown) in the second labyrinth chamber 90, and the transceiver housing portion 85 Flows into the transmitter / receiver housing 85 through the third oil opening 85a formed in the ceiling wall. At this time, the flow of the oil flowing into the second labyrinth chamber 90 is given resistance by the resistance plate.

  Further, the oil that has flowed into the oil accommodating portion 81 from the first oil opening 83 a flows into the detection tube 86 through the first labyrinth chamber 89, the second labyrinth chamber 90, and the transceiver accommodating portion 85. At this time, the oil level in the detection tube 86 fluctuates corresponding to the fluctuation of the oil level in the oil pan 13. That is, the oil level in the detection tube 86 substantially matches the oil level in the oil pan 13.

  The air vent pipe 87 is formed in an elongated cylindrical shape. The air vent tube 87 has a smaller diameter than the detection tube 86. The air vent tube 87 protrudes upward at a portion slightly shifted from the center of the ceiling wall of the first labyrinth chamber partition 83 to the opposite side to the detection tube 86 so that the lower end opening faces the first labyrinth chamber 89. It is installed.

  A first cap member 94 is provided at the upper end of the air vent pipe 87 so as to cover the upper end. The first cap member 94 is formed in a covered cylindrical shape.

  The oil that has flowed into the oil storage portion 81 from the first oil opening 83 a flows into the air vent pipe 87 through the first labyrinth chamber 89. At this time, the oil level in the air vent pipe 87 fluctuates corresponding to the fluctuation of the oil level in the oil pan 13. That is, the oil level in the air vent pipe 87 substantially matches the oil level in the oil pan 13.

  Further, the air contained in the oil that has flowed into the oil accommodating portion 81 passes through the air vent pipe 87 and is discharged from the lower end opening of the first cap member 94 to the outside of the oil accommodating portion 81. Thus, the reason why the air contained in the oil is discharged out of the oil container 81 is that if the oil is contained in the air, the ultrasonic pulse is irregularly reflected and the detection accuracy of the oil level sensor SW9 is lowered.

  A second cap member 95 is provided at the upper ends of the detection tube 86 and the air bleeding tube 87 so as to cover the upper ends. The second cap member 95 is formed in a covered and bottomed cylindrical shape. The second cap member 95 prevents oil in the oil pan 13 from flowing into the detection tube 86 from its upper end opening.

  An air opening 95 a is formed in the ceiling wall of the second cap member 95. The air in the detection tube 86 can flow out of the oil storage portion 81 from the air opening 95a. The detection tube 86 and the first cap member 94 penetrate the bottom wall of the second cap member 95.

  The base portion 82 supports the oil storage portion 81. The base portion 82 is fixed to the bottom wall of the oil pan 13. The base part 82 has a base main body 82a and a connector part 82b.

  The base body 82a is formed hollow. The base body 82a accommodates the circuit board 96. The circuit board 96 is electrically connected to the transmitter / receiver 88. The circuit board 96 calculates the distance between the transmitter / receiver 88 and the oil level in the detection tube 86 based on the time from the transmission of the ultrasonic pulse to the reception of the reflected wave measured by the transmitter / receiver 88. (Calculate). Thereby, the oil level in the detection tube 86 is detected.

  The connector portion 82b protrudes outward from the side wall of the base body 82a. The connector part 82b is formed hollow. The connector part 82b accommodates the connector 97. The connector 97 electrically connects the circuit board 96 and the ECU 10.

  A plurality of ribs 98 are formed on the outer side of the oil accommodating portion 81.

  The oil pump 72 supplies and circulates oil stored in the oil pan 13 to the rotating portion of the engine 1 and the lubricating portion of the sliding portion. The oil pump 72 is driven by a chain (not shown) by the crankshaft 15 to pump oil. The oil pump 72 configured as described above is controlled by the ECU 10 mainly based on the temperature of the engine coolant, the engine speed, and the engine load.

  As shown in FIG. 2, the ECU 10 includes a crank angle sensor SW4 that detects the rotation angle of the crankshaft 15 and an oil level sensor SW9 that is provided in the oil pan 13 and detects the oil level in the oil pan 13. A vehicle speed sensor SW10 that detects the vehicle speed of the vehicle, an oil temperature sensor SW11 that detects the temperature of oil in the oil pan 13 (hereinafter referred to as oil temperature), a front-rear G sensor SW12 that detects acceleration in the longitudinal direction of the vehicle, and Detection signals of a lateral G sensor SW13 (acceleration sensor) that detects the acceleration in the lateral direction of the vehicle are input, and various calculations are performed based on these detection signals to determine the state of the oil level in the oil pan 13 and the engine 1. And an oil lamp (warning) provided on an instrument panel (not shown) It outputs a control signal to the lamp) 73 (informing means).

  The ECU 10 includes a calculation unit 10a (calculation unit), a storage unit 10b, and a determination unit 10c (determination unit). When the vehicle is operating (engine operation), the calculation unit 10a is based on the detected value (unit: mm) of the oil level sensor SW9 (hereinafter referred to as the oil level average value) in the oil pan 13 based on the detected value. ) Is calculated. The calculation unit 10a includes an extraction unit 10d (impact suppression unit, extraction unit), a correction unit 10e, and an average calculation unit 10f.

  When the extraction condition is satisfied, the extraction unit 10d extracts (samples) the detection value (output raw data) of the oil level sensor SW9 when the extraction condition is satisfied.

  Here, the extraction condition is a predetermined condition that can be determined that extraction of the detection value of the oil level sensor SW9 is appropriate. In the present embodiment, (1) the communication between the oil level sensor SW9 and the ECU 10 is in a normal state, and (2) the oil supply pressure (discharge pressure; hereinafter referred to as oil pressure) by the oil pump 72 is a predetermined pressure. (3) The engine speed is 750 to 3000 rpm, (4) The vehicle speed is 5 km / h or more, (5) Oil in the oil pan 13 Extracted with the temperature being 20 to 120 ° C., (6) the longitudinal acceleration being less than 0.2 G, and (7) the lateral acceleration being less than 0.2 G (predetermined value). The condition is met.

  The condition (1) is set in order to prevent the oil level sensor SW9 and the ECU 10 from calculating the oil level average value when the oil level sensor SW9 or the ECU 10 is in an abnormal state.

  The above condition (2) is set because the oil level fluctuates when switching to low control or high control (high pressure control) that makes the oil pressure a predetermined pressure or higher. This is because when the oil level average value is calculated, the accuracy is lowered and the logic is complicated (for example, both the oil level correction maps for low control and high control are required). Also, on the high pressure side, the amount of oil circulation is large and the engine speed is mainly high, so the oil level fluctuates greatly and is not suitable for oil level stability detection.

  The above condition (3) is set because the aeration increases or the oil level is disturbed by the rotation of the crankshaft or the chain when the engine speed becomes high, so that the oil level detection accuracy decreases. Because. The upper limit (3000 rpm) of the engine speed is set based on the engine speed at the time of switching between the low control and the high control of the hydraulic pressure. On the other hand, the lower limit (750 rpm) is set based on, for example, the idling speed.

  The reason why the condition (4) is set is that if the oil level is detected when the vehicle is stopped, the detection accuracy of the oil level is lowered when the vehicle is inclined. On the other hand, during traveling, the frequency of continuous traveling on a regular slope is low, so the oil level detection accuracy does not decrease.

  The oil temperature range of the above condition (5) is set to a range including the oil temperature during a short distance and a short time of driving that completes the driving cycle before the warm-up of the engine 1 is completed. In particular, when short-distance / short-time driving is repeated, the oil temperature is low, so the fuel mixed in the oil does not evaporate, the oil dilution proceeds, and the oil level increases. On the other hand, when the oil temperature is too low, there is a problem that the viscosity and circulation characteristics of the oil become unstable. Therefore, the lower limit value (20 ° C.) of the oil temperature is set based on the rising characteristics of the oil temperature during the short distance and short time travel, the travel time thereof, and the above-described adverse effects. On the other hand, the upper limit (120 ° C.) is set based on the oil temperature during high-speed traveling.

  The above condition (6) is set because the fluctuation of the oil level increases as the longitudinal acceleration increases, which is not suitable for detecting the stability of the oil level. The reason why the value is set to “less than 0.2 G” is that the rate of acceleration in the front-rear direction is less than 0.2 G is high when the vehicle is traveling, and does not have a significant effect on securing the parameter for calculating the average oil level. Because.

  The reason why the condition (7) is set is that when the acceleration in the lateral direction increases, the oil level fluctuates, which is not suitable for oil level stability detection. In addition, the reason for setting “less than 0.2 G” is that when the vehicle travels, the rate of lateral acceleration is less than 0.2 G is high, and the calculation of the oil level average value has no significant effect on securing the parameter. Because. Since the engine 1 is mounted horizontally on the front portion of the vehicle, and the oil level sensor SW9 is disposed in the vehicle front-rear direction center portion in the oil pan 13 and closer to one side in the vehicle lateral direction, Lateral acceleration has a greater effect on oil level fluctuations than longitudinal acceleration.

  As described above, the extraction unit 10d selects and removes the detection value when the oil level is unstable and the detection value when the oil level sensor SW9 cannot be detected from the detection value of the oil level sensor SW9, and performs other detections. Extract the value.

  However, the extraction unit 10d determines that the duration of the state in which the lateral acceleration is 0.2G or more is less than 5 seconds when the lateral acceleration is 0.2G (predetermined value) or more while the vehicle is running. ), The detected value of the oil level sensor SW9 is not extracted even if the extraction condition is satisfied for 7 seconds (predetermined period) from the time when it becomes less than 0.2G (returned) again.

  By the way, when the lateral acceleration becomes 0.2 G or more (for example, when the vehicle turns), the oil level in the oil level sensor SW9 fluctuates at a low frequency due to the deviation of the oil in the oil pan 13, and the oil level The oil level in the sensor SW9 varies. Here, in the oil level sensor SW9, the labyrinth chambers 89 and 90 (damping means) are provided to suppress high-frequency fluctuations in the oil level in the oil level sensor SW9. Although the oil in SW9 does not flow out to oil pan 13, a response delay of oil level sensor SW9 occurs with respect to the low frequency fluctuation of the oil surface. For this reason, even if the lateral acceleration becomes less than 0.2 G again, and the oil shift in the oil pan 13 disappears, the oil level in the oil level sensor SW9 is almost stabilized (the oil level sensor SW9 is in a normal state). Time). That is, even if the lateral acceleration becomes less than 0.2 G again, for a while after that, the detected value of the oil level sensor SW9 is affected by the lateral acceleration (low frequency fluctuation of the oil surface). Therefore, when the lateral acceleration becomes 0.2G or more while the vehicle is running, the detection value of the oil level sensor SW9 is not extracted for 7 seconds from when it becomes less than 0.2G again. “7 seconds” was set because the response delay time of the oil level sensor SW9 was about 7 seconds with respect to the low-frequency fluctuation of the oil level when the lateral acceleration was generated. is there.

  Furthermore, the extraction unit 10d becomes less than 0.2G again when the lateral acceleration is 0.2 G or more and the direction is constant for 5 seconds (predetermined time) or more when the vehicle is running. Even if the extraction condition is satisfied for 30 seconds (second predetermined period) from the time of (return), the detection value of the oil level sensor SW9 is not extracted.

  By the way, when the lateral acceleration is 0.2 G or more and the state in which the direction is constant continues for a relatively long time (for example, when turning in a certain direction for a relatively long time), in particular, When the oil level in the oil pan 13 approaches or reaches an L level, which will be described later, the oil level sensor SW9 is exposed from the oil by the deviation of the oil in the oil pan 13, and the oil in the oil level sensor SW9 is opened to the first opening. The air flows from 83a to the oil pan 13 and air flows into the oil level sensor SW9. At this time, even if the lateral acceleration becomes less than 0.2 G again, the oil flows again into the oil level sensor SW9 and the oil level is almost stabilized (oil) It takes time until the level sensor SW9 becomes normal). Therefore, when the lateral acceleration is 0.2G or more and the direction is constant for 5 seconds or more while the vehicle is running, the oil level is again for 30 seconds from when it becomes less than 0.2G again. The detection value of the sensor SW9 is not extracted. The reason for setting “30 seconds” is that, if the experiment was performed in advance, it took about 30 seconds for the oil level sensor SW9 to become normal when all the oil in the oil level sensor SW9 was discharged. is there. The “30 seconds” includes the response delay time (7 seconds) of the oil level sensor SW9.

  As described above, when the extraction condition is satisfied, the extraction unit 10d again becomes less than 0.2 G when the lateral acceleration becomes 0.2 G or more from the detection value of the oil level sensor SW9. It was detected again within 7 seconds from the time when it was detected, and when the lateral acceleration was 0.2 G or more and the direction was constant for 5 seconds or more, it again became less than 0.2 G. Extract things other than those detected within 30 seconds from the hour.

  The correction unit 10e corrects the detection value (sample value) of the oil level sensor SW9 extracted by the extraction unit 10d for each detection value, and a value (hereinafter referred to as an oil level in the oil pan 13 when the engine is stopped). , The value corresponding to the oil level at the time of stop) is predicted and calculated. This calculation is performed in detail as follows.

  First, calculation of the oil level equivalent value at the time of stop for determining the X level will be described. Here, the X level is an allowable upper limit level of oil in the oil pan 13 when the engine is stopped (see FIG. 3).

  First, an oil level correction map for X level determination is read from the storage unit 10b. This oil level correction map is stored in advance in the storage unit 10b, and by performing an experiment in advance, the relationship between the engine speed and oil temperature and the correction coefficient (control constant) using the engine speed and oil temperature as parameters. Is stipulated. Here, when the engine speed changes, the oil supply amount changes and the oil level changes. Further, when the oil temperature changes, the viscosity of the oil changes, and the volume of the oil changes due to expansion and contraction of the oil itself, so that the amount of circulating oil changes and the oil level changes.

  Next, using the read oil level correction map, a correction coefficient is calculated based on the engine speed and the oil temperature detected by the crank angle sensor SW4 and the oil temperature sensor SW11, respectively. Subsequently, based on the detected value of the oil level sensor SW9 and the calculated correction coefficient, after the engine 1 has been warmed up (oil temperature is about 80 ° C.), the ignition level is turned off and the engine oil level is equivalent to that when the engine is left for 5 minutes. Calculate the value.

  Next, calculation of the oil level equivalent value at the time of determination for the L level side determination will be described. Here, the L level is the lower limit level of oil in the oil pan 13 when the engine is stopped (see FIG. 3).

  First, an oil level correction map for L level side determination is read from the storage unit 10b. This oil level correction map is stored in advance in the storage unit 10b, and by performing an experiment in advance, the relationship between the engine speed and oil temperature and the correction coefficient is determined using the engine speed and oil temperature as parameters. .

  Next, using the read oil level correction map, a correction coefficient is calculated based on the engine speed and the oil temperature detected by the crank angle sensor SW4 and the oil temperature sensor SW11, respectively. Subsequently, based on the detected value of the oil level sensor SW9 and the calculated correction coefficient, a value corresponding to the oil level at a stop when the engine 1 is warmed up and left for 5 minutes after the engine is warmed up is calculated.

  Here, when the oil level in the oil pan 13 approaches or reaches the X level, in the oil pump 72 and the balancer device, the volume of the portion immersed in the oil increases, and the X level side and the L level side of the oil pan 13 are increased. Then, since the shape is different, when the oil level in the oil pan 13 approaches or reaches the X level, the fluctuation of the oil level is larger than when the oil level approaches or reaches the L level. Therefore, the oil level correction map for the X level determination and the oil level correction map for the L level determination are different.

  The average calculation unit 10f predicts and calculates the oil level average value by averaging the oil level equivalent value at stop calculated by the correction unit 10e. In detail, when the oil level equivalent value for stopping at the X level is obtained for 3000 data and when driving 100 km, whichever comes first, the oil level at the time of stopping By averaging the equivalent values, an oil level average value AX for determining the X level corresponding to the oil level in the oil pan 13 when the engine is stopped and the vehicle is level is calculated. Further, the average calculation unit 10f is obtained up to that time when the oil level equivalent value at the time of stopping for L level side determination is obtained for 3000 data, or when traveling 100 km, whichever is earlier. The average oil level equivalent value AL for determining the L level corresponding to the oil level in the oil pan 13 when the engine is stopped and when the vehicle is horizontal is calculated by averaging the oil level equivalent value when the vehicle is stopped.

  When the oil level average value is calculated in this way, the influence of a running disturbance (for example, longitudinal acceleration or lateral acceleration) that changes the oil level is excluded. In other words, when driving for a certain period of time, the frequency of forward acceleration and backward acceleration, and the frequency of acceleration of leftward and rightward acceleration are almost the same, respectively, and the acceleration in the front-rear direction and the lateral direction Oil level fluctuations due to

  The determination unit 10c determines whether or not the oil level average value AX for X level side determination calculated by the average calculation unit 10f is greater than or equal to a predetermined upper limit value SX corresponding to the X level.

  Furthermore, the determination unit 10c determines whether or not the oil level average value AL for L-level determination calculated by the average calculation unit 10f is equal to or less than a predetermined lower limit SL corresponding to the L level.

  The K level shown in FIG. 3 is the detection limit (detection upper limit level) of the oil level sensor SW9, and the F level is the normal upper limit level of oil in the oil pan 13 when the engine is stopped. Further, as shown in FIG. 3, even when the oil level in the oil pan 13 reaches the X level, F level, or L level when the engine is stopped, the oil level is lowered during engine operation.

  When the determination unit 10c determines that the oil level average value AX for determination on the X level side is equal to or greater than the predetermined upper limit value SX twice, the ECU 10 is when the engine is stopped and when the vehicle is level. Assuming that the oil level in the oil pan 13 has reached the X level, that is, the lighting condition is satisfied, a control signal is output to the oil lamp 73 and the oil lamp 73 is turned on. As a result, the fact that the oil level in the oil pan 13 has reached the X level is notified, and oil replacement is urged.

  Further, when the determination unit 10c determines that the L level side determination oil level average value AL is equal to or less than the predetermined lower limit value SL twice, the ECU 10 determines the oil when the engine is stopped and the vehicle is level. Assuming that the oil level in the pan 13 has reached the L level, that is, the lighting condition is satisfied, a control signal is output to the oil lamp 73 to light the oil lamp 73. As a result, the fact that the oil level in the oil pan 13 has reached the L level is notified, and oil supply or replacement is urged.

  As described above, the calculation of the average oil level and the determination of the oil level are continued without resetting the logic until the lighting condition is satisfied. The same applies when straddling two driving cycles.

  Next, the oil level determination procedure of the ECU 10 will be described.

  First, the procedure for determining the oil level on the X level side will be described with reference to the flowchart shown in FIG. In step SA1, the detection value of the oil level sensor SW9 is input. In the subsequent step SA2, when the extraction condition is satisfied, the detection value of the oil level sensor SW9 input in step SA1 is extracted by the extraction unit 10d. (1) The communication between the oil level sensor SW9 and the ECU 10 is in a normal state, (2) the hydraulic pressure is low-controlled, (3) the engine speed is 750 to 3000 rpm, and (4) the vehicle speed. Is 5 km / h or more, (5) the oil temperature in the oil pan 13 is 20 to 120 ° C., (6) the longitudinal acceleration is less than 0.2 G, and (7) lateral The extraction condition is established when the acceleration in the direction is less than 0.2 G.

  However, when the lateral acceleration becomes 0.2 G or more, even if the extraction condition is satisfied for 7 seconds from when it becomes less than 0.2 G again, the oil level sensor SW9 input in step SA1 is satisfied. Do not extract detected values. Furthermore, when the lateral acceleration is 0.2 G or more and the direction is constant for 5 seconds or more, the extraction condition is satisfied for 30 seconds from when it becomes less than 0.2 G again. However, the detection value of the oil level sensor SW9 input in step SA1 is not extracted.

  In step SA3, the correction unit 10e corrects the detected value of the oil level sensor SW9 extracted in step SA2, and predicts and calculates a value corresponding to the oil level at the time of stop for X level side determination. This calculation is performed in detail as follows. First, an oil level correction map for X level side determination is read from the storage unit 10b. Next, using the read oil level correction map, a correction coefficient is calculated based on the engine speed and the oil temperature detected by the crank angle sensor SW4 and the oil temperature sensor SW11, respectively. Subsequently, based on the detected value of the oil level sensor SW9 and the calculated correction coefficient, a value corresponding to the oil level at a stop when the engine 1 is warmed up and left for 5 minutes after the engine is warmed up is calculated.

  In the subsequent step SA4, it is determined whether or not the oil level equivalent value at the time of stop calculated in step SA3 has been obtained for 3000 data or the vehicle has traveled 100 km. If the decision result in the step SA4 is YES and the oil level equivalent value at the time of stopping is obtained for 3000 data or the vehicle has traveled 100 km, the process proceeds to a step SA5. On the other hand, when the determination result is NO and the oil level equivalent value at the time of stopping is not obtained for 3000 data and the vehicle is not traveling 100 km, the process returns to step SA1.

  In step SA5, the average oil level average value AX for determination on the X level side is predicted and calculated by averaging the oil level equivalent value at stop calculated in step SA3 by the average calculator 10f. In detail, when the oil level equivalent value at the time of stopping is obtained for 3000 data, and when driving 100 km, whichever is earlier, average the oil level equivalent value at the time of stopping obtained up to that time Is used to calculate the oil level average value AX.

  In subsequent step SA6, it is determined whether or not the oil level average value AX calculated in step SA5 is equal to or greater than a predetermined upper limit value SX. If the determination result in step SA6 is YES and the value is equal to or greater than the upper limit SX, it is determined that the oil level in the oil pan 13 has reached the X level when the engine is stopped and the vehicle is level, and the process proceeds to step SA7. On the other hand, if the determination result is NO and less than the upper limit value SX, the process returns to step SA1.

  In step SA7, it is determined whether or not it is determined that the oil level average value AX is not less than the predetermined upper limit value SX (determined as NG) in step SA6 twice. If the determination result in step SA7 is YES and the NG determination is continuous twice, the process proceeds to step SA8. On the other hand, if the determination result is NO and the NG determination is the first time or the like, the process returns to step SA1 in order to calculate the oil level average value once more (one cycle) in order to prevent erroneous lighting of the oil lamp 73. .

  In step SA8, a control signal is output to the oil lamp 73, and the oil lamp 73 is turned on. Then go to the end.

  If the ignition is turned off after the oil lamp 73 is turned on, the oil lamp 73 is turned off. After that, when the oil is changed and the logic is reset, the oil lamp 73 does not light up when the ignition is turned on again. On the other hand, if the oil is not exchanged, the oil lamp 73 is turned on again when the ignition is turned on again.

  Next, the L level side oil level determination procedure will be described with reference to the flowchart shown in FIG. Since step SB1 and step SB2 are the same processes as step SA1 and step SA2, respectively, description thereof is omitted.

  In step SB3, the detection value of the oil level sensor SW9 extracted in step SB2 is corrected by the correction unit 10e, and a stop time oil level equivalent value for determination on the L level side is predicted and calculated. This calculation is performed in detail as follows. First, an oil level correction map for L level side determination is read from the storage unit 10b. Next, using the read oil level correction map, a correction coefficient is calculated based on the engine speed and the oil temperature detected by the crank angle sensor SW4 and the oil temperature sensor SW11, respectively. Subsequently, based on the detected value of the oil level sensor SW9 and the calculated correction coefficient, a value corresponding to the oil level at a stop when the engine 1 is warmed up and left for 5 minutes after the engine is warmed up is calculated.

  In subsequent step SB4, it is determined whether or not the oil level equivalent value at the time of stop calculated in step SB3 has been obtained for 3000 data or the vehicle has traveled 100 km. If the determination result in step SB4 is YES and the oil level equivalent value at the time of stopping is obtained for 3000 data, or if the vehicle has traveled 100 km, the process proceeds to step SB5. On the other hand, when the determination result is NO and the oil level equivalent value at the time of stop is not obtained for 3000 data and the vehicle is not traveling 100 km, the process returns to step SB1.

  In step SB5, the average oil level average value AL for L side determination is predicted and calculated by averaging the oil level equivalent value calculated in step SB3 by the average calculator 10f. In detail, when the oil level equivalent value at the time of stopping is obtained for 3000 data, and when driving 100 km, whichever is earlier, average the oil level equivalent value at the time of stopping obtained up to that time To calculate the oil level average value AL.

  In subsequent step SB6, it is determined whether or not the oil level average value AL calculated in step SB5 is equal to or smaller than a predetermined lower limit value SL. If the determination result in step SB6 is YES and is equal to or lower than the lower limit value SL, it is determined that the oil level in the oil pan 13 has reached the L level when the engine is stopped and the vehicle is level, and the process proceeds to step SB7. On the other hand, if the determination result is NO and is greater than the lower limit value SL, the process returns to step SB1.

  In step SB7, it is determined in step SB6 whether or not the oil level average value AL is determined to be equal to or lower than the predetermined lower limit SL (NG determined) is continuous twice. If the determination result in step SB7 is YES and the NG determination is continuous twice, the process proceeds to step SB8. On the other hand, if the determination result is NO and the NG determination is the first time or the like, the process returns to step SB1 in order to calculate the oil level average value one more time in order to prevent erroneous lighting of the oil lamp 73.

  In step SB8, a control signal is output to the oil lamp 73, and the oil lamp 73 is turned on. Then go to the end.

  If the ignition is turned off after the oil lamp 73 is turned on, the oil lamp 73 is turned off. After that, when the oil is replenished or replaced, the oil lamp 73 does not light up when the ignition is turned on again. On the other hand, if the oil is not replenished or replaced, the oil lamp 73 is turned on again when the ignition is turned on again.

-Effect-
As described above, according to the present embodiment, the oil level from the time when the extraction unit 10d, which is the influence suppressing unit, becomes less than 0.2G again when the detection value of the lateral G sensor SW13 becomes 0.2G or more. The influence of the detected value of the oil level sensor SW9 detected until the oil becomes almost stable on the calculation of the average oil level value is made smaller than when the detected value of the lateral G sensor SW13 is less than 0.2G. Specifically, from the detection value of the oil level sensor SW9, when the detection value of the lateral G sensor SW13 becomes 0.2G or more, other than those detected within 7 seconds from when it again becomes less than 0.2G. Extract things. In other words, the extraction unit 10d detects the oil level detected when the detected value of the lateral G sensor SW13 is 0.2G or more and until the oil level is almost stabilized after the value again becomes less than 0.2G. The detection value of the sensor SW9 is not extracted. Furthermore, the extraction unit 10d starts again from when the detection value of the oil level sensor SW9 becomes less than 0.2G again when the detection value of the lateral G sensor SW13 becomes 0.2G or more continues for 5 seconds or more. Extract anything other than that detected in 30 seconds. That is, the extraction unit 10d becomes less than 0.2G again when the oil in the oil level sensor SW9 flows out continuously when the detection value of the lateral G sensor SW13 becomes 0.2G or more for 5 seconds or more. Until the oil flows again into the oil level sensor SW9 and the oil level is almost stabilized. As described above, the oil level in the oil pan 13 can be detected with high accuracy. Therefore, it is possible to accurately determine whether the oil level in the oil pan 13 is an appropriate level.

  Further, the extraction unit 10d extracts the detection value of the oil level sensor SW9 when the extraction condition is satisfied. That is, the extraction unit 10d performs the extraction when the oil level fluctuation is relatively small. Here, (1) the communication between the oil level sensor SW9 and the ECU 10 is in a normal state, (2) the hydraulic pressure is controlled to be low, (3) the engine speed is 750 to 3000 rpm, (4) The vehicle speed is 5 km / h or more, (5) the oil temperature in the oil pan 13 is 20 to 120 ° C., (6) the longitudinal acceleration is less than 0.2 G, and (7) The extraction condition is established when the lateral acceleration is less than 0.2 G. For this reason, the oil level in the oil pan 13 can be detected with high accuracy. Therefore, it is possible to accurately determine whether the oil level in the oil pan 13 is an appropriate level.

(Other embodiments)
In the above embodiment, the fuel of the engine 1 is mainly composed of light oil. However, the fuel is not limited to this, and may be alcohol fuel (for example, ethanol fuel).

  Further, in the above embodiment, when the extraction condition is satisfied, from the value detected by the oil level sensor SW9, when the lateral acceleration becomes 0.2G or more, it becomes less than 0.2G again. What was detected during 7 seconds, and when the lateral acceleration is 0.2 G or more and the state in which the direction is a constant direction continues for 5 seconds or more, it is 30 again from when it becomes less than 0.2 G again. Detection values other than those detected during the second are extracted, but when the lateral acceleration becomes 0.2 G or more, the detected value is detected within 7 seconds from the time when it becomes less than 0.2 G again. , And when the lateral acceleration is 0.2 G or more and the state in which the direction is constant continues for 5 seconds or more, the detected value is detected within 30 seconds from when it becomes less than 0.2 G again. For calculating the average oil level As long as the effect of lateral acceleration is smaller than when less than 0.2 G, but it is not limited thereto.

  In the above embodiment, the predetermined value according to the present invention is set to 0.2 G, the predetermined period is set to 7 seconds, and the second predetermined period is set to 30 seconds. However, the predetermined value is set to any other value. Also good.

  Moreover, in the said embodiment, although the predetermined period which concerns on this invention was set to fixed time (7 second), time until it becomes less than 0.2 G again after lateral acceleration becomes 0.2 G or more. A longer value may be set longer. According to this, the predetermined period is set longer as the time from when the detection value of the lateral G sensor SW13 becomes 0.2G or more until it becomes less than 0.2G again. That is, the predetermined period is set according to the turning time of the vehicle. For this reason, the oil level in the oil pan 13 can be detected with higher accuracy. Therefore, it can be determined more accurately whether the oil level in the oil pan 13 is an appropriate level.

  Further, in the above embodiment, the detection value of the oil level sensor SW9 is extracted at the time of low oil pressure control (when the extraction condition is satisfied). The detection value of the oil level sensor SW9 may be extracted.

  Moreover, in the said embodiment, when the acceleration of a horizontal direction becomes 0.2 G or more, the detection value of oil level sensor SW9 is not extracted, but it is not limited to this. For example, when the engine 1 is mounted vertically, the detection value of the oil level sensor SW9 may not be extracted when the longitudinal acceleration becomes 0.2 G or more. Alternatively, depending on the arrangement position of the oil level sensor SW9 in the oil pan 13, when the longitudinal acceleration becomes 0.2G or more, or when the lateral acceleration becomes 0.2G or more, the oil level The detection value of the sensor SW9 may not be extracted.

  In the above-described embodiment, the oil lamp 73 is turned on when the determination unit 10c determines NG twice in succession. However, the present invention is not limited to this. For example, when the NG determination is performed once, the oil lamp 73 73 may be lit.

  As described above, the engine oil level detection device according to the present invention can be applied to applications that require accurate determination of whether the oil level in the oil pan is an appropriate level.

1 Engine 10 ECU
10a Calculation unit (calculation means)
10b Determination unit (determination means)
10c Extraction unit (effect suppression means, extraction means)
13 Oil pan
72 Oil pump
81 Oil container
83a 1st oil opening
88 Transceiver (detector)
89 1st labyrinth chamber (dumping means)
90 Second labyrinth chamber (dumping means)
SW9 Oil level sensor SW13 Lateral G sensor (acceleration sensor)

Claims (5)

An engine oil level detection device for detecting an oil level stored in an oil pan of an engine mounted on a vehicle,
The oil pan is provided with an opening through which the oil in the oil pan can flow in and out. An oil level sensor having damping means for suppressing fluctuations in the oil level in the oil storage unit, and a detection unit for detecting the oil level in the oil pan by detecting the oil level in the oil storage unit;
Calculation means for calculating an average value of the oil level in the oil pan based on the detection value of the oil level sensor;
Determining means for determining whether the average value of the oil level calculated by the calculating means is equal to or higher than a predetermined upper limit value, or whether it is equal to or lower than a predetermined lower limit value;
An acceleration sensor for detecting the acceleration of the vehicle,
The calculation means is
When the detected value of the acceleration sensor is equal to or higher than a predetermined value, the average value of the oil level of the detected value of the oil level sensor detected for at least a predetermined period from when it becomes less than the predetermined value again. An oil level detecting device for an engine, comprising: an influence suppressing means for making the influence on the calculation of the engine smaller than when the detected value of the acceleration sensor is less than the predetermined value. The engine oil level detection device according to claim 1,
The influence suppression means has an extraction means for extracting a value other than that detected during the predetermined period from the detection value of the oil level sensor,
The engine oil level detection device according to claim 1, wherein the calculation means is configured to calculate an average value of the oil level based on a detection value of the oil level sensor extracted by the extraction means. The engine oil level detection device according to claim 2,
The oil level detection of the engine is characterized in that the predetermined period is set longer as the time from when the detected value of the acceleration sensor becomes equal to or higher than the predetermined value until it becomes less than the predetermined value again. apparatus. The engine oil level detection device according to any one of claims 1 to 3,
The influence suppression means is configured to detect the predetermined value from when the value detected by the acceleration sensor becomes less than the predetermined value again when the value detected by the acceleration sensor is equal to or higher than the predetermined value for a predetermined time or longer. Having extraction means for extracting things other than those detected during the second predetermined period longer than the period;
The engine oil level detection device according to claim 1, wherein the calculation means is configured to calculate an average value of the oil level based on a detection value of the oil level sensor extracted by the extraction means. In the engine oil level detection device according to any one of claims 2 to 4,
An oil pump for supplying the oil stored in the oil pan to the lubrication part of the engine;
The extraction means is configured to perform the extraction when the oil supply pressure by the oil pump is a predetermined pressure or less, or when the oil supply amount by the oil pump is a predetermined amount or less. An oil level detection device for an engine.

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