JP2017061877A - Engine oil level measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy for measuring oil level.SOLUTION: An oil measurement device includes: a level sensor 8 for actually measuring oil level in an oil pan 13; a supply amount acquisition part 66 for obtaining an oil supply amount supplied into an engine from an oil pump 41; and an estimation part 67 for estimating oil level in the oil pan 13 by correcting a value actually measured by the level sensor 8 based on the oil supply amount obtained by the supply amount acquisition part 66.SELECTED DRAWING: Figure 6

Description

  The technology disclosed herein relates to an engine oil level measuring device.

  Conventionally, a measuring device for measuring an oil level in an oil pan of an engine is known.

  For example, the oil level measuring device according to Patent Document 1 includes a level sensor that measures the oil level in the oil pan. Furthermore, this oil level measuring device corrects the measured value of the level sensor based on the engine rotational speed and the oil temperature in order to improve the measurement accuracy of the oil level.

Japanese Patent Laying-Open No. 2015-227942

  By the way, during the engine operation, the oil in the oil pan is supplied into the engine, and the oil level in the oil pan is lowered accordingly. As described above, the oil level measurement device according to Patent Document 1 corrects the measured value of the level sensor based on the engine rotation speed and the oil temperature, but there is room for further improvement in the measurement accuracy.

  The technology disclosed herein has been made in view of such a point, and an object thereof is to improve the measurement accuracy of the oil level.

  The technique disclosed herein is directed to an oil level measuring device that measures an oil level in an oil pan during engine operation. The oil level measuring device includes a level sensor that measures the oil level in the oil pan, a supply amount obtaining unit that obtains the amount of oil supplied from the oil pump to the engine, and the actual value of the level sensor An estimation unit that estimates the oil level in the oil pan by correcting the amount based on the supply amount obtained by the amount acquisition unit.

  According to this configuration, the supply amount acquisition unit obtains the supply amount of oil supplied from the oil pump into the engine. And an estimation part correct | amends the measured value of a level sensor based on the calculated | required supply amount. In other words, since the measured value of the level sensor is corrected based on the amount of oil supplied to the engine, it circulates or remains in the engine compared to the case where the measured value of the level sensor is simply corrected at the engine speed. The oil level in the oil pan can be measured in consideration of the effect of the amount of oil that is being used more accurately.

  The oil level measurement device further includes a viscosity detection unit that detects a value related to the viscosity of the oil, and the estimation unit includes the supply amount obtained by the supply amount acquisition unit and a detection value of the viscosity detection unit. The oil level in the oil pan may be estimated by correcting the measured value of the level sensor based on the above.

  According to this configuration, the actually measured value of the level sensor is corrected not only based on the amount of oil supplied into the engine but also based on the viscosity of the oil. When the oil viscosity decreases, the amount of oil leakage inside the engine increases, and the amount of oil returned from the engine to the oil pan increases. That is, the amount of oil remaining inside the engine during engine operation depends on the balance between the amount of oil supplied to the engine and the amount of return to the oil pan. According to the above configuration, since the actual measurement value of the level sensor is corrected based on the viscosity of the oil, the oil level can be estimated in consideration of the return amount to the oil pan accurately.

  Further, the oil pump is configured such that the capacity can be adjusted by the control of the capacity control unit, and the supply amount acquisition unit includes the capacity of the oil pump, the rotational speed of the engine, and the detection value of the viscosity detection unit. The supply amount may be obtained based on the above.

  According to this configuration, the oil pump is a variable displacement type. The discharge amount of such an oil pump varies depending on the capacity of the oil pump, the engine rotation speed, and the oil viscosity. The supply amount of oil supplied into the engine correlates with the discharge amount of the oil pump. For this reason, the amount of oil supplied into the engine is determined based on the oil pump capacity, the value related to the engine speed and viscosity, and the amount of oil supplied in consideration of the oil pump discharge rate. It can be obtained with high accuracy.

  The viscosity detection unit may be an oil temperature detection unit that detects the oil temperature of the oil as a value related to the viscosity of the oil.

  Oil temperature correlates with oil viscosity. As the oil temperature increases, the viscosity decreases, while as the oil temperature decreases, the viscosity increases. That is, the oil viscosity can be substantially detected by detecting the oil temperature. In addition, oil temperature is also correlated with oil volume. If the oil temperature increases, the oil expands and increases in volume, while if the oil temperature decreases, the oil contracts and decreases in volume. That is, by correcting the measured value of the level sensor based on the oil temperature, the oil level can be accurately estimated in consideration of the oil volume variation as well as the oil viscosity.

  The oil temperature detection unit further includes a first oil temperature sensor that detects the oil temperature of the oil supplied into the engine, and a second oil temperature sensor that detects the oil temperature of the oil in the oil pan. You may go out.

  During engine operation, the oil temperature of the oil supplied into the engine and the oil temperature of the oil in the oil pan can be different. Specifically, since the engine is hot during engine operation, the oil temperature of the oil supplied into the engine is higher than the oil temperature of the oil in the oil pan. The amount of oil leakage inside the engine greatly depends on the oil temperature of the oil supplied to the engine, while the oil volume fluctuation in the oil pan greatly depends on the oil temperature of the oil in the oil pan. . That is, by detecting the oil temperature at different locations between the first oil temperature sensor and the second oil temperature sensor, the oil leakage amount inside the engine and the oil volume fluctuation in the oil pan are respectively suitable. The temperature can be taken into account, and as a result, the oil level can be estimated with high accuracy.

  The oil level measurement device further includes a hydraulic pressure detection unit that detects a hydraulic pressure of oil supplied into the engine, and the estimation unit is configured to detect the hydraulic pressure detected by the hydraulic pressure detection unit when the hydraulic pressure is equal to or lower than a predetermined threshold. The oil level may be estimated.

  According to this configuration, since the oil level is measured and estimated when the oil level in the oil pan is relatively stable, the oil level can be accurately measured. In other words, when the oil pressure is high, the amount of oil supplied to the engine is large, and the amount of oil in the oil pan varies greatly, so the oil level in the oil pan, that is, the variation in oil level is compared. Big. In addition, when the oil pressure is high, the engine is often operating at a high load and high speed. In such a case, the oil in the oil pan is agitated by the crankshaft. The fluctuation of becomes relatively large. By performing the estimation of the oil level when the oil pressure is low, it is possible to avoid performing the actual measurement and estimation of the oil level when the oil level fluctuation is large. Thereby, the measurement accuracy of the oil level can be further improved.

  According to the oil level measurement device, the oil level measurement accuracy can be improved.

FIG. 1 is a diagram showing a schematic configuration of an engine. FIG. 2 is a hydraulic circuit diagram of the oil supply device. FIG. 3 is a partial cross-sectional view of the engine showing a state in which the level sensor is provided in the oil pan. FIG. 4 is a longitudinal sectional view showing a schematic configuration of the level sensor. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a functional block diagram relating to hydraulic control and oil level measurement of the ECU. FIG. 7 is an image diagram of a discharge amount map. FIG. 8 is an image diagram of the correction amount map. FIG. 9 is a diagram illustrating an oil level characteristic that is a relationship of the oil level with respect to the amount of oil in the oil pan. FIG. 10 is a flowchart showing an oil level determination procedure.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of an engine 100 according to the embodiment.

  The engine 100 includes an engine body 1, an intake system that supplies air to the engine body 1, an exhaust system that exhausts exhaust gas from the engine body 1, a large turbocharger 34 and a small turbocharger 35, an engine An oil supply device 200 (not shown in FIG. 1) for supplying lubricating oil (hereinafter referred to as “oil”) to the main body 1, an oil level measuring device for measuring an oil level in an oil pan 13 described later, and the engine 100 ECU60 which controls the whole.

  The engine body 1 is a diesel engine to which a fuel mainly composed of light oil is supplied. The engine body 1 is disposed below a cylinder block 11 provided with a plurality of cylinders 11a (only one is shown), a cylinder head 12 disposed on the cylinder block 11, and a cylinder block 11. And an oil pan 13 in which oil is stored. A piston 14 is fitted in each cylinder 11a of the engine body 1 so as to be able to reciprocate, and a cavity defining a reentrant combustion chamber 14a is formed on the top surface of the piston 14. The piston 14 is connected to the crankshaft 15 via a connecting rod 14b.

  The cylinder head 12 is formed with an intake port 16 and an exhaust port 17 communicating with the combustion chamber 14a. The cylinder head 12 includes an injector 18 that injects fuel, a glow plug 19 that warms intake air when the engine body 1 is cold to enhance the ignitability of the fuel, and an intake valve 110 that opens and closes the intake port 16. And 111 for opening and closing the exhaust port 17 are provided. 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.

  The cylinder head 12 is provided with a variable valve timing mechanism (hereinafter referred to as “VVT”) that changes the valve characteristics of the intake valve 110 and the exhaust valve 111 (not shown in FIG. 1). The intake side VVT is an electric type, and the exhaust side VVT is a hydraulic type.

  Further, the cylinder head 12 is provided with a hydraulic lash adjuster (hereinafter referred to as “HLA”) that automatically adjusts the valve clearances of the intake valve 110 and the exhaust valve 111 to zero by hydraulic pressure. (Not shown in FIG. 1). The HLA provided in the first cylinder 11a and the fourth cylinder 11a includes a valve stop mechanism that stops the operation of the intake valve 110 and the exhaust valve 111, respectively. The engine 100 operates all the intake valves 110 and exhaust valves 111 of the first to fourth cylinders 11a during all cylinder operation, while the intake valves 110 and exhaust valves of the first and fourth cylinders 11a operate during reduced cylinder operation. 111 is stopped, and the intake valve 110 and the exhaust valve 111 of the second and third cylinders 11a are operated.

  An intake passage 20 constituting an intake system is connected to one side surface of the engine body 1 so as to communicate with the intake port 16 of each cylinder 11a. On the other hand, an exhaust passage 30 constituting an exhaust system is connected to the other side surface of the engine body 1 so as to communicate with the exhaust port 17 of each cylinder 11a.

  The intake system includes an air cleaner 21 that filters intake air, an intercooler 22 that cools air, a throttle valve 23 that adjusts the amount of intake air into the combustion chamber 14a of each cylinder 11a, and a surge tank 24. Yes. The intake passage 20 on the downstream side of the surge tank 24 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.

The exhaust system includes an exhaust purification device 31 that purifies harmful components in the exhaust gas, and a silencer 32. The upstream portion of the exhaust passage 30 includes 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. The exhaust purification device 31 includes an oxidation catalyst 31a and a DPF 31b, which are arranged in this order from the upstream side. The oxidation catalyst 31a promotes a reaction in which CO and HC in the exhaust gas are oxidized to produce CO ₂ and H ₂ O. The DPF 31b collects PM such as soot contained in the exhaust gas of the engine 100, and is, for example, a wall flow filter formed of a heat-resistant ceramic material such as silicon carbide (SiC) or cordierite. Or a three-dimensional mesh filter formed of heat-resistant ceramic fibers.

  The intake passage 20 and the exhaust passage 30 are connected by an EGR passage 33 for returning a part of the exhaust gas to the intake passage 20. The EGR passage 33 is provided with an EGR valve 33a for adjusting the recirculation amount of the exhaust gas to the intake passage 20, and an EGR cooler 33b for cooling the exhaust gas with engine coolant.

  The large turbocharger 34 has a large compressor 34 a disposed in the intake passage 20 and a large turbine 34 b disposed in the exhaust passage 30. The large compressor 34 a is disposed between the air cleaner 21 and the intercooler 22 in the intake passage 20. On the other hand, the large turbine 34b is disposed between the exhaust manifold and the oxidation catalyst 31a in the exhaust passage 30.

  The small turbocharger 35 has a small compressor 35 a disposed in the intake passage 20 and a small turbine 35 b disposed in the exhaust passage 30. The small compressor 35 a is disposed on the downstream side of the large compressor 34 a in the intake passage 20. On the other hand, the small turbine 35 b is disposed on the upstream side of the large turbine 34 b in the exhaust passage 30.

  The small turbocharger 35 is relatively small, and the large turbocharger 34 is relatively large. That is, the large turbine 34 b of the large turbocharger 34 has a larger inertia than the small turbine 35 b of the small turbocharger 35.

  A small intake bypass passage 36 that bypasses the small compressor 35 a is connected to the intake passage 20. The small intake bypass passage 36 is provided with a small intake bypass valve 36 a for adjusting the amount of air flowing to the small intake bypass passage 36.

  A small exhaust bypass passage 37 that bypasses the small turbine 35b and a large exhaust bypass passage 38 that bypasses the large turbine 34b are connected to the exhaust passage 30. The small exhaust bypass passage 37 is provided with a regulating valve 37a for adjusting the exhaust amount flowing into the small exhaust bypass passage 37, and the large exhaust bypass passage 38 has an exhaust amount flowing into the large exhaust bypass passage 38. A wastegate valve 38a for adjusting the pressure is provided.

<Oil supply device>
Next, the oil supply apparatus 200 will be described with reference to FIG. FIG. 2 shows a hydraulic circuit diagram of the oil supply device 200.

  The oil supply device 200 includes a variable displacement oil pump 41 that is rotationally driven by the crankshaft 15, and an oil supply passage 5 that is connected to the oil pump 41 and through which oil flows. Oil pump 41 is an auxiliary machine driven by engine 100.

  The oil pump 41 is a known variable displacement oil pump and is driven by the crankshaft 15. The oil pump 41 is attached to the lower surface of the cylinder block 11 and is housed in the oil pan 13. Specifically, the oil pump 41 includes a drive shaft 41a that is rotationally driven by the crankshaft 15, a rotor 41b that is coupled to the drive shaft 41a, and a plurality of vanes 41c that are provided so as to be movable forward and backward in the radial direction from the rotor 41b. The cam ring 41d configured to accommodate the rotor 41b and the vane 41c and adjust the amount of eccentricity with respect to the rotation center of the rotor 41b, and bias the cam ring 41d in a direction in which the amount of eccentricity with respect to the rotation center of the rotor 41b increases. It has a spring 41e, a ring member 41f disposed inside the rotor 41b, and a housing 41g for accommodating the rotor 41b, vane 41c, cam ring 41d, spring 41e and ring member 41f.

  Although not shown, one end of the drive shaft 41a protrudes outward from the housing 41g, and a driven sprocket is connected to the one end. A timing chain is wound around the driven sprocket. This timing chain is also wound around the drive sprocket of the crankshaft 15. Thus, the rotor 41b is rotationally driven by the crankshaft 15 via the timing chain.

  When the rotor 41b rotates, each vane 41c slides on the inner peripheral surface of the cam ring 41d. As a result, the pump chamber (hydraulic oil chamber) 41i is defined by the rotor 41b, the two adjacent vanes 41c, the cam ring 41d, and the housing 41g.

  The housing 41g is formed with a suction port 41j through which oil is sucked into the pump chamber 41i and a discharge port 41k through which oil is discharged from the pump chamber 41i. An oil strainer 41l is connected to the suction port 41j. The oil strainer 41l is immersed in the oil stored in the oil pan 13. That is, the oil stored in the oil pan 13 is sucked into the pump chamber 41i from the suction port 41j through the oil strainer 41l. On the other hand, the oil supply path 5 is connected to the discharge port 41k. That is, the oil boosted by the oil pump 41 is discharged from the discharge port 41k to the oil supply passage 5.

  The cam ring 41d is supported by the housing 41g so as to swing around a predetermined fulcrum. The spring 41e biases the cam ring 41d toward one side around the fulcrum. A pressure chamber 41m is defined between the cam ring 41d and the housing 41g. The pressure chamber 41m is configured to be supplied with oil from the outside. The oil pressure in the oil pressure chamber 41m acts on the cam ring 41d. Therefore, the cam ring 41d swings according to the balance between the biasing force of the spring 41e and the hydraulic pressure of the pressure chamber 41m, and the amount of eccentricity of the cam ring 41d with respect to the rotation center of the rotor 41b is determined. Depending on the amount of eccentricity of the cam ring 41d, the capacity of the oil pump 41 changes, and the amount of oil discharged changes.

  Oil is supplied to the pressure chamber 41m from an oil control valve 44 described later. That is, the capacity of the oil pump 41 is controlled by the oil control valve 44.

  The oil supply path 5 is formed of a pipe and a flow path formed in the cylinder block 11 and the cylinder head 12. The oil supply passage 5 includes a main gallery 5a extending in the cylinder row direction in the cylinder block 11, a first communication passage 5b connecting the oil pump 41 and the main gallery 5a, and a second communication passage extending from the main gallery 5a to the cylinder head 12. 5c, a third communication path 5d extending in the horizontal direction between the intake side and the exhaust side in the cylinder head 12, a control oil supply path 5e branched from the main gallery 5a, and a third communication path 5d branched from the third communication path 5d. 1 to 5 oil supply passages 5f to 5j.

  The first communication passage 5 b is connected to the discharge port 41 k of the oil pump 41. In the first communication path 5b, an oil filter 42 and an oil cooler 43 are provided in order from the oil pump 41 side. In other words, the oil discharged from the oil pump 41 to the first communication passage 5b is filtered by the oil filter 42, the oil temperature is adjusted by the oil cooler 43, and then flows into the main gallery 5a.

  In the main gallery 5a, an oil jet 51a that injects oil to the back side of the four pistons 14, a bearing metal 52a of five bearing portions that rotatably supports the crankshaft 15, and four connecting rods 14b are rotatable. Bearing metal 52b disposed on the connected crank pin, an oil supply part 53a for supplying oil to the hydraulic chain tensioner, an oil jet 51b for injecting oil to the timing chain, and the hydraulic pressure of the oil flowing through the main gallery 5a Is connected to a first oil temperature sensor 50b. The hydraulic pressure sensor 50a is an example of a hydraulic pressure detection unit. The first oil temperature sensor 50b is an example of a viscosity detection unit. Oil is always supplied to the main gallery 5a. The oil jet 51a has a check valve and a nozzle, and when a hydraulic pressure of a predetermined value or more acts, the check valve opens and injects oil from the nozzle.

  The control oil supply passage 5 e branches from the main gallery 5 a and is connected to the pressure chamber 41 m of the oil pump 41 via the oil control valve 44. An oil filter 55a is provided in the control oil supply passage 5e. A part of the oil in the main gallery 5a passes through the control oil supply passage 5e, and the oil pressure is adjusted by the oil control valve 44, and then flows into the pressure chamber 41m of the oil pump 41. That is, the pressure of the pressure chamber 41 m is adjusted by the oil control valve 44.

  The oil control valve 44 is a linear solenoid valve. The oil control valve 44 adjusts the flow rate of oil supplied to the pressure chamber 41m according to the duty ratio of the input control signal. The oil control valve 44 is an example of a capacity control unit.

  The second communication path 5c allows the main gallery 5a and the third communication path 5d to communicate with each other. Oil flowing through the main gallery 5a flows into the third communication path 5d through the second communication path 5c. The oil flowing into the third communication path 5d is distributed to the intake side and the exhaust side of the cylinder head 12 via the third communication path 5d.

  The first oil supply passage 5f includes an oil supply portion 53b of a bearing metal that supports the cam journal of the intake side camshaft, an oil supply portion 53c of a thrust bearing of the intake side camshaft, and a valve stop mechanism on the intake side. An HLA pivot mechanism 57b, an HLA 57a without an intake side valve stop mechanism, an intake side oil shower 54a, and an oil supply portion 53d of a sliding portion of the intake side VVT are connected.

  The second oil supply passage 5g includes a bearing metal oil supply portion 53e that supports the cam journal of the exhaust camshaft, an oil supply portion 53f of the exhaust camshaft thrust bearing, and an exhaust valve stop mechanism. An HLA pivot mechanism 57e, an exhaust-side valve stop mechanism-less HLA 57d, and an exhaust-side oil shower 54b are connected.

  The third oil supply passage 5h is connected to the exhaust side VVT 112 via the first direction switching valve 56a. The third oil supply passage 5h is connected to an oil supply portion 53e located at the forefront of the oil supply portion 53e of the bearing metal of the exhaust camshaft. An oil filter 55b is connected to the upstream side of the first direction switching valve 56a in the third oil supply passage 5h. The flow rate of oil supplied to the exhaust side VVT 112 is adjusted by the first direction switching valve 56a.

  The fourth oil supply passage 5i is connected to the valve stop mechanism 57c of the HLA with a valve stop mechanism of the first cylinder and the valve stop mechanism 57f of the HLA with a valve stop mechanism through the second direction switching valve 56b. An oil filter 55c is connected to the upstream side of the second direction switching valve 56b in the fourth oil supply passage 5i. Oil supply to the valve stop mechanism 57c and the valve stop mechanism 57f of the first cylinder is controlled by the second direction switching valve 56b.

  The fifth oil supply passage 5j is connected to the valve stop mechanism 57c of the HLA with a valve stop mechanism of the fourth cylinder and the valve stop mechanism 57f of the HLA with a valve stop mechanism through a third direction switching valve 56c. An oil filter 55d is connected to the upstream side of the third direction switching valve 56c in the fifth oil supply passage 5j. The oil supply to the valve stop mechanism 57c and the valve stop mechanism 57f of the fourth cylinder is controlled by the third direction switching valve 56c.

  The oil supplied to each part of the engine 100 is dropped on the oil pan 13 through a drain oil passage (not shown) and is recirculated again by the oil pump 41.

<Oil level measuring device>
Next, the oil level measuring device will be described.

  The oil level measuring device includes a level sensor 8 that measures the oil level (oil level height) in the oil pan 13, a first oil temperature sensor 50b and a second oil temperature sensor 13a that detect the oil temperature, and oil supply. An oil pressure sensor 50a for detecting the oil pressure in the passage 5, a supply amount obtaining unit 66 for obtaining the amount of oil supplied from the oil pump 41 to the oil supply passage 5, and an estimating unit 67 for estimating the oil level in the oil pan 13. And an oil indicator 45 provided on the instrument panel for displaying the oil level. The oil level measuring device measures the oil level in the oil pan 13 and displays a warning on the oil indicator 45 when it is necessary to replace or replenish the oil. The supply amount acquisition unit 66 and the estimation unit 67 are configured by the ECU 60.

  The oil pressure sensor 50a and the first oil temperature sensor 50b are provided in the oil supply passage 5 as described above. That is, the oil pressure sensor 50a detects the oil pressure in the oil supply passage 5 (that is, the oil pressure of the oil supplied into the engine), and the first oil temperature sensor 50b supplies the oil temperature in the oil supply passage 5 (ie, the oil supply inside the engine). The oil temperature of the applied oil (hereinafter referred to as “first oil temperature”) is detected. The second oil temperature sensor 13 a is provided in the oil pan 13. That is, the second oil temperature sensor 13a detects the oil temperature in the oil pan 13 (hereinafter referred to as “second oil temperature”). The second oil temperature sensor 13a may be incorporated in the level sensor 8.

<Level sensor>
First, the configuration of the level sensor 8 will be described with reference to FIGS. FIG. 3 is a partial cross-sectional view of the engine showing a state in which the level sensor is provided in the oil pan. FIG. 4 is a longitudinal sectional view showing a schematic configuration of the level sensor. 5 is a cross-sectional view taken along line VV in FIG.

  The level sensor 8 is an ultrasonic level sensor and measures the oil level using ultrasonic waves. As shown in FIG. 3, the level sensor 8 is disposed at a substantially central portion of the oil pan 13 in the vehicle front-rear direction and closer to one side in the vehicle lateral direction (left-right direction). The level sensor 8 has an oil storage part 81 and a base part 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. A plurality of ribs 98 are formed outside the oil storage portion 81.

  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. The first labyrinth chamber 89 and the second labyrinth chamber 90 constitute damping means according to the present invention that suppresses fluctuations in the oil level in the level sensor 8.

  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 tube 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 containing portion 81 is that if air is contained in the oil, the ultrasonic pulse is irregularly reflected and the detection accuracy of the level sensor 8 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 60.

  The ECU 60 includes a CPU, a memory, a counter timer group, an interface, a memory, and a processor having a path connecting these units. The ECU 60 receives detection results from various sensors. For example, the ECU 60 includes a water temperature sensor SW1 that detects the temperature of the cooling water of the engine 100, an airflow sensor SW2 that detects the amount of air taken in by the engine 100, and a supercharging pressure that detects the pressure of the air supplied to the combustion chamber 14a. Sensor SW3, crank angle sensor SW4 for detecting the rotation angle of the crankshaft 15, vehicle speed sensor SW5 for detecting the vehicle speed of the vehicle, front-rear G sensor SW6 for detecting the vehicle longitudinal acceleration, and detecting the vehicle lateral acceleration The lateral G sensor SW7, the hydraulic pressure sensor 50a, the first oil temperature sensor 50b, the second oil temperature sensor 13a, and the level sensor 8 are connected.

  The ECU 60 determines the operating state of the engine 100 based on these detection results, and controls the engine 100 and the oil supply device 200. For example, the ECU 60 determines a target torque mainly based on the engine speed and the accelerator opening, and controls the fuel injection by the injector 18 so as to generate the target torque.

  One of the controls by the ECU 60 is measurement of the oil level in the oil pan 13. Hereinafter, measurement of the oil level by the ECU 60 will be described. FIG. 6 shows a functional block diagram of the ECU 60 relating to hydraulic control and oil level measurement. In FIG. 6, elements necessary for hydraulic control and oil level measurement are mainly shown.

  The ECU 60 includes a hydraulic control unit 61 that controls the oil supply device 200, a measurement unit 62 that measures the oil level in the oil pan 13, a storage unit 63, and a determination unit 64 that determines whether the oil level is normal or abnormal. Have.

  The hydraulic control unit 61 determines the operating state of the engine 100 based on various detection results, and the oil control valve 44, the first direction switching valve 56a, the second direction switching valve 56b, and the third direction according to the determined operating state. The switching valve 56c is controlled. For example, the hydraulic control unit 61 controls the discharge amount of the oil pump 41 according to the operating state of the engine 100. Specifically, the hydraulic control unit 61 sets a target hydraulic pressure according to the operating state of the engine 100, and the oil pump 41 via the oil control valve 44 so that the hydraulic pressure detected by the hydraulic sensor 50a becomes the target hydraulic pressure. To control. The hydraulic control unit 61 controls the capacity of the oil pump 41 by adjusting the duty ratio of the control signal supplied to the oil control valve 44.

  Measuring unit 62 measures the oil level in oil pan 13 during operation of engine 100. The measurement unit 62 includes an extraction unit 65 that extracts (samples) a detection value (actual value) of the level sensor 8, a supply amount acquisition unit 66 that calculates a supply amount of oil supplied from the oil pump 41 to the oil supply passage 5, And an estimation unit 67 for estimating the oil level in the oil pan 13.

  When the extraction condition is satisfied, the extraction unit 65 extracts (samples) the detection value (output raw data) of the level sensor 8 at the time when the extraction condition is satisfied.

  Here, the extraction condition is a predetermined condition that can be determined that the extraction of the detection value of the level sensor 8 is appropriate. In the present embodiment, (1) the communication between the level sensor 8 and the ECU 60 is in a normal state, (2) the oil pressure in the oil supply passage 5 detected by the oil pressure sensor 50a is equal to or less than a predetermined threshold, and (3) the engine. The rotational speed is 750 to 3000 rpm, (4) the vehicle speed is 5 km / h or more, (5) the second oil temperature in the oil pan 13 is 20 to 120 ° C., and (6) the longitudinal direction. The extraction condition is established when the acceleration is less than 0.2 G and (7) the lateral acceleration is less than 0.2 G (predetermined value).

  The condition (1) is set in order to prevent the level sensor 8 and the ECU 60 from calculating the oil level average value in an abnormal state.

  The condition (2) is set because when the hydraulic pressure is high, the amount of oil circulating in the oil pan 13 is large due to the large amount of oil circulation, and the operating condition of the engine 100 is high and high load. This is because the oil level in the oil pan 13 is vigorously stirred by the crankshaft 15 and the oil level fluctuates greatly.

  The 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 detection accuracy of the oil level is lowered. 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 condition (5) is set to a range including the oil temperature during short-distance / short-time driving that completes the driving cycle before the warm-up of the engine 100 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 rise characteristic 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 reason why the condition (6) is set is that when the acceleration in the front-rear direction increases, the oil level fluctuates, so that it is not suitable for oil level stability detection. 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, so that it 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. The engine 100 is mounted horizontally on the front portion of the vehicle, and the level sensor 8 is located in the vehicle front-rear direction center portion in the oil pan 13 and closer to one side in the vehicle lateral direction. Directional acceleration has a greater effect on oil level fluctuations than longitudinal acceleration.

  In addition to the above extraction conditions, the inclination state when the vehicle is stopped is detected by a G sensor or the like. When the vehicle is in a substantially horizontal state, the oil level is detected, and the oil value when the vehicle travels is detected using this detection value. It may be used for level estimation.

  As described above, the extraction unit 65 selects and removes the detection value when the oil level is unstable and the detection value when the level sensor 8 cannot be detected from the detection value of the level sensor 8, and obtains the other detection values. Extract.

  However, when the lateral acceleration becomes 0.2 G (predetermined value) or more while the vehicle is running, the extraction unit 65 (for example, the duration of the state where the lateral acceleration is 0.2 G or more is less than 5 seconds) ), The detection value of the level sensor 8 is not extracted even if the extraction condition is satisfied for 7 seconds (predetermined period) from the time when it becomes less than 0.2 G (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 level sensor 8 fluctuates at a low frequency due to the deviation of the oil in the oil pan 13, and the level sensor 8 The oil level inside fluctuates. Here, in the level sensor 8, by providing the labyrinth chambers 89 and 90 (damping means), the high frequency fluctuation of the oil level in the level sensor 8 is suppressed. Therefore, when the acceleration in the lateral direction occurs, the level sensor 8 Although the oil does not flow out to the oil pan 13, a response delay of the level sensor 8 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, the oil level in the level sensor 8 is almost stabilized even when the oil in the oil pan 13 is no longer offset (the level sensor 8 is in a normal state). ) Takes time. That is, even if the lateral acceleration becomes less than 0.2 G again, the detected value of the level sensor 8 is influenced by the lateral acceleration (low frequency fluctuation of the oil surface) for a while after that. Therefore, when the lateral acceleration becomes 0.2 G or more during traveling of the vehicle, the detection value of the level sensor 8 is not extracted for 7 seconds from the time when the acceleration again becomes less than 0.2 G. The reason why “7 seconds” was set is that when the experiment was performed in advance, the response delay time of the level sensor 8 was about 7 seconds with respect to the low frequency fluctuation of the oil level when the lateral acceleration occurred. .

  Furthermore, the extraction unit 65 again becomes less than 0.2 G 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 (predetermined time) or more while 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 level sensor 8 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 level sensor 8 is exposed from the oil by the deviation of the oil in the oil pan 13, and the oil in the level sensor 8 is exposed to the first oil opening 83a. Flows out into the oil pan 13 and air flows into the level sensor 8. At this time, even if the lateral acceleration becomes less than 0.2 G again, and the oil is not offset in the oil pan 13, the oil flows again into the level sensor 8 and the oil level is almost stabilized (level sensor It takes time until 8 becomes normal). Therefore, when the lateral acceleration is 0.2 G or more and the direction is constant for 5 seconds or more while the vehicle is running, the level sensor is again for 30 seconds from when it becomes less than 0.2 G again. 8 detection values are not extracted. The reason why “30 seconds” was set is that, if the experiment was conducted in advance, it took about 30 seconds for the level sensor 8 to become normal when all the oil in the level sensor 8 was discharged. The “30 seconds” includes the response delay time (7 seconds) of the level sensor 8.

  As described above, the extraction unit 65 again becomes less than 0.2 G when the lateral acceleration is 0.2 G or more from the detection value of the level sensor 8 when the extraction condition is satisfied. Detected within 7 seconds from the time, and when the lateral acceleration is 0.2G or more and the direction is in a constant direction for 5 seconds or more, again becomes less than 0.2G To those other than those detected within 30 seconds.

  The supply amount acquisition unit 66 estimates the supply amount of oil supplied from the oil pump 41 to the oil supply passage 5 based on the engine speed and the capacity of the oil pump 41. Specifically, a discharge amount map as shown in FIG. 7 is stored in the storage unit 63. In the discharge amount map, the discharge amount of the oil pump 41 according to the engine speed and the capacity of the oil pump 41 is defined. Normally, the higher the engine rotational speed, the higher the rotational speed of the drive shaft 41a that is rotationally driven by the crankshaft 15. Therefore, the discharge amount of the oil pump 41 increases. Further, the larger the capacity of the oil pump 41, the larger the discharge amount of the oil pump 41. The discharge amount map is obtained in advance by experiments or the like and stored in the storage unit 63. In the present embodiment, the duty ratio of the control signal output from the hydraulic control unit 61 to the oil control valve 44 is used as the capacity of the oil pump 41.

  Further, the discharge amount of the oil pump 41 varies depending on the oil temperature, that is, the viscosity of the oil. That is, as the oil temperature decreases, the viscosity of the oil decreases and the discharge amount of the oil pump 41 increases. Therefore, such a discharge amount map is stored in the storage unit 63 for each oil temperature (that is, oil viscosity).

  The supply amount acquisition unit 66 reads a discharge amount map corresponding to the second oil temperature in the oil pan 13 from the storage unit 63 based on the detection result of the second oil temperature sensor 13a. The supply amount acquisition unit 66 acquires the discharge amount of the oil pump 41 by comparing the engine rotation speed detected by the crank angle sensor SW4 and the duty ratio of the control signal to the oil control valve 44 with the discharge amount map. To do. That is, the supply amount acquisition unit 66 estimates the supply amount of oil supplied from the oil pump 41 to the oil supply passage 5 based on the oil temperature in addition to the engine speed and the capacity of the oil pump 41. Although the supply amount acquisition unit 66 uses the second oil temperature as the oil temperature when selecting the discharge amount map, the first oil temperature in the oil supply passage 5 may be used. Both the oil temperature and the second oil temperature may be used.

  Next, the estimation unit 67 corrects the detection value of the level sensor 8 extracted by the extraction unit 65 based on the oil supply amount acquired by the supply amount acquisition unit 66, and estimates the oil level in the oil pan 13. To do. That is, during operation of the engine 100, the oil in the oil pan 13 is pumped up by the oil pump 41 and supplied to the inside of the engine, so that the oil pan 13 during operation of the engine 100 (that is, during operation of the oil pump 41). The oil level in the engine is lower than that when the engine 100 is stopped (that is, when the oil pump 41 is stopped) by the amount of oil remaining in the engine. Further, the oil temperature of the oil during operation of the engine 100 has fluctuated since the engine 100 was stopped (usually high), and when the oil temperature changes, the oil expands or contracts, so that the volume of the oil increases. fluctuate. Also by this, the oil level in the oil pan 13 during operation of the engine 100 fluctuates since the engine 100 is stopped. Therefore, the estimation unit 67 corrects the detection value of the level sensor 8 extracted during the operation of the engine 100 based on the oil supply amount to the oil supply passage 5 and the oil temperature, so that the oil level during the stop of the engine 100 is obtained. (Hereinafter referred to as “oil level at stop”).

  Every time the detection value of the level sensor 8 is extracted by the extraction unit 65, the estimation unit 67 corrects the detection value to obtain the oil level at the time of stop. Further, the estimation unit 67 finally estimates the stop oil level by averaging the stop oil level.

  Specifically, the estimation unit 67 sets the correction amount for correcting the oil amount in the oil pan 13 during operation of the engine 100 to the oil amount while the engine 100 is stopped, and the oil temperature and the discharge amount of the oil pump 41. Ask based on. As described above, the amount of oil in the oil pan 13 during the operation of the engine 100 is due to the amount of oil remaining in the engine and the oil volume fluctuation due to the oil temperature change. It has fluctuated from. The estimation unit 67 obtains the correction amount of the oil amount in consideration of the residual oil amount and the oil volume fluctuation based on the oil temperature and the discharge amount of the oil pump 41.

  Specifically, the residual amount of oil depends on the balance between the amount of oil supplied into the engine and the amount of oil returned from the engine to the oil pan 13. Since the oil supply passage 5 of the present embodiment is not provided with components for adjusting the hydraulic pressure such as a relief valve, the discharge amount of the oil pump 41 corresponds to the supply amount of oil supplied to the oil supply passage 5. Further, the return amount of oil depends on the viscosity of the oil. That is, when the viscosity of the oil decreases, the amount of oil leakage inside the engine increases, and the amount of oil return from the engine to the oil pan increases. Since the viscosity of the oil is correlated with the oil temperature, that is, the return amount of the oil depends on the oil temperature. Therefore, the estimation unit 67 obtains the correction amount of the oil amount in consideration of the oil supply amount into the engine and the oil return amount from the engine based on the discharge amount of the oil pump 41 and the oil temperature. .

  Oil volume variation depends on oil temperature. If the oil temperature increases, the oil expands and increases in volume, while if the oil temperature decreases, the oil contracts and decreases in volume. Therefore, the estimation unit 67 obtains the correction amount of the oil amount in consideration of the oil volume variation based on the oil temperature.

  As described above, the estimation unit 67 obtains the correction amount of the oil amount by comprehensively considering the residual oil amount and the oil volume fluctuation based on the oil temperature and the discharge amount of the oil pump 41. At this time, the estimation unit 67 uses both the first oil temperature that is the oil temperature of the oil supply passage 5 and the second oil temperature that is the oil temperature in the oil pan 13 as the oil temperature. The oil temperature having a large influence on the return amount of oil is the first oil temperature, and the oil temperature having a large influence on the volume fluctuation of the oil in the oil pan 13 is the second oil temperature. That is, the estimation unit 67 uses an oil temperature suitable for each when considering the residual amount of oil and the volume variation of the oil. Thereby, the correction amount of the oil amount can be obtained in consideration of the remaining amount of oil and the volume variation of the oil with higher accuracy.

  A correction amount map as shown in FIG. 8 is stored in the storage unit 63. In the correction amount map, an oil amount correction amount corresponding to the discharge amount of the oil pump 41 and the oil temperature is defined. In FIG. 8, only one oil temperature is shown, but actually, the first oil temperature of the oil supply passage 5 and the second oil temperature of the oil pan 13 are considered. That is, the correction amount map defines oil amount correction amounts for three parameters of the oil supply amount, the first oil temperature, and the second oil temperature. The correction amount map is obtained in advance by experiments or the like and stored in the storage unit 63. In the present embodiment, after the engine 100 has been warmed up (oil temperature is about 80 ° C.), the oil state in the oil pan 13 when the ignition is turned off and left for 5 minutes is the oil pan when the engine 100 is stopped. 13 is regarded as the state of oil in 13 and the correction amount is obtained.

  The estimation unit 67 reads the correction amount map from the storage unit 63. And the estimation part 67 is based on the oil supply amount (namely, discharge amount of the oil pump 41) acquired by the supply amount acquisition part 66, the 1st oil temperature from the 1st oil temperature sensor 50b, and the 2nd oil temperature sensor 13a. The oil amount correction amount is obtained by comparing the second oil temperature with the correction amount map.

  Further, the storage unit 63 stores an oil level characteristic indicating the relationship between the oil level and the oil amount in the oil pan 13 as shown in FIG. The cross-sectional area of the oil pan 13 changes according to the height in the oil pan 13, and components and structures such as the oil pump 41 and the level sensor 8 exist in the oil pan 13. Therefore, even if the amount of oil in the oil pan 13 varies by a certain amount, the amount of variation in the oil level varies depending on the oil level in the oil pan 13 at that time (that is, the height of the oil surface). Therefore, the oil level in the oil pan 13 changes nonlinearly with respect to the oil amount as shown in FIG. This oil level characteristic is obtained in advance by experiments or the like and stored in the storage unit 63.

  Since the oil level characteristic depends on the shape of the oil pan 13 and the components and structures inside the oil pan 13, there may be an oil pan in which the oil level changes linearly with respect to the oil amount.

  First, the estimation unit 67 reads the oil level characteristic from the storage unit 63. Then, the oil amount corresponding to the detected value is obtained by comparing the detected value of the level sensor 8 with the oil level characteristic. The estimation unit 67 estimates the oil amount in the oil pan 13 when the engine 100 is stopped by adding the correction amount of the oil amount described above to the obtained oil amount. Thereafter, the estimation unit 67 obtains the oil level at the time of stop by comparing the oil amount when the engine 100 is stopped with the oil level characteristic. The oil level at the time of stop is an estimated value of the oil level in the oil pan 13 when the engine 100 is warmed up (oil temperature is about 80 ° C.) and left to stand for 5 minutes as described above.

  In this way, the estimation part 67 estimates the oil level at the time of a stop. The measurement unit 62 causes the oil indicator 45 to display the oil level at the time of stop estimated by the estimation unit 67. Thus, the driver can always know the oil level at the time of stop in the oil pan 13.

  The determination unit 64 determines whether the oil needs to be replaced or replenished based on the oil level at the time of stop measured by the measurement unit 62. Specifically, the determination unit 64 averages the oil level at the time of stop measured by the measurement unit 62, and determines whether or not oil replacement or replenishment is necessary based on the average value of the oil level at the time of stop.

  Specifically, the determination unit 64 averages the oil level at the time of the stop when the oil level at the time of the stop is obtained for 3000 data, and when it travels 100 km, whichever is earlier. .

  When the average value of the oil level at the time of stop is calculated in this way, the influence of running disturbance (for example, longitudinal acceleration or lateral acceleration) that changes the oil level is excluded. In other words, when traveling for a certain period of time, the occurrence frequency of the forward acceleration and the backward acceleration, and the occurrence frequency of the acceleration in the left direction and the acceleration in the right direction are almost equal, respectively. Oil level fluctuations are offset. That is, the oil level when the engine 100 is stopped while the vehicle is level is obtained.

  The determination unit 64 determines whether the average value of the oil level at stop is equal to or greater than a predetermined upper limit value, and determines whether the average value of the oil level at stop is equal to or less than a predetermined lower limit value. In the present embodiment, the upper limit value is set to the X level shown in FIG. 3, and the lower limit value is set to the L level shown in FIG. The X level is higher than the normal upper limit level F of the oil in the oil pan 13. This is because the engine 100 is a diesel engine and post-injection is performed for post-processing of the DPF 31b. In the diesel engine, unburned fuel during post-injection can be stored in the oil pan 13. That is, in the oil pan 13, the X level that is higher than the normal upper limit level F by the amount of unburned fuel in addition to oil is set to the upper limit oil level that can be allowed by the oil pan 13.

  The determination unit 64 continuously determines twice when the average value of the oil level during stoppage is equal to or higher than the upper limit value, or continuously when the average value of the oil level during stoppage is equal to or lower than the lower limit value. When it is determined that the oil needs to be replaced or replenished, a control signal is output to the oil indicator 45 to cause the oil indicator 45 to display a warning. This informs the driver of the need for oil replacement or replenishment.

  The calculation of the average value of the oil level at the time of stop and the determination of the oil level are continued without resetting the logic until it is determined that the oil needs to be replaced or replenished. The same applies when straddling a plurality of driving cycles.

  Next, the oil level determination procedure of the ECU 60 will be described with reference to FIG. FIG. 10 is a flowchart showing an oil level determination procedure.

  In step S1, the extraction unit 65 reads the detection value of the level sensor 8 and the like. In subsequent step S2, the extraction unit 65 extracts the detection value of the level sensor 8 when the above-described extraction condition is satisfied. However, when the lateral acceleration is 0.2 G or more, the detection value of the level sensor 8 is not extracted even if the extraction condition is satisfied for 7 seconds from the time when the acceleration again becomes less than 0.2 G. 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 level sensor 8 is not extracted.

  In step S3, the supply amount acquisition unit 66 acquires the supply amount of oil, and the estimation unit 67 corrects the detected value of the extracted level sensor 8 based on the supply amount of oil and the oil temperature, and stops. Find the oil level. The estimation unit 67 outputs a control signal to the oil indicator 45 and causes the oil indicator 45 to display the oil level at the time of stop.

  Thereafter, in step S4, the estimation unit 67 determines whether or not the oil level at the time of stopping has been obtained for 3000 data or has traveled 100 km. If the oil level at the time of stop is not obtained for 3000 data and the vehicle is not traveling 100 km, the flow returns to step SA1 and repeats the processing from reading the detected value of the level sensor 8 and the like.

  On the other hand, when the oil level at the time of stop is obtained for 3000 data, or when the vehicle travels 100 km, the estimation unit 67 averages the oil level at the time of stop in step S5.

  In the subsequent step S6, the determination unit 64 determines whether or not the average oil level at the time of stoppage obtained in step S5 is equal to or greater than a predetermined upper limit value L1, and the average value Level of the oil level at the time of stoppage is It is determined whether or not the value is equal to or less than a predetermined lower limit value L2. When the average value Level of the oil level at the time of stop is smaller than the upper limit value L1 and larger than the lower limit value L2, the flow returns to step S1. At this time, the count of the number of oil level data at the time of stop and the measurement of the travel distance are reset.

  On the other hand, when the average value Level of the oil level at the time of stop is equal to or higher than the upper limit value L1 or equal to or lower than the lower limit value L2, the determination unit 64 determines that the average value Level of the oil level at stop is the upper limit value in step S7. It is determined whether or not the determination that it is equal to or greater than L1 or equal to or less than the lower limit L2 (that is, NG determination) has continued twice. When the NG determination is the first time, the flow returns to step S1 in order to calculate the average value Level of the oil level at the time of stop (one cycle) in order to prevent erroneous determination.

  On the other hand, when the NG determination is continuous twice, the determination unit 64 outputs a control signal to the oil indicator 45 and causes the oil indicator 45 to display a warning in step S8.

  If the ignition is turned off after the warning is displayed on the oil indicator 45, the oil indicator 45 is turned off. Thereafter, when the oil is replenished or changed, and the logic is reset, the oil indicator 45 does not display a warning when the ignition is turned on again. On the other hand, if the oil is not replenished or changed, the oil indicator 45 displays the warning again when the ignition is turned on again.

  As described above, the oil measuring device includes the level sensor 8 that measures the oil level in the oil pan 13, the supply amount acquisition unit 66 that calculates the supply amount of oil supplied from the oil pump 41 to the engine, and the level sensor. And an estimation unit 67 that estimates the oil level in the oil pan 13 by correcting the actual measurement value of 8 based on the supply amount obtained by the supply amount acquisition unit 66.

  According to this configuration, the supply amount acquisition unit 66 obtains the discharge amount of the oil pump 41 corresponding to the supply amount of oil supplied from the oil pump 41 into the engine. And the estimation part 67 correct | amends the measured value of the level sensor 8 based on the calculated | required discharge amount. That is, since the actual measurement value of the level sensor 8 is corrected based on the amount of oil supplied to the engine, compared with the case where the actual measurement value of the level sensor 8 is simply corrected by the engine rotational speed, The oil level in the oil pan 13 can be measured in consideration of the influence of the remaining oil amount with higher accuracy.

  The oil level measurement device further includes a first oil temperature sensor 50b, and the estimation unit 67 is based on the supply amount obtained by the supply amount acquisition unit 66 and the detected temperature of the first oil temperature sensor 50b. The oil level in the oil pan 13 is estimated by correcting the actually measured value of 8.

  According to this configuration, the actual measurement value of the level sensor 8 is corrected not only based on the amount of oil supplied into the engine but also based on the oil temperature. As the oil temperature increases, the viscosity of the oil decreases, the amount of oil leakage inside the engine increases, and the amount of oil returned from the engine interior to the oil pan 13 increases. By correcting the actual measurement value of the level sensor 8 based on the oil temperature, the oil level can be estimated in consideration of the return amount to the oil pan 13 accurately.

  The oil pump 41 is configured such that the capacity can be adjusted by the control of the oil control valve 44, and the supply amount acquisition unit 66 is based on the capacity of the oil pump 41, the rotational speed of the engine 100, and the oil temperature. Discharge amount, that is, an oil supply amount.

  According to this configuration, the oil pump 41 is a variable displacement type. The discharge amount of such an oil pump can be obtained based on the capacity of the oil pump, the engine rotation speed, and the oil temperature. That is, it is possible to accurately obtain the oil supply amount in consideration of the discharge amount of the oil pump with high accuracy.

<< Other Embodiments >>
As described above, the embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated by the said embodiment and it can also be set as a new embodiment. In addition, among the components described in the attached drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the technology. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  About the said embodiment, it is good also as following structures.

  In the embodiment, the fuel of the engine 100 is mainly composed of light oil. However, the present invention is not limited to this. For example, an engine using gasoline or alcohol fuel (for example, ethanol fuel) may be used. In this case, the upper limit value of the oil level can be set to the F level instead of the X level.

  Moreover, in the said embodiment, when extraction conditions are satisfied, from the detection value of the level sensor 8, when lateral acceleration becomes 0.2 G or more, it becomes 7 again from when it became less than 0.2 G. Detected during the second and 30 seconds from the time when the lateral acceleration is 0.2 G or more and the direction is constant for 5 seconds or more and again becomes less than 0.2 G Although the thing other than what was detected between these is extracted, it is not restricted to this. These detection values may be extracted without being excluded. Or the structure which makes the influence with respect to calculation of an oil level average value of these detection values smaller than when the acceleration of a horizontal direction is less than 0.2 G may be sufficient. The numerical values such as 0.2G and 7 seconds described above can be set to arbitrary values.

  In addition, the extraction condition of the detection value of the level sensor 8 is merely an example, and any condition may be omitted or another condition may be added.

  Further, in the determination of the oil level, the oil level at the time of stop is averaged, but the oil level may be determined by each of the estimated oil levels at the time of stop instead of the average. Moreover, when averaging the oil level at the time of a stop, the conditions (3000 data or 100 km driving | running | working) which perform an average can be set arbitrarily. The oil level at the time of stop displayed on the oil indicator 45 may be an average value.

  Further, in the above embodiment, when the determination unit 10c makes the NG determination twice consecutively, the oil indicator 45 is displayed with a warning. However, the present invention is not limited to this. For example, when the NG determination is made once, A warning display may be displayed on the oil indicator 45.

  As described above, the technique disclosed herein is useful for an engine oil level measuring device.

DESCRIPTION OF SYMBOLS 100 Engine 200 Oil supply apparatus 13 Oil pan 13a 2nd oil temperature sensor 41 Oil pump 44 Oil control valve 50a Oil pressure sensor 50b 1st oil temperature sensor 66 Supply amount acquisition part 67 Estimation part 8 Level sensor

Claims (6)

An oil level measuring device that measures an oil level in an oil pan during engine operation,
A level sensor that actually measures the oil level in the oil pan;
A supply amount obtaining unit for obtaining a supply amount of oil supplied from the oil pump into the engine;
An oil level measurement apparatus comprising: an estimation unit that estimates an oil level in the oil pan by correcting an actual measurement value of the level sensor based on a supply amount obtained by the supply amount acquisition unit. In the oil level measuring device according to claim 1,
A viscosity detector for detecting a value related to the viscosity of the oil;
The estimation unit estimates an oil level in the oil pan by correcting an actual measurement value of the level sensor based on the supply amount obtained by the supply amount acquisition unit and a detection value of the viscosity detection unit. Oil level measuring device. In the oil level measuring device according to claim 2,
The oil pump is configured such that the capacity can be adjusted,
The oil level measuring device, wherein the supply amount obtaining unit obtains the supply amount based on a capacity of the oil pump, a rotational speed of the engine, and a detection value of the viscosity detection unit. In the oil level measuring device according to claim 2 or 3,
The oil level measuring device, wherein the viscosity detecting unit is an oil temperature detecting unit that detects an oil temperature of the oil as a value related to the viscosity of the oil. In the oil level measuring device according to claim 4,
The oil temperature detection unit includes a first oil temperature sensor that detects an oil temperature of oil supplied into the engine, and a second oil temperature sensor that detects an oil temperature of the oil in the oil pan. A characteristic oil level measuring device. In the oil level measuring device according to any one of claims 1 to 5,
A hydraulic pressure detection unit for detecting the hydraulic pressure of oil supplied to the engine;
The estimation unit is configured to estimate an oil level when an oil pressure detected by the oil pressure detection unit is a predetermined threshold value or less.

Images