WO2013080353A1 - Egrシステムの異常診断装置 - Google Patents
Egrシステムの異常診断装置 Download PDFInfo
- Publication number
- WO2013080353A1 WO2013080353A1 PCT/JP2011/077780 JP2011077780W WO2013080353A1 WO 2013080353 A1 WO2013080353 A1 WO 2013080353A1 JP 2011077780 W JP2011077780 W JP 2011077780W WO 2013080353 A1 WO2013080353 A1 WO 2013080353A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- egr
- pressure
- value
- blockage
- cooler
- Prior art date
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/49—Detecting, diagnosing or indicating an abnormal function of the EGR system
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/45—Sensors specially adapted for EGR systems
- F02M26/46—Sensors specially adapted for EGR systems for determining the characteristics of gases, e.g. composition
- F02M26/47—Sensors specially adapted for EGR systems for determining the characteristics of gases, e.g. composition the characteristics being temperatures, pressures or flow rates
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P2025/00—Measuring
- F01P2025/04—Pressure
- F01P2025/06—Pressure for determining flow
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B29/00—Engines characterised by provision for charging or scavenging not provided for in groups F02B25/00, F02B27/00 or F02B33/00 - F02B39/00; Details thereof
- F02B29/04—Cooling of air intake supply
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
- F02D41/0065—Specific aspects of external EGR control
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/02—EGR systems specially adapted for supercharged engines
- F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
- F02M26/05—High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/02—EGR systems specially adapted for supercharged engines
- F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
- F02M26/06—Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
- F02M26/14—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system
- F02M26/15—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the exhaust system in relation to engine exhaust purifying apparatus
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the present invention relates to an abnormality diagnosis device for an EGR system mounted on, for example, an internal combustion engine of an automobile.
- the present invention relates to an improvement for identifying a blockage site in an EGR system.
- the state where the flow area of the EGR passage is small (partially closed state) and the state where the EGR passage is completely closed (completely closed state) are both expressed as “blocked”. I will do it.
- the EGR system includes an EGR passage that allows the engine exhaust passage and the intake passage to communicate with each other, and an EGR valve provided in the EGR passage. Then, by adjusting the opening of the EGR valve, the amount of exhaust gas recirculated from the exhaust passage to the intake passage via the EGR passage (EGR gas amount) is adjusted, and the EGR rate during intake is set in advance. The target EGR rate is set.
- EGR gas amount the amount of exhaust gas recirculated from the exhaust passage to the intake passage via the EGR passage
- the target EGR rate is set.
- an EGR cooler is provided in the EGR passage.
- an EGR cooler is applied to the EGR passage of the EGR mechanism.
- LPL-EGR mechanism a system including a high pressure EGR mechanism (hereinafter referred to as “HPL-EGR mechanism”) and a low pressure EGR mechanism (hereinafter referred to as “LPL-EGR mechanism”).
- HPL-EGR mechanism high pressure EGR mechanism
- LPL-EGR mechanism low pressure EGR mechanism
- the HPL (High Pressure Loop) -EGR mechanism recirculates the exhaust gas from the exhaust passage upstream of the turbocharger turbine (for example, the exhaust manifold) to the intake passage downstream of the turbocharger compressor. ing.
- an LPL (Low Pressure Loop) -EGR mechanism recirculates exhaust gas from an exhaust passage downstream of the turbocharger turbine to an intake passage upstream of the turbocharger compressor. For this reason, in the LPL-EGR mechanism, exhaust gas can be recirculated to the intake air before being supercharged by the compressor (relatively low pressure intake area), so that the recirculation amount can be greatly increased, and exhaust emission can be reduced. A big effect is obtained in improvement.
- the MPL (Middle Pressure Loop) -EGR system is used in a low load operation region of an engine by using only the HPL-EGR mechanism.
- the exhaust gas at the temperature is recirculated to stabilize the combustion and suppress the emission of HC and CO.
- only the LPL-EGR mechanism is used to recirculate the exhaust gas having a relatively low temperature, thereby suppressing the generation of smoke due to the high temperature of the intake air.
- the generation of HC, CO, and smoke is suppressed by using both the HPL-EGR mechanism and the LPL-EGR mechanism to recirculate the exhaust gas.
- the EPL cooler is not applied to the HPL-EGR mechanism that is intended to recirculate the relatively high temperature exhaust gas, and the LPL ⁇ that is intended to recirculate the relatively low temperature exhaust gas.
- the EGR cooler is applied only to the EGR mechanism.
- the EGR cooler significantly reduces the amount of NOx generated by suppressing the high temperature of the intake air by cooling the EGR gas and lowering the combustion temperature, and this EGR cooler is closed. Then, since the exhaust emission is remarkably deteriorated, a particularly high accuracy is required with respect to the presence or absence of blockage inside the EGR cooler.
- the present invention has been made in view of this point, and an object of the present invention is to provide an abnormality diagnosis device for an EGR system that can identify a blockage location in an EGR mechanism to which an EGR cooler is applied. It is in.
- the solution principle of the present invention taken to achieve the above object is that the EGR mechanism to which the EGR cooler is applied recognizes the differential pressure between the upstream side and the downstream side of the EGR cooler, and this differential pressure and the reference The closing position is specified by comparison with a value (for example, a value when the EGR mechanism is not closed). That is, when the differential pressure is large, the pressure loss between the upstream side and the downstream side of the EGR cooler is large, so it is determined that a blockage has occurred inside the EGR cooler. When the pressure is small, the pressure loss on the upstream side or the downstream side is larger than the pressure acquisition position, so it is determined that a blockage has occurred inside the piping member other than the EGR cooler. I am doing so.
- the present invention includes a piping member and an EGR cooler coupled to the piping member, and a part of the exhaust gas discharged to the exhaust system of the internal combustion engine passes through the piping member and the EGR cooler to the intake system.
- An abnormality diagnosis device for the EGR system to be refluxed is assumed.
- a differential pressure between the upstream pressure and the downstream pressure of the EGR cooler is detected, and the detected differential pressure value is higher than a preset reference differential pressure value, When the differential pressure value is higher than a predetermined cooler blockage determination value, it is determined that a blockage has occurred inside the EGR cooler, while the detected differential pressure value is greater than the reference differential pressure value.
- the differential pressure value becomes lower than a predetermined pipe blockage determination value, it is determined that a blockage has occurred inside the pipe member.
- the differential pressure between the upstream pressure and the downstream pressure of the EGR cooler deviates from the reference differential pressure value as the degree of blockage increases. .
- the divergence direction is the positive side (the side where the detected differential pressure value is higher)
- the amount becomes a predetermined amount or more and the detected differential pressure value becomes higher than a predetermined cooler blockage determination value it is determined that a blockage has occurred inside the EGR cooler.
- the divergence direction is the negative side (the side where the detected differential pressure value is low)
- the divergence may occur due to an increase in pressure loss inside the piping member upstream or downstream of the EGR cooler. It can be determined that the difference is greater than or equal to a predetermined amount, and when the detected differential pressure value is lower than a predetermined pipe blockage determination value, the pipe member is blocked. It is determined that it has occurred.
- the reference differential pressure value is specifically a differential pressure value between the upstream pressure and the downstream pressure of the EGR cooler when no blockage occurs in either the EGR cooler or the piping member.
- the reference differential pressure value which is the differential pressure value when no blockage has occurred
- the actual differential pressure value the differential pressure value between the upstream pressure and the downstream pressure of the EGR cooler
- the cooler blockage determination value is set as a value corresponding to the degree of blockage of the EGR cooler corresponding to a predetermined exhaust emission deterioration allowable limit.
- the pipe blockage judgment value is set as a value corresponding to the degree of blockage of the pipe member corresponding to a predetermined exhaust gas deterioration allowable limit.
- the EGR cooler when the EGR cooler is blocked and the degree of blockage increases, the exhaust emission deteriorates. However, the EGR cooler corresponding to a limit (so-called OBD regulation value) that allows the deterioration is acceptable.
- OBD regulation value a limit that allows the deterioration is acceptable.
- each determination value (cooler blockage determination value and pipe blockage determination value) is set in this way, the blockage occurs at the time when the blockage degree reaches the exhaust emission deterioration allowable limit or immediately before it reaches. In addition to being able to determine, the blockage location can be specified. For this reason, the internal combustion engine is not continuously operated in a state where the exhaust emission exceeds the allowable deterioration limit.
- the upstream pressure of the EGR cooler is The pressure at the location where the EGR cooler and the upstream piping member are connected, or at a position closer to the EGR cooler than the connection location.
- the downstream pressure of the EGR cooler is a connection location between the EGR cooler and the downstream piping member or a pressure closer to the EGR cooler than the connection location.
- the piping member since the detected differential pressure value becomes lower than the piping blockage determination value regardless of where the blockage occurs in the piping members (upstream piping member and downstream piping member), the piping member It is possible to improve the determination accuracy in the case where a blockage occurs inside the. Further, even when the pressure at the position closer to the EGR cooler than the above-mentioned connection location is detected, in the situation where the blockage occurs inside the EGR cooler, it is integrally formed on the upstream side and the downstream side of the EGR cooler. Generally, the EGR cooler is clogged before the pipe inside. Therefore, if the differential pressure value is higher than the cooler clogging judgment value, the EGR cooler is clogged. Since it can be determined that the determination is being made, the determination accuracy can be increased.
- a high pressure EGR mechanism that recirculates exhaust gas upstream of the turbocharger turbine in the exhaust system of the internal combustion engine to the intake system, and recirculates exhaust gas downstream of the turbocharger turbine in the exhaust system to the intake system and the EGR
- the blockage location in the low-pressure EGR mechanism is determined. It is the structure which performs.
- a differential pressure sensor that detects a differential pressure between the upstream pressure and the downstream pressure of the EGR cooler is provided, and the recirculation amount of the exhaust gas is determined based on the upstream pressure of the EGR cooler detected by the differential pressure sensor.
- the differential pressure between the pressure and the downstream pressure, the opening degree of the EGR valve for adjusting the exhaust gas recirculation amount, the temperature of the exhaust gas, and the pressure of the exhaust gas are estimated as parameters.
- the differential pressure sensor can be used both as a sensor for specifying a blockage location in the EGR system and a sensor for estimating the exhaust gas recirculation amount in the EGR system.
- the closing position can be specified based on the differential pressure between the upstream side and the downstream side of the EGR cooler. For this reason, when the blockage has occurred inside the EGR cooler, it can be determined with high accuracy. It is also possible to identify the blockage inside the EGR cooler and the blockage inside the piping member connected to the EGR cooler with high accuracy.
- FIG. 1 is a diagram illustrating a schematic configuration of an engine according to the embodiment.
- FIG. 2 is a diagram showing the configuration of the LPL-EGR mechanism.
- FIG. 3 is a block diagram showing a configuration of a control system such as an ECU.
- FIG. 4 is a diagram showing a map for setting the mode of the MPL-EGR system when the engine is warm.
- FIG. 5 is a diagram showing a map for setting the mode of the MPL-EGR system when the engine is cold.
- FIG. 6 is a flowchart showing a procedure of abnormality diagnosis operation of the MPL-EGR system.
- FIG. 7 is a diagram illustrating an example of a relationship between the blocking rate and the NOx generation amount when blocking occurs in the LPL-EGR mechanism.
- FIG. 8 is a diagram illustrating an example of the relationship between the blockage rate and the differential pressure in the case where the blockage occurs inside the low pressure EGR cooler and the case where the blockage occurs inside the pipe.
- FIG. 1 is a diagram showing a schematic configuration of an engine (internal combustion engine) 1 according to the present embodiment.
- the engine 1 shown in FIG. 1 is a diesel engine having four cylinders 11, 11,..., And each cylinder 11 has an injector (fuel injection valve) 2 capable of directly injecting fuel into the cylinder 11.
- injectors 2 are constituted by piezoelectric injectors (piezo elements) inside, for example, piezo injectors that are appropriately opened to inject and supply fuel into the cylinder 11. Further, the fuel boosted by a high-pressure fuel pump (not shown) is supplied to the injector 2 via a common rail 21.
- Each cylinder 11 is connected to an intake passage 3 constituting an intake system.
- An air cleaner 31 is provided at the upstream end of the intake passage 3.
- a compressor 41, an intercooler 32, and an intake throttle valve (diesel throttle) 33 of a turbocharger (centrifugal supercharger) 4 are sequentially provided in the intake passage 3 along the direction of intake air flow. .
- the intake air introduced into the intake passage 3 is purified by the air cleaner 31, then supercharged by the compressor 41 and cooled by the intercooler 32. Thereafter, the intake air passes through the intake throttle valve 33 and is introduced into each cylinder 11.
- the intake air introduced into each cylinder 11 is compressed in the compression stroke, and fuel is burned by being injected into the cylinder 11 from the injector 2.
- a piston (not shown) reciprocates in the cylinder, and an engine output is obtained by rotating the crankshaft via the connecting rod.
- the intake throttle valve 33 is fully opened during normal operation. For example, when the vehicle is decelerated, the intake throttle valve 33 is predetermined as necessary (for example, when it is necessary to prevent a temperature drop of the oxidation catalyst 51 described later). It is closed to the opening.
- Each cylinder 11 is connected to an exhaust passage 5 constituting an exhaust system.
- a turbine 42 of the turbocharger 4 is provided in the middle of the exhaust passage 5.
- an oxidation catalyst (DOC) 51 and a particulate filter (DPF) 52, an exhaust throttle valve 53, and a muffler 54 are arranged along the exhaust flow direction. are provided in order.
- the exhaust gas (burned gas) generated by the combustion in each cylinder 11 is discharged to the exhaust passage 5.
- the exhaust gas discharged into the exhaust passage 5 passes through a turbine 42 provided in the middle of the exhaust passage 5 and is then purified by an oxidation catalyst 51 and a particulate filter 52, and then passes through an exhaust throttle valve 53 and a muffler 54. And released into the atmosphere.
- the engine 1 according to the present embodiment is provided with an MPL-EGR system including an HPL-EGR mechanism (high pressure EGR mechanism) 6 and an LPL-EGR mechanism (low pressure EGR mechanism) 7.
- HPL-EGR mechanism high pressure EGR mechanism
- LPL-EGR mechanism low pressure EGR mechanism
- the HPL-EGR mechanism 6 sends exhaust gas from the exhaust passage 5 (for example, the exhaust manifold) upstream of the turbine 42 of the turbocharger 4 to the intake passage 3 downstream of the intake throttle valve 33 (downstream of the compressor 41).
- a high-pressure EGR passage 61 that leads a part (high-pressure EGR gas) and a high-pressure EGR valve 62 that can change the flow passage area of the high-pressure EGR passage 61 are provided.
- the amount of high-pressure EGR gas recirculated (recirculated) by the HPL-EGR mechanism 6 is adjusted by the opening degree of the high-pressure EGR valve 62. Further, if necessary, the opening degree of the intake throttle valve 33 is decreased (the degree of closing is increased), and thereby the recirculation amount of the high-pressure EGR gas may be increased.
- the LPL-EGR mechanism 7 exhausts from the exhaust passage 5 downstream of the particulate filter 52 (downstream of the turbine 42) and upstream of the exhaust throttle valve 53 to the intake passage 3 upstream of the compressor 41.
- a low-pressure EGR passage 71 that guides a part of the gas (low-pressure EGR gas), a low-pressure EGR valve 72 that can change the flow area of the low-pressure EGR passage 71, and a low-pressure EGR gas that cools the low-pressure EGR gas that flows through the low-pressure EGR passage 71 EGR cooler 73 is provided.
- the amount of low-pressure EGR gas recirculated (recirculated) by the LPL-EGR mechanism 7 is adjusted by the opening degree of the low-pressure EGR valve 72. Further, the opening degree of the exhaust throttle valve 53 is reduced as necessary, and thereby the recirculation amount of the low pressure EGR gas may be increased.
- LPL-EGR mechanism 7 The configuration of the LPL-EGR mechanism 7 will be specifically described below.
- FIG. 2 is a diagram showing the LPL-EGR mechanism 7.
- the LPL-EGR mechanism 7 includes an upstream pipe 74, the low pressure EGR cooler 73, a downstream pipe 75, the low pressure EGR valve 72, and a differential pressure sensor 89.
- the upstream pipe 74 is a metal pipe, one end of which is connected to the exhaust pipe (pipe constituting the exhaust passage 5) 5A and the other end is connected to the low-pressure EGR cooler 73. This is a piping member that leads to the low-pressure EGR cooler 73.
- An upstream flange 74a and a downstream flange 74b having bolt holes (not shown) are integrally formed at both ends in the longitudinal direction of the upstream pipe 74.
- the upstream pipe 74 may be formed of a resin or rubber pipe.
- the low pressure EGR cooler 73 is provided with an introduction pipe member 73a for introducing EGR gas and a lead-out pipe member 73b for leading EGR gas. Further, an upstream flange 73c is integrally formed with the introduction pipe member 73a, and a downstream flange 73d is integrally formed with the outlet pipe member 73b. Further, bolt holes (not shown) are formed in the flanges 73c and 73d.
- downstream side pipe 75 is a metal pipe, one end of which is connected to the low pressure EGR cooler 73 and the other end is connected to the intake pipe (pipe constituting the intake passage 3) 3A. It is a piping member that guides the flowd EGR gas to the intake piping 3A.
- An upstream flange 75a and a downstream flange 75b having bolt holes (not shown) are integrally formed at both ends in the longitudinal direction of the downstream pipe 75.
- the downstream pipe 75 may also be formed of a resin or rubber pipe.
- flanges 5a and 3a similar to the above are formed at the connection place of the LPL-EGR mechanism 7 in each of the exhaust pipe 5A and the intake pipe 3A.
- the flange 5a of the exhaust pipe 5A and the upstream flange 74a of the upstream pipe 74 are overlapped, the downstream flange 74b of the upstream pipe 74 and the upstream flange 73c of the low pressure EGR cooler 73 are overlapped, and the low pressure EGR
- the downstream flange 73d of the cooler 73 and the upstream flange 75a of the downstream pipe 75 are overlapped, and further, the downstream flange 75b of the downstream pipe 75 and the flange 3a of the intake pipe 3A are overlapped, and these flanges are integrated. Bolts are tightened.
- the three members of the upstream side piping 74, the low pressure EGR cooler 73, and the downstream side piping 75 are connected to each other so that EGR gas can be circulated. Exchange).
- the low-pressure EGR valve 72 is provided in the downstream pipe 75.
- the differential pressure sensor 89 has a configuration in which an upstream gas introduction pipe 89b and a downstream gas introduction pipe 89c are connected to the sensor body 89a.
- the upstream gas introduction pipe 89b is connected to the introduction pipe member 73a of the low-pressure EGR cooler 73, and introduces the internal pressure of the introduction pipe member 73a into the sensor body 89a.
- the downstream side gas introduction pipe 89c is connected to the outlet pipe member 73b of the low pressure EGR cooler 73, and introduces the internal pressure of the outlet pipe member 73b into the sensor body 89a.
- the sensor main body 89a generates a differential pressure signal corresponding to the pressure difference between the internal pressure of the introduction pipe member 73a and the internal pressure of the outlet pipe member 73b (pressure difference between the upstream side and the downstream side of the low pressure EGR valve 72). It outputs to ECU (Electronic Control Unit) 10 mentioned later.
- ECU Electronic Control Unit
- the ECU 10 includes an A / F sensor 80, an air flow meter 81, an intake air temperature sensor 82, an intake air pressure sensor 83, an exhaust air temperature sensor 84, a water temperature sensor 85, a crank position sensor 86, an accelerator opening sensor 87, and an intake throttle valve opening sensor 88. These are electrically connected to various sensors such as the differential pressure sensor 89, the high pressure EGR valve opening sensor 8H, and the low pressure EGR valve opening sensor 8L described above.
- the A / F sensor 80 is a sensor that detects the oxygen concentration in the exhaust gas downstream of the particulate filter 52, and outputs a detection signal that continuously changes in accordance with the oxygen concentration.
- the air flow meter 81 is a sensor that measures the amount of air flowing into the intake passage 3 from the atmosphere.
- the intake air temperature sensor 82 is a sensor that detects the temperature of the air flowing through the intake passage 3 (the temperature upstream of the intake throttle valve 33).
- the intake pressure sensor 83 is a sensor that detects the pressure downstream of the intake throttle valve 33 (for example, in the intake manifold).
- the exhaust temperature sensor 84 is a sensor that detects the temperature of the exhaust gas flowing through the exhaust passage 5 (the temperature on the upstream side of the exhaust throttle valve 53).
- the water temperature sensor 85 is a sensor that detects the temperature of the cooling water circulating inside the engine 1.
- the crank position sensor 86 is a sensor that detects the rotational position of the crankshaft of the engine 1.
- the accelerator opening sensor 87 is a sensor that detects an operation amount (accelerator opening) of the accelerator pedal by the driver.
- the intake throttle valve opening sensor 88 is a sensor that detects the opening of the intake throttle valve 33.
- the differential pressure sensor 89 is a sensor that measures the differential pressure between the upstream side pressure and the downstream side pressure of the low pressure EGR cooler 73 in the LPL-EGR mechanism 7 as described above.
- the high pressure EGR valve opening sensor 8H is a sensor that detects the opening of the high pressure EGR valve 62.
- the low pressure EGR valve opening sensor 8L is a sensor that detects the opening of the low pressure EGR valve 72.
- the ECU 10 controls the injector 2, the intake throttle valve 33, the exhaust throttle valve 53, the high pressure EGR valve 62, and the low pressure EGR valve 72 based on the detected values and measured values of the various sensors 80 to 89, 8H, and 8L.
- the ECU 10 controls the usage state of the HPL-EGR mechanism 6 and the LPL-EGR mechanism 7 according to the operating state (engine load or the like) of the engine 1.
- the EGR mechanisms 6 and 7 to be used are selected according to the map of FIG. That is, when the engine 1 is in the low load operation state, the ECU 10 recirculates the exhaust gas using the HPL-EGR mechanism 6 (recirculation operation in the high pressure EGR region). When the engine 1 is in a high load operation state, the ECU 10 recirculates the exhaust gas by the LPL-EGR mechanism 7 (reflux operation in the low pressure EGR region).
- Region X in FIG. 4 is when the required acceleration to the vehicle is high (during transient operation) or the like, and both the high pressure EGR valve 62 of the HPL-EGR mechanism 6 and the low pressure EGR valve 72 of the LPL-EGR mechanism 7 are closed. This is an operating region where the EGR gas is not recirculated.
- the usage mode of the HPL-EGR mechanism 6 and the LPL-EGR mechanism 7 is switched according to the operating state of the engine 1, or when the EGR mechanisms 6 and 7 are used together, Therefore, an appropriate amount of EGR gas can be recirculated in a proper operation region, and the NOx concentration in the exhaust gas can be suitably reduced.
- the ECU 10 uses the HPL-EGR mechanism 6 to recirculate the exhaust gas in the operation region other than the region X, as shown in the map of FIG. I do. This is because the HPL-EGR mechanism 6 that does not include an EGR cooler is utilized to recirculate the exhaust gas having a relatively high temperature, thereby prematurely warming up the engine 1 and activating the oxidation catalyst 51 early. Because.
- the control of the EGR gas amount in the HPL-EGR mechanism 6 and the control of the EGR gas amount in the LPL-EGR mechanism 7 will be described.
- the control of the EGR gas amount in the HPL-EGR mechanism 6 and the control of the EGR gas amount in the LPL-EGR mechanism 7 are independent controls.
- the target EGR gas recirculation amount (hereinafter referred to as “target high-pressure EGR gas return”).
- the flow rate ”) and the estimated EGR gas recirculation amount (hereinafter referred to as“ estimated high pressure EGR gas recirculation amount ”), and the high pressure EGR gas recirculation amount approaches the target high pressure EGR gas recirculation amount.
- the opening degree of the EGR valve 62 and the opening degree of the intake throttle valve 33 are feedback controlled (hereinafter referred to as “EGR feedback control”).
- the target high-pressure EGR gas recirculation amount in this case is set according to the operating state of the engine 1 (particularly the engine load).
- the estimated high-pressure EGR gas recirculation amount is detected by the intake pressure sensor 83, the opening degree of the high-pressure EGR valve 62 detected by the high-pressure EGR valve opening sensor 8H, the intake air temperature detected by the intake air temperature sensor 82, and the like.
- the pressure in the intake manifold and the differential pressure between the pressure in the intake manifold and the pressure in the exhaust manifold are used as parameters, respectively, and are obtained from predetermined arithmetic expressions or maps stored in the ROM (Read Only Memory) of the ECU 10 in advance. .
- the pressure in the exhaust manifold is obtained from a predetermined arithmetic expression or map stored in advance in the ROM of the ECU 10 using the pressure in the intake manifold, the operating state amount of the engine 1 and the like as parameters.
- the target EGR gas recirculation amount (hereinafter referred to as “target low pressure EGR”).
- Gas recirculation amount) and the estimated EGR gas recirculation amount (hereinafter referred to as “estimated low pressure EGR gas recirculation amount"), and the estimated low pressure EGR gas recirculation amount approaches the target low pressure EGR gas recirculation amount.
- the opening degree of the low pressure EGR valve 72 and the opening degree of the exhaust throttle valve 53 are feedback controlled (EGR feedback control).
- the target low-pressure EGR gas recirculation amount in this case is set according to the operating state of the engine 1 (particularly the engine load). Further, the estimated low-pressure EGR gas recirculation amount is the opening of the low-pressure EGR valve 72 detected by the low-pressure EGR valve opening sensor 8L, the temperature of the exhaust detected by the exhaust temperature sensor 84, and the downstream of the particulate filter 52.
- the exhaust pressure and the differential pressure between the upstream pressure and the downstream pressure of the low pressure EGR cooler 73 detected by the differential pressure sensor 89 are used as parameters to obtain from a predetermined arithmetic expression or map stored in advance in the ROM of the ECU 10. It is done.
- the exhaust pressure downstream of the particulate filter 52 is obtained from a predetermined arithmetic expression or map stored in advance in the ROM of the ECU 10 with the pressure in the intake manifold, the operating state amount of the engine 1 and the like as parameters.
- the target high-pressure EGR gas return is performed so that the intake air amount detected by the air flow meter 81 matches the target intake air amount set according to the engine load, the engine speed, and the like.
- the flow rate is set, and as described above, the opening degree of the high pressure EGR valve 62 is feedback controlled so that the estimated high pressure EGR gas recirculation amount matches the target high pressure EGR gas recirculation amount.
- the low pressure EGR valve 72 is maintained fully closed.
- the intake air amount obtained by the air flow meter 81 is smaller than the target value and the actual EGR rate is higher than the target EGR rate (EGR rate determined according to the operating state of the engine 1 or the like)
- the opening degree of the high pressure EGR valve 62 is increased so as to increase the amount of EGR gas. If the estimated high pressure EGR gas recirculation amount does not reach the target high pressure EGR gas recirculation amount even if the opening amount of the high pressure EGR valve 62 is increased in this way, the opening amount of the intake throttle valve 33 is decreased ( The amount of EGR gas recirculated through the high pressure EGR passage 61 is increased by decreasing the pressure on the downstream side of the intake throttle valve 33. This brings the actual EGR rate closer to the target EGR rate.
- the control mode in which the EGR gas is recirculated using only the HPL-EGR mechanism 6 will be referred to as an HPL mode.
- the target value of the intake air amount and the target value of the EGR gas amount may each have a certain range to be a target range.
- the opening degree of the high pressure EGR valve 62 may be adjusted so that the EGR gas amount becomes a target value or a target range.
- the target low pressure EGR gas return is performed so that the intake air amount detected by the air flow meter 81 matches the target intake air amount set according to the engine load, the engine speed, and the like.
- the flow rate is set, and as described above, the opening degree of the low pressure EGR valve 72 is feedback-controlled so that the estimated low pressure EGR gas recirculation amount matches the target low pressure EGR gas recirculation amount.
- the high pressure EGR valve 62 is kept fully closed (unless the amount of EGR gas is insufficient).
- the opening degree of the low pressure EGR valve 72 is reduced so as to reduce the amount of EGR gas.
- the opening degree of the low pressure EGR valve 72 is increased so as to increase the amount of EGR gas. If the estimated low pressure EGR gas recirculation amount does not reach the target low pressure EGR gas recirculation amount even if the opening amount of the low pressure EGR valve 72 is increased in this way, the opening amount of the high pressure EGR valve 62 is increased, Alternatively, the amount of EGR gas is increased by decreasing the opening degree of the exhaust throttle valve 53 (increasing the closing degree). This brings the actual EGR rate closer to the target EGR rate.
- a control mode in which the EGR gas is recirculated using only the LPL-EGR mechanism 7 is referred to as an LPL mode.
- the target value of the intake air amount and the target value of the EGR gas amount may each have a certain range to be a target range.
- the opening degree of the low pressure EGR valve 72 may be adjusted so that the EGR gas amount becomes a target value or a target range.
- the opening degree of the high pressure EGR valve 62 is controlled so that the estimated high pressure EGR gas recirculation amount reaches the target high pressure EGR gas recirculation amount.
- the opening degree control for the high pressure EGR valve 62 is the same as that in the low load operation described above.
- the opening degree of the low pressure EGR valve 72 is controlled so that the estimated low pressure EGR gas recirculation amount reaches the target low pressure EGR gas recirculation amount.
- the opening degree control for the low-pressure EGR valve 72 is the same as in the above-described high-load operation.
- a control mode for supplying EGR gas using both the HPL-EGR mechanism 6 and the LPL-EGR mechanism 7 is referred to as an MPL mode.
- the target value of the intake air amount and the target value of the EGR gas amount may each have a certain range to be a target range.
- the opening degrees of the low pressure EGR valve 72 and the high pressure EGR valve 62 may be adjusted so that the EGR gas amount becomes a target value or a target range.
- the differential pressure sensor 89 causes a differential pressure between the upstream pressure and the downstream pressure of the low pressure EGR cooler 73 (more specifically, the internal pressure of the introduction pipe member 73a and the internal pressure of the discharge pipe member 73b). Pressure difference).
- the differential pressure value (hereinafter referred to as “actual differential pressure value”) and the differential pressure value (hereinafter referred to as “reference differential pressure value”) when no blockage occurs in the LPL-EGR mechanism 7. ).
- This reference differential pressure value is obtained in advance through experiments and simulations.
- the predetermined value (the deviation) for determining that the blockage has occurred is set to correspond to the pressure difference when the blockage state that should be determined as “blocking” due to legal regulations or the like is established. (Details will be described later).
- This flowchart is performed at a predetermined timing (for example, once in one trip of the vehicle (a period from when the ignition is turned on until it is turned off)).
- step ST1 it is determined whether or not a precondition for executing the abnormality diagnosis operation is satisfied.
- Preconditions include, for example, that the differential pressure sensor 89 is operating normally, no abnormality has occurred in the high pressure EGR valve 62 and the low pressure EGR valve 72, and the operation mode of the engine 1 is the normal combustion mode. And so on.
- the determination that the differential pressure sensor 89 is operating normally and the determination that the EGR valves 62 and 72 are operating normally can be performed by a known determination operation. Omitted.
- the normal combustion mode of the engine 1 is an operation mode in which the EGR gas is recirculated, and is a state that is not when the required acceleration for the vehicle is high or when the particulate filter 52 is being regenerated.
- step ST1 If at least one of these preconditions is not satisfied, a NO determination is made in step ST1, and the abnormality diagnosis operation is returned as impossible.
- step ST1 the process proceeds to step ST2, and it is determined whether or not the condition for starting the abnormality diagnosis operation is satisfied.
- a condition for starting the abnormality diagnosis operation for example, the engine speed is within a predetermined range, the fuel injection amount from the injector 2 is within a predetermined range, and the opening of the low pressure EGR valve 72 is within a predetermined range.
- the EGR gas amount is set to “0” during the transient operation of the engine 1, the absence of such a situation is set as a condition for starting the abnormality diagnosis operation.
- the fuel injection charge is set to “0”, and the opening amount of the intake throttle valve 33 is reduced to reduce the exhaust amount and suppress the temperature drop of the oxidation catalyst 51.
- the EGR gas amount is set to “0”, the absence of such a situation is set as a condition for starting the abnormality diagnosis operation.
- the flow rate of the EGR gas in the low pressure EGR passage 71 needs to be secured to some extent.
- the opening condition is within a predetermined range as a condition for starting the abnormality diagnosis operation.
- the engine operation region in which the opening degree of the low pressure EGR valve 72 is within a predetermined range is a region surrounded by a broken line in FIG. That is, it is an operation region on the relatively high load side in the LPL mode or in the MPL mode.
- step ST2 If any one of these abnormality diagnosis operation start conditions is not satisfied, NO is determined in step ST2, and the abnormality diagnosis operation is returned as impossible.
- step ST ⁇ b> 2 if the abnormality diagnosis operation start condition is satisfied and YES is determined in step ST ⁇ b> 2, the process proceeds to step ST ⁇ b> 3, and the upstream side pressure and the downstream side pressure of the low pressure EGR cooler 73 detected by the differential pressure sensor 89. Information on the differential pressure (actual differential pressure value) is acquired.
- step ST4 the differential pressure value (actual differential pressure value) is not less than a predetermined value a (piping blockage judgment value in the present invention) and not more than a predetermined value b (cooler blockage judgment value in the present invention). It is determined whether or not (a ⁇ actual differential pressure value ⁇ b).
- the predetermined values a and b are set to correspond to a pressure difference in a closed state that should be determined as “closed” due to legal regulations.
- the predetermined value “a” is set as a value corresponding to the degree of blockage serving as a threshold for determining that the upstream side piping 74 or the downstream side piping 75 is blocked
- the predetermined value “b” is the low pressure EGR. It is set as a value corresponding to the degree of blockage that is a threshold for determining that blockage has occurred inside the cooler 73.
- FIG. 7 shows a blockage rate in the case where blockage occurs in the LPL-EGR mechanism 7 (the ratio of the passage area being narrowed in the case where blockage occurs in the LPL-EGR mechanism 7 (blocked). It is a figure which shows an example of the relationship between the area / passage area when the obstruction
- the blockage rate corresponding to the NOx generation amount corresponding to the regulation value shown in FIG. 7 (so-called OBD regulation value; allowable exhaust gas deterioration limit)
- the blockage rate A (for example, 90%) in the figure is obtained. That is, in order to determine that the NOx generation amount reaches the regulation value, it is necessary to determine with high accuracy that the blockage rate has reached A in the figure.
- FIG. 8 shows an example of the relationship between the clogging rate and the differential pressure when the clogging occurs inside the low pressure EGR cooler 73 and when the clogging occurs inside the upstream side piping 74 or the downstream side piping 75.
- the differential pressure value B in FIG. 8 is a reference differential pressure value when the occlusion rate is “0” (no occlusion). That is, it is a differential pressure value corresponding to the original pressure loss in the internal resistance of each of the pipes 74 and 75 and the low pressure EGR cooler 73. In other words, when the detected differential pressure value is “B”, the LPL-EGR mechanism 7 is not clogged (no deposit is present) or is clogged slightly (the deposit is little). ) State.
- the actual differential pressure value increases as the blockage rate increases (see the solid line in FIG. 8). Then, it deviates toward the positive side with respect to the reference differential pressure value B. This is because the pressure loss increases due to the blockage inside the low pressure EGR cooler 73. That is, the pressure on the exhaust passage 5 side (the upstream pipe 74 side) is increased due to the blockage inside the low pressure EGR cooler 73, whereas the pressure on the intake passage 3 side (the downstream pipe 75 side) is increased. This is because the negative suction pressure acts and the differential pressure between them increases.
- the blockage rate is “A” in the figure, that is, the blockage rate that is the NOx generation amount corresponding to the regulation value is when the differential pressure is “b” in the figure. is there.
- the differential pressure becomes “b” in the figure, a clogging has occurred inside the low pressure EGR cooler 73, and the clogging rate is “A” in the figure, and the NOx corresponding to the above regulation value. It can be determined that the occlusion rate is the generation amount.
- the actual differential pressure value decreases as the clogging rate increases (see the broken line in FIG. 8).
- the differential pressure value B deviates to the negative side. This is because when there is no blockage, a relatively large amount of EGR gas flows inside the low-pressure EGR cooler 73, so that a differential pressure value corresponding to the original pressure loss inside the low-pressure EGR cooler 73 is obtained. Although it is obtained, when a blockage occurs on the upstream side or downstream side of the low pressure EGR cooler 73, the amount of EGR gas flowing inside the low pressure EGR cooler 73 is extremely reduced, so that the differential pressure is also large. This is because it cannot be obtained.
- the blockage rate is “A” in the figure, that is, the blockage rate that is the NOx generation amount corresponding to the regulation value is when the differential pressure is “a” in the figure. is there. That is, if the differential pressure becomes “a” in the figure, the upstream pipe 74 or the downstream pipe 75 is blocked, and the blocking rate is “A” in the figure, and the above restriction is applied. It can be determined that the blockage rate is the NOx generation amount corresponding to the value.
- the differential pressure value (actual differential pressure value) is a range that is not less than the predetermined value a and not more than the predetermined value b (a ⁇ actual differential pressure). It is determined whether or not value ⁇ b).
- step ST4 when the differential pressure value is in the range of the predetermined value a or more and the predetermined value b or less, and if YES is determined in step ST4, the process proceeds to step ST5, and normality determination is performed. That is, it is determined that the LPL-EGR mechanism 7 is not blocked, or is in a blocked state in which the NOx generation amount can be suppressed below the regulation value, and the process returns.
- step ST4 determines whether the differential pressure value is less than the predetermined value a and not more than the predetermined value b. If the differential pressure value is not less than the predetermined value a and not more than the predetermined value b, NO is determined in step ST4, and the process proceeds to step ST6, where abnormality is determined. That is, it is determined that an abnormality has occurred somewhere in the LPL-EGR mechanism 7 (an obstruction in which the amount of NOx generated reaches the regulation value has occurred).
- step ST7 it is determined whether or not the actual differential pressure value exceeds the predetermined value b.
- step ST7 If the actual differential pressure value exceeds the predetermined value b and a YES determination is made in step ST7, the process proceeds to step ST8, where it is determined that a blockage has occurred inside the low pressure EGR cooler 73.
- abnormality determination for example, abnormality information (information indicating that a blockage has occurred inside the low-pressure EGR cooler 73) is written in the diagnosis provided in the ECU 10. In addition, a warning is issued to the driver as necessary.
- step ST7 if the actual differential pressure value does not exceed the predetermined value b and a NO determination is made in step ST7, the actual differential pressure value is below the predetermined value a. Therefore, the process proceeds to step ST9. It is determined that a blockage has occurred inside the upstream pipe 74 or the downstream pipe 75. Accompanying this abnormality determination, for example, abnormality information (information indicating that the upstream pipe 74 or the downstream pipe 75 is clogged) is written in the diagnosis provided in the ECU 10. In addition, a warning is issued to the driver as necessary.
- abnormality information information indicating that the upstream pipe 74 or the downstream pipe 75 is clogged
- the blockage location is specified.
- the blockage point in the LPL-EGR mechanism 7 based on the differential pressure between the upstream pressure and the downstream pressure of the low pressure EGR cooler 73. For this reason, when the blockage has occurred inside the low pressure EGR cooler 73, it can be determined with high accuracy. Further, since the blockage inside the low-pressure EGR cooler 73 and the blockage inside the pipes 74 and 75 connected to the low-pressure EGR cooler 73 can be identified with high accuracy, replacement of the part in which the blockage occurs is performed. In such a case, it is possible to eliminate unnecessary parts replacement (a state in which piping parts that have not been blocked must be replaced).
- this abnormality diagnosis (diagnosis of the obstruction
- Abnormal diagnosis can be performed at an early stage.
- the differential pressure sensor 89 is used as a sensor for specifying a blockage location in the LPL-EGR mechanism 7 and a sensor for estimating the exhaust gas recirculation amount in the LPL-EGR mechanism 7. Can also be used.
- the present invention when the LPL-EGR mechanism 7 is blocked, the case where the present invention is used to identify the blocked portion has been described.
- the present invention is not limited to this, and if the HPL-EGR mechanism 6 is provided with an EGR cooler, if the HPL-EGR mechanism 6 is blocked, the blockage location is specified. It is also possible to use the present invention as an object.
- the present invention is applied to the engine 1 including the two EGR mechanisms 6 and 7 .
- the present invention is not limited to this, and can also be applied to an engine having one EGR mechanism and an engine having three or more EGR mechanisms. Also in this case, it becomes possible to specify the closed portion in the same manner as described above for the EGR mechanism provided with the EGR cooler.
- the pressure introduction point upstream of the low pressure EGR cooler 73 (the connection point of the upstream gas introduction pipe 89 b) is lower than the connection point between the low pressure EGR cooler 73 and the upstream pipe 74. It was a close position.
- the present invention is not limited to this, and may be a connecting portion (between the flanges 74b and 73c) between the low pressure EGR cooler 73 and the upstream pipe 74.
- a connection point on the downstream side of the low pressure EGR cooler 73 (a connection point of the downstream gas introduction pipe 89c)
- a connection point between the low pressure EGR cooler 73 and the downstream side pipe 75 (between the flanges 73d and 75a). Good.
- the present invention can be applied to blockage diagnosis of an MPL-EGR system mounted on a diesel engine.
Abstract
Description
上記の目的を達成するために講じられた本発明の解決原理は、EGRクーラが適用されたEGR機構に対し、EGRクーラの上流側と下流側との差圧を認識し、この差圧と基準値(例えばEGR機構が閉塞していない状態での値)との比較によって閉塞位置を特定するようにしている。つまり、差圧が大きい場合には、EGRクーラの上流側と下流側の間での圧力損失が大きくなっていることになるので、EGRクーラの内部で閉塞が発生していると判定し、差圧が小さい場合には、上記圧力取得位置よりも上流側または下流側での圧力損失が大きくなっていることになるので、EGRクーラ以外の配管部材の内部で閉塞が発生していると判定するようにしている。
具体的に、本発明は、配管部材およびその配管部材に連結されたEGRクーラを備え、内燃機関の排気系に排出された排気ガスの一部を上記配管部材および上記EGRクーラを経て吸気系に還流させるEGRシステムの異常診断装置を前提とする。このEGRシステムの異常診断装置に対し、上記EGRクーラの上流側圧力と下流側圧力との差圧を検出し、その検出した差圧値が、予め設定された基準差圧値よりも高くなり、その差圧値が所定のクーラ閉塞判定値よりも高くなった場合には上記EGRクーラの内部で閉塞が発生していると判定する一方、上記検出した差圧値が、上記基準差圧値よりも低くなり、その差圧値が所定の配管閉塞判定値よりも低くなった場合には上記配管部材の内部で閉塞が発生していると判定するようにしている。
図1は、本実施形態に係るエンジン(内燃機関)1の概略構成を示す図である。この図1に示すエンジン1は、4つの気筒11,11,…を有するディーゼルエンジンであって、各気筒11には、その気筒11内へ燃料を直接噴射可能なインジェクタ(燃料噴射弁)2がそれぞれ設けられている。これらインジェクタ2は、例えば内部に圧電素子(ピエゾ素子)を備え、適宜開弁して気筒11内に燃料を噴射供給するピエゾインジェクタにより構成されている。また、このインジェクタ2には、図示しない高圧燃料ポンプによって昇圧された燃料がコモンレール21を介して供給されている。
本実施形態に係るエンジン1には、HPL-EGR機構(高圧EGR機構)6およびLPL-EGR機構(低圧EGR機構)7を備えたMPL-EGRシステムが設けられている。
以下、このLPL-EGR機構7の構成について具体的に説明する。
図3に示すように、上記インジェクタ2、吸気絞り弁33、排気絞り弁53、高圧EGRバルブ62および低圧EGRバルブ72は、ECU10と電気的に接続されている。
次に、上記MPL-EGRシステムの基本制御について説明する。
上述した如く、エンジン負荷が比較的低いとき(低負荷領域)には、HPL-EGR機構6のみを用いてEGRガスが還流される。この運転領域をHPL領域という。なお、冷却水温度が低いときにもHPL-EGR機構6のみを用いてEGRガスが還流される。
上述した如く、エンジン負荷が比較的高いとき(高負荷領域)には、LPL-EGR機構7のみを用いてEGRガスが還流される。この運転領域をLPL領域という。
上述した如く、エンジンが中負荷運転であるとき(中負荷領域)には、HPL-EGR機構6とLPL-EGR機構7とを併用してEGRガスが還流される。このHPL領域とLPL領域との間の領域をMPL領域という。
次に、本実施形態の特徴とする動作であるLPL-EGR機構7の異常診断動作について説明する。この異常診断動作は、LPL-EGR機構7の内部で閉塞が発生している場合に、LPL-EGR機構7を構成している部材である上記上流側配管74、低圧EGRクーラ73、下流側配管75のうち、低圧EGRクーラ73の内部で閉塞が発生しているのか、上流側配管74または下流側配管75の内部で閉塞が発生しているのかを判別するものである。
以上説明した実施形態は、自動車に搭載される直列4気筒ディーゼルエンジンに本発明を適用した場合について説明した。本発明は、自動車用に限らず、その他の用途に使用されるエンジンにも適用可能である。また、気筒数やエンジン形式(直列型エンジン、V型エンジン、水平対向型エンジン等の別)についても特に限定されるものではない。
3 吸気通路(吸気系)
4 ターボチャージャ(過給機)
42 タービン
5 排気通路(排気系)
6 HPL-EGR機構(高圧EGR機構)
7 LPL-EGR機構(低圧EGR機構)
73 低圧EGRクーラ
74 上流側配管(配管部材)
75 下流側配管(配管部材)
89 差圧センサ
10 ECU
Claims (7)
- 配管部材およびその配管部材に連結されたEGRクーラを備え、内燃機関の排気系に排出された排気ガスの一部を上記配管部材および上記EGRクーラを経て吸気系に還流させるEGRシステムの異常診断装置において、
上記EGRクーラの上流側圧力と下流側圧力との差圧を検出し、その検出した差圧値が、予め設定された基準差圧値よりも高くなり、その差圧値が所定のクーラ閉塞判定値よりも高くなった場合には上記EGRクーラの内部で閉塞が発生していると判定する一方、上記検出した差圧値が、上記基準差圧値よりも低くなり、その差圧値が所定の配管閉塞判定値よりも低くなった場合には上記配管部材の内部で閉塞が発生していると判定する構成となっていることを特徴とするEGRシステムの異常診断装置。 - 請求項1記載のEGRシステムの異常診断装置において、
上記基準差圧値は、EGRクーラおよび配管部材の何れにも閉塞が発生していない場合における上記EGRクーラの上流側圧力と下流側圧力との差圧値であることを特徴とするEGRシステムの異常診断装置。 - 請求項1または2記載のEGRシステムの異常診断装置において、
上記クーラ閉塞判定値は、予め規定された排気エミッションの悪化許容限界に対応する上記EGRクーラの閉塞度合いに応じた値として設定されていることを特徴とするEGRシステムの異常診断装置。 - 請求項1、2または3記載のEGRシステムの異常診断装置において、
上記配管閉塞判定値は、予め規定された排気エミッションの悪化許容限界に対応する上記配管部材の閉塞度合いに応じた値として設定されていることを特徴とするEGRシステムの異常診断装置。 - 請求項1~4のうち何れか一つに記載のEGRシステムの異常診断装置において、
上記配管部材は、EGRクーラの上流側に連結された上流側配管部材、および、EGRクーラの下流側に連結された下流側配管部材であり、
上記EGRクーラの上流側圧力は、このEGRクーラと上記上流側配管部材との連結箇所、または、この連結箇所よりもEGRクーラ寄りの位置の圧力であり、
上記EGRクーラの下流側圧力は、このEGRクーラと上記下流側配管部材との連結箇所、または、この連結箇所よりもEGRクーラ寄りの位置の圧力であることを特徴とするEGRシステムの異常診断装置。 - 請求項1~5のうち何れか一つに記載のEGRシステムの異常診断装置において、
上記内燃機関の排気系における過給機のタービン上流側の排気ガスを吸気系に還流する高圧EGR機構と、排気系における過給機のタービン下流側の排気ガスを吸気系に還流するとともに上記EGRクーラを備えた低圧EGR機構とを有するEGRシステムに対して、この低圧EGR機構におけるEGRクーラの上流側圧力と下流側圧力との差圧を検出することで、この低圧EGR機構における閉塞箇所の判定を行う構成となっていることを特徴とするEGRシステムの異常診断装置。 - 請求項1~6のうち何れか一つに記載のEGRシステムの異常診断装置において、
上記EGRクーラの上流側圧力と下流側圧力との差圧を検出する差圧センサを備えており、
上記排気ガスの還流量は、上記差圧センサによって検出された上記EGRクーラの上流側圧力と下流側圧力との差圧、排気ガスの還流量を調整するEGRバルブの開度、排気ガスの温度、排気ガスの圧力それぞれをパラメータとして推定されることを特徴とするEGRシステムの異常診断装置。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP11859654.3A EP2636879B1 (en) | 2011-12-01 | 2011-12-01 | Fault diagnosis device for egr system |
CN201180016245.8A CN103249940B (zh) | 2011-12-01 | 2011-12-01 | Egr系统的异常诊断装置 |
US13/583,182 US9261052B2 (en) | 2011-12-01 | 2011-12-01 | Failure diagnosis apparatus of EGR system |
JP2012534468A JP5327393B1 (ja) | 2011-12-01 | 2011-12-01 | Egrシステムの異常診断装置 |
PCT/JP2011/077780 WO2013080353A1 (ja) | 2011-12-01 | 2011-12-01 | Egrシステムの異常診断装置 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2011/077780 WO2013080353A1 (ja) | 2011-12-01 | 2011-12-01 | Egrシステムの異常診断装置 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013080353A1 true WO2013080353A1 (ja) | 2013-06-06 |
Family
ID=48523101
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/077780 WO2013080353A1 (ja) | 2011-12-01 | 2011-12-01 | Egrシステムの異常診断装置 |
Country Status (5)
Country | Link |
---|---|
US (1) | US9261052B2 (ja) |
EP (1) | EP2636879B1 (ja) |
JP (1) | JP5327393B1 (ja) |
CN (1) | CN103249940B (ja) |
WO (1) | WO2013080353A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015068274A (ja) * | 2013-09-30 | 2015-04-13 | マツダ株式会社 | エンジンの排気ガス還流制御装置 |
JP2015209765A (ja) * | 2014-04-23 | 2015-11-24 | 日産自動車株式会社 | エンジン制御装置 |
JP2016109031A (ja) * | 2014-12-05 | 2016-06-20 | トヨタ自動車株式会社 | 内燃機関の制御装置 |
Families Citing this family (29)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102011002553A1 (de) * | 2011-01-12 | 2012-07-12 | Ford Global Technologies, Llc | Aufgeladene Brennkraftmaschine und Verfahren zum Betreiben einer derartigen Brennkraftmaschine |
FR2981408B1 (fr) * | 2011-10-12 | 2013-10-18 | IFP Energies Nouvelles | Procede de commande d'une vanne integree dans un circuit de recirculation des gaz d'echappement d'un moteur |
JP6028795B2 (ja) * | 2012-05-09 | 2016-11-16 | トヨタ自動車株式会社 | 内燃機関の制御装置 |
JP5897403B2 (ja) * | 2012-05-25 | 2016-03-30 | 日野自動車株式会社 | 異常検出方法 |
CN104487690B (zh) * | 2012-07-18 | 2017-09-29 | 日产自动车株式会社 | 内燃机 |
JP2014185546A (ja) * | 2013-03-22 | 2014-10-02 | Toyota Motor Corp | 車両の制御装置および制御方法 |
JP6090089B2 (ja) * | 2013-09-30 | 2017-03-08 | マツダ株式会社 | エンジンの排気ガス還流制御装置 |
US9797343B2 (en) | 2013-11-08 | 2017-10-24 | Ford Global Technologies, Llc | Determining exhaust gas recirculation cooler fouling using DPOV sensor |
CN103759907B (zh) * | 2014-01-23 | 2016-05-11 | 潍柴动力股份有限公司 | 一种egr管路故障检测方法 |
US9441564B2 (en) | 2014-04-14 | 2016-09-13 | Ford Global Technologies, Llc | Methods and systems for adjusting EGR based on an impact of PCV hydrocarbons on an intake oxygen sensor |
US9234476B2 (en) | 2014-04-14 | 2016-01-12 | Ford Global Technologies, Llc | Methods and systems for determining a fuel concentration in engine oil using an intake oxygen sensor |
US9670830B2 (en) * | 2014-10-29 | 2017-06-06 | GM Global Technology Operations LLC | Method and apparatus for monitoring a coolant system for an exhaust gas recirculation system |
CN107110013A (zh) * | 2015-01-16 | 2017-08-29 | 三菱重工业株式会社 | 可变容量型涡轮增压机的异常判定装置 |
CN104819072B (zh) * | 2015-04-29 | 2017-12-05 | 潍柴动力股份有限公司 | 一种egr冷却器气体报警方法及装置 |
JP6380914B2 (ja) * | 2016-03-04 | 2018-08-29 | マツダ株式会社 | エンジンの制御装置 |
CN106224133B (zh) * | 2016-08-30 | 2018-08-31 | 潍柴动力股份有限公司 | Egr管路故障检测方法 |
CN107803071B (zh) * | 2016-09-09 | 2020-01-17 | 中微半导体设备(上海)股份有限公司 | 一种排气系统及防止尘粒回流的装置及方法 |
US9909541B1 (en) | 2016-10-18 | 2018-03-06 | Ford Global Technologies, Llc | Method and system for exhaust heat exchanger diagnostics |
DE102017200290A1 (de) * | 2017-01-10 | 2018-07-12 | Robert Bosch Gmbh | Verfahren und Computerprogrammprodukt zur Erkennung und Unterscheidung eines Durchflussfehlers und eines Dynamikfehlers einer Abgasrückführung |
US10344691B2 (en) * | 2017-11-01 | 2019-07-09 | Fca Us Llc | Robust low pressure exhaust gas recirculation system control for a turbocharged gasoline engine |
US11073100B2 (en) * | 2018-11-16 | 2021-07-27 | Fca Us Llc | Cylinder based low pressure cooled exhaust gas recirculation transient measurement methodology |
CN110566381B (zh) * | 2018-11-30 | 2021-07-20 | 长城汽车股份有限公司 | 发动机egr系统和发动机egr系统的诊断策略 |
CN111024401B (zh) * | 2019-12-26 | 2022-04-05 | 潍柴动力股份有限公司 | 一种egr冷却器故障诊断方法、装置、设备及存储介质 |
CN111413100B (zh) * | 2020-03-26 | 2022-03-08 | 安徽华菱汽车有限公司 | 一种模拟egr系统废气循环量异常的报错方法与系统 |
US11215532B2 (en) * | 2020-05-04 | 2022-01-04 | Ford Global Technologies, Llc | Methods and systems for exhaust gas recirculation system diagnostics |
CN114251202A (zh) * | 2020-09-24 | 2022-03-29 | 深圳臻宇新能源动力科技有限公司 | 发动机egr系统及其诊断方法 |
JP7480730B2 (ja) * | 2021-03-16 | 2024-05-10 | トヨタ自動車株式会社 | Egr弁の劣化度算出システム、内燃機関の制御装置、及び車両 |
CN113398428A (zh) * | 2021-06-30 | 2021-09-17 | 南京康友医疗科技有限公司 | 一种动态监测的引流导管以及监测方法 |
CN115045781A (zh) * | 2022-06-10 | 2022-09-13 | 哈尔滨东安汽车动力股份有限公司 | 一种实现高egr率的低压冷却egr系统 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0763122A (ja) * | 1993-08-20 | 1995-03-07 | Aisin Seiki Co Ltd | 排ガス還流管の異常判定装置 |
JP2001289125A (ja) * | 2000-03-31 | 2001-10-19 | Mitsubishi Motors Corp | Egrクーラ装置 |
JP2008064046A (ja) * | 2006-09-08 | 2008-03-21 | Mazda Motor Corp | エンジンの排気ガス還流装置 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5137004A (en) * | 1990-08-28 | 1992-08-11 | Nissan Motor Co., Ltd. | Trouble diagnosis device for EGR system |
US6164270A (en) * | 1999-08-09 | 2000-12-26 | Ford Global Technologies, Inc. | Exhaust gas recirculation fault detection system |
JP2001207916A (ja) * | 2000-01-21 | 2001-08-03 | Toyota Motor Corp | 内燃機関の排気還流装置 |
JP3868926B2 (ja) * | 2003-06-03 | 2007-01-17 | ヤンマー株式会社 | ディーゼル機関の排気ガス還流制御装置 |
JP4415963B2 (ja) * | 2006-03-17 | 2010-02-17 | トヨタ自動車株式会社 | 内燃機関の排気浄化装置 |
JP2008150955A (ja) * | 2006-12-14 | 2008-07-03 | Denso Corp | 排気還流装置 |
JP5470384B2 (ja) * | 2008-07-16 | 2014-04-16 | ボーグワーナー インコーポレーテッド | エンジンシステムの冷却サブシステムの、そのサブシステム内で検出された動圧に応じた診断 |
JP2010190176A (ja) * | 2009-02-20 | 2010-09-02 | Toyota Motor Corp | 内燃機関の異常判定装置 |
US8359827B2 (en) * | 2009-02-24 | 2013-01-29 | Toyota Jidosha Kabushiki Kaisha | Abnormality diagnosis system and method for diagnosing abnormality in filter regeneration system |
JP5141610B2 (ja) | 2009-03-19 | 2013-02-13 | トヨタ自動車株式会社 | 内燃機関の排気浄化装置 |
JP2011089470A (ja) * | 2009-10-22 | 2011-05-06 | Toyota Motor Corp | Egrシステムの故障診断装置 |
GB2492770A (en) * | 2011-07-11 | 2013-01-16 | Gm Global Tech Operations Inc | Method and apparatus for operating an exhaust gas recirculation system |
-
2011
- 2011-12-01 CN CN201180016245.8A patent/CN103249940B/zh not_active Expired - Fee Related
- 2011-12-01 US US13/583,182 patent/US9261052B2/en not_active Expired - Fee Related
- 2011-12-01 JP JP2012534468A patent/JP5327393B1/ja not_active Expired - Fee Related
- 2011-12-01 EP EP11859654.3A patent/EP2636879B1/en not_active Not-in-force
- 2011-12-01 WO PCT/JP2011/077780 patent/WO2013080353A1/ja active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0763122A (ja) * | 1993-08-20 | 1995-03-07 | Aisin Seiki Co Ltd | 排ガス還流管の異常判定装置 |
JP2001289125A (ja) * | 2000-03-31 | 2001-10-19 | Mitsubishi Motors Corp | Egrクーラ装置 |
JP2008064046A (ja) * | 2006-09-08 | 2008-03-21 | Mazda Motor Corp | エンジンの排気ガス還流装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2636879A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015068274A (ja) * | 2013-09-30 | 2015-04-13 | マツダ株式会社 | エンジンの排気ガス還流制御装置 |
JP2015209765A (ja) * | 2014-04-23 | 2015-11-24 | 日産自動車株式会社 | エンジン制御装置 |
JP2016109031A (ja) * | 2014-12-05 | 2016-06-20 | トヨタ自動車株式会社 | 内燃機関の制御装置 |
Also Published As
Publication number | Publication date |
---|---|
EP2636879A4 (en) | 2016-05-25 |
EP2636879B1 (en) | 2017-08-16 |
JPWO2013080353A1 (ja) | 2015-04-27 |
JP5327393B1 (ja) | 2013-10-30 |
CN103249940B (zh) | 2015-08-05 |
US20130139795A1 (en) | 2013-06-06 |
CN103249940A (zh) | 2013-08-14 |
US9261052B2 (en) | 2016-02-16 |
EP2636879A1 (en) | 2013-09-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5327393B1 (ja) | Egrシステムの異常診断装置 | |
US7284366B2 (en) | System and method for operating an engine having an exhaust gas recirculation system | |
US8392098B2 (en) | Abnormality diagnosis device of internal combustion engine | |
US8091535B2 (en) | Internal combustion engine with an exhaust-gas recirculation and method for operating an internal combustion engine | |
JP5741032B2 (ja) | 内燃機関の排気再循環システム | |
US20070056266A1 (en) | System and method for regenerating a NOx storage and conversion device | |
JP5935813B2 (ja) | 内燃機関の制御装置 | |
JP3876778B2 (ja) | エンジンの燃料噴射制御装置 | |
JP5803622B2 (ja) | Egrシステムの異常診断装置 | |
JP5621638B2 (ja) | 内燃機関の排気再循環システム | |
JP4061742B2 (ja) | エンジンの排気ガス還流装置 | |
JP2010138834A (ja) | 内燃機関の吸気温センサ異常診断装置 | |
JP5111534B2 (ja) | 内燃機関のegr制御装置 | |
JP2008106636A (ja) | エンジンの異常検出装置 | |
JP2013148067A (ja) | 内燃機関の制御装置 | |
JP4710729B2 (ja) | 内燃機関の制御装置 | |
JP2010190176A (ja) | 内燃機関の異常判定装置 | |
KR101713720B1 (ko) | 실린더로 공급되는 이지알 가스의 비율을 연산방법 | |
JP2007255194A (ja) | 内燃機関の制御装置 | |
JP4919056B2 (ja) | 内燃機関の制御装置 | |
JP6943673B2 (ja) | 制御装置および制御方法 | |
JP6842382B2 (ja) | 制御装置および制御方法 | |
JP2013253532A (ja) | 過給エンジンのegr装置 | |
JP2013221445A (ja) | 内燃機関のガス温度推定装置及び故障診断装置 | |
JP2012188948A (ja) | 蓄圧式egrシステム |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2012534468 Country of ref document: JP Kind code of ref document: A |
|
REEP | Request for entry into the european phase |
Ref document number: 2011859654 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13583182 Country of ref document: US Ref document number: 2011859654 Country of ref document: EP |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11859654 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |