CN115111091B - Fuel oil leakage diagnosis method for fuel oil vehicle evaporation system - Google Patents
Fuel oil leakage diagnosis method for fuel oil vehicle evaporation system Download PDFInfo
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- CN115111091B CN115111091B CN202210453301.4A CN202210453301A CN115111091B CN 115111091 B CN115111091 B CN 115111091B CN 202210453301 A CN202210453301 A CN 202210453301A CN 115111091 B CN115111091 B CN 115111091B
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- 238000001704 evaporation Methods 0.000 title claims abstract description 69
- 230000008020 evaporation Effects 0.000 title claims abstract description 69
- 238000003745 diagnosis Methods 0.000 title claims abstract description 61
- 238000000034 method Methods 0.000 title claims abstract description 35
- 239000000295 fuel oil Substances 0.000 title claims abstract description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 84
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 84
- 239000000446 fuel Substances 0.000 claims abstract description 55
- 238000009423 ventilation Methods 0.000 claims abstract description 17
- 239000003921 oil Substances 0.000 claims description 49
- 238000011010 flushing procedure Methods 0.000 claims description 16
- 239000007789 gas Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 230000004913 activation Effects 0.000 claims description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 239000001301 oxygen Substances 0.000 claims description 4
- 230000000737 periodic effect Effects 0.000 claims description 4
- 230000007423 decrease Effects 0.000 claims description 3
- 238000010926 purge Methods 0.000 claims description 3
- 230000010354 integration Effects 0.000 claims description 2
- 238000011161 development Methods 0.000 abstract description 4
- 230000008569 process Effects 0.000 description 11
- 230000008859 change Effects 0.000 description 9
- 238000012544 monitoring process Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 8
- 238000001514 detection method Methods 0.000 description 7
- 238000009834 vaporization Methods 0.000 description 6
- 230000008016 vaporization Effects 0.000 description 6
- 238000012937 correction Methods 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 238000003795 desorption Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000033228 biological regulation Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229920005549 butyl rubber Polymers 0.000 description 1
- 238000002405 diagnostic procedure Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002000 scavenging effect Effects 0.000 description 1
Classifications
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- 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
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0809—Judging failure of purge control system
-
- 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
- F02D41/22—Safety or indicating devices for abnormal conditions
-
- 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
- F02D41/22—Safety or indicating devices for abnormal conditions
- F02D2041/224—Diagnosis of the fuel system
- F02D2041/225—Leakage detection
-
- 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
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Supplying Secondary Fuel Or The Like To Fuel, Air Or Fuel-Air Mixtures (AREA)
Abstract
According to the diagnosis method for fuel leakage of the fuel oil vehicle evaporation system, the engine is opened through the carbon tank electromagnetic valve to form vacuum degree with the air inlet manifold under the idle working condition, after the vacuum degree is required, the carbon tank electromagnetic valve and the carbon tank ventilation stop valve are closed, and under the closed space, the evaporation system is monitored to recover the normal pressure rate so as to judge the actual leakage amount, so that whether the evaporation system is leaked or not is judged, the problems of low electric balance performance and overhigh cost of the whole vehicle are solved, the electric balance of the whole vehicle is influenced, and meanwhile, the development cost is greatly saved.
Description
Technical Field
The invention relates to the technical field of fuel vehicle control, in particular to a method for diagnosing fuel leakage of a fuel vehicle evaporation system.
Background
With the development of industry and technology, especially the rapid rise of the automobile industry, the environmental impact caused by industrial waste gas and automobile exhaust is increasingly severe, and strict requirements are made on automobile emissions for further reducing and limiting automobile exhaust pollution, and national outlet GB18532-2016 light automobile pollutant emission limit value and measuring method. The national six-emission regulations increase the requirements for diagnosing fuel evaporation systems, requiring that the OBD on-board diagnostic system should have the capability of monitoring leakage fault diagnosis of evaporation systems of 1mm and above, and that the IUPR rate meet 0.226.
At present, the main machine factory in China mainly adopts DMTL (methyl methacrylate-butyl rubber) as a main scheme for diagnosing the vehicle fuel evaporation system, the DMTL is an external evaporation system leakage monitoring module, the detection principle is that air is pumped into an oil tank system through an air pump, so that the pressure of the oil tank is increased, the current of the air pump indirectly reflects the pressure increase condition in the oil tank, the tightness of the oil tank system is evaluated, and the judgment standard is as follows:
1) If a closed oil tank system: when the air pump works, the pressure of the oil tank rises, and the current rises rapidly. 2) If a leaking tank system is present: there is little or no rise in tank pressure and the air pump current is slow or no rise.
According to the scheme, a fuel leakage diagnosis module is additionally added, the cost of the whole vehicle is increased, a DMTL needs to stabilize working conditions when a reference current of a leakage hole of 0.5mm is formed, diagnosis is needed to be carried out after the whole vehicle is powered down, and the electric balance performance of the whole vehicle is influenced; the scheme becomes a great limiting factor in the whole vehicle development process of the current fuel vehicle.
Disclosure of Invention
Aiming at the problems in the prior art, a diagnosis method of fuel leakage of a fuel oil vehicle evaporation system is conceived, an engine is opened through a carbon tank electromagnetic valve to form vacuum degree with an air inlet manifold under an idle working condition, after the vacuum degree is required, the carbon tank electromagnetic valve and a carbon tank ventilation stop valve are closed, and under a closed space, the evaporation system is monitored to recover to normal pressure rate so as to judge the actual leakage amount.
The technical scheme adopted for realizing the invention is as follows: the method for diagnosing the fuel leakage of the fuel oil vehicle evaporation system is characterized by comprising the following steps of:
1) And (3) performing carbon tank flushing calibration:
(1) Calibrating the delay time of the electromagnetic valve of the carbon tank:
under the idle working condition, the delay time calibration of the carbon tank electromagnetic valve adopts a direct calibration method or an indirect calibration method;
(2) Calibrating the periodic characteristics of the electromagnetic valve of the carbon tank:
the delay time of the carbon tank electromagnetic valve is reduced, and the periodic characteristic of the carbon tank electromagnetic valve is calibrated to be long;
(3) Calibration of activation conditions of a carbon tank flushing function:
when the fuel cut-off and the oxygen removal are carried out, the air-fuel ratio condition is exited; the water temperature condition meets the preset of the evaporation system; presetting an engine starting time counting condition; the pressure of the oil tank has no obvious fluctuation; the voltage is kept normal;
2) Evaporation system leak diagnosis calibration:
(1) The evaporation system is started in leakage diagnosis, and the following conditions are achieved:
(1) starting water temperature is 4-35 ℃;
(2) the ambient temperature is 4-35 ℃;
(3) tnsez >600s after engine start;
(4) setting the idle speed B_ llr, wherein the vehicle speed is less than or equal to 3km/h;
(5) the voltage of the battery is 11-16V;
(6) the tank pressure pttp_w is between-25 and 10hPa;
(7) the ratio pspu of the manifold to the ambient pressure is less than or equal to 0.7;
(8) integration of canister purge flow imsteini >8g
(2) The evaporation system leak diagnosis abort includes one of the following conditions:
(1) the pressure of the oil tank continuously drops beyond the limit value after the vacuumizing is finished;
(2) the oil gas is evaporated severely;
(3) the oil gas is seriously condensed;
(4) the deviation between the actual flushing amount and the target is too large;
(5) after the carbon tank is closed and washed, the pressure of the oil tank does not enter into stability for a long time;
(3) Judging the diagnosis ending condition of the evaporation system:
the first stage: closing a carbon tank stop ventilation valve, opening a carbon tank electromagnetic valve, and increasing the vacuum degree of an evaporation system due to the vacuum degree of an intake manifold; if the vacuum degree of the evaporation system is not increased, the system detects a coarse leakage fault and diagnosis is stopped;
and a second stage: when the evaporation system reaches the required vacuum degree, the carbon tank electromagnetic valve is closed, the carbon tank electromagnetic valve and the carbon tank stop ventilation valve are both closed, the vacuum degree of the evaporation system can decline due to leakage, and the leakage of the evaporation system of 1mm is detected according to the decline gradient;
and a third stage: and after the fuel leakage diagnosis of the evaporation system is finished, the carbon tank stop vent valve can be opened, the normally open state is kept, and the carbon tank electromagnetic valve is closed.
Further, the direct calibration method comprises the following steps:
1) Setting the minimum duty ratio opening of the carbon tank electromagnetic valve, wherein the carbon tank electromagnetic valve is in a closed state due to the existence of delay time;
2) And gradually adjusting the duty ratio opening of the electromagnetic valve until the value of the flow sensor changes, and determining the delay time of the electromagnetic valve of the carbon tank.
Further, the indirect calibration method comprises the following steps:
1) Setting the frequency of a carbon tank electromagnetic valve, and gradually opening the carbon tank electromagnetic valve;
2) And gradually adjusting the duty ratio opening of the electromagnetic valve until the value of the flow sensor changes, and then counteracting the output duty ratio and the delay time, and calculating the delay time.
The diagnosis method for the fuel leakage of the fuel vehicle evaporation system has the beneficial effects that:
1. after the fact that the vehicle meets the preset diagnosis enabling conditions is determined, the working states of the carbon tank electromagnetic valve and the carbon tank stop ventilation valve are controlled through the engine control unit, and the pressure value in the evaporation system is monitored, so that whether leakage exists in the evaporation system is judged, the problem that a DMTL scheme needs to be operated in a later operation stage is avoided, the influence on the electric balance of the whole vehicle is avoided, and meanwhile development cost is greatly saved;
2. the diagnosis method for fuel leakage of the fuel oil vehicle evaporation system solves the problems of low electric balance performance and high cost of the whole vehicle during running after the existing whole vehicle is powered down, can meet the requirement of regulations, and effectively ensures the IUPR rate of OBD diagnosis.
Drawings
FIG. 1 is a schematic block diagram of a canister flush calibration;
FIG. 2 is a schematic block diagram of an evaporation system diagnostic;
FIG. 3 is a schematic diagram of a crude leak diagnostic method for diagnosing fuel leaks in a fuel vehicle vaporization system;
FIG. 4 is a complete leak diagnostic schematic diagram of a method for diagnosing fuel leaks in a fuel vehicle vaporization system.
Detailed Description
The invention is described in further detail below with reference to fig. 1-4 and the specific examples, which are provided for illustration only and are not intended to limit the invention.
And when the vehicle is in an idle working condition, the carbon tank electromagnetic valve is opened, and in the carbon tank desorption process, fuel leakage diagnosis is carried out, the state information of the vehicle is monitored through the ECU, and whether the current vehicle meets the preset condition is judged according to the state information.
If the preset condition is met, the engine control unit ECU is used for closing the carbon tank stop ventilation valve, opening a carbon tank electromagnetic valve with a certain opening degree, gradually forming negative pressure in the evaporation system, and acquiring the pressure of the oil tank in the evaporation system in real time. If the oil tank pressure cannot be quickly reduced in the process of forming the negative pressure, the oil tank pressure is smaller than the preset oil tank pressure reduction rate preset by the engine control unit, and the rough leakage fault of the evaporation system is monitored; if the pressure drop rate meets a preset value, when the pressure drops to a certain preset value, the ECU closes the carbon tank ventilation stop valve, and diagnosis enters a pressure maintaining diagnosis stage; acquiring the pressure change rate of the oil tank in the pressure maintaining stage, and if the pressure recovery pressure rate of the oil tank in the pressure maintaining stage is smaller than the preset rate reported by the fault, enabling the evaporation system to have no leakage fault; if the pressure recovery rate of the oil tank in the pressure maintaining stage is greater than the preset rate of fault report, the evaporation system has leakage fault; after the diagnosis is completed, the ECU controls the carbon tank stop ventilation valve and the carbon tank electromagnetic valve to restore to the original states, and the diagnosis is completed.
The basic working principle of the fuel oil leakage diagnosis method of the fuel oil vehicle evaporation system is as follows: under the idle working condition, the engine is opened through the carbon tank electromagnetic valve and forms vacuum degree with the air inlet manifold, the carbon tank electromagnetic valve and the carbon tank ventilation stop valve are closed after the vacuum degree is required, and the speed of the evaporation system for recovering normal pressure under the airtight space is monitored so as to judge the actual leakage quantity.
Example 1:
FIG. 1 is a schematic diagram of a module for the canister purge calibration of the present invention. The canister flush calibration includes: the device comprises a carbon tank flushing activation condition module, a carbon tank flushing target flow module, a carbon tank flushing process gas mixture self-learning correction module, a carbon tank flushing process fuel injection quantity correction module, an actual flow calculation module, an oxygen sensor signal processing module and a gas mixture control module.
A canister flush activation condition module for monitoring whether a current vehicle meets preset diagnostic enabling conditions including, but not limited to, the following: air-fuel ratio condition, air-fuel ratio condition exits when driving fuel cut-off and oxygen scavenging; the water temperature condition meets the preset of the evaporation system; presetting an engine starting time counting condition; detecting the off-line; the pressure of the oil tank has no obvious fluctuation; the voltage is kept normal; if the diagnosis condition is met, sending a diagnosis condition meeting state bit through an engine control unit;
the actual flow calculating module is used for monitoring the atmospheric environment pressure and the air inlet manifold pressure of the current vehicle, monitoring the pressure through the engine control power ECU and calculating the actual flow in the current carbon tank flushing process by combining the opening of the electromagnetic valve of the carbon tank;
the carbon tank flushing target flow module is used for calculating the control period and the duty ratio of the carbon tank electromagnetic valve at the next moment by combining the current actual desorption flow and controlling the carbon tank electromagnetic valve so as to adjust the desorption flow; in calibrating the canister valve control period, the period should be as long as possible in order to minimize the effect of the delay time. The small duty cycle results in a long canister valve closing time, thus making the oil and gas distribution uneven. However, when the duty cycle is relatively small, the flow through the canister valve is also small and thus has limited adverse effects on canister flushing. If the engine speed is increased throughout a continuous long control period, this uneven distribution of oil and gas increases with increasing speed, and in order to avoid this, the control period of the canister valve should be reduced as the engine speed increases.
Small duty cycle, long off time, shorter cycle at high rotational speed
Medium duty cycle-medium off time-rotational speed has less effect on cycle
Large duty cycle-short off time-period independent of rotational speed
And the mixed gas self-learning deviation correction module is used for calculating the content of oil vapor in the carbon tank flushing flow, correcting parameters of the mixed gas module, removing the compensation of the oil vapor in the carbon tank flushing process, and further finishing the correction of the relative fuel injection amount in the carbon tank flushing process.
Example 2:
referring to fig. 2, which is a schematic diagram of the evaporation system diagnosis module of the present invention, the fuel diagnosis device includes: the device comprises a processor, a memory, a carbon tank electromagnetic valve, a carbon tank ventilation stop valve, an evaporation pipeline and a communication bus. The communication bus is used for realizing signal connection among the components, and the memory can be a high-speed RAM memory or a stable NVM memory, and can be a storage device independent of a processor.
As shown in fig. 2, the memory may include an engine control system and a fuel vapor system leak diagnostic routine, and the processor may retrieve the fuel vapor system leak diagnostic routine from the memory and perform the following operations:
monitoring state information of the vehicle through an engine control unit ECU when the vehicle runs and is in an idle state; judging whether the current vehicle meets a preset diagnosis enabling condition according to the described state information; if the current vehicle meets the preset diagnosis enabling condition, closing a carbon tank ventilation stop valve through an engine control unit, and opening a carbon tank electromagnetic valve to a preset opening degree to form negative pressure in an evaporation system; then closing the electromagnetic valve of the carbon tank to form a sealed space; acquiring a pressure change value of an oil tank in an evaporation system, and determining whether leakage exists in the evaporation system according to the pressure change;
the processor may call a fuel vaporization system leak diagnostic routine from the memory and perform the following operations:
the voltage value output by the pressure sensor is acquired by the engine control unit ECU, and is converted into a corresponding evaporation system pressure value, and is continuously recorded. Calculating a pressure change value in the evaporation system according to the pressure values of the pressure sensors;
and comparing the pressure change value with a reference pressure change value, and determining whether leakage exists in the evaporation system according to a comparison result.
The processor may call a fuel vaporization system leak diagnostic routine from the memory and perform the following operations:
monitoring, by the engine control unit ECU, status flag information of a power supply status, a leak diagnosis output status, a safety status, an oil level status, a leak request transmission status, and/or an atmospheric pressure status of the vehicle;
and determining whether the current vehicle meets the basic condition of diagnosis leakage according to the state identification bit information.
The processor may call a fuel vaporization system leak diagnostic routine from the memory and perform the following operations:
when the carbon tank ventilation stop valve is closed and the carbon tank electromagnetic valve is opened through the engine control unit ECU, a negative pressure pumping process is performed at the moment, and the pressure monitoring is performed by the oil tank pressure sensor;
and recording the negative pressure falling rate in the negative pressure pumping stage, comparing the pressure change value with a reference pressure change value, and determining whether leakage exists in the evaporation system according to a comparison result. If the rate is smaller than the predetermined value, it is determined that a coarse leak exists.
The processor may call a fuel vaporization system leak diagnostic routine from the memory and perform the following operations:
the preset diagnostic enable conditions include a diagnostic leakage basic condition, a leakage diagnostic ambient condition, a lighting condition, a diagnostic leakage operating condition, and an engine running state.
Example 3:
as shown in fig. 3, a rough leakage diagnosis schematic diagram of a fuel leakage diagnosis method of a fuel evaporation system of a fuel vehicle according to the present invention is shown, after the vehicle enters an idle operation condition and operates for a period of time under the idle operation condition, the engine control unit ECU monitors vehicle state information, where the time of the idle operation condition can be set according to actual conditions, and the present invention is preferably 10s; after the vehicle is powered down and flameout reaches a preset time, the state information of the vehicle is acquired through the engine control unit ECU, wherein the state information comprises the state information of the vehicle, the state information of the environment and the like, such as the running time of the engine, the oil level, the ambient temperature, the atmospheric pressure, the oil filling request, the component failure and the like.
After the engine control unit ECU acquires the state information, it is determined whether the current vehicle satisfies a preset diagnosis enabling condition according to the acquired state information, where the preset diagnosis enabling condition may include a diagnosis leakage basic condition, a leakage diagnosis environmental condition, a lighting condition, a diagnosis leakage operation condition, an engine running state, and the like. The diagnosis enabling condition is preset by a user and can be adjusted according to actual requirements, the diagnosis enabling condition comprises the setting of conditions related to vehicle fuel leakage detection and the setting of a value range when the diagnosis condition is met, and if the vehicle fuel leakage detection needs to meet the current vehicle oil pressure range of 15-85%, the current environment temperature range of 4-35 ℃ and the current altitude of 2440 m or below, namely when the current atmospheric pressure is 72kpa or above, the current vehicle can be judged to meet the preset diagnosis enabling condition and the fuel leakage detection can be carried out when the conditions are all within the allowable range; when any one of the conditions is not within the allowable range, it may be determined that the current vehicle does not meet the preset diagnosis enabling condition, and it is necessary to wait for the next stage to perform the determination.
Judging whether the current vehicle meets the preset conditions according to the state information, if so, closing a carbon tank stop vent valve and opening a carbon tank electromagnetic valve with a certain opening degree through an engine control unit, gradually forming negative pressure in an evaporation system, and acquiring the pressure of an oil tank in the evaporation system in real time. If the oil tank pressure cannot be quickly reduced in the process of forming the negative pressure, the oil tank pressure is smaller than the preset oil tank pressure reduction rate preset by the engine control unit, and the rough leakage fault of the evaporation system is monitored;
as described above, when the engine control unit ECU detects that a rough leak occurs in the evaporation system, the canister vent shutoff valve is opened and normal engine control is resumed. The state identification bit information of the power supply state, the leak diagnosis output state, the safety state, the oil level state, the leak request transmission state, and/or the atmospheric pressure state of the vehicle is monitored by the engine control unit ECU.
Example 4:
as shown in fig. 4, a complete leak diagnosis diagram of a fuel leak diagnosis method of a fuel evaporation system of a fuel vehicle according to the present invention is shown, and after the vehicle enters an idle operation condition and operates for a period of time under the idle operation condition, vehicle status information is monitored by an engine control unit ECU. The time of the idle running condition can be set according to the actual situation, and the invention is preferably 10s. After the vehicle is powered down and flameout reaches a preset time, the state information of the vehicle is acquired through the engine control unit ECU, wherein the state information comprises the state information of the vehicle, the state information of the environment and the like, such as the running time of the engine, the oil level, the ambient temperature, the atmospheric pressure, the oil filling request, the component failure and the like.
And after the engine control unit ECU acquires the state information, judging whether the current vehicle meets a preset diagnosis enabling condition according to the acquired state information. The preset diagnostic enable conditions may include a diagnostic leakage basic condition, a leakage diagnostic ambient condition, a lighting condition, a diagnostic leakage operating condition, an engine running state, and the like. The diagnosis enabling condition is preset by a user and can be adjusted according to actual requirements, the diagnosis enabling condition comprises the setting of conditions related to vehicle fuel leakage detection and the setting of a value range when the diagnosis conditions are met, and if the vehicle fuel leakage detection needs to meet the current vehicle oil pressure range of 15-85%, the current environment temperature range of 4-35 ℃ and the current altitude of 2440 m or below, namely when the current atmospheric pressure is 72kpa or above, the current vehicle can be judged to meet the preset diagnosis enabling condition and the fuel leakage detection can be carried out when the conditions are all within the allowable range; when any one of the conditions is not within the allowable range, it may be determined that the current vehicle does not meet the preset diagnosis enabling condition, and it is necessary to wait for the next stage to perform the determination.
Monitoring state information of the vehicle through the ECU, and judging whether the current vehicle meets the preset condition according to the state information; if the preset condition is met, closing the carbon tank stop vent valve and opening a carbon tank electromagnetic valve with a certain opening degree through the engine control unit, gradually forming negative pressure in the evaporation system, and acquiring the pressure of the oil tank in the evaporation system in real time.
If the oil tank pressure cannot be quickly reduced in the process of forming the negative pressure, the oil tank pressure is smaller than the preset oil tank pressure reduction rate preset by the engine control unit, and the rough leakage fault of the evaporation system is monitored;
if the pressure drop rate meets a preset value, when the pressure drops to a certain preset value, the ECU closes the carbon tank ventilation stop valve, and diagnosis enters a pressure maintaining diagnosis stage;
acquiring the pressure change rate of the oil tank in the pressure maintaining stage, and if the pressure recovery pressure rate of the oil tank in the pressure maintaining stage is smaller than the preset rate reported by the fault, enabling the evaporation system to have no leakage fault; if the pressure recovery rate of the oil tank in the pressure maintaining stage is greater than the preset rate of fault report, the evaporation system has leakage fault;
after the diagnosis is completed, the ECU controls the carbon tank stop ventilation valve and the carbon tank electromagnetic valve to restore to the original states, and the diagnosis is completed.
The foregoing is merely a preferred embodiment of the invention, and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the invention, which are intended to be comprehended within the scope of the invention.
Claims (3)
1. The method for diagnosing the fuel leakage of the fuel oil vehicle evaporation system is characterized by comprising the following steps of:
1) And (3) performing carbon tank flushing calibration:
(1) Calibrating the delay time of the electromagnetic valve of the carbon tank:
under the idle working condition, the delay time calibration of the carbon tank electromagnetic valve adopts a direct calibration method or an indirect calibration method;
(2) Calibrating the periodic characteristics of the electromagnetic valve of the carbon tank:
reducing the delay time of the carbon tank electromagnetic valve, and calibrating the periodic characteristic of the carbon tank electromagnetic valve to be normally open;
(3) Calibration of activation conditions of a carbon tank flushing function:
when the fuel cut-off and the oxygen removal are carried out, the air-fuel ratio condition is exited; the water temperature condition meets the preset of the evaporation system; presetting an engine starting time counting condition; the pressure of the oil tank has no obvious fluctuation; the voltage is kept normal;
2) And (3) diagnosing and calibrating leakage of the evaporation system:
(1) The evaporation system is started in leakage diagnosis, and the following conditions are achieved:
(1) starting water temperature is 4-35 ℃;
(2) the ambient temperature is 4-35 ℃;
(3) tnsez >600s after engine start;
(4) setting the idle speed B_ llr, wherein the vehicle speed is less than or equal to 3km/h;
(5) the voltage of the battery is 11-16V;
(6) the tank pressure pttp_w is between-25 and 10hPa;
(7) the ratio pspu of the manifold to the ambient pressure is less than or equal to 0.7;
(8) integration of canister purge flow imsteini >8g
(2) The evaporation system leakage diagnosis abort comprises one of the following conditions:
(1) the pressure of the oil tank continuously drops beyond the limit value after the vacuumizing is finished;
(2) the oil gas is evaporated severely;
(3) the oil gas is seriously condensed;
(4) the deviation between the actual flushing amount and the target is too large;
(5) after the carbon tank is closed and washed, the pressure of the oil tank does not enter into stability for a long time;
(3) Judging the diagnosis ending condition of the evaporation system:
the first stage: closing a carbon tank stop ventilation valve, opening a carbon tank electromagnetic valve, and increasing the vacuum degree of an evaporation system due to the vacuum degree of an intake manifold; if the vacuum degree of the evaporation system is not increased, the system detects a coarse leakage fault and diagnosis is stopped;
and a second stage: when the evaporation system reaches the required vacuum degree, the carbon tank electromagnetic valve is closed, the carbon tank electromagnetic valve and the carbon tank stop ventilation valve are both closed, the vacuum degree of the evaporation system can decline due to leakage, and the leakage of the evaporation system of 1mm is detected according to the declining gradient;
and a third stage: and after the fuel leakage diagnosis of the evaporation system is finished, the carbon tank stop ventilation valve can be opened, the normally open state is kept, and the carbon tank electromagnetic valve is closed.
2. The method for diagnosing fuel leakage in a fuel vapor system of a fuel vehicle according to claim 1, wherein said direct calibration method comprises the steps of:
1) Setting the minimum duty ratio opening of the carbon tank electromagnetic valve, wherein the carbon tank electromagnetic valve is in a closed state due to the existence of delay time;
2) And gradually adjusting the duty ratio opening of the electromagnetic valve until the value of the flow sensor changes, and determining the delay time of the electromagnetic valve of the carbon tank.
3. The method for diagnosing fuel leakage in a fuel vapor system of a fuel vehicle as recited in claim 1, wherein said indirect calibration method comprises the steps of:
1) Setting the frequency of a carbon tank electromagnetic valve, and gradually opening the carbon tank electromagnetic valve;
and gradually adjusting the duty ratio opening of the electromagnetic valve until the value of the flow sensor changes, and then counteracting the output duty ratio and the delay time, and calculating the delay time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210453301.4A CN115111091B (en) | 2022-04-27 | 2022-04-27 | Fuel oil leakage diagnosis method for fuel oil vehicle evaporation system |
Applications Claiming Priority (1)
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Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5975062A (en) * | 1997-03-11 | 1999-11-02 | Pierburg Ag | Apparatus and method for periodically cleaning a charcoal canister and for periodically checking leak-tightness of a fuel system of an internal combustion engine |
| EP0969198A2 (en) * | 1998-07-02 | 2000-01-05 | Pierburg Aktiengesellschaft | Device for flushing a charcoal canister and for leak testing of a vehicle engine fuel tank installation connected to said canister |
| KR20070061698A (en) * | 2005-12-10 | 2007-06-14 | 현대자동차주식회사 | Apparatus for leakage diagnosis of evaporated gsa on vehicle and method thereof |
| KR20090116449A (en) * | 2008-05-07 | 2009-11-11 | 콘티넨탈 오토모티브 시스템 주식회사 | Method for detecting leak of fuel tank |
| CN106337762A (en) * | 2016-09-07 | 2017-01-18 | 中国第汽车股份有限公司 | Automobile fuel evaporation discharge control and diagnostic system |
| CN108151987A (en) * | 2017-12-22 | 2018-06-12 | 江铃汽车股份有限公司 | Diagnostic method, device and the system of fuel evaporation leakage |
| CN108223200A (en) * | 2017-12-14 | 2018-06-29 | 湖南吉利汽车部件有限公司 | A kind of system and diagnostic method for supporting fuel vaporization leakage diagnosis |
| CN110044556A (en) * | 2019-04-10 | 2019-07-23 | 重庆长安汽车股份有限公司 | A kind of detection device and detection method of vehicle fuel oil evaporation system sealing |
| CN111255587A (en) * | 2018-11-30 | 2020-06-09 | 联合汽车电子有限公司 | Control method and system for engine oil tank leakage diagnosis |
| CN111946477A (en) * | 2020-07-23 | 2020-11-17 | 东风汽车集团有限公司 | Method for monitoring leakage of carbon tank cleaning electromagnetic valve |
| CN112776789A (en) * | 2019-11-08 | 2021-05-11 | 广州汽车集团股份有限公司 | Brake vacuum power system leakage diagnosis method and system and storage medium |
| CN113494388A (en) * | 2020-04-06 | 2021-10-12 | 联合汽车电子有限公司 | Fuel oil evaporative emission leakage diagnosis system and method |
| CN113550836A (en) * | 2021-08-13 | 2021-10-26 | 安徽江淮汽车集团股份有限公司 | Carbon tank electromagnetic valve leakage diagnosis method |
| CN114215664A (en) * | 2021-12-24 | 2022-03-22 | 安徽江淮汽车集团股份有限公司 | Method and system for diagnosing leakage of evaporation system for fuel vehicle |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4483523B2 (en) * | 2004-10-25 | 2010-06-16 | トヨタ自動車株式会社 | Evaporative fuel processing device for internal combustion engine |
| US11008963B2 (en) * | 2019-09-10 | 2021-05-18 | Ford Global Technologies, Llc | Systems and methods for controlling purge flow from a vehicle fuel vapor storage canister |
-
2022
- 2022-04-27 CN CN202210453301.4A patent/CN115111091B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5975062A (en) * | 1997-03-11 | 1999-11-02 | Pierburg Ag | Apparatus and method for periodically cleaning a charcoal canister and for periodically checking leak-tightness of a fuel system of an internal combustion engine |
| EP0969198A2 (en) * | 1998-07-02 | 2000-01-05 | Pierburg Aktiengesellschaft | Device for flushing a charcoal canister and for leak testing of a vehicle engine fuel tank installation connected to said canister |
| KR20070061698A (en) * | 2005-12-10 | 2007-06-14 | 현대자동차주식회사 | Apparatus for leakage diagnosis of evaporated gsa on vehicle and method thereof |
| KR20090116449A (en) * | 2008-05-07 | 2009-11-11 | 콘티넨탈 오토모티브 시스템 주식회사 | Method for detecting leak of fuel tank |
| CN106337762A (en) * | 2016-09-07 | 2017-01-18 | 中国第汽车股份有限公司 | Automobile fuel evaporation discharge control and diagnostic system |
| CN108223200A (en) * | 2017-12-14 | 2018-06-29 | 湖南吉利汽车部件有限公司 | A kind of system and diagnostic method for supporting fuel vaporization leakage diagnosis |
| CN108151987A (en) * | 2017-12-22 | 2018-06-12 | 江铃汽车股份有限公司 | Diagnostic method, device and the system of fuel evaporation leakage |
| CN111255587A (en) * | 2018-11-30 | 2020-06-09 | 联合汽车电子有限公司 | Control method and system for engine oil tank leakage diagnosis |
| CN110044556A (en) * | 2019-04-10 | 2019-07-23 | 重庆长安汽车股份有限公司 | A kind of detection device and detection method of vehicle fuel oil evaporation system sealing |
| CN112776789A (en) * | 2019-11-08 | 2021-05-11 | 广州汽车集团股份有限公司 | Brake vacuum power system leakage diagnosis method and system and storage medium |
| CN113494388A (en) * | 2020-04-06 | 2021-10-12 | 联合汽车电子有限公司 | Fuel oil evaporative emission leakage diagnosis system and method |
| CN111946477A (en) * | 2020-07-23 | 2020-11-17 | 东风汽车集团有限公司 | Method for monitoring leakage of carbon tank cleaning electromagnetic valve |
| CN113550836A (en) * | 2021-08-13 | 2021-10-26 | 安徽江淮汽车集团股份有限公司 | Carbon tank electromagnetic valve leakage diagnosis method |
| CN114215664A (en) * | 2021-12-24 | 2022-03-22 | 安徽江淮汽车集团股份有限公司 | Method and system for diagnosing leakage of evaporation system for fuel vehicle |
Non-Patent Citations (1)
| Title |
|---|
| 国六燃油蒸发系统泄漏诊断模块介绍及测试;杜玉彪;;汽车实用技术(第24期);69-72页 * |
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