CN107448307A - Exhaust control device and its control method for internal combustion engine - Google Patents
Exhaust control device and its control method for internal combustion engine Download PDFInfo
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- CN107448307A CN107448307A CN201710213846.7A CN201710213846A CN107448307A CN 107448307 A CN107448307 A CN 107448307A CN 201710213846 A CN201710213846 A CN 201710213846A CN 107448307 A CN107448307 A CN 107448307A
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- fuel ratio
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- temperature
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/101—Three-way catalysts
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- 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
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2260/00—Exhaust treating devices having provisions not otherwise provided for
- F01N2260/04—Exhaust treating devices having provisions not otherwise provided for for regeneration or reactivation, e.g. of catalyst
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/04—Methods of control or diagnosing
- F01N2900/0412—Methods of control or diagnosing using pre-calibrated maps, tables or charts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/06—Parameters used for exhaust control or diagnosing
- F01N2900/08—Parameters used for exhaust control or diagnosing said parameters being related to the engine
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/06—Parameters used for exhaust control or diagnosing
- F01N2900/14—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust gas
- F01N2900/1402—Exhaust gas composition
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/06—Parameters used for exhaust control or diagnosing
- F01N2900/14—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust gas
- F01N2900/1404—Exhaust gas temperature
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/08—Exhaust gas treatment apparatus parameters
- F02D2200/0802—Temperature of the exhaust gas treatment apparatus
- F02D2200/0804—Estimation of the temperature of the exhaust gas treatment apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2250/00—Engine control related to specific problems or objectives
- F02D2250/32—Air-fuel ratio control in a diesel engine
-
- 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
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Materials Engineering (AREA)
- Toxicology (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Analytical Chemistry (AREA)
Abstract
The application is related to a kind of exhaust control device and its control method for internal combustion engine.Wherein, the exhaust control device for internal combustion engine includes：Estimation unit, it is configured to during the execution of catalyst Regeneration control, and working condition based on acquired internal combustion engine and the difference that is arranged between dilute air-fuel ratio of target air-fuel ratio and dense air-fuel ratio are come the temperature of estimated catalyst；Determining unit, it is configured to during the execution of catalyst Regeneration control, it is determined that whether the temperature of estimated catalyst is higher than threshold value；And forbid unit, it is configured to during the execution of catalyst Regeneration control, when it is determined that the temperature of estimated catalyst forbids catalyst Regeneration control when being higher than threshold value.
Description
Technical field
The present invention relates to the exhaust control device and its control method for internal combustion engine.
Background technology
The target air-fuel ratio of a cylinder in known multiple cylinders by by internal combustion engine be arranged to dense air-fuel ratio and
The so-called shake that the target air-fuel ratio of other cylinders is arranged to dilute air-fuel ratio is controlled to improve the technology (example of the temperature of catalyst
Such as, referring to Japanese Unexamined Patent Publication No No.9-088663 (JP 9-088663 A)).
The content of the invention
It is contemplated that by the way that the temperature of catalyst to be increased to above to the temperature model by above-mentioned technology come activated catalyst
The temperature range enclosed, regenerates catalyst.
Here, the dense air-fuel ratio for being arranged to target air-fuel ratio in above-mentioned technology and dilute air-fuel ratio are arranged to depending on interior
The working condition of combustion engine and change to reduce influence to cornering ability.Then, when performing the control for regenerating catalyst, deposit
In following possibility：The temperature of catalyst is excessive by the dense air-fuel ratio and dilute air-fuel ratio of the working condition according to internal combustion engine or setting
Increase, more than for temperature range necessary to making catalyst regeneration.
Therefore, the invention provides a kind of exhaust control device and its control method for internal combustion engine, wherein, waste gas control
Device processed suppresses that the target air-fuel ratio of a cylinder is being arranged into dense air-fuel ratio and is setting the target air-fuel ratio of other cylinders
The excessive increase for the catalyst temperature being set to during the execution of the catalyst Regeneration control of dilute air-fuel ratio.
Above mentioned problem can be included by the exhaust control device solution for internal combustion engine, the exhaust control device：Catalyst,
It is configured to the waste gas that purification is discharged from multiple cylinders of internal combustion engine；Acquiring unit, it is configured to the work for obtaining internal combustion engine
Make state；Control unit, it is configured to perform catalyst Regeneration control, and catalyst Regeneration control includes following control：Pass through
By the target air-fuel ratio of at least one cylinder in multiple cylinders be arranged to less than stoichiometric air-fuel ratio dense air-fuel ratio and
The target air-fuel ratio of other cylinders in multiple cylinders is disposed above to dilute air-fuel ratio of stoichiometric air-fuel ratio, improves catalysis
The temperature of agent is so that catalyst regenerates；Estimation unit, it is configured to during the execution of catalyst Regeneration control, based on being obtained
The working condition of the internal combustion engine taken and it is arranged to the difference between dilute air-fuel ratio of target air-fuel ratio and dense air-fuel ratio to estimate
The temperature of catalyst；Determining unit, it is configured to during the execution of catalyst Regeneration control, it is determined that estimated catalyst
Temperature whether be higher than threshold value；And forbid unit, it is configured to during the execution of catalyst Regeneration control, when it is determined that institute
When the temperature of the catalyst of estimation is higher than threshold value, forbid catalyst Regeneration control.The aspect of the present invention can be carried out as follows restriction.
A kind of exhaust control device for internal combustion engine, the exhaust control device include：Catalyst, it is configured to purification from internal combustion engine
Multiple cylinders discharge waste gas；And electronic control unit, it is configured to, i) obtain internal combustion engine working condition, ii) hold
Row catalyst Regeneration control, catalyst Regeneration control include following control：By by least one cylinder in multiple cylinders
Target air-fuel ratio is arranged to the dense air-fuel ratio less than stoichiometric air-fuel ratio and by the target of other cylinders in multiple cylinders
Air-fuel ratio is disposed above dilute air-fuel ratio of stoichiometric air-fuel ratio, improves the temperature of catalyst so that catalyst regenerates；iii)
During the execution of catalyst Regeneration control, working condition based on acquired internal combustion engine and it is arranged to target air-fuel ratio
Dilute air-fuel ratio and dense air-fuel ratio between difference carry out the temperature of estimated catalyst；Iv) during the execution of catalyst Regeneration control,
It is determined that whether the temperature of the catalyst of estimation is higher than threshold value；And v) during the execution of catalyst Regeneration control, when electronics control
When unit processed determines that the temperature of the catalyst of estimation is higher than threshold value, forbid catalyst Regeneration control.One kind is for being used for internal combustion engine
Exhaust control device control method, the exhaust control device includes being configured to purification discharging from multiple cylinders of internal combustion engine
Waste gas catalyst, control method includes：I) working condition of internal combustion engine is obtained；Ii catalyst Regeneration control, catalysis) are performed
Agent Regeneration control includes following control：By the way that the target air-fuel ratio of at least one cylinder in multiple cylinders is arranged to less than change
Learn the dense air-fuel ratio of stoichiometry air and the target air-fuel ratio of other cylinders in multiple cylinders is disposed above chemical meter
Dilute air-fuel ratio of air-fuel ratio is measured, improves the temperature of catalyst so that catalyst regenerates；Iii) in the execution of catalyst Regeneration control
Period, working condition based on acquired internal combustion engine and be arranged to target air-fuel ratio dilute air-fuel ratio and dense air-fuel ratio it
Between difference carry out the temperature of estimated catalyst；Iv) during the execution of catalyst Regeneration control, it is determined that the temperature of estimated catalyst
Whether degree is higher than threshold value；And v) during the execution of catalyst Regeneration control, when electronic control unit determines estimated urge
When the temperature of agent is higher than threshold value, forbid catalyst Regeneration control.
During the execution of catalyst Regeneration control, working condition based on internal combustion engine and it is arranged to target air-fuel ratio
Dilute air-fuel ratio and dense air-fuel ratio between poor size come accurate estimated catalyst temperature.When the temperature of the catalyst of estimation
During higher than threshold value, forbid catalyst Regeneration control and so as to suppress the excessive increase of the temperature of catalyst.
During the execution of catalyst Regeneration control, unit is forbidden to may be configured to when the estimated catalyst of determination
Temperature forbids catalyst Regeneration control when being higher than threshold value in scheduled time slot.
According to the present invention it is possible to provide a kind of exhaust control device for internal combustion engine, the exhaust control device suppresses
The target air-fuel ratio of one cylinder is arranged to dense air-fuel ratio and the target air-fuel ratio of other cylinders is arranged to dilute air-fuel ratio
Catalyst Regeneration control execution during catalyst temperature excessive increase.
Brief description of the drawings
Feature, advantage and the technology of the illustrative embodiments of the present invention and industry meaning are described below in reference to accompanying drawing
Justice, the identical element of identical reference instruction in the accompanying drawings, and in the accompanying drawings：
Fig. 1 is the figure for the configuration for schematically showing exhaust control device；
Fig. 2 is the flow chart for showing to be forbidden by the regeneration that ECU is performed the example of control；
Fig. 3 A and Fig. 3 B are the figures for the example for showing catalyst temperature figure；
Fig. 4 is to show that the time diagram of the example of control is forbidden in regeneration；
Fig. 5 is the flow chart for showing to be forbidden by the regeneration that ECU is performed the modified example of control；And
Fig. 6 is to show that the time diagram of the modified example of control is forbidden in regeneration.
Embodiment
Fig. 1 is the figure for the configuration for schematically showing exhaust control device 1 (exhaust control device for being used for internal combustion engine).Such as
Shown in Fig. 1, exhaust control device 1 includes the three-way catalyst 31 of the waste gas of cleaning internal combustion engines 20.Internal combustion engine 20 makes air fuel
Mixture burns to cause piston 24 to move back and forth in the combustion chamber 23 of cylinder block 21.Internal combustion engine 20 is in-line four cylinder gasoline hair
Motivation, but its not limited to this, as long as it includes multiple cylinders, such as it can be diesel engine.
At the cylinder cover of internal combustion engine 20 for each cylinder be provided with open and close air inlet inlet valve Vi and
Open and close the exhaust valve Ve of exhaust outlet.For each cylinder, the spark of the air fuel mixture in combustion chamber 23 is lighted
Plug 27 is attached to the top of cylinder head.
The air inlet of each cylinder is connected to vacuum tank (surge tank) 18 via the branch pipe of each cylinder.Air inlet pipe 10
The upstream side of vacuum tank 18 is connected to, and air cleaner 19 is arranged in the upstream end of air inlet pipe 10.Air inlet pipe 10 is provided with
Detect the airometer 15 of the amount of air inlet and the electronically controlled choke valve 13 from upstream side then.
The injector 12 for injecting fuel into air inlet is installed at the air inlet of each cylinder.Injected from injector 12
Fuel mixes with air inlet, forms air fuel mixture, and air fuel mixture is inhaled into combustion when air inlet Vi is opened
Room 23 is burnt, is compressed by piston 24, and lighted and burnt by spark plug 27.
On the other hand, the exhaust outlet of each cylinder is connected to blast pipe 30 via the branch pipe of each cylinder.In blast pipe 30
It is provided with three-way catalyst 31.Three-way catalyst 31 has oxygen absorption (occlusion) ability and purifies NOx, HC and CO.
In three-way catalyst 31, one or more Catalytic Layers are formed in the substrate of cordierite etc. --- particularly honeycomb substrate
On, wherein, one or more Catalytic Layers include catalyst carrier such as aluminum oxide (Al2O3) and carried by catalyst carrier
Catalyst metals such as platinum (Pt), palladium (Pd) or rhodium (Rh).Three-way catalyst 31 is multiple cylinders of the purification from internal combustion engine 20
The example of the catalyst of the waste gas of discharge and can be oxidation catalyst or coated with oxidation catalyst gasoline particles filtering
Device.
In the air-fuel ratio sensor 33 of the air-fuel ratio of the upstream of three-way catalyst 31 installation detection waste gas.Air-fuel ratio sensor
33 be so-called wide area air-fuel ratio sensor, and it can continuously detect the air-fuel ratio on relatively wide region and export and sky
Fire the signal than proportional value.
Exhaust control device 1 includes electronic control unit (ECU) 50.ECU 50 includes CPU (CPU), random
Access memory (RAM), read-only storage (ROM) and memory cell.ECU 50 is stored in ROM or memory cell by performing
Program perform various types of controls.ECU 50, which performs regeneration described below, to be forbidden controlling.Regeneration forbids control to pass through
ECU 50 acquiring unit, control unit, estimation unit, determining unit and forbid unit to be performed, wherein, it is described obtain it is single
Member, control unit, estimation unit, determining unit and unit is forbidden functionally to be realized by CPU, ROM and RAM.Details
It will be described below.
Spark plug 27, choke valve 13 and injector 12 etc. are electrically connected to ECU 50.In addition to airometer 15, air-fuel ratio passes
Sensor 33, detect internal combustion engine 20 crankangle crank angle sensor 25, detect accelerator opening accel sensor
11 or various other sensors are electrically connected to ECU 50 via unshowned analog-digital converter etc..ECU 50 is based on each biography
The detected value of sensor controls spark plug 27, choke valve 13, injector 12 etc. to obtain desired output power, and controls igniting
Time, the amount for injecting fuel, fuel injection time, throttle valve opening etc..
It is described below by ECU 50 to set target air-fuel ratio.Do not performing catalyst Regeneration control described below
Normal condition under, target air-fuel ratio is set based on ordinary air-fuel ratio figure, wherein, ordinary air-fuel ratio figure is based on internal combustion engine 20
Engine speed and engine load.Ordinary air-fuel ratio figure is obtained in advance by experiment, and is stored in ECU 50 ROM.
For example, target air-fuel ratio is arranged into stoichiometric air-fuel ratio in the slow-speed of revolution and low-load region, and turn in height
Target air-fuel ratio is arranged in speed and high-load region denseer with stoichiometric air-fuel ratio.When there is provided during target air-fuel ratio,
The amount of the fuel injected in each cylinder is by feedback control so that the air-fuel ratio detected by air-fuel ratio sensor 33 reaches target
Air-fuel ratio.The mesh based on engine speed and engine load can be calculated using calculation formula rather than ordinary air-fuel ratio figure
Mark air-fuel ratio.
ECU 50 can perform following catalyst Regeneration control：It is predetermined by the way that the temperature of three-way catalyst 31 is brought up to
Sulfide (the SO being deposited on three-way catalyst 31 is removed in temperature rangeX) so that the detergent power of three-way catalyst 31 is again
It is raw.In catalyst Regeneration control, so-called shake control is performed：The target air-fuel ratio of a cylinder in multiple cylinders is set
It is set to the dense air-fuel ratio less than stoichiometric air-fuel ratio and by being disposed above of target air-fuel ratio in other three cylinders
Learn dilute air-fuel ratio of stoichiometry air.The average value of the target air-fuel ratio of all cylinders is arranged to stoichiometric air-fuel ratio.
Similarly, the target air-fuel ratio in catalyst Regeneration control is set based on regeneration air-fuel ratio figure, wherein, regeneration is empty
Combustion is based on engine speed and engine load than figure.Regeneration air-fuel ratio figure is obtained in advance by experiment, and is stored in ECU
In 50 ROM.For example, dense air-fuel ratio is arranged into scope from 9 to 12, and dilute air-fuel ratio is arranged to scope from 15 to 16.
When engine speed and engine load become big, dense air-fuel ratio is set smaller and dilute air-fuel ratio is set bigger.
The dense air-fuel ratio of target air-fuel ratio is arranged to based on regeneration air-fuel ratio figure and dilute air-fuel ratio is configured to depend on
The engine speed of internal combustion engine 20 and the variable in the less scope of influence to cornering ability of engine load.It can make
The catalyst Regeneration control based on engine speed and engine load is calculated with calculation formula rather than regeneration air-fuel ratio figure
In target air-fuel ratio.Catalyst Regeneration control is not performed under idling work state or when accelerator opening is zero.
When performing catalyst Regeneration control as described above, the cylinder discharge of dense air-fuel ratio is configured to from target air-fuel ratio
Residual fuel be attached to three-way catalyst 31 and due to the waste gas of dilute air-fuel brake specific exhaust emission and in poor atmosphere (lean
Atmosphere burnt in).Therefore, the temperature of three-way catalyst 31 is raised to remove SOX。
However, during three-way catalyst 31 is maintained at the execution of catalyst Regeneration control of higher temperature, exist with
Lower possibility：The temperature of three-way catalyst 31 is according to the working condition of internal combustion engine 20 or is arranged to the dense air-fuel ratio of target air-fuel ratio
Excessively increase with dilute air-fuel ratio, exceeded for temperature range necessary to regeneration.Therefore, ECU 50 regenerates in catalyst and controlled
During the execution of system, execution forbids the regeneration of catalyst Regeneration control to forbid controlling.
Fig. 2 is the flow chart for the example that control is forbidden in the regeneration for showing to be performed by ECU 50.Control shown in Fig. 2 is according to pre-
Fixed cycle is repeatedly executed at predetermined intervals.ECU 50 determine whether to be carrying out catalyst Regeneration control (step S1) and the control it is determined that
Terminate when being as a result negative.
When the determination result in step S1 is certainly, ECU 50 obtains the engine speed of internal combustion engine 20 and engine is born
Lotus (step S3).Specifically, engine speed is obtained based on the output valve from crank angle sensor 25, and based on from
The output valve of accel sensor 11 obtains engine load.Step S3 processing is by the work of acquisition internal combustion engine 20
The example for the processing that the acquiring unit of state performs.
Then, ECU 50 obtains the dilute air-fuel ratio for being arranged to target air-fuel ratio in catalyst Regeneration control and dense air-fuel
Poor size than between is poor (step S5) as air-fuel ratio.Specifically, obtain by subtracting dense air-fuel ratio from dilute air-fuel ratio
And the value obtained is poor as air-fuel ratio.It can obtain by subtracting dilute air-fuel ratio from dense air-fuel ratio the absolute value of value that obtains
It is poor as air-fuel ratio.
Then, ECU 50 estimates the temperature (step S7) of three-way catalyst 31.Specifically, estimated based on catalyst temperature figure
Count three-way catalyst 31 temperature, wherein, engine speed of the catalyst temperature figure based on acquisition, obtain engine load and
Air-fuel ratio is poor.Catalyst temperature figure is obtained and is stored in ECU 50 ROM by experiment in advance.Step S7 processing be by
The example for the processing that estimation unit performs, wherein, during the execution of catalyst Regeneration control, estimation unit is based in acquisition
The working condition of combustion engine 20 and it is arranged to the poor size between dilute air-fuel ratio of target air-fuel ratio and dense air-fuel ratio to estimate
Count the temperature of three-way catalyst 31.
Fig. 3 A and Fig. 3 B show the example of catalyst temperature figure.Trunnion axis represents engine speed, and vertical axis represents to start
Machine load, and show multiple thermoisopleths.Fig. 3 A show the catalyst temperature figure when air-fuel ratio difference is relatively large, and
Fig. 3 B show the catalyst temperature figure when air-fuel ratio difference is relatively small.Here, temperature T1 to T6 increases to temperature from temperature T1
Spend T6.
As shown in Figure 3 A and Figure 3 B, under conditions of engine speed and engine load are constant when air-fuel ratio difference become compared with
When big, the temperature of three-way catalyst 31 is estimated higher.Catalyst temperature figure can be based on accurately to estimate in catalyst again
The temperature of three-way catalyst 31 during the execution of raw control.Hair can be based on using calculation formula rather than catalyst temperature figure
Motivation rotating speed, engine load and air-fuel ratio difference estimate the temperature of three-way catalyst 31.
Then, ECU 50 determines whether the temperature of the three-way catalyst 31 of estimation is higher than threshold value (step S9) and the control
It is determined that result terminates when being negative.Whether excessively threshold value is for determining the temperature of three-way catalyst 31 increased value, the threshold
Value is arranged to the slightly smaller than value of the heat-resisting ceiling temperature of three-way catalyst 31 and for example, 900 degree, but not limited to this.Step
S9 processing is the example of the processing performed by determining unit, wherein, during the execution of catalyst Regeneration control, determining unit
It is determined that whether the temperature of the three-way catalyst 31 of estimation is higher than threshold value.
When the determination result in step S9 is certainly, ECU 50 forbids catalyst Regeneration control (step S11).It is being catalyzed
In the agent Regeneration control forbidden period, the target air-fuel ratio of all cylinders is configured to identical.Specifically, based in step S3
The engine speed and engine load of middle acquisition, target empty is set based on the ordinary air-fuel ratio figure used in normal work
Combustion ratio.Therefore, it is suppressed that the excessive increase of the temperature of three-way catalyst 31.In the catalyst Regeneration control forbidden period,
The target air-fuel ratio of all cylinders can be configured to stoichiometric air-fuel ratio.Step S9 processing is by forbidding unit to perform
Processing example, wherein, when determined in the implementation procedure in catalyst Regeneration control estimation three-way catalyst 31 temperature
During higher than threshold value, unit is forbidden to forbid catalyst Regeneration control.
Forbid controlling to describe regeneration below with reference to time diagram.Fig. 4 is to show that the time of the example of control is forbidden in regeneration
Figure.In fig. 4 it is shown that following waveform：The waveform instruction car speed, idling determine mark, engine speed, engine
Load, the temperature for the three-way catalyst 31 estimated, catalyst regeneration execution flag, target air-fuel ratio are configured to dilute air-fuel ratio
Target air-fuel ratio and target air-fuel ratio in cylinder are configured to the target air-fuel ratio in the cylinder of dense air-fuel ratio.In Fig. 4,
For ease of understanding, the temperature of the three-way catalyst 31 of estimation is also illustrated in the period for not performing catalyst Regeneration control
Degree.
Catalyst regeneration execution flag is closed in time t1, and please when sending catalyst regeneration in time t2
Catalyst regeneration execution flag is opened when asking.Then, ECU 50 performs catalyst Regeneration control：By the target in a cylinder
Air-fuel ratio is arranged to dense air-fuel ratio and the target air-fuel ratio in other cylinders is arranged into dilute air-fuel ratio.
When idling determines that mark is opened in time t3, determine that engine 10 is under idling work state and closed
Catalyst regenerates execution flag to stop catalyst Regeneration control --- and it is also such even if having issued catalyst regeneration request.When idle
Speed determines mark when the time, t4 was closed, and determines that engine 10 leaves idling work state and opens catalyst regeneration and performs
Mark to perform catalyst Regeneration control again.When idling determines that mark is opened again in time t5, catalyst is closed again
Execution flag is given birth to stop catalyst Regeneration control.
When idling determines mark when the time, t6 was closed, unlatching catalyst regenerates execution flag to perform catalyst again
Regeneration control.When the three-element catalytic that the air-fuel ratio difference between dilute air-fuel ratio and dense air-fuel ratio increases and estimated after time t 6
The temperature of agent 31 closes catalyst regeneration execution flag to forbid urging when the time, t7 became to be above threshold value during scheduled time slot
Agent Regeneration control.Hereafter, idling determines that mark enters one in the temperature for the three-way catalyst 31 that time t8 is opened and is estimated
Step reduces.
Because that forbid catalyst Regeneration control during the execution of catalyst Regeneration control, so three-element catalytic
The temperature of agent 31 is reduced and the excessive increase of temperature is suppressed.Correspondingly, can reduce three-way catalyst 31 due to heat and
The possibility of degeneration.When catalyst Regeneration control is prohibited, keep forbidding the state of catalyst Regeneration control in the trip
Untill firing key is closed.Then, when predetermined condition is satisfied in trip next time, catalyst can be performed again
It is raw to control to remove the sulfide being deposited on three-way catalyst 31.
Instead of the temperature for such as estimating three-way catalyst 31 in the above-described techniques, it may be considered that temperature in use sensor comes direct
Measure the temperature of three-way catalyst 31 or be based on using the temperature sensor for the upstream and downstream for being arranged in three-way catalyst 31
Difference between the temperature detected estimates the temperature of three-way catalyst 31.However, in this case, part count increase be present
Possibility.In this embodiment, because the temperature of three-way catalyst 31 can be estimated without using such temperature sensor
Degree, it is possible to the increase of suppression component number.
The modified example that control is forbidden in regeneration is described below.Fig. 5 is to show to forbid controlling by the regeneration that ECU 50 is performed
Modified example flow chart.Fig. 6 is to show that the time diagram of the modified example of control is forbidden in regeneration.Step S1, S3, S5, S7 and
S9 processing forbids the processing in control identical with the regeneration shown in Fig. 2, therefore will not be repeated again.From time t1 then
Between t7 period in working condition such as engine speed be identical, therefore will not be repeated again.
As shown in figure 5, when the determination result in step S9 is certainly, ECU 50 forbids catalyst again in scheduled time slot
Raw control (step S11a).Scheduled time slot is suitable for suppressing the excessive increased period of the temperature of three-way catalyst 31, makes a reservation for
Period is obtained and is stored in ECU 50 ROM by experiment in advance.The scope of scheduled time slot for example from 500ms to
1500ms, but not limited to this.When having gone over the catalyst Regeneration control forbidden period, in response to catalyst regeneration request
And catalyst Regeneration control is performed again.
As shown in fig. 6, in the past time t7 ' of scheduled time slot since the forbidden time t7 of catalyst Regeneration control
Place, releases and catalyst Regeneration control is forbidden, and opens catalyst regeneration execution flag, and performs catalyst regeneration control again
System.When idling determines hereafter mark is opened in time t8, catalyst regeneration execution flag is closed and catalyst regenerates
Control stops.
By forbidding catalyst Regeneration control to suppress the temperature of three-way catalyst 31 in scheduled time slot in this way
Excessively increase, after the scheduled time slot past to catalyst Regeneration control when forbidding being released from, the temperature of three-way catalyst 31
Increase again, therefore the sulfide being deposited on three-way catalyst 31 can be removed as early as possible.
The forbidden scheduled time slot of catalyst Regeneration control is not limited to above-mentioned example.For example, catalyst Regeneration control is banned
Scheduled time slot only can be until idling work was marked by the period untill opening after being prohibited in catalyst Regeneration control.
In the state of idling work mark is opened, catalyst regeneration execution flag is closed as described above.Then, when catalyst again
When working condition becomes idling work state after raw control is prohibited, it can essentially be returned in working condition from idling work
Catalyst Regeneration control is just performed afterwards.The forbidden scheduled time slot of catalyst Regeneration control can be controlled until catalyst regenerates
Period after system is prohibited untill accelerator opening vanishing.In this case, because the shape for being not zero in accelerator opening
Catalyst Regeneration control is performed under state, so catalysis can essentially just be performed after the value that accelerator opening becomes beyond zero
Agent Regeneration control.
Although the illustrative embodiments of the present invention are described in detail above, it is specific that the present invention is not limited to this
Illustrative embodiments, but can in a variety of manners modify and not deviate by the present invention described in appended claims
Main idea.
In the above-described embodiment, example of the inline four-cylinder engine as internal combustion engine is described, but bag can be used
Include the V-type multi-cylinder engine of the catalyst for each arranging (bank).In this case, will be every in catalyst Regeneration control
The target air-fuel ratio of a cylinder in individual row is arranged to dense air-fuel ratio, and the target air-fuel ratio in other cylinders is arranged into dilute sky
Ratio is fired, and is arranged for each to perform catalyst Regeneration control.
Claims (3)
1. a kind of exhaust control device for internal combustion engine, the exhaust control device is characterised by including：
Catalyst, the catalyst are configured to the waste gas that purification is discharged from multiple cylinders of the internal combustion engine；And
Electronic control unit, the electronic control unit are configured to：
I) working condition of the internal combustion engine is obtained,
Ii catalyst Regeneration control) is performed, the catalyst Regeneration control includes following control：By by the multiple cylinder
The target air-fuel ratio of at least one cylinder be arranged to dense air-fuel ratio less than stoichiometric air-fuel ratio and by the multiple vapour
The target air-fuel ratio of other cylinders in cylinder is disposed above dilute air-fuel ratio of the stoichiometric air-fuel ratio, improves the catalysis
The temperature of agent so that the catalyst regenerates,
Iii) during the execution of the catalyst Regeneration control, working condition based on the acquired internal combustion engine and by
The difference between dilute air-fuel ratio of target air-fuel ratio and the dense air-fuel ratio is arranged to estimate the temperature of the catalyst,
Iv) during the execution of the catalyst Regeneration control, it is determined that whether the temperature of the estimated catalyst is higher than threshold
Value, and
V) during the execution of the catalyst Regeneration control, when the electronic control unit determines the estimated catalyst
Temperature when being higher than the threshold value, forbid the catalyst Regeneration control.
2. exhaust control device according to claim 1, it is characterised in that：
The electronic control unit is configured to during the execution of the catalyst Regeneration control, when the electronic control unit
It is determined that when the temperature of the estimated catalyst is higher than the threshold value, forbid the catalyst regeneration control in scheduled time slot
System.
3. a kind of control method for being directed to the exhaust control device for internal combustion engine, the exhaust control device includes being configured to
The catalyst of the waste gas discharged from multiple cylinders of the internal combustion engine is purified, the control method is characterised by including：
I) working condition of the internal combustion engine is obtained；
Ii catalyst Regeneration control) is performed, the catalyst Regeneration control includes following control：By by the multiple cylinder
The target air-fuel ratio of at least one cylinder be arranged to dense air-fuel ratio less than stoichiometric air-fuel ratio and by the multiple vapour
The target air-fuel ratio of other cylinders in cylinder is disposed above dilute air-fuel ratio of the stoichiometric air-fuel ratio, improves the catalysis
The temperature of agent is so that the catalyst regenerates；
Iii) during the execution of the catalyst Regeneration control, working condition based on the acquired internal combustion engine and by
The difference between dilute air-fuel ratio of target air-fuel ratio and the dense air-fuel ratio is arranged to estimate the temperature of the catalyst；
Iv) during the execution of the catalyst Regeneration control, it is determined that whether the temperature of the estimated catalyst is higher than threshold
Value；And
V) during the execution of the catalyst Regeneration control, when the electronic control unit determines the estimated catalyst
Temperature when being higher than the threshold value, forbid the catalyst Regeneration control.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016075168A JP2017186931A (en) | 2016-04-04 | 2016-04-04 | Exhaust emission control device for internal combustion engine |
| JP2016-075168 | 2016-04-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107448307A true CN107448307A (en) | 2017-12-08 |
Family
ID=59960735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710213846.7A Pending CN107448307A (en) | 2016-04-04 | 2017-04-01 | Exhaust control device and its control method for internal combustion engine |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US20170284269A1 (en) |
| JP (1) | JP2017186931A (en) |
| CN (1) | CN107448307A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111594335A (en) * | 2019-02-20 | 2020-08-28 | 丰田自动车株式会社 | Catalyst warm-up monitoring device, system, method, control device, data analysis device, and reception device for internal combustion engine |
| CN114837774A (en) * | 2021-02-02 | 2022-08-02 | 北京福田康明斯发动机有限公司 | Method, system, storage medium and electronic device for controlling DPF to exit regeneration prohibition |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180128145A1 (en) * | 2016-11-09 | 2018-05-10 | Ford Global Technologies, Llc | Method and system for an exhaust diverter valve |
| JP6870560B2 (en) * | 2017-10-06 | 2021-05-12 | トヨタ自動車株式会社 | Internal combustion engine control device |
| JP6881247B2 (en) * | 2017-11-08 | 2021-06-02 | トヨタ自動車株式会社 | Internal combustion engine control device |
| JP7000947B2 (en) * | 2018-03-26 | 2022-01-19 | トヨタ自動車株式会社 | Internal combustion engine control device |
| JP7020242B2 (en) * | 2018-03-29 | 2022-02-16 | トヨタ自動車株式会社 | Internal combustion engine control device |
| JP7003878B2 (en) * | 2018-08-30 | 2022-01-21 | トヨタ自動車株式会社 | Exhaust purification device for internal combustion engine |
| JP2021060026A (en) * | 2019-10-09 | 2021-04-15 | トヨタ自動車株式会社 | Vehicle and control method for the same |
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2017
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- 2017-04-01 CN CN201710213846.7A patent/CN107448307A/en active Pending
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| JP2000337137A (en) * | 1998-04-15 | 2000-12-05 | Nissan Motor Co Ltd | Exhaust emission control device for internal combustion engine |
| CN101163871A (en) * | 2005-04-21 | 2008-04-16 | 五十铃自动车株式会社 | Exhaust gas purifying method and purifier |
| CN101868607A (en) * | 2007-11-21 | 2010-10-20 | 丰田自动车株式会社 | Control apparatus for internal combustion engine |
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| CN114837774A (en) * | 2021-02-02 | 2022-08-02 | 北京福田康明斯发动机有限公司 | Method, system, storage medium and electronic device for controlling DPF to exit regeneration prohibition |
Also Published As
| Publication number | Publication date |
|---|---|
| US20170284269A1 (en) | 2017-10-05 |
| JP2017186931A (en) | 2017-10-12 |
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