• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: To improve an air environment preserving characteristic by suppressing NOx exhaust caused by temporary stop and resumed operation of an engine in an economic running vehicle or hybrid vehicle. CONSTITUTION: In an engine operation of a vehicle which intermittently operates an internal combustion engine, fuel for catalyst reduction is temporarily supplied before starting combustion of the fuel to return to engine operation so that operation of an exhaust emission control catalyst is not returned with oxygen accumulated when the engine is temporarily stopped, and the oxygen accumulated in the exhaust emission control catalyst with temporary stop of the engine is reduced.
    公开号:KR20020090843A
    申请号:KR1020020004065
    申请日:2002-01-24
    公开日:2002-12-05
    发明作者:오이야스히로；이노우에도시오
    申请人:도요타지도샤가부시키가이샤；
    IPC主号:
    专利说明:

    NOx emission control method for an intermittent operation type internal combustion engine of a vehicle
    [12] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving an internal combustion engine for a vehicle, and more particularly, comprising an exhaust purification catalyst having a function of accumulating oxygen in an exhaust system of an internal combustion engine, and pausing the engine when a predetermined engine rest condition is established. The present invention relates to a method of driving an engine of a vehicle configured to return the engine to an operation when the rest condition is extinguished, while suppressing the emission of NOx accompanying the engine pause.
    [13] Currently, exhaust purification catalysts such as three-way catalysts are generally provided in exhaust systems of internal combustion engines of vehicles such as automobiles. This type of exhaust purification catalyst reacts with NOx and CO or HC, which are harmful components contained in the exhaust of an internal combustion engine, to convert them into harmless N 2 , CO 2 or H 2 O, When the exhaust or air with excess oxygen passes through the equilibrium, the oxygen accumulates. When the internal combustion engine is stopped for a long time, since the exhaust purification catalyst is naturally exposed to oxygen in the atmosphere, the catalyst is in a state of accumulating oxygen to the saturation limit. When the exhaust purification catalyst is in a state of accumulating oxygen, the purification function for NOx is lowered. Therefore, in response to this, it is known that when the engine is started, the amount of fuel that is suitable for the amount of oxygen stored in the catalyst is temporarily increased from the value of the theoretical air-fuel ratio, and the catalyst is reduced by the increased amount of fuel. It is losing and being carried out.
    [14] However, in recent years, due to the need for saving fuel resources and preservation of the atmospheric environment, even when the vehicle is in operation, at the time of suspension of the vehicle due to signal waiting or delay or when driving by an electric motor is more preferable than by an internal combustion engine. The economy run China hybrid car which pauses an internal combustion engine attracts attention. In economy and hybrid vehicles, the engine pause during vehicle operation is usually about 10 minutes at the present time, and the exhaust purification catalyst accumulates oxygen by invading air from the outlet of the exhaust system during that time. Although the internal combustion engine is stopped, the supply of fuel is stopped, and since the internal combustion engine rotates several times even after the fuel is shut off, the exhaust system removes air containing no fuel component and exhaust purification catalyst. Accumulates oxygen.
    [15] In addition, in particular, the hybrid car currently produced and sold by the present applicant has a drive structure as shown in the accompanying Figure 1, but in this case, the fuel to the engine for suspending the operation of the internal combustion engine is Even if the supply is cut off, the engine may still be idle. That is, in the structure shown in FIG. 1, 1 is an internal combustion engine, and the engine is connected to the generator 3 and the electric motor 4 via the drive coupling device 2 provided with a planetary gear mechanism, The axles 7a, 7b of the pair of drive wheels 6a, 6b are connected to each other via the differential gear mechanism 8 via the transmission 5, and here the clutch that has been always standing in the conventional vehicle drive system. Is not installed. This is based on the rotational speed of the wheel and the input torque (both positive and negative) to the wheel, the rotational speed and output torque of the engine and the motor, and the rotational speed and load torque of the generator via the planetary gear mechanism of the drive coupling device 2. It is controlled by the synthesis of. Therefore, even when the vehicle is in the decelerated state or the vehicle is in the electric drive state, the engine output is unnecessary, the fuel supply to the engine is cut off, and the engine may stop the rotation. The engine may continue to rotate while being substantially at rest. The stopping of the engine, including the idle of such engine, will be specifically referred to herein as engine resting. In Fig. 1, 9 is a battery or other power storage device, 10 is an inverter, 11 is a catalytic converter using a three-way catalyst or the like installed in an exhaust system of an engine, 12 is an electric control device, and the electric control device is operated according to the present invention. As information related to the signal, the signal indicating the pedal amount Dp of the accelerator pedal, the signal indicating the vehicle speed Sv, the signal indicating the crank angle θe, the signal indicating the temperature Te of the engine, the temperature of the catalytic converter ( A signal indicating Tc) is input.
    [16] The present invention takes account of the above or other possible diversity relating to the engine idle state associated with the engine pause during vehicle operation in an economy or hybrid car, and the diversity of the oxygen accumulation state of the exhaust purification catalyst accompanying it. In this way, the exhaust purification catalyst which accumulated oxygen in various states every engine pause can be reduced more effectively, and the engine which can suppress NOx emission when the engine returns to operation due to the accumulation of oxygen in the exhaust purification catalyst can be suppressed. An object of the present invention is to provide an intermittent operation method.
    [1] 1 is a schematic diagram illustrating an example of a drive system of a hybrid car.
    [2] 2 is a flowchart showing a part of one comprehensive embodiment of the NOx emission suppression driving method of an intermittent driving internal combustion engine for a vehicle according to the present invention;
    [3] FIG. 3 is a flow diagram of the same aspect as FIG. 2 connected from a portion of A to a portion of A of FIG.
    [4] 4 is a flow diagram of the same aspect as FIGS. 2 and 3 connected from the portion of B to the portion of B of FIG.
    [5] * Description of the symbols for the main parts of the drawings *
    [6] 1: Internal combustion engine 2: Drive connection device
    [7] 3: generator 4: electric motor
    [8] 5: transmission 6a, 6b: axle
    [9] 7a, 7b: wheel 8: differential gear mechanism
    [10] 9: power storage device 10: inverter
    [11] 11: catalytic converter 12: electric control device
    [17] In order to solve the above problems, the present invention includes an exhaust purification catalyst having a function of accumulating oxygen in an exhaust system of an internal combustion engine, and temporarily stops the engine temporarily when a predetermined engine stop condition is established, and stops the engine. An engine operation method for suppressing the emission of NOx accompanying an engine pause of a vehicle configured to restore the engine when the condition disappears, and the engine pause before starting combustion of fuel for engine return to operation. Accompanying is to propose an engine operating method comprising an operation process for reducing the oxygen accumulated in the exhaust purification catalyst.
    [18] In the engine operation method as described above, the operation step may be to temporarily supply fuel only for one period of the fuel cut idle, when the engine pause includes a state in which the engine idles in a fuel cut off state.
    [19] In this case, the fuel supply may be resumed so that the fuel temporary supply resumes operation according to the operation demand when the engine pause continues from the engine operating state, when cranking for the engine operation returning, or when the engine pause returns to the idle state. At this time, it may be performed prior to the resumption, and it may be performed by operating the ignition device as usual, or may be performed without operating the ignition device.
    [20] Even if the supply of fuel to the engine is cut off for the engine to be paused, the engine idles at least several revolutions and the exhaust purification catalyst accumulates oxygen. When the fuel cell is temporarily supplied, the exhaust purification catalyst to accumulate oxygen caused by engine revolution can be reduced at that place, and NOx can be suppressed from being discharged when the engine returns to operation.
    [21] In addition, when the engine rotation is lowered below a predetermined threshold rotational speed by the engine pause, the engine returns to operation by cranking. The cranking start of the engine is to drive the engine by an electric motor to gradually increase its rotational speed and to start the injection of fuel at a portion where the rotational speed reaches a certain height. Therefore, when engine starting by cranking is performed, at least until the engine rotational speed reaches the predetermined height, at least after the engine starts to crank, before combustion of fuel is started to return the engine to operation. There is an engine idle time. Therefore, if fuel is temporarily supplied by selecting the idle time at the beginning of the cranking, this also causes no delay in returning to operation by engine cranking, and before combustion of fuel for starting operation of the engine is started. For example, the exhaust purification catalyst which has accumulated oxygen in a warm state can be immediately reduced by the combustible component, and NOx can be suppressed from being discharged when the engine returns to operation.
    [22] In addition, when the engine continues to idle at the above threshold speed even when the engine is paused, cranking is necessary when the engine is newly returned from the idle idle state by the operation request to the engine. There is a time allowance for the regular supply of fuel to the present one, compared to the case of cranking. Therefore, at this time, before starting the regular supply of fuel to the request for operation to the engine, by temporarily supplying fuel, the fuel for catalytic reduction is carried to the exhaust purification catalyst by being put in the exhaust stream during idle. The exhaust purification catalyst, which accumulates oxygen in a turbulent state, is immediately reduced and the NOx is discharged when the engine returns to operation without causing any delay in the return of the engine to the operation request to the engine. It can be suppressed.
    [23] Hereinafter, one embodiment which comprehensively includes several embodiments of the present invention described above will be described in detail. 2, 3 and 4 are flow charts showing the control flow in such a comprehensive embodiment by being stuck together in portions of A and B, respectively.
    [24] The control shown in this flowchart is started at the same time that the vehicle starts to be driven by the closing configuration of the ignition switch of the vehicle, which is not shown in the drawing. As is well known in this kind of control technology, the control is performed during execution of the control. Cycles through these flowcharts at intervals of several tens of milliseconds.
    [25] In step 1, data required for control as shown in FIG. 1 is read out. Since the control through the flowchart returns to the step 1 from the last return, in step 1, the read data based on the running state of the vehicle is updated every tens of milliseconds.
    [26] In step 2, it is determined whether the engine pause condition is satisfied based on the data read in step 1. This determination may be made in various examples, the details of which are not the subject of the present invention. If the answer is YES, then control proceeds to step 3, where fuel cutoff is executed. Control then proceeds to step 4, where a flag F1 indicating that the fuel cut is executed is set to one. As is well known in the art, this kind of flags are all reset to zero at the start of control, and any of the flags used afterwards are the same.
    [27] In step 5, it is determined whether or not the flag F2 is set to one. When control reaches the excitation, since F2 is 0, control proceeds to step 6, and it is determined whether or not the engine speed Ne is above a certain threshold Neo. This threshold (Neo) is intended to be performed when the engine is idle at a higher rotational speed, the catalytic reduction treatment when the engine enters a pause, and the catalytic reduction treatment is performed when the engine is returned to operation. It is a standard value. When the answer is NO, that is, when the engine speed is lowered to Neo or lower, control proceeds to step 7 and the flag 2 is set to 1, whereby the judgment at step 6 is fixed. Control then proceeds to step 8, and it is determined whether or not the flag F3 is one. This flag F3 is later set to 1 when the control reaches step 16, and is reset to 0 until then. As long as the answer is no, control proceeds to step 9.
    [28] In step 9, it is determined whether or not the catalyst reduction treatment permission conditions are satisfied. This mainly confirms whether or not the temperature of the catalyst is turbulent above a predetermined activation temperature, and also considers that if the catalyst temperature is too high, overheating may occur due to the reduction treatment. If the answer is yes, control proceeds to step 10. If the answer is no, the following control is suspended.
    [29] In step 10, it is determined whether or not the flag F4 is 1, and when the answer is no, control proceeds to step 11, the timer 1 is set, and in step 12 the flag F4 is set to 1. These steps 10 to 12 are for starting timer 1 here.
    [30] Subsequently, in step 13, it is determined whether timer 1 has timed out. If the answer is no, control proceeds to step 14, where a temporary supply (injection) of fuel for catalytic reduction is performed. This may be done by either of two things, whether operating an ignition device normally or not operating an ignition device. This temporary fuel supply is performed for the time set by the timer 1, and when that time passes, control will progress to step 15, stopping the temporary supply of fuel and indicating that the temporary fuel supply for catalyst reduction was terminated by step 16. The flag F3 is set to one. Therefore, when the temporary supply of fuel for catalytic reduction is performed until the end here, the control circulates through steps 1 to 8 until the engine pause is newly performed, and waits for the answer of step 2 to change to no.
    [31] When the engine pause period has elapsed or when the output request to the engine is issued by the accelerator pedal being stepped in the middle, the answer of step 2 changes from yes to no. From this, the control proceeds to step 17, and it is judged whether or not the flag F4 is set to one. If the answer is yes, control proceeds to step 18, where it is determined whether the engine speed Ne is greater than or equal to a predetermined threshold speed Neco that the engine can return to operation only by resuming fuel supply without requiring cranking. do. If the answer is no, control proceeds to step 19, where the flag F4 is set to 1, whereby the judgment at step 18 is fixed. When control advances from this to step 20, cranking is performed here.
    [32] When cranking is started, it is determined in step 21 whether the engine speed Ne has reached a predetermined speed Nec2 at which start of supply (injection) of regular fuel at the start of engine cranking has started. . If the answer is no, control proceeds to step 22. In step 22, it is determined whether or not the flag F3 is set to one. The flag F3 is set to 1 in step 16 when the fuel temporary supply started in step 14 above is completed. When the flag F3 is set to 1, the reduction of the catalyst is finished and at the time of cranking. Since there is no need for this already, the control returns to Step 1 as it is at this time, it cycles through Step 22 while cranking, and waits for Ne to reach Nec2.
    [33] If the answer to step 22 is no, then control proceeds to step 23, and it is determined whether or not the same catalytic reduction treatment permission conditions as in step 9 above are satisfied. And if the answer is yes, then control proceeds to step 24, where the engine speed Ne is a speed lower than Nec2, and the predetermined end of when the temporary fuel supply for catalytic reduction is performed at the beginning of cranking. It is determined whether or not the threshold Nec1 has been reached. Since initially the answer is no, control proceeds to step 25, and the temporary supply of fuel for catalytic reduction is started. The temporary fuel supply performed at the beginning of the cranking may be performed by operating the ignition device as usual, but here as one more preferred embodiment, it is performed without operating the ignition device. In this case, the amount of fuel temporary supply can be set to a desired value by setting the value of Nec1. If the answer to step 24 changes from no to yes, then the fuel temporary supply is stopped in step 26.
    [34] In this way, even after completion | finish of catalyst reduction, cranking continues and if engine speed further rises and the answer of step 21 changes from no to yes, control goes to step 27, and the normal fuel at the time of cranking start is started. Supply is initiated, and the engine increases the rotational speed by itself. In order to confirm the result, control proceeds to step 28, and whether or not the flag F5 is 1 is judged, and proceeds to step 29 by answering No only once the first time, and then timer 2 is set. In step 30, the flag F5 is set to one. In step 31, it is judged whether the engine speed Ne reached the predetermined threshold Nec3 which shows that engine started smoothly. Initially, the answer is still no, and control proceeds to step 32 where it is determined whether the timer 2 has timed out. If the answer is no, control returns to step 1, and control continues while reading data again. If the engine starts normally, the answer of step 31 changes from no to yes, in which case the control proceeds to step 33, where all the flags from F1 to F5 are reset to 0, where the control unit It returns to a state and becomes a state which can endure the control of the next engine pause.
    [35] However, if the engine does not start normally for some reason and the time elapses with the answer of step 31 being no, and the answer of step 32 changes from no to yes, control proceeds to step 34, and the engine fails to start. An alarm is issued to indicate to the driver. In this embodiment, control ends here. This is merely an embodiment, and when the answer to step 32 is an example, what automatic control may be performed and what automatic control is performed at this time is not an object of the present invention.
    [36] When the answer to step 18 is no, that is, after the engine pauses, and when the engine is returned to operation, when the engine speed Ne is equal to or greater than Neco, control proceeds to step 35, and the flag F1 is set to 1. It is judged whether or not it is recognized. In this case, the answer is no when the engine shut-off of the engine pause has not yet been performed. At this time, the control proceeds to step 36, and the normal fuel supply in accordance with the engine output request is continued.
    [37] If the answer to step 35 is YES, then control proceeds to step 37 and it is determined whether the flag F3 is one. The flag F3 is set when the engine temporarily enters the pause and the fuel temporary supply for the catalyst reduction is performed while the period is rotating. Therefore, when the flag F3 is set to 1, since the catalytic reduction process does not need to be newly renewed, control proceeds to step 36.
    [38] If the answer to step 37 is no, then control proceeds to step 38, and it is determined whether or not the flag F6 is set to one. This flag F6 is set later when the control reaches step 46, and is reset to zero until then. Next, in step 39, it is determined whether the same catalytic reduction treatment permission conditions as in step 9 or step 23 above are satisfied. If the answer is yes, then control proceeds to step 40. Subsequently, it is determined whether or not the flag F7 is set to 1 in step 40, and this step 40 and subsequent steps 41 and 42 are for starting a new timer 3. After the timer 3 is started in this manner, the control proceeds to step 43, and whether the timer 3 has timed out, that is, whether the temporary supply of fuel for catalyst reduction initiated in the next step 44 has been performed for a predetermined time. Is judged. In this case, the temporary fuel supply which is performed for the set time by the timer 3 and ends in step 45 may be performed by operating the ignition device as usual, but in the illustrated embodiment, as one more preferred embodiment, the operation is performed without operating the ignition device. All. This temporary supply of fuel without ignition is performed for catalytic reduction prior to return to the normal fuel, supply, when the engine's return to operation is possible only by the return of the fuel to the normal supply without cranking. Since such fuel temporary supply may be performed once for one engine pause, after it ends in step 45 and the flag F6 indicating it in step 46 is set to 1, control goes from step 38 to step 36. Take a path heading. When the control step 36 is reached, all of the flags F1 to F7 are reset to zero in step 47, and the control is in a state in preparation for the next engine pause.
    [39] As described above, the flowcharts shown in FIGS. 2, 3 and 4 combine several aspects of the NOx emission suppression driving method of the intermittent driving internal combustion engine for vehicles according to the present invention in a comprehensive combination thereof. The present invention is not limited to performing all of the control in all these aspects, but it will be apparent that these aspects may be appropriately selected and executed within the scope of the present invention.
    [40] The present invention further improves the atmosphere environmental preservation characteristics by suppressing NOx emission accompanying engine pause and return to operation in economy and hybrid cars. In engine operation of a vehicle intermittently operating an internal combustion engine, the catalyst for reducing the catalyst before starting combustion of the fuel for returning to operation of the engine so that the exhaust purification catalyst returns to operation with accumulated oxygen when the engine is paused. Accompanying the engine pause which does not perform temporary supply, the oxygen accumulated in the exhaust purification catalyst is reduced.
    权利要求:
    Claims (7)
    [1" claim-type="Currently amended] An exhaust purification catalyst having a function of accumulating oxygen in the exhaust system of the internal combustion engine, and temporarily stopping the engine when a predetermined engine idle condition is established, and returning the engine to operation when the engine idle condition expires; An engine driving method for suppressing the emission of NOx accompanying an engine pause of a configured vehicle, and prior to starting combustion of fuel for returning to engine operation, oxygen accumulated in the exhaust purification catalyst accompanying an engine pause An engine operating method comprising the operation process to reduce the.
    [2" claim-type="Currently amended] 2. The engine according to claim 1, wherein the operation step is to temporarily supply fuel to only one time of the fuel cut idle when the engine pause includes a state in which the engine idles in a fuel cut off state. Driving way.
    [3" claim-type="Currently amended] 3. The engine operation method according to claim 2, wherein the fuel temporary supply is performed at engine idle which continues from an engine operating state.
    [4" claim-type="Currently amended] 3. The engine running method according to claim 2, wherein the fuel temporary supply is performed at the beginning of cranking for returning to engine operation.
    [5" claim-type="Currently amended] 3. The engine operation method according to claim 2, wherein the fuel temporary supply is performed prior to the normal supply of fuel when the engine in the idle state is returned to operation in accordance with an operation request to the engine.
    [6" claim-type="Currently amended] 6. The engine operation method according to any one of claims 2 to 5, wherein the temporary fuel supply is performed by operating an ignition device.
    [7" claim-type="Currently amended] 6. The engine driving method according to any one of claims 2 to 5, wherein the temporary fuel supply is performed without operating the ignition device.
    类似技术:
    公开号 | 公开日 | 专利标题
    CN103661360B|2016-01-27|For controlling the method and apparatus that in motor vehicle driven by mixed power, driving engine is shut down
    JP3904192B2|2007-04-11|Vehicle drive device
    JP3775012B2|2006-05-17|Hybrid drive device for vehicle
    DE60129651T2|2008-06-26|Hybrid vehicle with NOx reduction system and method for operating desselbem
    US7840337B2|2010-11-23|Method for controlling an overrun condition of a hybrid vehicle and hybrid vehicle
    KR101045078B1|2011-06-28|Hybrid vehicle and its control method
    US6792750B2|2004-09-21|Emission control apparatus of internal combustion engine and control method for the emission control apparatus
    JP3870505B2|2007-01-17|Hybrid drive device for vehicle
    KR100551923B1|2006-02-16|Operation method and operation control device of internal combustion engine for vehicle that temporarily stops engine
    US6593713B2|2003-07-15|Control apparatus for hybrid vehicle
    US9518287B2|2016-12-13|NOx control during engine idle-stop operations
    US7503413B2|2009-03-17|System and method for controlling stopping and starting of a vehicle engine
    JP3463361B2|2003-11-05|Engine automatic stop and start device
    JP4144570B2|2008-09-03|Control method of hybrid vehicle
    CN101898550B|2014-12-24|Method for controlling restart of an engine
    US6476573B2|2002-11-05|Control apparatus for hybrid vehicle
    US6434928B1|2002-08-20|Apparatus and method of purification of exhaust emission of internal combustion engine
    JP4175371B2|2008-11-05|Internal combustion engine device, its control method, and power output device
    US6904342B2|2005-06-07|Control apparatus for energy storage device in motor vehicle
    JP3772683B2|2006-05-10|Control device for hybrid vehicle
    JP3214427B2|2001-10-02|Drive control device for hybrid vehicle
    JP4197038B2|2008-12-17|Hybrid vehicle and control method thereof
    US6829887B2|2004-12-14|Apparatus and method for controlling vehicle so as to purify exhaust emission from engine
    JP4207966B2|2009-01-14|Power output device, its control method, and vehicle
    US20020043410A1|2002-04-18|Hybrid vehicle and method in which the engine is preheated before start
    同族专利:
    公开号 | 公开日
    US20040194452A1|2004-10-07|
    JP3815256B2|2006-08-30|
    DE10223733B4|2008-02-28|
    US6742327B2|2004-06-01|
    KR100444420B1|2004-08-16|
    DE10223733A1|2003-01-09|
    US7152395B2|2006-12-26|
    JP2002349251A|2002-12-04|
    US20020179070A1|2002-12-05|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2001-05-29|Priority to JPJP-P-2001-00160201
    2001-05-29|Priority to JP2001160201A
    2002-01-24|Application filed by 도요타지도샤가부시키가이샤
    2002-12-05|Publication of KR20020090843A
    2004-08-16|Application granted
    2004-08-16|Publication of KR100444420B1
    优先权:
    申请号 | 申请日 | 专利标题
    JPJP-P-2001-00160201|2001-05-29|
    JP2001160201A|JP3815256B2|2001-05-29|2001-05-29|NOx emission suppression operation method for intermittent operation internal combustion engine for vehicle|
    [返回顶部]