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    • 专利摘要:
    The present invention relates to a method pertaining to adaptation of at least one injector (301-306) for a combustion engine (101), such that said engine (101) comprises at least one combustion chamber, fuel is injected into said at least combustion chamber by use of said at least one injector (301- 306) and a post-treatment system (200) is provided to treat an exhaust flow arising from combustion in said engine (101). Adaptation comprises a plurality of injections by means of said at least one injector (301-306) whereby unburnt fuel is supplied to said post-treatment system (200) via said combustion chamber. The method comprises, after a first injection (i) from said plurality of injections, the steps of estimating an amount (Mest) of unburnt fuel which has become stored in said post-treatment system(200), and conducting a second injection (i+1) following upon said first injection (i) if said estimated fuel stored (Mest) is less than a first amount (ML). The invention relates also to a system and a vehicle.
    公开号:SE1151141A1
    申请号:SE1151141
    申请日:2011-12-01
    公开日:2013-06-02
    发明作者:Andreas Bolin
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    l0 l5 20 25 30 manufacturing tolerances. For the above reasons, e.g. manufacture or assembly of the internal combustion engine a mapping, such as e.g. a look-up table, where the actual amount of fuel supplied is stated for specific opening hours and for the pressure to which the fuel supplied when opening the injector is pressurized.
    The amount of fuel that is actually supplied to a combustion chamber when an injector is opened is thus directly affected by the opening time the injector is open, as well as the pressure to which the fuel is pressurized. The injection pressure can be arranged to always be the same, but can also be arranged to vary, whereby different amounts of fuel can thus be specified for one and the same opening time, but for different injection pressures.
    The amount of fuel to be actually supplied to a combustion chamber at any given time is usually determined by a control unit in the vehicle's internal control system, which determines an amount of fuel for injection, e.g. based on the prevailing operating conditions of the vehicle, and which then with the aid of said mapping determines opening hours for each injector.
    When operating an internal combustion engine, it is important that the actual amount of fuel supplied to the internal combustion chamber of the internal combustion engine also corresponds to the intended amount of fuel for injection as above. This is thus achieved by means of said mapping, where the injectors are calibrated individually in the manufacture of the injector and / or internal combustion engine, so that the mapping can be adapted for each individual injector.
    However, the properties of an injector can change over time, e.g. pga. wear of the hole (s) through which fuel injection takes place, with the consequence that a certain opening time no longer necessarily means that the desired amount of fuel is supplied at a specific opening time. For this reason, an adaptation of the injectors is usually carried out, regularly or if necessary, whereby the opening time of the injectors is corrected if necessary.
    SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of adapting at least one injector to an internal combustion engine of a vehicle. This object is achieved with a method according to claim 1.
    The present invention relates to a method of adapting at least one injector to an internal combustion engine, said internal combustion engine comprising at least one combustion chamber, and wherein fuel is injected into said at least one combustion chamber by utilizing said at least one injector system, an exhaust stream resulting from combustion at said internal combustion engine. The adaptation comprises a plurality of injections by means of said at least one injector where unburned fuel is supplied to said after-treatment system via said combustion chamber.
    The method comprises the steps of, after a first injection of said plurality of injections: - estimating an amount of unburned fuel stored in said after-treatment system, and - if said estimated stored fuel amount is less than a first fuel amount, performing a second injection following said first injection.
    By estimating according to the present invention an amount of unburned fuel stored in a post-adaptation after-treatment system and only performing a subsequent injection into a sequence of injections in an adaptation scheme when the estimated stored fuel amount is less than a first fuel amount, it can be ensured that it does not a larger amount of fuel is stored than can be allowed to oxidize or evaporate in the after-treatment system in the event of a subsequent possible temperature increase.
    Thus, a method is provided which can reduce or completely eliminate problems in adapting injectors to an internal combustion engine. For example. the risk of non-reversible so-called poisoning is reduced, ie. the risk that situations where hydrocarbons get stuck in the active sites present in catalysts where the catalyst reaction takes place and causes permanent damage can be reduced. In addition, the risk of harmful overheating caused by rapid oxidation of large amounts of stored fuel in the after-treatment system is reduced, where the fuel storage is caused by injector injection when low temperatures in the after-treatment system prevail.
    Additional features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments and the accompanying drawings.
    Brief Description of the Drawings Fig. 1a shows a driveline in a vehicle in which the present invention can be used to advantage.
    Fig. 1b shows a control unit in a vehicle control system.
    Fig. 2 shows an example of a finishing system in a vehicle in which the present invention can be used to advantage. Fig. 3 schematically shows an injection system in the vehicle shown in Fig. 1.
    Fig. 4 schematically shows a method according to an exemplary embodiment of the present invention.
    Detailed Description of Preferred Embodiments Fig. 1a schematically shows a driveline in a vehicle 100 according to an embodiment of the present invention. The vehicle 100 schematically shown in Fig. 1 comprises only one axle with drive wheels 113, 114, but the invention is also applicable to vehicles where more than one axle is provided with drive wheels, as well as to vehicles with one or more additional axles, such as one or more several support axles. The driveline comprises an internal combustion engine 101, which is connected in a conventional manner, via a shaft outgoing on the internal combustion engine 101, usually via a flywheel 102, to a gearbox 103 via a clutch 106.
    The internal combustion engine 101 is controlled by the control system of the vehicle via a control unit 115. Likewise, the clutch 106, which e.g. may be an automatically controlled clutch, and the gearbox 103 of the vehicle control system by means of one or more applicable control units (not shown). Of course, the driveline of the vehicle can also be of another type such as of a type with conventional automatic transmission etc.
    A shaft 107 emanating from the gearbox 103 then drives the drive wheels 113, 114 via an end gear 108, such as e.g. a conventional differential, and drive shafts 104, 105 connected to said final gear 108.
    Internal combustion engines in vehicles of the type shown in Fig. 1a are often provided with controllable injectors to supply the desired amount of fuel at the desired time, and in addition at a desired time in the combustion cycle, such as at a specific piston position in the case of a piston engine. , to the combustion chamber of the internal combustion engine.
    Fig. 3 schematically shows the fuel injection system for the internal combustion engine 101 exemplified in Fig. 1a. According to the following, the fuel injection system consists of a so-called common rail system, but the invention is equally applicable to other types of injection systems. The internal combustion engine 101 consists of a six-cylinder internal combustion engine with a respective injector for each combustion chamber (cylinder), schematically indicated as 301-306. Each injector is thus responsible for injecting (supplying) fuel into a respective combustion chamber. As will be appreciated, the internal combustion engine may be an engine with any number of cylinders (combustion chambers). Likewise, two or more injectors per combustion chamber can be used. The injectors 301-306 are individually controlled by actuators (not shown) arranged respectively and arranged at each injector, which, based on received control signals, control the opening / closing of the injectors 301-306.
    The control signals for controlling the opening / closing of the injectors of the injectors can be generated by any applicable control unit, such as in this example the motor control unit 115. The control unit 115 thus determines the amount of fuel to be actually injected at any given time, e.g. based on the prevailing operating conditions of the vehicle. Specifically how the required amount of fuel is determined is well described in the prior art, which is why this is not described in more detail. The control unit 115 uses a mapping such as e.g. a table as above to translate a desired amount of fuel into a corresponding opening time for the injectors.
    The injection system shown in Fig. 3 further consists of a so-called Common Rail system, which means that all injectors (and thus combustion chambers) are operated by a common fuel pipe 307 (Common Rail), which by means of a fuel pump 308 is filled with fuel at the same time as the fuel in the pipe 307, also with by means of the fuel pump 308, is pressurized to a certain pressure. The highly pressurized fuel in the common pipe 307 is then injected into the combustion chamber of the combustion engine 101 at the opening of the respective injectors 301-306. Several openings / closures of a specific injector can be performed during one and the same combustion cycle.
    Regardless of how injection takes place during an combustion cycle in an combustion chamber, such as if it takes place by means of one or more successive injections, etc., it is very important that the actual amount of fuel injected into the combustion engine combustion chamber really corresponds to the intended amount of fuel for injection. If the actual amount of fuel injected becomes too small in relation to the desired amount of fuel injected, the internal combustion engine will exhibit lower performance than intended, and compared to what has been promised, with poorer drivability as a result. Conversely, if the amount of fuel injected becomes too high in relation to the intended amount of fuel, the internal combustion engine may exhibit improved performance, such as higher torque / power than intended. This in turn can cause damage to the internal combustion engine and / or other components present in the vehicle that are not dimensioned for the higher power.
    It is therefore very important that the amount of fuel injected actually corresponds to the intended amount of fuel. For this reason, a mapping, such as a look-up table, is also generated as above in the manufacture / assembly of the internal combustion engine 101 and / or the injectors 301-306, where the desired amount of fuel for supply to an internal combustion chamber is translated to a certain opening time for each injector. in order to take into account individual differences from injector to injector. Ie. the injectors are calibrated at injector level so that the mapping can be adapted for each individual injector. Thus, although in the manufacture of a vehicle it can be ensured that the internal combustion engine functions in the intended manner, the properties of an injector can change over time, whereby a certain opening time no longer safely results in the injection of the intended amount of fuel. For example. For example, the properties of the injectors can be changed in such a way that a higher amount of fuel than desired is injected for a given opening time / injection pressure ratio, with disadvantages as above as a result. For this reason, an adaptation of the injectors is usually carried out, regularly or if necessary, where the opening time of the injectors is corrected so that the amount of fuel actually supplied to the combustion also corresponds to the intended amount of supplied fuel.
    Adaptation to a system according to Fig. 3 can be performed as follows. First, the pipeline 307 is pressurized with pressurized fuel by means of the fuel pump 308, whereby continued fuel supply by means of the fuel pump 308 is then shut off.
    This means that the pipe 307 will contain a certain amount of fuel of a certain pressure. By then opening and closing an injector, such as the injector 301, so that the injector is open during a first opening time to effect an injection of an expected amount of fuel, the actual amount of fuel injected can be determined by the opening time and a determination of the pressure difference. (pressure drop) that occurs in the tube 307 when a portion of the fuel stored in the tube 307 upon opening the injector 301 is supplied to the combustion chamber of the internal combustion engine. The pressure difference can e.g. determined with the aid of an applicable pressure sensor. The actual amount of fuel injected can then be compared with the expected amount of fuel injected, whereby the opening time stored in the vehicle's control system for a certain desired amount of fuel can be shortened or extended if necessary so that the actual amount of fuel injected will continue to correspond to the expected amount of fuel. This determination is performed individually for each respective injector 301-306, and possibly also for different injection pressures if different injection pressures are used in the operation of the internal combustion engine.
    When adapting the internal combustion engine injectors, a number of injections are thus performed, where the number of injections depends on the number of injectors and the number of different opening times to be tested. In addition, each injector / opening time combination may be arranged to be tested several times during an adaptation. Thus, in the case of a complete adaptation of the 101 injectors of the internal combustion engine, a large number of injections can be performed. However, since the pressure difference in the fuel pipe 307 must be determined for each respective injection, no other injection can take place at the same time. However, the adaptation is still usually carried out while driving the vehicle, which means that adaptation is usually carried out at so-called "Towing", ie in situations where the vehicle is driven with a closed driveline, ie. with the internal combustion engine l11 connected to the vehicle's drive wheels ll3, ll4, at the same time as the fuel supply to the internal combustion engine l1l is shut off. This is usually done when there is a reduced driving force requirement, such as when driving in seals. Furthermore, the fuel is injected so late during the combustion step of the combustion cycle that no or only parts of the fuel are combusted in the combustion chambers, whereby fuel will follow the exhaust gas flow to the after-treatment system. For example. the injection can take place 30-40 10 15 20 25 30 10 crankshaft degrees, or even later, after the upper dead center. Such injection angles mean that the fuel in principle does not ignite at all but instead follows the exhaust gas stream in unburned form. The adaptation thus means that unburned fuel will be supplied to the vehicle's normally occurring after-treatment system.
    Due to increased regulatory interests regarding pollution and air quality, especially in metropolitan areas, emission standards and regulations have been developed in many jurisdictions, and in an effort to comply with these emission regulations, systems have been developed for after-treatment (purification) of the exhaust gases formed during combustion. in the internal combustion engine.
    These after-treatment systems often involve some form of catalytic purification process, where one or more catalysts are used to purify the exhaust gases. Vehicles with a diesel engine often include a particulate filter to capture the soot particles formed during the combustion of fuel in the internal combustion chamber of the internal combustion engine.
    In Fig. 2, the finishing system 200 of the vehicle shown in Fig. 1 is shown in more detail, and the system shown is only an example of a finishing system. The figure shows the internal combustion engine 101 of the vehicle 100, and the exhaust gases generated during combustion (exhaust gas flow) are led to the after-treatment system via a turbocharger 220.
    The turbocharger can be of different types and the function for different types of turbochargers is well known, and is therefore not described in more detail here. The exhaust gas stream is then passed through a pipe 204 (indicated by arrows) to a particulate filter (DPF) 202 via an oxidation catalyst (Diesel Oxidation Catalyst, DOC) 205. 10 l5 20 25 30 ll The oxidation catalyst DOC 205 is normally used primarily to oxidize residual hydrocarbons and carbon monoxide in the exhaust gas to carbon dioxide and water. During the oxidation of hydrocarbons (ie oxidation of unburned fuel) heat is also formed, e.g. can be used to raise the temperature of the particle filter when emptying, so-called regeneration, of the particle filter.
    Finishing systems of the type shown may also include other components such as e.g. a (in the present example) downstream of the particulate filter 202 arranged SCR (Selective Catalytic Reduction) catalyst 201. SCR catalysts are generally used to reduce the amount of nitrogen oxides NOX.
    The finishing system 200 may also include more components than those exemplified above, or fewer.
    For example. the after-treatment system in addition to, or instead of, the DOC 205 may comprise an ASC (ammonia grinding) catalyst (not shown).
    The adaptation will thus lead to a supply of unburned fuel to the after-treatment system. Although the supply of unburned fuel in certain situations is desirable, such as in e.g. certain types of particle filter regeneration, the supply during adaptation can have undesirable consequences. If the prevailing heat in the finishing system is high during the adaptation, the unburned fuel can be oxidized (ignited) and thus further raise the temperature for all or parts of the finishing system. If this temperature rise becomes too high, there is a risk of damage to components in the finishing system. On the other hand, if the prevailing temperature in the after-treatment system is low and the unburned fuel is thus not oxidized, hydrocarbons will get stuck in e.g. the active sites present in catalysts where the catalyst reaction takes place, thus preventing the substances which one actually wants to react in the catalyst from reaching the catalytic site. The catalyst is thus "poisoned" by the unburned fuel. Heating the catalyst to such a temperature that the stored fuel is oxidized or evaporated can reverse this negative poisoning, but if excessive amounts of fuel are stored in the catalyst it can be non-reversible, ie. permanent, poisoning occurs, whereby the catalyst function can thus deteriorate slightly each time an adaptation is performed.
    In the case where large amounts of fuel are stored in the catalyst, when it is heated at a later time and a large amount of fuel "releases" and at the same time is oxidized, the catalyst temperature rises at least locally to very high levels, with the result that the so-called "Wash coat", which is a carrier for catalytic materials and which is used to increase the effective area of the catalyst, overheats whereby surfaces can sinter together and permanently reduce the active area of the catalyst. In general, hydrocarbons (ie unburned fuel) are easy to adhere. in the various parts of the after-treatment system with a risk of poisoning and / or overheating damage as a result.
    Supply of unburned fuel to the after-treatment system can thus lead to unwanted and potentially harmful storage of unburned fuel. According to the present invention, there is provided a method and system for reducing the risk of adverse effects in the aftertreatment system upon adaptation of the internal combustion engine injectors. An exemplary method 400 according to the present invention is shown in Fig. 4. The invention may be implemented in any applicable control unit, such as e.g. the motor control unit 115 shown, but also in a control unit dedicated to the present invention, or in whole or in part in one or more other control units already existing in the vehicle. In general, control systems in modern vehicles consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECUs) such as the control units, or controllers, 115 and various components located on the vehicle. Such a control system can comprise a large number of control units, and the responsibility for a specific function can be divided into more than one control unit. For the sake of simplicity, only the control unit 115 is shown in Fig. 1a.
    Control units of the type shown are normally arranged to receive sensor signals from different parts of the vehicle. The function of the controller 115 (or the controller (s) to which the present invention is implemented) is likely to e.g. depend on information such as e.g. received sensor signals from various sensors arranged at the internal combustion engine, as well as from other control units such as the control unit responsible for temperature determinations in the after-treatment system and / or signals from temperature sensors in the after-treatment system.
    Furthermore, such control units are usually arranged to emit control signals to various vehicle parts and components. For example. the control unit 115 will emit signals to e.g. the actuators of the injectors. The control is often controlled by programmed instructions. These programmed instructions typically consist of a computer program, which when executed in a computer or controller causes the computer / controller to perform the desired control, such as method steps of the present invention. The computer program is usually part of a computer program product, wherein the computer program product comprises a digital storage medium 121 (see Fig. 1b) with the computer program 109 stored on said storage medium 121.
    Said digital storage medium 121 may e.g. consists of someone from the group: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc., and be 10 15 14 arranged in or in connection with the control unit, the computer program being executed by the control unit. By following the instructions of the other computer program, the behavior of the vehicle in a specific situation can thus be adapted.
    An exemplary control unit (control unit 115) is shown schematically in Fig. 1b, wherein the control unit may in turn comprise a calculation unit 120, which may consist of e.g. any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or an Application Specific Integrated Circuit (ASIC). The computing unit 120 is connected to a memory unit 121, which provides the computing unit 120 e.g. the stored program code 109 and / or the stored data calculation unit 120 need to be able to perform calculations. The calculation unit 120 is also arranged to store partial or final results of calculations in the memory unit 121.
    Furthermore, the control unit is provided with devices 122, 123, 124, 125 for receiving and transmitting input and output signals, respectively. These input and output signals may contain waveforms, pulses, or other attributes, which of the input 122 devices 125, 125 may be detected as information for processing the computing unit 120. The output signals 123, 124 for transmitting output signals are arranged to convert calculation results from the computing unit. 120 to output signals for transmission to other parts of the vehicle control system and / or the component (s) for which the signals are intended. Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may consist of one or more of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems 10 15 20 25 30 15 Transport), or any other bus configuration; or by a wireless connection. Returning to Fig. 4, it is determined in step 401 whether adaptation of injectors should be initiated. If so, the procedure proceeds to step 402 while a counter is set to = 1. The transition from step 401 to 402 may be subject to different conditions. For example. it may be decided that adaptation should be performed due to the fact that a certain time has elapsed since the previous adaptation and / or for some other reason. In general, reference is made to the prior art regarding the applicable conditions for starting the adaptation. Furthermore, according to the above, it may be required that the vehicle is driven with the fuel supply switched off, such as when towing, so it may also be required that this criterion must be met at the transition from steps 401-402. The invention itself is, however, applicable in all cases where unburned fuel is supplied during adaptation, ie. even in cases where adaptation is performed with ongoing fuel supply to generate a propulsion force.
    However, the invention is exemplified below for the case where adaptation is performed during towing.
    As mentioned above, the number of injections during a complete adaptation process can consist of a rather large number of injections, so it is not certain that a complete adaptation will have time to be performed during the time the vehicle is traveling during towing. A total adaptation of all injectors for all injection times can therefore be divided into a plurality or a large number of consecutive occasions where the vehicle is driven during towing. In addition to the criterion that towing must be met, there are as described below also criteria which according to the present invention must be met in order for the adaptation to be carried out. The counter i represents injection no. i, where in e.g. can represent l0 l5 20 25 30 l6 adaptation of a certain injector and a certain opening time.
    The adaptation can be arranged to be carried out according to a schedule with a number of injector / injection time combinations in as above, where the injectors are adapted one by one and for different opening hours and possibly. different injection pressures.
    In step 402, injection number i is performed in the adaptation scheme, in this case injection number 1. In the case where the adaptation has previously been interrupted, e.g. pga. due to the fact that the driving of the vehicle has changed from towing to an operating condition where torque is required and fuel is thus injected to propel the vehicle, in the transition from step 401 to step 402 can instead be set to the next uncompleted injection, ie. the adaptation can be resumed where it was previously interrupted. The injection performed in step 402 is performed as above with fuel supply to the fuel pipe 307 turned off. The pressure in the fuel pipe 307 in such systems can e.g. amount to any applicable pressure in the range 1000-2000 bar.
    After the injection i has been performed in step 402, the process proceeds to step 403 where an amount of Mi injected fuel is determined for the injection i. This determination can be performed as above using the injector opening time and the pressure / pressure change the fuel tube 307 undergoes during injection i. determined in any applicable form such as e.g. volume and / or mass. Depending on a prevailing temperature T in the after-treatment system, the process then proceeds to step 404 or 405. If the temperature T in the after-treatment system is below a temperature TO, the process continues to step 404, where an estimated stored amount of fuel is accumulated as previously estimated Mg fi plus that in step 403 determined amount Mi. If, on the other hand, the temperature T in the aftertreatment system exceeds the temperature T = T0, the process proceeds instead to step 405, where the amount of fuel M injected and estimated in the aftertreatment system is determined as a function of time since prior injection into and prevailing temperature T .
    The temperature T can be arranged to be measured at an appropriate place in the finishing system, such as e.g. at a particulate filter and / or the oxidation catalyst. The temperature TO means that the temperature T in the after-treatment system is so high that the injected fuel which is supplied in unburned form to the after-treatment system begins to oxidize and thus does not to the same extent give rise to undesired storage in the after-treatment system. TO can e.g. be in the range 200-250 °, but also higher or lower. The temperature information is an example, and actual values may deviate from these. For example. the way in which the temperatures are determined / calculated can have an effect on the temperature limits. Regarding the example of a finishing system shown in Fig. 2, the temperature T can e.g. is determined upstream and / or downstream of the oxidation catalyst 205 and / or upstream and / or downstream of the particulate filter 202. Furthermore, the temperature TO e.g. determined as a weighted value based on a plurality of temperature sensors. Likewise, another suitable temperature sensor can be used, e.g. together with a model of the finishing system and / or e.g. current exhaust flow, to calculate a temperature T for the after-treatment system.
    At lower temperatures where T oxidation, whereby added fuel is substantially stored. Thus, as long as the temperature T in the aftertreatment system is less than TO, the injected fuel amounts Mi accumulate in step 404. When the temperature T in the aftertreatment system exceeds TO, the injected fuel will be completely or partially oxidized, so the estimated accumulated stored amount of fuel Measure in step 405 takes this into account by subtracting an estimated oxidized amount of fuel from the estimated accumulated stored amount of fuel by means of the time between the injections and the prevailing temperature T in the after-treatment system. The accumulated stored amount of fuel Measures can thus be increased by a smaller amount than that determined in step 403, or, depending on the prevailing temperature T, t.o.m. decrease even though the injection has been performed.
    The process then proceeds to step 406 where it is determined whether the estimated stored fuel quantity Measure is greater than or equal to a set quantity limit ML.
    The amount limit ML may be set to any applicable amount of fuel such as, but not limited to, an arbitrary number of grams of fuel in the range of 1-50 grams, such as e.g. in the order of 10 grams. The quantity limit ML can be set based on the prevailing configuration of the current finishing system and can also be arranged to vary with prevailing operating parameters for the vehicle. As long as it is determined in step 406 that the amount of fuel injected is less than the amount limit ML, the injection counter is counted up to 1 and the process proceeds to step 413 to determine whether the adaptation is complete, in which case the process is terminated in step 412. to step 402 for performing the next injection in. It should be noted that the process shown may be subordinate to an overall process, where the adaptation is interrupted if the vehicle changes from towing to another mode of operation as above. The total amount of fuel that is supplied / injected during an individual injection can e.g. be an arbitrarily applicable number of 10 milligrams in the range of 1-500 mg of fuel, so that the amount limitation ML can be an amount corresponding to a plurality of injections.
    If it is determined in step 406 that the estimated accumulated stored amount of fuel Mæt exceeds the set amount limit ML, the procedure proceeds to step 407, where it is determined whether a temperature T prevailing in the vehicle aftertreatment system is in an interval T0 TO there as defined above. The upper temperature limit T1 can be set to an upper limit above which continued injection of unburned fuel should not / must not take place as further temperature increase may entail a risk of damage to components included in the after-treatment system. As long as the temperature T in step 407 is found to be in said interval, the method returns to step 402, via step 413, to determine whether the adaptation is complete, at the same time as the injection counter i is counted up by 1.
    If, on the other hand, it is found in step 407 that the temperature T is higher than the upper temperature limit T1, the procedure proceeds to step 408, at the same time as a timer t1 is set equal to 0. In step 408 it is determined whether the temperature T is still higher than the temperature T1, and so long if so, the procedure remains in step 408 so that no further injections are performed with the risk of unwanted / harmful temperature rise. When then the temperature T in the finishing system has dropped to a temperature T, the process returns to step 402 at the same time as the injection counter i is set equal to i + 1, but only via step 409 to determine whether the adaptation is complete. If the adaptation is complete, the process is terminated in step 412. Since the high temperature will have resulted in any accumulated unburned fuel Mæt in the after-treatment system being at least partially oxidized, the accumulated estimated amount of injected fuel Mæt may be transferred to step 402 is reduced in any applicable way, e.g. as a function of the time t1 the process has been in step 408 and / or the prevailing temperature T of the finishing system while the process has remained in step 408.
    Thus, depending on the time the process has remained in step 408, the accumulated amount of fuel may have been reduced to a greater or lesser extent, and if the process has been in step 408 long enough, the accumulated amount of fuel will have been reduced to zero, but may thus , depending on time / temperature, assume some value between 0 and the accumulated amount Measure.
    Instead of determining in step 408 whether the temperature T is higher than the temperature T1, in this step it can instead be compared whether the temperature T is higher than someone compared with the temperature T1 lower temperature. Ie. a hysteresis function can be applied because in e.g. step 408 may be unsuitable to continue the adaptation if the temperature T is only below T1 by a single degree or part thereof, as there is then a risk that the temperature T1 is quickly exceeded again with the risk that the temperature T will fluctuate around T1 with slow adaptation process as a result. In general, similar hysteresis function can be applied to the other temperature limits applied with reference to Fig. 4.
    Furthermore, if in step 407 it is instead determined that the temperature T is less than the temperature TO, the process proceeds to step 410. The process remains in step 4110 as long as the temperature T in the finishing system is below the temperature TO. The reason for this is that as long as the temperature T in the after-treatment system is below the temperature TO, no or substantially no fuel will be oxidized in the after-treatment system, which in turn means that added unburned fuel will be stored completely or at least to a large extent in the after-treatment system. above as a result. Thus, when the process has reached step 410 due to that the estimated accumulated stored fuel quantity Measures is equal to or exceeds the fuel quantity limit ML, with continued adaptation, the accumulated amount of unburned fuel would thus continue to rise to even higher levels exceeding ML.
    Thus, when the estimated accumulated amount of fuel Mæt has reached the amount of ML, the accumulated amount of fuel Mæt has also reached the limit of accumulated amount of unburned fuel in the after-treatment system that is allowed without significant risk of components in the after-treatment system being damaged by a subsequent temperature increase. By proceeding in this way, it can be ensured during the injector adaptation that a greater amount of unburned fuel is never stored in the after-treatment system than can be allowed to oxidize, with associated additional heat increase, without risk of damage in a subsequent temperature increase in the after-treatment system.
    The process thus remains in step 410 as long as the temperature T in the after-treatment system is below the temperature TO, since in this case substantially no oxidation of stored fuel will take place, whereby the amount of stored fuel will not decrease either. When then the temperature increases, the process proceeds, provided that T 10 is still less than T1, to step 411 at the same time as a timer tg is started. If in step 410 it is determined that T> T1, the procedure proceeds instead to step 408 as above.
    The temperature rise can e.g. due to the fact that, when the adaptation has been interrupted, the vehicle has been driven under conditions where the internal combustion engine has operated actively and generated an exhaust gas flow with a higher temperature, with associated temperature increase in the after-treatment system as a result.
    In step 411, it is first determined whether the adaptation is complete, ie. whether all injections made in the adaptation have been performed. If so, the adaptation ends in step 412. If the adaptation is not complete, the procedure remains in step 411 until the timer tg has reached a set time tT2. This value constitutes a period of time during which, due to that the temperature T in the finishing system exceeds TO, stored fuel in the finishing system will be oxidized and the stored amount of Mæt will thus decrease. The timer tg can e.g. set to a value that results in a reduction of the estimated stored fuel quantity Measure with a fuel quantity corresponding to one or more future injections in. Alternatively, the time can be set to a time corresponding to an expected oxidation of x% of stored fuel, such as 10%, 50% or other applicable percentage in the range O-100%. The timer value can e.g. be arranged to depend on the current temperature in the finishing system. The higher the temperature in excess of the temperature TO, the faster the oxidation of stored fuel, and thus the reduction of stored fuel, will take place.
    Depending on how long the tT2 timer tg has been set to, it can also be advantageous in step 411 to monitor the temperature T. If e.g. tg has been set to a relatively long time, the temperature T during the time 10 15 20 25 30 23 can be changed in such a way that it, e.g. pga. changed driving conditions, e.g. will exceed T1, in which case the method may proceed to step 408. Conversely, if T will be less than TO, the method may be arranged to return to step 410.
    According to one embodiment, no timer is set at all at the transition to step 411, when the temperature TO e.g. can be set to such a level that injected fuel will certainly be oxidized, nor will any increase in stored fuel occur as long as the temperature in the after-treatment system exceeds TO.
    Thus, according to the present invention, there is provided a method which can reduce or completely eliminate problems such as poisoning and / or overheating caused by fuel storage in aftertreatment systems by monitoring the amount of unburned fuel in the aftertreatment system. As will be appreciated, the method shown in Fig. 4 is only an example of how the present invention may be realized.
    Furthermore, the present invention has been exemplified above in connection with vehicles. However, the invention is also applicable to arbitrary vessels / processes where finishing systems as above are applicable, such as e.g. water or aircraft with combustion processes as above.
    Further embodiments of the method and system according to the invention are found in the appended claims. It should also be noted that the system can be modified according to various embodiments of the method according to the invention (and vice versa) and that the present invention is thus in no way limited to the above-described embodiments of the method according to the invention, but relates to and includes all embodiments within the appended the scope of protection of the independent requirements.
    权利要求:
    Claims (1)
    [1]
    A method of adapting at least one injector (301-306) to an internal combustion engine, said internal combustion engine (101) comprising at least one combustion chamber, and wherein fuel is injected into said at least one combustion chamber by utilizing said at least one injector (301-306), wherein a post-treatment system (200) is provided for treating an exhaust stream resulting from combustion at said internal combustion engine (101), and wherein said adaptation comprises a plurality of injections by means of said at least one injector (301-306). ) where unburned fuel is supplied to said after-treatment system (200) via said combustion chamber, characterized by the steps of, after a first injection (i) of said plurality of injections: - estimating an amount (Mñm) of unburned fuel stored in said after-treatment system (200), and - if said estimated stored fuel quantity (Mæt) is less than a first fuel quantity (ML), perform a after said first injection (i) the following second injection (i + 1). A method according to claim 1, wherein, in said injections, fuel is injected at a time in the combustion cycle where no or only a part of said fuel is combusted in said combustion chamber. A method according to claim 1 or 2, wherein said estimated stored amount of fuel (Mäï) is an accumulation of estimated amounts (Mi) of injected fuel for a plurality of said injections. A method according to any one of the preceding claims, further comprising: - determining a temperature (T) for said after-treatment system (200), and - estimating said amount (Measure) of unburned fuel stored in said after-treatment system (200) if said temperature (T) is less than a first value (TM). the preceding claim, further comprising, in said estimating (Measuring) the amount of unburned fuel stored in said finishing system (200): estimating a conversion, such as oxidation, of stored fuel in said finishing system (200), said estimating (Measuring) of said amount of unburned fuel stored in said after-treatment system (200) consists of a difference between a supplied amount of unburned fuel and a subsequent e-processing system converted amount of fuel. A method according to claim 5, wherein said conversion of stored unburned fuel in said after-treatment system is determined as a function of a temperature (T) for said after-treatment system and / or a first elapsed time (t; t fl. A method according to any one of the preceding claims, further comprising: : - when said estimated stored fuel quantity (Mæt) exceeds said first fuel quantity (ML), determining a temperature (T) for said after-treatment system (200), and - when said temperature (T) exceeds a first temperature (TO) but falls below a second , compared to said first temperature, higher temperature (T1), performing a subsequent injection (j), said first l0 l5 20 25 30 l0. ll. 27 temperature (T0) being constituted by a temperature (T) at which fuel is oxidized in A method according to any one of the preceding claims, further comprising: - determining a temperature (T) for said finishing system (200), and - when said temperature (T) exceeds tiger a second temperature (T1), interrupt said adaptation. A method according to claim 8, further comprising resuming said adaptation when said temperature (T) has dropped to a temperature below said second temperature (TU. A method according to any one of the preceding claims, further comprising: - when said estimated stored amount of fuel (Measure) exceeds one first amount of fuel (ML), determining a temperature (T) for said after-treatment system (200), and - when said temperature (T) is below a first temperature (TO), said first temperature (TM being a temperature below which substantially no fuel oxidized in said finishing system (200), interrupting said adaptation, and, - when said temperature (T) of said finishing system (200) has risen to a higher temperature compared to said first temperature (TO), resume said adaptation. further comprising resuming said adaptation when a second time (tT2) has elapsed since said temperature (T) of said finishing system (200) s to a higher temperature compared to said first temperature (TO). A method according to any one of the preceding claims, further comprising, in an injection (i) at said adaptation, - estimating an amount of fuel (Mi) injected with said injector (301-306) , - comparing said estimated amount of fuel (Mi) with an expected amount of fuel, and - correcting an opening time for said injector (301-306) based on said comparison. A method according to any one of the preceding claims, wherein in said adaptation said at least one injector (301-306) is adapted for a plurality of opening hours. A method according to any one of the preceding claims, wherein said internal combustion engine (101) is arranged to propel a vehicle (100), and wherein, upon propulsion of said vehicle (100), fuel is injected into said combustion chamber, said adaptation being performed when said vehicle (100) driven with said fuel injection for propulsion turned off. Computer program comprising program code, which when said program code is executed in a computer causes said computer to perform the method according to any one of claims 1-14. A computer program product comprising a computer readable medium 17 and a computer program according to claim 15, wherein said computer program is included in said computer readable medium. A system for adapting at least one injector (301-306) to an internal combustion engine (101), said internal combustion engine (101) comprising at least one combustion chamber, and wherein fuel is arranged to be injected into said at least one combustion chamber by utilizing said at least one combustion chamber. (301-306), wherein a post-treatment system (200) is provided for treating an exhaust gas from said combustion at said internal combustion engine (101), and said adaptation comprises a plurality of injections (i) by means of said at least one injector. (301-306), where unburned fuel is supplied to said after-treatment system (200) via said combustion chamber, characterized by the system comprising: - means for, after a first injection (i) of said plurality of injections, estimating an amount of unburned fuel (Measure) as stored in said finishing system (200), and - means for performing a second injection after said first injection (i) injection (i + 1) if said estimated stored fuel quantity (Mæt) is less than a first fuel quantity (ML). Vehicle (100), characterized in that it comprises a system according to claim 17.
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    同族专利:
    公开号 | 公开日
    DE112012004664T5|2014-08-28|
    WO2013081529A1|2013-06-06|
    SE536233C2|2013-07-09|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US6021754A|1997-12-19|2000-02-08|Caterpillar Inc.|Method and apparatus for dynamically calibrating a fuel injector|
    DE10212428B4|2002-03-21|2004-05-13|Robert Bosch Gmbh|Method for protecting an internal combustion engine|
    DE102006032245B4|2006-07-12|2008-11-06|Continental Automotive Gmbh|Adaptation method of an injection system of an internal combustion engine|
    DE102007042994A1|2007-09-10|2009-03-12|Robert Bosch Gmbh|Method for assessing an operation of an injection valve when applying a drive voltage and corresponding evaluation device|FR3066554B1|2017-05-18|2021-11-19|Continental Automotive France|CONTROL PROCESS DEDICATED TO THE OPTIMIZATION OF THE MANAGEMENT OF THE INJECTION MEANS OF AN INTERNAL COMBUSTION ENGINE|
    法律状态:
    2021-08-03| NUG| Patent has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    SE1151141A|SE536233C2|2011-12-01|2011-12-01|Method and system for adapting at least one injector to an internal combustion engine|SE1151141A| SE536233C2|2011-12-01|2011-12-01|Method and system for adapting at least one injector to an internal combustion engine|
    DE112012004664.1T| DE112012004664T5|2011-12-01|2012-11-20|Method and system related to an adaptation of at least one injector for an internal combustion engine|
    PCT/SE2012/051277| WO2013081529A1|2011-12-01|2012-11-20|Method and system pertaining to adaptation of at least one injector for a combustion engine|
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