Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D45/00—Electrical control not provided for in groups F02D41/00 - F02D43/00
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M15/00—Testing of engines
  • G01M15/04—Testing internal-combustion engines
  • G01M15/11—Testing internal-combustion engines by detecting misfire
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
• • 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
  • F02D2200/10—Parameters related to the engine output, e.g. engine torque or engine speed
  • F02D2200/1015—Engines misfires

Definitions

• the present invention relates to a misfire detection device that detects misfire based on rotational fluctuations of an internal combustion engine, and more particularly to a misfire detection device for an internal combustion engine that includes a flywheel damper.
• misfire a phenomenon in which the air-fuel mixture in the combustion chamber is not ignited, so-called “misfire”, may occur depending on conditions such as temperature and spark plug condition.
• misfire occurs, not only the engine speed decreases, but the unburned air-fuel mixture is discharged into the exhaust passage, and there is a concern about deterioration of exhaust emission and adverse effects on the exhaust purification catalyst. For this reason, it is necessary to detect the occurrence of misfire and notify the driver, etc. in order to deal with the misfire abnormality of the internal combustion engine at an early stage.
• misfire detection device that detects misfire in a multi-cylinder internal combustion engine, paying attention to the fact that fluctuations in engine speed (hereinafter simply referred to as rotation fluctuations) increase when misfire occurs.
• rotation fluctuations fluctuation in engine speed
• misfire determination apparatus for determining the above (see, for example, Japanese Patent Application Laid-Open Nos. 05-203395 and Japanese Patent No. 30.603007).
• the basic principle of misfire determination in such a misfire detection device is as follows.
• this calculated value device of elapsed time
• a rotation angle sensor for example, a crank position sensor
• rotation fluctuations may occur due to misfire, and rotation fluctuations may also occur due to backlash caused by changes over time such as a flywheel.
• rotation fluctuations may occur due to backlash caused by changes over time such as a flywheel.
• rough roads such as uneven roads and gravel roads
• torque from the rear wheels of the vehicle is transmitted via the propeller shaft, which may cause rotational fluctuations in the flywheel. . If rotation fluctuations occur due to factors other than such misfires, it is difficult to distinguish them from rotation fluctuations due to misfires, and misfire detection may occur.
• the flywheel damper As a flywheel attached to an internal combustion engine (hereinafter, also referred to as an engine), a flywheel damper that absorbs engine rotation fluctuations and torsional vibration of a rotating shaft to suppress vibration of a drive system is known.
• an engine using a flywheel damper has a problem in that the rotational fluctuation is disturbed when a misfire occurs, and the reliability of misfire detection is reduced. The reason will be described below.
• the flywheel damper includes an engine side plate 2 1 (hereinafter referred to as a front plate 2 1) connected to the engine crankshaft and a transmission side plate 2 2 connected to the transmission side.
• rear plate 2 2 (Hereinafter referred to as rear plate 2 2), and a spring 23 is arranged between the front plate 21 and the rear plate 2 2.
• a rotation angle sensor for example, a crank position sensor
• this type of flywheel damper 2 has a backlash (play: for example, 6 ° ( ⁇ 3 °)) between the rear plate 2 2 and the spring 2 3, so that during normal idling operation (low Minor rotational fluctuations under the load (low rotation) are absorbed by the above-mentioned backlash. Therefore, as indicated by arrow B in FIG. 7, the state in which the spring 23 is not in contact with either the front plate 21 or the rear plate 22 is maintained. In this state, the front plate 21 has a slight rotational fluctuation (for example, a fluctuation in the range of 80 to 80 rpm), but the rear plate 2 2 has a substantially constant rotation (for example, 8 0 5 rpm). It becomes. In the flywheel damper 2, power is transmitted to a friction mechanism (not shown) or the like when the spring 23 is not in contact with the rear plate 22.
• a friction mechanism not shown
• the rear plate 2 2 moves within the range of the above-mentioned backlash, and the spring 2 3 moves to either the front plate 2 1 or the rear plate 2 2. In some cases, misdetection of misfire may not occur.
• the rotational fluctuation amount due to misfire exceeds the threshold value and misfire occurs.
• the second cylinder for example, the fourth cylinder
• the speed of the front plate 2.1 engine speed
• the speed of the rear plate 2 2 transmission-side rotation
• the front plate 2 1 drops to 790 rpm and lower than the 8 0 5 rpm rear plate 2 2
• the rear plate 2 2 is one end of the spring 2 3 2 Three Touch a.
• an engine employing a flyhole damper has a problem that misfire is erroneously detected in the idling operation region (low load, low rotation region: region A in Fig. 4). Also, in the medium load operating range (C range in Fig. 4), there are situations where the rear plate 22 is in contact with the spring 23 and not in contact (range C in Fig. 7). Rotational fluctuation may be disturbed, and misfire may be falsely detected.
• the present invention has been made in view of such circumstances, and in an internal combustion engine that employs a flywheel damper, it is possible to reduce the influence of rotational fluctuations caused by the flywheel damper, and to perform misfire detection with high reliability. It is an object of the present invention to provide a misfire detection device for an internal combustion engine.
• the present invention relates to a misfire detection device for an internal combustion engine that detects a misfire based on engine rotation fluctuation in an internal combustion engine equipped with a flywheel damper, and an operation region that is affected by the flywheel damper in the misfire detection is set in advance. It is determined whether or not the operating state of the internal combustion engine is within the “operating region affected by the flywheel damper”-and when it is within the “operating region affected by the flywheel damper”, misfire detection is performed. Restrict.
• Examples of the process for limiting misfire detection in the present invention include a cylinder specifying process for specifying a misfire cylinder or a cylinder number determining process for determining the number of misfire cylinders. Furthermore, the process of stopping (cancelling) misfire detection itself is also included in the process of limiting misfire detection.
• the misfire detection when the operating state of the internal combustion engine is within the “operating region affected by the flywheel damper”, the misfire detection is limited, and therefore, the rotation fluctuation behavior caused by the flywheel damper is caused. False detection can be eliminated and misfire detection performance can be improved.
• the total misfire power and the misfire power per cylinder are determined. It may be configured such that both force increment values are updated (incremented) and only the count value of the total misfire counter is updated (incremented) when it is within the “operating region affected by the flywheel damper”. If such a configuration is adopted, the count value of the total misfire counter is Regardless of the operation area of Seki, it is always updated when a misfire occurs. As a result, the count value (total misfire code) of the total misfire counter can be left as highly reliable data.
• FIG. 1 is a schematic configuration diagram showing an example of an engine to which the misfire detection device of the present invention is applied.
• FIG. 2 is a block diagram showing the configuration of a control system such as ECU.
• Fig. 3 is a flowchart showing the details of the misfire detection process executed by ECU.
• FIG. 4 is a diagram showing a determination map M used for misfire detection processing.
• FIG. 5 is a diagram showing an example of a change pattern of the rotational fluctuation amount when a misfire occurs.
• FIG. 6 is a diagram showing another example of the change pattern of the rotational fluctuation amount when a misfire occurs.
• FIG. 7 is a diagram schematically showing the configuration of the flywheel damper.
• Fig. 8 is an illustration of a problem (misfire detection) that occurs in an engine that uses a flywheel damper.
• BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.
• FIG. 1 is a diagram showing a schematic configuration of an engine to which the present invention is applied.
• Fig. 1 shows only the configuration of one engine cylinder.
• the engine 1 is a six-cylinder gasoline engine having six cylinders (first cylinder # 1 to sixth cylinder # 6), which is a piston 10 that forms a combustion chamber 1a and a crankshaft 15 that is an output shaft. It has.
• the piston 10 is connected to the crankshaft 15 via a connecting rod 16, and the reciprocating motion of the piston 10 is converted into rotation of the crankshaft 15 by the connecting rod 16.
• the crankshaft 15 of the engine 1 is connected to a transmission (not shown) via a flywheel damper 2 having a structure similar to that shown in FIG.
• the crankshaft 15 is provided with a signal rotor 17 having a plurality of protrusions (teeth) 17a.
• a crank position sensor 36 is disposed near the side of the signal rotor 17.
• the crank position sensor 36 is, for example, an electromagnetic pickup, and generates a pulse-like signal (output pulse) corresponding to the protrusion 17 a of the signal rotor 17 when the crankshaft 15 rotates.
• a spark plug 3 is disposed in the combustion chamber 1 a of the engine 1.
• the ignition timing of the spark plug 3 is adjusted by the igniter 4.
• the engine 1 is provided with a water temperature sensor 31 for detecting the engine water temperature (cooling water temperature).
• An intake passage 11 and an exhaust passage 12 are connected to the combustion chamber 1 a of the engine 1.
• An intake valve 1 3 is provided between the intake passage 1 1 and the combustion chamber 1 a. By opening and closing the intake valve 1 3, the intake passage 1 1 and the combustion chamber 1 a are communicated or blocked. Is done.
• an exhaust valve 14 is provided between the exhaust passage 12 and the combustion chamber 1a, and the exhaust passage 14 and the combustion chamber 1a communicate with each other by opening and closing the exhaust valve 14 and opening. Or blocked.
• the intake valve 1 3 and the exhaust valve 1 4 are opened and closed by the intake camshaft 1 8 through which the rotation of the crankshaft 15 is transmitted This is done by each rotation of the exhaust camshaft 19.
• a cam position sensor 37 for discriminating a cylinder is disposed in the vicinity of the intake camshaft 18.
• the cam position sensor 37 is an electromagnetic pickup, for example, and is arranged so as to face one protrusion (tooth) on the outer peripheral surface of the rotor integrally provided on the intake camshaft 18 (not shown).
• a pulse signal is output. Since the intake camshaft 1 8 rotates at a rotational speed of 1 Z 2 of the crankshaft 1 5, the cam position sensor 3 7 outputs one pulse-like signal each time the crankshaft 1 5 rotates 7 20 degrees. (Output pulse) is generated.
• the intake passage 11 includes an air cleaner 7, a hot-wire air flow meter 3 2, an intake air temperature sensor 3 3 (built in the air flow meter 3 2), and electronic control for adjusting the intake air amount of the engine 1.
• a spout valve 5 of the type is arranged.
• the spout pulp 5 is driven by a throttle motor 5a.
• the opening degree of the throttle valve 5 is detected by a throttle position sensor 35.
• a 0 2 sensor 3 4 and a three-way catalyst 8 for detecting the oxygen concentration in the exhaust gas are arranged in the exhaust passage 12 of the engine 1.
• An injector (fuel injection valve) 6 for fuel injection is disposed in the intake passage 11.
• the injector 6 is supplied with fuel of a predetermined pressure from a fuel tank by a fuel pump (none of which is shown), and the fuel is injected into the intake passage 11.
• This injected fuel is mixed with the intake air to be mixed into the combustion chamber 1a of the engine 1.
• the air-fuel mixture (fuel + air) introduced into combustion chamber 1a is ignited by spark plug 3 and combusts and explodes. Combustion of the air-fuel mixture in the combustion chamber 1a ⁇ Explosion causes the piston 10 to reciprocate and the crankshaft 15 to rotate.
• the engine 1 burns in the order of the first cylinder # 1, the second cylinder # 2, the third cylinder # 3, the fourth cylinder # 4, the fifth cylinder # 5, and the sixth cylinder # 6.
• E C U electronic control unit
• ECU 1 0 0 is CPU 1 0 1, R OM 1 0 2, R AM I 03, Packup RAMI 04, total misfire counter 105, and misfire power per cylinder 106.
• the ROM 102 stores various control programs, maps that are referred to when the various control programs are executed, and the like.
• the CPU 101 executes arithmetic processing based on various control programs and maps stored in the ROM 102.
• the RAM 103 is a memory that temporarily stores calculation results in the CPU 101, data input from each sensor, etc., and the knock-up RAMI 04 stores the data to be saved when the engine 1 is stopped. It is a non-volatile memory.
• ROM 102, CPU 101, RAMI 03, backup RAM 104, total misfire power counter 105, and cylinder misfire power counter 106 are connected to each other via bus 109, and are connected to external input circuit 107 and external output. Connected to circuit 108.
• the external input circuit 107 is connected to a water temperature sensor 31, an air flow meter 32, an intake air temperature sensor 3 3, 0 2 sensor 34, a throttle position sensor 3 5, a crank position sensor 36, a cam position sensor 37, and the like. Yes.
• the external output circuit 108 is connected to an injector 6, an igniter 4 of a spark plug 3, a throttle motor 5a of a throttle valve 5 and an indicator lamp 9 for warning of a misfire abnormality.
• the ECU 100 includes a water temperature sensor 31, an air flow meter 32, an intake air temperature sensor 33, an O 2 sensor 34, a throttle position sensor 35, a crank position sensor 36, a force position sensor 37, and an accelerator position sensor (not shown). Etc.) Various control of engine 1 is executed based on the output of various sensors. Furthermore, the ECU 100 executes the following misfire detection process.
• the misfire detection process uses a decision map M as shown in FIG.
• This determination map M is created using the rotation speed and load of the engine 1 as parameters, and is set in advance in the ROM 102 of the ECU 100.
• Judgment map M is a map used to determine whether or not to perform cylinder identification processing for identifying misfiring cylinders.
• A, B, C, and D areas are set, and these four Among the regions, the region A (idling operation region) and the region C (medium load carrying region) are regions where the cylinder specifying process is stopped.
• the A, B, C, and D regions of the judgment map M are indicated by the arrow ranges “A”, “B”, “C”, and “D” of the flywheel damper 2 shown in FIG.
• the A region and the C region (the operation region affected by the flywheel damper) where the misfire cylinder specific processing is stopped are determined by the play (play amount) of the flywheel damper 2 described above. It should be determined in consideration of the behavior of the rotational fluctuation that occurs (influence on misfire detection).
• the engine speed and load are changed, and the low rotation / low load range to the high rotation range (red zone) 'high load (WOT: Wide O en Thrott Rotational fluctuation at misfire may be measured under various operating conditions up to 1 e), and based on the measurement results, areas where it is difficult to identify the misfiring cylinder may be determined and the A area and C area may be set.
• WOT Wide O en Thrott Rotational fluctuation at misfire
• areas where it is difficult to identify the misfiring cylinder may be determined and the A area and C area may be set.
• using a computer, etc. simulate rotational fluctuations during misfires under various operating conditions from low to low load range to high rotation range and high load, and identify misfire cylinders based on the simulation results. Areas A and C may be set for areas that are difficult to do.
• the ECU 100 performs cranking during the explosion stroke of each cylinder # 1 to # 6 of the engine 1 based on the output of the crank position sensor 36 and the cam position sensor 37.
• T 1 (1st cylinder # 1), T 2 (2nd cylinder # 2), T 3 (3rd cylinder # 3) , T4 (fourth cylinder # 4), T5 (fifth cylinder # 5), T6 (sixth cylinder # 6) are calculated in sequence, and the deviation of the elapsed time, that is, the rotational fluctuation of each cylinder # 1 to # 6
• the quantities ⁇ 1 to ⁇ 6 are calculated sequentially.
• ⁇ 1 (1st cylinder # 1) [T1-T6]
• ⁇ 2 (2nd cylinder # 2) [ ⁇ 2- ⁇ 1]
• ⁇ 3 (3rd cylinder # 3) [ ⁇ 3 - ⁇ 2]
• ⁇ 4 (4th cylinder # 4) [ ⁇ 4- ⁇ 3]
• ⁇ 5 (5th cylinder # 5) [ ⁇ 5— ⁇ 4]
• ⁇ 6 (6th cylinder # 6) [ ⁇ 6- ⁇ 5].
• the ECU 100 determines that any one or more of the rotational fluctuation amounts ⁇ 1 to ⁇ 6 of the cylinders # 1 to # 6 obtained by the above calculation exceed a predetermined threshold (see FIGS. 5 and 6). Determine that a misfire has occurred.
• misfire detection and cylinder identification process are processes executed in steps ST2 and ST6 of the misfire detection routine shown in FIG.
• This misfire detection routine is repeatedly executed at predetermined time intervals.
• step ST1 the ECU 100 determines whether or not a predetermined misfire detection execution condition is satisfied. If the determination result is a negative determination, the ECU 100 once ends the misfire detection routine. On the other hand, if the determination result of step ST1 is affirmative, that is, if the misfire detection execution condition is satisfied, the process proceeds to step ST2.
• misfire detection execution condition is a condition stipulated by laws and regulations.
• the misfire detection execution condition is a positive torque range when fuel cut is not performed, and the operation state of engine 1 is It is in the range of [(idling rotation 1 150 rpm) to (red rotation)].
• step ST2 the ECU 100 determines whether or not misfire has occurred in the cylinders # 1 to # 6 of the engine 1 by the above-described method, and the determination result is negative determination, that is, misfire has occurred. If not, the misfire detection routine is terminated. On the other hand, if the determination result in step ST2 is affirmative, that is, if a misfire has occurred in any of the cylinders # 1 to # 6 of engine 1, the process proceeds to step ST3.
• step ST3 the ECU 100 determines that the current operating state of the engine 1 Rotation speed (load) force Determine whether or not it is within the A area or C area of the judgment map M shown in Fig. 4. If the judgment result is affirmative, that is, the engine 1 when a misfire occurs If the operating state is within the “region affected by the flywheel damper”, the misfire cylinder specific processing is not executed (step ST 4), and only the total misfire counter 1 0 5 is incremented in step ST 5. Later, this misfire detection routine is temporarily terminated.
• step ST 3 determines whether the operating state of engine 1 when a misfire has occurred is within the B region or D region (the operating state of engine 1 is the effect of flywheel dampers). If it is “out of range”, go to step ST6.
• step ST 6 the ECU 1 0 0 identifies the cylinder in which misfire has occurred by the above-described cylinder identifying process, and in step ST 7, the total misfire counter 1 0 5 is incremented and the misfire in each cylinder is performed. After incrementing force counter 1 0 6, this misfire detection routine is terminated.
• the misfire abnormality warning that is, the lighting of the indicator lamp 9 is determined using the count value of the total misfire counter 1 0 5, and the count value of the total misfire counter 1 0 5 is a predetermined value (for example, 3 0 to When it reaches 6 counts, the indicator lamp 9 is turned on.
• misfire detection process when the operating state of the engine 1 is within “region (A region or region) J that is affected by the fly-hoist noise damper”, the cylinder identifying process for identifying the misfire cylinder is stopped. Therefore, for example, when there is a misdetection as shown in Fig. 8, “2-cylinder continuous misfire (for example, 3rd cylinder # 3 and 4th cylinder # 4 continuous misfire), the second cylinder of the continuous misfire. (For example, misdetection that misfire of cylinder 4 # 4 cannot be detected) and “If misfire does not occur, misfire (for example, misfire of cylinder 6 # 6) occurs.
• misfire detection it is possible to eliminate the “misdetection such as being detected if it is done” and to improve the reliability of misfire detection. Moreover, since the misfire detection itself is performed regardless of whether or not the operating state of the engine 1 is within the “region affected by the flywheel damper”, the misfire detection function can be ensured.
• misfire codes that do not know which cylinders are misfired (total misfire codes)” and “cylinder specific codes” as the misfire codes stipulated in the law, etc. Detailed investigation is conducted using two kinds of codes. In this example of misfire detection processing, the total misfire power counter 1 0 5 count is always incremented when a misfire occurs regardless of the engine 1 operating range. As a result, the count value of the total misfire counter 10 5, that is, the total misfire code, remains as highly reliable data, and it becomes possible to conduct a detailed investigation at a service factory or the like.
• the count value of the cylinder misfire counter 10 06 is not incremented.
• the count value of 1 06 that is, the cylinder identification code
• the cylinder identification code that includes false detection due to the effect of flywheel damper 2 remains. Compared to this, it is advantageous for conducting detailed inspections.
• the misfire is one cylinder misfire (see Fig. 5), two cylinder continuous misfire (see Fig. 6), or intermittent two cylinder misfire (one between two misfires).
• a cylinder number determination process may be performed to determine whether a misfire occurs in which normal combustion exists. In this case, when the operating state of the engine 1 is within the “region affected by the flywheel damper”, both the cylinder specifying process and the cylinder number determining process are stopped. In addition, instead of the cylinder specifying process, only the cylinder number determining process may be executed. In this case, when the operating state of the engine 1 is in the “region affected by the flywheel damper”, the cylinder The number determination process should be stopped.
• the cylinder specifying process is stopped when the operating state of the engine 1 is in the “region affected by the flywheel damper”, but the present invention is not limited to this. You can stop the misfire detection itself when is in the “region affected by the flywheel damper”.
• the present invention is not limited to this, but can be applied to other multi-cylinder gasoline engines having any number of cylinders, such as a four-cylinder gasoline engine. Further, the present invention can be applied to various types of multi-cylinder gasoline engines such as an in-line type or V-type multi-cylinder engine, or a vertical or horizontal multi-cylinder engine. Furthermore, the present invention is not limited to a gasoline engine, but can be applied to an ignition engine that uses other fuels such as LPG (Night Petroleum Gas) and LNG (Liquefied Natural Gas).
• LPG Light Petroleum Gas
• LNG Liquefied Natural Gas

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

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• 2005
  • 2005-04-20 JP JP2005122962A patent/JP4353130B2/ja not_active Expired - Fee Related
• 2006
  • 2006-04-19 EP EP06732342.8A patent/EP1873383B1/en not_active Ceased
  • 2006-04-19 KR KR1020077026827A patent/KR100959214B1/ko not_active Expired - Fee Related
  • 2006-04-19 CN CN2006800135676A patent/CN101163874B/zh not_active Expired - Fee Related
  • 2006-04-19 WO PCT/JP2006/308686 patent/WO2006112544A1/ja not_active Ceased
  • 2006-04-19 US US11/912,155 patent/US7607345B2/en not_active Expired - Fee Related

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