WO1990002874A1 - Engine misfire detection and engine exhaust systems - Google Patents
Engine misfire detection and engine exhaust systems Download PDFInfo
- Publication number
- WO1990002874A1 WO1990002874A1 PCT/EP1988/000824 EP8800824W WO9002874A1 WO 1990002874 A1 WO1990002874 A1 WO 1990002874A1 EP 8800824 W EP8800824 W EP 8800824W WO 9002874 A1 WO9002874 A1 WO 9002874A1
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- WIPO (PCT)
- Prior art keywords
- lambda
- engine
- cylinder
- catalyser
- sensor
- Prior art date
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/008—Controlling each cylinder individually
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1439—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the position of the sensor
- F02D41/1441—Plural sensors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1473—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation method
- F02D41/1474—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation method by detecting the commutation time of the sensor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
Definitions
- the present invention relates to a method of detecting misfire in a multi-cylinder internal
- Fig. 1 is a diagrammatic representation of a four stroke internal combustion engine whose exhaust system contains a catalyser, fitted with lambda sensors in accordance with one embodiment of the invention
- Fig. 2 is a graph showing the output voltages of the lambda sensors
- Fig. 3 is a schematic circuit diagram of an electronic fuel injection system operable with lambda control in accordance with another embodiment of the invention.
- Fig. 4 is a series of graphs relating to the embodiment of Fig. 3;
- Fig. 5 is a logic diagram relating to one mode of operation of the embodiment of Fig. 3;
- Fig. 6 is a series of graphs relating to the mode of operation of Fig. 5;
- Fig. 7 is a logic diagram relating to an
- Fig. 8 is a graph showing the use of window discriminators.
- Fig. 9 is a diagram explaining the expected gas travel time.
- a four-stroke petrol engine 10 for a vehicle has an exhaust system 12 containing at least one silencer 14 and an exhaust gas catalyser 16.
- the catalyser 16 is so disposed in the exhaust system that it runs at about 550°C, this being the optimum temperature for catalysing the reduction of nitrogen oxide and the simultaneous oxidation of carbon monoxide and hydrocarbons, using up any
- lambda sensors 18 and 20 are fitted in the exhaust system 12 upstream and downstream of the catalyser 16.
- the lambda sensors comprise a solid electrolyte and, as is well known, they deliver an output voltage which is dependant upon the residual oxygen content of the exhaust gases.
- the sensor voltages are shown very diagrammatically in Fig. 2.
- the output voltage u 1 of the upstream sensor 18 fluctuates slightly in
- the voltage u 2 of the downstream sensor 20 is substantially constant. Assuming the fuel/air mixture fed to the engine is in stoichiometric relationship or slightly lean, the average of the slightly rippling voltage u 1 is about the same as the voltage u 2 .
- the fuel and oxygen are combusted in th e c a tal ys e r 16 s o th a t th e ou tpu t voltage u 2 of the downstream sensor 20 does not fall and it may even rise slightly.
- the outputs of the sensors are connected to a comparator 22 which delivers an output signal S when the voltage u 2 -u 1 exceeds a predetermined value ⁇ u.
- a smoothing circuit 24 can be arranged between the sensor 18 and the
- the alarm signal s can be used to trigger an audible and/or visible alarm or to stop or restrict the fuel supply to the engine. If the misfiring cylinder can be identified, in the case of an internal combustion engine with petrol injection, the fuel supply to the faulty cylinder can be cut off by holding the respective inj e ction v alve clo sed .
- One way o f dete ctin g the faulty cylinder is to provide, instead of a single upstream sensor 18, several separate sensors in
- Fig. 3 shows an electronic fuel injection system for a four-stroke, four cylinder internal combustion engine having electronically controlled fuel injection and ignition systems.
- the four injection valves 26,28,30,32 (shown diagrammatically) are opened and closed in timed
- the injection valves 26-32 are individual to the
- 34 also controls the four spark plugs 38, 40, 42 and 44 (shown diagrammatically) via an ignition coil and distributor 46.
- the computer 34 controls the injection valves
- the operating parameters include a reference pulse BM 1 inlet pressure p (vacuum), load L (pedal position), engine speed n, the air number ⁇ , as
- the reference pulses BM are obtained in timed relation to rotation of the crankshaft and are for synchronisation purposes.
- the engine operates witn lambda control and the lambda sensor (like the sensor 18 of Fig. 1) is arranged upstream of a catalyser in the exhaust gas system of the engine.
- Lambda is arranged upstream of a catalyser in the exhaust gas system of the engine.
- control is control in accordance with the composition of the exhaust gases, and in particular, upon the oxygen content of the exhaust gases, whereby the
- fuel/air ratio is that which provides for optimum combustion, i.e., close to stoichiometric and
- Fig. 4 shows at A the output of the lambda
- the air number ⁇ fluctuates between two extremes in accordance with on-off control by the servo loop forming part of the electronic control.
- a high air number ⁇ >1 denotes a lean mixture whereby the fuel injection system operates to increase the injected fuel quantity until the air number ⁇ 1 whereupon the injected fuel quantity is decreased.
- Each on-off fluctuation lasts for several, e.g., six, revolutions of the crankshaft.
- the output voltage u ⁇ of the lambda sensor is fed to a window discriminator to ascertain whether the voltage u ⁇ both rises above an upper threshold u max and falls below a lower threshold w min within 720° of crankshaft rotation. If it does, a pulse is sent to a misfire counter, whose count is shown at curve D in Fig. 4. When the counter has counted, say eight misfires an alarm signal s is
- the window discriminator extends over 180° crankshaft angle, once for each cylinder, the cylinders being identified by the ignition trigger pulses and it is checked whether the sensor u ⁇ voltage first falls below the upper threshold u max and then below the lower
- a counting pulse is delivered to a respective counter and when the counter is counted out, a fault signal s is delivered to indicate an alarm and to which
- the fault signal s can be used in this case to inhibit the fuel injection signal to the respective injection valve by interrupting the corresponding output from the computer 34 of the
- a storage time counter is also used, as shown in Fig. 5. For each cylinder, it is checked whether within the respective window of 180° crankshaft angle u ⁇ ⁇ u max and u ⁇ ⁇ u min .
- a stepping pulse is applied to the fault counter. If it does not, a stepping pulse is applied to the storage time counter. Once the fault counter is counted out, the alarm signal s is delivered.
- both counters are re-set. In other words if fewer than the number of misfires needed to count out the fault counter take place within the count-out period of the storage time counter, no fault is indicated.
- the total count of each of the two counters can be adjusted to suit the operating conditions of the engine.
- an empirically determined characteristic can be stored in the
- Curve A is the output voltage u ⁇ of the lambda sensor. It can be seen that the output is not as regular as
- Fig. 4(A) would suggest but the overall pattern of Fig. 4(A) is perceptible in Fig. 6(A).
- Curve B in Fig. 6 represents synchronising pulses obtained from the ignition system.
- a misfire signal is applied to a fault counter as described above. Also, as described above, the fault counter can be re-set in the absence of any further misfire signals within a predetermined,
- Fig. 8 shows how the uncombusted exhaust gases from a misfiring cylinder can be identified by the lambda sensor. For a four cylinder, four stroke engine, the working cycle of 720° crankshaft angle is divided into four windows of 180° each. The window in which the falling flank of the sensor voltage u ⁇ crosses the upper and lower threshold corresponds to the
- Fig. 9 shows the gas travel time measured from the TDC of the misfiring cylinder. It is typically 560° crankshaft angle but does vary according to engine operating parameters. Thus, the signals identifying the cylinders must be delayed by this gas travel time before correlating them with the misfire signal obtained from the lambda probe.
- the expected gas travel time can be derived from an empirically determined characteristic field which is stored in the computer and which gives the expected gas travel time in dependence on engine operating characteristics, such as engine speed n and/or engine load L.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
Misfire is detected in an internal combustion engine by monitoring the voltage (uμ) of a lambda sensor disposed in the exhaust system upstream of a catalyser. This voltage is either compared with the voltge of another lambda sensor downstream of the catalyser or is processed, in the case of lambda control, to detect troughs in the sensor voltage (uμ). The phase relationship between the sensor voltage fluctuations and the engine timing identifies when the gases exhausted from a misfiring cylinder reach the lambda sensor. Knowing the expected gas travel time in relation to TDC, the misfiring cylinder is identified and the fuel injection to the misfiring cylinder can be terminated. This prevents unburnt fuel/air mixture from reaching the catalyser where it would combust and overheat the catalyser.
Description
DESCRIPTION
ENGINE MISFIRE DETECTION AND ENGINE EXHAUST SYSTEMS
The present invention relates to a method of detecting misfire in a multi-cylinder internal
combustion engine and to an apparatus for protecting an exhaust system of a multi-cylinder internal
combustion engine, which exhaust system includes a catalyser.
It is known that exhaust gas catalysers and even the exhaust manifolds of internal combustion engines can be damaged or destroyed due to overheating. The danger of overheating arises in the event of a misfire, that is to say, the fuel/air mixture in one or more of the combustion chambers fails to ignite through faulty ignition. The uncombusted mixture when it reaches the catalyser whose working temperature is around 550°C is immediately ignited, rapidly heating the catalyser to a temperature at which the catalyst is destroyed. There is even the danger of the motor vehicle in which the engine is installed being set alight.
It is an object of the invention to provide a method and apparatus whereby faulty combustion or misfire can be immediately identified so that steps can be taken to prevent consequential overheating of the exhaust system, particularly of the catalyser.
Advantages of the Invention
These disadvantages are avoided by the method claimed in claim 1 and the apparatus claimed in claim 5. Not only is a misfire promptly detected through the oxygen content of the uncombusted gases leaving the engine, but measures can be taken to enable the faultily operating cylinder or cylinder group to be identified. In the case of petrol injection individual to the cylinder or the cylinder groups, the feeding of
further fuel to the misfiring combustion chamber can be prevented.
Further advantageous features of the invention are mentioned in the dependant claims.
Drawings
The invention is further described, by way of example, with reference to the accompanying drawings, in which:-
Fig. 1 is a diagrammatic representation of a four stroke internal combustion engine whose exhaust system contains a catalyser, fitted with lambda sensors in accordance with one embodiment of the invention;
Fig. 2 is a graph showing the output voltages of the lambda sensors;
Fig. 3 is a schematic circuit diagram of an electronic fuel injection system operable with lambda control in accordance with another embodiment of the invention;
Fig. 4 is a series of graphs relating to the embodiment of Fig. 3;
Fig. 5 is a logic diagram relating to one mode of operation of the embodiment of Fig. 3;
Fig. 6 is a series of graphs relating to the mode of operation of Fig. 5;
Fig. 7 is a logic diagram relating to an
alternative mode of operation;
Fig. 8 is a graph showing the use of window discriminators; and
Fig. 9 is a diagram explaining the expected gas travel time.
Description of the Preferred Embodiment
Referring first to Fig. 1, a four-stroke petrol engine 10 for a vehicle has an exhaust system 12 containing at least one silencer 14 and an exhaust gas catalyser 16. The catalyser 16 is so disposed in the exhaust system that it runs at about 550°C, this being
the optimum temperature for catalysing the reduction of nitrogen oxide and the simultaneous oxidation of carbon monoxide and hydrocarbons, using up any
residual oxygen in the exhaust gases.
Should there be a misfire in one of the engine cylinders, the uncombusted gases exhausted from that cylinder are caused to ignite in the catalyser. This causes the catalyser to heat up rapidly to a temperature at which the expensive catalyst is destroyed and
there is a danger of the vehicle itself being set on fire, unless appropriate counter measures are taken.
According to the embodiment of Fig. 1, lambda sensors 18 and 20 are fitted in the exhaust system 12 upstream and downstream of the catalyser 16. The lambda sensors comprise a solid electrolyte and, as is well known, they deliver an output voltage which is dependant upon the residual oxygen content of the exhaust gases. The sensor voltages are shown very diagrammatically in Fig. 2. The output voltage u1 of the upstream sensor 18 fluctuates slightly in
synchronism with the exhaust strokes of the engine cylinder. On the other hand, residual oxygen is
consumed in the catalyser 16 so that the output
voltage u2 of the downstream sensor 20 is substantially constant. Assuming the fuel/air mixture fed to the engine is in stoichiometric relationship or slightly lean, the average of the slightly rippling voltage u1 is about the same as the voltage u2.
In Fig. 2, it is assumed that one cylinder
commences to misfire so that uncombusted fuel and air reach the upstream sensor 18 and the oxygen in the air causes a sudden drop in the voltage u1. On the other hand, the fuel and oxygen are combusted in th e c a tal ys e r 16 s o th a t th e ou tpu t voltage u2 of the downstream sensor 20 does not fall and it may even rise slightly.
To detect the occurrence of the sudden change in u2-u1, the outputs of the sensors are connected to a comparator 22 which delivers an output signal S when the voltage u2-u1 exceeds a predetermined value Δu.
To reduce the likelihood of the fluctuations in the voltage u1 triggering a false alarm, a smoothing circuit 24 can be arranged between the sensor 18 and the
comparator 22.
The alarm signal s can be used to trigger an audible and/or visible alarm or to stop or restrict the fuel supply to the engine. If the misfiring cylinder can be identified, in the case of an internal combustion engine with petrol injection, the fuel supply to the faulty cylinder can be cut off by holding the respective inj e ction v alve clo sed . One way o f dete ctin g the faulty cylinder is to provide, instead of a single upstream sensor 18, several separate sensors in
respective branch tracts of the exhaust system leading from the engine exhaust valves. The output of voltage of each such sensor is then compared with that of the downstream sensor.
In the case of an engine fitted with lambda
control, in which the injected fuel quantity is
adjusted in response to the air number λ of the exhaust gases as measured by the upstream sensor 18, the
unconsumed oxygen in the event of a misfire and the consequent lowering of the output voltage u1 cause the lambda control to regulate the engine to a
leaner mixture so that the undulating output voltage u 2 then climbs back substantially to its previous value, as shown, in the event that the engine is
not immediately stopped.
Fig. 3 shows an electronic fuel injection system for a four-stroke, four cylinder internal combustion engine having electronically controlled fuel injection and ignition systems. The four injection valves 26,28,30,32 (shown
diagrammatically) are opened and closed in timed
relation to the crankshaft rotation under the control of a computer 34 and via end stage amplifiers 36.
The injection valves 26-32 are individual to the
four cylinders of the engine in that they inject the fuel into the engine inlet manifold branches adjacent the respective engine inlet valves. The computer
34 also controls the four spark plugs 38, 40, 42 and 44 (shown diagrammatically) via an ignition coil and distributor 46.
The computer 34 controls the injection valves
26-32 and the ignition trigger voltages suppled to the ignition coil 46 in accordance with operating parameters to provide the optimum injected fuel quantities, injection timing and ignition timing in conventional manner. The operating parameters include a reference pulse BM1 inlet pressure p (vacuum), load L (pedal position), engine speed n, the air number λ, as
measured by a lambda sensor in the engine exhaust system, and engine cooling water temperature T. The reference pulses BM are obtained in timed relation to rotation of the crankshaft and are for synchronisation purposes.
During normal running, the engine operates witn lambda control and the lambda sensor (like the sensor 18 of Fig. 1) is arranged upstream of a catalyser in the exhaust gas system of the engine. Lambda
control is control in accordance with the composition of the exhaust gases, and in particular, upon the oxygen content of the exhaust gases, whereby the
fuel/air ratio is that which provides for optimum combustion, i.e., close to stoichiometric and
minimum pollutants in the exhaust gases reaching the catalyser.
Fig. 4 shows at A the output of the lambda
sensor and at B, the instants of ignition of the individual cylinders so that the timed relationship between the changes in the measured air number λ and the individual combustion operations can be seen.
In normal operation as seen at the left of Fig. 4, the air number λ fluctuates between two extremes in accordance with on-off control by the servo loop forming part of the electronic control. In other words, a high air number λ>1 denotes a lean mixture whereby the fuel injection system operates to increase the injected fuel quantity until the air number λ<1 whereupon the injected fuel quantity is decreased.
Each on-off fluctuation lasts for several, e.g., six, revolutions of the crankshaft.
At the instant T1, one cylinder starts to misfire and in Fig. 4 continues to do so at every working stroke. The result is that the lambda sensor or oxygen sensor erroneously measures that the mixture is, on average, too lean so that the computer 34 .
operates to increase the injected fuel quantity until the lambda sensor again indicates an average air number λ=1, as shown in Fig. 4 by curve C. However, bec ause of th e now over - ric h mi xture an d the unc o nver ted oxygen from the misfiring cylinder, the output of the lambda sensor exhibits a sudden dip once for every two revolutions of the crankshaft as shown at the right-hand side of Fig. 4. To detect this situation, the output of the lambda probe is evaluated in a misfire detector 48 as will now be described.
In the simplest version, the output voltage uλ of the lambda sensor is fed to a window discriminator to ascertain whether the voltage uλ both rises above an upper threshold umax and falls below a lower threshold wmin within 720° of crankshaft rotation. If it does,
a pulse is sent to a misfire counter, whose count is shown at curve D in Fig. 4. When the counter has counted, say eight misfires an alarm signal s is
delivered.
If it is desired to identify the misfiring cylinder the window discriminator extends over 180° crankshaft angle, once for each cylinder, the cylinders being identified by the ignition trigger pulses and it is checked whether the sensor uλ voltage first falls below the upper threshold umax and then below the lower
threshold umin within each 180° window. If it does, a counting pulse is delivered to a respective counter and when the counter is counted out, a fault signal s is delivered to indicate an alarm and to which
cylinder it relates. The fault signal s can be used in this case to inhibit the fuel injection signal to the respective injection valve by interrupting the corresponding output from the computer 34 of the
end stage ampl i f i er 36 .
S p ur i o us misfires are not harmful to the
catalyser and it is desirable to prevent the misfire detector 48 from responding to misfiring at spaced random intervals. For this purpose, a storage time counter is also used, as shown in Fig. 5. For each cylinder, it is checked whether within the respective window of 180° crankshaft angle uλ < umax and uλ < umin.
If it does, a stepping pulse is applied to the fault counter. If it does not, a stepping pulse is applied to the storage time counter. Once the fault counter is counted out, the alarm signal s is delivered.
However, should the storage time counter be counted out before the fault counter has been counted out, both counters are re-set. In other words if fewer than the number of misfires needed to count out the fault counter take place within the count-out period of the storage time counter, no fault is indicated.
The total count of each of the two counters can be adjusted to suit the operating conditions of the engine. Thus, for each counter, an empirically determined characteristic can be stored in the
computer 34 to determine in accordance with, say engine speed n and engine load L, the number of misfires to be counted in the fault counter to
trigger the alarm signal s and the number of crankshaft revolutions without misfire to be counted in the storage time counter before detected misfires are to be disregarded.
Fig. 6 illustrates this operation further. Curve A is the output voltage uλ of the lambda sensor. It can be seen that the output is not as regular as
Fig. 4(A) would suggest but the overall pattern of Fig. 4(A) is perceptible in Fig. 6(A). Curve B in Fig. 6 represents synchronising pulses obtained from the ignition system. Curve C represents the count of the fault counter. It can be seen that, following the start of misfiring at T1, the sensor voltage uλ falls below umax = 110mV and then below umin = 50mV to step the fault counter on 1. Over the following four working cycles (2x4=8 revolutions), the sensor voltage uλ does not rise above umax so that it cannot fall through the upper threshold to step the fault
counter further and the latter is then re-set by the storage time counter timing out (counting out). The fault counter is then counted to 2 before being re-set However, the effect of the lambda control then
becomes apparent and the sensor voltage uλ rises to significant values between the troughs and the fault counter is rapidly counted out to trigger the alarm at T2. Curve D shows that the catalyser temperature only rises a few tens of degrees before the alarm is triggered. Fig. 6 assumes that no counter-measures are taken after the alarm is triggered or otherwise
the sensor voltage uλ would not follow the course shown after T2.
Another possibility is for the amplitude of the fluctuations in the output voltage uλ of the lambda sensor to be measured in window discriminators
within a corresponding 180° crankshaft angle for each cylinder. Should the difference between the highest and lowest values of the sensor voltage uλ exceed a value predetermined in accordance with engine speed and/or load, a misfire signal is applied to a fault counter as described above. Also, as described above, the fault counter can be re-set in the absence of any further misfire signals within a predetermined,
possible speed and/or load dependant interval. This is shown further in Fig. 7.
Since it takes time for the gases exhausted from a misfiring cylinder to reach the lambda sensor, the gas travel time must be taken into account in order to identify a misfiring cylinder by reference to the sensor output voltage and the ignition trigger pulses. Fig. 8 shows how the uncombusted exhaust gases from a misfiring cylinder can be identified by the lambda sensor. For a four cylinder, four stroke engine, the working cycle of 720° crankshaft angle is divided into four windows of 180° each. The window in which the falling flank of the sensor voltage uλ crosses the upper and lower threshold corresponds to the
uncombusted gases. Therefore, to ascertain the cylinder from which these gases came, it is necessary to delay the ignition pulses by the time taken for the working stroke of a cylinder to take place and the time taken for the gases to travel through the exhaust tract as far as the lambda sensor. Fig. 9 shows the gas travel time measured from the TDC of the misfiring cylinder. It is typically 560° crankshaft angle but does vary
according to engine operating parameters. Thus, the signals identifying the cylinders must be delayed by this gas travel time before correlating them with the misfire signal obtained from the lambda probe.
Whilst mention is made above of using the ignition trigger signals as cylinder identification signals, inasmuch as the ignition trigger signal is close to TDC, this is not essential. It is possible to obtain cylinder identification signals in other ways, e.g., by dividing the interval between successive reference marks BM by the number of cylinders as shown in Fig. 9.
The expected gas travel time can be derived from an empirically determined characteristic field which is stored in the computer and which gives the expected gas travel time in dependence on engine operating characteristics, such as engine speed n and/or engine load L.
Claims
1. Method of detecting misfire in a multicylinder internal combustion engine, characterised in that the output voltage of a lambda sensor in the exhaust system is monitored and is compared with a reference voltage, and a departure of the
difference between the sensor and reference voltages from an expected value is signalled as a misfire in at least one of the cylinders.
2. Method according to claim 1 for an
internal combustion engine whose exhaust system
contains a catalyser, characterised in that the
outputs of two lambda sensors arranged respectively upstream and downstream of the catalyser are compared and an increase in the difference between the output voltages of the two lambda sensors is taken as
signalling a misfire in at least one cylinder.
3. Method according to claim 1, for an internal combustion engine equipped with a lambda control system, characterised in that fluctuations in the output voltage of the lambda sensor of the lambda control system are monitored and, if these fluctuations exceed a reference amplitude or cross a reference threshold, this is taken as signalling a misfire in at least one cylinder.
4. Method according to claim 3, characterised in that the instant of a fluctuation in the output voltage of the lambda sensor outside a threshold is compared with the instant of a reference mark (BM) indicative of a predetermined angular position of the crankshaft and the time difference between these instants is used to determine which cylinder has misfired, taking into account the expected time for the exhaust gases to travel from the engine exhaust valve to the lambda sensor.
5. Apparatus for protecting an exhaust system of a multi-cylinder internal combustion engine, which exhaust system includes a catalyser, characterised in that a comparing device is provided for comparing the output voltage of a lambda sensor disposed upstream o f the c a tal yser wi th a re ferenc e va lue no t no rmal ly reached and an output signal of the comparing device, indicative of a misfire is applied to means whereby uncombusted exhaust gases are prevented from reaching the catalyser.
6. Apparatus according to claim 5, characterised in that a second lambda sensor is disposed downstream of the catalyser and the difference between the output voltages of the lambda sensors is compared in a
comparator with a reference threshold.
7. Apparatus according to claim 5, for an
internal combustion engine equipped with a lambda control system, characterised in that a device is provided for monitoring fluctuations in the output voltage of the lambda sensor within a working cycle of the engine.
8. Apparatus according to claim 7, ch arac terised in that the trou ghs in the o utput v oltage (uλ) of the lambda probe are detected to detect a misfire.
9. Apparatus according to claim 8, characterised in that the misfires are counted in a fault counter and an alarm signal (s) is provided when the fault counter is counted out.
10. Apparatus according to claim 9, characterised in that a storage time counter is provided and counts the time elapsed between detected misfires and both counters are re-set in the event of the storage time counter being counted out.
11. Apparatus according to claim 9 or 10,
characterised in that the count-out time of either or both of the counters can be adjusted in dependence upon operating parameters of the engine.
12. Apparatus according to claim 11, characterised in that either or both counters are adjusted in
accordance with a stored characteristic field.
13. Apparatus according to any of claims 8 to 12, characterised in that the troughs of the output voltage are detected by ascertaining whether the
output voltage (uλ) fluctuates beyond an upper
threshold (umax) and a lower threshold (umin) or
fluctuates outside a predetermined amplitude at least within a working cycle of the engine.
14. Apparatus according to claim 13, characterised in that the fluctuations are measured within a window defined by the crankshaft angle for a working cycle divided by the number of cylinders to enable a misfiring cylinder to be identified.
15. Apparatus according to any of claims 7 to 14, characterised in that the expected gas travel time as measured between the TDC or ignition trigger pulses of a given cylinder and the instant at which the gases exhausted from the cylinder reach the lambda sensor is taken into account to identify a misfiring cylinder.
16. Apparatus according to claim 15, characterised in that a characteristic field is stored in the computer and gives the expected gas travel time in dependence upon at least one engine operating parameter.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/EP1988/000824 WO1990002874A1 (en) | 1988-09-10 | 1988-09-10 | Engine misfire detection and engine exhaust systems |
JP63507354A JP2885813B2 (en) | 1988-09-10 | 1988-09-10 | Engine misfire detection and exhaust system |
EP19880907670 EP0387254A1 (en) | 1988-09-10 | 1988-09-10 | Engine misfire detection and engine exhaust systems |
KR1019900700944A KR900702200A (en) | 1988-09-10 | 1990-05-07 | Engine ignition detection and engine exhaust system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/EP1988/000824 WO1990002874A1 (en) | 1988-09-10 | 1988-09-10 | Engine misfire detection and engine exhaust systems |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1990002874A1 true WO1990002874A1 (en) | 1990-03-22 |
Family
ID=8165323
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1988/000824 WO1990002874A1 (en) | 1988-09-10 | 1988-09-10 | Engine misfire detection and engine exhaust systems |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0387254A1 (en) |
JP (1) | JP2885813B2 (en) |
KR (1) | KR900702200A (en) |
WO (1) | WO1990002874A1 (en) |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4132335A1 (en) * | 1990-09-29 | 1992-04-09 | Suzuki Motor Co | DEVICE FOR DETECTING A FLAME SPILL IN AN INTERNAL COMBUSTION ENGINE |
DE4035957A1 (en) * | 1990-11-09 | 1992-05-14 | Bosch Gmbh Robert | METHOD FOR FUNCTION MONITORING OF INTERNAL COMBUSTION ENGINES |
DE4303241A1 (en) * | 1992-02-04 | 1993-08-05 | Mitsubishi Electric Corp | Detection and decision device for combustion engine misfiring - applies correction to engine control when misfiring is detected at intervals of less than predetermined min. |
EP0990787A2 (en) * | 1998-10-03 | 2000-04-05 | Ford Motor Company Limited | Method for identifying the engine cycle of an injection IC engine |
WO2002073019A2 (en) * | 2001-03-10 | 2002-09-19 | Volkswagen Aktiengesellschaft | Method for operating internal combustion engines |
FR2837529A1 (en) * | 2002-03-21 | 2003-09-26 | Bosch Gmbh Robert | Engine overheating protection system includes temperature sensor in exhaust linked to control cutting fuel supply |
FR2862346A1 (en) | 2003-11-14 | 2005-05-20 | Bosch Gmbh Robert | Combustion failure detecting method for internal combustion engine e.g. gasoline engine, involves emitting warning signal when threshold of lambda signal of lambda probes exceeds in direction of poor combustion |
WO2005073543A1 (en) * | 2004-01-28 | 2005-08-11 | Siemens Aktiengesellschaft | Method for adapting detection of a measuring signal of a waste gas probe |
US7280906B2 (en) | 2003-11-14 | 2007-10-09 | Robert Bosch Gmbh | Method for detecting misfires of an internal combustion engine and device for carrying out the method |
US7458249B2 (en) | 2005-03-21 | 2008-12-02 | Robert Bosch Gmbh | Method and device for operating an internal combustion engine |
GB2512102A (en) * | 2013-03-20 | 2014-09-24 | Perkins Engines Co Ltd | Method and apparatus for identifying unstable combustion in an internal combustion engine |
WO2015032487A1 (en) * | 2013-09-04 | 2015-03-12 | Man Diesel & Turbo Se | Method for operating an internal combustion engine |
US20160053701A1 (en) * | 2014-08-19 | 2016-02-25 | Denso Corporation | Individual cylinder air-fuel ratio control device of internal combustion engine |
US9920700B2 (en) | 2013-07-29 | 2018-03-20 | Man Diesel & Turbo Se | Method for operation of an internal combustion engine |
DE102019201669A1 (en) * | 2019-02-08 | 2020-08-13 | Vitesco Technologies GmbH | Method and device for recognizing and differentiating a cause of at least one misfire of an internal combustion engine |
US10823640B2 (en) | 2018-01-18 | 2020-11-03 | Toyota Jidosha Kabushiki Kaisha | Misfire detection device and method for detecting misfire for internal combustion engine |
CN112392616A (en) * | 2020-11-18 | 2021-02-23 | 潍柴动力股份有限公司 | Control method and device and power system |
Families Citing this family (1)
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JP5471035B2 (en) | 2009-05-26 | 2014-04-16 | ソニー株式会社 | Display device, display device manufacturing method, and electronic apparatus |
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US3969932A (en) * | 1974-09-17 | 1976-07-20 | Robert Bosch G.M.B.H. | Method and apparatus for monitoring the activity of catalytic reactors |
US4030349A (en) * | 1976-08-16 | 1977-06-21 | Beckman Instruments, Inc. | Engine analysis apparatus |
DE3201372A1 (en) * | 1981-01-20 | 1982-08-05 | Nissan Motor | Feedback control system for the air/fuel ratio of an internal combustion engine with a plurality of cylinders and feedback control method for the air/fuel ratio of an internal combustion engine with a plurality of cylinders |
US4696277A (en) * | 1985-11-04 | 1987-09-29 | Nippondenso Co., Ltd. | Engine alarm system |
DE3614535A1 (en) * | 1986-04-29 | 1987-11-05 | Comuna Metall Vorrichtungs U M | Internal combustion engine with exhaust emission control |
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JPH061236B2 (en) * | 1984-10-30 | 1994-01-05 | マツダ株式会社 | Engine misfire detection device |
JPH0689707B2 (en) * | 1986-03-29 | 1994-11-09 | 三菱自動車工業株式会社 | Misfire identification method for specific cylinder in multi-cylinder engine |
-
1988
- 1988-09-10 JP JP63507354A patent/JP2885813B2/en not_active Expired - Fee Related
- 1988-09-10 EP EP19880907670 patent/EP0387254A1/en not_active Withdrawn
- 1988-09-10 WO PCT/EP1988/000824 patent/WO1990002874A1/en not_active Application Discontinuation
-
1990
- 1990-05-07 KR KR1019900700944A patent/KR900702200A/en not_active Application Discontinuation
Patent Citations (5)
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US3969932A (en) * | 1974-09-17 | 1976-07-20 | Robert Bosch G.M.B.H. | Method and apparatus for monitoring the activity of catalytic reactors |
US4030349A (en) * | 1976-08-16 | 1977-06-21 | Beckman Instruments, Inc. | Engine analysis apparatus |
DE3201372A1 (en) * | 1981-01-20 | 1982-08-05 | Nissan Motor | Feedback control system for the air/fuel ratio of an internal combustion engine with a plurality of cylinders and feedback control method for the air/fuel ratio of an internal combustion engine with a plurality of cylinders |
US4696277A (en) * | 1985-11-04 | 1987-09-29 | Nippondenso Co., Ltd. | Engine alarm system |
DE3614535A1 (en) * | 1986-04-29 | 1987-11-05 | Comuna Metall Vorrichtungs U M | Internal combustion engine with exhaust emission control |
Cited By (32)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4132335A1 (en) * | 1990-09-29 | 1992-04-09 | Suzuki Motor Co | DEVICE FOR DETECTING A FLAME SPILL IN AN INTERNAL COMBUSTION ENGINE |
DE4035957A1 (en) * | 1990-11-09 | 1992-05-14 | Bosch Gmbh Robert | METHOD FOR FUNCTION MONITORING OF INTERNAL COMBUSTION ENGINES |
US5201293A (en) * | 1990-11-09 | 1993-04-13 | Robert Bosch Gmbh | Method of monitoring the operation of an internal combustion engine |
DE4303241A1 (en) * | 1992-02-04 | 1993-08-05 | Mitsubishi Electric Corp | Detection and decision device for combustion engine misfiring - applies correction to engine control when misfiring is detected at intervals of less than predetermined min. |
US5359882A (en) * | 1992-02-04 | 1994-11-01 | Mitsubishi Denki Kabushiki Kaisha | Apparatus for detection and decision of occurrence of misfire in internal combustion engine |
EP0990787A3 (en) * | 1998-10-03 | 2002-02-27 | Ford Motor Company Limited | Method for identifying the engine cycle of an injection IC engine |
EP0990787A2 (en) * | 1998-10-03 | 2000-04-05 | Ford Motor Company Limited | Method for identifying the engine cycle of an injection IC engine |
WO2002073019A2 (en) * | 2001-03-10 | 2002-09-19 | Volkswagen Aktiengesellschaft | Method for operating internal combustion engines |
WO2002073019A3 (en) * | 2001-03-10 | 2002-12-12 | Volkswagen Ag | Method for operating internal combustion engines |
US6968679B2 (en) | 2001-03-10 | 2005-11-29 | Volkswagen Ag | Method for operating an internal combustion engine |
FR2837529A1 (en) * | 2002-03-21 | 2003-09-26 | Bosch Gmbh Robert | Engine overheating protection system includes temperature sensor in exhaust linked to control cutting fuel supply |
FR2862346A1 (en) | 2003-11-14 | 2005-05-20 | Bosch Gmbh Robert | Combustion failure detecting method for internal combustion engine e.g. gasoline engine, involves emitting warning signal when threshold of lambda signal of lambda probes exceeds in direction of poor combustion |
US7280906B2 (en) | 2003-11-14 | 2007-10-09 | Robert Bosch Gmbh | Method for detecting misfires of an internal combustion engine and device for carrying out the method |
WO2005073543A1 (en) * | 2004-01-28 | 2005-08-11 | Siemens Aktiengesellschaft | Method for adapting detection of a measuring signal of a waste gas probe |
US7331214B2 (en) | 2004-01-28 | 2008-02-19 | Siemens Aktiengesellschaft | Method for adapting the detection of a measuring signal of a waste gas probe |
DE102005012942B4 (en) | 2005-03-21 | 2018-12-13 | Robert Bosch Gmbh | Method and device for operating an internal combustion engine |
US7458249B2 (en) | 2005-03-21 | 2008-12-02 | Robert Bosch Gmbh | Method and device for operating an internal combustion engine |
GB2512102A (en) * | 2013-03-20 | 2014-09-24 | Perkins Engines Co Ltd | Method and apparatus for identifying unstable combustion in an internal combustion engine |
GB2512102B (en) * | 2013-03-20 | 2016-03-30 | Perkins Engines Co Ltd | Method and apparatus for identifying unstable combustion in an internal combustion engine |
US9920700B2 (en) | 2013-07-29 | 2018-03-20 | Man Diesel & Turbo Se | Method for operation of an internal combustion engine |
CN105683543A (en) * | 2013-09-04 | 2016-06-15 | 曼柴油机和涡轮机欧洲股份公司 | Method for operating internal combustion engine |
WO2015032487A1 (en) * | 2013-09-04 | 2015-03-12 | Man Diesel & Turbo Se | Method for operating an internal combustion engine |
US10174692B2 (en) | 2013-09-04 | 2019-01-08 | Man Energy Solutions Se | Method for operating an internal combustion engine |
KR101937000B1 (en) * | 2013-09-04 | 2019-01-09 | 만 에너지 솔루션즈 에스이 | Method for operating an internal combustion engine |
US9790882B2 (en) | 2014-08-19 | 2017-10-17 | Denso Corporation | Individual cylinder air-fuel ratio control device of internal combustion engine |
US9890726B2 (en) * | 2014-08-19 | 2018-02-13 | Denso Corporation | Individual cylinder air-fuel ratio control device of internal combustion engine |
US20160053701A1 (en) * | 2014-08-19 | 2016-02-25 | Denso Corporation | Individual cylinder air-fuel ratio control device of internal combustion engine |
US10823640B2 (en) | 2018-01-18 | 2020-11-03 | Toyota Jidosha Kabushiki Kaisha | Misfire detection device and method for detecting misfire for internal combustion engine |
DE102019201669A1 (en) * | 2019-02-08 | 2020-08-13 | Vitesco Technologies GmbH | Method and device for recognizing and differentiating a cause of at least one misfire of an internal combustion engine |
DE102019201669B4 (en) * | 2019-02-08 | 2020-11-12 | Vitesco Technologies GmbH | Method and device for recognizing and differentiating a cause of at least one misfire of an internal combustion engine |
US11802814B2 (en) | 2019-02-08 | 2023-10-31 | Vitesco Technologies GmbH | Method and device for identifying and distinguishing a cause of at least one misfire of an internal combustion engine |
CN112392616A (en) * | 2020-11-18 | 2021-02-23 | 潍柴动力股份有限公司 | Control method and device and power system |
Also Published As
Publication number | Publication date |
---|---|
JP2885813B2 (en) | 1999-04-26 |
EP0387254A1 (en) | 1990-09-19 |
KR900702200A (en) | 1990-12-06 |
JPH03501148A (en) | 1991-03-14 |
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