JP2010084774A - Misfire determining device and misfire determining method for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately and accurately determine a misfire of an internal combustion engine. <P>SOLUTION: A rotational fluctuation Nxd is given as a variation in rotation speed N of a crankshaft at every 120 degrees crank angle CA, corresponding to an ignition timing in each cylinder of a six-cylinder engine. A difference between the rotation fluctuation Nxd and a previous rotational fluctuation Nxd at a crank angle of 360 degrees before the specific crank angle is calculated as a rotational fluctuation difference Nxdflux, and the specific rotational fluctuation Nxd at the specific crank angle and the previous rotational fluctuation Nxd at the crank angle of 360 degrees before the specific crank angle are summed up to give a total rotational fluctuation Nxdint (S100-S140). There are performed a single misfire determination process which is a single misfire determination logic determining a single misfire pattern by using the calculated rotational fluctuation Nxd, the rotational fluctuation difference Nxdflx and the total rotational fluctuation Nxdint, a consecutive misfire determination process which is a consecutive misfire determination logic determining a consecutive misfire pattern, and an intermittent misfire determination process which is an intermittent misfire determination logic determining an intermittent misfire pattern (S150-S170), thereby determining the engine misfire. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a misfire determination device and a misfire determination method for an internal combustion engine, and more particularly to a misfire determination device and a misfire determination method for an internal combustion engine that determine misfire in a multi-cylinder internal combustion engine.

  Conventionally, as this type of misfire determination device for an internal combustion engine, a device for determining misfire based on a torque correction amount of a motor attached to a crankshaft of the engine has been proposed (see, for example, Patent Document 1). In this apparatus, vibration suppression control is performed so as to cancel torque fluctuations generated in the crankshaft of the engine by torque from the motor, and misfire is determined using the torque correction value of the motor for this vibration suppression control.

JP 2001-65402 A

  However, the above-described misfire determination apparatus for an internal combustion engine cannot accurately determine engine misfire. In addition to a single misfire that causes only one specific cylinder to misfire, an engine misfire may result in a misfire that occurs when two consecutive cylinders misfire or two cylinders that sandwich one combustion cylinder among a plurality of cylinders. While there is a deletion fire. For this reason, if misfire is determined using the motor torque correction value for vibration suppression control, misfire cannot be accurately determined because such misfire patterns are not considered. Accurate determination of engine misfire can be useful for subsequent responses and the like, and can be used for smoother operation of devices such as automobiles equipped with the engine.

  An object of the misfire determination apparatus and the misfire determination method of the present invention is to determine the misfire of the internal combustion engine more accurately. Another object of the misfire determination apparatus and misfire determination method of the present invention is to more appropriately determine the misfire of the internal combustion engine including the misfire pattern.

  The internal combustion engine misfire determination apparatus and misfire determination method of the present invention employ the following means in order to achieve at least a part of the above-described object.

An internal combustion engine misfire determination device of the present invention,
A misfire determination device for an internal combustion engine that determines misfire in a multi-cylinder internal combustion engine,
Rotational position detecting means for detecting the rotational position of the crankshaft of the internal combustion engine;
Rotation fluctuation calculating means for sequentially calculating the rotation fluctuation of the internal combustion engine at a crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine based on the detected rotation position;
Misfire determination means for determining misfire of the internal combustion engine using determination logic of different misfire patterns based on the sequentially calculated rotation fluctuations;
It is a summary to provide.

In the misfire determination apparatus for an internal combustion engine according to the present invention, the rotational fluctuation of the internal combustion engine at the crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine is sequentially calculated based on the rotational position of the crankshaft of the internal combustion engine, and is sequentially calculated. The misfire of the internal combustion engine is determined by using a plurality of different misfire pattern determination logics based on the rotational fluctuation. As a result, it is possible to determine the misfire of the internal combustion engine appropriately and accurately including the misfire pattern. Here, the “internal combustion engine” can be considered to be mounted on a hybrid vehicle that is operated by setting the operation point of the internal combustion engine independently of the running state.

  In such a misfire determination device for an internal combustion engine of the present invention, the misfire determination means includes a single misfire determination logic for determining a single misfire pattern in which only one cylinder among the plurality of cylinders is misfiring, and a continuous among the plurality of cylinders. A continuous misfire determination logic for determining a continuous misfire pattern in which two cylinders are misfiring, and a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring It may be a means for determining misfire of the internal combustion engine using a plurality of determination logics including any of them. Here, “successive two cylinders” in the continuous misfire pattern means two cylinders that are consecutive in the firing order, and “two cylinders that sandwich one combustion cylinder” in the intermittent fire pattern sandwiches one combustion cylinder in the firing order. Means a cylinder.

  In the misfire determination device for an internal combustion engine according to the aspect of the present invention, the single misfire determination logic according to the present invention is configured to determine misfire by using a plurality of determination logics including any of the single misfire determination logic, the continuous misfire determination logic, and the intermediate misfire determination logic. Is a rotation in which only one rotational fluctuation among the rotational fluctuations sequentially calculated by the rotational fluctuation calculating means for one cycle of the internal combustion engine is equal to or greater than a predetermined value for single misfire and equal to or greater than the predetermined value for single misfire. It may be logic that determines single misfire when the ratio between the target rotational fluctuation that is fluctuation and the rotational fluctuation other than the target rotational fluctuation is within a predetermined ratio range for single misfire. In this case, the other rotation fluctuation is any one of a rotation fluctuation three times before the target rotation fluctuation, a rotation fluctuation immediately before the target rotation fluctuation, and a rotation fluctuation immediately after the target rotation fluctuation. It can also be characterized by including one. In this way, it is possible to determine the single misfire of the internal combustion engine more appropriately and accurately. In the misfire device for an internal combustion engine of the present invention of these aspects, the rotational speed detection means for detecting the rotational speed of the internal combustion engine, and the predetermined single misfire predetermined tendency to decrease as the detected rotational speed of the internal combustion engine increases. A first single misfire predetermined value adjusting means for adjusting the value, an intake air amount detecting means for detecting the intake air amount of the internal combustion engine, and the detected intake air amount Second single misfire predetermined value adjusting means for calculating the cycle intake air amount per cycle of the internal combustion engine and adjusting the predetermined value for single misfire so as to increase as the calculated cycle intake air amount increases; It can also be provided. In this way, it is possible to determine the single misfire of the internal combustion engine more appropriately and accurately.

Further, in the misfire determination device for an internal combustion engine according to the aspect of the present invention, wherein the misfire is determined using a plurality of determination logics including any one of single misfire determination logic, continuous misfire determination logic, and intermediate misfire determination logic, the continuous misfire determination The logic calculates a rotational fluctuation difference that is a difference between the sequentially calculated rotational fluctuation and a rotational fluctuation calculated 360 degrees before the rotational fluctuation, and is calculated for one cycle of the internal combustion engine. It is also possible to use logic that determines continuous misfire when only one rotational fluctuation difference is equal to or greater than a predetermined value for continuous misfire. In this case, the continuous misfire determination logic is configured such that a ratio between a target rotational fluctuation difference that is a rotational fluctuation difference equal to or greater than the predetermined value for continuous misfire and a rotational fluctuation difference other than the target rotational fluctuation difference is a predetermined ratio for continuous misfire. It can also be the logic which determines that it is a continuous misfire when it becomes a range. Further, in this case, the other rotational fluctuation difference is a rotational fluctuation difference three times before the target rotational fluctuation difference, a rotational fluctuation difference one prior to the target rotational fluctuation difference, and one subsequent to the target rotational fluctuation difference. Any one of the rotational fluctuation differences may be included. In this way, it is possible to determine the continuous misfire of the internal combustion engine more appropriately and accurately. In the misfire determination device for an internal combustion engine of the present invention of these aspects, the rotational speed detection means for detecting the rotational speed of the internal combustion engine, and the continuous misfire for the tendency to decrease as the detected rotational speed of the internal combustion engine increases. A predetermined value adjusting means for first continuous misfire that adjusts a predetermined value, an intake air amount detecting means for detecting an intake air amount of the internal combustion engine, and the detected intake air amount Second continuous misfire predetermined value adjusting means for calculating the cycle intake air amount per cycle of the internal combustion engine and adjusting the predetermined value for continuous misfire so as to increase as the calculated cycle intake air amount increases. , Can also be provided. In this way, it is possible to determine the continuous misfire of the internal combustion engine more appropriately and accurately.

  Furthermore, in the misfire determination device for an internal combustion engine according to the aspect of the present invention, wherein the misfire is determined using a plurality of determination logics including any one of single misfire determination logic, continuous misfire determination logic, and intermediate misfire determination logic. The logic calculates a rotation fluctuation sum that is a sum of the rotation fluctuations that are sequentially calculated and a rotation fluctuation that is calculated 360 degrees before the rotation fluctuation, and is calculated for one cycle of the internal combustion engine. It is also possible to use a logic for determining an intermediate deficit fire when only one rotation fluctuation sum is equal to or greater than a predetermined value for the intermediate deletion fire. In this case, the inter-missing fire determination logic is configured such that a ratio between a target rotational fluctuation sum that is a rotational fluctuation sum that is equal to or greater than the predetermined value for the inter-fiscal fire and a rotational rotational sum other than the target rotational fluctuation sum is a predetermined ratio for the inter-missing fire. It can be assumed that the logic is that it is determined that there is an intermission when the range is reached. Furthermore, in this case, the other rotational fluctuation sum may be a rotational fluctuation sum immediately before the target rotational fluctuation sum. In this way, it is possible to determine the missing fire during the internal combustion engine more appropriately and accurately. In the misfire determination apparatus for an internal combustion engine according to the present invention of these aspects, the rotational speed detection means for detecting the rotational speed of the internal combustion engine, and the intermediate-fire engine for the intermittent fire tend to decrease as the detected rotational speed of the internal combustion engine increases. A predetermined value adjusting means for first misfire that adjusts a predetermined value, an intake air amount detecting means for detecting an intake air amount of the internal combustion engine, and the detected intake air amount Calculating a cycle intake air amount per cycle of the internal combustion engine, and adjusting a predetermined value for the intermediate flash failure so as to increase as the calculated cycle intake air amount increases. , Can also be provided.

  Further, in the misfire determination device for an internal combustion engine according to the aspect of the present invention in which misfire is determined using a plurality of determination logics including any one of single misfire determination logic, continuous misfire determination logic, and intermediate misfire determination logic, the internal combustion engine includes: The misfire determination means includes the single misfire determination logic, the continuous misfire determination logic, the intermediate misfire determination logic, and the opposed misfire in which two opposed cylinders of a plurality of cylinders are misfiring. Any of an oncoming misfire determination logic for determining a pattern and a random misfire determination logic for determining a random misfire pattern in which any one of a plurality of cylinders misfires irregularly during one cycle of the internal combustion engine It may be a means for determining misfire of the internal combustion engine using a plurality of determination logics including the above. Here, the “opposing two cylinders” in the opposed misfire pattern correspond to, for example, the first and fourth cylinders in the firing order in the case of six cylinders, and the first cylinder in the firing order in the case of eight cylinders. This means that the misfiring two cylinders have a mirror image relationship so that the fifth cylinder corresponds. In addition, “randomly misfiring” in the random misfire pattern means that only one cylinder in the firing order is misfiring in one cycle and only the other cylinders in the firing order are misfiring in other cycles. Thus, it means a case where only one cylinder is misfired during one cycle, but the misfired cylinder is changed.

In the misfire determination device for an internal combustion engine according to the present invention in which misfire is determined using the opposed misfire determination logic or the random misfire determination logic, the opposed misfire determination logic includes a crank rotation based on the sequentially calculated rotation fluctuation and the rotation fluctuation. A rotational fluctuation difference, which is a difference from a rotational fluctuation calculated at an angle of 120 degrees before, is calculated, and two rotational fluctuation differences among the rotational fluctuation differences calculated for one cycle of the internal combustion engine are predetermined for counter misfire. It can also be the logic which determines that it is an opposite misfire when it becomes more than a value. In this case, the counter misfire determination logic is configured such that a ratio of two target rotation fluctuation differences, which are two rotation fluctuation differences that are equal to or greater than the predetermined value for counter misfire, is within the first counter misfire predetermined ratio range and the two targets. It is assumed that the logic is such that it is determined that the misfire is a counter misfire when the ratio between the sum of the rotation fluctuation differences and the other rotation fluctuation difference other than the two target rotation fluctuation differences falls within the second counter misfire predetermined ratio range. You can also. Further, in this case, the other rotational fluctuation difference is one of a rotational fluctuation difference one previous to the two target rotational fluctuation differences and a rotational fluctuation difference two previous to the two target rotational fluctuation differences. It can also be characterized by including. In this way, it is possible to determine the counter misfire of the internal combustion engine more accurately and accurately. In the misfire determination apparatus for an internal combustion engine according to the present invention of these aspects, the rotational speed detection means for detecting the rotational speed of the internal combustion engine, and the counter-fire misfires tend to decrease as the detected rotational speed of the internal combustion engine increases. A first counter misfire predetermined value adjusting means for adjusting a predetermined value, an intake air amount detecting means for detecting an intake air amount of the internal combustion engine, and the detected intake air amount A second counter misfire predetermined value adjusting means for calculating a cycle intake air amount per cycle of the internal combustion engine and adjusting the counter misfire predetermined value so as to increase as the calculated cycle intake air amount increases. , Can also be provided.

  Further, in the misfire determination device for an internal combustion engine according to the present invention in which misfire is determined using an opposing misfire determination logic or a random misfire determination logic, the random misfire determination logic is based on the sequentially calculated rotation fluctuation and the rotation fluctuation. A rotation fluctuation difference, which is a difference from a rotation fluctuation calculated 90 degrees before the crank angle, is calculated, and one of the rotation fluctuation differences calculated for one cycle of the internal combustion engine is used for random misfire. It can also be the logic which determines with random misfire when it becomes more than a predetermined value. In this case, the random misfire determination logic is configured such that a ratio between a target rotational fluctuation difference that is a rotational fluctuation difference equal to or greater than the random misfire predetermined value and a rotational fluctuation difference other than the target rotational fluctuation difference is a predetermined ratio for random misfire. It can also be the logic which determines that it is a random misfire when it becomes a range. Further, in this case, the other rotational fluctuation difference is a rotational fluctuation difference one before the target rotational fluctuation difference, a rotational fluctuation difference one immediately after the target rotational fluctuation difference, and a third after the target rotational fluctuation difference. Any one of the rotational fluctuation differences may be included. In this way, it is possible to determine the random misfire of the internal combustion engine more appropriately and accurately. In the misfire determination apparatus for an internal combustion engine according to the present invention of these aspects, the rotational speed detection means for detecting the rotational speed of the internal combustion engine, and the random misfire detection device tend to decrease as the detected rotational speed of the internal combustion engine increases. First random misfire predetermined value adjusting means for adjusting a predetermined value, intake air amount detecting means for detecting the intake air amount of the internal combustion engine, and the detected intake air amount Second random misfire predetermined value adjusting means for calculating a predetermined value for random misfire so as to calculate a cycle intake air amount per cycle of the internal combustion engine and to increase as the calculated cycle intake air amount increases. , Can also be provided.

  In the misfire determination apparatus for an internal combustion engine according to the present invention, the rotation fluctuation calculating means calculates a rotation angular speed for each predetermined crank angle of a crankshaft of the internal combustion engine and corresponds to an ignition timing of each cylinder of the internal combustion engine. And a means for calculating rotational fluctuations based on a difference in rotational angular velocity before the predetermined crank angle from the rotational angular velocity. The rotation fluctuation calculating means may be a means for calculating a rotation angular acceleration corresponding to the ignition timing of each cylinder of the internal combustion engine as the rotation fluctuation.

A first misfire determination method for an internal combustion engine according to the present invention includes:
An internal combustion engine misfire determination method for determining misfire in a multi-cylinder internal combustion engine,
Based on the rotational position of the crankshaft of the internal combustion engine, sequentially calculating the rotational fluctuation of the internal combustion engine at a crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine,
Single misfire determination logic for determining a single misfire pattern in which only one cylinder of a plurality of cylinders is misfired based on the sequentially calculated rotation fluctuation, and two consecutive cylinders of the plurality of cylinders are misfired. A plurality of determination logics including any one of a continuous misfire determination logic for determining a continuous misfire pattern and a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring. The gist is to determine misfire of the internal combustion engine using

In the first misfire determination method for an internal combustion engine of the present invention, the rotational fluctuation of the internal combustion engine at the crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine is sequentially calculated based on the rotational position of the crankshaft of the internal combustion engine, A single misfire determination logic for determining a single misfire pattern in which only one cylinder among a plurality of cylinders is misfired based on the sequentially calculated rotation fluctuation, and two consecutive cylinders among the plurality of cylinders are misfired. A plurality of determination logics including any one of a continuous misfire determination logic for determining a continuous misfire pattern and a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring. Is used to determine misfire of the internal combustion engine. Therefore, the misfire of the internal combustion engine can be accurately determined appropriately including the misfire pattern.

A second misfire determination method for an internal combustion engine according to the present invention includes:
An internal combustion engine misfire determination method for determining misfire in an internal combustion engine of a plurality of cylinders that is an even number,
Based on the rotational position of the crankshaft of the internal combustion engine, sequentially calculating the rotational fluctuation of the internal combustion engine at a crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine,
Single misfire determination logic for determining a single misfire pattern in which only one cylinder of a plurality of cylinders is misfired based on the sequentially calculated rotation fluctuation, and two consecutive cylinders of the plurality of cylinders are misfired. A continuous misfire determination logic for determining a continuous misfire pattern, a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring, and a plurality of cylinders facing each other A counter misfire determination logic for determining a counter misfire pattern in which two cylinders are misfiring, and a random misfire pattern in which any one of a plurality of cylinders misfires irregularly during one cycle of the internal combustion engine. The gist is to determine misfire of the internal combustion engine using a plurality of determination logics including any of random misfire determination logic to be determined.

  In the second misfire determination method for an internal combustion engine of the present invention, the rotational fluctuation of the internal combustion engine at the crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine is sequentially calculated based on the rotational position of the crankshaft of the internal combustion engine, A single misfire determination logic for determining a single misfire pattern in which only one cylinder among a plurality of cylinders is misfired based on the sequentially calculated rotation fluctuation, and two consecutive cylinders among the plurality of cylinders are misfired. A continuous misfire determination logic for determining a continuous misfire pattern, and a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring, and two of the plurality of cylinders facing each other. Opposing misfire determination logic for determining an opposing misfire pattern in which a cylinder is misfiring, and any one of a plurality of cylinders is irregular during one cycle of the internal combustion engine Determining a misfire of the internal combustion engine with a plurality of decision logic containing either random misfire judgment logic determines random misfire pattern is misfiring. Therefore, the misfire of the internal combustion engine can be accurately determined appropriately including the misfire pattern.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 equipped with a misfire determination device for an internal combustion engine as one embodiment of the present invention. FIG. 2 is a configuration diagram showing an outline of a configuration of an engine electronic control unit 24 that functions as a misfire determination device for an internal combustion engine and an engine 22 that is operation-controlled by the engine electronic control unit 24. 4 is a flowchart showing an example of misfire determination processing executed by an engine electronic control unit 24. It is a flowchart which shows an example of a single misfire determination process. It is a flowchart which shows an example of a continuous misfire determination process. It is a flowchart which shows an example of an interstitial deletion fire determination process. It is explanatory drawing which shows an example of the relationship between 1st single misfire determination value A1, the rotation speed N of the crankshaft 26, and the intake air amount Ga per rotation of the crankshaft 26. FIG. It is explanatory drawing which shows an example of the time change of the rotation fluctuation | variation Nxd when the single misfire has arisen. It is explanatory drawing which shows an example of the relationship between 1st continuous misfire determination value B1, the rotation speed N of the crankshaft 26, and the intake air amount Ga per rotation of the crankshaft 26. It is explanatory drawing which shows an example of the time change of the rotation fluctuation difference Nxdf1x when producing the continuous misfire. It is explanatory drawing which shows an example of the relationship between the 1st deletion fire judgment value C1, the rotation speed N of the crankshaft 26, and the intake air amount Ga per rotation of the crankshaft 26. It is explanatory drawing which shows an example of the time change of the rotation fluctuation sum Nxdint when producing the interstitial fire. It is a flowchart which shows an example of the misfire determination process performed by the engine electronic control unit 24 of 2nd Example. It is a flowchart which shows an example of an opposing misfire determination process. It is a flowchart which shows an example of a random misfire determination process. It is explanatory drawing which shows an example of the relationship between the 1st opposing misfire determination value D1, the rotation speed N of the crankshaft 26, and the intake air amount Ga per rotation of the crankshaft 26. It is explanatory drawing which shows an example of the time change of the rotation fluctuation difference Nxd120 when the opposite misfire has arisen. It is explanatory drawing which shows an example of the relationship between the 1st random misfire determination value E1, the rotation speed N of the crankshaft 26, and the intake air amount Ga per rotation of the crankshaft 26. It is explanatory drawing which shows an example of the time change of the rotation fluctuation difference Nxd90 when the random misfire has arisen.

  Next, the form for implementing this invention is demonstrated using an Example.

FIG. 1 is a block diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a misfire determination device for an internal combustion engine as an embodiment of the present invention. FIG. 2 is an electronic control for an engine that functions as a misfire determination device for the internal combustion engine. FIG. 2 is a configuration diagram showing an outline of a configuration of a unit 24 and an engine 22 that is controlled by the engine electronic control unit 24; As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22 that is operated and controlled by an engine electronic control unit (abbreviated as engine ECU in FIG. 1) 24, and a crankshaft 26 as an output shaft of the engine 22. And a planetary gear mechanism 30 in which a ring gear is connected to a drive shaft connected to the axles of the drive wheels 69a and 69b, and a sun gear of the planetary gear mechanism 30 and an electronic control for a motor via an inverter 41. Unit (abbreviated as motor ECU in FIG. 1)
The motor MG1 capable of generating power under the control of the motor 40 and the power received by the motor electronic control unit 40 via the inverter 42 attached to the drive shaft connected to the axles of the drive wheels 69a, 69b can be input / output. MG2, a battery 50 capable of exchanging electric power with motors MG1 and MG2 via inverters 41 and 42, and a hybrid electronic control unit 70 for controlling the entire hybrid vehicle 20. The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port (not shown), and And a communication port. The hybrid electronic control unit 70 includes a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, and a brake. The brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine electronic control unit 24, the motor electronic control unit 40, and the like via a communication port, and the engine electronic control unit 24 and the motor electronic control unit 40 are connected. Various control signals and data are exchanged with 40 and the like.

  The engine 22 is configured as an in-line 6-cylinder internal combustion engine that can output power by using a hydrocarbon fuel such as gasoline or light oil. As shown in FIG. The fuel is sucked through the fuel injection valve 126 and gasoline is injected from the fuel injection valve 126 to mix the sucked air and gasoline. The air-fuel mixture is sucked into the fuel chamber through the intake valve 128, and an electric spark is generated by the spark plug 130. The reciprocating motion of the piston 132 which is caused to explode and burn by the energy is converted into the rotational motion of the crankshaft 26. Exhaust gas from the engine 22 is discharged to the outside air through a purification device (three-way catalyst) 134 that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). In the engine 22 of the embodiment, the piston 132 of each cylinder is attached to the crankshaft 26 so that the ignition timing of each cylinder differs by 120 ° CA.

The engine electronic control unit 24 for controlling the engine 22 is configured as a microprocessor centered on a CPU 24a. In addition to the CPU 24a, a ROM 24b for storing processing programs, a RAM 24c for temporarily storing data, and a RAM 24c (not shown). Equipped with flash memory, input / output port and communication port. Signals from various sensors that detect the state of the engine 22 are input to the engine electronic control unit 24 via an input port (not shown). For example, in the engine electronic control unit 24, the cooling from the crank angle CA of the crank angle sensor 140 that detects the crank angle CA as the rotation angle of the crankshaft 26 and the coolant temperature sensor 142 that detects the temperature of the cooling water of the engine 22. Water temperature, intake valve 128 for intake and exhaust to the combustion chamber, cam position from cam position sensor 144 for detecting the rotational position of the camshaft for opening and closing the exhaust valve, and throttle valve position sensor 146 for detecting the position of the throttle valve 124 The intake air amount Ga from the vacuum sensor 148 that detects the throttle position and the intake air amount as the load of the engine 22 is input via the input port. Here, the crank angle sensor 140 is configured as an MRE rotation sensor in which a magnetoresistive element is disposed at a position facing a magnet rotor (not shown) attached to the crankshaft 26, and has a predetermined angle (for example, a crank angle of 10 ° CA). A pulse is output every time. In the embodiment, the crank angle CA is specified using the pulse generated by the crank angle sensor 140 and the rotational speed N of the engine 22 is calculated. Various control signals for driving the engine 22 are output from the engine electronic control unit 24 via an output port (not shown). For example, the engine ECU 24 sends a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, a control signal to the ignition coil 138 integrated with the igniter, and the intake valve 128. A control signal or the like to the variable valve timing mechanism 150 capable of changing the opening / closing timing is output through the output port. As described above, the engine electronic control unit 24 communicates with the hybrid electronic control unit 70, and controls the operation of the engine 22 by the control signal from the hybrid electronic control unit 70, and the engine 22 is controlled as necessary. Outputs data related to operation status.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when determining the misfire of the engine 22 by the engine electronic control unit 24 will be described. FIG. 3 is a flowchart showing an example of misfire determination processing executed by the engine electronic control unit 24. This misfire determination process is always repeated after the engine 22 is started.

  When the misfire determination process is executed, first, a process for inputting data necessary for determination of a misfire such as the crank angle CA from the crank angle sensor 140 and the intake air amount Ga from the vacuum sensor 148 is executed (step S100). . Subsequently, the rotational speed N of the crankshaft 26 for each crank angle of 60 ° CA is calculated based on the input crank angle CA (step S110). The rotation speed N for each crank angle of 60 ° CA can be obtained from the interval with the pulse before the crank angle of 10 ° CA. Then, the rotation fluctuation Nxd for each crank angle 120 ° CA is calculated as the difference in the rotational speed N for each crank angle 60 ° CA corresponding to the ignition timing of each cylinder of the engine 22 (step S120). Then, the difference between the calculated rotation fluctuation Nxd and the rotation fluctuation Nxd before the crank angle 360 ° CA is calculated as the rotation fluctuation difference Nxdflx (step S130), and the crank angle 360 ° CA is calculated with respect to the calculated rotation fluctuation Nxd. The sum with the previous rotational fluctuation Nxd is calculated as the rotational fluctuation sum Nxdint (step S140). Here, as described above, the rotational fluctuation Nxd is calculated for each crank angle of 120 ° CA. Therefore, the rotational fluctuation Nxd before the crank angle of 360 ° CA is the rotational fluctuation of the previous three. In the flowchart in the figure, the rotation fluctuations Nxd (n) and Nxd (n-3) are shown to represent this.

  When the rotational fluctuation Nxd, the rotational fluctuation difference Nxdflx, and the rotational fluctuation sum Nxdint are calculated in this way, the single misfire determination for determining the single misfire pattern in which only one of the six cylinders misfires is performed using these calculated values. Processing (step S150), continuous misfire determination processing (step S160) for determining a continuous misfire pattern in which two consecutive cylinders among the six cylinders are misfired, and two cylinders sandwiching one combustion cylinder among the six cylinders are misfired During this time, a deletion fire determination process (step S170) for determining a deletion fire pattern is executed, and when a single misfire, a continuous misfire, or an intermediate deletion fire has occurred, these are detected and the misfire determination process is terminated. In the embodiment, the single misfire determination process is executed according to the flowchart illustrated in FIG. 4, the continuous misfire determination process is executed according to the flowchart illustrated in FIG. 5, and the intermediate misfire determination process is executed according to the flowchart illustrated in FIG. 6. Hereinafter, the single misfire determination process, the continuous misfire determination process, and the inter-missing fire determination process will be described in order with reference to FIGS.

In the single misfire determination process, as shown in the flowchart of FIG. 4, first, the first single misfire is determined as one of determination values for determining single misfire based on the rotational speed N of the crankshaft 26 and the intake air amount Ga. A misfire determination value A1 is set (step S200). Here, the first single misfire determination value A1 is set so as to decrease as the rotation speed N of the crankshaft 26 increases, and to increase as the intake air amount Ga per rotation of the crankshaft 26 increases. An example of the relationship between the first single misfire determination value A1, the rotational speed N of the crankshaft 26, and the intake air amount Ga per one rotation of the crankshaft 26 is shown in FIG. When the first single misfire determination value A1 is thus set, the rotational fluctuation Nxd is compared with the first single misfire determination value A1 (step S210).
When the rotational fluctuation Nxd is equal to or less than the first single misfire determination value A1, it is determined that no single misfire has occurred, and the process is terminated. When the rotational fluctuation Nxd exceeds the first single misfire determination value A1, the excessive rotational fluctuation Nxd is determined as the third misfiring cylinder (step S220), and the rotational fluctuation Nxd (0 corresponding to the cylinder three immediately before the misfiring cylinder) is determined. ) Is divided by the rotational fluctuation Nxd (3) of the misfiring cylinder to calculate the rotational fluctuation ratio Nja2 (step S230), and the rotational fluctuation Nxd (2) corresponding to the cylinder immediately before the misfiring cylinder is rotated by the rotation of the misfiring cylinder. The rotational fluctuation ratio Nja3 is calculated by dividing by the fluctuation Nxd (3) (step S240), and the rotational fluctuation Nxd (4) corresponding to the cylinder immediately after the misfiring cylinder is further changed to the rotational fluctuation Nxd (3) of the misfiring cylinder. The rotation fluctuation ratio Nja4 is calculated by dividing by (step S250). Then, it is determined whether or not the calculated rotation fluctuation ratio Nja2 is within the range of the second single misfire determination values A21 and A22 (step S260), and the calculated rotation fluctuation ratio Nja3 is determined as the third single misfire determination value A31, It is determined whether it is within the range of A32 (step S270), and further, it is determined whether the calculated rotation fluctuation ratio Nja4 is within the range of the fourth single misfire determination values A41, A42 (step S280). . Here, the second single misfire determination values A21 and A22, the third single misfire determination values A31 and A32, and the fourth single misfire determination values A41 and A42 are the rotation fluctuation ratio Nja2 and the rotation fluctuation ratio Nja3 when a single misfire occurs. , It is determined by experiments or the like so as to be smaller and larger than the rotation fluctuation ratio Nja4. The rotation fluctuation ratio Nja2 is in the range of the second single misfire determination values A21, A22, the rotation fluctuation ratio Nja3 is in the range of the third single misfire determination values A31, A32, and the rotation fluctuation ratio Nja4 is in the fourth unit. When it is within the range of the misfire determination values A41 and A42, the fact that it is a single misfire is output (step S290), the processing is terminated, and the rotation fluctuation ratio Nja2 is not within the range of the second single misfire determination values A21 and A22. Or when the rotational fluctuation ratio Nja3 is not within the range of the third single misfire determination value A31, A32 or when the rotational fluctuation ratio Nja4 is not within the range of the fourth single misfire determination value A41, A42. It is determined that no has occurred, and the process ends. FIG. 8 is an explanatory diagram illustrating an example of a temporal change in the rotational fluctuation Nxd when a single misfire occurs. As shown in the figure, when single misfire occurs, only one cylinder in one cycle has a pattern in which the rotational fluctuation Nxd clearly exceeds the first single misfire determination value A1. In the embodiment, attention is paid to this clearly determinable value, and it is determined that the pattern is a single misfire using the rotation fluctuation ratio Nja2, the rotation fluctuation ratio Nja3, and the rotation fluctuation ratio Nja4. Thereby, single misfire can be determined more appropriately and accurately.

In the continuous misfire determination process, as shown in the flowchart of FIG. 5, first, the first continuous as one of the determination values for determining continuous misfire based on the rotation speed N of the crankshaft 26 and the intake air amount Ga. A misfire determination value B1 is set (step S300). Here, like the first single misfire determination value A1, the first continuous misfire determination value B1 tends to decrease as the rotation speed N of the crankshaft 26 increases, and the intake air amount Ga per rotation of the crankshaft 26 increases. The larger the value, the larger the tendency. An example of the relationship between the first continuous misfire determination value B1, the rotational speed N of the crankshaft 26, and the intake air amount Ga per one rotation of the crankshaft 26 is shown in FIG. When the first continuous misfire determination value B1 is thus set, the rotational fluctuation difference Nxdf1x is compared with the first continuous misfire determination value B1 (step S310). When the rotational fluctuation difference Nxdf1x is equal to or less than the first continuous misfire determination value B1, It is determined that it has not occurred, and the process is terminated. When the rotational fluctuation difference Nxdflx exceeds the first continuous misfire determination value B1, the exceeded rotational fluctuation difference Nxdf1x is determined as the third misfire cylinder (step S320), and the rotational fluctuation difference corresponding to the cylinder immediately before the misfire cylinder is determined. The rotation fluctuation difference ratio Njb2 is calculated by dividing Nxdflx (2) by the rotation fluctuation difference Nxdflx (3) of the misfire cylinder (step S330), and the rotation fluctuation difference Nxdflx (4) corresponding to the cylinder immediately after the misfire cylinder. ) Is divided by the rotational fluctuation difference Nxdflx (3) of the misfired cylinder to calculate the rotational fluctuation difference ratio Njb3 (step S340). Then, it is determined whether or not the calculated rotational fluctuation difference ratio Njb2 is within the range of the second continuous misfire determination values B21 and B22, and the calculated rotational fluctuation difference ratio Njb3 is within the range of the third continuous misfire determination values B31 and B32. It is determined whether it is within (step S350). Here, the second continuous misfire determination values B21 and B22 and the third continuous misfire determination values B31 and B32 are smaller and larger values than the rotational fluctuation difference ratio Njb2 and the rotational fluctuation difference ratio Njb3 when continuous misfire occurs. It is determined by experiments. When the rotational fluctuation difference ratio Njb2 is not within the range of the second continuous misfire determination values B21 and B22 and the rotational fluctuation difference ratio Njb3 is not within the range of the third continuous misfire determination values B31 and B32, continuous misfire does not occur. Determine and end the process. On the other hand, when the rotational fluctuation difference ratio Njb2 is within the range of the second continuous misfire determination values B21 and B22, or when the rotational fluctuation difference ratio Njb3 is within the range of the third continuous misfire determination values B31 and B32, three misfire cylinders are detected. A rotational fluctuation difference ratio Njb4 is calculated by dividing the rotational fluctuation difference Nxdflx (0) corresponding to the previous cylinder by the rotational fluctuation difference Nxdflx (3) of the misfire cylinder (step S360), and the calculated rotational fluctuation difference ratio Njb4 is It is determined whether or not it is within the range of the fourth continuous misfire determination values B41 and B42 (step S370). Here, the fourth continuous misfire determination values B41 and B42 are determined by experiments or the like so as to be smaller and larger than the rotation fluctuation difference ratio Njb4 when continuous misfire occurs. When the rotational fluctuation difference ratio Njb4 is within the range of the fourth continuous misfire determination values B41 and B42, the fact that continuous misfire is output is output (step S380), the process is terminated, and the rotational fluctuation differential ratio Nja4 is the fourth continuous misfire. When it is not within the range of the determination values B41 and B42, it is determined that no continuous misfire has occurred, and the process is terminated. FIG. 10 is an explanatory diagram illustrating an example of a temporal change in the rotational fluctuation difference Nxdf1x when the continuous misfire occurs. As shown in the figure, when continuous misfire occurs, the rotational fluctuation difference Nxdf1x clearly exceeds the first continuous misfire determination value B1. In this embodiment, attention is paid to this clearly determinable value, and the pattern is determined to be continuously misfired using the rotational fluctuation difference ratio Njb2, the rotational fluctuation difference ratio Njb3, and the rotational fluctuation difference ratio Njb4. Thereby, continuous misfire can be determined more appropriately and accurately.

  As shown in the flowchart of FIG. 6, in the intermittent fire determination process, first, the first intermittent as one of the determination values for determining the intermittent fire based on the rotational speed N of the crankshaft 26 and the intake air amount Ga. A misfire determination value C1 is set (step S400). Here, the first continuous misfire determination value C1 is set so as to decrease as the rotation speed N of the crankshaft 26 increases, and to increase as the intake air amount Ga per rotation of the crankshaft 26 increases. FIG. 11 shows an example of the relationship among the first inter-missing fire determination value C1, the rotation speed N of the crankshaft 26, and the intake air amount Ga per rotation of the crankshaft 26. When the first inter-period deletion fire determination value C1 is thus set, the rotational fluctuation sum Nxdint is compared with the first inter-period deletion fire determination value C1 (step S410), and when the rotational fluctuation sum Nxdint is equal to or less than the first inter-period deletion fire determination value C1, It is determined that it has not occurred, and the process is terminated. When the rotational fluctuation sum Nxdint exceeds the first inter-missing missing fire determination value C1, the excessive rotational fluctuation sum Nxdint is determined as the third misfire cylinder (step S420), and the rotational fluctuation sum corresponding to the cylinder immediately before the misfire cylinder is determined. The rotation fluctuation sum ratio Njc2 is calculated by dividing Nxdint (2) by the rotation fluctuation sum Nxdint (3) of the misfire cylinder (step S430), and the calculated rotation fluctuation sum ratio Njc2 is less than the second inter-missing deletion fire determination value C2. Is determined (step S440). Here, the second intercalation fire determination value C2 is a value larger than the rotational fluctuation sum ratio Njc2 when the intercalation fire is generated, and is smaller than the rotational fluctuation sum Njc2 when no intercalation fire is generated. It is determined by experiments. When the rotational fluctuation sum ratio Njc2 is less than the second inter-blank fire determination value C2, a message indicating that the inter-firing fire is generated is output (step S450), the process is terminated, and the rotational fluctuation sum ratio Njc2 is greater than or equal to the second inter-flame fire determination value C2. In some cases, it is determined that there is no missing fire, and the process is terminated. FIG. 12 is an explanatory diagram showing an example of a temporal change in the rotational fluctuation sum Nxdint when an interstitial fire is generated. As shown in the figure, when an intermittent fire is generated, the rotational fluctuation sum Nxdint clearly exceeds the first intermittent fire determination value C1. In the embodiment, attention is paid to this clearly determinable value, and it is determined by using the rotational fluctuation sum ratio Njc2 that the pattern is an intermittent fire. As a result, it is possible to more accurately determine the intermission fire.

According to the misfire determination apparatus in the hybrid vehicle 20 of the embodiment described above, the single misfire determination process, the continuous misfire determination process, and the inter-missing fire determination process are executed using the rotation fluctuation Nxd, the rotation fluctuation difference Nxdf1x, and the rotation fluctuation sum Nxdint. Thus, single misfire, continuous misfire, and intermittent fire can be determined more appropriately and accurately. That is, since misfire of the engine 22 is determined using a plurality of different determination logics that take into account the misfire pattern, the misfire of the engine 22 can be determined more accurately and accurately including the misfire pattern.

  Further, according to the misfire determination device in the hybrid vehicle 20 of the embodiment, the rotational fluctuation Nxd that is the fluctuation value of the rotational speed N of the crankshaft 26 for each crank angle 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22 is calculated. By using it, it is possible to determine single misfire more clearly and accurately. In addition, since the determination is made using the first single misfire determination value A1 corresponding to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26, it is possible to determine single misfire more appropriately. it can. Further, according to the misfire determination device in the hybrid vehicle 20 of the embodiment, the rotation fluctuation ratio Nja2 that is the three previous rotation fluctuations Nxd (0) with respect to the rotation fluctuation Nxd (3) exceeding the first single misfire determination value A1 Using the rotation fluctuation ratio Nja3 which is the previous rotation fluctuation Nxd (2) with respect to the rotation fluctuation Nxd (3), and the rotation fluctuation ratio Nja4 which is the next rotation fluctuation Nxd (4) with respect to the rotation fluctuation Nxd (3). Since single misfire pattern determination is performed, single misfire can be determined more appropriately. Thus, by appropriately determining the single misfire, the response to the single misfire can be made more appropriate.

  Furthermore, according to the misfire determination device in the hybrid vehicle 20 of the embodiment, the rotation fluctuation Nxd, which is the fluctuation value of the rotation speed N of the crankshaft 26 for each crank angle 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22, is determined. By using the rotational fluctuation difference Nxdf1x, which is the difference from the crank angle 360 ° CA, it is possible to determine continuous misfire more clearly and accurately. Moreover, since the determination is made using the first continuous misfire determination value B1 corresponding to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26, it is possible to more appropriately determine the continuous misfire. it can. Further, according to the misfire determination device in the hybrid vehicle 20 of the embodiment, the rotational fluctuation difference that is the previous rotational fluctuation difference Nxdflx (2) with respect to the rotational fluctuation difference Nxdflx (3) exceeding the first continuous misfire judgment value B1. The rotation fluctuation difference ratio Njb3, which is the next rotation fluctuation difference Nxdflx (4) with respect to the ratio Njb2 and the rotation fluctuation difference Nxdflx (3), and the three previous rotation fluctuation differences Nxdflx (0) with respect to the rotation fluctuation difference Nxdflx (3). Since the continuous misfire pattern determination is performed using a certain rotation fluctuation difference ratio Njb4, it is possible to determine the continuous misfire more appropriately. By appropriately determining continuous misfire as described above, it is possible to make the response to continuous misfire more appropriate.

  Alternatively, according to the misfire determination device in the hybrid vehicle 20 of the embodiment, the rotation fluctuation Nxd, which is the fluctuation value of the rotation speed N of the crankshaft 26 for each crank angle 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22, is determined. By using the rotational fluctuation sum Nxdint which is the sum of the crank angle of 360 ° CA, it is possible to more clearly and accurately determine the missing fire. In addition, since the determination is made using the first inter-missile fire determination value C1 corresponding to the rotational speed N of the crankshaft 26 and the intake air amount Ga per one rotation of the crankshaft 26, it is possible to more appropriately determine the inter-fibre fire. it can. Further, according to the misfire determination device in the hybrid vehicle 20 of the embodiment, the rotational fluctuation sum that is the previous rotational fluctuation sum Nxdint (2) with respect to the rotational fluctuation sum Nxdint (3) exceeding the first inter-missing fire judgment value C1. Since the pattern determination of the intermittent fire is performed using the ratio Njc2, it is possible to determine the intermittent fire more appropriately. Thus, by appropriately determining the inter-missing fire, the response to the inter-missing fire can be made more appropriate.

In the misfire determination device in the hybrid vehicle 20 of the embodiment, the single misfire determination process, the continuous misfire determination process, and the intermediate loss fire determination process are executed by using the rotation fluctuation Nxd, the rotation fluctuation difference Nxdf1x, and the rotation fluctuation sum Nxdint. However, such misfire determination logic is not limited to single misfire determination processing, continuous misfire determination processing, and interim deletion fire determination processing, and other misfire determination logic is used to determine other misfire patterns. It is good also as what determines misfire. In addition, it is not necessary to determine misfires using all misfire determination logics in single misfire determination processing, continuous misfire determination processing, and inter-missing fire determination processing, and it is assumed that misfire is determined using any of these misfire determination logics. It doesn't matter.

  In the misfire determination apparatus in the hybrid vehicle 20 of the embodiment, the rotational fluctuation Nxd for each crank angle 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22 is calculated as the difference in the rotational speed N for each crank angle 60 ° CA. However, it may be calculated as a difference in the rotational speed N for different crank angles. Further, the rotational angular acceleration for each crank angle of 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22 may be calculated and used as the rotational fluctuation Nxd.

  In the single misfire determination process in the misfire determination apparatus of the hybrid vehicle 20 of the embodiment, the first single misfire determination value A1 according to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26 is used. However, the single misfire is determined by using the first single misfire determination value A1 corresponding to only the intake air amount Ga per rotation of the crankshaft 26 regardless of the rotational speed N of the crankshaft 26. The single misfire may be determined using the first single misfire determination value A1 corresponding to only the rotation speed N of the crankshaft 26 regardless of the intake air amount Ga per rotation of the crankshaft 26. It is good also as what to do. The single misfire may be determined using the first single misfire determination value A1 set regardless of the rotational speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26.

  In the single misfire determination process in the misfire determination device of the hybrid vehicle 20 of the embodiment, the rotation fluctuation ratio Nja2 that is the three previous rotation fluctuations Nxd (0) with respect to the rotation fluctuation Nxd (3) exceeding the first single misfire determination value A1. And the rotational fluctuation ratio Nja3 which is the previous rotational fluctuation Nxd (2) with respect to the rotational fluctuation Nxd (3), and the rotational fluctuation ratio Nja4 which is the subsequent rotational fluctuation Nxd (4) with respect to the rotational fluctuation Nxd (3). However, it is not necessary to perform single misfire pattern determination using all of the rotational fluctuation ratio Nja2, the rotational fluctuation ratio Nja3, and the rotational fluctuation ratio Nja4. Simple misfire pattern determination may be performed, or none of these may be used. Further, the single misfire pattern determination may be performed using a rotation fluctuation ratio different from the rotation fluctuation ratio Nja2, the rotation fluctuation ratio Nja3, and the rotation fluctuation ratio Nja4.

  In the continuous misfire determination process in the misfire determination device of the hybrid vehicle 20 of the embodiment, the first continuous misfire determination value B1 according to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26 is used. However, the continuous misfire is determined by using the first continuous misfire determination value B1 corresponding to only the intake air amount Ga per rotation of the crankshaft 26 regardless of the rotational speed N of the crankshaft 26. It is also possible to determine the continuous misfire by using the first continuous misfire determination value B1 corresponding to only the rotation speed N of the crankshaft 26 regardless of the intake air amount Ga per rotation of the crankshaft 26. It is good also as what to do. Further, the continuous misfire may be determined using the first continuous misfire determination value B1 set regardless of the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26.

In the continuous misfire determination process in the misfire determination device of the hybrid vehicle 20 of the embodiment, the rotational fluctuation that is the previous rotational fluctuation difference Nxdflx (2) with respect to the rotational fluctuation difference Nxdflx (3) exceeding the first continuous misfire determination value B1. The rotation fluctuation difference ratio Njb3, which is the next rotation fluctuation difference Nxdflx (4) with respect to the difference ratio Njb2 and the rotation fluctuation difference Nxdflx (3), and the three previous rotation fluctuation differences Nxdflx (0) with respect to the rotation fluctuation difference Nxdflx (3). Although the continuous misfire pattern determination is performed using the rotational fluctuation difference ratio Njb4, the continuous misfire pattern determination is performed using all of the rotational fluctuation difference ratio Njb2, the rotational fluctuation difference ratio Njb3, and the rotational fluctuation difference ratio Njb4. It is not necessary to perform any of these, and it is possible to use any of these to determine the pattern of continuous misfire, It may be as not using. Further, it is also possible to perform continuous misfire pattern determination using a rotation fluctuation difference ratio different from the rotation fluctuation difference ratio Njb2, the rotation fluctuation difference ratio Njb3, and the rotation fluctuation difference ratio Njb4.

  In the misfire determination process in the misfire determination device of the hybrid vehicle 20 of the embodiment, the first misfire determination value C1 according to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26 is used. In this case, it is determined that the intermediate flash failure is determined. However, regardless of the rotational speed N of the crankshaft 26, the first intermediate flash failure determination value C1 corresponding to only the intake air amount Ga per rotation of the crankshaft 26 is used. It is also possible to determine whether or not there is an intermediate flash failure using the first intermediate flash failure determination value C1 corresponding only to the rotational speed N of the crankshaft 26 regardless of the intake air amount Ga per rotation of the crankshaft 26. It is good also as what to do. Further, it may be possible to determine the intermittent fire using the first intermittent fire determination value C1 set irrespective of the rotational speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26.

  In the misfire determination process in the misfire determination device of the hybrid vehicle 20 of the embodiment, the rotational fluctuation that is the previous rotational fluctuation sum Nxdint (2) with respect to the rotational fluctuation sum Nxdint (3) that exceeds the first intermediate misfire determination value C1. Although it is assumed that the pattern determination of the intermediate deletion fire is performed using the sum ratio Njc2, the pattern determination of the intermediate deletion fire may not be performed using the rotational fluctuation sum ratio Njc2. In addition, it is possible to determine the pattern of the intercalation fire using a rotational fluctuation sum ratio different from the rotational fluctuation sum ratio Njc2.

  Next, a hybrid vehicle 20B equipped with a misfire determination device for an internal combustion engine as a second embodiment of the present invention will be described. The hardware configuration of the hybrid vehicle 20B of the second embodiment and the misfire determination device for the internal combustion engine mounted on the vehicle is the hybrid vehicle 20 and the misfire determination device for the internal combustion engine of the first embodiment described with reference to FIGS. Has the same hardware configuration. Therefore, in order to avoid redundant description, the hybrid configuration of the hybrid vehicle 20B of the second embodiment and the hardware configuration of the misfire determination device for the internal combustion engine mounted on the vehicle are determined for the misfire determination of the hybrid vehicle 20 of the first embodiment and the internal combustion engine. The same reference numerals as those of the hardware configuration of the apparatus are attached, and detailed description thereof is omitted.

Next, the operation of the thus configured hybrid vehicle 20B of the second embodiment, particularly the operation when determining the misfire of the engine 22 by the engine electronic control unit 24 will be described. The engine electronic control unit 24 of the second embodiment executes the misfire determination process of FIG. 13 instead of the misfire determination process of FIG. When the misfire determination process is executed, first, data necessary for determination of the misfire is input, such as the crank angle CA from the crank angle sensor 140 and the intake air amount Ga from the vacuum sensor 148 (step S500). Based on the angle CA, the rotational speed N of the crankshaft 26 for each crank angle 30 ° CA is calculated (step S510), and the rotational fluctuation Nxd for each 30 ° CA is calculated as the difference in the rotational speed N for each crank angle 30 ° CA. Calculate (step S520). The difference between the rotational fluctuation Nxd at the ignition timing of each cylinder of the engine 22 and the rotational fluctuation Nxd before the crank angle 90 ° CA, the difference with the rotational fluctuation Nxd before the crank angle 120 ° CA, and the crank angle 360 ° CA. The difference from the previous rotational fluctuation Nxd is calculated as a 90-degree rotational fluctuation difference Nxd90, a 120-degree rotational fluctuation difference Nxd120, a 360-degree rotational fluctuation difference Nxd360 (steps S530 to 550), and the rotation at the ignition timing of each cylinder of the engine 22 The sum of the fluctuation Nxd and the rotation fluctuation Nxd before the crank angle 360 ° CA is calculated as the rotation fluctuation sum Nxdint (step S560). Here, as described above, the rotational fluctuation Nxd is calculated for each crank angle of 30 ° CA. Therefore, the rotational fluctuations Nxd before the crank angles of 90 ° CA, 120 ° CA, and 360 ° CA are respectively three before and four. Rotational fluctuation before and 12 before. In the flowchart in the figure, the rotation fluctuations Nxd (n), Nxd (n-3) Nxd (n-4) Nxd (n-12) are shown to represent this.

  When the rotational fluctuation Nxd, the rotational fluctuation differences Nxd90, Nxd120, Nxd360, and the rotational fluctuation sum Nxdint are calculated in this way, a single misfire pattern in which only one cylinder among the six cylinders misfires is determined using these calculated values. Single misfire determination processing (step S570), continuous misfire determination processing (step S580) for determining a continuous misfire pattern in which two consecutive cylinders among the six cylinders are misfiring, and one combustion cylinder among the six cylinders is sandwiched A misfire determination process (step S590) during which a misfire pattern is determined while two cylinders are misfiring, and an opposing misfire determination process (step S600) for determining an opposing misfire pattern in which two of the six cylinders are misfiring. ) And random misfiring that one of the six cylinders misfires irregularly during one cycle of the engine 22 Perform random misfire determination process (step S610) of constant, single misfire and continuous misfiring, intermittent misfire counter misfire, and terminates the detecting misfire determination process them when the random misfire has occurred. Here, the single misfire determination process is executed according to the flowchart illustrated in FIG. 4, the continuous misfire determination process is executed according to the flowchart illustrated in FIG. 5, and the intermediate misfire determination process is executed according to the flowchart illustrated in FIG. 6. The determination process is executed according to the flowchart of FIG. 14, and the random misfire determination process is executed according to the flowchart of FIG. Among these processes, the single misfire determination process, the continuous misfire determination process, and the intermittent fire determination process are the same as those in FIGS. 4 to 6 although the crank angle used for the calculation of the rotational speed N and the calculation of the rotational fluctuation Nxd is different. Since it is used, further explanation is omitted to avoid redundant description. Hereinafter, the opposing misfire determination process and the random misfire determination process will be described in order with reference to FIGS. 14 and 15.

In the facing misfire determination process, as shown in the flowchart of FIG. 14, first, the first facing as one of the determination values for determining the facing misfire based on the rotation speed N of the crankshaft 26 and the intake air amount Ga. A misfire determination value D1 is set (step S700). Here, like the first single misfire determination value A1, the first opposed misfire determination value D1 tends to decrease as the rotation speed N of the crankshaft 26 increases, and the intake air amount Ga per rotation of the crankshaft 26 increases. The larger the value, the larger the tendency. An example of the relationship between the first counter misfire determination value D1, the rotational speed N of the crankshaft 26, and the intake air amount Ga per revolution of the crankshaft 26 is shown in FIG. When the first counter misfire determination value D1 is thus set, the rotation fluctuation difference Nxd120 is compared with the first counter misfire determination value D1 (step S710). When the rotation fluctuation difference Nxd120 is equal to or less than the first counter misfire determination value D1, It is determined that it has not occurred, and the process is terminated. When the rotational fluctuation difference Nxd120 exceeds the first opposing misfire determination value D1, the exceeded rotational fluctuation difference Nxd120 is determined as the first misfire cylinder (step S720), and the third cylinder after the misfire cylinder is also designated as the misfire cylinder. Is calculated by dividing the rotational fluctuation difference Nxd120 (4) corresponding to the difference by the rotational fluctuation difference Nxd120 (1) of the misfire cylinder (step S730), and the cylinder immediately after the misfire cylinder or two The rotational fluctuation difference Nxd120 (2), the rotational fluctuation difference Nxd120 (3), the rotational fluctuation difference Nxd120 (5), and the rotational fluctuation difference Nxd120 (6) corresponding to the subsequent cylinder are respectively represented as a rotational fluctuation difference Nxd120 (1) of the misfire cylinder. Similarly, the rotational fluctuation difference ratio Njd3, the rotational fluctuation difference ratio Njd4, and the rotational fluctuation difference ratio Njd5 are divided by the sum of the rotational fluctuation difference Nxd120 (4) of the misfire cylinder. Calculating a rotational fluctuation difference ratio Njd6 (step S740~S770). Then, it is determined whether or not the calculated rotational fluctuation difference ratio Njd2 is larger than the second opposing misfire determination value D21 and the reciprocal of the rotational fluctuation difference ratio Njd2 is larger than the second opposing misfire determination value D22 (steps S780 and S790). It is determined whether or not the calculated rotational fluctuation difference ratios Njd3 to Njd6 are less than the third counter misfire determination value D32, the fourth counter misfire determination value D42, the fifth counter misfire determination value D52, and the sixth counter misfire determination value D62, respectively. (Steps S800 to S830). Here, the second opposing misfire determination values D21 and D22 are determined by experiments or the like so as to be a value smaller than the rotational fluctuation difference ratio Njd2 when the opposing misfire occurs or its reciprocal. The third counter misfire determination value D32, the fourth counter misfire determination value D42, the fifth counter misfire determination value D52, and the sixth counter misfire determination value D62 are based on the rotational fluctuation difference ratio Njd3 to Njd6 when the counter misfire occurs. It is determined by experiment etc. so that it may become a small value. When the rotational fluctuation difference ratio Njd2 is less than or equal to the second opposing misfire determination value D21, when the reciprocal of the rotational fluctuation difference ratio Njd2 is less than or equal to the second opposing misfire determination value D22, or any of the rotational fluctuation difference ratios Njd3 to Njd6 When the third counter misfire determination value D32, the fourth counter misfire determination value D42, the fifth counter misfire determination value D52, or the sixth counter misfire determination value D62 is greater than or equal to, it is determined that no counter misfire has occurred and the process is terminated. To do. On the other hand, the rotational fluctuation difference ratio Njd2 is larger than the second opposing misfire determination value D21, and the reciprocal of the rotational fluctuation difference ratio Njd2 is larger than the second opposing misfire determination value D22. Further, any of the rotational fluctuation difference ratios Njd3 to Njd6 corresponds. When it is less than the third counter misfire determination value D32, the fourth counter misfire determination value D42, the fifth counter misfire determination value D52, or the sixth counter misfire determination value D62, it outputs that it is counter misfire (step S840). End the process. FIG. 17 is an explanatory diagram illustrating an example of a temporal change in the rotation variation difference Nxd120 when the counter misfire occurs. As shown in the drawing, when the counter misfire occurs, the rotational fluctuation difference Nxd120 is a pattern that clearly exceeds the first counter misfire determination value D1. In the embodiment, attention is paid to this clearly determinable value, and it is determined that the pattern is opposite misfire using the rotational fluctuation difference ratio Njd2 and its reciprocal, and the rotational fluctuation difference ratios Njd3 to Njd6. Thereby, it is possible to determine the facing misfire more accurately and accurately.

In the random misfire determination process, as shown in the flowchart of FIG. 15, first, a first random value as one of determination values for determining random misfire based on the rotational speed N of the crankshaft 26 and the intake air amount Ga. A misfire determination value E1 is set (step S900). Here, like the first single misfire determination value A1, the first random misfire determination value E1 tends to decrease as the rotation speed N of the crankshaft 26 increases, and the intake air amount Ga per rotation of the crankshaft 26 increases. The larger the value, the larger the tendency. FIG. 18 shows an example of the relationship among the first random misfire determination value E1, the rotation speed N of the crankshaft 26, and the intake air amount Ga per rotation of the crankshaft 26. When the first random misfire determination value E1 is thus set, the rotational fluctuation difference Nxd90 is compared with the first random misfire determination value E1 (step S910). When the rotational fluctuation difference Nxd90 is equal to or less than the first random misfire determination value E1, It is determined that it has not occurred, and the process is terminated. When the rotational fluctuation difference Nxd90 exceeds the first random misfire determination value E1, the exceeded rotational fluctuation difference Nxd90 is determined as the third misfire cylinder (step S920), and the cylinder immediately after or one before the misfire cylinder. The rotation fluctuation difference Nxd90 (4), the rotation fluctuation difference Nxd90 (2), and the rotation fluctuation difference Nxd90 (0) corresponding to the third cylinder are divided by the rotation fluctuation difference Nxd90 (3) of the misfire cylinder, respectively. The difference ratio Nje2, the rotation fluctuation difference ratio Nje3, and the rotation fluctuation difference ratio Nje4 are calculated (steps S930 to S950). Then, whether the calculated rotation fluctuation difference ratio Nje2 is equal to or greater than the second random misfire determination value E21, whether the rotation fluctuation difference ratio Nje3 is less than the third random misfire determination value E32, and whether the rotation fluctuation difference ratio Nje4 is It is determined whether or not it is within the range of the fourth random misfire determination values E41 and E42 (steps S960 to S980). Here, the third random misfire determination value E32 is a rotation fluctuation difference ratio when a random misfire occurs so that the second random misfire determination value E21 is smaller than the rotation fluctuation difference ratio Nje2 when the random misfire occurs. The fourth random misfire determination values E41 and E42 are determined by experiments or the like so that the fourth random misfire determination values E41 and E42 are smaller and larger than the rotational fluctuation difference ratio Nje4 when random misfire occurs. . When the rotational fluctuation difference ratio Nje2 is less than the second random misfire determination value E21, when the rotational fluctuation difference ratio Nje3 is greater than or equal to the third random misfire determination value E32, or when the rotational fluctuation difference ratio Nje4 is the fourth random misfire determination value. When it is outside the range of E41 and E42, it is determined that no random misfire has occurred, and the process is terminated. On the other hand, the rotation fluctuation difference ratio Nje2 is greater than or equal to the second random misfire determination value E21, the rotation fluctuation difference ratio Nje3 is less than the third random misfire determination value E32, and the rotation fluctuation difference ratio Nje4 is the fourth random misfire determination value. If it is within the range of E41 and E42, a message indicating random misfire is output (step S990), and the process is terminated. FIG. 19 is an explanatory diagram illustrating an example of a temporal change in the rotational fluctuation difference Nxd90 when a random misfire occurs. As shown in the figure, when random misfire occurs, the rotational fluctuation difference Nxd90 is a pattern that clearly exceeds the first random misfire determination value E1. In the embodiment, attention is paid to this clearly determinable value, and it is determined that the pattern is a random misfire using the rotational fluctuation difference ratios Nje2 to Nje4. Thereby, random misfire can be determined more appropriately and accurately.

  According to the misfire determination device in the hybrid vehicle 20B of the second embodiment described above, single misfire determination processing, continuous misfire determination processing, intermittent using the rotation fluctuation Nxd, the rotation fluctuation differences Nxd90, Nxd120, Nxd360, and the rotation fluctuation sum Nxdint. By executing the misfire determination process, the counter misfire determination process, and the random misfire determination process, it is possible to determine single misfire, continuous misfire, interim misfire, counter misfire, and random misfire more accurately and accurately. That is, since misfire of the engine 22 is determined using a plurality of different determination logics that take into account the misfire pattern, the misfire of the engine 22 can be determined more accurately and accurately including the misfire pattern.

  Further, according to the misfire determination apparatus in the hybrid vehicle 20 of the second embodiment, the rotational fluctuation that is the fluctuation value of the rotational speed N of the crankshaft 26 at every crank angle of 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22. By using the rotational fluctuation difference Nxd120, which is a difference between Nxd and a crank angle of 120 ° CA, it is possible to determine the counter misfire more clearly and accurately. Moreover, since the determination is made using the first counter misfire determination value D1 according to the rotational speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26, it is possible to determine the counter misfire more appropriately. it can. Further, according to the misfire determination device in the hybrid vehicle 20B of the second embodiment, the ratio of the rotation fluctuation difference Nxd120 (1) exceeding the first counter fire determination value D1 and the rotation fluctuation difference Nxd120 (4) and the inverse thereof, The rotational fluctuation difference Nxd120 (2), the rotational fluctuation difference Nxd120 (3), the rotational fluctuation difference Nxd120 (5), and the rotational fluctuation difference Nxd120 (6) corresponding to the one cylinder after the misfire cylinder and the two cylinders after the misfire cylinder, respectively. The rotational fluctuation difference ratio Njd3, the rotational fluctuation difference ratio Njd4, the rotational fluctuation difference ratio Njd5, and the rotational fluctuation difference ratio divided by the sum of the rotational fluctuation difference Nxd120 (1) of the misfire cylinder and the rotational fluctuation difference Nxd120 (4) of the misfire cylinder. Since the counter misfire pattern is determined using Njd6, the counter misfire can be determined more appropriately. By appropriately determining the counter misfire as described above, the response to the counter misfire can be made more appropriate.

  Furthermore, according to the misfire determination device in the hybrid vehicle 20B of the second embodiment, the rotational fluctuation that is the fluctuation value of the rotational speed N of the crankshaft 26 at every crank angle of 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22. By using the rotational fluctuation difference Nxd90, which is the difference between Nxd and a crank angle of 90 ° CA, it is possible to determine random misfire more clearly and appropriately with high accuracy. Moreover, since the determination is made using the first random misfire determination value E1 corresponding to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26, it is possible to more appropriately determine the random misfire. it can. Further, according to the misfire determination device in the hybrid vehicle 20 of the embodiment, the rotation fluctuation difference that is the next rotation fluctuation difference Nxd90 (4) with respect to the rotation fluctuation difference Nxd90 (3) exceeding the first random misfire determination value E1. The rotation fluctuation difference ratio Nje3, which is the previous rotation fluctuation difference Nxd90 (2) with respect to the ratio Nje2 and the rotation fluctuation difference Nxd90 (3), and the rotation fluctuation difference Nxd90 (0) three times before the rotation fluctuation difference Nxd90 (3). Since random misfire pattern determination is performed using a certain rotational fluctuation difference ratio Nje4, random misfire can be determined more appropriately. By appropriately determining random misfire as described above, it is possible to make the response to random misfire more appropriate.

Of course, according to the misfire determination device in the hybrid vehicle 20B of the second embodiment, similarly to the hybrid vehicle 20 of the first embodiment, single misfire, continuous misfire, and intermediate misfire can be more clearly and accurately determined. it can.

  In the misfire determination device in the hybrid vehicle 20B of the second embodiment, the single misfire determination process, the continuous misfire determination process, the intermediate misfire determination process, the counter change using the rotation fluctuation Nxd, the rotation fluctuation differences Nxd90, Nxd120, Nxd360, and the rotation fluctuation sum Nxdint. By executing the misfire determination process and the random misfire determination process, single misfire, continuous misfire, inter-missing fire, opposing misfire, and random misfire are determined. These misfire determination logics include single misfire determination process and continuous misfire determination process. The misfire is determined by using misfire determination logic that determines other misfire patterns, without being limited to the inter-missing fire determination processing, the opposing misfire determination processing, and the random misfire determination processing. In addition, it is not necessary to determine misfires using all the misfire determination logics in the single misfire determination process, the continuous misfire determination process, the intermediate misfire determination process, the opposing misfire determination process, and the random misfire determination process. This may be used to determine misfire.

  In the misfire determination device in the hybrid vehicle 20B of the second embodiment, the rotational fluctuation Nxd for each crank angle 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22 is calculated as the difference in the rotational speed N for each crank angle 30 ° CA. However, it may be calculated as a difference between the rotational speeds N for different crank angles. Further, the rotational angular acceleration for each crank angle of 120 ° CA corresponding to the ignition timing of each cylinder of the engine 22 may be calculated and used as the rotational fluctuation Nxd.

  In the counter-fire determination process in the misfire determination device of the hybrid vehicle 20B of the second embodiment, the first counter-misfire determination value D1 according to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26. The counter misfire is determined by using the first counter misfire determination value D1 corresponding to only the intake air amount Ga per rotation of the crankshaft 26 regardless of the rotational speed N of the crankshaft 26. The counter misfire may be determined, or the counter misfire may be determined using the first counter misfire determination value D1 corresponding only to the rotation speed N of the crankshaft 26 regardless of the intake air amount Ga per rotation of the crankshaft 26. It is good also as what determines. The single misfire may be determined using the first counter misfire determination value D1 set regardless of the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26.

  In the counter misfire determination process in the misfire determination device of the hybrid vehicle 20B of the second embodiment, the rotation is the ratio of the rotation variation difference Nxd120 (1) and the rotation variation difference Nxd120 (4) exceeding the first counter misfire determination value D1. Fluctuation difference ratio Njd2 and its reciprocal, rotation fluctuation difference Nxd120 (2), rotation fluctuation difference Nxd120 (3), rotation fluctuation difference Nxd120 (5) corresponding to the cylinder immediately after the misfire cylinder and two cylinders after The rotational fluctuation difference ratio Njd3, the rotational fluctuation difference ratio Njd4, and the rotational fluctuation difference obtained by dividing the fluctuation difference Nxd120 (6) by the sum of the rotational fluctuation difference Nxd120 (1) of the misfire cylinder and the rotational fluctuation difference Nxd120 (4) of the misfire cylinder. The counter misfire pattern is determined using the difference ratio Njd5 and the rotational fluctuation difference ratio Njd6. However, the rotational fluctuation difference ratio Njd2 and its reciprocal, the rotational fluctuation difference ratio, are determined. It is not necessary to determine the counter misfire pattern by using all of jd3, rotation fluctuation difference ratio Njd4, rotation fluctuation difference ratio Njd5, and rotation fluctuation difference ratio Njd6. Or any of these may not be used. Further, the counter misfire pattern determination is performed using a rotation fluctuation ratio different from the rotation fluctuation difference ratio Njd2 and its reciprocal, rotation fluctuation difference ratio Njd3, rotation fluctuation difference ratio Njd4, rotation fluctuation difference ratio Njd5, and rotation fluctuation difference ratio Njd6. There is no problem as well.

In the random misfire determination process in the misfire determination apparatus of the hybrid vehicle 20B of the second embodiment, the first random misfire determination value E1 according to the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26. The random misfire is determined by using the first random misfire determination value E1 corresponding to only the intake air amount Ga per rotation of the crankshaft 26 regardless of the rotational speed N of the crankshaft 26. The random misfire may be determined, or the random misfire may be determined using the first random misfire determination value E1 corresponding only to the rotation speed N of the crankshaft 26 regardless of the intake air amount Ga per rotation of the crankshaft 26. It is good also as what determines. The random misfire may be determined using the first random misfire determination value D1 set irrespective of the rotation speed N of the crankshaft 26 and the intake air amount Ga per rotation of the crankshaft 26.

  In the random misfire determination process in the misfire determination device of the hybrid vehicle 20 of the embodiment, the rotational fluctuation that is the next rotational fluctuation difference Nxd90 (4) with respect to the rotational fluctuation difference Nxd90 (3) exceeding the first random misfire judgment value E1. The rotational fluctuation difference ratio Nje3, which is the previous rotational fluctuation difference Nxd90 (2) with respect to the difference ratio Nje2 and the rotational fluctuation difference Nxd90 (3), and the three previous rotational fluctuation differences Nxd90 (0) with respect to the rotational fluctuation difference Nxd90 (3). The random misfire pattern determination is performed using the rotational fluctuation difference ratio Nje4. However, the random misfire pattern determination is performed using all of the rotational fluctuation difference ratio Nje2, the rotational fluctuation difference ratio Nje3, and the rotational fluctuation difference ratio Nje4. It is not necessary to perform any of these, and any of these may be used to perform random misfire pattern determination. It may be as not using even a deviation. Alternatively, the random misfire pattern determination may be performed using a rotation fluctuation difference ratio different from the rotation fluctuation difference ratio Nje2, the rotation fluctuation difference ratio Nje3, and the rotation fluctuation difference ratio Nje4.

  In the hybrid vehicle 20B of the second embodiment, similarly to the hybrid vehicle 20 of the first embodiment, modified examples of the single misfire determination process, the continuous misfire determination process, and the intermediate loss fire determination process can be applied.

  In the misfire determination apparatus in the hybrid vehicles 20 and 20B of the first embodiment and the second embodiment, the misfire of the in-line 6-cylinder engine 22 is determined. However, any engine can be used as long as it is a multi-cylinder engine. Can be applied.

  In the first and second embodiments, the misfire determination device for the engine 22 of the hybrid vehicle 20 including the engine 22, the planetary gear mechanism 30, and the two motors MG1 and MG2 has been described. You may apply as a misfire determination apparatus of the mounted engine, and may apply as a misfire determination apparatus mounted in motor vehicles other than a hybrid vehicle. Moreover, you may apply as a misfire determination apparatus of the internal combustion engine incorporated in the moving bodies other than a motor vehicle, or the installation which does not move.

  In 1st Example and 2nd Example, although demonstrated as a form as a misfire determination apparatus of the engine 22 mounted in the hybrid vehicles 20 and 20B, it applies as a form of the misfire determination method of the engine 22 of the hybrid cars 20 and 20B Of course, you may do.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in manufacturing industries such as internal combustion engines and automobiles equipped with the same.

  20, 20B Hybrid vehicle, 22 engine, 24 engine electronic control unit, 24a CPU, 24b ROM, 24c RAM, 26 crankshaft, 30 planetary gear mechanism, 40 motor electronic control unit, 41, 42 inverter, 50 battery, 69a 69b Drive wheel, 70 Hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 Vehicle speed sensor, 122 Air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve, 130 Spark plug, 132 Piston, 134 Purification device, 1 6 throttle motor, 138 an ignition coil, 140 crank angle sensor, 142 temperature sensor, 144 a cam position sensor, 146 a throttle valve position sensor, 148 vacuum sensor, 150 a variable valve timing mechanism.

Claims (32)

A misfire determination device for an internal combustion engine that determines misfire in a multi-cylinder internal combustion engine,
Rotational position detecting means for detecting the rotational position of the crankshaft of the internal combustion engine;
Rotation fluctuation calculating means for sequentially calculating the rotation fluctuation of the internal combustion engine at a crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine based on the detected rotation position;
Misfire determination means for determining misfire of the internal combustion engine using determination logic of different misfire patterns based on the sequentially calculated rotation fluctuations;
A misfire determination apparatus for an internal combustion engine.   The misfire determination means includes a single misfire determination logic for determining a single misfire pattern in which only one cylinder among a plurality of cylinders is misfired, and a continuous misfire pattern in which two consecutive cylinders among the plurality of cylinders are misfired. The determination logic includes a plurality of determination logics including any one of a continuous misfire determination logic for determining and a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring. 2. The misfire determination apparatus for an internal combustion engine according to claim 1, which is means for determining misfire of the internal combustion engine.   The single misfire determination logic is configured such that only one rotation fluctuation among the rotation fluctuations sequentially calculated by the rotation fluctuation calculation means for one cycle of the internal combustion engine is equal to or greater than a predetermined value for single misfire and 3. The logic for determining that a single misfire occurs when a ratio of a target rotational fluctuation that is a rotational fluctuation that is equal to or greater than a value and a rotational fluctuation other than the target rotational fluctuation is within a predetermined ratio range for single misfire. A misfire determination device for an internal combustion engine.   The other rotational fluctuation includes any one of a rotational fluctuation three times before the target rotational fluctuation, a rotational fluctuation immediately before the target rotational fluctuation, and a rotational fluctuation immediately after the target rotational fluctuation. The misfire determination apparatus for an internal combustion engine according to claim 3, wherein: A misfire determination device for an internal combustion engine according to claim 3 or 4,
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
First single misfire predetermined value adjusting means for adjusting the single misfire predetermined value so as to decrease as the detected rotational speed of the internal combustion engine increases;
A misfire determination apparatus for an internal combustion engine. A misfire determination device for an internal combustion engine according to any one of claims 3 to 5,
Intake air amount detection means for detecting the intake air amount of the internal combustion engine;
A second single unit that calculates the cycle intake air amount per cycle of the internal combustion engine from the detected intake air amount and adjusts the single misfire predetermined value so as to increase as the calculated cycle intake air amount increases. A predetermined value adjusting means for misfire;
A misfire determination apparatus for an internal combustion engine.   The continuous misfire determination logic calculates a rotational fluctuation difference that is a difference between the sequentially calculated rotational fluctuation and a rotational fluctuation that is calculated 360 degrees before the rotational fluctuation, and in one cycle of the internal combustion engine. 7. A misfire determination apparatus for an internal combustion engine according to claim 2, wherein the misfire determination apparatus is a logic for determining a continuous misfire when only one rotation fluctuation difference among the calculated rotation fluctuation differences exceeds a predetermined value for continuous misfire. .   In the continuous misfire determination logic, a ratio between a target rotational fluctuation difference that is a rotational fluctuation difference that is equal to or greater than a predetermined value for continuous misfire and a rotational fluctuation difference other than the target rotational fluctuation difference is a predetermined ratio range for continuous misfire. 8. The misfire determination apparatus for an internal combustion engine according to claim 7, wherein the logic is to determine that the misfire is sometimes continuous.   The other rotational fluctuation difference includes a rotational fluctuation difference three times before the target rotational fluctuation difference, a rotational fluctuation difference immediately before the target rotational fluctuation difference, and a rotational fluctuation difference immediately after the target rotational fluctuation difference. The misfire determination apparatus for an internal combustion engine according to claim 8, comprising any one of the following. A misfire determination device for an internal combustion engine according to any one of claims 7 to 9,
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
First continuous misfire predetermined value adjusting means for adjusting the predetermined value for continuous misfire so as to decrease as the detected rotational speed of the internal combustion engine increases;
A misfire determination apparatus for an internal combustion engine. A misfire determination device for an internal combustion engine according to any one of claims 7 to 10,
Intake air amount detection means for detecting the intake air amount of the internal combustion engine;
A second continuous value for calculating the predetermined value for continuous misfire so as to calculate a cycle intake air amount per cycle of the internal combustion engine from the detected intake air amount and to increase as the calculated cycle intake air amount increases. A predetermined value adjusting means for misfire;
A misfire determination apparatus for an internal combustion engine.   The intermediate fire determining logic calculates a rotational fluctuation sum that is a sum of the sequentially calculated rotational fluctuation and a rotational fluctuation that is calculated 360 degrees before the rotational fluctuation, and in one cycle of the internal combustion engine The misfire determination device for an internal combustion engine according to any one of claims 2 to 11, wherein the misfire determination logic is a logic for determining a short misfire when only one of the rotational fluctuation sums calculated with respect to the sum of the rotational fluctuations exceeds a predetermined value for the short misfire. .   The intermediate deletion fire determination logic is configured such that a ratio between a target rotational fluctuation sum that is a rotational fluctuation sum equal to or greater than a predetermined value for the intermediate deletion fire and a rotational rotational sum other than the target rotational fluctuation sum is within a predetermined ratio range for the intermediate deletion fire. 13. The misfire determination apparatus for an internal combustion engine according to claim 12, wherein the logic is to determine that the fire is sometimes short.   14. The misfire determination apparatus for an internal combustion engine according to claim 13, wherein the other rotational fluctuation sum is a rotational fluctuation sum immediately preceding the target rotational fluctuation sum. The misfire determination device for an internal combustion engine according to any one of claims 12 to 14,
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
A first predetermined value adjustment means for a first flashing fire that adjusts the predetermined value for the first flashing fire in a tendency to decrease as the detected rotational speed of the internal combustion engine increases;
A misfire determination apparatus for an internal combustion engine. A misfire determination device for an internal combustion engine according to any one of claims 12 to 15,
Intake air amount detection means for detecting the intake air amount of the internal combustion engine;
A second intermittent operation that calculates a cycle intake air amount per cycle of the internal combustion engine from the detected intake air amount and adjusts the predetermined value for the intermission error so as to increase as the calculated cycle intake air amount increases. A predetermined value adjusting means for misfire;
A misfire determination apparatus for an internal combustion engine. A misfire determination device for an internal combustion engine according to claim 2,
The internal combustion engine is an even cylinder,
The misfire determination means is configured to determine the single misfire determination logic, the continuous misfire determination logic, the intermediate misfire determination logic, and an opposing misfire pattern in which two opposing cylinders among a plurality of cylinders are misfiring. A plurality of determinations including determination logic and random misfire determination logic for determining a random misfire pattern in which any one of a plurality of cylinders misfires irregularly during one cycle of the internal combustion engine. A misfire determination apparatus for an internal combustion engine, which is means for determining misfire of the internal combustion engine using logic.   The counter misfire determination logic calculates a rotation fluctuation difference that is a difference between the rotation fluctuation calculated sequentially and the rotation fluctuation calculated 120 degrees before the rotation fluctuation, and is performed in one cycle of the internal combustion engine. 18. The misfire determination device for an internal combustion engine according to claim 17, wherein the misfire determination device for an internal combustion engine is a logic for determining an opposite misfire when two of the rotation fluctuation differences calculated for the difference become equal to or greater than a predetermined value for opposite misfire.   The counter misfire determination logic is configured such that a ratio of two target rotation fluctuation differences, which are two rotation fluctuation differences that are equal to or greater than the predetermined value for counter misfire, is within a first counter misfire predetermined ratio range and the two target rotation fluctuation differences. 19. The internal combustion engine according to claim 18, wherein the internal combustion engine is configured to determine that it is counter misfire when a ratio between a sum of the two and a difference in rotation fluctuation other than the two target rotation fluctuation differences falls within a predetermined ratio range for second counter misfire. Misfire detection device.   The other rotational fluctuation difference includes any one of a rotational fluctuation difference one previous to the two target rotational fluctuation differences and a rotational fluctuation difference two previous to the two target rotational fluctuation differences. The misfire determination device for an internal combustion engine according to claim 19. A misfire determination device for an internal combustion engine according to any one of claims 18 to 20,
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
First opposed misfire predetermined value adjusting means for adjusting the predetermined value for opposed misfire so as to decrease as the detected rotational speed of the internal combustion engine increases;
A misfire determination apparatus for an internal combustion engine. A misfire determination device for an internal combustion engine according to any one of claims 18 to 21,
Intake air amount detection means for detecting the intake air amount of the internal combustion engine;
A second counter which calculates the cycle intake air amount per cycle of the internal combustion engine from the detected intake air amount and adjusts the predetermined value for counter misfire so as to increase as the calculated cycle intake air amount increases. A predetermined value adjusting means for misfire;
A misfire determination apparatus for an internal combustion engine.   The random misfire determination logic calculates a rotation fluctuation difference that is a difference between the rotation fluctuation calculated sequentially and a rotation fluctuation calculated 90 degrees before the rotation fluctuation, and in one cycle of the internal combustion engine 23. The misfire determination apparatus for an internal combustion engine according to claim 17, wherein the misfire determination apparatus is an internal combustion engine misfire determination logic that determines random misfire when one of the rotation fluctuation differences calculated for the rotation fluctuation difference exceeds a predetermined value for random misfire.   In the random misfire determination logic, a ratio between a target rotational fluctuation difference that is a rotational fluctuation difference that is equal to or larger than the random misfire predetermined value and a rotational fluctuation difference other than the target rotational fluctuation difference is within a predetermined range for random misfire. 24. The misfire determination device for an internal combustion engine according to claim 23, wherein the logic is sometimes determined to be a random misfire.   The other rotational fluctuation difference includes a rotational fluctuation difference immediately before the target rotational fluctuation difference, a rotational fluctuation difference immediately after the target rotational fluctuation difference, and a rotational fluctuation difference three times after the target rotational fluctuation difference. 25. The misfire determination device for an internal combustion engine according to claim 24, comprising any one of them. 26. A misfire determination device for an internal combustion engine according to claim 23, wherein:
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
First random misfire predetermined value adjusting means for adjusting the random misfire predetermined value so as to decrease as the detected rotational speed of the internal combustion engine increases;
A misfire determination apparatus for an internal combustion engine. 27. A misfire determination device for an internal combustion engine according to any one of claims 23 to 26, wherein:
Intake air amount detection means for detecting the intake air amount of the internal combustion engine;
A second random for calculating the predetermined value for random misfire so as to calculate a cycle intake air amount per cycle of the internal combustion engine from the detected intake air amount and to increase as the calculated cycle intake air amount increases. A predetermined value adjusting means for misfire;
A misfire determination apparatus for an internal combustion engine.   The rotation fluctuation calculating means calculates a rotation angular velocity for each predetermined crank angle of the crankshaft of the internal combustion engine and a rotation angular velocity corresponding to the ignition timing of each cylinder of the internal combustion engine and a rotation angle velocity before the predetermined crank angle from the rotation angular velocity. 28. The misfire determination device for an internal combustion engine according to claim 1, which is means for calculating a rotational fluctuation based on a difference in rotational angular velocity.   28. The misfire determination device for an internal combustion engine according to any one of claims 1 to 27, wherein the rotation fluctuation calculating means is a means for calculating a rotation angular acceleration corresponding to an ignition timing of each cylinder of the internal combustion engine as the rotation fluctuation.   30. The misfire determination device for an internal combustion engine according to any one of claims 1 to 29, wherein the internal combustion engine is mounted on a hybrid vehicle that is operated by setting an operation point of the internal combustion engine independently of a traveling state. An internal combustion engine misfire determination method for determining misfire in a multi-cylinder internal combustion engine,
Based on the rotational position of the crankshaft of the internal combustion engine, sequentially calculating the rotational fluctuation of the internal combustion engine at a crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine,
Single misfire determination logic for determining a single misfire pattern in which only one cylinder of a plurality of cylinders is misfired based on the sequentially calculated rotation fluctuation, and two consecutive cylinders of the plurality of cylinders are misfired. A plurality of determination logics including any one of a continuous misfire determination logic for determining a continuous misfire pattern and a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring. A misfire determination method for an internal combustion engine that determines misfire of the internal combustion engine using An internal combustion engine misfire determination method for determining misfire in an internal combustion engine of a plurality of cylinders that is an even number,
Based on the rotational position of the crankshaft of the internal combustion engine, sequentially calculating the rotational fluctuation of the internal combustion engine at a crank angle corresponding to the ignition timing of each cylinder of the internal combustion engine,
Single misfire determination logic for determining a single misfire pattern in which only one cylinder of a plurality of cylinders is misfired based on the sequentially calculated rotation fluctuation, and two consecutive cylinders of the plurality of cylinders are misfired. A continuous misfire determination logic for determining a continuous misfire pattern, a deletion fire determination logic for determining a deletion fire pattern while two cylinders sandwiching one combustion cylinder among a plurality of cylinders are misfiring, and a plurality of cylinders facing each other A counter misfire determination logic for determining a counter misfire pattern in which two cylinders are misfiring, and a random misfire pattern in which any one of a plurality of cylinders misfires irregularly during one cycle of the internal combustion engine. A misfire determination method for an internal combustion engine that determines misfire of the internal combustion engine using a plurality of determination logics including any of random misfire determination logic for determination.

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