JP7413000B2 - Internal combustion engine system and misfire detection method - Google Patents

Description

The present invention relates to an internal combustion engine system and a misfire detection method.

As a technique for detecting a misfire in an internal combustion engine, a technique for detecting a misfire based on rotational fluctuations of the internal combustion engine is known. In this technology for detecting misfires in internal combustion engines, a ring gear is installed on the crankshaft, and rotational fluctuations are detected by detecting an uneven pattern on the outer periphery of the ring gear.

Japanese Patent Application Publication No. 4-370344

However, in the conventional technology as described above, it is necessary to install a ring gear on the crankshaft, so there is a problem that the size of the internal combustion engine becomes large.

The present invention was made to solve the above problems, and its purpose is to provide an internal combustion engine system and a misfire detection method that can downsize the internal combustion engine.

In order to solve the above problem, one aspect of the present invention includes an internal combustion engine having a crankshaft, and under a first condition, applying rotational force to the crankshaft via a rotor directly connected to the crankshaft, Under a second condition different from the first condition, a rotating electrical machine that generates electricity by receiving the rotational force of the crankshaft, and a rotor position that detects the rotational position of the rotor and indicates the rotational position of the rotor. a rotor position detection unit that outputs information; and a drive that controls a drive circuit that rotationally drives the rotor of the rotating electrical machine based on the rotor position information output by the rotor position detection unit under the first condition. a control unit; and a misfire detection unit that detects occurrence of a misfire in the internal combustion engine based on the rotation speed of the rotor or the rotation period of the rotor , and the rotating electrical machine includes a stator around which a coil is wound. and the rotor, in which a plurality of magnets are arranged with alternating magnetic poles along the inner peripheral surface, and the rotor is rotatably disposed around the stator, and the rotor position detection section is built in the rotating electric machine. a plurality of magnetic sensors arranged opposite to the rotor to detect the polarity of the opposing magnets; and a plurality of magnetic sensors configured to detect the rotor position information based on output signals output from the magnetic sensors. and a rotor position determination unit that outputs an output, and the misfire detection unit detects that a misfire has occurred in the internal combustion engine based on the rotation speed of the rotor or the rotation period of the rotor based on the output signal of the magnetic sensor. This is an internal combustion engine system characterized by detecting .

Further, in one aspect of the present invention, the internal combustion engine system described above includes a timer that measures and outputs an interval at which the output of the magnetic sensor is switched based on an output signal of the magnetic sensor , and the misfire detection unit The occurrence of a misfire in the internal combustion engine may be detected based on the output result of the timer corresponding to the rotation speed of the rotor or the rotation period of the rotor .

Further, in one aspect of the present invention, in the internal combustion engine system described above, the misfire detection unit detects when the output result of the timer corresponding to the rotation speed of the rotor or the rotation period of the rotor becomes equal to or higher than a predetermined threshold value. Additionally, it may be determined that a misfire in the internal combustion engine has occurred.

Further, in one aspect of the present invention, the internal combustion engine system described above includes an output storage section that stores a plurality of output results most recently outputted by the timer, and the misfire detection section stores the output results of the output storage section . Among the plurality of output results corresponding to the rotational speed of the rotor or the rotational period of the rotor , if a result exceeding a predetermined threshold value occurs a predetermined number of times or more, it is determined that a misfire in the internal combustion engine has occurred. You may also do so.

Further, in one aspect of the present invention, the internal combustion engine system described above includes an output storage section that stores a plurality of output results most recently outputted by the timer, and the misfire detection section stores the output results of the output storage section . It may be determined that a misfire in the internal combustion engine has occurred when an average value of the plurality of output results corresponding to the rotational speed of the rotor or the rotational period of the rotor is equal to or higher than a predetermined threshold value.

Further, in one aspect of the present invention, in the above internal combustion engine system, the number of slots, which is the number of the coils, is 18, and the number of magnetic poles, which is the number of the magnets, is 12, and the rotating electrical machine is The motor may function as a three-phase brushless motor, and the plurality of magnetic sensors may detect and output polarities of the magnets corresponding to the three phases.

Further, one aspect of the present invention provides an internal combustion engine having a crankshaft, and applying a rotational force to the crankshaft via a rotor directly connected to the crankshaft under a first condition, A misfire detection method for an internal combustion engine system comprising: a rotating electric machine that generates electricity by receiving the rotational force of the crankshaft ; a rotor position detection section; a drive control section; and a misfire detection section, under a second condition different from the above. The rotating electric machine includes a stator around which a coil is wound, and a rotor in which a plurality of magnets are arranged along an inner circumferential surface with alternating magnetic poles, and is rotatably arranged around the stator. and the rotor position detection unit includes a plurality of magnetic sensors built into the rotating electrical machine, which are arranged to face the rotor and detect polarities of the opposing magnets; a rotor position determination section that outputs rotor position information based on an output signal output from a magnetic sensor, the rotor position detection section detecting the rotational position of the rotor, and the rotor position determination section that detects the rotational position of the rotor . a rotor position detection step of outputting rotor position information; and the drive control unit detects the rotor of the rotating electrical machine based on the rotor position information outputted by the rotor position detection step under the first condition. a drive control step of controlling a drive circuit for rotationally driving; and the misfire detection section detecting that a misfire in the internal combustion engine has occurred based on the rotation speed of the rotor or the rotation period of the rotor based on the rotor position information. A misfire detection method is characterized in that it includes a misfire detection step of detecting a misfire.

According to the present invention, the configuration of an internal combustion engine can be simplified and the internal combustion engine can be downsized.

FIG. 1 is a block diagram showing an example of an internal combustion engine system according to a first embodiment. It is a sectional view showing an example of composition of a starter generator in a 1st embodiment. FIG. 3 is a plan view showing the positional relationship between a magnet and a stator in the first embodiment. FIG. 3 is a diagram showing the positional relationship between a magnet and a Hall element in the first embodiment. It is a figure showing an example of the output signal of the Hall element in a 1st embodiment. 3 is a flowchart illustrating an example of the operation of the internal combustion engine system according to the first embodiment. 7 is a flowchart illustrating an example of the operation of the internal combustion engine system according to the second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An internal combustion engine system and a misfire detection method according to an embodiment of the present invention will be described below with reference to the drawings.

[First embodiment]
FIG. 1 is a block diagram showing an example of an internal combustion engine system 1 according to a first embodiment.
As shown in FIG. 1, the internal combustion engine system 1 includes an internal combustion engine 2, a crankshaft 3, a starter generator 4, a battery 5, a drive circuit 40, and a control section 50.

The internal combustion engine 2 is, for example, an engine that drives a two-wheeled vehicle or a car. The internal combustion engine 2 has a crankshaft 3 as a rotating shaft, and applies rotational force to the crankshaft 3.
The crankshaft 3 is directly connected to a rotor 10, which will be described later.

The starter generator 4 (an example of a rotating electrical machine) has the functions of both a starter motor for the internal combustion engine 2 and an alternating current generator that generates electricity from the rotation of the internal combustion engine 2. When starting the internal combustion engine 2 (under a first condition), the starter generator 4 applies rotational force to the crankshaft 3 via a rotor 10 directly connected to the crankshaft 3 to start the internal combustion engine 2. . Furthermore, when the internal combustion engine 2 is in operation (under the second condition), the starter generator 4 receives the rotational force of the crankshaft 3 and generates electricity. The starter generator 4 is, for example, an outer rotor type three-phase brushless motor type.
Further, the starter generator 4 includes a rotor 10 and a stator 20.

The rotor 10 (an example of a rotor) is directly connected to the crankshaft 3 and rotatably arranged around the stator 20. Further, the rotor 10 is formed in a cylindrical shape with a bottom, and a plurality of magnets 11 are arranged along the inner peripheral surface with alternating magnetic poles.

The stator 20 is arranged inside the rotor 10 and includes a plurality of coils 21 and a plurality of Hall elements 31.
Here, examples of arrangement of each component of the rotor 10 and the stator 20 will be described with reference to FIGS. 2 to 4.

FIG. 2 is a sectional view showing an example of the configuration of the starter generator 4 in this embodiment.
In the following description, the direction of the rotational axis of the rotor 10 is simply referred to as the axial direction, the radial direction of the stator 20 orthogonal to the rotational axis direction is simply referred to as the radial direction, and the rotational direction of the rotor 10 is simply referred to as the rotational direction or the circumferential direction. It is called direction.

As shown in FIG. 2, a magnet 11 is arranged inside a rotor 10 that is directly connected to the crankshaft 3. Further, the stator 20 is arranged inside the rotor 10 so that the coil 21 faces the magnet 11.

A sensor case 22 formed in an arc shape is disposed in the stator 20 , and the Hall element 31 is fixed by the sensor case 22 at a position facing the magnet 11 .

Moreover, FIG. 3 is a plan view showing the positional relationship between the magnet 11 and the stator 20 in this embodiment.
As shown in FIG. 3, the stator 20 includes a stator core 23 made of laminated electromagnetic steel plates, and a coil 21 that is a three-phase winding wound around the stator core 23. The stator core 23 has a main body portion 23a formed in an annular shape, and a plurality of teeth portions 23b projecting radially outward from the outer peripheral surface of the main body portion. Each tooth portion 23b is formed into a substantially T-shape when viewed from above in the axial direction.

Each tooth portion 23b is assigned to three phases (U phase, V phase, W phase). Further, the coil 21 is wound around each tooth portion 23b.
As shown in FIG. 3, the starter generator 4 in this embodiment has 12 poles and 18 slots, and the number of coils 21 and teeth portions 23b is 18. The 18 coils 21 and teeth portions 23b are assigned in the order of U phase, V phase, W phase, . . . in the circumferential direction. In the following description, the U-phase coil 21 will be referred to as a U-phase coil 21U, the V-phase coil 21 will be referred to as a V-phase coil 21V, and the W-phase coil 21 will be referred to as a W-phase coil 21W.

On the inner circumferential surface of the rotor 10, a plurality of magnets 11 are arranged at equal intervals in the circumferential direction, and the magnets 11 are alternately magnetized with north and south poles. That is, on the inner peripheral surface of the rotor 10, N-pole magnets (hereinafter referred to as "N-pole magnets") 11N and S-pole magnets (hereinafter referred to as "S-pole magnets") 11S are alternately arranged in the circumferential direction. They are installed at equal intervals along the line.

Here, the entire radially inner surface of the N-pole magnet 11N is magnetized to the N-pole, and the entire radially inner surface of the S-pole magnet 11S is magnetized to the S-pole.
In this embodiment, the number of magnetic poles, which is the number of magnets 11, is twelve.

Further, three Hall elements 31 are arranged by the sensor case 22 to face the magnets 11 of the rotor 10, as shown in FIG. The three Hall elements 31 are arranged at intervals of 120 electrical degrees.
FIG. 4 is a diagram showing the positional relationship between the magnet 11 and the Hall element 31 in this embodiment.

In this embodiment, the Hall element 31 for the V phase is referred to as the Hall element 31-1, the Hall element 31 for the U phase is referred to as the Hall element 31-2, and the Hall element 31 for the W phase is referred to as the Hall element 31. It is called -3. Moreover, when referring to an arbitrary Hall element built into the starter generator 4, it will be described as a Hall element 31.

The Hall element 31 (an example of a magnetic sensor) detects and outputs the polarity of the opposing magnet 11. The Hall element 31 outputs, for example, the polarity of the magnet 11 as a binary signal. The Hall element 31-1 outputs an output signal for detecting the rotational position of the rotor 10 for V-phase, and the Hall element 31-2 outputs an output signal for detecting the rotational position of the rotor 10 for U-phase. Output. Further, the Hall element 31-3 outputs an output signal for detecting the rotational position of the W-phase rotor 10. Details of the output signals of each Hall element 31 will be described later with reference to FIG.

Returning to the description of FIG. 1, the battery 5 is, for example, a lead acid battery or a lithium ion battery, and supplies electric power when the starter generator 4 is driven as a three-phase brushless motor (under the first condition). Further, when the starter generator 4 is operated as a generator (under the second condition), the battery 5 is charged with a portion of the generated power.

The drive circuit 40 is, for example, an inverter circuit, which converts direct current supplied from the battery 5 into alternating current and sends drive signals to each of the coils 21 (U-phase coil 21U, V-phase coil 21V, W-phase coil 21W). and rotates the rotor 10. The drive circuit 40 outputs drive signals for each phase based on control signals output by a drive control section 51 of a control section 50, which will be described later. In this embodiment, the starter generator 4 is a three-phase brushless motor, and the drive circuit 40 outputs a 120-degree energization drive signal as the U-phase, V-phase, and W-phase drive signals.
Further, the drive circuit 40 rectifies the AC power generated by the starter generator 4 and charges the battery 5.

The control unit 50 is, for example, a processor including a CPU (Central Processing Unit), and controls the starter generator 4 in an integrated manner. The control section 50 includes a rotor position determination section 32 , a drive control section 51 , a timer 52 , an output storage section 53 , and a misfire determination section 54 .
Note that in this embodiment, the Hall elements 31 (31-1 to 31-3) and the rotor position determining section 32 correspond to the rotor position detecting section 30. That is, the rotor position detection section 30 includes a Hall element 31 (31-1 to 31-3) and a rotor position determination section 32.

The rotor position detection unit 30 detects the rotational position of the rotor 10 and outputs rotor position information indicating the rotational position of the rotor 10. The rotor position detection section 30 detects the rotational position of the rotor 10 based on the output signals of the plurality of Hall elements 31 (31-1 to 31-3). Here, the output signals of the Hall elements 31 (31-1 to 31-3) will be explained with reference to FIG.

FIG. 5 is a diagram showing an example of an output signal of the Hall element 31 in this embodiment.
In FIG. 5, waveform W1 is a U-phase detection signal and represents the output signal of Hall element 31-1, and waveform W2 is a V-phase detection signal and represents the output signal of Hall element 31-2. Further, waveform W3 is a W-phase detection signal, and indicates the output signal of the Hall element 31-3. Moreover, the horizontal axis indicates time.

The U-phase detection signal, V-phase detection signal, and W-phase detection signal are rectangular wave signals whose phases are shifted by 120 degrees (120 degrees in electrical angle), and the control signal for the drive circuit 40 is determined based on the switching timing of each signal. It is now possible to generate.
Further, for example, the interval TR1 between the fall of the W-phase detection signal at time T1 and the rise of the V-phase detection signal at time T2 indicates a mechanical angle of 10 degrees of the rotor 10, and the V-phase detection signal at time T2 The interval TR2 between the rise of the W-phase detection signal at time T3 and the rise of the W-phase detection signal at time T3 indicates the mechanical angle of the rotor 10 of 20 degrees. In this way, by detecting the switching intervals of the U-phase detection signal, the V-phase detection signal, and the W-phase detection signal, it is possible to measure the rotational speed in mechanical angle.

Returning to the explanation of FIG. 1 again, the rotor position determination unit 32 detects position information of the rotor 10 based on the output signals of the Hall elements 31 (31-1 to 31-3), and indicates the rotational position of the rotor 10. Output rotor position information. When starting the internal combustion engine 2, the rotor position determination unit 32 generates, for example, a timing signal for performing 120-degree energization control as rotor position information based on the output signal of the Hall element 31, and generates the timing signal as rotor position information. is output to the drive control section 51.

Further, the rotor position determination unit 32 is configured to measure the time interval at which the output pattern output by the Hall element 31 changes, based on the output signal of the Hall element 31, for example, when the internal combustion engine 2 is in operation. A control signal for the timer 52 is generated, and the control signal is output to the timer 52.
In this way, the rotor position determination unit 32 performs the above-described processing when starting the internal combustion engine 2 (first condition) and when the internal combustion engine 2 is in operation (second condition). Switch and execute. That is, the rotor position determination unit 32 generates different rotor position information when starting the internal combustion engine 2 (first condition) and when the internal combustion engine 2 is operating (second condition). Then, the drive control unit 51 and the timer 52 switch and output the output.

The drive control unit 51 controls the drive circuit 40 that rotationally drives the rotor 10 of the starter generator 4 based on the rotor position information output by the rotor position detection unit 30. The drive control unit 51 outputs, for example, a control signal for 120-degree energization control to the drive circuit 40 using the timing signal output from the rotor position detection unit 30 as rotor position information.

Note that in this embodiment, the timer 52, the output storage section 53, and the misfire determination section 54 correspond to the misfire detection section 60. That is, the misfire detection section 60 includes a timer 52, an output storage section 53, and a misfire determination section 54.

The timer 52 measures the time interval at which the output pattern output by the Hall element 31 changes, and outputs the time to the misfire determination section 54 . That is, the timer 52 uses the control signal of the timer 52 outputted from the rotor position detection section 30 as rotor position information, and measures the time interval at which the output pattern switches, such as the interval TR1 in FIG. 5 described above. The timer 52 outputs the measurement result of the interval at which the output pattern changes to the misfire determination section 54.

The misfire determination unit 54 detects that a misfire has occurred in the internal combustion engine 2 based on the amount of change per unit time in the rotational position of the rotor 10 based on the rotor position information output by the rotor position detection unit 30. The misfire determining unit 54 detects that a misfire has occurred in the internal combustion engine 2, based on, for example, a change in the switching interval output by the timer 52. Here, the switching interval time, which is the output result of the timer 52, corresponds to the rotational speed of the rotor 10 (that is, the amount of change in the rotational position of the rotor 10 per unit time) or the rotation period of the rotor 10. The misfire determination unit 54 determines that a misfire in the internal combustion engine 2 has occurred when the output value (output result) of the timer 52 exceeds a predetermined threshold value.

Further, the misfire determination unit 54 sequentially stores the output results of the timer 52 in the output storage unit 53. The misfire determining unit 54 determines that a misfire in the internal combustion engine 2 has occurred, for example, when output results exceeding a predetermined threshold value occur a predetermined number of times or more among the plurality of output results stored in the output storage unit 53. do.

As described above, the output storage unit 53 stores a plurality of output results most recently output by the timer 52.
Note that when the misfire determination unit 54 determines that a misfire has occurred in the internal combustion engine 2, it outputs warning information indicating that a misfire has occurred in the internal combustion engine 2, and lights up a warning light, for example.

Next, the operation of the internal combustion engine system 1 according to this embodiment will be explained with reference to the drawings.
FIG. 6 is a flowchart showing an example of the operation of the internal combustion engine system 1 according to the first embodiment.

As shown in FIG. 6, the control unit 50 of the internal combustion engine system 1 first determines whether or not to drive the motor (step S101). That is, the rotor position determination section 32 of the control section 50 (rotor position detection section 30) determines whether or not the starter generator 4 is driven as a motor. When driving the starter generator 4 as a motor (step S101: YES), the rotor position determination unit 32 advances the process to step S107. Further, when the starter generator 4 is not driven as a motor (step S101: NO), the rotor position determination unit 32 advances the process to step S102.

Note that the case where the starter generator 4 is not driven as a motor corresponds to, for example, the case where the internal combustion engine 2 is operating and the starter generator 4 is used as a generator.

In step S102, the rotor position determination unit 32 detects a change in the output pattern of the Hall element 31. The rotor position determination unit 32 measures the time interval at which the output pattern output by the Hall elements 31 switches, based on the output signals of the three-phase Hall elements 31 (31-1 to 31-3) as shown in FIG. A control signal for the timer 52 is generated.

Next, the rotor position determining unit 32 switches the timer 52 to measure the interval (step S103). That is, the rotor position determination unit 32 outputs to the timer 52 a control signal for the timer 52 for measuring the interval at which the output pattern is switched as described above.

Next, the misfire determination section 54 of the control section 50 stores the output result of the timer 52 in the output storage section 53 (step S104). The misfire determination unit 54 sequentially stores the switching interval time, which is the output result output from the timer 52, in the output storage unit 53. As a result, the output storage unit 53 stores a plurality of output results most recently output by the timer 52.

Next, the misfire determination unit 54 determines whether or not the number of times that the most recent output result of the timer 52 has exceeded a predetermined threshold value is equal to or greater than a predetermined number of times (step S105). That is, the misfire determination unit 54 refers to the output results of the timer 52 stored in the output storage unit 53, and determines whether or not any of the most recent output results of the timer 52 exceeds a predetermined threshold value. , the number of times the output result exceeds a predetermined threshold is counted. The misfire determination unit 54 determines whether the number of times the output result exceeds the predetermined threshold value is equal to or greater than the predetermined number of times.

If the number of output results exceeding a predetermined threshold is equal to or greater than a predetermined number (step S105: YES), the misfire determination unit 54 advances the process to step S106. Further, if the number of output results exceeding a predetermined threshold value is less than the predetermined number of times (step S105: NO), the misfire determination unit 54 returns the process to step S101.

In step S106, the misfire determining unit 54 determines that the internal combustion engine 2 has misfired. The misfire determination unit 54 outputs warning information indicating that a misfire has occurred in the internal combustion engine 2, and lights up a warning light, for example. After the process in step S106, the misfire determination unit 54 returns the process to step S101.

Further, in step S107 (when the starter generator 4 is driven as a motor), the rotor position determination unit 32 of the rotor position detection unit 30 detects the rotational position of the rotor 10 based on the output of the Hall element 31. The rotor position determination unit 32 generates, for example, a timing signal for performing 120-degree energization control as rotor position information based on the output signals of the three-phase Hall elements 31 (31-1 to 31-3). , outputs the timing signal to the drive control section 51 of the control section 50.

Next, the drive control unit 51 controls the drive circuit 40 based on the rotational position of the rotor 10 (step S108). That is, the drive control unit 51 controls the drive circuit 40 to perform 120-degree energization control based on the timing signal output by the rotor position detection unit 30. For example, the drive control section 51 outputs to the drive circuit 40 a control signal that drives the inverter circuit of the drive circuit 40. Thereby, the drive circuit 40 outputs three-phase (U-phase, V-phase, and W-phase) drive signals to the starter generator 4, and uses the drive signals to rotate (drive) the starter generator 4 as a motor. After the process in step S108, the drive control unit 51 returns the process to step S101.

As explained above, the internal combustion engine system 1 according to the present embodiment includes the internal combustion engine 2 having the crankshaft 3, the starter generator 4 (rotating electric machine), the rotor position detection section 30, the drive control section 51, and the misfire A detection unit 60 is provided. The starter generator 4 applies rotational force to the crankshaft 3 via a rotor 10 directly connected to the crankshaft 3 under a first condition (for example, when starting the internal combustion engine 2). Further, the starter generator 4 receives the rotational force of the crankshaft 3 and generates electricity under a second condition different from the first condition (for example, when the internal combustion engine 2 is operating). The rotor position detection unit 30 detects the rotational position of the rotor 10 and outputs rotor position information indicating the rotational position of the rotor 10. The drive control unit 51 controls the drive circuit 40 that rotationally drives the rotor 10 of the starter generator 4 based on the rotor position information output by the rotor position detection unit 30 under the first condition. The misfire detection unit 60 detects the occurrence of a misfire in the internal combustion engine 2 based on the amount of change per unit time in the rotational position of the rotor 10 based on the rotor position information.

As a result, the internal combustion engine system 1 according to the present embodiment uses the rotor position information detected by the rotor position detection unit 30 to perform drive control when the starter generator 4 is driven as a motor (under the first condition) and the internal combustion engine. It is used both for detecting a misfire in the internal combustion engine 2 when the internal combustion engine 2 is operating (second condition). That is, in the internal combustion engine system 1 according to the present embodiment, the already provided rotor position detection section 30 is also used to detect a misfire in the internal combustion engine 2. Therefore, the internal combustion engine system 1 according to the present embodiment does not require a ring gear to be installed on the crankshaft 3, for example, unlike the conventional technology, and the configuration of the internal combustion engine 2 can be simplified. Therefore, in the internal combustion engine system 1 according to the present embodiment, the configuration of the internal combustion engine 2 can be simplified, and the internal combustion engine 2 can be made smaller.

Further, in this embodiment, the starter generator 4 includes a stator 20 around which a coil 21 is wound, and a plurality of magnets 11 arranged along the inner peripheral surface with alternating magnetic poles, and are arranged to freely rotate around the stator 20. It has a rotor 10 provided therein. The rotor position detection unit 30 is a plurality of Hall elements 31 (magnetic sensors) built into the starter generator 4, and is disposed facing the rotor 10, and detects and outputs the polarity of the facing magnet 11. It has a Hall element 31 of.

As a result, the internal combustion engine system 1 according to the present embodiment utilizes a plurality of Hall elements 31 (magnetic sensors) built into the starter generator 4, so that it is not necessary to separately provide a sensor for detecting a misfire in the internal combustion engine 2. Therefore, the configuration of the internal combustion engine 2 can be simplified.

Further, the internal combustion engine system 1 according to the present embodiment includes a timer 52 that measures and outputs the time interval at which the output pattern output by the Hall element 31 changes. The misfire detection section 60 (misfire determination section 54) detects the occurrence of a misfire in the internal combustion engine 2 based on the change in the switching interval output by the timer 52.
Thereby, the internal combustion engine system 1 according to the present embodiment can appropriately detect a misfire in the internal combustion engine 2 with a simple configuration.

Furthermore, in this embodiment, the misfire detection section 60 (misfire determination section 54) determines that a misfire in the internal combustion engine 2 has occurred when the output value of the timer 52 becomes equal to or greater than a predetermined threshold value.
Here, the output value of the timer 52 indicates the time interval at which the output pattern output by the Hall element 31 is switched, so if the internal combustion engine 2 misfires, the internal combustion engine 2 will no longer be able to obtain power, and the timer It is conceivable that the output value of 52 becomes large. Therefore, in this embodiment, the misfire detection section 60 (misfire determination section 54) can appropriately detect a misfire in the internal combustion engine 2 by a simple method of making a determination using a predetermined threshold value.

Furthermore, the internal combustion engine system 1 according to the present embodiment includes an output storage unit 53 that stores a plurality of output results most recently output by the timer 52. The misfire detection section 60 (misfire determination section 54) determines that a misfire in the internal combustion engine 2 has occurred when a predetermined threshold value or more has occurred a predetermined number of times or more among the plurality of output results stored in the output storage section 53. It is determined that this has occurred.

For example, when a vehicle equipped with the internal combustion engine 2 is traveling on a rough road, there may be a case where the output result of the timer 52 suddenly exceeds a predetermined threshold value. According to the above-described configuration, the internal combustion engine system 1 according to the present embodiment is able to accurately determine that a misfire has occurred in the internal combustion engine 2 even when the temperature suddenly exceeds the predetermined threshold value. I can do it. That is, the internal combustion engine system 1 according to the present embodiment can reduce misdetection of misfire in the internal combustion engine 2.

Further, in this embodiment, the number of slots, which is the number of coils 21, is 18, and the number of magnetic poles, which is the number of magnets 11, is 12. The starter generator 4 functions as a 3-phase brushless motor with 12 poles and 18 slots. The plurality of Hall elements 31 detect and output the polarities of the magnets 11 corresponding to the three phases.

As a result, in the internal combustion engine system 1 according to the present embodiment, the minimum resolution by the rotor position detection unit 30 is 10 degrees of mechanical angle (see interval TR1 in FIG. 5), and the detection accuracy of misfire in the internal combustion engine 2 can be improved. .

Further, the misfire detection method according to the present embodiment includes an internal combustion engine 2 having a crankshaft 3, applying a rotational force to the crankshaft 3 through a rotor 10 directly connected to the crankshaft 3 under a first condition, and , a misfire detection method for an internal combustion engine system 1 comprising a starter generator 4 that receives rotational force of a crankshaft 3 to generate electricity under a second condition different from the first condition, the method comprising: detecting a rotor position; , a drive control step, and a misfire detection step. In the rotor position detection step, the rotor position detection section 30 detects the rotational position of the rotor 10 and outputs rotor position information indicating the rotational position of the rotor 10. In the drive control step, the drive control unit 51 controls a drive circuit that rotationally drives the rotor 10 of the starter generator 4 under the first condition based on the rotor position information output in the rotor position detection step. In the misfire detection step, the misfire detection section 60 (misfire determination section 54) detects that a misfire has occurred in the internal combustion engine 2 based on the amount of change per unit time in the rotational position of the rotor 10 based on the rotor position information. .

As a result, the misfire detection method according to the present embodiment can achieve the same effects as the internal combustion engine system 1 according to the present embodiment described above, and can simplify the configuration of the internal combustion engine 2 and downsize the internal combustion engine 2. I can do it.

[Second embodiment]
Next, an internal combustion engine system 1 according to a second embodiment will be described with reference to the drawings.
In this embodiment, a modification example of detection of a misfire in the internal combustion engine 2 by the misfire detection section 60 (misfire determination section 54) will be described.

Note that the basic configuration of the internal combustion engine system 1 according to this embodiment is the same as that of the first embodiment shown in FIGS. 1 to 4 described above, and therefore the description thereof will be omitted here.
In this embodiment, the process of determining misfire in the internal combustion engine 2 by the misfire determining unit 54 is different from the first embodiment, and the process of the misfire determining unit 54 in this embodiment will be described below.

The misfire determination unit 54 in this embodiment determines that a misfire in the internal combustion engine 2 has occurred when the average value of the plurality of output results stored in the output storage unit 53 is equal to or greater than a predetermined threshold value. For example, the misfire determination section 54 acquires the output results of the most recent predetermined number of times from the output storage section 53, and calculates the average value of the output results of the predetermined number of times. The misfire determining unit 54 determines that a misfire in the internal combustion engine 2 has occurred when the average value of the calculated output results is equal to or greater than a predetermined threshold value.

Next, with reference to FIG. 7, the operation of the internal combustion engine system 1 according to this embodiment will be described.
FIG. 7 is a flowchart showing an example of the operation of the internal combustion engine system 1 according to this embodiment.

In FIG. 7, the processing from step S201 to step S204 is the same as the processing from step S101 to step S104 shown in FIG. 6 described above, so the description thereof will be omitted here.

In step S205, the misfire determination unit 54 generates an average value of the most recent predetermined number of output results of the timer. That is, the misfire determination section 54 acquires the output results of the timer 52 stored in the output storage section 53 for the most recent predetermined number of times. The misfire determination unit 54 generates an average value of the output results of the timer 52 obtained for the most recent predetermined number of times.

Next, the misfire determination unit 54 determines whether the average value is greater than or equal to a predetermined threshold (step S206). If the generated average value is greater than or equal to the predetermined threshold (step S206: YES), the misfire determination unit 54 advances the process to step S207. Further, if the generated average value is less than the predetermined threshold (step S206: NO), the misfire determination unit 54 returns the process to step S201.

In step S207, the misfire determining unit 54 determines that the internal combustion engine 2 has misfired. The misfire determination unit 54 outputs warning information indicating that a misfire has occurred in the internal combustion engine 2, and lights up a warning light, for example. After the process in step S207, the misfire determination unit 54 returns the process to step S201.

Furthermore, since the processing in step S208 and step S209 is similar to the processing in step S107 and step S109 shown in FIG. 6 described above, the description thereof will be omitted here. After the process in step S209, the drive control unit 51 returns the process to step S201.

As explained above, the internal combustion engine system 1 according to the present embodiment includes the internal combustion engine 2 having the crankshaft 3, the starter generator 4 (rotating electric machine), the rotor position detection section 30, the drive control section 51, and the misfire It includes a determination unit 54, a timer 52, and an output storage unit 53 that stores a plurality of output results most recently output by the timer 52. The misfire determining unit 54 (misfire detecting unit 60) in this embodiment determines that a misfire has occurred in the internal combustion engine 2 when the average value of the plurality of output results stored in the output storage unit 53 is equal to or greater than a predetermined threshold. judge.

As a result, the internal combustion engine system 1 according to the present embodiment maintains the average value even if the value suddenly exceeds a predetermined threshold value, such as when a vehicle equipped with the internal combustion engine 2 is traveling on a rough road. By using this, it is possible to accurately determine that a misfire in the internal combustion engine 2 has occurred. That is, the internal combustion engine system 1 according to the present embodiment can reduce misdetection of misfire in the internal combustion engine 2, similarly to the first embodiment.

Note that the present invention is not limited to the above-described embodiments, and can be modified without departing from the spirit of the present invention.
For example, in each of the embodiments described above, a Hall element is used as an example of a magnetic sensor, but the present invention is not limited to this, and other magnetic sensors may be used.

Further, in each of the above embodiments, an example has been described in which the internal combustion engine system 1 includes three Hall elements 31 (31-1 to 31-3) of U-phase, V-phase, and W-phase. A Hall element 31 that generates an ignition timing signal for igniting the internal combustion engine 2 may be additionally provided.

Further, in each of the above embodiments, an example has been described in which the rotor position determination unit 32 is included in the control unit 50, but the rotor position determination unit 32 is not limited to this, and the rotor position determination unit 32 is included in the control unit 50. You may prepare it. Further, the control unit 50 is not limited to controlling the starter generator 4, and may include controlling the internal combustion engine 2, for example.

Further, in each of the above embodiments, an example has been described in which the starter generator 4 is a 3-phase brushless motor with 12 poles and 18 slots, but the starter generator 4 is not limited to this, and other numbers of poles and other slots It may be several motors.

Furthermore, in the second embodiment described above, the misfire detection section 60 (misfire determination section 54) uses an average value of a plurality of output results. A weighted average value may also be used.

Note that each component included in the internal combustion engine system 1 described above has a computer system therein. Then, a program for realizing the functions of each component of the internal combustion engine system 1 described above is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed. Processing in each component included in the internal combustion engine system 1 described above may also be performed. Here, "reading a program recorded on a recording medium into a computer system and executing it" includes installing the program on the computer system. The "computer system" here includes hardware such as an OS and peripheral devices.
Further, a "computer system" may include a plurality of computer devices connected via a network including the Internet, a WAN, a LAN, a communication line such as a dedicated line, etc. Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into computer systems. In this way, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM.

The recording medium also includes a recording medium provided internally or externally that can be accessed from the distribution server for distributing the program. Note that the program may be divided into a plurality of parts, downloaded at different timings, and then combined into each component of the internal combustion engine system 1, or the distribution servers that distribute each of the divided programs may be different. Furthermore, a ``computer-readable recording medium'' refers to a storage medium that retains a program for a certain period of time, such as volatile memory (RAM) inside a computer system that serves as a server or client when a program is transmitted via a network. This shall also include things. Moreover, the above-mentioned program may be for realizing a part of the above-mentioned functions. Furthermore, it may be a so-called difference file (difference program) that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

Further, some or all of the functions described above may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each of the above-mentioned functions may be implemented as an individual processor, or some or all of them may be integrated into a processor. Moreover, the method of circuit integration is not limited to LSI, but may be implemented using a dedicated circuit or a general-purpose processor. Further, if an integrated circuit technology that replaces LSI emerges due to advances in semiconductor technology, an integrated circuit based on this technology may be used.

1 Internal combustion engine system 2 Internal combustion engine 3 Crankshaft 4 Starter generator 5 Battery 10 Rotor 11 Magnet 11N N pole magnet 11S S pole magnet 20 Stator 21 Coil 21U U phase coil 21V V phase coil 21W W phase coil 22 Sensor case 30 Rotor position Detection section 31, 31-1, 31-2, 31-3 Hall element 32 Rotor position determination section 40 Drive circuit 50 Control section 51 Drive control section 52 Timer 53 Output storage section 54 Misfire determination section 60 Misfire detection section

Claims (7)

an internal combustion engine having a crankshaft;
Under a first condition, a rotational force is applied to the crankshaft via a rotor directly connected to the crankshaft, and under a second condition different from the first condition, the rotational force of the crankshaft is applied. A rotating electric machine that receives electricity and generates electricity,
a rotor position detection unit that detects a rotational position of the rotor and outputs rotor position information indicating the rotational position of the rotor;
a drive control unit that controls a drive circuit that rotationally drives the rotor of the rotating electrical machine based on the rotor position information output by the rotor position detection unit under the first condition;
a misfire detection unit that detects that a misfire has occurred in the internal combustion engine based on the rotation speed of the rotor or the rotation period of the rotor based on the rotor position information;
Prepare ,
The rotating electric machine includes a stator around which a coil is wound, and a rotor in which a plurality of magnets are arranged along an inner circumferential surface with alternating magnetic poles, and is rotatably disposed around the stator,
The rotor position detection section includes a plurality of magnetic sensors built into the rotating electrical machine, which are arranged to face the rotor and detect polarities of the opposing magnets, and a plurality of magnetic sensors that detect the polarity of the opposing magnets. and a rotor position determination unit that outputs the rotor position information based on the output signal to be output.
An internal combustion engine system characterized by: a timer that measures and outputs the interval at which the output of the magnetic sensor changes based on the output signal of the magnetic sensor ;
The misfire detection unit detects occurrence of a misfire in the internal combustion engine based on an output result of the timer corresponding to a rotation speed of the rotor or a rotation period of the rotor . The internal combustion engine system described. The misfire detection unit determines that a misfire has occurred in the internal combustion engine when the output result of the timer corresponding to the rotation speed of the rotor or the rotation period of the rotor becomes a predetermined threshold or more. The internal combustion engine system according to claim 2 . comprising an output storage unit that stores a plurality of output results most recently output by the timer,
The misfire detection section is configured to detect, among the plurality of output results corresponding to the rotational speed of the rotor or the rotation period of the rotor , which are stored in the output storage section, an output result that exceeds a predetermined threshold value occurs a predetermined number of times or more. The internal combustion engine system according to claim 2 , wherein it is determined that a misfire in the internal combustion engine has occurred when the internal combustion engine has a misfire. comprising an output storage unit that stores a plurality of output results most recently output by the timer,
The misfire detection section detects whether the internal combustion engine is activated when the average value of the plurality of output results corresponding to the rotational speed of the rotor or the rotation period of the rotor, which is stored in the output storage section, is equal to or higher than a predetermined threshold value. The internal combustion engine system according to claim 2 , wherein it is determined that a misfire has occurred. The number of slots, which is the number of coils, is 18,
The number of magnetic poles, which is the number of the magnets, is 12,
The rotating electric machine functions as a three-phase brushless motor,
The internal combustion engine system according to any one of claims 1 to 5 , wherein the plurality of magnetic sensors detect and output polarities of the magnets corresponding to three phases. An internal combustion engine having a crankshaft, under a first condition, applying rotational force to the crankshaft via a rotor directly connected to the crankshaft, and under a second condition different from the first condition. A misfire detection method for an internal combustion engine system comprising: a rotating electrical machine that generates electricity by receiving the rotational force of the crankshaft ; a rotor position detection section; a drive control section; and a misfire detection section .
The rotating electric machine includes a stator around which a coil is wound, and a rotor in which a plurality of magnets are arranged along an inner circumferential surface with alternating magnetic poles, and is rotatably disposed around the stator,
The rotor position detection section includes a plurality of magnetic sensors built into the rotating electrical machine, which are arranged to face the rotor and detect polarities of the opposing magnets, and a plurality of magnetic sensors that detect the polarity of the opposing magnets. and a rotor position determination unit that outputs rotor position information based on the output signal to be output,
a rotor position detection step in which the rotor position detection unit detects the rotational position of the rotor and outputs the rotor position information indicating the rotational position of the rotor;
a drive control step in which the drive control unit controls a drive circuit that rotationally drives the rotor of the rotating electrical machine based on the rotor position information output by the rotor position detection step under the first condition; ,
a misfire detection step in which the misfire detection unit detects that a misfire has occurred in the internal combustion engine based on the rotation speed of the rotor or the rotation period of the rotor based on the rotor position information;
A misfire detection method comprising :

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