JP2023120525A - Internal combustion engine control apparatus - Google Patents

Abstract

To suppress a fuel injection from being not started when restarting an internal combustion engine.SOLUTION: A control apparatus executes first processing for acquiring a BTDC indicating a position of a piston in a specific cylinder that is a cylinder meeting with a compression stroke. The control apparatus executes second processing for turning on a postponing flag when the BTDC is equal to or less than a first threshold ZA. The control apparatus executes third processing for turning off the postponing flag when the BTDC is equal to or less than a second threshold ZB. The control apparatus executes fourth processing for determining the fuel injection in the specific cylinder when the postponing flag is turned off, and postponing the fuel injection in the specific cylinder when the postponing flag is turned on. The control apparatus repetitively executes the first to fourth processing at a certain control cycle from when the restart of an internal combustion engine is requested to when the fuel is combusted first in the cylinder. In the third processing, the postponing flag is turned off even when a compression stroke of a cylinder meeting with the compression stroke before one control cycle is ended.SELECTED DRAWING: Figure 3

Description

The present invention relates to a control device for an internal combustion engine.

The internal combustion engine of Patent Document 1 includes a cylinder, an intake passage, an exhaust passage, a piston, a crankshaft, and a fuel injection valve. A cylinder is a space for burning fuel. The intake passage introduces intake air into the cylinder. The exhaust passage discharges exhaust from the cylinder. The piston reciprocates within the cylinder. The crankshaft rotates due to the reciprocating motion of the pistons. The fuel injection valve supplies fuel into the cylinder.

The control device for an internal combustion engine disclosed in Patent Document 1 acquires the position of a piston in a cylinder that is undergoing a compression stroke when restarting the internal combustion engine from a state in which fuel combustion in the cylinder is interrupted. The controller then causes the fuel injector to inject an amount of fuel based on the position of the piston. As a result, an amount of fuel corresponding to the amount of intake air present in the cylinder undergoing the compression stroke is supplied to the cylinder.

JP 2013-252725 A

In a control device for an internal combustion engine such as that disclosed in Patent Document 1, when restarting the internal combustion engine, fuel may be injected not from the cylinder which is undergoing the compression stroke but from the cylinder which is undergoing the next compression stroke. As described above, the following process is known as a process for determining the cylinder to which fuel is to be injected first when restarting the internal combustion engine. First, the cylinder that is in the compression stroke at the time when there is a request to restart the internal combustion engine is identified. It also acquires the position of the piston in that particular cylinder. Then, if the position of the piston is on the advance side of the compression top dead center by a certain amount or more, fuel injection is started from that specific cylinder. On the other hand, when the position of the piston is close to the compression top dead center, the fuel injection in the specific cylinder is postponed. When the fuel injection in the specific cylinder is postponed, the postponement of the fuel injection is canceled when the position of the piston reaches between the position of the piston where the fuel is injected and the compression top dead center. By canceling the postponement of fuel injection in this manner, fuel injection is started from the cylinder that undergoes the compression stroke next to the specific cylinder.

However, the series of controls described above assumes that the rotation speed of the crankshaft is low when the internal combustion engine is restarted. If the rotation speed of the crankshaft when restarting the internal combustion engine is high, the crankshaft rotates greatly even during one control cycle of the control device, and as a result, the position of the piston also changes greatly. Therefore, for example, after fuel injection in a specific cylinder is postponed in a certain control cycle, there is a possibility that the position of the piston has already passed compression top dead center when the next control cycle starts. In this case, the condition for canceling the postponement of fuel injection, that is, "the position of the piston is between the position of the piston at which fuel is injected and the compression top dead center," is not satisfied. Therefore, it is possible that the postponement of fuel injection remains effective and fuel injection is not started after that.

A control device for an internal combustion engine for solving the above-mentioned problems includes a cylinder for burning fuel, an intake passage for introducing intake air into the cylinder, an exhaust passage for discharging exhaust gas from the cylinder, and reciprocating motion in the cylinder. A control device that is applied to an internal combustion engine comprising a piston, a crankshaft that rotates due to the reciprocating motion of the piston, and a fuel injection valve that supplies fuel to the cylinder, and that controls the restart of the internal combustion engine. a first process for obtaining the position of the piston in the specific cylinder when the internal combustion engine is restarted when the cylinder undergoing the compression stroke is the specific cylinder; and a skip flag is OFF. the position of the piston obtained in the first process is a send-off range defined as a range from a position on the advance side of the position of the piston when fuel is injected in the specific cylinder to compression top dead center a second process for turning on the send-off flag when the send-off flag is ON; a third process of turning off the send-off flag when within a cancel range defined as a range from the position of the piston to the compression top dead center; and after the second process or the third process, the a fourth process of determining fuel injection in the specific cylinder when the skip flag is OFF, and skipping fuel injection in the specific cylinder when the skip flag is ON; The first process to the fourth process are repeatedly executed at a constant control cycle from when a request to restart the engine is issued until the fuel is first burned in the cylinder, and in the third process, the The send-off flag is also turned OFF when the compression stroke of the cylinder that entered the compression stroke one control cycle before the third process has ended.

According to the above configuration, even when the compression stroke of the cylinder that was in the compression stroke one control cycle before has ended in the third process, the skip flag is turned OFF. In other words, even if the condition that the position of the piston is within the cancel range is not satisfied, the send-off flag is turned OFF. As a result, it is possible to prevent the fuel injection from starting due to the high rotation speed of the crankshaft when there is a request to restart the internal combustion engine.

1 is a schematic configuration diagram of a vehicle; FIG. 1 is a schematic configuration diagram of an internal combustion engine; FIG. It is a flow chart which shows change control of a send-off flag.

<Mechanical Configuration of Vehicle>
An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. First, the mechanical configuration of vehicle 100 will be described.

As shown in FIG. 1, a vehicle 100 has an internal combustion engine 10 . As shown in FIG. 2 , the internal combustion engine 10 includes multiple cylinders 11 , an intake passage 12 , an exhaust passage 13 , multiple pistons 16 , multiple connecting rods 17 , and a crankshaft 18 .

As shown in FIG. 2, the cylinder 11 is a space for burning a mixture of fuel and intake air. In this embodiment, the internal combustion engine 10 has six cylinders 11 . The internal combustion engine 10 is a so-called in-line six-cylinder engine in which six cylinders 11 are arranged in a row. Hereinafter, when the six cylinders 11 are collectively described, they are simply referred to as cylinders 11 . Also, when explaining the six cylinders 11 separately, the order in which the six cylinders 11 are arranged will be the first cylinder 11A, second cylinder 11B, third cylinder 11C, fourth cylinder 11D, fifth cylinder 11E, and so on. It is called the 6th cylinder 11F. Note that FIG. 2 shows only one cylinder 11 as a representative.

The piston 16 is positioned inside the cylinder 11 . Piston 16 is connected to crankshaft 18 via connecting rod 17 . The piston 16 reciprocates inside the cylinder 11 by combusting a mixture of fuel and intake air in the cylinder 11 . The reciprocating motion of the piston 16 causes the crankshaft 18 to rotate.

The intake passage 12 is connected to the cylinder 11 . The intake passage 12 introduces intake air into each cylinder 11 from the outside of the internal combustion engine 10 . The exhaust passage 13 is connected to the cylinder 11 . The exhaust passage 13 discharges the exhaust from each cylinder 11 to the outside of the internal combustion engine 10 .

The internal combustion engine 10 includes a throttle valve 21 , a plurality of port injection valves 22 , a plurality of in-cylinder injection valves 23 , a plurality of ignition devices 24 , a plurality of intake valves 26 and a plurality of exhaust valves 27 .

The throttle valve 21 is positioned in the middle of the intake passage 12 . The throttle valve 21 adjusts the amount of intake air flowing through the intake passage 12 . The port injection valve 22 is positioned near the cylinder 11 in the intake passage 12 . The port injection valve 22 supplies fuel into the cylinder 11 through the intake passage 12 by injecting fuel into the intake passage 12 . The internal combustion engine 10 has six port injection valves 22 corresponding to the six cylinders 11 . A part including the tip of in-cylinder injection valve 23 is located inside cylinder 11 . In-cylinder injection valve 23 supplies fuel into cylinder 11 by injecting fuel into cylinder 11 . The internal combustion engine 10 has six in-cylinder injection valves 23 corresponding to the six cylinders 11 . In this embodiment, the port injection valve 22 and the in-cylinder injection valve 23 are fuel injection valves that supply fuel into the cylinder 11 .

A part including the tip of the ignition device 24 is located inside the cylinder 11 . The ignition device 24 ignites the mixture of fuel and intake air by spark discharge. The internal combustion engine 10 has six ignition devices 24 corresponding to the six cylinders 11 . The six ignition devices 24 ignite the first cylinder 11A, the fifth cylinder 11E, the third cylinder 11C, the sixth cylinder 11F, the second cylinder 11B, and the fourth cylinder 11D in this order. In other words, the internal combustion engine 10 undergoes combustion strokes in order of the first cylinder 11A, the fifth cylinder 11E, the third cylinder 11C, the sixth cylinder 11F, the second cylinder 11B, and the fourth cylinder 11D. Each cylinder 11 repeats an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke each time the crankshaft 18 rotates twice. Therefore, in the internal combustion engine 10, one of the six cylinders 11 enters a new combustion stroke each time the crankshaft 18 rotates by 120 degrees.

The intake valve 26 is positioned at the downstream end of the intake passage 12 . The intake valve 26 opens and closes the downstream end of the intake passage 12 by driving force from a valve mechanism (not shown). The internal combustion engine 10 has six intake valves 26 corresponding to the six cylinders 11 . The exhaust valve 27 is positioned at the upstream end of the exhaust passage 13 . The exhaust valve 27 opens and closes the upstream end of the exhaust passage 13 by driving force from a valve mechanism (not shown). The internal combustion engine 10 has six exhaust valves 27 corresponding to the six cylinders 11 .

As shown in FIG. 1 , vehicle 100 includes clutch 31 , motor generator 40 , automatic transmission 61 , differential mechanism 62 , and multiple drive wheels 63 .
The motor generator 40 has a rotating shaft 41 , a rotor 42 and a stator 43 . The rotating shaft 41 is connected to the rotor 42 . Therefore, the rotating shaft 41 is rotatable with respect to the stator 43 . A rotating shaft 41 of the motor generator 40 is connected to the crankshaft 18 of the internal combustion engine 10 via the clutch 31 . The connected state of the clutch 31 is switched between an engaged state and a disengaged state according to the pressure of oil supplied to the inside of the clutch 31 .

A rotating shaft 41 of the motor generator 40 is connected to drive wheels 63 via an automatic transmission 61 and a differential mechanism 62 . An example of the automatic transmission 61 is a stepped automatic transmission. The automatic transmission 61 can change the gear ratio step by step. The differential mechanism 62 allows the left and right drive wheels 63 to have different rotational speeds.

<Electrical Configuration of Vehicle>
As shown in FIG. 1 , vehicle 100 includes battery 71 and inverter 72 . Battery 71 stores electric power generated by motor generator 40 when motor generator 40 functions as a generator. Battery 71 supplies electric power to motor generator 40 when motor generator 40 functions as an electric motor. Inverter 72 adjusts the amount of electric power transferred between motor generator 40 and battery 71 .

As shown in FIG. 1 , the vehicle 100 includes an accelerator operation amount sensor 81 , a vehicle speed sensor 82 and a crank angle sensor 83 . An accelerator operation amount sensor 81 detects an accelerator operation amount ACC, which is an operation amount of an accelerator pedal (not shown) operated by a driver. Vehicle speed sensor 82 detects vehicle speed SP, which is the speed of vehicle 100 . A crank angle sensor 83 detects a crank angle SC, which is the angular position of the crankshaft 18 .

As shown in FIG. 1 , vehicle 100 includes control device 90 . The control device 90 acquires a signal indicating the accelerator operation amount ACC from the accelerator operation amount sensor 81 . Control device 90 acquires a signal indicating vehicle speed SP from vehicle speed sensor 82 . Control device 90 acquires a signal indicating crank angle SC from crank angle sensor 83 . The control device 90 calculates an engine rotation speed NE, which is the rotation speed of the crankshaft 18, based on the crank angle SC.

Based on the accelerator operation amount ACC and the vehicle speed SP, the control device 90 calculates a vehicle required driving force, which is a required value of the driving force necessary for the vehicle 100 to travel. The control device 90 determines torque distribution of the internal combustion engine 10 and the motor generator 40 based on the vehicle required driving force. The control device 90 controls the output of the internal combustion engine 10 and the power running and regeneration of the motor generator 40 based on the torque distribution of the internal combustion engine 10 and the motor generator 40 .

The control device 90 outputs a control signal to the internal combustion engine 10 to adjust the opening degree of the throttle valve 21, adjust the fuel injection amount from the port injection valve 22, and adjust the fuel injection amount from the in-cylinder injection valve 23. , adjustment of the ignition timing of the ignition device 24, and various other controls. Control device 90 also outputs a control signal to inverter 72 in controlling motor generator 40 . Control device 90 controls motor generator 40 by adjusting the amount of electric power transferred between motor generator 40 and battery 71 via inverter 72 .

The control device 90 controls the engagement state of the clutch 31 by outputting a control signal to the clutch 31 . Control device 90 controls the gear ratio of automatic transmission 61 by outputting a control signal to automatic transmission 61 .

The control device 90 executes an automatic stop process of interrupting the combustion of fuel in the cylinder 11 and controlling the throttle valve 21 to a closed state when a stop condition, which is a predetermined condition, is satisfied. . Here, one example of the stop condition is that the vehicle required driving force becomes smaller due to the accelerator operation amount ACC becoming zero.

When there is a request to restart the internal combustion engine 10 while the internal combustion engine 10 is stopped by the automatic stop processing, the control device 90 executes one of the low speed restart processing and the high speed restart processing to control the internal combustion engine. Engine 10 is restarted. An example of when there is a request to restart the internal combustion engine 10 is that the vehicle required driving force increases due to the accelerator operation amount ACC becoming greater than zero.

The control device 90 restarts the internal combustion engine 10 by executing the low-speed restart process when the rotational speed A is equal to or less than a predetermined specified rotational speed A. Here, an example of the prescribed rotation speed A is several hundred rpm. In the low-speed restart process, the control device 90 first outputs a control signal to the clutch 31 to control the connection state of the clutch 31 to the engaged state. By outputting a control signal to the inverter 72 , the control device 90 applies torque from the rotation shaft 41 of the motor generator 40 to the crankshaft 18 of the internal combustion engine 10 via the clutch 31 . As a result, the engine speed NE increases. Furthermore, the control device 90 supplies fuel into the cylinder 11 by controlling the port injection valve 22 and the in-cylinder injection valve 23 . Further, the control device 90 controls the ignition device 24 to ignite the mixture of fuel and intake air in the cylinder 11 by spark discharge. As a result, the internal combustion engine 10 is restarted.

Further, when the engine rotation speed NE is higher than the specified rotation speed A, the control device 90 restarts the internal combustion engine 10 by executing the high-speed restart process. In the high-speed restart process, the control device 90 first outputs a control signal to the clutch 31 to control the connected state of the clutch 31 to the released state. Fuel is supplied into the cylinder 11 by controlling the port injection valve 22 and the in-cylinder injection valve 23 . Further, the control device 90 controls the ignition device 24 to ignite the mixture of fuel and intake air in the cylinder 11 by spark discharge. As a result, the internal combustion engine 10 is restarted. After that, the control device 90 outputs a control signal to the clutch 31 to control the connected state of the clutch 31 to the engaged state.

When the internal combustion engine 10 is restarted, the control device 90 executes a skipping process of skipping the fuel injection in the specific cylinder according to the skipping flag. Here, the specific cylinder is the cylinder 11 that is undergoing a compression stroke at the time of execution of the send-off process. In the skipping process, when the skipping flag is OFF, the control device 90 determines execution of fuel injection in the specific injection. On the other hand, in the skipping process, when the skipping flag is ON, the control device 90 skips execution of the fuel injection in the specific injection. In the present embodiment, the control device 90 executes the send-off process after executing the switch control of the send-off flag, which will be described later. That is, the control device 90 executes the send-off process based on the send-off flag after switching control. Note that switching control is control for switching from one of ON and OFF of the send-off flag to the other. In this embodiment, the send-off process is the fourth process.

In this embodiment, the control device 90 repeatedly executes various kinds of processing at regular control cycles. That is, the control device 90 repeatedly executes the above-described send-off process at a constant control cycle. An example of one control cycle is several milliseconds to ten and several milliseconds.

The controller 90 can be configured as a circuit including one or more processors that perform various processes according to a computer program (software). Note that the control device 90 is configured as a circuit including one or more dedicated hardware circuits, such as an application specific integrated circuit (ASIC), or a combination thereof, which executes at least part of the various types of processing. may The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to perform processes. Memory or computer-readable media includes any media that can be accessed by a general purpose or special purpose computer.

<Switching control of send-off flag>
Next, switching control executed by the control device 90 will be described. The control device 90 repeats switching control of the skip flag at a constant control cycle from when the restart of the internal combustion engine 10 is requested until when fuel is first combusted in the cylinder 11 . Here, the control cycle of the switching control is the same as the control cycle of the above-described send-off process. Further, when the fuel is first combusted in the cylinder 11, for example, when the air-fuel mixture in the cylinder 11 to which the fuel is first supplied is spark-discharged, the control device 90 controls the ignition device 24. It should be noted that the send-off flag is OFF at the time when there is a request to restart the internal combustion engine 10 .

As shown in FIG. 3, when the control device 90 starts switching control of the send-off flag, the process proceeds to step S11. In step S11, the control device 90 identifies the specific cylinder at the time of processing in step S11 based on the crank angle SC. That is, the control device 90 identifies the cylinder 11 that is undergoing a compression stroke at the time of processing in step S11. Then, the control device 90 identifies the position of the piston 16 within the specific cylinder. Specifically, the control device 90 calculates, as the position of the piston 16, the amount of change in the crank angle SC required for the piston 16 to move to the top dead center of the compression stroke at the time of processing in step S11, so-called BTDC. . Therefore, the control device 90 calculates a smaller value as BTDC as the piston 16 in the specific cylinder is closer to the top dead center. As a specific example, it is assumed that the crank angle SC from the reference angle is 90 degrees at the time of processing in step S11. It is also assumed that the first cylinder 11A reaches the top dead center of the compression stroke when the crank angle SC from the reference angle is 120 degrees. In this case, the control device 90 first identifies the first cylinder 11A as the specific cylinder. Then, the control device 90 subtracts 90 degrees, which is the crank angle SC at the time of processing in step S11, from 120 degrees, which is the crank angle SC at which the first cylinder 11A reaches the top dead center of the compression stroke, and calculates 30 degrees as BTDC. Calculate as Also, the control device 90 stores the calculated BTDC. In this embodiment, since the internal combustion engine 10 has six cylinders 11, one cylinder 11 or two cylinders 11 may undergo compression strokes at the same time. When the two cylinders 11 are in the compression stroke, the control device 90 specifies the cylinder 11 whose position of the piston 16 is close to the top dead center of the compression stroke as the specific cylinder. The process of step S11 is an example of the first process of acquiring the position of the piston 16 in the specific cylinder when the internal combustion engine 10 is restarted. After that, the control device 90 advances the process to step S12.

In step S12, the control device 90 determines whether or not the send-off flag is OFF. In step S12, when the control device 90 determines that the send-off flag is OFF (S12: YES), the control device 90 advances the process to step S21.

In step S21, the control device 90 determines whether or not BTDC is equal to or less than a predetermined first threshold value ZA. Here, the first threshold value ZA is determined as a crank angle SC that is advanced by a predetermined angle from the crank angle SC at which the in-cylinder injection valve 23 starts injecting fuel into the specific cylinder. In this embodiment, an example of the first threshold ZA is several tens of degrees. Note that the range of the crank angle SC from the first threshold value ZA to the compression top dead center corresponds to a "delay range" defined as a range for determining whether or not fuel injection in a specific cylinder is to be deferred. In step S21, when the control device 90 determines that BTDC is greater than the first threshold value ZA (S21: NO), the control device 90 ends this switching control. In this case, the send-off flag remains OFF.

On the other hand, in step S21, when the control device 90 determines that BTDC is equal to or less than the first threshold value ZA (S21: YES), the control device 90 advances the process to step S26. In other words, when the position of the piston 16 in the specific cylinder obtained in the first process is within the see-off range, the control device 90 advances the process to step S26.

In step S26, the control device 90 turns ON the send-off flag. In this embodiment, the processing of steps S21 and S26 is the second processing. After that, the control device 90 terminates the current switching control.

In step S12 described above, when the control device 90 determines that the send-off flag is ON (S12: NO), the control device 90 advances the process to step S31.
In step S31, the control device 90 determines whether or not BTDC is equal to or less than a predetermined second threshold value ZB. Here, the second threshold value ZB is determined as the crank angle SC at which the in-cylinder injection valve 23 starts injecting fuel into the specific cylinder. Therefore, the second threshold ZB is a value smaller than the first threshold ZA. In the present embodiment, an example of the second threshold ZB is about ten degrees to several tens of degrees. The range of the crank angle SC from the second threshold value ZB to the compression top dead center corresponds to a "cancellation range" defined as a range for determining whether or not to turn off the send-off flag that is in the ON state. do. In step S31, when the control device 90 determines that BTDC is equal to or less than the second threshold value ZB (S31: YES), the control device 90 advances the process to step S36. In other words, when the position of the piston 16 in the specific cylinder acquired in the first process is within the cancellation range, the control device 90 advances the process to step S36. On the other hand, in step S31, when the control device 90 determines that BTDC is greater than the second threshold value ZB (S31: NO), the control device 90 advances the process to step S32.

In step S32, the control device 90 determines whether or not the cylinder 11, which entered the compression stroke one control cycle before, has completed the compression stroke. Specifically, when the BTDC in the current control cycle is greater than the BTDC in the previous control cycle, the control device 90 determines that the cylinder 11 undergoing a compression stroke one control cycle before is in compression. It is determined that the process has ended. On the other hand, when the BTDC in the current control cycle is equal to or less than the BTDC in the previous control cycle, the control device 90 causes the cylinder 11 that was in the compression stroke one control cycle before to finish the compression stroke. determine that it is not. In step S32, when the control device 90 determines that the cylinder 11, which was undergoing a compression stroke one control cycle before, has not finished the compression stroke (S32: NO), the control device 90 end switching control. In this case, the send-off flag remains ON.

On the other hand, in step S32, when the control device 90 determines that the cylinder 11, which was in the compression stroke one control cycle before, has completed the compression stroke (S32: YES), the control device 90 advances the process to step S36.

In step S36, the control device 90 turns off the send-off flag. In this embodiment, the processing of steps S31, S32, and S36 is the third processing. After that, the control device 90 terminates the current switching control.

<Action of this embodiment>
For example, in the vehicle 100, it is assumed that the engine rotation speed NE is relatively low when the restart of the internal combustion engine 10 is requested. It is also assumed that the first cylinder 11A is in the compression stroke when a request to restart the internal combustion engine 10 is made. Furthermore, it is assumed that BTDC when a request for restarting the internal combustion engine 10 is made is equal to or less than the first threshold value ZA and is greater than the second threshold value ZB. In this case, since BTDC is equal to or less than the first threshold value ZA at the time of execution of the switching control for the first time, an affirmative determination is made in step S21. Then, the send-off flag is turned ON in step S26. As a result, fuel injection in the first cylinder 11A is postponed. Also, since the crankshaft 18 is rotating, BTDC gradually decreases as time passes. Then, for example, assume that the second switching control is executed in a situation where BTDC is equal to or less than the second threshold value ZB. In this case, an affirmative determination is made in step S31. Then, the send-off flag is turned off in step S36. As a result, fuel injection becomes possible in the fifth cylinder 11E, which undergoes the compression stroke next to the first cylinder 11A.

On the other hand, it is assumed that the engine rotation speed NE is relatively high when there is a request to restart the internal combustion engine 10 . In this case, the amount of change in the crank angle SC during one control cycle of the control device 90 is large. Therefore, even if BTDC actually becomes equal to or lower than the second threshold value ZB, the second switching control may not be executed at that timing. In this case, the second switching control is executed after the compression stroke of the first cylinder 11A ends. At this time, the specific cylinder is the fifth cylinder 11E, which undergoes the compression stroke next to the first cylinder 11A. Therefore, BTDC is calculated for the fifth cylinder 11E, which has newly become a specific cylinder. As a result, BTDC becomes larger than the second threshold value ZB, so the affirmative determination is not made in step S31.

<Effects of this embodiment>
(1) In the present embodiment, when a negative determination is made in step S31, the control device 90 further performs the process of step S32. When the control device 90 makes an affirmative determination in step S32, that is, when it determines that the cylinder 11, which entered the compression stroke one control cycle before, has completed the compression stroke, the control device 90 does not Turn off the flag. As a result, for example, in the second switching control, even if a positive determination is not made in step S31, a positive determination is made in step S32 so that the send-off flag is turned OFF. In other words, even if the engine rotation speed NE is relatively high when there is a request to restart the internal combustion engine 10, the skip flag is turned OFF. As a result, it is possible to prevent a situation in which the fuel injection is not started due to the high engine speed NE when there is a request to restart the internal combustion engine 10 .

<Change example>
This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- In the above embodiment, the process of step S32 may be changed.
Specifically, in step S32, the process of determining whether or not the cylinder 11 that was in the compression stroke one control cycle before has completed the compression stroke may be changed. For example, first, in the internal combustion engine 10, each time the crankshaft 18 rotates by 120 degrees, one of the six cylinders 11 starts a new combustion stroke. Therefore, in the internal combustion engine 10, based on the crank angle SC from the reference angle, it is possible to determine, for example, whether the first cylinder 11A has completed the compression stroke. Therefore, the control device 90 may determine whether or not the target cylinder 11 has completed the compression stroke based on the crank angle SC from the reference angle.

- In the above embodiment, the configuration of the vehicle 100 may be changed.
For example, vehicle 100 may not include motor generator 40 . Note that even with this configuration, if the engine rotation speed NE is high to some extent when there is a request to restart the internal combustion engine 10, the internal combustion engine 10 is restarted without applying the torque from the motor generator 40. Is possible. Further, if the engine rotation speed NE is zero when a request for restarting the internal combustion engine 10 is made, the internal combustion engine 10 can be restarted by cranking with a starter motor, for example.

- For example, the internal combustion engine 10 may have five or less cylinders 11 or seven or more cylinders 11 . Also, for example, the internal combustion engine 10 may not include the port injection valve 22 .

REFERENCE SIGNS LIST 10 Internal combustion engine 11 Cylinder 12 Intake passage 13 Exhaust passage 16 Piston 17 Connecting rod 18 Crankshaft 21 Throttle valve 22 Port injection valve 23 In-cylinder injection valve 24 Ignition device 26 Intake valve 27 Exhaust valve 31 Clutch 40 Motor generator 41 Rotating shaft 61 Automatic transmission 62 Differential mechanism 63 Drive wheel 71 Battery 72 Inverter 81 Accelerator operation amount sensor 82 Vehicle speed sensor 83 Crank angle sensor 90 ... control device 100 ... vehicle

Claims (1)

A cylinder that burns fuel, an intake passage that introduces intake air into the cylinder, an exhaust passage that discharges exhaust gas from the cylinder, a piston that reciprocates in the cylinder, and a crankshaft that rotates due to the reciprocation of the piston. , and a fuel injection valve that supplies fuel to the cylinder, and is applied to an internal combustion engine for controlling the restart of the internal combustion engine,
a first process of obtaining the position of the piston in the specific cylinder when the internal combustion engine is restarted when the cylinder undergoing a compression stroke is the specific cylinder;
When the send-off flag is OFF, the position of the piston acquired in the first process is a range from a position on the advance side of the position of the piston when fuel injection is performed in the specific cylinder to compression top dead center. a second process of turning on the send-off flag when within the send-off range defined as
When the skip flag is ON, the position of the piston acquired in the first process is determined as a range from the position of the piston when fuel is injected in the specific cylinder to the compression top dead center. a third process of turning off the send-off flag when within the range;
After the second process or the third process, fuel injection in the specific cylinder is determined when the skip flag is OFF, and fuel injection in the specific cylinder is skipped when the skip flag is ON. a fourth process;
is executable and
repeatedly executing the first to fourth processes at a constant control cycle from when the restart of the internal combustion engine is requested until the fuel is first burned in the cylinder;
In the third process, the send-off flag is turned OFF even when the compression stroke of the cylinder that entered the compression stroke one control cycle before the third process has ended.

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