JP4946704B2 - Idle stop car - Google Patents

Description

  The present invention relates to an idle stop vehicle in which an engine is rotated by an electric motor when starting after an idle stop, and more specifically, an idle stop having a decompression function for reducing in-cylinder pressure during compression for starting the engine at the start. Related to cars.

  2. Description of the Related Art An idle stop type hybrid vehicle that includes an electric motor as a driving source in addition to an engine and starts the engine by cranking the engine when starting after the idle stop is already well known.

There is a technique called decompression (or decompression) that is known as a technique related to starting an engine, although it is not special for a hybrid vehicle. This decompression reduces the force required for cranking by reducing the in-cylinder pressure when the engine is compressed when starting. Regarding the start control by decompression, a mechanism for restricting the movement of the intake valve or the exhaust valve to the closed position is provided, and until the engine speed exceeds the resonance speed range by this decompression mechanism when starting the engine, There is a technique for reducing the in-cylinder pressure (Patent Document 1).
Japanese Patent Laid-Open No. 08-028313 (paragraph numbers 0017,0027)

  According to decompression, when the engine is rotated by an electric motor when starting after an idle stop, the remaining capacity of the battery of the electric motor is small and sufficient torque cannot be obtained by the electric motor. Since the reaction force can be reduced, it is avoided that the start of the engine is hindered due to insufficient output of the electric motor. However, starting the engine with the in-cylinder pressure reduced by decompression reduces the effective compression ratio of the engine due to the reduction of the in-cylinder pressure. There is a problem that discharge of water is encouraged.

  In an idle stop vehicle in which an engine is rotated by an electric motor when starting after an idle stop, the present invention secures engine startability by reducing the in-cylinder pressure and reduces the excess air ratio associated with the reduction in in-cylinder pressure. The purpose is to suppress the discharge of unburned material by control.

An idle stop vehicle according to the present invention includes an engine, an electric motor configured to transmit torque to the engine, a pressure adjusting device for reducing in-cylinder pressure during compression of the engine, and the engine And a control unit for controlling the electric motor, and the control unit generates a command signal for the electric motor for rotating the engine when starting after an idle stop, and the command signal After the engine starts rotating, it is determined whether or not a predetermined start condition is satisfied for the engine, and when the engine is started when the predetermined start condition is satisfied, the pressure adjusting device It is determined whether or not the in-cylinder pressure is reduced, and the in-cylinder pressure is reduced to reduce the in-cylinder pressure. At the time, as a starting fuel amount that is an amount of fuel supplied when starting the engine, a first amount that gives a predetermined excess air ratio according to the in-cylinder pressure reduced by the pressure adjusting device is set. The control unit sets the first amount as the starting fuel amount at the time of starting by reducing the in-cylinder pressure, and the normal amount other than the case of performing by reducing the in-cylinder pressure. At the time of start, a second amount that gives an excess air ratio larger than the predetermined excess air ratio is set.

  According to the present invention, when starting after an idle stop, the pressure adjusting device reduces the in-cylinder pressure when the engine is compressed, thereby reducing the load on the electric motor when the engine is rotated. Even when a sufficient torque cannot be obtained by the electric motor due to a lack of capacity or the like, the engine can be rotated and reliably started. Further, when starting the engine by reducing the in-cylinder pressure by the pressure adjusting device, the in-cylinder pressure is set by setting the starting fuel amount for the engine to an amount that gives a predetermined excess air ratio corresponding to the reduced in-cylinder pressure. It is possible to maintain the excess air ratio necessary for ensuring the ignitability with respect to the reduction of the amount of fire and to suppress the discharge of unburned matter.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a configuration of a vehicle drive system according to an embodiment of the present invention.

  The vehicle according to the present embodiment is a parallel hybrid vehicle, and includes an engine 1 that is an internal combustion engine and an electric motor (hereinafter referred to as “motor generator”) 2 as drive sources.

  The engine 1 employs a variable-type engine (corresponding to a “pressure adjusting device”) configured such that the valve timing can be changed as the valve operating device 11 of the intake valve, and the closing timing of the intake valve is determined by the crank angle. Is delayed so that the substantial compression ratio of the engine 1 (hereinafter referred to as “effective compression ratio”) is reduced, and the in-cylinder pressure during compression can be reduced. The device for reducing the in-cylinder pressure at the time of compression is not limited to the one that delays the closing timing of the intake valve in this way, but the one that temporarily opens the intake valve during the compression stroke, or the one that closes the intake valve You may employ | adopt what restrict | limits operation | movement so that this may not close completely. The in-cylinder pressure can be reduced not only by the intake valve but also by changing the valve timing of the exhaust valve. In the present embodiment, the in-cylinder pressure is reduced by the valve operating device 11 by delaying the phase of the cam shaft in the engine 1 with respect to the crankshaft by a hydraulic actuator (not shown).

  The motor generator 2 can be operated as either a motor or a generator. The engine 1 and the motor generator 2 are in a state in which the crankshaft of the engine 1 and the rotation shaft of the motor generator 2 are coaxially connected to each other, and drive torque is generated only by either the engine 1 or the motor generator 2. The driving torque can be generated by both the engine 1 and the motor generator 2. The motor generator 2 is an AC motor and operates with an AC current supplied with the battery 3 as a power source. When the motor generator 2 is operated as a motor, the direct current from the battery 3 is converted into an alternating current by the inverter 4 and supplied to the motor generator 2. On the other hand, when the motor generator 2 is operated as a generator, the alternating current generated by the motor generator 2 is converted into a direct current by the inverter 4 and supplied to the battery 3. In this way, the battery 3 can be charged both when the vehicle is running and when the vehicle is stopped by operating the motor generator 2 as a generator. In FIG. 1, for convenience of explanation, the main body of the motor generator 2 is indicated by a two-dot chain line, and the relationship between the rotor 21 and the stator 22 and the rotating shaft 23 is shown as the internal structure.

  An automatic transmission 5 having a torque converter 51 is provided on the output side of the motor generator 2, and driving torque generated by the engine 1 and the motor generator 2 is transmitted through the automatic transmission 5 to a predetermined speed. It is configured to be transmitted to the drive shaft 6 by a ratio.

  The drive torque after the shift by the automatic transmission 5 is transmitted to the left and right drive wheels 8a and 8b via the drive shaft 6 and the differential 7 to propel the vehicle.

  An electronic control unit (corresponding to a “control unit”, hereinafter referred to as “ECM”) 101 performs drive control of the vehicle, and also has a function as a “start control device” according to the present embodiment. . The ECM 101 outputs these command signals to the engine 1 (including the actuator of the valve gear 11), the motor generator 2 (specifically, the inverter 4) and the automatic transmission 5. The ECM 101 is provided with a detection signal from the accelerator sensor 151 for detecting an operation amount of the accelerator pedal (hereinafter referred to as “accelerator operation amount”) by the driver as a signal relating to the driving condition of the vehicle. A signal from the crank angle sensor 152 that outputs a signal for each crank angle or reference crank angle (the ECM 101 calculates the engine speed based on this), and the rotational speed of the output shaft of the automatic transmission 5 is detected. A detection signal from the rotation speed sensor 153, a signal from the brake switch 154 that outputs an ON signal while the brake pedal is depressed, a detection signal from the current sensor 155 for detecting the remaining capacity of the battery 3, etc. Is entered. The remaining capacity of the battery 3 can be calculated by integrating current values detected by the current sensor 155 when the battery 3 is charged and discharged. In the present embodiment, the detection signal from the rotation speed sensor 153 is used as an indication of the state quantity corresponding to the vehicle speed.

  The ECM 101 executes predetermined calculations based on various input signals and controls the engine 1 and the like. The ECM 101 performs idle stop control for stopping the engine 1 based on the establishment of a predetermined idle stop condition, and reduces the in-cylinder pressure during compression by the valve gear 11 when starting after the idle stop. In this case, the excess air ratio of the air-fuel mixture formed in the cylinder is reduced as a control for suppressing the discharge of unburned matter. In the present embodiment, the excess air ratio is reduced by adjusting the fuel injection amount. The idle stop condition is established when the brake pedal is depressed in a state where the accelerator operation amount is equal to or less than a predetermined amount and the vehicle speed is equal to or less than a predetermined value. Further, the stop release after the idle stop is performed when the brake pedal is returned and the accelerator pedal is depressed after the idle stop is executed.

  Hereinafter, the operation of the ECM 101 according to the present embodiment will be described with reference to flowcharts.

  FIG. 2 shows a flowchart of a basic routine of control (hereinafter referred to as “start control”) performed when the ECM 101 starts after the idle stop.

  In S101, it is determined whether or not an idle stop is being performed. When the idle stop is being performed, the process proceeds to S102, and when the idle stop is not being performed, the process proceeds to S110. The idle stop is executed when the idle stop condition is satisfied by the process of S204 (FIG. 3) described later.

  In S102, it is determined whether or not there is a start request. If there is a start request, the process proceeds to S103. If not, the routine is terminated without performing the subsequent processing, and the idle stop is continued. The determination as to whether or not there has been a start request is made based on the accelerator operation amount, and it is determined that the start request has been made when an accelerator operation amount equal to or greater than a predetermined amount is detected.

  In S103, for starting the engine 1, the engine 1 is rotated by motoring (powering of the motor generator 2). In the present embodiment, the motor generator 2 generates a driving torque of the vehicle in a low speed range until the start of the engine 1 is completed, and the vehicle starts with the start of this motoring.

  In S104, it is determined whether or not the engine 1 can be started. The determination as to whether or not the engine can be started is made based on the engine speed NE, and it is determined that the engine can be started when it has reached a predetermined engine speed NEstr. If the engine can be started, the process proceeds to S105. If the engine cannot be started, the process returns to S103 to continue the motoring and increase the engine speed NE.

  In S105, when starting the engine 1, it is determined whether or not the in-cylinder pressure during compression is being reduced by the valve gear 11. When it is reduced, the process proceeds to S106, and when it is not reduced, this routine is ended. By reducing the in-cylinder pressure at the time of compression, the substantial compression ratio (hereinafter referred to as “effective compression ratio”) CR of the engine 1 is lowered. Whether or not to reduce the in-cylinder pressure is determined by the ECM 101 in a separately provided control routine. When it is determined that the remaining capacity of the battery 3 is small and the motor generator 2 cannot generate sufficient torque for motoring when the engine 1 is started, the ECM 101 sends a command signal to the actuator of the valve gear 11. To reduce the in-cylinder pressure.

  In S106, the amount of fuel supplied to the engine 1 at the time of starting (hereinafter referred to as “starting fuel amount”) is corrected, and the excess air ratio LAMD is reduced. The excess air ratio LAMD at the time of starting is set with the characteristics shown in FIG. 4 and decreases as the effective compression ratio CR is greatly reduced by greatly reducing the in-cylinder pressure. Reduce. FIG. 4 shows a reduction margin dLAMD of the excess air ratio with respect to the effective compression ratio CR, and this reduction margin dLAMD increases as the effective compression ratio CR is smaller. In this embodiment, such a characteristic of the excess air ratio LAMD is achieved by adjusting the starting fuel amount. By setting a lower limit limiter LMTQ that determines the minimum amount of the starting fuel amount, and limiting the starting fuel amount to a value equal to or greater than the lower limit limiter LMTQ, the characteristic of the excess air ratio LAMD is realized. In this embodiment, the lower limit limiter LMTQ of the starting fuel amount is set in advance as table data as shown in FIG. 5, and this table data is searched based on the operating angle of the valve gear 11 during actual operation. Is set. The lower limit limiter LMTQ is set to a larger value as the effective compression ratio CR is smaller, and greatly reduces the excess air ratio LAMD. The excess air ratio is corrected not only by limiting the starting fuel amount with the lower limit limiter LMTQ, but also by setting the starting fuel amount when reducing the in-cylinder pressure in advance corresponding to the effective compression ratio CR. Is also possible. The starting fuel amount in this case is set to a larger value as the effective compression ratio CR is smaller, assuming that the excess air ratio LAMD corresponding to the effective compression ratio CR is given.

  In S107, the power generation torque of the motor generator 2 (a negative torque, the magnitude of which is indicated by an absolute value) is corrected. Since the engine torque increases due to the limit of the starting fuel amount by the lower limit limiter LMTQ, a negative torque corresponding to the increase is generated by the motor generator 2 to suppress the occurrence of a shock due to the increase of the engine torque. By directly calculating the correction of the power generation torque in the form of feedforward control, it is possible to suppress the occurrence of a shock without a delay as in the case of a method such as rotational speed control. In the present embodiment, the engine torque increase amount dTE corresponding to the effective compression ratio CR and the accelerator operation amount APO is calculated with reference to a correction map set in advance with a tendency as shown in FIG. dTE is added to the power generation torque of the motor generator 2 at the start. The engine torque increase amount dTE is set to a larger value as the effective compression ratio CR is smaller and the accelerator operation amount APO is smaller.

  In S <b> 108, a signal for instructing the actuator of the valve gear 11 to release the in-cylinder pressure reduction is generated. Based on this, the valve gear 11 operates to advance the closing timing of the intake valve and return the effective compression ratio CR to that during normal operation.

  In S109, the engine 1 is started by supplying the starting fuel amount limited by the lower limiter LMTQ.

  In S110, an engine control routine is executed to control the operation of the engine 1 during idling and traveling.

  FIG. 3 is a flowchart of an engine control routine. In the present embodiment, this routine is configured as a subroutine (S110) of the basic routine shown in FIG.

  In S201, it is determined whether or not an idle condition is satisfied. When it is established, the process proceeds to S202, and when it is not established, the process proceeds to S205. The idle condition is determined to be satisfied when the accelerator operation amount is equal to or less than a predetermined amount and the vehicle speed is equal to or less than a predetermined value.

  In S202, the engine 1 is idled by controlling the rotational speed of the motor generator 2.

  In S203, it is determined whether an idle stop condition is satisfied. When it is established, the process proceeds to S204, and when it is not established, this routine is terminated without performing the process of S204. The idle stop condition is determined to be satisfied when the brake pedal is depressed when the idle condition (S201) is satisfied.

  In S204, the fuel supply to the engine 1 is stopped and the engine 1 is stopped.

  In S205, the engine torque is controlled. The engine torque is controlled by calculating the basic torque of the engine 1 based on the operating conditions such as the amount of accelerator operation and the engine speed, and setting the target torque TEtrg with various corrections to the target torque TEtrg. On the other hand, the fuel is supplied in an amount corresponding to the basic torque TEtrg.

  In S206, it is determined whether or not the reduction of the in-cylinder pressure by the valve gear 11 is being released. If it is being canceled, the process proceeds to S207. If it is not being canceled and has already been completed, this routine is terminated without performing the processes of S207 and 208.

  In S207, the target torque TEtrg of the engine 1 is limited to a value equal to or greater than a predetermined lower limit limiter LMTT. In the present embodiment, the lower limit limiter LMTT is set in advance as table data having a tendency as shown in FIG. 7, and is changed to a smaller value as the effective compression ratio CR increases as the decompression release progresses. .

  In S208, the surplus of the engine torque limited by the lower limit limiter LMTT with respect to the target torque TEtrg is added to the power generation torque of the motor generator 2, and this surplus is absorbed in the power generation torque.

  Next, the content of the above power generation control will be further described with reference to the time chart shown in FIG.

  When the idle condition is established by determining that the accelerator pedal is returned, the operation mode of the engine 1 shifts to idling. In idling, the engine 1 is controlled at a constant output, and the engine speed NE is controlled to a predetermined idle speed NEidl by controlling the rotational speed of the motor generator 2. If the brake pedal is depressed while the idle condition is established, the idle stop condition is established, the fuel supply to the engine 1 is stopped, and the engine 1 is stopped (time t0).

  When the accelerator pedal is depressed, the idle stop condition is canceled and a start request is generated (time t1). When the start request is generated, the motor generator 2 operates to rotate the engine 1. In the present embodiment, the effective compression ratio CR of the engine 1 is reduced according to the starting condition. Here, when the remaining capacity of the battery 3 is small and sufficient torque for starting the engine 1 cannot be generated by the motor generator 2, the closing timing of the intake valve is delayed by the valve operating device 11 to compress the engine 1. The in-cylinder pressure (that is, the effective compression ratio CR) at the time is reduced.

  When the engine speed NE reaches a predetermined start speed NEstr by motoring, it is assumed that the engine 1 can be started and fuel supply to the engine 1 is started (time t2). Here, since the effective compression ratio CR is reduced when the engine 1 is started, the lower limit limiter LMTQ is set, thereby limiting the starting fuel amount and sufficiently reducing the excess air ratio LAMD (in FIG. 8). In this case, the reduction allowance dLAMD is shown.) In response to the setting of the starting fuel amount, an engine torque increase amount dTE corresponding to the restriction by the lower limit limiter LMTQ is calculated, and the calculated dTE is added to the power generation torque of the motor generator 2.

  After the engine 1 is started, the mode is shifted to the traveling mode by the engine 1. A target torque TEtrg of the engine 1 corresponding to the operating condition such as the accelerator operation amount is set, and the engine torque is controlled to the target torque TEtrg. After the engine 1 is started, the torque actually generated in the engine 1 is limited to a value equal to or higher than the lower limit limiter LMTT until the reduction of the in-cylinder pressure by the valve gear 11 is released (time t3). The surplus (= TE−TEtrg) of the engine torque limited by the lower limit limiter LMTT with respect to the target torque TEtrg is added to the power generation torque of the motor generator 2 and used as energy for power generation.

  After the reduction of the in-cylinder pressure is released (time t3), the engine torque is controlled to the target torque TEtrg, and the vehicle is propelled by the driving torque from the engine 1.

  According to this embodiment, the following effects can be obtained.

  In the present embodiment, the load on the motor generator 2 when the engine 1 is rotated for starting is reduced by reducing the in-cylinder pressure at the time of compression of the engine 1 when starting after the idle stop. Even if a sufficient torque for motoring cannot be obtained by the motor generator 2 due to a lack of the remaining capacity 3, the engine 1 can be rotated and reliably started.

  In this embodiment, the starting fuel amount for the engine 1 is limited by the lower limit limiter LMTQ at the time of starting by reducing the in-cylinder pressure (that is, the effective compression ratio CR), and the excess air ratio LAMD is set to the effective compression ratio CR (“ It is possible to maintain the excess air ratio necessary for ensuring ignitability and suppress the discharge of unburned components.

  In the above, when the remaining capacity of the battery 3 is sufficiently secured, the in-cylinder pressure during the compression of the engine 1 is not reduced (hereinafter referred to as “decompression”), and the in-cylinder at the time of normal start. The pressure was maintained. However, the present invention is not limited to such control, and the decompression is performed even when the remaining capacity of the battery 3 is secured. In such a case, the engine speed NE increases when the engine 1 is started. Then, when the resonance rotational speed range (the upper limit rotational speed NErsn is shown in FIG. 8) is removed, the reduction of the in-cylinder pressure may be cancelled. In FIG. 8, the change in the operating angle of the valve gear 11 in this case is indicated by a two-dot chain line B. The starting rotational speed NEstr for determining whether or not the engine 1 can be started is set to a value larger than the upper limit rotational speed NErsn.

  Further, in the above, when the remaining amount of the battery 3 is small by giving the starting fuel amount the tendency as shown in FIG. 5, the effective compression ratio CR is reduced to a value smaller than the value CR1. Although it was decided that the correction for reducing the excess air ratio LAMD was substantially performed, the excess air ratio LAMD was reduced over the entire effective compression ratio CR regardless of the reduction cost of the effective compression ratio CR. Also good.

  In the above description, when the engine 1 is started by decompression, the starting fuel amount limited by the lower limiter LMTQ is the “first amount”, and the normal in-cylinder pressure (effective compression ratio CR) is maintained regardless of the decompression. The starting fuel amount that is set at the time of starting is set to the “second amount”, and the starting fuel amount (= LMTQb) that is set when the in-cylinder pressure reduced by the compression is equal to or greater than the value CR1 Corresponds to an amount of 3.

The block diagram of the drive system of the idle stop vehicle which concerns on one Embodiment of this invention Flow chart of basic routine of start control according to the embodiment Engine control routine flowchart Explanatory drawing which shows the characteristic given to the excess air ratio in the case of decompression Setting example of lower limiter for starting fuel amount to realize characteristics shown in FIG. Setting example of engine torque increase by limiting the amount of starting fuel Setting example of lower limiter for engine torque after engine start Time chart showing details of start control

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 11 ... Valve operating device as "pressure reduction device", 2 ... Motor generator as "electric motor", 3 ... Battery, 4 ... Inverter, 5 ... Automatic transmission, 51 ... Torque converter, 6 ... Drive Axis 7: Differential 8a 8b Drive wheel 101 Electronic control unit 151 “Control unit” 151 Accelerator sensor 152 Crank angle sensor 153 Vehicle speed sensor 154 Brake switch 155 Battery current Sensor.

Claims (8)

Engine,
An electric motor configured to transmit torque to the engine;
A pressure adjusting device for reducing in-cylinder pressure during compression of the engine;
A control unit for controlling the engine and the electric motor,
The control unit is
When starting after an idle stop, a command signal for the electric motor for rotating the engine is generated,
After the engine starts rotating based on the command signal, it is determined whether or not a predetermined start condition is established for the engine,
When starting the engine due to the establishment of the predetermined start condition, it is determined whether or not the in-cylinder pressure is reduced by the pressure adjusting device,
At the time of starting with the in-cylinder pressure being reduced, a predetermined amount of air corresponding to the in-cylinder pressure reduced by the pressure adjusting device is used as a starting fuel amount that is an amount of fuel supplied when starting the engine. Set the first amount that gives the excess rate,
The control unit sets the first amount as the starting fuel amount when the start is performed while reducing the in-cylinder pressure, and the normal start time other than when the start is performed with the in-cylinder pressure being reduced. In the idling stop vehicle, a second amount that gives an excess air ratio larger than the predetermined excess air ratio is set. Engine,
An electric motor configured to transmit torque to the engine;
A pressure adjusting device for reducing in-cylinder pressure during compression of the engine;
A control unit for controlling the engine and the electric motor,
The control unit is
When starting after an idle stop, a command signal for the electric motor for rotating the engine is generated,
After the engine starts rotating based on the command signal, it is determined whether or not a predetermined start condition is established for the engine,
When starting the engine due to the establishment of the predetermined start condition, it is determined whether or not the in-cylinder pressure is reduced by the pressure adjusting device,
At the time of starting with the in-cylinder pressure being reduced, a predetermined amount of air corresponding to the in-cylinder pressure reduced by the pressure adjusting device is used as a starting fuel amount that is an amount of fuel supplied when starting the engine. Set the first amount that gives the excess rate,
The control unit sets a fuel supply amount that gives a smaller excess air ratio as the first amount when the in-cylinder pressure is greatly reduced when starting with the in-cylinder pressure being reduced. Idle stop car. Engine,
An electric motor configured to transmit torque to the engine;
A pressure adjusting device for reducing in-cylinder pressure during compression of the engine;
A control unit for controlling the engine and the electric motor,
The control unit is
When starting after an idle stop, a command signal for the electric motor for rotating the engine is generated,
After the engine starts rotating based on the command signal, it is determined whether or not a predetermined start condition is established for the engine,
When starting the engine due to the establishment of the predetermined start condition, it is determined whether or not the in-cylinder pressure is reduced by the pressure adjusting device,
At the time of starting with the in-cylinder pressure being reduced, a predetermined amount of air corresponding to the in-cylinder pressure reduced by the pressure adjusting device is used as a starting fuel amount that is an amount of fuel supplied when starting the engine. Set the first amount that gives the excess rate,
The control unit sets the first amount when the amount of reduction in the in-cylinder pressure is larger than a predetermined value at the time of starting by reducing the in-cylinder pressure. When the reduction amount is less than or equal to the predetermined value, the idling stop vehicle that sets a third amount that gives an excess air ratio larger than the predetermined excess air ratio as the starting fuel amount. Engine,
An electric motor configured to transmit torque to the engine;
A pressure adjusting device for reducing in-cylinder pressure during compression of the engine;
A control unit for controlling the engine and the electric motor,
The control unit is
When starting after an idle stop, a command signal for the electric motor for rotating the engine is generated,
After the engine starts rotating based on the command signal, it is determined whether or not a predetermined start condition is established for the engine,
When starting the engine due to the establishment of the predetermined start condition, it is determined whether or not the in-cylinder pressure is reduced by the pressure adjusting device,
At the time of starting with the in-cylinder pressure being reduced, a predetermined amount of air corresponding to the in-cylinder pressure reduced by the pressure adjusting device is used as a starting fuel amount that is an amount of fuel supplied when starting the engine. Set the first amount that gives the excess rate,
The control unit is an idle stop vehicle that reduces the torque of the electric motor in response to setting of the starting fuel amount by the first amount when the engine is started. 5. The idle stop vehicle according to claim 4, wherein the control unit changes a torque reduction amount when reducing the torque of the electric motor according to the magnitude of the engine torque generated by the setting of the first amount. Engine,
An electric motor configured to transmit torque to the engine;
A pressure adjusting device for reducing in-cylinder pressure during compression of the engine;
A control unit for controlling the engine and the electric motor,
The control unit is
When starting after an idle stop, a command signal for the electric motor for rotating the engine is generated,
After the engine starts rotating based on the command signal, it is determined whether or not a predetermined start condition is established for the engine,
When starting the engine due to the establishment of the predetermined start condition, it is determined whether or not the in-cylinder pressure is reduced by the pressure adjusting device,
At the time of starting with the in-cylinder pressure being reduced, a predetermined amount of air corresponding to the in-cylinder pressure reduced by the pressure adjusting device is used as a starting fuel amount that is an amount of fuel supplied when starting the engine. Set the first amount that gives the excess rate,
The control unit is
While driving with the engine after the engine is started, the target torque of the engine is set according to the operating conditions, and the actual engine torque is controlled to approach this target torque,
A characteristic in which the actual engine torque is decreased as the in-cylinder pressure increases until the decrease in the in-cylinder pressure by the pressure adjusting device is released after the start performed by setting the first amount. An idling stop vehicle that is set in advance and limited to a lower limit torque that is larger than the target torque. The control unit controls the torque of the electric motor so as to cancel the surplus of the actual engine torque with respect to the target torque until the reduction of the in-cylinder pressure is released after the engine is started. Item 7. The idle stop vehicle according to item 6. Engine,
An electric motor configured to transmit torque to the engine;
A pressure adjusting device for reducing in-cylinder pressure during compression of the engine,
When starting after idling stop, the electric motor rotates the engine,
After the engine starts rotating, when a predetermined start condition is established for the engine, the engine is started,
At the time of starting performed by reducing the in-cylinder pressure by the pressure adjusting device, the excess air ratio when starting the engine is smaller than that at the time of normal starting other than when performing by reducing the in-cylinder pressure. Idle stop car limited to less than excess air ratio.

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