JP2015017543A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device which can properly perform a restart conforming to an actual engine stop position.SOLUTION: When a crank angle Acr (ECU value) is within a prescribed range which sandwiches a prescribed stop-time crank angle Acrpre even if the crank angle Acr (ECU value) at an engine stop time is acquired at different values with respect to an actual engine stop position which is substantially the same, a constant control value according to the prescribed stop-time crank angle Acrpre is set, and an engine 14 is restarted by using the control value, and thereby an operation state at a restart of the engine is stabilized. That is, since the engine stop-time crank angle Acr for use in control can be made to approximate an actual value rather than the crank angle Acr (ECU value), the operation state at the restart of the engine is stabilized.

Description

  The present invention relates to a control device for automatically stopping and restarting an engine in a vehicle including a four-cycle engine having a plurality of cylinders.

  A vehicle control apparatus that automatically stops and restarts a four-cycle engine having a plurality of cylinders is well known. For example, a starter for a direct injection internal combustion engine described in Patent Document 1 is this. In Patent Document 1, the crank angle when the engine is stopped is detected (stored), and at the time of cranking at the time of restart, the cylinder is in the compression stroke and is injected at a fuel injection amount corresponding to the piston position. It is disclosed that the engine is restarted by igniting at a time when it can be effectively converted into engine rotation.

JP 2000-265879 A

  By the way, as described in Patent Document 1, the crank angle when the engine is stopped is likely to be concentrated in the vicinity of a specific crank angle. For example, in automatic engine stop, it is most likely to stop near a position where the angle from the top dead center (TDC) is half of the cylinder interval of the engine. At this time, depending on the number of cylinders of the engine and the detection interval of the crank angle sensor that detects the crank angle, there is a case where the stop at an angle that is half the cylinder interval of the engine cannot be detected correctly. Specifically, in an 8-cylinder engine, when the detection interval of the crank angle sensor is 6 ° or 10 °, the cylinder interval is 90 ° (CA), and the half angle is 45 CA. 45CA is not divisible by the detection interval of 6 ° or 10 °, and any crank angle sensor cannot be used to correctly detect an angle half the cylinder interval of the engine (for example, 10 ° In this case, the detected value is 40 CA or 50 CA. Then, there is a possibility that control (for example, setting of the fuel injection amount according to the crank angle) at the time of restart after the automatic stop of the engine cannot be appropriately performed. Note that the above-described problems are not known, and no proposal has been made yet to appropriately perform the control after the stop (at the time of restart) regardless of the number of cylinders of the engine and the detection interval of the crank angle sensor. .

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to provide a vehicle control device that can appropriately perform a restart suitable for an actual engine stop position. is there.

  The subject matter of the first invention for achieving the above object is (a) a vehicle control device for automatically stopping and restarting a four-cycle engine having a plurality of cylinders, and (b) a predetermined A crank angle acquisition unit that acquires a crank angle of the engine based on a signal detected at an interval of (c), and (c) a restart of the engine based on the crank angle at the time of engine stop acquired by the crank angle acquisition unit. A restart-related value setting unit that sets a control value related to start, and (d) the restart-related value setting unit is a predetermined stop time when the acquired crank angle at the time of engine stop is obtained in advance. If the crank angle is within a predetermined range, a constant control value related to the restart is set according to the predetermined crank angle when the engine is stopped, regardless of the acquired crank angle when the engine is stopped. There is to be.

  In this way, even if the crank angle at the time of engine stop may be acquired with a different value with respect to the actual engine stop position that is substantially the same, the acquired crank angle at the time of engine stop is within a predetermined range. In this case, since the engine is restarted using a constant control value, the operation state at the time of engine restart is stabilized. That is, the engine stop position can be made closer to the actual value than the acquired crank angle when the engine is stopped, so that the operation state at the time of engine restart is stabilized. Therefore, the restart suitable for the actual engine stop position can be appropriately performed.

  Here, the second invention is the vehicle control apparatus according to the first invention, wherein the restart related value setting unit is configured such that the acquired crank angle when the engine is stopped is the predetermined crank angle when stopped. Is outside the predetermined range, the control value related to the restart is set according to the acquired crank angle when the engine is stopped. In this way, when the acquired crank angle when the engine is stopped is outside the predetermined range, the engine is restarted using the control value corresponding to the acquired crank angle when the engine is stopped. Therefore, it is possible to appropriately perform the restart suitable for the actual engine stop position.

  Further, a third aspect of the present invention is the vehicle control apparatus according to the first aspect or the second aspect, wherein the restart related value setting unit is based on the acquired crank angle when the engine is stopped. A fuel injection amount setting unit configured to set a fuel injection amount at the time of restarting the engine, wherein the fuel injection amount setting unit has a predetermined crank angle at which the acquired engine stop angle sandwiches the predetermined stop crank angle; If it is within the range, a constant fuel injection amount corresponding to the predetermined stop crank angle is set regardless of the acquired crank angle when the engine is stopped. In this way, even if the crank angle at the time of engine stop may be acquired with a different value with respect to the substantially same actual engine stop position, a constant fuel injection amount is used at the time of engine restart. The operation state when the engine is restarted is stabilized.

  According to a fourth aspect of the invention, in the vehicle control apparatus according to the third aspect of the invention, an ignition start is performed in which a cylinder is burned and the engine is rotated when the engine is started, and the fuel injection amount setting is performed. The part is to set a fuel injection amount to the cylinder to be burned first when the engine is restarted. If it does in this way, the driving | running state at the time of the engine restart accompanying ignition start will be stabilized.

  According to a fifth aspect of the present invention, in the vehicle control device according to the first aspect or the second aspect, the vehicle includes an electric motor provided in a power transmission path between the engine and the drive wheels, and A clutch for connecting / disconnecting the electric motor to / from the engine, and the restart related value setting unit is configured to engage the clutch when the engine is restarted based on the acquired crank angle when the engine is stopped. A clutch engagement timing setting section for setting the clutch engagement timing setting section when the acquired crank angle at the time of engine stop is within a predetermined range sandwiching the predetermined crank angle at the time of stop. Regardless of the acquired crank angle at the time of engine stop, the predetermined clutch engagement timing according to the predetermined crank angle at the time of stop is set. In this way, even when the crank angle at the time of engine stop is acquired with a different value from the substantially same actual engine stop position, a constant clutch engagement timing is set at the time of engine restart. Since the clutch is engaged, the clutch control is stable, and the engine operation timing is likely to be constant.

  According to a sixth aspect of the present invention, in the vehicle control device according to any one of the first to fifth aspects, the predetermined stop crank angle is determined by the crank angle acquisition unit. A value between adjacent crank angles acquired at intervals, and the cylinder angle corresponding to when any cylinder of the engine stops at the top dead center position, or a cylinder from the top dead center This is the corresponding crank angle when stopping at a position advanced by half the interval of the crank angle. In this way, when the crank angle at the stop position at which the engine is likely to stop is a crank angle that cannot be acquired by the crank angle acquisition unit, the restart suitable for the actual engine stop position is appropriately performed. be able to.

It is a figure explaining the schematic structure of the power transmission device with which the present invention was equipped, and the principal part of the control system in vehicles. It is a figure explaining the schematic structure of the engine of FIG. 1, and is a figure explaining the principal part of the control system in an engine among the control systems in a vehicle. It is a figure for demonstrating each valve opening time of an intake valve and an exhaust valve. It is a functional block diagram explaining the principal part of the control function of an electronic controller. It is a figure which shows an example that ECU value differs even if the real position at the time of an engine stop is the same. It is a figure which shows an example that ECU value differs even if the real position at the time of an engine stop is the same. It is a flowchart explaining the control operation | movement for performing the restart suitable for the principal part of the control operation | movement of an electronic controller, ie, an actual engine stop position.

  In the present invention, the vehicle preferably includes an engine, an electric motor provided in a power transmission path between the engine and driving wheels, and a clutch that connects and disconnects the electric motor to the engine. The vehicle includes a transmission that forms part of a power transmission path between the electric motor and the drive wheels. This transmission includes a manual transmission such as a known synchronous mesh type parallel two-shaft transmission having a plurality of pairs of transmission gears that are always meshed between two shafts, various automatic transmissions (planetary gear automatic transmission, synchronous mesh). Type parallel two-shaft automatic transmission, DCT, CVT, etc.). This automatic transmission is constituted by an automatic transmission alone, an automatic transmission having a fluid transmission, or an automatic transmission having a sub-transmission. The clutch is a wet or dry engagement device capable of disconnecting the engine from the drive wheel. The engine is, for example, an internal combustion engine such as a gasoline engine that generates power by burning fuel. In particular, the engine in the case of ignition start at the time of engine start is a direct injection type four-cycle gasoline engine in which fuel is directly injected into each cylinder.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a power transmission device 12 provided in a vehicle 10 to which the present invention is applied, and a diagram illustrating a main part of a control system for various controls in the vehicle 10. . 2 is a diagram for explaining a schematic configuration of the engine 14 of FIG. 1 in particular, and a diagram for explaining a main part of a control system for output control and the like in the engine 14 among the control systems in the vehicle 10. It is.

  In FIG. 1, a vehicle 10 is a hybrid vehicle including an engine 14 that functions as a driving force source for traveling and an electric motor MG. The power transmission device 12 includes an engine connecting / disconnecting clutch K0 (hereinafter referred to as a clutch K0), a torque converter 16, an automatic transmission 18 and the like in order from the engine 14 side in a transmission case 20 as a non-rotating member. ing. The power transmission device 12 is connected to a propeller shaft 26 connected to a transmission output shaft 24 that is an output rotating member of the automatic transmission 18, a differential gear 28 connected to the propeller shaft 26, and the differential gear 28. And a pair of axles 30 and the like. The pump impeller 16a of the torque converter 16 is connected to the engine connecting shaft 32 via the clutch K0 and is directly connected to the electric motor MG. The turbine impeller 16 b of the torque converter 16 is directly connected to a transmission input shaft 34 that is an input rotation member of the automatic transmission 18. The pump impeller 16a is rotationally driven by the engine 14 (and / or the electric motor MG), thereby generating hydraulic pressure for executing the shift control of the automatic transmission 18, the engagement release control of the clutch K0, and the like. A mechanical oil pump 22 is connected. The power transmission device 12 configured in this way is suitably used for, for example, the FR type vehicle 10. In the power transmission device 12, the power of the engine 14 (the torque and the force are synonymous unless otherwise distinguished) is generated between the crankshaft 36 (see FIG. 2) of the engine 14 and the clutch K0 when the clutch K0 is engaged. The engine coupling shaft 32 to be coupled is transmitted to the pair of drive wheels 38 through the clutch K0, the torque converter 16, the automatic transmission 18, the propeller shaft 26, the differential gear 28, the pair of axles 30, and the like in order. Thus, the power transmission device 12 constitutes a power transmission path from the engine 14 to the drive wheel 38.

  The automatic transmission 18 constitutes a part of the power transmission path between the engine 14 and the electric motor MG and the drive wheels 38, and the power from the driving power source for driving (the engine 14 and the electric motor MG) is directed to the drive wheels 38. A transmission for transmission. The automatic transmission 18 is, for example, a known planetary gear type multi-stage transmission in which a plurality of shift stages having different gear ratios γ (= transmission input shaft rotation speed Nin / transmission output shaft rotation speed Nout) are selectively established. Alternatively, a known continuously variable transmission or the like in which the speed ratio γ is continuously changed steplessly.

  The electric motor MG is a so-called motor generator having a function as a motor that generates mechanical power from electric energy and a function as a generator that generates electric energy from mechanical energy. The electric motor MG generates driving power using electric energy supplied from the power storage device 44 via the inverter 42 instead of or in addition to the engine 14. The electric motor MG converts the power of the engine 14 and the driven force input from the drive wheel 38 side into electric energy by regeneration, and stores the electric energy in the power storage device 44 via the inverter 42. The electric motor MG is provided in a power transmission path between the engine 14 and the drive wheel 38, and is connected to a power transmission path between the clutch K0 and the torque converter 16, and between the motor MG and the pump impeller 16a. Power is transmitted between each other. Therefore, the electric motor MG is connected to the transmission input shaft 34 of the automatic transmission 18 so as to be able to transmit power without using the clutch K0.

  The clutch K0 is, for example, a wet multi-plate hydraulic friction engagement device, and is engaged and released by the hydraulic control circuit 40 using the hydraulic pressure generated by the oil pump 22 as a base pressure. In the engagement release control, the torque capacity of the clutch K0 (hereinafter referred to as K0 torque) is changed by adjusting the pressure of a linear solenoid valve or the like in the hydraulic control circuit 40, for example. In the engaged state of the clutch K0, the pump impeller 16a and the engine 14 are integrally rotated via the engine connecting shaft 32. On the other hand, in the released state of the clutch K0, power transmission between the engine 14 and the pump impeller 16a is interrupted. That is, the engine 14 and the driving wheel 38 are disconnected by releasing the clutch K0. Since the electric motor MG is connected to the pump impeller 16a, the clutch K0 is provided in a power transmission path between the engine 14 and the motor MG, and a clutch that connects and disconnects the power transmission path, that is, the motor MG is connected to the engine 14. It also functions as a clutch that connects and disconnects.

  In FIG. 2, the engine 14 is a known direct-injection four-cycle gasoline engine that has, for example, a plurality of cylinders 50 and directly injects fuel into the cylinders 50. The engine 14 includes a combustion chamber 52 provided between a cylinder head and a piston, an intake pipe 54 connected to an intake port of the combustion chamber 52, and an exhaust pipe 56 connected to an exhaust port of the combustion chamber 52. A fuel injection device 58 provided in the cylinder head for directly injecting fuel F into the combustion chamber 52; an ignition device 60 for igniting an air-fuel mixture in the combustion chamber 52; and an intake valve for opening or closing the intake port of the combustion chamber 52 62, an exhaust valve 64 that opens or closes the exhaust port of the combustion chamber 52, an intake valve drive device 66 that opens and closes by reciprocating the intake valve 62 in synchronization with the rotation of the crankshaft 36, and an exhaust valve 64 And an exhaust valve driving device 68 that opens and closes by reciprocating in synchronization with the rotation of the crankshaft 36.

  An electronic throttle valve 70 is provided in the intake pipe 54 of the engine 14, and the electronic throttle valve 70 is opened and closed by a throttle actuator 72. In the engine 14, the fuel F is injected and supplied from the fuel injection device 58 to the intake air sucked into the combustion chamber 52 from the intake pipe 54 to form a mixture, and the mixture is ignited and burned by the ignition device 60. . Thereby, the engine 14 is driven, and the air-fuel mixture after combustion is sent into the exhaust pipe 56 as exhaust gas.

  FIG. 3 is a diagram for explaining the opening timing VTin of the intake valve 62 and the opening timing VTex of the exhaust valve 64. In FIG. 3, an arrow A indicates the valve opening timing VTin of the intake valve 62, that is, the range of the crank angle Acr at which the intake valve 62 is open. An arrow B indicates the valve opening timing VTex of the exhaust valve 64, that is, the range of the crank angle Acr at which the exhaust valve 64 is open. The valve opening timing VT in the present embodiment is a period during which the valve is opened (valve opening time) from the time when the valve opens (valve opening time) to the time when the valve closes (valve closing time), and indicates the valve opening time. is not.

  Returning to FIGS. 1 and 2, the vehicle 10 is provided with an electronic control unit (ECU) 90 including a control device of the vehicle 10 related to, for example, the engagement release control of the clutch K <b> 0 and the start control of the engine 14. The electronic control unit 90 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 90 performs output control of the engine 14, drive control of the motor MG including regeneration control of the motor MG, shift control of the automatic transmission 18, torque capacity control of the clutch K0, and the like. If necessary, it is configured separately for engine control, motor control, hydraulic control, and the like. As shown in FIGS. 1 and 2, the electronic control unit 90 includes various sensors (for example, a crank position sensor 74, a turbine rotational speed sensor 76, an output shaft rotational speed sensor 78, an electric motor rotational speed sensor 80, an accelerator opening sensor 82, Various signals (for example, a crank angle Acr indicating a crank position and a crank speed corresponding to the engine rotational speed Ne, a turbine rotational speed Nt, that is, a transmission input shaft rotation) based on values detected by a throttle sensor 84, an air flow meter 86, a battery sensor 88, etc. The transmission output shaft rotation speed Nout corresponding to the speed Nin, the vehicle speed V, the motor rotation speed Nm, the accelerator opening θacc corresponding to the driver's request for driving the vehicle 10, the throttle valve opening θth, the intake air amount Qair, the power storage The charging state (charging capacity) SOC and the like of the device 44 are respectively supplied. As shown in FIGS. 1 and 2, for example, the engine control command signal Se for controlling the output of the engine 14, the motor control command signal Sm for controlling the operation of the motor MG, the clutch K 0, A hydraulic command signal Sp for operating an electromagnetic valve (solenoid valve) or the like included in the hydraulic control circuit 40 to control the hydraulic actuator of the automatic transmission 18 includes a fuel injection device 58, an ignition device 60, and a throttle actuator 72. Are output to the engine control device such as the inverter 42, the hydraulic control circuit 40, and the like.

  FIG. 4 is a functional block diagram for explaining a main part of the control function by the electronic control unit 90. In FIG. 4, the electronic control unit 90 includes a crank angle acquisition unit, that is, a crank angle acquisition unit 92, and a hybrid control unit, that is, a hybrid control unit 94.

  The crank angle acquisition unit 92 acquires the crank angle Acr of the engine 14 based on signals detected at predetermined intervals. Specifically, returning to FIG. 2, a rotating body 89 such as a rotation detection rotor and a rotation detection drum is integrally fixed coaxially with the crankshaft 36 and rotates together with the crankshaft 36. In addition, the crank position sensor 74 is provided at a position facing a plurality of teeth 89a formed at substantially equal intervals along the circumferential direction, for example, on the outer circumferential portion of the rotating body 89 in the radial direction. As the crank position sensor 74, for example, an electromagnetic pickup type, Hall element type, MRE (Magnetic Resistance Element) type sensor or the like is employed. For example, in the case of an electromagnetic pickup sensor, the rotation of the rotating body 89 changes the air gap between the crank position sensor 74 and the teeth 89a, so that the frequency changes according to the rotational speed of the rotating body 89. An alternating voltage is generated from the crank position sensor 74. The AC voltage is supplied to the electronic control unit 90, and the supplied AC voltage is converted into a rectangular wave pulse signal P by the electronic control unit 90. The crank angle acquisition unit 92 counts up or down the crank angle Acr based on the rising (or falling) of the pulse signal P detected at a predetermined interval corresponding to the interval between the plurality of teeth 89a. To get. In order to obtain the absolute position of the crank angle Acr, for example, a rotating body 89 lacking any of the plurality of teeth 89a is used, or another rotating member that rotates in conjunction with the rotation of the crankshaft 36 ( For example, it is desirable to use a sensor signal for detecting the position of the camshaft.

  The hybrid control unit 94 has a function as an engine drive control unit that controls the drive of the engine 14 and a function as a motor operation control unit that controls an operation as a driving force source or a generator by the electric motor MG via the inverter 42. In addition, hybrid drive control by the engine 14 and the electric motor MG is executed by these control functions. For example, the hybrid control unit 94 calculates a required driving force Fdtgt as a required driving amount for the vehicle 10 by the driver based on the accelerator opening θacc and the vehicle speed V. Then, the hybrid control unit 94 considers transmission loss, auxiliary load, gear ratio γ of the automatic transmission 18, charge capacity SOC of the power storage device 44, etc., and a driving power source for travel that can obtain the required driving force Fdtgt. Command signals (engine output control command signal Se and motor control command signal Sm) for controlling the driving force source for traveling are output so as to be the output of (engine 14 and motor MG). The required drive amount includes, in addition to the required drive force Fdtgt [N] in the drive wheel 38, the required drive torque [Nm] in the drive wheel 38, the required drive power [W] in the drive wheel 38, and the transmission output shaft 24. The required transmission output torque or the like can also be used. Further, the accelerator opening degree θacc [%], the intake air amount Qair [g / sec], or the like can also be used as the required drive amount.

  Specifically, for example, when the required driving force Fdtgt is within a range that can be covered only by the output of the electric motor MG, the hybrid control unit 94 uses only the electric motor MG as a driving power source for traveling with the clutch K0 released. A traveling motor (EV traveling) is performed. On the other hand, for example, when the required driving force Fdtgt is in a range that can not be covered unless at least the output of the engine 14 is used, the hybrid control unit 94 keeps at least the engine 14 for traveling with the clutch K0 engaged. An engine traveling that travels as a driving force source, that is, a hybrid traveling (EHV traveling) is performed. In addition, the hybrid control unit 94 requests charging of the power storage device 44 when the EV drive cannot be performed because discharge of the power storage device 44 is restricted based on, for example, the dischargeable power calculated from the charge capacity SOC or the power storage device temperature. If the engine 14 or the equipment related to the engine 14 needs to be warmed up, the engine 14 is operated.

  Based on the required driving force Fdtgt or the like, the hybrid control unit 94 automatically stops the engine 14 while the engine is running, or restarts the engine 14 after the engine is stopped, and switches between EV running and EHV running. Further, the hybrid control unit 94 is a so-called automatic stop of the engine 14 in a predetermined traveling state such as when the vehicle speed V is decreasing toward zero and the accelerator is off, or when the vehicle is braked off. Perform idling stop. The hybrid control unit 94 restarts the engine 14 when a predetermined condition such as brake-off or accelerator-on is satisfied during idling stop.

  The hybrid control unit 94 controls the released clutch K0 toward engagement, for example, to crank the engine 14 by the electric motor MG, and starts fuel supply, engine ignition, and the like to start the engine 14 ( Unless otherwise distinguished, restarting is also synonymous). In this starting method, the clutch K0 is controlled so that a K0 torque for transmitting an engine starting torque, which is a torque necessary for starting the engine, to the engine 14 side can be obtained. Since the engine start torque corresponds to the MG torque Tm that flows to the engine 14 side via the clutch K0, the MG torque Tm that flows to the drive wheel 38 side is reduced by that amount. For this reason, this starting method corresponds to K0 torque for transmitting the engine starting torque to the engine 14 side in addition to the MG torque Tm necessary for satisfying the required driving torque in order to suppress the drop of the driving torque. MG torque to be increased (hereinafter, this increase is referred to as K0 compensation torque (or MG compensation torque)).

  In the EV traveling of the present embodiment, the EV traveling region is reduced by the amount of securing the MG compensation torque in preparation for engine start with respect to the maximum MG torque Tm that can be output by the electric motor MG. In other words, if the MG compensation torque can be suppressed, the EV travel range can be expanded. Therefore, in addition to the start method for controlling the clutch K0 toward engagement, the hybrid control unit 94 executes ignition start for burning the cylinders of the engine 14 and rotating the engine 14 when starting the engine. That is, the hybrid control unit 94 covers a part of the engine starting torque by performing the ignition start. In the engine starting method by the ignition start, for example, fuel is injected into a cylinder of the engine 14 stopped in the expansion stroke (that is, in a cylinder in the expansion stroke of the engine 14 whose rotation is stopped) and ignited (ignition). Then, the engine is started by burning the cylinder and rotating the crankshaft 36 by pushing down the piston by the generated explosion torque.

  When a part of the engine starting torque is covered by the ignition start, it is preferable to perform the ignition start in order to move the stopped piston. That is, it is suitable for suppressing the MG compensation torque to overcome the friction torque of the engine 14 at the start of the engine start by the explosion torque accompanying the start of ignition. Therefore, when the restart of the engine 14 is requested during EV traveling, the hybrid control unit 94 first performs ignition start and rotates the engine 14. Thereafter, the hybrid control unit 94 increases the engine rotation speed Ne by the electric motor MG by controlling the clutch K0 toward engagement. Then, after the engine rotational speed Ne is synchronized with the electric motor rotational speed Nmg, the hybrid controller 94 fully engages the clutch K0 and shifts to EHV traveling. The friction torque of the engine 14 at the time of starting the engine is a compression torque corresponding to the pumping loss, a mechanical friction torque corresponding to the sliding resistance, and a mechanical friction torque of the intake valve driving device 66 and the exhaust valve driving device 68. Total torque. However, the friction torque of the engine 14 at the start of the engine start when moving the stopped piston is exclusively the sliding resistance and the mechanical friction torque of the intake valve driving device 66 and the like because the engine rotational speed Ne is extremely low. Become.

  By the way, when the crank angle Acr is acquired based on the pulse signal P detected at a predetermined interval as in the present embodiment, the actual crank angle Acr when the engine is stopped (that is, when the engine 14 is stopped rotating). (Also called actual position) may not be detected correctly. Specifically, in an 8-cylinder engine, the explosion interval is 90 CA, and the half angle is 45 CA. Therefore, any cylinder is likely to stop at a position where it becomes TDC or 45 ATDC. When the engine is stopped, overshoot and reverse rotation may be repeated. Therefore, as shown in FIGS. 5 and 6, the crank angle Acr (also referred to as the ECU value) acquired by the crank angle acquisition unit 92 may be different even if the actual position when the engine is stopped is substantially the same. 5 and 6 show an example in which the detection interval of the crank position sensor 74 is 10 ° and the engine is stopped at a position near 45ATDC in an 8-cylinder engine. In FIG. 5, when the ECU value is 40CA and 50CA, the average actual position when the engine is stopped is substantially the same. In FIG. 6, when the engine is stopped at 45CA while rotating forward as shown in the behavior A at the time of stoppage, or when the engine is stopped at 45CA by reverse rotation before 50CA at the time of overshoot, the actual position = 45CA ECU value = 40CA. Further, as shown in stop-time behavior B, when the engine is counted up to 50 CA at the time of overshoot and the engine is stopped at 45 CA without returning to 40 CA, the ECU value = 50 CA with respect to the actual position = 45 CA. Thus, even if the actual position when the engine is stopped is the same, the ECU value may be different due to the difference in behavior when the engine is stopped.

  The electronic control unit 90 usually sets the fuel injection amount at the time of starting the engine based on the ECU value. When the ECU value = 40CA and the ECU value = 50CA are compared, the set fuel injection amount is reduced when the ECU value = 40CA. Therefore, if the actual position is the same 45CA, the lean value is obtained when the ECU value = 40CA. When the ECU value = 50 CA, the engine is in a rich state. If it does so, there exists a possibility that the driving | running state at the time of engine restart may not be stabilized. Further, the electronic control unit 90 operates the clutch K0 at the start of ignition in accordance with the start of the engine, and increases the engine rotational speed Ne with the assistance of the electric motor MG. At this time, the electronic control unit 90 sets the engagement timing of the clutch K0 in accordance with the start of the rotation of the engine 14 based on the ECU value, for example. When comparing the ECU value = 40CA and the ECU value = 50CA, if the actual position is the same 45CA, as shown in FIG. 6, the ECU value = 40CA counts up from 50CA, and the ECU value = 50CA. Since the count is counted up from 60CA, even if the actual start timing (rotation start timing) is the same, the operation time until the next count up (that is, the timing for detecting the start of rotation) is different. Then, the engagement timing of the clutch K0 is different, and the control of the clutch K0 may not be stable. Therefore, when the actual position when the engine is stopped is the crank angle Acr that cannot be acquired by the crank angle acquisition unit 92, there is a possibility that the control at the restart after the automatic stop of the engine 14 cannot be performed appropriately. .

  Therefore, as shown in FIG. 4, the electronic control unit 90 further includes an engine state determination unit, that is, an engine state determination unit 96, and a restart related value setting unit, that is, a restart related value setting unit 98.

  The engine state determination unit 96 determines whether there is an engine stop request for requesting the engine 14 to stop, for example, on the premise of restart. For example, the engine state determination unit 96 determines that the required driving force Fdtgt is within the range that can be covered only by the output of the electric motor MG during EHV traveling, or the discharge restriction of the power storage device 44, the charging request of the power storage device 44, the engine 14 and the like. When the warm-up request is canceled and EV traveling is performed, it is determined that there is an engine stop request on the assumption of restart.

  If the engine state determination unit 96 determines that there is an engine stop request, the hybrid control unit 94 stops both fuel injection and ignition to the engine 14, and the crank angle acquisition unit 92 stops the engine 14 that has stopped. The crank angle Acr is detected.

  The engine state determination unit 96 uses the crank angle Acr at the time of engine stop acquired by the crank angle acquisition unit 92 (hereinafter referred to as the crank angle Acr at the time of engine stop (ECU value)) when the engine 14 is stopped. It is determined whether or not the crank angle Acr is within a predetermined range sandwiched by a predetermined stop-time crank angle Acrpre obtained in advance. The predetermined stop crank angle Acrpre is a value between adjacent crank angles Acr (ECU value). The predetermined crank angle Acrpre at the time of stop is an actual crank angle Acr at which the engine 14 is likely to stop, and the corresponding crank angle Acr when any cylinder of the engine 14 stops at the TDC position. Alternatively, the crank angle Acr corresponding to when stopping at a position advanced from the TDC by a crank angle Acr that is half the cylinder interval. The predetermined range is a crank angle Acr (ECU value) obtained in advance that may be acquired by the crank angle acquisition unit 92 with respect to the actual position.

  Specifically, in an 8-cylinder engine, any cylinder of the engine 14 is likely to stop at the TDC position (that is, 90 ATDC position) or 45 ATDC position. Here, in the 8-cylinder engine, when any cylinder is at a position of 45ATDC, for example, assuming TDC as a reference point, there are eight positions of 45CA, 135CA, 225CA, 315CA, 405CA, 495CA, 585CA, and 675CA. Exists. In this embodiment, these eight positions are handled as 45 CA for convenience. Similarly, when one of the cylinders is at the TDC position, the eight positions are treated as 0 CA (or 90 CA) for convenience. When the crank angle Acr is acquired using TDC as a reference point, if the detection interval is 10 CA, the ECU value is 0 CA when the actual position is 0 CA, while the ECU value is 40 CA or 50 CA when the actual position is 45 CA. Accordingly, in such a case, the engine state determination unit 96 determines that the crank angle Acr (ECU value) when the engine is stopped is 40 CA or 50 CA as a value within a predetermined range sandwiching 45 CA as the predetermined stop crank angle Acrpre. It is determined whether or not.

  The restart related value setting unit 98 sets a control value related to restart of the engine 14 based on the crank angle Acr (ECU value) when the engine is stopped. Specifically, the restart-related value setting unit 98 determines that the engine angle determination unit 96 determines that the crank angle Acr (ECU value) when the engine is stopped is within a predetermined range with the predetermined crank angle Acrpre when stopped. In this case, regardless of the crank angle Acr (ECU value) when the engine is stopped, a control value related to a constant engine restart is set according to a predetermined crank angle Acrpre at the time of stop. For example, in an 8-cylinder engine, when the crank angle Acr (ECU value) when the engine is stopped is 40 CA or 50 CA, the restart related value setting unit 98 sets the crank angle Acr when the engine is stopped to the ECU value (= 40 CA). , 50CA) instead of 45CA, a control value related to a certain engine restart corresponding to the 45CA is set. On the other hand, when the engine state determination unit 96 determines that the crank angle Acr (ECU value) when the engine is stopped is outside the predetermined range (that is, the crank angle Acr (ECU value)). Is determined to be outside the predetermined range), a control value related to engine restart is set according to the crank angle Acr (ECU value) at the time of engine stop. For example, in an 8-cylinder engine, when the crank angle Acr (ECU value) when the engine is stopped is not 40 CA or 50 CA, the restart related value setting unit 98 uses the crank angle Acr when the engine is stopped as its ECU value. Set the control value related to engine restart according to the value.

  The control value related to engine restart is, for example, the fuel injection amount at engine restart. Further, the control value related to the engine restart is, for example, the engagement timing of the clutch K0 when the engine is restarted. Therefore, the restart related value setting unit 98 is a fuel injection amount setting means for setting the fuel injection amount at the time of engine restart, that is, the fuel injection amount setting unit 100 based on the crank angle Acr (ECU value) at the time of engine stop. And a clutch engagement timing setting means 102 for setting the engagement timing of the clutch K0 when the engine is restarted based on the crank angle Acr (ECU value) when the engine is stopped.

  When the engine state determination unit 96 determines that the crank angle Acr (ECU value) when the engine is stopped is within a predetermined range sandwiching the predetermined stop crank angle Acrpre, the fuel injection amount setting unit 100 stops the engine. Regardless of the crank angle Acr (ECU value) at the time, a constant fuel injection amount is set according to a predetermined crank angle Acrpre at the time of stop. On the other hand, when the engine state determination unit 96 determines that the crank angle Acr (ECU value) when the engine is stopped is outside the predetermined range, the fuel injection amount setting unit 100 determines that the crank angle when the engine is stopped. A fuel injection amount corresponding to Acr (ECU value) is set. This fuel injection amount is, for example, the fuel injection amount to the cylinder to be burned first when the engine is restarted. That is, the fuel injection amount setting unit 100 sets the fuel injection amount to the cylinder to be burned first when the engine is restarted.

  When it is determined by the engine state determination unit 96 that the crank angle Acr (ECU value) when the engine is stopped is within a predetermined range across the predetermined stop crank angle Acrpre, the clutch engagement timing setting unit 102 Regardless of the crank angle Acr (ECU value) at the time of stop, a constant engagement timing of the clutch K0 corresponding to a predetermined crank angle Acrpre at the time of stop is set. On the other hand, when the engine state determination unit 96 determines that the crank angle Acr (ECU value) when the engine is stopped is outside the predetermined range, the clutch engagement timing setting unit 102 The engagement timing of the clutch K0 is set according to the angle Acr (ECU value). The engagement timing of the clutch K0 is set, for example, as an engagement start time after a predetermined time has elapsed from the time when engine restart is determined, or as a transition time from the start of engagement to the completion of engagement.

  FIG. 7 is a flowchart for explaining the main part of the control operation of the electronic control unit 90, that is, the control operation for appropriately performing the restart in accordance with the actual engine stop position. For example, the control operation is extremely in the order of several milliseconds to several tens of milliseconds. It is executed repeatedly with a short cycle time. Further, the state of the vehicle 10 that is the premise of FIG. 7 is, for example, when the engine 14 is an 8-cylinder engine and the detection interval of the crank position sensor 74 is 10 °.

  In FIG. 7, first, in step (hereinafter, step is omitted) S10 corresponding to the engine state determination unit 96, it is determined whether there is an engine stop request on the assumption of restart, for example. If the determination in S10 is negative, this routine is terminated. If the determination is positive, in S20 corresponding to the hybrid control unit 94, for example, both fuel injection and ignition for the engine 14 are stopped. Next, in S30 corresponding to the crank angle acquisition unit 92, for example, the crank angle Acr (ECU value) when the engine is stopped is detected. Next, in S40 corresponding to the engine state determination unit 96, for example, it is determined whether or not the crank angle Acr (ECU value) at the time of engine stop detected in S30 is 40CA or 50CA. If the determination in S40 is affirmative, in S50 corresponding to the restart-related value setting unit 98 and the hybrid control unit 94, for example, the crank angle Acr at the time of engine stop is set to 45CA instead of the ECU value, and according to 45CA. A control value related to constant engine restart is set, and the subsequent control is performed. On the other hand, when the determination in S40 is negative, in S60 corresponding to the restart related value setting unit 98 and the hybrid control unit 94, for example, the crank angle Acr at the time of engine stop is set as an ECU value, and the ECU value is determined accordingly. The control value related to the engine restart is set, and the subsequent control is performed.

  As described above, according to the present embodiment, even when the crank angle Acr (ECU value) at the time of engine stop is acquired with a different value with respect to the actual engine stop position that is substantially the same, When the crank angle Acr (ECU value) is within a predetermined range across the predetermined stop crank angle Acrpre, the restart related value setting unit 98 sets a constant control value according to the predetermined stop crank angle Acrpre. Since the hybrid controller 94 restarts the engine 14 using the control value, the operating state at the time of engine restart is stabilized. That is, the crank angle Acr when the engine is stopped for control can be made closer to the actual value than the crank angle Acr (ECU value), so that the operation state at the time of engine restart is stabilized. Therefore, the restart suitable for the actual engine stop position can be appropriately performed.

  Further, according to this embodiment, when the crank angle Acr (ECU value) when the engine is stopped is outside a predetermined range across the predetermined stop crank angle Acrpre, the restart related value setting unit 98 sets the crank angle Acrpre. A control value related to the engine restart according to Acr (ECU value) is set, and the engine 14 is restarted using the control value by the hybrid control unit 94. Therefore, the restart that matches the actual engine stop position is performed. Can be performed appropriately.

  Further, according to the present embodiment, the fuel injection amount setting unit 100 determines that the crank angle Acr when the crank angle Acr (ECU value) when the engine is stopped is within a predetermined range sandwiching the predetermined crank angle Acrpre when stopped. Regardless of the (ECU value), a constant fuel injection amount is set according to the predetermined crank angle Acrpre at the time of stop, so that the crank angle Acr (ECU value) is substantially the same as the actual engine stop position. Even if the values are acquired at different values, a constant fuel injection amount is used when the engine is restarted, so that the operating state at the time of engine restart is stable.

  Further, according to the present embodiment, the fuel injection amount setting unit 100 sets the fuel injection amount to the cylinder to be burned first when the engine is restarted, so that the operation state at the time of engine restart accompanying ignition start is stabilized. .

  Further, according to the present embodiment, the clutch engagement timing setting unit 102 determines that the crank angle Acr (ECU value) when the engine is stopped is within a predetermined range sandwiching the predetermined crank angle Acrpre when the engine is stopped. Regardless of Acr (ECU value), a constant clutch K0 engagement timing is set in accordance with a predetermined stop crank angle Acrpre, so that the crank angle Acr ( Even when the ECU value is acquired with a different value, the clutch K0 is engaged using a fixed engagement timing of the clutch K0 when the engine is restarted, so that the clutch control is stable and the engine operation timing is It tends to be constant.

  Further, according to this embodiment, the predetermined stop crank angle Acrpre is a value between the adjacent crank angles Acr (ECU value), and any cylinder of the engine 14 is at the TDC position. Since the crank angle Acr corresponding to when the engine 14 is stopped, or the crank angle Acr corresponding to when the cylinder 14 is stopped at a position advanced by a crank angle Acr that is half the cylinder interval from the TDC, the actual position where the engine 14 is likely to stop is When the crank angle Acr cannot be acquired by the crank angle acquisition unit 92, it is possible to appropriately perform the restart that matches the actual engine stop position.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, an 8-cylinder engine is illustrated as the engine 14, 10 ° is illustrated as the detection interval of the crank position sensor 74, and TDC is illustrated as the reference point of the crank angle Acr. However, the present invention is not limited thereto. For example, the present invention can be applied even if the engine 14 is a 4-cylinder engine, a 6-cylinder engine, or the like. Further, the present invention can be applied even when the detection interval of the crank position sensor 74 is 6 °, 8 °, or the like. Further, the present invention can be applied even if the reference point of the crank angle Acr is 90ATDC, BDC or the like. The point is that there are two crank angles Acr (ECU value) sandwiching the actual crank position with respect to the actual crank position at which the engine 14 is likely to stop (that is, the predetermined crank angle Acrpre at the time of stop). The present invention can be applied.

  In the above-described embodiment, the fuel injection amount at the time of engine restart and the engagement timing of the clutch K0 are exemplified as the control values related to the engine restart. However, the present invention is not limited to this. For example, as a control value related to engine restart, ignition timing at the time of engine restart or the like is also assumed.

  In the above-described embodiment, the ignition start is executed for the cylinder in the expansion stroke, and the engine 14 is started by the electric motor MG. However, the present invention is not limited to this. For example, the cylinder to be burned first and the cylinder to which fuel is first injected are not necessarily cylinders in the expansion stroke. Alternatively, the engine 14 may be started by a starter motor provided separately from the electric motor MG while assisting by ignition start. If the engine can be started only by starting ignition, it is not necessary to start the engine 14 by the electric motor MG (or starter). Further, when starting the engine 14 in the rotation stop state, it is not always necessary to increase the engine rotational speed Ne from zero by starting ignition, and the engine rotational speed Ne may be started to increase by a starter.

  In the above-described embodiment, the vehicle 10 is provided with the torque converter 16 and the automatic transmission 18, but the torque converter 16 and the automatic transmission 18 are not necessarily provided. Further, although the vehicle 10 is provided with the clutch K0 and the electric motor MG, an aspect in which the engagement timing of the clutch K0 when the engine is restarted is set based on the crank angle Acr (ECU value) when the engine is stopped. Except for this, the clutch K0 and the electric motor MG are not necessarily provided.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 14: Engine 38: Drive wheel 50: Cylinder
90: Electronic control device (control device)
92: Crank angle acquisition unit 98: Restart related value setting unit 100: Fuel injection amount setting unit 102: Clutch engagement timing setting unit K0: Engine connection / disconnection clutch (clutch)
MG: Electric motor

Claims (6)

A vehicle control device for automatically stopping and restarting a four-cycle engine having a plurality of cylinders,
A crank angle obtaining unit for obtaining a crank angle of the engine based on a signal detected at a predetermined interval;
A restart related value setting unit for setting a control value related to restart of the engine based on the crank angle at the time of engine stop acquired by the crank angle acquisition unit;
The restart related value setting unit, when the acquired crank angle at the time of engine stop is in a predetermined range sandwiching the predetermined crank angle at the time of stop obtained in advance, the acquired crank angle at the time of engine stop Regardless of the above, the vehicle control apparatus is characterized in that a constant control value related to the restart is set in accordance with the predetermined stop crank angle.   The restart-related value setting unit determines whether the acquired crank angle when the engine is stopped is outside a predetermined range sandwiching the predetermined crank angle when the engine is stopped according to the acquired crank angle when the engine is stopped. The vehicle control device according to claim 1, wherein a control value related to the restart is set. The restart-related value setting unit includes a fuel injection amount setting unit that sets a fuel injection amount when the engine is restarted based on the acquired crank angle when the engine is stopped.
The fuel injection amount setting unit, when the acquired crank angle at the time of engine stop is in a predetermined range sandwiching the predetermined crank angle at the time of stop, regardless of the acquired crank angle at the time of engine stop, 3. The vehicle control device according to claim 1, wherein a constant fuel injection amount is set in accordance with the predetermined stop crank angle. When starting the engine, the ignition is started by burning the cylinder and rotating the engine,
4. The vehicle control device according to claim 3, wherein the fuel injection amount setting unit sets a fuel injection amount to a cylinder to be burned first when the engine is restarted. The vehicle includes an electric motor provided in a power transmission path between the engine and driving wheels, and a clutch that connects and disconnects the electric motor to and from the engine.
The restart-related value setting unit includes a clutch engagement timing setting unit that sets an engagement timing of the clutch when the engine is restarted based on the acquired crank angle when the engine is stopped.
When the acquired crank angle at the time of engine stop is in a predetermined range sandwiching the predetermined crank angle at the time of stop, the clutch engagement timing setting unit is independent of the acquired crank angle at the time of engine stop. 3. The vehicle control device according to claim 1, wherein a constant engagement timing of the clutch is set in accordance with the predetermined stop crank angle.   The predetermined crank angle at the time of stop is a value between adjacent crank angles acquired at the predetermined interval by the crank angle acquisition unit, and any one of the cylinders of the engine is located at a top dead center position. 6. The crank angle corresponding to when the vehicle is stopped at a crank angle, or the crank angle corresponding to when the vehicle is stopped at a position advanced from the top dead center by a crank angle that is half the cylinder interval. The vehicle control device according to any one of the above.

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