Engine starting device

Abstract

To provide an engine starting device that ensures reliable engine starting. [Solution] When the engine 2 is started by the starter 4 when the intake valve 24 is not at its most retarded closing time, the valve timing device 28 is driven, and the clutch oil pump 7 is stopped during the period the valve timing device 28 is driven, and then the oil pump 7 is driven to increase the hydraulic pressure supplied to the clutch. When the engine 2 is started by the motor 1 when the intake valve 24 is not at its most retarded closing time, the oil pump 7 is driven, and the valve timing device 28 is stopped during the period the oil pump 7 is driven, and then the valve timing device 28 is driven to retard the closing time of the intake valve.

Description

Technical Field

[0001] The present invention relates to an engine starting device.

Background Art

[0002] Patent Document 1 discloses an engine equipped with an electric valve timing changing device capable of changing the closing timing of an intake valve, wherein the closing timing of the intake valve is set to the most retarded angle side timing before engine startup in order to improve engine startability.

[0003] Patent Document 2 discloses a vehicle equipped with an engine and a motor as drive sources.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of Invention

Problem to be Solved by the Invention

[0005] In vehicles equipped with an engine and a motor as drive sources, studies have been conducted to provide a clutch that connects and disconnects the engine and the motor, and to use an electric device as a device that supplies hydraulic pressure to the clutch. However, if the valve timing changing device and the oil pump are configured to be electric, and these and the starter are simply configured to operate by power supply from a common battery, the power consumption of the battery becomes excessively large accompanying the operation of these components during engine startup, and the starter or the clutch may not operate properly, leading to a risk of deterioration in engine startability.

[0006] The present invention has been made in view of the circumstances as described above, and an object of the present invention is to provide an engine starting device that can ensure engine startability. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides an engine having an electrically operated valve timing device capable of changing the closing timing of an intake valve, a starter and a motor capable of starting the engine, a hydraulic clutch capable of connecting and disconnecting the engine and the motor, an electrically operated oil pump that supplies hydraulic pressure to the clutch, a battery that supplies power to the starter, the valve timing device and the oil pump, and a control unit that controls the valve timing device, the starter, the motor and the oil pump, wherein when the engine is started by the starter when the closing timing of the intake valve is not at the most retarded timing, the control unit changes the closing timing of the intake valve The valve timing device is driven to retard the valve timing, and the oil pump is stopped for at least a portion of the period during which the valve timing device is driven, and then the oil pump is driven to increase the hydraulic pressure supplied to the clutch. When the engine is started by the motor while the intake valve is not closed at the time of the most retarded timing, the oil pump is driven to increase the hydraulic pressure supplied to the clutch, and the valve timing device is stopped for at least a portion of the period during which the oil pump is driven, and then the valve timing device is driven to retard the closing timing of the intake valve (Claim 1).

[0008] When starting the engine with a starter, there is no need to connect the engine and the motor, so the hydraulic pressure supplied to the clutch can be low. In response to this, in the present invention, when starting the engine with a starter when the intake valve is not at its most retarded timing, the oil pump is stopped for at least a portion of the valve timing device's operating period, and then the oil pump is started. As a result, the period during which the oil pump and the valve timing device operate simultaneously can be kept short, thereby preventing excessive battery power consumption, and the valve timing device can retard the intake valve closing timing earlier, allowing the engine to start early and smoothly.

[0009] On the other hand, when starting an engine with a motor, it is necessary to connect the engine and the motor, which requires increasing the hydraulic pressure supplied to the clutch. In response to this, in the present invention, when starting the engine with a motor while the intake valve is not at its most retarded timing, the valve timing device is stopped for at least a portion of the oil pump's operating period, and then the valve timing device is started. As a result, the period during which the oil pump and valve timing device operate simultaneously can be kept short, thereby preventing excessive battery power consumption, and the hydraulic pressure supplied to the clutch can be increased early to connect the engine and motor with the clutch, that is, the engine can be brought into a state where it can be started by the motor. Moreover, the clutch engagement time, which occurs after the oil pump is started, can be used to retard the intake valve's closing timing. As a result, the engine and motor can be connected in a short time, and the intake valve's closing timing can be brought to its most retarded timing, allowing the engine to be started early and smoothly.

[0010] In the above configuration, preferably, the vehicle is further equipped with an electric vehicle-mounted device powered by the battery, wherein when the engine is started by the starter when the intake valve is not closed at the latest angle, the control unit drives both the oil pump and the valve timing device before power is supplied to the vehicle-mounted device, temporarily stops the oil pump when power is supplied to the vehicle-mounted device, and then restarts the oil pump. When the engine is started by the motor when the intake valve is not closed at the latest angle, the control unit drives both the oil pump and the valve timing device before power is supplied to the vehicle-mounted device, temporarily stops the valve timing device when power is supplied to the vehicle-mounted device, and then restarts the valve timing device (Claim 2).

[0011] In this configuration, before power is supplied to the on-board equipment and when the simultaneous operation of the oil pump and valve timing device can keep the battery power consumption relatively low, both the oil pump and valve timing device are operated. On the other hand, when power is supplied to the on-board equipment and the simultaneous operation of the on-board equipment, oil pump, and valve timing device increases the battery power consumption, one of the oil pump or valve timing device is operated preferentially. Therefore, while preventing excessive battery power consumption due to the simultaneous operation of the on-board equipment, oil pump, and valve timing device, both the connection between the engine and motor and the change to the retarded timing of the intake valve closing can be performed early.

[0012] In the above configuration, preferably, when the motor starts the engine while the intake valve is not closed at the latest timing, the control unit stops driving the valve timing device from the time it starts supplying power to the onboard equipment until the hydraulic pressure supplied to the clutch reaches a predetermined determination hydraulic pressure (Claim 3).

[0013] This configuration allows for an earlier increase in hydraulic pressure supplied to the clutch, enabling a more reliable and earlier connection between the engine and motor.

[0014] In the above configuration, preferably, when a predetermined retardation control condition is met while the engine is stopped, the control unit drives the valve timing device so that the closing time of the intake valve is the most retarded time, and the retardation control condition includes the condition that the closing time of the intake valve is not the most retarded time and that the user has performed a specific action (Claim 4).

[0015] With this configuration, the valve timing device is driven while the engine is stopped, which increases the likelihood that the intake valve will be at its most retarded timing when the engine starts. However, if the valve timing device is driven while the engine is stopped in this way, the battery's charge will be low before the engine starts, and if the battery's power consumption is high when the engine starts, there is a risk that the battery will not be able to output sufficient power to the valve timing device and the like. In contrast, the present invention prevents the battery's power consumption from becoming excessive when the engine starts, as described above. Therefore, it is possible to ensure that the power supplied from the battery to the valve timing device and the like is secured when the engine starts, while increasing the likelihood that the intake valve will be at its most retarded timing when the engine starts. [Effects of the Invention]

[0016] As explained above, the engine starting device of the present invention ensures the starting performance of the engine. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram of a vehicle equipped with an engine starting device according to an embodiment of the present invention. [Figure 2] This is a schematic diagram illustrating the configuration of the intake SVT. [Figure 3] This is a block diagram showing the vehicle's control system. [Figure 4] This is a flowchart showing the procedure for controlling the ignition timing retardation when the engine is stopped. [Figure 5] This is a flowchart illustrating the procedure for vehicle starting control. [Figure 6] This is a flowchart showing the procedure of motor start control. [Figure 7] This is a flowchart showing the procedure of starter start control. [Figure 8] This is a map diagram showing the relationship between battery temperature, battery SOC, and start mode. [Figure 9] This is a time chart schematically showing the temporal change of each parameter in the motor start mode. [Figure 10] This is a time chart schematically showing the temporal change of each parameter in the starter start mode. [Modes for Carrying Out the Invention]

[0018] Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

[0019] (Overall Configuration) Figure 1 is a schematic configuration diagram of a vehicle V to which an engine starting device D according to an embodiment of the present invention is applied. Figure 2 is a schematic configuration diagram for explaining the configurations of an engine 2 and an intake SVT 28 to be described later. Figure 3 is a block diagram showing the control system of the vehicle V. The vehicle V is equipped with a motor 1, an engine 2, a clutch 3, a starter 4, a high-voltage battery 31, and a low-voltage battery 32. Both the motor 1 and the engine 2 are capable of driving wheels 13 as driving sources for the vehicle V. That is, the vehicle V of the present embodiment is a hybrid vehicle that uses both the motor 1 and the engine 2 as driving sources.

[0020] Motor 1 is a motor generator that combines the functions of both a motor and a generator. For example, Motor 1 consists of a three-phase AC synchronous electric motor. Motor 1 operates as a motor and generates the driving force to rotate the wheels 13. The output shaft (rotor shaft) of Motor 1 is connected to the wheels 13 via an automatic transmission (AT) 5 and a differential 11, and the rotation of the output shaft of Motor 1 is transmitted to the wheels 13 through these. Motor 1 also operates as a motor and generates the driving force to rotate the engine 2. In other words, Motor 1 also acts as a starting device that forcibly rotates the engine 2 to start it. Furthermore, Motor 1 operates as a generator when the vehicle V is decelerating, etc., and generates electricity by receiving the rotational force transmitted from the wheels 13. This Motor 1 corresponds to the "motor" of the present invention.

[0021] The high-voltage battery 31 is a rechargeable secondary battery. For example, the high-voltage battery 31 is a lithium-ion battery. The high-voltage battery 31 and the motor 1 are electrically connected via an inverter 34. The high-voltage battery 31 supplies driving power to the motor 1 and also receives and stores the power generated by the motor 1. The inverter 34 controls the rotational speed of the motor 1 by adjusting the power between the motor 1 and the high-voltage battery 31, which converts between DC and AC.

[0022] The high-voltage battery 31 is equipped with a battery sensor SN5 that detects the input and output current to the high-voltage battery 31. The current value detected by the battery sensor SN5 is used to determine the battery SOC (State of Charge: the ratio of the current charge amount to the charge amount when the high-voltage battery 31 is fully charged). Specifically, the PCM 101, which will be described later, calculates the charge amount and discharge amount of the high-voltage battery 31 per unit time based on the value detected by the battery sensor SN5, and calculates the battery SOC by integrating these values. The high-voltage battery 31 is also equipped with a battery temperature sensor SN6 that detects the battery temperature, which is the temperature of the high-voltage battery 31.

[0023] Engine 2 has cylinders 20 that divide the combustion chamber. Engine 2 generates power by the combustion of a fuel-air mixture in the combustion chamber. In this embodiment, a four-cycle, four-cylinder gasoline engine with four cylinders 20 arranged in series and using gasoline as the main fuel is used as engine 2. Engine 2 is provided with an injector 22 for injecting fuel and a spark plug 23 for igniting the fuel-air mixture. In this embodiment, the injector 22 injects fuel directly into the combustion chamber of each cylinder 20. The fuel-air mixture injected from the injector 22 is combusted by ignition by the spark plug 23. As a result, the piston 21 fitted in each cylinder 20 reciprocates, and the crankshaft 26 connected to each piston 21 rotates.

[0024] The engine 2 is equipped with an intake valve 24 that opens and closes the opening of an intake port for introducing intake air into each cylinder 20, and an exhaust valve 25 that opens and closes the opening of an exhaust port for releasing exhaust gas from each cylinder 20.

[0025] Each intake valve 24 is driven by an intake valve train mechanism 24A, which includes an intake camshaft 24C. The intake valve train mechanism 24A incorporates an intake SVT 28. The intake SVT 28 changes the phase (rotational phase) of the intake camshaft 24C relative to the phase (rotational phase) of the crankshaft 26, and consequently, the opening and closing timing of the intake valves 24. The intake SVT 28 changes the opening and closing timing of the intake valves 24 by the same amount while maintaining the lift amount and opening duration of the intake valves 24 constant. The intake camshaft 24C is shared by all intake valves 24 of all cylinders 20, and the opening and closing timing of all intake valves 24 of all cylinders 20 is changed collectively by the intake SVT 28. The intake SVT 28 is electrically powered and changes the opening and closing timing of the intake valves 24 by receiving electricity. The intake SVT 28 corresponds to the "valve timing device" of the present invention.

[0026] Engine 2 is equipped with an intake cam angle sensor SN4 for detecting the phase of the intake camshaft 24C. Although not shown in the figures, in this embodiment, the exhaust valve train mechanism 25A is also equipped with an exhaust SVT, which is configured similarly to the intake SVT 28 to change the opening and closing timing of the exhaust valve 25, and a sensor for detecting the phase of the exhaust camshaft.

[0027] The clutch 3 connects the motor 1 and the engine 2 in a way that allows for disconnection and reconnection. Specifically, the clutch 3 connects the rotating shaft (rotor shaft) of the motor 1 and the crankshaft 26, which is the output shaft of the engine 2, in series, or disconnects them. The clutch 3 includes a pair of clutch plates 3A that are axially opposed to each other. The clutch 3 is displaceable between a tightened state in which the clutch plates 3A are pressed against each other and the motor 1 and engine 2 are connected, and a disconnected state in which the clutch plates 3A are separated and the connection between the motor 1 and engine 2 is released.

[0028] The clutch 3 is hydraulic, and its engagement and disengagement are switched by a hydraulic adjustment device 6. The hydraulic adjustment device 6 switches the clutch 3 by adjusting the hydraulic pressure supplied from the clutch oil pump 7. Specifically, when the clutch 3 is engaged, the hydraulic adjustment device 6 increases the hydraulic pressure acting on the clutch plates 3A to press the clutch plates 3A together, and when the clutch 3 is disengaged, it reduces the hydraulic pressure to release the pressure between the clutch plates 3A.

[0029] When motor 1 is operating as a motor and engine 2 is running (specifically, when engine 2 is burning the fuel-air mixture and generating a torque higher than the torque required for self-sustaining rotation), and clutch 3 is engaged to connect motor 1 and engine 2, the torques of both motor 1 and engine 2 are transmitted to the wheels 13 via the automatic transmission 5, etc. On the other hand, when motor 1 is operating as a motor and clutch 3 is disengaged to release motor 1 and engine 2, only the torque of motor 1 is transmitted to the wheels 13. Furthermore, when motor 1 is operating as a motor and engine 2 is stopped, and clutch 3 is engaged to connect motor 1 and engine 2, the torque of motor 1 is transmitted to engine 2, and engine 2 is forcibly driven to rotate by motor 1.

[0030] The starter 4 is a motor used to start the engine 2. The starter 4 is connected to the crankshaft 26 of the engine 2 via a belt or the like. When power is supplied, the starter 4 rotates and forcibly drives the crankshaft 26 to rotate. As described above, the motor 1 can also start the engine 2, and in this embodiment, the starter 4 and the motor 1 are mounted as the starting device for the engine 2. However, the drive voltage of the starter 4 is lower than the drive voltage of the motor 1, and the output torque of the starter 4 is smaller than the output torque of the motor 1.

[0031] The low-voltage battery 32 is a rechargeable secondary battery, similar to the high-voltage battery 31. However, the low-voltage battery 32 has a lower nominal voltage than the high-voltage battery 31. For example, a 24V lithium-ion battery is used as the high-voltage battery 31, and a 12V lead-acid battery is used as the low-voltage battery 32. As described above, the starter 4, which has a lower drive voltage than the motor 1, is powered by the low-voltage battery 32. In addition to the starter 4, the low-voltage battery 32 also powers the injector 22, spark plug 23, and clutch oil pump 7. Furthermore, the low-voltage battery 32 also powers the PCM 101, ECM 102, SVT-DU 103, etc., which will be described later. The low-voltage battery 32 is electrically connected to a generator driven by the engine 2 and is charged as the engine 2 rotates.

[0032] The low-voltage battery 32 is electrically connected to the high-voltage battery 31 via a DC-DC converter 33. The DC-DC converter 33 can step down the high-voltage DC current output from the high-voltage battery 31 and supply it to the low-voltage battery 32. The power source for the DC-DC converter 33 is the low-voltage battery 32, and the DC-DC converter 33 starts up and operates by being powered by the low-voltage battery 32. The DC-DC converter 33 corresponds to the "in-vehicle equipment" of the present invention.

[0033] The DC-DC converter 33 is connected to a CAN (Controller Area Network) bus provided on the vehicle V, and the CAN bus is powered by a low-voltage battery 32 or the like via the DC-DC converter 33. In this embodiment, the PCM 101 (described later), the controller that controls the display provided on the vehicle V, etc., are connected to each other by the CAN bus and communicate via CAN, and the DC-DC converter 33 supplies a low-voltage DC current to the CAN bus.

[0034] (Structure of intake SVT) As shown in Figure 2, the intake SVT 28 according to this embodiment includes a case 281, a rotor 242 and an inner gear 283 housed inside the case 281, and a control motor 28M.

[0035] The case 281, rotor 242, and inner gear 283 are each substantially cylindrical in shape. The rotor 242 is coaxially connected to the intake camshaft 24C. A ring gear 282A, which includes multiple internal teeth, is formed on the inner circumferential surface of the rotor 242. A sprocket 281A is formed on the outer circumferential surface of the case 281. The case 281 is connected to the crankshaft 26 of the engine 2 via a timing chain 201 engaged with the sprocket 281A. The inner gear 283 is rotatably supported by the case 281, with some of the external teeth formed on its outer circumferential surface meshing with the internal teeth of the ring gear 282A. The inner gear 283 is positioned eccentrically with respect to the intake camshaft 24C. The number of external teeth on the inner gear 283 is fewer than the number of internal teeth on the ring gear 282A, and these constitute an internal planetary gear mechanism.

[0036] The control motor 28M is connected to the inner gear 283 via shafts 284A and 285. The control motor 28M rotates the inner gear 283 relative to the rotor 242, thereby rotating the intake camshaft 24C, which is connected to the rotor 282, relative to the crankshaft 26, which is connected to the inner gear 283 via the case 281 and timing chain 201, and changing the opening and closing timing of the intake valve 24. Specifically, when the engine 2 is stopped, when the control motor 28M is driven to rotate and its rotational speed is greater than 0, the intake camshaft 24C rotates relative to the crankshaft, which has a rotational speed of 0 (zero), and the opening and closing timing of the intake valve 24 is changed. Also, when the engine 2 is running, the rotational speed of the control motor 28M is increased or decreased relative to the rotational speed of the case 281, which changes the phase of the intake camshaft 24C relative to the crankshaft and changes the opening and closing timing of the intake valve 24.

[0037] Furthermore, the intake SVT28 is configured such that the range of rotation of the inner gear 283 relative to the rotor 242, and consequently the range of rotation of the intake camshaft 24C relative to the crankshaft 26, is restricted to a predetermined range, and the opening and closing timing of the intake valve 24 changes only within that predetermined range.

[0038] The structure of the exhaust SVT29 is the same as that of the intake SVT28, so its explanation will be omitted. Hereafter, the control motor 28M of the intake SVT28 will be referred to as the intake SVT motor 28M. The intake SVT motor 28M is, for example, a brushless motor.

[0039] (Control system) Vehicle V is equipped with a PCM (Power train Control Module) 101, an ECM (Engine Control Module) 102, and an SVT-DU (SVT-Drive Unit) 104 as units 100 for controlling various parts of vehicle V. The PCM 101 is a unit that comprehensively controls vehicle V. In this embodiment, the motor 1, hydraulic regulator 6, clutch oil pump 7, starter 4, and DC-DC converter 33 are controlled by the PCM 101. The ECM 102 is a unit that mainly controls various parts of the engine 2. The ECM 102 controls the injectors 22 and spark plugs 23 provided in the engine 2. The SVT-DU 104 is a unit that controls the intake SVT 28 and exhaust SVT 29. The SVT-DU 104 controls the control motor (intake SVT motor) 28M of the intake SVT 28 and the control motor of the exhaust SVT 29. The PCM101 and ECM102, and the ECM102 and SVT-DU104 are interconnected in a way that allows for mutual communication. The PCM101, ECM102, and SVT-DU104 are all microprocessors and are composed of well-known CPUs, ROMs, RAMs, etc. The unit 100, which includes the PCM101, ECM102, and SVT-DU104, corresponds to the "control unit" of the present invention. Hereinafter, the unit 100, that is, the PCM101, ECM102, and SVT-DU104 collectively referred to as the control unit 100, will be used as appropriate.

[0040] The control unit 100 receives detection signals sequentially from various sensors installed in the vehicle V. In addition to the battery sensor SN5, battery temperature sensor SN6, and intake cam angle sensor SN4, the control unit 100 receives detection signals from the crank angle sensor SN1, engine temperature sensor SN2, and accelerator pedal position sensor SN3. The crank angle sensor SN1 and engine temperature sensor SN2 are installed in the engine 2. The crank angle sensor SN1 detects the rotation angle (crank angle) and the rotational speed of the crank shaft 26, i.e., the engine speed. The engine temperature sensor SN2 detects the temperature of the engine 2. Specifically, the temperature of the engine 2 is highly correlated with the temperature of the lubricating oil that flows through and lubricates various parts of the engine 2. Therefore, in this embodiment, the engine temperature sensor SN2 detects the temperature of the lubricating oil as the temperature of the engine 2. The vehicle V is equipped with an accelerator pedal that is pressed by the driver to accelerate or decelerate the vehicle V. The accelerator pedal position sensor SN3 detects the accelerator pedal position, which is the amount the accelerator pedal is pressed.

[0041] The control unit 100 also receives signals from various switches installed on the vehicle V sequentially. The vehicle V is equipped with a start switch SW1, which is operated by the driver to switch the vehicle V on and off. When a predetermined operation is performed on the start switch SW1, the control unit 100 determines that there has been a vehicle start request to start the vehicle V. The predetermined operation is, for example, a pressing operation on the start switch SW1. The vehicle V is equipped with a door open / close switch SW2, which outputs a signal corresponding to the open / closed state of the doors installed on the vehicle V. The control unit 100 receives signals from the start switch SW1 and the door open / close switch SW2.

[0042] (Tilt control during stopping) Next, we will explain the stopping angle retardation control performed by the control unit 100.

[0043] If the closing timing of the intake valve 24 at the start of engine 2 is set to the latest possible timing, the most retarded timing, and the intake valve 24 is configured to close near or past top dead center of compression, the compression resistance on the piston 21 can be kept low, and the starting performance of engine 2 can be improved. Therefore, in this embodiment, when engine 2 is stopped, the intake SVT 28 is controlled so that the closing timing of the intake valve 24, and thus the opening and closing timing, is set to the most retarded timing in preparation for the next engine start. Specifically, when engine 2 is stopped (when engine 2 transitions from a running state to a stopped state), the control unit 100 issues a command to the intake SVT motor 28M so that the closing timing of the intake valve 24 is set to the most retarded timing.

[0044] With the above control, when the engine 2 is stopped, the closing timing of the intake valve 24 is basically set to the retarded timing. That is, the relative position of the inner gear 283 and case 281 of the intake SVT 28 with respect to the ring gear 282A is set to the timing when the opening and closing timing of the intake valve 24 is retarded. However, if the frictional resistance between the inner gear 283 and the ring gear 282A of the intake SVT 28 is small, the ring gear 282A and consequently the intake camshaft 24C may rotate against the frictional resistance while the engine 2 is stopped, and the closing timing of the intake valve 24 may shift from the retarded timing toward the advanced timing. Therefore, in this embodiment, retarded timing control is implemented when the vehicle V and engine 2 are stopped to return the opening and closing timing of the intake valve 24 to the retarded timing.

[0045] In the following, the rotational phase of the intake camshaft 24C relative to the crankshaft 26 will be referred to as the phase of the intake SVT 28. Furthermore, the state in which the opening and closing timing of the intake valve 24 is at its most retarded angle will be referred to as the intake SVT 28 being at its most retarded angle, and changing the phase of the intake SVT 28 so that the opening and closing timing of the intake valve 24 is retarded will be referred to as retarding the phase of the intake SVT 28.

[0046] Figure 4 is a flowchart showing the procedure for stopping ignition timing retardation control. As described above, stopping ignition timing retardation control is performed while the vehicle V is stopped. Therefore, the control unit 100 first determines whether or not the vehicle V is stopped (step S1). This determination is made, for example, based on a signal from the start switch SW1. If the determination in step S1 is NO and the vehicle V is not stopped, the control unit 100 terminates the process (returns to step S1).

[0047] On the other hand, if the determination in step S1 is YES and the vehicle V is stopped, the control unit 100 determines whether the closed door of the vehicle V has been opened, that is, whether the user has performed the action of opening the door (step S2). This determination is made based on the signal from the door open / close switch SW2. Here, this action of opening the door corresponds to the "specific action" of the present invention.

[0048] If the determination in step S2 is NO and the action of opening the door has not been performed, the control unit 100 terminates the process (returns to step S1). On the other hand, if the determination in step S2 is YES and the action of opening the door has been performed, the control unit 100 determines whether the number of stopping ignition retardation cycles is less than or equal to the determination cycle (step S3). The number of stopping ignition retardation cycles is the number of times stopping ignition retardation control has been performed, specifically the number of times the intake SVT28 has been started while the vehicle V is stopped. The determination cycle is set in advance and stored in the control unit 100. The determination cycle is set to, for example, about 5 times. The stopping ignition retardation cycle is reset to 0 (zero) when the vehicle V is released from being stopped.

[0049] If the determination in step S3 is NO and the number of retardation cycles at stop is greater than the determination cycle, the control unit 100 terminates the process (returns to step S1). On the other hand, if the determination in step S3 is YES and the number of retardation cycles at stop is less than or equal to the determination cycle, the control unit 100 then determines whether the intake SVT 28 is at its retarded angle (step S4). This determination is made based on the detection value of the intake cam angle sensor SN4. Note that the determination of whether the intake SVT 28 is at its retarded angle, which is made in step S12 of the vehicle start control described later, step S35 of the motor start control described later, and step S51 of the starter start control described later, is also made based on the detection value of the intake cam angle sensor SN4.

[0050] If the determination in step S4 is YES and the intake SVT28 is at its slowest angle, the control unit 100 terminates the process (returns to step S1). On the other hand, if the determination in step S4 is NO and the intake SVT28 is not at its slowest angle, the control unit 100 counts up the number of times the angle is retarded at stop (step S5) and drives the intake SVT28 (step S6).

[0051] In this specification, the state in which the intake SVT 28 is energized is referred to as the intake SVT 28 being driven, and the state in which the intake SVT 28 is driven includes both the state in which the intake SVT motor 28M is rotating and the state in which the intake SVT motor 28M is not rotating but is energized. Furthermore, the state in which the intake SVT 28 is stopped (driven) refers to the state in which the power supply to the intake SVT 28 is stopped.

[0052] In step S6, the control unit 100 outputs a command signal to the intake SVT 28 so that the intake SVT motor 28M rotates in a direction that retards the opening and closing timing of the intake valve 24. The control unit 100 also adjusts the amount of current supplied to the intake SVT 28 (intake SVT motor 28M) so that the torque it applies to the intake camshaft 24C is such that the torque allows the intake camshaft 24C to rotate relative to the crankshaft 26. By performing this step S6, the phase of the intake SVT 28 is retarded toward the retarded phase.

[0053] Next, the control unit 100 determines whether the driving time of the intake SVT 28 is equal to or greater than a predetermined determination time (step S7). Specifically, the control unit 100 measures the duration of energization of the intake SVT 28 and uses this measured time as the driving time of the intake SVT 28 to make the determination in step S7. The determination time is set in advance and stored in the control unit 100. The determination time is set to a sufficiently large value, and by continuously energizing for the determination time, the intake SVT 28 reaches its slowest angle. The determination time is set to, for example, about 250 seconds. In this embodiment, even if the intake SVT 28 reaches its slowest angle before the driving time of the intake SVT 28 reaches the determination time, the amount of energization supplied to the intake SVT 28 is maintained at the same amount as before the intake SVT 28 reached its slowest angle, and torque is applied to the intake camshaft 24C that allows it to rotate relative to the crankshaft 26. Accordingly, the phase of the intake camshaft 24C relative to the crankshaft 26 is maintained at a phase corresponding to the most retarded timing, and the intake SVT 28 is maintained at the most retarded angle at least until the determination time is reached. Alternatively, the current may be reduced after the intake SVT 28 reaches its most retarded angle.

[0054] If the determination in step S7 is YES and the drive time of the intake SVT 28 is equal to or greater than the determination time, the control unit 100 terminates processing (returns to step S1). On the other hand, if the determination in step S7 is NO and the drive time of the intake SVT 28 is less than the determination time, the control unit 100 basically returns to step S6 and continues driving the intake SVT 28. However, if a vehicle start request is made before the drive time reaches the determination time, the control unit 100 proceeds to step S12 shown in Figure 5.

[0055] Thus, in this embodiment, when the vehicle V is stopped, and the number of stopping time retardations is less than or equal to the determination number, and the operation to open the door is performed while the intake SVT 28 is not at its most retarded angle, the intake SVT 28 is driven and retarded so that its phase, i.e., the opening and closing timing of the intake valve 24, is at its most retarded angle.

[0056] (Vehicle starting control) Next, the vehicle start control, which is performed by the control unit 100 when the vehicle V is started and includes step S12 described above, will be explained using the flowchart in Figure 5. Hereinafter, the driving of the intake SVT 28 while the vehicle V is stopped and no vehicle start request has been issued, as performed in step S6 described above, will be referred to as the stationary driving of the intake SVT 28.

[0057] As described above, vehicle start control is the control of vehicle V when it is started, and the control unit 100 first determines whether or not there has been a vehicle start request (step S11). This determination is made based on the signal from the start switch SW1. If the determination in step S11 is NO and there is no vehicle V start request, the control unit 100 repeats the determination. The determination in step S11 is repeated at predetermined intervals while vehicle V is stopped.

[0058] If the determination in step S11 is YES and a request to start the vehicle V is made, the control unit 100 determines whether the intake SVT 28 is at its slowest angle (step S12). As described above, step S12 is also performed if a request to start the vehicle V is made while the intake SVT 28 is being driven while stationary (when the determination in step S8 in Figure 8 is YES).

[0059] If the determination in step S12 is YES and the intake SVT 28 is at its slowest angle, the control unit 100 proceeds to step S14. On the other hand, if the determination in step S12 is NO and the intake SVT 28 is not at its slowest angle, the control unit 100 drives the intake SVT 28 (step S13). Here, if a vehicle V start request is made while the intake SVT 28 is being driven while stationary, the intake SVT 28 is already being driven, so in this case, the driving of the intake SVT 28 will continue. On the other hand, if the intake SVT 28 is not being driven while stationary, the driving of the intake SVT 28 is started in step S13. In step S13, similar to step S6, the control unit 100 rotates the intake SVT motor 28M in a direction that retards the opening and closing timing of the intake valve 24, and adjusts the amount of current supplied to the intake SVT 28 so that the torque that the intake SVT 28 applies to the intake camshaft 24C is sufficient to rotate the intake camshaft 24C relative to the crankshaft 26. After step S13, the control unit 100 proceeds to step S14.

[0060] In step S14, the control unit 100 starts driving the clutch oil pump 7. Specifically, the control unit 100 starts supplying power to the clutch oil pump 7 and starts it to rotate. This starts the increase in the hydraulic pressure supplied to the hydraulic pressure adjustment device 6 and, consequently, the hydraulic pressure that can be supplied to the clutch 3. Hereinafter, the hydraulic pressure supplied to the hydraulic pressure adjustment device 6 and, consequently, the hydraulic pressure that can be supplied to the clutch 3 will be referred to as the clutch hydraulic pressure.

[0061] Next, the control unit 100 starts supplying power to the DC-DC converter 33 in order to start it up (step S15).

[0062] Next, the control unit 100 performs starting control according to the starting mode of the vehicle V (steps S16 to S20). In this embodiment, three starting modes are set for the starting mode of the vehicle V: EV starting mode, motor starting mode, and starter starting mode. The EV starting mode is a mode in which only motor 1 is started without starting engine 2, and the vehicle V is driven using only motor 1 without starting engine 2 thereafter. Both the motor starting mode and the starter starting mode are modes in which both motor 1 and engine 2 are started. However, in the motor starting mode, engine 2 is started by motor 1, and in the starter starting mode, engine 2 is started by starter 4.

[0063] The control unit 100 determines the starting mode according to the battery temperature and battery SOC. Figure 8 is a map showing the relationship between battery temperature (horizontal axis) and battery SOC (vertical axis) and the starting mode.

[0064] From the standpoint of vehicle V's exhaust gas performance and quietness, it is desirable that the engine 2 is driven infrequently. However, when the temperature of the high-voltage battery 31 is low, its internal resistance increases, causing the output voltage of the high-voltage battery 31 to decrease. Therefore, in this case, the drive voltage of the motor 1 also decreases, and there is a risk that the motor 1 alone may not be able to secure the output necessary to drive vehicle V. Also, when the state of charge (SOC) of the high-voltage battery 31 is low, there is a risk that the drive voltage of the motor 1 will decrease due to a large voltage drop, etc.

[0065] In this embodiment, if the battery temperature is higher than a predetermined determination temperature and the battery SOC is higher than a predetermined second SOC (when the battery temperature and battery SOC are in region C shown in Figure 8), the EV start mode is set to start mode in order to drive the vehicle V with only the motor 1. Otherwise, both the motor 1 and the engine 2 are started. However, if the temperature or SOC of the high-voltage battery 31 is low, the drive voltage of the motor 1 will be low, which may make it difficult to start the engine 2 with the motor 1. Therefore, if the battery temperature is below the determination temperature (when the battery temperature and battery SOC are in region A1 shown in Figure 6), or if the battery SOC is below the first SOC which is lower than the second SOC (when the battery temperature and battery SOC are in region A2 shown in Figure 6), the starter start mode is set to start mode and the engine 2 is started by the starter 4. On the other hand, if the battery temperature is higher than the judgment temperature and the battery SOC is higher than the first SOC but less than or equal to the second SOC (when the battery temperature and battery SOC are in region B shown in Figure 6), the starter starting mode is set to the starting mode and the motor 1 starts the engine 2.

[0066] The control unit determines the starting mode by comparing the battery SOC calculated based on the value detected by the battery sensor SN5 and the battery temperature detected by the battery temperature sensor SN6 with the first SOC, second SOC, and determination temperature, as described above. The first SOC, second SOC, and determination temperature are pre-set and stored in the control unit 100.

[0067] Returning to Figure 5, if the control unit 100 determines the starting mode to be the EV starting mode (if the determination in step S16 is YES), it performs EV driving control to drive the vehicle V using the motor 1 (step S17). Specifically, the control unit 100 starts the motor 1 without starting the engine 2, and changes the rotational speed of the motor 1 according to the accelerator opening, etc. The timing of starting the motor 1 is determined to be when conditions such as the accelerator opening becoming greater than 0 are met.

[0068] On the other hand, if the control unit 100 determines the starting mode to be the motor starting mode (if the determination in step S16 is NO and the determination in step S18 is YES), it performs motor starting control to start the engine 2 using the motor 1 (step S19). Also, if the control unit 100 determines the starting mode to be the starter starting mode (if the determinations in steps S16 and S18 are NO), it performs motor starting control to start the engine 2 using the starter 4 (step S20). After the motor starting control and starter starting control have been performed, the control unit 100 drives the vehicle V using both the engine 2 and the motor 1 as the driving sources.

[0069] Next, motor start control will be explained using the flowchart in Figure 6. When motor start control is initiated, the control unit 100 determines whether or not the DC-DC converter 33 has finished starting up (step S31). As described above, the DC-DC converter 33 supplies power to the CAN bus, and when the DC-DC converter 33 has finished starting up, CAN communication within the vehicle V begins. The CAN bus is connected to the PCM 101. Therefore, for example, the control unit 100 (PCM 101) makes the determination in step S31 based on the communication status of CAN communication between itself and other controllers.

[0070] If the determination in step S31 is YES and the DC-DC converter 33 has started up, the control unit 100 then determines whether the clutch hydraulic pressure is equal to or greater than the determination hydraulic pressure, that is, whether the clutch hydraulic pressure has reached the determination hydraulic pressure (step S33). In this embodiment, a hydraulic pressure sensor for detecting the clutch hydraulic pressure is provided, and the determination in step S33 is made based on the value detected by this hydraulic pressure sensor. The determination hydraulic pressure is set in advance and stored in the control unit 100. If the determination in step S33 is YES and the clutch hydraulic pressure is equal to or greater than the determination hydraulic pressure, the control unit 100 proceeds to step S34.

[0071] On the other hand, if the determination in step S31 is NO and the DC-DC converter 33 has not yet started up, or if the determination in step S31 is YES and the DC-DC converter 33 has started up but the clutch hydraulic pressure has not reached the determination hydraulic pressure, the control unit 100 stops the intake SVT 28 (step S32). In other words, the power supply to the intake SVT 28 is stopped. If the intake SVT 28 is already stopped, this state is maintained. Specifically, the intake SVT 28 is driven if the determination in step S12 is NO and the intake SVT 28 is not at its slowest angle at the time of the vehicle start request. Therefore, if the determination in step S12 is NO, the state of the intake SVT 28 is switched from the driven state to the stopped state, and if the determination in step S12 is YES, the stopped state of the intake SVT 28 is maintained in step S32. After step S32, the control unit 100 returns to step S31 and repeats the steps from step S31 onwards.

[0072] In step S34, the control unit 100 initiates the engagement of the clutch 3. Specifically, the control unit 100 instructs the hydraulic pressure regulator 6 to increase the hydraulic pressure acting on the clutch plate 3A so that the clutch 3 transitions from the disengaged state to the engaged state.

[0073] Furthermore, the control unit 100 determines whether the intake SVT 28 is at its slowest angle (step S35). If the determination in step S35 is NO and the intake SVT 28 is not at its slowest angle, the control unit 100 restarts driving the intake SVT 28 and drives it until the determination in step S35 becomes YES, that is, until the intake SVT 28 is at its slowest angle. On the other hand, if the determination in step S35 is NO and the intake SVT 28 is at its slowest angle, the control unit 100 proceeds to step S37.

[0074] Thus, if the intake SVT28 is not at its slowest angle when a vehicle start request is made, the control unit 100 starts driving the intake SVT28. However, when the motor start mode is determined to be the start mode, the intake SVT28 is temporarily stopped until the DC-DC converter 33 has finished starting up and the clutch hydraulic pressure is equal to or greater than the determination hydraulic pressure. Once the DC-DC converter 33 has finished starting up and the clutch hydraulic pressure is equal to or greater than the determination hydraulic pressure, the intake SVT28 is restarted. Hereinafter, the condition that the DC-DC converter 33 has finished starting up and the clutch hydraulic pressure is equal to or greater than the determination hydraulic pressure will be referred to as the motor drive permission condition.

[0075] In step S37, the control unit 100 determines whether or not the clutch 3 has been fully engaged. This determination is made based, for example, on the detected value of a sensor that detects the hydraulic pressure acting on the clutch plate 3A. If the determination in step S37 is NO and the clutch 3 has not been fully engaged, the control unit 100 continues to increase the hydraulic pressure acting on the clutch plate 3A using the hydraulic pressure adjustment device 6, and waits for this determination to become YES.

[0076] On the other hand, if the determination in step S37 is YES and the clutch 3 is fully engaged, the control unit 100 starts driving the motor 1 (step S38). As described above, the clutch 3 is fully engaged at this point. From here, the engine 2 starts to rotate in conjunction with the driving (rotation) of the motor 1. After that, the control unit 100 waits for the engine speed to reach a predetermined first rotational speed or higher (waiting for the determination in step S39 to be YES) and then starts combustion in the engine 2 (step S40). Specifically, when the engine speed reaches a predetermined first rotational speed or higher, the control unit 100 starts the injectors 22 and spark plugs 23 to supply fuel to each cylinder 20 and ignite the fuel-air mixture in each cylinder 20. As a result, the motor 1 and engine 2 start up, and the motor start control ends.

[0077] Next, the starter start control will be explained using the flowchart in Figure 7. When the starter start control is initiated, the control unit 100 determines whether the oil pump stop conditions are met, such as the intake SVT 28 being at its slowest angle or the DC-DC converter 33 having finished starting (step S51). The determination of whether or not the DC-DC converter 33 has finished starting is performed in the same way as in step S31.

[0078] If the determination in step S51 is YES and the oil pump stop condition is met, the control unit 100 proceeds to step S53. On the other hand, if the determination in step S51 is NO and the oil pump stop condition is not met, the control unit 100 stops the clutch oil pump 7 (step S52). That is, the power supply to the clutch oil pump 7 is stopped. After step S52, the control unit 100 returns to step S51 and stops the clutch oil pump 7 until the determination in step S51 is YES.

[0079] In step S53, the control unit 100 drives the clutch oil pump 7 (step S53). If the clutch oil pump 7 had stopped driving due to the oil pump stop condition not being met, its driving is restarted. In other cases, if the clutch oil pump 7 is not stopped, its driving continues.

[0080] Thus, when the starter starting mode is determined to the starting mode and the oil pump stop condition is not met, the clutch oil pump 7 is started to drive when a vehicle start request is issued, but the clutch oil pump 7 is temporarily stopped driving during the period when the oil pump stop condition is not met.

[0081] After step S53, the control unit 100 waits for the conditions to be met (waiting for the judgment in step S54 to be YES) that the intake SVT 28 is at its slowest angle and the DC-DC converter 33 has finished starting up, and then drives (energizes) the starter 4 to start the rotation of the engine 2 (step S55). The control unit 100 also waits for the engine 2 to rotate a predetermined number of times and then starts combustion in the engine 2 (step S55).

[0082] Subsequently, the control unit 100 waits for the engine speed to reach a predetermined second rotational speed or higher (waiting for the determination in step S56 to be YES) and then starts driving the motor 1 (step S57). After that, the control unit 100 engages the clutch 3 (step S57). Although not shown in the diagram, the clutch 3 is engaged under the condition that the clutch hydraulic pressure is equal to or greater than the determination hydraulic pressure. As a result, the motor 1 and engine 2 start, and the starter start control ends.

[0083] Figures 9 and 10 are time charts illustrating the changes in various parameters during vehicle V startup. Figure 9 is the chart for when the starting mode is motor start mode, and Figure 10 is the chart for when the starting mode is starter mode. In Figures 9 and 10, the door open flag indicates that the door of vehicle V is open; it is 1 when the door is open and 0 when it is closed. The vehicle start request flag indicates that a vehicle V start request has been made; it is 0 when vehicle V is stopped and 1 when a vehicle start request is made.

[0084] (Motor start mode) In the example in Figure 9, at time t11, the door of the stationary vehicle V is opened, and the door open flag changes from 0 to 1. Figure 9 illustrates the case where, at this time, the intake SVT28 is not at its most retarded angle, and the number of retardation cycles while stationary is less than or equal to the number of cycles determined. As a result, at time t11, the intake SVT28 starts to drive, and the phase retardation of the intake SVT28 begins. Subsequently, the door of vehicle V is closed, and the door open flag returns to 0.

[0085] In the example shown in Figure 9, at time t12, after time t11, a predetermined operation is performed on the start switch SW1, and a vehicle start request is issued. When the vehicle start request is issued, the clutch oil pump 7 is started to drive. As a result, the rotational speed of the clutch oil pump 7 increases after time t12. Figure 9 illustrates the case where the phase of the intake SVT 28 has not reached its retarded angle at time t12. As a result, the intake SVT 28 continues to drive after time t12, and the phase of the intake SVT 28 continues to retard. Also, when the vehicle start request is issued, the DC-DC converter 33 is energized. As a result, the DC-DC converter 33 is energized at time t13, after time t12.

[0086] As described above, when the starting mode is motor starting mode, the intake SVT28 is temporarily suspended from the time the DC-DC converter 33 starts up until it has finished starting up and the motor drive permission conditions are met, which include the clutch hydraulic pressure being equal to or greater than the judgment hydraulic pressure. As a result, in the example in Figure 9, at time t13, the drive of the intake SVT28 is stopped and the phase retardation of the intake SVT28 is stopped.

[0087] In the example shown in Figure 9, the DC-DC converter 33 is started up at time t14. Then, at time t15, the clutch hydraulic pressure reaches the judgment pressure, and the increase in the rotational speed of the clutch oil pump 7 stops. The clutch hydraulic pressure reaches the judgment pressure when the rotational speed of the clutch oil pump 7 reaches a predetermined rotational speed. Once the clutch hydraulic pressure reaches the judgment pressure, the clutch oil pump 7 is driven at a constant rotational speed to maintain this pressure. Thus, as shown at time t15 in Figure 9, the timing when the rotational speed of the clutch oil pump 7 reaches the predetermined rotational speed and then stops increasing is the timing when the clutch hydraulic pressure reaches the judgment pressure.

[0088] In the example in Figure 9, at time t15, the above motor drive permission conditions are met, namely that the DC-DC converter 33 has finished starting up and the clutch hydraulic pressure has reached the judgment hydraulic pressure. However, in the example in Figure 9, at time t15, the intake SVT 28 has not yet reached its most retarded angle. As a result, at time t15, the drive of the intake SVT 28 is restarted, and the phase of the intake SVT 28 is retarded again.

[0089] When the starting mode is motor starting mode, clutch 3 is engaged when the motor drive permission condition is met. In the example in Figure 9, clutch 3 is engaged at time t15.

[0090] In the example shown in Figure 9, clutch 3 is fully engaged at time t16, after time t15. Meanwhile, at time t16, the intake SVT28 is not yet at its most retarded angle, and it reaches its most retarded angle at time t17, after time t16. As a result, in the example shown in Figure 9, at time t16, the motor 1 starts to drive, the rotational speed of motor 1 begins to increase, and the rotational speed of engine 2 also begins to increase. Combustion of engine 2 begins at time t18, when the rotational speed of engine 2 reaches or exceeds the first rotational speed. Furthermore, the intake SVT28 continues to be energized after time t17, and when combustion in engine 2 begins, the amount of energization is adjusted so that the phase of the intake SVT28 corresponds to the rotational speed of engine 2.

[0091] (Starter mode) In the example in Figure 10, at time t1, the door of the stationary vehicle V is opened, and the door open flag changes from 0 to 1. Figure 10 illustrates the case where, at this time, the intake SVT28 is not at its most retarded angle, and the number of retardation cycles while stationary is less than or equal to the number of cycles determined. Therefore, at time t1, the intake SVT28 is driven, and the phase of the intake SVT28 changes to the retarded side. Subsequently, the door of vehicle V is closed, and the door open flag becomes 0.

[0092] In the example shown in Figure 10, a vehicle start request is issued at time t2, after time t1. When the vehicle start request is issued, the clutch oil pump 7 is started to drive. As a result, the rotational speed of the clutch oil pump 7 increases from time t2 onward. Figure 10 illustrates the case where the phase of the intake SVT 28 has not yet reached its retarded angle at time t2. As a result, the intake SVT 28 continues to drive after time t2, and the phase of the intake SVT 28 remains retarded. Also, when the vehicle start request is issued, the DC-DC converter 33 is energized. As a result, the DC-DC converter 33 is energized at time t3, after time t2.

[0093] As described above, when the starting mode is starter starting mode, the clutch oil pump 7 is stopped until the oil pump stop conditions are met, such as when the intake SVT 28 is at its slowest angle or when the DC-DC converter 33 has finished starting up. As a result, in the example in Figure 10, at time t3, the drive of the clutch oil pump 7 is stopped, and the increase in the rotational speed of the clutch oil pump 7 stops.

[0094] In the example shown in Figure 10, at time t4, the DC-DC converter 33 completes its startup, and the oil pump stop condition is no longer met. As a result, at time t4, the clutch oil pump 7 is restarted, and its rotational speed begins to increase again. Also, when the starting mode is the starter start mode, the starter 4 is driven when the DC-DC converter 33 has completed its startup and the intake SVT 28 is at its slowest angle. As a result, the starter 4 is driven at time t5, and the engine 2 is driven to rotate by the starter 4. After the engine 2 has rotated a predetermined number of times, combustion in the engine 2 begins.

[0095] In the example shown in Figure 10, at time t7, the engine speed reaches a predetermined second rotational speed or higher. As a result, the motor 1 is started to drive at time t7. Also in the example shown in Figure 10, at time t6, which is before time t7, the clutch hydraulic pressure reaches the judgment hydraulic pressure. As a result, at time t8, which is after time t7, the clutch 3 is switched from the disengaged state to the engaged state.

[0096] Furthermore, the intake SVT28 remains energized even after time t5, and when combustion in engine 2 begins, the amount of energization is adjusted so that the phase of the intake SVT28 corresponds to the rotational speed of engine 2. Also, when the clutch hydraulic pressure reaches the judgment hydraulic pressure, the clutch oil pump 7 is driven at a constant rotational speed to maintain the clutch hydraulic pressure at the judgment hydraulic pressure. As a result, the increase in the rotational speed of the clutch oil pump 7 stops at time t6.

[0097] (action, etc.) As explained above, in the above embodiment, when the starting mode is determined to be the starter starting mode and the engine 2 is started by the starter 4, after the engine 2 has started (after time t7 in Figure 10), the motor 1 is started to drive and the engine 2 and motor 1 are connected by the clutch 3. Therefore, the engine 2 can be started even when the clutch hydraulic pressure is low. Correspondingly, in the above embodiment, for a period of time (times t3 to t4 in Figure 10) of the driving period of the intake SVT 28 after the vehicle start request has been issued (times t2 to t5 in Figure 10), the drive of the clutch oil pump 7 is temporarily stopped. Then, after that (after time t4 in Figure 10), the oil pump 7 is driven to increase the clutch hydraulic pressure. In other words, retarding the closing timing of the intake valve 24 takes precedence over increasing the clutch hydraulic pressure. Therefore, according to the above embodiment, in the starter starting mode, the period during which the clutch oil pump 7 and the intake SVT 28 operate (are energized) simultaneously can be kept short, preventing excessive power consumption of the low-voltage battery 32. Furthermore, the intake SVT 28 drives the intake valve 24 to its latest closing timing earlier, allowing the engine 2 to start earlier while the intake valve 24 is at its latest closing timing, thus enabling the engine 2 to start early and smoothly.

[0098] Furthermore, in the above embodiment, when the starting mode is determined to be the motor starting mode and the engine 2 is started by the motor 1, and it is necessary to engage the clutch 3 in order to start the engine 2, the drive of the intake SVT 28 is temporarily stopped for a portion of the driving period of the clutch oil pump 7 (times t12 to t15 in Figure 9) (times t13 to t15 in Figure 9). Then, after that (after time t15 in Figure 9), the state of the clutch 3 transitions from the disengaged state to the engaged state, and the intake SVT 28 is driven.

[0099] Therefore, according to the above embodiment, in the motor starting mode, the period during which the clutch oil pump 7 and the intake SVT 28 operate (are energized) simultaneously can be kept short, preventing excessive power consumption of the low-voltage battery 32. Furthermore, the clutch hydraulic pressure can be increased early to engage the clutch 3, thereby connecting the motor 1 and the engine 2 early and starting the engine 2 with the motor 1. In addition, the time it takes for the clutch 3 to transition from the disengaged state to the engaged state (times t15-t16 in Figure 9) can be used to more reliably set the closing timing of the intake valve 24 to the slowest angle. Consequently, the engine 2 can be started early and smoothly.

[0100] Furthermore, in the above embodiment, in the starter starting mode, before the DC-DC converter 33 is started, when the power consumption of the low-voltage battery 32 can be kept relatively low even when the clutch oil pump 7 and the intake SVT 28 are operated simultaneously (times t2 to t3 in Figure 10), both the intake SVT 28 and the clutch oil pump 7 are driven, and when the DC-DC converter 33 starts to start (at time t3 in Figure 10), the clutch oil pump 7 is stopped. Therefore, while preventing the power consumption of the low-voltage battery 32 from becoming excessive due to the startup of the DC-DC converter 33 and the driving of the clutch oil pump 7 and intake SVT 28, the transition to the latest closing angle of the intake valve 24, the increase in clutch hydraulic pressure, and the startup of the DC-DC converter 33 can be achieved early. In particular, the power consumption of the low-voltage battery 32 increases when the DC-DC converter 33 is started. Therefore, by stopping the clutch oil pump 7 while the DC-DC converter 33 is starting up, the DC-DC converter 33 can be started up relatively early while reliably suppressing the decrease in power consumption of the low-voltage battery 32.

[0101] Furthermore, in the above embodiment, even in the motor start mode, before the DC-DC converter 33 is started, when the power consumption of the low-voltage battery 32 can be kept relatively low even when the clutch oil pump 7 and the intake SVT 28 are operated simultaneously (times t12 to t13 in Figure 9), both the intake SVT 28 and the clutch oil pump 7 are driven, and when the DC-DC converter 33 starts up (at time t13 in Figure 9), the intake SVT 28 is stopped. Therefore, while preventing the power consumption of the low-voltage battery 32 from becoming excessive due to the start of the DC-DC converter 33 and the driving of the clutch oil pump 7 and intake SVT 28, the increase in clutch hydraulic pressure, i.e., the transition to the clutch 3 being engaged, the transition to the latest closing angle of the intake valve 24, and the start of the DC-DC converter 33 can be achieved early.

[0102] In particular, in the above embodiment, in the motor start mode, the intake SVT 28 is stopped while the clutch oil pump 7 is driven until the clutch hydraulic pressure reaches the judgment hydraulic pressure (until time t15 in Figure 9). Therefore, the increase in clutch hydraulic pressure, that is, the transition to the clutch 3's engaged state and consequently the starting of the engine 2 by the motor 1 can be achieved more quickly.

[0103] Furthermore, in the above embodiment, if the door of vehicle V is opened while the engine 2 and vehicle V are stopped and the intake SVT 28 is not at its most retarded angle, the intake SVT 28 is driven and its phase is retarded. Therefore, the possibility that the intake SVT 28 is at its most retarded angle, that is, the possibility that the intake valve 24 is at its most retarded angle, can be increased when the engine 2 is started, and the opportunities to retard the intake SVT 28 when the engine 2 is started can be reduced. If it is not necessary to retard the intake SVT 28 when the engine 2 is started, the time required to achieve this can be shortened, and the engine 2 can be started earlier. However, if the intake SVT 28 is driven while the engine 2 and vehicle V are stopped in this way, the amount of charge stored in the low-voltage battery 32 will decrease before the engine 2 is started. If the power consumption of the low-voltage battery 32 is large when the engine 2 is started, there is a risk that the low-voltage battery 32 will not be able to output sufficient power to the intake SVT 28, clutch oil pump 7, DC-DC converter 33, etc. In contrast, in the above embodiment, the excessive power consumption of the low-voltage battery 32 during engine 2 startup is avoided. Therefore, early and successful starting of engine 2 can be achieved more reliably.

[0104] (modified version) In the above embodiment, when the intake SVT 28 is not at its slowest angle and the starting mode is either the motor starting mode or the starter starting mode, the period from when the vehicle starting request is issued until the DC-DC converter 33 starts to start (times t12-t13 in Figure 9, and t2-t3 in Figure 10) is described in which both the intake SVT 28 and the clutch oil pump 7 are driven. Alternatively, during the above period, only one of the intake SVT 28 or the clutch oil pump 7 may be driven and the other stopped. Specifically, when the starting mode is the motor starting mode, the clutch oil pump 7 may be driven while the intake SVT 28 is stopped during the above period. In this case, the intake SVT 28 will be stopped for the entire period after the vehicle starting request is issued when the clutch oil pump 7 is driven to increase the clutch hydraulic pressure (times t12-t15 in Figure 9). Furthermore, when the starting mode is the starter starting mode, the intake SVT 28 may be driven while the clutch oil pump 7 is stopped during the above period (times t2 to t3 in Figure 10). Alternatively, when the starting mode is the starter starting mode, the intake SVT 28 may be stopped from being driven for the entire period after a vehicle start request has been issued and the intake SVT 28 is driven and its phase is retarded toward the retarded angle (times t2 to t5 in Figure 10).

[0105] Furthermore, in the above embodiment, a case was described in which one of the intake SVT 28 and the clutch oil pump 7 is stopped when the DC-DC converter 33 is started. However, the system may also be configured to stop one of the intake SVT 28 and the clutch oil pump 7 when another in-vehicle device powered by the low-voltage battery 32 is started.

[0106] Furthermore, in the above embodiment, when the starting mode is the starter starting mode, the case in which the clutch oil pump 7, which had been temporarily stopped, is restarted once the DC-DC converter 33 has finished starting up was described. Alternatively, the clutch oil pump 7 may be temporarily stopped until the DC-DC converter 33 has finished starting up and the intake SVT 28 reaches its slowest angle.

[0107] Furthermore, in the above embodiment, a case was described in which it is determined whether or not the clutch hydraulic pressure has reached a determination hydraulic pressure based on the detected value of a hydraulic pressure sensor that detects the clutch hydraulic pressure, but the specific procedure for such determination is not limited to this. Also, a case was described in which it is determined whether or not the clutch 3 has been fully engaged based on the detected value of a sensor that detects the hydraulic pressure acting on the clutch plate 3A, but the specific procedure for such determination is not limited to this.

[0108] Furthermore, the specific structure of the intake SVT28 and the specific configuration of engine 2, such as the number of cylinders, are not limited to those described above. [Explanation of symbols]

[0109] 1 motor 2 engines 3. Clutch 4 Starters 7. Clutch oil pump (oil pump) 24 Intake valve 28. Intake SVT (Valve Timing Changer) 31 High-voltage battery 32 Low-voltage battery (battery) 33. DC-DC converter (automotive equipment) 100 control units D Starting device V Vehicle

Claims

1. An engine having an electrically operated valve timing device that can change the closing timing of the intake valves, The engines are each equipped with a starter and a motor capable of starting them, A hydraulic clutch capable of disconnecting the engine and the motor, An electric oil pump that supplies hydraulic pressure to the clutch, A battery that supplies power to the starter, the valve timing device, and the oil pump, The system comprises a valve timing device, a starter, a motor, and a control unit that controls the oil pump, The control unit is When the engine is started by the starter while the intake valve is not in the most retarded position, the valve timing device is driven to retard the intake valve's closing timing, and the oil pump is stopped for at least a portion of the period during which the valve timing device is driven, and then the oil pump is driven to increase the hydraulic pressure supplied to the clutch. An engine starting device characterized in that, when the motor starts the engine while the intake valve is not closed at the time of the most retarded angle, the oil pump is driven to increase the hydraulic pressure supplied to the clutch, the drive of the valve timing device is stopped for at least a portion of the period during which the oil pump is driven, and then the valve timing device is driven to retard the closing time of the intake valve.

2. In the engine starting device according to claim 1, The vehicle further comprises an electric in-vehicle device powered by the aforementioned battery, The control unit is When the engine is started by the starter while the intake valve is not closed at the retarded timing, both the oil pump and the valve timing device are driven before power is supplied to the on-board equipment, the oil pump is temporarily stopped when power is supplied to the on-board equipment, and then the oil pump is restarted. An engine starting device characterized in that, when the motor starts the engine while the intake valve is not closed at the retarded timing, both the oil pump and the valve timing device are driven before the power is supplied to the on-board equipment, the drive of the valve timing device is temporarily stopped when the power is supplied to the on-board equipment, and the drive of the valve timing device is then restarted.

3. In the engine starting device according to claim 2, An engine starting device characterized in that, when the motor starts the engine while the intake valve is not closed at the latest timing, the control unit stops driving the valve timing device from the time it starts supplying power to the onboard equipment until the hydraulic pressure supplied to the clutch reaches a predetermined determination hydraulic pressure.

4. In the engine starting device according to any one of claims 1 to 3, When a predetermined timing retardation control condition is met while the engine is stopped, the control unit drives the valve timing device so that the closing timing of the intake valve is the timing of the most retarded timing. An engine starting device characterized in that the aforementioned timing retardation control conditions include the condition that the timing of closing the intake valve is not at the timing of the most retarded timing, and that the user has performed a specific action.

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