JP2013095161A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device that can suppress the occurrence of a shock at the starting of an engine.SOLUTION: The vehicle control device includes a direct injection engine, a rotating electrical machine arranged on the driving wheel side from the engine and a clutch which disconnects the engine and the rotating electrical machine. Therein, the clutch is put in the semi-engaged state and the engine is started (S2-Y) and, when the number of rotation of the engine during the rising is synchronized with the number of rotation of the rotating electrical machine, the torque of the engine exceeds a torque capacity of the clutch (S3-Y). In such a case, the number of rotation of the engine is raised to a number of rotation larger than the number of rotation of the rotating electrical machine and, then, the clutch is perfectly engaged (S4).

Description

  The present invention relates to a vehicle control device.

  Conventionally, a vehicle in which an engine and a rotating electrical machine are connected via a clutch is known. For example, Patent Document 1 discloses a method in which an internal drag engine is started by a slip torque controlled clutch transmitting engine drag torque to the internal combustion engine.

JP 2009-527411 A

  Here, if the clutch is not properly controlled, a shock may occur when the engine is started. For example, when the engine is started with the clutch half-engaged, a shock may occur if the timing for completely engaging the clutch is not appropriate.

  The objective of this invention is providing the vehicle control apparatus which can suppress generation | occurrence | production of the shock at the time of engine starting.

  A vehicle control apparatus according to the present invention includes a direct injection engine, a rotating electrical machine disposed closer to a drive wheel than the engine, and a clutch that connects and disconnects the engine and the rotating electrical machine, and the clutch is half-engaged. The engine is started as a combined state, and the engine torque exceeds the torque capacity of the clutch when the rotational speed of the rising engine and the rotational speed of the rotating electrical machine are synchronized. And the clutch is fully engaged after the rotational speed is increased to a rotational speed larger than the rotational speed of the rotating electrical machine.

  In the vehicle control device, when the minimum torque that can be output by the engine at the time of synchronization exceeds the torque capacity of the clutch, the engine speed is increased to a speed greater than the speed of the rotating electrical machine. It is preferable that the clutch is fully engaged.

  In the vehicle control device, after the engine speed is increased to a rotational speed greater than the rotational speed of the rotating electrical machine, the rotational speed difference between the engine speed and the rotating electrical machine speed decreases. Preferably, the clutch is fully engaged when

  A vehicle control device according to the present invention includes a direct injection engine, a rotating electrical machine disposed closer to the drive wheel than the engine, and a clutch that connects and disconnects the engine and the rotating electrical machine, and the clutch is in a half-engaged state. When starting the engine and the engine speed exceeds the clutch torque capacity when the engine speed and the rotating electrical machine speed are rising, the engine rotational speed is set to the rotational speed of the rotating electrical machine. The clutch is fully engaged after the engine speed is increased to a greater value. Therefore, according to the vehicle control device of the present invention, there is an effect that it is possible to suppress the occurrence of a shock when starting the engine.

FIG. 1 is a flowchart showing engine start control according to the embodiment. FIG. 2 is a diagram illustrating a main part of the vehicle according to the embodiment. FIG. 3 is a time chart for explaining the occurrence of a shock during synchronization. FIG. 4 is a time chart according to the embodiment.

  Hereinafter, a vehicle control device according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The embodiment will be described with reference to FIGS. 1 to 4. The present embodiment relates to a vehicle control device. FIG. 1 is a flowchart showing engine start control according to the embodiment of the present invention, and FIG. 2 is a diagram showing a main part of the vehicle according to the embodiment.

  A hybrid vehicle 100 shown in FIG. 2 includes an engine 1, a K0 clutch 2, a rotating electrical machine MG, a torque converter 4, a transmission 5, and drive wheels 8. The engine 1 is connected to the rotating electrical machine MG, the torque converter 4, the transmission 5, and the drive wheels 8 via the K0 clutch 2. That is, the rotating electrical machine MG is disposed closer to the drive wheel 8 than the engine 1, and the K0 clutch 2 connects and disconnects the engine 1 and the rotating electrical machine MG. The K0 clutch 2 is interposed between the crankshaft 1a of the engine 1 and the rotating shaft 3 of the rotating electrical machine MG. The K0 clutch 2 is, for example, a wet multi-plate clutch device, which connects the engine 1 and the rotating electrical machine MG in the engaged state, and disconnects the engine 1 and the rotating electrical machine MG in the opened state.

  The rotating electrical machine MG has a function as a motor (electric motor) and a function as a generator. The rotating electrical machine MG is connected to a battery via an inverter. The rotating electrical machine MG can convert electric power supplied from the battery into mechanical power and output it, and can be driven by the input power to convert mechanical power into electric power. The electric power generated by the rotating electrical machine MG can be stored in the battery. As the rotating electrical machine MG, for example, an AC synchronous motor generator can be used.

  Torque converter 4 is disposed closer to drive wheel 8 than rotating electrical machine MG. The input shaft 4a of the torque converter 4 is connected to the rotating shaft 3 of the rotating electrical machine MG. The torque converter 4 can transmit torque input to the input shaft 4a to the input shaft 5a of the transmission 5 via the working fluid. Further, the torque converter 4 has a lock-up mechanism, and in the lock-up state, the torque input to the input shaft 4a is directly transmitted to the input shaft 5a of the transmission 5.

  The transmission 5 is an automatic transmission, for example, a stepped automatic transmission (A / T). The transmission 5 is not limited to this, and may be a continuously variable automatic transmission (CVT) or the like. The output shaft 5 b of the transmission 5 is connected to the drive wheels 8 via the differential mechanism 6 and the drive shaft 7.

  The engine 1 is a direct injection engine having an injector that directly injects fuel into a cylinder and an ignition plug that ignites an air-fuel mixture in the cylinder. The engine 1 converts the combustion energy of the fuel into a rotational motion of the crankshaft 1a and outputs it. The output torque of the engine 1 is transmitted to the drive wheels 8 via the K0 clutch 2, the rotating electrical machine MG, the torque converter 4, the transmission 5, the differential mechanism 6 and the drive shaft 7.

  The hybrid vehicle 100 is equipped with an electronic control unit (ECU) 50. The ECU 50 can control the fuel injection timing, the fuel injection amount, the ignition timing, and the like of the engine 1. Further, the ECU 50 can control the K0 clutch 2, the rotating electrical machine MG, the torque converter 4, and the transmission 5. The ECU 50 can control the release / engagement and the degree of engagement of the K0 clutch 2. When the K0 clutch 2 has a hydraulic actuator, the ECU 50 controls the degree of engagement (torque capacity) of the K0 clutch 2 by adjusting the supply hydraulic pressure. Further, the ECU 50 can perform the slip control of the K0 clutch 2 based on the engine speed and the rotational speed of the rotating electrical machine MG. The vehicle control device 1-1 of the present embodiment includes an engine 1, a K0 clutch 2, a rotating electrical machine MG, and an ECU 50.

  The hybrid vehicle 100 can selectively execute hybrid traveling or EV traveling. The hybrid travel is a travel mode in which the hybrid vehicle 100 travels using at least the engine 1 of the engine 1 and the rotating electrical machine MG as a power source. In hybrid travel, the rotating electrical machine MG can be used as a power source in addition to the engine 1. In hybrid traveling, the rotating electrical machine MG may function as a generator, or may be idled without load.

  EV traveling is a traveling mode in which the engine 1 is stopped and the rotating electrical machine MG is used as a power source. In EV traveling, the rotating electrical machine MG may appropriately generate power depending on the traveling state, the state of charge of the battery, and the like. When performing EV travel, the K0 clutch 2 is released and the engine 1 is stopped.

  The hybrid vehicle 100 can also perform inertial traveling in which the hybrid vehicle 100 travels by inertia by separating the engine 1 from the drive wheels 8. Inertia traveling is executed, for example, when there is no acceleration request or when the required driving force is small. In inertial running, the K0 clutch 2 is released, and transmission of power between the engine 1, the rotating electrical machine MG, and the drive wheels 8 is interrupted. That is, the engine brake is not applied to the drive wheels 8. As a result, the load on the drive wheels 8 becomes smaller than when the K0 clutch 2 is engaged and the engine 1 is connected to the drive wheels 8. By executing inertial running, it is possible to improve fuel efficiency at light loads. During inertial running, the engine 1 can be stopped to suppress fuel consumption.

  When starting the engine 1 such as when shifting from EV traveling to hybrid (HV) traveling, the ECU 50 performs start control of the engine 1. In the hybrid vehicle 100 of the present embodiment, at least the following two starting methods can be executed.

(Ignition start)
The ignition start is a start method for starting the engine 1 by starting the rotation of the engine 1 mainly by energy generated by combustion of the engine 1. The engine 1 of the hybrid vehicle 100 of this embodiment is a direct injection engine in which fuel is directly injected into a cylinder. Therefore, from the state where the engine 1 is stopped, it is possible to start the engine 1 by supplying fuel into the cylinder and starting combustion by ignition. In the ignition start, the start of the engine 1 can be assisted by setting the K0 clutch 2 in a half-engaged state.

  Specifically, the ECU 50 sets the supply hydraulic pressure to the K0 clutch 2 as the standby hydraulic pressure until the rotation speed of the engine 1 starts to increase when starting by fuel injection and ignition to the engine 1. The standby hydraulic pressure is set to a hydraulic pressure at which the engine 1 does not start to rotate depending on the torque transmitted from the driving wheel 8 side to the engine 1 via the K0 clutch 2. That is, the standby hydraulic pressure is the clutch hydraulic pressure when the K0 clutch 2 is engaged and the engine 1 waits for the start of autonomous rotation. The K0 clutch 2 is engaged by the standby hydraulic pressure, and torque is transmitted from the rotating electrical machine MG side, so that the necessary torque of the engine 1 for starting rotation is reduced.

  When the rotational speed of the engine 1 starts to increase, the ECU 50 increases the hydraulic pressure supplied to the K0 clutch 2 to the assist hydraulic pressure. The assist hydraulic pressure is higher than the standby hydraulic pressure, and is a hydraulic pressure that can assist the increase in rotation by transmitting a torque in the positive direction to the engine 1. Further, the ECU 50 increases the supply hydraulic pressure to the K0 clutch 2 to the engagement hydraulic pressure when the engine rotation speed is synchronized with the rotation speed of the rotating electrical machine MG. The engagement hydraulic pressure is higher than the assist hydraulic pressure, and is a hydraulic pressure that allows the K0 clutch 2 to be completely engaged. The engagement hydraulic pressure is, for example, a line pressure supplied from a hydraulic pressure source. When the K0 clutch 2 is completely engaged, the ignition start is completed.

(K0 slip start)
The K0 slip start is a start method for starting the engine 1 by performing motoring with the torque transmitted through the K0 clutch 2 and starting the rotation of the engine 1. In the K0 slip start, the hydraulic pressure supplied to the K0 clutch 2 from the state in which the engine 1 is stopped is set to the motoring hydraulic pressure. The motoring hydraulic pressure is higher than the assist hydraulic pressure and lower than the engagement hydraulic pressure. The motoring hydraulic pressure is an engagement hydraulic pressure that can transmit at least torque sufficient to start rotation of the engine 1 against the friction torque of the engine 1 that is stopped. The motoring hydraulic pressure is an engagement hydraulic pressure at which the K0 clutch 2 is in a half-engaged state and the engine speed can be gradually increased.

  The ECU 50 sets the hydraulic pressure supplied to the K0 clutch 2 as a motoring hydraulic pressure, and causes the rotating electrical machine MG to output a torque required for cranking the engine 1 in addition to the torque corresponding to the required driving force. Thus, the engine 1 can be started by engaging the K0 clutch 2 and cranking with the torque of the rotating electrical machine MG.

  When the engine speed increases to a predetermined speed due to motoring of the rotating electrical machine MG, the ECU 50 starts fuel injection and ignition for the engine 1 and starts the engine 1. When the engine speed is synchronized with the rotational speed of the rotating electrical machine MG, the hydraulic pressure supplied to the K0 clutch 2 is the engagement hydraulic pressure. When the K0 clutch 2 is completely engaged, the K0 slip start is completed.

  When there is a request for starting the engine 1, the ECU 50 starts the engine 1 by the ignition start if the ignition start is possible, and starts the engine 1 by the K0 slip start if the ignition start is impossible. In the case of K0 slip start, the torque required for motoring of the engine 1 is output by the rotating electrical machine MG. Therefore, in order to secure the torque necessary for motoring, the output torque for traveling by the rotating electrical machine MG is limited. On the other hand, in the case of ignition start, the rotating electrical machine MG only needs to be able to assist the autonomous rotation of the engine 1. From this, it is possible to increase the proportion of the torque that can be used for travel driving out of the output torque of the rotating electrical machine MG by giving priority to the ignition start in the start of the engine 1. Therefore, it is possible to reduce the size of the rotating electrical machine MG and expand the EV travel area.

  Here, a shock may occur depending on the relationship between the engine torque and the torque capacity of the K0 clutch 2 during the rotation synchronization in which the rotation speed Nmg of the rotating electrical machine MG and the engine rotation speed Ne are synchronized when the engine is started. . Specifically, when the minimum engine torque Te is larger than the torque capacity of the K0 clutch 2 (hereinafter also simply referred to as “K0 torque”) Tk0, as described below with reference to FIG. Will occur. FIG. 3 is a time chart for explaining the occurrence of a shock during synchronization.

  3, (a) is the rotational speed, (b) is the surge tank pressure, (c) is the hydraulic pressure supplied to the K0 clutch 2 (hereinafter also simply referred to as “K0 hydraulic pressure”), and (d) and (e) are the torques. , (F) shows the output torque for the drive wheel 8. The broken line 101 represents the rotational speed Nmg of the rotating electrical machine MG, the solid line 102 represents the engine rotational speed Ne, the broken line 103 represents the K0 torque Tk0, the solid lines 104 and 106 represent the minimum engine torque Te, and the broken line 105 represents the torque Tmg of the rotating electrical machine MG. The solid line for the K0 hydraulic pressure indicates the command value, and the broken line indicates the actual value. FIG. 3 shows the occurrence of a shock when the engine 1 is started with the rotational speed Nmg of the rotating electrical machine MG being low.

  The minimum engine torque Te shown in FIG. 3 is the lowest output torque of the engine 1 in the adjustable range, and is the lowest torque that can be output by the engine 1 at each time point. The minimum engine torque Te is, for example, the output torque of the engine 1 when the ignition timing of the engine 1 is set to the most retarded timing within a range where no misfire occurs.

  When the engine 1 is started with the rotational speed Nmg of the rotating electrical machine MG being low, the rotational speed Nmg of the rotating electrical machine MG and the engine rotational speed Ne are synchronized at a low rotational speed in the process of increasing the engine rotational speed Ne. The minimum engine torque Te (104, 106) becomes a large torque immediately after the start of rotation, and thereafter decreases as the surge tank pressure decreases. While the engine speed Ne is low, the speed at which air escapes from the surge tank through the cylinder of the engine 1 is slow, so the surge tank pressure is high and the intake amount of the engine 1 increases. As a result, when the engine is started with the rotation speed Nmg of the rotating electrical machine MG being low, the rotation speed is synchronized with the minimum engine torque Te not being reduced so much.

  For this reason, as shown in FIG. 3, at the time t2 when the rotation is synchronized, the minimum engine torque Te may exceed the K0 torque Tk0. In this case, when the engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG are synchronized, the K0 clutch 2 cannot slide completely and slips. Due to slippage of the K0 clutch 2, the engine speed Ne exceeds the rotational speed Nmg of the rotating electrical machine MG immediately after the rotation is synchronized at time t2. That is, before and after the rotation is synchronized, the differential rotation between the engine rotation speed Ne and the rotation speed Nmg of the rotating electrical machine MG is in the reverse direction. As a result, the direction of the torque transmitted through the K0 clutch 2 is also reversed, causing a shock.

  Further, as in the conventional control, when it is determined that the K0 clutch 2 is completely engaged when the engine speed Ne and the rotation speed Nmg of the rotating electrical machine MG are synchronized and the K0 hydraulic pressure is increased, further shock is caused. It will be generated. The actual value of the K0 hydraulic pressure rises later than the command value. For this reason, even if the command value of the K0 oil pressure is increased at the time of rotation synchronization (time t2), the K0 clutch 2 continues to slip and the engine speed Ne is increased until the actual value of the K0 oil pressure increases. The number of rotations exceeds Nmg. In this state, the hydraulic pressure increases rapidly, so that the K0 clutch 2 that has slipped is suddenly engaged at time t3. For this reason, in addition to the shock when the rotation speed difference is reversed, a shock due to sudden engagement occurs.

  The vehicle control device 1-1 of the present embodiment has an engine torque of the K0 clutch 2 when the rising engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG are synchronized so that the occurrence of such a shock can be suppressed. When the torque capacity is exceeded, the engine rotation is intentionally increased and the engine rotation is engaged from above. In other words, the engine speed Ne is increased to a rotational speed greater than the rotational speed Nmg of the rotating electrical machine MG, and then the K0 clutch 2 is completely engaged. The engine torque to be compared with the torque capacity of the K0 clutch 2 at the time of rotation synchronization may be the lowest engine torque Te or the engine torque that is actually output. When the minimum engine torque Te is compared with the torque capacity of the K0 clutch 2, an engine start control for suppressing the shock only when the occurrence of the shock cannot be suppressed by adjusting the engine torque (second start control described later). Can be moved to.

  The operation of this embodiment will be described with reference to FIGS. FIG. 4 is a time chart according to the present embodiment. In FIG. 4, (a) shows the rotational speed, (b) shows the surge tank pressure, (c) shows the K0 oil pressure, and (d) and (e) show the torque. The broken line 201 represents the rotational speed Nmg of the rotating electrical machine MG, the solid line 202 represents the engine rotational speed Ne, the broken line 203 represents the K0 torque Tk0, the solid lines 204 and 206 represent the minimum engine torque Te, and the broken line 205 represents the torque Tmg of the rotating electrical machine MG. The torque Tmg of the rotating electrical machine MG shown in the figure can be a compensation torque that compensates for torque fluctuations when starting the engine. The rotating electrical machine MG can output a torque corresponding to the required driving force in addition to the compensation torque.

  FIG. 4 shows the transition when the engine is started in a state where the rotational speed Nmg of the rotating electrical machine MG is low as in FIG. At the time t5 when the engine speed Ne is synchronized with the rotation speed Nmg of the rotating electrical machine MG, the minimum engine torque Te exceeds the K0 torque Tk0.

  The control flow shown in FIG. 1 is repeatedly executed at predetermined intervals, for example. First, in step S1, the ECU 50 determines whether or not the engine is being started. As a result of the determination, if it is determined that the engine is being started (step S1-Y), the process proceeds to step S2, and if not (step S1-N), the control flow ends.

  In step S2, the ECU 50 determines whether or not the travel range is being started. In step S2, it is determined whether the engine 1 is started from the state where the K0 clutch 2 is slipping. When the engine 1 is started while the hybrid vehicle 100 is stopped, the engine may not be started from the state where the K0 clutch 2 is slipping. For example, when the engine is started with the shift position in the P range, the engine 1 is started by cranking by the rotating electrical machine MG after the K0 clutch 2 is completely engaged by the hydraulic pressure of the electric oil pump. In this case, since the engine 1 is started from a state where the K0 torque Tk0 is sufficiently large, no slip of the K0 clutch 2 occurs and no shock at the time of start occurs.

  On the other hand, when the engine is started with the shift position in the travel range, the engine 1 is started from the state where the K0 clutch 2 is slipping in the ignition start or the K0 slip start. The ECU 50 makes an affirmative determination in step S2 when the shift position selected in the transmission 5 is the forward travel range, and the selected shift position is forward travel such as the P range, R range, or N range. If it is a shift position other than the shift position, a negative determination is made in step S2. As a result of the determination in step S2, if it is determined that the running range is being started (step S2-Y), the process proceeds to step S3. If not (step S2-N), the control flow ends.

  In step S3, the ECU 50 determines whether or not the motor rotation speed is equal to or less than a threshold value. The ECU 50 determines whether or not the motor rotation speed (the rotation speed Nmg of the rotating electrical machine MG) is equal to or less than a predetermined threshold value. When the motor rotational speed is low, the engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG are synchronized in a short time after the start of the engine 1 is started. The threshold value in step S3 is a value with which it can be determined whether or not the K0 torque Tk0 is below the minimum engine torque Te at the time of rotation synchronization. That is, in step S3, it is predicted whether or not the K0 torque Tk0 is lower than the minimum engine torque Te when the engine speed Ne and the rotation speed Nmg of the rotating electrical machine MG are synchronized.

  This threshold value can be determined in advance based on experimental results or the like, and may be variable according to the engine cooling water temperature, the oil temperature of the K0 clutch 2, or the like. The threshold value may be an idle speed of the engine 1 or a speed near the idle speed. As a result of the determination in step S3, if it is determined that the motor rotational speed is equal to or less than the threshold value (step S3-Y), the process proceeds to step S4, and if not (step S3-N), the process proceeds to step S5.

  In step S3, instead of the determination based on the motor rotation speed, a determination based on respective transition predictions of the engine torque Te and the K0 torque Tk0 may be made. The transition prediction of the K0 torque Tk0 can be calculated based on the actual value or command value of the K0 torque Tk0. In this case, the ECU 50 makes an affirmative determination in step S3 when the predicted value of the engine torque Te exceeds the predicted value of the K0 torque Tk0 when the engine rotational speed Ne is synchronized with the rotational speed Nmg of the rotating electrical machine MG.

  In step S4, the ECU 50 selects the second start control. The ECU 50 can execute the first start control or the second start control in the ignition start. The first start control is control for completely engaging the K0 clutch 2 when the engine speed Ne and the rotation speed Nmg of the rotating electrical machine MG are synchronized in the process of increasing the engine speed Ne at the time of starting the engine. On the other hand, the second start control is control in which the engine speed Ne is once increased to a speed higher than the speed Nmg of the rotating electrical machine MG when the engine is started, and then the K0 clutch 2 is completely engaged. If an affirmative determination is made in step S3, the minimum engine torque Te during rotation synchronization remains larger than the K0 torque Tk0, and it is predicted that a shock will occur in the first start control. Two-start control is selected.

  The ECU 50 adjusts the K0 torque Tk0 so as to allow the engine rotational speed Ne to rise to a rotational speed higher than the rotational speed Nmg of the rotating electrical machine MG when the engine 1 is started. For example, the ECU 50 maintains the K0 hydraulic pressure at the assist hydraulic pressure P1 until at least the engine rotational speed Ne exceeds the rotational speed Nmg of the rotating electrical machine MG. As described above, in the present embodiment, the engine rotational speed Ne is intentionally increased to a rotational speed larger than the rotational speed Nmg of the rotating electrical machine MG, and then the K0 clutch 2 is completely engaged. Thereby, generation | occurrence | production of the shock when the differential rotation of K0 clutch 2 reverses can be suppressed. By not rapidly increasing the K0 hydraulic pressure at time t5 when the rotation is synchronized, a shock when the torque transmission direction is reversed is suppressed. Note that, at time t5 when the differential rotation of the K0 clutch 2 is reversed, the K0 hydraulic pressure may be temporarily reduced to suppress the shock.

  The ECU 50 sweeps up the K0 hydraulic pressure when the increasing engine rotational speed Ne is synchronized with the rotational speed Nmg of the rotating electrical machine MG. Thereby, the K0 torque Tk0 gradually increases from time t5. Between times t5 and t6, the engine speed Ne changes above the rotational speed Nmg of the rotating electrical machine MG. During this time, the engine rotational speed Ne reaches a peak and starts decreasing, and the magnitude of the differential rotation between the engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG begins to decrease. Further, the magnitude relationship between the K0 torque Tk0 and the minimum engine torque Te is reversed between time t5 and t6, and the K0 torque Tk0 exceeds the minimum engine torque Te. Then, at time t6, the engine rotational speed Ne is synchronized with the rotational speed Nmg of the rotating electrical machine MG. At time t6, since the K0 torque Tk0 exceeds the minimum engine torque Te, the K0 clutch 2 is completely engaged, and thereafter, the engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG are maintained in a matched state. The The ECU 50 increases the K0 hydraulic pressure to the engagement hydraulic pressure P2 in synchronization with the complete engagement of the K0 clutch 2 or after the complete engagement.

  Further, the ECU 50 controls the torque Tmg of the rotating electrical machine MG. The ECU 50 assists the start by outputting torque to the rotating electrical machine MG when the engine 1 is started. For example, the ECU 50 causes the rotating electrical machine MG to output a positive torque from the time t4 when starting the engine 1 to the time t5 when the engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG are first synchronized. . Thereby, the resistance to the start of rotation of the engine 1 can be reduced by the torque of the rotating electrical machine MG transmitted through the K0 clutch 2. Further, after the rotation of the engine 1 is started, an increase in the rotational speed of the engine 1 is assisted by the torque of the rotating electrical machine MG.

  The ECU 50 changes the output torque of the rotating electrical machine MG to a negative torque when the engine speed Ne and the rotational speed Nmg of the rotating electrical machine MG are synchronized at time t5. When the magnitude relationship between the engine speed Ne and the rotational speed Nmg of the rotating electrical machine MG is switched, the direction of the torque transmitted by the K0 clutch 2 is reversed. The ECU 50 absorbs fluctuations in torque by reversing the sign of the torque Tmg of the rotating electrical machine MG with respect to the reversal of the torque transmission direction, and suppresses the occurrence of shock. The amount of change in the torque Tmg of the rotating electrical machine MG at this time can be such that the magnitude of the positive torque before the change is equal to the magnitude of the negative torque after the change. The rotating electrical machine MG performs regenerative power generation to generate negative torque.

  The ECU 50 reduces the magnitude of the negative torque of the rotating electrical machine MG when the engine speed Ne and the rotational speed Nmg of the rotating electrical machine MG are synchronized and the K0 clutch 2 is completely engaged at time t6. The ECU 50 ends the second start control when the start of the engine 1 is completed and the engine speed Ne is synchronized with the speed Nmg of the rotating electrical machine MG and the K0 clutch 2 is completely engaged. When step S4 is executed, the control flow ends.

  In step S5, the ECU 50 selects the first start control. As described with reference to FIG. 3, the ECU 50 fully engages the K0 clutch 2 when the engine rotational speed Ne rises and the engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG are first synchronized. . When step S5 is executed, this control flow ends.

Note that when the engine speed Ne is first synchronized with the rotational speed Nmg of the rotating electrical machine MG at time t5, the engine speed Ne may not blow up and the K0 clutch 2 may be completely engaged. If this is estimated from the rotation change and the rotary electric machine MG is controlled, a determination delay such as a processing delay or a rotation measurement error occurs, and there is a possibility that the torque cannot be properly compensated and a shock occurs. Therefore, it is preferable that the torque Tmg of the rotating electrical machine MG is compensated based on a torque that is smaller of either the K0 torque Tk0 or the output torque Teng of the engine 1. That is, it is preferable to calculate the torque Tmg of the rotating electrical machine MG based on the following formula (1).
Tmg = −MIN (Tk0, Teng) (1)
Here, the output torque Teng of the engine 1 is the actual output torque of the engine 1, but may be the minimum engine torque Te instead.

  As described above, the output torque Teng of the engine 1 exceeds the K0 torque Tk0 by determining the compensation torque of the rotating electrical machine MG based on the torque selected from the output torque Teng and the K0 torque Tk0 of the engine 1. During this time, the K0 torque Tk0 is compensated by the rotating electrical machine MG. On the other hand, when the K0 torque Tk0 exceeds the output torque Teng of the engine 1, the output torque Teng of the engine 1 is compensated by the rotating electrical machine MG. Thereby, an appropriate torque can be output to the rotating electrical machine MG according to the transmission torque of the K0 clutch 2, and the occurrence of shock can be suppressed.

  According to the vehicle control device 1-1 of the present embodiment, when the K0 clutch 2 shifts to the complete engagement from the rotation synchronization, the K0 clutch 2 is prevented from slipping and generating a shock. As a method of suppressing the shock, it is conceivable to suppress the slip of the K0 clutch 2 by setting the K0 torque Tk0 at the start of ignition to a large value. However, this method has a problem that the fuel consumption is lowered. According to the engine start control of the vehicle control device 1-1 of the present embodiment, it is possible to suppress the occurrence of a shock while suppressing a decrease in fuel consumption.

  Note that the engine start control of the present embodiment may be executed not only at the time of ignition start but also at the time of K0 slip start. At the start of ignition, the rising speed of the engine speed Ne increases, so it can be said that the engine start control according to the present embodiment is easy to exert advantages. Further, instead of the direct injection engine, the engine start control of this embodiment may be performed by a vehicle equipped with a port injection engine.

  In the present embodiment, the engine speed Ne is increased to a rotational speed greater than the rotational speed Nmg of the rotating electrical machine MG, and then when the engine rotational speed Ne is first synchronized with the rotational speed Nmg of the rotating electrical machine MG, the K0 clutch 2 However, the timing at which the K0 clutch 2 is completely engaged is not limited to this.

  The complete engagement of the K0 clutch 2 is performed, for example, when the differential rotation (rotational speed difference) between the engine rotational speed Ne and the rotational speed Nmg of the rotating electrical machine MG is reduced, that is, the engine rotational speed Ne is rotated by the rotating electrical machine MG. It is preferably made when the number Nmg is exceeded and the rotational speeds of both are approaching. In this way, the shock when fully engaged is suppressed.

  The complete engagement of the K0 clutch 2 is preferably performed after the minimum engine torque Te becomes equal to or less than the K0 torque Tk0. In this way, the occurrence of shock due to the sliding of the K0 clutch 2 is suppressed.

[Modification of Embodiment]
A modification of the embodiment will be described. In addition to the engine start control of the above embodiment, the fuel cut may be performed when the K0 clutch 2 is completely engaged. Thereby, there exists an advantage that generation | occurrence | production of a shock can further be suppressed.

  Referring to FIG. 4, as in the above embodiment, the ECU 50 fully engages the K0 clutch 2 after increasing the engine speed Ne to a speed higher than the rotational speed Nmg of the rotating electrical machine MG. . In this modification, the ECU 50 performs a fuel cut that stops the fuel supply to the engine 1 when the K0 clutch 2 is fully engaged, that is, when the engine speed Ne and the rotation speed Nmg of the rotating electrical machine MG are synchronized. Run. For example, the ECU 50 predicts a timing at which the engine speed Ne and the rotational speed Nmg of the rotating electrical machine MG are synchronized, and performs fuel injection control so that fuel cut is started before the timing at which the rotation is synchronized.

  Further, the ECU 50 may control the hydraulic pressure supplied to the K0 clutch 2 so that the K0 clutch 2 is completely engaged at the rotation synchronization timing. For example, the ECU 50 may output a command value for the K0 oil pressure so that the actual value of the K0 oil pressure becomes the engagement oil pressure at the synchronization timing. When the K0 clutch 2 is completely engaged, the ECU 50 ends the fuel cut and restarts the fuel supply to the engine 1. As described above, the fuel cut is performed in accordance with the timing of the complete engagement of the K0 clutch 2, thereby suppressing the occurrence of a shock.

  The contents disclosed in the above embodiments can be executed in appropriate combination.

1-1 Vehicle control device 1 Engine 2 K0 clutch 8 Drive wheel 50 ECU
100 Hybrid vehicle Tk0 K0 clutch torque capacity (clutch torque)
Te Engine torque Tmg Torque of rotating electrical machine

Claims (3)

A direct injection engine,
A rotating electrical machine disposed on the drive wheel side of the engine;
A clutch for connecting and disconnecting the engine and the rotating electrical machine;
With
When the engine is started with the clutch in a semi-engaged state, when the rotational speed of the rising engine and the rotational speed of the rotating electrical machine are synchronized, the torque of the engine reduces the torque capacity of the clutch. When exceeding, the vehicle control apparatus is characterized in that after the engine speed is increased to a speed greater than the rotational speed of the rotating electrical machine, the clutch is completely engaged. If the minimum torque that can be output by the engine at the time of synchronization exceeds the torque capacity of the clutch, the engine speed is increased to a speed greater than the speed of the rotating electrical machine, and then the clutch is fully engaged. The vehicle control device according to claim 1. The clutch when the rotational speed difference between the rotational speed of the engine and the rotational speed of the rotating electrical machine decreases after the rotational speed of the engine is increased to a rotational speed greater than the rotational speed of the rotating electrical machine. The vehicle control device according to claim 1 or 2, wherein the vehicle control device is completely engaged.

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