JP4257608B2 - Hybrid vehicle drive device and control method thereof - Google Patents

Description

  The present invention relates to a drive device mounted on a hybrid vehicle that travels using both an engine and a motor, and a control method therefor.

  As a technique related to control at the time of engine start in a drive device mounted on a hybrid vehicle that travels using both an engine and a motor, for example, the following technique is described in Patent Document 1 below. This technology uses a motor to drive a parallel hybrid vehicle having an engine separation clutch to start the engine by fastening the engine separation clutch while maintaining a smooth vehicle response to the driver's request using a motor. In this control technique, the motor is controlled in a speed following control mode that performs control adapted to whatever torque is necessary to obtain a desired set speed throughout the engine start. That is, when starting the engine, first, an engine separation clutch is engaged, a desired speed is commanded to the motor, fuel is supplied to the engine, and the engine is started. After that, calculate the desired engine torque and increase the engine torque proportionally while gradually decreasing the motor torque until the motor torque reaches zero while maintaining the vehicle speed using, for example, a proportional integral controller To control.

  Here, the setting of the desired speed of the motor is based on the operation state of the entire vehicle and the driver's request, and can be either a trajectory based on the vehicle speed and acceleration at a current time and a past time, or a constant value. On the other hand, if the driver is not currently commanding the operating torque and a power transmission unit such as an automatic transmission that transmits the driving force from the engine and motor to the wheels is not coupled, the desired set speed is Set to the desired idle speed of the engine.

JP 2003-129926 A (page 1-5, FIG. 1-2)

  However, the above-mentioned Patent Document 1 does not disclose how it is appropriate to perform control to start the engine when there is an engine start request in a coast state where the vehicle is traveling inertially. It is only disclosed that the power transmission unit is not coupled when the driver does not command the operating torque and the motor set speed is set to the desired engine idle speed when the engine is started. It is.

  Here, when control is performed so that the power transmission unit is not always coupled when the driver does not command the operating torque, the wheel and the motor are disconnected in the coast state. Therefore, regenerative braking of the motor cannot be performed using the driving force transmitted from the wheel side to the motor. Therefore, there is a problem that the fuel efficiency of the hybrid vehicle is not positively affected.

  On the other hand, if control is performed so that the power transmission unit is always coupled in the coast state, the engine may not be able to be started quickly when an engine start request is made, depending on the number of revolutions on the motor side of the engine separation clutch. There is a problem that there is. In other words, in order to start the engine, it is necessary to rotate the crankshaft of the engine at a certain speed or more, but the speed of the vehicle is low and the speed of the engine separation clutch on the motor side is the speed at which the engine can be started. If not, the engine cannot be started even if the engine separation clutch is engaged as it is. Therefore, in order to prevent the effect of increasing the rotational speed of the motor from being transmitted to the wheel side, the power transmission unit is once separated and then the engine separation clutch is engaged to increase the rotational speed of the motor and start the engine. Need to do. However, if such control is performed after an engine start request is received, the engine cannot be started during operation control for engaging or separating the engine separation clutch or the power transmission unit. It takes a long time, and there is a problem that the driver's response to an accelerator operation or the like is poor and may give a feeling of sluggishness.

  The present invention has been made in view of the above-mentioned problems, and the object thereof is possible while ensuring the speed of engine start when there is a request for engine start in a coast state where the vehicle is traveling inertially. As long as the regenerative braking of the motor is used, it is possible to provide a hybrid vehicle drive device and a control method thereof that can improve the fuel efficiency of the vehicle.

In order to achieve the above object, the hybrid vehicle driving device according to the present invention includes a motor, a first clutch that transmits or disconnects driving force between the motor and the engine, the motor, and the engine. A second clutch that transmits or disconnects one or both of the driving forces to the wheel side, and a control device that controls the operation of the motor, the first clutch, and the second clutch. When the engine is in a stopped state and the vehicle is coasting in an inertial state, at least a predetermined waiting time in which the number of rotations on the motor side of the first clutch is set to be equal to or higher than the number of engine startable rotations when it is less rotational speed, by opening the second clutch engages said first clutch, and a standby state in which the output torque of the motor to zero, the engine When the rotation speed of the wheel a stop state is zero is that performs control of the engagement of the second clutch by opening the first clutch.

  According to this characteristic configuration, when the vehicle is running in inertia and at least the rotation speed of the first clutch on the motor side is equal to or lower than a predetermined standby rotation speed set to be equal to or higher than the engine startable rotation speed The motor and the engine are connected by engaging the first clutch while continuing the inertial running with the engine and the motor disconnected from the wheel side by releasing the second clutch. Since the engine is on standby in a state where cranking of the engine can be started immediately, the engine can be started quickly when there is an engine start request.

  In addition, when the engine is in a stopped state and the vehicle is in a coasting state in which the vehicle is running inertial, when the rotational speed on the motor side of the first clutch is greater than the standby rotational speed, It is preferable that the first clutch is released and the second clutch is engaged, and the motor is controlled to perform regenerative braking.

  Thus, in a state where the rotation speed of the first clutch on the motor side is larger than the standby rotation speed and the engine can be started only by engaging the first clutch, the second clutch is engaged. Since the regenerative braking by the motor is performed as it is, the fuel consumption of the vehicle can be improved while ensuring the quick start of the engine.

  In addition, the number of rotations on the motor side of the first clutch decreases from when the engine is requested to start to the engine startable rotation speed until the first clutch is engaged. It is preferable to set the number of rotations to be obtained.

  As a result, there is an engine start request in a state where the vehicle is in a coasting state and the motor side rotation speed of the first clutch is slightly higher than the standby rotation speed, and thus is not in the standby state. In this case, it is possible to prevent the motor side rotation speed of the first clutch from being equal to or lower than the engine startable rotation speed until the first clutch is engaged, and the engine can be started reliably. .

  Further, when setting the standby rotational speed, it comprises a road gradient detection device that detects the gradient of the road on which the vehicle is running, the control device based on the road gradient detected by the road gradient detection device, It is also suitable as a configuration for setting the standby rotational speed.

  Thereby, it is possible to set an appropriate standby rotation speed in accordance with the gradient of the road on which the vehicle is traveling. Accordingly, the number of rotations at which the motor side rotation speed of the first clutch can be reduced during the period from when the engine start request is made to when the first clutch is engaged is appropriate in accordance with changes in road gradient. It is possible to set a proper standby rotational speed. Therefore, it is possible to control the regenerative braking state to be as long as possible while ensuring the quick start of the engine, and to improve the fuel efficiency of the vehicle.

  In addition, when there is an engine start request in the standby state, the control device starts the engine with a rotation speed of the motor equal to or higher than a rotation speed at which the engine can be started, and after the engine starts, It is preferable to perform control for releasing the first clutch and engaging the second clutch, and then engaging the first clutch.

  As a result, the engine is cranked and started by rotation of the motor with the second clutch released, and after the engine is started, the first clutch is released and the second clutch is engaged. Since the first clutch is engaged, fluctuations in the rotation speed of the motor at the time of starting the engine are not transmitted to the wheel side, and it is possible to prevent a large load from being applied to the second clutch. Therefore, the engine can be reliably started while maintaining a smooth operation state of the wheels.

A characteristic configuration of a control method for a hybrid vehicle drive device according to the present invention includes a motor, a first clutch that transmits or disconnects a driving force between the motor and the engine, and one or both of the motor and the engine. And a second clutch that transmits or disconnects the driving force to the wheel side of the vehicle, wherein the engine is stopped and the vehicle is traveling inertially. In the state, when at least the rotation speed of the first clutch on the motor side is equal to or lower than a predetermined standby rotation speed set to be equal to or higher than the engine startable rotation speed, the second clutch is opened and the first clutch is opened. engaging the clutch, the output torque of the motor to zero, when the rotation speed of the wheel the engine is a stopped state is zero, opens the first clutch It lies in the engaged the second clutch Te.

  According to this characteristic configuration, when the vehicle is running in inertia and at least the rotation speed of the first clutch on the motor side is equal to or lower than a predetermined standby rotation speed set to be equal to or higher than the engine startable rotation speed The motor and the engine are connected by engaging the first clutch while continuing the inertial running with the engine and the motor disconnected from the wheel side by releasing the second clutch. Since the engine is on standby in a state where cranking of the engine can be started immediately, the engine can be started quickly when there is an engine start request.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram showing an outline of a system configuration of a hybrid vehicle drive device according to the present embodiment.

  The drive device 1 according to the present embodiment is mounted on a hybrid vehicle, transmits the driving force of one or both of the motor / generator M / G and the engine E to the wheels W, and also when the engine E is stopped, the motor / generator M / G. This is a device for starting the engine E by transmitting the driving force of G to the engine E. Therefore, the driving device 1 includes a motor / generator M / G, a first clutch C1 that transmits or disconnects driving force between the motor / generator M / G and the engine E, a motor / generator M / G, and a wheel W. , And a transmission 2 that also functions as a second clutch C2 that transmits or disconnects the driving force of one or both of the motor / generator M / G and the engine E to the wheel W side, and their operations It has the control apparatus 3 which performs control. The output shaft 4 of the transmission 2 is connected to a differential gear 5 from which driving force is transmitted to the wheels W via the driving shaft 6. Here, as the engine E, an internal combustion engine such as a gasoline engine or a diesel engine is preferably used.

  As shown in FIG. 1, the system configuration of the drive device 1 is a gear shift that also functions as an engine E, a first clutch C1, a motor / generator M / G, and a second clutch C2 along the transmission path of the driving force. It can represent as a structure connected in series of the machine 2 and the wheel W in order. In FIG. 1, in order to express the system configuration of the drive device 1 according to the present embodiment in an easy-to-understand manner, the inside of the transmission 2 is separated into a second clutch C2 and a transmission mechanism 7 and functionally expressed. Yes.

The motor / generator M / G receives the supply of electric power from the battery 9 converted from direct current to alternating current by the inverter 8 and rotationally drives the intermediate shaft 10. The intermediate shaft 10 has one end connected to a crankshaft 11 that rotates synchronously with a crankshaft (not shown) of the engine E via a first clutch C1, and the other end connected to a transmission mechanism of the transmission 2 via a second clutch C2. 7 is connected. Accordingly, the motor / generator M / G can start (crank) the engine E when the first clutch C1 is engaged, and drive the wheels W when the second clutch C2 is engaged. It has a configuration that can.
Further, the motor / generator M / G can be operated as a generator by the driving force from the engine E in a state where the first clutch C1 is engaged. Further, in a coast state where the second clutch C2 is engaged and the vehicle is traveling inertially, it can be operated as a generator by the driving force from the wheel side. In this case, the electric power generated by the motor / generator M / G is converted from alternating current to direct current by the inverter 8 and stored in the battery 9.
The operation control of the motor / generator M / G is performed based on a control signal from the M / G control device 12.

The first clutch C1 is disposed between the motor / generator M / G and the engine E, and the intermediate shaft 10 that is rotationally driven by the motor / generator M / G and a crank that rotates in synchronization with a crankshaft (not shown) of the engine E. By connecting or disconnecting the shaft 11, the driving force is transmitted or disconnected between the engine E and the motor / generator M / G.
Therefore, when the engine E is stopped, the driving force of the motor / generator M / G can be transmitted to the engine E by engaging the first clutch C1, and the engine E can be started. The driving force of the engine E is transmitted to the wheels W via the transmission 2 by engaging the first clutch C1.
As such a first clutch C1, a clutch capable of transmitting a driving force while sliding in a half-engaged state from the start of engagement to a fully engaged state is preferably used. A wet multi-plate clutch or the like is used.
The operation control of the first clutch C1 is performed based on a control signal from the first clutch control device 13.

Here, the transmission 2 is disposed between the motor / generator M / G and the wheels W, and is rotated from the intermediate shaft 10 that is rotationally driven by the driving force of one or both of the motor / generator M / G and the engine E. The input rotation is shifted at a desired speed ratio and output to the output shaft 4, and the driving force (rotation) is transmitted to the output shaft 4 or disconnected.
As such a transmission 2, a stepped or continuously variable automatic transmission is preferably used. In the present embodiment, a stepped automatic transmission such as a six-stage is used as the transmission 2, which changes the input rotation transmitted via the intermediate shaft 10 at a desired gear ratio and outputs the output shaft. 4 has a planetary gear train for output to 4 and a clutch and brake for controlling the operation of this planetary gear train. The transmission 2 switches to a desired gear position by engaging or releasing these clutches and brakes, or does not transmit the driving force input from the intermediate shaft 10 to the output shaft 4. It can be in an idle (neutral) state.
That is, the transmission 2 switches between a transmission state in which a desired shift speed is selected and the driving force input from the intermediate shaft 10 is transmitted to the output shaft 4 and an idling state in which the driving force is not transmitted to the output shaft 4. Therefore, it also functions as the second clutch C2. Therefore, as described above, the transmission 2 can be considered as having the second clutch C2 and the transmission mechanism 7 from a functional viewpoint.
In the present embodiment, the operation control of the transmission 2 is performed based on a control signal from the transmission control device 14.

The control device 3 includes an engine control device 15 that controls the operation of the engine E, an M / G control device 12 that controls the operation of the motor / generator M / G, and a first clutch control device 13 that controls the operation of the first clutch C1. A transmission control device 14 that controls the operation of the transmission 2 and a vehicle control device 16 that controls the operation of the entire vehicle are provided.
Further, the vehicle control device 16 includes a rotation speed sensor 17 that detects the rotation speed Rm of the intermediate shaft 10, a vehicle speed sensor 18 that detects the rotation speed of the output shaft 4 of the transmission 2, and the depression amount of the accelerator pedal 19 (accelerator opening). The detection signal from the accelerator sensor 20 for detecting the degree) and the brake sensor 22 for detecting the depression amount of the brake pedal 21 are input.
Furthermore, the memory 23 of the vehicle control device 16 stores information on the status flag and the standby flag determined by the vehicle control device 16 based on information from each part of the vehicle, as will be described later.

Next, operation control of the drive device 1 according to the present embodiment will be described based on the drawings.
2 to 5 are flowcharts showing operation control of the drive device 1 according to the present embodiment. FIG. 6 is an example of a timing chart showing an operation state of each part when the engine is started from the coast state in the drive device 1 according to the present embodiment.
Hereinafter, the operation control of the drive device 1 according to the present embodiment will be described in detail with a focus on the operation control when the engine E is in the stopped state and the vehicle is in the coasting state where the vehicle is inertial.

  FIG. 2 shows any one of the four control processes of “motor running”, “high-speed engine start”, “low-speed engine start”, and “engine + motor / generator travel” in the drive device 1 according to the present embodiment. It is a flowchart which shows the flow of a process in the control apparatus 3 at the time of selecting these. As shown in this figure, when the state flag stored in the memory 23 is in the “EV” state indicating “motor running” (step # 01: YES), the control device 3 controls the “motor running”. The process is selected and executed (step # 02), and when the state flag is in the state of “EstartH” indicating “high speed engine start” (step # 03: YES), the control of “high speed engine start” is performed. The process is selected and executed (step # 04), and when the state flag is in the state of “EstartL” indicating “low speed engine start” (step # 05: YES), the control of “low speed engine start” is performed. When the process is selected and executed (step # 06) and the status flag is “E + M / G” indicating “engine + motor / generator running” (step # 07: YES), “engine + mode” is selected. The control process of “data generator running” is selected and executed (step # 08).

  Here, the state flag is based on information from each part of the vehicle including the accelerator sensor 20, the brake sensor 22, the vehicle speed sensor 18, and the rotation speed sensor 17, and specifically, information from each part of the vehicle is used as a parameter. It is determined in the vehicle control device 16 based on a map indicating the running state to be performed. The determined state flag is stored in the memory 23.

  FIG. 3 is a flowchart showing details of the control process of step # 02 “motor running” in the flowchart of FIG. As shown in this figure, in the “motor running” control process, the state flag remains “EV” indicating “motor running” until an engine start request is made (step # 11: NO) (step # 11). 12). Here, the engine start request is for the case where the accelerator opening becomes large and the output torque is insufficient with only the motor / generator M / G, or the remaining amount of the battery 9 for driving the motor / generator M / G has decreased. In some cases, the vehicle control device 16 outputs the engine control device 15, the M / G control device 12, the first clutch control device 13, and the transmission control device 14.

  Next, the control device 3 determines whether or not the vehicle is in a coasting state where the vehicle is traveling inertia (step # 13). Here, the coast state can be determined based on the accelerator opening detected by the accelerator sensor 20 and the rotational speed of the output shaft 4 detected by the vehicle speed sensor 18. That is, when the accelerator opening is “0” and the rotational speed of the output shaft 4 is not “0”, it can be determined that the vehicle is in a coasting state where the vehicle is traveling inertially. The coasting state in which the vehicle is traveling in inertia is performed when the brake pedal 21 is depressed and braked, when the motor / generator M / G is performing regenerative braking, or both. The case where the torque in the deceleration direction is acting on the wheel W as in the case where the wheel is present is also included.

  When the vehicle is in a coast state (step # 13: YES), the control device 3 next determines whether or not the rotational speed Rm of the intermediate shaft 10 is equal to or lower than a predetermined standby rotational speed Rs (step #). 14). Here, the rotational speed Rm of the intermediate shaft 10 is detected by the rotational speed sensor 17. Since the intermediate shaft 10 is connected to the motor / generator M / G side of the first clutch C1, the rotational speed Rm of the intermediate shaft 10 is equal to the rotational speed of the first clutch C1 on the motor / generator M / G side. equal.

  Here, the predetermined standby rotational speed Rs is set to a rotational speed equal to or higher than the engine startable rotational speed. Specifically, the standby rotational speed Rs is such that the rotational speed Rm of the intermediate shaft 10 decreases from when the engine start request is made until the first clutch C1 is engaged with respect to the engine startable rotational speed. It is preferable to set the number of rotations to be obtained. That is, for example, when the vehicle goes up a slope in a coast state, the rotational speed Rm of the intermediate shaft 10 may suddenly decrease from when the engine start request is engaged until the first clutch C1 is engaged. . Therefore, the maximum number of revolutions Rm of the intermediate shaft 10 that may decrease between when the engine start request is made in the coast state and when the first clutch C1 is engaged is, for example, 30 in the coast state. Experiment on how much the rotational speed Rm of the intermediate shaft 10 decreases during the time from when the engine start request is made to when the first clutch C1 is engaged while climbing up a steep uphill of about% Or by simulation. Then, it is preferable that the rotation speed obtained by adding the obtained decrease in the rotation speed to the engine startable rotation speed is set as the standby rotation speed Rs. Such a decrease in the rotational speed varies depending on the vehicle, but is about 300 to 500 rpm, for example.

The engine startable rotational speed is the rotational speed Rm of the intermediate shaft 10 that can be started by cranking the engine E by bringing the first clutch C1 into a fully engaged state (the motor / generator M of the first clutch C1). / G side rotational speed). Specifically, it is about the idling speed of the engine E, for example, about 600 to 700 rpm.
Accordingly, the standby rotation speed Rs is, for example, about 900 to 1200 rpm.

  By setting the standby rotational speed Rs in this way, the first clutch C1 is engaged when there is an engine start request when the rotational speed Rm of the intermediate shaft 10 is slightly higher than the standby rotational speed. In the meantime, the rotation speed Rm of the intermediate shaft 10 becomes equal to or less than the engine startable rotation speed, so that it is possible to prevent the engine E from starting.

When the vehicle is not in the coast state (step # 13: NO), and when the vehicle is in the coast state (step # 13: YES), the rotational speed Rm of the intermediate shaft 10 is greater than the predetermined standby rotational speed Rs (step # 14). : NO), the process proceeds to step # 15. That is, the control device 3 sets the operating pressure P1 of the first clutch C1 to “0” (step # 15), and the operating pressure P2 of the second clutch C2 is completely engaged so that the second clutch C2 is in a fully engaged state. The pressure is set to P2e (step # 16), and the motor / generator M / G is operated so that the output torque Tmg of the motor / generator M / G matches the required torque Tth (step # 17).
At this time, the vehicle control device 16 turns off the standby flag stored in the memory 23 (step # 18).

  Here, the required torque Tth is determined by the vehicle control device 16 based on the information on the accelerator opening detected by the accelerator sensor 20. Therefore, the relationship between the accelerator opening when the accelerator pedal is depressed by the driver and the output torque Tmg of the motor / generator M / G is matched to the relationship between the accelerator opening and the engine output torque. This is preferable. This is to prevent the output torque with respect to the accelerator opening being different between when traveling by the engine and when traveling by the motor / generator M / G. Therefore, here, the required torque Tth is determined in accordance with the accelerator opening detected by the accelerator sensor 20 so as to coincide with the output torque of the engine at the accelerator opening at that time. As a result, the motor travel reflecting the output request by the driver's accelerator operation can be performed without giving the driver an uncomfortable feeling during the motor travel.

Further, in the coast state where the accelerator opening is “0”, the required torque Tth is “0” or less. Note that the case where the required torque Tth is smaller than “0” differs depending on the vehicle control method. For example, when the brake pedal 21 is depressed and the vehicle is braked, or both the brake pedal 21 and the accelerator pedal 19 are There is a case where the wheel W is required to be decelerated, for example, when the engine is not depressed but the engine brake is effective.
Therefore, in this state, the motor / generator M / G is not supplied with the electric power from the battery 9, and the transmission 2 including the output shaft 4 and the second clutch C <b> 2 from the wheels W of the vehicle traveling inertially. It will be in the state which is driven by the driving force transmitted via this and is performing regenerative braking.

On the other hand, when the vehicle is in a coasting state (step # 13: YES) and the rotation speed Rm of the intermediate shaft 10 is equal to or less than a predetermined standby rotation speed Rs (step # 14: YES), the process proceeds to step # 19. move on. That is, the control device 3 sets the operating pressure P2 of the second clutch C2 to the standby pressure P2s (step # 19), and the operating pressure P1 of the first clutch C1 is completely engaged so that the first clutch C1 is in a fully engaged state. The pressure is set to P1e (step # 20). Then, the output torque Tmg of the motor / generator M / G is set to “0” (step # 21).
Here, the standby pressure P2s of the second clutch C2 is a pressure that brings the second clutch C2 into an open state, and is an arbitrary value between a pressure that puts the second clutch C2 in a state immediately before the start of engagement and a pressure “0”. The pressure can be Accordingly, in this state, no driving force is transmitted between the motor / generator M / G and the wheel W side, so that the regenerative braking of the motor / generator M / G is not performed.
As a result, the states of the first clutch C1 and the second clutch C2 become a standby state in which the engine start at the time of low rotation (step # 06) can be immediately started. Therefore, the vehicle control device 16 turns on the standby flag stored in the memory 23 (step # 22).

If there is an engine start request (step # 11: YES), the control device 3 determines whether or not the standby flag stored in the memory 23 is ON (step # 23). When the standby flag is not ON (step # 23: NO), the control device 3 sets the state flag stored in the memory 23 to “EstartH” indicating “high-speed engine start” (step # 24). ). As a result, as shown in the flowchart of FIG. 2, “high engine start” control (step # 04) is performed. On the other hand, when the standby flag is ON (step # 23: YES), the state flag stored in the memory 23 is set to “EstartL” indicating “low-speed engine start” (step # 25). Thereby, as shown in the flowchart of FIG. 2, the “low engine start” control (step # 06) is performed.
This completes the control process for “motor running”.

FIG. 4 is a flowchart showing details of the control process of Step # 04 “Engine Start at High Rotation” in the flowchart of FIG. As shown in this figure, in the control process of “high-speed engine start”, first, the control device 3 determines whether or not the operating pressure P1 of the first clutch C1 is the standby pressure P1s (step #). 31) When the operating pressure P1 of the first clutch C1 is not the standby pressure P1s (step # 31: NO), the operating pressure P1 of the first clutch C1 is set to the standby pressure P1s (step # 32). Here, the standby pressure P1s of the first clutch C1 is a pressure for setting the first clutch C1 in a preparation state before the start of engagement, and is set to a pressure for operating the first clutch C1 to a state immediately before the start of engagement. It is preferable.
Then, with the operating pressure P2 of the second clutch C2 set to the complete engagement pressure P2e (step # 33), the motor / generator M / G so that the output torque Tmg of the motor / generator M / G matches the required torque Tth. Is operated (step # 34).

  When the operating pressure P1 of the first clutch C1 becomes the standby pressure P1s (step # 31: YES), the control device 3 determines whether or not the engine E is in a complete explosion state (step # 35). ). Whether or not the engine has completely exploded is determined based on detection signals input to the engine control device 15 from various sensors provided in the engine.

  When the engine E is not in the complete explosion state (step # 35: NO), the control device 3 keeps the operating pressure P2 of the second clutch C2 at the complete engagement pressure P2e (step # 36). The operating pressure P1 of one clutch C1 is increased to the full engagement pressure P1e at which the first clutch C1 is in a fully engaged state (step # 37). In the present embodiment, the control for increasing the operating pressure P1 of the first clutch C1 to the full engagement pressure P1e is performed by detecting the slip amount of the first clutch C1 and until the slip amount becomes zero. Feedback control is performed to increase the operating pressure P1.

Then, the clutch transmission torque Tc transmitted from the motor / generator M / G to the engine E side via the first clutch C1 is detected (step # 38). This clutch transmission torque Tc corresponds to the torque used for cranking and starting the engine E by the motor / generator M / G via the first clutch C1.
The clutch transmission torque Tc can be detected by, for example, calculating the clutch transmission torque Tc in the vehicle control device 16 based on the operating pressure P1 of the first clutch C1. That is, at this time, the first clutch C1 is controlled to increase its operating pressure P1 to the full engagement pressure P1e (step # 37), and the larger the torque transmitted in the first clutch C1, the higher the operating pressure. Engagement is performed by P1 and by full engagement pressure P1e. Therefore, the operating pressure P1 of the first clutch C1 has a certain relationship with the clutch transmission torque Tc transmitted by the first clutch C1. Therefore, the vehicle control device 16 calculates the clutch transmission torque Tc based on the operating pressure P1 of the first clutch C1 using a relational expression or table between the operating pressure P1 of the first clutch C1 and the clutch transmission torque Tc. Can do.

  Then, the control device 3 operates the motor / generator M / G so that the output torque Tmg of the motor / generator M / G becomes a torque obtained by adding the clutch transmission torque Tc to the required torque Tth (step # 39). As a result, the engine E can be started while the motor traveling reflecting the output request by the driver's accelerator operation is performed. The required torque Tth is determined by the vehicle control device 16 based on the accelerator opening information detected by the accelerator sensor 20 as described above.

When the engine E reaches the complete explosion state (step # 35: YES), the control device 3 sets the state flag stored in the memory 23 to “E + M” indicating “engine + motor / generator running”. / G "(step # 40). Thereby, as shown in the flowchart of FIG. 2, the “engine + motor / generator running” control (step # 08) is performed.
This completes the control process for “starting the engine at high speed”.

  FIG. 5 is a flowchart showing details of the control process of step # 06 “engine start at low speed” in the flowchart of FIG. As described above, when the control process of “engine start at low speed” is performed, the standby flag is ON (see step # 23 in FIG. 3), and the operating pressure P2 of the second clutch C2 is the standby pressure P2s ( In step # 19), the operating pressure P1 of the first clutch C1 is in a standby state where the full engagement pressure P1e (step # 20). Therefore, when there is an engine start request in this standby state, the engine E can be started only by setting the rotational speed of the motor / generator M / G to the engine start rotational speed Res, as will be described later.

Therefore, as shown in FIG. 2, in the control process of “low speed engine start”, the control device 3 first determines whether or not the engine E is in a complete explosion state (step # 51). Whether or not the engine has completely exploded is determined based on detection signals input to the engine control device 15 from various sensors provided in the engine.
When the engine E is not in the complete explosion state (step # 51: NO), the control device 3 sets the operating pressure P2 of the second clutch C2 to the standby pressure P2s (step # 52), and the first clutch C1 With the operating pressure P1 kept at the full engagement pressure P1e (step # 53), the rotational speed control is performed so that the rotational speed Rmg of the motor / generator M / G is set to the engine start rotational speed Res (step # 54).

The engine start rotational speed Res is set to a rotational speed that is equal to or higher than the rotational speed of the motor / generator M / G capable of starting the engine E when the first clutch C1 is fully engaged. In the present embodiment, since the intermediate shaft 10 is directly driven by the motor / generator M / G, the rotational speed Rmg of the motor / generator M / G and the rotational speed Rm of the intermediate shaft 10 are the same. Therefore, the engine start rotational speed Res is the same rotational speed as the engine startable rotational speed that is used as a reference when the standby rotational speed Rs is determined, specifically, the idling rotational speed of the engine E, for example, 600 to 700 rpm. It will be about.
The rotation speed control for maintaining the motor / generator M / G at the predetermined rotation speed in this way is performed so that the motor / generator M / G has the predetermined rotation speed regardless of the load acting on the intermediate shaft 10. This can be done by controlling the output torque Tmg of the generator M / G.

  As a result, the second clutch C2 is disengaged so that the driving force from one or both of the motor / generator M / G and the engine E is not transmitted to the output shaft 4 (see regions C and D in FIG. 6). In a state where fluctuations in the rotational speed Rmg of the motor / generator M / G do not affect the running state of the vehicle, the rotational speed Rmg of the motor / generator M / G is set to a rotational speed at which the engine E can be started. The engine E can be started up by raising. Accordingly, even when the rotational speed Rm of the intermediate shaft 10 is reduced to the engine startable rotational speed or less in the coast state, and the engine E cannot be started even if the first clutch C1 is completely engaged. The engine E can be reliably started while maintaining the smooth operation state of the wheel W without transmitting the fluctuation of the rotational speed Rmg of the motor / generator M / G to the wheel W when the engine E is started.

When the engine E reaches the complete explosion state (step # 51: YES), the control device 3 determines that the rotation speed Rmg of the motor / generator M / G is equal to the rotation speed of the second clutch C2 on the wheel W side. It is determined whether or not the rotational speed is Rw (hereinafter referred to as “second clutch wheel side rotational speed”) (step # 55).
Here, the second clutch wheel-side rotation speed Rw is determined when the second clutch C2 is completely engaged, with the motor / generator M / G side (the intermediate shaft 10 side) and the wheel W side (the second clutch C2 side) This is the rotational speed of the motor / generator M / G when the rotational speed of the transmission mechanism 7 side) is substantially the same with a difference within a predetermined range. That is, the second clutch wheel-side rotation speed Rw is different depending on the traveling speed of the vehicle at that time and the gear stage selected in the transmission mechanism 7. Here, the traveling speed of the vehicle can be detected by the vehicle speed sensor 18. The gear stage of the transmission mechanism 7 is controlled by the transmission control device 14.
In this determination of step # 55, the second clutch wheel side rotational speed Rw is set to a value having a certain range, and the rotational speed Rmg of the motor / generator M / G is equal to the second clutch wheel side rotational speed Rw. If it is within the range, it is preferable to judge that the condition is satisfied.

When the rotational speed Rmg of the motor / generator M / G is not the second clutch wheel side rotational speed Rw (step # 55: NO), the operating pressure P2 of the second clutch C2 is kept at the standby pressure P2s (step #). 56) The operating pressure P1 of the first clutch C1 is set to the standby pressure P1s (step # 57). Then, the rotational speed control is performed so that the rotational speed Rmg of the motor / generator M / G is set to the second clutch wheel side rotational speed Rw (step # 58).
The rotational speed control in which the rotational speed Rmg of the motor / generator M / G is set to the second clutch wheel-side rotational speed Rw is determined by the vehicle traveling speed detected by the vehicle speed sensor 18 and the speed stage selected by the speed change mechanism 7. Based on the second clutch wheel side rotational speed Rw determined from the information, the output torque Tmg of the motor / generator M / G necessary for setting the rotational speed Rmg of the motor / generator M / G to the second clutch wheel side rotational speed Rw. Can be calculated by controlling the motor / generator M / G according to the calculation result.
Thus, by matching the rotational speeds of the motor / generator M / G side and the wheel W side of the second clutch C2, when the second clutch C2 is engaged, the motor / generator M / G side By absorbing the difference in rotational speed from the wheel W side, it is possible to prevent fluctuations in the driving force from being transmitted to the wheel side. Therefore, it is possible to prevent a large load from being applied to the second clutch C2 when the second clutch C2 is engaged, and to maintain a smooth operation state of the wheels.

When the rotational speed Rmg of the motor / generator M / G becomes the second clutch wheel side rotational speed Rw (step # 55: YES), the operating pressure P2 of the second clutch C2 is the full engagement pressure P2e. Is determined (step # 59). This is a determination as to whether or not the second clutch C2 is in a fully engaged state. If the operating pressure P2 of the second clutch C2 is not the complete engagement pressure P2e (step # 59: NO), the operating pressure P1 of the first clutch C1 is kept at the standby pressure P1s (step # 60). ), The operating pressure P2 of the second clutch C2 is set to the complete engagement pressure P2e (step # 61). During this time, the rotational speed control is performed so that the rotational speed Rmg of the motor / generator M / G is maintained at the second clutch wheel-side rotational speed Rw (step # 62).
Thus, the wheel W can be driven by the driving force of the motor / generator M / G while maintaining the smooth operation state of the wheel.

When the operating pressure P2 of the second clutch C2 becomes the complete engagement pressure P2e (step # 59: YES), the control device 3 sets the status flag stored in the memory 23 to “engine + motor”. “E + M / G” indicating “generator running” is set (step # 63). Thereby, as shown in the flowchart of FIG. 2, the “engine + motor / generator running” control (step # 08) is performed.
This completes the control process for “starting the engine at low speed”.

  FIG. 6 shows the components in the case where the engine E is requested and the engine E is started after the rotation speed Rm of the intermediate shaft 10 is reduced from the state higher than the standby rotation speed Rs to the standby rotation speed Rs or less after the vehicle is coasted. It is an example of the timing chart which shows an operation state.

  In the example shown in this figure, in the region A, the accelerator pedal 19 is not depressed by the driver, the accelerator opening is “0”, and the vehicle speed (output shaft rotation speed) gradually increases while the vehicle travels in the coast state. It has dropped to. At this time, the operating pressure P1 of the first clutch C1 is “0”, the operating pressure P2 of the second clutch C2 is the complete engagement pressure P2e (see steps # 15 and 16 in FIG. 3), and the engine E is stopped. The motor / generator M / G is driven by the driving force transmitted from the wheels W through the transmission 2 including the output shaft 4 and the second clutch C2, and performs regenerative braking. Accordingly, the output torque Tmg of the motor / generator M / G at this time is negative.

  When the vehicle enters the region B, that is, when the vehicle speed (output shaft rotational speed) decreases and the rotational speed Rm of the intermediate shaft 10 (the rotational speed Rmg of the motor / generator M / G) becomes equal to or lower than the standby rotational speed Rs. In addition, the operating pressure P2 of the second clutch C2 becomes the standby pressure P2s, and the operating pressure P1 of the first clutch C1 becomes the complete engagement pressure P1e (see steps # 19 and 20 in FIG. 3). Further, since the motor / generator M / G is separated from the wheel W side, the output torque Tmg of the motor / generator M / G is “0”, and the rotational speed Rmg of the motor / generator M / G is also “0”. Thus, the regenerative braking is finished.

In the region C, the motor / generator M / G and the engine E are applied to the wheels W while the operating pressure P2 of the second clutch C2 is the standby pressure P2s and the operating pressure P1 of the first clutch C1 is the complete engagement pressure P1e. The vehicle continues the inertial running in the idle running state where the driving force from one or both is not transmitted.
The operation of each unit in the areas A to C so far is performed according to the control process shown in the flowchart of FIG.

Then, when the accelerator pedal 19 is depressed by the driver, the control device 3 starts the control of “starting the engine at low speed” shown in the flowchart of FIG. In the example shown in FIG. 6, when entering the region D, the accelerator pedal 19 is greatly depressed from the coast state, and the engine start control is performed because the output torque is insufficient only with the motor / generator M / G. It has been broken. That is, while the operating pressure P2 of the second clutch C2 is the standby pressure P2s and the operating pressure P1 of the first clutch C1 is the full engagement pressure P1e, the rotational speed Rmg of the motor / generator M / G is set to the engine start rotational speed Res. Thus, the rotational speed control is performed (see steps # 52 to # 54 in FIG. 5). As a result, the rotational speed Rmg of the motor / generator M / G is increased, the cranking of the engine E is performed, and the engine E is started.
At this time, the output torque Tmg of the motor / generator M / G is increased by an amount necessary for cranking the engine E by setting the engine speed Rmg of the motor / generator M / G to the engine start speed Res. Yes.

In a region E after the engine E is completely exploded and started, the control device 3 keeps the operating pressure P2 of the second clutch C2 at the standby pressure P2s and sets the operating pressure P1 of the first clutch C1 as the standby pressure P1s. The rotation speed Rmg of the motor / generator M / G is set as the second clutch wheel-side rotation speed Rw (see steps # 56 to 58 in FIG. 5).
In the region F, the operating pressure P1 of the first clutch C1 is maintained at the standby pressure P1s and the rotational speed Rmg of the motor / generator M / G is maintained at the second clutch wheel side rotational speed Rw (step # in FIG. 5). 60 and 62), the working pressure P2 of the second clutch C2 is set to the complete engagement pressure P2e (see step # 61 in FIG. 5). As a result, the wheels W are driven by the driving force of the motor / generator M / G.

  Thereafter, “engine + motor / generator traveling” is performed after the region G. That is, in the region G, the output torque Tmg of the motor / generator M / G is decreased to increase the output torque Te of the engine E, and the operating pressure P1 of the first clutch C1 is increased toward the complete engagement pressure P1e. . During this time, the output torque Te of the engine E is transmitted while the output torque Te of the engine E is increased and the first clutch C1 is slid in the half-engaged state. Thereby, the fluctuation | variation of the output torque Te transmitted to the wheel W side is made gentle. At this time, the output torque Te of the engine E is increased until it becomes equal to the torque obtained by adding the torque (power generation torque) Teg required for the power generation of the motor / generator M / G to the required torque Tth.

As shown in the region H, even after the output torque Te of the engine E becomes constant, the operating pressure P1 of the first clutch C1 is increased until the full engagement pressure P1e is reached. As the operating pressure P1 of the first clutch C1 increases, the difference between the rotational speed Rmg of the motor / generator M / G and the rotational speed Re of the engine E decreases.
Then, as shown in region I, after the operating pressure P1 of the first clutch C1 reaches the complete engagement pressure P1e, the rotational speed Re of the engine E and the rotational speed Rmg of the motor / generator M / G The motor / generator M / G is driven to rotate by the driving force of the engine E and operates as a generator.

  When the control process of “starting engine at low speed” is performed as described above, the control device 3 controls the motor / generator M / G in the regions D to F where the second clutch C2 is in the released state. Thus, the rotational speed control is performed, and the torque control is performed on the motor / generator M / G in the regions G to I where the second clutch C2 is in the fully engaged state.

[Another embodiment]
(1) In the above embodiment, when the vehicle is in an coasting state where the vehicle is traveling inertially, the rotational speed Rm of the intermediate shaft 10, that is, the rotational speed of the first clutch C1 on the motor / generator M / G side is predetermined. When the rotational speed is higher than the standby rotational speed Rs, a control process is adopted in which the first clutch C1 is disengaged and the second clutch C2 is engaged and the motor / generator M / G performs regenerative braking. However, the scope of application is not limited to this. That is, the present invention performs the control for setting the standby state as described above when at least the rotation speed of the first clutch C1 on the motor / generator M / G side is equal to or less than the standby rotation speed Rs. Control in the case where the rotation speed of the clutch C1 on the motor / generator M / G side is larger than the standby rotation speed Rs is not particularly limited.
Therefore, for example, even when the rotation speed of the first clutch C1 on the motor / generator M / G side is larger than the standby rotation speed Rs, the second clutch C2 is released and the first clutch C1 is engaged. It is also possible to perform control. With such a configuration, regenerative braking by the motor / generator M / G cannot be performed even in a state where the engine E can be started only by engaging the first clutch C1, but there has been an engine start request. In this case, the speed of starting the engine can be ensured.

(2) In the above embodiment, the case where the standby rotational speed Rs is set to a preset fixed value has been described. However, the setting of the standby rotational speed Rs in the present invention is not limited to such a fixed value. Therefore, it is also one preferred embodiment that the control device 3 changes and sets the standby rotation speed Rs based on the gradient of the road on which the vehicle is traveling.
That is, when the vehicle is driving on a sloped road in a coastal state, the first clutch is started from the time when the engine is requested to start according to the slope angle (including the direction of the slope, up or down). The extent to which the rotational speed Rm of the intermediate shaft 10 decreases before engaging C1 is different. Accordingly, the amount of decrease in the rotational speed Rm of the intermediate shaft 10 from when the engine start request is made until the first clutch C1 is engaged is calculated according to the inclination angle of the road gradient. It is preferable to set the standby rotational speed Rs according to the road gradient.
It is also a preferred embodiment that the standby rotational speed Rs corresponding to the road gradient calculated in this way is stored in the memory 23 in advance as a table.
In this case, although not shown, the driving device 1 needs to be configured to include a road gradient detection device that detects the gradient of the road on which the vehicle is traveling. As such a road gradient detection device, a known inclination sensor or the like can be used.

(3) In the above embodiment, based on the detection signal from the rotational speed sensor 17 that detects the rotational speed of the intermediate shaft 10, the rotational speed Rm of the intermediate shaft 10, that is, the motor / generator M / G side of the first clutch C1. However, the means for detecting the rotational speed of the first clutch C1 on the motor / generator M / G side is not limited to this, and the first clutch C1 is directly or indirectly detected. Any means capable of detecting the number of rotations on the motor / generator M / G side may be used. Therefore, for example, it is also a preferred embodiment that the rotational speed of the first clutch C1 on the motor / generator M / G side is directly detected by a rotational speed sensor or the like provided in the first clutch C1. is there.

  The present invention can be suitably used for a hybrid vehicle that travels using both an engine and a motor.

The conceptual diagram which shows the outline of the system configuration | structure of the drive device for hybrid vehicles which concerns on embodiment of this invention. The flowchart which shows the flow of the process of selection of the control process in the drive device for hybrid vehicles which concerns on embodiment of this invention. The flowchart which shows the detail of control processing of step # 02 "motor running" in the flowchart of FIG. FIG. 2 is a flowchart showing details of the control process of step # 04 “engine start at high speed” in the flowchart of FIG. FIG. 2 is a flowchart showing details of the control process of step # 06 “engine start at low speed” in the flowchart of FIG. In the hybrid vehicle drive device according to the embodiment of the present invention, the timing chart showing the operation state of each part when the engine E is started after the vehicle is in a coasting state and the rotational speed of the intermediate shaft is reduced to the standby rotational speed Rs or less. Example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive apparatus 2 Transmission 3 Control apparatus 4 Output shaft E Engine M / G Motor generator W Wheel C1 First clutch C2 Second clutch Rm The rotation speed of the intermediate shaft (the rotation speed of the first clutch on the motor / generator side)
Rs Standby rotational speed Rmg Motor / generator rotational speed Rt Threshold rotational speed Rw Second clutch wheel side rotational speed

Claims (6)

A motor, a first clutch that transmits or disconnects driving force between the motor and the engine, and a second clutch that transmits or disconnects driving force of one or both of the motor and the engine to the wheel side A controller for controlling the operation of the motor, the first clutch, and the second clutch, and a hybrid vehicle drive device comprising:
In the control device, when the engine is in a stopped state and the vehicle is in a coasting state in which the vehicle is running inertial, at least the rotation speed on the motor side of the first clutch is set to be equal to or higher than the engine startable rotation speed. When the engine speed is equal to or lower than the predetermined standby rotational speed, the second clutch is released, the first clutch is engaged, the motor is set in a standby state in which the output torque is zero, and the engine is stopped and the engine is stopped. A hybrid vehicle drive device that performs control to release the first clutch and engage the second clutch when the number of rotations of the wheels is zero.
  When the engine is stopped and the vehicle is in an inertia coasting state, the control device is configured such that when the rotational speed on the motor side of the first clutch is greater than the standby rotational speed, 2. The hybrid vehicle drive device according to claim 1, wherein one of the clutches is released and the second clutch is engaged, and the motor is controlled to perform regenerative braking.   The standby rotational speed is a speed at which the rotational speed on the motor side of the first clutch can be reduced from when the engine start request is made to when the first clutch is engaged. The hybrid vehicle drive device according to claim 1, wherein the number of rotations is set to a number added. A road gradient detection device that detects the gradient of the road on which the vehicle is running,
The hybrid vehicle drive device according to claim 1, wherein the control device sets the standby rotation speed based on a road gradient detected by the road gradient detection device.   When there is an engine start request in the standby state, the control device starts the engine by setting the rotation speed of the motor to be equal to or higher than the rotation speed at which the engine can be started. The hybrid vehicle drive device according to any one of claims 1 to 3, wherein control is performed to release the clutch and engage the second clutch, and then engage the first clutch. A motor, a first clutch that transmits or disconnects driving force between the motor and the engine, and a second clutch that transmits or disconnects driving force of one or both of the motor and the engine to the wheel side , A method for controlling a hybrid vehicle drive device comprising:
When the engine is in a stopped state and the vehicle is in a coasting state where the vehicle is running inertially, a predetermined standby rotation in which at least the motor side rotation speed of the first clutch is set to be equal to or higher than the engine startable rotation speed When the number is less than or equal to the number, the second clutch is disengaged and the first clutch is engaged, the output torque of the motor is set to zero, the engine is stopped, and the rotation speed of the wheel is zero The method for controlling a hybrid vehicle driving device, wherein the first clutch is released and the second clutch is engaged.

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