Hybrid vehicles

Abstract

The present invention provides a vehicle comprising an HCTU (control device) that, when switching from an engine travel mode (first travel mode) for traveling with an engine as the drive source to a second travel mode for traveling with a front motor as the drive source, the switch being made while the connection between the front motor and the axle is disconnected, synchronizes a converted motor speed ωmd with an axle speed ωd before initiating operation of a second actuator to connect the front motor and the axle by means of a motor clutch. If the rate α of change per unit time of the axle speed ωd is equal to or greater than a predetermined value α1 during the synchronization of the converted motor speed ωmd and the axle speed ωd, the HCTU calculates an expected arrival time Δt until the converted motor speed ωmd will reach the axle speed ωd, and once the expected arrival time Δt is not greater than a predetermined operation time ta of the second actuator, the HCTU initiates operation of the second actuator to connect the front motor and the axle by means of the motor clutch.

Description

Technical Field

[0004] , , , ,

[0001] The present invention relates to a hybrid vehicle.

Background Art

[0002] Conventionally, in a hybrid vehicle equipped with an internal combustion engine and a motor as drive sources, when switching the driving mode, a technique related to controlling the rotational speed of the motor to synchronize with the rotational speed of a member to which the motor is connected is known. For example, Patent Document 1 describes a power split mechanism having a first rotating element connected to an engine, a second rotating element connected to a first motor having a power generation function, and a third rotating element connected to a second motor and an output member, a transmission provided between the engine and the power split mechanism, and an engagement device for setting the transmission in a neutral state or a shifted state. In this hybrid vehicle, when switching the transmission from the neutral state to the shifted state, by controlling the rotational speed of the motor, when the differential rotational speed of the engagement device becomes within a predetermined rotational speed determined in advance as the difference from the synchronous rotational speed, the engagement of the engagement device is started while controlling the torque of the motor to be constant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, in hybrid vehicles equipped with an internal combustion engine and an electric motor as power sources, there are cases where the vehicle transitions from a driving mode in which the vehicle is driven by the internal combustion engine with the motor and axle disconnected, to a driving mode in which it is driven by at least the electric motor. In this case, in order to suppress the shock when connecting the motor to the axle, as described above, rotational synchronization control is performed to synchronize the motor rotation speed with the axle rotation speed when switching driving modes.

[0005] However, because it takes time for the motor speed to synchronize with the axle speed, if the vehicle decelerates rapidly before coming to a stop, for example, synchronization may not be completed in time for the vehicle to come to a complete stop. As a result, when the vehicle restarts, the connection between the motor and the axle may not be completed, and it may not be possible to start driving using the motor's power promptly. Also, if the vehicle accelerates rapidly, for example, if it takes time for the motor speed to synchronize with the axle speed, the driver may not be able to obtain sufficient power to meet their acceleration request. Thus, it is necessary to complete the connection between the motor and the axle as quickly as possible when the vehicle decelerates or accelerates rapidly.

[0006] This invention has been made in view of these problems, and its objective is to provide a hybrid vehicle that can quickly connect the electric motor and the axle while suppressing the occurrence of shocks as much as possible during sudden deceleration and sudden acceleration. [Means for solving the problem]

[0007] To achieve the above objective, the hybrid vehicle of the present invention comprises an internal combustion engine, a traction motor, an engagement device for switching between connecting and disconnecting the traction motor and an axle, an actuator for operating the engagement device, and a control device that, when switching from a first driving mode in which the vehicle is driven by the internal combustion engine with the traction motor and the axle disconnected, to a second driving mode in which the vehicle is driven by at least the traction motor, synchronizes the motor speed and the axle speed before starting the operation of the actuator to connect the traction motor and the axle using the engagement device. The control device calculates an estimated arrival time for the motor speed to reach the axle speed based on the motor speed and the axle speed when the absolute value of the rate of change of the axle speed per unit time is greater than or equal to a predetermined value during the synchronization of the motor speed and the axle speed, and starts the operation of the actuator to connect the traction motor and the axle using the engagement device when the estimated arrival time is less than or equal to a predetermined operating time of the actuator.

[0008] With this configuration, if the absolute value of the rate of change of the axle rotation speed is greater than or equal to a predetermined value and the vehicle undergoes rapid deceleration or acceleration, the connection between the traction motor and the axle is initiated so that the expected time it takes for the motor rotation speed to reach the axle rotation speed roughly coincides with the predetermined operating time of the actuator. As a result, the traction motor and the axle are connected near the point in time when the motor rotation speed reaches the axle rotation speed. Therefore, according to the hybrid vehicle of the present invention, it is possible to quickly connect the traction motor and the axle while suppressing the occurrence of shocks as much as possible during rapid deceleration and acceleration.

[0009] Furthermore, it is preferable that the predetermined operating time is set to different values ​​depending on whether the absolute value of the rate of change is greater than or equal to the predetermined value or less than the predetermined value. With this configuration, when the vehicle is undergoing rapid deceleration or acceleration, the operating time of the actuator can be appropriately adjusted to more effectively suppress the occurrence of shocks caused by the connection between the electric motor for driving and the axle.

[0010] Furthermore, it is preferable that the predetermined operating time is set shorter when the absolute value of the rate of change is greater than or equal to the predetermined value compared to when the absolute value of the rate of change is less than the predetermined value. With this configuration, when the vehicle is rapidly decelerating or accelerating, the operating time of the actuator can be shortened compared to normal conditions, thereby improving the accuracy of calculating the predicted arrival time. In other words, the predicted arrival time and the predetermined operating time of the actuator can be made to be closer to the same value, increasing the probability that the connection between the traction motor and the axle will be completed when the motor rotation speed reaches the axle rotation speed. As a result, the occurrence of shocks can be suppressed more effectively.

[0011] Furthermore, it is preferable that the control device calculates the expected arrival time when the rate of change is greater than or equal to the predetermined value on the deceleration side during synchronization of the motor rotation speed and the axle rotation speed, and starts operating the actuator when the expected arrival time becomes less than or equal to the predetermined operating time. This configuration makes it possible to quickly connect the electric motor and the axle during rapid deceleration, in which the effects of the shock caused by the connection between the electric motor and the axle are less noticeable to the vehicle's occupants. [Effects of the Invention]

[0012] According to the hybrid vehicle of the present invention, the electric motor for driving and the axle can be quickly connected while suppressing the occurrence of shocks as much as possible during sudden deceleration and sudden acceleration. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing a hybrid vehicle according to an embodiment. [Figure 2] This is an explanatory diagram illustrating the time-dependent changes in axle rotation speed and converted motor rotation speed. [Figure 3] This is an explanatory diagram illustrating the time-dependent changes in axle rotation speed and converted motor rotation speed during rapid deceleration of a vehicle, as a comparative example. [Figure 4]This flowchart shows an example of the engagement control process in the embodiment. [Figure 5] This is an explanatory diagram illustrating the time-dependent changes in axle rotation speed and converted motor rotation speed during rapid deceleration of a vehicle when the engagement control of the embodiment is performed. [Figure 6] This is an explanatory diagram illustrating the time-dependent changes in axle rotation speed and converted motor rotation speed during rapid acceleration of a vehicle when the engagement control of the embodiment is performed. [Modes for carrying out the invention]

[0014] Hereinafter, an embodiment of the present invention will be described based on the drawings. Figure 1 is a schematic diagram showing a hybrid vehicle of the embodiment. The hybrid vehicle 1 (hereinafter referred to as "vehicle 1") is a plug-in hybrid (PHEV) vehicle that can be driven by the output of an engine 2 (internal combustion engine) to drive the front wheels 3, and is equipped with a front motor 4 (electric motor for driving) that drives the front wheels 3.

[0015] Engine 2 drives the axle 8 of the front wheel 3 via the reduction gear 7, and also drives the motor generator 9 via the reduction gear 7 to generate electricity. The front motor 4 is powered by the drive battery 11 and the motor generator 9 via the front inverter 10, and drives the axle 8 of the front wheel 3 via the reduction gear 7.

[0016] The reduction gear 7 incorporates an engine clutch 7a that switches the transmission of power between the output shaft of the engine 2 and the axle 8, and a motor clutch 7b that switches the transmission of power between the front motor 4 and the axle 8. The engine clutch 7a and motor clutch 7b (engaging devices) are wet multi-plate hydraulic friction engaging devices. The engine clutch 7a is operated by hydraulic pressure from a hydraulic first actuator 31, and the motor clutch 7b is operated by hydraulic pressure from a hydraulic second actuator 32. Note that the engine clutch 7a and motor clutch 7b are not limited to hydraulic friction engaging devices but may also be electrically operated friction engaging devices, or not limited to friction engaging devices but may also be meshing type engaging devices.

[0017] Further, the vehicle 1 of the present embodiment includes a motor rotation speed detection sensor 41 that detects the rotation speed of the front motor 4, and an axle rotation speed detection sensor 42 that detects the axle rotation speed ωd of the axle 8. The motor rotation speed detection sensor 41 and the axle rotation speed detection sensor 42 output the detection results to a hybrid control unit 20 (control device; hereinafter referred to as "HCTU20").

[0018] The drive battery 11 is composed of a secondary battery such as a lithium-ion battery, and has a battery module (not shown) formed by combining a plurality of battery cells. The drive battery 11 is provided with a battery monitoring unit 11a that monitors the charge rate (State Of Charge) of the battery module. Further, the vehicle 1 includes a charger 21 that externally charges the drive battery 11 with an external power source, and external power supply is also possible.

[0019] The HCTU20 is a control device that performs comprehensive control of the vehicle 1, and is configured to include an input / output device, a storage device (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), and the like. The HCTU20 inputs detection amounts detected by various sensors (not shown) such as the accelerator opening, brake stroke, vehicle speed, and wheel speed, and various operation information. Further, the HCTU20 inputs the rotation speed of the front motor 4 from the motor rotation speed detection sensor 41 and the axle rotation speed ωd of the axle 8 from the axle rotation speed detection sensor 42. The HCTU20 calculates the motor rotation speed as the axle conversion value obtained by dividing the input rotation speed of the front motor 4 by the reduction ratio of the reduction gear 7. In the following description, the motor rotation speed as the axle conversion value is referred to as "converted motor rotation speed ωmd".

[0020] Based on various detected amounts and various operation information input, etc., the HCTU20 calculates information necessary for controlling the vehicle 1, such as the required driving force required for the running of the vehicle 1. Based on the calculated information, the HCTU20 outputs various control signals to the engine control unit 14, the front inverter 10, the reduction gear 7, etc., and controls the outputs of the engine 2 and the front motor 4, the output of the motor generator 9 (generated electric power), the operations of the first actuator 31 and the second actuator 32, etc.

[0021] Also, the HCTU20 controls the running mode of the vehicle 1. The running mode of the vehicle 1 includes an EV running mode, a series running mode, a parallel running mode, and an engine running mode. In the EV running mode, the engine 2 is stopped, and the front motor 4 is driven by the electric power supplied from the driving battery 11 to run the vehicle 1. In the series running mode, the engine 2 operates the motor generator 9, and the front motor 4 is driven by the electric power generated by the motor generator 9 and the electric power supplied from the driving battery 11 to run the vehicle 1. In the parallel running mode, power is mechanically transmitted from the engine 2 to the axle 8 via the reduction gear 7, and the front motor 4 is driven to run by the electric power generated by the motor generator 9 or the electric power supplied from the driving battery 11. Also, in the engine running mode, power is mechanically transmitted from the engine 2 to the axle 8 via the reduction gear 7 to run the vehicle 1.

[0022] In the vehicle 1 of this embodiment, in engine driving mode, the motor clutch 7b is released by the second actuator 32, and the connection between the front motor 4 and the axle 8 is released. This reduces the load acting on the axle 8 when power from the front motor 4 is not used for driving. On the other hand, in EV driving mode, series driving mode, and parallel driving mode, the motor clutch 7b is engaged by the second actuator 32, and the front motor 4 and the axle 8 are connected. Hereinafter, the engine driving mode in which the connection between the front motor 4 and the axle 8 is released will be appropriately referred to as the "first driving mode," and the EV driving mode, series driving mode, and parallel driving mode in which the front motor 4 and the axle 8 are connected will be appropriately referred to as the "second driving mode."

[0023] The HCTU20 then switches the above-mentioned driving mode depending on the fulfillment of various predetermined conditions. For example, when the vehicle speed falls below a first predetermined vehicle speed while driving in engine driving mode, the HCTU20 switches the driving mode to series driving mode. Also, for example, when the vehicle speed rises above a second predetermined vehicle speed (greater than the first predetermined vehicle speed) while driving in engine driving mode, the HCTU20 switches the driving mode to parallel driving mode. In this way, when switching the driving mode from the first driving mode (engine driving mode) to the second driving mode (EV driving mode, series driving mode, or parallel driving mode), the front motor 4 and the axle 8 are connected by the engagement of the motor clutch 7b. At that time, the HCTU20 performs rotational synchronization control to synchronize the above-mentioned converted motor rotation speed ωmd of the front motor 4 with the axle rotation speed ωd.

[0024] Rotational synchronous control will be explained with reference to Figure 2. Figure 2 is an explanatory diagram illustrating the time change of the axle rotation speed ωd and the converted motor rotation speed ωmd. In Figure 2 and Figures 3 to 6 described later, the axle rotation speed ωd is shown by a dashed line and the converted motor rotation speed ωmd is shown by a solid line. Now, let's assume that vehicle 1, which is running in engine driving mode, has decelerated and then stopped. As shown in the figure, when the vehicle speed becomes below the first predetermined vehicle speed and the conditions for transitioning to series driving mode are met, rotational synchronous control of the converted motor rotation speed ωmd to the axle rotation speed ωd is started at time t1. Rotational synchronous control is a control that drives the front motor 4 so that the converted motor rotation speed ωmd converges to the axle rotation speed ωd using feedback control such as PID control. For example, rotational synchronization is determined to be complete when the difference in rotation speed between the converted motor rotation speed ωmd and the axle rotation speed ωd remains within a predetermined range for a predetermined synchronization completion determination time.

[0025] When the HCTU20 determines that rotational synchronization is complete at time t2, it starts operating the second actuator 32 to engage the motor clutch 7b. At this time, the second actuator 32 operates for a predetermined operating time ta. The operating time ta is the time required from the determination that rotational synchronization is complete until the motor clutch 7b is fully engaged, and is predetermined considering the time it takes for the HCTU20 to output an operation command to the second actuator 32 and the operating delay time of the second actuator 32. Furthermore, the second actuator 32 is configured to allow adjustment of the operating time ta as appropriate.

[0026] As a result, at time t3, the motor clutch 7b fully engages, connecting the front motor 4 and the axle 8, and thereafter, as shown by the solid line, the converted motor rotation speed ωmd and the axle rotation speed ωd become equal. In this way, by connecting the front motor 4 and the axle 8 before the vehicle 1 has finished coming to a complete stop at time t4, when the vehicle 1 restarts, it is possible to quickly start driving using the power of the front motor 4 in EV driving mode or series driving mode.

[0027] In contrast, Figure 3 is an explanatory diagram illustrating the time changes of the axle rotation speed ωd and the converted motor rotation speed ωmd during rapid deceleration of vehicle 1 as a comparative example. In the example shown in Figure 3, it is assumed that vehicle 1, which is running in engine driving mode, decelerates more rapidly than in the example shown in Figure 2. In this case, even if the front motor 4 is driven and controlled so that the converted motor rotation speed ωmd converges to the axle rotation speed ωd after rotation synchronization control is started at time t1, rotation synchronization may not be completed by the time vehicle 1 stops at time t2. As a result, the front motor 4 and the axle 8 cannot be connected before vehicle 1 stops, and vehicle 1 will not be able to quickly start driving using the power of the front motor 4 when it restarts.

[0028] Furthermore, for example, when vehicle 1, which is running in engine-driven mode, switches to parallel driving mode because its speed exceeds a second predetermined speed, if vehicle 1 is accelerating rapidly, it may take time to synchronize the converted motor rotation speed ωmd with the axle rotation speed ωd, similar to the example shown in Figure 3 above, and it may not be possible to quickly connect the front motor 4 and the axle 8. As a result, sufficient output may not be obtained in response to the driver's acceleration request.

[0029] As described above, during rapid deceleration or acceleration of vehicle 1, it is required to quickly complete the connection of the front motor 4 to the axle 8. Therefore, vehicle 1 in this embodiment performs engagement control of the motor clutch 7b, which will be described below. Figure 4 is a flowchart showing an example of the engagement control process in this embodiment. The process shown in Figure 4 is performed by the HCTU 20 when rotational synchronous control is started.

[0030] First, the HCTU20 obtains the axle rotation speed ωd and the converted motor rotation speed ωmd (step S10). Specifically, the HCTU20 obtains the axle rotation speed ωd detected by the axle rotation speed detection sensor 42. The HCTU20 also obtains the rotation speed detected by the motor rotation speed detection sensor 41 and calculates and obtains the above converted motor rotation speed ωmd. Next, the HCTU20 calculates the rate of change α per unit time of the axle rotation speed ωd (step S11). The rate of change α is a positive value when vehicle 1 is accelerating and a negative value when vehicle 1 is decelerating.

[0031] Next, the HCTU20 determines whether the absolute value of the calculated rate of change α is less than a predetermined value α1 (step S12). That is, the HCTU20 determines whether the vehicle 1 has decelerated or accelerated rapidly during the execution of rotational synchronization control. The predetermined value α1 and the above unit time can be arbitrarily determined as values ​​that allow for the determination that the vehicle 1 has decelerated or accelerated rapidly. Then, when the HCTU20 determines that the absolute value of the rate of change α is less than the predetermined value α1 (Yes in step S12), that is, when it determines that the vehicle 1 has not decelerated or accelerated rapidly, it determines whether the rotational synchronization between the converted motor rotation speed ωmd and the axle rotation speed ωd has been completed (step S13). As described above, the HCTU20 determines that rotational synchronization has been completed if the difference in rotational speed between the converted motor rotation speed ωmd and the axle rotation speed ωd remains within a predetermined range for a predetermined synchronization completion determination time.

[0032] When HCTU20 determines that rotational synchronization is not complete (No in step S13), it repeatedly executes the processes from step S10 onward. On the other hand, when HCTU20 determines that synchronization is complete (Yes in step S13), it outputs an operation instruction to the second actuator 32 (step S14) and terminates this routine. As a result, once the second actuator 32 has completed the engagement of the motor clutch 7b, the front motor 4 and the axle 8 are connected, and thereafter, the converted motor rotation speed ωmd and the axle rotation speed ωd match, as illustrated in Figure 2.

[0033] In response to this, when the HCTU20 determines that the absolute value of the rate of change α is greater than or equal to a predetermined value α1 (No in step S12), that is, when it determines that vehicle 1 has decelerated or accelerated rapidly, it calculates the expected arrival time Δt (see Figure 5) until the converted motor rotation speed ωmd and the axle rotation speed ωd coincide (step S15). The expected arrival time Δt should be calculated based on the difference in rotations between the converted motor rotation speed ωmd and the axle rotation speed ωd, the rate of change of the converted motor rotation speed ωmd per unit time, and the above rate of change α of the axle rotation speed ωd. Note that in the process of step S15, the latest converted motor rotation speed ωmd and axle rotation speed ωd at the time of execution are obtained and the expected arrival time Δt is calculated.

[0034] Next, HCTU20 determines whether the calculated estimated arrival time Δt is less than or equal to the predetermined operating time ta of the second actuator 32 (step S16). If HCTU20 determines that the estimated arrival time Δt is greater than the operating time ta (No in step S16), it repeatedly executes the processes from step S15 onwards. On the other hand, if HCTU20 determines that the estimated arrival time Δt is less than or equal to the operating time ta (Yes in step S16), it outputs an operation command to the second actuator 32 (step S14) and terminates this routine.

[0035] The operation of the engagement control of this embodiment will be explained in detail with reference to Figures 5 and 6. First, Figure 5 is an explanatory diagram illustrating the time change of the axle rotation speed ωd and the converted motor rotation speed ωmd during rapid deceleration of the vehicle 1 when the engagement control of this embodiment is performed. Now, suppose that after rotation synchronous control is started at time t1, the rate of change α of the axle rotation speed ωd becomes greater than or equal to a predetermined value α1 on the deceleration side (negative side) due to the rapid deceleration of the vehicle 1. As a result, the expected arrival time Δt until the converted motor rotation speed ωmd and the axle rotation speed ωd match is calculated, and when the expected arrival time Δt becomes less than or equal to the operating time ta at time t2, an operation instruction is output to the second actuator 32 and the second actuator 32 starts operating. As a result, after the operating time ta has elapsed, the engagement of the motor clutch 7b is completed at time t3, and the front motor 4 and the axle 8 are connected, and thereafter, as shown by the solid line, the converted motor rotation speed ωmd and the axle rotation speed ωd become equal values. The dashed line in the figure shows the behavior of the converted motor rotation speed ωmd when the second actuator 32 is not activated (the behavior exemplified in Figure 3).

[0036] In this way, by starting the operation of the second actuator 32 when the expected arrival time Δt becomes less than or equal to the operating time ta, the motor clutch 7b can be fully engaged near the point in time when the converted motor rotation speed ωmd and the axle rotation speed ωd coincide (intersect). This allows the front motor 4 and axle 8 to be connected before synchronization is complete, while suppressing the occurrence of shock as much as possible. Therefore, the front motor 4 and axle 8 are connected before the vehicle 1 stops, and it is possible to start driving by outputting power from the front motor 4 when restarting. Also, in this case, since the vehicle 1 is under conditions of rapid deceleration, the impact of the shock felt by the occupants of the vehicle 1 due to the engagement of the motor clutch 7b is considered to be small.

[0037] Next, Figure 6 is an explanatory diagram illustrating the time changes of the axle rotation speed ωd and the converted motor rotation speed ωmd during rapid acceleration of vehicle 1 when the engagement control of the embodiment is performed. In the example shown in Figure 6, it is assumed that vehicle 1, which is running in engine driving mode, is rapidly accelerating. In this case as well, after rotation synchronization control is started at time t1, the rate of change α of the axle rotation speed ωd becomes greater than or equal to a predetermined value α1 on the acceleration side (positive side) due to the rapid acceleration of vehicle 1, and the expected arrival time Δt is calculated. Then, when the expected arrival time Δt becomes less than or equal to the operating time ta at time t2, an operation instruction is output to the second actuator 32 and the second actuator 32 starts operating. As a result, the motor clutch 7b fully engages near the point in time when the converted motor rotation speed ωmd and the axle rotation speed ωd coincide (intersect). This makes it possible to connect the front motor 4 and the axle 8 before waiting for synchronization to be completed while suppressing the occurrence of shock as much as possible, and to quickly output the power of the front motor 4 to respond to the driver's acceleration request. Furthermore, in this case, since both the converted motor rotation speed ωmd and the axle rotation speed ωd are increasing, even if the motor clutch 7b is engaged before rotational synchronization is complete, the impact of the shock felt by the driver is considered to be small.

[0038] Here, Figures 5 and 6 show an example where the expected arrival time Δt and the predetermined operating time ta of the second actuator 32 coincide. However, in reality, errors may occur between the expected arrival time Δt and the operating time ta. Therefore, the motor clutch 7b is not necessarily fully engaged when the converted motor rotation speed ωmd reaches the axle rotation speed ωd (time t3). To minimize the error between the expected arrival time Δt and the operating time ta, the predetermined operating time ta may be set to different values ​​depending on whether the rate of change α is greater than or equal to a predetermined value α1 or less than a predetermined value α1. More specifically, the predetermined operating time ta may be set shorter when the rate of change α is greater than or equal to a predetermined value α1 compared to when the rate of change α is less than a predetermined value α1.

[0039] Now, as illustrated in Figure 5, suppose that the operating time ta of the second actuator 32 is set to a shorter operating time ta2 when the rate of change α is greater than or equal to a predetermined value α1. In this case, the expected arrival time Δt2 when the operating time is less than or equal to ta2 will be shorter than the expected arrival time Δt mentioned above, and as a result, the accuracy of calculating the expected arrival time Δt2 can be improved. In other words, the expected arrival time Δt2 and the predetermined operating time ta2 of the actuator can be made to be closer approximations, and the probability that the motor clutch 7b fully engages when the converted motor rotation speed ωmd reaches the axle rotation speed ωd can be increased. As a result, the occurrence of shock can be suppressed more effectively.

[0040] Furthermore, if operating the second actuator 32 more gradually can suppress the occurrence of shocks, the operating time ta of the second actuator 32 may be set to a longer time. In other words, the operating time ta may be adjusted as appropriate depending on the calculation accuracy of the expected arrival time Δt and the magnitude of the shock caused by the speed of the motor clutch 7b engagement operation. In this way, by appropriately adjusting the operating time ta of the second actuator 32 when the vehicle 1 is undergoing rapid deceleration or rapid acceleration, the occurrence of shocks caused by the connection between the front motor 4 and the axle 8 can be suppressed more effectively.

[0041] As described above, in the vehicle 1 of the embodiment, when the rate of change α of the axle rotation speed ωd is greater than or equal to a predetermined value α1 and the vehicle 1 undergoes rapid deceleration or rapid acceleration, the connection between the front motor 4 and the axle 8 is initiated such that the expected arrival time Δt until the converted motor rotation speed ωmd reaches the axle rotation speed ωd and the predetermined operating time ta of the second actuator 32 are roughly the same. As a result, the front motor 4 and the axle 8 are connected near the time when the converted motor rotation speed ωmd reaches the axle rotation speed ωd. Therefore, with vehicle 1, it is possible to quickly connect the front motor 4 and the axle 8 while suppressing the occurrence of shocks as much as possible during rapid deceleration or rapid acceleration.

[0042] This concludes the description of the embodiments, but the aspects of the present invention are not limited to these embodiments. For example, in this embodiment, the present invention is applied to vehicle 1 as a plug-in hybrid vehicle, but the present invention may be applied to a hybrid vehicle equipped with an internal combustion engine as a drive source and a motor for driving.

[0043] Furthermore, in this embodiment, steps S15 and S16 are executed both during rapid deceleration and rapid acceleration of the vehicle 1, that is, when the absolute value of the rate of change α of the axle rotation speed ωd is greater than or equal to a predetermined value α1. However, steps S15 and S16 may be executed only during rapid deceleration of the vehicle 1, that is, only when the rate of change α of the axle rotation speed ωd is greater than or equal to a predetermined value α1 on the deceleration side (negative side). With this configuration, as described above, it is possible to quickly connect the front motor 4 and the axle 8 during rapid deceleration, when the occupant of the vehicle 1 is less likely to feel the shock caused by the connection between the front motor 4 and the axle 8.

[0044] Furthermore, in this embodiment, rotational synchronous control and the processing shown in Figure 4 are performed using the converted motor rotational speed ωmd and the axle rotational speed ωd. However, rotational synchronous control and the processing shown in Figure 4 may also be performed using the motor-converted value of the axle rotational speed ωd and the rotational speed of the front motor 4. In other words, "synchronizing the motor rotational speed and the axle rotational speed" and "the motor rotational speed reaching the axle rotational speed" refer to rotational speeds that take into account the gear ratio in a mechanism such as the reduction gear 7 placed between the front motor 4 and the axle 8. [Explanation of Symbols]

[0045] 1. Vehicle (Hybrid Vehicle) 2. Engine (internal combustion engine) 4. Front motor (electric motor for driving) 7 Reducer 7b Motor clutch (engagement device) 8 axles 20 HCTU (Hybrid Control Unit: Control Device) 32. Second Actuator (Actuator) 41 Motor rotation speed detection sensor 42. Axle rotation speed detection sensor ta, ta2 operating time α rate of change α1 Predetermined value Δt, Δt2: Estimated arrival time ωd axle rotation speed ωmd converted motor rotation speed (motor rotation speed)

Claims

1. Internal combustion engines and Electric motor for propulsion, An engagement device that switches between connecting and disconnecting the aforementioned electric motor for driving and the axle, An actuator for operating the engagement device, The vehicle is equipped with a control device that, when switching from a first driving mode in which the vehicle is driven by the internal combustion engine with the connection between the electric motor and the axle released, to a second driving mode in which the vehicle is driven by at least the electric motor, synchronizes the motor rotation speed and the axle rotation speed before starting the operation of the actuator to connect the electric motor and the axle using the engagement device, The control device is A hybrid vehicle in which, during synchronization between the motor rotation speed and the axle rotation speed, the absolute value of the rate of change of the axle rotation speed per unit time is greater than or equal to a predetermined value, the expected arrival time for the motor rotation speed to reach the axle rotation speed is calculated based on the motor rotation speed and the axle rotation speed, and when the expected arrival time is less than or equal to a predetermined operating time of the actuator, which is the time required from the determination that synchronization between the motor rotation speed and the axle rotation speed is complete until the engagement device is fully engaged, the actuator is started to operate so as to connect the traction electric motor and the axle with the engagement device.

2. The hybrid vehicle according to claim 1, wherein the predetermined operating time is set to different values ​​depending on whether the absolute value of the rate of change is greater than or equal to the predetermined value or whether the absolute value of the rate of change is less than the predetermined value.

3. The hybrid vehicle according to claim 2, wherein the predetermined operating time is set shorter when the absolute value of the rate of change is greater than or equal to the predetermined value compared to when the absolute value of the rate of change is less than the predetermined value.

4. The hybrid vehicle according to any one of claims 1 to 3, wherein the control device calculates the expected arrival time when the rate of change is greater than or equal to a predetermined value on the deceleration side during synchronization of the motor rotation speed and the axle rotation speed, and starts operating the actuator when the expected arrival time becomes less than or equal to a predetermined operating time.

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