JP2015221613A - Hybrid electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid electric vehicle capable of improving power transmission efficiency.SOLUTION: A hybrid electric vehicle 1 running by transmitting rotation power output from any of or both of an engine 11 and a motor 17A to driving wheels 19, and including a generator 12A provided in a power transmission path between the engine 11 and the motor 17A, comprises at least two clutches (clutches 15A, 15B) provided between the generator 12A and the motor 17A; and a control device 10 (control unit) disengaging the clutches during electrically driven running by the motor 17A while the generator 12A generates electric power.

Description

  The present invention relates to a hybrid vehicle.

  The hybrid vehicle includes a traveling engine and an electric motor, and is capable of traveling using only the engine, traveling using only the electric motor, and traveling in which the engine and the electric motor cooperate. Further, the hybrid vehicle has a battery that supplies electric power to the electric motor and is charged when the electric motor operates as a generator, and has an inverter that controls transmission and reception of electric power between the battery and the electric motor.

  In such a hybrid vehicle, for example, one clutch is provided in the power transmission system, and the engine / generator system and the motor / axle system are separated by this one clutch during the series hybrid travel (Patent Document). 1).

JP 2011-225034 A

  By the way, in the hybrid vehicle capable of series hybrid travel disclosed in Patent Document 1, the clutch is disengaged and the vehicle travels while generating power. However, considering the travel system, the propeller shaft that is not related to the electric travel is driven along with the driving of the wheels. Since the portion from the clutch to the electric motor also rotates, the power transmission efficiency decreases due to the rotational resistance. On the other hand, when considering the generator system, the portion from the clutch of the propeller shaft that is not related to power generation to the generator is also rotated, so that the power generation efficiency is also lowered. In particular, in the case of a vehicle such as a truck in which the engine and the drive shaft are separated from each other, the propeller shaft becomes longer, so that the power transmission efficiency is significantly reduced.

  The present invention has been made under such a background, and an object thereof is to provide a hybrid vehicle capable of improving power transmission efficiency.

  The present invention is a hybrid vehicle that travels by transmitting the rotational output of either the engine or the electric motor, or the rotational output from both to the drive wheels, and having a generator in the power transmission path between the engine and the electric motor. At least two clutches are provided in the power transmission path between the generator and the electric motor, and a controller for disconnecting the clutch is provided during the electric running by the electric motor while generating electric power by the generator.

  Another aspect of the present invention is the above-described hybrid vehicle, which is provided in a power transmission path between the generator and the differential, and a power transmission path between the power generator and the differential. The first clutch and the second clutch provided in the power transmission path between the differential and the electric motor, and the control unit travels by transmitting only the driving force of the electric motor to the driving wheels. The first clutch and the second clutch are disconnected.

  Further, in the hybrid vehicle described above, the control unit connects the first clutch and the second clutch when starting braking, and warms up the lubricating oil for operating the differential by rotating the differential. It can be performed.

  ADVANTAGE OF THE INVENTION According to this invention, the hybrid vehicle which can improve power transmission efficiency can be provided.

It is a principal part block diagram of the hybrid vehicle which concerns on 1st Embodiment of this invention. It is a block diagram of the control apparatus of FIG. It is a flowchart which shows operation | movement of the control apparatus of FIG. It is a principal part block diagram of the hybrid vehicle which concerns on 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the control apparatus shown in FIG. It is a principal part block diagram of the hybrid vehicle which concerns on 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the control apparatus shown in FIG.

  A hybrid vehicle according to an embodiment of the present invention will be described with reference to FIGS. In addition, about a control method, operation | movement of the control apparatus which a hybrid vehicle has is demonstrated as an example.

(First embodiment)
FIG. 1 is a diagram showing a main configuration of a hybrid vehicle 1 according to the first embodiment of the present invention. As shown in FIG. 1, the hybrid vehicle 1 includes a control device 10, an engine 11, a generator 12A, a battery 13, an inverter 14, clutches 15A and 15B, a propeller shaft 16, an electric motor 17A, a differential 18 and a drive wheel 19. Have as a configuration. The output of the engine 11 is input to the generator 12A, and the output of the generator 12A is input to the differential 18 via the propeller shaft 16 provided with the clutches 15A and 15B at both ends thereof and transmitted to the drive wheels 19. The control device 10 controls the connection state of the two clutches (clutch 15A, 15B) by running mode determination and clutch control.

  The hybrid vehicle 1 travels by transmitting rotational outputs from both drive sources of the engine 11 and the electric motor 17A to the drive wheels 19, and travels only by the engine 11 (hereinafter referred to as engine travel mode), and only by the electric motor 17A. Any one of traveling modes (hereinafter referred to as an electric traveling mode) and traveling (hereinafter referred to as a hybrid traveling mode) in which the engine 11 and the electric motor 17A cooperate with each other can be selected.

  The hybrid vehicle 1 can charge (regenerate) the battery 13 by operating the electric motor 17 </ b> A as a generator by the rotational force of the drive wheels 19 during deceleration or traveling on a downhill road. Further, the hybrid vehicle 1 can charge the battery 13 by operating the generator 12 </ b> A as a generator by the power of the engine 11 while traveling in the engine traveling mode.

  The control device 10 controls operations of the engine 11, the generator 12A, the battery 13, the inverter 14, the clutches 15A and 15B, and the electric motor 17A. In actuality, the engine 11, the generator 12A, the battery 13, the inverter 14, the clutches 15A and 15B, and the electric motor 17A are provided with individual ECUs (Electric Control Units), which are each connected to a CAN (Control Area Network). Although there is a case where control is carried out in cooperation with each other while performing communication, here, a description will be given as a single control device 10.

  The engine 11 is an engine that uses gasoline, light oil, CNG (Compressed Natural Gas), or the like as fuel. If applicable, the engine 11 is not limited to the engine.

  The generator 12A is an AC generator, for example. The input shaft of the generator 12 </ b> A is the output shaft of the engine 11. The input shaft of the generator 12A and the output shaft of the engine 11 may be a common shaft member. The generator 12A has an output shaft that is input to the clutch 15A. That is, the output shaft of the generator 12 </ b> A is also the output shaft of the engine 11. The output of the generator 12A is transmitted to the drive wheels 19 through the propeller shaft 16, the clutch 15B, and the differential 18. The hybrid vehicle 1 can start the engine 11 by the generator 12A.

  The battery 13 supplies electric power to the electric motor 17A and is charged by electric power generated by the generator 12A when the generator 12A operates as a generator.

  The inverter 14 converts the DC power of the battery 13 into three-phase AC power and supplies it to the motor 17A. When the motor 17A operates as a generator, the inverter 14 converts the three-phase AC power generated by the motor 17A into DC power. Converted and supplied to the battery 13. Therefore, when electric power is supplied from the battery 13 to the electric motor 17A, the torque of the electric motor 17A is reduced or stopped by reducing or stopping the output of the inverter 14. On the other hand, when electric power is supplied from the electric motor 17A to the battery 13, the charging power of the battery 13 is reduced or stopped by reducing or stopping the output of the inverter 14.

  The clutches 15A and 15B mechanically connect or disconnect the rotating shaft of the generator 12A and the rotating shaft of the electric motor 17A. When the clutches 15A and 15B are mechanically connected, the hybrid vehicle 1 can select either the engine travel mode or the hybrid travel mode.

  On the other hand, when the clutches 15A and 15B are disconnected, the hybrid vehicle 1 travels by the electric motor 17A. However, the electric motor 17A does not receive the friction of the engine 11 and the rotational resistance of the propeller shaft 16, and thus travels efficiently. Is possible. Further, during the power generation by the generator 12A, the rotational resistance of the propeller shaft 16 is not received, so that power can be generated efficiently. When the clutches 15A and 15B are disconnected, the hybrid vehicle 1 can efficiently regenerate without receiving the friction of the engine 11 and the rotational resistance of the propeller shaft 16 when the electric motor 17A is regenerating. It is.

  The electric motor 17 </ b> A is a motor that is driven by being supplied with electric power from the battery 13 via the inverter 14. The electric motor 17 </ b> A generates driving power for the hybrid vehicle 1 by the electric power supplied from the battery 13, and operates to charge the battery 13 by being driven by the power from the other. In addition, when the hybrid vehicle 1 decelerates or travels on a downhill road, the rotation of the drive wheels 19 is transmitted to the electric motor 17A via the differential 18 to operate as a generator.

  As shown in FIG. 2, the control device 10 of the hybrid vehicle 1 includes a mode determination unit 10A and a clutch control unit 10B. Mode determination unit 10A determines whether the travel mode of hybrid vehicle 1 is any one of an engine travel mode, an electric travel mode, and a hybrid travel mode. 10 A of mode determination parts supply the information which shows the state of driving modes to the clutch control part 10B. The clutch control unit 10B controls the connection state (coupled or disconnected) of the clutches 15A and 15B based on the determination information of the mode determination unit 10B. Specifically, the clutch control unit 10B disconnects the clutches 15A and 15B in the electric travel mode, and mechanically connects the clutches 15A and 15B in the engine travel mode and the hybrid travel mode. .

  Next, the operation of the control device 10 will be described. FIG. 3 is a flowchart showing the operation of the control device 10. The START condition in the flowchart of FIG. 3 is a condition that the key switch (not shown) of the hybrid vehicle 1 is in the ON state and the control device 10 is in operation. Note that the processing from START to step S2 or step S3 in the flowchart of FIG. 3 is processing for one cycle, and if the driving mode is changed even after the processing for one cycle is completed, the processing is repeated again. The determination of S1 is started.

  In step S <b> 1, the mode determination unit 10 </ b> A of the control device 10 determines whether or not the travel mode determined from the charged amount of electric power (SOC), the vehicle speed, the accelerator opening, and the like is the electric travel mode. The determination result by the mode determination unit 10A is supplied to the clutch control unit 10B. When the clutch control unit 10B determines that the electric travel mode is set in the determination in step S1 (YES in step S1), the clutch control unit 10B sets the clutches 15A and 15B to be disconnected (clutch disengagement, step S2). If it is determined that the vehicle is in the hybrid travel mode (NO in step S1), the clutches 15A and 15B are mechanically connected (clutch connection, step S3).

  As described above, in the case of the electric travel mode, that is, when traveling using the electric motor 17A as a power source, both the clutches 15A and 15B are disconnected so that the propeller shaft 16 is not rotated, so the propeller shaft 16 is rotated. This eliminates the resistance generated by this, improves the power transmission efficiency and improves fuel efficiency. In addition, during the power generation by the generator 12, the rotation resistance of the propeller shaft 16 is not received, so that power can be generated efficiently.

  Further, in the case of the engine travel mode or the hybrid travel mode, that is, in the case of travel by the engine 11, both the clutches 15A and 15B are connected, so that the power of the engine 11 can be mechanically transmitted to the axle and traveled. For example, power transmission efficiency during high-speed traveling can be improved.

(Second Embodiment)
FIG. 4 is a main part configuration diagram of a hybrid vehicle 1A according to the second embodiment of the present invention. In addition, about the structure which is common in the hybrid vehicle 1 which concerns on 1st Embodiment shown in FIG. 1, while attaching the same code | symbol, the description is abbreviate | omitted.

  In the hybrid vehicle 1A shown in FIG. 4, unlike the hybrid vehicle 1 shown in FIG. 1, the engine output is input to the generator 12A, and the output of the generator 12A passes through the propeller shaft 16 that can be connected and disconnected by the clutch 15A. To the differential 18. Electric motors 17B and 17C are provided between the differential 18 and the drive wheel 19, and clutches 15C and 15D are further provided between the differential 18 and the electric motors 17B and 17C. By controlling, the connection state of the three clutches (clutches 15A, 15C, 15D) is controlled. Although not shown, the control device 30 also has functions corresponding to the mode determination unit 10A and the clutch control unit 10B of the control device 10.

  FIG. 5 is a flowchart showing the operation of the control device 30 shown in FIG. The START condition in the flowchart of FIG. 5 is a condition that the key switch (not shown) of the hybrid vehicle 1A is in the ON state and the control device 30 is in operation. Note that the processing from START to step S12 or step S13 in the flowchart of FIG. 5 is processing for one cycle, and if the driving mode is changed even after the processing for one cycle is completed, the processing is repeated again. The determination in S11 is started.

  In step S11, the control device 30 determines whether or not the travel mode of the hybrid vehicle 10 is the electric travel mode (motor travel). When it is in the electric travel mode (electric motor travel) in the determination in step S11, the control device 30 sets all the three clutches (clutch 15A, 15C, 15D) to a disconnected state (step S12), and sets the engine travel mode and the hybrid. When it is determined that the travel mode is set (NO in step S11), the three clutches (clutches 15A, 15C, and 15D) are mechanically connected (step S13).

  As a result, the control device 30 disengages all three clutches in the electric travel mode, so that the propeller shaft 16 and the differential 18 can be prevented from rotating. As a result, the control device 30 can eliminate the resistance caused by the rotation of the propeller shaft 16 and the differential 18, thereby improving the power transmission efficiency and improving the fuel efficiency. Further, during the power generation by the generator 12A, the rotational resistance of the propeller shaft 16 is not received, so that power can be generated efficiently. In the case of the engine traveling mode or the hybrid traveling mode, the control device 30 can bring all three clutches (clutches 15A, 15C, 15D) into a mechanically connected state, and the engine power can be reduced to the axle. Therefore, the power transmission efficiency during high speed traveling can be improved.

  The hybrid vehicle 1A of the second embodiment does not have a clutch corresponding to the clutch 15B of the hybrid vehicle 1 of the first embodiment, but includes the clutch corresponding to the clutch 15B and includes the above three clutches. You may make it perform control similar to (clutch 15A, 15C, 15D).

(Third embodiment)
FIG. 6 is a main part configuration diagram of a hybrid vehicle 1B according to the third embodiment of the present invention. In addition, about the structure which is common in the hybrid vehicle 1 and 1A which concerns on 1st Embodiment shown in FIG. 1, and 2nd Embodiment shown in FIG. 4, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The hybrid vehicle 1B shown in FIG. 6 has the same configuration as the hybrid vehicle 1A shown in FIG. 4, but the control of the clutches 15A, 15C, and 15D is different. In the hybrid vehicle 1B, the clutch 15A, 15C, 15D is mechanically connected to control the differential 18 to rotate when the electric motor 17A is braked. Although not shown, the control device 40 also has functions corresponding to the mode determination unit 10A and the clutch control unit 10B of the control device 10.

  FIG. 7 is a flowchart showing the operation of the control device 40 shown in FIG. The START condition in the flowchart of FIG. 7 is a condition that the key switch (not shown) of the hybrid vehicle 1B is in the ON state and the control device 40 is in operation. Note that the processing from START to step S22 or step S23 in the flowchart of FIG. 7 is processing for one cycle, and if the driving mode is changed even after the processing for one cycle is completed, the processing is repeated again. The determination in S21 is started.

  In step S21, the control device 40 determines whether or not the travel mode of the hybrid vehicle 10 is an electric travel mode (motor travel). When it is in the electric travel mode (motor travel) in the determination in step S21 (YES in step S21), control device 40 sets all three clutches (clutch 15A, 15C, 15D) to a disconnected state (step S22). The process proceeds to step S24. However, when the control device 40 determines that the engine travel mode or the hybrid travel mode is set (NO in step S21), the three clutches (clutches 15A, 15C, and 15D) are mechanically connected (steps). S23).

  Even when all three clutches are disconnected in step S24, control device 40 connects clutch 15C and clutch 15D during braking.

  As described above, the control device 40 disconnects all the three clutches (clutches 15A, 15C, and 15D) in the electric travel mode, so that the propeller shaft 16 and the differential 18 are not rotated. be able to. As a result, the control device 40 can eliminate the resistance caused by the rotation of the propeller shaft 16 and the differential 18, thereby improving the power transmission efficiency and improving the fuel efficiency. Further, during the power generation by the generator 12A, the rotational resistance of the propeller shaft 16 is not received, so that power can be generated efficiently. The control device 40 can be in a state where all three clutches (clutches 15A, 15C, 15D) are connected when the engine is running, and the engine power is mechanically transmitted to the axle for running. Power transmission efficiency during traveling can be improved.

  Further, the control device 40 can warm up the lubricating oil of the differential 18 by mechanically connecting the clutch 15C and the clutch 15D and rotating the differential 18 when the electric motor 17A is braked. Thereby, compared with the case where the lubricating oil is warmed up with the driving force at the time of the motor power running, the battery discharge charge loss and the electromechanical conversion loss for stirring the lubricating oil of the differential 18 can be eliminated, so that the warming up can be performed efficiently. be able to. This is because, when the temperature of the lubricating oil of the differential 18 is increased by taking-out energy from the regeneratively charged battery, in addition to the stirring power of the lubricating oil of the differential 18, a loss during motor-to-inverter electromechanical conversion, and inverter-> battery charging This is because a loss at the time of battery → inverter discharge and a loss at the time of inverter → motor electrical conversion occur. In the hybrid vehicle 1B, the clutch 15C and the clutch 15D are mechanically coupled when the electric motor 17A is braked. However, the clutch is not limited to when the electric motor 17A is braked, but after the predetermined time has elapsed since the electric motor 17A is braked. Each of 15C and clutch 15D may be mechanically coupled. Further, regardless of the braking of the electric motor 17A, the clutch 15C and the clutch 15D may be mechanically connected periodically, and the differential 18 may be rotated to warm up the lubricating oil of the differential 18.

DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle 10, 30, 40 ... Control apparatus, 11 ... Engine, 12 ... Electric motor, 13 ... Battery, 14 ... Inverter, 15A, 15B, 15C, 15D ... Clutch, 16 ... Propeller shaft, 17 ... Electric motor, 18 ... differential, 19 ... drive wheels

Claims (3)

In a hybrid vehicle that travels by transmitting the rotational output of either the engine or the electric motor, or the rotational output from both to the drive wheels, and having a generator in the power transmission path between the engine and the electric motor,
At least two clutches are provided in a power transmission path between the generator and the electric motor, and a control unit that disconnects the clutch during electric running by the electric motor while generating electric power by the generator A hybrid vehicle characterized by that.
The hybrid vehicle according to claim 1,
A differential provided in a power transmission path between the generator and the motor;
A first clutch provided in a power transmission path between the generator and the differential;
A second clutch provided in a power transmission path between the differential and the electric motor;
The controller is
A hybrid vehicle characterized in that the first clutch and the second clutch are disengaged when traveling by transmitting only the driving force of the electric motor to the driving wheels.
The hybrid vehicle according to claim 2,
The controller is
A hybrid that warms up lubricating oil for operating the differential by rotating the differential by connecting the first clutch and the second clutch when starting braking of the electric motor. Automobile.

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