JP2018078681A - Vehicle driving device - Google Patents

Abstract

To effectively use the power of a motor. A power transmission mechanism 30 includes a first power transmission path 31 formed between a first motor 21 and a drive wheel 11, and a second motor 22 formed between a second motor 22 and the drive wheel 11. A power transmission path 32, a first one-way clutch 36, and a clutch mechanism 37 are provided. The first one-way clutch is provided in the second power transmission path 32 and is configured to allow transmission of power by forward rotation of the second motor 22 from the second motor 22 toward the drive wheels 11. The clutch mechanism 37 is provided in parallel with the first one-way clutch 36 in the second power transmission path 32 and is configured to be switchable between an engaged state that allows power transmission and an open state that prohibits power transmission. [Selection] Figure 1

Description

  This disclosure relates to a vehicle drive device.

  Conventionally, an electric vehicle such as an electric vehicle is known. This type of electric vehicle is provided with a vehicle drive device that drives the drive wheels of the electric vehicle. For example, Patent Document 1 discloses a power control device for an electric vehicle. In the power control apparatus disclosed in Patent Document 1, four motors (first motor, second motor, third motor, and fourth motor) that are controlled independently of each other are reduced between the second motor and the third motor. The first motor and the fourth motor are located on the outermost side. A clutch is provided between the first motor and the second motor, between the second motor and the speed reducer, between the speed reducer and the third motor, and between the third motor and the fourth motor. It has been. Note that these clutches are constituted by, for example, one-way clutches as shown in FIG.

  In the configuration shown in FIG. 1 of Patent Document 1, a first one-way clutch that transmits torque only in a direction from the first motor to the second motor is provided between the first motor and the second motor. Yes. A second one-way clutch that transmits torque only in the direction from the second motor to the speed reducer is provided between the second motor and the speed reducer. A third one-way clutch that transmits torque only in the direction from the third motor to the reduction gear is provided between the reduction gear and the third motor. A fourth one-way clutch that transmits torque only in the direction from the fourth motor to the third motor is provided between the third motor and the fourth motor. Torque input to the speed reducer is transmitted from the differential gear in the speed reducer to the wheels via the drive shaft.

  In the power control device shown in FIG. 1 of Patent Document 1, when acceleration is performed with a partial load, only one motor (second motor) generates a driving force and another motor (first motor). The motor, the third motor, and the fourth motor) do not generate a driving force. At this time, when the rotational speed of the second motor is higher than the rotational speed of the input shaft of the speed reducer, the second one-way clutch is engaged, and the driving force of the second motor is transmitted to the wheels. During this time, the other one-way clutches (the first one-way clutch, the third one-way clutch, and the fourth one-way clutch) are in a free state, and the driving force of the second motor is the other motor (the first motor and the third motor). It is not transmitted to the fourth motor).

JP-A-6-153325

  In a configuration using a one-way clutch such as the power control device (vehicle drive device) disclosed in FIG. 1 of Patent Document 1, the one-way clutch provided between the motor and the wheels (drive wheels) It is configured to allow transmission of forward rotation power (power by forward rotation of the motor) toward the vehicle. Therefore, the power by the normal rotation of the motor can be transmitted to the wheels. However, transmission of reverse rotational power from the motor to the wheels (power by reverse rotation of the motor) is blocked by a one-way clutch provided between the motor and the wheels. Accordingly, it is difficult to transmit the power generated by the reverse rotation of the motor to the wheels, and it is difficult to effectively use the power of the motor. For example, it has been difficult to effectively use the power of the motor when the electric vehicle moves backward.

  Accordingly, an object of the present disclosure is to provide a vehicle drive device that can effectively use the power of the motor.

  The present disclosure relates to a vehicle drive device that drives drive wheels of an electric vehicle, and the vehicle drive device is provided between a first motor, a second motor, the first motor, the second motor, and the drive wheels. A power transmission mechanism configured to transmit power, the power transmission mechanism including a first power transmission path formed between the first motor and the drive wheel, the second motor, and the A second power transmission path formed between the drive wheels and the second power transmission path, which is provided in the second power transmission path, allows transmission of power by the forward rotation of the second motor from the second motor toward the drive wheels. The first one-way clutch configured as described above can be switched between a fastening state that is provided in parallel with the first one-way clutch in the second power transmission path to allow power transmission and an open state that prohibits power transmission. In And a made a clutch mechanism.

  According to this disclosure, by setting the clutch mechanism to the open state, transmission of power from the drive wheel to the second motor can be prevented, so that the second motor is rotated (in conjunction with the rotation of the drive wheel). The second motor being rotated). Thereby, the power of the first motor can be used effectively. In addition, since the power generated by the forward rotation of the second motor can be transmitted from the second motor to the drive wheels via the first one-way clutch, the power of the second motor can be used effectively. Furthermore, by setting the clutch mechanism to the engaged state, the power generated by the reverse rotation of the second motor can be transmitted from the second motor to the drive wheels via the clutch mechanism in the engaged state. Can be used effectively.

1 is a conceptual diagram illustrating the configuration of a vehicle drive device according to a first embodiment. FIG. 3 is a conceptual diagram for explaining an operation of the vehicle drive device in a forward mode (at high load) according to the first embodiment. FIG. 3 is a conceptual diagram for explaining an operation of the vehicle drive device in a reverse mode according to the first embodiment. It is a graph for demonstrating the power characteristic of a motor. FIG. 10 is a conceptual diagram for explaining an operation of the vehicle drive device in a second forward mode of a modification of the first embodiment. FIG. 5 is a conceptual diagram illustrating the configuration of a vehicle drive device according to a second embodiment. FIG. 10 is a conceptual diagram for explaining an operation of the vehicle drive device in a forward mode (high load) of the second embodiment. FIG. 10 is a conceptual diagram for explaining an operation of a vehicle drive device in a reverse mode according to a second embodiment. It is a conceptual diagram which illustrates the modification 1 of a vehicle drive device. It is a conceptual diagram which illustrates the modification 2 of a vehicle drive device.

  Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 illustrates the configuration of a vehicle drive device 10 according to the first embodiment. The vehicle drive device 10 is configured to drive drive wheels 11 of an electric vehicle, and includes a first motor 21, a second motor 22, a power transmission mechanism 30, a shift selector 40, and a controller 50. I have.

  In the following description, forward rotation refers to rotation in a predetermined forward rotation direction, and reverse rotation refers to rotation in a reverse rotation direction that is the reverse direction of the forward rotation direction. The forward rotation direction is the same rotation direction as the rotation direction for generating power that can rotate the drive wheels 11 in the direction in which the electric vehicle moves forward.

[First motor]
The first motor 21 is configured to be switchable between driving and stopping. Moreover, the 1st motor 21 is comprised so that the rotation direction and rotation speed at the time of a drive are changeable. With such a configuration, the first motor 21 can be switched between forward rotation, reverse rotation, and stop. The forward rotation of the first motor 21 is a rotation in a predetermined forward rotation direction (the rotation direction indicated by the solid line arrow in FIG. 1), and the reverse rotation of the first motor 21 is a forward rotation. This is the rotation in the opposite direction (the direction of rotation indicated by the broken arrow in FIG. 3). For example, the first motor 21 is constituted by a permanent magnet motor.

[Second motor]
The second motor 22 is configured to be able to switch between driving and stopping. Moreover, the 2nd motor 22 is comprised so that a rotation direction and rotation speed at the time of a drive are changeable. With such a configuration, the second motor 22 can be switched between forward rotation, reverse rotation, and stop. The forward rotation of the second motor 22 is a rotation in a predetermined forward rotation direction (the rotation direction indicated by the solid line arrow in FIG. 2), and the reverse rotation of the second motor 22 is a forward rotation. This is the rotation in the opposite direction (the direction of rotation indicated by the broken arrow in FIG. 3). For example, the second motor 22 is a permanent magnet motor.

[Power transmission mechanism]
The power transmission mechanism 30 is configured to transmit power between the first motor 21, the second motor 22, and the drive wheels 11. In addition, when at least one of the power generated by the positive rotation of the first motor 21 and the power generated by the positive rotation of the second motor 22 is transmitted to the drive wheels 11, the direction in which the electric vehicle is advanced (the solid line arrow in FIG. 1). The driving wheel 11 rotates in the rotation direction indicated by. On the other hand, when at least one of the motive power due to the reverse rotation of the first motor 21 and the motive power due to the reverse rotation of the second motor 22 is transmitted to the drive wheels 11, the direction in which the electric vehicle is moved backward (broken arrows in FIG. 3). The driving wheel 11 rotates in the rotation direction indicated by.

  In this example, the power transmission mechanism 30 includes a first power transmission path 31 formed between the first motor 21 and the drive wheel 11, and a second power formed between the second motor 22 and the drive wheel 11. The power transmission path 32 includes a first one-way clutch 36 and a clutch mechanism 37 that constitute a part of the second power transmission path 32.

<First power transmission path>
The first power transmission path 31 is a path for transmitting power between the first motor 21 and the drive wheels 11. In this example, the first power transmission path 31 includes a drive shaft 101, a differential gear 102, a first shaft 201, and a first gear 202. Drive wheels 11 are connected to both ends of the drive shaft 101. The differential gear 102 is connected to the drive shaft 101. The first shaft 201 is connected to the first motor 21. The first gear 202 is connected to the first shaft 201 and is engaged with the differential gear 102.

  The power (forward rotation power and reverse rotation power) by the rotation of the first motor 21 is transmitted to the drive wheels 11 through the first shaft 201, the first gear 202, the differential gear 102, and the drive shaft 101 in order. Further, the power generated by the rotation of the drive wheels 11 is transmitted to the first motor 21 via the drive shaft 101, the differential gear 102, the first gear 202, and the first shaft 201 in order.

<Second power transmission path>
The second power transmission path 32 is a path for transmitting power between the second motor 22 and the drive wheels 11. In this example, the second power transmission path 32 includes a drive shaft 101, a differential gear 102, a second shaft 301, a first one-way clutch 36, and a clutch mechanism 37. The second shaft 301 is connected to the second motor 22.

<First one-way clutch>
The first one-way clutch 36 is provided in the second power transmission path 32 and is configured to allow transmission of positive rotational power (power due to normal rotation of the second motor 22) from the second motor 22 toward the drive wheels 11. ing. The first one-way clutch 36 is configured to prohibit transmission of reverse rotational power (power due to reverse rotation of the second motor 22) from the second motor 22 toward the drive wheels 11.

  Here, a configuration example of the first one-way clutch 36 will be described in detail. In this example, the first one-way clutch 36 has an inner ring and an outer ring. The inner ring and the outer ring are formed in a cylindrical shape, the inner ring is fitted in the outer ring, and the outer surface of the outer ring is formed in a gear shape. The first one-way clutch 36 transmits power by rotating the outer ring together with the inner ring when the inner ring rotates in the forward rotation direction with respect to the outer ring, and the inner ring when the inner ring rotates in the reverse rotation direction with respect to the outer ring. Is configured to idle and not transmit power.

  In this example, the first one-way clutch 36 is provided between the second shaft 301 and the differential gear 102. The first one-way clutch 36 is connected to the second shaft 301 and engaged with the differential gear 102. Specifically, the inner ring of the first one-way clutch 36 is connected to the second shaft 301, and the outer ring of the first one-way clutch 36 is engaged with the differential gear 102. Thus, the inner ring of the first one-way clutch is configured to rotate in conjunction with the rotation of the second motor 22, and the outer ring of the first one-way clutch is configured to rotate in conjunction with the rotation of the drive wheel 11. Has been.

<Clutch mechanism>
The clutch mechanism 37 is provided in parallel with the first one-way clutch 36 in the second power transmission path 32 and is configured to be able to switch between an engaged state and a released state. The fastened state is a state that allows power transmission, and the open state is a state that prohibits power transmission.

  In this example, the clutch mechanism 37 has a first clutch member and a second clutch member. The first clutch member and the second clutch member are formed in a cylindrical shape and meshed with each other in the axial direction, and the outer peripheral surface of the second clutch member is formed in a gear shape. The clutch mechanism 37 is set to an engaged state (a state in which power transmission is allowed) by engaging the first clutch member and the second clutch member, and separates the first clutch member from the second clutch member. Is set to an open state (a state in which transmission of power is prohibited).

  In this example, the clutch mechanism 37 is provided in parallel with the first one-way clutch 36 between the second shaft 301 and the differential gear 102. The clutch mechanism 37 is connected to the second shaft 301 and engaged with the differential gear 102. Specifically, the first clutch member of the clutch mechanism 37 is connected to the second shaft 301, and the second clutch member of the clutch mechanism 37 is engaged with the differential gear 102. Accordingly, the first clutch member of the clutch mechanism 37 is configured to rotate in conjunction with the rotation of the second motor 22, and the second clutch member of the clutch mechanism 37 rotates in conjunction with the rotation of the drive wheel 11. Is configured to do.

  In this example, the clutch mechanism 37 is a dog clutch.

  When the clutch mechanism 37 is set to the open state, the power generated by the forward rotation of the second motor 22 passes through the second shaft 301, the first one-way clutch 36, the differential gear 102, and the drive shaft 101 in order. 11 is transmitted. When the clutch mechanism 37 is set to the released state, the transmission of the reverse rotation power (power by the reverse rotation of the second motor 22) from the second motor 22 to the drive wheel 11 is transmitted to the first one-way clutch 36 and the release. Transmission of power from the drive wheel 11 to the second motor 22 (power generated by rotation of the drive wheel 11) is also blocked by the first one-way clutch 36 and the opened clutch mechanism 37.

  On the other hand, when the clutch mechanism 37 is set to the engaged state, the power due to the reverse rotation of the second motor 22 sequentially passes through the second shaft 301, the engaged clutch mechanism 37, the differential gear 102, and the drive shaft 101. Is transmitted to the drive wheels 11. Further, the power generated by the rotation of the drive wheels 11 is transmitted to the second motor 22 via the drive shaft 101, the differential gear 102, the clutch mechanism 37 in the engaged state, and the second shaft 301 in order.

[Shift selector]
The shift selector 40 is configured to be operated by the driver of the electric vehicle to switch the operation mode of the electric vehicle. Specifically, the shift selector 40 has operation levers that can be moved to a plurality of range positions respectively corresponding to a plurality of operation modes of the electric vehicle, and the operation levers are operated by a driver of the electric vehicle. It is configured to be arranged at any one of the range positions. The shift selector 40 is configured to set the operation mode of the electric vehicle to an operation mode corresponding to the range position where the operation lever is arranged among the plurality of operation modes.

  In this example, the electric vehicle is configured to be able to switch its operation mode to a plurality of operation modes (a plurality of operation modes including a forward mode and a reverse mode). The forward mode is an operation mode for moving the electric vehicle forward, and the reverse mode is an operation mode for moving the electric vehicle backward. The shift selector 40 is configured to be able to select a plurality of operation modes including a forward mode and a reverse mode.

  In this example, the clutch mechanism 37 is configured to switch between the engaged state and the released state in conjunction with the operation of the shift selector 40. Specifically, in this example, the clutch mechanism 37 is connected to the shift selector 40 by the link mechanism 41. The link mechanism 41 is configured to connect the shift selector 40 and the clutch mechanism 37 and mechanically switch between the engaged state and the released state of the clutch mechanism 37 in conjunction with the operation of the shift selector 40.

  For example, the link mechanism 41 is configured by a mechanical element such as a wire or a rod that connects the operation lever of the shift selector and the first clutch member (or the second clutch member) of the clutch mechanism 37.

[Controller (control unit)]
The controller 50 includes detection signals from various sensors (for example, the vehicle speed sensor 51) provided in each part of the electric vehicle and operation parts (for example, a shift selector 40, an accelerator pedal (not shown), etc.) provided in each part of the electric vehicle. Based on these operations, each part of the vehicle drive device 10 (specifically, the first motor 21 and the second motor 22) is controlled. For example, the controller 50 is configured by an ECU (Electronic Control Unit), an arithmetic processing unit such as a CPU (Central Processing Unit), and a memory (storage unit) that stores a program and information for operating the arithmetic processing unit. have.

  In this example, the vehicle speed sensor 51 is configured to detect the rotational speed of the drive wheels 11 that is correlated with the traveling speed of the electric vehicle. And the controller 50 is comprised so that the travel speed of an electric vehicle may be acquired based on the detection signal (detection signal which showed the rotation speed of the driving wheel 11) of the vehicle speed sensor 51. FIG.

[Forward mode]
Next, the operation of the vehicle drive device 10 in the forward mode of the first embodiment will be described with reference to FIGS. In the forward mode, the clutch mechanism 37 is set to an open state (a state in which transmission of power is prohibited). In addition, at least one of the first motor 21 and the second motor 22 rotates forward to rotate the drive wheels 11 in a direction to advance the electric vehicle. Specifically, when the travel request load of the electric vehicle is lower than a predetermined forward load threshold in the forward mode in which the electric vehicle is moved forward (that is, when the travel request load of the electric vehicle is a low load in the forward mode), The first motor 21 rotates forward to rotate the drive wheel 11. On the other hand, when the travel request load of the electric vehicle exceeds the forward load threshold value in the forward mode (that is, when the travel request load of the electric vehicle is a high load in the forward mode), both the first motor 21 and the second motor 22 The drive wheel 11 is rotated in the forward direction. The travel demand load can be obtained based on, for example, an operation amount of an accelerator pedal (not shown).

[Forward mode (at low load)]
As shown in FIG. 1, in the forward mode, the clutch mechanism 37 is set to the released state in conjunction with the operation of the shift selector 40 (selection of the forward mode). When the travel request load of the electric vehicle is a low load in the forward mode, the controller 50 rotates the first motor 21 in the normal direction. In addition, the controller 50 controls the second motor 22 so that the forward rotation power (power due to the forward rotation of the second motor 22) is not transmitted from the second motor 22 toward the drive wheel 11. For example, the controller 50 controls the second motor 22 so that the rotational speed of the second motor 22 in the forward rotation direction is lower than the rotational speed of the outer ring of the first one-way clutch 36. Note that the state that “the rotational speed of the second motor 22 in the forward rotation direction is lower than the rotational speed of the outer ring of the first one-way clutch 36” includes not only the state in which the second motor 22 rotates forward but also the second motor 22. The state in which the number of rotations becomes zero (that is, the second motor 22 is stopped) is also included. Further, the rotation speed of the outer wheel of the first one-way clutch 36 can be obtained based on the rotation speed of the drive wheel 11 detected by the vehicle speed sensor 51 and the reduction ratio in the second power transmission path 32.

  In the forward mode (when the load is low), only the power generated by the positive rotation of the first motor 21 is transmitted to the drive wheels 11 via the first power transmission path 31, and the drive wheels 11 rotate in the direction of moving the electric vehicle forward. . In this way, the electric vehicle can be advanced using the power generated by the positive rotation of the first motor 21. Note that transmission of power from the drive wheel 11 to the second motor 22 (power generated by rotation of the drive wheel 11) is blocked by the first one-way clutch 36 and the clutch mechanism 37 in the opened state. Thereby, the accompanying rotation of the second motor 22 (rotation of the second motor 22 in conjunction with the rotation of the drive wheels 11) can be prevented.

[Forward mode (high load)]
As shown in FIG. 2, in the forward mode, the clutch mechanism 37 is set to the released state in conjunction with the operation of the shift selector 40 (selection of the forward mode). When the travel request load of the electric vehicle is high in the forward mode, the controller 50 rotates both the first motor 21 and the second motor 22 in the normal direction. Specifically, the controller 50 controls the second motor 22 so that the positive rotation power (the power by the positive rotation of the second motor 22) is transmitted from the second motor 22 to the drive wheel 11. For example, the controller 50 controls the second motor 22 so that the rotation speed of the second motor 22 in the forward rotation direction exceeds the rotation speed of the outer ring of the first one-way clutch 36. Note that the controller 50 sets the second motor 22 so that the rotational speed of the second motor 22 in the forward rotation direction exceeds the rotational speed of the outer ring of the first one-way clutch 36 even when the second motor 22 is in a no-load state. The motor 22 is controlled.

  In order to control in this manner, the controller 50 controls the first motor 21 and the second motor 22 so that the torque distribution (target torque distribution) of the first motor 21 and the second motor 22 becomes a desired torque distribution. A torque command is output to control the first motor 21 and the second motor 22. Here, the target torque may be evenly allocated to the first motor 21 and the second motor 22, and a portion exceeding the maximum torque of the first motor 21 (part of the target torque) is allocated to the second motor 22. Thus, the target torque may be allocated to the first motor 21 and the second motor 22, and the torque distribution of the first motor 21 and the second motor 22 is the optimum torque distribution based on the efficiency map measured in advance. Thus, the target torque may be assigned to the first motor 21 and the second motor 22.

  With the above operation, in the forward mode (during high load), the power generated by the positive rotation of the first motor 21 is transmitted to the drive wheels 11 via the first power transmission path 31, and the drive wheels are driven in the direction of moving the electric vehicle forward. 11 rotates. Further, the power generated by the forward rotation of the second motor 22 is transmitted to the drive wheels 11 via the second power transmission path 32 (specifically, the second shaft 301, the first one-way clutch 36, the differential gear 102, and the drive shaft 101). Communicated. Thereby, rotation of the drive wheel 11 (rotation in the direction in which the electric vehicle moves forward) can be assisted.

  Note that the controller 50 monitors the speed, acceleration, and the like of the operation amount of an accelerator pedal (not shown), and the travel request load is abrupt in a state where the travel request load is low (that is, in the forward mode (at low load)). The second motor 22 is normally rotated in advance at a rotation speed lower than the rotation speed of the outer ring of the first one-way clutch 36 (rotation speed in the positive rotation direction). It may be configured. With this configuration, the travel request load is higher than when the second motor 22 is stopped until the travel request load suddenly increases and becomes a high load in a state where the travel request load is low. A time lag from the time when the load is applied to the time when the positive rotation power of the second motor 22 (power by the positive rotation) is transmitted to the drive wheels 11 can be reduced.

[Reverse mode]
Next, the operation of the vehicle drive device 10 in the reverse mode of the first embodiment will be described with reference to FIG. In the reverse mode, the clutch mechanism 37 is set to an engaged state (a state where transmission of power is allowed). In addition, at least one of the first motor 21 and the second motor 22 rotates in the reverse direction to rotate the drive wheels 11 in a direction in which the electric vehicle moves backward.

  As shown in FIG. 3, in the reverse mode in which the electric vehicle is moved backward, the clutch mechanism 37 is set to the engaged state in conjunction with the operation of the shift selector 40 (selection of the reverse mode). Then, the controller 50 reversely rotates at least one of the first motor 21 and the second motor. Specifically, in the reverse mode, the controller 50 performs the first motor 21 and the second motor based on the travel request load of the electric vehicle so that power (drive torque) necessary for moving the electric vehicle backward is obtained. The motor 22 is controlled.

  When the first motor 21 rotates in reverse, the power generated by the reverse rotation of the first motor 21 is transmitted to the drive wheels 11 via the first power transmission path 31 and the drive wheels 11 rotate in the direction in which the electric vehicle moves backward. Thus, the electric vehicle can be moved backward using the power generated by the reverse rotation of the first motor 21.

  When the second motor 22 rotates in the reverse direction, the power generated by the reverse rotation of the second motor 22 is supplied to the second power transmission path 32 (specifically, the second shaft 301 and the clutch mechanism 37 in the engaged state, the differential gear 102, and the drive shaft 101). Is transmitted to the drive wheel 11 via the wheel, and the drive wheel 11 rotates in a direction to move the electric vehicle backward. Thus, the electric vehicle can be moved backward using the power generated by the reverse rotation of the second motor 22.

  In the reverse mode, the first motor 21 and the second motor 22 are mechanically connected to each other (that is, a state in which power can be transmitted between the first motor 21 and the second motor 22). Therefore, the torque distribution (target torque distribution) of the first motor 21 and the second motor 22 can be arbitrarily set so as to obtain the power (drive torque) necessary for moving the electric vehicle backward. Is possible. Therefore, it is not always necessary to reversely rotate both the first motor 21 and the second motor 22. For example, the controller 50 rotates the reverse rotation power of the first motor 21 (power by reverse rotation) and the reverse rotation of the second motor 22. When the required driving torque can be obtained only by the reverse rotational power of one of the motors, the first motor 21 and the second motor are such that only one of the motors reversely rotates and the other motor stops. 22 may be controlled. Further, the controller 50 determines the power of the first motor 21 and the second motor 22 when the power (driving torque) required to move the electric vehicle backward is relatively large (for example, when the electric vehicle is moved backward on an uphill). You may control the 1st motor 21 and the 2nd motor 22 so that both may reversely rotate.

[Comparative example of vehicle drive device]
Next, a vehicle drive device that includes the first one-way clutch 36 but does not include the clutch mechanism 37 (hereinafter referred to as “comparative example of vehicle drive device”) will be described.

  In the comparative example of the vehicle drive device, the first one-way clutch provided in the second power transmission path 32 transmits the reverse rotation power (power by the reverse rotation of the second motor 22) from the second motor 22 to the drive wheel 11. Blocked at 36. For this reason, the power generated by the reverse rotation of the second motor 22 cannot be transmitted to the drive wheels 11, and the power of the second motor 22 cannot be used effectively. For example, the power of the second motor 22 cannot be used effectively when the electric vehicle moves backward. Therefore, in the comparative example of the vehicle drive device, another drive source (for example, an engine and a transmission) is provided to assist the rotation of the drive wheels 11 (rotation in the direction in which the electric vehicle moves backward) when the electric vehicle moves backward. It will be necessary.

  In the comparative example of the vehicle drive device, it is conceivable to provide a wet multi-plate clutch instead of the first one-way clutch 36. However, the wet multi-plate clutch requires higher-precision control than the one-way clutch. For example, when the first one-way clutch 36 is used, the first one-way clutch 36 is engaged and disengaged by controlling the second motor 22 (rotation control) (that is, a state in which power transmission is permitted and a state in which power transmission is prohibited). However, when a wet multi-plate clutch is used instead of the first one-way clutch 36, not only the second motor 22 but also the wet multi-plate clutch must be controlled separately. It is necessary to coordinate the control and the control of the wet multi-plate clutch. As described above, when the wet multi-plate clutch is used instead of the first one-way clutch 36, a configuration for controlling the wet multi-plate clutch is required, so that the electric vehicle can be reduced in size and cost. Is difficult.

[Effects of the embodiment]
In the vehicle drive device 10 according to this embodiment, a first one-way clutch 36 and a clutch mechanism 37 are provided in parallel in a second power transmission path 32 formed between the second motor 22 and the drive wheels 11. .

  In the vehicle drive device 10 according to this embodiment, since the clutch mechanism 37 is set to an open state, transmission of power from the drive wheels 11 to the second motor 22 can be prevented. The accompanying rotation (the second motor 22 being rotated in conjunction with the rotation of the drive wheel 11) can be prevented. As a result, the power of the first motor 21 (especially power by forward rotation) can be used effectively. Further, since the power generated by the positive rotation of the second motor 22 can be transmitted from the second motor 22 to the drive wheel 11 via the first one-way clutch 36, the power of the second motor 22 (particularly, the power generated by the positive rotation). Can be used effectively.

  Furthermore, in the vehicle drive device 10 according to this embodiment, the clutch mechanism 37 is set to the engaged state, whereby the power generated by the reverse rotation of the second motor 22 is driven from the second motor 22 via the engaged clutch mechanism 37. It can be transmitted to the wheel 11. Thereby, the power (especially power by reverse rotation) of the second motor 22 can be used effectively. For example, when the electric vehicle is moved backward on an uphill, the rotation of the drive wheels 11 (rotation in the direction of moving the electric vehicle backward) is performed using both the power by the reverse rotation of the first motor 21 and the power by the reverse rotation of the second motor 22. )It can be performed.

  The clutch mechanism 37 is switched mainly when the electric vehicle stops. Therefore, the clutch mechanism 37 can be configured by a clutch (for example, a dog clutch) that does not require high-precision control such as a half clutch. Further, the clutch mechanism 37 is configured by a dog clutch (a relatively inexpensive clutch), so that the cost of the clutch mechanism 37 can be reduced. The clutch mechanism 37 is not limited to a dog clutch, and may be constituted by other dry clutches.

  Further, the shift selector 40 and the clutch mechanism 37 are connected by a link mechanism 41 (a relatively inexpensive and small mechanism), and the clutch mechanism 37 is directly operated by the shift selector 40. Cost reduction and size reduction of the mechanism for interlocking with the clutch mechanism 37 can be realized. Note that the shift selector 40 and the clutch mechanism 37 may be configured to be interlocked by electronic control. For example, a sensor that detects the position of the shift selector 40 (position of the operation lever) and outputs a detection signal, an actuator that drives the clutch mechanism 37, and a control unit that controls the actuator based on the detection signal from the sensor The shift selector 40 and the clutch mechanism 37 may be electronically connected by a control mechanism having the control mechanism.

[Motor power characteristics]
In general, the motor is efficient when the required travel load is in a high load state, but the efficiency tends to be slightly lower when the required travel load such as city driving is in a low load state. Therefore, when the electric vehicle is provided with a plurality of motors, the outputs of the plurality of motors are set so that the output of one of the plurality of motors is relatively small, and the travel request load is 1 in the low load state. The operating point efficiency can be increased by concentrating the load on one motor (a motor having a relatively small output).

  In addition, the permanent magnet motor is suitable for driving an electric vehicle because of its relatively good driving efficiency, but eddy current loss (power loss) occurs due to rotation of the magnet. Therefore, when the running state of the electric vehicle is a state like inertia running, the eddy current loss acts as a brake and the running resistance of the electric vehicle tends to increase.

  Here, the power characteristics of the first motor 21 and the second motor 22 will be described with reference to FIG. FIG. 4 shows power characteristics of the first motor 21 and the second motor 22 that are suitable when the electric vehicle is driven mainly in an urban area. In FIG. 4, the first power characteristic curve L1 corresponds to the power characteristic of the first motor 21 (that is, the driving force that can be generated in the first motor 21). The second power characteristic curve L2 is obtained by combining a curve corresponding to the power characteristic of the first motor 21 (first power characteristic curve L1) and a curve corresponding to the power characteristic of the second motor 22 (not shown). This corresponds to a curve (that is, the total amount of driving force that can be generated in the first motor 21 and the second motor 22).

  The driving force and speed in the first power characteristic curve L1 are based on the gear ratio in the vehicle drive device 10, the diameter of the driving wheel 11 (tire diameter), etc., and the torque and the rotational speed in the torque rotational speed characteristic of the first motor 21. Can be obtained by converting them respectively. Further, the percentages (95%, 85%, 75%, 65%) in the figure indicate the overall efficiency of the first motor 21. The overall efficiency of the first motor 21 includes copper loss and iron loss of the first motor 21.

  When an electric vehicle travels mainly in an urban area, the operating point of the electric vehicle is in a low-speed and low-load region R1 (a region where the speed is relatively low and the required travel load is relatively low, the hatched region in FIG. 4). There is a tendency to concentrate. In this case, the first motor 21 has a relatively high efficiency in a low output region (an output region where the required travel load falls below a predetermined load threshold) corresponding to urban driving (medium / low speed / low load driving) of the electric vehicle. It is preferable that it is comprised so that it may become. With this configuration, the drive wheels 11 can be efficiently driven using the power of the first motor 21.

  In addition, as shown in FIG. 4, the driving force of the electric vehicle can be improved by assisting the driving of the driving wheels 11 using the power of the second motor 22.

(Modification of Embodiment 1)
The electric vehicle may be configured to be able to switch its operation mode to a plurality of operation modes (a plurality of operation modes including a first forward mode, a second forward mode, and a reverse mode). The first forward mode is an operation mode in which the electric vehicle moves forward. The second forward mode is an operation mode in which the electric vehicle moves forward at a vehicle deceleration higher than the vehicle deceleration in the first forward mode. The shift selector 40 may be configured to select a plurality of operation modes including a first forward mode, a second forward mode, and a reverse mode. For example, the shift selector 40 has an operation lever that can move to a plurality of range positions including a drive range position, a low range position, and a reverse range position, and the operation lever is operated by the driver of the electric vehicle to operate the plurality of ranges. It is configured to be arranged at any one of the positions. The shift selector 40 is configured to set the operation mode of the electric vehicle to an operation mode corresponding to the range position where the operation lever is arranged among the plurality of operation modes. The drive range position (D range position) is a range position corresponding to the first forward mode, and the low range position (L range position) is a range position corresponding to the second forward mode, and the reverse range position (R (Range position) is a range position corresponding to the reverse mode.

[First forward mode]
The operation of the vehicle drive device 10 in the first forward mode is the same as the operation of the vehicle drive device 10 in the forward mode shown in FIGS. That is, in the first forward mode, the clutch mechanism 37 is set to an open state (a state in which transmission of power is prohibited), and at least one of the first motor 21 and the second motor 22 rotates forward to rotate the electric vehicle. The drive wheel 11 is rotated in the direction to advance.

[Second forward mode]
Next, the operation of the vehicle drive device 10 in the second forward mode will be described with reference to FIG. In the second forward mode, the clutch mechanism 37 is set to an engaged state (a state in which power transmission is allowed). Further, the first motor 21 rotates in the forward direction, and the second motor 22 enters a state (non-driving state) in which no power is generated by the forward rotation.

  As shown in FIG. 5, in the second forward mode, the clutch mechanism 37 is set to the engaged state in conjunction with the operation of the shift selector 40 (selection of the second forward mode). Then, the controller 50 rotates the first motor forward. In addition, the controller 50 controls the second motor 22 so that the second motor 22 is in a non-driving state (a state in which power is not generated by forward rotation). For example, the controller 50 blocks the supply of electric power (electric power for causing the second motor 22 to rotate forward) to the second motor 22.

  In the second forward mode, power generated by the positive rotation of the first motor 21 is transmitted to the drive wheels 11 via the first power transmission path 31, and the drive wheels 11 rotate in the direction in which the electric vehicle moves forward. In addition, since the clutch mechanism 37 is set in the engaged state, the power generated by the rotation of the drive wheels 11 is transmitted to the second power transmission path 32 (specifically, the drive shaft 101 and the differential gear 102, the clutch mechanism 37 in the engaged state, and the first Is transmitted to the second motor 22 via the two shafts 301), and the second motor 22 is rotated in the forward rotation direction. As a result, power loss (specifically, eddy current loss) occurs in the second motor 22, so that the vehicle deceleration of the electric vehicle can be increased.

[Reverse mode]
The operation of the vehicle drive device 10 in the reverse mode is the same as the operation of the vehicle drive device 10 in the reverse mode shown in FIG. That is, in the reverse mode, the clutch mechanism 37 is set to an engaged state (a state in which power transmission is allowed), and at least one of the first motor 21 and the second motor 22 rotates reversely to move the electric vehicle backward. The drive wheel 11 is rotated in the direction.

[Effects of Modification of Embodiment 1]
As described above, when the operation mode of the electric vehicle is set to the second forward mode, the power generated by the rotation of the drive wheels 11 is transmitted to the second motor 22 by setting the clutch mechanism 37 to the engaged state. Can do. As a result, power loss (specifically, eddy current loss) can be generated in the second motor 22, so that the vehicle deceleration of the electric vehicle can be increased.

  When the electric vehicle is switched from the first forward mode to the second forward mode while the electric vehicle is traveling, the clutch mechanism 37 is engaged from the released state while the second clutch member of the clutch mechanism 37 is rotating. It will be switched to the state. In this case, in a state where the rotation of the first clutch member of the clutch mechanism 37 and the rotation of the second clutch member are synchronized, the first clutch member and the second clutch member of the clutch mechanism 37 are engaged with each other, and the clutch mechanism 37 is engaged. Is preferably switched to the fastening state. The controller 50 can control the rotation of the first clutch member of the clutch mechanism 37 by controlling the rotation of the second motor 22. For example, the controller 50 synchronizes the rotation of the first clutch member of the clutch mechanism 37 and the rotation of the second clutch member in conjunction with the operation of the shift selector 40 (switching from the first forward mode to the second forward mode). Thus, the rotation of the second motor 22 may be controlled. The clutch mechanism 37 is preferably switched from the released state to the engaged state after the rotation of the first clutch member and the rotation of the second clutch member are synchronized.

(Embodiment 2)
FIG. 6 illustrates the configuration of the vehicle drive device 10 according to the second embodiment. In the second embodiment, the electric vehicle has a rotational load 60. The rotational load 60 is, for example, an air conditioner compressor provided in an electric vehicle. In the second embodiment, the power transmission mechanism 30 includes a third power transmission path 33 and a third power transmission formed between the second motor 22 and the rotational load 60 in addition to the configuration shown in FIG. And a second one-way clutch 38 constituting a part of the path 33. Other configurations are the same as those of the vehicle drive device 10 shown in FIG.

<Third power transmission path>
The third power transmission path 33 is a path for transmitting power between the second motor 22 and the rotational load 60. In this example, the third power transmission path 33 includes a second shaft 301, a second gear 302, and a second one-way clutch 38. The second gear 302 is connected to the second shaft 301.

<Second one-way clutch>
The second one-way clutch 38 is provided in the third power transmission path 33 and is configured to allow transmission of reverse rotational power (power due to reverse rotation of the second motor 22) from the second motor 22 to the rotational load 60. ing. The second one-way clutch 38 is configured to prohibit transmission of forward rotational power (power due to forward rotation of the second motor 22) from the second motor 22 toward the rotational load 60.

  Here, a configuration example of the second one-way clutch 38 will be described in detail. In this example, the second one-way clutch 38 has an inner ring and an outer ring. The inner ring and the outer ring are formed in a cylindrical shape, the inner ring is fitted in the outer ring, and the outer surface of the outer ring is formed in a gear shape. The second one-way clutch 38 transmits power by rotating the inner ring together with the outer ring when the outer ring rotates in the normal rotation direction (the rotation direction indicated by the solid line in FIG. 6) with respect to the inner ring. Thus, when the outer ring rotates in the reverse rotation direction (the reverse direction of the normal rotation direction), the outer ring idles so that power is not transmitted.

  In this example, the second one-way clutch 38 is provided between the second gear 302 and the rotational load 60. The inner ring of the second one-way clutch 38 is connected to the drive shaft of the rotational load 60, and the outer ring of the second one-way clutch is engaged with the second gear 302. Thereby, the rotational load 60 is configured to rotate in conjunction with the rotation of the inner ring of the second one-way clutch 38, and the outer ring of the second one-way clutch 38 rotates in conjunction with the rotation of the second motor 22. It is configured.

  The power by the reverse rotation of the second motor 22 is transmitted to the rotational load 60 through the second shaft 301, the second gear 302, and the second one-way clutch 38 in order. It should be noted that transmission of positive rotational power from the second motor 22 toward the rotational load 60 (power by the positive rotation of the second motor 22) is blocked by the second one-way clutch 38.

[Second motor]
In the second embodiment, in the second motor 22, the clutch mechanism 37 is set to an open state (a state in which transmission of power is permitted), and power generated by the positive rotation of the second motor 22 is transmitted to the drive wheels 11. If this is not required, the rotational load 60 is rotated in the reverse direction. Specifically, the second motor 22 rotates in the reverse direction when the electric vehicle is stopped or when the travel request load of the electric vehicle is a low load in the forward mode.

〔controller〕
In the second embodiment, the controller 50 opens the clutch mechanism 37 when the electric vehicle moves forward by the forward rotation of the first motor 21 and the rotational load 60 is driven by the reverse rotation of the second motor 22. When the state is switched to the fastening state, the reverse rotation of the second motor 22 is prohibited until the electric vehicle stops. Specifically, the controller 50 controls the second motor 22 so that the second motor 22 is in a non-driven state (a state in which power is not generated by forward rotation). At this time, the controller 50 causes the clutch mechanism 37 to be in an open state when the electric vehicle moves forward by the forward rotation of the first motor 21 and the rotational load 60 is driven by the reverse rotation of the second motor 22. The second motor 22 is controlled so that the rotation speed of the second motor 22 in the reverse rotation direction becomes zero, and when the rotation speed of the second motor 22 in the reverse rotation direction becomes zero, The second motor 22 may be controlled so that the two motors 22 are not driven.

[Forward mode (at low load)]
Next, the operation of the vehicle drive device 10 in the forward mode (at the time of low load) according to the second embodiment will be described with reference to FIG. In the forward mode, the clutch mechanism 37 is set to an open state (a state in which transmission of power is prohibited). In the forward mode, when the travel request load of the electric vehicle is low, only the first motor 21 rotates forward and the second motor 22 rotates reversely.

  As shown in FIG. 6, in the forward mode, the clutch mechanism 37 is set to the released state in conjunction with the operation of the shift selector 40 (selection of the forward mode). When the travel request load of the electric vehicle is a low load in the forward mode, the controller 50 rotates the first motor 21 forward and reversely rotates the second motor 22. Thereby, only the motive power due to the positive rotation of the first motor 21 is transmitted to the drive wheels 11 via the first power transmission path 31, and the drive wheels 11 rotate in the direction in which the electric vehicle moves forward. In this way, the electric vehicle can be advanced using the power generated by the positive rotation of the first motor 21. Note that transmission of positive rotational power (power generated by rotation of the drive wheel 11) from the drive wheel 11 to the second motor 22 is blocked by the first one-way clutch 36 and the opened clutch mechanism 37. Thereby, the accompanying rotation of the second motor 22 can be prevented. Further, the power by the reverse rotation of the second motor 22 is transmitted to the rotational load 60 via the third power transmission path 33 (specifically, the second shaft 301, the second gear 302, and the second one-way clutch 38), The rotational load 60 is driven. Thus, the rotational load 60 can be driven using the power generated by the reverse rotation of the second motor 22.

[Forward mode (high load)]
Next, the operation of the vehicle drive device 10 in the forward mode (at the time of high load) of the second embodiment will be described with reference to FIG. In the forward mode, the clutch mechanism 37 is set to an open state (a state in which transmission of power is prohibited). In the forward mode, when the travel demand load of the electric vehicle is high, both the first motor 21 and the second motor 22 rotate forward to rotate the drive wheels 11 in a direction to advance the electric vehicle.

  As shown in FIG. 7, in the forward mode, the clutch mechanism 37 is set to the released state in conjunction with the operation of the shift selector 40 (selection of the forward mode). When the travel request load of the electric vehicle is high in the forward mode, the controller 50 rotates both the first motor 21 and the second motor 22 in the normal direction. Specifically, the controller 50 controls the second motor 22 so that the positive rotation power (the power by the positive rotation of the second motor 22) is transmitted from the second motor 22 to the drive wheel 11. For example, the controller 50 controls the second motor 22 so that the rotation speed of the second motor 22 in the forward rotation direction exceeds the rotation speed of the outer ring of the first one-way clutch 36.

  In order to control in this manner, as in the first embodiment, the controller 50 controls the first motor so that the torque distribution (target torque distribution) of the first motor 21 and the second motor 22 is a desired torque distribution. A torque command is output to the first motor 21 and the second motor 22 to control the first motor 21 and the second motor 22.

  With the above operation, in the forward mode (during high load), the power generated by the positive rotation of the first motor 21 is transmitted to the drive wheels 11 via the first power transmission path 31, and the drive wheels are driven in the direction of moving the electric vehicle forward. 11 rotates. Further, the power generated by the forward rotation of the second motor 22 is transmitted to the drive wheels 11 via the second power transmission path 32 (specifically, the second shaft 301, the first one-way clutch 36, the differential gear 102, and the drive shaft 101). Communicated. Thereby, rotation of the drive wheel 11 (rotation in the direction in which the electric vehicle moves forward) can be assisted. It should be noted that transmission of positive rotational power from the second motor 22 toward the rotational load 60 (power by the positive rotation of the second motor 22) is blocked by the second one-way clutch 38.

  As in the first embodiment, the controller 50 monitors the speed, acceleration, and the like of the operation amount of an accelerator pedal (not shown), and the travel request load is in a low load state (that is, the forward mode (at low load)). ) In the second motor 22 at a rotation speed (rotational speed in the forward rotation direction) lower than the rotational speed of the outer ring of the first one-way clutch 36. May be configured in advance to rotate forward.

[Reverse mode]
Next, the operation of the vehicle drive device 10 in the reverse mode of the second embodiment will be described with reference to FIG. The operation of the vehicle drive device 10 in the reverse mode of the second embodiment is the same as the operation of the vehicle drive device 10 in the reverse mode of the first embodiment shown in FIG. That is, in the reverse mode of the second embodiment, the clutch mechanism 37 is set to an engaged state (a state in which power transmission is permitted). In addition, at least one of the first motor 21 and the second motor 22 rotates in the reverse direction to rotate the drive wheels 11 in a direction in which the electric vehicle moves backward.

  In the second embodiment, the power generated by the reverse rotation of the second motor 22 rotates via the third power transmission path 33 (specifically, the second shaft 301, the second gear 302, and the second one-way clutch 38). It is also transmitted to the load 60. Thereby, the rotational load 60 is driven.

[Effects of Embodiment 2]
As described above, by providing the second one-way clutch 38 in the third power transmission path 33 formed between the second motor 22 and the rotational load 60, the second motor 22 rotates using the power generated by the reverse rotation. The load 60 can be driven.

  In addition, when the clutch mechanism 37 is set to the open state and it is not required to transmit the power generated by the forward rotation of the second motor 22 to the drive wheels 11, the second motor 22 is rotated in the reverse direction, thereby the second motor. The power generated by the reverse rotation 22 can be effectively transmitted to the rotational load 60.

  Further, since the second motor 22 can be used both for driving the drive wheels 11 and for driving the rotational load 60, it is not necessary to provide a separate drive source for driving the rotational load 60. Therefore, the electric vehicle can be reduced in size and cost.

  Further, the controller 50 moves the clutch mechanism 37 from the released state to the engaged state when the electric vehicle advances by the forward rotation of the first motor 21 and the rotational load 60 is driven by the reverse rotation of the second motor 22. When switched, reverse rotation of the second motor 22 is prohibited until the electric vehicle stops. By such control, damage at the time of switching of the clutch mechanism 37 can be reduced.

(Variation 1 of vehicle drive device)
The power transmission mechanism 30 may be configured as shown in FIG. In the example of FIG. 9, the first power transmission path 31 includes a drive shaft 101, a differential gear 102, a first gear 202, and a first shaft 201. The second power transmission path 32 includes a drive shaft 101, a differential gear 102, a first gear 202, a first shaft 201, a connection gear 203, a first one-way clutch 36, a clutch mechanism 37, and a second shaft. 301. In the example of FIG. 9, the first power transmission path 31 overlaps with a part of the second power transmission path 32.

  Drive wheels 11 are connected to both ends of the drive shaft 101. The differential gear 102 is connected to the drive shaft 101. The first shaft 201 is connected to the first motor 21. The first gear 202 is connected to the first shaft 201 and is engaged with the differential gear 102. The connection gear 203 is connected to the first shaft 201. The second shaft 301 is connected to the second motor 22. The first one-way clutch 36 has an inner ring coupled to the second shaft 301 and an outer ring engaged with the coupling gear 203. The first clutch member of the clutch mechanism 37 is connected to the second shaft 301, and the second clutch member is engaged with the connecting gear 203.

  Even when configured as described above, the power transmission mechanism 30 can transmit power among the first motor 21, the second motor 22, and the drive wheels 11. The same effect as that of the first embodiment can be obtained also in the vehicle drive device 10 shown in FIG.

(Variation 2 of vehicle drive device)
Further, the power transmission mechanism 30 may be configured as shown in FIG. In the example of FIG. 10, the first power transmission path 31 includes a drive shaft 103, a differential gear 104, a first gear 202, and a first shaft 201. The second power transmission path 32 includes a drive shaft 101, a differential gear 102, a second shaft 301, a first one-way clutch 36, and a clutch mechanism 37.

  Drive wheels 12 are connected to both ends of the drive shaft 103. The differential gear 104 is connected to the drive shaft 103. The first shaft 201 is connected to the first motor 21. The first gear 202 is connected to the first shaft 201 and is engaged with the differential gear 102.

  Drive wheels 11 are connected to both ends of the drive shaft 101. The differential gear 102 is connected to the drive shaft 101. The second shaft 301 is connected to the second motor 22. The first one-way clutch 36 has an inner ring connected to the second shaft 301 and an outer ring engaged with the differential gear 102. The clutch mechanism 37 has a first clutch member connected to the second shaft 301, and the second clutch member is engaged with the differential gear 102.

  In the example of FIG. 10, when the power by the positive rotation of the first motor 21 is transmitted to the drive wheel 12, the drive wheel 11 and the drive wheel 11 in the direction in which the electric vehicle moves forward (the rotation direction indicated by the solid line arrow in FIG. 10). When the driving wheel 12 rotates and the power generated by the reverse rotation of the first motor 21 is transmitted to the driving wheel 12, the driving wheel 11 and the driving wheel 12 rotate in a direction in which the electric vehicle moves backward. Further, when the power by the positive rotation of the second motor 22 is transmitted to the drive wheels 11, the drive wheels 11 and the drive wheels 12 are moved in the direction in which the electric vehicle moves forward (the rotation direction indicated by the solid line arrow in FIG. 10). When the rotatory power is transmitted to the drive wheels 11 by the reverse rotation of the second motor 22, the drive wheels 11 and the drive wheels 12 rotate in the direction in which the electric vehicle moves backward.

  Even when configured as described above, the power transmission mechanism 30 can transmit power among the first motor 21, the second motor 22, and the drive wheels 11. The same effect as that of the first embodiment can be obtained also in the vehicle drive device 10 shown in FIG.

(Other embodiments)
Moreover, you may implement combining the above embodiment and modification suitably. The above embodiments and modifications are essentially preferable examples, and are not intended to limit the scope of this disclosure, its application, or its use.

  As described above, this disclosure is applicable to a vehicle drive device.

DESCRIPTION OF SYMBOLS 10 Vehicle drive device 11, 12 Drive wheel 21 1st motor 22 2nd motor 30 Power transmission mechanism 31 1st power transmission path 32 2nd power transmission path 33 3rd power transmission path 36 1st one-way clutch 37 Clutch mechanism 38 2nd One-way clutch 40 Shift selector 41 Link mechanism 50 Controller (control unit)
51 Vehicle speed sensor 60 Rotational load

Claims (11)

A vehicle drive device for driving drive wheels of an electric vehicle,
A first motor;
A second motor;
A power transmission mechanism configured to transmit power between the first motor, the second motor, and the drive wheel;
The power transmission mechanism is
A first power transmission path formed between the first motor and the drive wheel;
A second power transmission path formed between the second motor and the drive wheel;
A first one-way clutch provided in the second power transmission path and configured to allow transmission of power by forward rotation of the second motor from the second motor toward the drive wheel;
A clutch mechanism provided in parallel with the first one-way clutch in the second power transmission path and configured to be able to switch between a fastening state allowing transmission of power and an open state prohibiting transmission of power; The vehicle drive device characterized by the above-mentioned. In claim 1,
When at least one of the power due to the positive rotation of the first motor and the power due to the positive rotation of the second motor is transmitted to the drive wheel, the drive wheel rotates in a direction to advance the electric vehicle,
When at least one of the power generated by the reverse rotation of the first motor and the power generated by the reverse rotation of the second motor is transmitted to the drive wheel, the drive wheel rotates in a direction to move the electric vehicle backward.
The vehicle drive apparatus according to claim 1, wherein the clutch mechanism is set in the engaged state when the electric vehicle is moved backward. In claim 2,
The vehicle drive apparatus according to claim 1, wherein the clutch mechanism is set to the open state when the electric vehicle is moved forward. In claim 3,
In the forward mode in which the electric vehicle moves forward, when the travel demand load of the electric vehicle is lower than a predetermined forward load threshold value, the first motor rotates forward to rotate the drive wheel,
In the forward mode, when the travel demand load of the electric vehicle exceeds the forward load threshold, both the first motor and the second motor rotate forward to rotate the driving wheel. apparatus. In claim 2,
The operation mode of the electric vehicle includes a first forward mode in which the electric vehicle is advanced, a second forward mode in which the electric vehicle is advanced at a vehicle deceleration higher than the vehicle deceleration in the first forward mode, and the electric vehicle It can be switched to the reverse mode to reverse the vehicle,
The clutch mechanism is set to the open state when the operation mode of the electric vehicle is set to the first forward mode, and the operation mode of the electric vehicle is set to the second forward mode or the reverse mode. The vehicle drive device is set to the fastening state when the vehicle is engaged. In any one of Claims 1-5,
The electric vehicle has a rotational load,
The power transmission mechanism is
A third power transmission path formed between the second motor and the rotational load;
A second one-way clutch provided in the third power transmission path and configured to allow transmission of power by reverse rotation of the second motor from the second motor toward the rotational load. The vehicle drive device characterized by these. In claim 6,
The second motor rotates in the reverse direction when the clutch mechanism is set in the released state and it is not required to transmit the power generated by the forward rotation of the second motor to the driving wheels. Drive device. In claim 6 or 7,
When the clutch mechanism is switched from the disengaged state to the engaged state when the electric vehicle moves forward by forward rotation of the first motor and the rotational load is driven by reverse rotation of the second motor, A vehicle drive device comprising a control unit that prohibits reverse rotation of the second motor until the electric vehicle stops. In any one of Claims 1-8,
The vehicle drive apparatus according to claim 1, wherein the clutch mechanism is a dog clutch. In any one of Claims 1-9,
A shift selector configured to be operated by a driver of the electric vehicle to switch a driving mode of the electric vehicle;
The vehicle drive device, wherein the clutch mechanism is configured to switch between the engaged state and the released state in conjunction with an operation of the shift selector. In claim 10,
A link mechanism configured to connect the shift selector and the clutch mechanism and mechanically switch between an engaged state and a released state of the clutch mechanism in conjunction with an operation of the shift selector is provided. A vehicle drive device.

Images