Hybrid vehicle

Abstract

To provide a hybrid vehicle that can reduce power loss at the time of travelling when torque of an engine is transmitted to a driving wheel.SOLUTION: A hybrid vehicle is provided with a fly wheel 5, a motor 2 and a power division mechanism 7 whose driving wheel 11 differentially rotates, and is further provided with a locking gear 26, provided to be movable to a lock position where the gear engages with an outer tooth 25 of the fly wheel 5 and to a release position where the engagement with the outer tooth 25 thereof is released, which engages with the outer tooth to make braking torque counteracting to torque of the outer tooth act on the outer tooth, and an actuator 27 that switches the locking gear 26 between the lock position and the release position, which is configured to be able to set a first travelling mode in which the locking gear 26 is moved to the lock position to engage with the outer tooth and a second travelling mode in which the locking gear 26 is moved to the release position to release the engagement with the outer tooth thereof.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hybrid vehicle having an engine and a motor as driving power sources.

Background Art

[0002] Patent Document 1 describes a hybrid vehicle including a power split mechanism that divides and transmits the torque of an engine to a first motor and drive wheels, and a second motor is connected to the drive wheels. This hybrid vehicle includes an engagement device that selectively fixes an input element of the power split mechanism in order to transmit the torque of the first motor to the drive wheels and cause the vehicle to travel. The engagement device includes two gears that mesh with external teeth formed on each of a flywheel connected to the output shaft of the engine and a damper mechanism connected to the input element of the power split mechanism, an engagement clutch that selectively engages and disengages these gears, and a one-way clutch that allows a gear meshing with the external teeth of the damper mechanism to rotate only on one side. Then, by outputting driving torque from the first motor in a state where the engagement clutch is disengaged, the one-way clutch engages and is configured to transmit the torque of the first motor to the drive wheels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the hybrid vehicle described in Patent Document 1 travels by transmitting torque from the engine to the drive wheels, the engagement clutch is engaged to connect the flywheel and the damper mechanism. In that case, torque is transmitted in the order of the flywheel, the gear meshing with the external teeth of the flywheel, the engagement clutch, the gear meshing with the external teeth of the damper mechanism, and the damper mechanism from the output shaft of the engine. Since mechanical losses corresponding to gear slippage and the like occur in those meshing surfaces, there is a possibility that the fuel efficiency during running with the engine driving deteriorates.

[0005] The present invention has been made paying attention to the above technical problems, and an object thereof is to provide a hybrid vehicle capable of reducing power loss during running when the torque of the engine is transmitted to the drive wheels.

Means for Solving the Problems

[0006] In order to achieve the above object, the present invention provides an engine, a flywheel connected to the output shaft of the engine, a motor, a first rotating element connected to the output shaft of the flywheel, a second rotating element connected to the motor, and A hybrid vehicle including a power split mechanism in which at least three rotating elements of a third rotating element connected to a drive wheel differentially rotate, the flywheel has external teeth, and a lock position meshing with the external teeth and a release position where the engagement with the external teeth is released And a lock gear that applies a braking torque against the torque of the external teeth by engaging with the external teeth, and an actuator that switches the lock gear between the lock position and the release position. The lock gear is moved to the lock position and engaged with the external teeth, and a first running mode in which the drive torque is output from the motor and the vehicle runs, and the lock gear is moved to the release position to disengage the engagement with the external teeth. It is configured to be able to set at least two running modes including a second running mode of running in a state where Furthermore, it includes a controller for controlling the motor, and when the locking gear does not move to the locking position within a predetermined period after starting to move from the release position, the controller outputs torque from the motor to rotate the flywheel. It is characterized by the above.

[0007] In the present invention, the locking gear may be configured to move between the locked position and the released position along an axis parallel to the rotation center axis of the flywheel.

[0009] In the present invention, a torque limiter may be further provided that prohibits rotation of the locking gear when the torque acting on the locking gear is less than a predetermined upper limit torque, and permits rotation of the locking gear when the torque acting on the locking gear is equal to or greater than the upper limit torque.

[0010] In the present invention, another motor torque-transmissibly connected to the drive wheel or another drive wheel may be further provided, and the first traveling mode may include a mode in which torque is output from the motor and the other motor to travel.

Advantages of the Invention

[0011] According to the present invention, external teeth are formed on a flywheel connected to a first rotating element of a power split mechanism, and a locking gear is provided so as to be movable between a locked position meshing with the external teeth and a released position where the meshing with the external teeth is released. Further, the locking gear is configured to be able to apply a braking torque against the torque of the external teeth by meshing with the external teeth. Then, by meshing the locking gear with the external teeth of the flywheel, when torque is input from the motor to the power split mechanism, the torque can be transmitted to the drive wheels to travel. Also, by releasing the meshing between the locking gear and the external teeth of the flywheel, torque can be transmitted from the engine to the drive wheels via the power split mechanism to travel. When a mode of transmitting torque from the engine to the drive wheels via the power split mechanism to travel is set in this way, it is possible to suppress the occurrence of power losses such as rotating the locking gear. Further, since external teeth are formed on a flywheel having a relatively large outer diameter and the rotation of the flywheel is restricted by meshing a locking gear with the external teeth, the load acting on the locking gear can be reduced and the locking gear can be miniaturized.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described based on the embodiments shown in the drawings. Note that the embodiments described below are merely examples when the present invention is embodied, and do not limit the present invention.

[0014] FIG. 1 shows an example of a hybrid vehicle (hereinafter referred to as a vehicle) according to an embodiment of the present invention. This vehicle Ve includes an engine (ENG) 1, a first motor (MG1) 2, and a second motor (MG2) 3 as driving power sources.

[0015] The engine 1 can be configured in the same manner as a conventional gasoline engine or diesel engine, and is configured to generate torque by burning a mixture of supplied air and fuel.

[0016] In addition, each of the motors 2 and 3, in addition to the function as a motor that outputs driving torque when electricity is supplied, similar to a motor as a driving power source provided in a conventional electric vehicle or hybrid vehicle, has a function as a generator that generates electric power when torque is input and it is rotated. Specifically, it is configured by a permanent magnet type synchronous motor, an induction motor, or the like.

[0017] A flywheel 5 is connected to the output shaft 4 of the engine 1, and an input shaft 8 of a power split mechanism 7 described later is connected to the flywheel 5 via a spring damper 6. Note that a torque limiter 9 is provided between the flywheel 5 and the spring damper 6 to limit the transmitted torque to less than a predetermined limit torque by relatively rotating the flywheel 5 and the spring damper 6 when a torque equal to or greater than the predetermined limit torque acts.

[0018] The input shaft 8 is arranged on the same straight line as the output shaft 4 of the engine 1, and a mechanical oil pump 10 is connected to the tip thereof. In addition, a power split mechanism 7 is connected to an intermediate portion in the axial direction of the input shaft 8. That is, the input shaft 8 passes through the power split mechanism 7.

[0019] The power split mechanism 7 is a differential mechanism configured to split the torque of the input shaft 8 between the first motor 2 and the drive wheels 11. In the example shown in FIG. 1, it is constituted by a single pinion type planetary gear mechanism. That is, it is constituted by a sun gear 12, a ring gear 13 arranged concentrically with the sun gear 12, a plurality of pinion gears 14 that mesh with the sun gear 12 and the ring gear 13 and are arranged side by side in the circumferential direction of the input shaft 8, and a carrier 15 that holds each pinion gear 14 so as to be revolvable about the rotation center axis of the input shaft 8 and holds each pinion gear 14 so as to be rotatable. That is, the sun gear 12, the ring gear 13, and the carrier 15 are configured to rotate differentially. And the input shaft 8 is connected to the carrier 15, and the first motor 2 is connected to the sun gear 12. Note that the first motor 2 corresponds to the "motor" in the embodiment of the present invention, the carrier 15 corresponds to the "first rotating element" in the embodiment of the present invention, the sun gear 12 corresponds to the "second rotating element" in the embodiment of the present invention, and the ring gear 13 corresponds to the "third rotating element" in the embodiment of the present invention.

[0020] An output gear 16 is formed on the outer peripheral surface of the ring gear 13, and a driven gear 17 meshes with the output gear 16. This driven gear 17 is attached to one end of a countershaft 18 arranged parallel to the input shaft 8, and a counter drive gear 19 is attached to the other end of the countershaft 18. A ring gear 21 of a differential gear unit 20 meshes with the counter drive gear 19, and the left and right drive wheels 11 are connected to the differential gear unit 20. For convenience, only one drive wheel 11 is shown in FIG. 1.

[0021] The above-described driven gear 17 further meshes with a drive gear 22 having a smaller diameter than the driven gear 17, and the second motor 3 is connected to the drive gear 22. That is, the drive gear 22 is attached to the tip of the output shaft 23 of the second motor 3. That is, the second motor 3 and the drive wheel 11 are connected so as to be able to transmit torque. This second motor 3 corresponds to the "other motor" in the embodiment of the present invention.

[0022] The vehicle Ve configured as described above outputs a reaction torque corresponding to the torque input from the engine 1 to the power split mechanism 7 (hereinafter referred to as engine torque) from the first motor 2, whereby a part of the engine torque is transmitted to the drive wheels 11 and the vehicle can travel. That is, when the vehicle Ve travels by the power of the engine 1, the carrier 15 serves as an input element, the sun gear 12 serves as a reaction element, and the ring gear 13 serves as an output element. In that case, the torque of the second motor 3 may be applied at the driven gear 17 portion and the vehicle may travel. The mode of transmitting this engine torque to the drive wheels 11 and traveling is referred to as an HV traveling mode in the following description.

[0023] Further, the vehicle Ve shown in FIG. 1 can also set a single EV traveling mode in which the combustion of the air-fuel mixture by the engine 1 is stopped, the energization to the first motor 2 is stopped, and the drive torque is output from the second motor 3 to travel. Since the inertia of the engine 1 is larger than the inertia of the first motor 2, in the single EV traveling mode, the rotation of the engine 1 stops and the first motor 2 idles at a rotation speed corresponding to the vehicle speed and the gear ratio of the power split mechanism 7.

[0024] Furthermore, the vehicle Ve shown in FIG. 1 is configured to be able to set a dual EV driving mode in which the combustion of the air-fuel mixture by the engine 1 is stopped and driving torque is output from the first motor 2 to drive. That is, the carrier 15 that functions as an input element in the HV driving mode is made to function as a reaction force element in the dual EV driving mode, and the sun gear 12 that functions as a reaction force element in the HV driving mode is made to function as an input element in the dual EV driving mode. A brake mechanism 24 is provided to selectively prohibit the rotation of the flywheel 5. Note that the dual EV driving mode corresponds to the "first driving mode" in the embodiment of the present invention, and the HV driving mode and the single EV driving mode correspond to the "second driving mode" in the embodiment of the present invention.

[0025] Specifically, external teeth 25 are formed on the outer peripheral surface of the flywheel 5, and a locking gear 26 provided so as to be movable along an axis parallel to the output shaft 4 and the input shaft 8 is provided so as to be able to mesh with the external teeth 25. The locking gear 26 is supported by an actuator 27 such as a motor so as to be movable in the axial direction, and is held by a fixed member such as a case. By meshing with the external teeth 25 of the flywheel 5, it is configured to apply a braking torque that counteracts the torque of the external teeth 25. In the following description, the external teeth 25 are referred to as the flywheel gear 25.

[0026] Therefore, by meshing the locking gear 26 with the flywheel gear 25, the rotation of the carrier 15 is prohibited, and by outputting driving torque from the first motor 2, torque corresponding to the driving torque of the first motor 2 and the gear ratio of the power split mechanism 7 can be transmitted to the drive wheels 11. When outputting driving torque from the first motor 2, usually, the driving torque of the second motor 3 is applied at the driven gear 17 portion. Therefore, this driving mode is called the dual EV driving mode.

[0027] Fig. 2 shows a perspective view for explaining an example of the brake mechanism 24 provided with the actuator 27 for axially moving the above-described locking gear 26, and Fig. 3 shows a sectional view taken along line III-III in Fig. 2. The brake mechanism 24 shown in Figs. 2 and 3 includes a locking motor 27a as the actuator 27, a cam portion 28 for converting the rotational motion of the locking motor 27a into a linear motion in the axial direction, and a torque limiter portion 29 configured to receive the reaction force of the torque acting on the locking gear 26 to prohibit the rotation of the locking gear 26 and permit the rotation of the locking gear 26 when a torque equal to or greater than a predetermined upper limit torque acts on the locking gear 26, and a housing portion 30 for housing the locking gear 26.

[0028] The locking motor 27a can be configured by a DC motor that generates torque when a DC current is supplied from a battery (not shown), and is attached to the side surface 31a of the cam housing 31 that houses the cam portion 28. The output shaft 32 of the locking motor 27a extends to the inside of the cam housing 31, and a worm gear 33 is integrally rotatably attached to the tip thereof. The tip of this worm gear 33 is rotatably held by a partition wall portion 34 provided inside the cam housing 31.

[0029] A wheel gear 35 is provided below the cam housing 31 so as to be rotatable about an axis intersecting the rotation center axis of the worm gear 33, and the wheel gear 35 and the worm gear 33 are meshed with each other. That is, it constitutes a speed reduction mechanism that amplifies the torque output from the locking motor 27a and transmits it to the wheel gear 35, and reduces the rotational speed (or rotation angle) of the wheel gear 35 with respect to the rotational speed (or rotation angle) of the locking motor 27a. In addition, since the upper part of the cam housing 31 in Figs. 2 and 3 is configured to be abutted against an engine body (not shown) and sealed, in the example shown in Figs. 2 and 3, the upper part of the cam housing 31 is open.

[0030] On the side surface 31b of the cam housing 31 that faces the side surface 31a to which the locking motor 27a is attached, a through hole is formed. A cylindrical limiter housing 36 is attached to the side surface 31b such that its hollow portion communicates with the through hole.

[0031] Inside the limiter housing 36, a friction engagement portion 37 is provided. This friction engagement portion 37 is configured such that when the torque acting on the support shaft 38 exceeds the upper limit torque by applying a frictional force to the support shaft 38 that supports the locking gear 26, the support shaft 38 rotates relative to it. In other words, when the torque acting on the support shaft 38 is less than the upper limit torque, it is integrated with the support shaft 38 and configured to prohibit the rotation of the support shaft 38.

[0032] This friction engagement portion 37 can be configured, for example, by integrally forming an annular plate arranged at a predetermined interval along the axial direction of the support shaft 38 on the support shaft 38, integrally forming a support plate alternately arranged with the annular plate on the inner surface of the limiter housing 36, and bringing these plates into frictional contact to prohibit the rotation of the support shaft 38.

[0033] Further, the friction engagement portion 37 is configured to be integrally formed with the support shaft 38 and movable in the axial direction of the support shaft 38, and the friction engagement portion 37 and the wheel gear 35 are connected by a link bar 39. Specifically, one end of the link bar 39 is rotatably connected to a position radially displaced (eccentric position) from the rotation center axis of the wheel gear 35, and the other end is attached to the friction engagement portion 37. Therefore, in the example shown in FIG. 2, when the wheel gear 35 rotates counterclockwise, the friction engagement portion 37 is configured to move to the left side in FIG. 2. When the friction engagement portion 37 is configured to contact the plate member as described above, the distance between the plate members facing each other is formed to be equal to a predetermined movement amount of the support shaft 38, and by pressing the annular plate integrated with the support shaft 38, the frictional force between the annular plate and the support plate is configured to be a predetermined frictional force.

[0034] A housing portion 30 is connected to an end of the limiter housing 36 on the side opposite to the cam housing 31. This housing portion 30 is composed of a fixing portion 40 bolted to the engine body and a tip portion 41 formed such that a part of the locking gear 26 is exposed to the outside.

[0035] The fixing portion 40 is formed in a substantially rhombic shape, and through holes 42 into which bolts (not shown) are inserted are formed on both the upper and lower sides in FIGS. 2 and 3. Further, a hollow portion 43 communicating with the limiter housing 36 is formed in the fixing portion 40, and the locking gear 26 is housed in the hollow portion 43. That is, the inner diameter of the hollow portion 43 is formed to be larger than the outer diameter of the locking gear 26 and is formed to be able to house a part of the tip of the friction engagement portion 37.

[0036] The tip portion 41 is configured such that when the locking gear 26 moves in the axial direction, a part of the locking gear 26 is exposed to the outside. Specifically, the tip portion 41 is formed in a conical shape, and a notch portion 44 is formed in a part thereof. And a part of the flywheel gear 25 is inserted into the notch portion 44. That is, when the locking gear 26 moves in the axial direction, the flywheel gear 25 inserted into the notch portion 44 and the locking gear 26 are configured to mesh with each other.

[0037] When the above-described brake mechanism 24 is required to prohibit the rotation of the flywheel 5, the wheel gear 35 is rotated counterclockwise in FIG. 2. By rotating the wheel gear 35 in this way, the friction engagement portion 37 is pressed to the left side in FIG. 2 via the link bar 39, and the support shaft 38 integrally with the friction engagement portion 37 moves in the axial direction. As a result, when the locking gear 26 moves to the notch portion 44, the locking gear 26 and the flywheel gear 25 mesh with each other. Further, in the case where the torque limiter portion 29 is configured to prohibit the rotation of the support shaft 38 by bringing the plate members facing each other into contact as described above, when the locking gear 26 moves to the notch portion 44, the plate members come into contact with each other to generate a braking torque that counteracts the torque acting on the support shaft 38.

[0038] FIG. 4 is a diagram showing the positional relationship between the flywheel gear 25 and the locking gear 26, where (a) shows a state where the flywheel gear 25 and the locking gear 26 are meshed, (b) shows a state where the meshing between the flywheel gear 25 and the locking gear 26 is released, and (c) shows a state where the flywheel gear 25 and the locking gear 26 are in contact with each other in the axial direction.

[0039] As described above, by operating the locking motor 27a, the locking gear 26 moves in the axial direction, causing the flywheel gear 25 and the locking gear 26 to mesh with each other as shown in FIGS. 4(a) and 4(b), and the meshing to be released. On the other hand, when the locking gear 26 is moved to mesh with the flywheel gear 25 from a state where the flywheel gear 25 and the locking gear 26 are not meshed, if the phases of the flywheel gear 25 and the locking gear 26 match, the locking gear 26 contacts the side surface of the flywheel gear 25 as shown in FIG. 4(c). In such a case, as indicated by the arrow in FIG. 4(c), torque is applied to the flywheel 5, and the flywheel gear 25 and the locking gear 26 are rotated relative to each other to mesh the flywheel gear 25 and the locking gear 26 with each other.

[0040] Specifically, by outputting torque from the first motor 2, torque is applied to the flywheel 5 via the power split mechanism 7. As a result, the flywheel gear 25 and the locking gear 26 rotate relative to each other, enabling the flywheel gear 25 and the locking gear 26 to mesh with each other. When torque is output from the first motor 2 as described above, a part of the torque acts on the drive wheels 11. Therefore, in the direction of driving the vehicle Ve, that is, in the case of the drive range, it is the direction of causing the vehicle Ve to travel forward, and in the case of the reverse range, it is preferable to output torque in the direction of causing the vehicle Ve to travel backward. By determining the direction of the torque output from the first motor 2 in accordance with the driving range in this way, the flywheel gear 25 and the locking gear 26 can be meshed with each other, and at the same time, the vehicle Ve can be driven in the intended direction, and the control can be simplified.

[0041] In the hybrid vehicle according to the embodiment of the present invention, as described above, an electronic control unit (hereinafter referred to as ECU) 45 for controlling the locking motor 27a and the first motor 2 is provided. This ECU 45 is mainly composed of a microcomputer, similar to a conventional ECU. That is, signals are input to the ECU 45 from various sensors provided in the vehicle Ve, and based on these signals and arithmetic expressions and maps stored in advance, signals are output to the locking motor 27a and the first motor 2. Note that the ECU 45 corresponds to the "controller" in the embodiment of the present invention.

[0042] FIG. 5 is a block diagram functionally showing the configuration of the ECU 45. In the example shown in FIG. 5, the ECU 45 is configured to receive signals such as vehicle speed, required driving force, remaining charge amount (SOC) of a power storage device (not shown), temperature of the power storage device, and position of the locking gear 26. Similar to a conventional vehicle, the vehicle speed can be detected by a vehicle speed sensor, and the required driving force can be detected by an accelerator opening sensor or the like. The power storage device is a so-called hybrid battery electrically connected to the first motor 2 and the second motor 3, and the remaining charge amount can be detected based on the output voltage of the power storage device. Furthermore, the temperature of the power storage device can be detected by a thermistor or the like. Additionally, the position of the locking gear 26 may be detected based on the rotation angle of the locking motor 27a or the rotation angle of the wheel gear 35, or the movement amount of the locking gear 26 may be directly detected.

[0043] This ECU 45 is composed of a driving mode setting unit 46, a gear position determination unit 47, a locking motor control unit 48, and an MG1 torque control unit 49. The driving mode setting unit 46 is configured to set a driving mode based on vehicle speed, required driving force, SOC, temperature of the power storage device, etc. Specifically, for example, when the SOC is equal to or higher than a predetermined value and the temperature of the power storage device is lower than a predetermined temperature, it is configured to set either a single EV driving mode or a dual EV driving mode. Further, in such a case, when driving at a low vehicle speed and with a low required driving force, the single EV driving mode is set, and when driving at a high vehicle speed or with a high required driving force, the dual EV driving mode is set.

[0044] The gear position determination unit 47 determines the position of the locking gear 26, and is configured to determine the position of the locking gear 26 based on a sensor that detects data corresponding to the position of the locking gear 26 input to the ECU 45, for example, the rotation angle of the locking motor 27a or the wheel gear 35, or a signal that detects the movement amount of the locking gear 26. That is, it is configured to determine whether the position of the locking gear 26 is a locked position meshing with the flywheel gear 25 or an unlocked position where the meshing with the flywheel gear 25 is released.

[0045] The locking motor control unit 48 is configured to move the locking gear 26 to a position corresponding to the driving mode set by the driving mode setting unit 46. That is, when the dual EV driving mode is set by the driving mode setting unit 46 and it is determined by the gear position determination unit 47 that the position of the locking gear 26 is the unlocked position, it is configured to energize the locking motor 27a with electric power in the direction of moving the locking gear 26 to the locked position. Similarly, when a driving mode other than the dual EV driving mode is set by the driving mode setting unit 46 and it is determined by the gear position determination unit 47 that the position of the locking gear 26 is the locked position, it is configured to energize the locking motor 27a with electric power in the direction of moving the locking gear 26 to the unlocked position.

[0046] When the lock gear 26 contacts the flywheel gear 25 as described above, the MG1 torque control unit 49 is configured to output a signal for energizing the first motor 2 when the flywheel gear 25 and the lock gear 26 cannot mesh with each other.

[0047] FIG. 6 is a flowchart for explaining an example of the control executed by the ECU 45. First, it is determined whether or not a switch to the dual EV driving mode has been determined (step S1). This step S1 can be determined based on whether the driving mode set by the above-described driving mode setting unit 46 has switched from a driving mode other than the dual EV driving mode to the dual EV driving mode.

[0048] If it is affirmatively determined in step S1 because a switch to the dual EV driving mode has been determined, it is determined whether or not the position of the lock gear 26 is the locked position (step S2). This step S2 can be determined based on the position of the lock gear 26 determined by the above-described gear position determination unit 47.

[0049] If it is affirmatively determined in step S2 because the position of the lock gear 26 is the locked position, a request to stop the lock motor 27a and a request to stop driving the first motor 2 for meshing the lock gear 26 and the flywheel gear 25 are output (step S3), and this routine is temporarily terminated. That is, if the lock motor 27a has been energized by the routine executed immediately before, or if torque for meshing the lock gear 26 and the flywheel gear 25 has been output from the first motor 2, the energization of the lock motor 27a is stopped, or the energization of the first motor 2 is stopped.

[0050] On the contrary, when it is negatively determined in step S2 because the position of the locking gear 26 is not the locking position, a request to drive the locking motor 27a (locking side) is output (step S4). That is, in the example shown in FIGS. 2 and 3, energization is started so that the locking motor 27a outputs torque in the direction of rotating the wheel gear 35 counterclockwise.

[0051] Next, it is determined whether or not the period during which the position of the locking gear 26 is not the locking position continues for a predetermined period or more (step S5). This step S5 is a step for determining whether or not the locking gear 26 can move to the locking position due to contact between the side surface of the flywheel gear 25 and the locking gear 26. Therefore, in step S5, the time required for the locking gear 26 to reach the locking position after starting to energize the locking motor 27a is determined in advance in consideration of the sliding resistance of the brake mechanism 24 and the like, and it is determined whether or not the counted time since starting to execute step S4 exceeds the above time.

[0052] When it is affirmatively determined in step S5 because the period during which the position of the locking gear 26 is not the locking position continues for a predetermined period or more, it is assumed that the locking gear 26 is in contact with the side surface of the flywheel gear 25. Therefore, as described above, the MG1 torque control unit 49 outputs a request to drive the first motor 2 (step S6), and this routine is temporarily terminated. On the contrary, when it is negatively determined in step S5 because the period during which the position of the locking gear 26 is not the locking position is less than the predetermined period, this routine is temporarily terminated as it is.

[0053] On the other hand, when determining the switch to another driving mode from the dual EV driving mode or the like, and it is negatively determined in step S1 because the switch to the dual EV driving mode has not been determined, it is determined whether or not the position of the locking gear 26 is the locking position (step S7). This step S7 can be determined in the same manner as step S2.

[0054] When it is positively determined in step S7 that the position of the locking gear 26 is the locked position, a request (release side) to drive the locking motor 27a is output (step S8), and this routine is temporarily terminated. That is, in the example shown in FIGS. 2 and 3, energization is started so that torque in the direction of rotating the wheel gear 35 clockwise is output from the locking motor 27a.

[0055] On the contrary, when it is negatively determined in step S7 that the position of the locking gear 26 is not the locked position, a request to stop the locking motor 27a is output (step S9), and this routine is temporarily terminated.

[0056] FIG. 7 shows a time chart for explaining changes in the torque of the locking motor 27a, the position of the locking gear 26, the torque of the first motor 2, etc. when the flowchart shown in FIG. 6 is executed when switching to the dual EV driving mode.

[0057] In the example shown in FIG. 7, since a driving mode other than the dual EV driving mode is set at time t0, the position of the locking gear 26 is at the released position. It is determined at time t1 to switch to the dual EV driving mode. At time t1, since the position of the locking gear 26 is the released position, it is negatively determined in step S2 in FIG. 6. Therefore, a drive request for the locking motor 27a is output. That is, the drive request flag of the locking motor 27a is switched on, and as a result, the torque of the locking motor 27a gradually increases.

[0058] When the locking motor 27a is driven, the locking gear 26 starts to move toward the locking position, and the counting during the period when it is not in the locking position is started. At time t1, since the count is less than the threshold value (predetermined period), a negative determination is made in step S5 in FIG. 6. Therefore, at time t1, the flag (MG1 drive request flag) indicating the drive request for the first motor 2 for meshing the locking gear 26 and the flywheel gear 25 is off, and here, the first motor 2 is stopped. If there is a request to drive the first motor 2 due to other control or the like, torque corresponding to the request may be output from the first motor 2.

[0059] FIG. 7 shows an example in which the locking gear 26 cannot be moved to the locking position due to the contact between the flywheel gear 25 and the locking gear 26. Therefore, in FIG. 7, at time t2, due to the contact between the flywheel gear 25 and the locking gear 26, after time t2, the position of the locking gear 26 is maintained at a predetermined position.

[0060] When a predetermined period elapses during which the locking gear 26 cannot move to the locking position without the contact state between the flywheel gear 25 and the locking gear 26 being resolved (time t3), an affirmative determination is made in step S5 in FIG. 6. Therefore, at time t3, the MG1 drive request flag is switched on, and torque is being output from the first motor 2. As a result, at time t4, as the flywheel 5 rotates, the phases of the flywheel gear 25 and the locking gear 26 are shifted, and the locking gear 26 starts to move further toward the locking side. In the example shown in FIG. 7, torque in the direction of rotating the first motor 2 in the direction opposite to the engine 1 (that is, drive torque in the direction of moving the vehicle Ve forward) is being output.

[0061] When the locking gear 26 moves to the locked position (at time t5), the drive request flag of the locking motor 27a is switched off. Therefore, the energization of the locking motor 27a is stopped, and the torque of the locking motor 27a decreases to 0 torque. Similarly, when the MG1 drive request flag is switched off, the torque of the first motor 2 is controlled to 0 torque.

[0062] Fig. 8 shows a time chart for explaining changes in the torque of the locking motor 27a, the position of the locking gear 26, etc. when the flowchart shown in Fig. 6 is executed when switching from the dual EV driving mode to another driving mode.

[0063] In the example shown in Fig. 8, since the dual EV driving mode is set at time t10, the position of the locking gear 26 is at the locked position. When a driving mode other than the dual EV driving mode is selected at time t11, step S8 in Fig. 6 is executed. Therefore, a drive request for the locking motor 27a is output. That is, the drive request flag of the locking motor 27a is switched on, and as a result, the torque of the locking motor 27a gradually increases.

[0064] When the locking motor 27a drives, the locking gear 26 starts to move toward the released position, and at time t12, the locking gear 26 reaches the released position. Therefore, at time t12, the energization of the locking motor 27a is stopped, and the torque of the locking motor 27a decreases to 0 torque.

[0065] By configuring the locking gear 26 to be switched between the locked position and the released position as described above, it is possible to suppress the occurrence of power losses such as rotating the locking gear 26 during driving in a driving mode with the locking gear 26 switched to the released position, specifically, during driving in the HV driving mode or the single EV driving mode.

[0066] In addition, external teeth 25 are formed on the flywheel 5 having a relatively large outer diameter, and a locking gear 26 is meshed with the external teeth 25 to limit the rotation of the flywheel 5, so that the load acting on the locking gear 26 can be reduced. Therefore, the locking gear 26 can be miniaturized.

[0067] Furthermore, by configuring the locking gear 26 to be movable in the axial direction parallel to the rotation center axis of the flywheel 5, an actuator 27 for moving the locking gear 26 can be attached to the outer surface of the engine 1, and the mountability of the actuator 27 can be improved.

[0068] Note that the actuator in the embodiment of the present invention is not limited to the above-described locking motor 27a, and for example, an actuator using a solenoid may be used. An example of a brake mechanism 24 using a solenoid is schematically shown in FIG. 9. The brake mechanism 24 shown in FIG. 9 is provided with a locking gear 50 that is movable between a locked position meshing with the flywheel gear 25 and a released position where the meshing is released, similarly to the brake mechanism 24 shown in FIG. 2.

[0069] This locking gear 50 is formed in a cylindrical shape, and spline teeth are formed on its inner surface. A support shaft 51 is inserted into the locking gear 50. This support shaft 51 is connected to a fixing member 52 such as a case, and spline teeth are formed at its tip. That is, the locking gear 50 and the support shaft 51 are spline-engaged.

[0070] A fork 53 is connected so as to press the locking gear 50 in the axial direction. That is, an annular groove is formed on the outer peripheral surface of the locking gear 50, and one end of the fork 53 is configured to engage with the groove.

[0071] This fork 53 extends in a direction intersecting the central axis of the support shaft 51, and its central portion is rotatably held by the fixing member 52. A plunger 54 made of a magnetic material is attached to the other end of the fork 53. That is, when the plunger 54 moves back and forth, the fork 53 rotates, and accordingly, the locking gear 50 is configured to move back and forth.

[0072] This plunger 54 is disposed to penetrate the solenoid 27b that functions as the actuator 27 and is provided so as to be movable in the axial direction. That is, by energizing the solenoid 27b, the plunger 54 is configured to press the other end of the fork 53 to one side. Further, a reaction force mechanism (not shown) such as a return spring is provided to apply a load to the plunger 54 in a direction opposite to the electromagnetic force acting on the plunger 54 when the solenoid 27b is energized.

[0073] When the solenoid 27b is not energized, in the brake mechanism 24 configured as described above, the plunger 54 receives a load from the reaction force mechanism, so that the plunger 54 moves to the left as shown in FIG. 9(a). Accordingly, the locking gear 50 moves in a direction away from the flywheel gear 25 (that is, toward the release position side). On the other hand, when the solenoid 27b is energized, an electromagnetic force corresponding to the electric power acts on the plunger 54. Therefore, when an electromagnetic force greater than the load received by the plunger 54 from the reaction force mechanism acts on the plunger 54, the plunger 54 moves to the right as shown in FIG. 9(b). Accordingly, the locking gear 50 meshes with the flywheel gear 25. That is, the locking gear 50 moves to the locking position.

[0074] In the state where the locking gear 50 and the flywheel gear 25 are engaged as described above, the vehicle Ve can be driven by outputting driving torque from the first motor 2. On the other hand, if the solenoid 27b is continuously energized to maintain the state where the locking gear 50 and the flywheel gear 25 are engaged, the power consumption of the vehicle Ve increases. Therefore, when driving torque is output from the first motor 2 in the forward driving direction of the vehicle Ve and that torque acts on the flywheel 5, the meshing state between the locking gear 50 and the flywheel gear 25 can be maintained without energizing the solenoid 27b.

[0075] Specifically, the spline teeth of the locking gear 50 and the support shaft 51 are each formed by being twisted at a predetermined angle with respect to the axial direction of the support shaft 51. That is, as shown in Fig. 10(a), when torque acts on the flywheel 5 and the spline teeth of the locking gear 50 and the support shaft 51 come into contact, the axial component of the reaction force load received by the spline teeth formed on the locking gear 50 from the spline teeth formed on the support shaft 51 among the reaction force loads acting on the locking gear 50 is configured to be in the direction (the left side in Fig. 10) of maintaining the meshing state between the locking gear 50 and the flywheel gear 25. Therefore, the locking gear 50 can be maintained in the locked position without energizing the solenoid 27b.

[0076] Also, when torque is output from the engine 1, as shown in Fig. 10(b), a torque in the direction opposite to the direction of the torque acting on the flywheel 5 in the dual EV driving mode acts on the flywheel 5. Therefore, when switching from the dual EV driving mode to the HV driving mode, the engine 1 can be driven without waiting for the meshing between the locking gear 50 and the flywheel gear 25 to be released. That is, the switch from the dual driving mode to the HV driving mode can be performed quickly.

[0077] In the example shown in FIG. 10, although the meshing state between the locking gear 50 and the flywheel gear 25 is configured to be maintained by the torque acting on the locking gear 50, other holding mechanisms or the like may be provided to maintain the meshing between the locking gear 50 and the flywheel gear 25.

[0078] The power split mechanism in the embodiment of the present invention is not limited to being configured by the single pinion type planetary gear mechanism shown in FIG. 1, and may be other differential mechanisms such as a double pinion type planetary gear mechanism, or may be configured by a compound planetary gear mechanism in which a plurality of planetary gear mechanisms are connected, that is, a differential mechanism having four or more rotating elements that differentially rotate. Further, the second motor 3 is not limited to being connected to the drive wheel 11 to which torque is transmitted from the engine 1 or the first motor 2, and may be connected to other drive wheels.

Explanation of Reference Numerals

[0079] 1 Engine 2, 3 Motors 4, 23, 32 Output shafts 5 Flywheel 7 Power split mechanism 8 Input shaft 11 Drive wheel 12 Sun gear 13, 21 Ring gears 14 Pinion gear 15 Carrier 24 Brake mechanism 25 Flywheel gear (external teeth) 26, 50 Locking gears 27 Actuator 27a Locking motor 27b Solenoid 29 Torque limiter section 45 Electronic control unit (ECU) Ve Vehicle

Claims

Hybrid vehicle comprising an engine, a flywheel connected to the output shaft of the engine, a motor, at least three rotating elements including a first rotating element connected to the output shaft of the flywheel, a second rotating element connected to the motor, and a third rotating element connected to a drive wheel, and a power split mechanism in which the at least three rotating elements rotate differentially, wherein the flywheel has external teeth, a locking gear that is movably provided between a locking position where it meshes with the external teeth and a release position where the engagement with the external teeth is released, and that applies a braking torque against the torque of the external teeth by engaging with the external teeth, further comprising an actuator for switching the locking gear between the locking position and the release position, configured to be able to set at least two driving modes, namely a first driving mode in which the locking gear is moved to the locking position to engage with the external teeth and the motor outputs a driving torque to drive, and a second driving mode in which the locking gear is moved to the release position to release the engagement with the external teeth and driving is performed, and further, comprising a controller for controlling the motor, wherein the controller, if the locking gear does not move to the locking position within a predetermined period after starting to move from the release position to the locking position, outputs torque from the motor to rotate the flywheel Hybrid vehicle characterized by the above. Claim 2 The hybrid vehicle according to claim 1, wherein the locking gear is configured to move between the locking position and the release position along an axis parallel to the rotation center axis of the flywheel Hybrid vehicle characterized by the above. Claim 3 The hybrid vehicle according to claim 1, further comprising a torque limiter that prohibits rotation of the locking gear when the torque acting on the locking gear is less than a predetermined upper limit torque, and permits rotation of the locking gear when the torque acting on the locking gear is greater than or equal to the upper limit torque Hybrid vehicle characterized by the above. Claim 4 The hybrid vehicle according to claim 1, further comprising another motor that is torque-transmittably connected to the drive wheel or another drive wheel, wherein the first driving mode includes a mode in which torque is output from the motor and the other motor to drive A hybrid vehicle characterized by

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