Hybrid vehicle control device

Abstract

To provide a hybrid vehicle control device capable of appropriately suppressing occurrence of vibrations and resonances during traveling on a rough road or a corrugated road so as to improve traveling performance and power performance.SOLUTION: A hybrid vehicle control device comprises: a driving power source which has an engine, a first motor, and a second motor; and a power transmission unit which is constituted of a first planetary gear mechanism and a second planetary gear mechanism, transmits torque through a drive system between the engine and the first motor and driving wheels, and has a first clutch and a second clutch for switching a transmission state of the torque. When excess input is applied to the drive system, the hybrid vehicle control device sets a disconnection mode of disconnecting the engine and the first motor from the drive system, and executes engine rotational speed control of causing the engine to operate so as to maintain an engine rotational speed higher than an idling rotational speed (step S5).SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a control device for a hybrid vehicle equipped with an engine (internal combustion engine) and a motor as driving power sources. [Background technology]

[0002] Patent Document 1 describes a lock-up clutch control device for an automatic transmission that aims to reduce vibrations that occur in the vehicle body when the vehicle is traveling on rough roads. The lock-up clutch control device for an automatic transmission described in Patent Document 1 controls an automatic transmission equipped with a lock-up clutch that can be switched between an engaged state and a disengaged state. If the control device described in Patent Document 1 determines that the road surface on which the vehicle is traveling is rough, it forcibly disengages the lock-up clutch (releases).

[0003] Furthermore, Patent Document 2 describes a hybrid vehicle drive system that aims to diversify driving modes. The hybrid vehicle drive system described in Patent Document 2 includes a power split mechanism (first planetary gear mechanism) that performs differential action using a first carrier to which power output from the engine is input, a first sun gear connected to a first motor, and a first ring gear, and a second planetary gear mechanism that performs differential action using a second carrier connected to the first ring gear, a second ring gear connected to an output gear, and a second sun gear. The system also includes a first clutch mechanism that selectively connects either the first carrier or the first sun gear to the second sun gear, and a second clutch mechanism that selectively connects any two elements of the second planetary gear mechanism (e.g., the second sun gear and the second ring gear) to integrate the second planetary gear mechanism. The hybrid vehicle drive device described in Patent Document 2 is configured to be able to output driving torque (driving torque) from all power sources: the engine, the first motor, and the second motor connected to the output gear.

[0004] Patent Document 3 describes a hybrid vehicle drive system that aims to reduce vibration when resonance occurs in the drive system. Like the hybrid vehicle drive system described in Patent Document 2, the hybrid vehicle drive system described in Patent Document 3 includes a power split device and a transmission, both of which are configured using planetary gear mechanisms. The power split device is connected to output shafts of an engine, a first motor, and a second motor. The transmission is provided between the engine and the power distribution device, and changes the speed of the engine rotation and outputs it to the power distribution device. The system also includes an engagement device (clutch, brake) that enables the engine to be disconnected from the power distribution device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-298145 [Patent Document 2] Patent No. 6451524 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-94153 Summary of the Invention [Problem to be solved by the invention]

[0006] When a vehicle travels on rough roads, unpaved roads, or undulating roads with continuous unevenness, rotational fluctuations in the drive wheels can cause torsional resonance in the vibration system of the drivetrain from the drive power source to the drive wheels. When such resonance occurs, conventional techniques for suppressing resonance and vibration are known, such as by disengaging a torque converter lockup clutch (as described in Patent Document 1) or an engagement device (as described in Patent Document 3) to disconnect the engine from the drivetrain. In particular, the hybrid vehicle drivetrain described in Patent Document 3 detects resonance in the drivetrain and, if the vehicle speed falls below a predetermined value, stops the engine and disengages the clutch after the engine stops. If the vehicle speed exceeds the predetermined value, the clutch is disengaged while the engine is operating autonomously (idling). By using such control, the hybrid vehicle drivetrain described in Patent Document 3 is said to be able to suppress resonance in the drivetrain while preventing overrotation of the pinion of the planetary gear mechanism.

[0007] However, the hybrid vehicle drive system and the conventional technology described in Patent Document 3 do not specifically consider a situation in which the clutch is disengaged to suppress resonance and vibration, and then re-engaged to drive the hybrid vehicle. As a result, sufficient clutch engagement responsiveness may not be achieved when the clutch is re-engaged. When a hybrid vehicle travels on rough roads, uneven roads, or the like, the clutch is disengaged to suppress vibration and resonance as described above, but the requirements for driving force and driving force responsiveness are also high to ensure the vehicle's ability to travel on rough roads, uneven roads, or the like. However, the hybrid vehicle drive system and the conventional technology described in Patent Document 3 may not provide sufficient responsiveness when the clutch is re-engaged, as described above. Ultimately, this may result in a decrease in the hybrid vehicle's rough road performance and power performance.

[0008] This invention was devised with a focus on the above-mentioned technical problems, and aims to provide a control device for a hybrid vehicle that can appropriately suppress the occurrence of vibrations and resonance when traveling on rough or undulating roads, and can improve rough road driving performance and power performance. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a control device for a hybrid vehicle that includes a driving force source having an engine, a first motor, and a second motor, and a power transmission unit that is constituted by a first planetary gear mechanism and a second planetary gear mechanism, and that transmits torque in a drive system between the engine and the first motor and drive wheels, and has at least two engagement mechanisms of a first clutch and a second clutch that operate to an engaged state or a disengaged state, respectively, to switch the torque transmission state, and that is capable of running in at least three modes selectively set to a first mode in which the first clutch is engaged and the second clutch is disengaged, a second mode in which the first clutch is disengaged and the second clutch is engaged, and a disengagement mode in which both the first clutch and the second clutch are disengaged. a sensor for detecting vibration or load in the drive train; a controller for controlling the driving force source, the first clutch, and the second clutch, La and The controller comprises: Based on the vibration or the load detected by the sensor, When an excessive input occurs in the drive system, causing large vibrations or loads exceeding a predetermined threshold value, If there is an excessive input, In this case, the disconnection mode is set to disconnect the engine and the first motor from the drive train, and Continue to run Transfer Or start it, The engine speed control is performed to maintain the engine speed higher than the idling speed.

[0010] Also, this invention In the previousThe first planetary gear mechanism has three rotation elements: a first input element connected to the engine, a first reaction element connected to the first motor, and a first output element. The second planetary gear mechanism has a second input element connected to the first output element, and a second reaction element connected to an output member that transmits the torque to the drive wheels. and used as the output element of the power transmission section. a second output element, and a second reaction element; the first clutch selectively connects the first input element and the second reaction element; the second clutch selectively connects any two of the rotation elements in the second planetary gear mechanism; and the first mode is By making the first motor function as a generator with the first clutch engaged and the second clutch released, Please enter the second item The engine is connected via the first clutch. The rotation speed of the second output element is reduced relative to the rotation speed of the Possible low The second mode is a speed mode. By making the first motor function as a generator with the second clutch engaged and the first clutch released, Please enter the second item The engine is connected to the engine via the first planetary gear mechanism. The rotation speed of the second output element relative to the rotation speed High speed that can be Gear mode It may be.

[0011] Also, this invention In the above, the first clutch has engaging elements that transmit torque by engaging with each other, The controller Before by La Engine speed control The control is to control the engine speed, To the first clutch In the above-mentioned Synchronize the rotation speed of the coupling elements The control may be such that

[0012] In addition, the controller in the present invention controls the rotation speed of the first motor in addition to the engine rotation speed control. to the front The rotational speeds of the engaging elements are synchronized. Motor speed control is performed to control the speed to match the It may be configured as follows.

[0013] Furthermore, the hybrid vehicle of the present invention can be run by further setting a fixed gear mode in which both the first clutch and the second clutch are engaged, and the controller of the present invention may be configured to first transition to the high gear mode and then set the disconnection mode if the excessive input occurs while the fixed gear mode is set.

[0014] Furthermore, the controller in the present invention may be configured to continue the high-speed gear mode without transitioning to the disconnection mode if the vibration or the load falls below a predetermined allowable value when transitioning to the high-speed gear mode due to the excessive input.

[0015] The hybrid vehicle of the present invention is ,before The first motor and the power transmission unit are disposed adjacent to each other on the same rotation axis, and are assembled in a case in this order: the first motor, the power transmission unit; the rotation shaft of the first motor is supported by a bearing disposed at least between the first motor and the power transmission unit in the direction of the rotation axis; and the sensor is installed on the first motor side of the bearing in the direction of the rotation axis. But still stomach. [Effects of the Invention]

[0016] The hybrid vehicle controlled by this invention can be set to multiple modes by controlling the operation of multiple engagement mechanisms provided in the power transmission unit. Among the multiple modes, an appropriate mode is selected and set according to the driving state of the hybrid vehicle. For example, the hybrid vehicle can be set to an appropriate mode according to the driver's request, such as driving that prioritizes fuel efficiency or driving performance. The multiple modes can include at least three modes: a first mode, a second mode, and a disconnection mode. The first mode and the second mode differ in the torque transmission state in the power transmission unit. For example, the first mode is a low-speed mode in which the output rotation speed of the power transmission unit is reduced relative to the input rotation speed. The second mode is a high-speed mode in which the output rotation speed of the power transmission unit is increased relative to the input rotation speed. The disconnection mode enables so-called EV driving, in which the engine and the first motor are disconnected from the driveline and the hybrid vehicle is driven by the output of the second motor. During such EV driving, by setting the disconnection mode and disconnecting the engine and the first motor from the drivetrain, it is possible to reduce inertial resistance and drag loss and improve energy efficiency during EV driving.

[0017] The disconnection mode is also selected, for example, when the hybrid vehicle is traveling on a rough road or an uneven road. By disconnecting the engine and the first motor from the driveline in response to large vibrations or loads (excessive inputs) input from the road surface to the driveline of the hybrid vehicle, vibrations and resonance in the driveline can be suppressed. Meanwhile, when a hybrid vehicle travels on such rough roads or uneven roads, the requirements for the hybrid vehicle's driving force and the responsiveness of that driving force are high to ensure off-road performance. In contrast, conventional control stops the engine in the disconnection mode. Alternatively, the engine is controlled to an idling state. Therefore, when the disconnection mode is ended and the engagement mechanism is re-engaged to accelerate, there is a possibility that sufficient driving force cannot be obtained. Therefore, in the hybrid vehicle control device of the present invention, when the disconnection mode is set in response to an excessive input from the outside, the engine is operated without being stopped (or, if the engine was stopped during EV driving, the engine is started), and engine speed control is performed. By controlling the engine speed, the engine speed is maintained at a higher speed than the idling speed. Therefore, when the disengagement mode is ended and the engagement mechanism is re-engaged to accelerate, the synchronization of the engagement mechanism can be accelerated. This allows the engine output to generate driving force with good responsiveness.

[0018] Furthermore, in the hybrid vehicle control device of the present invention, the rotational speeds of the engaging elements of the first clutch that are engaged with each other are synchronized by controlling the engine speed in the disconnection mode as described above. The first clutch is an engagement mechanism that is engaged when the low-speed mode is set as the first mode, and by synchronizing the engaging elements of the first clutch during the disconnection mode, the first clutch can be placed in a state where it can be immediately engaged and ready to immediately switch to the low-speed mode. Therefore, when the disconnection mode is ended and the vehicle is accelerated, the first clutch can be immediately engaged to switch to the low-speed mode, and a large driving force can be generated with good responsiveness using the engine output torque amplified in the low-speed mode.

[0019] Furthermore, in the hybrid vehicle control device of the present invention, in addition to the engine speed control in the disconnection mode as described above, motor speed control is also performed to control the speed of the first motor. By performing motor speed control with good controllability together with engine speed control, the speeds of the engaging elements of the first clutch that are engaged with each other are synchronized. Therefore, the first clutch can be synchronized more quickly and appropriately.

[0020] Furthermore, the hybrid vehicle controlled by this invention can further set a fixed-speed mode (or direct-coupled mode) in addition to the first mode (low-speed mode), second mode (high-speed mode), and decoupled mode. The fixed-speed mode is set by engaging both the first clutch and the second clutch. By engaging both the first clutch and the second clutch, the first planetary gear mechanism and the second planetary gear mechanism rotate together (without differential rotation), resulting in a so-called direct-coupled state between the engine and the output member. Therefore, in the fixed-speed mode, driving force is generated using the output torque of both the engine and the first motor, making it possible to generate the largest driving force possible for a hybrid vehicle. Furthermore, in the fixed-speed mode, relative rotation between the rotating elements of the first planetary gear mechanism and the second planetary gear mechanism does not occur, thereby suppressing energy loss and improving energy efficiency.

[0021] If an excessive input is applied to the hybrid vehicle while the fixed gear mode is set as described above, the hybrid vehicle control device of the present invention first disengages the first clutch and sets the second mode (high-speed gear mode). Then, after transitioning to the high-speed gear mode, the second clutch is disengaged and the disconnection mode is set. In this way, when switching from the fixed gear mode to the disconnection mode, transitioning to the disconnection mode via the high-speed gear mode makes it possible to suppress the load (generation or amplification of vibration) input from outside during the mode transition compared to transitioning via the low-speed gear mode.

[0022] Furthermore, in the hybrid vehicle control device of the present invention, if the excessive input falls below the allowable value while the high-speed gear mode is set during the transition from the fixed gear mode to the disconnection mode as described above, the high-speed gear mode is continued without transitioning to the disconnection mode. In such a case, the reduction in the excessive input prevents the occurrence of harmful vibrations and resonance. Furthermore, by continuing the high-speed gear mode without transitioning to the disconnection mode, subsequent requests for acceleration and large driving force can be responded to with good responsiveness.

[0023] The hybrid vehicle of the present invention is equipped with a sensor that detects vibrations or loads in the driveline to determine whether the driveline has experienced an excessive input. The sensor may be, for example, a torque sensor, and the control device for the hybrid vehicle of the present invention determines whether the excessive input has occurred based on the detection results of the sensor. Therefore, engine speed control and motor speed control in the disconnection mode can be performed accurately and appropriately based on data directly detected by the torque sensor or other sensor.

[0024] The sensor described above is installed between the first motor and the power transmission unit in the direction of the rotation axis within a case in which the first motor and the power transmission unit are assembled. The first motor is assembled to the case first, followed by the power transmission unit. The sensor, including electrical wiring, can be installed while the first motor is assembled to the case, before the power transmission unit, which has a complex structure, is assembled. This makes it easy to assemble the sensor. This ultimately improves the ease of assembly of the hybrid vehicle controlled by this invention.

[0025] Therefore, the hybrid vehicle control device of the present invention can appropriately suppress the occurrence of vibrations and resonance when the hybrid vehicle travels on rough or uneven roads, and can improve the rough road driving performance and power performance of the hybrid vehicle. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram for explaining a hybrid vehicle that is an object of control in the present invention, showing an example of the configuration and control system of the hybrid vehicle. [Figure 2] FIG. 10 is a diagram showing another example of a hybrid vehicle to be controlled by the present invention (an example in which a torque sensor is installed between a one-way clutch and a power transmission unit in a drive train). [Figure 3] FIG. 10 is a diagram showing another example of a hybrid vehicle to be controlled by the present invention (an example in which a torque sensor is installed midway through a reduction gear mechanism in a drive train). [Figure 4] FIG. 1 is a nomographic diagram for explaining the operating states of the engine (ENG) and the first motor (MG1), and the engaged and released states of the first clutch (Lo-Clutch) and the second clutch (Hi-Clutch) when the "low-speed mode" is set, showing the rotational states of each rotating element (S, C, R) of the first planetary gear mechanism and each rotating element (S', C', R') of the second planetary gear mechanism. [Figure 5] FIG. 1 is a nomographic diagram illustrating the operating states of the engine (ENG) and the first motor (MG1), and the engaged and disengaged states of the first clutch (Lo-Clutch) and the second clutch (Hi-Clutch) when the "high-speed mode" is set, showing the rotational states of the rotating elements (S, C, R) of the first planetary gear mechanism and the rotating elements (S', C', R') of the second planetary gear mechanism. [Figure 6] This is a nomographic diagram for explaining the operating states of the engine (ENG) and the first motor (MG1), and the engaged and released states of the first clutch (Lo-Clutch) and the second clutch (Hi-Clutch) when the "disconnection mode" is set, showing the rotational states of each rotating element (S, C, R) of the first planetary gear mechanism and each rotating element (S', C', R') of the second planetary gear mechanism (state when engine speed control and motor speed control are not being executed). [Figure 7]FIG. 10 is a diagram showing an image of the operation of sequentially switching between "low-speed mode," "high-speed mode," "fixed-speed mode," and "disconnection mode." [Figure 8] FIG. 1 is a diagram showing an image of a transmission mechanism (switching mechanism) configured using a shift drum. [Figure 9] 4 is a flowchart for explaining an example of control (control for maintaining a predetermined engine speed by performing engine speed control) executed by the control device for a hybrid vehicle of the present invention. [Figure 10] 10 is a flowchart for explaining another example of control executed by the control device for a hybrid vehicle of the present invention (control for synchronizing the first clutch by executing motor rotation speed control together with engine rotation speed control). [Figure 11] This is a nomographic diagram for explaining the operating states of the engine (ENG) and the first motor (MG1), and the engaged and released states of the first clutch (Lo-Clutch) and the second clutch (Hi-Clutch) when the "disconnection mode" is set, showing the rotational states of the rotating elements (S, C, R) of the first planetary gear mechanism and the rotating elements (S', C', R') of the second planetary gear mechanism (the state in which the first clutch is synchronized by executing engine speed control and motor speed control). [Figure 12] 10 is a flowchart for explaining another example of control executed by the control device for a hybrid vehicle of the present invention (control that takes into consideration the load and vibration that occur during transition to the "disconnection mode"). DETAILED DESCRIPTION OF THE INVENTION

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following embodiments are merely examples of specific embodiments of the present invention and are not intended to limit the scope of the present invention.

[0028] The vehicle to be controlled in the embodiment of the present invention is a hybrid vehicle that uses an engine (internal combustion engine) and a motor as a driving force source. The hybrid vehicle to be controlled in the embodiment of the present invention also includes a power transmission unit that transmits torque between the driving force source and the drive wheels. The power transmission unit is provided with engagement mechanisms including at least two clutches, and is configured to switch the torque transmission state by operating each engagement mechanism to an engaged or disengaged state. Figure 1 shows an example of a drive unit (drive system and control system) of a hybrid vehicle to be controlled in the embodiment of the present invention.

[0029] The hybrid vehicle Ve shown in Fig. 1 includes an engine (ENG) 1, a first motor (MG1) 2, and a second motor (MG2) 3 as driving force sources. The hybrid vehicle Ve also includes a power transmission unit 5 that transmits torque between the engine 1 and the first motor 2 and drive wheels 4 and functions as a power split mechanism and a transmission mechanism, as well as a plurality of engagement mechanisms 6 that operate between an engaged state and a disengaged state to switch the torque transmission state in the power transmission unit 5. In the example shown in Fig. 1, the engagement mechanisms 6 include a first clutch 7 and a second clutch 8. The hybrid vehicle Ve also includes a detection unit 9 that detects various data used for control, and a controller 10 that controls the driving force sources, the first clutch 7, and the second clutch 8, respectively.

[0030] The engine 1 is an internal combustion engine, such as a gasoline engine or a diesel engine, that burns fuel to obtain power (mechanical energy), and is configured to electrically control its operating state, such as adjusting its output and starting and stopping. In the case of a gasoline engine, the throttle valve opening, the amount of fuel supplied or injected, the ignition on / off, and the ignition timing are electrically controlled. In the case of a diesel engine, the fuel injection amount, fuel injection timing, or throttle valve opening (in an EGR system) are electrically controlled.

[0031] The first motor 2 converts electrical energy into mechanical energy (or rotational energy), or converts mechanical energy (or rotational energy) into electrical energy. The first motor 2 is disposed coaxially with the engine 1 and is connected to the engine 1 and drive wheels 4 via a power transmission unit 5 so that power can be transmitted. The first motor 2 also functions as a generator that generates electric power when driven by the torque output by the engine 1. That is, the first motor 2 is a motor with a power generating function (a so-called motor-generator) and is configured, for example, by a permanent magnet synchronous motor or an induction motor. A battery (not shown) is connected to the first motor 2 via an inverter (not shown). Therefore, the first motor 2 can function as a generator, and the generated electric power can be stored in the battery. Alternatively, the electric power stored in the battery can be supplied to the first motor 2, causing the first motor 2 to function as an electric motor and output drive torque.

[0032] The second motor 3 converts electrical energy into mechanical energy (or rotational energy), or converts mechanical energy (or rotational energy) into electrical energy. The second motor 3 is connected to the drive wheels 4 via a pinion 3b connected to the rotary shaft 3a and a reduction gear mechanism 16 (described later) so as to be capable of transmitting power. The second motor 3 functions at least as an electric motor that is driven by a supply of electric power and outputs torque. In the hybrid vehicle Ve according to the embodiment of the present invention, the second motor 3 also functions as a generator that generates electric power by receiving torque from an external source and being driven. That is, like the first motor 2, the second motor 3 is a motor with a power generating function (a so-called motor-generator) and is configured, for example, by a permanent magnet synchronous motor or an induction motor. A battery (not shown) is connected to the second motor 3 via an inverter (not shown). Therefore, electric power stored in the battery can be supplied to the second motor 3, causing the second motor 3 to function as an electric motor and output drive torque. In addition, the second motor 3 can function as a generator using torque transmitted from the drive wheels 4, and the regenerated power generated at that time can be stored in a battery. Furthermore, the first motor 2 and the second motor 3 are connected via an inverter so that they can exchange power with each other. Therefore, for example, it is possible to supply power generated by the first motor 2 directly to the second motor 3, and have the second motor 3 output drive torque.

[0033] The power transmission unit 5 transmits the output torque of the engine 1 and the output torque of the first motor 2 to the drive wheels 4. The power transmission unit 5 is disposed adjacent to the first motor 2 on the same rotational axis AL as the first motor 2 and the engine 1. In the example shown in FIG. 1 , the power transmission unit 5 is disposed to the right of the first motor 2 in the direction of the rotational axis AL. The power transmission unit 5 and the first motor 2 are housed and assembled inside a common "case" or "housing" (not shown). Therefore, the power transmission unit 5 and the first motor 2 are assembled into the "case" in the order of first motor 2, followed by the power transmission unit 5. The power transmission unit 5 is mainly composed of two "planetary gear mechanisms": a first planetary gear mechanism 11 that functions as a so-called "power split mechanism," and a second planetary gear mechanism 12 that functions as a "speed change mechanism" or "reduction mechanism."

[0034] The first planetary gear mechanism 11 has three rotating elements: a sun gear 11a, a ring gear 11b, and a carrier 11c. In the example shown in FIG. 1, the sun gear 11a constitutes a reaction element (corresponding to a first reaction element in the embodiments of the present invention) of the first planetary gear mechanism 11, and is connected to the first motor 2. The ring gear 11b constitutes an output element (corresponding to a first output element in the embodiments of the present invention) of the first planetary gear mechanism 11, and is connected to a "second input element" (sun gear 12a) of the second planetary gear mechanism 12, which will be described later. The carrier 11c constitutes an input element (corresponding to a first input element in the embodiments of the present invention) of the first planetary gear mechanism 11, and is connected to the engine 1.

[0035] The second planetary gear mechanism 12 has three rotating elements: a sun gear 12a, a ring gear 12b, and a carrier 12c. In the example shown in FIG. 1, the sun gear 12a constitutes the input element (corresponding to the second input element in the embodiment of the present invention) of the second planetary gear mechanism 12, and is connected to the "first output element" (ring gear 11b) of the first planetary gear mechanism 11. The ring gear 12b constitutes the output element (corresponding to the second output element in the embodiment of the present invention) of the second planetary gear mechanism 12, and an output gear 15 (described later) is formed on its outer periphery. The carrier 12c constitutes the reaction element (corresponding to the second reaction element in the embodiment of the present invention) of the second planetary gear mechanism 12, and is selectively connected to the engine 1 and the carrier 11c of the first planetary gear mechanism 11 or the ring gear 12b of the second planetary gear mechanism 12 by a first clutch 7 and a second clutch 8 (described later).

[0036] 1 shows an example in which the first planetary gear mechanism 11 and the second planetary gear mechanism 12 are both configured as single-pinion "planetary gear mechanisms," but the first planetary gear mechanism 11 and the second planetary gear mechanism 12 in the embodiments of the present invention may each be configured as double-pinion "planetary gear mechanisms." Alternatively, they may be "compound planetary gear mechanisms" such as Ravigneaux types, or "compound planetary gear mechanisms" that combine single-pinion and double-pinion types.

[0037] In the power transmission unit 5, the ring gear 11b of the first planetary gear mechanism 11 and the sun gear 12a of the second planetary gear mechanism 12 are connected to each other. The sun gear 11a of the first planetary gear mechanism 11 is connected to the rotating shaft 2a of the first motor 2. The carrier 11c of the first planetary gear mechanism 11 is connected to the output shaft 1a of the engine 1 via a torque limiter 13, a one-way clutch 14, and the like. The one-way clutch 14 is fixed to, for example, a housing (not shown) and is configured to engage and stop the rotation of the output shaft 1a when torque is applied in the reverse rotation direction (rotation in the direction opposite to the rotation direction of the engine 1). As described above, the one-way clutch 14 only needs to be configured to prevent the output shaft 1a of the engine 1 and the carrier 11c of the first planetary gear mechanism 11 from rotating in the negative rotation direction. Therefore, instead of the one-way clutch 14, a "brake" (not shown) that selectively stops the rotation of the output shaft 1a of the engine 1 and the carrier 11c may be used. The ring gear 12b of the second planetary gear mechanism 12 serves as an "output member" and has an externally toothed output gear 15 formed on its outer periphery. The output gear 15 is connected to the driving wheels 4 via a reduction gear mechanism 16, a differential gear 17, and a drive shaft 18. Therefore, the ring gear 12b of the second planetary gear mechanism 12 corresponds to the output element of the power transmission unit 5 in this embodiment of the present invention.

[0038] The first clutch 7 is selectively engaged to connect the carrier 11c of the first planetary gear mechanism 11 and the output shaft 1a of the engine 1 with the carrier 12c of the second planetary gear mechanism 12. The first clutch 7 is configured with a meshing engagement mechanism such as a dog clutch. Alternatively, the first clutch 7 may be a friction engagement mechanism such as a wet multi-plate clutch.

[0039] The second clutch 8 is selectively engaged to connect the ring gear 12b of the second planetary gear mechanism 12 to the carrier 12c of the second planetary gear mechanism 12. Connecting the ring gear 12b and the carrier 12c of the second planetary gear mechanism 12 by the second clutch 8 integrates all of the rotating elements of the second planetary gear mechanism 12. Similar to the first clutch 7, the second clutch 8 is configured with a mesh-type engagement mechanism such as a dog clutch. Alternatively, the second clutch 8 may be a friction-type engagement mechanism such as a wet multi-plate clutch.

[0040] The detection unit 9 is a device or apparatus for acquiring various data and information required to control the hybrid vehicle Ve, and includes, for example, a power supply unit, a microcomputer, sensors, an input / output interface, etc. The detection unit 9 detects various data for controlling the driving power sources (engine 1, first motor 2, second motor 3), the first clutch 7, and the second clutch 8. In particular, the detection unit 9 in this embodiment of the present invention has a torque sensor 9a.

[0041] The torque sensor 9a detects vibrations or loads in the drivetrain between the drive power source (engine 1, first motor 2, second motor 3) and the drive wheels 4. Specifically, the torque sensor 9a detects the torque of a predetermined "rotating member" in the drivetrain of the hybrid vehicle Ve. Various well-known "torque sensors" with various configurations can be used as the torque sensor 9a. For example, a contact-type "torque sensor" using a strain gauge or a non-contact-type "torque sensor" using electromagnetism can be used. In the example shown in FIG. 1 , the torque sensor 9a is installed inside a "case" that houses the first motor 2 and the power transmission unit 5, between the first motor 2 and the power transmission unit 5 in the direction of the rotation axis AL of the first motor 2 and the power transmission unit 5, and on the outer periphery of the rotating shaft 2a of the first motor 2. More specifically, the torque sensor 9a is installed on the first motor side (left side in FIG. 1 ) in the direction of the rotation axis AL of a bearing 19 disposed between the first motor 2 and the power transmission unit 5. The rotating shaft 2a of the first motor 2 is supported by the above-mentioned bearing 19 and bearing 20. The bearing 19 is disposed on the power transmission unit 5 side (right side in FIG. 1) in the direction of the rotation axis AL of the rotating shaft 2a. The bearing 20 is disposed on the opposite side of the bearing 19 in the direction of the rotation axis AL of the rotating shaft 2a (left side in FIG. 1).

[0042] As described above, the first motor 2 and the power transmission unit 5 are assembled into a common "case," with the first motor 2 first assembled and then the power transmission unit 5 assembled. Therefore, the torque sensor 9a, including electrical wiring, can be installed in advance while the first motor 2 is assembled into the "case," before the power transmission unit 5, which has a complex structure, is assembled. This makes it easy to assemble the torque sensor 9a.

[0043] In the hybrid vehicle Ve according to the embodiment of the present invention, the installation location of the torque sensor 9a is not limited to the example shown in FIG. 1. For example, as shown in FIG. 2, the torque sensor 9a may be installed between the one-way clutch 14 and the power transmission unit 5 in the drive system of the hybrid vehicle Ve. Alternatively, as shown in FIG. 3, the torque sensor 9a may be installed inside the reduction gear mechanism 16 in the drive system of the hybrid vehicle Ve. Alternatively, although not shown, the torque sensor 9a may be installed adjacent to the coil ends (not shown) of the first motor 2 or the second motor 3. Alternatively, the torque sensor 9a may be installed adjacent to the resolvers (not shown) of the first motor 2 or the second motor 3. By installing the torque sensor 9a in the drive system of the hybrid vehicle Ve, it is possible to detect torque and torque fluctuations in the drive system and accurately and easily determine whether or not large vibrations or loads (excessive inputs) are being input to the hybrid vehicle Ve from the road surface.

[0044] In addition to the torque sensor 9a described above, the detection unit 9 includes various sensors and devices, such as a vehicle speed sensor (or wheel speed sensor) 9b that detects the vehicle speed, an engine speed sensor 9c that detects the rotational speed of the engine 1, a motor rotational speed sensor (or resolver) 9d that detects the rotational speeds of the first motor 2 and the second motor 3, an oil pressure sensor 9e that detects the oil pressure (engagement oil pressure) supplied to an actuator (not shown) of the first clutch 7 and an actuator (not shown) of the second clutch 8, a stroke sensor 9f that detects the stroke positions of the first clutch 7 and the second clutch 8, and a clutch rotational speed sensor 9g that detects the rotational speeds of the "engagement elements" (not shown) of the first clutch 7 and the second clutch 8. The detection unit 9 is electrically connected to a controller 10 (described later) and outputs electrical signals corresponding to the detected or calculated values ​​of the various sensors, devices, and apparatuses described above to the controller 10 as detection data.

[0045] The controller 10 is an electronic control device mainly composed of, for example, a microcomputer, and in the example shown in FIG. 1 , it mainly controls the operation of the engine 1, the first motor 2, the second motor 3, the first clutch 7, and the second clutch 8. Various data detected or calculated by the detection unit 9 is input to the controller 10. The controller 10 performs calculations using the input data, pre-stored data, calculation formulas, and the like. The controller 10 then outputs the calculation results as control command signals, and is configured to control the operation of the engine 1, the first motor 2, the second motor 3, the first clutch 7, and the second clutch 8, as described above. Note that while FIG. 1 shows an example in which one controller 10 is provided, multiple controllers 10 may be provided for each device or equipment to be controlled or for each control content. For example, the controller 10 may be configured as being divided into a "hybrid controller" (not shown) that performs comprehensive calculations and judgments based on input signals from the detection unit 9, an "engine controller" (not shown) that controls the engine 1, "motor controllers" (not shown) that control the first motor 2 and the second motor 3, respectively, and "clutch controllers" (not shown) that control the first clutch 7 and the second clutch 8, respectively.

[0046] The configuration (gear train) of the hybrid vehicle Ve in the embodiment of the present invention is not limited to the example shown in Fig. 1 above. The coupling relationship between the respective rotating elements of the first planetary gear mechanism 11 and the second planetary gear mechanism 12 that constitute the power transmission unit 5 may be different. For example, the configuration of a hybrid vehicle as disclosed in "Fig. 1" of the aforementioned Patent Document 2 or the configuration of a hybrid vehicle as disclosed in "Fig. 1" of the aforementioned Patent Document 3 can also be subject to control in the embodiment of the present invention.

[0047] The hybrid vehicle Ve configured as described above can set a plurality of driving modes (torque transmission forms) by changing the torque transmission state in the power transmission unit 5 by the first clutch 7 and the second clutch 8. For example, the hybrid vehicle Ve can run in four modes selectively setting different torque transmission states in the power transmission unit 5: a "low-speed mode" (first mode) in which only the first clutch 7 is engaged, a "high-speed mode" (second mode) in which only the second clutch 8 is engaged, a "disconnected mode" in which both the first clutch 7 and the second clutch 8 are released, and a "fixed-speed mode" (or direct-coupled mode) in which both the first clutch 7 and the second clutch 8 are engaged.

[0048] The "low-speed mode" corresponds to the "first mode" in the embodiment of the present invention, and is set by engaging the first clutch 7 (Lo-Clutch) and disengaging the second clutch 8 (Hi-Clutch), as shown in FIG. 4. Engaging the first clutch 7 connects the carrier 11c (C) of the first planetary gear mechanism 11 and the carrier 12c (C') of the second planetary gear mechanism 12. In this "low-speed mode," the first motor 2 is rotated in the reverse rotation direction (the direction opposite to the rotation direction of the engine 1), and the output torque of the engine 1 is transmitted to the output gear 15 in a state where the rotation speed of the ring gear 12b (R') of the second planetary gear mechanism 12 is reduced relative to the rotation speed of the carrier 12c (C'). In other words, the power transmission unit 5 functions as a speed reduction mechanism, amplifying the output torque of the engine 1. In this case, the output torque is amplified by the first motor 2 outputting so-called negative torque in a direction that reduces its rotation speed, and therefore the first motor 2 functions as a generator. Note that even if the first motor 2 rotates in the same direction as the rotation direction of the engine 1 (positive direction), the power transmission unit 5 can function as a reducer or even as a speed increaser, in which case the first motor 2 functions as an electric motor that consumes power to rotate.

[0049] The "high-speed gear mode" corresponds to the "second mode" in the embodiment of the present invention, and is set by disengaging the first clutch 7 (Lo-Clutch) and engaging the second clutch 8 (Hi-Clutch), as shown in FIG. 5. Engaging the second clutch 8 connects the ring gear 12b (R') of the second planetary gear mechanism 12 to the carrier 12c (C') of the second planetary gear mechanism 12, causing the entire second planetary gear mechanism 12 to rotate integrally. In this "high-speed gear mode," the first motor 2 is rotated in the forward direction, increasing or decreasing the rotation speed of the engine 1, and the output torque of the engine 1 and the first motor 2 is transmitted to the output gear 15. In the example shown in Fig. 5, the first motor 2 functions as a generator, and the rotation speed of the sun gear 11a(S) connected to it is set to a lower rotation speed than the carrier 11c(C) to which torque is transmitted from the engine 1, thereby setting a so-called high-speed stage state in which the output rotation speed (e.g., ring gear 12b(R')) is higher than the input rotation speed (e.g., engine rotation speed) of the power transmission unit 5. Note that if the rotation speed of the first motor 2 is controlled so that the rotation speed of the sun gear 11a(S) is higher than the rotation speed of the carrier 11c(C) to which torque is transmitted from the engine 1 (state shown in Fig. 5), a so-called low-speed stage state is set in which the output rotation speed of the power transmission unit 5 is lower than the input rotation speed. In this case, the first motor 2 functions as a generator, unlike in the low-speed stage mode described above.

[0050] The "low gear mode" and "high gear mode" have different ratios of output torque and rotation speed of the first motor 2 to the engine 1. The "low gear mode" is suitable for high loads, and the "high gear mode" is suitable for low loads or high-speed driving. Therefore, by appropriately switching between the "low gear mode" and the "high gear mode" depending on the driving state of the hybrid vehicle Ve or the driving force demands on the hybrid vehicle Ve, it is possible to suppress increases in the output torque and rotation speed of the first motor 2 and improve the energy efficiency of the hybrid vehicle Ve.

[0051] As shown in FIG. 6, the "disconnection mode" is set by disengaging both the first clutch 7 (Lo-Clutch) and the second clutch 8 (Hi-Clutch). With both the first clutch 7 and the second clutch 8 disengaged, the carrier 12c (C') of the second planetary gear mechanism 12 and the sun gear (S) of the first planetary gear mechanism 11 rotate without receiving any reaction force. As a result, the engine 1 and the first motor 2 are both in a state where they can rotate freely (without transmitting torque to the output gear 15). In other words, the engine 1 and the first motor 2 are in a state where they are disconnected from the drivetrain of the hybrid vehicle Ve.

[0052] In the "disconnection mode" described above, the engine 1 and first motor 2 are disconnected from the drivetrain of the hybrid vehicle Ve, and the hybrid vehicle Ve is driven by the output of the second motor 3, enabling so-called EV driving. During such EV driving, setting this "disconnection mode" and disconnecting the engine 1 and first motor 2, which have large inertial mass, from the drivetrain reduces inertial resistance and drag loss, and improves energy efficiency during EV driving.

[0053] Furthermore, the "disconnection mode" is also selected, for example, when the hybrid vehicle Ve travels on a rough road or an uneven road. By disconnecting the engine 1 and the first motor 2 from the drive system in response to large vibrations or loads (excessive inputs) input from the road surface to the drive system of the hybrid vehicle Ve, the inertia of the drive system can be reduced and vibrations and resonances in the drive system can be suppressed. The control device for a hybrid vehicle according to an embodiment of the present invention executes control to solve various problems that arise when the "disconnection mode" is selected due to the above-described excessive inputs. Details of such control will be described later using specific examples.

[0054] The "fixed gear mode" is set by engaging both the first clutch 7 and the second clutch 8. The "fixed gear mode" is a so-called "direct-coupled mode," in which all of the rotating elements in the first planetary gear mechanism 11 and the second planetary gear mechanism 12 of the power transmission unit 5 rotate together, and the engine 1 and the first motor 2 are directly coupled to the output gear 15. In this "fixed gear mode," driving force may be generated solely by the output torque of the engine 1. Alternatively, driving force may be generated by adding the output torque of the first motor 2 or the second motor 3 to the output torque of the engine 1. Alternatively, driving force may be generated by adding the output torque of both the first motor 2 and the second motor 3 to the output torque of the engine 1. In other words, in this "fixed gear mode," it is possible to use the torques output by all of the driving force sources, the engine 1, the first motor 2, and the second motor 3, and therefore the hybrid vehicle Ve can generate the largest driving force. Furthermore, in the "fixed stage mode," no relative rotation occurs between the rotating elements of the first planetary gear mechanism 11 and the second planetary gear mechanism 12, so energy loss can be suppressed and energy efficiency can be improved.

[0055] Switching between the "low-speed gear mode" and the "high-speed gear mode" as described above is performed, for example, via the "fixed-speed gear mode" as shown in FIG. 7. As described above, in the "fixed-speed gear mode," all of the rotating elements of the power transmission unit 5 rotate integrally, and the "engagement elements" of the first clutch 7 and the second clutch 8 rotate synchronously. Therefore, even if the first clutch 7 and the second clutch 8 are configured with a meshing engagement mechanism (dog clutch), for example, the switching operation between engagement and release can be easily performed. Furthermore, as described below, when the "fixed-speed gear mode" is set, switching to the "disengagement mode" due to excessive input from the road surface as described above is performed via the "high-speed gear mode." By transitioning to the "disengagement mode" via the "high-speed gear mode," it is possible to suppress the generation or amplification of vibrations caused by excessive input. Furthermore, for example, by configuring a speed change mechanism or a switching mechanism (not shown) that operates the first clutch 7 and the second clutch 8 in conjunction with each other using a shift drum 21 as shown in FIG. 8, it is possible to easily perform orderly (sequential) switching between the above-mentioned "low speed mode," "high speed mode," "fixed speed mode," and "disconnection mode."

[0056] As described above, when the hybrid vehicle Ve travels on a rough road or an uneven road, the "disconnection mode" can be set to suppress vibrations and resonances in the drivetrain due to excessive input from the road surface. On the other hand, there are cases where a larger driving force is required when the driving resistance of the rough road is high or when the "disconnection mode" is terminated. In such cases, conventional control may not be able to obtain sufficient driving force. Therefore, the hybrid vehicle control device according to the embodiment of the present invention is configured to execute control, for example, as shown in the flowchart of FIG. 9, to obtain sufficient driving force with good responsiveness even when the "disconnection mode" is set due to excessive input from the road surface.

[0057] 9, first, in step S1, it is determined whether the hybrid vehicle Ve is in disconnected driving mode, that is, whether the hybrid vehicle Ve is in a state where the "disconnection mode" is set and the engine 1 and the first motor 2 are disconnected from the drivetrain. If the determination in step S1 is negative because the hybrid vehicle Ve is not in a driving state where the "disconnection mode" is set, the routine shown in the flowchart of FIG. 9 is temporarily terminated without executing any further control.

[0058] On the other hand, if the hybrid vehicle Ve is running in the "disconnection mode" and therefore the answer to step S1 is affirmative, the process proceeds to step S2.

[0059] In step S2, it is determined whether or not the disconnection driving is due to an excessive input. As described above, the hybrid vehicle Ve in this embodiment of the present invention sets the "disconnection mode" to disconnect the engine 1 and the first motor 2 from the drivetrain when performing EV driving using the output of the second motor 3. The "disconnection mode" is also set if excessive input is received from the road surface when driving on a rough road, an uneven road, or the like. Therefore, if the determination in step S2 is negative because the "disconnection mode" has been set for EV driving, i.e., because the disconnection driving is not due to an excessive input, the process proceeds to steps S3 and S4.

[0060] In the hybrid vehicle control device according to the embodiment of the present invention, when a large vibration, load, or torque exceeding a predetermined threshold occurs in the drivetrain of the hybrid vehicle Ve, it is determined that an excessive input has occurred. For example, when the torque acting on a predetermined rotating member in the drivetrain, or the magnitude of torque fluctuation detected by the torque sensor 9a as described above, is greater than a predetermined threshold, it is determined that an excessive input has occurred.

[0061] In step S3, the operation of the engine 1 is stopped in order to perform EV running using the output of the second motor 3.

[0062] Then, in step S4, EV running is performed using the output of the second motor 3. Thereafter, the routine shown in the flowchart of Fig. 9 is temporarily ended.

[0063] On the other hand, if the above step S2 gives a positive judgment that the vehicle is being driven in a disconnected state due to excessive input, that is, the currently set "disconnection mode" is the "disconnection mode" that was set to suppress the occurrence of vibrations and resonance due to the influence of the excessive input because it was determined that there was excessive input, then the process proceeds to step S5.

[0064] In step S5, engine speed control is executed, and the first clutch 7 enters a clutch engagement standby state. Specifically, the operation of the engine 1 continues without being stopped, and the engine speed is maintained at a state higher than the idling speed. Note that, for example, if EV driving has already been performed and the operation of the engine 1 has been stopped, the engine 1 is started, and the engine speed is maintained at a state higher than the idling speed. By controlling the engine speed at a high speed equal to or higher than a certain level in this manner, the differential rotation between the engagement elements of the first clutch 7 decreases (the engagement elements become more likely to synchronize), and the first clutch 7 enters a clutch engagement standby state, making it easier to engage. Furthermore, by maintaining the engine speed at a certain level or higher, when a large driving force is required, the engine 1 can output torque with good responsiveness, thereby generating driving force for the hybrid vehicle.

[0065] Once the engine speed control is executed in step S5 as described above, the routine shown in the flowchart of FIG. 9 is temporarily terminated.

[0066] The engine speed control shown in step S5 in the flowchart of Fig. 9 above may also be executed as shown in steps S11 and S12 in the flowchart of Fig. 10. That is, in the control device for a hybrid vehicle according to the embodiment of the present invention, in addition to the engine speed control as described above, motor speed control by the first motor 2 may also be executed to synchronize the rotation speed of the engagement element of the first clutch 7. Note that in the flowchart of Fig. 10, steps that have the same control content as those described in the flowchart of Fig. 9 above are assigned the same step numbers as those in the flowchart of Fig. 9 above.

[0067] In the flowchart of FIG. 10, in step S11, engine speed control is executed, and the first clutch 7 enters a clutch engagement standby state. The engine speed control in this case may be the same as that in step S5 in the flowchart of FIG. 9. However, in the example shown in the flowchart of FIG. 10, in order to smoothly transition from the "disconnection mode" to the "low-speed mode," the engine speed control in step S11 controls the speed of the engine 1, thereby actively synchronizing the speeds of the engaging elements of the first clutch 7 that engage with each other. This places the first clutch 7 in a state where it can be immediately engaged, and maintains a state where it can quickly transition from the "disconnection mode" to the "low-speed mode."

[0068] In step S5 in the flowchart of FIG. 9, the rotation speeds of the engagement elements of the first clutch 7 may be actively synchronized by engine speed control, as in the control shown in step S11 in the flowchart of FIG. 10.

[0069] Then, in step S12, motor rotation speed control is executed together with engine rotation speed control. In this motor rotation speed control in step S12, the rotation speed of the first motor 2 is controlled, thereby actively synchronizing the rotation speeds of the mutually engaged engagement elements of the first clutch 7. As a result, the first clutch 7 enters a clutch engagement standby state in which the rotation speeds of the engagement elements are synchronized. That is, as shown in FIG. 11 , by synchronizing the rotation speed of the carrier 11c(C) of the first planetary gear mechanism 11 and the rotation speed of the carrier 12c(C') of the second planetary gear mechanism 12 through engine rotation speed control and motor rotation speed control, rotation speed synchronization control is executed to zero the differential rotation between the engagement elements of the first clutch 7. As shown in the nomographic diagram of Figure 11, by synchronizing the rotation speed of the carrier 11c(C) and the rotation speed of the carrier 12c(C') in the power transmission unit 5 through the engine rotation speed control and motor rotation speed control as described above, the nomographic diagram becomes substantially the same as the "low speed mode" state shown in Figure 4. Therefore, the first clutch 7 becomes easily engageable, and a smooth transition from the "disconnection mode" to the "low speed mode" can be achieved.

[0070] The engine rotation speed control in step S11 and the motor rotation speed control in step S12 may be executed in parallel to synchronize the rotation speeds of the engagement elements of the first clutch 7. In other words, the engine rotation speed control and the motor rotation speed control may be controlled in coordination to synchronize the rotation speeds of the engagement elements of the first clutch 7.

[0071] As described above, once the engine rotation speed control and the motor rotation speed control are executed in steps S11 and S12, the routine shown in the flowchart of FIG. 10 is temporarily ended.

[0072] In this way, in the control device for a hybrid vehicle according to the embodiment of the present invention, by executing both engine speed control and motor speed control with good controllability, the speeds of the engagement elements of the first clutch 7 are actively synchronized. This allows for faster synchronization of the first clutch 7. This allows for faster and more appropriate transition from the "disconnection mode" to the "low-speed mode."

[0073] Furthermore, when setting the "disconnection mode," the control device for a hybrid vehicle in this embodiment of the present invention can also execute the control shown in the flowchart of Figure 12 to suppress the load and vibration that occurs during the transition to the "disconnection mode."

[0074] In the flowchart of Fig. 12, first, in step S21, it is determined whether an excessive input has been detected. As described above, an excessive input is a large vibration or load transmitted from the road surface to the drivetrain of the hybrid vehicle Ve. For example, an excessive input is determined when the torque acting on a predetermined rotating member in the drivetrain detected by the torque sensor 9a is greater than a predetermined threshold. If an excessive input has not yet been detected and the determination is negative in step S21, the routine shown in the flowchart of Fig. 12 is temporarily terminated without executing any further control.

[0075] On the other hand, if an excessive input is detected and the answer in step S21 is affirmative, the process proceeds to step S22.

[0076] In step S22, it is determined whether the currently set mode is the "high speed mode" (Hi mode). For example, it is possible to determine whether the "high speed mode" is set by detecting the engagement oil pressure of the first clutch 7 and the second clutch 8 and determining the engaged or released state of the first clutch 7 and the second clutch 8. The "high speed mode" is set when the first clutch 7 is released and the second clutch 8 is engaged.

[0077] If the currently set mode is the "high speed mode" (Hi mode) and therefore the answer to step S22 is affirmative, the process proceeds to step S23.

[0078] In step S23, the second clutch 8 (Hi-Clutch) is released. By releasing the second clutch 8 while the "high-speed gear mode" is set, both the first clutch 7 and the second clutch 8 are released, and the "disconnection mode" is set. In other words, the "high-speed gear mode" is switched to the "disconnection mode."

[0079] Then, in step S23, disconnected running is performed. That is, the "disconnected mode" is set, and EV running is performed using the output of the second motor 3 with the engine 1 and first motor 2 disconnected from the drivetrain. Then, the routine shown in the flowchart of FIG. 12 is temporarily ended.

[0080] On the other hand, if the currently set mode is not the "high speed mode" (Hi mode) and therefore the answer to step S22 is negative, the process proceeds to step S25.

[0081] In step S25, it is determined whether the currently set mode is the "low speed mode" (Lo mode). As in step S22 above, it is possible to determine whether the "low speed mode" is set by detecting the engagement oil pressure of the first clutch 7 and the second clutch 8 and determining the engaged or released state of the first clutch 7 and the second clutch 8. The "low speed mode" is set when the first clutch 7 is engaged and the second clutch 8 is released.

[0082] If the currently set mode is the "low speed mode" (Lo mode) and therefore the answer to step S25 is affirmative, the process proceeds to step S26.

[0083] In step S26, the first clutch 7 (Lo-Clutch) is released. By releasing the first clutch 7 while the "low speed mode" is set, both the first clutch 7 and the second clutch 8 are released, and the "disconnect mode" is set. In other words, the "low speed mode" is switched to the "disconnect mode."

[0084] Then, the process proceeds to step S24, where the "disconnection mode" is set as before, and EV driving is performed using the output of the second motor 3 with the engine 1 and first motor 2 disconnected from the drivetrain. After that, the routine shown in the flowchart of Fig. 12 is temporarily ended.

[0085] On the other hand, if the currently set mode is not the "low speed mode" (Lo mode) and therefore the answer to step S25 is negative, the process proceeds to step S27.

[0086] In step S27, it is determined whether the currently set mode is the "fixed gear mode." As in steps S22 and S25 above, it is possible to determine whether the "fixed gear mode" is set by detecting the engagement oil pressures of the first clutch 7 and the second clutch 8 and determining the engaged or released states of the first clutch 7 and the second clutch 8. The "fixed gear mode" is set when both the first clutch 7 and the second clutch 8 are engaged.

[0087] If the currently set mode is not the "fixed gear mode" and therefore the answer to step S25 is negative, the process proceeds to step S24. In other words, in this case, the "disconnection mode" has already been set, and the process proceeds to step S24, where disconnected driving is performed as before. That is, in the "disconnection mode," EV driving is performed using the output of the second motor 3 with the engine 1 and first motor 2 disconnected from the drivetrain. Thereafter, the routine shown in the flowchart of FIG. 12 is temporarily terminated.

[0088] On the other hand, if the currently set mode is the "fixed stage mode" and therefore the answer to step S27 is affirmative, the process proceeds to step S28.

[0089] In step S28, the mode is shifted from the "fixed gear mode" to the "high speed gear mode." Specifically, the "high speed gear mode" is set by releasing the first clutch 7 from a state in which both the first clutch 7 and the second clutch 8 are engaged in the "fixed gear mode."

[0090] Step S28 corresponds to a situation in which an excessive input is applied to the hybrid vehicle Ve while the "fixed gear mode" is set. In this case, the control device for a hybrid vehicle according to an embodiment of the present invention first transitions to the "high gear mode" and then transitions to the "disconnection mode" in step S30, which will be described later. In this way, when switching from the "fixed gear mode" to the "disconnection mode" due to an excessive input, transitioning to the "disconnection mode" via the "high gear mode" can suppress the load (generation or amplification of vibration) input from the outside during the mode transition compared to if transitioning via the "low gear mode." This reduces vibration during the transition transition, enabling a smooth transition from the "fixed gear mode" to the "disconnection mode."

[0091] Next, in step S29, it is determined whether the excessive input continues. It is determined whether the excessive input determined in the initial step S21 continues to act at a certain level. For example, if the torque acting on a predetermined rotating member in the drivetrain currently detected by the torque sensor 9a is greater than a predetermined allowable value, it is determined that the excessive input continues. The "predetermined allowable value" in this case may be the same value as the "predetermined threshold value" in step S21 described above. Alternatively, it may be a value (smaller than the "predetermined threshold value" in step S21) that is determined in advance, for example, based on the results of a running experiment or a simulation using an actual vehicle, separate from the "predetermined threshold value" in step S21.

[0092] If the excessive input continues and the answer to step S29 is affirmative, the process proceeds to step S30. Note that in the control device for a hybrid vehicle according to the embodiment of the present invention, step S29 may be omitted and control may be executed to proceed directly from step S28 to the next step S30.

[0093] In step S30, the second clutch 8 (Hi-Clutch) is released. By releasing the second clutch 8 while the "high-speed gear mode" is set, both the first clutch 7 and the second clutch 8 are released, and the "disconnection mode" is set. In other words, the "high-speed gear mode" is switched to the "disconnection mode."

[0094] Then, the process proceeds to step S24, where the "disconnection mode" is set as before, and EV driving is performed using the output of the second motor 3 with the engine 1 and first motor 2 disconnected from the drivetrain. After that, the routine shown in the flowchart of Fig. 12 is temporarily ended.

[0095] On the other hand, if the excessive input is not continuing, that is, if the excessive input determined in the initial step S21 has decreased and a negative determination is made in step S29, the routine shown in the flowchart of FIG. 12 is temporarily terminated without executing any further control.

[0096] In short, in this case, when the mode transitions from "fixed gear mode" to "disconnect mode" via "high-speed gear mode" due to excessive input to the drivetrain, the excessive input decreases to a level within the tolerance (below the tolerance) in "high-speed gear mode" during the transition. In such a case, the mode does not transition to "disconnect mode" but continues in "high-speed gear mode." It can be determined that the reduction in the excessive input as described above prevents the occurrence of harmful vibrations and resonance. Furthermore, by continuing in "high-speed gear mode" without transitioning to "disconnect mode," subsequent requests for acceleration and requests for large driving force can be responded to with good responsiveness.

[0097] As described above, the hybrid vehicle control device according to the embodiment of the present invention can appropriately suppress the occurrence of vibrations and resonances caused by excessive input to the drivetrain when the hybrid vehicle Ve travels on rough or uneven roads, thereby improving the rough road driving performance and power performance of the hybrid vehicle Ve. [Explanation of symbols]

[0098] 1 Engine (power source: ENG) 1a (engine) output shaft 2. First motor (driving power source: MG1) 2a (First motor) rotating shaft 3 Second motor (driving power source: MG2) 3a Rotating shaft (of second motor) 3b (Second motor) pinion 4 drive wheels 5 Power transmission section 6 Engagement mechanism 7 First clutch (engagement mechanism) 8 Second clutch (engagement mechanism) 9. Detection unit 9a (detection part) torque sensor 9b (detection part) vehicle speed sensor 9c (detection part) engine speed sensor 9d (Detection section) Motor rotation speed sensor (or resolver) 9e Oil pressure sensor (detection section) 9f Stroke sensor (detection part) 9g Clutch rotation speed sensor (detection part) 10 Controller (ECU) 11 First planetary gear mechanism (power transmission section) 11a Sun gear (first reaction element) (of first planetary gear mechanism) 11b (first planetary gear mechanism) ring gear (first output element) 11c Carrier (first input element) (of first planetary gear mechanism) 12 Second planetary gear mechanism (power transmission section) 12a Sun gear (second input element) (of second planetary gear mechanism) 12b (Second planetary gear mechanism) ring gear (second output element) 12c Carrier (second reaction element) (of second planetary gear mechanism) 13 Torque limiter 14 One-way clutch 15 Output gear (output member) 16 Reduction gear mechanism 17 Differential gear 18 Drive shaft 19 Bearings 20 Bearings 21 Shift drum AL rotation axis Ve Hybrid Vehicle

Claims

1. a power transmission unit that is configured with a first planetary gear mechanism and a second planetary gear mechanism, and that transmits torque in a drive system between the engine and the first motor and drive wheels, and that has at least two engagement mechanisms of a first clutch and a second clutch that operate to an engaged state or a disengaged state, respectively, to switch the torque transmission state; and a control device for a hybrid vehicle that can run in at least three modes selectively set: a first mode in which the first clutch is engaged and the second clutch is disengaged; a second mode in which the first clutch is disengaged and the second clutch is engaged; and a disengagement mode in which both the first clutch and the second clutch are disengaged, a sensor for detecting vibration or load in the drive train; a controller that controls the driving power source, the first clutch, and the second clutch, The controller determining, based on the vibration or the load detected by the sensor, that an excessive input has occurred in the drivetrain, causing a large vibration or load exceeding a predetermined threshold; When the excessive input occurs, the disconnection mode is set to disconnect the engine and the first motor from the drive train, and The engine is continuously operated or started, and engine speed control is performed to maintain the engine speed higher than the idling speed. A control device for a hybrid vehicle.

2. 2. The control device for a hybrid vehicle according to claim 1, the first planetary gear mechanism has three rotation elements: a first input element connected to the engine, a first reaction element connected to the first motor, and a first output element; the second planetary gear mechanism has three rotation elements: a second input element connected to the first output element, a second output element connected to an output member that transmits the torque to the drive wheels and serves as an output element of the power transmission unit, and a second reaction element; the first clutch selectively connects the first input element and the second reaction element; the second clutch selectively connects any two of the rotating elements in the second planetary gear mechanism, the first mode is a low-speed mode in which the rotation speed of the second output element can be reduced relative to the rotation speed of the engine connected to the second input element via the first clutch by causing the first motor to function as a generator with the first clutch engaged and the second clutch released, The second mode is a high-speed stage mode in which the rotation speed of the second output element can be made higher than the rotation speed of the engine connected to the second input element via the first planetary gear mechanism by causing the first motor to function as a generator with the second clutch engaged and the first clutch released. A control device for a hybrid vehicle.

3. 3. The control device for a hybrid vehicle according to claim 2, the first clutch has engagement elements that transmit torque by engaging with each other, The engine speed control by the controller is a control for setting the engine speed to a speed that synchronizes the speeds of the engaging elements in the first clutch. A control device for a hybrid vehicle.

4. 4. The control device for a hybrid vehicle according to claim 3, The controller In addition to the engine speed control, a motor speed control is executed to control the speed of the first motor to a speed that synchronizes the speeds of the engaging elements. A control device for a hybrid vehicle.

5. The control device for a hybrid vehicle according to any one of claims 2 to 4, The hybrid vehicle can be driven in a fixed stage mode in which both the first clutch and the second clutch are engaged, The controller If the excessive input occurs while the fixed stage mode is set, the disconnection mode is set after transitioning to the high speed stage mode. A control device for a hybrid vehicle.

6. 6. The control device for a hybrid vehicle according to claim 5, The controller When the high-speed gear mode is entered due to the excessive input, if the vibration or the load falls below a predetermined allowable value, the high-speed gear mode is continued. A control device for a hybrid vehicle.

7. The control device for a hybrid vehicle according to any one of claims 1 to 4, the first motor and the power transmission unit are disposed adjacent to each other on the same rotation axis, and are assembled in a case in this order, the first motor and the power transmission unit; a rotation shaft of the first motor is supported by a bearing disposed at least between the first motor and the power transmission unit in the direction of the rotation axis, The sensor is disposed on the first motor side of the bearing in the direction of the rotation axis. A control device for a hybrid vehicle.

8. 6. The control device for a hybrid vehicle according to claim 5, the first motor and the power transmission unit are disposed adjacent to each other on the same rotation axis, and are assembled in a case in this order, the first motor and the power transmission unit; a rotation shaft of the first motor is supported by a bearing disposed at least between the first motor and the power transmission unit in the direction of the rotation axis, The sensor is disposed on the first motor side of the bearing in the direction of the rotation axis. A control device for a hybrid vehicle.

9. 7. The control device for a hybrid vehicle according to claim 6, the first motor and the power transmission unit are disposed adjacent to each other on the same rotation axis, and are assembled in a case in this order, the first motor and the power transmission unit; a rotation shaft of the first motor is supported by a bearing disposed at least between the first motor and the power transmission unit in the direction of the rotation axis, The sensor is disposed on the first motor side of the bearing in the direction of the rotation axis. A control device for a hybrid vehicle.

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