JP2014046860A - Hybrid system - Google Patents

Abstract

To provide a simple configuration.
An engine ENG, a first rotating machine MG1, a second rotating machine MG2, a carrier C to which an engine rotating shaft 11 is connected, a sun gear S to which an MG1 rotating shaft 12 is connected, and a second rotating machine. A differential gear 20 having a plurality of rotary elements capable of differential rotation, including the ring gear R to which the MG 2 and the drive wheels W are connected, the engine ENG, the first rotary machine MG1, the second rotary machine MG2, and the drive wheels W. Between the first one-way clutch 51 and the engine ENG. The first ENway clutch 51 and the engine ENG are connected to each other while the EV ENG is running and the engine ENG is started. A second one-way clutch 52 that stops the rotation of the engagement elements on the engine ENG and the first rotating machine MG1 side in the first one-way clutch 51 when starting It is provided with.
[Selection] Figure 1

Description

  The present invention relates to a hybrid system of a hybrid vehicle that uses an engine and a rotating machine as power sources.

  Conventionally, as this type of hybrid system, a system including an engine, two rotating machines, and a power distribution mechanism (planetary gear mechanism) is known. For example, the following Patent Document 1 discloses a hybrid system in which a rotating shaft of an engine, a rotating shaft of a first rotating machine, a rotating shaft of a second rotating machine, and a driving wheel are connected to respective rotating elements of a power distribution mechanism. Has been. In this hybrid system, a one-way clutch is disposed between the ring gear of the power distribution mechanism, the rotating shaft of the second rotating machine, and the driving wheel, and the second rotating machine and the driving wheel are separated from the engine and the first rotating machine. be able to. The one-way clutch transmits the rotation of the ring gear to the drive wheel when traveling with the engine torque, but does not transmit the rotation of the drive wheel to the ring gear.

Japanese Patent No. 3593992

  By the way, in the conventional hybrid system, when the engine is started, the rotation of the first rotating machine is transmitted to the rotation shaft of the engine to raise the rotation of the engine. At that time, the rotation of the first rotating machine is transmitted to the rotation shaft of the engine by fixing the ring gear of the power distribution mechanism. For this reason, this hybrid system is provided with a control brake capable of stopping the rotation of the ring gear between the ring gear and the one-way clutch. Thus, the conventional hybrid system needs to be provided with a control brake (which may be a control clutch) in order to start the engine, and the system configuration is complicated.

  Therefore, an object of the present invention is to provide a hybrid system having a simple configuration that improves the disadvantages of the conventional example.

  In order to achieve the above object, the present invention includes an engine, a first rotating machine, a second rotating machine, a rotating element to which the rotating shaft of the engine is connected, and a rotating shaft of the first rotating machine. A differential device having a plurality of rotating elements capable of differential rotation, including a rotating element and a rotating element connected to the second rotating machine and drive wheels, the engine, the first rotating machine, and the second rotating machine Between the engine and the drive wheel, and in a disengaged state in which the engine is separated from that during the EV traveling that travels only by the power of the second rotating machine and when the engine is started. A first one-way clutch that is engaged during HV traveling that is driven by the power of a two-rotor, and when the engine is started, the engine and the first rotating machine side of the first one-way clutch are A second screw for stopping the rotation of the engaging element; It is characterized in that it comprises a-way clutch, a.

  Here, it is desirable to provide a control device for controlling the first rotating machine so that the first one-way clutch is not engaged after the start control of the engine is started.

  In addition, it is desirable to provide a control device for controlling the first rotating machine so as to engage the first one-way clutch while suppressing the engagement speed of the first one-way clutch after the engine is started.

  In the hybrid system according to the present invention, the engine, the first rotating machine, the second rotating machine, and the driving wheel are separated by a first one-way clutch that does not require an operation control device such as an actuator. Further, in this hybrid system, when the engine is started, the rotation element of the differential gear is fixed by the second one-way clutch, so that the rotation of the engine can be lifted by the first rotating machine. Therefore, in this hybrid system, a starter motor for starting the engine becomes unnecessary. In this hybrid system, the rotation element is also fixed by a second one-way clutch that does not require an operation control device such as an actuator, and the fixed element is controlled by a conventional control brake (or control clutch). There is no need to fix. Therefore, this hybrid system can reduce the number of parts as compared with the conventional system, and can reduce the size of the system, the weight of the system, and the cost of the system. In addition, since this hybrid system has a reduced number of parts, it can be constructed with a simple configuration.

FIG. 1 is a skeleton diagram showing the configuration of an embodiment of a hybrid system according to the present invention. FIG. 2 is an input / output relationship diagram of the embodiment. FIG. 3 is an operation engagement table of the first and second one-way clutches. FIG. 4 is a flowchart for explaining the operation when starting the engine. FIG. 5 is an alignment chart during EV traveling. FIG. 6 is a collinear diagram when the rotation of the engine is lifted. FIG. 7 is an alignment chart for explaining the control of the first rotating machine after the start control of the engine is started. FIG. 8 is a flowchart for explaining another operation when starting the engine. FIG. 9 is an alignment chart when switching from the EV travel mode to the HV travel mode. FIG. 10 is an alignment chart during HV traveling. FIG. 11 is a skeleton diagram showing a configuration of a modified example of the hybrid system according to the present invention.

  Embodiments of a hybrid system according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

[Example]
An embodiment of a hybrid system according to the present invention will be described with reference to FIGS.

  Reference numeral 1-1 in FIG. 1 indicates a hybrid system of the present embodiment. Moreover, the code | symbol 100 of FIG. 1 shows the hybrid vehicle by which this hybrid system 1-1 is mounted.

  The hybrid system 1-1 includes an engine ENG, a first rotating machine MG1, and a second rotating machine MG2.

  The engine ENG is an engine such as an internal combustion engine or an external combustion engine that outputs mechanical power (engine torque) from an engine rotation shaft (crankshaft) 11. The operation of the engine ENG is controlled by an electronic control device (hereinafter referred to as “engine ECU”) 91 as an engine control device shown in FIG. The engine ECU 91 controls the output torque of the engine ENG (hereinafter referred to as “engine torque”) by performing, for example, opening control of an electronic throttle valve, ignition control by output of an ignition signal, fuel injection control, and the like. To do.

  The first rotating machine MG1 and the second rotating machine MG2 are motor generators (motor generators) having a function as a motor (motor) at the time of power running drive and a function as a generator (generator) at the time of regenerative drive. is there. The operations of the first and second rotating machines MG1 and MG2 are controlled by an electronic control unit (hereinafter referred to as “MG ECU”) 92 as a rotating machine control device shown in FIG. The first and second rotating machines MG1, MG2 are connected to a secondary battery (not shown) via an inverter (not shown), and are connected to respective rotating shafts (MG1 rotating shaft 12, MG2 rotating shaft 13). The input mechanical energy (rotational torque) can be converted into electrical energy and stored in the secondary battery. In addition, the first and second rotating machines MG1 and MG2 use mechanical energy supplied from the secondary battery or electric energy generated by the other rotating machine (second and first rotating machines MG2 and MG1) as mechanical energy. (Rotational torque) can be converted and output as mechanical power (output torque) from the respective rotary shafts (MG1 rotary shaft 12 and MG2 rotary shaft 13). For example, the MGECU 92 adjusts the current value supplied to the first rotating machine MG1 and the second rotating machine MG2 to output torque (hereinafter referred to as “MG1 torque”) of the first rotating machine MG1 and the second rotation. The output torque of the machine MG2 (hereinafter referred to as “MG2 torque”) is controlled.

  Further, in this hybrid system 1-1, power is transmitted between the engine ENG, the first rotating machine MG1, and the second rotating machine MG2, and power is transmitted between these and the drive wheels W. The power transmission device which can do is provided. The power transmission device includes a differential device 20. The hybrid system 1-1 of the present embodiment is a multi-shaft type in which the engine rotation shaft 11 and the MG1 rotation shaft 12 are arranged concentrically, and the MG2 rotation shaft 13 is arranged in parallel with a space therebetween. Is. The differential device 20 is disposed concentrically between the engine rotation shaft 11 and the MG1 rotation shaft 12.

  The differential device 20 includes a planetary mechanism including a plurality of rotating elements capable of differential rotation as a power split mechanism. As the planetary mechanism, a single pinion type planetary gear mechanism, a double pinion type planetary gear mechanism, a Ravigneaux type planetary gear mechanism, or the like is applicable. The illustrated differential device 20 includes one single-pinion type planetary gear mechanism, and includes a sun gear S, a ring gear R, a plurality of pinion gears P, and a carrier C as rotating elements.

  In the differential device 20, one of the sun gear S, the ring gear R, and the carrier C is connected to the engine ENG, the remaining one is connected to the first rotating machine MG1, and the last one is the second. It is connected to rotating machine MG2 and drive wheel W. In this example, the engine ENG is connected to the carrier C, the first rotating machine MG1 is connected to the sun gear S, and the second rotating machine MG2 and the drive wheels W are connected to the ring gear R. The carrier C is coupled so as to be able to rotate integrally with the engine rotation shaft 11 and constitutes a power transmission element between the differential device 20 and the engine ENG. The sun gear S is coupled to the MG1 rotation shaft 12 so as to be rotatable integrally, and constitutes a power transmission element between the differential device 20 and the first rotating machine MG1. The ring gear R is connected to the MG2 rotating shaft 13 and the driving wheel W through the following gear group and the like, and constitutes a power transmission element between the differential device 20 and the second rotating machine MG2 and the driving wheel W.

  The ring gear R is connected to a first gear 31 that is concentrically arranged and can rotate integrally. The first gear 31 is an external gear that is in mesh with the second gear 32. The ring gear R may have external teeth as the first gear 31 on the outer peripheral surface thereof. The second gear 32 is fixed to a rotation shaft (output shaft 14) arranged to be shifted parallel to the rotation shaft of the first gear 31 (concentric with the engine rotation shaft 11 and the MG1 rotation shaft 12). . The output shaft 14 is a rotating shaft that bears output of power to the drive wheel W side in the power transmission device. The engine torque is transmitted to the drive wheel W side through the output shaft 14. A third gear 33 is fixed to the output shaft 14. The third gear 33 is an external gear that meshes with the fourth gear 34. The fourth gear 34 is fixed to the MG2 rotation shaft 13. Accordingly, the MG2 torque is transmitted to the drive wheel W side through the output shaft 14. A fifth gear 35 is further fixed to the output shaft 14 between the second gear 32 and the third gear 33. The fifth gear 35 is an external gear in mesh with the sixth gear 36 as a diff ring gear. The sixth gear 36 is attached to the differential device 41. The differential device 41 is connected to the drive wheels W via the left and right drive shafts 42.

  As shown in FIG. 2, the hybrid system 1-1 includes an integrated ECU (hereinafter referred to as “HVECU”) 90 that performs overall control of the engine ECU 91 and MGECU 92 and performs integrated control of the system. These constitute the control device of this system.

  Various sensors such as a vehicle speed sensor, an accelerator opening sensor, an MG1 rotational speed sensor, an MG2 rotational speed sensor, an output shaft rotational speed sensor, and a battery sensor are connected to the HVECU 90. The HVECU 90 uses the various sensors to determine the vehicle speed, the accelerator opening, the rotational speed of the first rotating machine MG1 (MG1 rotational speed), the rotational speed of the second rotating machine MG2 (MG2 rotational speed), and the output shaft 14 of the power transmission device. , The secondary battery SOC (State of Charge), and the like.

  The HVECU 90 calculates a required driving force, a required power, a required torque, and the like for the hybrid vehicle 100 based on the acquired information. For example, the HVECU 90 calculates the required engine torque, the required MG1 torque, and the required MG2 torque based on the calculated required vehicle driving force. The HVECU 90 transmits the requested engine torque to the engine ECU 91 to be output to the engine ENG, and transmits the requested MG1 torque and the requested MG2 torque to the MGECU 92 to be output to the first rotating machine MG1 and the second rotating machine MG2.

  In this hybrid system 1-1, an electric vehicle (EV) travel mode and a hybrid (HV) travel mode are set, and the hybrid vehicle 100 can travel in any one of the travel modes.

  The EV travel mode is a travel mode in which the power of the second rotating machine MG2 is transmitted to the drive wheels W to travel. In this hybrid system 1-1, when traveling in the EV traveling mode (hereinafter referred to as "EV traveling"), the engine ENG is stopped to improve fuel consumption. The HV traveling mode is a traveling mode in which the power of the engine ENG and the power of the second rotating machine MG2 are transmitted to the drive wheels W. In the hybrid system 1-1, the first rotating machine MG1 can be operated as a generator when traveling in the HV traveling mode (hereinafter referred to as "HV traveling"). By regenerating electric power in this way, it is possible to improve power consumption.

  Here, the power transmission device of the hybrid system 1-1 includes first and second one-way clutches 51 and 52 between the engine ENG, the first rotating machine MG1, the second rotating machine MG2, and the drive wheels W. . The first one-way clutch 51 is a connecting / disconnecting device provided so as to be disconnected during EV traveling and when the engine ENG is started while being connected during HV traveling. The second one-way clutch 52 is a connecting / disconnecting device provided for fixing the ring gear R of the differential device 20 when starting the engine ENG.

  Specifically, the first one-way clutch 51 of this embodiment is disposed between the second gear 32 and the output shaft 14. In this example, the second gear 32 is divided into two parts on the differential device 20 side and the output shaft 14 side, and the first component 32a on the differential device 20 side and the second component 32b on the output shaft 14 side are A first one-way clutch 51 is interposed between them. The first component 32 a has external teeth that mesh with the first gear 31, and rotates integrally with a first engagement element (not shown) of the first one-way clutch 51. On the other hand, the second component 32 b is fixed to the output shaft 14 and rotates together with the second engagement element (not shown) of the first one-way clutch 51 together with the output shaft 14.

  The first one-way clutch 51 is used when the rotation speed of the second engagement element is larger than the rotation speed of the first engagement element, that is, between the first engagement element and the second engagement element. When the rotational speed difference occurs, the released state is established, and when the rotational speeds of the first engaging element and the second engaging element coincide with each other, or the rotational speed of the first engaging element is equal to that of the second engaging element. It is configured to be engaged when it is about to increase with respect to the rotational speed. For example, the first one-way clutch 51 is a disconnect type that has a gap between the first engagement element and the second engagement element when such a rotational speed difference occurs.

  The engagement state is a state in which the first engagement element and the second engagement element rotate together. That is, when the first one-way clutch 51 is in the engaged state, the first component 32a and the second component 32b are integrated, so that the second gear 32 rotates together with the output shaft 14. Accordingly, at this time, the rotation (torque) of the first gear 31 can be transmitted to the output shaft 14 via the second gear 32. On the other hand, the released state is a state in which rotation (torque) cannot be transmitted between the first engagement element and the second engagement element. That is, since the rotation (torque) of the first component 32a cannot be transmitted to the second component 32b when the first one-way clutch 51 is in the released state, the rotation (torque) of the first gear 31 is transmitted to the output shaft 14. I can't.

  As shown in FIG. 3, the first one-way clutch 51 (OWC1) is released during EV traveling. That is, during EV traveling, the output shaft 14 and the second component 32b rotate in the normal rotation direction (the rotation direction of the output shaft 14 during forward movement is defined as normal rotation) by the MG2 torque, while the engine speed And the MG1 rotational speed are set to 0, the rotational speed of the first component 32a is also 0. For this reason, in the first one-way clutch 51 during EV traveling, the rotation speed of the second engagement element is larger than the rotation speed of the first engagement element. Accordingly, the first one-way clutch 51 is released during EV traveling, and disconnects the engine ENG, the first rotating machine MG1, the second rotating machine MG2, and the drive wheels W so that power cannot be transmitted. Here, at that time, the second one-way clutch 52 (OWC2) may be engaged with a first engagement element and a second engagement element described later, or may be released. FIG. 3 is an operation engagement table of the first and second one-way clutches 51 and 52. In this operation engagement table, “◯” indicates the engaged state, and “X” indicates the released state. Further, “Δ” indicates that it is in an engaged state or a released state.

  For example, the HVECU 90 switches the travel mode from the EV travel mode to the HV travel mode when the required vehicle driving force exceeds a predetermined magnitude or when the SOC of the secondary battery decreases. At the time of switching, the HVECU 90 restarts the stopped engine ENG. In this hybrid system 1-1, the first rotation machine MG1 is operated as an electric motor, and the engine rotation speed at which the engine ENG can be started with the MG1 rotation speed and the MG1 torque of the first rotation machine MG1 driven by power running ( Hereinafter, it is referred to as “starting rotational speed”). In this hybrid system 1-1, ignition or the like is performed (for example, in the case of a gasoline engine) when the engine speed increases to a start speed (a speed at which the engine ENG can be started) or higher. Start ENG.

  Hereinafter, the operation at the time of engine start will be described with reference to the flowchart of FIG.

  Here, a case where an engine start request is made during EV traveling will be described. During EV traveling, as shown in the collinear diagram of the hybrid system 1-1 in FIG. 5, the second rotating machine MG <b> 2 outputs negative torque by negative rotation, and the MG <b> 2 torque is transmitted to the output shaft 14, thereby driving A driving force is generated in the wheel W. At that time, the output shaft 14 is rotating forward. Further, during this EV traveling, the engine speed and the MG1 speed are zero. For this reason, in the first one-way clutch 51, as described above, a rotational speed difference is generated between the first engagement element and the second engagement element. Accordingly, the first one-way clutch 51 is in a released state. In the alignment chart, “MG1” represents the sun gear shaft to which the first rotating machine MG1 is connected, and “ENG” represents the carrier shaft to which the engine ENG is connected. “R” represents the rotation axis of the first component 32a connected to the ring gear R. “OUT” represents the output shaft 14 connected to the second component 32b, and “MG2” represents the MG2 rotation shaft 13. Each axis is the same in the nomograph described later.

  When an engine start request is made during the EV travel (step ST1), the HVECU 90 causes the engine ENG to rotate up under the control of the first rotating machine MG1 (step ST2).

  At that time, the HVECU 90 controls the first rotating machine MG1 so that a positive torque is output by the positive rotation (FIG. 6). In the hybrid system 1-1, the second one-way clutch 52 is engaged while the released state of the first one-way clutch 51 is maintained by the control of the first rotating machine MG1 (FIG. 3). In the second one-way clutch 52, the second engagement element described below tries to rotate in the negative rotation direction together with the first component 32a in accordance with the control of the first rotating machine MG1, so that the second engagement element is Engage with the first engagement element described below to enter the engaged state. As a result, the first component 32a is fixed to, for example, the casing CA of the system and cannot be rotated. Therefore, in the differential device 20, the ring gear R cannot be rotated. Therefore, in the engine ENG, the MG1 rotation speed and the MG1 torque are transmitted to the engine rotation shaft 11, and the rotation is lifted against the torque caused by the inertia. The control of the first rotating machine MG1 is continued at least until the engine speed reaches the starting speed.

  Here, the second one-way clutch 52 is disposed between the first component 32a and the casing CA of the system. Similar to the first one-way clutch 51, the second one-way clutch 52 includes a first engagement element (not shown) and a second engagement element (not shown). The first engagement element is fixed to the casing CA. The second engagement element is fixed to the first component 32a so as to rotate together with the first component 32a. The second one-way clutch 52 stops the rotation of the first component 32a when starting the engine ENG, so that the first engagement of the first one-way clutch 51 on the side of the engine ENG and the first rotating machine MG1 is stopped. It stops the rotation of the element.

  The second one-way clutch 52 is used when the rotation speed of the second engagement element is larger than the rotation speed of the first engagement element, that is, between the first engagement element and the second engagement element. When the rotational speed difference occurs, the released state is established, and when the rotational speeds of the first engaging element and the second engaging element coincide with each other, or the rotational speed of the second engaging element is equal to that of the first engaging element. What is necessary is just to be comprised so that it may be in an engagement state, when it is going to become large with respect to rotation speed. For example, as the second one-way clutch 52, a disconnect type that has a gap between the first engagement element and the second engagement element when such a rotational speed difference occurs is used. In this example, since the rotation speed of the first engagement element is always 0, the second one-way clutch 52 allows one of the positive rotation and the negative rotation and tries to rotate in the other direction at 0 rotation. You may use what is stopped.

  The second one-way clutch 52 is engaged when the engine ENG is started, and is released during EV traveling or HV traveling.

  The HVECU 90 determines whether or not the engine rotational speed Ne has become equal to or higher than the starting rotational speed Ne0 (step ST3). If the engine speed Ne has not reached the starting speed Ne0, the HVECU 90 returns to step ST2 and continues to control the first rotating machine MG1.

  On the other hand, when the engine speed Ne becomes equal to or higher than the start speed Ne0, the HVECU 90 starts engine start control (step ST4). For example, in the case of a gasoline engine, the engine start control refers to control of the fuel injection amount and ignition timing.

  Here, in this hybrid system 1-1, as the engine start control is started, the direction of rotation of the first component 32a is switched from the negative rotation direction to the positive rotation direction, so that the second one-way clutch 52 is in the released state. Become. And the 1st component 32a begins to rotate by forward rotation. As described above, the first component 32a is stopped by the engaged second one-way clutch 52 before the rotation direction is switched. On the other hand, the second component 32b rotates in the forward rotation direction together with the output shaft 14. This is because the hybrid vehicle 100 at this time is still in EV travel.

  Switching from EV traveling to HV traveling is realized by the first one-way clutch 51 being engaged when the rotational speed of the first component 32a catches up with the rotational speed of the second component 32b. However, the first one-way clutch 51 may be engaged during the engine start control or immediately after the engine is started (that is, after the start control of the engine ENG is started). The accompanying shock may be transmitted to the output shaft 14.

  Therefore, the HVECU 90 is engaged with the first one-way clutch 51 after the start control of the engine ENG is started in order to suppress the occurrence of such a shock in the output shaft 14 when the travel mode is switched from the EV travel mode to the HV travel mode. The first rotating machine MG1 is controlled so as not to become (step ST5). Therefore, in this hybrid system 1-1, the rotation speed (hereinafter referred to as “input-side rotation speed”) Nin of the first engagement element (that is, the first component 32 a) of the first one-way clutch 51. A rotation sensor (not shown) for detection may be provided. For example, the rotation sensor detects a rotation angle of the first engagement element or the first component 32a of the first one-way clutch 51. In the hybrid system 1-1, the rotation speed of the second engagement element (that is, the second component 32 b and the output shaft 14) of the first one-way clutch 51 (hereinafter referred to as “output-side rotation speed”). A rotation sensor (not shown) for detecting Nout may be provided. This rotation sensor detects, for example, the rotation angle of the second engagement element, the second component 32b, or the output shaft 14 of the first one-way clutch 51.

  For example, the HVECU 90 performs the first rotation so that the input-side rotational speed Nin of the first one-way clutch 51 does not exceed the output-side rotational speed Nout of the first one-way clutch 51 after starting the engine start control or immediately after starting the engine. The machine MG1 is controlled (Nout> Nin). At that time, the HVECU 90 controls at least one of the MG1 rotation speed and the MG1 torque of the first rotating machine MG1. For example, in the collinear diagram of FIG. 7, the MG1 rotational speed is increased or decreased so that the first one-way clutch 51 is not engaged while the engine ENG is held at the idling rotational speed.

  Thus, in this hybrid system 1-1, the engine is started in a disconnected state in which power cannot be transmitted between the engine ENG and the first rotating machine MG1, the second rotating machine MG2, and the drive wheels W. The power consumption when controlling the first rotating machine MG1 can be kept low, and a reduction in power consumption when starting the engine can be suppressed.

  Further, in the hybrid system 1-1, the separation between them is realized by the first one-way clutch 51 that does not require an operation control device such as an actuator. Further, in this hybrid system 1-1, when starting the engine ENG, the ring gear R of the differential device 20 is fixed by the second one-way clutch 52, so the rotation of the engine ENG is lifted by the first rotating machine MG1. be able to. Therefore, in this hybrid system 1-1, a starter motor for starting the engine ENG is not required. In the hybrid system 1-1, the ring gear R is also fixed by the second one-way clutch 52 that does not require an operation control device such as an actuator, and a conventional control brake (or control clutch) is used. ), It is not necessary to fix the ring gear R. Therefore, this hybrid system 1-1 can reduce the number of parts as compared with the conventional system, and can reduce the size of the system, the weight of the system, and the cost of the system. Moreover, since this hybrid system 1-1 reduces the number of parts, it can be constructed with a simple configuration.

  Furthermore, in this hybrid system 1-1, the first rotary machine MG1 is controlled during the engine start control or immediately after the engine start so that the first one-way clutch 51 is not engaged. The occurrence of shock at the output shaft 14 during the engine start or immediately after the engine is started can be suppressed. Therefore, since this hybrid system 1-1 can suppress the driving force fluctuation in the driving wheel W accompanying the engine start, the driver does not feel uncomfortable due to such driving force fluctuation. Therefore, this hybrid system 1-1 can also improve the drivability when starting the engine.

  Moreover, in this hybrid system 1-1, since the disconnect type is used for the first one-way clutch 51, drag loss in the first one-way clutch 51 during EV traveling can be reduced. The electricity cost can be improved. Furthermore, in this hybrid system 1-1, since the disconnect type is used for the second one-way clutch 52, drag loss in the second one-way clutch 52 during HV traveling can be reduced. It is possible to improve electricity consumption and fuel consumption.

  By the way, in this hybrid system 1-1, after starting engine start control or after control of the 1st rotary machine MG1 for suppressing generation | occurrence | production of the shock in the output shaft 14, the 1st one-way clutch 51 is made. The driving mode is switched from the EV driving mode to the HV driving mode. For this reason, in the hybrid system 1-1, after the engine start control is started or after the control of the first rotating machine MG1 for suppressing the occurrence of shock at the output shaft 14, the first one-way clutch 51 is provided. The first rotating machine MG1 is controlled so as to suppress the occurrence of a shock associated with the engagement and the occurrence of a shock in the output shaft 14 due to the engagement. Again, at least one of the MG1 rotation speed and the MG1 torque of the first rotating machine MG1 is controlled.

  For example, in the flowchart shown in FIG. 8, the HVECU 90 has a predetermined rate of change in the relative rotational speed between the input side rotational speed Nin and the output side rotational speed Nout of the first one-way clutch 51 after starting the engine start control in step ST4. The first rotating machine MG1 is controlled so as to be as follows (step ST6). More specifically, the control of the first rotating machine MG1 is executed after the engine is started. Note that steps ST1 to ST4 in FIG. 8 are the same as steps ST1 to ST4 in FIG.

  The predetermined value is caused by, for example, the rate of change at which the occurrence of shock in the first one-way clutch 51 is suppressed when the first one-way clutch 51 is engaged, and the engagement of the first one-way clutch 51. What is necessary is just to obtain | require the change rate in which generation | occurrence | production of the shock in the output shaft 14 is suppressed by experiment or simulation, and to determine in the direction which can suppress generation | occurrence | production of both the shocks of them. That is, since the first one-way clutch 51 is engaged while the engagement speed is suppressed, the occurrence of a shock at the time of engagement can be suppressed. In the nomogram of FIG. 9, the MG1 rotational speed is decreased so that the first one-way clutch 51 is gently engaged while the engine ENG is held at the idling rotational speed, and the input side rotational speed Nin is set to the output side rotational speed. Nout is brought close to a predetermined increase rate (for example, an increase rate corresponding to the predetermined value).

  In this manner, in addition to the above-described effects, the hybrid system 1-1 can suppress the occurrence of shock in the first one-way clutch 51 when the first one-way clutch 51 is engaged. The occurrence of shock at the output shaft 14 due to the engagement of the one-way clutch 51 is also suppressed. Therefore, fluctuations in the driving force on the drive wheels W when the running mode is switched from the EV running mode to the HV running mode can be suppressed, so that the driver does not feel uncomfortable due to such driving force fluctuations. Therefore, this hybrid system 1-1 can improve the drivability at the time of driving mode switching.

  Here, in this way, the first one-way clutch 51 is engaged during HV traveling (FIG. 3). During HV traveling, the first component 32a rotates in the normal rotation direction due to the engine torque, while the output shaft 14 and the second component 32b rotate in the positive rotation direction due to the MG2 torque. In this case, the first engagement element becomes the second engagement element if the rotation speed of the first component 32a is an engine rotation speed that tends to exceed the rotation speed of the second component 32b. Engage. For this reason, at this time, the first one-way clutch 51 is engaged. However, when the engine speed is not such, the speed of the second component 32b exceeds the speed of the first component 32a, so that the first one-way clutch 51 is released and drives the engine torque. I can't tell the wheel W. Accordingly, at this time, the first MG1 torque of the first rotating machine MG1 and at least one of the MG1 rotation speeds are controlled so that the rotation speeds of the first component 32a and the second component 32b can be synchronized. By increasing the rotation speed of the component 32a, the engaged state of the first one-way clutch 51 is maintained and the HV traveling is continued. In the collinear diagram of FIG. 10, the first rotary machine MG1 generates negative torque by positive rotation, thereby maintaining the engaged state of the first one-way clutch 51 while regenerating electric power by the first rotary machine MG1. ing.

[Modification]
In the above-described embodiment, the multi-shaft hybrid system 1-1 has been described as an example. However, the technique described in the embodiment can also be applied to the single-shaft hybrid system 1-2 illustrated in FIG. It is. And in the hybrid system 1-2, the same effect as the hybrid system 1-1 can be acquired by implementing the same control as the Example.

  The hybrid system 1-2 includes the engine ENG, the first rotating machine MG1, and the second rotating machine MG2 as in the hybrid system 1-1, but includes the engine rotating shaft 11, the MG1 rotating shaft 12, and the MG2 rotating shaft. 13 differs from the hybrid system 1-1 in that they are arranged concentrically.

  Also in this hybrid system 1-2, it is possible to transmit power between the engine ENG, the first rotating machine MG1 and the second rotating machine MG2 and between these and the drive wheels W. A power transmission device is provided. The power transmission device here includes a differential device 120. The differential device 120 is disposed concentrically between the first rotating machine MG1 and the second rotating machine MG2.

  The differential device 120 includes two planetary mechanisms composed of a plurality of rotating elements capable of differential rotation as power splitting mechanisms. As the planetary mechanism, a single pinion type planetary gear mechanism, a double pinion type planetary gear mechanism, a Ravigneaux type planetary gear mechanism, or the like is applicable. The illustrated differential device 120 includes two single pinion type planetary gear mechanisms (a first planetary gear mechanism 121 and a second planetary gear mechanism 122). Here, the first planetary gear mechanism 121 is disposed on the engine ENG and the first rotating machine MG1 side, and the second planetary gear mechanism 122 is disposed on the second rotating machine MG2 side.

  The first planetary gear mechanism 121 has a sun gear S1, a ring gear R1, a plurality of pinion gears P1, and a carrier C1 as rotating elements. In the first planetary gear mechanism 121, one of the sun gear S1, the ring gear R1, and the carrier C1 is connected to the engine ENG, the remaining one is connected to the first rotating machine MG1, and the last one is the first one. It is connected to the two-rotor MG2 and the drive wheel W. In this example, the engine ENG and the carrier C1 are connected so as to be able to rotate integrally, the first rotating machine MG1 and the sun gear S1 are connected so as to be able to rotate integrally, and the second rotating machine MG2 and the drive wheels W are connected to the ring gear. Link to R1.

  The second planetary gear mechanism 122 includes a sun gear S2, a ring gear R2, a plurality of pinion gears P2, and a carrier C2 as rotating elements. In the second planetary gear mechanism 122, one of the sun gear S2, the ring gear R2, and the carrier C2 is connected to the second rotating machine MG2, one of the remaining ones is connected to the driving wheel W, and the last one is Connected to the housing CA. In this example, the second rotating machine MG2 and the sun gear S2 are connected so as to be able to rotate integrally, the carrier C2 is connected to the casing CA, and the driving wheel W is connected to the ring gear R2, and the carrier-fixed second planetary gear mechanism. 122.

  Here, in the differential device 120, the ring gears R1 and R2 are integrated. Accordingly, the ring gear R1 of the first planetary gear mechanism 121 is connected to the second rotating machine MG2 via the second planetary gear mechanism 122. Each ring gear R1, R2 is connected to the drive wheel W via the following gear group and the like.

  The ring gears R1 and R2 are connected to a first gear 131 that is concentrically arranged and can rotate integrally. The first gear 131 is an external gear that meshes with the second gear 132. Each of the ring gears R1 and R2 may have external teeth as the first gear 131 on the outer peripheral surface thereof as shown in FIG. The second gear 132 is a rotating shaft (output shaft 114) that is arranged in parallel with the rotating shaft of the first gear 131 (concentric with the engine rotating shaft 11, the MG1 rotating shaft 12, and the MG2 rotating shaft 13). ). The output shaft 114 is a rotating shaft that bears output of power to the drive wheel W side in the power transmission device. Engine torque and MG2 torque are transmitted to the drive wheel W side through the output shaft 114. A third gear 133 is fixed to the output shaft 114. The third gear 133 is an external gear in mesh with the fourth gear 134 as a diff ring gear. The fourth gear 134 is attached to the differential device 41. The differential device 41 is connected to the drive wheels W via the left and right drive shafts 42.

  The power transmission device of the hybrid system 1-2 includes first and second one-way clutches 151, 152 between the engine ENG, the first rotating machine MG1, the second rotating machine MG2, and the drive wheels W. The first one-way clutch 151 is a connecting / disconnecting device provided so as to be disconnected when the EV traveling mode is established while the first one-way clutch 151 is connected when the EV traveling mode is established. The second one-way clutch 152 is a connecting / disconnecting device provided for fixing the ring gear R1 of the first planetary gear mechanism 121 when the engine ENG is started.

  Specifically, the first one-way clutch 151 of the present modification is provided on the ring gear R1 of the first planetary gear mechanism 121. In this example, the ring gear R1 is divided into two parts, that is, the engine ENG and the first rotating machine MG1 side (input side) and the second rotating machine MG2 and the drive wheel W side (output side). A first one-way clutch 151 is interposed between the component 161 and the second component 162 on the output side. The first component 161 has an inner tooth of a ring gear R1 that meshes with the pinion gear P1, and rotates together with a first engagement element (not shown) of the first one-way clutch 151. On the other hand, the second component 162 has the first gear 131 and the inner teeth of the ring gear R2, and rotates together with the second engagement element (not shown) of the first one-way clutch 151.

  The first one-way clutch 151 is equivalent to the first one-way clutch 51 of the embodiment, and when the rotation speed of the second engagement element is larger than the rotation speed of the first engagement element, that is, When a rotational speed difference occurs between the first engagement element and the second engagement element, the release state is established, and when the respective rotational speeds of the first engagement element and the second engagement element coincide with each other, or The first engagement element is configured to be engaged when the rotation speed of the first engagement element is about to increase with respect to the rotation speed of the second engagement element. Therefore, as the first one-way clutch 151, a disconnect type similar to the first one-way clutch 51 of the embodiment can be used.

  The first one-way clutch 151 during EV traveling is in a released state because the rotation speed of the second engagement element is greater than the rotation speed (= 0) of the first engagement element. The first one-way clutch 151 is also released when the engine ENG is started. On the other hand, the vehicle is engaged during HV traveling.

  The second one-way clutch 152 is disposed between the first component 161 and the casing CA. The second one-way clutch 152 includes a first engagement element (not shown) fixed to the casing CA, and a second engagement fixed to the first component 161 so as to rotate together with the first component 161. A combination element (not shown). The second one-way clutch 152 is used when the rotation speed of the second engagement element is larger than the rotation speed of the first engagement element, that is, between the first engagement element and the second engagement element. When the rotational speed difference occurs, the released state is established, and when the rotational speeds of the first engaging element and the second engaging element coincide with each other, or the rotational speed of the second engaging element is equal to that of the first engaging element. It is configured to be in an engaged state when it is about to increase with respect to the rotational speed. Therefore, as the second one-way clutch 152, a disconnect type similar to the second one-way clutch 52 of the embodiment can be used. Since the rotation speed of the first engagement element is always 0, the second one-way clutch 152 allows one of positive rotation and negative rotation, and is locked at 0 rotation when attempting to rotate in the other direction. You may use things. The second one-way clutch 152 is engaged when the engine ENG is started, and is released during EV traveling or HV traveling.

1-1, 1-2 Hybrid system 11 Engine rotation shaft 12 MG1 rotation shaft 13 MG2 rotation shaft 14, 114 Output shaft 20, 120 Differential device 32 Second gear 32a, 161 First component 32b, 162 Second component 51,151 First one-way clutch 52,152 Second one-way clutch 121 First planetary gear mechanism 122 Second planetary gear mechanism C, C1, C2 Carrier CA Case 90 Integrated ECU
91 Engine ECU
ENG Engine MG1 First rotating machine MG2 Second rotating machine P, P1, P2 Pinion gear R, R1, R2 Ring gear S, S1, S2 Sun gear W Drive wheel

Claims (3)

With the agency,
A first rotating machine;
A second rotating machine,
Differential rotation including a rotating element to which the rotating shaft of the engine is connected, a rotating element to which the rotating shaft of the first rotating machine is connected, and a rotating element to which the second rotating machine and drive wheels are connected. A differential having a plurality of possible rotating elements;
The EV is disposed between the engine and the first rotating machine and the second rotating machine and the driving wheel, and travels between them using only the power of the second rotating machine and when the engine is started. A first one-way clutch that is in an engaged state in which it is in a released state to be disconnected while being connected during HV traveling that travels between the engine and the power of the second rotating machine,
A second one-way clutch that stops rotation of the engagement element on the first rotating machine side in the first one-way clutch when starting the engine;
A hybrid system characterized by comprising   2. The hybrid system according to claim 1, further comprising a control device that controls the first rotating machine so that the first one-way clutch is not engaged after the start control of the engine is started.   The control device for controlling the first rotating machine so as to engage the first one-way clutch while suppressing the engagement speed of the first one-way clutch after the engine is started. Hybrid system.

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