JP5929642B2 - Hybrid vehicle drive device - Google Patents

Description

  The present invention relates to a hybrid vehicle drive device.

  Conventionally, a hybrid vehicle including a clutch for separating an engine is known. For example, Patent Literature 1 discloses a hybrid vehicle in which a clutch is disposed between an internal combustion engine and an output shaft, and a one-way clutch serving as a braking unit is disposed between the output shaft and a casing. .

JP-A-8-295140

  In a hybrid vehicle provided with a clutch for disconnecting the engine, it is desired that the responsiveness when starting the engine can be improved. For example, it is preferable that the responsiveness when starting the engine can be improved by the torque transmitted through the clutch.

  An object of the present invention is to provide a drive device for a hybrid vehicle that can improve responsiveness when starting an engine.

The hybrid vehicle drive device of the present invention includes an engine, a first rotating machine, a second rotating machine, a first rotating element connected to the first rotating machine, and a second rotating element connected to the engine. A differential section having the second rotating machine and a third rotating element connected to the output shaft, and a clutch for intermittently connecting the second rotating element and the engine, and releasing the clutch, And the first rotating machine that is executed at the time of transition from the running state using the second rotating machine as a power source to the running state where the clutch is engaged and the engine and the second rotating machine are used as a power source. has a rotation control, the when the rotation control is executed, and means for executing in parallel engagement control for the clutch and the semi-engaged state, before Symbol the in the rotation control the first rotating machine direction of speed change is Unlike in accordance with the vehicle speed, the vehicle speed is in the high vehicle speed In this case, the rotation speed of the first rotating machine is changed in the negative direction in the rotation control, and when the vehicle speed is low, the rotation speed of the first rotating machine is changed in the positive direction in the rotation control. and wherein a call.

  In the hybrid vehicle drive device, when the rotation speed of the first rotation machine is changed in the negative direction in the rotation control, the rotation speed of the second rotation element is equal to or lower than the first rotation speed. When the rotation speed of the second rotating element is equal to or higher than the second rotation speed, the first rotation machine is changed when the rotation speed of the first rotation machine is changed in the positive direction in the rotation control. It is preferable to stop the rotation speed change.

The hybrid vehicle drive device of the present invention includes an engine, a first rotating machine, a second rotating machine, a first rotating element connected to the first rotating machine, and a second rotating element connected to the engine. A differential section having the second rotating machine and a third rotating element connected to the output shaft, and a clutch for intermittently connecting the second rotating element and the engine, and releasing the clutch, And the first rotating machine that is executed at the time of transition from the running state using the second rotating machine as a power source to the running state where the clutch is engaged and the engine and the second rotating machine are used as a power source. The rotation control has a rotation control, the direction of the rotation speed change of the first rotating machine in the rotation control is different depending on the vehicle speed, and in the rotation control to change the rotation speed of the first rotation machine in the negative direction, When the rotation speed of the second rotation element falls below the first rotation speed, When stopping the rotation speed change of the first rotating machine and changing the rotation speed of the first rotating machine in the positive direction in the rotation control, when the rotation speed of the second rotating element is equal to or higher than the second rotation speed, the speed change of the first rotating machine stops, before Symbol first rotational speed, based on the rotational speed that allows fuel injection of the engine, the second rotational speed, full engagement of the clutch time required until to, or characterized that you are based on at least one of the upper limit of the difference is allowable speed in the clutch.

  The hybrid vehicle drive device according to the present invention shifts from a traveling state in which the clutch is released and the second rotating machine is used as a power source to a traveling state in which the clutch is engaged and the engine and the second rotating machine are used as a power source. The rotation control of the first rotating machine is executed when the rotation is performed, and the direction of the rotational speed change of the first rotating machine in the rotation control varies depending on the vehicle speed. According to the hybrid vehicle drive device of the present invention, there is an effect that the responsiveness when starting the engine can be improved.

FIG. 1 is a flowchart showing the operation of the hybrid vehicle drive device according to the embodiment. FIG. 2 is a skeleton diagram of the vehicle according to the embodiment. FIG. 3 is a diagram illustrating an operation engagement table of the hybrid vehicle drive device according to the embodiment. FIG. 4 is a collinear diagram related to clutch release EV travel. FIG. 5 is a collinear diagram showing clutch release EV traveling at a high vehicle speed. FIG. 6 is a collinear diagram showing predetermined start control at high vehicle speed. FIG. 7 is a collinear diagram showing the MG1 rotation speed fixation of the predetermined start control at a high vehicle speed. FIG. 8 is a collinear diagram showing complete engagement of the clutch in predetermined start control at high vehicle speed. FIG. 9 is an alignment chart showing engine start of the predetermined start control at a high vehicle speed. FIG. 10 is an alignment chart showing HV traveling after completion of predetermined start control at high vehicle speed. FIG. 11 is a collinear diagram showing clutch release EV traveling at a low vehicle speed. FIG. 12 is a collinear diagram showing the predetermined start control at a low vehicle speed. FIG. 13 is a collinear diagram showing the MG1 rotation speed fixing of the predetermined start control at a low vehicle speed. FIG. 14 is a collinear diagram showing complete engagement of the clutch in the predetermined start control at low vehicle speed. FIG. 15 is an alignment chart showing engine start of the predetermined start control at a low vehicle speed. FIG. 16 is an alignment chart showing HV traveling after completion of predetermined start control at low vehicle speed.

  Hereinafter, a drive device for a hybrid vehicle according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The embodiment will be described with reference to FIGS. 1 to 16. The present embodiment relates to a hybrid vehicle drive device. FIG. 1 is a flowchart showing the operation of the hybrid vehicle drive device according to the embodiment of the present invention, FIG. 2 is a skeleton diagram of the vehicle according to the embodiment, and FIG. 3 is an operation of the hybrid vehicle drive device according to the embodiment. The figure which shows an engagement table | surface, FIG. 4 is a collinear diagram which concerns on clutch releasing EV driving | running | working.

  The hybrid vehicle driving device 1-1 according to the present embodiment releases the clutch K0, stops the engine 1 and the first rotating machine MG1, and performs the second rotation in the hybrid system having the engine disconnecting clutch (clutch K0). When starting the engine from the EV running state where the machine MG2 is used as a power source, the control for changing the rotational speed of the first rotary machine MG1 to the positive rotation direction or the negative rotation direction, and the engagement control while sliding the clutch K0, The engine 1 has a start method for starting the engine 1 at the same time. Further, the direction of change in the rotational speed (positive direction / negative direction) of the first rotary machine MG1 when the engine is started varies depending on the vehicle speed. As a result, it is possible to achieve both improvement in engine start response and protection of the clutch K0.

  As shown in FIG. 2, the vehicle 100 according to the present embodiment is a hybrid (HV) vehicle having an engine 1, a first rotating machine MG1, and a second rotating machine MG2 as power sources. Vehicle 100 may be a plug-in hybrid (PHV) vehicle that can be charged by an external power source. The vehicle 100 includes a first planetary gear mechanism 10, a second planetary gear mechanism 20, a clutch K0, and an ECU 50 in addition to the power source described above.

  Further, the hybrid vehicle drive device 1-1 according to the present embodiment includes the engine 1, the first rotating machine MG1, the second rotating machine MG2, the first planetary gear mechanism 10, and the clutch K0. The hybrid vehicle drive device 1-1 may further include a control device such as the ECU 50. The hybrid vehicle drive device 1-1 can be applied to an FF (front engine front wheel drive) vehicle, an RR (rear engine rear wheel drive) vehicle, or the like. The hybrid vehicle drive device 1-1 is mounted on the vehicle 100 such that the axial direction is the vehicle width direction, for example.

  The engine 1, which is an engine, converts the combustion energy of the fuel into a rotational motion of the output shaft 1a and outputs it. The output shaft 1a of the engine 1 is connected to the input shaft 2 via a clutch K0. The input shaft 2 is disposed coaxially with the output shaft 1a of the engine 1 and on an extension line of the output shaft 1a. The input shaft 2 is connected to the first carrier 14 of the first planetary gear mechanism 10.

  The first planetary gear mechanism 10 of the present embodiment is a differential unit to which the engine 1 and the first rotary machine MG1 are connected. The first planetary gear mechanism 10 has a function as a power distribution mechanism that distributes the power of the engine 1 to the first rotary machine MG1 side and the output shaft 40 side. That is, in the hybrid vehicle drive device 1-1 according to the present embodiment, power split is performed in the first planetary gear mechanism 10 in the preceding stage among the two planetary gear mechanisms 10 and 20. The hybrid vehicle drive device 1-1 can cause the first rotating machine MG1 to generate electric power with the distributed power, and can cause the second rotating machine MG2 to be powered with the generated electric power. The first planetary gear mechanism 10 is a single pinion type and includes a first sun gear 11, a first pinion gear 12, a first ring gear 13, and a first carrier 14.

  The first ring gear 13 is coaxial with the first sun gear 11 and is disposed on the radially outer side of the first sun gear 11. The first pinion gear 12 is disposed between the first sun gear 11 and the first ring gear 13 and meshes with the first sun gear 11 and the first ring gear 13, respectively. The first pinion gear 12 is rotatably supported by the first carrier 14. The first carrier 14 is connected to the input shaft 2 and rotates integrally with the input shaft 2. Therefore, the first pinion gear 12 can rotate (revolve) around the central axis of the input shaft 2 together with the first carrier 14, and can be supported by the first carrier 14 to rotate (rotate) around the central axis of the first pinion gear 12. It is possible.

  The first sun gear 11 is connected to the rotary shaft 33 of the first rotary machine MG1. The rotating shaft 33 of the first rotating machine MG1 is disposed coaxially with the input shaft 2 and rotates integrally with the first sun gear 11. The first sun gear 11 of the present embodiment corresponds to the first rotating element connected to the first rotating machine MG1. The first carrier 14 corresponds to a second rotating element connected to the engine 1. The first ring gear 13 corresponds to a third rotating element connected to the second rotating machine MG2 and the output shaft 40.

  The clutch K0 is a clutch that connects and disconnects the first carrier 14 and the engine 1. The clutch K0 can be, for example, a friction engagement clutch. For example, the clutch K0 is controlled by hydraulic pressure to be engaged or released. The fully engaged clutch K0 connects the output shaft 1a of the engine 1 and the first carrier 14 so that the output shaft 1a and the first carrier 14 can rotate together. On the other hand, the released clutch K0 disconnects the output shaft 1a of the engine 1 from the first carrier 14 and allows relative rotation between the output shaft 1a and the first carrier 14. Note that the clutch K0 can be controlled to a half-engaged state. The half-engaged clutch K <b> 0 allows relative rotation between the output shaft 1 a and the first carrier 14.

  The second planetary gear mechanism 20 has a function as a speed reducing mechanism that decelerates and outputs the rotation of the second rotating machine MG2. The second planetary gear mechanism 20 is a single pinion type and includes a second sun gear 21, a second pinion gear 22, a second ring gear 23, and a second carrier 24. The second planetary gear mechanism 20 is disposed coaxially with the first planetary gear mechanism 10 and faces the engine 1 with the first planetary gear mechanism 10 interposed therebetween.

  The second ring gear 23 is coaxial with the second sun gear 21 and is disposed on the radially outer side of the second sun gear 21. The second pinion gear 22 is disposed between the second sun gear 21 and the second ring gear 23 and meshes with the second sun gear 21 and the second ring gear 23, respectively. The second pinion gear 22 is rotatably supported by the second carrier 24. The second carrier 24 is connected to the vehicle body side and is restricted from rotating. The second pinion gear 22 is supported by the second carrier 24 and can rotate (rotate) around the central axis of the second pinion gear 22.

  The second sun gear 21 is connected to the rotary shaft 34 of the second rotary machine MG2. The rotating shaft 34 of the second rotating machine MG2 is disposed coaxially with the input shaft 2 and rotates integrally with the second sun gear 21. The second ring gear 23 is an output element of the second planetary gear mechanism 20 and outputs the rotation input to the second sun gear 21 from the second rotating machine MG2 to the output shaft 40.

  The output shaft 40 is an output shaft of the first planetary gear mechanism 10 and the second planetary gear mechanism 20. The output shaft 40 has a cylindrical shape and is rotatably supported on the same axis as the input shaft 2. The first ring gear 13 and the second ring gear 23 are internal gears disposed on the inner peripheral surface of the output shaft 40. Accordingly, the first ring gear 13 and the second ring gear 23 are always connected and rotate integrally.

  The counter drive gear 25 is an external gear disposed on the outer peripheral surface of the output shaft 40. The torque of the engine 1 transmitted through the first planetary gear mechanism 10 and the torque of the second rotating machine MG2 transmitted through the second planetary gear mechanism 20 are output from the counter drive gear 25 to driving wheels (not shown). Is done.

  The first rotating machine MG1 and the second rotating machine MG2 each have a function as a motor (electric motor) and a function as a generator. The first rotary machine MG1 and the second rotary machine MG2 are connected to a battery via an inverter. The first rotating machine MG1 and the second rotating machine MG2 can convert the electric power supplied from the battery into mechanical power and output it, and are driven by the input power to convert the mechanical power into electric power. Can be converted. The electric power generated by the rotating machines MG1 and MG2 can be stored in the battery. As the first rotating machine MG1 and the second rotating machine MG2, for example, an AC synchronous motor generator can be used.

  The ECU 50 is an electronic control unit having a computer. The ECU 50 has a function of integrally controlling the entire vehicle 100. The ECU 50 can control the first rotary machine MG1 and the second rotary machine MG2. For example, the ECU 50 adjusts the current value supplied to the first rotary machine MG1, controls the output torque of the first rotary machine MG1, and adjusts the current value supplied to the second rotary machine MG2. The output torque of the second rotary machine MG2 can be controlled.

  The ECU 50 can control the engine 1. For example, the ECU 50 can control the opening degree of the electronic throttle valve of the engine 1, perform ignition control of the engine 1 by outputting an ignition signal, and perform fuel injection control for the engine 1. The ECU 50 can control the output torque of the engine 1 by opening control, injection control, ignition control, etc. of the electronic throttle valve.

  The ECU 50 is connected to an engine speed sensor, a vehicle speed sensor, an accelerator opening sensor, an MG1 speed sensor, an MG2 speed sensor, an input shaft speed sensor, an output shaft speed sensor, a battery sensor, and the like. By these sensors, the ECU 50 causes the engine speed Ne, the vehicle speed, the accelerator opening, the rotation speed of the first rotating machine MG1 (hereinafter also referred to as “MG1 rotation speed”) Ng, and the rotation speed of the second rotating machine MG2. (Hereinafter also referred to as “MG2 rotational speed”) Nm, rotational speed of input shaft 2 (hereinafter also referred to as “input shaft rotational speed”) Ni, rotational speed of output shaft 40, battery state SOC, etc. can do. The input shaft rotational speed Ni is also the rotational speed of the first carrier 14.

  The ECU 50 can calculate the required driving force, required power, required torque, and the like for the vehicle 100 based on the acquired information. The ECU 50 also describes the output torque of the first rotating machine MG1 (hereinafter also referred to as “MG1 torque”) and the output torque of the second rotating machine MG2 (hereinafter referred to as “MG2 torque”) based on the calculated request value. And the output torque of the engine 1 (hereinafter also referred to as “engine torque”). The ECU 50 controls the supply current to each of the rotating machines MG1, MG2 based on the MG1 torque command value and the MG2 torque command value. The ECU 50 controls the fuel injection amount, injection timing, ignition timing, and the like of the engine 1 based on the engine torque command value.

  The ECU 50 controls the clutch K0 based on a travel mode described later. The ECU 50 outputs a command value for the hydraulic pressure supplied to the clutch K0. A hydraulic control device (not shown) controls the hydraulic pressure supplied to the clutch K0 in accordance with the command value for the hydraulic pressure.

  The vehicle 100 can selectively execute hybrid (HV) traveling or EV traveling. The HV travel is a travel mode in which the vehicle 100 travels using the engine 1 and the second rotary machine MG2 as power sources. In HV traveling, the second rotary machine MG2 can be idled or the second rotary machine MG2 can generate power. EV traveling is a traveling mode in which the second rotating machine MG2 is used as a power source. In EV traveling, it is possible to travel with the engine 1 stopped.

  In the engagement table of FIG. 3, “◯” in the column of the clutch K0 indicates engagement, and “−” indicates release. In the vehicle 100, the clutch release EV travel or the clutch engagement EV travel (normal EV travel) can be selectively executed as the EV travel.

  As shown in FIG. 3, the clutch release EV running is an EV mode in which the clutch K0 is released and the second rotary machine MG2 is used as a power source. A nomographic chart relating to the clutch release EV traveling is shown in FIG. In FIG. 4, the left axis indicates the rotation speed of the first sun gear 11 and the MG1 rotation speed Ng, the central axis indicates the input shaft rotation speed Ni and the engine rotation speed Ne, and the right axis indicates the first ring gear. The rotational speed of 13 is shown. In FIG. 4, the black triangle indicates the MG1 rotational speed Ng, the black square indicates the input shaft rotational speed Ni, and the black circle indicates the engine rotational speed Ne. In the rotation directions of the first planetary gear mechanism 10 and the second planetary gear mechanism 20, the positive direction is the rotation direction of the output shaft 40 when the vehicle 100 moves forward, and the negative direction is opposite to the positive direction. The direction of rotation shall be indicated.

  In the clutch release EV traveling, the engine 1 is disconnected from the first carrier 14 by releasing the clutch K0. Therefore, the engine speed Ne is zero. In the clutch release EV travel, the vehicle 100 is driven by the MG2 torque using the second rotary machine MG2 as a power source. In the clutch release EV traveling, the MG1 rotation speed Ng may be controlled to a low rotation, for example, 0 rotation, so as to travel. Thereby, the drag loss of the first rotary machine MG1 can be reduced. Further, even when the MG1 torque is set to 0, the MG1 torque may not be applied when the MG1 rotation speed Ng can be maintained at 0 using the cogging torque. Alternatively, the MG1 rotation speed Ng may be set to 0 by d-axis locking of the first rotating machine MG1.

  In the clutch engagement EV travel (normal EV travel), as shown in FIG. 3, the clutch K0 is engaged and the EV travel is performed. In the clutch engagement EV traveling, the second rotary machine MG2 is used as a power source, and the vehicle 100 is driven by the MG2 torque. In the clutch engagement EV traveling, the engine speed Ne and the input shaft speed Ni are 0, and the first rotating machine MG1 rotates negatively.

  In HV traveling, as shown in FIG. 3, the clutch K0 is engaged, and the engine 1 and the first carrier 14 are connected. Torque output from the engine 1 is input to the first carrier 14. The first rotating machine MG1 generates a negative torque as a reaction torque against the engine torque, and outputs the engine torque from the first ring gear 13. As a result, the engine torque is transmitted from the output shaft 40 to the drive wheels via a differential device or the like, thereby generating a driving force for driving the vehicle 100 forward.

  For example, the ECU 50 can select either the clutch engagement EV travel or the clutch release EV travel during EV travel based on the travel state, the battery charge state SOC, or the like. Further, the ECU 50 can select either EV traveling or HV traveling based on the required driving force, vehicle speed, battery state of charge SOC, and the like.

  Here, when starting the engine 1 during the clutch release EV travel, there is a problem that the procedure is increased and the responsiveness is likely to be lowered. For example, when the engine is started in the clutch release EV traveling, the following method can be considered.

(1-1) The first rotating machine MG1 performs a rotation synchronization operation for setting the differential rotation speed of the clutch K0 to 0 (or substantially 0).
(1-2) The clutch K0 is engaged.
(1-3) The engine speed Ne is increased by the first rotating machine MG1, ignited, and the engine 1 is started.

  In the starting method in which (1-1) to (1-3) are performed in order, there are many starting sequences, and the engine starting time and the rising time of acceleration torque become long, and drivability may be reduced.

  In addition, the MG1 rotation speed Ng and the rotation speed of the first pinion gear 12 increase, which may cause over-rotation and increase in loss. Further, when the MG1 rotation speed Ng is high, the power generation of the first rotating machine MG1 becomes large, and the battery acceptance limit may occur. As a result, there is a possibility that the first rotating machine MG1 cannot generate the necessary torque when starting the engine due to the shortage of the maximum torque of the first rotating machine MG1. Such a problem occurs remarkably at high vehicle speeds.

  Further, when starting the engine in the clutch release EV running, the following method is also conceivable.

(2-1) Engage the clutch K0 while sliding to increase the engine speed Ne.
(2-2) Ignition is performed and the engine 1 is started.

  In the case of the starting methods (2-1) and (2-2) described above, when the clutch K0 is completely engaged, the engine speed Ne may be insufficient, and fuel injection may not be permitted. When the engine speed Ne when the clutch K0 is fully engaged is lower than the lower limit engine speed allowing fuel injection, the engine 1 is further increased by the first rotating machine MG1 and then the engine 1 is started. As a result, the responsiveness at the time of starting the engine is lowered.

  As described below, the hybrid vehicle drive device 1-1 according to the present embodiment controls the rotation of the first rotating machine MG1 (hereinafter referred to as “starting MG1” when transitioning from the clutch release EV traveling to the HV traveling. Predetermined start control for executing in parallel a control that fully engages after half-engagement of the clutch K0 (hereinafter also referred to as “engagement control at start”). Have

  The direction of the rotational speed change of the first rotary machine MG1 in the start-up MG1 rotation control differs depending on the vehicle speed. Thereby, according to the hybrid vehicle drive device 1-1 according to the present embodiment, it is possible to improve the responsiveness when starting the engine.

  In the present embodiment, when the vehicle speed V is equal to or higher than the vehicle speed threshold Vt, the MG1 rotation speed Ng is changed in the negative direction as shown in FIG. At high vehicle speeds, the differential rotation of the clutch K0 at the start of engine start is large. On the other hand, by changing the MG1 rotational speed Ng in the negative direction in the starting MG1 rotational control, the differential rotational speed of the clutch K0 can be reduced, and the frictional energy of the clutch K0 can be reduced or the clutch K0 can be completely engaged. Can be shortened.

  On the other hand, when the vehicle speed V is less than the vehicle speed threshold value Vt, the MG1 rotation speed Ng is changed in the positive direction as shown in FIG. At a low vehicle speed, the input shaft speed Ni at the start of engine start is small. For this reason, even if the clutch K0 is completely engaged, the engine speed Ne does not increase sufficiently, and fuel injection may not be performed. On the other hand, the input shaft rotational speed Ni can be increased by changing the MG1 rotational speed Ng in the positive direction in the starting MG1 rotational control. Accordingly, the shortage of the engine speed Ne when the clutch K0 is completely engaged is suppressed. Therefore, the occurrence of a procedure for increasing the engine speed Ne by the first rotating machine MG1 after the clutch K0 is completely engaged is suppressed, and the engine start time can be shortened.

  The predetermined start control according to the present embodiment will be described in detail below, when the vehicle speed V is equal to or higher than the vehicle speed threshold value Vt (at high vehicle speed) and when the vehicle speed V is less than the vehicle speed threshold value Vt (at low vehicle speed). explain.

(When V ≧ Vt)
FIG. 5 is a collinear diagram showing clutch release EV travel at high vehicle speed, FIG. 6 is a collinear diagram showing predetermined start control at high vehicle speed, and FIG. 7 is MG1 rotation speed of predetermined start control at high vehicle speed. FIG. 8 is a collinear diagram showing complete engagement of the clutch K0 in the predetermined start control at high vehicle speed, and FIG. 9 is an collinear diagram showing engine start in the predetermined start control at high vehicle speed. FIG. 10 is an alignment chart showing HV traveling after completion of predetermined start control at high vehicle speed.

  In the traveling state shown in FIG. 5, the vehicle speed V is equal to or higher than the vehicle speed threshold value Vt, and the differential rotation between the input shaft rotational speed Ni and the engine rotational speed Ne, that is, the differential rotation of the clutch K0 is large. In this case, as shown in FIG. 6, the ECU 50 changes the MG1 rotation speed Ng in the negative direction in the starting MG1 rotation control, and engages the clutch K0 while sliding the clutch K0. The ECU 50 changes the MG1 rotation speed Ng, which was 0 or substantially 0, in the negative direction, and decreases the input shaft rotation speed Ni.

  Further, the ECU 50 supplies hydraulic pressure to the clutch K0, and puts the clutch K0 in a half-engaged state. Due to the engagement of the clutch K0, the engine speed Ne increases due to the torque transmitted through the clutch K0. Due to the decrease in the input shaft rotational speed Ni and the increase in the engine rotational speed Ne, the differential rotational speed of the clutch K0 decreases. Further, the ECU 50 gradually increases the hydraulic pressure supplied to the clutch K0 to increase the torque capacity. Note that the increase speed of the supply hydraulic pressure for the clutch K0 in the start-time engagement control is smaller than the maximum speed. The increasing speed of the hydraulic pressure supplied to the clutch K0 is, for example, a reaction force cancellation torque that the second rotating machine MG2 compensates for a torque (reaction force torque) that is generated by engagement of the clutch K0 and that reduces the vehicle speed. It is preferable that the speed is in a range where the output can be output.

  When changing the MG1 rotation speed Ng in the negative direction in the starting MG1 rotation control, the ECU 50 stops the change in the MG1 rotation speed Ng when the input shaft rotation speed Ni becomes equal to or less than the first rotation speed Nit_1. FIG. 7 shows a state where the input shaft rotational speed Ni is equal to or lower than the first rotational speed Nit_1 and the change in the MG1 rotational speed Ng is stopped. By stopping the MG1 rotational speed Ng, the engine rotational speed Ne when the clutch K0 is completely engaged can be suppressed by continuing to operate the MG1 rotational speed Ng in the negative rotational direction.

  The first rotation speed Nit_1 is determined so as to restrict the engine rotation speed Ne from being less than the engine injection permission rotation speed, for example. The first rotational speed Nit_1 in the present embodiment is based on the engine rotational speed Ne that permits fuel injection of the engine 1 and is equal to or higher than the lower limit rotational speed that permits fuel injection. This suppresses the occurrence of a problem that the engine speed Ne when the clutch K0 is completely engaged is too low to perform fuel injection.

  Therefore, according to the predetermined start control of the present embodiment, it is possible to eliminate the need for the control to lift the engine speed Ne, which has decreased too much after the clutch K0 is completely engaged, by the first rotating machine MG1, and the engine The starting time can be shortened.

  FIG. 8 shows an alignment chart when the clutch K0 is completely engaged. At this time, the input shaft rotation speed Ni and the engine rotation speed Ne are equal to or higher than the first rotation speed Nit_1, and fuel injection and ignition of the engine 1 are permitted. That is, according to the predetermined start control of the present embodiment, fuel injection and ignition can be started when the clutch K0 is completely engaged. The ECU 50 commands the fuel injection of the engine 1 and ignites the engine 1 to start the engine 1 as shown in FIG.

  When the start of the engine 1 is completed, the ECU 50 starts HV traveling (see FIG. 10). The ECU 50 controls the engine 1 so as to output the engine torque determined based on the required driving force. Further, the ECU 50 causes the first rotating machine MG1 to output a negative torque so as to function as a reaction force receiver, and causes the engine torque to be output from the first ring gear 13 to the output shaft 40.

(When V <Vt)
FIG. 11 is a collinear diagram showing clutch release EV travel at low vehicle speed, FIG. 12 is a collinear diagram showing predetermined start control at low vehicle speed, and FIG. 13 is MG1 rotation speed of predetermined start control at low vehicle speed. FIG. 14 is a collinear diagram showing complete engagement of the clutch K0 in the predetermined start control at low vehicle speed, and FIG. 15 is an collinear diagram showing engine start in the predetermined start control at low vehicle speed. FIG. 16 is an alignment chart showing HV traveling after completion of predetermined start control at low vehicle speed.

  In the traveling state shown in FIG. 11, the vehicle speed V is less than the vehicle speed threshold value Vt, and the differential rotation between the input shaft rotational speed Ni and the engine rotational speed Ne, that is, the differential rotation of the clutch K0 is small. Since the input shaft rotational speed Ni is small, there is a high possibility that even if the clutch K0 is completely engaged as it is, the engine rotational speed Ne does not increase to the rotational speed at which fuel injection is permitted. In this case, as shown in FIG. 12, the ECU 50 changes the MG1 rotation speed Ng in the positive direction in the starting MG1 rotation control, and engages the clutch K0 while sliding the clutch K0. The ECU 50 changes the MG1 rotation speed Ng, which was 0 or substantially 0, in the positive direction, and increases the input shaft rotation speed Ni.

  Further, the ECU 50 supplies hydraulic pressure to the clutch K0, and puts the clutch K0 in a half-engaged state. The engine speed Ne increases due to the engagement of the clutch K0. The ECU 50 gradually increases the hydraulic pressure supplied to the clutch K0 to increase the torque capacity. The differential rotation between the input shaft rotational speed Ni and the engine rotational speed Ne decreases as the degree of engagement increases due to the increase in the supply hydraulic pressure.

  When changing the MG1 rotation speed Ng in the positive direction in the start-up MG1 rotation control, the ECU 50 stops the change in the MG1 rotation speed Ng when the input shaft rotation speed Ni becomes equal to or higher than the second rotation speed Nit_2. FIG. 13 shows a state where the input shaft rotational speed Ni is equal to or higher than the second rotational speed Nit_2 and the change in the MG1 rotational speed Ng is stopped. By stopping the MG1 rotational speed Ng, it is possible to suppress the input shaft rotational speed Ni from rising more than necessary by continuously operating the MG1 rotational speed Ng in the positive direction. Thereby, it is possible to shorten the time until the clutch K0 is completely engaged and to reduce the frictional energy of the clutch K0.

  The second rotational speed Nit_2 is preferably, for example, a rotational speed based on at least one of the time required until the clutch K0 is completely engaged or the upper limit of the differential rotational speed allowed in the clutch K0. In other words, the second rotational speed Nit_2 is preferably determined based on at least one of the viewpoint of improving the response of starting the engine and the resistance of the clutch K0. The second rotation speed Nit_2 is, for example, less than the upper limit rotation speed at which the differential rotation of the clutch K0 is allowed by a conformance test, and the time from the start of engagement of the clutch K0 to the complete engagement can be shortened. Can be determined as follows. The differential rotation speed allowed in the clutch K0 may be determined based on the amount of heat generated by the clutch K0, for example.

  The second rotational speed Nit_2 may be a rotational speed that allows fuel injection of the engine 1. In this way, after the clutch K0 is completely engaged, the engine 1 can be started by promptly performing fuel injection and ignition.

  FIG. 14 shows an alignment chart when the clutch K0 is completely engaged. Since the input shaft rotational speed Ni is increased by the MG1 rotation control at start-up, the fuel injection and ignition of the engine 1 can be performed promptly after the clutch K0 is completely engaged. If the engine speed Ne has not reached the speed at which fuel injection is permitted when the clutch K0 is fully engaged, the ECU 50 increases the engine speed Ne by the first rotating machine MG1. When the engine speed Ne has reached the speed at which fuel injection is permitted, fuel injection is performed, and the engine 1 is ignited and the engine 1 is started as shown in FIG.

  When the start of the engine 1 is completed, the ECU 50 starts HV traveling (see FIG. 16). The ECU 50 controls the engine 1 so as to output the engine torque determined based on the required driving force. Further, the ECU 50 causes the first rotary machine MG1 to output a negative torque to function as a reaction force receiver, and causes the output shaft 40 to output the engine torque.

  With reference to FIG. 1, the flow of the predetermined start control of this embodiment will be described. The control flow shown in FIG. 1 is executed during traveling, and is repeatedly executed, for example, at predetermined intervals.

  First, in step S10, the ECU 50 determines whether or not the clutch release EV traveling is in progress. As a result of the determination, if it is determined that the clutch release EV traveling is being performed (step S10-Y), the process proceeds to step S20, and if not (step S10-N), the control flow ends.

  In step S20, the ECU 50 determines whether an engine start determination has been made. As a result of the determination, if it is determined that the engine start determination has been made (step S20-Y), the process proceeds to step S30, and if not (step S20-N), the control flow ends.

  In step S30, the ECU 50 determines whether or not the vehicle speed V is equal to or higher than the vehicle speed threshold value Vt. As a result of the determination, if it is determined that the vehicle speed V is equal to or higher than the vehicle speed threshold Vt (step S30-Y), the process proceeds to step S40, and if not (step S30-N), the process proceeds to step S60.

  In step S40, the ECU 50 operates the MG1 rotation speed Ng to the negative rotation side to engage the clutch K0. The ECU 50 changes the MG1 rotation speed Ng in the negative direction and performs control to increase the degree of engagement of the clutch K0 in parallel with this. When step S40 is executed, the process proceeds to step S50.

  In step S50, the ECU 50 determines whether or not the input shaft rotational speed Ni is equal to or lower than the first rotational speed Nit_1. As a result of the determination, if it is determined that the input shaft rotational speed Ni is equal to or less than the first rotational speed Nit_1 (step S50-Y), the process proceeds to step S80, and otherwise (step S50-N). Control goes to step S40.

  In step S60, the ECU 50 operates the MG1 rotation speed Ng to the positive rotation side to engage the clutch K0. The ECU 50 changes the MG1 rotation speed Ng in the positive direction and performs control to increase the degree of engagement of the clutch K0 in parallel with this. When step S60 is executed, the process proceeds to step S70.

  In step S70, the ECU 50 determines whether or not the input shaft rotational speed Ni is greater than or equal to the second rotational speed Nit_2. As a result of the determination, if it is determined that the input shaft rotational speed Ni is greater than or equal to the second rotational speed Nit_2 (step S70-Y), the process proceeds to step S80, and if not (step S70-N), step is performed. The process proceeds to S60.

  In step S80, the MG1 rotation speed Ng is fixed by the ECU 50. The ECU 50 stops changing the MG1 rotational speed Ng and maintains the MG1 rotational speed Ng constant. When the clutch K0 is not yet fully engaged, the MG1 rotation speed Ng is fixed, but the operation of increasing the supply hydraulic pressure and completely engaging the clutch K0 is continued. When step S80 is executed and the clutch K0 is completely engaged, the process proceeds to step S90.

  In step S90, the ECU 50 completes the engine start. The ECU 50 starts the engine 1 by executing fuel injection and ignition when the engine speed Ne is at a speed that allows fuel injection. If the engine speed Ne has not reached the speed at which fuel injection is permitted, the engine speed Ne is increased by the first rotating machine MG1, and then fuel injection and ignition are executed to start the engine 1. When step S90 is executed, the process proceeds to step S100.

  In step S100, the ECU 50 executes HV traveling. When step S100 is executed, the control flow ends.

  As described above, according to the hybrid vehicle drive device 1-1 of the present embodiment, when the engine 1 is started from the clutch release EV travel, the start-time MG1 rotation control and the start-time engagement control are performed in parallel. Executed. Further, the direction of change of the MG1 rotation speed Ng in the MG1 rotation control at the start differs depending on the vehicle speed V. Therefore, the response of engine start can be improved.

  When the start time MG1 rotation control and the start time engagement control are executed in parallel, it is sufficient that the start time MG1 rotation control execution period and the start time engagement control execution period overlap. Either one of the controls may be started first or may be ended first. In the present embodiment, the start-time MG1 rotation control and the start-time engagement control are started simultaneously.

  In the predetermined start control of the present embodiment, the MG1 rotational speed Ng changes in the negative direction so as to reduce the differential rotational speed of the clutch K0 at high vehicle speeds, and the input shaft rotational speed Ni is increased at low vehicle speeds. At the same time, the MG1 rotational speed Ng changes in the positive direction. Therefore, at the time of high vehicle speed, the time required until the clutch K0 is completely engaged can be shortened to improve the engine start response. In addition, when the vehicle speed is low, a shortage of the engine speed Ne when the clutch K0 is completely engaged can be suppressed, and the engine start-up response can be improved.

  In addition, when changing the MG1 rotation speed Ng in the negative direction in the starting MG1 rotation control, the change in the MG1 rotation speed Ng stops when the rotation speed of the first carrier 14 (input shaft 2) becomes equal to or less than the first rotation speed Nit_1. When the MG1 rotation speed Ng is changed in the positive direction in the starting MG1 rotation control, the change in the MG1 rotation speed Ng is stopped when the rotation speed of the first carrier 14 becomes equal to or higher than the second rotation speed Nit_2. Therefore, it is possible to prevent the input shaft rotational speed Ni from becoming too low or too high by the start-up MG1 rotation control.

  The first rotational speed Nit_1 is based on the rotational speed that permits fuel injection of the engine. Therefore, the engine speed Ne when the clutch K0 is completely engaged can be set to the engine speed Ne at which fuel injection is permitted. The second rotational speed Nit_2 is based on at least one of the time required until the clutch K0 is completely engaged and the upper limit of the differential rotational speed allowed in the clutch K0. Therefore, it is possible to prevent the differential rotational speed of the clutch K0 from becoming too large, thereby shortening the time required until the clutch K0 is completely engaged, and reducing the frictional energy of the clutch K0.

  The first rotation speed Nit_1 is preferably a rotation speed equal to or higher than the second rotation speed Nit_2. This is because the required power is often greater in the high vehicle speed range than in the low vehicle speed range. When the required power is large, the target operating point of the engine 1 after the engine is started becomes an operating point of high rotation. If the engine speed Ne at the time of starting the engine is low, the time required for shifting to the target operating point after the engine starts increases, and inertia loss due to a change in the engine speed Ne increases, resulting in a decrease in drivability. there's a possibility that. On the other hand, by setting the first rotation speed Nit_1 to be equal to or higher than the second rotation speed Nit_2, it is possible to improve the responsiveness to the required power when starting the engine 1 by the predetermined start control.

  In the present embodiment, the first rotating element connected to the first rotating machine MG1 is the first sun gear 11, the second rotating element connected to the engine 1 is the first carrier 14, the second rotating machine MG2, and the output shaft. Although the 3rd rotation element connected to 40 was the 1st ring gear 13, it is not limited to this. The first rotating machine MG1, the engine 1, the second rotating machine MG2, and the output shaft 40 may be connected to different rotating elements of the differential unit.

  In the predetermined start control, the start-time engagement control may be omitted. That is, the hybrid vehicle drive device 1-1 only needs to have at least the MG1 rotation control at the start. The start-up MG1 rotation control may be started before the engagement of the clutch K0 is started or may be started simultaneously with the start of the engagement of the clutch K0. Even when the starting engagement control is not executed, the responsiveness when starting the engine 1 can be improved by the starting MG1 rotation control. When the MG1 rotation control at the time of starting is executed, if the clutch is fully engaged after being half-engaged, there is a further advantage that shock is suppressed.

[First Modification of Embodiment]
In the above embodiment, instead of the vehicle speed V, based on the MG2 rotation speed Nm, the direction of change of the MG1 rotation speed Ng in the start-up MG1 rotation control may be varied. For example, when the absolute value of the MG2 rotational speed Nm is equal to or larger than the absolute value of the threshold value Nmt as shown in the following formula (1), the MG1 rotational speed Ng is changed in the negative direction in the MG1 rotational control at the start.
| Nm | ≧ | Nmt | (1)

On the other hand, when the absolute value of the MG2 rotational speed Nm is less than the absolute value of the threshold Nmt as shown in the following formula (2), the MG1 rotational speed Ng is changed in the positive direction in the starting MG1 rotational control.
| Nm | <| Nmt | (2)

  Note that, in the gear train in which the MG2 rotational speed Nm is positive when the vehicle 100 moves forward, the absolute value is not used, and the MG1 rotational speed in the starting MG1 rotational control is based on the comparison result between the MG2 rotational speed Nm and the positive threshold value Nmt. The direction of the number change may be determined. In general, the rotational speed sensors of the rotating machines MG1 and MG2 have higher detection accuracy than the vehicle speed sensor. Therefore, when making the MG1 rotation speed Ng of the MG1 rotation control at the time of start different from the MG2 rotation speed Nm, the detection accuracy near the threshold is improved and the risk of erroneous detection and the like is reduced.

[Second Modification of Embodiment]
In the above embodiment, instead of stopping the change in the MG1 rotation speed Ng based on the input shaft rotation speed Ni, the change in the MG1 rotation speed Ng may be stopped based on the MG1 rotation speed Ng.

  For example, in the starting MG1 rotation control, when the MG1 rotation speed Ng is changed in the negative direction, the change in the MG1 rotation speed Ng is stopped when the MG1 rotation speed Ng becomes equal to or less than the first MG1 rotation speed Ngt_1. Further, in the starting MG1 rotation control, when the MG1 rotation speed Ng is changed in the positive direction, the change in the MG1 rotation speed Ng is stopped when the MG1 rotation speed Ng becomes equal to or higher than the second MG1 rotation speed Ngt_2. The first MG1 rotation speed Ngt_1 and the second MG1 rotation speed Ngt_2 are variable according to the vehicle speed or the MG2 rotation speed Nm. That is, based on the vehicle speed or the MG2 rotational speed Nm and the threshold value (Nit_1, Nit_2) of the input shaft rotational speed Ni, the first MG1 rotational speed Ngt_1 and the second MG1 rotational speed Ngt_2 that are threshold values of the MG1 rotational speed Ng. Is determined.

  As described above, according to the method of stopping the change of the MG1 rotation speed Ng in the MG1 rotation control at the start based on the MG1 rotation speed Ng, the existing MG1 rotation speed sensor can be used, and the input shaft rotation is newly performed. There is no need to provide a number sensor or the like. In addition, the logic for calculating the input shaft rotational speed Ni from the rotational speeds Ng and Nm of the rotating machines MG1 and MG2 can be omitted, and the calculation load on the ECU 50 can be reduced.

  The contents disclosed in the above embodiments and modifications can be executed in appropriate combination.

1-1 Hybrid Vehicle Drive Device 1 Engine 2 Input Shaft 10 First Planetary Gear Mechanism 11 First Sun Gear 12 First Pinion Gear 13 First Ring Gear 14 First Carrier 20 Second Planetary Gear Mechanism 40 Output Shaft 100 Vehicle K0 Clutch MG1 First Rotating machine MG2 Second rotating machine Ne Engine speed Ni Input shaft speed Ng MG1 speed Nm MG2 speed

Claims (3)

With the agency,
The first rotating machine,
A second rotating machine,
A differential section having a first rotating element connected to the first rotating machine, a second rotating element connected to the engine, and a third rotating element connected to the second rotating machine and an output shaft; ,
A clutch for intermittently connecting the second rotating element and the engine;
With
Executed when the clutch is disengaged and the running state using the second rotating machine as a power source is changed to the running state where the clutch is engaged and the engine and the second rotating machine are used as a power source. Having rotation control of the first rotating machine ,
Means for executing, in parallel, engagement control for bringing the clutch into a semi-engaged state when the rotation control is executed;
Direction of the rotation speed variation of the first rotating machine before Symbol rotation control Unlike in accordance with the vehicle speed,
When the vehicle speed is high, the rotation speed of the first rotating machine is changed in the negative direction in the rotation control, and when the vehicle speed is low, the rotation of the first rotating machine is rotated in the rotation control. Change the number in the positive direction
The hybrid vehicle drive system according to claim and this. When changing the rotation speed of the first rotating machine in the negative direction in the rotation control, the rotation speed change of the first rotating machine is stopped when the rotation speed of the second rotating element is equal to or lower than the first rotation speed, When changing the rotation speed of the first rotating machine in the positive direction in the rotation control, the rotation speed change of the first rotating machine is stopped when the rotation speed of the second rotating element becomes equal to or higher than the second rotation speed.
The hybrid vehicle drive system according to 請 Motomeko 1. With the agency,
The first rotating machine,
A second rotating machine,
A differential section having a first rotating element connected to the first rotating machine, a second rotating element connected to the engine, and a third rotating element connected to the second rotating machine and an output shaft; ,
A clutch for intermittently connecting the second rotating element and the engine;
With
Executed when the clutch is disengaged and the running state using the second rotating machine as a power source is changed to the running state where the clutch is engaged and the engine and the second rotating machine are used as a power source. Having rotation control of the first rotating machine,
The direction of the rotational speed change of the first rotating machine in the rotation control differs depending on the vehicle speed,
When changing the rotation speed of the first rotating machine in the negative direction in the rotation control, the rotation speed change of the first rotating machine is stopped when the rotation speed of the second rotating element is equal to or lower than the first rotation speed, When changing the rotation speed of the first rotating machine in the positive direction in the rotation control, when the rotation speed of the second rotating element is equal to or higher than the second rotation speed, the rotation speed change of the first rotating machine is stopped.
The first rotational speed is based on a rotational speed that allows fuel injection of the engine,
The second rotational speed is based on at least one of a time required until the clutch is completely engaged or an upper limit of the differential rotational speed allowed in the clutch.
Hybrid vehicle drive device, characterized in that.

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