JP5842486B2 - Engine start control device - Google Patents

Description

  The present invention relates to an engine start control device for a hybrid vehicle having an engine and a motor as power sources.

  Conventionally, an engine, a first motor / generator, a second motor / generator, a first rotating element coupled to the output shaft of the engine, a second rotating element coupled to the rotating shaft of the first motor / generator, and the second 2. Description of the Related Art A hybrid vehicle including a differential mechanism having at least a third rotating element coupled to a rotating shaft of two motors / generators and driving wheels is known.

  For example, in Patent Document 1 below, in this type of hybrid vehicle, the engine is disposed between the output shaft of the engine and the rotation shaft of the first rotation element, and allows normal rotation of the output shaft. There is disclosed a technique that includes a one-way clutch that does not allow the reverse rotation of the motor, and performs so-called EV traveling with the outputs of both the first motor / generator and the second motor / generator. In this hybrid vehicle, when the engine is started from the EV running state, the engine speed is increased by the output of the first motor / generator to crank the engine.

  Patent Document 2 listed below discloses a technique related to motoring control for maintaining the engine speed at a predetermined speed or higher during EV traveling by the output of the second motor / generator in this type of hybrid vehicle. Yes. In this hybrid vehicle, the engine speed is motored to the idle speed by controlling one of the rotating elements in the differential mechanism by controlling the engagement of the brake unit. Patent Document 3 below discloses a hybrid vehicle of this type that includes a one-way clutch that is connected to an output shaft of an engine and prevents reverse rotation of the engine.

JP 2010-254179 A JP 2009-208723 A JP 2002-103999 A

  By the way, in the hybrid vehicle described in Patent Document 1, vehicle drive torque (wheel drive torque) is generated by the outputs of both the first motor / generator and the second motor / generator during EV traveling. If the output of the first motor / generator is used to increase the engine speed when the engine is started from the EV running state, the vehicle driving torque is reduced accordingly.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an engine start control device that can improve the disadvantages of the conventional example and can suppress a decrease in drive torque when starting the engine from an EV traveling state.

To achieve the above object, the present invention provides an engine, a first motor / generator, a second motor / generator, a first rotating element coupled to an output shaft of the engine, and rotation of the first motor / generator. A differential mechanism having at least a second rotating element connected to a shaft, a rotating shaft of the second motor / generator and a third rotating element connected to a drive wheel, an output shaft of the engine, and the first rotating element An engine start control device for a hybrid vehicle, which is arranged between a rotary shaft and a one-way clutch that allows forward rotation of the output shaft but does not allow reverse rotation of the output shaft. A brake element for increasing the rotation of the first rotating element in the forward rotation direction by controlling at least one of the rotating elements in the differential mechanism; If for the output of each of the motor / generator and the second motor / generator is started the engine stopped in the EV driving state of the power, Gyoshi Kakarigosei the brake element, by the engagement control of the brake element Before the engine start control is performed, the output distribution of the first motor / generator and the second motor / generator is changed so as to reduce the brake torque during the engagement control of the brake element .

  When changing the output distribution, it is preferable to increase the second motor / generator within a range up to a maximum value.

To achieve the above object, the present invention provides an engine, a first motor / generator, a second motor / generator, a first rotating element coupled to an output shaft of the engine, and rotation of the first motor / generator. A differential mechanism having at least a second rotating element connected to a shaft, a rotating shaft of the second motor / generator and a third rotating element connected to a drive wheel, an output shaft of the engine, and the first rotating element An engine start control device for a hybrid vehicle, which is arranged between a rotary shaft and a one-way clutch that allows forward rotation of the output shaft but does not allow reverse rotation of the output shaft. A brake element for increasing the rotation of the first rotating element in the forward rotation direction by controlling at least one of the rotating elements in the differential mechanism; If for the output of each of the motor / generator and the second motor / generator is started the engine stopped in the EV running state as power, said brake elements to control the engagement, due to engagement of the front Symbol brake element If running the engine starting control is insufficient cranking rotational speed of the engine, after the execution of the engine start control by the engagement control of the brake element, the first motor the shortage of cranking rotation speed of its / it is characterized that you increase the output of the generator.

  The engine start control device according to the present invention controls the engagement of the brake element and outputs the engine output when the engine is started in the EV running state powered by the outputs of the first and second motors / generators. The rotation in the forward rotation direction of the first rotating element to which the shaft is connected is increased. That is, during this engine start control, the output of the first motor / generator is not used in order to increase the speed of the first rotating element in the forward rotation direction. Therefore, according to this engine start control device, the engine is started in the EV running state using the outputs of the first and second motors / generators as power without reducing the drive torque transmitted to the drive wheels. be able to.

FIG. 1 is a diagram illustrating an example of a hybrid vehicle to which an engine start control device according to the present invention is applied. FIG. 2 is a conventional collinear diagram in an EV traveling state in which the outputs of the first and second motors / generators are used as power. FIG. 3 is a diagram for explaining the output characteristics of the first and second motor / generators. FIG. 4 is a collinear diagram showing conventional engine start control by the output of the first motor / generator. FIG. 5 is an alignment chart of an embodiment in which a brake element shaft is newly added. FIG. 6 is an alignment chart illustrating engine start control by brake element engagement control. FIG. 7 is a diagram illustrating an example of an alignment chart after completion of engine start. FIG. 8 is a collinear diagram of the embodiment in the EV traveling state in which the outputs of the first and second motors / generators are used as power, and shows the state before the engagement control of the brake element. . FIG. 9 is a collinear diagram of the embodiment in the EV traveling state in which the outputs of the first and second motors / generators are used as power, and shows a state after the engagement control of the brake element. . FIG. 10 is a collinear diagram illustrating a case where the first motor / generator and the brake element are subjected to engine starting resistance torque. FIG. 11 is a collinear diagram illustrating a case where the second motor / generator and the brake element are subjected to engine starting resistance torque. FIG. 12 is a collinear diagram illustrating the torque of each shaft during engine start control by brake element engagement control. FIG. 13 is an alignment chart illustrating engine start control by brake element engagement control during high-speed traveling. FIG. 14 is a collinear diagram illustrating engine start control by brake element engagement control during low-speed traveling. FIG. 15 is an alignment chart for explaining an operation after execution of engine start control by brake element engagement control during low-speed traveling. FIG. 16 is a flowchart illustrating engine start control. FIG. 17 is a collinear diagram when switching from the EV running state powered by the outputs of the first and second motor / generators to the EV running state powered only by the output of the second motor / generator. . FIG. 18 is a collinear diagram illustrating engine start control from an EV traveling state in which only the output of the second motor / generator of FIG. 17 is used as power. FIG. 19 is a collinear diagram when the output distribution of the second motor / generator is increased in the EV traveling state in which the outputs of the first and second motor / generators are used as power. FIG. 20 is an alignment chart illustrating engine start control by brake element engagement control from the EV traveling state of FIG. FIG. 21 is a flowchart illustrating engine start control. FIG. 22 is a diagram showing a power split device and a brake device having a Ravigneaux type differential mechanism. FIG. 23 is a collinear diagram of a power split device having a Ravigneaux type differential mechanism and a brake device. FIG. 24 is a diagram showing a power split device and a brake device having another type of Ravigneaux type differential mechanism. FIG. 25 is a collinear diagram of a power split device and a brake device having another type of Ravigneaux type differential mechanism.

  Embodiments of an engine start control device 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 an engine start control device according to the present invention will be described with reference to FIGS.

  First, a hybrid vehicle to which the engine start control device is applied will be described. This engine start control device includes an engine serving as a power source, first and second motor / generators (MG1, MG2), a first rotating element coupled to an output shaft of the engine, and a rotating shaft of the first motor / generator. A differential mechanism having at least a second rotating element coupled to the rotating shaft of the second motor / generator and a third rotating element coupled to the drive wheel; an output shaft of the engine and a rotating shaft of the first rotating element; A hybrid vehicle including a one-way clutch (OWC) that is disposed between and allows forward rotation of the output shaft, but does not allow reverse rotation of the output shaft, is applied. An example of the hybrid vehicle will be described with reference to FIG.

  Reference numeral 1 in FIG. 1 indicates a hybrid vehicle of the present embodiment. The hybrid vehicle 1 includes an engine 10 and first and second motor / generators 20 and 30. The engine 10 is a power source such as an internal combustion engine or an external combustion engine that outputs mechanical power (engine torque) from an output shaft (crankshaft) 11. The operation of the engine 10 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 101. The first and second motor / generators 20 and 30 can be operated as power sources by power running drive, and can also be operated as generators by regenerative drive. The operations of the first and second motor / generators 20 and 30 are controlled via an inverter 81 by a motor / generator electronic control unit (hereinafter referred to as “MGECU”) 102.

  The hybrid vehicle 1 is provided with a power split device 40 and a brake device 50. The power split device 40 includes a first differential mechanism 41 and a second differential mechanism 42 that are planetary gear mechanisms. The first and second differential mechanisms 41 and 42 have a plurality of rotating elements that engage with each other. Further, the brake device 50 can stop the rotation of a certain rotating element in the second differential mechanism 42.

  The first differential mechanism 41 includes a sun gear S1, a ring gear R1, a plurality of pinion gears P1 that mesh with the sun gear S1 and the ring gear R1, and first and second carriers C11 and C12 that hold the respective pinion gears P1 so as to rotate and revolve. Is provided. In this example, since the output shaft 11 of the engine 10 is connected to the rotating shaft 43 of the first carrier C11 via the one-way clutch 15, the first carrier C11 serves as the first rotating element described above. In this example, since the rotation shaft 21 of the first motor / generator 20 is connected to the sun gear S1 directly or via a rotation shaft (not shown), the sun gear S1 serves as the second rotation element described above. In this example, the rotation shaft 31 of the second motor / generator 30 is coupled to the ring gear R1 via the reduction gear 60, the rotation shaft 44 of the carrier C2 of the second differential mechanism 42, and the carrier C2. The ring gear R1 is the third rotating element described above.

  In the hybrid vehicle 1, the ring gear R1 is connected to a final reduction gear 70 with a differential mechanism via a carrier C2 and a rotating shaft 44 of a second differential mechanism 42, which will be described later, and the power of each power source. Is transmitted to the drive wheels WL and WR.

  Here, the one-way clutch 15 allows the rotation (forward rotation) of the output shaft 11 of the engine 10 in the forward direction, but does not allow the rotation (reverse rotation) in the opposite direction. The positive direction refers to the rotational direction of the output shaft 11 when the engine 10 outputs engine torque.

  The reduction gear 60 is, for example, a two-speed reduction mechanism that switches between a high speed stage and a low speed stage. Although not shown, the reduction gear 60 includes a first sun gear, a second sun gear having a diameter larger than that of the first sun gear arranged concentrically with respect to the first sun gear and shifted in the axial direction. A ring gear arranged concentrically with respect to the sun gear, a plurality of short pinion gears meshed with the first sun gear, a plurality of long pinion gears meshed with the second sun gear and the short pinion gear, and meshed with the ring gear; A planetary gear mechanism having a short pinion gear and a carrier that holds each long pinion gear in a rotatable and revolving manner, and the first sun gear, the second sun gear, the ring gear, and the carrier serve as rotating elements to perform differential action. Has been. The speed reduction device 60 further includes a first brake that permits or restricts relative rotation of the first sun gear with respect to the rotation shaft 31 of the second motor / generator 30, and a second brake that permits or restricts rotation of the ring gear. Is provided. In the reduction gear 60, the gear position is switched between the high speed stage and the low speed stage by controlling the operations of the first and second brakes. The operation of the reduction gear 60 is controlled by an electronic control unit for shifting (hereinafter referred to as “shift ECU”) 103.

  The second differential mechanism 42 includes a sun gear S2, a ring gear R2, a plurality of pinion gears P2 that mesh with the sun gear S2 and the ring gear R2, and a carrier C2 that holds the pinion gears P2 so as to rotate and revolve. In this example, the second carrier C12 of the first differential mechanism 41 is connected to the ring gear R2, and these can rotate together. The carrier C2 is connected to the ring gear R1 of the first differential mechanism 41, and can rotate integrally with the ring gear R1. Further, a brake device 50 is connected to the sun gear S2.

  In the brake device 50, the engagement operation and the release operation are controlled by the transmission ECU 103. The brake device 50 includes a rotating member 51 that rotates integrally with the sun gear S2 of the second differential mechanism 42, a holding member 52 that is fixed to the inner wall of the casing CA, and the rotating member 51 and the holding member 52. And a brake operating unit 53 to be engaged or released. The brake operation unit 53 is a coil unit including an electromagnetic coil, for example. The sun gear S2 can rotate when the brake device 50 is in the released state, and cannot rotate when the brake device 50 is in the engaged state.

  The brake device 50 is used for switching the shift mode in the power split device 40. The brake device 50 can switch the transmission mode to the fixed transmission ratio mode when in the engaged state, and can switch the transmission mode to the continuously variable transmission ratio mode when in the released state.

  The hybrid vehicle 1 is provided with an integrated ECU (hereinafter referred to as “HVECU”) 104 that performs overall control of the engine ECU 101, the MGECU 102, and the transmission ECU 103, and constitutes an engine start control device.

  In this hybrid vehicle 1, an engine traveling mode in which the vehicle travels only with the output of the engine 10, an EV traveling mode in which the vehicle can travel with the output of at least one of the first and second motor / generators 20, 30, A hybrid travel mode is prepared in which the vehicle travels with the output of at least one of the first and second motor / generators 20 and 30. In the hybrid vehicle 1, when a drive torque increase request is made, for example, by the driver's accelerator operation during the travel in the EV travel mode, the stopped engine 10 is started and the engine travel mode or the hybrid travel mode is started. To migrate.

  Conventionally, in the configuration having the same configuration as that of the hybrid vehicle 1 of the present embodiment, the engine speed is increased to the cranking speed using the output of the first motor / generator 20 when the engine is started. Here, the engine speed required for starting the engine 10, for example, the engine speed at which ignition or the like can be performed is referred to as cranking speed. At this time, for example, if the EV running (hereinafter referred to as “MG2EV running”) is performed only with the output torque (hereinafter referred to as “MG2 output torque”) Tmg2 of the second motor / generator 30, this MG2EV. The driving torque Tdr during traveling does not change even if the output torque (hereinafter referred to as “MG1 output torque”) Tmg1 of the first motor / generator 20 is used to increase the engine speed. Hereinafter, the “drive torque Tdr” is a torque required for vehicle travel that is generated against travel resistance (air resistance, rolling resistance, etc.), and is the torque of the ring gear R1 of the first differential mechanism 41. This is the one converted into rotational torque.

  In order to start the engine 10, it is necessary to apply a starting torque Tengstart to the output shaft 11, that is, the first carrier C11. The starting torque Tengstart is a rotational torque necessary for normal rotation of the output shaft 11 and the first carrier C11, and the starting resistance torque of the engine 10 applied to the output shaft 11 and the first carrier C11 ( This is against Tengstartc) (rotational resistance due to pump loss or friction of the engine 10). In the hybrid vehicle 1, when the engine 10 is started during MG2EV traveling, the starting torque Tengstart is generated in the first carrier C11 using the MG1 output torque Tmg1.

  Here, in the case of EV traveling (hereinafter referred to as “MG1 & 2EV traveling”) using both MG1 output torque Tmg1 and MG2 output torque Tmg2, driving according to MG1 output torque Tmg1 and MG2 output torque Tmg2 is performed. Torque Tdr is generated in the ring gear R1 (Tdr = Tmg1r + Tmg2r).

  “Tmg1r” is a rotational torque (hereinafter referred to as “MG1 drive torque”) that acts on the ring gear R1 by the MG1 output torque Tmg1. “Tmg2r” is rotational torque (hereinafter referred to as “MG2 drive torque”) that acts on the ring gear R1 by the MG2 output torque Tmg2. The MG1 driving torque Tmg1r and the MG2 driving torque Tmg2r during the MG1 & 2EV traveling can be calculated by the following equations 1 and 2, respectively. “Ρ” in the equation is obtained by dividing the number of teeth Zs1 of the sun gear S1 by the number of teeth Zr1 of the ring gear R1 (ρ = Zs1 / Zr1). “Gmg2” is a gear ratio between the second motor / generator 30 and the ring gear R1.

Tmg1r = Tmg1 × 1 / ρ (1)
Tmg2r = Tmg2 × Gmg2 (2)

  FIG. 2 shows an alignment chart during the MG1 & 2EV traveling. The alignment chart includes three axes arranged in this order from the left: a sun gear shaft (MG1 axis), a carrier shaft (engine shaft), and a ring gear shaft (MG2 shaft & output shaft).

  In the hybrid vehicle 1, the engine 10 may be requested to start even during MG1 & 2EV traveling.

  For example, even if the MG1 output torque Tmg1 and the MG2 output torque Tmg2 are output to the maximum values (the maximum MG1 output torque Tmg1max and the maximum MG2 output torque Tmg2max shown in FIG. 3), the start request is the maximum MG1 in the ring gear R1. This is performed when the addition value of the drive torque Tmg1rmax and the maximum MG2 drive torque Tmg2rmax does not satisfy the drive torque increase request (required drive torque Treq in the ring gear R1) by the driver's accelerator operation. For convenience, in FIG. 3, the first motor / generator 20 and the second motor / generator 30 are shown as having the same output characteristics. However, the output characteristics are the same as shown in FIG. They may be different from each other.

  The engine start request during MG1 & 2EV traveling is also performed when the battery output to the first and second motor / generators 20 and 30 cannot satisfy the driver's required drive torque Treq. For example, some batteries are limited in time for output to the first and second motor / generators 20 and 30. If the output is not within the allowable output time, the battery has its size. I can not continue to output. For this reason, the output from the battery to the first and second motor / generators 20 and 30 may decrease due to the limitation of the output possible time. In this case, the driver's required drive torque Treq On the other hand, the MG1 driving torque Tmg1r and the MG2 driving torque Tmg2r may be insufficient. Accordingly, at that time, a start request for the engine 10 is commanded from the vehicle side in order to compensate for the shortage. Further, when the SOC amount of the battery is reduced, a start request for the engine 10 is commanded from the vehicle side.

  However, at the time of starting the engine from the MG1 & 2EV running state, when the MG1 output torque Tmg1 is partially used to increase the engine speed as shown in FIG. 4, the MG1 driving torque Tmg1r that has been output so far is used. Cannot be applied to the ring gear R1. In the ring gear R1, the MG1 driving torque Tmg1r used for raising the engine speed and the reaction torque of the starting resistance torque Tengstartc of the engine 10 (hereinafter referred to as “starting resistance reaction torque”). The drive torque Tdr is reduced by the amount corresponding to Tengstartr. As a result, when the engine is started from the conventional MG1 & 2EV traveling state, the drive torque Tdr is reduced more than during MG1 & 2EV traveling. The decrease in the drive torque Tdr is temporary until the engine start is completed. However, even though it is temporary, conventionally, for example, even though the driver requests acceleration by an accelerator operation, the driver may feel a deceleration and feel uncomfortable. There is.

  Therefore, in the past, engine start control was performed using a collinear diagram such as FIG. 2 comprising three axes, but in this embodiment, as shown in FIG. Brake element shafts (hereinafter referred to as “brake shafts”) are arranged, and engine start control is performed using a nomographic chart including the four axes.

  The brake element is to control at least one of the rotation elements S1, R1, P1, C11, and C12 in the first differential mechanism 41 (stop, increase / decrease in rotation speed, reverse rotation in rotation direction, etc.). By controlling the rotation of the rotating element by its own engagement control, the rotation of the first carrier C11 as the first rotating element in the forward rotation direction is accelerated as shown in FIG. It is something to be made.

  In the hybrid vehicle 1, when the first carrier C11 is accelerated in the forward rotation direction by the engagement control of the brake element, the engine speed is increased, and the engine 10 is started up to the cranking speed. it can. Then, in the hybrid vehicle 1, after the start of the engine 10 is completed, traveling using the engine 10 is performed in the same manner as in the past (FIG. 7).

  In the hybrid vehicle 1 of the present embodiment, the brake device 50 described above is used as a brake element. When the engagement control of the brake device 50 is performed, the rotation of the sun gear S2 of the second differential mechanism 42 stops, so that each rotation element S1, of the first differential mechanism 41 is connected via the second differential mechanism 42. This is because the rotation of R1, P1, C11, and C12 can be controlled, and the first carrier C11, which is one of them, can be accelerated in the forward rotation direction.

  Below, let us look at the torque at each axis (mainly the ring gear shaft) on the nomograph.

  When the brake element is in the released state, as described above, the MG1 driving torque Tmg1r (= Tmg1 × 1 / ρ) and the MG2 driving torque Tmg2r (Tmg2 × Gmg2) are acting on the ring gear R1 during MG1 & 2EV traveling (FIG. 8). Here, the ratio between the sun gear shaft and the brake shaft, between the brake shaft and the carrier shaft, and between the carrier shaft and the ring gear shaft is A: B: C. Accordingly, the MG1 driving torque Tmg1r during the MG1 & 2EV traveling is expressed by a modified expression of Expression 1 (Expression 3 below).

  Tmg1r = Tmg1 × (A + B) / C (3)

  When there is an engine start request during the MG1 & 2EV traveling, the engine start control device controls the engagement of the released brake element so that it is between the brake members (for example, between the rotating member 51 and the holding member 52). The brake torque Tb is generated so that the relative speed is zero and complete engagement. As a result, on the alignment chart, the EV traveling at the carrier shaft fulcrum is changed to the EV traveling at the brake shaft fulcrum (FIG. 9). At this time, in the ring gear R1, the MG2 drive torque Tmg2r does not change by being a brake shaft fulcrum, but the MG1 drive torque Tmg1r changes as shown in Equation 4 below.

  Tmg1r = Tmg1 × A / (B + C) (4)

  Thus, the MG1 driving torque Tmg1r during the MG1 & 2EV traveling changes before and after the brake element is engaged. For example, when the ratio A: B: C is assumed to be 2: 1: 1 :, the MG1 driving torque Tmg1r is calculated from the equation 3 as “Tmg1r = 3 * Tmg1” during the MG1 & 2EV traveling before the brake element engagement control. "become. On the other hand, during the MG1 & 2EV traveling after the engagement control, the MG1 driving torque Tmg1r becomes “Tmg1r = Tmg1” from the equation 4. That is, in this specific example, the MG1 driving torque Tmg1r is reduced to 1/3 before the engagement control by the brake element engagement control.

  Therefore, when starting the engine 10 during MG1 & 2EV travel, the engine start control device controls the MG1 output torque Tmg1 so that the MG1 drive torque Tmg1r does not change before and after the engagement control of the brake element. In the specific example, the MG1 output torque Tmg1 is tripled before the brake element engagement control. Thereby, the change of the drive torque Tdr before and after the engagement of the brake element can be eliminated.

  However, as described above, the starting resistance torque Tengstartc of the engine 10 acts on the first carrier C11. In order to increase the engine speed of the stopped engine 10, it is necessary to cancel the starting resistance torque Tengstartc. In this hybrid vehicle 1, the starting resistance torque Tengstartc is assigned to the first motor / generator 20 or the second motor / generator 30.

  For example, FIG. 10 is an example in which the first motor / generator 20 and the brake element are given the starting resistance torque Tengstartc. In this case, the starting resistance reaction torque Tengstarts (Equation 5 below) acts on the sun gear S1 as a share of the starting resistance torque Tengstartc. Further, the starting resistance reaction force torque Tengstartb (the following formula 6) acts on the brake element as a share of the starting resistance torque Tengstartc.

Tengstarts = Tengstartc × B / A (5)
Tengstartb = Tengstartc × (A + B) / A (6)

  The starting resistance torque Tengstartc is canceled by causing the first motor / generator 20 to output the starting resistance reaction force torque Tengstarts in the sun gear S1 and outputting the starting resistance reaction force torque Tengstartb to the brake element.

  Therefore, during the engagement control of the brake element or after the engagement control, the starting resistance of the MG1 output torque Tmg1 in the sun gear S1 with respect to the MG1 output torque Tmg1 (= Tmg1ev) before the engagement control is expressed by the following Expression 7. Increase by the reaction torque Tengstarts.

  Tmg1 = Tmg1ev + Tengstarts (7)

  Here, in order to fully engage the brake element, in addition to the start resistance reaction force torque Tengstartb, the reaction force torque Tmg1b acting on the brake element according to the MG1 output torque Tmg1 is output as the brake torque Tb. There is a need (Formula 8 below). The reaction torque Tmg1b is expressed by the following formula 9.

Tb = Tmg1b + Tengstartb (8)
Tmg1b = Tmg1 × (A + B + C) / (B + C) (9)

  FIG. 11 shows an example in which the starting resistance torque Tengstartc is provided to the second motor / generator 30 and the brake element. In this case, a starting resistance reaction force torque Tengstartr (Equation 10 below) acts on the ring gear R1 as a share of the starting resistance torque Tengstartc. Further, a starting resistance reaction force torque Tengstartb (formula 11 below) acts on the brake element as a share of the starting resistance torque Tengstartc.

Tengstartr = Tengstartc × B / (B + C) (10)
Tengstartb = Tengstartc × C / (B + C) (11)

  The starting resistance torque Tengstartc is canceled by causing the second motor / generator 30 to output the starting resistance reaction force torque Tengstartr in the ring gear R1 and outputting the starting resistance reaction force torque Tengstartb to the brake element.

Accordingly, during or after the engagement control of the brake element, the starting resistance of the MG2 driving torque Tmg2r in the ring gear R1 is compared with the MG2 driving torque Tmg2r (= Tmg2rev) before the engagement control as shown in the following Expression 12. Increase by the reaction torque Tengstartr.
Tmg2r = Tmg2rev + Tengstartr
= Tmg2 × Gmg2 + Tengstartr (12)

  Even in this case, in order to fully engage the brake element, in addition to the start resistance reaction force torque Tengstartb, as shown in the above equation 8, the reaction force torque Tmg1b corresponding to the MG1 output torque Tmg1 Must be output as the brake torque Tb.

  Here, the starting resistance torque Tengstartc is illustrated as being applied to the second motor / generator 30 and the brake element. Therefore, when starting the engine 10 during MG1 & 2EV traveling, the engine start control device increases the MG1 output torque Tmg1 so that the MG1 drive torque Tmg1r does not change before and after the engagement of the brake element, together with the engagement control of the brake element. (FIG. 12). The MG1 output torque Tmg1 is “Tmg1r * (B + C) / A” based on Equation 4 above. During this engagement control, the engine start control device outputs the brake torque Tb expressed by the above equation 8.

  Here, the MG2 drive torque Tmg2r is increased by the start resistance reaction force torque Tengstartr compared to before the brake element engagement control. However, as described above, the starting resistance reaction force torque Tengstartr cancels the starting resistance torque Tengstartc together with the starting resistance reaction force torque Tengstartb of the brake element. For this reason, the magnitude of the MG2 drive torque Tmg2r transmitted to the drive wheel side is the same as that before the brake element engagement control. Therefore, since the engine start control device does not change the drive torque toward the drive wheel before and after the engagement of the brake element, the vehicle drive torque (wheel drive torque) before the engagement control is being engaged and engaged. While maintaining the control, the engine 10 can be started during the MG1 & 2EV traveling. Therefore, according to this engine start control device, the driver does not feel deceleration when starting the engine, and therefore does not feel uncomfortable against his own acceleration request.

  Further, this engine start control device uses the brake device 50 as a brake element, thereby reducing the driving torque Tdr without causing an increase in cost and an increase in the size of the power split device 40 as compared with the prior art. In addition, the engine 10 can be started from the MG1 & 2EV traveling state.

  Further, in the present embodiment, the engine starting during the MG1 & 2 EV traveling is performed using the existing configuration (the brake device 50 and the second differential mechanism 42), but as a brake element used for the engine starting, The rotation of at least one of the rotating elements S1, R1, P1, C11, and C12 in the first differential mechanism 41 is controlled, thereby increasing the rotation of the sun gear S1 that is the first rotating element in the forward rotation direction. A dedicated engine starter may be provided.

[Modification 1]
By the way, in the hybrid vehicle 1 of the present embodiment, the engine speed may not be increased to the cranking speed required for starting the engine 10 even if the engagement control of the brake element is performed. For example, when the vehicle is traveling at a high speed, as shown in FIG. 13, the rotational difference between the brake elements is large before and after the engagement, so that the engine speed can be increased to the cranking speed by fully engaging the brake element. However, as shown in FIG. 14, when the vehicle is traveling at a low speed, the rotational difference between the brake elements before and after the engagement is small, so even if the brake elements are completely engaged, the engine speed cannot be increased to the cranking speed. there is a possibility.

  In view of this, the engine start control device according to this modified example performs the engine start control based on the engagement control of the brake element described above when there is an engine start request during the MG1 & 2EV traveling, and the engine rotation as shown in FIG. When the number does not reach the cranking rotation speed, the brake element is controlled to be released, and engine start control is performed using the conventional MG1 output torque Tmg1 (FIG. 15).

  Thus, the engine start control device can start the engine 10 even at a low vehicle speed at which the engine speed cannot be increased to the cranking speed by the engagement control of the brake element. In this case, since engine start control is performed by brake element engagement control at the first stage, when engine start control is performed by the conventional MG1 output torque Tmg1 at the second stage, MG1 being output The torque value assigned for increasing the engine speed from the output torque Tmg1 can be kept lower than before. Therefore, according to the engine start control device of this modified example, the drive torque Tdr, that is, the engine start control by the MG1 output torque Tmg1 from the beginning without performing the engagement control of the brake element, that is, Reduction in vehicle driving torque (wheel driving torque) can be minimized. Therefore, this engine start control device can start the engine 10 during MG1 & 2EV traveling while suppressing the driver's uncomfortable feeling as much as possible.

[Modification 2]
In the first modification described above, the engine start control is performed by the engagement control of the brake element, and as a result, the engine start control by the conventional MG1 output torque Tmg1 is executed. Such a situation requiring the two-stage engine start control is at a low vehicle speed as described above, and can be determined in advance from the vehicle speed.

  Therefore, in the engine start control device of this modification, when the vehicle speed V (detected by the vehicle speed sensor 91) exceeds the predetermined vehicle speed V0, if the engine is requested to start during MG1 & 2EV traveling, the embodiment described above is used. As described above, the engine 10 is started by engine start control based on brake element engagement control. On the other hand, when the vehicle speed V is equal to or lower than the predetermined vehicle speed V0, the MG2EV travel is performed without executing the MG1 & 2EV travel. Then, if there is an engine start request during the MG2EV traveling, the engine start control device executes engine start control with the conventional MG1 output torque Tmg1. The predetermined vehicle speed V0 is a maximum vehicle speed out of vehicle speeds at which the engine speed cannot be raised to the cranking speed by brake element engagement control, or a corrected vehicle speed obtained by correcting the maximum vehicle speed based on a vehicle speed detection error or the like. That is.

  Thus, in the engine start control device, when the vehicle speed V exceeds the predetermined vehicle speed V0, even if the engine 10 is started during MG1 & 2EV travel, the drive torque Tdr does not change as in the above-described embodiment. Therefore, the engine start control device can start the engine 10 during MG1 & 2EV traveling while maintaining the vehicle drive torque (wheel drive torque) before the engagement control of the brake element during the engagement control and after the engagement control. it can. On the other hand, when the vehicle speed V is equal to or lower than the predetermined vehicle speed V0, the engine start control device is in MG2EV travel instead of MG1 & 2EV travel. Therefore, even if the MG1 output torque Tmg1 is used when starting the engine 10, the drive torque It has no effect on Tdr. Therefore, the engine start control device can start the engine 10 without changing the vehicle drive torque (wheel drive torque). In other words, the engine start control device operates the engine 10 without changing the vehicle drive torque (wheel drive torque) even at low vehicle speeds where the engine speed cannot be increased to the cranking speed by the brake element engagement control. Can be started. Thus, according to this engine start control device, the engine 10 can be started without changing the vehicle drive torque (wheel drive torque) regardless of the vehicle speed, and the driver does not feel uncomfortable.

[Modification 3]
The engine start control devices of the above-described embodiment and the first and second modifications perform engine start during MG1 & 2EV traveling by engaging the brake element. For this reason, a brake torque Tb is generated in the brake element. In this modification, the load on the brake element is reduced by reducing the brake torque Tb, and the durability of the brake element is improved.

  Here, the implementation requirements for the MG1 & 2EV traveling are roughly classified into the following two forms.

  First, EV traveling according to the driver's request for increase in drive torque (required drive torque Treq in the ring gear R1) can be performed only with the MG2 output torque Tmg2, but the MG1 output torque Tmg1 and the MG2 output torque Tmg2 are used together. This is a case where the vehicle is driven in MG1 & 2EV. The first and second motors / generators 20 and 30 at a certain vehicle speed not only have different rotation speeds, but also have different high efficiency regions at operating points. For this reason, EV traveling may be more efficient when performed only with the MG2 output torque Tmg2, or may be performed more efficiently when performed together with the MG1 output torque Tmg1 than when performed only with the MG2 output torque Tmg2. Because there is. Further, when the MG2EV traveling is performed, the second motor / generator 30 becomes high temperature, and there is a possibility that the output of the MG2 output torque Tmg2 is lowered and the durability of the second motor / generator 30 is lowered. This is because, under such circumstances, it is possible to prevent the second motor / generator 30 from becoming hot by performing MG1 & 2EV traveling together with the MG1 output torque Tmg1.

  Whether this is the case can be clarified by comparing the driver's required driving torque Treq in the ring gear R1 with the torque that can be output by the second motor / generator 30. The torque that can be output by the second motor / generator 30 is a value obtained by subtracting the starting resistance reaction force torque Tengstartr in the ring gear R1 from the maximum MG2 driving torque Tmg2rmax in the ring gear R1 based on the maximum MG2 output torque Tmg2max. If the required driving torque Treq is equal to or less than the subtraction value, if EV traveling is to be performed, the higher efficiency is selected from among MG2EV traveling or MG1 & 2EV traveling.

  If there is an engine start request during the MG1 & 2EV travel performed in this way, the required drive torque Treq can be satisfied with only the MG2 drive torque Tmg2r, so that the MG1 & 2EV travel is switched to the MG2EV travel. After that, the engine start control by the conventional MG1 output torque Tmg1 is executed.

  Further, as an implementation requirement of the MG1 & 2EV traveling, the maximum MG2 driving torque Tmg2rmax is insufficient with respect to the driver's requested driving torque Treq in the ring gear R1, and the MG1 driving torque Tmg1r based on the MG1 output torque Tmg1 is not added. This also applies to the case where the drive torque Treq cannot be generated. Whether this is the case or not is determined by comparing the required drive torque Treq with the torque that can be output by the second motor / generator 30, and the required drive torque Treq and the first and second motor / generators 20. , 30 from the comparison result with the torque that can be output. The torque that can be output by the second motor / generator 30 is a value obtained by subtracting the starting resistance reaction force torque Tengstartr in the ring gear R1 from the maximum MG2 driving torque Tmg2rmax, as described above. The torque that can be output by the first and second motor / generators 20 and 30 is obtained by subtracting the starting resistance reaction torque Tengstartr in the ring gear R1 from the added value of the maximum MG1 driving torque Tmg1rmax and the maximum MG2 driving torque Tmg2rmax. Value. The required drive torque Treq is larger than the value obtained by subtracting the starting resistance reaction torque Tengstartr from the maximum MG2 drive torque Tmg2rmax, and the required drive torque Treq is started from the added value of the maximum MG1 drive torque Tmg1rmax and the maximum MG2 drive torque Tmg2rmax If the resistance reaction force torque Tengstartr is equal to or less than the value obtained by subtracting the resistance reaction torque Tengstartr, the MG1 & 2EV travel is performed if the EV travel is performed.

  When there is an engine start request during the MG1 & 2EV traveling performed in this way, the requested drive torque Treq cannot be satisfied only by the MG2 drive torque Tmg2r. Therefore, the engine start control device includes the MG2 output torque Tmg2 Is increased within the range up to the maximum value (maximum MG2 output torque Tmg2max), and the difference between the required drive torque Treq and the MG2 drive torque Tmg2r is supplemented by the MG1 drive torque Tmg1r. Here, the MG2 output torque Tmg2 is increased to the maximum MG2 output torque Tmg2max, and the difference between the required drive torque Treq and the maximum MG2 drive torque Tmg2rmax is supplemented by the MG1 drive torque Tmg1r. Then, the engine start control device executes engine start control based on brake element engagement control. During the engine start control, the starting resistance torque Tengstartc is applied to the first motor / generator 20 and the brake element. Accordingly, the MG1 output torque Tmg1 is increased by the start resistance reaction force torque Tengstarts in the sun gear S1. Also, the brake torque Tb is increased by the starting resistance reaction force torque Tengstartb.

  Hereinafter, a description will be given with reference to the flowchart of FIG.

  First, during the MG1 & 2EV traveling as shown in FIG. 8 (step ST5), the engine start control device starts the starting resistance reaction force from the sum of the driver's required drive torque Treq, the maximum MG1 drive torque Tmg1rmax, and the maximum MG2 drive torque Tmg2rmax. A value obtained by subtracting the torque Tengstartr is compared, and it is determined whether or not the required drive torque Treq is larger than the subtracted value (step ST10).

  When the required drive torque Treq is equal to or less than the subtraction value, the engine start control device determines whether the battery output to the first and second motor / generators 20 and 30 satisfies the driver's required drive torque Treq. Is determined (step ST15). The determination in step ST15 takes into account the restrictions on the battery output possible time and the SOC amount described above.

  If an affirmative determination is made in step ST15, the first and second motor / generators 20 and 30 can generate the driver's required drive torque Treq without being restricted by the battery. For this reason, in this case, the engine start control device returns to step ST5 and continues the MG1 & 2EV travel. On the other hand, if a negative determination is made in step ST15, the first and second motor / generators 20 and 30 cannot generate the driver's required drive torque Treq due to battery restrictions.

  If the required drive torque Treq is larger than the subtraction value in step ST10 or if a negative determination is made in step ST15, the engine start control device determines that the engine 10 needs to be started (step ST20), and the current drive The torque Tdr is compared with a value obtained by subtracting the starting resistance reaction force torque Tengstartr from the maximum MG2 drive torque Tmg2rmax to determine whether or not the current drive torque Tdr is equal to or less than the subtracted value (step ST25).

  The determination in step ST25 is for determining which of the above-mentioned requirements for execution of MG1 & 2EV traveling is applicable. If an affirmative determination is made in this step ST25 (Tdr ≦ Tmg2rmax−Tengstartr), EV traveling that satisfies the current driving torque Tdr can be performed with only the MG2 output torque Tmg2, but the battery power consumption is suppressed by increasing the efficiency. In order to obtain an effect, this indicates that the vehicle is in a state where MG1 & 2EV travel is being performed. On the other hand, if a negative determination is made in step ST25 (Tdr> Tmg2rmax−Tengstartr), EV driving that satisfies the current driving torque Tdr cannot be performed with only the MG2 output torque Tmg2, so MG1 & 2EV is to compensate for the shortage. It represents that the vehicle is running.

  If an affirmative determination is made in step ST25, the engine start control device generates the current drive torque Tdr as MG2 drive torque Tmg2r as shown in FIG. 17, and starts the engine with the conventional MG1 output torque Tmg1 as shown in FIG. Control is executed (step ST30). At this time, the starting resistance torque Tengstartc is assigned to the second motor / generator 30. Therefore, the second motor / generator 30 outputs the MG2 output torque Tmg2 so that the MG2 drive torque Tmg2r increases by the starting resistance reaction force torque Tengstartr.

  On the other hand, if a negative determination is made in step ST25, the engine start control device generates the maximum MG2 drive torque Tmg2rmax by causing the second motor / generator 30 to output the maximum MG2 output torque Tmg2max as shown in FIG. At the same time, a shortage (Tdr−Tmg2rmax) with respect to the current drive torque Tdr is generated by the MG1 drive torque Tmg1r based on the MG1 output torque Tmg1 (step ST35). Then, as shown in FIG. 20, the engine start control device executes engine start control based on brake element engagement control (step ST40). At that time, since the second motor / generator 30 has already output the maximum MG2 output torque Tmg2max, the starting resistance torque Tengstartc is assigned to the first motor / generator 20 and the brake element. Accordingly, the first motor / generator 20 increases the MG1 output torque Tmg1 by the starting resistance reaction force torque Tengstarts. In the brake element, the brake torque Tb is increased by the starting resistance reaction force torque Tengstartb. The brake torque Tb is output as the sum of the starting resistance reaction force torque Tengstartb and the reaction force torque Tmg1b corresponding to the MG1 output torque Tmg1, as shown in the above-described Expression 8.

  The engine start control device thus performs engine start control. Then, after the start is completed, the hybrid vehicle 1 travels using the engine torque (step ST45).

  As described above, in this modified example, if there is an engine start request during MG1 & 2EV travel, if the current drive torque Tdr can be borne only by MG2 output torque Tmg2, EV by MG2 output torque Tmg2 from MG1 & 2EV travel Switching to running is performed, and the engine start control is performed by the conventional MG1 output torque Tmg1 by the first motor / generator 20 in which the burden on the driving torque Tdr is eliminated. For this reason, the engine start control device at this time can start the engine 10 without changing the vehicle drive torque (wheel drive torque).

  Further, in this modified example, if there is an engine start request during MG1 & 2EV traveling, if the current driving torque Tdr cannot be borne only by the MG2 output torque Tmg2, the MG2 output torque Tmg2 is increased to the maximum MG2 output torque Tmg2max. At the same time, an insufficiency relative to the current drive torque Tdr is generated by the MG1 output torque Tmg1. And in this modification, engine starting control is performed by engagement control of a brake element. Therefore, also at this time, the engine start control device can start the engine 10 without changing the vehicle drive torque (wheel drive torque). In other words, the engine start control device according to this modification, when there is an engine start request during MG1 & 2EV travel, does not require any vehicle drive torque (wheel drive torque), regardless of the implementation requirements for the MG1 & 2EV travel. Since the engine 10 can be started without being changed, the driver does not feel uncomfortable.

  Furthermore, in this modified example, after the MG1 output torque Tmg1 is decreased and the MG2 output torque Tmg2 is increased and switched to MG1 & 2EV traveling, engine start control is performed by brake element engagement control. For this reason, the engine start control device of this modification can reduce the brake torque Tb output to the brake element as compared with the above-described embodiment.

  For example, the aforementioned A: B: C is set to 2: 1: 1. Further, in the MG1 & 2EV traveling state of FIG. 8, Tmg1 (Tmg1ev) = 50 Nm, Tmg2r = 200 Nm, and Tmg2rmax = 300 Nm. In this case, the MG1 driving torque Tmg1r becomes 150 Nm based on the above equation 3, and the driving torque Tdr = 350 Nm acts on the ring gear R1 by the MG1 output torque Tmg1 and the MG2 output torque Tmg2.

  The engine start control device of the above-described embodiment performs engine start control by brake element engagement control from the MG1 & 2EV traveling state of FIG. The MG1 output torque Tmg1 at the time of engine start control is a modified expression “Tmg1r *” of Expression 4 shown in FIG. 12 so that the MG1 drive torque Tmg1r (= 150 Nm) is the same as that before the brake element engagement control. (B + C) / A ”is 150 Nm. At this time, the starting resistance torque Tengstartc (= 100 Nm) is handled by the second motor / generator 30 and the brake element by 50 Nm. Therefore, the MG2 driving torque Tmg2r is 250 Nm obtained by adding the starting resistance reaction force torque Tengstartr (= 50 Nm) to the original 200 Nm. Further, the brake torque Tb is 350 Nm that is the sum of the starting resistance reaction force torque Tengstartb (= 50 Nm) and the reaction force torque Tmg1b (= 300 Nm) calculated from Equation 9 above.

  On the other hand, the engine start control device of this modified example increases the MG1 & 2EV running state of FIG. 8 from the maximum MG2 drive torque Tmg2rmax (= 300 Nm), and reduces the shortage of 50 Nm of the drive torque Tdr (= 350 Nm) to the MG1 drive torque Tmg1r. To pay. In order to generate the MG1 drive torque Tmg1r (= 50 Nm), it is understood that the MG1 output torque Tmg1 should be output by about 17 Nm based on Equation 3. The engine start control device of this modification performs engine start control by brake element engagement control from the MG1 & 2EV running state of FIG. Here, since it becomes a brake shaft fulcrum as the brake element is engaged, MG1 driving torque Tmg1r (= 50 Nm) is generated by outputting MG1 output torque Tmg1 based on Expression 4 to 50 Nm. During the engine start control, the second motor / generator 30 outputs the maximum MG2 output torque Tmg2max, so that the starting resistance torque Tengstartc (= 100 Nm) is handled by the first motor / generator 20 and the brake element. Become. The starting resistance reaction force torque Tengstarts in the sun gear S1 is 50 Nm based on Equation 5. On the other hand, the starting resistance reaction torque Tengstartb of the brake element is 150 Nm based on Equation 6. Therefore, the MG1 output torque Tmg1 is 100 Nm obtained by adding the starting resistance reaction torque Tengstarts (= 50 Nm) to the original 50 Nm. Further, the brake torque Tb is 250 Nm that is the sum of the starting resistance reaction force torque Tengstartb (= 150 Nm) and the reaction force torque Tmg1b (= 100 Nm) calculated from Equation 9 above.

  Thus, the engine start control device of this modification can reduce the brake torque Tb as compared with the above-described embodiment. Therefore, the engine start control device of this modification can reduce the load on the brake element, and can improve the durability of the brake element.

  By the way, this modification may be applied to the engine start control devices of Modifications 1 and 2 described above. In the engine start control devices of the first and second modifications, the same effect as that of this modification can be obtained.

  For example, when applied to the engine start control device of the first modification, before performing the engine start control by the engagement control of the brake element at the first stage, the above arithmetic processing according to the flowchart of FIG. 16 is executed, Engine start control is performed according to the determination result of step ST25. Then, when a negative determination is made in step ST25, the engine start control device generates the drive torque Tdr using the second motor / generator 30 as much as possible, and outputs the shortage with respect to the drive torque Tdr to the MG1 output. The engine is generated with the torque Tmg1, and then the engine start control is performed by the first stage brake element engagement control. If the engine start control does not reach the cranking rotational speed, the engine start control device performs engine start control with the conventional MG1 output torque Tmg1.

  Further, the engine start control device of Modification 2 performs engine start control by brake element engagement control when the vehicle speed V exceeds a predetermined vehicle speed V0. For this reason, when this modification is applied to the engine start control device of Modification 2, if the vehicle speed V exceeds the predetermined vehicle speed V0, the above-described arithmetic processing according to the flowchart of FIG. What is necessary is just to perform engine start control according to the determination result.

  On the other hand, when the present modification is applied to the engine start control device of the modification 2, the above calculation process according to the flowchart of FIG. The engine start control according to may be performed. For example, this is shown in the flowchart of FIG. In the description of the flowchart of FIG. 21, the description of the parts common to the flowchart of FIG.

  During the MG1 & 2EV traveling as shown in FIG. 8 (step ST5), the engine start control device determines that the vehicle speed V is equal to or lower than the predetermined vehicle speed V0 and the driver's required drive torque Treq is from the maximum MG2 drive torque Tmg2rmax. It is determined whether or not the value is larger than the value obtained by subtracting Tengstartr (step ST7). That is, the determination in step ST7 is to see whether or not an engine start request is made when the vehicle speed V during MG1 & 2EV traveling is equal to or lower than the predetermined vehicle speed V0.

  If a negative determination is made in step ST7, the process proceeds to step ST10 described above. Subsequent arithmetic processing is the same as the flowchart of FIG. On the other hand, if an affirmative determination is made in step ST7, the engine start control device proceeds to step ST20 because the engine 10 needs to be started. In this case, the vehicle speed V is equal to or lower than the predetermined vehicle speed V0, but engine start control is executed according to the determination result of step ST25.

[Modification 4]
The engine start control device of the above-described embodiment and Modification 1-3 has been described by taking the hybrid vehicle 1 including the power split device 40 and the brake device 50 shown in FIG. 1 as an example. In addition to this, each of these engine start control devices can be applied to a hybrid vehicle including a power split device composed of a Ravigneaux type differential mechanism shown below, and the same effects as those described above are provided. Can be obtained.

  For example, FIG. 22 illustrates a power split device 140 having a Ravigneaux type differential mechanism and a brake device 150.

  The differential mechanism includes a first sun gear S1, a second sun gear S2, a ring gear R, a plurality of long pinion gears PL that mesh with the first sun gear S1 and the ring gear R, and a plurality of short pins that mesh with the second sun gear S2 and the long pinion gear PL. A carrier C that holds the pinion gear PS and the long pinion gears PL and the short pinion gears PS so as to rotate and revolve is provided. In this example, the output shaft 11 of the engine 10 is connected to the ring gear R. Here, the first motor / generator 20 is connected to the first sun gear S1, and the second motor / generator 30 is connected to the second sun gear S2. Further, the second sun gear S2 is also connected to the output shaft 144 of the power split device 140, that is, the drive wheel side.

  In this differential mechanism, the ring gear R, the first sun gear S1, and the second sun gear S2 are a first rotating element, a second rotating element, and a third rotating element, respectively.

  The brake device 150 includes a rotating member 151 that rotates integrally with the carrier C of the differential mechanism, and a holding member 152 that is fixed to the inner wall of the casing CA. The brake device 150 is provided with a brake operating unit that engages or releases the rotating member 151 and the holding member 152. The brake operation part is a coil unit provided with an electromagnetic coil, for example.

  The alignment chart in this hybrid vehicle is as shown in FIG. In the differential mechanism, the ring gear R can be accelerated in the forward rotation direction by controlling the engagement of the brake device 150 as a brake element. Therefore, in this hybrid vehicle, the same effect can be obtained by applying any one of the engine start control devices of the above-described embodiment and Modification 1-3.

  FIG. 24 illustrates a power split device 240 having a Ravigneaux type differential mechanism and a brake device 250.

  The differential mechanism includes a first sun gear S1, a second sun gear S2, a ring gear R, a plurality of long pinion gears PL that mesh with the first sun gear S1 and the ring gear R, and a plurality of short gears that mesh with the second sun gear S2 and the long pinion gear PL. A carrier C that holds the pinion gear PS and the long pinion gears PL and the short pinion gears PS so as to rotate and revolve is provided. In this example, the output shaft 11 of the engine 10 is connected to the carrier C. Further, here, the first motor / generator 20 is connected to the second sun gear S2, and the second motor / generator 30 is connected to the first sun gear S1. Further, the first sun gear S1 is also connected to the output shaft 244 of the power split device 240, that is, the drive wheel side.

  In this differential mechanism, the carrier C, the second sun gear S2, and the first sun gear S1 serve as a first rotating element, a second rotating element, and a third rotating element, respectively.

  The brake device 250 includes a rotating member 251 that rotates integrally with the ring gear R of the differential mechanism, and a holding member 252 that is fixed to the inner wall of the casing CA. The brake device 250 is provided with a brake operating unit that engages or releases the rotating member 251 and the holding member 252. The brake operation part is a coil unit provided with an electromagnetic coil, for example.

  The alignment chart in this hybrid vehicle is as shown in FIG. In the differential mechanism, the carrier C can be accelerated in the forward rotation direction by controlling engagement of the brake device 250 as a brake element. Therefore, in this hybrid vehicle, the same effect can be obtained by applying any one of the engine start control devices of the above-described embodiment and Modification 1-3.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 10 Engine 11 Output shaft 15 One-way clutch 20 1st motor / generator 21 Rotating shaft 30 2nd motor / generator 31 Rotating shaft 40 Power split device 41 1st differential mechanism 42 2nd differential mechanism 50 Brake device 101 Engine ECU
102 MGECU
103 transmission ECU
104 Integrated ECU (HVECU)
140,240 Power split device 150,250 Brake device C, C2 Carrier C11 First carrier C12 Second carrier P1, P2 Pinion gear PL Long pinion gear PS Short pinion gear R, R1, R2 Ring gear S1 Sun gear, First sun gear S2 Sun gear, Second Sun gear

Claims (3)

An engine, a first motor / generator, a second motor / generator, a first rotating element coupled to the output shaft of the engine, a second rotating element coupled to the rotating shaft of the first motor / generator, and the A differential mechanism having at least a third rotating element coupled to a rotating shaft and a driving wheel of the second motor / generator, and disposed between the output shaft of the engine and the rotating shaft of the first rotating element; In an engine start control device for a hybrid vehicle including a one-way clutch that allows forward rotation of the shaft but does not allow reverse rotation of the output shaft,
A brake element is provided that accelerates the rotation of the first rotating element in the forward rotation direction by controlling at least one of the rotating elements in the differential mechanism in accordance with the engagement control,
When to start the engine during stops output of each of the first motor / generator and the second motor / generator in the EV driving state of the power, Gyoshi Kakarigosei the brake element,
Before the engine start control by the engagement control of the brake element is performed, the output distribution of the first motor / generator and the second motor / generator is changed so as to reduce the brake torque during the engagement control of the brake element. An engine start control device characterized by: When changing the output distribution, the second motor / generator serial mounting of the engine start control apparatus in claim 1 which is characterized in that increase in the range up to the maximum value. An engine, a first motor / generator, a second motor / generator, a first rotating element coupled to the output shaft of the engine, a second rotating element coupled to the rotating shaft of the first motor / generator, and the A differential mechanism having at least a third rotating element coupled to a rotating shaft and a driving wheel of the second motor / generator, and disposed between the output shaft of the engine and the rotating shaft of the first rotating element; In an engine start control device for a hybrid vehicle including a one-way clutch that allows forward rotation of the shaft but does not allow reverse rotation of the output shaft,
A brake element is provided that accelerates the rotation of the first rotating element in the forward rotation direction by controlling at least one of the rotating elements in the differential mechanism in accordance with the engagement control,
When starting the engine that is stopped in an EV running state powered by the outputs of the first motor / generator and the second motor / generator, the brake element is engaged and controlled,
Before SL If running the engine starting control by the engagement control of the brake element is insufficient cranking rotational speed of the engine, after the execution of the engine start control by the engagement control of the brake element, its cranking Rotation engine start control apparatus, characterized in that increasing the shortage of the number of the output of the first motor / generator.

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