JP2009067256A - Controller of vehicle drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve fuel efficiency by reducing energy consumption due to rotational speed control that is performed when an automatic transmission part is held in a neutral state in order to secure controllability in switching the automatic transmission part to a state of power transmission. <P>SOLUTION: If the automatic transmission part 20 is held in a neutral state while an engine 10 is maintained in a predetermined operating condition, the rotational speed (second motor rotational speed nmg2) of a transmission member 18 is controlled by a first motor generator MG1 to reach a predetermined target rotational speed nmtag in order to secure controllability for a shift from N to D. The total energies consumed by the engine 10 and the first motor generator MG1 are taken into consideration and the target rotational speed nmtag is determined while the oil temperature Toil of operating fluid and the rotational speed NOUT of an output shaft are used as parameters in such a way that the total energies are minimized, so that energy consumption due to the rotational speed control of the transmission member 18 at neutral is reduced to further improve fuel efficiency. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle drive device, and more particularly to an improvement of a control device that controls the rotational speed of a transmission member that transmits power to the automatic transmission unit when the automatic transmission unit is in a neutral state. It is.

  (a) an automatic transmission unit, (b) a transmission member that transmits power transmitted from a power source through a differential gear mechanism to the automatic transmission unit, and (c) a rotational speed of the transmission member can be changed. A rotating machine, and (d) relative to the power source via the differential gear mechanism in a neutral state in which the input clutch of the automatic transmission unit is released while maintaining the power source in a predetermined operating state. 2. Description of the Related Art A vehicle drive device is known that includes a neutral-time rotation control unit that controls a rotation speed of a transmission member that is rotatable to a predetermined target rotation speed by the rotating machine. The device described in Patent Document 1 is an example, and a planetary gear device is used as a differential gear mechanism. The ring gear is a transmission member, and the motor generator is disposed as a rotating machine on the carrier. In the neutral state in which the engine coupled to the sun gear is maintained in a predetermined operating state and the input clutch disposed between the ring gear and the automatic transmission unit is released, the transmission member is used using the motor generator. By controlling the rotation speed of the (ring gear) to be a synchronous rotation speed that matches the rotation speed on the automatic transmission side, good controllability is obtained when the input clutch is engaged and switched to the power transmission state. Therefore, it is possible to switch with excellent responsiveness while suppressing the engagement shock.

On the other hand, Patent Document 2 describes the automatic transmission unit that performs a shift by a combination of disengagement of a plurality of hydraulic friction engagement devices. In this case, the automatic transmission unit is driven by power. If the rotation speed of the transmission member is synchronously controlled so as to coincide with the rotation speed of the input rotation element when switched to the transmission state, the same effect as in Patent Document 1 can be expected.
Japanese Patent No. 3584809 JP 2005-264762 A

  However, as in Patent Document 2, in the case of an automatic transmission that performs a shift by a combination of disengagement of a plurality of hydraulic friction engagement devices, the rotational speed of the input rotation element of the automatic transmission when the neutral state is set is Since it is not known, even if the rotational speed of the transmission member is controlled to a predetermined synchronous rotational speed (rotational speed when switched to the power transmission state), it does not necessarily match the rotational speed of the input rotary element, and hydraulic friction engagement There has been a problem that the power consumption of the rotating machine increases due to the drag torque of the device or the engine load increases, resulting in a deterioration in fuel consumption.

  For example, FIG. 12 shows a neutral state in which the clutches C1 and C2 and the brakes B1 to B3 of the automatic transmission unit 20 are all released to cut off power transmission in the vehicle drive device of FIG. The switching clutch C0 and the switching brake B0 of the transmission unit 11 are also released, the engine 10 as a power source is operated at the idle rotation NEidl, and the seventh rotation element RE7 connected to the output shaft 22 is set to the vehicle speed V. This is a case where the motor is rotated at a corresponding predetermined output shaft rotational speed NOUT. In this case, it is assumed that, for example, the third speed gear stage “3rd” is established by the N → D shift and the first clutch C1 and the first brake B1 are engaged as indicated by the black circle “●”. The first motor generator MG1 controls the rotational speed (synchronous control) so that the third rotational element RE3 (same as the transmission member 18) connected to the eighth rotational element RE8 by the first clutch C1 has the synchronous rotational speed nmtag_D. However, the actual rotational speed of the eighth rotating element RE8 does not necessarily correspond to the third speed gear stage “3rd”, and is indicated by, for example, a white circle “◯” depending on the sliding resistance of each part. Is different. For this reason, a rotational speed difference is generated with the third rotational element RE3 that is synchronously controlled by the first motor generator MG1, and drag torque is generated by the first clutch C1 according to the rotational speed difference. In order to reduce the rotational speed of the third rotating element RE3 against the above, electric power is consumed by the first motor generator MG1, or the load on the engine 10 increases, resulting in poor fuel consumption.

  Although the drag torque of the clutch C1 has been described, strictly speaking, the effects of the drag torque of other clutches and brakes, other sliding resistances, and the like are complicated, and the power consumption of the first motor generator MG1 increases. The load on the engine 10 is increased, which affects fuel consumption.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to make the automatic transmission unit in a neutral state in order to ensure controllability when the automatic transmission unit is switched to the power transmission state. This is to further reduce fuel consumption by reducing energy consumption associated with rotational speed control performed in this case.

  In order to achieve such an object, the present invention provides: (a) an automatic transmission unit that performs a shift by a combination of disengagement of a plurality of hydraulic friction engagement devices; and (b) a power source through a differential gear mechanism. In a control device for a vehicle drive device comprising: a transmission member that transmits the transmitted power to the automatic transmission unit; and (c) a rotating machine that can change a rotation speed of the transmission member. When the automatic transmission is in a neutral state while maintaining the power source in a predetermined operating state, the rotational speed of the transmission member that is rotatable relative to the power source via the differential gear mechanism (E) the target rotation speed is a total energy consumption of the power source and the rotating machine. Considering its energy consumption Characterized in that it is set to be as small as possible.

  According to a second aspect of the present invention, in the control device for a vehicle drive device according to the first aspect, the target rotational speed includes an oil temperature of hydraulic oil for engaging the hydraulic friction engagement device and an output rotational speed of the automatic transmission unit. It is defined as a parameter.

  In such a control device for a vehicle drive device, the rotation speed of the transmission member becomes the predetermined target rotation speed when the automatic transmission unit is in the neutral state while the power source is maintained in the predetermined operation state. The target rotational speed is set so that the energy consumption is as small as possible in consideration of the total energy consumption of the power source and the rotating machine. Energy consumption accompanying the rotation speed control of the transmission member is reduced, and fuel efficiency is further improved.

  Here, the energy consumption of the power source and the rotating machine is affected by the drag torque of the hydraulic friction engagement device provided in the automatic transmission unit, the sliding resistance at the rotation support unit of each unit, and the like. The sliding resistance varies depending on the viscosity of the hydraulic oil, that is, the oil temperature and the rotation speed. For this reason, as in the second aspect of the invention, if the target rotation speed is determined by using the oil temperature of the hydraulic oil and the output rotation speed of the automatic transmission unit as parameters, the energy consumption associated with the rotation speed control can be reduced more efficiently. Can improve fuel efficiency.

  If the target rotational speed is set based on the energy consumption in this manner, the controllability at the time of switching may be impaired due to deviation from the synchronous rotational speed when the automatic transmission unit is switched to the power transmission state. In order to ensure controllability, it is not always necessary to perform rotational speed control so that the rotational speed of the transmission member exactly matches the synchronous rotational speed, and the target rotational speed is set so that the energy consumption is minimized. Even so, it is unlikely that the controllability at the time of switching will be greatly impaired. However, in order to ensure controllability at the time of switching, it is possible to provide an upper limit guard and a lower limit guard at the target rotational speed as necessary.

  The vehicle drive device of the present invention is configured to have a drive source such as an internal combustion engine such as an engine or an electric motor, and power is transmitted from the drive source to the transmission member via a differential gear mechanism. . The drive source is basically operated in accordance with the driver's output request amount such as the accelerator operation amount, and this is the same when the automatic transmission unit is in the neutral state. When a motor generator or an electric motor is used as a drive source in addition to the engine, they can be used as a rotating machine for controlling the rotation speed of the transmission member, and a plurality of motor generators or electric motors are used as the drive source. In this case, a part of the rotating machine can be used as a rotating machine for controlling the rotational speed, but the rotating machine for controlling the rotational speed can be arranged separately from the drive source. As the rotating machine, a generator can be used in addition to the electric motor or the motor generator.

  In carrying out the present invention, for example, (a) the differential gear mechanism includes a first rotating element connected to a motor generator, a second rotating element connected to an engine as the power source, and the transmission member. (B) a reaction force received by the motor generator so that the power of the engine is automatically transmitted from the transmission member via the planetary gear device. (C) The motor generator is also used as the rotating machine, and is controlled by the motor generator so that the rotational speed of the transmission member becomes the target rotational speed via the planetary gear unit. Configured to be. In this case, the differential gear mechanism functions as a composite distribution mechanism that combines the outputs of the engine and the motor generator and transmits them to the transmission member, or distributes the engine output to the motor generator and the transmission member. As the differential gear mechanism, the planetary gear device is preferably used as described above, but a bevel gear type differential mechanism can also be adopted.

  The differential gear mechanism is also configured to transmit the output of the power source to the transmission member by engaging a clutch provided between the two rotating elements without connecting a rotating machine such as a motor generator. It is also possible to configure such that the transmission element is forwardly or reversely driven by the output of the power source by fixing the reaction force element to be non-rotatable by the brake. Furthermore, it is also possible to employ a transmission mechanism that can establish a plurality of gear stages with different transmission ratios by combining a plurality of planetary gear devices as a differential gear mechanism. In either case, the clutch and brake are released. Thus, the rotational speed control by the neutral-time rotation control means is performed in a state where the transmission member can rotate relative to the power source. In this case, the target rotational speed may be determined so that the consumed energy becomes as small as possible, including the drag torque of the hydraulic friction engagement device provided in the differential gear mechanism.

  The automatic transmission unit performs gear shifting by a hydraulic friction engagement device such as a clutch or a brake, and is preferably used for a forward / reverse switching device or an automatic transmission that can establish a plurality of gear stages having different gear ratios. It is done. The automatic transmission unit is connected to the transmission member via, for example, a single input clutch, and a plurality of rotating elements are alternatively or simultaneously connected to the transmission member via a plurality of input clutches. However, various modes of connection with the transmission member are possible. The rotating element connected to the transmission member via the input clutch and the like can rotate relative to the output-side rotating member such as the output shaft in the neutral state, and can perform drag torque and rotation support of the hydraulic friction engagement device. Based on the sliding resistance or the like of the part, it is rotated at a predetermined rotational speed.

  The target rotation speed when the rotation speed control of the transmission member is performed by the neutral rotation control means is set so that the total energy consumption of the power source and the rotating machine is as small as possible. For example, an engine that is an internal combustion engine as the power source When the rotating machine is operated with the electric energy generated by the engine, the energy conversion efficiency of the electric path such as the power generation efficiency, the charging efficiency of the power storage device, and the discharge efficiency is taken into consideration. A target rotational speed that minimizes the fuel consumption may be determined. In the case where the rotating machine is a motor generator or a generator and the power storage device is charged by generating electric power by controlling the rotating speed of the transmission member, the target rotating speed that minimizes the fuel consumption may be determined in consideration of the energy conversion efficiency. . A target rotational speed may be set such that the power running torque of the rotating machine is zero.

  The target rotational speed is preferably determined by using the oil temperature of the hydraulic oil and the output rotational speed of the automatic transmission unit as parameters, as in the second aspect of the invention, for example, which is obtained in advance based on experiments and simulations, and stored as a map or the like. Is done. Since the output rotation speed corresponds to the vehicle speed, the vehicle speed can be set as a parameter, or another rotation speed having a certain relationship with the output rotation speed can be used.

  Further, in the neutral state, the rotation speed of the power source is generally kept at idle rotation when the accelerator is OFF. Therefore, when setting the target rotation speed, the power source is maintained so that the rotation speed of the power source is maintained at the idle rotation speed. Assuming that the source is driven and controlled, a target rotation speed that minimizes energy consumption may be obtained. However, if the rotational speed of the power source changes due to an accelerator operation, etc., the target rotational speed that minimizes the energy consumption also changes accordingly, so the target rotational speed is set using the rotational speed of the power source as a parameter. You can also. Although it is possible to set the target rotational speed using parameters such as drag resistance and other various physical quantities that affect the sliding resistance, setting the target rotational speed to minimize the energy consumption in all operating states For example, the target rotational speed may be set using only one of the hydraulic oil temperature and the output rotational speed of the automatic transmission as a parameter, or the operating state such as the oil temperature or the output rotational speed. Regardless of the difference, a constant target rotational speed with as little energy consumption as possible may be set.

  On the other hand, when the target rotational speed is set based only on energy consumption, when the automatic transmission unit is switched to the power transmission state by N → D shift or the like, the rotational speed of the transmission member is greatly separated from the synchronous rotational speed. The controllability of the vehicle is impaired, and there is a possibility that a shock may occur or the switching responsiveness may be deteriorated, so the gear stage that is established when the automatic transmission unit is switched to the power transmission state is determined based on the vehicle speed or the like, The synchronous rotational speed of the transmission member is calculated from the gear ratio of the gear stage, and a predetermined upper / lower limit guard is determined based on the synchronous rotational speed in consideration of controllability at the time of switching, and within the range of the upper / lower limit guard It is desirable to set the target rotation speed. Even if the target rotational speed is set based only on the consumed energy, it is not necessary to set the guard if the controllability at the time of switching can be sufficiently secured.

  The neutral state in which the rotation speed control is performed by the neutral rotation control means may be neutral according to a driver's selection operation such as a shift lever, or may be neutral automatically when the accelerator is off. This rotational speed control is effective when performed while the vehicle is running, but can also be performed when the vehicle is stopped.

  For example, when the rotating machine is an electric motor or a motor generator, the power running torque is feedback controlled when the rotating machine is an electric motor or a motor generator, and when the rotating machine is a generator or a motor generator. The regenerative torque (or power generation torque) is feedback controlled. When a motor generator is used as the rotating machine, the rotational speed control may be performed by controlling both the power running torque and the regenerative torque depending on whether the speed is increased or decreased. Note that when the rotational speed of the transmission member reaches a predetermined allowable range near the target rotational speed, the rotational speed control can be interrupted.

  The rotational speed control of the transmission member by the neutral-time rotation control means does not always have to be performed when the automatic transmission unit is in the neutral state while the power source is maintained in a predetermined operating state. Rotation speed control may be switched between execution and non-execution depending on driving conditions such as accelerator operation, brake operation, or driving conditions, or synchronous rotation speed as a target rotation speed under certain conditions. Can be set so that synchronization control is performed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a skeleton diagram for explaining a vehicle drive device to which the present invention is preferably applied, and is for a hybrid vehicle including an engine 10 and motor generators MG1 and MG2 as power sources. In FIG. 1, a transmission mechanism 8 includes an input shaft 14 disposed on a common axis in a transmission case 12 (hereinafter referred to as a case 12) as a non-rotating member attached to a vehicle body, and the input shaft 14. A switching transmission 11 connected directly or indirectly via a pulsation absorbing damper (vibration damping device) (not shown) and the like and connected in series to the switching transmission 11 via a transmission member (transmission shaft) 18. A stepped automatic transmission unit 20 (hereinafter referred to as an automatic transmission unit 20) functioning as an automatic transmission and an output shaft 22 connected to the automatic transmission unit 20 are provided in series. This speed change mechanism 8 is preferably used in an FR (front engine / rear drive) type vehicle vertically installed in the vehicle, and outputs the outputs of the engine 10 and the motor generators MG1 and MG2 from the output shaft 22 to the differential gear. It transmits to a pair of drive wheel 38 through the apparatus (final reduction gear) 36, a pair of axles, etc. one by one. Note that the motor generators MG1, MG2, the switching transmission 11 and the automatic transmission 20 are configured substantially symmetrically with respect to the axis, and therefore the lower half is omitted in FIG. The output shaft rotation speed NOUT, which is the rotation speed of the output shaft 22, is the output rotation speed of the automatic transmission unit 20.

  The switching-type transmission unit 11 is a mechanical mechanism that mechanically synthesizes or distributes the output of the engine 10 input to the first motor generator MG1 and the input shaft 14, and outputs the output of the engine 10 to the first motor generator. The MG1 and the transmission member 18 are distributed, or the output of the engine 10 and the output of the first motor generator MG1 are combined and output to the transmission member 18, and the transmission member 18 rotates integrally. The second motor generator MG2 is provided. The motor generators MG1 and MG2 both have functions as an electric motor and a generator. The first motor generator MG1 is mainly used as a generator to generate a reaction force, and the second motor generator MG2 is mainly an electric motor. Used to output the driving force. The second motor rotation speed Nmg2, which is the rotation speed of the second motor generator MG2, is the rotation speed of the transmission member 18, and the first motor generator MG1 is also used as a rotating machine for controlling the rotation speed of the transmission member 18 in the neutral state. It is done.

  The composite distribution mechanism 16 includes a single pinion type first planetary gear unit 24 having a predetermined gear ratio (number of teeth of the ring gear / number of teeth of the sun gear) ρ1, for example, about “0.418”, a switching clutch C0, and a switching brake. B0 is mainly provided. The first planetary gear unit 24 includes a first sun gear S1, a first carrier CA1 that supports the first planetary gear P1 so as to rotate and revolve, and a first ring gear that meshes with the first sun gear S1 via the first planetary gear P1. R1 is provided as three rotating elements.

  The first carrier CA1 is connected to the input shaft 14, that is, the engine 10, the first sun gear S1 is connected to the first motor generator MG1, and the first ring gear R1 is connected to the transmission member 18. The switching brake B0 is provided between the first sun gear S1 and the transmission case 12, and the switching clutch C0 is provided between the first sun gear S1 and the first carrier CA1. When the switching clutch C0 and the switching brake B0 are released, the first sun gear S1, the first carrier CA1, and the first ring gear R1 are brought into a differential state in which a differential action capable of rotating relative to each other is applied. The output of the engine 10 is distributed to the first motor generator MG1 and the transmission member 18, and the second motor generator MG2 is generated by electric energy generated from the first motor generator MG1 with a part of the distributed output of the engine 10. Is driven, for example, in a so-called continuously variable transmission state (electric CVT state), and the rotation of the transmission member 18 is continuously changed regardless of the predetermined rotation of the engine 10. That is, the switch-type transmission unit 11 is an electric continuously variable transmission whose speed ratio γ0 (the rotational speed of the input shaft 14 / the rotational speed of the transmission member 18) is continuously changed from the minimum value γ0min to the maximum value γ0max. Is a continuously variable transmission state that functions as The first planetary gear unit 24 corresponds to a differential gear mechanism.

  On the other hand, when the switching clutch C0 is engaged and the first sun gear S1 and the first carrier CA1 are integrally engaged, the three rotating elements S1, CA1, and R1 of the first planetary gear device 24 are integrally rotated. Since the rotational speed NE of the engine 10 and the second motor rotational speed Nmg2 that is the rotational speed of the transmission member 18 coincide with each other because the non-differential state is made, the switch-type transmission unit 11 has a gear ratio. A constant transmission state is set in which γ0 functions as a transmission with “1” fixed. Further, when the switching brake B0 is engaged instead of the switching clutch C0 and the first sun gear S1 is set to the non-differential state in which the first sun gear S1 is not rotated, the first ring gear R1 is increased more than the first carrier CA1. Since it is rotated at high speed, the switching-type transmission unit 11 is set to a constant transmission state that functions as an acceleration transmission in which the transmission ratio γ0 is fixed to a value smaller than “1”, for example, about 0.7. Thus, in the present embodiment, the switching clutch C0 and the switching brake B0 have the continuously variable transmission section 11 operating as a continuously variable transmission in which the gear ratio can be continuously changed and the continuously variable transmission. A locked state in which the gear ratio γ0 is locked at a constant speed without operating as a machine and a continuously variable transmission operation is deactivated, that is, a constant speed state in which the gear is operated as a single-stage or multiple-stage transmission with one or more gear ratios. For example, it functions as an operating state switching device that selectively switches to a constant speed shifting state in which the speed ratio γ0 is constant and operates as a single-stage or multiple-stage transmission.

  The automatic transmission unit 20 includes a single pinion type second planetary gear device 26, a single pinion type third planetary gear device 28, and a single pinion type fourth planetary gear device 30. The second planetary gear device 26 includes a second sun gear S2, a second carrier CA2 that supports the second planetary gear P2 so as to rotate and revolve, and a second ring gear R2 that meshes with the second sun gear S2 via the second planetary gear P2. For example, it has a predetermined gear ratio ρ2 of about “0.562”. The third planetary gear device 28 includes a third sun gear S3, a third carrier CA3 that supports the third planetary gear P3 so as to rotate and revolve, and a third ring gear R3 that meshes with the third sun gear S3 via the third planetary gear P3. For example, and has a predetermined gear ratio ρ3 of about “0.425”. The fourth planetary gear device 30 includes a fourth sun gear S4, a fourth carrier CA4 that supports the fourth planetary gear P4 so as to rotate and revolve, and a fourth ring gear R4 that meshes with the fourth sun gear S4 via the fourth planetary gear P4. For example, it has a predetermined gear ratio ρ4 of about “0.421”.

  In the automatic transmission unit 20, the second sun gear S2 and the third sun gear S3 are integrally connected to each other, selectively connected to the transmission member 18 via the second clutch C2, and via the first brake B1. The second carrier CA2 is selectively connected to the case 12 via the second brake B2, and the fourth ring gear R4 is selectively connected to the case 12 via the third brake B3. The second ring gear R2, the third carrier CA3 and the fourth carrier CA4 are integrally connected to each other and connected to the output shaft 22, and the third ring gear R3 and the fourth sun gear S4 are integrally connected to each other. It is selectively connected to the transmission member 18 via the first clutch C1.

  The switching clutch C0, the first clutch C1, the second clutch C2, the switching brake B0, the first brake B1, the second brake B2, and the third brake B3 (hereinafter simply referred to as the clutch C and the brake B unless otherwise specified). ) Is a hydraulic friction engagement device often used in an automatic transmission for a vehicle, and is a wet type multi-plate type in which a plurality of friction plates stacked on each other are pressed by a hydraulic actuator, or a rotating drum One end of one or two bands wound around the outer peripheral surface is constituted by a band brake or the like that is tightened by a hydraulic actuator, and is for selectively connecting the members on both sides of the band brake.

  In the speed change mechanism 8 configured as described above, for example, as shown in the engagement operation table of FIG. 2, either the clutch C or the brake B is selectively engaged, so that the first speed Any one of the gear stage “1st” to the fifth speed gear stage “5th”, the reverse gear stage “R”, or the neutral “N” is selectively established, and a predetermined gear ratio γ ( = Rotational speed NIN of the input shaft 14 / rotational speed NOUT of the output shaft 22). In particular, in this embodiment, the composite distribution mechanism 16 is provided with the switching clutch C0 and the switching brake B0, and the switching type transmission unit 11 has been described above by engaging either the switching clutch C0 or the switching brake B0. In addition to the continuously variable transmission state that operates as a continuously variable transmission, it is possible to constitute a constant transmission state that operates as a transmission having a constant gear ratio γ0. Therefore, the speed change mechanism 8 includes the switching type transmission unit 11 and the automatic transmission unit 20 which are brought into the constant speed changing state by engaging any one of the switching clutch C0 and the switching brake B0, and as a stepped transmission as a whole. The switching type transmission unit 11 and the automatic transmission unit 20 which are in a continuously variable transmission state and in which the switching clutch C0 and the switching brake B0 are both released to be in a continuously variable transmission state are electrically connected as a whole. A continuously variable transmission state that operates as a continuously variable transmission is set.

  For example, when the speed change mechanism 8 functions as a stepped transmission, as shown in FIG. 2, the gear ratio γ is set to a maximum value, for example, “due to the engagement of the switching clutch C 0, the first clutch C 1, and the third brake B 3. The first speed gear stage “1st” of about 3.357 ”is established, and the gear ratio γ is set to the first speed gear stage“ 1st ”by the engagement of the switching clutch C0, the first clutch C1, and the second brake B2. The second speed gear stage “2nd”, which is smaller than, for example, “2.180”, is established, and the gear ratio γ is set to the second speed by the engagement of the switching clutch C0, the first clutch C1, and the first brake B1. The third speed gear stage “3rd”, which is smaller than the speed gear stage “2nd”, for example, about “1.424” is established, and the engagement of the switching clutch C0, the first clutch C1, and the second clutch C2 Speed change The fourth speed gear stage “4th” in which γ is smaller than the third speed gear stage “3rd”, for example, about “1.000”, is established, and the first clutch C1, the second clutch C2, and the switching brake B0 are established. As a result, the fifth speed gear stage “5th” in which the speed ratio γ is smaller than the fourth speed gear stage “4th”, for example, about “0.705” is established.

  When the transmission mechanism 8 functions as a continuously variable transmission, both the switching clutch C0 and the switching brake B0 in the engagement table shown in FIG. 2 are released. Thereby, the switching-type transmission unit 11 functions as a continuously variable transmission, and the automatic transmission unit 20 in series functions as a stepped transmission, whereby the first speed, the second speed, and the third speed of the automatic transmission unit 20 are achieved. For each of the first and fourth gears “1st” to “4th”, the rotational speed input to the automatic transmission unit 20, that is, the second motor rotational speed Nmg2 is changed steplessly, and each gear stage “ 1st "to" 4th "provides a stepless transmission ratio range. Accordingly, the gear ratio between the gear stages “1st” to “4th” can be continuously changed continuously, and the total speed ratio (total speed ratio) γT of the speed change mechanism 8 as a whole can be obtained steplessly. It becomes like this.

  On the other hand, by the engagement of the second clutch C2 and the third brake B3, the reverse gear stage “R” having a gear ratio γ of, for example, “3.209” is established, and all the clutch C and the brake B are released. As a result, the power transmission cut-off state, that is, neutral “N” is established. In these reverse gear stages “R” and neutral “N”, both the switching clutch C0 and the switching brake B0 are released, so that the switching transmission 11 is substantially in a continuously variable transmission state.

  FIG. 3 shows a transmission mechanism 8 including a switching transmission 11 that functions as a continuously variable transmission or a first transmission, and an automatic transmission 20 that functions as a stepped transmission or a second transmission. The collinear diagram which can connect the rotational speed of each rotation element from which a connection state differs for every step | line with a straight line is shown. The collinear diagram of FIG. 3 is a two-dimensional coordinate that shows the relative relationship of the gear ratio ρ of each planetary gear unit 24, 26, 28, 30 in the horizontal axis direction and the relative rotational speed in the vertical axis direction. Of the three horizontal axes, the lower horizontal line X1 indicates the rotational speed 0, and the upper horizontal line X2 indicates the rotational speed "1.0", that is, the rotational speed NE of the engine 10 connected to the input shaft 14, An axis XG indicates the rotational speed of the transmission member 18. Further, the three vertical lines Y1, Y2, Y3 corresponding to the three rotating elements of the combining / distributing mechanism 16 constituting the switching type transmission unit 11 are first rotations configured by the first sun gear S1 in order from the left side. The element RE1, the second rotation element RE2 constituted by the first carrier CA1, and the third rotation element RE3 constituted by the first ring gear R1 are shown, and the distance between them is the first planetary gear unit 24. Is determined according to the gear ratio ρ1. Further, the five vertical lines Y4, Y5, Y6, Y7, Y8 of the automatic transmission unit 20 are, in order from the left, the fourth rotating element RE4, the second rotating element RE4 configured by the second sun gear S2 and the third sun gear S3. Consists of a fifth rotating element RE5 configured by a carrier CA2, a sixth rotating element RE6 configured by a fourth ring gear R4, a second ring gear R2, a third carrier CA3, and a fourth carrier CA4. The eighth rotation element RE8 composed of the seventh rotation element RE7, the third ring gear R3, and the fourth sun gear S4 is shown respectively, and the distance between them is the second, third, and fourth planetary gear units 26. , 28 and 30 are respectively determined according to the gear ratios ρ2, ρ3 and ρ4.

  With reference to the collinear diagram of FIG. 3, the switching-type transmission unit 11 will be described in detail. The rotational speed of the first sun gear S1 and the rotation of the first ring gear R1 are represented by an oblique straight line L0 passing through the intersection of Y2 and X2. The relationship with speed is shown. For example, when the continuously variable transmission state is switched by releasing the switching clutch C0 and the switching brake B0, the reaction force generated by the power generation (regenerative torque) of the first motor generator MG1 is controlled to change the straight line L0 and the vertical line Y1. When the rotation of the first sun gear S1 indicated by the intersection of the first sun gear S1 is raised or lowered, the rotation speed of the first ring gear R1 indicated by the intersection of the straight line L0 and the vertical line Y3, that is, the rotation speed of the transmission member 18 is the second. The motor rotation speed Nmg2 is lowered or raised. Further, when the first sun gear S1 and the first carrier CA1 are connected by the engagement of the switching clutch C0, the three rotating elements are brought into a locked state in which the three rotating elements are integrally rotated, so that the straight line L0 is made to coincide with the horizontal line X2. The transmission member 18 is rotated at the same rotation as the engine rotation speed NE. When the rotation of the first sun gear S1 is stopped by the engagement of the switching brake B0, the straight line L0 is in the state shown in FIG. 3, and the first ring gear R1, that is, the transmission indicated by the intersection of the straight line L0 and the vertical line Y3. The second motor rotation speed Nmg2 that is the rotation speed of the member 18 is a rotation increased from the engine rotation speed NE.

  The automatic transmission unit 20 will be described in detail with reference to the collinear diagram of FIG. 3. The rotational speed of the eighth rotating element RE8 is indicated by the engagement of the first clutch C1 and the third brake B3. A seventh rotation element connected to the output shaft 22 and an oblique straight line L1 passing through the intersection of the vertical line Y8 and the horizontal line X2 and the intersection of the vertical line Y6 and the horizontal line X1 indicating the rotation speed of the sixth rotation element RE6. The rotational speed of the output shaft 22 (output shaft rotational speed NOUT) at the first speed gear stage “1st” is shown at the intersection with the vertical line Y7 indicating the rotational speed of RE7. Similarly, an intersection of an oblique straight line L2 determined by engaging the first clutch C1 and the second brake B2 and a vertical line Y7 indicating the rotation speed of the seventh rotation element RE7 connected to the output shaft 22 Thus, the rotational speed of the output shaft 22 at the second speed gear stage “2nd” is shown. At the intersection of an oblique straight line L3 determined by engaging the first clutch C1 and the first brake B1, and a vertical line Y7 indicating the rotational speed of the seventh rotating element RE7 connected to the output shaft 22, The rotational speed of the output shaft 22 at the third speed gear stage “3rd” is shown. At the intersection of a horizontal straight line L4 determined by engaging the first clutch C1 and the second clutch C2, and a vertical line Y7 indicating the rotational speed of the seventh rotating element RE7 connected to the output shaft 22, The rotational speed of the output shaft 22 at the fourth speed gear stage “4th” is shown. In the first speed gear stage “1st” to the fourth speed gear stage “4th”, the switching clutch C0 is engaged, and as a result, the switching speed is changed to the eighth rotation element RE8 at the same rotational speed as the engine rotational speed NE. Power from the unit 11, that is, the combining / distributing mechanism 16 is input. However, when the switching brake B0 is engaged instead of the switching clutch C0, the power from the switching transmission 11 is input at a higher rotational speed than the engine rotational speed NE, so the first clutch C1, the second clutch At the intersection of the horizontal straight line L5 determined by the engagement of the clutch C2 and the switching brake B0 and the vertical line Y7 indicating the rotational speed of the seventh rotating element RE7 connected to the output shaft 22, the fifth gear The rotational speed of the output shaft 22 at the stage “5th” is shown.

  FIG. 4 illustrates a signal input to the electronic control device 40 for controlling the speed change mechanism 8 of the present embodiment and a signal output from the electronic control device 40. The electronic control unit 40 includes a so-called microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like, and performs signal processing in accordance with a program stored in advance in the ROM while using a temporary storage function of the RAM. By performing the above, hybrid drive control relating to the engine 10 and motor generators MG1, MG2 and shift control of the automatic transmission unit 20 are executed.

  The electronic control unit 40 includes a signal indicating the engine water temperature, a signal indicating the shift operation position, a signal indicating the engine rotation speed NE that is the rotation speed of the engine 10, and a gear ratio row setting from the sensors and switches shown in FIG. A signal indicating a value, a signal for instructing an M (manual shift) mode, an air conditioner signal indicating the operation of the air conditioner, a vehicle speed signal corresponding to the rotational speed NOUT of the output shaft 22, and the temperature (oil temperature) of the hydraulic oil of the automatic transmission 20 An oil temperature signal indicating Toil, a signal indicating a side brake operation, a signal indicating a foot brake operation, a catalyst temperature signal indicating a catalyst temperature, an accelerator operation amount signal indicating an operation amount (output required amount) of an accelerator pedal, a cam angle signal, Snow mode setting signal indicating snow mode setting, acceleration signal indicating vehicle longitudinal acceleration, auto cruise signal indicating auto cruise driving , A vehicle weight signal indicating the weight of the vehicle, a wheel speed signal indicating the wheel speed of each drive wheel, and a stepped gear for switching the switching-type transmission unit 11 to a constant speed shift state in order to cause the transmission mechanism 8 to function as a stepped transmission. A signal indicating the presence / absence of a switch operation, a signal indicating the presence / absence of a continuously variable switch operation for switching the switching-type transmission unit 11 to a continuously variable transmission state in order to cause the transmission mechanism 8 to function as a continuously variable transmission, the first motor generator MG1 A signal representing the rotation speed Nmg1, a signal representing the rotation speed Nmg2 of the second motor generator MG2, and the like are respectively supplied. Further, the electronic control unit 40 receives a drive signal for a throttle actuator that controls the opening of the throttle valve, a boost pressure adjustment signal for adjusting the boost pressure, and an electric air conditioner drive signal for operating the electric air conditioner. An ignition signal for instructing the ignition timing of the engine 10, an instruction signal for instructing the operation of the motor generators MG1 and MG2, a shift position (operation position) display signal for operating the shift indicator, and a gear ratio for displaying the gear ratio A display signal, a snow mode display signal for displaying that it is in the snow mode, an ABS operation signal for operating an ABS actuator for preventing the wheel from slipping during braking, and M for displaying that the M mode is selected Mode display signal, hydraulic friction engagement device for composite distribution mechanism 16 and automatic transmission unit 20 A valve command signal for operating an electromagnetic valve included in the hydraulic control circuit 42 to control the hydraulic actuator, a drive command signal for operating an electric hydraulic pump that is a hydraulic source of the hydraulic control circuit 42, and driving an electric heater Signal for driving, a signal to the computer for cruise control control, etc. are output respectively.

  FIG. 5 is a functional block diagram for explaining a main part of the control function by the electronic control unit 40. In FIG. 5, the switching control means 50 selectively switches the transmission mechanism 8 between the continuously variable transmission state and the stepped transmission state based on the vehicle state. That is, whether the speed change mechanism 8 is a stepped control region for switching to the stepped shift state is determined from, for example, the vehicle speed V and the switching map indicated by the broken line and the two-dot chain line in FIG. Judgment is made based on the vehicle state indicated by the output torque Tout (other driving force-related values are acceptable), and in the case of a stepped control region of high vehicle speed or high output torque, the hybrid control means 52 is hybrid controlled or A signal for disabling or prohibiting the stepless shift control is output, and the stepped shift control means 54 is permitted to perform a shift control at a preset stepped shift. The output torque Tout is obtained based on, for example, the accelerator operation amount, the throttle valve opening, and the like.

  The hybrid control means 52 operates the engine 10 in an efficient operating range in the continuously variable transmission state of the transmission mechanism 8, that is, the continuously variable transmission state of the switching transmission 11, while the engine 10 and the first motor generator MG1 and In other words, the distribution of the driving force with the second motor generator MG2 is changed so as to be optimized, and the transmission gear ratio γ0 of the switching transmission 11 as an electrical continuously variable transmission is controlled. Further, the stepped shift control means 54 is based on the vehicle state indicated by the vehicle speed V and the output torque Tout from the shift map indicated by the solid line and the alternate long and short dash line in FIG. Is determined, and the speed change control of the speed change mechanism 8 is executed. FIG. 2 shows a combination of operations of the hydraulic friction engagement device, that is, the clutch C and the brake B, selected in the shift control at this time. That is, the entire transmission mechanism 8, that is, the switching transmission unit 11 and the automatic transmission unit 20 function as a so-called stepped automatic transmission, and the gear stage is achieved according to the engagement table shown in FIG.

  On the other hand, when the switching control unit 50 determines that the transmission mechanism 8 is a continuously variable control region for switching the transmission mechanism 8 to the continuously variable transmission state according to the switching map stored in advance in the map storage unit 56, the transmission mechanism 8 as a whole. A command for releasing the switching clutch C0 and the switching brake B0 is output to the hydraulic control circuit 42 so that the continuously variable transmission unit 11 is in a continuously variable transmission state so that a continuously variable transmission is possible so that a continuously variable transmission state is obtained. At the same time, a signal for permitting hybrid control is output to the hybrid control means 52, and the automatic transmission unit 20 is automatically shifted to the stepped shift control means 54 according to the shift map stored in advance in the map storage means 56. Output a signal that permits this. In this case, the stepped shift control means 54 performs an automatic shift by an operation excluding the engagement of the switching clutch C0 and the switching brake B0 in the engagement table of FIG. As described above, the switching-type transmission unit 11 switched to the continuously variable transmission state based on the predetermined condition by the switching control means 50 functions as a continuously variable transmission, and the serial automatic transmission unit 20 functions as a stepped transmission. As a result, an appropriate magnitude of driving force can be obtained, and at the same time, the automatic transmission unit 20 can be connected to the first speed, second speed, third speed, and fourth speed of the automatic transmission unit 20. The input rotation speed, that is, the second motor rotation speed Nmg2 is changed steplessly, and a stepless gear ratio range is obtained for each gear step. Therefore, the gear ratio between the respective gear stages is continuously variable continuously, and the transmission mechanism 8 as a whole is in a continuously variable transmission state, so that the total gear ratio γT can be obtained continuously.

  The hybrid control means 52 calculates the driver's required output from, for example, the accelerator operation amount and the vehicle speed V, calculates the required driving force from the driver's required output and the charge request value, and calculates the engine speed NE and the total output. Based on the total output and the engine rotational speed NE, the engine 10 is controlled to obtain a predetermined engine output, and the power generation amount of the first motor generator MG1 is controlled. The hybrid control means 52 executes the control in consideration of the gear position of the automatic transmission unit 20, or issues a shift command to the automatic transmission unit 20 for improving fuel consumption. In such hybrid control, the engine rotational speed NE determined to operate the engine 10 in an efficient operating range, the rotational speed of the transmission member 18 determined by the vehicle speed V and the gear stage of the automatic transmission unit 20, that is, the second motor rotation. In order to match the speed Nmg2, the switching transmission 11 is made to function as an electrical continuously variable transmission. That is, the hybrid control means 52 makes the total speed ratio γT of the speed change mechanism 8 so that the engine 10 is operated along a prestored optimum fuel efficiency rate curve that achieves both drivability and fuel efficiency during continuously variable speed travel. The target gear ratio is determined, the gear ratio γ0 of the switching transmission 11 is controlled so as to obtain the target value, and the total gear ratio γT is controlled within the changeable range, for example, in the range of 13 to 0.5. Will do.

  At this time, since the hybrid control means 52 supplies the electric energy generated by the first motor generator MG1 to the power storage device 60 and the second motor generator MG2 through the inverter 58, the main part of the power of the engine 10 is mechanically transmitted. Although it is transmitted to the member 18, a part of the motive power of the engine 10 is consumed for the power generation of the first motor generator MG1, converted into electric energy there, supplied to the second motor generator MG2 through the inverter 58, 2 is transmitted from the motor generator MG2 to the transmission member 18. Electrical path from conversion of part of the power of the engine 10 into electrical energy and conversion of the electrical energy into mechanical energy by a device related from the generation of the electrical energy to consumption by the second motor generator MG2. Is configured. Further, the hybrid control means 52 can make the motor travel by the electric CVT function of the switching transmission 11 regardless of whether the engine 10 is stopped or idling. Further, the hybrid control means 52 operates the first motor generator MG1 and / or the second motor generator MG2 even when the switching type transmission unit 11 is in the stepped transmission state (constant transmission state) while the engine 10 is stopped. It can also be driven by a motor.

  Thereby, for example, in low-medium speed travel and low-medium power travel of the vehicle, the speed change mechanism 8 is set to a continuously variable transmission state to ensure the fuel efficiency of the vehicle, but the vehicle speed V exceeds a predetermined determination vehicle speed. In this case, the transmission mechanism 8 is in a stepped transmission state in which it operates as a stepped transmission, and the output of the engine 10 is transmitted to the drive wheels 38 exclusively through a mechanical power transmission path. As a result, the conversion loss between the power and electric energy generated when operating as is suppressed, and the fuel consumption is improved. When the output torque Tout exceeds a predetermined determination value, the output mechanism T10 is in a stepped shift state in which the speed change mechanism 8 operates as a stepped transmission, and the output of the engine 10 is driven by a drive wheel exclusively through a mechanical power transmission path. In other words, the region where the electric continuously variable transmission is operated is the low and medium speed traveling and the low and medium power traveling of the vehicle, and in other words, the electric energy that should be generated by the first motor generator MG1. The maximum value of electrical energy transmitted by first motor generator MG1 can be reduced, and first motor generator MG1 or a vehicle drive device including the first motor generator MG1 can be further downsized.

  5 and 7, a shift operation device 72 that is a manual transmission operation device including a shift lever 74 that is operated to select a plurality of types of shift positions is disposed beside the driver's seat, for example. The shift lever 74 is in a neutral state in which all clutches C and brakes B of the speed change mechanism 8 are released and power transmission is interrupted, and the parking position “P (parking)” for locking the output shaft 22, reverse drive The reverse travel position “R (reverse)” for traveling, the neutral position “N (neutral)” that sets the speed change mechanism 8 to the neutral state, the forward automatic shift travel position “D (drive)”, and the forward manual shift travel position “ "M (manual)" is provided so as to be manually operated. In the “D” position, an automatic shift mode is established in which shift control is performed using all gear stages “1st” to “5th”.

  The “M” position is provided, for example, adjacent to the width direction of the vehicle at the same position as the “D” position in the longitudinal direction of the vehicle, and when the shift lever 74 is operated to the “M” position, Any of the five shift ranges from the D range to the L range is selected according to the operation of the shift lever 74. Specifically, at the “M” position, an upshift position “+” and a downshift position “−” are provided in the front-rear direction of the vehicle, and the shift lever 74 has their upshift position “+”. "Or downshift position"-", the shift range is increased or decreased one by one. The five speed ranges, D range to L range, are a plurality of types of shifts with different total speed ratios γT on the high speed side (minimum speed ratio) in the change range of the total speed ratio γT that allows automatic transmission control of the speed change mechanism 8. Specifically, the high-speed gear stage that can change the speed of the automatic transmission unit 20 is reduced by one, and the fastest gear stage of the D range is the fifth speed gear stage “5th”. , The fourth speed gear stage is “4th”, the third range is the third speed gear stage “3rd”, the second range is the second speed gear stage “2nd”, and the L range is the first speed gear stage “1st”. The shift lever 74 is automatically returned from the upshift position “+” and the downshift position “−” to the “M” position by a biasing means such as a spring.

The shift operation device 72 is provided with a shift position sensor 76 for detecting the operation position of the shift lever 74, and outputs a shift position signal P _SH indicating the operation position of the shift lever 74 to the shift position determination means 70. To do. The shift position determination means 70 determines to which operating position the shift lever 74 has been operated based on the shift position signal _PSH, and to the upshift position “+” or the downshift position “−” at the “M” position. It is determined whether or not an operation has been performed. The stepped shift control means 54 performs the shift control of the automatic transmission unit 20 of the transmission mechanism 8 according to the shift position determined by the shift position determination means 70 and is operated to the “N” position. If this occurs, all the clutches C and brakes B of the transmission mechanism 8 are released to bring the transmission mechanism 8 into the neutral state.

  Here, when the vehicle is running or when the vehicle is stopped, the shift lever 74 is operated to the “N” position, and the clutch 10 and the brake B of the speed change mechanism 8 are all released to the neutral state. Except for the second rotating element RE2 (carrier CA1) and the seventh rotating element RE7 (ring gear R2 and carriers CA3, CA4) connected to the output shaft 20, the other rotating elements RE1, RE3 to RE6, RE8 Since the transmission member 18 is rotatable including the transmission member 18, the controllability when the predetermined gear stage is established with the N → D shift operated to the “D” position thereafter is deteriorated, and a shock occurs or the gear shifts. There is a risk of poor response. That is, in the neutral state, the engine rotational speed NE is normally maintained at the idle rotational speed NEidl, and the second motor rotational speed Nmg2, which is the rotational speed of the transmission member 18, is determined based on the idle rotational speed NEidl. It converges to a predetermined rotation speed according to the drag torque of C0, C1, C2, or the sliding resistance of the rotation support portion, etc., but if the engine rotation speed NE changes due to the accelerator pedal being depressed, etc. When the second motor rotation speed Nmg2 changes and the first clutch C1 is engaged and controlled to establish a predetermined gear stage in accordance with the N → D shift, the second motor rotation speed Nmg2 changes suddenly and greatly. A shock occurs, or the required time for engaging the first clutch C1 is lengthened and a predetermined driving force can be obtained. It is there for that response may become worse in.

  In order to prevent such deterioration of controllability during the N → D shift, the electronic control unit 40 further includes a neutral-time rotation control means 80 (see FIG. 5), and the first motor generator MG1 at the neutral time. Thus, the rotational speed control of the second motor rotational speed Nmg2, which is the rotational speed of the transmission member 18, is performed. FIG. 8 is a flowchart specifically explaining the processing contents of the rotational speed control executed by the neutral rotation control means 80, and is repeatedly executed at a predetermined cycle time.

  In step S1 of FIG. 8, it is determined whether or not the operation position of the shift lever 74 is the “N” position. If it is not the “N” position, step S4 is executed. Step S4 is a step that ends without performing the rotational speed control. In this case, since the automatic transmission unit 20 is established with a predetermined gear according to the operation position of the shift lever 74, the second step is executed. The motor rotation speed Nmg2 is set to a predetermined rotation speed according to the gear ratio of the gear stage and the output shaft rotation speed NOUT.

  If the operation position of the shift lever 74 is the “N” position and the determination in step S1 is YES (positive), then step S2 is executed, and the target rotation when the rotation speed control of the transmission member 18 is performed. The speed nmtag is calculated. As the target rotational speed nmtag, the controllability at the time of switching the stepped transmission unit 20 from the neutral to a predetermined gear stage while maintaining the switching transmission unit 11 in a continuously variable transmission state in accordance with the N → D shift is ensured. In the above, it is conceivable that the synchronous rotational speed is determined according to the gear ratio of the gear stage and the vehicle speed V, but it is transmitted via the input rotational elements of the automatic transmission unit 20 in the neutral state, that is, the clutches C1 and C2. Since the rotation speeds of the eighth rotation element RE8 and the fourth rotation element RE4 connected to the member 18 are not known, the rotation speed of the transmission member 18 (second motor rotation speed Nmg2) is set to the target rotation speed nmtag = synchronous rotation speed. Even if it is controlled, it does not necessarily match the rotational speed of the input rotation element, and the first motor generator MG1 is caused by the drag torque of the clutch C and the brake B, etc. Engine load power consumption or increased by or increasing, sometimes fuel consumption is deteriorated.

  For example, in FIG. 12, when the N → D shift is performed, the third speed gear stage “3rd” is established as indicated by a broken line, and the first clutch C1 and the first brake B1 are indicated as indicated by a black circle “●”. , The third rotation element RE3 connected to the eighth rotation element RE8 by the first clutch C1, that is, the synchronous rotation speed nmtag_D of the transmission member 18, is calculated, and the rotation speed of the transmission member 18 is calculated. This is a case where the synchronous control is performed so that the second motor rotational speed Nmg2 is the synchronous rotational speed nmtag_D. However, in the neutral state before the N → D shift is performed, the rotation speed of the eighth rotation element RE8 does not necessarily correspond to the third speed gear stage “3rd”. It is normal that it is shifted as shown by “◯”. For this reason, a rotational speed difference is generated between the transmission member 18 (third rotational element RE3) and the eighth rotational element RE8 that are synchronously controlled so as to achieve the synchronous rotational speed nmtag_D, and the first rotational speed varies depending on the rotational speed difference. A drag torque is generated by one clutch C1, and the power consumption of the first motor generator MG1 increases or the engine increases in order to reduce the rotation speed of the transmission member 18 (second motor rotation speed Nmg2) against the drag torque. Fuel consumption worsens due to increased load.

  On the other hand, in the present embodiment, the target rotational speed nmtag is determined so that the consumed energy becomes as small as possible in consideration of the total consumed energy of the engine 10 and the first motor generator MG1. The energy consumption of the engine 10 and the first motor generator MG1 is affected by the drag torque of the clutch C and the brake B provided in the speed change mechanism 8 and the sliding resistance at the rotation support portion of each part. Since the resistance varies depending on the viscosity of the hydraulic oil, that is, the oil temperature Toil and the rotation speed, the target rotation speed nmtag is determined with the oil temperature Toil and the output shaft rotation speed NOUT of the hydraulic oil as parameters. The first motor generator MG1 controls the rotational speed by controlling both the power running torque and the regenerative torque. When the power running torque control is performed, the electric energy of the power storage device 60 charged by the engine 10 is used. Therefore, the target rotational speed nmtag is determined so that the fuel efficiency is finally minimized in consideration of the energy conversion efficiency of the electric path such as the power generation efficiency, the charging efficiency of the power storage device 60, and the discharging efficiency.

  FIG. 9 is a diagram showing an example of the map nmtag_map of the target rotational speed nmtag that is determined in advance using the oil temperature Toil and the output shaft rotational speed NOUT as parameters, and the map nmtag_map is previously stored in the map storage means 56. Is remembered. Therefore, in step S2, the target rotational speed nmtag may be calculated from the target rotational speed map nmtag_map by map interpolation or the like based on the actual oil temperature Toil and the output shaft rotational speed NOUT.

  The target rotation speed map nmtag_map can be set as follows, for example, through experiments or simulations. That is, in the neutral state, the engine speed NE is generally held at the idle speed NEidl when the accelerator is OFF, and therefore the engine speed NE is maintained so that the engine speed NE is maintained at the idle speed NEidl for the target speed nmtag. In the state where the oil temperature Toil and the output shaft rotation speed NOUT are kept constant, the first motor generator MG1 continuously changes the second motor rotation speed Nmg2 while keeping the oil temperature Toil and the output shaft rotation speed NOUT constant. Is obtained as a graph (consumption energy characteristic) as shown in FIG. 10, and the second motor rotation speed Nmg2 at which the consumption energy is minimized is set as the target rotation speed nmtag. Then, by examining the energy consumption characteristics in the same manner as described above while sequentially changing the output shaft rotational speed NOUT while keeping the oil temperature Toil constant, as shown in FIG. 11, the output shaft at a certain oil temperature Toil is obtained. Data of the target rotational speed nmtag with the minimum energy consumption with respect to the rotational speed NOUT can be obtained. The adjustment of the output shaft rotational speed NOUT can be performed by connecting an electric motor or the like to the output shaft 22, for example. Further, the target rotation speed map nmtag_map shown in FIG. 9 is obtained by examining the relationship between the output shaft rotation speed NOUT and the target rotation speed nmtag as shown in FIG. 11 for each oil temperature Toil while sequentially changing the oil temperature Toil. Obtainable. 10 and 11 are merely examples, and do not necessarily match the actual characteristics of the vehicle drive device.

  Here, when the target rotational speed nmtag is set based on the consumed energy in this way, the rotational speed of the transmission member 18 (second motor rotational speed) when the automatic transmission unit 20 is switched to the power transmission state by the N → D shift. Nmg2) may deviate from the synchronous rotational speed nmtag_D, and the controllability at the time of switching may be impaired. However, in order to ensure the controllability at the time of switching, the rotational speed of the transmission member 18 exactly matches the synchronous rotational speed nmtag_D. It is not always necessary to perform the rotational speed control so that the controllability at the time of switching is greatly impaired even if the target rotational speed nmtag is set so that the energy consumption becomes as small as possible. However, in order to ensure a predetermined controllability at the time of switching, an upper limit guard and a lower limit guard can be provided on the target rotation speed nmtag as necessary. That is, the gear stage established when the automatic transmission unit 20 is switched to the power transmission state is obtained from, for example, the shift map of FIG. 6 based on the vehicle speed V and the like, and the synchronous rotational speed of the transmission member 18 is determined from the gear ratio of the gear stage. nmtag_D is calculated, a predetermined lower limit guard nmgd1 and an upper limit guard nmgd2 are set based on the synchronous rotation speed nmtag_D in consideration of controllability at the time of switching, and the upper and lower limit guards nmgd1 as shown in FIG. The target rotation speed nmtag may be determined within a range of ˜nmgd2.

  Further, since the output shaft rotation speed NOUT corresponds to the vehicle speed V, the target rotation speed map nmtag_map can be set using the vehicle speed V as a parameter instead of the output shaft rotation speed NOUT, and is constant with respect to the output shaft rotation speed NOUT. It is also possible to use other rotational speeds having the relationship Further, if the rotational speed of the engine 10 changes due to an accelerator operation or the like, the target rotational speed nmtag that minimizes the energy consumption also changes accordingly, so the target rotational speed nmtag is set using the engine rotational speed NE as a parameter. You can also The target rotational speed nmtag may be set using only one of the hydraulic oil temperature Toil and the output shaft rotational speed nout as a parameter, or the oil temperature Toil, the output shaft rotational speed NOUT, etc. Regardless of the difference in the operating state, a constant target rotational speed nmtag that minimizes energy consumption may be set.

  When the target rotational speed nmtag is thus set in step S2, step S3 is executed next, and the first motor is set so that the rotational speed of the transmission member 18, that is, the second motor rotational speed Nmg2 becomes the target rotational speed nmtag. The power running torque and regenerative torque of the generator MG1 are feedback-controlled. In the present embodiment, the rotation speed control of the second motor rotation speed Nmg2 is performed by the torque control of the first motor generator MG1, but the rotation speed of the transmission member 18 is controlled by controlling the torque of the second motor generator MG2. That is, the rotational speed control of the second motor rotational speed Nmg2, which is its own rotational speed, can be performed.

  Thus, in the vehicle drive device of this embodiment, when the automatic transmission 20 is in the neutral state while the engine 10 is maintained in a predetermined operating state, the controllability at the time of the N → D shift is ensured. Therefore, the first motor generator MG1 is controlled so that the rotation speed of the transmission member 18 (second motor rotation speed nmg2) becomes a predetermined target rotation speed nmtag, and the target rotation speed nmtag is determined by the engine 10. Since the total energy consumption of the first motor generator MG1 is taken into consideration and the energy consumption is set to be minimum, the energy consumption associated with the rotational speed control of the transmission member 18 at the neutral time is reduced and the fuel consumption is reduced. Is further improved.

  The energy consumption of the engine 10 and the first motor generator MG1 is influenced by the drag torque of the clutch C and the brake B provided in the transmission mechanism 8 including the automatic transmission unit 20, the sliding resistance at the rotation support units of each unit, and the like. The drag torque and sliding resistance vary depending on the viscosity of the hydraulic oil, that is, the oil temperature Toil and the rotational speed. In this embodiment, the target rotational speed nmtag is set with the oil temperature Toil and the output shaft rotational speed NOUT as parameters. Therefore, it is possible to more efficiently reduce the energy consumption accompanying the rotational speed control and improve the fuel consumption.

  Further, when the target rotational speed nmtag is set based on the consumed energy in this way, the controllability when the automatic transmission unit 20 is switched to the power transmission state by an N → D shift or the like may be impaired. In order to ensure the controllability, it is not always necessary to perform the rotational speed control so that the rotational speed of the transmission member 18 exactly matches the synchronous rotational speed nmtag_D, and in this embodiment, the lower limit guard nmgd1 is necessary. And by providing the upper limit guard nmgd2, the controllability at the time of switching is sufficiently ensured.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating a configuration of a hybrid vehicle drive device to which the present invention is preferably applied. 2 is an operation table for explaining a relationship between a speed change operation and a hydraulic friction engagement device used in the case where the vehicle drive device of FIG. FIG. 6 is a collinear diagram illustrating the relative rotational speeds of the respective gear stages when the speed change mechanism of the vehicle drive device of FIG. It is a figure explaining the input-output signal of the electronic controller provided in the vehicle drive device of FIG. It is a functional block diagram explaining the principal part of the control action of the electronic controller of FIG. It is a figure explaining the switching operation | movement of the switching control means of FIG. It is a figure explaining an example of the shift operation apparatus operated in order to select a some shift position, (a) is a figure which shows a shift pattern, (b) is a figure explaining several shift ranges which can be selected in M mode. It is. FIG. 6 is a flowchart for specifically explaining processing contents of a neutral rotation control means in FIG. 5. FIG. It is a figure explaining an example of the target rotational speed map used when calculating target rotational speed nmtag by step S2 of FIG. It is a figure which shows an example of the energy consumption characteristic used as the foundation of the target rotational speed map of FIG. It is a figure which shows an example of the target rotational speed data obtained by investigating the energy consumption characteristic of FIG. 10, changing an output shaft rotational speed sequentially. It is a figure explaining the operation | movement at the time of drag | drug torque generate | occur | producing when a synchronous rotational speed is set as a target rotational speed using the alignment chart which shows the relative rotational speed of a several rotation element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10: Engine (power source) 18: Transmission member 20: Automatic transmission part 24: 1st planetary gear apparatus (differential gear mechanism) 40: Electronic control unit 80: Neutral rotation control means C1, C2: Clutch (hydraulic friction) B1, B2: Brake (hydraulic friction engagement device) MG1: First motor generator (power source, rotating machine) Nmg2: Second motor rotation speed (rotation speed of transmission member) NOUT: Output shaft rotation speed (Output rotation speed) nmtag: Target rotation speed Toil: Oil temperature

Claims (2)

An automatic transmission unit that performs a shift by a combination of disengagement of a plurality of hydraulic friction engagement devices;
A transmission member for transmitting power transmitted from a power source through a differential gear mechanism to the automatic transmission unit;
A rotating machine capable of changing the rotation speed of the transmission member;
In a control device for a vehicle drive device comprising:
Rotation of the transmission member that is rotatable relative to the power source via the differential gear mechanism when the automatic transmission is in a neutral state while maintaining the power source in a predetermined operating state. A neutral-time rotation control means for controlling using the rotating machine so that the speed becomes a predetermined target rotation speed;
The target rotational speed is set so that the consumed energy becomes as small as possible in consideration of the total consumed energy of the power source and the rotating machine. . 2. The vehicle according to claim 1, wherein the target rotation speed is determined by using an oil temperature of hydraulic oil that engages the hydraulic friction engagement device and an output rotation speed of the automatic transmission unit as parameters. Drive device controller.

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