JP2012183907A - Hybrid vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch a travel mode to a parallel mode, without causing any of deterioration of an electric storage means, degradation of fuel consumption, and deterioration of drivability, when changing to an acceleration request from regenerative braking in a series mode.SOLUTION: In a hybrid vehicle (1) having a clutch device (CL1) capable of switching between the series mode and the parallel mode, a control device (100) includes: a generative control means for controlling one rotary electric machine (MG2) so that power regeneration is performed during deceleration in a travel period in the series mode; a SOC identification means for identifying SOC of an electric storage device; and a rotation synchronization control means for controlling the other rotary electric machine (MG1) so that an engagement device assumes a rotation synchronized state by consuming part of regenerative power produced by electric power regeneration when SOC of the electric storage device is a predetermined value or more in a period during which electric power regeneration is performed.

Description

  The present invention relates to a technical field of a hybrid vehicle control device that controls a hybrid vehicle including a switching clutch for switching a traveling mode between a series mode and a parallel mode.

  This type of hybrid vehicle is disclosed in Patent Document 1. According to the hybrid vehicle disclosed in Patent Document 1, the configuration of a parallel hybrid vehicle can be realized by coupling the switching clutch, and the configuration of the series hybrid vehicle can be achieved by disconnecting the switching clutch and fixing the planetary gear ring gear with a brake. Is realized.

  Further, this hybrid vehicle has a direct connection mode in which the engine, MG1 and MG2 are directly connected, and in the direct connection mode, it is possible to output a larger torque than in the parallel mode.

  Patent Document 2 discloses a technology in which electric power regenerated by MG2 is supplied to MG1, MG1 is operated as a motor, and the engine is motored by the power of MG1.

  Patent Document 3 discloses a technique for operating a generator without causing fuel injection by driving a generator when the rechargeable power is lower than the regenerative power during the regenerative operation of the electric motor.

  Patent Document 4 discloses a technique for powering MG1 during MG2 regeneration.

JP 2003-237392 A JP 2010-018212 A JP 2001-238303 A JP 2010-058579 A

  When the power motor is disconnected from the engine by the control of the switching clutch and travels in the series mode, power regeneration is appropriately performed using the power motor, for example, during deceleration.

  At this time, the regenerative power generated by the power regeneration is supplied to the power storage means such as a battery, but in a region where the SOC of the power storage means is sufficiently high (State of Charge: the ratio of the charge amount to the capacity) The regenerative power may exceed the charge limit value Win of the power storage means.

  In this case, it is possible to convert this surplus regenerative power into kinetic energy (rotational energy) by driving a power generation motor on the engine side based on the disclosure contents of the above-described various conventional techniques.

On the other hand, it is not uncommon for an acceleration request to be generated after the end of deceleration under traveling control in series mode using only the power motor as a power source (ie, EV (Electric Vehicle) traveling). .

  Here, when the engine start, that is, the shift to the parallel mode is required due to the acceleration request generated after the deceleration, it is necessary to engage the switching clutch.

  Here, in particular, when the switching clutch requires rotation synchronization between the engagement elements, there is a time loss for synchronizing the rotation speed of the engagement element on the engine side with the rotation speed on the axle side (power motor side). As a result, a temporary decrease in power performance becomes apparent.

  Also, if the engine is started before the request to switch to the parallel mode is actually generated on the assumption that such a time loss occurs, the engine is started in an operating region where the engine is not originally required to start. As a result, fuel consumption is clearly reduced.

  That is, the above-described various conventional technologies and technologies conceivable therefrom have room for improvement in the transition control to the parallel mode in the case where an acceleration request is generated during regenerative braking in the series mode. Further, since this type of problem is also related to the physical power storage capability of the power storage means, it can be a significant and serious problem when it is necessary to downsize the power storage device.

  The present invention has been made in view of the technical problems described above, and in the case of switching from regenerative braking to acceleration request in the series mode, the relative deterioration of the power storage means, the relative deterioration of fuel consumption, and the drivability are improved. It is an object of the present invention to provide a control device for a hybrid vehicle that can shift to a parallel mode without causing any relative decrease.

In order to solve the above-described problem, a control device for a hybrid vehicle according to the present invention includes an internal combustion engine, a plurality of rotating electrical machines, and a pair of engagement elements, and the pair of engagement elements are in an engaged state. Corresponding to the parallel mode capable of transmitting the power of the internal combustion engine to the axle and the state where the pair of engagement elements are released, Between the plurality of rotating electrical machines and a clutch device capable of transmitting power and switching a traveling mode between the internal combustion engine and a series mode in which another rotating electrical machine of the plurality of rotating electrical machines is separated from the axle. A hybrid vehicle control device that includes a power storage device capable of inputting / outputting electric power, wherein power regeneration is not performed during deceleration during the traveling period in the series mode. Regenerative control means for controlling the one rotating electric machine, SOC specifying means for specifying the SOC of the power storage device, and when the specified SOC is equal to or greater than a predetermined value during the period of power regeneration. And a rotation synchronization control means for controlling the other rotating electrical machine so that a part of the regenerative power generated by the power regeneration is consumed and the pair of engagement elements are in a rotation synchronization state. (Claim 1).

“Parallel mode” according to the present invention refers to a power rotating electrical machine (in short, a motor generator) capable of inputting / outputting power (preferably torque) to / from an axle, fuel type, fuel As an engine capable of generating power by combustion of fuel, which can take various modes regardless of its physical, mechanical or electrical configuration, such as supply mode, fuel combustion mode, intake / exhaust system configuration and cylinder arrangement It means a mode in which the vehicle is allowed to travel while appropriately using the internal combustion engine as a power supply element for the axle. In the parallel mode, it is preferable that the power of the internal combustion engine and the power of the rotating electrical machine for power supply can cooperate with each other to provide the required power. It is also possible to run the vehicle only with the power of the electric machine.

  On the other hand, the “series mode” according to the present invention refers to the power rotating electrical machine described above while disconnecting the other rotating electrical machine and the axle from the internal combustion engine and the plurality of rotating electrical machines and blocking power transmission therebetween. It means a mode in which the vehicle is driven as a driving power source.

  In the series mode, the internal combustion engine that can function as a power source in the parallel mode is appropriately driven to generate drive power for the power rotating electrical machine. That is, among the plurality of rotating electrical machines, the other rotating electrical machines can be regenerated (that is, generate electric power) by being driven by the internal combustion engine. It can function as a motor generator.

  However, it goes without saying that in this type of hybrid vehicle in which the traveling mode can be switched between the series mode and the parallel mode, power can be supplied from the regenerative rotating electrical machine to the axle in the parallel mode. Similarly, the power rotary electric machine is a name for convenience. Naturally, in various situations where it is not necessary to supply power (preferably torque) to the axle, the power rotary electric machine appropriately regenerates power (that is, , Power generation) can be performed.

  The clutch device according to the present invention, which is configured to be selectively switchable based on the definitions of the series mode and the parallel mode, cuts off the power path (preferably torque path) from the power rotating electrical machine to the axle. The power path (preferably the torque path) from the internal combustion engine and the regenerative rotating electrical machine to the axles can be cut off.

  The hybrid vehicle control device according to the present invention is a device for controlling such a hybrid vehicle, for example, one or a plurality of CPUs (Central Processing Units), MPUs (Micro Processing Units), various processors or various controllers, Alternatively, various processing units such as a single or a plurality of ECUs (Electronic Controlled Units), which may appropriately include various storage means such as ROM (Read Only Memory), RAM (Random Access Memory), buffer memory or flash memory, Various computer systems such as various controllers or microcomputer devices can be used.

  According to the control apparatus for a hybrid vehicle according to the present invention, when the deceleration regeneration request is made during EV traveling in the series mode, the regeneration control unit appropriately executes power regeneration by one rotating electrical machine. The regenerative torque in the power regeneration is a kind of braking force for the vehicle, and is a reasonable braking force that can be replaced with a physical braking force in the same manner as an engine brake in a normal vehicle.

  The regenerative power (generated power) generated by this power regeneration is supplied to the power storage device via an appropriate power converter, charging device, etc., and the power storage device is charged. The power storage device is, for example, a high-voltage battery having an output of about several hundred volts, in which secondary battery cells having an output of about several volts, such as nickel metal hydride battery cells and lithium ion battery cells, are connected in series in units of several hundred pieces.

  Here, the SOC of this type of power storage device that functions as a power buffer has a physical or control upper limit value. The physical actual value is the SOC when the amount of charge corresponds to the capacity, and is, for example, 100 (%) (Note that such an expression method of the SOC is an example, It does not limit the technical scope at all). Further, the upper limit value for control is a relatively high value, for example, about 80 to 90 (%), which is set in advance as a value that should not be constantly exceeded in actual operation of the power storage device.

  Here, in particular, in the process of continuing power regeneration, the SOC of the power storage device may exceed this type of upper limit value or may be predicted to exceed in the future. In such a case, the charge limit value Win that is appropriately set for protecting the power storage device decreases, and it becomes impossible to supply all of the regenerative power to the power storage device.

  Therefore, according to the control apparatus for a hybrid vehicle according to the present invention, when the SOC of the power storage device specified by the SOC specifying means is a predetermined value or more, a part of the regenerative power is obtained by the action of the rotation synchronization control means. It is configured to be absorbed by the regenerative rotating electrical machine described above.

  Note that “absorb” means that the regenerative rotating electrical machine is maintained in a power running state. That is, a part of regenerative electric power, which is electric energy, is converted into rotational energy (kinetic energy) of a regenerative rotating electrical machine and stored.

  The practical aspect related to “specific” in the present invention includes, for example, detection, calculation, estimation, identification, selection or acquisition, and is not intended to be limited in any way.

  “SOC” according to the present invention means an index value corresponding to the ratio of the actual charge amount to the capacity of the power storage means (that is, the maximum charge amount), in other words, the charge rate. The SOC is normally set to be 100 (%) in the fully charged state of the cell and 0 (%) in the fully discharged state, but as long as it is set or standardized according to a preset rule, There is no limit to its practical aspect.

  The SOC of the power storage means may be specified by a technique such as map fitting based on the output voltage, output current, temperature, or the like of the battery or cell, or by various known calculations. Alternatively, when the input / output current of the battery can be grasped, the amount of change in the SOC from a certain point in time is estimated from information on various time transitions such as the time integrated value and the time integrated value of the input / output current, and the SOC It may be used as appropriate for identification. In addition, as long as the SOC of each cell can be specified, the SOC may be specified based on the cell SOC and the capacity of each cell. Needless to say, the SOC specifying method is not limited to the one exemplified here, and various known methods can be applied.

  By the way, there are various driving conditions for the hybrid vehicle, and during such deceleration regeneration, sudden acceleration may be required in many cases. In such a situation, when the required output exceeds the performance limit of the power rotating electrical machine, or when it can be predicted in the future, it is necessary to shift from the series mode to the parallel mode.

  However, since the rotation from the series mode to the parallel mode requires the rotation synchronization between the engagement elements in the clutch device, the time loss required for this rotation synchronization leads to a temporary decrease in power performance, It becomes a factor which reduces drivability.

  Note that the rotation synchronization between the engagement elements is indispensable in a meshing engagement device such as a dog clutch device or a cam lock device, and the rotation synchronization between engagement elements is physically performed like a wet multi-plate clutch device. Even an engagement device that is not required in construction is effective from the viewpoint of preventing wear of the clutch device.

  Therefore, in the hybrid vehicle control device according to the present invention, the rotation synchronization control means converts a part of the regenerative power surplus in the power regeneration process of the power rotating electrical machine into the rotational energy of the regenerative rotating electrical machine. In the process of consumption (storage), the rotation of the other engagement element, which is different from the one engagement element that is uniquely in a rotational relationship with the axle, out of the pair of engagement elements of the clutch device, It is configured to pull up to the rotational speed.

  As a result, the clutch device is already ready for engagement during the deceleration regeneration period, and when it is necessary to switch the series mode to the parallel mode due to an acceleration request or the like, the clutch device quickly and smoothly enters the parallel mode. Can be realized. At this time, since it is not necessary to start the internal combustion engine forward, there is no relative deterioration in fuel consumption.

  In other words, according to the hybrid vehicle control apparatus of the present invention, the series mode is changed to the parallel mode without causing any of the relative deterioration of the power storage means, the relative deterioration of the fuel consumption, and the relative decrease of the drivability. Can be realized.

  In one aspect of the control apparatus for a hybrid vehicle according to the present invention, the accelerator opening specifying means for specifying the accelerator opening, and when the specified accelerator opening is equal to or greater than a predetermined value, the rotation synchronization state is established. Further comprising switching control means for switching the driving mode of the hybrid vehicle to the parallel mode by engaging a pair of engaging elements (claim 2).

  According to this aspect, the presence / absence of a request to shift to the parallel mode is quickly and accurately determined based on the accelerator opening that correlates with the required output of the vehicle or the required driving force.

  For this reason, the switching control means can quickly and smoothly switch the traveling mode to the parallel mode while satisfying the required output or required driving force of the vehicle and suppressing deterioration of fuel consumption.

  In addition, the practical aspect in which the switching control means switches the traveling mode to the parallel mode can take various aspects according to the practical aspect of the clutch device.

  In this aspect, when the detected accelerator opening is less than the predetermined value at least in a state where the accelerator operation is occurring, the rotational energy of the other rotating electrical machines is converted into electrical energy, and the conversion is performed. Drive control means for powering the one rotating electrical machine with electric energy generated as a result of the operation may be further provided.

  In this case, the series mode is maintained after the deceleration regeneration is completed, but the drive control means converts the rotational energy stored in the regenerative rotating electrical machine into electrical energy (that is, the regenerative rotating electrical The power rotating electrical machine can be driven by the regenerative power while effectively using a part of the surplus regenerative power stored during the deceleration regeneration.

  In another aspect of the hybrid vehicle control device according to the present invention, the hybrid vehicle is capable of inputting and outputting torque as the power between a first rotating electrical machine as the other rotating electrical machine and an axle. A second rotating electric machine as a rotating electric machine, a first rotating element connected to the first rotating electric machine, a second rotating element connected to the internal combustion engine, and a third rotating element connected to an output shaft connected to the axle. And a power transmission mechanism including a plurality of rotating elements having a differential action with respect to each other, wherein the clutch device is disposed between the output shaft and the axle in a state where the pair of engaging elements are released. The regenerative control means controls the second rotating electrical machine so that the power regeneration is performed, and the rotation synchronization control means is configured so that the pair of engagement elements are in a rotation synchronization state. The first Rolling electric machine to control (claim 4).

  The power transmission mechanism includes at least a first rotation element coupled to the first rotating electrical machine, a second rotation element coupled to the internal combustion engine, and a third rotation element coupled to the output shaft of the power transmission mechanism. It is preferably configured as a differential mechanism having two degrees of freedom of rotation, which includes a plurality of rotating elements that make a differential action.

  At this time, the number of rotating elements or differential mechanisms provided in the power transmission mechanism may be ambiguous. For example, the power transmission mechanism may include one or a plurality of various differential gear mechanisms such as a planetary gear mechanism. In the case of including a plurality of planetary gear mechanisms, a part of the rotating element constituting each planetary gear mechanism may be appropriately shared between the plurality of planetary gear mechanisms.

  In view of the differential action between the rotating elements in the power transmission mechanism, the first rotating element coupled to the first rotating electrical machine functions as a reaction force element that applies reaction torque to the internal combustion engine. As for the torque of the internal combustion engine input through the second rotating element, a part of the direct torque corresponding to the reaction torque is transmitted to the output shaft through the third rotating element. In the configuration of such a power transmission mechanism, the operating point of the internal combustion engine can be continuously variable at least within a predetermined range by the first rotating electrical machine. Therefore, the power transmission mechanism and the first rotating electrical machine preferably function as a kind of electric CVT (Continuously Variable Transmission) in the parallel mode.

  On the other hand, the second rotating electrical machine is directly connected to the output shaft of the power transmission mechanism on the axle side of the clutch device, or indirectly connected to the axle via various reduction gear mechanisms, etc. Two inputs and outputs are possible. In the second rotating electrical machine, for example, when torque is input through a power transmission path that sequentially passes through the drive wheels and the axle in the positive rotation region (that is, negative torque), etc., power regeneration using the input torque is performed. Is possible. In addition, for example, by supplying a positive torque (that is, powering) to the axle in the positive rotation region, it is possible to bear at least a part of the driving torque supplied to the axle.

  Such a vehicle configuration is one of the configurations that can be adopted by the hybrid vehicle according to the present invention, and is also a preferred form for constructing a hybrid system called a so-called series / parallel hybrid.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

1 is a schematic configuration diagram conceptually illustrating a configuration of a hybrid vehicle according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram conceptually showing a configuration of a hybrid drive device in the hybrid vehicle of FIG. 1. FIG. 3 is an operation alignment chart illustrating one operation state of the hybrid drive device of FIG. 2. 2 is a flowchart of series EV control executed by an ECU in the hybrid vehicle of FIG. FIG. 5 is an operation alignment chart illustrating one operation state of the hybrid drive device in the series EV control of FIG. 4.

<Embodiment of the Invention>
Embodiments of the present invention will be described below with reference to the drawings.

<Configuration of Embodiment>
First, with reference to FIG. 1, the structure of the hybrid vehicle 1 which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle 1.

  In FIG. 1, the hybrid vehicle 1 includes an ECU 100, a PCU (Power Control Unit) 11, a battery 12, an accelerator position sensor 13, a vehicle speed sensor 14, and a hybrid drive device 10 according to the present invention. It is.

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM, and the like, and is configured to be able to control the operation of each part of the hybrid vehicle 1. It is an example of a “control device for a hybrid vehicle”. The ECU 100 is configured to be able to execute a series EV control control described later according to a control program stored in the ROM.

  The ECU 100 is configured to function as an example of each of “regeneration control means”, “SOC specification means”, “rotation synchronization control means”, “accelerator opening specification means”, and “drive control means” according to the present invention. The integrated electronic control unit is configured such that all the operations related to these means are executed by the ECU 100. However, the physical, mechanical, and electrical configurations of each of the units according to the present invention are not limited to this. For example, each of these units includes a plurality of ECUs, various processing units, various controllers, a microcomputer device, and the like. It may be configured as various computer systems.

  The hybrid drive device 10 drives the hybrid vehicle 1 by supplying drive torque as drive force to the left axle DSL (corresponding to the left front wheel FL) and the right axle DSR (corresponding to the right front wheel FR), which are the axles of the hybrid vehicle 1. Drive unit. The detailed configuration of the hybrid drive device 10 will be described later. In the following description, the term “axle DS” will be used as appropriate to indicate the axle regardless of whether it is left or right.

  The PCU 11 converts the DC power extracted from the battery 12 into AC power and supplies it to a motor generator MG1 and a motor generator MG2, which will be described later, and also converts AC power generated by the motor generator MG1 and the motor generator MG2 into DC power. Including an inverter (not shown) configured to be supplied to the battery 12, and the power input / output between the battery 12 and each motor generator or the power input / output between the motor generators (ie, in this case, This is a control unit configured to be able to control power transfer between the motor generators without passing through the battery 12. The PCU 11 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  The battery 12 has a configuration in which a plurality (for example, several hundreds) of unit battery cells such as lithium ion battery cells are connected in series, and a power supply source related to power for powering the motor generator MG1 and the motor generator MG2. And is an example of the “power storage device” according to the present invention.

  The accelerator opening sensor 13 is a sensor configured to be able to detect an accelerator opening Ta as an operation amount of an accelerator pedal (not shown) of the hybrid vehicle 1. The accelerator opening sensor 13 is electrically connected to the ECU 100, and the detected accelerator opening Ta is referred to by the ECU 100 at a constant or indefinite period.

  The vehicle speed sensor 14 is a sensor configured to be able to detect the vehicle speed V of the hybrid vehicle 1. The vehicle speed sensor 14 is electrically connected to the ECU 100, and the detected vehicle speed V is referred to by the ECU 100 at a constant or indefinite period.

  Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 2, the hybrid drive device 10 includes an engine 200, a power split mechanism 300, a motor generator MG1 (hereinafter appropriately referred to as “MG1”), a motor generator MG2 (hereinafter appropriately referred to as “MG2”), an input shaft. 400, an MG1 output shaft 500, an output shaft 600, an MG2 reduction mechanism 700, an MG2 output shaft 800, a brake device BR1, a clutch device CL1, and a clutch device CL2.

  The engine 200 is a gasoline engine that is an example of an “internal combustion engine” according to the present invention that is configured to function as a main power source of the hybrid vehicle 1. The engine 200 is a known gasoline engine, and a detailed configuration thereof is omitted here, but the engine torque Te that is the output power of the engine 200 is input to the input shaft of the power split mechanism 300 via a crankshaft (not shown). 400 is transmitted.

  The engine 200 is merely an example of a practical aspect that can be adopted by the internal combustion engine according to the present invention. The practical aspect of the internal combustion engine according to the present invention is not limited to the engine 200, and various known engines can be employed. It is.

  Motor generator MG1 is a motor generator having a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy, and is an example of the “first rotating electrical machine” according to the present invention. Yes, it is an example of the regenerative rotating electrical machine described above.

  The motor generator MG2 is a motor generator that is an example of the “second rotating electrical machine” according to the present invention, which is larger than the motor generator MG1, and the power rotating electrical machine described above. It has a power running function that converts kinetic energy and a regenerative function that converts kinetic energy into electrical energy.

  Motor generators MG1 and MG2 are configured as synchronous motor generators, and include, for example, a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator wound with a three-phase coil that forms a rotating magnetic field. Of course, other configurations may be used.

  The power split mechanism 300 is a planetary gear mechanism that is an example of the “power transmission mechanism” according to the present invention.

  The power split mechanism 300 includes a sun gear S1 as an example of the “first rotating element” according to the present invention provided in the center, and a “third rotation” according to the present invention provided concentrically around the outer periphery of the sun gear S1. The ring gear R1, which is another example of the “element”, a plurality of pinion gears (not shown) which are arranged between the sun gear S1 and the ring gear R1 and revolve around the outer periphery of the sun gear S1, and each of the pinion gears And a carrier C1 as another example of the “second rotating element” according to the present invention, which supports the rotating shaft.

  The sun gear S1 is a reaction force element that bears a reaction force torque that antagonizes the engine torque Te, and is fixed to the MG1 output shaft 500 that is an output rotation shaft of the motor generator MG1. Therefore, the rotational speed of sun gear S1 is equivalent to MG1 rotational speed Nmg1, which is the rotational speed of motor generator MG1.

  The ring gear R1 is an output element of the power split mechanism 300, and is connected to the output shaft 600 of the power split mechanism 300 so as to share the rotation axis.

  As described above, the carrier C1 is coupled to the input shaft 400 coupled to the crankshaft of the engine 200 so as to share its rotational axis, and the rotational speed thereof is equal to the engine rotational speed Ne of the engine 200. Is equivalent.

  MG2 reduction mechanism 700 includes ring gear R2 that can rotate integrally with output shaft 600 of power split device 300, sun gear S2 that is connected to MG2 output shaft 800 that is the output rotation shaft of motor generator MG2, and ring gear R2 and sun gear S2. It is a planetary gear mechanism that includes a carrier C2 that rotatably supports the rotation shafts of a plurality of meshing pinion gears (not shown) and that is non-rotatably fixed to a fixed element.

  MG2 reduction mechanism 700 is a reduction mechanism that reduces and transmits rotation speed Nmg2 of motor generator MG2 to output shaft 600 of power split device 300 according to a reduction ratio determined according to the gear ratio of each gear.

  The configuration of MG2 reduction mechanism 400 is merely one form that can be adopted by a mechanism that decelerates the rotation of motor generator MG2, and this type of reduction mechanism can have various forms. Further, this type of reduction mechanism is not necessarily provided in the hybrid drive device.

  The brake device BR1 is a well-known various brake device that can lock the ring gear R1 of the power transmission mechanism 300 in a non-rotatable manner. As the brake device BR1, for example, a wet multi-plate brake device or a dog clutch device can be used.

  The clutch device CL1 is a rotation-synchronized engagement device such as a dog clutch device that can engage the ring gear R2 of the MG2 reduction mechanism 700 and the ring gear R1 of the power split mechanism 300. It is an example of such a “clutch device”.

  As a supplement, in a meshing engagement device such as a dog clutch device, the meshing teeth formed on the opposing surfaces of the pair of engagement elements are meshed with each other. Need to be. That is, when one or both of the pair of engaging elements is actually stroked along the facing direction and engaged with each other, rotational synchronization of the pair of engaging elements is required as a preparation stage.

  In the present embodiment, the ring gear R2 of the MG2 reduction mechanism 700 has a unique rotational relationship with the axle (the rotational speed of the ring gear R2 is the vehicle speed (the rotational speed of the saddle axle DS) because the carrier C2 is fixed). Therefore, by adjusting the rotation speed of the ring gear R1 of the power split mechanism 300, the rotation of both is synchronized.

  The clutch device CL2 is a rotation-synchronized engagement device such as a dog clutch device that can engage the sun gear S1 and the ring gear R1 of the power split mechanism 300. In the engaged state in which the engagement elements of the clutch device CL2 are engaged, the sun gear S1 and the ring gear R1 are fixed. Therefore, the carrier is arranged on the structure of the power split mechanism 300 as a differential mechanism with two degrees of rotation. C1 also rotates at the same speed as these, and a so-called “directly connected running mode” is realized. In addition, since the correlation with this invention is thin regarding direct drive mode, further description is abbreviate | omitted.

  In the hybrid drive device 10, a rotation sensor such as a resolver is appropriately attached to each output shaft so that the rotation speed of the detection part can be detected. These rotation sensors are in a state of being electrically connected to the ECU 100, and the detected rotation speed is sent to the ECU 100 at a constant or indefinite period.

<Operation of Embodiment>
<Details of driving mode>
The hybrid vehicle 1 according to the present embodiment can select the parallel mode and the series mode as the travel mode by the action of the clutch device CL1 provided in the hybrid drive device 10.

  Here, the travel mode of the hybrid vehicle 1 will be described with reference to FIG. Here, FIG. 3 is an operation alignment chart illustrating one operation state of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof will be omitted as appropriate.

  In FIG. 3, the vertical axis represents the rotation speed, and the horizontal axis represents the sun gear S1 (uniquely motor generator MG1), carrier C1 (uniquely engine 200) and ring gear R1 (uniquely) in order from the left. The output shaft 600), the ring gear R2 (unique with the vehicle speed V), the carrier C2 and the sun gear S2 (uniquely the motor generator MG2) are shown. As a whole, in each of FIGS. 3A, 3B, and 3C, the left half represents the state of the power split mechanism 300, and the right half represents the state of the MG2 reduction mechanism 600.

  Here, power split mechanism 300 and MG2 reduction mechanism 600 are two-degree-of-freedom planetary gear mechanisms each composed of a plurality of rotational elements that are in a differential relationship with each other. Of the sun gear, carrier, and ring gear, When the rotational speeds of the two elements are determined, the rotational speed of the remaining one rotational element is inevitably determined. That is, on the operation collinear diagram, the operation state of each rotary element can be represented by one operation collinear line corresponding to one operation state of the hybrid drive device 10 on a one-to-one basis.

  FIG. 3A shows an operation alignment chart corresponding to the series EV mode.

  The series EV mode is an EV traveling (electric vehicle traveling) mode included in the concept of the “series mode” according to the present invention.

  In the series EV mode and the series HV mode described later (both are examples of the “series mode” according to the present invention), the pair of engaging elements constituting the clutch device CL1 are mutually released. As a result, the power split mechanism 300 is separated from the axle DS at least in transmission of torque.

  As a result, in a situation where the SOC of battery 12 does not need to be taken into consideration, motor generator MG2 is driven by power supply from battery 12 as the series EV mode, and hybrid vehicle 1 travels only by the torque of motor generator MG2. .

  As illustrated in FIG. 3A, in the series EV mode, the motor generator MG2 is driven. Note that due to the configuration of the MG2 reduction mechanism, the rotational speed of the MG2 is transmitted in a state where the sign is reversed. Therefore, in this case, the lower side than the illustrated zero point is a rotation region corresponding to forward traveling.

  On the other hand, FIG. 3B shows an operation alignment chart corresponding to the parallel HV mode.

  The parallel HV mode is an example of the “parallel mode” according to the present invention, and is a traveling mode in which the motor generator MG2 and the engine 200 are cooperatively used as a power source.

  In the parallel HV mode, the pair of engagement elements of the clutch device CL1 are engaged. As a result, the direct torque (determined by the gear ratio of the power split mechanism 300) output to the ring gear R1 as the output element of the power split mechanism 300 is determined through the clutch device CL1 and the ring gear R2. Provided to DS. In addition, motor generator MG2 can transmit torque to axle DS independently of power split mechanism 300 because of the configuration of hybrid drive device 10.

  As a result, for example, it is possible to take measures such as outputting from the motor generator MG2 what is insufficient with the direct torque of the engine 200. Further, due to the configuration of power split mechanism 300, motor generator MG1 bears a reaction torque corresponding to a part of the engine torque, and functions as a rotation speed control mechanism of engine 200. For this reason, in the parallel HV mode, the operating point of the engine 200 can always be maintained at the optimal operating point.

  On the other hand, FIG. 3C shows an operation alignment chart corresponding to the series HV mode. In the series HV mode, the pair of engaging elements of the clutch device CL1 are maintained in a state of being separated from each other, as in the above-described series EV mode.

  Here, when the SOC of battery 12 is insufficient when supplying torque from motor generator MG2, motor generator MG1 can be driven by the regenerative power of MG1 using motor generator MG1 as a generator. Engine 200 is driven to cause MG1 to perform regenerative driving.

  In order to start engine 200, it is necessary to crank engine 200 by driving power generator motor MG1. However, if no measures are taken, the rotation-free ring gear R1 has a smaller friction loss than the engine 200, so that the rotation speed of the engine 200 is increased instead of the ring gear R1. The rotational speed will increase. In order to prevent such a situation, in the series HV mode, the ring gear R1 is fixed by the brake device BR1. As a result, the rotation speed of the engine 200 becomes unambiguous according to the MG1 rotation speed Nmg1, and the flow of cranking → starting → torque providing can be realized.

<Details of Series EV Control>
Next, the details of the series EV control executed by the ECU 100 will be described with reference to FIG. FIG. 4 is a flowchart of the series EV control. Note that the series EV control is control that is executed during the execution period of the series EV mode and the series HV mode described above (which is simply a difference between whether or not the battery 12 needs to be charged).

  In FIG. 4, ECU 100 determines whether or not the traveling condition of hybrid vehicle 1 satisfies the power regeneration condition (step S101). Here, the “power regeneration condition” is a condition defined as a condition that the motor generator MG2 should be regeneratively driven to generate power, and considering that the power source in the series mode is only the motor generator MG2. In short, this corresponds to whether or not the vehicle is in a deceleration state. If the power regeneration condition is not satisfied (step S101: NO), for example, if the vehicle is traveling with an accelerator pedal operation or the vehicle is stopped, the process enters a standby state in step S101.

  When the power regeneration condition is satisfied (step S101: YES), ECU 100 controls motor generator MG2 to the power regeneration state via control of PCU 11 (step S102).

  When motor generator MG2 is controlled to the power regeneration state, ECU 100 determines whether or not the SOC of battery 12 is greater than the threshold value (step S103). The SOC of the battery 12 is determined by the ECU 100 appropriately correcting the reference value selected from the control map using the battery voltage and the battery temperature as parameters, based on the integrated value of the input / output current value of the battery. Assume that you are always aware. However, when various detection means such as an SOC sensor are attached to the battery 12, they may be referred to by acquiring their detection values.

  Here, the SOC threshold value is variable according to the scale of the regenerative power related to the power regeneration at that time, but for example, refers to a value belonging to an area of about 80 to 90% in terms of SOC. Qualitatively, when the regenerative power at that time is continuously obtained, or when the average value of the regenerative power in a certain past period is continuously obtained, the battery 12 is overcharged in the near future. It is a value that can be determined to reach the region.

  Alternatively, the SOC threshold value may be an SOC value at which the charging limit value Win of the battery 12 (the power value allowed to be charged per unit time) is less than the regenerative power value at that time. Since the charging limit value Win normally changes according to the SOC of the battery 12, such a determination is also suitable.

  When the SOC is equal to or less than the threshold value (step S103: NO), ECU 100 returns the process to step S102 and continues power regeneration by MG2. That is, in this case, since there is no problem in actual operation of the battery 12, normal power regeneration (deceleration regeneration control) is continued.

  On the other hand, when the SOC is higher than the threshold value (step S103: YES), ECU 100 controls motor generator MG1 to the negative rotational power running state by using a part of the surplus power among the regenerative power of MG2 (step S103). S104). Note that the negative rotational power running state means a negative torque state, and controlling to the negative rotational power running state means that the electric energy generated by the power regeneration of the motor generator MG2 is converted into rotational energy as kinetic energy. It means to convert and store.

  Here, a part of the regenerative power of MG2 is used, but depending on the SOC of battery 12, most or all of the regenerative power may be consumed by powering of MG1. In this case, the output torque of MG1 may be balanced with the regenerative torque of MG2.

  Here, ECU 100 increases the rotational speed of ring gear R1 to a value corresponding to the synchronous rotational speed of clutch device CL1 in the process of powering control by motor generator MG1 (step S105). As described above, when the pair of engagement elements shifts to the rotationally synchronized state, the preparation for engagement of the clutch device CL1 is completed.

  When the rotation synchronization control is executed, the ECU 100 determines whether or not the accelerator opening degree Ta is larger than a threshold value (step S106). If accelerator opening degree Ta is equal to or smaller than the threshold value, the rotational energy previously stored in motor generator MG1 is converted into electric energy (ie, conversion from power running to regeneration) (step S111), and this converted electric energy is converted. The motor generator MG2 is power-driven in such a manner that the vehicle is used to run the vehicle (step S112).

  Note that the traveling mode returns to the normal series EV mode when the energy stored in motor generator MG1 is exhausted. When step S112 is executed, the series EV control ends.

  In addition, although illustration is abbreviate | omitted, the presence or absence of the accelerator operation by a driver | operator may be determined as a step before step S106. If the accelerator operation is not detected or stays in a very small area such as a so-called dead zone, the process may be in a standby state.

  On the other hand, when the accelerator opening degree Ta is not less than the threshold value in step S106 (step S106: YES), the ECU 100 first engages the clutch device CL1 (step S107). That is, at this stage, the traveling mode is switched to the parallel mode.

  Subsequently, ECU 100 regeneratively drives motor generator MG1 as in step S111. At this time, since the clutch device CL1 is in an engaged state, the rotational speed of the engine 200 inevitably increases, and the engine 200 enters a so-called cranking state.

  When engine 200 is cranked and reaches a predetermined cranking rotation speed, ECU 100 starts engine 200 by, for example, starting fuel supply from the fuel injection device of engine 200 (step S109).

  After the engine is started, the traveling state of the hybrid vehicle 1 is controlled in accordance with the parallel mode control law as already described (step S110).

  When step S110 is executed, the series EV control ends.

  Here, the execution process of the series EV control will be described visually with reference to FIG. FIG. 5 is an operation collinear diagram illustrating one operation state of the hybrid drive apparatus 10 in the execution process of the series EV control. In the figure, the same reference numerals are given to the same portions as those in FIG. 3, and the description thereof will be omitted as appropriate.

  In FIG. 5, FIG. 5 (a) shows a traveling state in the series EV mode which is a premise of the series EV control. In this state, MG2 enters a power regeneration state (that is, a negative torque state) at a rotational speed that is uniquely determined according to the vehicle speed.

  FIG. 5B shows a state in which steps S104 and S105 are executed in the series EV control. In this state, MG1 enters a power running state (negative rotation negative torque state) using a part of the regenerative power of MG2, and stores energy. In the process, the rotational speed of the ring gear R1 of the power split mechanism 300 is synchronized with the ring gear R2 of the MG2 reduction mechanism 600. At this stage, as indicated by a broken line in the figure, the clutch device CL1 is in an engagement preparation state.

  FIG. 5C shows the state of step S110 in the series EV control. In this state, the clutch CL1 is engaged (solid line), and the traveling state of the hybrid vehicle 1 is controlled by coordinating the engine torque Te and the torque of the MG2.

  As described above, according to the series EV control according to the present embodiment, when the SOC of the battery 12 exceeds the threshold at the time of deceleration regeneration during traveling in the series EV mode, the surplus regenerative power is used to generate MG1. In addition to storing energy, the clutch device CL1 can be maintained in the engagement ready state.

  Therefore, when an acceleration request is actually generated by the driver's accelerator operation or the like, the clutch device CL1 can be engaged quickly and smoothly, and the traveling mode can be switched to the parallel HV mode.

  Therefore, it is possible to protect the battery 12 from deterioration due to overcharging and to suitably suppress a relative decrease in drivability without causing a relative deterioration in fuel consumption.

  Note that the situation where the SOC of the battery 12 exceeds the threshold value may be caused by a natural increase in the process of changing the SOC with time (long regeneration period) or a sudden increase in regenerative torque. According to the series EV control according to the present embodiment, the above-described effects are reliably ensured for any reason.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and control of a hybrid vehicle involving such a change. The apparatus is also included in the technical scope of the present invention.

  According to the present invention, a first engagement mechanism that switches between a continuously variable transmission mode and a fixed transmission mode by selectively locking the first motor generator, and a second motor generator from a drive shaft. The present invention can be applied to a hybrid vehicle including a second engagement mechanism to be separated.

  DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle, 10 ... Hybrid drive device, 100 ... ECU, 200 ... Engine, 300 ... Power split mechanism, 400 ... Input shaft, 500 ... MG1 output shaft, 600 ... Output shaft, 700 ... MG2 reduction mechanism, 800 ... MG2 Output shaft, BR1 ... brake, CL1 ... clutch device, CL2 ... clutch device.

Claims (4)

An internal combustion engine;
A plurality of rotating electrical machines;
A parallel mode capable of transmitting the power of the internal combustion engine to an axle corresponding to a state in which the pair of engagement elements are engaged, and the pair of engagement elements are released. A series mode corresponding to a state and transmitting power of one rotating electric machine among the plurality of rotating electric machines to the axle and separating the axle from the other rotating electric machine of the internal combustion engine and the plurality of rotating electric machines; A clutch device capable of switching between driving modes,
A hybrid vehicle control device that controls a hybrid vehicle including a power storage device capable of inputting / outputting electric power to / from the plurality of rotating electrical machines,
Regenerative control means for controlling the one rotating electric machine so that power regeneration is performed at the time of deceleration during the traveling period in the series mode;
SOC specifying means for specifying the SOC of the power storage device;
When the specified SOC is greater than or equal to a predetermined value during the period in which the power regeneration is performed, a part of the regenerative power generated by the power regeneration is consumed, and the pair of engagement elements are in a rotation synchronization state. And a rotation synchronization control means for controlling the other rotating electric machine. Accelerator opening specifying means for specifying the accelerator opening;
Switching control means for switching the driving mode of the hybrid vehicle to the parallel mode by engaging a pair of engaging elements in the rotation-synchronized state when the specified accelerator opening is equal to or greater than a predetermined value; The hybrid vehicle control device according to claim 1, further comprising: When at least the accelerator operation is occurring and the detected accelerator opening is less than the predetermined value, the rotational energy of the other rotating electric machine is converted into electric energy, and the electric power generated as a result of the conversion is converted. The hybrid vehicle control device according to claim 3, further comprising drive control means for powering the one rotating electrical machine with energy. The hybrid vehicle
A first rotating electrical machine as the other rotating electrical machine;
A second rotating electrical machine as the one rotating electrical machine capable of inputting / outputting torque as power as to the axle;
A plurality of mutually differential actions including a first rotating element connected to the first rotating electrical machine, a second rotating element connected to the internal combustion engine, and a third rotating element connected to an output shaft connected to the axle. A power transmission mechanism having a rotating element of
The clutch device interrupts torque transmission between the output shaft and the axle in a state where the pair of engagement elements are released;
The regeneration control means controls the second rotating electric machine so that the power regeneration is performed,
4. The hybrid vehicle according to claim 1, wherein the rotation synchronization control unit controls the first rotating electric machine so that the pair of engagement elements are in a rotation synchronization state. 5. Control device.

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