JP2015120422A - Control device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an excessive rotation of a motor during reverse traveling.SOLUTION: A control device (500) of a hybrid vehicle controls a hybrid vehicle (1) that includes: an internal combustion engine (200) capable of performing a lean combustion; a first motor (MG1); a differential mechanism (300) connected to an output shaft (5) of the internal combustion engine, a rotary shaft of the first motor, and a drive shaft (6) respectively; a second motor (MG2); and a transmission (400) disposed between the differential mechanism and drive shaft. The control device of the hybrid vehicle includes: determination means (510) for determining whether required drive force is higher than a prescribed threshold during reverse traveling by driving the internal combustion engine; control means (530) for controlling the internal combustion engine so as not to perform a lean combustion when the required drive force is determined to be higher than the prescribed threshold; and threshold setting means (520) for setting the prescribed threshold to be smaller, as a gear ratio of the transmission is a lower speed side.

Description

  The present invention relates to a technical field of a hybrid vehicle control device that controls a hybrid vehicle including, for example, an internal combustion engine and an electric motor as a power source.

  As a control device for this type of hybrid vehicle, there is known one that causes an internal combustion engine to perform lean combustion (see, for example, Patent Documents 1 to 5). When the internal combustion engine is burned lean, for example, the fuel consumption efficiency is improved, but the output torque of the internal combustion engine is likely to fluctuate. For this reason, Patent Document 1 proposes a technique of compensating (offset) the output torque from the internal combustion engine with the torque of the electric motor.

JP 2007-125920 A JP 2006-090265 A JP 2006-090138 A JP 2004-156505 A JP 2006-177307 A

  In a hybrid vehicle, when performing reverse running while the internal combustion engine is operated, it is sometimes required to reduce the direct torque of the internal combustion engine in order to increase the torque according to the required driving force. However, for example, as in Patent Document 1 described above, when the output torque from the internal combustion engine is to be compensated with the torque of the electric motor, the rotational speed of the electric motor tends to increase. In particular, during lean combustion, fluctuations in the output torque of the internal combustion engine increase, resulting in a technical problem that the electric motor that compensates for it may be in an overspeed state.

  Examples of problems to be solved by the present invention include the above. An object of the present invention is to provide a hybrid vehicle control device that can suppress over-rotation of an electric motor during reverse traveling.

  A control device for a hybrid vehicle according to the present invention includes an internal combustion engine capable of lean combustion, a first electric motor capable of inputting and outputting power, an output shaft of the internal combustion engine, a rotating shaft of the first electric motor, and a drive shaft. A control device for controlling a hybrid vehicle, comprising: a differential mechanism connected; a second electric motor capable of inputting / outputting power to / from the drive shaft; and a transmission provided between the differential mechanism and drive wheels. And determining means for determining whether or not the required driving force is higher than a predetermined threshold during reverse running with the internal combustion engine being driven, and when it is determined that the required driving force is higher than the predetermined threshold, Control means for controlling the internal combustion engine so as not to perform lean combustion, and threshold setting means for setting the predetermined threshold value smaller as the gear ratio of the transmission is at a lower speed side.

  The hybrid vehicle according to the present invention has various modes regardless of fuel type, fuel supply mode, fuel combustion mode, intake / exhaust system configuration, cylinder arrangement, and the like as a power source capable of supplying power to the drive shaft. The vehicle includes at least an internal combustion engine that can be employed, and a first electric motor and a second electric motor that can be configured as a motor generator such as a motor generator. The internal combustion engine according to the present invention is configured to be capable of lean combustion. That is, it is configured to be able to realize a mode of operation in which the air-fuel ratio is lower than usual.

  The output shaft of the internal combustion engine and the rotation shaft of the first motor are connected to the drive shaft via a differential mechanism configured as, for example, a planetary gear mechanism. Therefore, the differential mechanism functions as a power transmission mechanism that transmits power between the internal combustion engine, the first electric motor, and the drive shaft. On the other hand, the second electric motor is configured to be able to input and output power to the drive shaft. For example, a transmission including a plurality of gears is provided between the differential mechanism and the drive wheels.

  The hybrid vehicle control device according to the present invention is a control device that controls such a hybrid vehicle, and includes, 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 plural 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.

  When the hybrid vehicle control device of the present invention is in operation, it is first determined by the determining means whether or not the required driving force is higher than a predetermined threshold during reverse running with the internal combustion engine driven. Specifically, the determination unit determines whether reverse traveling is performed by driving the internal combustion engine while the hybrid vehicle is traveling. When it is determined that the reverse running is being performed by driving the internal combustion engine, the required driving force is compared with a predetermined threshold value, and a determination result as to whether the required driving force is higher than the predetermined threshold value is output. .

  When the determination means determines that the required driving force is higher than the predetermined threshold value, the control means controls the internal combustion engine to prevent lean combustion. That is, the internal combustion engine according to the present invention is controlled so as to appropriately perform lean combustion in accordance with a predetermined condition during normal traveling, but is in reverse traveling with the internal combustion engine driven, and a required driving force is predetermined. If it is higher than the threshold value, lean combustion of the internal combustion engine is limited.

  Here, in particular, in the hybrid vehicle according to the present invention, in order to increase the reverse torque according to the required driving force when the reverse running is performed by driving the internal combustion engine, the direct torque of the internal combustion engine is set as much as possible. It is required to be small. On the other hand, in order to reduce the direct torque of the internal combustion engine, the torque may be compensated by the first electric motor connected to the internal combustion engine through the differential mechanism. However, when the required driving force increases, the rotational speed of the first electric motor that compensates for the torque tends to increase. In particular, when the internal combustion engine performs lean combustion, the torque fluctuation of the internal combustion engine increases, which may cause the first electric motor to over-rotate.

  However, in the present invention, as described above, when the required driving force is higher than the predetermined threshold during reverse running with the internal combustion engine driven, lean combustion of the internal combustion engine is limited. Therefore, it is possible to effectively suppress over-rotation of the first electric motor.

  Furthermore, in the present invention, the threshold value setting means sets the predetermined threshold value for determining whether or not to limit lean combustion to be smaller as the gear ratio of the transmission is lower (that is, as the gear ratio is higher). The Conversely, the predetermined threshold value is set to be larger as the gear ratio of the transmission is higher (that is, as the gear ratio is lower). As a result, when the gear ratio of the transmission is on the low speed side, the predetermined threshold is set to a relatively small value, and it becomes easy to limit lean combustion. On the other hand, when the gear ratio of the transmission is on the high speed side, the predetermined threshold is set to a relatively large value, and it becomes difficult to limit lean combustion.

  Here, in the hybrid vehicle according to the present invention, the lower the gear ratio of the transmission, the higher the rotational speed of the output shaft at the same vehicle speed. Therefore, if the required driving force is the same, the lower the gear ratio, the higher the rotational speed of the first electric motor. Therefore, the over-rotation of the first electric motor is more likely to occur as the gear ratio of the gear ratio is lower. For this reason, if the predetermined threshold value is decreased as the gear ratio of the transmission is lower, the lean combustion is more likely to be limited as the over-rotation is more likely to occur. As a result, it is possible to suppress over-rotation of the first electric motor very efficiently.

  As described above, according to the hybrid vehicle control device of the present invention, it is possible to effectively suppress over-rotation of the electric motor during reverse traveling.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

1 is a skeleton diagram showing an overall configuration of a hybrid vehicle according to an embodiment. It is a speed diagram of the hybrid vehicle which concerns on embodiment. It is an operation | movement engagement table | surface of the hybrid vehicle which concerns on embodiment. It is a schematic block diagram which shows the structure of the internal combustion engine of the hybrid vehicle which concerns on embodiment. It is a map which shows the operating point of the internal combustion engine of the hybrid vehicle which concerns on embodiment. It is a map which shows the relationship between an air fuel ratio and MG1 rotation speed upper limit. It is a block diagram which shows the structure of the control apparatus of the hybrid vehicle which concerns on embodiment. It is a flowchart which shows operation | movement of the control apparatus of the hybrid vehicle which concerns on embodiment. It is a map which shows the relationship between a gear ratio and a request | requirement driving force threshold value.

  Hereinafter, an embodiment of a control device for a hybrid vehicle will be described.

(1) Overall Configuration of Hybrid Vehicle First, the overall configuration (particularly, the configuration of the drive mechanism) of the hybrid vehicle 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a skeleton diagram showing the overall configuration of the hybrid vehicle according to the embodiment.

  As shown in FIG. 1, the hybrid vehicle 1 according to the present embodiment is configured as a hybrid vehicle that combines a plurality of power sources. Specifically, the hybrid vehicle 1 includes an engine 200, a motor generator MG1, and a motor generator MG2 as driving power sources.

  The engine 200 is a gasoline engine that functions as a main power source of the hybrid vehicle 1 and is an example of the “internal combustion engine” according to the present invention.

  Motor generators MG1 and MG2 have a power running function that converts electrical energy into kinetic energy, and a regeneration function that converts kinetic energy into electrical energy. An example is a motor generator. The motor generators MG1 and MG2 are configured as electric motors including, 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. You may have a structure.

  Engine 200 and motor generators MG1 and MG2 are connected to each other via a single pinion type planetary gear mechanism 300 which is an example of the “differential mechanism” of the present invention. The planetary gear mechanism 300 includes a sun gear S0 as an external gear, a ring gear R0 as an internal gear arranged coaxially with the sun gear S0, and a carrier CA0 that holds the pinion meshing with the sun gear S0 and the ring gear R0 so as to be able to rotate and revolve. And have.

  The engine output shaft 5 that is the output shaft of the engine 200 is connected to the carrier CA0 of the planetary gear mechanism 300, and the engine output shaft 5 rotates integrally with the carrier CA1. Therefore, the engine torque output from engine 200 is transmitted to carrier CA1. Motor generator MG1 is coupled to sun gear S0 of planetary gear mechanism 300. Motor generator MG2 is connected to drive shaft 6 connected to ring gear R0 of planetary gear mechanism 300. Torque output from engine 200 and motor generators MG1 and MG2 is output via drive shaft 6.

  The drive shaft 6 is connected to a transmission 400 that changes the gear ratio of the hybrid vehicle. The transmission 400 includes two planetary gear mechanisms (specifically, a planetary gear mechanism including a sun gear S1, a ring gear R1 and a carrier CA1, and a planetary gear mechanism including a sun gear S2, a ring gear R2 and a carrier CA2), and a first clutch. C1 and second clutch C2, one-way clutch F1, first brake B1 and second brake B2 are provided.

  In the two planetary gear mechanisms, one carrier CA1 and the other ring gear R2 are connected to each other. Also, one ring gear R1 and the other carrier CA2 are connected to each other.

  The first clutch C1 is configured to be able to change the power transmission state between the drive shaft 6 and the sun gear S2. The second clutch C2 is configured to be able to change the power transmission state between the drive shaft 6 and the carrier CA1.

  The one-way clutch F1 is configured to be able to change the power transmission state between the carrier CA1 and the ring gear R2 in a predetermined one direction.

  The first brake is configured to be able to fix the rotation of the sun gear S1. The second brake is configured to be able to fix the rotation of the carrier CA1 and the ring gear R2.

  The torque transmitted via the transmission 400 is configured to be output to the axle side via the carrier CA2.

  Note that the above-described configuration of the transmission 400 is merely an example, and a different form of transmission 400 may be used as a mechanism for changing the gear ratio of the hybrid vehicle.

(2) Gear Ratio Realized by Transmission Next, the gear ratio realizable by the transmission 400 according to the present embodiment will be specifically described with reference to FIGS. FIG. 2 is a velocity diagram of the hybrid vehicle according to the embodiment. FIG. 3 is an operation engagement table of the hybrid vehicle according to the embodiment.

  As shown in FIGS. 2 and 3, the transmission 400 according to the present embodiment can change the gear ratio of the hybrid vehicle 1 in four stages. Specifically, by engaging the first clutch C1, the second brake B1, and the one-way clutch F1, and releasing the second clutch C2 and the first brake B1, the gear ratio 1ST (that is, the highest gear ratio). High state) is realized. By engaging the first clutch C1 and the first brake B1, and releasing the second clutch C2, the second brake B2, and the one-way clutch F1, the gear ratio is 2ND (that is, the second highest gear ratio state). Is realized. By engaging the first clutch C1 and the second clutch C2 and releasing the first brake B1, the second brake B2 and the one-way clutch F1, the gear ratio 3RD (ie, the third highest gear ratio state). Is realized. By engaging the second clutch C2 and the first brake and releasing the first clutch C1, the second brake B2, and the one-way clutch F1, a gear ratio 4TH (that is, the state with the lowest gear ratio) is realized. The

(3) Configuration of Engine of Hybrid Vehicle Next, a configuration around the engine 200 of the hybrid vehicle 1 according to the present embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic configuration diagram showing the configuration of the internal combustion engine of the hybrid vehicle according to the embodiment.

  In FIG. 4, the engine 200 according to the present embodiment is configured as a supercharged engine including a compressor 110 and a turbine 120.

  The compressor 110 compresses the air that has flowed in and supplies the compressed air downstream. Turbine 120 rotates using exhaust gas supplied from engine 200 via exhaust pipe 115 as power. The turbine 120 is connected to the compressor 110 via a shaft, and is configured to be able to rotate integrally with each other. That is, the turbine 120 and the compressor 110 constitute a turbocharger.

  The engine 200 is, for example, an in-line four-cylinder engine in which four cylinders 201 are arranged in series in a cylinder block. Although detailed illustration is omitted here, the engine 200 performs the reciprocating motion of the piston that occurs when the air-fuel mixture burns inside each cylinder 201 via the connecting rod. It can be converted into a rotational motion.

  An air flow meter 102 is provided in the intake pipe 101 on the inlet side (that is, upstream side of the compressor 110) of the compressor 110. The air flow meter 102 is configured to be able to detect the amount of air sucked from the outside. Further, an intake throttle valve 103 is provided downstream of the air flow meter 102. The intake throttle valve 103 is an electronically controlled valve, for example, and is configured such that its opening / closing operation is controlled by a throttle valve motor (not shown). The amount of air flowing into the intake pipe 101 is adjusted by opening and closing the intake throttle valve 103.

  An intercooler 113 is provided on the intake pipe 111 on the outlet side of the compressor 110 (that is, on the downstream side of the compressor 110) and on the intake side (that is, on the upstream side of the cylinder 201) of the engine 200. The intercooler 113 is configured to be able to cool intake air and increase the supercharging efficiency of the air.

  In the combustion chamber in the cylinder 201 of the engine 200, an air-fuel mixture obtained by mixing the air supplied through the intake pipe 111 and the fuel injected and supplied from the injector 210 is sucked. The air-fuel mixture introduced into the cylinder 201 from the intake side is ignited by a spark plug (not shown), compression ignition, or the like, and an explosion process is performed in the cylinder 201. When the explosion process is performed, the burned air-fuel mixture (including a partially unburned air-fuel mixture) is discharged to an exhaust port (not shown) in the exhaust process following the explosion process. The exhaust discharged to the exhaust port is guided to the exhaust pipe 115.

  The exhaust pipe 121 on the outlet side of the turbine 120 (that is, the downstream side of the turbine 120) includes an EGR pipe 125, an EGR valve 126, and an EGR cooler 127 in addition to the start converter 123 and the aftertreatment device 124. A system is provided.

  The start converter 123 includes, for example, an oxidation catalyst, and purifies substances contained in the exhaust gas that has passed through the turbine 120.

  The post-processing device 124 is provided downstream of the start converter 123 in the exhaust pipe 122 and collects and reduces particulate matter contained in the exhaust.

  The EGR pipe 125 is configured so that the exhaust downstream of the start converter 123 can be returned to the intake pipe 101 on the inlet side of the compressor 110. An EGR valve 126 is provided on the EGR pipe 125, and the amount of EGR gas can be adjusted. An EGR cooler 127 that cools the recirculated EGR gas is provided on the EGR pipe 125.

(4) Engine Combustion Mode Next, a combustion mode that can be realized by the engine 200 according to this embodiment described above will be described with reference to FIGS. 5 and 6. FIG. 5 is a map showing operating points of the internal combustion engine of the hybrid vehicle according to the embodiment. FIG. 6 is a map showing the relationship between the air-fuel ratio and the MG1 rotation speed upper limit.

  In FIG. 5, since the engine 200 according to the present embodiment is configured as a supercharged engine as described above, supercharging combustion while supercharging is realized in addition to normal NA (Natural Aspiration) combustion. It is possible. In addition, for each of these NA combustion and supercharging combustion, stoichiometric combustion in which combustion is performed with an air-fuel mixture having a concentration close to the stoichiometric air-fuel ratio, and lean combustion in which combustion is performed with an air-fuel mixture thinner than the stoichiometric air-fuel ratio is possible.

  Each combustion state is selected from the relationship between the engine speed and the engine torque so as to realize an operation close to the optimum fuel efficiency operation point indicated by a thick solid line in the figure. However, the operation at the optimum fuel efficiency operation point does not necessarily need to be realized, and the operation at the operation point deviating from the optimum fuel efficiency operation point may be realized according to the situation and specifications.

  In FIG. 6, the motor generator MG1 is configured to be able to output a torque that compensates (cancels) the engine torque, for example, when the direct torque of the engine 200 should be reduced. In this case, motor generator MG1 is required to have a higher rotational speed as the engine rotational speed is larger.

  Here, when the engine 200 is performing lean combustion, fluctuations in the engine speed are likely to occur due to its characteristics. Therefore, at the time of lean combustion, the rotational speed of motor generator MG1 that compensates for engine torque is also likely to vary. Therefore, for motor generator MG1 according to the present embodiment, an upper limit value is set in accordance with the air-fuel ratio in order to prevent overspeeding when the engine speed increases rapidly. Specifically, the upper limit value of motor generator MG1 is set to be lower as the air-fuel ratio is larger (the amount of relative air is larger).

(5) Configuration of Hybrid Vehicle Control Device Next, the configuration of the hybrid vehicle control device according to the embodiment will be described with reference to FIG. FIG. 7 is a block diagram showing the configuration of the control device for the hybrid vehicle according to the embodiment.

  In FIG. 7, the hybrid vehicle control device according to the present embodiment is configured as an ECU 500 capable of executing control of each part of the hybrid vehicle. The ECU 500 includes at least a lean combustion restriction determination unit 510, a required driving force threshold setting unit 520, and a combustion mode control unit 530.

  The lean combustion restriction determination unit 510 is an example of the “determination unit” according to the present invention, and is configured to be able to determine whether or not to restrict lean combustion in the engine 200. Specifically, the lean combustion restriction determination unit 510 uses the information regarding the travel mode of the hybrid vehicle 1 input from the outside, the information regarding the required driving force, and the required driving force threshold input from the required driving force threshold setting unit 520. Based on this, it is determined whether or not to limit lean combustion. The determination result by the lean combustion restriction determination unit 510 can be output to the combustion mode control unit 530.

  The required driving force threshold value setting unit 520 is an example of the “threshold setting means” of the present invention, and is configured to be able to set the required driving force threshold value used for the determination by the lean combustion restriction determination unit 510. Specifically, required driving force threshold value setting unit 520 sets a required driving force threshold value based on information regarding the gear ratio of transmission 400 input from the outside, and outputs the threshold value to lean combustion restriction determination unit 510. The required driving force threshold value is an example of the “predetermined threshold value” in the present invention.

  Combustion mode control unit 530 is an example of the “control means” in the present invention, and is configured to be able to control the combustion mode (see FIG. 5) of engine 200. Specifically, combustion mode control unit 530 controls the combustion mode of engine 200 based on the determination result of lean combustion restriction determination unit 510.

  Specific processing executed in each of the above-described lean combustion restriction determination unit 110, required driving force threshold setting unit 120, and combustion mode control unit 130 will be described in detail below.

(6) Operation of Hybrid Vehicle Control Device Next, the operation of the hybrid vehicle control device according to the present embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing the operation of the control device for the hybrid vehicle according to the embodiment.

  In FIG. 8, when the hybrid vehicle control apparatus 500 according to the present embodiment operates, first, the lean combustion restriction determination unit 110 determines whether or not the hybrid vehicle 1 is running in reverse with the engine 200 being driven. (Step S101). Whether or not the engine 200 is driven in reverse traveling can be determined based on, for example, information regarding the traveling mode of the hybrid vehicle 1 input from the outside. Or when ECU500 is provided with the travel mode control means which controls the travel mode of the hybrid vehicle 1, you may acquire the present travel mode from a travel mode control means.

  When the lean combustion restriction determination unit 110 determines that the hybrid vehicle 1 is not in reverse running with the engine 200 driven (step S101: NO), the combustion mode control unit 130 displays a normal map (see FIG. 5). The used combustion mode is switched (step S106).

  On the other hand, when the lean combustion restriction determination unit 110 determines that the hybrid vehicle 1 is in reverse running with the engine 200 driven (step S101: YES), the required driving force threshold setting unit 120 sets the current gear stage. Is read (step S102). That is, it is read whether the gear ratio realized by the current transmission is 1ST, 2ND, 3RD, or 4TH. In this case, the required driving force threshold value setting unit 120 may directly acquire the gear stage of the transmission 400, or each part of the transmission 400 (specifically, the first clutch C1, the second clutch C2, and the one-way The current gear stage may be indirectly detected from the engaged state of the clutch F1, the first brake B1, and the second brake B2) (see FIG. 3).

  Subsequently, the required driving force threshold setting unit 120 sets a required driving force threshold based on the read gear. Below, the setting method of a request | requirement driving force threshold value is demonstrated concretely with reference to FIG. FIG. 9 is a map showing the relationship between the gear ratio and the required driving force threshold value.

  As shown in FIG. 9, the required driving force threshold is set to be smaller as the gear ratio of the hybrid vehicle 1 is higher (that is, as the speed is lower). In other words, the lower the gear ratio of the hybrid vehicle 1 (that is, the higher the speed side), the larger the gear ratio is set. Although FIG. 9 illustrates an example in which the required driving force threshold changes linearly with respect to the gear ratio of the hybrid vehicle, as long as the required driving force threshold is monotonously decreased with respect to an increase in the gear ratio. The effects according to this embodiment to be described later can be exhibited.

  Returning to FIG. 8, the required driving force threshold set by the required driving force threshold setting unit 120 is input to the lean combustion restriction determination unit 110. Then, the lean combustion restriction determination unit 110 compares the required driving force for the current hybrid vehicle 1 with the required driving force threshold value, and determines whether the required driving force is larger than the required driving force threshold value (step S104). .

  When the lean combustion restriction determination unit 110 determines that the required driving force is equal to or less than the required driving force threshold (step S104: NO), the combustion mode control unit 130 performs switching of the combustion mode using the normal map ( Step S106).

On the other hand, when the lean combustion restriction determination unit 110 determines that the required driving force is equal to or less than the required driving force threshold (step S104: NO), the combustion mode control unit 130 temporarily prohibits lean combustion of the engine 200. (Step S105).

  Here, in particular, in the hybrid vehicle 1 according to the present embodiment, when it is intended to achieve reverse running with the engine 200 driven, in order to increase the reverse torque according to the required driving force, the direct torque of the engine 200 Is required to be as small as possible. On the other hand, in order to reduce the direct torque of engine 200, the torque may be compensated by motor generator MG1 connected to engine 200 through a differential mechanism. However, when the required driving force increases, the rotational speed of motor generator MG1 that compensates for torque tends to increase. In particular, when engine 200 undergoes lean combustion, torque fluctuations of engine 200 increase, and motor generator MG1 may over-rotate.

  On the other hand, in the present embodiment, as described above, when the required driving force is higher than the required driving force threshold during reverse running with the engine 200 driven, lean combustion of the engine 200 is limited. That is, when it is required to increase the reverse torque, the load on the motor generator MG1 increases, so that the engine torque varies greatly (that is, there is a possibility of imposing a further load on the motor generator MG1). Combustion is limited. As a result, over-rotation of motor generator MG1 can be effectively suppressed.

  Furthermore, in the present embodiment, as described above, the required driving force threshold setting unit 120 sets the required driving force threshold for determining whether or not to limit lean combustion in accordance with the gear ratio of the transmission 400. ing. Specifically, the smaller the gear ratio is, the smaller the gear ratio is set (that is, the higher the gear ratio). As a result, when the gear ratio of the transmission 400 is on the low speed side, the required driving force threshold is set to a relatively small value, and the lean combustion is easily restricted. On the other hand, when the gear ratio of the transmission 400 is on the high speed side, the required driving force threshold is set to a relatively large value, and it becomes difficult to limit lean combustion.

  Here, in the hybrid vehicle 1 according to the present embodiment, the lower the gear ratio of the transmission 300 is, the higher the rotational speed of the output shaft at the same vehicle speed. Therefore, if the required driving force is the same, the lower the gear ratio, the higher the rotational speed of motor generator MG1. Therefore, over-rotation of motor generator MG1 is more likely to occur as the gear ratio of gear ratio 400 is lower. For this reason, if the required driving force threshold is reduced as the gear ratio of the transmission 400 is lower, lean combustion is more likely to be restricted as the motor generator MG1 is more likely to over-rotate. As a result, over-rotation of motor generator MG1 can be suppressed extremely efficiently.

  As described above, according to hybrid vehicle control apparatus 100 of the present embodiment, it is possible to effectively suppress over-rotation of motor generator MG1 during reverse traveling.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The control device is also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 101,111 Intake pipe 102 Air flow meter 103 Intake throttle valve 110 Compressor 113 Intercooler 120 Turbine 115,121 Exhaust pipe 123 Start converter 124 After-treatment device 125 EGR pipe 126 EGR valve 127 EGR cooler 200 Engine 201 Cylinder 210 Injector 300 Planetary gear mechanism 400 Transmission 400 Control unit 410 Forced charging control unit 420 Inter-battery charging control unit 500 ECU
510 Lean Combustion Limit Determination Unit 520 Required Driving Force Threshold Setting Unit 530 Combustion Mode Control Unit MG1, MG2 Motor Generator S0, S1, S2 Sun Gear CA0, CA1, CA2 Carrier R0, R1, R2 Ring Gear C1, C2 Clutch F1 One-way Clutch B1 , B2 brake

Claims (1)

An internal combustion engine capable of lean combustion;
A first electric motor capable of inputting and outputting power;
A differential mechanism coupled to each of an output shaft of the internal combustion engine, a rotation shaft of the first electric motor, and a drive shaft;
A second electric motor capable of inputting and outputting power to the drive shaft;
A control device for controlling a hybrid vehicle comprising: a transmission provided between the differential mechanism and drive wheels;
Determining means for determining whether or not the required driving force is higher than a predetermined threshold during reverse running with the internal combustion engine driven;
Control means for controlling the internal combustion engine so as not to perform the lean combustion when it is determined that the required driving force is higher than the predetermined threshold;
A control device for a hybrid vehicle, comprising: threshold setting means configured to set the predetermined threshold value smaller as the gear ratio of the transmission is lower.

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