JP2013063736A - Hybrid vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in fuel economy during failure in a transmission, in a hybrid vehicle.SOLUTION: This control device (100) for a hybrid vehicle controls the hybrid vehicle (1) comprising an internal combustion engine (200), a stepped transmission (30) changing the rotation speed of the internal combustion engine to transmit it to wheels (FL, FR), and a rotary electric machine (MG) having an electric storage means (12). The control device for the hybrid vehicle comprises: a transmission failure detection means (110) for detecting failure of the stepped transmission; limiting means (120, 130) for limiting the torque of the internal combustion engine so that charging and discharging power of the rotary electric machine does not exceed a predetermined upper limit value or a lower limit value when the failure in the stepped transmission is detected; and charge limit range change means (150, 160) for enlarging, when the failure in the stepped transmission is detected, a charging limit range of the electric storage means as compared with that when the failure in the transmission is not detected.

Description

  The present invention relates to a technical field of a control device for controlling a hybrid vehicle including a power element including an internal combustion engine and a rotating electric machine, and a stepped transmission.

  In this type of hybrid vehicle, traveling in a more appropriate fuel consumption state is realized by appropriately switching gears by a transmission. Therefore, if the transmission breaks down while the hybrid vehicle is traveling, there is a possibility that traveling in an appropriate fuel consumption state cannot be realized.

  Assuming such a case, in Patent Document 1, for example, in a vehicle in which the connection of the motor can be switched between the input shaft and the output shaft of the transmission, the motor is used when the transmission is fixed at a specific shift stage. A technique has been proposed in which the connection is switched to the output shaft. Patent Document 2 proposes a technique for fixing the output characteristics of an engine when a transmission fails. Further, Patent Document 3 proposes a technique in which when a transmission fails and is fixed to a gear having a low gear ratio, the required torque is limited and the engine and the motor are controlled based on the limited required torque.

JP 2010-247689 Japanese Patent Laid-Open No. 05-104989 JP 2005-313865 A

  In the hybrid vehicle, the difference between the output power and the required power of the internal combustion engine is charged into the power storage means such as a battery by the regenerative operation of the rotating electrical machine. Here, if the transmission breaks down and is fixed to a gear with a low gear ratio, the rotational speed of the internal combustion engine becomes extremely high with respect to the required power, and the charge amount to the power storage means cannot be accepted. There is a risk of becoming higher. In this case, it becomes difficult to bring the operating point of the internal combustion engine close to the optimum fuel consumption line, and as a result, fuel consumption deteriorates.

  However, Patent Documents 1 to 3 mentioned above do not mention at all that the amount of charge to the power storage means becomes too high when the transmission fails. Moreover, even if the transmission control described in Patent Documents 1 to 3 is performed, it is difficult to prevent the amount of charge to the power storage unit from becoming too high. That is, the techniques described in Patent Documents 1 to 3 have a technical problem that there is a possibility that fuel consumption may deteriorate when the transmission fails.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a control device for a hybrid vehicle that can prevent deterioration of fuel consumption when a transmission malfunctions.

  In order to solve the above-described problems, a control device for a hybrid vehicle of the present invention includes an internal combustion engine, a stepped transmission that shifts the rotational speed of the internal combustion engine and transmits the speed to wheels, and a rotating electrical machine having a power storage unit. A control device for a hybrid vehicle, comprising: a transmission failure detecting means for detecting a failure of the stepped transmission; and a charging / discharging power of the rotating electrical machine when a failure of the stepped transmission is detected. Limiting means for limiting the torque of the internal combustion engine so as not to exceed an upper limit value or a lower limit value, and when a failure of the stepped transmission is detected, a charge limitation range of the power storage means is set to the failure of the transmission. Charging limit range changing means for making the size larger than that in the case where no is detected.

  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 power elements capable of supplying power to the drive shaft. A vehicle including at least an internal combustion engine that can be employed and a rotating electrical machine that can be configured as a motor generator such as a motor generator. The rotating electrical machine can charge power obtained by regeneration in a power storage means such as a battery, and can be powered by power supplied from the power storage means. The internal combustion engine and the rotating electric machine are connected to a stepped transmission including a plurality of gears, for example. As a result, an appropriate gear ratio is realized in the stepped transmission, and fuel consumption can be improved.

  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.

  During the operation of the hybrid vehicle control device according to the present invention, first, the failure of the stepped transmission is detected by the transmission failure detection means. Note that “failure of a stepped transmission” here refers to a situation in which a normal operation cannot be performed in a stepped transmission. For example, the gear stage is fixed due to a malfunction of an actuator of the stepped transmission. The state which will end up is mentioned.

  Particularly in the present invention, when a failure of the stepped transmission is detected, the torque of the internal combustion engine is limited by the limiting means. Specifically, the torque of the internal combustion engine is such that the charging / discharging power of the rotating electrical machine does not exceed a predetermined upper limit value or lower limit value (that is, not to exceed the upper limit value or lower than the lower limit value). Limited. Here, the “predetermined upper limit value or lower limit value” is a value corresponding to the amount of charge that can be instantaneously accepted by the power storage means of the rotating electrical machine or the amount of discharge that can be discharged. And so on.

  For example, the limiting means calculates the charge / discharge power of the rotating electrical machine from the difference between the required power required to be output to the axle and the actual output power of the internal combustion engine, and the calculated charge / discharge power of the rotating electrical machine is The torque of the internal combustion engine is limited so as not to exceed a predetermined upper limit value or lower limit value. That is, when the charging / discharging power of the rotating electrical machine does not exceed the predetermined upper limit value or lower limit value, the restriction means does not restrict the internal combustion engine. On the other hand, when the charge / discharge power of the rotating electrical machine exceeds a predetermined upper limit value or lower limit value, control is performed to limit the upper limit value of the torque to the internal combustion engine.

  Here, if the stepped transmission fails and is fixed to a gear with a low gear ratio, the rotational speed of the internal combustion engine becomes extremely high with respect to the required power, and the output power from the internal combustion engine increases. There is a risk of passing. In such a case, the charge / discharge power of the rotating electrical machine increases, and the charge / discharge to the power storage means may exceed an allowable amount. If the allowable amount of the power storage means is exceeded, it becomes difficult to bring the operating point of the internal combustion engine close to the optimum fuel consumption line, and as a result, the fuel consumption deteriorates.

  However, in the present invention, as described above, when a failure of the stepped transmission is detected, the torque of the internal combustion engine is limited. Thereby, the output power from an internal combustion engine will be restrict | limited, and the charging / discharging power of a rotary electric machine will be in a fixed range. Therefore, it is possible to prevent the charge / discharge power of the rotating electrical machine from increasing and the charge / discharge of the power storage means from exceeding an allowable amount. For this reason, traveling can be continued in a state where the operating point of the internal combustion engine is close to the optimum fuel consumption line.

  When limiting the torque of the internal combustion engine, it may be difficult to maintain the speed of the hybrid vehicle depending on the rotational speed of the internal combustion engine at the time of detecting the failure of the stepped transmission. In such a case, it is preferable that the torque of the internal combustion engine is not limited rapidly but is limited in stages so as to gradually reduce the speed of the hybrid vehicle.

  Further, in the present invention, when a failure of the stepped transmission is detected, the charging limit range changing unit changes the charging limit range of the power storage unit so as to increase. Specifically, the upper limit value of SOC (State Of Charge) is increased or the lower limit value is decreased. Note that the charging limit range may be changed so as to increase by a predetermined value set in advance, or may be changed according to a value determined based on various parameters in the hybrid vehicle. .

  The hybrid vehicle travels while switching between a mode (so-called EV mode) that travels only by the output from the rotating electrical machine and a mode (so-called HV mode) that travels using both the internal combustion engine and the rotating electrical machine. When switching from the mode to the HV mode, it is required to start the stopped internal combustion engine. However, since a relatively large power is required for starting the internal combustion engine, from the viewpoint of improving fuel efficiency, the number of start times of the internal combustion engine (in other words, the number of times of switching from the EV mode to the HV mode) is as much as possible. Less is preferred.

  However, in the present invention, in particular, when a failure of the stepped transmission is detected, the charging limit range of the power storage means is changed to be large. As a result, the travel distance in the EV mode can be extended. Therefore, the number of start-ups of the internal combustion engine can be reduced, and deterioration of fuel consumption when a stepped transmission fails can be prevented.

  As described above, according to the hybrid vehicle control device of the present invention, it is possible to prevent deterioration of fuel consumption when a stepped transmission fails.

  In one aspect of the hybrid vehicle of the present invention, the charge limit range changing means increases the charge limit range of the power storage means as the average value of the power required for the internal combustion engine and the rotating electrical machine is large. .

  According to this aspect, when the failure of the stepped transmission is detected, the charging limit range of the power storage means is the power required for the internal combustion engine and the rotating electrical machine as power elements (hereinafter referred to as “required power” as appropriate). It changes so that it may become large based on the average value in a predetermined period. The charging limit range of the power storage means may be changed so as to continuously increase in proportion to the average value of the required power for a predetermined period, or the average value of the required power for a predetermined period exceeds a predetermined threshold value. You may change so that it may become large in steps every time.

  When the required power is relatively large, the fuel consumption can be effectively improved by changing the charging limit range of the power storage means to be large. On the other hand, when the required power is relatively small, the mileage in the EV mode is relatively long without changing the charging control range of the power storage means so that the influence on fuel consumption deterioration is small. . Therefore, if the charging limit range of the power storage means is changed according to the required power, the inconvenience (for example, deterioration of the power storage means, etc.) caused by increasing the charging limit range of the power storage means is prevented, and the fuel consumption is deteriorated. Can be prevented.

  Further, in a hybrid vehicle, it is not realistic to continue running with the required power being constant, and it is considered that the value varies depending on the running situation. Therefore, by using the average value of the required power over a predetermined period, it is possible to suitably change the charging limit range of the power storage means. The “predetermined period” here is calculated theoretically, experimentally, or empirically in advance so as to effectively prevent fuel consumption deterioration.

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

1 is a schematic configuration diagram conceptually showing a configuration of a hybrid vehicle. 1 is a schematic configuration diagram conceptually showing a configuration of a hybrid drive device. It is a mimetic diagram which illustrates one section composition of an engine. 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 a series of operation | movement of the control apparatus of the hybrid vehicle which concerns on embodiment. It is a map which shows the thermal efficiency of an engine. It is a graph which shows the SOC restriction | limiting range at the time of normal control and a transmission failure.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the overall configuration of the hybrid vehicle according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle.

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

  The ECU 100 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like, and is configured to be able to control the operation of each part of the hybrid vehicle 1, and is an example of the “hybrid vehicle control device” of the present invention. The ECU 100 is configured to execute various controls in the hybrid vehicle 1 according to a control program stored in, for example, a ROM.

  The PCU 11 converts the DC power extracted from the battery 12 into AC power and supplies it to a motor generator MG described later. Further, an inverter (not shown) that can convert AC power generated by motor generator MG into DC power and supply it to battery 12 is included. That is, the PCU 11 inputs and outputs power between the battery 12 and the motor generator, or inputs and outputs power between the motor generators (that is, in this case, the power is exchanged between the motor generators without going through the battery 12. Is a power control unit configured to be controllable. The PCU 11 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  The battery 12 is a rechargeable power storage unit that functions as a power supply source related to power for powering the motor generator MG. The amount of power stored in the battery 12 can be detected by the ECU 100 or the like.

  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.

  The hybrid drive device 10 is a power unit that functions as a power train of the hybrid vehicle 1. 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.

  In FIG. 2, the hybrid drive apparatus 10 mainly includes an engine 200, a transmission 30, a motor generator MG, a connection switching mechanism 40, and a speed reduction mechanism 70.

  The engine 200 is a gasoline engine which is an example of the “internal combustion engine” according to the present invention, and is configured to function as a main power source of the hybrid vehicle 1. Here, the detailed configuration of the engine 200 will be described with reference to FIG. FIG. 3 is a schematic view illustrating one cross-sectional configuration of the engine.

  The “internal combustion engine” in the present invention includes, for example, a 2-cycle or 4-cycle reciprocating engine, and has at least one cylinder, and various fuels such as gasoline, light oil, alcohol, etc. in the combustion chamber inside the cylinder. Includes an engine configured to be able to take out the force generated when the air-fuel mixture containing gas is burned as a driving force through appropriate physical or mechanical transmission means such as pistons, connecting rods and crankshafts. It is a concept to do. As long as the concept is satisfied, the configuration of the internal combustion engine according to the present invention is not limited to that of the engine 200 and may have various aspects. Further, the engine 200 is an in-line four-cylinder engine in which four cylinders 201 are arranged in series in a direction perpendicular to the paper surface, but the configuration of each cylinder 201 is equal to each other. Only the cylinder 201 will be described.

  In FIG. 3, the engine 200 burns the air-fuel mixture through an ignition operation by an ignition device 202 in which a part of a spark plug (not shown) is exposed in a combustion chamber in a cylinder 201, and the explosive force due to such combustion. The reciprocating motion of the piston 203 that occurs in response to the above is converted into the rotational motion of the crankshaft 205 via the connecting rod 204.

  In the vicinity of the crankshaft 205, a crank position sensor 206 for detecting the rotational position (ie, crank angle) of the crankshaft 205 is installed. The crank position sensor 206 is electrically connected to the ECU 100 (not shown), and the ECU 100 calculates the engine speed NE of the engine 200 based on the crank angle signal output from the crank position sensor 206. It is the composition which becomes.

  In the engine 200, air sucked from the outside passes through the intake pipe 207 and is guided into the cylinder 201 through the intake port 210 when the intake valve 211 is opened. On the other hand, the fuel injection valve of the injector 212 is exposed at the intake port 210, so that fuel can be injected into the intake port 210. The fuel injected from the injector 212 is mixed with the intake air before and after the opening timing of the intake valve 211 to become the above-described mixture.

  The fuel is stored in a fuel tank (not shown), and is supplied to the injector 212 via a delivery pipe (not shown) by the action of a feed pump (not shown). The air-fuel mixture combusted inside the cylinder 201 becomes exhaust, and is led to the exhaust pipe 215 via the exhaust port 214 when the exhaust valve 213 that opens and closes in conjunction with the opening and closing of the intake valve 211 is opened.

  On the other hand, on the upstream side of the intake port 210 in the intake pipe 207, a throttle valve 208 capable of adjusting the intake air amount related to the intake air guided through a cleaner (not shown) is disposed. The throttle valve 208 is configured such that its drive state is controlled by a throttle valve motor 209 electrically connected to the ECU 100. The ECU 100 basically controls the throttle valve motor 209 so as to obtain a throttle opening corresponding to the opening of an accelerator pedal (not shown) (that is, the accelerator opening Ta described above). It is also possible to adjust the throttle opening without intervention of the driver's intention through the operation control of 209. That is, the throttle valve 208 is configured as a kind of electronically controlled throttle valve.

  A three-way catalyst 216 is installed in the exhaust pipe 215. The three-way catalyst 216 is configured to reduce NOx (nitrogen oxides) in the exhaust discharged from the engine 200 and at the same time to oxidize CO (carbon monoxide) and HC (hydrocarbon) in the exhaust. It is. In addition, the form which a catalyst apparatus can take is not limited to such a three-way catalyst, For example, instead of or in addition to the three-way catalyst, various catalysts such as an NSR catalyst (NOx storage reduction catalyst) or an oxidation catalyst are installed. May be.

  An air-fuel ratio sensor 217 configured to be able to detect the exhaust air-fuel ratio of the engine 200 is installed in the exhaust pipe 215. Further, a water temperature sensor 218 for detecting the cooling water temperature related to the cooling water (LLC) circulated and supplied to cool the engine 200 is disposed in the water jacket installed in the cylinder block that houses the cylinder 201. ing. The air-fuel ratio sensor 217 and the water temperature sensor 218 are electrically connected to the ECU 100, and the detected air-fuel ratio and cooling water temperature are grasped by the ECU 100 at a constant or indefinite detection cycle. .

  Returning to FIG. 2, the mechanical power output from the engine 200 via the engine output shaft 15 is transmitted to the transmission input shaft 28 via the friction clutch device 20.

  The transmission 30 is an example of the “stepped transmission” in the present invention, and the mechanical power received by the transmission input shaft 28 is shifted by any one of the plurality of shift stages 31 to 34 to change the speed. It can be transmitted to the machine output shaft 60. Specifically, the transmission 30 is configured as a parallel shaft gear device including a plurality of gear pairs. In the present embodiment, the first speed gear stage 31, the second speed gear stage 32, A third speed gear stage 33 and a fourth speed gear stage 34 are provided. Note that the reduction ratio of the first speed gear stage 31 to the fourth speed gear stage 34 decreases in the order of the first speed gear stage 31, the second speed gear stage 32, the third speed gear stage 33, and the fourth speed gear stage 34. It is comprised so that it may become.

  Each of the gear stages 31, 32, 33, 34 of the transmission 30 is a main gear 31a, 32a, 33a, 34a that is a gear on the transmission input shaft 28 side, and a counter gear that is a gear on the transmission output shaft 60 side. 31c, 32c, 33c, 34c. The main gears 31a, 32a, 33a, 34a mesh with the corresponding counter gears 31c, 32c, 33c, 34c. In each of the shift stages 31, 32, 33, 34, one of the main gear and the counter gear is configured to be rotatable with respect to the transmission input shaft 28 or the transmission output shaft 60. In each of the shift stages 31 to 34, a mesh clutch mechanism (for example, a dog clutch) (not shown) that couples a rotatable gear (main gear or counter gear) and the transmission input shaft 28 or the transmission output shaft 40 is provided. Each is provided.

  The power output from the transmission output shaft 60 is transmitted to the speed reduction mechanism 70 via the gears 46 and 48. Deceleration mechanism 70 outputs power transmitted to an axle (not shown).

  Motor generator MG is a motor generator having a power running function that converts electrical energy into kinetic energy and a regenerative function that converts kinetic energy into electrical energy. The motor generator MG is configured as, for example, a synchronous motor generator, and has a configuration 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. However, it may have other configurations. Motor generator MG is an example of the “rotary electric machine” according to the present invention.

  Connection switching mechanism 40 is a mechanism that switches the connection state of output shaft 50 of motor generator MG to transmission 30. The connection switching mechanism 40 includes a plurality of gears, a sleeve, and the like, and the connection state of the output shaft 50 of the motor generator MG can be changed by changing the position of the sleeve. The connection switching mechanism 40 according to the present embodiment includes an IN connection state in which the output shaft 50 of the motor generator MG is connected to the transmission input shaft 28, and the output of the motor generator MG via the gears 54a and 54b. The OUT connection state connected to the shaft 60 can be switched mutually.

  Next, a specific configuration of the ECU 100, which is an example of a control device for a hybrid vehicle according to the present embodiment, will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the hybrid vehicle control apparatus according to the embodiment.

  In FIG. 4, ECU 100 includes transmission failure detection unit 110, torque limit value calculation unit 120, torque limit unit 130, required power average value calculation unit 140, SOC limit range determination unit 150, and SOC limit range change unit 160. It is configured.

  The transmission failure detection unit 110 is an example of the “transmission failure detection means” in the present invention, and detects a failure of the transmission 30 (specifically, a state in which the gear position cannot be changed). Information on the failure of the transmission 30 detected by the transmission failure detection unit 110 is transmitted to the torque limit value calculation unit 120 and the SOC limit range determination unit 150, respectively.

  Torque limit value calculation unit 120 calculates a torque limit value for limiting the torque of engine 200 when transmission failure detection unit 110 detects a failure of transmission 30. A method for calculating the torque limit value will be described in detail later.

  The torque limiter 30 limits the engine output torque based on the torque limit value calculated by the torque limit value calculator 120.

  The torque limit value calculator 120 and the torque limiter 30 are examples of the “limiter” in the present invention.

  The required power average value calculation unit 140 includes, for example, an arithmetic circuit and a memory, and calculates an average value of power required for traveling of the hybrid vehicle 1 over a predetermined period. The average value calculated by the required power average value calculation unit 140 is transmitted to the SOC limit range determination unit 150.

  SOC limit range determining unit 150 determines an appropriate SOC limit range in battery 12 (see FIG. 1) based on the average value calculated by required power average value calculating unit 140. The SOC limit range determination unit 150 determines the SOC limit range using, for example, a map indicating the relationship between the average value of the required power for a predetermined period and the SOC limit range (specifically, the SOC upper limit value and the lower limit value). To do. A more specific method for determining the SOC limit range will be described later.

  SOC limit range changing unit 160 changes the SOC limit range in battery 12 to be the SOC limit range determined by SOC limit range determining unit 150.

  The required power average value calculating unit 140, the SOC limit range determining unit 150, and the SOC limit range changing unit 160 are examples of the “charge limit range changing unit” in the present invention.

  The ECU 100 described above is an integrated electronic control unit including the above-described parts, and all the operations related to the parts are configured to be executed by the ECU 100. However, the physical, mechanical, and electrical configurations of the above-described parts according to the present invention are not limited thereto. For example, each of these means includes various ECUs, various processing units, various controllers, microcomputer devices, and the like. It may be configured as a computer system or the like.

  Next, the operation of the hybrid vehicle control device according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing a series of operations of the hybrid vehicle control apparatus according to this embodiment.

  In FIG. 5, when the hybrid vehicle control device according to the present embodiment is in operation, it is first determined in the transmission failure detection unit 110 whether or not the transmission 30 has failed (step S01). Note that, when a failure of the transmission 30 is not detected (step S01: NO), the determination is continued until a failure of the transmission 30 is detected.

  When a failure of transmission 30 is detected (step S01: YES), it is determined whether motor generator MG is in a usable state (step S02). This determination may be performed in the transmission failure detection unit 110 or may be performed in another part. If motor generator MG is not usable (step S02: NO), the series of processes by the hybrid vehicle control device ends.

  When motor generator MG is usable (step S02: YES), torque limit value calculating unit 120 calculates a torque limit value for limiting the output torque of engine 200 (step S03). Hereinafter, a specific method for calculating the torque limit value will be described with reference to FIG. FIG. 6 is a map showing the thermal efficiency of the engine.

  In FIG. 6, for example, when the gear position is fixed to the lowest 1st due to a failure of the transmission 30, when attempting to run at a high vehicle speed, the operating point of the engine 200 becomes an operating point as indicated by a point A in the figure, Although traveling is possible, the thermal efficiency is deteriorated and the power difference from the optimum fuel consumption line is also increased.

  Here, the power difference between the actual output power of engine 200 and the optimum fuel consumption line is complemented by charging power Pchg_max in motor generator MG. However, since there is an upper limit value Pbmax in the charging power from motor generator MG to battery 12, if charging power Pchg_max becomes too large, battery 12 cannot accept the charging power, and as a result, the operating point of engine 200 is determined as the optimum fuel efficiency. It becomes difficult to get close to the line.

  Torque limit value calculating section 120 calculates a torque limit value such that charging power Pchg_max obtained by motor generator MG does not exceed upper limit value Pbmax of charging power in battery 12. Specifically, assuming that the power on the optimal fuel consumption line is Popt and the required power is Pdem, the charging power Pchg_max can be obtained by the following formula (1).

Pchg_max = Popt−Pdem (1)
When Pchg_max determined in this way is equal to or lower than the upper limit value Pbmax, the charging power does not exceed the allowable amount of the battery 12, and therefore the actual output power Preal of the engine 200 is made equal to the required power Pdem. . On the other hand, when the obtained Pchg_max exceeds the upper limit value Pbmax, the allowable amount of the battery 12 is exceeded, so that the actual output power Preal of the engine 200 is a value represented by the following formula (2). Limited.

Preal ≦ Popt−Pbmax (2)
The torque limit value calculation unit 120 calculates a torque limit value that realizes the actual output power Preal of the engine 200 described above.

  Returning to FIG. 5, when the torque limit value is calculated, control of the engine 200 based on the calculated torque limit value is performed by the torque limiter 130 (step S04). As a result, it is possible to prevent a state in which the charging power Pchg_max becomes too large and the battery 12 cannot be accepted. Therefore, even when the transmission 30 is out of order, it is possible to run in a state close to the optimum fuel consumption line, and as a result, deterioration of fuel consumption can be prevented.

  Note that the above-described effects of torque limitation of engine 200 are more pronounced when a relatively small motor generator MG with limited torque and rotational speed is used than with a relatively large motor generator without limited torque and rotational speed. To be demonstrated.

  Further, in the present embodiment, when the transmission 30 fails, the SOC limit range in the battery 12 is changed in addition to the limit of the output torque of the engine 200 described above. When changing the SOC limit range, first, the required power average value calculation unit 140 calculates the average value of the required power for a predetermined period (step S05).

  When the average value of the required power is calculated, the SOC limit range determination unit 150 determines an appropriate SOC limit range (specifically, the upper limit value and the lower limit value of the SOC) based on the calculated average value ( Step S06). Hereinafter, a more specific method for determining the SOC limit range will be described with reference to FIG. FIG. 7 is a graph showing the SOC limit range during normal control and when the transmission fails.

  As shown in FIG. 7, it is assumed that the SOC upper limit value and the lower limit value during normal control (that is, when the transmission 30 has not failed) are U1 and L1, respectively. On the other hand, the SOC upper limit value at the time of transmission failure is the same U1 as in the normal control when the average value of the required power is less than p1, but becomes P2 after the required power becomes P1 or more. Gradually rises and becomes U2 when P2 or higher. Further, the SOC lower limit value at the time of transmission failure is set to the same L1 as in the normal control when the average value of the required power is less than p1, and gradually until the required power becomes P2 after the required power becomes P1 or more. And when it becomes P2 or more, it is set to L2. That is, the SOC limit range at the time of transmission failure is expanded as the average value of the required power is larger.

  Returning to FIG. 5, when the SOC limit range is determined, the SOC limit range changing unit 160 changes the value to the value for which the SOC limit range is actually determined (step S07).

  The hybrid vehicle 1 travels while switching between the EV mode that travels only by the output from the motor generator MG and the HV mode that travels using both the engine 00 and the motor generator MG. However, the hybrid vehicle 1 switches from the EV mode to the HV mode. Sometimes it is required to start engine 200 that has been stopped. However, since a relatively large amount of power is required to start the engine 200, from the viewpoint of improving fuel efficiency, the number of start times of the engine 200 (in other words, the number of times of switching from the EV mode to the HV mode) is as much as possible. Less is preferred.

  On the other hand, in this embodiment, when a failure of the transmission 30 is detected, the SOC limit range of the battery 12 is changed so as to increase. As a result, the travel distance in the EV mode can be extended. Therefore, the number of start-ups of engine 200 can be reduced, and it is possible to more suitably prevent deterioration of fuel consumption when transmission 30 fails.

  Further, when the required power is relatively large, the fuel consumption can be effectively improved by changing the charging limit range of the power storage means to be large, but when the required power is relatively small, the power storage means Even if the charging control range is not changed to be larger, the travel distance in the EV mode becomes relatively longer, and therefore the influence on the deterioration of fuel consumption is reduced. Therefore, if the SOC limit range of the battery 12 is changed according to the average value of the required power as described above, inconvenience (for example, deterioration of the battery 12) due to the increase of the SOC limit range is prevented. , Can prevent deterioration of fuel consumption.

  As described above, according to the control apparatus for a hybrid vehicle according to the present embodiment, when a failure of the transmission 30 is detected, the output torque limit of the engine 200 and the SOC limit range are expanded. Therefore, it is possible to prevent the fuel consumption from deteriorating even when the transmission 30 fails.

  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, 10 ... Hybrid drive device, 11 ... PCU, 12 ... Battery, 13 ... Accelerator opening sensor, 14 ... Vehicle speed sensor, 28 ... Transmission input shaft, 30 ... Transmission, 40 ... Connection switching mechanism, 50 ... MG output shaft, 60 ... transmission output shaft, 70 ... deceleration mechanism, 100 ... ECU, 110 ... transmission failure detection unit, 120 ... torque limit value calculation unit, 130 ... torque limit unit, 140 ... calculation of required power average value 150, SOC limit range determining unit, 160 ... SOC limit range changing unit, 200, engine, MG, motor generator.

Claims (2)

A control apparatus for a hybrid vehicle, comprising: an internal combustion engine; a stepped transmission that shifts the rotational speed of the internal combustion engine and transmits the speed to a wheel; and a rotating electrical machine having power storage means,
Transmission failure detection means for detecting failure of the stepped transmission,
Limiting means for limiting the torque of the internal combustion engine so that the charge / discharge power of the rotating electrical machine does not exceed a predetermined upper limit value or lower limit value when a failure of the stepped transmission is detected;
Charge limit range changing means for increasing the charge limit range of the power storage means when a failure of the stepped transmission is detected as compared with a case where no fault of the transmission is detected. A control device for a hybrid vehicle.   The charge limit range changing unit increases the charge limit range of the power storage unit as the average value of power required for the internal combustion engine and the rotating electrical machine in a predetermined period increases. Hybrid vehicle control device.

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