JP2015113045A - Hybrid vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle control device that can obtain desired regenerative braking force irrespective of a battery state and suppress deterioration in an exhaust gas.SOLUTION: A hybrid vehicle control device determines which the state of a battery 14 is power receivable or not power receivable when executing a regenerative operation during deceleration of a vehicle. If it is determined that the state of the battery 14 is power receivable, hybrid vehicle control device drives a generator 35 with the regenerative electric power obtained by the regenerative operation to forcibly turn an engine 40 while an exhaust valve 56 is closed.

Description

  The present invention relates to a control apparatus for a hybrid vehicle having a motor and an engine, and more particularly to control during a regenerative operation in which power is generated using a motor during deceleration or the like.

  2. Description of the Related Art Conventionally, in a hybrid vehicle including a motor and an engine (internal combustion engine), a braking force (regenerative braking force) is performed by performing a regenerative operation in which power is generated by the motor using the rotation of wheels when the vehicle is decelerated. Techniques for obtaining are known. The electric power (regenerative electric power) obtained by the regenerative operation is generally used for charging the battery.

  However, for example, when the battery is in a state where power cannot be sufficiently received, such as when fully charged, there is a possibility that a desired regenerative braking force cannot be obtained by the regenerative operation. That is, the driver may feel uncomfortable due to a change in the regenerative braking force due to the regenerative operation.

  To solve this problem, when the battery is in a state where it cannot accept power, regenerative power is supplied to the generator directly connected to the engine, and the stopped engine is forcibly rotated. That is, there is one in which regenerative power is consumed by idling the engine (see, for example, Patent Document 1).

Japanese Patent No. 3164951

  By adopting the above-described technique, a desired regenerative braking force can be obtained even when the battery is in a state where power cannot be received (a state where power cannot be received).

  However, since the engine is idled, fresh air having a low temperature passes through the combustion chamber from the intake passage and flows into the exhaust passage, and accordingly, the temperature of the exhaust purification catalyst provided in the exhaust passage may decrease. . If the temperature of the exhaust purification catalyst decreases, the exhaust gas may be temporarily deteriorated when the engine is subsequently started.

  The present invention has been made in view of such circumstances, and provides a control device for a hybrid vehicle capable of obtaining a desired regenerative braking force and suppressing deterioration of exhaust gas regardless of the state of the battery. The purpose is to do.

  A first aspect of the present invention that solves the above problem is a control of a hybrid vehicle including an engine, a first motor generator that operates with electric power supplied from a battery, and a second motor generator connected to the engine. A regenerative operation control means for controlling a regenerative operation for generating electric power by the first motor generator using the rotation of wheels and braking the hybrid vehicle when the hybrid vehicle decelerates; and an exhaust valve of the engine A valve-closing holding mechanism that holds the battery in a closed state, and a power reception state determination unit that determines whether the battery is in a power reception enabled state or a power reception disabled state, and the regenerative operation control unit includes the power reception state When it is determined by the determination means that the battery is in an unreceivable state, the regenerative power obtained by the regenerative operation is used to generate the first power. Drives the motor generator, the control apparatus for a hybrid vehicle, characterized in that for forced rotation of the engine is closed the exhaust valve.

  According to a second aspect of the present invention, in the hybrid vehicle control device according to the first aspect, an airflow sensor that is disposed in an intake passage of the engine and detects an intake amount taken into the engine, and a detection of the airflow sensor. Intake air amount abnormality determining means for determining abnormality of the engine based on a value, and the intake air amount abnormality determining means performs the abnormality determination while the engine is forcibly rotated by the regenerative operation control means. The control apparatus for a hybrid vehicle is characterized by being interrupted.

  According to a third aspect of the present invention, in the hybrid vehicle control device according to the first or second aspect, an intake pressure sensor that is disposed in an intake passage of the engine and detects a pressure of air taken into the engine; Intake pressure abnormality determining means for determining abnormality of the engine based on a detection value of the intake pressure sensor, and the intake pressure abnormality determining means is configured to allow the regenerative operation control means to forcibly rotate the engine. In the control apparatus for a hybrid vehicle, the abnormality determination is interrupted.

  In the present invention, even when the battery is in a non-chargeable state during the regenerative operation, a desired regenerative braking force can be obtained by idling the engine with regenerative power. At this time, since the exhaust valve is kept closed, fresh air does not flow into the exhaust passage. For this reason, it is possible to suppress a decrease in the temperature of the exhaust purification catalyst provided in the exhaust passage. Therefore, when the engine is started after that, the exhaust gas can be favorably purified by the exhaust gas purification catalyst.

1 is a block diagram illustrating an overall configuration of a hybrid vehicle according to an embodiment of the present invention. It is a schematic block diagram which shows the control apparatus of the hybrid vehicle which concerns on one Embodiment of this invention. It is a flowchart which shows an example of control of the regeneration operation | movement which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  First, the overall configuration of the hybrid vehicle according to the present embodiment will be described. As shown in FIG. 1, a hybrid vehicle (hereinafter also simply referred to as “vehicle”) 10 according to the present embodiment includes a front motor 30 that is a first motor generator and an engine 40 as a driving source for traveling. ing. The driving force of the front motor 30 is transmitted to the front wheels 12 via the front drive transmission mechanism 11. The front motor 30 is connected to the battery 14 via a motor control unit (MCU) 13. Then, electric power corresponding to an occupant's pedal operation, for example, an operation of the accelerator pedal 15 (see FIG. 2) is supplied from the battery 14 to the front motor 30 via the MCU 13.

  The engine 40 is driven by burning the fuel supplied from the fuel tank 17. The engine 40 is connected to a generator 35 as a second motor generator via an output system 18. The generator 35 is connected to the battery 14 via a generator control unit (GCU) 19. The output system 18 is also connected to the front drive transmission mechanism 11 through the clutch 20 while being connected to the generator 35.

  Next, the schematic configuration of the engine 40 will be described with reference to FIG. 2, and the schematic configuration of the hybrid vehicle control device according to the present embodiment will be described.

  The engine 40 has a cylinder head 41 and a cylinder block 42, and a piston 43 is accommodated in the cylinder block 42. The piston 43 is connected to the crankshaft 45 via a connecting rod 44. The generator 35 described above is connected to the crankshaft 45. A combustion chamber 46 is formed by the piston 43, the cylinder head 41, and the cylinder block 42. The cylinder block 42 is provided with a water temperature sensor 47 that detects the temperature of cooling water that cools the engine 40.

  An intake port 48 is formed in the cylinder head 41, and an intake pipe (intake passage) 50 including an intake manifold 49 is connected to the intake port 48. The intake pipe 50 is provided with, for example, an intake pressure sensor (MAP sensor) 51 that detects intake pressure in the intake manifold 49. An intake valve 52 is provided in the intake port 48, and the intake port 48 is opened and closed by the intake valve 52. An exhaust port 53 is formed in the cylinder head 41, and an exhaust pipe (exhaust passage) 55 including an exhaust manifold 54 is connected to the exhaust port 53. The exhaust port 53 is provided with an exhaust valve 56, and the exhaust port 53 is opened and closed by the exhaust valve 56.

  Further, the engine 40 includes a variable valve mechanism 57, and each of the intake valve 52 and the exhaust valve 56 is configured such that the valve lift amount and the valve timing can be appropriately changed by the variable valve mechanism 57.

Further, a three-way catalyst 58 that is an exhaust purification catalyst is interposed in the exhaust pipe 55. The three-way catalyst 58 is provided with a catalyst temperature sensor 59 that detects the temperature of the catalyst and an O ₂ sensor 60 that detects the O ₂ concentration of the exhaust gas.

  The intake manifold 49 is provided with a fuel injection valve 61 for injecting fuel into the combustion chamber 46 of each cylinder. Although not shown, fuel is supplied to the fuel injection valve 61 from a high-pressure fuel delivery pipe. The fuel supplied from the low-pressure fuel pump in the fuel tank is supplied to the high-pressure fuel delivery pipe while being pressurized to a predetermined pressure by the high-pressure fuel pump. Although not shown, a spark plug is attached to the cylinder head 41 for each cylinder.

  Further, the intake pipe 50 is provided with a throttle valve 62 for adjusting the flow rate of the intake air amount (fresh air), and further, a throttle position sensor (TPS) 63 for detecting the opening degree of the throttle valve 62 is provided. . The opening degree of the throttle valve 62 is adjusted in conjunction with the operation of the accelerator pedal 15 and the like. An air flow sensor 63 for measuring the intake air amount is interposed upstream of the throttle valve 62.

  And the vehicle 10 provided with such various apparatuses is provided with the control part 70 which controls these various apparatuses collectively. The control unit 70 receives signals from various sensors provided in the vehicle 10, such as an accelerator pedal sensor 64 that detects the position of the accelerator pedal 15, a brake pedal sensor 65 that detects the position of the brake pedal 16, a vehicle speed sensor 66, and the like. Based on this, the traveling state of the vehicle 10 is accurately grasped, and various devices are comprehensively controlled based on that.

  For example, when the vehicle 10 is decelerated, a regenerative operation is performed in which the rotational energy of the wheels (the front wheels 12 in this embodiment) is converted into electric energy by the front motor 30 and regenerated, and a desired braking force (regenerative braking force) is generated. It has gained. As will be described in detail later, the regenerative electric power generated by the front motor 30 by this regenerative operation is recovered by the battery 14 or consumed by the generator 35 to obtain a desired regenerative braking force.

  Such regenerative operation is also appropriately controlled by a hybrid vehicle control device including various sensors provided in the vehicle 10 and a control unit 70, as will be described below. The control unit 70 includes a traveling state determination unit 71, a regenerative operation control unit 72, a power reception state determination unit 73, and an abnormality determination unit 74.

  The traveling state determination unit 71 determines the traveling state of the vehicle 10 based on the detection results of various sensors provided in the engine 40. For example, regarding the regenerative operation, the traveling state determination means 71 determines whether the vehicle 10 is in a decelerating state based on detection results of the accelerator pedal sensor 64, the brake pedal sensor 65, the vehicle speed sensor 66, the crank angle sensor 67, and the like. Determine whether.

  The regenerative operation control means 72 calculates the required deceleration when the traveling state determination means 71 detects that the vehicle 10 is in a decelerating state. This required deceleration is a deceleration required to decelerate the vehicle speed to a predetermined speed in a predetermined time, and is calculated from, for example, the position of the accelerator pedal 15, the position of the brake pedal 16, and the vehicle speed. Then, the regenerative operation control means 72 executes a regenerative operation in which the front motor 30 generates power using the rotation of the front wheels 12 in order to obtain a desired braking force (regenerative braking force) corresponding to the required deceleration.

  For example, in the present embodiment, the regenerative operation control means 72 calculates the required regenerative electric energy from the required deceleration and the vehicle speed, and executes the regenerative operation so that the necessary regenerative electric energy can be obtained by the power generation of the front motor 30. To do.

  Prior to the regeneration operation control means 72 performing the regeneration operation, the power reception state determination unit 73 is in a state where the battery 14 can accept the regenerative power (a state where power can be received) or a state where the regenerative power cannot be accepted (the power cannot be received). State). This determination condition may be determined as appropriate, but in the present embodiment, the power reception state determination unit 73 determines whether the battery 14 is in a power reception enabled state or in a power reception disabled state based on the charge rate (SOC) and temperature. It is determined whether it is.

  Specifically, the amount of power that can be received by the battery 14 (acceptable power amount) is calculated according to the charging rate of the battery 14 and the temperature of the battery 14. And when this receivable electric energy is more than the said required regenerative electric energy, the power receiving state determination means 73 determines with the battery 14 being a power receivable state. On the other hand, when the receivable power amount is smaller than the required regenerative power amount, the power receiving state determination unit 73 determines that the battery 14 is in a power unreceivable state.

  Then, when the power receiving state determining unit 73 determines that the battery 14 is in a power receivable state, the regenerative operation control unit 72 supplies the battery 14 with the power (regenerated power) generated by the front motor 30 during the regenerative operation. To do. That is, the regenerative power is recovered by the battery 14. Thereby, a desired braking force is obtained by the regenerative operation.

  On the other hand, when it is determined by the power reception state determination unit 73 that the battery 14 is in a power reception disabled state, the regenerative operation control unit 72 performs a power consumption operation. Specifically, the generator 35 is driven by regenerative electric power to force the engine 40 to rotate (motoring). That is, the engine 40 is forcibly rotated by the generator 35 in a state where the engine 40 is stopped. Thereby, regenerative electric power is consumed. Therefore, also in this case, a desired braking force can be obtained by the regenerative operation.

  Further, the regenerative operation control means 72 holds the exhaust valve 56 of the engine 40 in a closed state when executing such a power consumption operation. The method for holding the exhaust valve 56 in the closed state is not particularly limited, and an existing mechanism may be employed. In the present embodiment, the variable valve mechanism 57 is provided with a valve closing holding mechanism 57a, and the exhaust valve 56 is held in a closed state by regulating the rocker arm 57b swinging by the valve closing holding mechanism 57a. (See FIG. 2).

  Thereby, the temperature fall of the three way catalyst 58 which is an exhaust purification catalyst resulting from regenerative operation | movement can be suppressed. When the engine 40 is forcibly rotated by the power consumption operation, fresh air (outside air) having a low temperature flows from the intake pipe into the combustion chamber. However, since the exhaust valve 56 is maintained in the closed state, fresh air does not flow into the exhaust pipe 55 where the three-way catalyst 58 is disposed, and the temperature drop of the three-way catalyst 58 is suppressed. Can do. Therefore, when the fuel is subsequently supplied from the fuel injection valve 61 and the engine 40 is started, the deterioration of the exhaust gas temporarily can be suppressed.

  Further, the abnormality determination unit 74 determines the presence or absence of an abnormality in the engine 40 based on the detection results of various sensors provided in the engine 40. In the present embodiment, the abnormality determination unit 74 includes an intake air amount abnormality determination unit 74a and an intake pressure abnormality determination unit 74b. The intake air amount abnormality determination means 74a determines the presence or absence of an intake air amount abnormality based on the detection value of the air flow sensor 63 disposed in the intake pipe (intake passage) 50 of the engine 40. On the other hand, the intake pressure abnormality determining means 74b determines the presence or absence of an intake pressure abnormality based on the detected value of the intake pressure sensor 51 disposed in the intake pipe (intake passage) 50 of the engine 40.

  However, when the power consumption operation is performed with the exhaust valve 56 closed as described above, the abnormality determination unit 74 determines whether the engine 40 is abnormal based on the detection value of the intake pressure sensor 51 or the airflow sensor 63 during that time. Is preferably interrupted. Note that the interruption of the abnormality determination is not only to interrupt the abnormality determination by the abnormality determination unit 74, for example, but also to interrupt detection by these sensors by masking the intake pressure sensor 51 and the air flow sensor 63, for example. Shall also be included.

  When the power consumption operation is executed with the exhaust valve 56 closed, the intake air flowing into the combustion chamber 46 is discharged from the intake port 48 to the intake pipe 50 unlike during normal operation. For this reason, if the abnormality determination is performed based on the value detected by the above-described sensor provided in the intake pipe 50, there is a risk of erroneous determination. By interrupting the abnormality determination only while the power consumption operation is being performed, erroneous determination by the abnormality determination means 74 can be prevented.

  Next, an example of regenerative operation control according to the present embodiment will be described with reference to the flowchart of FIG.

  As described above, when the traveling state determination unit 71 detects that the vehicle 10 is in a decelerating state, first, in step S1, the regenerative operation control unit 72 calculates a required deceleration. Specifically, the required deceleration is calculated from the position of the accelerator pedal 15 detected by the accelerator pedal sensor 64, the position of the brake pedal 16 detected by the brake pedal sensor 65, and the vehicle speed detected by the vehicle speed sensor 66. To do. Next, the regenerative operation control means 72 calculates the required regenerative electric energy from the required deceleration and the vehicle speed (step S2). Thereafter, the power receiving state determination unit 73 determines whether the battery 14 is in a power receiving enabled state or a power receiving disabled state based on the necessary regenerative electric energy. Specifically, the power reception state determination means 73 calculates the acceptable power amount of the battery 14 from the charging rate (SOC) of the battery 14 and the temperature of the battery 14 (step S3). And it is determined whether this receivable electric energy is larger than a required regenerative electric energy (step S4).

  Here, when the receivable power amount of the battery 14 is equal to or greater than the necessary regenerative power amount (step S4: No), it is determined that the battery 14 is in a receivable state, and the regenerative power is supplied to the battery 14 to supply the battery. 14 is executed (step S5). On the other hand, when the receivable power amount of the battery 14 is smaller than the required regenerative power amount (step S4: Yes), it is determined that the battery 14 is in an unchargeable state, and the generator 35 is driven (step S6). At the same time, a power consumption operation is executed (step S7). That is, the variable valve mechanism 57 is controlled so that the exhaust valve 56 is closed, the intake valve 52 is appropriately controlled to adjust the pumping loss, and regenerative power is consumed by driving the generator 35. Thereby, control of a series of regenerative operations ends.

  As described above, according to the present invention, a desired regenerative braking force can be obtained by driving the generator 35 with the regenerative power and forcibly rotating the engine 40 even when the battery 14 is in a non-chargeable state during the regenerative operation. Can do. At that time, since the exhaust valve 56 is held in the closed state, fresh air does not flow into the exhaust pipe 55, and the temperature decrease of the three-way catalyst 58 can be suppressed. Therefore, when the engine 40 is started thereafter, the exhaust gas can be purified well by the three-way catalyst 58.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning, it can change suitably.

  For example, in the above-described embodiment, the present invention has been described by exemplifying a hybrid vehicle including a front motor and an engine. Of course, the vehicle includes a rear motor instead of the front motor or together with the front motor. Also good.

  In the above-described embodiment, when the receivable power amount of the battery is smaller than the required regenerative power amount, it is determined that the battery is in a power-receivable state. The determination as to whether the state is impossible is not limited to this. For example, even when the required regenerative power amount is larger than the receivable power amount, it may be determined that the battery is in a power receivable state until the battery charge rate (SOC) becomes substantially 100%. . That is, during the regenerative operation, the regenerative power may be supplied to the battery until the battery charge rate is fully charged, and then the regenerative power may be supplied to the generator.

10 Vehicle (hybrid vehicle)
11 Front drive transmission mechanism 12 Front wheel 13 Motor control unit (MCU)
14 Battery 15 Accelerator pedal 16 Brake pedal 17 Fuel tank 18 Output system 19 Generator control unit (GCU)
20 clutch 30 front motor (first motor generator)
35 Generator (second motor generator)
40 Engine 41 Cylinder head 42 Cylinder block 43 Piston 44 Connecting rod 45 Crankshaft 46 Combustion chamber 47 Water temperature sensor 48 Intake port 49 Intake manifold 50 Intake pipe (intake passage)
51 Intake pressure sensor (MAP sensor)
52 Intake valve 53 Exhaust port 54 Exhaust manifold 55 Exhaust pipe (exhaust passage)
56 Exhaust valve 57 Variable valve mechanism 57a Valve stop mechanism (valve closing mechanism)
57b Rocker arm 58 Three-way catalyst (exhaust gas purification catalyst)
59 catalyst temperature sensor 60 O ₂ sensor 61 fuel injection valve 62 throttle valve 63 air flow sensor 64 accelerator pedal sensor 65 brake pedal sensor 66 vehicle speed sensor 67 crank angle sensor 70 control unit 71 travel state determination means 72 regenerative operation control means 73 power reception state determination Means 74 Abnormality determining means 74a Intake amount abnormality determining means 74b Intake pressure abnormality determining means

Claims (3)

A control device for a hybrid vehicle, comprising: an engine; a first motor generator that operates with electric power supplied from a battery; and a second motor generator connected to the engine,
Regenerative operation control means for controlling regenerative operation for generating power by the first motor generator using rotation of wheels and braking the hybrid vehicle during deceleration of the hybrid vehicle;
A valve holding mechanism for holding the exhaust valve of the engine in a closed state;
Power receiving state determining means for determining whether the battery is in a power receiving enabled state or a power receiving disabled state,
The regenerative operation control means drives the second motor generator with regenerative electric power obtained by the regenerative operation when the power reception state determination means determines that the battery is in an unreceivable state, and the exhaust valve A control apparatus for a hybrid vehicle, wherein the engine is forcibly rotated in a closed state. In the hybrid vehicle control device according to claim 1,
An air flow sensor disposed in the intake passage of the engine for detecting the amount of intake air taken into the engine;
Intake amount abnormality determination means for determining abnormality of the engine based on a detection value of the air flow sensor,
The control device for a hybrid vehicle, wherein the intake air amount abnormality determination means interrupts the abnormality determination while the engine is forcibly rotated by the regenerative operation control means. In the control apparatus of the hybrid vehicle according to claim 1 or 2,
An intake pressure sensor that is disposed in the intake passage of the engine and detects the pressure of air taken into the engine;
An intake pressure abnormality determining means for determining abnormality of the engine based on a detection value of the intake pressure sensor;
The control apparatus for a hybrid vehicle, wherein the intake pressure abnormality determination means interrupts the abnormality determination while the engine is forcibly rotated by the regenerative operation control means.

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