JP2014172540A - Control unit of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control unit of a hybrid vehicle capable of suppressing a torque shock derived from switching of injectors at the time of starting an engine.SOLUTION: For starting an engine 10, a control unit 100 starts the engine 10 through fuel injection by a cylinder injection injector. After the engine 10 is started, if the temperature of the engine 10 falls below a predetermined threshold temperature, the fuel injection by the cylinder infection injector is switched to fuel injection by a port injection injector. After the engine 10 is warmed up, the fuel injection by the port injection injector is switched to the fuel injection by the cylinder injection injector. When switching from the fuel injection by the cylinder injection injector to the fuel injection by the port injection injector, the control unit 100 controls a motor generator 20 so as to suppress rotational deterioration of the engine 10 derived from the switching.

Description

  The present invention relates to a control device for a hybrid vehicle, and more particularly to a control device for a hybrid vehicle including an engine provided with a port injector and an in-cylinder injector.

  Conventionally, an engine having a port injection injector that injects fuel into an intake port and an in-cylinder injector that directly injects fuel into a cylinder, a function of applying driving force to the engine, and power generation driven by the engine There is known a hybrid vehicle including a motor generator having a function of performing the above and a traveling motor driven by electric power.

  For example, in Patent Document 1, in a hybrid vehicle having an engine including a port injector and an in-cylinder injector, a generator, and a traveling motor, the engine is used for a long time for power generation by the generator. If the fuel is injected only by the port injector during the idling operation, deposits accumulate at the injection port of the in-cylinder injector, and the in-cylinder injection is performed when the injection mode using the in-cylinder injector is shifted. The problem that the amount of fuel injection from the injector is smaller than the target is described.

  In order to cope with this problem, when the idling operation continues for a predetermined time or more, the fuel injection by the port injection injector is switched to the fuel injection by the in-cylinder injector, and the deposit accumulated in the injection port of the in-cylinder injector It is disclosed that when sufficient time has passed for removal of the fuel, the fuel injection by the in-cylinder injector is switched again to the fuel injection by the port injector.

  Furthermore, at this time, the combustion state is different between the case where the fuel is injected by the port injector and the case where the fuel is injected by the in-cylinder injector, so that a torque shock accompanying the switching of the injector occurs. In order to deal with this problem, it is disclosed that when the injector is switched, the fuel injection is temporarily stopped, and after the rotation of the engine is stopped, the fuel injection is resumed by the switched injector. As a result, it is possible to suppress torque shock during idling due to switching of the injector that performs fuel injection.

JP 2010-255440 A (paragraphs 0023 to 0040)

  By the way, in the case of an engine that uses a gaseous fuel such as natural gas, propane gas or hydrogen instead of a liquid fuel such as gasoline or light oil, in-cylinder injection is used at the time of starting the engine rather than using a port injector. It is preferable to use an injector. The reason is that gas has a smaller density than liquid and has a large volume even if the mass is the same. When port injection is performed and air and gaseous fuel are premixed, the volume (amount) of air is equal to the volume of gaseous fuel. In contrast, in-cylinder injection only introduces air into the cylinder first, and then the gaseous fuel is pressurized at a high pressure. Since it is injected into the cylinder, a large amount of air can be introduced into the cylinder (the air filling amount increases). As a result, a larger combustion energy or engine torque can be obtained, and a stable engine startability is ensured. This is because that.

  However, when an in-cylinder injector is used and the engine is started using gaseous fuel, the cylinder is caused by a rapid temperature drop due to adiabatic expansion of the gaseous fuel when the gaseous fuel is injected from the in-cylinder injector. A phenomenon called icing occurs in which water in the inside (for example, water generated by fuel combustion, water contained in air or gaseous fuel, etc.) adheres to the injector nozzle as ice. There is a problem that the in-cylinder injector malfunctions due to icing and fuel cannot be injected.

  The problem of this icing is that when the outside air temperature or the engine temperature is low, hydrogen that generates a large amount of water by combustion is used as fuel, or the in-cylinder injector is disposed in a part where the combustion stroke is not performed. This is a problem more likely to occur in a rotary engine or the like (that is, the temperature rise of the in-cylinder injector is delayed).

  In order to cope with the above problem, when starting the engine, the engine is started by fuel injection by the in-cylinder injector, and after the engine is started, until the engine is warmed up, the fuel injection by the in-cylinder injector is changed to the port. Switching to fuel injection by an injector for injection can be considered. And in that case, in order to suppress the torque shock accompanying the switching of the injector, as disclosed in Patent Document 1, it is proposed to temporarily stop the engine when switching the injector.

  However, it is not reasonable to stop the engine once started to suppress torque shock. In addition, when the engine is stopped, the power generation by the generator is temporarily interrupted. Further, when the engine is stopped, it is necessary to start the engine next, resulting in an increase in power consumption. In addition, there is a problem that vibration associated with engine stop and vibration associated with engine start occur.

  Therefore, an object of the present invention is to provide a control device for a hybrid vehicle that can suppress a torque shock accompanying switching of an injector without stopping the engine after the engine is started.

  In order to solve the above-mentioned problems, the present invention provides a port injection injector that injects fuel into an intake port, an in-cylinder injector that directly injects fuel into a cylinder, and a driving force applied to the engine. And a motor generator having a function of generating power by being driven by the engine, and at the time of starting the engine, the engine is started by fuel injection by the in-cylinder injector After the engine is started, when the engine temperature is lower than a predetermined threshold temperature, the fuel injection by the in-cylinder injector is switched to the fuel injection by the port injector, and the engine is warmed up. From the fuel injection by the port injection injector to the fuel injection by the in-cylinder injector When the engine control means for switching to injection and the fuel injection by the in-cylinder injector is switched to the fuel injection by the port injection injector, the motor generator is controlled so as to suppress a decrease in engine rotation caused by the switching. A hybrid vehicle control device comprising motor generator control means (claim 1).

  According to the present invention, in a hybrid vehicle including an engine and a motor generator, when the engine is started, the engine is started by fuel injection by the in-cylinder injector, so that the air filling amount increases and stable engine startability is achieved. Secured. When the engine temperature is lower than a predetermined threshold temperature after the engine is started, the fuel injection by the in-cylinder injector is switched to the fuel injection by the port injector (this is referred to as “first switching”). Even if the in-cylinder injector malfunctions due to icing, fuel is stably supplied from the port injector. After the engine is warmed up, the fuel injection by the port injection injector is switched again to the fuel injection by the in-cylinder injector (this is referred to as “second switching”). Stable fuel supply is performed using the internal injection injector.

  In addition, at the time of the first switching, the motor generator is controlled so as to suppress a decrease in the rotation of the engine accompanying the switching (the engine rotation is decreased because the air filling amount is reduced). Since the motor generator is controlled so as to provide the engine, a decrease in engine rotation associated with switching from the in-cylinder injector to the port injector is suppressed, and torque shock is suppressed.

  As described above, according to the present invention, there is provided a control device for a hybrid vehicle that can suppress a torque shock accompanying switching of an injector without stopping the engine after the engine is started.

  In the present invention, it is preferable that the motor generator control means suppresses an increase in engine rotation caused by the switching when switching from fuel injection by the port injection injector to fuel injection by the in-cylinder injector. The motor generator is controlled (Claim 2).

  According to this configuration, at the time of the second switching, the motor generator is controlled so as to suppress the increase in the rotation of the engine accompanying the switching (the engine rotation increases because the air filling amount increases). Since the motor generator is controlled so as to generate power by being driven, an increase in engine rotation accompanying switching from the port injector to the in-cylinder injector is suppressed, and torque shock is suppressed.

  In the present invention, preferably, a plurality of the in-cylinder injectors are provided in one cylinder, and the engine control means performs fuel injection according to a load when the fuel injection is performed by the in-cylinder injector. The number of in-cylinder injectors is changed, and when the number of in-cylinder injectors is changed, the motor generator control means controls the motor generator so as to suppress the engine rotational fluctuation caused by the change in the number of in-cylinder injectors. (Claim 3).

  According to this configuration, when performing the fuel injection by the in-cylinder injector, when the number of in-cylinder injectors that perform fuel injection is changed according to the load, the engine rotational fluctuation ( In other words, since the motor generator is controlled so as to suppress a reduction in rotation and a rise in rotation, that is, the motor generator is controlled so as to apply a driving force to the engine or to generate power by being driven by the engine. When the fuel injection is performed by the injector, the engine fluctuation due to the change in the number of in-cylinder injectors is suppressed, and the torque shock is suppressed.

  In the present invention, preferably, a battery for storing electric power generated by the motor generator is provided, and the motor control unit suppresses an increase in engine rotation when the temperature of the battery is lower than a predetermined threshold temperature. The motor generator is not controlled (claim 4).

  According to this configuration, since power generation by the motor generator is not performed at a low temperature when the capacity of the battery is reduced, excessive charging of the battery is avoided and deterioration of the battery is suppressed.

  In the present invention, preferably, the motor generator control means feedback-controls the motor generator so that a difference between an actual engine speed and a target engine speed converges within a preset allowable speed difference. (Claim 5).

  According to this configuration, the actual rotational speed of the engine converges to the target rotational speed within a preset allowable rotational speed difference without being affected by disturbance, so that an occupant is not allowed to feel uncomfortable or uncomfortable. Torque shock is reliably suppressed in the range.

  In the present invention, it is preferable that the engine control means stops the engine after scavenging the cylinder when the engine is stopped.

  According to this configuration, since moisture in the cylinder is removed when the engine is stopped, the problem of freezing at the next engine start is reduced. Therefore, at the next engine start, it is possible to reliably start the engine with fuel injection by the in-cylinder injector.

  The present invention provides a control device for a hybrid vehicle that can suppress a torque shock associated with switching of an injector after the engine is started. Therefore, an engine including a port injector and an in-cylinder injector, and the engine The present invention contributes to the development and improvement of the technology of a hybrid vehicle including a motor generator having a function of applying a driving force and a function of generating power by being driven by the engine and a traveling motor driven by electric power.

1 is a block configuration diagram of a hybrid vehicle according to an embodiment of the present invention. It is a control system figure of the hybrid car. It is a time chart which shows the change of the engine speed at the time of the engine start of the said hybrid vehicle, and the change of the torque which acts on the rotating shaft of a motor generator. It is a flowchart which shows a part of process operation regarding the engine starting by the control unit of the said hybrid vehicle. It is a flowchart which shows the remaining part of the said processing operation. It is a time chart which shows the effect | action of embodiment of this invention. It is a time chart which shows an example of the mode of switching from the fuel injection by the direct injection injector (in-cylinder injection) to the fuel injection by the premixing injector (port injection injector) at the time of starting the engine.

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

(1) Overall Configuration FIG. 1 is a block configuration diagram of a hybrid vehicle (hereinafter simply referred to as “vehicle”) 1 according to the present embodiment. This vehicle 1 is a series type hybrid vehicle. The vehicle 1 includes an engine 10, a motor generator 20, a battery 30, and a traveling motor 40.

  The motor generator 20 has a rotating shaft connected to the output shaft of the engine 10 (the eccentric shaft 13 shown in FIG. 2). The motor generator 20 has a function of applying a driving force to the engine 10 and a function of generating power by being driven by the engine 10. With the former function, the motor generator 20 can be started by driving the engine 10, for example. With the latter function, the motor generator 20 is driven by the engine 10 after being started, and can generate electric power for driving the traveling motor 40, for example.

  The battery 30 stores the electric power generated by the motor generator 20 (in other words, is charged with the electric power). In the present embodiment, the battery 30 is a relatively high voltage, large capacity battery. The battery 30 can be externally charged by a power source external to the vehicle 1.

  The traveling motor 40 is driven using at least one of the generated power of the motor generator 20 and the stored power of the battery 30. The driving force of the traveling motor 40 is transmitted to the left and right front wheels 61 as driving wheels via the differential device 60, and the vehicle 1 travels. The traveling motor 40 operates as a generator when the vehicle 1 is decelerated. The electric power generated by the traveling motor 40 is stored in the battery 30.

  An inverter 50 is interposed between the motor generator 20, the battery 30, and the traveling motor 40. The electric power generated by the motor generator 20 is supplied to at least one of the battery 30 and the traveling motor 40 via the inverter 50. Further, the stored power of the battery 30 is supplied to at least one of the motor generator 20 and the traveling motor 40 via the inverter 50.

  Although not shown, the motor generator 20 includes a rotor that rotates in conjunction with the rotation shaft, and a stator that is disposed around the rotor. A field coil for generating a magnetic field is wound around the rotor, and a three-phase coil for generating a magnetic field is wound around the stator. The field coil and the three-phase coil are individually connected to the inverter 50. When a current is applied from the inverter 50 to the three-phase coil, the motor generator 20 functions as a motor (electric motor) that generates torque. On the other hand, when the rotor is rotated by the rotating shaft (and thus the output shaft of engine 10), motor generator 20 functions as a generator (generator) that generates electric power.

  During power generation by the motor generator 20, current is applied from the inverter 50 to the field coil, and the rotor rotates in the magnetic field generated thereby, so that an induction current is generated in the three-phase coil of the stator. The amount of power generated by the motor generator 20 is adjusted by increasing or decreasing the current applied to the field coil. The higher the current applied to the field coil and the higher the magnetic flux density, the greater the amount of power generated by the motor generator 20.

  The engine 10 is operated for power generation by the motor generator 20. That is, the engine 10 is operated only to drive the motor generator 20. In the present embodiment, the engine 10 is a hydrogen engine that uses hydrogen stored in the hydrogen tank 70 as fuel (gaseous fuel).

  As shown in FIG. 2, the engine 10 is a twin-rotor type (corresponding to two cylinders) rotary piston engine. Two rotor housings 11 and three side housings (not shown) are alternately stacked to constitute an engine body.

  In FIG. 2, the two rotor housings 11 are depicted in an unfolded state. Further, in FIG. 2, the eccentric shafts 13 respectively drawn at the center portions of the two rotor housings 11 are a single unit in common. In FIG. 2, arrows drawn in the intake passage 14 and the exhaust passage 15 indicate the flow of intake and exhaust.

  Each rotor housing 11 and the side housings on both sides thereof form a bowl-shaped rotor accommodating chamber (corresponding to a cylinder) 11a. A rotor 12 having a substantially triangular shape is accommodated in each rotor accommodating chamber 11a. The rotor 12 has an apex seal (not shown) at each apex of the triangle. When the apex seal is in sliding contact with the inner peripheral surface of the trochoid of the rotor housing 11, three working chambers are defined in the rotor accommodating chamber 11a.

  The rotor 12 revolves around the eccentric shaft 13 while rotating around the eccentric shaft 13 with the apex seal in contact with the inner peripheral surface of the trochoid of the rotor housing 11. While the rotor 12 makes one rotation, the three working chambers move along the inner surface of the trochoid, and intake, compression, combustion (expansion), and exhaust strokes are performed in each working chamber. The rotational force generated thereby is taken out from the eccentric shaft 13 that is the output shaft of the engine 10 via the rotor 12.

  An intake passage 14 and an exhaust passage 15 are connected to the rotor accommodating chamber 11a. The intake passage 14 is one single path on the upstream side, but the downstream side is branched into two branch paths, and each branch path is connected so as to communicate with a working chamber in which an intake stroke is performed. The exhaust passage 15 is one single path on the downstream side, but is branched so that the upstream side branches into two branch paths, and each branch path communicates with a working chamber in which an exhaust stroke is performed.

  A throttle valve 16 is disposed on a single path upstream of the intake passage 14. The throttle valve 16 is driven by a throttle valve actuator 90 such as a stepping motor, and its opening degree is adjusted to adjust the flow area of the intake passage 14, that is, the intake air amount of the engine 10.

  Premixing injectors (corresponding to port injection injectors) 17 are respectively disposed on the branch paths downstream of the intake passage 14. The premixing injector 17 injects hydrogen supplied from the hydrogen tank 70 into a branch passage (corresponding to an intake port) on the downstream side of the intake passage 14. The hydrogen injected by the premixing injector 17 is supplied to the working chamber where the intake stroke is performed in a state of being mixed with air (premixed state). One premixing injector 17 is provided for each rotor housing 11.

  An exhaust gas purification catalyst 80 for purifying the exhaust gas is disposed in a single passage downstream of the exhaust passage 15. In the present embodiment, the exhaust gas purification catalyst 80 is a NOx storage reduction catalyst.

  Each rotor housing 11 is provided with a direct injection injector (corresponding to an in-cylinder injection) 18. The direct injection injector 18 directly injects hydrogen supplied from the hydrogen tank 70 into the rotor accommodating chamber 11a (that is, into the cylinder). Two direct injection injectors 18 are provided for each rotor housing 11. In each rotor housing 11, two direct injection injectors 18 are arranged so as to overlap in the axial direction of the eccentric shaft 13, and therefore only one appears in FIG. 2.

  Two spark plugs (leading side spark plug and trailing side spark plug) 19 are provided in each rotor housing 11. The spark plug 19 sparks and ignites a mixture of hydrogen and air injected by the premixing injector 17 or the direct injection injector 18.

  In the premixing injector 17, the temperature of the engine cooling water (engine water temperature) (corresponding to the temperature of the engine 10) detected by the engine water temperature sensor 106 is a predetermined threshold temperature (see, for example, Te1 in steps S13 and S17 in FIG. 5). Used when less than. On the other hand, the direct injection injector 18 is used when the engine water temperature is equal to or higher than the threshold temperature.

  The reason for this is that if hydrogen is injected from the direct injection injector 18 into the rotor accommodating chamber 11a when the engine water temperature is lower than the threshold temperature, a rapid temperature drop due to adiabatic expansion of hydrogen during injection causes the rotor to Moisture in the storage chamber 11a (for example, moisture generated by hydrogen combustion, moisture contained in the air or hydrogen, etc.) freezes into ice at the injection port of the direct injection injector 18, and the direct injection injector 18 This is because a malfunction occurs and fuel cannot be injected. Further, the water in the rotor accommodating chamber 11a is frozen as ice on the inner peripheral surface of the trochoid of the rotor housing 11, and the frozen ice is scraped into the injection port of the direct injection injector 18 by the apex seal of the rotor 12, so that This is because the fuel injection from the injector 18 is hindered.

  On the other hand, if the engine water temperature is equal to or higher than the threshold temperature, the frozen ice melts, and fuel injection from the direct injection injector 18 becomes possible. Further, even if hydrogen is injected into the rotor accommodating chamber 11a from the direct injection injector 18 when the engine water temperature is equal to or higher than the threshold temperature, the above-mentioned freezing does not occur. Fuel injection is permitted. By injecting hydrogen from the direct-injection injector 18 into the rotor accommodating chamber 11a, the air filling amount is increased, and a larger combustion energy or engine torque can be obtained.

  In the present embodiment, when the engine 10 is started, regardless of the engine water temperature (in other words, even if the engine water temperature is lower than the threshold temperature), the engine 10 is driven by fuel injection by the direct injection injector 18. Start. The reason is that when the engine is stopped last time, the engine temperature is usually high and the moisture in the rotor accommodating chamber 11a is evaporated. Therefore, when the engine 10 is started, the moisture in the rotor accommodating chamber 11a is small. This is because freezing hardly occurs. By using the direct injection injector 18, the air filling amount is increased, and stable startability of the engine 10 is ensured.

  However, if the combustion of fuel continues after the engine 10 is started, moisture in the rotor accommodating chamber 11a increases. In this case, if the engine water temperature is lower than the threshold temperature, icing may occur. In particular, in the present embodiment, the fuel is hydrogen that generates a large amount of moisture by combustion, and the engine 10 is a rotary engine in which the direct injection injector 18 is disposed in a portion where the combustion stroke is not performed. After the engine 10 is started, the moisture in the rotor accommodating chamber 11a is likely to increase, and the temperature of the direct injection injector 18 is unlikely to rise. That is, in this embodiment, the problem of freezing is likely to occur.

  Therefore, in this embodiment, after the engine 10 is started, when the engine water temperature is lower than the threshold temperature, the fuel injection by the direct injection injector 18 is switched to the fuel injection by the premixing injector 17. This will be described in detail later.

(2) Control System As shown in FIG. 2, the vehicle 1 includes a control unit 100. The control unit 100 is a controller based on a well-known microcomputer. The control unit 100 includes a central processing unit (CPU) that executes a program, a memory that includes, for example, a RAM and a ROM, and stores programs and data, and an input / output (I / O) bus that inputs and outputs electrical signals. And. The control unit 100 corresponds to engine control means and motor generator control means of the present invention.

  Detection signals from the battery current / voltage sensor 101, the accelerator opening sensor 102, the vehicle speed sensor 103, the rotation angle sensor 104, the air-fuel ratio sensor 105, the engine water temperature sensor 106, the tank pressure sensor 107, and the like are input to the control unit 100. The

  The battery current / voltage sensor 101 detects the current flowing in and out of the battery 30 and the voltage of the battery 30. The accelerator opening sensor 102 detects the amount of depression (accelerator opening) of an accelerator pedal (not shown). The vehicle speed sensor 103 detects the traveling speed of the vehicle 1. The rotation angle sensor 104 is provided on the eccentric shaft 13 and detects the rotation angle position of the eccentric shaft 13. The rotation angle sensor 104 also serves as an engine rotation speed sensor that detects the rotation speed of the engine 10. The air-fuel ratio sensor 105 detects the air-fuel ratio of the exhaust gas of the engine 10. The engine water temperature sensor 106 is provided in a water jacket (not shown) formed in the rotor housing 11 and detects the temperature of the engine coolant flowing through the water jacket (engine water temperature). The tank pressure sensor 107 detects the pressure in the hydrogen tank 70 (that is, the remaining amount of hydrogen).

  Based on the detection signal, the control unit 100 outputs control signals to the throttle valve actuator 90, the premixing injector 17, the direct injection injector 18, and the spark plug 19 to control the engine 10 (see FIG. 1). . The control unit 100 outputs a control signal to the inverter 50 based on the detection signal, and controls the motor generator 20 and the traveling motor 40 (see FIG. 1).

(3) Control Operation The control unit 100 controls the inverter 50 to change the operating state of the motor generator 20 into a driving state in which the engine 10 is driven by power supply from the battery 30 (function to apply driving force to the engine 10). And a power generation state in which power is generated by driving by the engine 10 and the generated power is supplied to the battery 30 and the traveling motor 40 (a state in which a function of generating power by being driven by the engine 10 is exhibited). Switch.

  Specifically, when engine 10 is started, control unit 100 starts engine 10 with the operating state of motor generator 20 as the driving state. After the engine 10 is started, the control unit 100 generates electric power with the operating state of the motor generator 20 as the power generation state. As shown in FIG. 2, the control unit 100 includes an engine start determination unit 100a (see FIG. 2) that determines whether or not the engine 10 has started.

  The inverter 50 transmits information regarding the current (drive current or generated current) flowing through the motor generator 20 and information regarding the voltage applied to the motor generator 20 to the control unit 100. The control unit 100 detects torque acting on the rotating shaft of the motor generator 20 based on the current information and voltage information (this is called detected torque). As shown in FIG. 3, the control unit 100 detects torque on the side where the motor generator 20 drives the engine 10 (torque when the motor generator 20 is in a driving state) as a positive (+) value, and the motor generator 20 20 detects the torque on the side driven by the engine 10 (torque when the motor generator 20 is in the power generation state) as a negative (−) value.

  In addition, the control unit 100 controls the inverter 50 to drive the traveling motor 40 using only the stored power of the battery 30 and to drive only using the generated power of the motor generator 20, It switches to the aspect driven using the electric power of both the battery 30 and the motor generator 20. FIG.

  Specifically, the control unit 100 detects the remaining capacity (SOC) of the battery 30 based on the current flowing into and out of the battery 30 detected by the battery current / voltage sensor 101 and the voltage of the battery 30. The control unit 100 drives the traveling motor 40 using only the stored power of the battery 30 based on the detected remaining capacity of the battery 30 and the remaining amount of hydrogen detected by the tank pressure sensor 107, or The motor generator 20 is used for driving only.

  When both the remaining capacity of the battery 30 and the remaining amount of hydrogen are relatively large, the traveling motor 40 may be driven only by the stored power of the battery 30 or only by the generated power of the motor generator 20. Any of them may be used. In this embodiment, in this case, an occupant of the vehicle 1 operates a travel mode selection switch (not shown) to select which mode to drive the travel motor 40.

  The control unit 100 detects the acceleration request level of the occupant based on detection signals from the accelerator opening sensor 102, the vehicle speed sensor 103, and the like. The control unit 100 may drive the traveling motor 40 in any manner, and when the traveling motor 40 is driven only by the stored power of the battery 30 (that is, when the engine 10 is stopped). On the other hand, when it is determined that the acceleration request level of the occupant is higher than a predetermined threshold level, the traveling motor 40 is switched to a mode in which both the battery 30 and the motor generator 20 are driven. Thereafter, when the control unit 100 determines that the accelerating request level of the occupant has become lower than the threshold level, the control unit 100 returns the driving motor 40 to a mode in which it is driven only by the stored power of the battery 30.

  When switching from a mode in which the traveling motor 40 is driven only by the stored power of the battery 30 to a mode in which it is driven only by the power generated by the motor generator 20 or a mode in which it is driven by the power of both the battery 30 and the motor generator 20 Since the motor generator 20 needs to generate electric power (that is, there is a request for starting the engine 10), the control unit 100 starts the stopped engine 10. Conversely, the driving motor 40 is driven only by the electric power generated by the motor generator 20, or the driving mode is driven by the electric power of both the battery 30 and the motor generator 20. When switching, it is not necessary to generate power by the motor generator 20 (that is, there is a request to stop the engine 10), so the control unit 100 stops the operating engine 10.

  When there is a request to start the engine 10 while the engine 10 is stopped, the control unit 100 rotates the engine 10 by driving the motor generator 20 at the first predetermined rotational speed N1 (see FIG. 3) ( While cranking), the engine 10 is started by performing fuel injection and ignition in the engine 10.

  In the present embodiment, since the eccentric shaft 13 of the engine 10 and the rotating shaft of the motor generator 20 are directly connected, the engine speed and the motor generator 20 are the same. Therefore, at the time of cranking before the fuel injection and ignition are started, the engine 10 is driven by the motor generator 20 and rotates at the first predetermined rotation speed N1. In the present embodiment, the first predetermined rotation speed N1 is set to, for example, 600 rpm to 1000 rpm.

  The control unit 100 does not perform the fuel injection and ignition until the predetermined time elapses from the start of cranking of the engine 10 (until time t1 in FIG. 3), and the control unit 100 (in the rotor accommodating chamber 11a of the engine 10 ( That is, the inside of the cylinder) is scavenged. The reason is that when the engine 10 is started, the air-fuel ratio is made rich, so if the fuel injected before the previous engine stop remains in the rotor accommodating chamber 11a, the air-fuel ratio becomes too rich. It is.

  During the scavenging, the control unit 100 fully opens the throttle valve 16 and introduces a large amount of air into the rotor accommodating chamber 11a. Thereby, scavenging in the rotor accommodating chamber 11a is performed smoothly in a short time. The predetermined time may be a time (for example, about several seconds) at which the scavenging of the remaining fuel in the rotor accommodating chamber 11a can be almost completed at the first predetermined rotation speed N1.

  As shown in FIG. 3, at the time of cranking before the fuel injection and ignition are started (at the time of scavenging), the torque acting on the rotating shaft of the motor generator 20 detected by the control unit 100, that is, the detected torque is the motor This is T1 which is a positive (+) value on the side where the generator 20 drives the engine 10. While the cranking of the engine 10 is being performed, the control unit 100 injects fuel at a predetermined fuel injection timing after the predetermined time has elapsed (after time t1 in FIG. 3), and performs ignition at a predetermined ignition timing. . Here, the fuel injection timing and the ignition timing are determined based on the rotational angle position of the eccentric shaft 13 detected by the rotational angle sensor 104.

  Fuel injection and ignition are started from time t1 in FIG. Thereby, the engine 10 tries to rotate independently. Therefore, the eccentric shaft 13 of the engine 10 tries to drive the rotating shaft of the motor generator 20. In other words, the motor generator 20 starts to be driven by the engine 10. As a result, the detected torque decreases from the torque T1 during cranking (scavenging) before fuel injection and ignition are started. Further, the engine speed increases from the first predetermined speed N1.

  As the fuel injection and ignition continue, the detected torque exceeds 0 from the positive (+) value on the side where the motor generator 20 drives the engine 10, and the motor generator 20 is driven by the engine 10. Negative (-) value. That is, the torque at which motor generator 20 is driven by engine 10 is greater than the torque at which motor generator 20 drives engine 10.

  At time t2 in FIG. 3, the detected torque is a negative (−) value and its absolute value becomes equal to or greater than a predetermined value T2. In other words, the torque at which the motor generator 20 is driven by the engine 10 is larger than the torque at which the motor generator 20 drives the engine 10 by a predetermined value T2 or more. Even if the driving of the engine 10 by the motor generator 20 is stopped at this time t2, there is a high possibility that the engine 10 continues to rotate independently without stopping. However, at the time point t2, the engine speed may not yet rise substantially from the cranking speed N1 (FIG. 3 shows such a case). In such a case, if the driving of the engine 10 by the motor generator 20 is stopped, the engine 10 may stop.

  Therefore, in this embodiment, the engine start determination unit 100a (see FIG. 2) determines that the detected torque is a negative (−) value and the absolute value thereof is a predetermined value T2 after the fuel injection and ignition are started. After that, the engine rotational speed detected by the rotational angle sensor 104 (the rotational angle sensor 104 also serves as the engine rotational speed sensor as described above) is equal to or higher than the second predetermined rotational speed N2 greater than the first predetermined rotational speed N1. When it becomes (time t3 in FIG. 3), it is determined that the engine 10 has started.

  The second predetermined rotational speed N2 is a rotational speed that is surely greater than the first predetermined rotational speed N1 in consideration of fluctuations in the engine rotational speed, and is as close as possible to the first predetermined rotational speed N1. . In the present embodiment, the second predetermined rotation speed N2 is set to a value that is, for example, 100 rpm to 150 rpm larger than the first predetermined rotation speed N1.

  Thus, in the present embodiment, after the possibility that the engine 10 continues to rotate autonomously becomes high, it is further determined whether or not the engine 10 has started based on the engine speed. Start determination is performed with high accuracy.

  When the engine start determination unit 100a determines that the engine 10 has started (time t3 in FIG. 3), the control unit 100 controls the inverter 50 to change the operating state of the motor generator 20 from the drive state to the power generation state. Switch to state. As a result, the power supply from the battery 30 to the motor generator 20 is stopped (the drive of the engine 10 is stopped), and the generated power of the motor generator 20 is supplied to the battery 30 and the traveling motor 40. Thus, even when the operating state of the motor generator 20 is switched to the power generation state, the engine 10 continues to rotate independently, and the engine speed increases to a third predetermined speed N3 that is greater than the second predetermined speed N2 (FIG. 6).

  The control unit 100 performs fuel injection so that the air-fuel ratio becomes rich until the engine start determining unit 100a determines that the engine 10 has started (until time t3 in FIGS. 3 and 6). After it is determined that the engine has started (after time t3 in FIG. 6), fuel injection is performed so that the air-fuel ratio becomes lean. By making the air-fuel ratio rich until it is determined that the engine 10 has started, the engine speed increases to a speed higher than the second predetermined speed N2, and the startability of the engine 10 is improved. Therefore, even if the air-fuel ratio is switched to lean after the engine speed has increased to the second predetermined speed N2, the engine speed increases well to the third predetermined speed N3.

  After determining that the engine 10 has been started by the engine start determining unit 100a (after time t3 in FIG. 6), the control unit 100 controls the engine 10 to set the engine speed to the third predetermined speed N3. When the engine speed is increased to a third predetermined speed (time t4 in FIG. 6), the engine 10 is operated at the third predetermined speed N3.

  The third predetermined rotation speed N3 is set to a value larger than the second predetermined rotation speed N2. The third predetermined rotation speed N3 varies according to the amount of power generated by the motor generator 20 (target power generation amount set based on the occupant acceleration request level and the like).

  The control unit 100 reduces the amount of power generated by the motor generator 20 when the engine water temperature detected by the engine water temperature sensor 106 is lower than a predetermined threshold temperature, compared to when it is equal to or higher than the threshold temperature. The threshold temperature is a temperature at which the rotational resistance of the eccentric shaft 13 of the engine 10 and the rotating shaft of the motor generator 20 becomes very large when the engine water temperature becomes lower than the threshold temperature. Thus, at a temperature at which the rotational resistance becomes very large, the load on the engine 10 is reduced by reducing the amount of power generated by the motor generator 20, thereby preventing deterioration of fuel consumption and emissions.

  When the engine water temperature is lower than the threshold temperature, the excess air ratio λ is made smaller than when the engine water temperature is equal to or higher than the threshold temperature. However, by reducing the amount of power generated by the motor generator 20, the excess air ratio λ Is not so small.

  In the present embodiment, the threshold temperature is the threshold temperature (see, for example, Te1 in steps S13 and S17 in FIG. 5) for selectively using (switching) the direct injection injector 18 and the premixing injector 17 described above. The same value (for example, around 0 ° C.) is set.

  As described above, when the engine 10 is started, the control unit 100 is used for direct injection until the engine start determining unit 100a determines that the engine 10 has started (until time t3 in FIGS. 3 and 6). Fuel injection is performed by the injector 18. On the other hand, after the engine start determination unit 100a determines that the engine 10 has started (after time t3 in FIG. 6), the control unit 100 detects that the engine water temperature detected by the engine water temperature sensor 106 is equal to or higher than the threshold temperature. In this case, the fuel injection by the direct injection injector 18 is continued. When the engine water temperature is lower than the threshold temperature, the fuel injection by the direct injection injector 18 is switched to the fuel injection by the premixing injector 17.

  In this embodiment, the control unit 100 performs fuel injection using one of the two direct injection injectors 18 provided per rotor housing 11 until it is determined that the engine 10 has started. When it is determined that the engine 10 has been started and the engine water temperature is equal to or higher than the threshold temperature, fuel injection is performed using two of the two direct injection injectors 18 provided per rotor housing 11. I do. However, fuel injection until it is determined that the engine 10 has started may also be performed using the two direct injection injectors 18.

  When the operation of the engine 10 continues after switching from the direct injection injector 18 to the premixing injector 17, the engine 10 is warmed up and the engine water temperature becomes equal to or higher than the threshold temperature. At this time, the control unit 100 switches from fuel injection by the premixing injector 17 to fuel injection by the direct injection injector 18 (time t5 in FIG. 6).

  By the way, since hydrogen is a gaseous fuel and has a lower density than liquid fuel such as gasoline and light oil, the volume is increased even if the mass is the same. Therefore, when air and hydrogen are premixed using the premixing injector 17, the volume (amount) of air is greatly reduced by the volume of hydrogen, and only a small amount of air is contained in the rotor accommodating chamber 11a (that is, in the cylinder). Can not be introduced. That is, the air filling amount is reduced. On the other hand, when the direct injection injector 18 is used, only air is first introduced into the rotor accommodating chamber 11a, and then hydrogen is injected into the rotor accommodating chamber 11a at a high pressure. Therefore, a large amount of air is injected into the rotor accommodating chamber. 11a can be introduced. That is, the air filling amount increases.

  Therefore, when the fuel injection by the direct injection injector 18 is switched to the fuel injection by the premixing injector 17, the engine torque decreases, and a torque shock occurs. Further, when the fuel injection by the premixing injector 17 is switched to the fuel injection by the direct injection injector 18, the engine torque increases, so that a torque shock is also generated.

  Therefore, in this embodiment, in order to suppress torque shock accompanying switching of the injector that performs fuel injection, the control unit 100 switches from fuel injection by the direct injection injector 18 to fuel injection by the premixing injector 17 ( At time t3 in FIG. 6, the motor generator 20 is controlled so as to suppress a decrease in the engine speed accompanying the switching (the engine speed decreases because the air filling amount decreases and the engine torque decreases). That is, the motor generator 20 is controlled so as to apply a driving force to the engine 10. Specifically, the control unit 100 controls the inverter 50, more specifically, by applying a current from the inverter 50 to the three-phase coil of the stator of the motor generator 20, thereby changing the operating state of the motor generator 20 to the battery. A driving state in which the engine 10 is driven by power supply from 30 (a state in which a function of applying a driving force to the engine 10 is exhibited) is set.

  Further, in this embodiment, in order to suppress a torque shock caused by switching of the injector that performs fuel injection, the control unit 100 switches from fuel injection by the premixing injector 17 to fuel injection by the direct injection injector 18 ( At time t5 in FIG. 6, the motor generator 20 is controlled so as to suppress an increase in the engine speed accompanying the switching (an increase in the air charge amount and an increase in the engine torque increases the engine speed). That is, the motor generator 20 is controlled so that it is driven by the engine 10 to generate power. Specifically, the control unit 100 controls the inverter 50, and more specifically, applies an electric current from the inverter 50 to the field coil of the rotor of the motor generator 20, thereby changing the operating state of the motor generator 20 to the engine 10. It is set as the electric power generation state (state which the function which drives with the engine 10 and produces electric power is exhibited) which generates electric power by drive by and supplies generated electric power to the battery 30 and the motor 40 for driving | running | working. More specifically, the negative (−) torque when the motor generator 20 is in the power generation state is increased to the negative (−) side.

  Further, as described above, after it is determined that the engine 10 has started, the control unit 100 continues the fuel injection by the direct injection injector 18 when the engine water temperature is equal to or higher than the threshold temperature. In addition, after it is determined that the engine 10 has started, the control unit 100 switches the injector that performs fuel injection from the direct injection injector 18 to the premixing injector 17 when the engine water temperature is lower than the threshold temperature. When the engine 10 is warmed up, the fuel injection injector is switched from the premixing injector 17 to the direct injection injector 18. When the fuel injection by the direct injection injector 18 is executed, the control unit 100 changes the number of direct injection injectors 18 that perform fuel injection from 1 to 2 or from 2 to 1 according to the load. Specifically, the control unit 100 performs fuel injection using one of the two direct injection injectors 18 provided per rotor housing 11 at light loads, and two at high loads. Is used to inject fuel.

  If the number of direct injection injectors 18 that perform fuel injection is changed from 2 to 1, the engine torque decreases, and a torque shock occurs. Further, when the number of direct injection injectors 18 that perform fuel injection is changed from 1 to 2, the engine torque increases, so that a torque shock is also generated.

  Therefore, in the present embodiment, the control unit 100 increases the number of direct injection injectors 18 that perform fuel injection from 2 to 1 in order to suppress torque shock associated with the change in the number of direct injection injectors 18 that perform fuel injection. When the engine speed is changed, the motor generator 20 is controlled so as to suppress a decrease in the engine speed accompanying the change in the number (the engine speed decreases because the engine torque decreases). That is, the motor generator 20 is controlled so as to apply a driving force to the engine 10. Specifically, the control unit 100 controls the inverter 50, more specifically, by applying a current from the inverter 50 to the three-phase coil of the stator of the motor generator 20, thereby changing the operating state of the motor generator 20 to the battery. A driving state in which the engine 10 is driven by power supply from 30 (a state in which a function of applying a driving force to the engine 10 is exhibited) is set.

  In the present embodiment, the control unit 100 changes the number of direct injection injectors 18 that perform fuel injection from 1 to 2 in order to suppress torque shocks associated with changes in the number of direct injection injectors 18 that perform fuel injection. When the engine speed is changed, the motor generator 20 is controlled so as to suppress an increase in the engine speed accompanying the change in the number (the engine speed increases because the engine torque increases). That is, the motor generator 20 is controlled so that it is driven by the engine 10 to generate power. Specifically, the control unit 100 controls the inverter 50, and more specifically, applies an electric current from the inverter 50 to the field coil of the rotor of the motor generator 20, thereby changing the operating state of the motor generator 20 to the engine 10. It is set as the electric power generation state (state which the function which drives with the engine 10 and produces electric power is exhibited) which generates electric power by drive by and supplies generated electric power to the battery 30 and the motor 40 for driving | running | working.

  Next, processing operations relating to the start of the engine 10 by the control unit 100 will be described based on the flowcharts shown in FIGS. This processing operation starts when there is a request for starting the engine 10 while the engine 10 is stopped (in other words, when there is a power generation request by the motor generator 20).

  That is, the control unit 100 rotates (cranks) the engine 10 at the first predetermined rotational speed N1 by driving the motor generator 20 in step S1. The control unit 100 measures the time from the start of cranking with a timer. During the cranking, the control unit 100 scavenges the fuel remaining in the rotor accommodating chamber 11a (inside the cylinder) of the engine 10 with the throttle valve 16 fully opened without performing fuel injection and ignition. The control unit 100 performs this scavenging for a predetermined time (for example, about several seconds).

  Next, in step S2, the control unit 100 starts fuel injection and ignition while continuing the cranking of the engine 10. Cranking while performing fuel injection and ignition in this way is called ignition cranking. The fuel injection during the ignition cranking is performed using the direct injection injector 18. The fuel injection amount at the time of starting the engine is set to an amount that makes the air-fuel ratio rich.

  Next, in step S3, the control unit 100 (more specifically, the engine start determination unit 100a) determines whether or not the detected torque is a negative (−) value and the absolute value thereof is equal to or greater than a predetermined value T2 ( In step S3 of FIG. 4, the requirement that the detected torque is a negative value is omitted). The control unit 100 proceeds to step S4 when the determination in step S3 is NO, and proceeds to step S9 when YES.

  In step S4, the control unit 100 determines whether or not the time measured by the timer from the start of cranking is greater than a preset reference time ta (for example, 10 seconds to 10 and several seconds). The control unit 100 returns to step S2 when the determination in step S4 is NO, and proceeds to step S5 when YES.

  In step S5, the control unit 100 determines that the engine 10 has stopped without increasing the output torque of the engine 10. In step S6, the control unit 100 determines whether the determination that the engine 10 has stopped has been performed twice or more. To do.

  When the determination in step S6 is NO, the control unit 100 resets the timer in step S7, and then returns to step S1. On the other hand, when the determination in step S6 is YES, the control unit 100, in step S8, displays a display panel or the like (not shown) provided on the instrument panel of the vehicle 1 so that an occupant (especially the driver) is visible. 2), after displaying an alarm indicating that the engine 10 has failed, this processing operation is terminated.

  The control unit 100 continues the ignition cranking in step S9. In step S10, the control unit 100 (more specifically, the engine start determination unit 100a) determines that the engine speed detected by the rotation angle sensor 104 (denoted as the detected speed in step S10 in FIG. 4) is the second predetermined rotation. It is determined whether or not the number is N2 or more.

  When the determination in step S10 is NO, the control unit 100 determines in step S11 that the time measured by the timer from the start of cranking is longer than a preset reference time ta (for example, 10 seconds to 10 seconds). Determine whether it is larger. The control unit 100 returns to step S9 when the determination in step S11 is NO, and proceeds to step S5 when YES. That is, even if the detected torque is a negative (−) value and the absolute value is equal to or greater than the predetermined value T2, the control unit 100 has the engine speed (detected speed) within the reference time ta. When the engine speed does not exceed the predetermined engine speed N2, it is determined in step S5 that the engine speed has decreased and the engine 10 has stopped.

  On the other hand, the control unit 100 (more specifically, the engine start determination unit 100a) determines that the engine 10 has started in step S12 when the determination in step S10 is YES.

  Next, in step S13, the control unit 100 determines whether or not the engine water temperature detected by the engine water temperature sensor 106 is lower than a predetermined threshold temperature Te1 (for example, near 0 ° C.). When the determination in step S13 is NO, that is, when the engine 10 is warmed up, the control unit 100 does not need to switch the injector, and therefore proceeds to step S20. If YES, that is, the engine 10 When the engine is not warmed up, it is necessary to switch the injector, and the process proceeds to step S14.

  In step S14, the control unit 100 switches the injector that performs fuel injection. Specifically, the control unit 100 converts the fuel injection from the direct injection injector 18 (indicated as direct injection INJ in step S14 of FIG. 5) to the premixing injector (indicated as premixing INJ in step S14 of FIG. 5). Switch to 17). The fuel injection amount after the engine is started is set to an amount that makes the air-fuel ratio lean.

  Next, in step S15, the control unit 100 controls the motor generator 20 so as to suppress a decrease in the engine speed associated with switching from the direct injection injector 18 to the premixing injector 17. That is, as described in step S15 of FIG. 5, the motor generator (MG) 20 is feedback (F / B) controlled so that the engine speed becomes the target engine speed, and driving force is applied to the engine 10. .

  Specifically, the control unit 100 indicates a solid line between the actual engine speed of the engine 10 (the engine speed detected by the rotation angle sensor 104) and the target engine speed of the engine 10 (from time t3 to time t4 in FIG. 6). The motor generator 20 is subjected to rotational feedback control by PI control (feedback control using a proportional feedback coefficient and an integral feedback coefficient) so that the difference from the engine rotational speed) converges within a preset allowable rotational speed difference. . As a result, the current applied from the inverter 50 to the three-phase coil of the stator of the motor generator 20 is controlled, and the torque has a positive (+) value so that the difference between the actual engine speed and the target engine speed converges. Is applied from the motor generator 20 to the engine 10.

  Next, in step S16, the control unit 100 sets the motor generator 20 in the power generation state (applying current from the inverter 50 to the field coil of the rotor of the motor generator 20) in order to secure electric power for driving the traveling motor 40. ). The power generation amount in step S16 is set to a smaller amount than the power generation amount in step S20 described later. The reason for this is that, as described above, before the engine 10 is warmed up (before NO is determined in the next step S17), the rotational resistance of the eccentric shaft 13 of the engine 10 and the rotating shaft of the motor generator 20 increases. This is because the load on the engine 10 is increased and the fuel consumption and emission are reduced.

  Next, in step S17, the control unit 100 determines whether or not the engine water temperature detected by the engine water temperature sensor 106 is lower than a predetermined threshold temperature Te1 (eg, near 0 ° C.). When the determination in step S17 is NO, that is, when the engine 10 is warmed up, the control unit 100 proceeds to step S18. When YES, that is, when the engine 10 is not yet warmed up, the control unit 100 proceeds to step S18. Return to S16.

  In step S18, the control unit 100 switches the injector that performs fuel injection. Specifically, the control unit 100 converts the fuel injection by the premixing injector 17 (indicated as premixing INJ in step S18 in FIG. 5) to the direct injection injector (indicated as direct injection INJ in step S18 in FIG. 5). Switch to 18).

  Next, in step S19, the control unit 100 controls the motor generator 20 so as to suppress an increase in the engine speed accompanying switching from the premixing injector 17 to the direct injection injector 18. That is, as described in step S19 of FIG. 5, the motor generator (MG) 20 is feedback (F / B) controlled so that the engine speed becomes the target engine speed, and the motor generator 20 generates power ( In other words, a braking force is applied to the engine 10).

  Specifically, the control unit 100 indicates a solid line between the actual engine speed of the engine 10 (the engine speed detected by the rotation angle sensor 104) and the target engine speed of the engine 10 (from time t5 to time t6 in FIG. 6). The motor generator 20 is subjected to rotational feedback control by PI control (feedback control using a proportional feedback coefficient and an integral feedback coefficient) so that the difference from the engine rotational speed) converges within a preset allowable rotational speed difference. . Thereby, the current applied to the field coil of the rotor of the motor generator 20 from the inverter 50 is controlled, and a negative (−) value torque that converges the difference between the actual rotational speed of the engine 10 and the target rotational speed is obtained. It is applied from the motor generator 20 to the engine 10.

  Next, in step S20, the control unit 100 sets the motor generator 20 in a power generation state (applying a current from the inverter 50 to the field coil of the rotor of the motor generator 20) in order to secure electric power for driving the traveling motor 40. ). The power generation amount in step S20 is set to be larger than the power generation amount in step S16 described above. The reason for this is that, as described above, after the engine 10 is warmed up (after NO is determined in step S17), the rotational resistance of the eccentric shaft 13 of the engine 10 and the rotating shaft of the motor generator 20 becomes small, and the engine 10 This is because the load of 10 is reduced and fuel consumption and emission are improved.

  Next, in step S21, the control unit 100 determines whether or not an engine stop condition is satisfied. That is, as described in step S <b> 21 of FIG. 5, the battery 30 detected based on the current flowing in and out of the battery 30 detected by the battery current / voltage sensor 101 and the voltage of the battery 30 by the power generation by the motor generator 20. It is determined whether or not the remaining capacity (SOC) is greater than a predetermined threshold capacity (40% in the example). The control unit 100 returns to step S20 when the determination in step S21 is NO, and proceeds to step S22 when YES.

  In step S22, the control unit 100 scavens the fuel remaining in the rotor accommodating chamber 11a (in the cylinder) of the engine 10 and then stops the engine 10. Specifically, the control unit 100 ends the fuel injection by the direct injection injector 18 and the ignition by the spark plug 19, and in this state, the throttle valve 16 is fully opened, and the motor generator 20 is turned on for a predetermined time (for example, about several seconds). As the drive state, after the engine 10 continues to rotate, the rotation of the engine 10 by the motor generator 20 is stopped. Thereafter, this processing operation is terminated.

(4) Operation, etc. As described above, in the present embodiment, hydrogen that is gaseous fuel in the premixing injector 17 and the rotor accommodating chamber 11a that inject hydrogen as gaseous fuel into the branch passage downstream of the intake passage 14. In the hybrid vehicle 1 including the engine 10 including the direct injection injector 18 that directly injects the fuel, and the motor generator 20 that has a function of applying a driving force to the engine 10 and a function of generating power by being driven by the engine 10, The characteristic configuration is adopted.

  That is, when the engine 10 is started (between time t1 and time t3 in FIG. 6), the control unit 100 starts the engine 10 by fuel injection by the direct injection injector 18, and after the engine 10 is started (time in FIG. 6). After t3), when the engine water temperature is lower than the predetermined threshold temperature Te1 (when YES at step S13), the fuel injection by the direct injection injector 18 is switched to the fuel injection by the premixing injector 17 (step S14). After the engine 10 is warmed up (after time t5 in FIG. 6) (NO in step S17), the fuel injection by the premixing injector 17 is switched to the fuel injection by the direct injection injector 18 (step S18).

  In that case, when the control unit 100 switches from the fuel injection by the direct injection injector 18 to the fuel injection by the premixing injector 17 (between time t3 and time t4 in FIG. 6), the engine speed associated with the switching. The motor generator 20 is controlled so as to suppress the decrease (see the dotted line (iii) in FIG. 6) (step S15) (see the solid line (v) in FIG. 6).

  According to this configuration, in the hybrid vehicle 1 including the engine 10 and the motor generator 20, when the engine 10 is started, the engine 10 is started by fuel injection by the direct injection injector 18, so that the air filling amount increases. A stable startability of the engine 10 is ensured. When the engine water temperature is lower than the predetermined threshold temperature Te1 after the engine 10 is started, the fuel injection by the direct injection injector 18 is switched to the fuel injection by the premixing injector 17 (that is, the first switching is performed). Even if the direct injection injector 18 malfunctions due to freezing, the fuel is stably supplied from the premixing injector 17. Then, after the engine 10 is warmed up, the fuel injection by the premixing injector 17 is switched again to the fuel injection by the direct injection injector 18 (that is, the second switching is performed), so the problem of icing is solved by the temperature rise. Stable fuel supply is performed using the direct injection injector 18.

  In addition, at the time of the first switching, the motor generator 20 is controlled so as to suppress a decrease in the rotation of the engine 10 accompanying the switching (the rotation of the engine 10 decreases because the air filling amount decreases), that is, Since the motor generator 20 is controlled so as to apply a driving force to the engine 10, a decrease in rotation of the engine 10 due to switching from the direct injection injector 18 to the premixing injector 17 is suppressed, and torque shock is suppressed. .

  For example, as indicated by a chain line (i) in FIG. 6, if the motor generator 20 is in a power generation state so that power generation in step S16 is performed immediately after the engine 10 is started, fuel injection by the direct injection injector 18 is predicted. As the mixing injector 17 switches to fuel injection, the torque of the engine 10 decreases. As a result, as indicated by a chain line (iii) in FIG. Occur.

  In order to cope with this, the control unit 100 controls the three-phase coil of the stator of the motor generator 20 from the inverter 50 so as to suppress a decrease in the engine speed (chain line (iii)) associated with the switching at the first switching. The current is applied to the motor generator 20 to change the operating state of the motor generator 20 to a driving state in which the engine 10 is driven by power supply from the battery 30 (a state in which a function for applying a driving force to the engine 10 is exhibited). Solid line (v) in FIG.

  As described above, according to the present embodiment, after the engine 10 is started, the control device for the hybrid vehicle 1 that can suppress the torque shock accompanying the switching of the injector without stopping the engine 10 is provided.

  Further, the control unit 100 increases the engine speed when switching from fuel injection by the premixing injector 17 to fuel injection by the direct injection injector 18 (between time t5 and time t6 in FIG. 6). The motor generator 20 is controlled so as to suppress (see the chain line (iv) in FIG. 6) (step S19) (see the solid line (vi) in FIG. 6).

  According to this configuration, at the time of the second switching, the motor generator 20 is controlled so as to suppress the increase in the rotation of the engine 10 (the increase in the amount of air filling increases the rotation of the engine 10) associated with the switching. That is, since the motor generator 20 is controlled so as to generate electric power by being driven by the engine 10, an increase in rotation of the engine 10 due to switching from the premixing injector 17 to the direct injection injector 18 is suppressed, and torque shock is generated. It is suppressed.

  For example, as indicated by a chain line (ii) in FIG. 6, after the engine 10 is warmed up (NO in step S17), if the motor generator 20 is in a power generation state so that power generation in step S20 is performed immediately, With the switching from the fuel injection by the injector 17 to the fuel injection by the direct injection injector 18, the torque of the engine 10 increases. As a result, as indicated by a chain line (iv) in FIG. Ascends and generates a torque shock.

  In order to cope with this, the control unit 100 switches from the inverter 50 to the field coil of the rotor of the motor generator 20 so as to suppress an increase in engine speed (chain line (iv)) accompanying the switching at the time of the second switching. A power generation state in which an electric current is applied and the operating state of the motor generator 20 is generated by driving by the engine 10 and the generated electric power is supplied to the battery 30 or the traveling motor 40 (the function of generating power by being driven by the engine 10 is exhibited. State (solid line (vi) in FIG. 6). More specifically, the negative (−) torque when the motor generator 20 is in the power generation state is increased to the negative (−) side.

  Further, the control unit 100 changes the number of direct injection injectors 18 that perform fuel injection from 1 to 2 or 2 to 1 according to the load when the fuel injection is performed by the direct injection injector 18. When the number of the injectors 18 is changed, the motor generator 20 is controlled so as to suppress the rotation fluctuation (that is, the rotation decrease or the rotation increase) of the engine 10 due to the change in the number.

  According to this configuration, when the number of direct injection injectors 18 that perform fuel injection is changed according to the load during the execution of fuel injection by the direct injection injector 18, the rotational fluctuation of the engine 10 accompanying the change in the number. Since the motor generator 20 is controlled so as to suppress this, that is, the motor generator 20 is controlled so as to apply a driving force to the engine 10 or to generate electric power by being driven by the engine 10, the direct injection injector 18. The rotational fluctuation of the engine 10 due to the change in the number of direct-injection injectors 18 at the time of performing fuel injection by is suppressed, and torque shock is suppressed.

  Further, in any case, when the control unit 100 suppresses the rotation reduction or the rotation increase of the engine 10, the actual rotation speed of the engine 10 (the engine rotation speed detected by the rotation angle sensor 104) and the engine 10 A difference between a target rotational speed (for example, an engine rotational speed indicated by a solid line from time t3 to time t4 in FIG. 6 or an engine rotational speed indicated by a solid line from time t5 to time t6) is set in advance. The motor generator 20 is feedback-controlled so as to converge within (see, for example, steps S15 and S19).

  According to this configuration, the actual rotational speed of the engine 10 converges to the target rotational speed within a preset allowable rotational speed difference without being affected by disturbance, so that the occupant does not feel uncomfortable or uncomfortable. Torque shock is reliably suppressed within a certain range.

  Further, when the engine 10 is stopped, the control unit 100 scavenges the inside of the rotor accommodating chamber 11a of the engine 10 and then stops the engine 10 (step S22).

  According to this configuration, since the moisture in the rotor accommodating chamber 11a (in the cylinder) is removed when the engine 10 is stopped, the problem of freezing at the next start of the engine 10 is reduced. Therefore, when the engine 10 is started next time, it is possible to reliably start the engine 10 with fuel injection by the direct injection injector 18.

  When the temperature of the battery 30 is lower than a predetermined threshold temperature, the control unit 100 controls the motor generator 20 that suppresses the increase in the rotation of the engine 10, that is, for example, during the second switching, the motor generator It is preferable not to perform control to set the operation state of 20 to the power generation state. When the temperature of the battery 30 is lower than the predetermined threshold temperature, the capacity of the battery 30 is reduced. Therefore, at such a low temperature, power generation by the motor generator 20 is suppressed to avoid excessive charging of the battery 30. This is because it is desirable to suppress deterioration of the battery 30.

  Moreover, in the said embodiment, although the engine 10 was a rotary piston engine, a reciprocating engine may be sufficient. Moreover, the engine using gaseous fuels (for example, natural gas, propane gas, etc.) other than hydrogen may be used.

  Further, when switching from the fuel injection by the direct injection injector 18 to the fuel injection by the premixing injector 17 (step S14), the control unit 100 may switch over the overlap period in which the fuel is injected from both the injectors 17 and 18. Good. For example, when it is determined at time t3 (see FIG. 6) that the engine 10 has started, the control unit 100 performs the first cylinder (one of the two rotor housings 11) and the first as shown in FIG. In the two cylinders (same as the other), the fuel injection by the direct injection injector 18 is switched to the fuel injection by the premixing injector 17 through an overlap period OL for a predetermined cycle (three rotations of the rotor 12 in the example of FIG. 7). May be.

  FIG. 7 shows pulses applied to the direct injection injector 18 and the premixing injector 17. The fuel injection amount increases as the pulse width increases. The sum of the fuel injection amount from the direct injection injector 18 and the fuel injection amount from the premixing injector 17 during the overlap period OL becomes the target fuel injection amount after it is determined that the engine 10 has started. In addition, the target fuel injection amount is distributed to the direct injection injector 18 and the premixing injector 17. The distribution ratio is constant during the overlap period OL in the example of FIG. However, as the overlap period OL progresses, the fuel injection amount from the direct injection injector 18 may decrease, and the fuel injection amount from the premixing injector 17 may increase.

  Similarly, when the control unit 100 switches from the fuel injection by the premixing injector 17 to the fuel injection by the direct injection injector 18 (step S18), the control unit 100 similarly switches through an overlap period in which fuel is injected from both the injectors 17 and 18. be able to.

1 Hybrid vehicle 10 Engine 17 Port injection injector (premixing injector)
18 In-cylinder injector (direct injector)
DESCRIPTION OF SYMBOLS 19 Spark plug 20 Motor generator 30 Battery 40 Driving motor 50 Inverter 70 Hydrogen tank 100 Control unit (engine control means, motor generator control means)

Claims (6)

An engine having a port injection injector that injects fuel into an intake port and an in-cylinder injector that directly injects fuel into a cylinder, a function of applying a driving force to the engine, and power generation by being driven by the engine A hybrid vehicle control device including a motor generator having a function,
When the engine is started, the engine is started by fuel injection by the in-cylinder injector. After the engine is started, when the engine temperature is lower than a predetermined threshold temperature, fuel injection by the in-cylinder injector is performed. Engine control means for switching from fuel injection by the port injection injector to fuel injection by the in-cylinder injector after the engine is warmed up from the fuel injection by the port injection injector
And a motor generator control means for controlling the motor generator so as to suppress a decrease in engine rotation caused by the switching when the fuel injection by the in-cylinder injector is switched to the fuel injection by the port injector. A hybrid vehicle control device. In the hybrid vehicle control device according to claim 1,
The motor generator control means controls the motor generator so as to suppress an increase in the rotation of the engine due to the switching at the time of switching from fuel injection by the port injection injector to fuel injection by the in-cylinder injector. A hybrid vehicle control device. In the hybrid vehicle control device according to claim 1 or 2,
A plurality of the in-cylinder injectors are provided in one cylinder,
The engine control means changes the number of in-cylinder injectors that perform fuel injection according to a load when performing fuel injection by the in-cylinder injector,
The motor generator control means controls the motor generator so as to suppress fluctuations in engine rotation caused by the change in the number of in-cylinder injectors when the number is changed. . In the hybrid vehicle control device according to claim 2 or 3,
A battery for storing electric power generated by the motor generator;
The control device for a hybrid vehicle, wherein the motor control means does not perform control of the motor generator that suppresses an increase in engine rotation when the temperature of the battery is lower than a predetermined threshold temperature. In the hybrid vehicle control device according to any one of claims 1 to 4,
The motor generator control means feedback-controls the motor generator so that the difference between the actual engine speed and the target engine speed converges within a preset allowable speed difference. Control device. In the hybrid vehicle control device according to any one of claims 1 to 5,
The control device for a hybrid vehicle, wherein the engine control means stops the engine after scavenging the cylinder when the engine is stopped.

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