JP5553019B2 - Internal combustion engine start control device for hybrid vehicle - Google Patents

Description

  The present invention relates to an internal combustion engine start control device for a hybrid vehicle including a motor and an engine (internal combustion engine) as a vehicle drive source.

  Conventionally, a hybrid vehicle in which a driving force of a vehicle is obtained by combining a motor and an engine has been developed and put into practical use. In recent years, a plug-in hybrid vehicle in which a battery for supplying power to a motor can be charged by an external commercial power source has been developed and put into practical use.

  In a plug-in hybrid vehicle, an EV travel mode in which driving wheels are driven using only a motor as a power source, and a series travel mode in which the motor is used as a power source and the engine is used as a power supply source (generator) for the motor, or the engine and motor And a parallel running mode using both of them as a power source, depending on the driving situation. Thereby, fuel consumption can be remarkably suppressed.

  In such a hybrid vehicle, according to the state of charge (SOC) of the battery during the EV travel mode, that is, when the remaining capacity of the battery decreases, the travel mode changes from the EV mode to the HV travel mode (series travel mode). The battery is charged (see, for example, Patent Document 1).

JP 2010-083394 A

  By the way, when the engine is feedback-controlled based on the detection result of an air-fuel ratio sensor (air-fuel ratio detector) provided in the exhaust passage, a time for warming and activating the air-fuel ratio sensor at the time of cold start of the engine It is necessary to ensure. This is because the air-fuel ratio cannot be accurately detected when the temperature of the air-fuel ratio sensor is low and not activated, and feedback control cannot be performed.

  The same applies to the engine mounted on the hybrid vehicle, and it is necessary to warm and activate the air-fuel ratio sensor even when the remaining capacity of the battery is reduced and the engine is cold-started as described above.

  However, at present, the activation of the air-fuel ratio sensor at the time of switching from the EV traveling mode to the series traveling mode or the parallel traveling mode in the hybrid vehicle is not considered. For this reason, there is a possibility that switching from the EV travel mode to the series travel mode or the like may not be performed smoothly. For example, when the remaining capacity of the battery decreases to a predetermined value at which the engine is to be started, if the activation of the air-fuel ratio sensor is started from that point, there will be a time lag until the engine is actually started (feedback control). Will occur. Such a time lag is preferably as small as possible, and it is desirable that the switching from the EV traveling mode to the series traveling mode or the like is performed smoothly.

  The present invention has been made in view of such circumstances, and provides an internal combustion engine start control device for a hybrid vehicle that can start an engine at an appropriate timing and can smoothly switch between driving modes. For the purpose.

A first aspect of the present invention that solves the above problem includes a drive motor and an internal combustion engine, a remaining capacity detection unit that detects a remaining capacity of a battery that supplies power to the drive motor, and the internal combustion engine. An internal combustion engine control means for performing feedback control of the operation of the internal combustion engine based on a detection result of an air / fuel ratio detector provided in an exhaust passage of the engine, and a detector preheating requirement for determining whether or not the air / fuel ratio detector needs to be preheated A determination unit; a generator that is driven by the operation of the internal combustion engine to generate power; an exhaust purification catalyst provided in the exhaust passage; and the electric motor supplied to the battery by stopping the internal combustion engine. and a catalyst warm-up necessity determining means for determining warm-up necessity of the exhaust gas purifying catalyst in the EV mode traveling by driving, in the EV travel mode, the remaining capacity is given When it becomes less than a predetermined second remaining capacity higher than one remaining capacity, preheating of the air-fuel ratio detector is started according to the determination result of the detector necessity determining means, and when it becomes less than the first remaining capacity thereafter An internal combustion engine start control device for a hybrid vehicle for starting an internal combustion engine, wherein the internal combustion engine control means includes a warm-up mode in which the internal combustion engine is operated to warm up at least the exhaust purification catalyst, and the internal combustion engine The internal combustion engine is controlled by a power generation mode in which the generator is driven by an output, and when the determination result of the catalyst warm-up necessity determination means is a necessary determination, the internal combustion engine is operated in the warm-up mode. After the engine is started, the internal combustion engine is operated in the power generation mode, and the detector preheating necessity determination unit is configured to supply the internal combustion engine even when the remaining capacity is equal to or less than the predetermined second remaining capacity. When starting Supplying the supply amount of heat applied to the time less than the predetermined amount is determined whether the preheating of the air-fuel ratio detector and disables the start of the preheating of the air-fuel ratio detector, given by the warm-up mode to the internal combustion engine When the amount of heat becomes larger than the predetermined amount, and before shifting to the power generation mode, it is determined that preheating of the air-fuel ratio detector is necessary and prohibition of starting preheating of the air-fuel ratio detector is prohibited. An internal combustion engine start control device for a hybrid vehicle is characterized by being released .

In the first aspect of the present invention, since the preheating (preheating) of the air-fuel ratio detector (air-fuel ratio sensor) is performed before starting the internal combustion engine (engine), the engine is started at an appropriate timing. It is possible to smoothly switch the driving mode. Further, it is possible to accurately determine whether the air-fuel ratio detector needs to be preheated. Furthermore, the exhaust gas can be favorably purified by warming up and activating the exhaust purification catalyst as necessary. It is also possible to improve fuel efficiency by avoiding useless start of the engine.

A second aspect of the present invention, prior Symbol detector preheating necessity determination means, and characterized in that the determination of the preheating necessity of the air-fuel ratio detector on the basis of the temperature of the cooling water for cooling the internal combustion engine An internal combustion engine start control device for a hybrid vehicle according to a first aspect is provided.

  In the second aspect, it is possible to more accurately determine whether the air-fuel ratio detector needs to be preheated.

According to a third aspect of the present invention, the catalyst warm-up necessity determining means is based on the temperature of cooling water that cools the internal combustion engine or the amount of heat supplied from the previous start to the stop of the internal combustion engine. In the internal combustion engine start control device for a hybrid vehicle according to the first or second aspect, it is determined whether or not the exhaust purification catalyst needs to be warmed up.

In the third aspect, it is possible to relatively easily and accurately determine whether the exhaust purification catalyst needs to be warmed up.

  In the present invention, the engine can be started at an appropriate timing when the traveling mode is switched. Therefore, the driving mode can be switched smoothly. Specifically, it is possible to smoothly switch between the EV traveling mode in which only the motor is operated and the series traveling mode or the parallel traveling mode in which the engine (internal combustion engine) is operated together with the motor.

1 is a schematic diagram of a hybrid vehicle according to an embodiment of the present invention. It is a block diagram which shows schematic structure of the control apparatus which concerns on one Embodiment of this invention. It is various graphs explaining an example of engine starting control. It is a flowchart which shows an example of the engine control which concerns on one Embodiment of this invention.

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

  As shown in FIG. 1, a hybrid vehicle (hereinafter also simply referred to as “vehicle”) 10 according to the present embodiment is a so-called plug-in hybrid vehicle, and uses a front motor 11, a rear motor 12, and an engine 13 for traveling. As a drive source. The driving force of the front motor 11 is transmitted to the front wheels 15 via the front drive transmission mechanism 14. The driving force of the rear motor 12 is transmitted to the rear wheel 17 via the rear drive transmission mechanism 16. A battery 19 is connected to the front motor 11 via a front (Fr) motor inverter 18, and a battery 19 is connected to the rear motor 12 via a rear (Re) motor inverter 20. Electric power corresponding to the passenger's pedal operation is supplied from the battery 19 to the motors 11 and 12 via the inverters 18 and 20.

  A sub-battery (12V battery) 22 for driving auxiliary machinery is connected to the battery 19 via a DC / DC converter 21. Moreover, the vehicle-mounted charger 23 is connected to the battery 19, and the battery 19 can be charged by connecting an external commercial power source.

  The engine 13 is driven by burning the fuel supplied from the fuel tank 24. The engine 13 is connected to a generator 26 via an output system 25. The generator 26 is connected to the battery 19 (and the front motor 11) via a generator inverter 27. The output system 25 is connected to the generator 26, and is also connected to the front drive transmission mechanism 14 via the clutch 28.

  When the engine 13 is started according to the driving state of the vehicle 10, the driving force of the engine 13 is first transmitted to the generator 26 via the output system 25. The generator 26 is operated by the driving force of the engine 13, and the electric power generated by the generator 26 is appropriately supplied to the front motor 11 and the battery 19. When the clutch 28 is connected in accordance with the driving state of the vehicle 10, the driving force of the engine 13 is transmitted to the front wheels 15 via the front drive transmission mechanism 14.

  Further, the vehicle 10 is provided with a control device 50 (see FIG. 2) that comprehensively controls various devices. For example, the control device 50 is connected to various sensors for detecting the operating state of the engine 13. In the present embodiment, the intake pipe 29 is provided with an intake air amount sensor (air flow sensor) 30 as an intake air amount measuring means for measuring the intake air amount, and the engine 13 is provided with a water temperature sensor 31 for detecting the temperature of the cooling water. An air-fuel ratio sensor (LAFS) 34 that detects the air-fuel ratio (oxygen concentration) of exhaust gas is provided upstream of the exhaust purification catalyst 33 in the exhaust pipe 32. Although not shown, the air-fuel ratio sensor 34 is provided with a heater and a detector that can estimate the temperature from the resistance of the heater. The control device 50 controls the operating state of the engine 13 based on detection signals from various sensors such as the intake air amount sensor 30, the water temperature sensor 31, and the air-fuel ratio sensor 34.

  In the vehicle 10 according to the present embodiment, the motors 11 and 12 and the engine 13 are controlled by such a control device 50, so that the traveling mode is appropriately switched according to the traveling state of the vehicle 10. ing. In the present embodiment, an EV travel mode using the motors 11 and 12 as a drive source and a series travel mode using the engine 13 as a power supply source for the motors 11 and 12 are appropriately switched according to the travel state of the vehicle 10. It has become.

  Incidentally, the engine 13 is basically feedback-controlled based on the detection result of the air-fuel ratio sensor 34 so that the exhaust air-fuel ratio becomes the target air-fuel ratio. However, when the air-fuel ratio sensor 34 is not activated, the exhaust air-fuel ratio cannot be detected accurately, and optimal feedback control may not be executed. Due to this, there is a possibility that the EV traveling mode in which the engine 13 is stopped is not smoothly switched to the series traveling mode in which the engine 13 is driven.

  Therefore, in the present invention, the engine 13 is started at a predetermined timing based on the remaining capacity (charged state: SOC) of the battery 19, and the air-fuel ratio sensor 34 is preheated (preheated) based on the remaining capacity of the battery 19. It was made to activate while 13 was stopped. As a result, the air-fuel ratio feedback can be started immediately after the engine 13 is started, the engine load can be changed without deteriorating the exhaust gas, and the smooth switching from the EV traveling mode to the series traveling mode can be performed. It can be carried out.

  Furthermore, in this embodiment, when the travel mode is switched from the EV travel mode to the series travel mode, the exhaust purification catalyst 33 is warmed up as necessary. This prevents the exhaust gas from deteriorating when the engine 13 is started.

  Hereinafter, the control of the engine 13 according to the present invention will be described. As shown in FIG. 2, an engine start control device (internal combustion engine start control device) 50 according to the present embodiment includes an SOC detection means (remaining capacity detection means) 51, an engine control means (internal combustion engine control means) 52, Detector preheating means 53, detector preheating necessity determining means 54, and catalyst warm-up necessity determining means 55 are provided.

  The SOC detection means 51 detects the remaining capacity (SOC) of the battery 19. Although not shown, the battery 19 is provided with a battery sensor such as a voltage sensor or a current sensor, and the SOC detection means 51 detects the remaining capacity of the battery 19 based on information from the battery sensor. (Calculate).

  The engine control means 52 appropriately controls the operation of the engine 13. For example, the start and stop of the engine 13 are controlled based on the detection result of the SOC detection means 51. Specifically, the engine control means 52 starts the engine 13 when the SOC detection means 51 detects that the remaining capacity of the battery 19 has become a predetermined first remaining capacity or less, and sets the travel mode to EV travel. Switch from mode to series travel mode. After that, when the remaining capacity of the battery 19 recovers to a predetermined amount or more, the engine 13 is stopped and the traveling mode is switched to the EV traveling mode again.

  The detector preheating means 53 preheats the air-fuel ratio sensor 34 when the engine 13 is stopped based on the detection result of the SOC detection means 51. That is, the detector preheating means 53 preheats the air-fuel ratio sensor 34 while the engine 13 is stopped in the EV traveling mode when the traveling mode is switched from the EV traveling mode to the series traveling mode. Specifically, when the detection result of the SOC detection means 51 becomes a predetermined second remaining capacity that is higher than the first remaining capacity, the heater (not shown) provided in the air-fuel ratio sensor 34 is energized. Preheating of the air-fuel ratio sensor 34 is started. Preferably, preheating is completed before the remaining capacity of the battery 19 reaches the first remaining capacity.

  The detector preheating necessity determination means 54 determines whether or not preheating of the air-fuel ratio sensor 34 is necessary based on the temperature of the air-fuel ratio sensor 34 while the engine 13 is stopped in the EV traveling mode.

  The air-fuel ratio sensor 34 is often made of a ceramic material, and there is a concern that it may be damaged by water during preheating. For this reason, in the present embodiment, whether the air-fuel ratio sensor 34 is preheated or not is determined based on the detection result of the water temperature sensor 31 provided in the engine 13 and the temperature of the air-fuel ratio sensor 34, taking into account the damage of the air-fuel ratio due to water. Judgment is made.

  Specifically, if the temperature (detection result) of the water temperature sensor 31 is equal to or higher than a predetermined temperature, it is determined that preheating is possible, and if the temperature is lower than the predetermined temperature, it is determined that preheating is impossible. Further, if the temperature of the air-fuel ratio sensor 34 is equal to or higher than a predetermined temperature, it is determined that preheating is not necessary, and if it is lower than the predetermined temperature, it is determined that preheating is necessary. When the detector preheating necessity determining means 54 determines that preheating is possible and preheating is necessary, the detector preheating means 53 preheats the air-fuel ratio sensor 34.

  In the present embodiment, whether or not preheating is possible is determined based on the temperature of the water temperature sensor 31, but the method for determining whether or not preheating is possible is not particularly limited. For example, whether or not to preheat may be determined based on the virtual temperature of the engine 13 estimated from the amount of heat given from the start of the engine to the stop and the time from the stop of the engine. At this time, the integral value of the fuel injection amount and the integral value of the intake air amount are used for the supply heat amount calculation.

  The catalyst warm-up necessity determination means 55 determines whether or not the exhaust purification catalyst 33 needs to be warmed up (whether warm-up is necessary) while the vehicle 10 is running in the EV travel mode and the engine 13 is stopped. Judgment is made. The necessity of this warm-up is determined based on the detection result of the water temperature sensor 31 provided in the engine 13, for example. That is, the necessity of warming up is determined based on the temperature of the exhaust purification catalyst 33 estimated from the detection result of the water temperature sensor 31.

  When it is determined by the catalyst warm-up necessity determining means 55 that the warm-up is unnecessary, the engine control means 52 operates the engine at an arbitrary rotation speed and load immediately after starting the engine 13 to drive the generator. To generate power (power generation mode). On the other hand, when the catalyst warm-up necessity determining unit 55 determines that the warm-up is necessary, the engine control unit 52 performs a minimum period of rotation and a load necessary for warm-up for a certain period after the engine 13 is started. The engine 13 is operated (warm-up mode). As a result, the exhaust purification catalyst 33 is activated at an early stage while suppressing the exhaust gas emission amount.

  In the present embodiment, it is determined whether the exhaust purification catalyst 33 needs to be warmed up based on the detection result of the water temperature sensor 31, but the method for determining whether the warming up is necessary is not particularly limited. For example, the necessity of warm-up may be determined based on the amount of heat supplied from the previous start to stop of the engine 13 and the time from the engine stop. At that time, the fuel injection amount integrated value and the intake air intake amount integrated value from the start can be used for the supply heat amount calculation.

  For example, when based on the fuel injection amount integral value, for example, the fuel injection amount integral value may be appropriately corrected by the ignition timing of the engine 13. Thereby, the necessity for warm-up can be determined more accurately.

  Next, an example of start control of the engine 13 by the engine start control device 50 according to the present embodiment, in particular, an example of start control of the engine 13 at the time of switching the travel mode will be described with reference to the graph of FIG.

  As shown in FIG. 3, when the vehicle starts traveling at time T0, the vehicle is traveling in the EV traveling mode, and the engine 13 has a rotational speed of 0, the remaining capacity of the battery 19 gradually decreases (T0). ~ T2). When the remaining capacity of the battery 19 becomes equal to or less than the first remaining capacity (SOC1) (T2), the engine 13 is started and the travel mode is switched from the EV travel mode to the series travel mode. Further, it is necessary to warm up the exhaust purification catalyst 33 based on the temperature of the exhaust purification catalyst 33 until the remaining capacity of the battery 19 becomes smaller than the first remaining capacity (SOC1) (T0 to T2). Is determined, the engine 13 is operated for a certain period in the warm-up mode in which the exhaust purification catalyst 33 is warmed up (T2 to T3), and the warm-up mode is switched to the power generation mode.

  Thereafter, when the vehicle 10 travels in the series travel mode (power generation mode), the remaining capacity of the battery 19 gradually increases, and the remaining capacity of the battery 19 is larger than the second remaining capacity (SOC2). When reaching (SOC3), the engine 13 is stopped (T4). That is, at this time, the travel mode is switched from the series travel mode to the EV travel mode.

  As the vehicle 10 travels again in the EV travel mode, the remaining capacity of the battery 19 gradually decreases (T4 to T6). If the remaining capacity of the battery 19 becomes smaller than the second remaining capacity (SOC2) during that time (T5), preheating of the air-fuel ratio sensor 34 is performed as necessary (T5 to T6). Specifically, until the remaining capacity of the battery 19 becomes smaller than the second remaining capacity (SOC2) (T4 to T5), the air-fuel ratio is based on the detection result of the water temperature sensor 31 and the temperature of the air-fuel ratio sensor 34. If it is determined that the sensor 34 can be preheated and necessary, preheating of the air-fuel ratio sensor 34 is performed while the engine 13 is stopped thereafter (T5 to T6).

  Even during the period from T1 to T2, it is determined that the preheating of the air-fuel ratio sensor 4 is necessary based on the temperature of the air-fuel ratio sensor 34. The preheating of the fuel ratio sensor 34 is not performed. This is because at this time (T2), the engine 13 has never been started since the vehicle started to travel. That is, if only the air-fuel ratio sensor 34 is warmed in a state where the engine 13 is cold, water drops or the like may adhere to the air-fuel ratio sensor 34 and may be damaged.

  Further, it is determined that the exhaust purification catalyst 33 does not need to be warmed up based on the temperature of the exhaust purification catalyst 33 until the remaining capacity of the battery 19 becomes smaller than the first remaining capacity (SOC1) (T4 to T6). Then, the engine 13 is operated in the power generation mode immediately after starting (T6-). For example, when the period from the previous stop of the engine 13 to the start of the current engine 13 is short, the temperature of the exhaust purification catalyst 33 is kept relatively high, so it is determined that warm-up is unnecessary.

  Thus, by appropriately controlling the start of the engine 13 at the time of switching the traveling mode, it is possible to smoothly switch from the EV traveling mode to the series traveling mode while suppressing the deterioration of the exhaust gas emission amount.

  Next, an example of engine 13 start control by the engine start control device 50 of the present embodiment will be further described with reference to the flowchart of FIG.

  While the vehicle 10 is traveling in the EV traveling mode, that is, while the engine 13 is stopped, the detector preheating necessity determining means 54 determines whether or not the air-fuel ratio sensor 34 needs to be preheated (preheating) (step S1). . When it is determined that preheating is possible and necessary, a preheat determination flag is set (Fa = 1), and when it is determined that preheating is impossible or unnecessary, the preheat determination flag is not set (Fa = 0).

  Further, the catalyst warm-up necessity determining means 55 determines whether or not the exhaust purification catalyst 33 needs to be warmed up (warming up) (step S2). When it is determined that the temperature of the exhaust purification catalyst 33 is low and warming up is necessary, a warm-up determination flag is set (Fb = 1), and when it is determined that warming-up is unnecessary, the warm-up determination flag is not set (Fb = 0).

Further, it is determined by the SOC detection means 51 whether or not the remaining capacity (SOC) of the battery 19 is smaller than the second remaining capacity (SOC2). The second remaining capacity (SOC2) is a value larger by a predetermined value α than the first remaining capacity (SOC1) at which the engine 13 is started by the engine control means 52 as described above, and is expressed by the following equation (1). Is done.
SOC2 = SOC1 + predetermined value α (1)

  If the remaining capacity of the battery 19 is greater than or equal to the second remaining capacity (SOC2) (step S3: No), the process returns to step S1 until the remaining capacity of the battery 19 is less than the second remaining capacity (SOC2). Steps S1 to S3 are repeated. On the other hand, when the remaining capacity of the battery 19 is smaller than the second remaining capacity (SOC2) (step S3: Yes), the process proceeds to step S4.

  In step S4, it is determined whether or not the preheat determination flag is set in step S1, that is, whether Fa = 1 or Fa = 0. If Fa = 1, that is, if it is determined by the detector preheating necessity determination means 54 that the air-fuel ratio sensor 34 can be preheated and necessary (step S4: Yes), the detector preheating means 53 is determined in step S5. After the preheat of the air-fuel ratio sensor 34 is started, the process proceeds to step S6. On the other hand, if Fa = 0 in step S4 (step S4: No), the process proceeds to step S6 without preheating the air-fuel ratio sensor 34 being started.

  When the SOC detection means 51 detects that the remaining capacity of the battery 19 is equal to or less than the first remaining capacity (SOC1) (step S6: Yes), the engine 13 is started by the engine control means 52. Note that the preheating of the air-fuel ratio sensor 34 is terminated at this point. As a starting procedure of the engine 13, first, in step S7, it is determined whether or not a warm-up determination flag is set, that is, whether Fb = 1 or Fb = 0. When the catalyst warm-up necessity determination unit 55 determines in step S2 that the exhaust purification catalyst 33 needs to be warmed up and Fb = 1 (step S7: Yes), the process proceeds to step S8. In step S8, the engine speed and engine output for catalyst warm-up (for warm-up mode) are determined, and then the engine 13 is started with the settings for this warm-up mode (step S9). Thereafter, when the temperature of the exhaust purification catalyst 33 exceeds a predetermined temperature (step 10: Yes), the engine speed and the engine output for the power generation mode are determined in step S11, and the engine 13 is controlled in the power generation mode (step). S12). That is, the control of the engine 13 is switched from the warm-up mode to the power generation mode, and the start control of the engine 13 at the time of switching the traveling mode is completed.

  As described above, according to the engine start control device 50 according to the present embodiment, when the travel mode is switched, the air-fuel ratio sensor 34 is preheated as necessary while the engine 13 is stopped. Therefore, after the engine 13 is started, it is possible to shift to an arbitrary operating point without significant deterioration of the exhaust gas, and the driving mode can be switched smoothly. Further, in the present embodiment, when the travel mode is switched, it is determined whether the exhaust purification catalyst 33 needs to be warmed up. Therefore, exhaust gas deterioration at the start of the engine 13 can be prevented.

  As mentioned above, although one embodiment of the present invention was described, of course, the present invention is not limited to this embodiment. The present invention can be modified as appropriate without departing from the scope of the invention.

  For example, in the above-described embodiment, the detector preheating necessity determination unit 54 and the catalyst warm-up necessity determination unit 55 perform each necessity determination based on the detection result of the water temperature sensor 31. Each necessity determination may be performed based on the time after stopping. Whether or not the air-fuel ratio sensor 34 is preheated and whether or not the exhaust purification catalyst needs to be warmed up can be determined from the time after the engine 13 is stopped. For this reason, whether or not it is necessary to preheat the air-fuel ratio sensor and warm up the exhaust purification catalyst can also be determined by the time after the engine 13 is stopped.

  Further, in the above-described embodiment, when the detector preheating necessity determination unit 54 determines that the air-fuel ratio sensor 34 can be preheated and necessary, the detector preheating unit 53 preheats the air-fuel ratio sensor 34. However, the detector preheating necessity determination means 54 is not necessarily provided. For example, when the remaining capacity of the battery 19 becomes equal to or less than the second remaining capacity (SOC2) by the SOC detection means 51, the warm-up of the air-fuel ratio sensor 34 may always be started by the detector preheating means 53.

  Similarly, the catalyst warm-up necessity determination unit 55 is not necessarily provided. For example, when the remaining capacity of the battery 19 becomes equal to or less than the first remaining capacity (SOC1) by the SOC detection unit 51, the engine control unit 52 The engine 13 may always be started in the warm-up mode.

  Further, for example, in the above-described embodiment, the present invention has been described by taking the switching between the EV traveling mode and the series traveling mode as an example. However, the present invention is naturally applicable to the switching between the EV traveling mode and the parallel traveling mode. Is something that can be done.

  In the above-described embodiment, each of the motors 11 and 12 and the engine 13 is controlled by one control device 50, but the configuration of the control device 50 is not particularly limited. For example, the control device 50 includes a motor control unit that controls the motors 11 and 12 and an engine control unit that controls the engine 13, and the motor control unit and the engine control unit can communicate with each other. It may be configured.

DESCRIPTION OF SYMBOLS 10 Vehicle 11, 12 Motor 13 Engine 19 Battery 29 Intake pipe 30 Intake amount sensor 31 Water temperature sensor 32 Exhaust pipe 33 Exhaust purification catalyst 34 Air-fuel ratio sensor 50 Engine start control device (internal combustion engine start control device)
51 SOC detection means (remaining capacity detection means)
52 Engine control means (internal combustion engine control means)
53 Detector preheating means 54 Detector preheating necessity judging means 55 Catalyst warming necessity judging means

Claims (3)

A remaining capacity detecting means for detecting a remaining capacity of a battery that has a driving motor and an internal combustion engine and supplies power to the driving motor, and a detection result of an air-fuel ratio detector provided in an exhaust passage of the internal combustion engine Based on the internal combustion engine control means for feedback control of the operation of the internal combustion engine, detector preheating necessity determination means for determining whether the air-fuel ratio detector needs to be preheated, and driven by the operation of the internal combustion engine. A generator for generating electricity, an exhaust purification catalyst provided in the exhaust passage, and the exhaust purification catalyst during an EV traveling mode in which the internal combustion engine is stopped and the drive motor is driven by electric power supplied from the battery Catalyst warm-up necessity determining means for determining whether or not warm-up is required ,
During the EV traveling mode, when the remaining capacity becomes equal to or less than a predetermined second remaining capacity that is higher than the predetermined first remaining capacity, the air-fuel ratio detector is preheated according to the determination result of the detector necessity determining means. An internal combustion engine start control device for a hybrid vehicle that starts and then starts the internal combustion engine when the first remaining capacity or less is reached,
The internal combustion engine control means includes at least a warm-up mode in which the internal combustion engine is operated to warm up the exhaust purification catalyst, and a power generation mode in which the generator is driven by the output of the internal combustion engine. And when the determination result of the catalyst warm-up necessity determining means is a necessity determination, the internal combustion engine is operated in the power generation mode after starting the internal combustion engine in the warm-up mode,
The detector preheating necessity determining means may determine that the amount of heat supplied from the start to the internal combustion engine is less than a predetermined amount even when the remaining capacity is less than the predetermined second remaining capacity. This is when the preheating of the air-fuel ratio detector is prohibited by determining that the air-fuel ratio detector is not preheated, and the amount of heat supplied to the internal combustion engine in the warm-up mode is greater than the predetermined amount. Then, before shifting to the power generation mode, it is determined that the preheating of the air-fuel ratio detector is necessary and the prohibition of starting the preheating of the air-fuel ratio detector is canceled. An internal combustion engine start control device for a vehicle.   2. The hybrid vehicle according to claim 1, wherein the detector preheating necessity determining unit determines whether the air-fuel ratio detector needs to be preheated based on a temperature of cooling water for cooling the internal combustion engine. Internal combustion engine start control device. The catalyst warm-up necessity determining means determines whether the exhaust purification catalyst needs to be warmed based on the temperature of the cooling water for cooling the internal combustion engine or the amount of heat supplied from the previous start to the stop of the internal combustion engine. The internal combustion engine start control device for a hybrid vehicle according to claim 1 or 2 , wherein the determination is performed.

Images