vehicle

Abstract

To suppress an output of an engine from being excessively limited when an exhaust of particulate materials from the engine is required.SOLUTION: A vehicle includes an engine and a control device for controlling the engine within a range of upper-limit power or less when an exhaust of particulate materials from the engine is required to suppress. When the exhaust of particulate materials is required to suppress, the control device delays an ignition timing of the engine on the basis of a rotation speed of the engine and a load ratio thereof, in comparison with a time when an output of the particulate material is not required to suppress, and sets upper-limit power on the basis of the ignition timing.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] Conventionally, for this type of vehicle, a system has been proposed in which, when the temperature of the engine piston is below a predetermined temperature, the injection timing of the in-cylinder fuel injection valve during the intake stroke injection is retarded compared to when the piston temperature is higher than the predetermined temperature, and, when the piston temperature is below the predetermined temperature and the intake air volume is below a predetermined amount, the ignition timing is retarded compared to the MBT (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-186965 A Summary of the Invention [Problem to be solved by the invention]

[0004] In vehicles equipped with engines, when there is a demand for suppression of emissions of particulate matter such as soot from the engine, the engine has been controlled within a range below an upper limit power in order to meet this demand. If this upper limit power is set uniformly to a relatively small value, the output of the engine may be excessively restricted.

[0005] The main object of the vehicle of the present invention is to suppress excessive restriction of engine output when suppression of particulate matter emissions from the engine is required. [Means for solving the problem]

[0006] In order to achieve the above-mentioned main object, the vehicle of the present invention employs the following means.

[0007] The vehicle of the present invention comprises: The engine, a control device that controls the engine within a range equal to or less than an upper limit power when suppression of particulate matter emissions from the engine is required; A vehicle comprising: When the suppression of emission of particulate matter is required, the control device retards an ignition timing of the engine based on a rotation speed and a load factor of the engine, compared to when the suppression of emission of particulate matter is not required, and sets the upper limit power based on the ignition timing. The gist of the present invention is as follows.

[0008] In the vehicle of the present invention, when suppression of particulate matter emissions from the engine is required, the engine is controlled within a range equal to or lower than the upper limit power, and when suppression of particulate matter emissions is required, the engine ignition timing is delayed based on the engine speed and load factor compared to when suppression of particulate matter emissions is not required, and the upper limit power is set based on the ignition timing, thereby making it possible to suppress excessive restriction of the engine output when suppression of particulate matter emissions from the engine is required, compared to when the upper limit power is set to a uniformly relatively small value.

[0009] In the vehicle of the present invention, the control device may set the upper limit power so that the upper limit power is larger the later the point in time is, when the particulate matter emission reduction is required. In this way, the upper limit power can be set more appropriately.

[0010] In the vehicle of the present invention, the request for suppression of emission of particulate matter may be made when an integrated air volume, which is an integrated value of an intake air volume, is less than an air volume threshold. In this case, the air volume threshold may be set to be higher as the engine start-up water temperature is lower. In this way, it is possible to more appropriately set whether or not to request suppression of emission of particulate matter.

[0011] In the vehicle of the present invention, the engine may have an in-cylinder injection valve that injects fuel into a cylinder, and the control device may inject fuel from the in-cylinder injection valve in a plurality of separate injections during the intake stroke when the reduction in particulate matter emissions is required. In this way, it is possible to reduce particulate matter emissions from the engine. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an outline of the configuration of an engine 22. [Diagram 3] 4 is a flowchart showing an example of a PN suppression request flag setting routine executed by the engine ECU 24. [Figure 4] 4 is a flowchart showing an example of an ignition control routine executed by an engine ECU 24. [Diagram 5] 10 is a flowchart showing an example of an upper limit power setting routine executed by the HVECU 70. [Figure 6] FIG. 4 is an explanatory diagram showing an example of an air amount threshold setting map; [Figure 7] FIG. 4 is an explanatory diagram showing an example of a delay amount setting map; [Figure 8] FIG. 4 is an explanatory diagram showing an example of an upper limit power setting map. [Figure 9] FIG. 13 is a diagram showing an outline of the configuration of a hybrid vehicle 220 according to a modified example. [Figure 10] FIG. 13 is a diagram showing the outline of the configuration of an engine vehicle 320 according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Next, a mode for carrying out the present invention will be described using examples. EXAMPLES

[0014] Fig. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 according to an embodiment of the present invention, and Fig. 2 is a schematic diagram showing the configuration of an engine 22. As shown in Fig. 1, the hybrid vehicle 20 of the embodiment includes the engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as HVECU) 70.

[0015] The engine 22 is configured as an internal combustion engine that uses fuel such as gasoline or diesel to output power through four strokes: intake, compression, expansion (explosive combustion), and exhaust. As shown in Fig. 2, the engine 22 has a port injection valve 125 that injects fuel into an intake port, and an in-cylinder injection valve 126 that injects fuel into a cylinder. By having the port injection valve 125 and the in-cylinder injection valve 126, the engine 22 can be operated in any one of a port injection mode, an in-cylinder injection mode, and a common injection mode.

[0016] In the port injection mode, air purified by the air cleaner 122 is drawn into the intake pipe 123 and passes through the throttle valve 124, while fuel is injected from the port injection valve 125, and the air and fuel are mixed. This mixture is then drawn into the combustion chamber 129 via the intake valve 128, where it is explosively combusted by an electric spark from the ignition plug 130, and the reciprocating motion of the piston 132, which is pushed down in the cylinder bore 131 by the energy of the explosive combustion, is converted into the rotational motion of the crankshaft 23. In the in-cylinder injection mode, air is drawn into the combustion chamber 129 in the same manner as in the port injection mode, and fuel is injected from the in-cylinder injection valve 126 during the intake stroke and compression stroke, and the fuel is explosively combusted by an electric spark from the ignition plug 130, to obtain the rotational motion of the crankshaft 23. In the common injection mode, fuel is injected from the port injection valve 125 when air is sucked into the combustion chamber 129, and fuel is injected from the in-cylinder injection valve 126 during the intake stroke and the compression stroke, and the fuel is exploded and burned by an electric spark from the spark plug 130 to obtain the rotational motion of the crankshaft 23. These injection modes are switched based on the operating state of the engine 22, etc. Exhaust exhaust discharged from the combustion chamber 129 to the exhaust pipe 134 via the exhaust valve 133 is discharged to the outside air via the purification device 135. The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust. Note that the purification catalyst 135a may be a four-way catalyst that combines the purification function of the three-way catalyst with the collection function of collecting particulate matter (PM: Particulate Matter) such as soot in the exhaust.

[0017] The engine 22 further includes a variable valve timing device 150. The variable valve timing device 150 is configured to be able to continuously change the opening and closing timing of the intake valve 128 and the exhaust valve 133.

[0018] The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24. The engine ECU 24 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, not shown. Signals from various sensors required for controlling the operation of the engine 22 are input to the engine ECU 24 via input ports. Examples of signals input to the engine ECU 24 include a crank angle θcr from a crank position sensor 140 that detects the rotational position of a crankshaft 23 of the engine 22, and a cooling water temperature Tw from a water temperature sensor 142 that detects the temperature of cooling water for the engine 22. Other examples of signals input to the engine ECU 24 include cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes the intake valve 128 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 133. Other examples include the throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air amount Qa from an air flow meter 123a attached upstream of the throttle valve 124 in the intake pipe 123, and the intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 in the intake pipe 123. Other examples include a front air-fuel ratio AFf from a front air-fuel ratio sensor 137 attached upstream of the purification device 135 in the exhaust pipe 134, and a rear air-fuel ratio AFr from a rear air-fuel ratio sensor 138 attached downstream of the purification device 135 in the exhaust pipe 134.

[0019] Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. Examples of signals output from the engine ECU 24 include a control signal to the throttle valve 124, a control signal to the port injection valve 125, a control signal to the in-cylinder injection valve 126, a control signal to the spark plug 130, and a control signal to the variable valve timing device 150.

[0020] The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates a load factor KL (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter 123a and the rotation speed Ne of the engine 22. Furthermore, the engine ECU 24 calculates the opening and closing timings VTi, VTo of the intake valve 128 and the exhaust valve 133 based on the angles (θci-θcr), (θco-θcr) of the cam angles θci, θco of the intake camshaft and the exhaust camshaft from the cam position sensor 144 relative to the crank angle θcr. In addition, the engine ECU 24 estimates the temperature Tc of the purification catalyst 135a of the purification device 135 based on the cooling water temperature Tw from the water temperature sensor 142, the rotation speed Ne of the engine 22, the load factor KL, and the ignition timing.

[0021] As shown in Fig. 1, the planetary gear 30 is configured as a single pinion type planetary gear mechanism. A rotor of a motor MG1 is connected to a sun gear of the planetary gear 30. A drive shaft 36 that is connected to drive wheels 39a, 39b via a differential gear 38 is connected to a ring gear of the planetary gear 30. A crankshaft 23 of the engine 22 is connected to a carrier of the planetary gear 30.

[0022] The motor MG1 is configured, for example, as a synchronous generator motor, and as described above, its rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured, for example, as a synchronous generator motor, and its rotor is connected to the drive shaft 36. The inverters 41, 42 are used to drive the motors MG1, MG2, and are connected to a battery 50 via a power line 54. The motors MG1, MG2 are rotationally driven by a motor electronic control unit (hereinafter referred to as "motor ECU") 40 controlling the switching of a plurality of switching elements (not shown) of the inverters 41, 42.

[0023] The motor ECU 40 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports (not shown). Signals from various sensors required for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input ports. Examples of signals input to the motor ECU 40 include rotational positions θm1 and θm2 from rotational position sensors (not shown) that detect the rotational positions of the rotors of the motors MG1 and MG2, and phase currents Iu1, Iv1, Iu2, and Iv2 from current sensors (not shown) that detect the phase currents flowing through the phases of the motors MG1 and MG2. The motor ECU 40 outputs switching control signals and the like to a plurality of switching elements (not shown) of the inverters 41 and 42 via the output ports. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the electrical angles θe1, θe2 and rotation speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position sensors.

[0024] The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel-hydrogen secondary battery, and as described above, is connected to the inverters 41, 42 via the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as the "battery ECU") 52.

[0025] Although not shown, the battery ECU 52 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. Signals from various sensors required for managing the battery 50 are input to the battery ECU 52 via an input port. Examples of signals input to the battery ECU 52 include a voltage Vb of the battery 50 from a voltage sensor (not shown) attached between the terminals of the battery 50, a current Ib of the battery 50 from a current sensor (not shown) attached to an output terminal of the battery 50, and a temperature Tb of the battery 50 from a temperature sensor (not shown) attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates a power storage ratio SOC of the battery 50 based on an integrated value of the current Ib of the battery 50 from the current sensor. The power storage ratio SOC is a ratio of the amount of power that can be discharged from the battery 50 to the total capacity of the battery 50.

[0026] Although not shown, the HVECU 70 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. Examples of signals input to the HVECU 70 include an ignition signal from an ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operation position of a shift lever 81. Other examples of signals input to the HVECU 70 include an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 87. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

[0027] In the hybrid vehicle 20 of the embodiment thus configured, the HVECU 70, the engine ECU 24, and the motor ECU 40 are controlled in a coordinated manner to basically switch between a hybrid driving mode (HV driving mode) in which the engine 22 is operated, and an electric driving mode (EV driving mode) in which the engine 22 is not operated, and the vehicle runs while operating the engine 22 intermittently.

[0028] In the HV driving mode, the HVECU 70 sets a driving torque Td* required for driving (required of the drive shaft 36) based on the accelerator opening Acc and the vehicle speed V, and calculates a driving power Pd* required for driving by multiplying the set driving torque Td* by the rotation speed Nd of the drive shaft 36 (the rotation speed Nm2 of the motor MG2). Next, a provisional target power Petmp, which is a provisional value of the target power Pe* of the engine 22, is set based on the driving power Pd* and the power storage ratio SOC of the battery 50, and the target power Pe* is set based on the set provisional target power Petmp. Then, the engine ECU 24 sets the target revolution speed Ne* and target torque Te* of the engine 22 and the torque commands Tm1* and Tm2* of the motors MG1 and MG2 so that the engine 22 outputs the target power Pe* and the running torque Td* to the drive shaft 36, and transmits the set target revolution speed Ne* and target torque Te* to the engine ECU 24 and also transmits the torque commands Tm1* and Tm2* to the motor ECU 40. The engine ECU 24 performs operation control of the engine 22, such as intake air amount control, fuel injection control, ignition control, and opening / closing timing control, so that the engine 22 is operated based on the target revolution speed Ne* and the target torque Te*. The intake air amount control is performed by controlling the opening of the throttle valve 124. The fuel injection control is performed by controlling the fuel injection amount from the port injection valve 125 and the in-cylinder injection valve 126 in the port injection mode, the in-cylinder injection mode, or the shared injection mode. The ignition control is performed by controlling the ignition timing of the spark plug 130. The opening and closing timing control is performed by controlling the opening and closing timing of the intake valve 128 and the exhaust valve 133 by the variable valve timing device 150. The motor ECU 40 performs switching control of a plurality of switching elements of the inverters 41, 42 so that the motors MG1, MG2 are driven by torque commands Tm1*, Tm2*.

[0029] In the EV driving mode, the HVECU 70 sets the driving torque Td* in the same manner as in the HV driving mode, sets the torque command Tm1* of the motor MG1 to a value of 0, sets the torque command Tm2* of the motor MG2 so that the driving torque Td* is output to the drive shaft 36, and transmits the set torque commands Tm1* and Tm2* to the motor ECU 40. The control of the inverters 41 and 42 by the motor ECU 40 has been described above.

[0030] In the HV driving mode, when the tentative target power Petmp falls below the threshold value Peref, it is determined that the stop condition for the engine 22 is satisfied, the engine 22 is stopped, and the mode is switched to the EV driving mode. In the EV driving mode, when the tentative target power Petmp calculated in the same manner as in the HV driving mode falls above the power threshold value Peref, it is determined that the start condition for the engine 22 is satisfied, the engine 22 is started, and the mode is switched to the HV driving mode.

[0031] Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the process of setting the PN suppression request flag Fpn, ignition control, and the process of setting the upper limit power Pelim, will be described. Here, the PN suppression request flag Fpn is a flag indicating whether or not a PN suppression request, which is a request for suppressing emissions of particulate matter such as soot from the engine 22 (suppressing the particulate matter number (PN)), has been made. The upper limit power Pelim is the power used to limit the output of the engine 22 when the PN suppression request flag Fpn is set to a value of 1 (when a PN suppression request has been made).

[0032] Fig. 3 is a flowchart showing an example of a PN suppression request flag setting routine executed by the engine ECU 24, Fig. 4 is a flowchart showing an example of an ignition control routine executed by the engine ECU 24, and Fig. 5 is a flowchart showing an example of an upper limit power setting routine executed by the HVECU 70. Each will be described below in order.

[0033] The PN suppression request flag setting routine of Fig. 3 will be described. Execution of this routine is started when the starting of the engine 22 is completed. The starting of the engine 22 is completed when fuel injection for a predetermined number of cycles (for example, two cycles) is performed for each cylinder of the engine 22, when complete explosion of the engine 22 is detected, etc.

[0034] 3 is executed, the engine ECU 24 first inputs the start-up water temperature Twst of the engine 22 (step S100). Here, as the start-up water temperature Twst, the cooling water temperature Tw detected by the water temperature sensor 142 when the engine 22 begins to start is input.

[0035] When the start-up water temperature Twst is input in this manner, the air volume threshold value Sqaref is set based on the input start-up water temperature Twst (step S110), the integrated air volume Sqa is input (step S120), and the input integrated air volume Sqa is compared with the air volume threshold value Sqaref (step S130).

[0036] Here, the integrated air amount Sqa is input as a value calculated as an integrated value of the intake air amount Qa detected by the air flow meter 123a after the rotation speed Ne of the engine 22 reaches or exceeds the rotation speed threshold during the start of the engine 22. The air amount threshold Sqaref is a threshold used to determine whether or not the warm-up of the combustion chamber 129 of the engine 22 is insufficient (not completed) and a PN suppression request needs to be made. The air amount threshold Sqaref can be set, for example, by applying the start-up water temperature Twst to an air amount threshold setting map in which the relationship between the start-up water temperature Twst and the air amount threshold Sqaref is previously determined. FIG. 6 is an explanatory diagram showing an example of the air amount threshold setting map. As shown in the figure, in a temperature region where the start-up water temperature Twst is less than the temperature threshold Tw1, the air amount threshold Sqaref is set to increase from the value 0 as the start-up water temperature Twst decreases, and in a temperature region where the start-up water temperature Twst is equal to or greater than the temperature threshold Tw1, the value 0 is set. This is based on the fact that the lower the start-up water temperature Twst, the less likely it is that fuel injected from the port injection valve 125 or the in-cylinder injection valve 126 will vaporize, and the amount of particulate matter that is likely to be discharged will increase. The temperature threshold value Tw1 is defined as a temperature at which it can be determined that the warm-up of the combustion chamber 129 is sufficient (completed). In other words, when the start-up water temperature Twst is equal to or higher than the temperature threshold value Tw1 and the air amount threshold value Sqaref is equal to 0, this means that the warm-up of the combustion chamber 129 is sufficient (completed) at the time when the start-up of the engine 22 is completed, and there is no need to make a PN suppression request.

[0037] When the integrated air volume Sqa is less than the air volume threshold Sqaref in step S130, it is determined that a PN suppression request needs to be made, the PN suppression request flag Fpn is set to a value of 1 (step S140), and the routine returns to step S120. When the integrated air volume Sqa is equal to or greater than the air volume threshold Sqaref in step S130, it is determined that a PN suppression request does not need to be made, the PN suppression request flag Fpn is set to a value of 0 (step S150), and this routine ends.

[0038] When the PN suppression request flag Fpn thus set is 0, that is, when the PN suppression request is not made, the HVECU 70 sets the tentative target power Petmp to the target power Pe*. At this time, the engine ECU 24 performs operation control of the engine 22 (hereinafter referred to as "normal operation control") in consideration of fuel economy, fuel dilution, emissions, drivability, and the like.

[0039] Also, when the PN suppression request flag Fpn is set to a value of 1, that is, when a PN suppression request is being made, the HVECU 70 sets the target power Pe* to a value obtained by limiting (upper limit guarding) the tentative target power Petmp with the upper limit power Pelim. The upper limit power Pelim is set by an upper limit power setting routine described later as the upper limit of a power range in which the emission of particulate matter from the engine 22 can be suppressed (the number of particulate matter can be reduced to an allowable amount or less). In this way, the output of the engine 22 is limited, so that the emission of particulate matter can be suppressed. Also, at this time, the engine ECU 24 performs operation control of the engine 22 (hereinafter referred to as "PN suppression operation control") by injecting fuel from the in-cylinder injection valve 126 multiple times during the intake stroke (for example, once each in the first half and the second half of the intake stroke) in the in-cylinder injection mode or the shared injection mode, or by retarding the ignition timing compared to the normal operation control. By injecting fuel from the in-cylinder injection valve 126 in a plurality of separate injections during the intake stroke, the injection length of the fuel injected from the in-cylinder injection valve 126 is shortened to prevent the fuel from hitting the cylinder bore 131 or the piston 132, and the fuel has time to be atomized, thereby making it possible to suppress the amount of particulate matter emissions. Furthermore, when the PN suppression request flag Fpn is set to a value of 1, the warm-up of the combustion chamber 129 is insufficient compared to when the PN suppression request flag Fpn is set to a value of 0, and the fuel injected from the in-cylinder injection valve 126 is likely to adhere to the cylinder bore 131 or the like, resulting in localized richness. Therefore, by retarding the ignition timing to suppress the rise in the combustion temperature, the amount of particulate matter emissions can be suppressed. The inventors have confirmed these facts through experiments and analysis.

[0040] Next, the ignition control routine of Fig. 4 will be described. This routine is repeatedly executed while the engine 22 is operating. When this routine is executed, the engine ECU 24 first inputs data such as the engine speed Ne, load factor KL, and PN suppression request flag Fpn of the engine 22 (step S200). Here, the engine speed Ne of the engine 22 is input with a value calculated based on the crank angle θcr of the engine 22 from the crank position sensor 140. The load factor KL is input with a value calculated based on the intake air amount Qa from the air flow meter 123a and the engine speed Ne of the engine 22.

[0041] When the data is input in this manner, a base ignition timing Tfbs, which is a base value of the target ignition timing Tf*, is set based on the input rotation speed Ne and load factor KL of the engine 22 (step S210). Here, the base ignition timing Tfbs can be set, for example, by applying the rotation speed Ne and the load factor KL to a base ignition timing setting map that predetermines the relationship between the rotation speed Ne and the load factor KL of the engine 22 and the base ignition timing Tfbs. The base ignition timing setting map is set based on the specifications of the engine 22 so that the engine 22 can be operated efficiently.

[0042] Next, the value of the PN suppression request flag Fpn is checked (step S220). If the PN suppression request flag Fpn is equal to 0, it is determined that the PN suppression request is not being made, and the base ignition timing Tfbs is set to the target ignition timing Tf* (step S230), and the ignition plug 130 is controlled so that ignition is performed at the set target ignition timing Tf* (step S260), after which this routine is terminated.

[0043] When the PN suppression request flag Fpn is equal to 1 in step S220, it is determined that a PN suppression request has been made. Then, the amount of retardation Tfd of the ignition timing is set based on the rotation speed Ne and the load factor KL (step S240). The target ignition timing Tf* is set to a timing that is later than the base ignition timing Tfbs by the amount of retardation Tfd (step S250). The ignition plug 130 is controlled so that ignition is performed at the set target ignition timing Tf* (step S260), and this routine is then terminated.

[0044] Here, the retard amount Tfd of the ignition timing can be set by applying the rotation speed Ne and the load factor KL to a retard amount setting map that predetermines the relationship between the rotation speed Ne and the load factor KL of the engine 22 and the retard amount Tfd of the ignition timing. FIG. 7 is an explanatory diagram showing an example of the retard amount setting map. This map is set based on the specifications of the engine 22. In the example of FIG. 7, the retard amount Tfd is set so that it gradually increases as the rotation speed Ne moves from the low rotation speed region to the medium rotation speed region and gradually decreases as the medium rotation speed region moves from the high rotation speed region, and the load factor KL gradually increases as the low load rate region moves from the medium load region and gradually decreases as the medium load region moves from the high load rate region. The retard amount Tfd is made smaller in the low rotation speed low load region than in the medium rotation speed medium load region in order to stabilize the combustion of the engine 22. In addition, the reason why the retard amount Tfd is made smaller in the high speed / high load range compared to the medium speed / medium load range is to prevent the afterburning exhaust gas from becoming excessively hot due to the ignition retard and to protect the exhaust system components.

[0045] Next, the upper limit power setting routine of Fig. 5 will be described. This routine is repeatedly executed when the PN suppression request flag Fpn is set to a value of 1 (PN suppression request is being made) and the engine 22 is operating. When this routine is executed, the HVECU 70 first inputs the target ignition timing Tf* of the engine 22 (step S300). Here, the target ignition timing Tf* is a value set by the ignition control routine of Fig. 4 and is executed by communication from the engine ECU 24.

[0046] When the data is input in this way, the upper limit power Pelim is set based on the input target ignition timing Tf* (step S310), and this routine ends. Here, the upper limit power Pelim can be set, for example, by applying the target ignition timing Tf* to an upper limit power setting map in which the relationship between the target ignition timing Tf* and the upper limit power Pelim is predetermined. FIG. 8 is an explanatory diagram showing an example of the upper limit power setting map. As shown in the figure, the upper limit power Pelim is set to be larger as the target ignition timing Tf* is later (the retard amount Tfd is larger). This is because the later the target ignition timing Tf* is, the lower the combustion temperature becomes and the smaller the amount of particulate matter emission becomes, so that the power of the engine 22 becomes larger when the amount of particulate matter emission becomes an allowable amount. By setting the upper limit power Pelim in this way, when the target ignition timing Tf* is relatively later, the upper limit power Pelim can be made relatively large, that is, the output restriction of the engine 22 can be loosened, and excessive restriction of the output of the engine 22 can be suppressed. As a result, when the target ignition timing Tf* is relatively slow, the intake air volume Qa is likely to become large and the accumulated air volume Sqa is likely to become large quickly, so that the time until the accumulated air volume Sqa becomes equal to or greater than the threshold value Sqaref, i.e., the time until the PN suppression request (output restriction of the engine 22) is released, can be made relatively short.

[0047] In the hybrid vehicle 20 of the embodiment described above, when a PN suppression request is made, the operation of the engine 22 is controlled within a range equal to or less than the upper limit power Pelim, and when a PN suppression request is made, the ignition timing of the engine 22 is retarded based on the rotation speed Ne and the load factor KL of the engine 22, and the upper limit power Pelim is set based on the ignition timing of the engine 22. This makes it possible to suppress excessive restriction of the output of the engine 22 compared to when a relatively small value is uniformly used for the upper limit power Pelim when a PN suppression request is made. As a result, it is possible to suppress the time until the integrated air amount Sqa becomes equal to or greater than the threshold value Sqaref, i.e., the time until the PN suppression request (the output restriction of the engine 22) is released from becoming excessively long.

[0048] In the hybrid vehicle 20 of the embodiment, when a PN suppression request is made, the retard amount Tfd is set based on the rotation speed Ne and the load factor KL of the engine 22. However, the retard amount Tfd may be set based on the cooling water temperature Tw in addition to the rotation speed Ne and the load factor KL. Also, if the engine 22 has an EGR device capable of performing exhaust gas recirculation (hereinafter referred to as "EGR (Exhaust Gas Recirculation)") that recirculates exhaust gas from the exhaust pipe 134 to the intake pipe 123, the retard amount Tfd may be set based on whether or not EGR is performed in addition to the rotation speed Ne and the load factor KL.

[0049] In the hybrid vehicle 20 of the embodiment, when a PN suppression request is made, the retard amount Tfd is set based on the rotation speed Ne and the load factor KL of the engine 22. However, the provisional retard amount Tfdtmp, which is a provisional value of the retard amount Tfd, may be set based on the rotation speed Ne and the load factor KL of the engine 22, and the maximum value of a plurality of provisional retard amounts including the set provisional retard amount Tfdtmp may be set to the retard amount Tfd. As the plurality of provisional retard amounts, in addition to the provisional retard amount Tfdtmp, for example, at least one of the provisional retard amount when regeneration of the purification catalyst 135a (combustion of particulate matter accumulated in the purification catalyst 135a) is requested when the purification catalyst 135a is configured as a four-way catalyst, the provisional retard amount when starting execution of EGR when an EGR device is provided, and the provisional retard amount when performing shift control of the transmission when a transmission is provided between the drive shaft 36 and the planetary gear 30 or the motor MG2 can be mentioned.

[0050] In the hybrid vehicle 20 of the embodiment, the integrated air amount Sqa is calculated as the integrated value of the intake air amount Qa from when the rotation speed Ne of the engine 22 reaches or exceeds the rotation speed threshold during the start of the engine 22. However, the integrated air amount Sqa may be calculated as the integrated value of the intake air amount Qa from the start of the start of the engine 22, the integrated value of the intake air amount Qa from the start of the fuel injection control or the ignition control of the engine 22, the integrated value of the intake air amount Qa from the completion of the start, or the like.

[0051] In the hybrid vehicle 20 of the embodiment, the air amount threshold value Sqaref is set based on the start-time water temperature Twst. However, the air amount threshold value Sqaref may be set based on the coolant temperature Tw (sequential value) of the engine 22.

[0052] In the hybrid vehicle 20 of the embodiment, the engine 22 has the port injection valve 125 and the in-cylinder injection valve 126. However, the engine 22 may have only one of the port injection valve 125 and the in-cylinder injection valve 126.

[0053] In the hybrid vehicle 20 of the embodiment, the variable valve timing device 150 of the engine 22 is configured to be capable of continuously changing the opening and closing timing of the intake valve 128 and the exhaust valve 133. However, the variable valve timing device 150 may be configured to be capable of continuously changing only one of the intake valve 128 and the exhaust valve 133.

[0054] In the embodiment, the engine 22 and the motor MG1 are connected to the drive shaft 36 connected to the drive wheels 39a, 39b via the planetary gear 30, and the motor MG2 is connected to the drive shaft 36, and the hybrid vehicle 20 is described, which runs while the engine 22 is intermittently operated. However, the present invention is not limited to this, and any vehicle having the engine 22 may be used. For example, as shown in a modified hybrid vehicle 220 of FIG. 9, a vehicle may be configured in which the motor MG is connected to the drive shaft 36 connected to the drive wheels 39a, 39b via a transmission 230, and the engine 22 is connected to the motor MG via a clutch 226. Also, as shown in a modified engine vehicle 320 of FIG. 10, a vehicle may be configured in which the engine 22 is connected to the drive shaft 36 connected to the drive wheels 39a, 39b via a transmission 330.

[0055] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on solving the problem will be described below. In the embodiment, the engine 22 corresponds to the "engine" and the engine ECU 24 corresponds to the "control device."

[0056] The correspondence between the main elements of the Examples and the main elements of the invention described in the Summary of the Problem column does not limit the elements of the invention described in the Summary of the Problem column, since the Examples are examples for specifically explaining the mode for implementing the invention described in the Summary of the Problem column. In other words, the interpretation of the invention described in the Summary of the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Summary of the Problem column.

[0057] Although the form for carrying out the present invention has been described above using examples, the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the gist of the present invention. [Industrial Applicability]

[0058] The present invention can be used in the vehicle manufacturing industry and the like. [Explanation of symbols]

[0059] 20,220 Hybrid vehicle, 22 Engine, 23 Crankshaft, 24 Engine ECU, 30 Planetary gear, 36 Drive shaft, 38 Differential gear, 39a,39b Drive wheel, 40 Motor ECU, 41,42 Inverter, 50 Battery, 52 Battery ECU, 54 Power line, 70 HVECU, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 87 Vehicle speed sensor, 122 Air cleaner, 123 Intake pipe, 123a Air flow meter, 123t Temperature sensor, 124 Throttle valve, 124a Throttle valve position sensor, 125 Port injector, 126 In-cylinder injector, 128 Intake valve, 129 Combustion chamber, 130 spark plug, 131 cylinder bore, 132 piston, 133 exhaust valve, 134 exhaust pipe, 135 purification device, 135a purification catalyst, 137 front air-fuel ratio sensor, 138 rear air-fuel ratio sensor, 140 crank position sensor, 142 water temperature sensor, 144 cam position sensor, 150 variable valve timing device, 226 clutch, 230, 330 transmission, 320 engine vehicle, MG1, MG2 motor.

Claims

[Claim 1] The engine, a control device that controls the engine within a range equal to or less than an upper limit power when suppression of particulate matter emissions from the engine is required; A vehicle comprising: When the suppression of emission of particulate matter is required, the control device retards an ignition timing of the engine based on a rotation speed and a load factor of the engine, compared to when the suppression of emission of particulate matter is not required, and sets the upper limit power based on the ignition timing. vehicle.

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