car

Abstract

To suppress deterioration in emission during catalyst warm-up.SOLUTION: A vehicle includes: an engine which has a catalyst device incorporating a catalyst for purifying exhaust air in an exhaust system and an in-cylinder injection valve; an automatic transmission which shifts the power from the engine and outputs it to a driving wheel side; and a control device which performs catalyst warm-up control that warms up the catalyst by performing multi-stage injections of performing fuel injection a plurality of times from the in-cylinder injection valve and retardation of ignition timing. The control device executes load factor increase control so that the request load factor to the engine is equal to or greater than a multi-stage injection realizing load factor that can realize the multi-stage injections during catalyst warm-up control.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle, and more particularly to a vehicle equipped with an engine having a direct injection valve and an automatic transmission. [Background technology]

[0002] Conventionally, for this type of automobile, there has been proposed an automobile in which fuel is injected in multiple increments from a fuel injection valve that injects fuel directly into the cylinders of the engine (see, for example, Patent Document 1). In this automobile, when the engine is operated under high load, the number of fuel injections is increased compared to when the engine is operated under low load, thereby suppressing the deterioration of emissions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-041089 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, immediately after starting an engine, a catalyst warm-up operation is performed to activate the catalyst in a purification device attached to the engine's exhaust system. At this time, it is preferable to operate the engine at a certain load and perform multi-stage injection, in which fuel is injected multiple times from the in-cylinder injection valve, to promote catalyst warm-up. In automobiles equipped with an automatic transmission that transmits power from the engine to the drive wheels by changing the speed, if the engine operating range changes to a deceleration range or a light load range as the vehicle speed changes, multi-stage injection cannot be performed, and emissions during catalyst warm-up may deteriorate.

[0005] The main purpose of the automobile of the present disclosure is to suppress deterioration of emissions during catalyst warm-up. [Means for solving the problem]

[0006] The automobile of the present disclosure employs the following measures to achieve the above-mentioned main object.

[0007] The vehicle of the present disclosure comprises: An automobile comprising: an engine having an in-cylinder injection valve and an exhaust system having a catalyst device incorporating a catalyst for purifying exhaust gas; an automatic transmission that changes the speed of power from the engine and outputs it to the drive wheels; and a control device that performs catalyst warm-up control to warm up the catalyst by performing multi-stage injection, in which fuel is injected multiple times from the in-cylinder injection valve, and by retarding the ignition timing, the control device executes load factor increase control during the catalyst warm-up control so that a required load factor for the engine becomes equal to or greater than a multi-stage injection realization load factor at which the multi-stage injection can be realized. It is characterized by:

[0008] In the vehicle disclosed herein, the control device performs catalyst warm-up control to warm up a catalyst in a catalytic converter attached to the engine's exhaust system by performing multiple fuel injections from a direct injection valve and retarding the ignition timing. The control device also performs load factor increase control during catalyst warm-up control to increase the required engine load factor to equal or exceed the multi-stage injection realization load factor at which multi-stage injection is possible. This allows catalyst warm-up via multi-stage injection to continue when the required engine load factor exceeds the multi-stage injection realization factor, thereby suppressing emissions deterioration compared to when catalyst warm-up via multi-stage injection cannot be continued.

[0009] In the vehicle of the present disclosure, the load factor increase control may be control that reduces the engine speed and increases the required load factor by upshifting a gear position of the automatic transmission, thereby making it possible to suppress deterioration of emissions by making the required load factor for the engine equal to or higher than the multi-stage injection realization load factor.

[0010] In the vehicle of the present disclosure, the vehicle may include an electric motor capable of inputting and outputting power to an input shaft or an output shaft of the automatic transmission, and an electric storage device that exchanges power with the electric motor, and the load factor increase control may be control that increases the required load factor by controlling the electric motor. In this case, the load factor increase control may be control that increases the required load factor by reducing the power running output of the electric motor when the electric motor is under power running control, and control the electric motor to increase the required load factor by regeneratively controlling the electric motor when the electric motor is not under power running control. In this way, the required load factor for the engine can be set to or above the multi-stage injection realization load factor, thereby suppressing deterioration of emissions without changing the gear position of the automatic transmission. Furthermore, in this case, the load factor increase control may be a control that increases the required load factor by regeneratively controlling the electric motor when the power storage rate of the power storage device is less than a predetermined rate while the electric motor is not being powered, and that reduces the engine speed by upshifting a gear of the automatic transmission when the power storage rate of the power storage device is equal to or greater than the predetermined rate while the electric motor is not being powered. In this way, even when the power storage rate of the power storage device is equal to or greater than the predetermined rate, the required load factor of the engine is increased by upshifting to be equal to or greater than the load factor that realizes multi-stage injection, thereby suppressing a deterioration in emissions. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present disclosure. [Figure 2] 1 is a diagram showing the outline of the configuration of an engine 22 mounted on a hybrid vehicle 20. FIG. [Figure 3] FIG. 10 is an explanatory diagram showing an example of the relationship between the engine load factor KL and emissions in the case of single injection and multi-stage injection. [Figure 4] 4 is a flowchart showing an example of a catalyst warm-up load factor change process executed by the engine ECU 24. [Figure 5]4 is a flowchart showing an example of load factor increase control executed by the engine ECU 24. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, a mode (embodiment) for carrying out the present disclosure will be described. Fig. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 according to one embodiment of the present disclosure. Fig. 2 is a configuration diagram showing an outline of the configuration of an engine 22 mounted on the hybrid vehicle 20. As shown in Fig. 1, the hybrid vehicle 20 of the example includes the engine 22, a motor 30, an inverter 32, a clutch K0, an automatic transmission 40, a high-voltage battery 60, a low-voltage battery 62, a DC / DC converter 64, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0013] The engine 22 is configured as a six-cylinder internal combustion engine that uses fuel such as gasoline or diesel and outputs power through four strokes: intake, compression, expansion (explosive combustion), and exhaust. As shown in FIG. 2, the engine 22 has a port injection valve 126 that injects fuel supplied from a fuel supply device 150 via a low-pressure supply pipe 153 into an intake port, and an in-cylinder injection valve 127 that injects fuel supplied from the fuel supply device 150 via a high-pressure supply pipe 158 into a cylinder. The in-cylinder injection valve 127 is disposed approximately at the center of the top of a combustion chamber 129 and injects fuel in a spray form. The spark plug 130 is disposed near the in-cylinder injection valve 127 so that it can ignite the fuel sprayed from the in-cylinder injection valve 127 in a spray form. The port injection valve 126 and the in-cylinder injection valve 127 enable the engine 22 to operate in any of a port injection mode, an in-cylinder injection mode, and a common injection mode. In the port injection mode, air purified by an air cleaner 122 is drawn into an intake pipe 123 and passes through a throttle valve 124 and a surge tank 125. At the same time, fuel is injected from a port injection valve 126 downstream of the surge tank 125 in the intake pipe 123 to mix the air and fuel. This mixture is then drawn into a combustion chamber 129 via an intake valve 128 and is explosively combusted by an electric spark from an ignition plug 130. The reciprocating motion of a piston 132, which is pushed down within the cylinder bore by the energy of the fuel, is converted into rotational motion of the crankshaft 23. In the direct injection mode, as in the port injection mode, air is drawn into the combustion chamber 129, and fuel is injected from a direct injection valve 127 during the intake stroke or compression stroke. The fuel is explosively combusted by an electric spark from the ignition plug 130 to generate rotational motion of the crankshaft 23. In the common injection mode, fuel is injected from port injection valve 126 when air is drawn into combustion chamber 129, and fuel is injected from in-cylinder injection valve 127 during the intake stroke and compression stroke, and the fuel is explosively burned by an electric spark from spark plug 130, generating rotational motion of crankshaft 23. These injection modes are switched based on the operating state of engine 22. Exhaust gas discharged from combustion chamber 129 through exhaust valve 133 into exhaust pipe 134 is discharged into the outside air via purification device 135.The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components in the exhaust gas, such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

[0014] The fuel supply device 150 is configured as a device that supplies fuel in a fuel tank 151 to the port injection valves 126 and the in-cylinder injection valves 127 of the engine 22. The fuel supply device 150 includes the fuel tank 151, a feed pump 152, a low-pressure supply pipe 153, a check valve 154, a relief pipe 155, a relief valve 156, a high-pressure pump 157, and a high-pressure supply pipe 158.

[0015] Feed pump 152 is disposed in fuel tank 151 and supplies fuel from within fuel tank 151 to low-pressure supply pipe 153. Low-pressure supply pipe 153 is connected to port injection valve 126. Check valve 154 is provided in low-pressure supply pipe 153 and allows fuel to flow in the direction from feed pump 152 to port injection valve 25, while restricting fuel flow in the opposite direction.

[0016] Relief pipe 155 is connected to low-pressure supply pipe 153 and fuel tank 151. Relief valve 156 is provided in relief pipe 155, and closes when the fuel pressure in low-pressure supply pipe 153 is below threshold Pflolim, and opens when the fuel pressure in low-pressure supply pipe 153 is equal to or higher than threshold Pflolim. When relief valve 156 opens, a portion of the fuel in low-pressure supply pipe 153 is returned to fuel tank 151 via relief pipe 155.

[0017] High-pressure pump 157 is driven by power from engine 22 (in this embodiment, rotation of the intake camshaft that opens and closes intake valve 128), and is configured as a pump that pressurizes fuel in low-pressure supply pipe 153 and supplies it to high-pressure supply pipe 158. High-pressure pump 157 has an electromagnetic valve 157a connected to its intake port that opens and closes when pressurizing the fuel, a check valve 157b connected to its discharge port that regulates backflow of fuel and maintains the fuel pressure in high-pressure supply pipe 158, and a plunger 157c that is actuated (moves up and down in FIG. 1 ) by rotation of engine 22 (rotation of the intake camshaft). When the electromagnetic valve 157a is opened while the engine 22 is running, the high-pressure pump 157 draws in fuel from the low-pressure supply pipe 153, and when the electromagnetic valve 157a is closed, the high-pressure pump 157 pressurizes the fuel to be supplied to the high-pressure supply pipe 158 by intermittently sending the fuel compressed by the plunger 157c to the high-pressure supply pipe 158 via the check valve 157b.

[0018] The operation of the engine 22 is controlled by an engine ECU 24 configured as a microcomputer. The engine ECU 24 receives signals from various sensors, via an input port, that are required to control the operation of the engine 22. Examples of such signals include a crank angle θcr from a crank position sensor 140 that detects the rotational position of a crankshaft 23 of the engine 22, a coolant temperature Tw from a water temperature sensor 142 that detects the temperature of the coolant for the engine 22, and cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes intake valves 128 and an exhaust camshaft that opens and closes exhaust valves 133. Other examples include a throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, an intake air amount Qa from an air flow meter 123a attached upstream of the throttle valve 124 in the intake pipe 123, an intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 in the intake pipe 123, and a surge pressure Ps from a pressure sensor 125a attached to the surge tank 125. Other examples include a front air-fuel ratio AF1 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 AF2 from a rear air-fuel ratio sensor 138 attached between the purification device 135 and the PM filter 136 in the exhaust pipe 134. Other examples include the fuel temperature Tftnk from the fuel temperature sensor 151t attached to the fuel tank 151, the rotation speed Np of the feed pump 152 from the rotation speed sensor 152a attached to the feed pump 152, the low fuel pressure PL from the fuel pressure sensor 153p, and the high fuel pressure PH from the fuel pressure sensor 158p.

[0019] The engine ECU 24 outputs various control signals via an output port for controlling the operation of the engine 22. 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 126, a control signal to the in-cylinder injection valve 127, and a control signal to the spark plug 130. Other examples include a control signal to the feed pump 152 of the fuel supply device 150 and a control signal to the electromagnetic valve 157a of the high-pressure pump 157.

[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 an integrated post-start air amount ΣQa, which is an integrated value of the intake air amount Qa from the air flow meter 123a since the engine was started, and calculates a load factor KL (the ratio of the volume of air actually taken in during one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa and the rotation speed Ne of the engine 22.

[0021] 1, a starter motor 25 for cranking the engine 22 and an alternator 26 for generating electricity using power from the engine 22 are connected to the crankshaft 23 of the engine 22. The starter motor 25 and the alternator 26 are connected to a low-voltage power line 63 together with a low-voltage battery 62, and are controlled by the HVECU 70.

[0022] The motor 30 is configured as a synchronous generator motor. A rotating shaft 31 to which the rotor of the motor 30 is fixed is connected to the crankshaft 23 of the engine 22 via a clutch K0 and is also connected to an input shaft 41 of an automatic transmission 45. The inverter 32 is used to drive the motor 30 and is connected to a high-voltage power line 61. The motor 30 is rotationally driven by a motor electronic control unit (hereinafter referred to as "motor ECU") 34 controlling the switching of multiple switching elements of the inverter 32.

[0023] The motor ECU 34 receives signals from various sensors via an input port. Examples of such signals include a rotational position θm from a rotational position sensor 30a that detects the rotational position of the rotor (rotating shaft 31) of the motor 30, and phase currents Iu and Iv from current sensors that detect the phase currents of each phase of the motor 30. The motor ECU 34 outputs control signals to the inverter 32 via an output port. The motor ECU 34 is connected to the HVECU 70 via a communication port. The motor ECU 34 calculates the rotation speed Nm of the motor 30 based on the rotational position θm of the rotor (rotating shaft 31) of the motor 30 from the rotational position sensor 30a.

[0024] The clutch K0 is configured as, for example, a hydraulically driven friction clutch, and is controlled by the HVECU 70 to connect and disconnect the crankshaft 23 of the engine 22 and the rotary shaft 31 of the motor 30.

[0025] The automatic transmission 40 includes a torque converter 43 and, for example, a six-speed automatic transmission 45. The torque converter 43 is configured as a typical fluid power transmission device and amplifies the torque of the input shaft 41 connected to the rotary shaft 31 of the motor 30 and transmits it to a transmission input shaft 44, which is the input shaft of the automatic transmission 45, or transmits the torque directly without amplifying it. The automatic transmission 45 includes the transmission input shaft 44, an output shaft 42 connected to drive wheels 49 via a differential gear 48, multiple planetary gears, and multiple hydraulically driven friction engagement elements (clutches and brakes). The automatic transmission 45 establishes forward gears (first through sixth) and reverse gears by engaging and disengaging the multiple friction engagement elements, transmitting power between the transmission input shaft 44 and the output shaft 42. The clutch K0 and the automatic transmission 45 are supplied with hydraulic oil from a mechanical oil pump or an electric oil pump, which is adjusted by a hydraulic control device (not shown). This hydraulic control device is controlled by the HVECU 70.

[0026] High-voltage battery 60 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery with a rated voltage of several hundred volts, and is connected to high-voltage power line 61 together with inverter 32. Low-voltage battery 62 is configured as, for example, a lead-acid battery with a rated voltage of about 12 V or 14 V, and is connected to low-voltage power line 63 together with starter motor 25 and alternator 26. DC / DC converter 64 is connected to high-voltage power line 61 and low-voltage power line 63. DC / DC converter 64 supplies power from high-voltage power line 61 to low-voltage power line 63 while stepping down the voltage.

[0027] The HVECU 70 receives signals from various sensors via an input port. Examples of such sensors include the rotation speed Nin from a rotation speed sensor 41a attached to the input shaft 41 of the automatic transmission 40, the rotation speed Nmi from a rotation speed sensor 44a attached to the transmission input shaft 44 of the automatic transmission 40, and the rotation speed Nout from a rotation speed sensor 42a attached to the output shaft 42 of the automatic transmission 40. Other examples of such sensors include the voltage Vbh of the high-voltage battery 60 from a voltage sensor attached between the terminals of the high-voltage battery 60, the current Ibh of the high-voltage battery 60 from a current sensor attached to the output terminal of the high-voltage battery 60, and the voltage Vbl of the low-voltage battery 62. Other examples include an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81, 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.

[0028] The HVECU 70 outputs various control signals via an output port. Examples of such signals include a control signal to the starter motor 25, a control signal to the alternator 26, a control signal to the clutch K0 and the automatic transmission 40 (hydraulic control device), and a control signal to the DC / DC converter 64. The HVECU 70 is connected to the engine ECU 24 and the motor ECU 34 via a communication port. The HVECU 70 calculates the power storage percentage SOC of the high-voltage battery 60 and input / output limits Win and Wout as the maximum allowable power that can be input and output to the high-voltage battery 60 based on the voltage Vbh and current Ib of the high-voltage battery 60.

[0029] In the hybrid vehicle 20 of this embodiment configured as described above, the engine 22, clutch K0, motor 30, and automatic transmission 40 are controlled by cooperative control between the HVECU 70, engine ECU 24, and motor ECU 34 so that the vehicle runs in hybrid driving mode (HV driving mode) or electric driving mode (EV driving mode).

[0030] In controlling the engine 22 and motor 30 in the HV driving mode, the HVECU 70 first sets a required torque Tout* required for driving (required from the output shaft 42 of the automatic transmission 40) based on the accelerator opening Acc and the vehicle speed V. Next, the HVECU 70 sets a required torque Tin* for the input shaft 41, obtained by dividing the required torque Tout* for the output shaft 42 by the rotation speed ratio Gt of the automatic transmission 40. Then, the HVECU 70 sets a target torque Te* for the engine 22 and a torque command Tm* for the motor 30 so that the required torque Tin* is output to the input shaft 41, and transmits the target torque Te* to the engine ECU 24 and the torque command Tm* to the motor ECU 34. The engine ECU 24 calculates a required load rate KL* from the target torque Te* and performs operation control (intake air amount control, fuel injection control, ignition control, etc.) of the engine 22 so that the engine 22 operates at the target torque Te*. The motor ECU 34 controls the switching of a plurality of switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0031] Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above will be described, particularly the operation during catalyst warm-up control for warming up the purification catalyst 135a in the purification device 135. Catalyst warm-up is performed by multi-stage injection, in which fuel is injected from the in-cylinder injection valve 127 in multiple injections from the intake stroke to the expansion stroke, because emissions are better than those of single injection, in which fuel is injected from the in-cylinder injection valve 127 only once during the intake stroke or compression stroke, as shown in FIG. 3. Therefore, in this embodiment, multi-stage injection is used. FIG. 3 is an explanatory diagram showing an example of the relationship between engine load factor KL and emissions for single injection and multi-stage injection. In the diagram, the solid line indicates multi-stage injection, and the dashed-dotted line indicates single injection. Note that with multi-stage injection, a minimum injection amount per injection is set, depending on the number of injections. Therefore, the load factor KL must be set to be equal to or greater than the minimum load factor that allows multi-stage injection (multi-stage injection realization load factor KLm).

[0032] 4 is a flowchart showing an example of a process for changing the load factor during catalyst warm-up executed by the engine ECU 24. This process is repeatedly executed while catalyst warm-up control is being executed. When the process for changing the load factor during catalyst warm-up is executed, the engine ECU 24 first determines whether or not the post-start cumulative air amount ΣQa, which is the cumulative value of the intake air amount Qa from the start of the engine 22 to the present, is less than a threshold value Qref (step S100). The threshold value Qref can be a predetermined value that represents the cumulative air amount required until catalyst warm-up has been completed to a certain extent. If it is determined that the post-start cumulative air amount ΣQa is equal to or greater than the threshold value Qref, it is determined that catalyst warm-up has been completed to a certain extent and that no deterioration in emissions will occur, and the process ends.

[0033] If it is determined in step S100 that the post-start cumulative air amount ΣQa is less than the threshold Qref, it is then determined whether the required load factor KL* of the engine 22 is less than the multi-injection realization load factor KLm (step S110). The required load factor KL* of the engine 22 is calculated as the load factor KL required to output the target torque Te* at the current rotation speed Ne. The multi-injection realization load factor KLm can be calculated as the lower limit of the range of load factors KL that can realize multi-injection, in which fuel is injected in multiple separate injections from the direct injection valve 127. If it is determined that the required load factor KL* of the engine 22 is equal to or greater than the multi-injection realization load factor KLm, it is determined that catalyst warm-up by multi-injection can be continued, and this process ends.

[0034] If it is determined in step S110 that the required load factor KL* of the engine 22 is less than the multi-injection realization load factor KLm, load factor increase control is performed to increase the load factor KL of the engine 22 (step S120), and the process ends. An example of the load factor increase control is shown in Fig. 5. Fig. 5 is a flowchart showing an example of the load factor increase control executed by the engine ECU 24.

[0035] When the load factor increase control is executed, the engine ECU 24 first determines whether the motor 30 is under powering control (step S200). Whether the motor 30 is under powering control can be determined by determining whether the torque command Tm* is a positive value (powering) or a negative value (regeneration). If it is determined that the motor 30 is under powering control, the engine ECU 24 reduces the powering torque (torque command Tm*) of the motor 30 and increases the target torque Te* required of the engine 22, thereby increasing the required load factor KL* of the engine 22 (step S210), and ends this process. The amount of reduction in the powering torque of the motor 30 can be calculated as the amount by which the required load factor KL* becomes the multi-injection realization load factor KLm. The motor 30 can be controlled by transmitting the reduced powering torque as the torque command Tm* to the HVECU 70 and the motor ECU 34, and controlling the switching of the switching elements of the inverter 32 so that the torque command Tm* received by the motor ECU 34 is output from the motor 30. At this time, the engine 22 is controlled by the engine ECU 24 changing the target torque Te* of the engine 22 to correspond to the amount of reduction in the powering torque of the motor 30, and transmitting the changed value to the HVECU 70, etc., so that the target torque Te* is output from the engine 22, that is, so that the load factor KL of the engine 22 becomes the required load factor KL* that is set to be equal to or greater than the multi-injection realization load factor KLm. Through these controls, catalyst warm-up by multi-injection can be continued even when the motor 30 is being powered.

[0036] If it is determined in step S200 that the motor 30 is not being powered (i.e., is being driven or is being regeneratively controlled), it is determined whether the power storage rate SOC of the high-voltage battery 60 is less than the threshold value Sref and whether the absolute value of the input limit Win of the high-voltage battery 60 is equal to or greater than the threshold value Wref (step S220). If it is determined that the power storage rate SOC of the high-voltage battery 60 is less than the threshold value Sref and the absolute value of the input limit Win of the high-voltage battery 60 is equal to or greater than the threshold value Wref, the torque command Tm* of the motor 30 is set to a negative value to perform regenerative control on the motor 30, and the target torque Te* required of the engine 22 is increased to increase the required load factor KL* of the engine 22 (step S230), and this process ends. The torque command Tm* of the motor 30 may be calculated as a value that makes the required load factor KL* equal to the multi-injection realization load factor KLm. At this time, the control of the motor 30 based on the torque command Tm* and the control of the engine 22 based on the target torque Te* are the same as when it is determined that the motor 30 is being powered. By these controls, even when the motor 30 is not being powered, if the storage ratio SOC of the high-voltage battery 60 is less than the threshold value Sref and the absolute value of the input limit Win of the high-voltage battery 60 is equal to or greater than the threshold value Wref, the catalyst warm-up by multi-stage injection can be continued.

[0037] If it is determined in step S220 that the power storage rate SOC of the high-voltage battery 60 is equal to or greater than the threshold value Sref, or if it is determined that the absolute value of the input limit Win of the high-voltage battery 60 is less than the threshold value Wref, the automatic transmission 40 is upshifted to reduce the rotation speed Ne of the engine 22 and increase the required load factor KL* of the engine 22 (step S240), and this process ends. The upshift can be performed by setting the gear where the required load factor KL* of the engine 22 is equal to or greater than the multi-stage injection realization load factor KLm as the target gear M*, and by controlling the automatic transmission 40 with the HVECU 70 so that the gear M becomes the target gear M*. In this case, the engine 22 is controlled by the engine ECU 24 by calculating a target torque Te* required to output a required torque Tout* to the output shaft 42 of the automatic transmission 40 at the engine speed Ne when the engine 22 is set to the target gear M*, and controlling the engine 22 so that the target torque Te* is output from the engine 22, i.e., so that the load factor KL of the engine 22 becomes equal to or greater than the multi-injection realization load factor KLm. With these controls, the motor 30 is not under powering control, and catalyst warm-up by multi-stage injection can be continued even when the power storage percentage SOC of the high-voltage battery 60 is equal to or greater than the threshold Sref or the absolute value of the input limit Win of the high-voltage battery 60 is less than the threshold Wref.

[0038] In the hybrid vehicle 20 of the embodiment described above, when the required load factor KL* of the engine 22 becomes less than the multi-injection realization load factor KLm while the catalyst warm-up control is being executed, load factor increase control is executed to increase the load factor KL of the engine 22 so that the required load factor KL* is equal to or greater than the multi-injection realization load factor KLm. This allows the catalyst to continue warming up through the multi-injection and suppresses the deterioration of emissions during the catalyst warm-up.

[0039] The hybrid vehicle 20 of the embodiment is equipped with the engine ECU 24, the motor ECU 34, and the HVECU 70. However, at least two of these may be configured as an integrated unit.

[0040] In the embodiment, the present disclosure is applied to the configuration of a hybrid vehicle having an engine 22, an automatic transmission 40, and a motor 30, but the present disclosure may also be applied to the configuration of an automobile having an engine and an automatic transmission without a motor.

[0041] The above describes the form for carrying out the present invention using examples, but 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 within the scope that does not deviate from the gist of the present invention. [Industrial Applicability]

[0042] The present invention can be used in the automobile manufacturing industry and the like. [Explanation of symbols]

[0043] 20 hybrid vehicles, 22 engines, 24 engine ECUs, 30 motors, 34 motor ECUs, 40 automatic transmissions, 70 HVECUs.

Claims

1. An automobile comprising: an engine having an in-cylinder injection valve and an exhaust system having a catalyst device incorporating a catalyst for purifying exhaust gas; an automatic transmission that changes the speed of power from the engine and outputs it to a drive wheel side; an electric motor that can input and output power to an input shaft or an output shaft of the automatic transmission; an electricity storage device that exchanges electric power with the electric motor; and a control device that performs catalyst warm-up control that warms up the catalyst by performing multi-stage injection that injects fuel multiple times from the in-cylinder injection valve and by retarding the ignition timing, the control device executes load factor increase control during the catalyst warm-up control so that a required load factor for the engine becomes equal to or greater than a multi-stage injection realization load factor at which the multi-stage injection can be realized, The load factor increase control is a control for increasing the required load factor by controlling the electric motor. car.

2. A motor vehicle according to claim 1, The load factor increase control is a control that increases the required load factor by reducing the power running output of the electric motor when the electric motor is under power running control, and increases the required load factor by performing regenerative control on the electric motor when the electric motor is not under power running control. car.

3. A motor vehicle according to claim 2, The load rate increase control is a control that increases the required load rate by performing regenerative control on the electric motor when the power storage rate of the power storage device is less than a predetermined rate while the electric motor is not being controlled to run in power, and that reduces the rotation speed of the engine by upshifting the gear stage of the automatic transmission when the power storage rate of the power storage device is equal to or greater than the predetermined rate while the electric motor is not being controlled to run in power. car.

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