Engine device

Abstract

To enable prompt and smooth switching between normal control, normal catalyst warming-up control and rapid catalyst warming-up control of an engine.SOLUTION: When switching is performed between normal control for controlling an engine in accordance with an accelerator opening, normal catalyst warming-up control for warming up a catalyst of a purification device by operating the engine at first predetermined speed by injecting fuel in an intake stroke and delaying ignition timing compared to the normal control, and rapid catalyst warming-up control for warming up the catalyst of the purification device by operating the engine at second predetermined speed by injecting fuel in a compression stroke or an expansion stroke and delaying the ignition timing compared to the normal catalyst warming-up control, intermediate transition control is executed from the control before the switching to the control after the switching.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an engine device, and more particularly to an engine device including an engine having an in-cylinder injection valve to which a purification device having a catalyst for purifying exhaust gas is attached to an exhaust system.

Background Art

[0002] Conventionally, as this type of technology, a technology has been proposed that performs catalyst warm-up by homogeneous combustion of an engine and catalyst warm-up by stratified combustion of the engine (see, for example, Patent Document 1). In this technology, until the catalyst bed temperature becomes equal to or higher than the catalyst warm-up completion temperature, the catalyst is warmed up relatively gently by homogeneous combustion of the engine at the first ignition timing. When there is no heating requirement when catalyst warm-up is required, the catalyst is warmed up relatively quickly by stratified combustion of the engine at a second ignition timing that is later than the first ignition timing until the catalyst bed temperature becomes equal to or higher than the catalyst warm-up completion temperature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described technology, when starting catalyst warm-up by homogeneous combustion of the engine or catalyst warm-up by stratified combustion of the engine, transition control is performed to shift the engine state such as the engine speed, throttle opening, ignition timing, fuel injection pattern, target air-fuel ratio, and intake valve opening / closing timing from the normal operation state to the state for performing catalyst warm-up. However, when performing transition control when switching from catalyst warm-up by homogeneous combustion of the engine to catalyst warm-up by stratified combustion of the engine or when switching from catalyst warm-up by stratified combustion of the engine to catalyst warm-up by homogeneous combustion of the engine, since the transition control is a transition from the normal operation state of the engine, after once transitioning to the normal operation state, it is necessary to transition to the control of the target catalyst warm-up, resulting in unnecessary state changes and taking time for the transition.

[0005] The main object of the engine device of the present invention is to quickly and smoothly switch between normal control of the engine, normal catalyst warm-up control, and rapid catalyst warm-up control.

Means for Solving the Problem

[0006] The engine device of the present invention has adopted the following means in order to achieve the above main object.

[0007] The engine device of the present invention an engine having an in-cylinder injection valve to which a purification device having a catalyst for purifying exhaust gas is attached to an exhaust system, a control device for controlling the engine, is an engine device comprising: when the control device switches between normal control for controlling the engine according to the accelerator opening, normal catalyst warm-up control for warming up the catalyst of the purification device by performing fuel injection in the intake stroke at a first predetermined engine speed and retarding the ignition timing from the normal control, and rapid catalyst warm-up control for warming up the catalyst of the purification device by performing fuel injection in the compression stroke or expansion stroke at a second predetermined engine speed and retarding the ignition timing from the normal catalyst warm-up control, an intermediate transition control is executed between the control before the switch and the control after the switch. It is characterized by the following.

[0008] In the engine device of the present invention, normal control for controlling the engine according to the accelerator opening, normal catalyst warm-up control for warming up the catalyst of the purification device by performing fuel injection in the intake stroke at a first predetermined rotational speed and retarding the ignition timing from the normal control, and rapid catalyst warm-up control for warming up the catalyst of the purification device by performing fuel injection in the compression stroke or expansion stroke at a second predetermined rotational speed and retarding the ignition timing from the normal catalyst warm-up control are switched. When switching this control, intermediate transition control is executed between the control before switching and the control after switching. Thereby, it is possible to quickly and smoothly switch between the normal control, the normal catalyst warm-up control, and the rapid catalyst warm-up control of the engine.

[0009] As the intermediate transition control, when switching from the rapid catalyst warm-up control to the normal catalyst warm-up control, control that gradually changes from the engine state of the rapid catalyst warm-up control to the engine state of the normal catalyst warm-up control can be used. When switching from the rapid catalyst warm-up control to the normal control, control that gradually changes from the engine state of the rapid catalyst warm-up control to a predetermined idle state where the engine is idling at a third predetermined rotational speed in the normal control can be used. When switching from the normal catalyst warm-up control to the normal control, control that gradually changes from the engine state of the normal catalyst warm-up control to the predetermined idle state can be used. Also, as the intermediate transition control, when switching from the normal control to the normal catalyst warm-up control, control that gradually changes from the predetermined idle state to the engine state of the normal catalyst warm-up control can be used. When switching from the normal control to the rapid catalyst warm-up control, control that gradually changes from the predetermined idle state to the engine state of the rapid catalyst warm-up control can be used. When switching from the normal catalyst warm-up control to the rapid catalyst warm-up control, control that gradually changes from the engine state of the normal catalyst warm-up control to the engine state of the rapid catalyst warm-up control can be used. Examples of the engine state include the engine rotational speed, throttle opening, ignition timing, fuel injection pattern, target air-fuel ratio, and intake valve opening / closing timing. Among these, the ignition timing requires particular gradual change because sudden change can cause misfire.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0011] Next, modes for carrying out the present invention will be described using examples.

Examples

[0012] FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device as an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of the engine 22. As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an 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.

[0013] The engine 22 is configured as a six-cylinder internal combustion engine that outputs power through four strokes of intake, compression, expansion (explosive combustion), and exhaust using fuel such as gasoline or diesel fuel. As shown in FIG. 2, the engine 22 includes a port injection valve 126 that injects fuel supplied from a fuel supply device 150 through 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 through a high-pressure supply pipe 158 into the cylinder. The in-cylinder injection valve 127 is disposed substantially at the center of the top of the combustion chamber 129 and injects fuel in a spray form. The ignition plug 130 is disposed in the vicinity of the in-cylinder injection valve 127 so as to be able to ignite the fuel sprayed in a spray form from the in-cylinder injection valve 127. By having the port injection valve 126 and the in-cylinder injection valve 127, the engine 22 can be operated in any one of a port injection mode, an in-cylinder injection mode, and a common injection mode. In the port injection mode, air cleaned by the air cleaner 122 is inhaled into the intake pipe 123, passed through the throttle valve 124 and the surge tank 125, and fuel is injected from the port injection valve 126 on the downstream side of the surge tank 125 in the intake pipe 123 to mix the air and fuel. Then, this air-fuel mixture is inhaled into the combustion chamber 129 through the intake valve 128 and explosively combusted by an electric spark from the ignition plug 130, and the reciprocating motion of the piston 132 pushed down by the energy in the cylinder bore is converted into the rotational motion of the crankshaft 23. In the in-cylinder injection mode, air is inhaled into the combustion chamber 129 in the same manner as in the port injection mode, fuel is injected from the in-cylinder injection valve 127 during the intake stroke and the compression stroke, and 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 126 when air is inhaled into the combustion chamber 129, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and the compression stroke, and explosively combusted by an electric spark from the ignition 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. The exhaust discharged from the combustion chamber 129 to the exhaust pipe 134 through the exhaust valve 133 is discharged to the outside air through 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 gas.

[0014] The fuel supply device 150 is configured as a device that supplies the fuel in the fuel tank 151 to the port injection valve 126 and the in-cylinder injection valve 127 of the engine 22. The fuel supply device 150 includes a 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] The feed pump 152 is configured as an electric pump that operates by receiving power from a battery (not shown) and is disposed in the fuel tank 151. This feed pump 152 supplies the fuel in the fuel tank 151 to the low-pressure supply pipe 153. The low-pressure supply pipe 153 is connected to the port injection valve 126. The check valve 154 is provided in the low-pressure supply pipe 153 and allows the flow of fuel in the direction from the feed pump 152 side to the port injection valve 126 side while restricting the flow of fuel in the reverse direction.

[0016] The relief pipe 155 is connected to the low-pressure supply pipe 153 and the fuel tank 151. The relief valve 156 is provided in the relief pipe 155 and closes when the fuel pressure in the low-pressure supply pipe 153 is less than the threshold value Pflolim and opens when the fuel pressure in the low-pressure supply pipe 153 is equal to or greater than the threshold value Pflolim. When the relief valve 156 opens, a part of the fuel in the low-pressure supply pipe 153 is returned to the fuel tank 151 via the relief pipe 155. In this way, an excessive fuel pressure in the low-pressure supply pipe 153 is suppressed.

[0017] The high-pressure pump 157 is configured as a pump that is driven by the power from the engine 22 (in the embodiment, the rotation of the intake camshaft that opens and closes the intake valve 128) and pressurizes the fuel in the low-pressure supply pipe 153 to supply it to the high-pressure supply pipe 158. The high-pressure pump 157 includes an electromagnetic valve 157a that is connected to its suction port and opens and closes when pressurizing the fuel, a check valve 157b that is connected to its discharge port to regulate the backflow of the fuel and maintain the fuel pressure in the high-pressure supply pipe 158, and a plunger 157c that operates (moves in the vertical direction in FIG. 1) by the rotation of the engine 22 (the rotation of the intake camshaft). During the operation of the engine 22, when the electromagnetic valve 157a is opened, the high-pressure pump 157 sucks the fuel in the low-pressure supply pipe 153, and when the electromagnetic valve 157a is closed, the fuel compressed by the plunger 157c is intermittently sent into the high-pressure supply pipe 158 through the check valve 157b, thereby pressurizing the fuel supplied to the high-pressure supply pipe 158.

[0018] The engine 22 is under operation control by the engine ECU 24. Although not shown, the engine ECU 24 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, input / output ports, and communication ports.

[0019] Signals from various sensors necessary 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 the crank angle θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 23 of the engine 22, and the cooling water temperature Tw from the water temperature sensor 142 that detects the temperature of the cooling water of the engine 22. Also included are the cam angles θci and θco from the cam position sensor 144 that detects the rotational position of the intake camshaft that opens and closes the intake valve 128 and the rotational position of the exhaust camshaft that opens and closes the exhaust valve 133. Further examples are the throttle opening TH from the throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air quantity Qa from the air flow meter 123a attached upstream of the throttle valve 124 in the intake pipe 123, the intake air temperature Ta from the temperature sensor 123t attached upstream of the throttle valve 124 in the intake pipe 123, and the surge pressure Ps from the pressure sensor 125a attached to the surge tank 125. Additionally, the front air-fuel ratio AF1 from the front air-fuel ratio sensor 137 attached upstream of the purification device 135 in the exhaust pipe 134 and the rear air-fuel ratio AF2 from the rear air-fuel ratio sensor 138 attached between the purification device 135 and the PM filter 136 in the exhaust pipe 134 can be cited. Moreover, the fuel temperature Tftnk from the fuel temperature sensor 151t attached to the fuel tank 151, the rotational speed Np of the feed pump 152 from the rotational speed sensor 152a attached to the feed pump 152, the low-pressure fuel pressure (the pressure of the fuel supplied to the port injection valve 126) PL from the fuel pressure sensor 153p attached near the port injection valve 126 in the low-pressure supply pipe 153 (for example, the low-pressure delivery pipe), and the high-pressure fuel pressure (the pressure of the fuel supplied to the in-cylinder injection valve 127) PH from the fuel pressure sensor 158p attached near the in-cylinder injection valve 127 in the high-pressure supply pipe 158 (for example, the high-pressure delivery pipe) can be included.

[0020] From the engine ECU 24, various control signals for controlling the operation of the engine 22 are output via the output ports. Examples of the 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, a control signal to the ignition plug 130, and a control signal to the variable valve timing mechanism 139 capable of changing the opening and closing timing of the intake valve 128. Also, 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 can be mentioned.

[0021] The engine ECU 24 is connected to the HV ECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. Also, the engine ECU 24 calculates the load factor KL (the ratio of the volume of air actually inhaled 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 rotational speed Ne of the engine 22.

[0022] As shown in FIG. 1, the planetary gear 30 is configured as a single pinion type planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. The drive shaft 36 connected to the drive wheels 39a, 39b via the differential gear 38 is connected to the ring gear of the planetary gear 30. The crankshaft 23 of the engine 22 is connected to the carrier of the planetary gear 30.

[0023] The motor MG1 is configured as a synchronous generator motor, for example. As described above, the rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured as a synchronous generator motor, for example, and the rotor is connected to the drive shaft 36. The inverters 41 and 42 are used to drive the motors MG1 and MG2 and are connected to the battery 50 via the power line 54. The motors MG1 and MG2 are rotationally driven by the motor electronic control unit (hereinafter referred to as "motor ECU") 40 by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42.

[0024] The motor ECU 40 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown. Signals from various sensors necessary for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input ports. Examples of the signals input to the motor ECU 40 include the rotational positions θm1 and θm2 from a rotational position sensor (not shown) that detects the rotational positions of the rotors of the motors MG1 and MG2, and the phase currents Iu1, Iv1, Iu2, and Iv2 from a current sensor (not shown) that detects the phase currents flowing through each phase of the motors MG1 and MG2. Switching control signals and the like to a plurality of switching elements (not shown) of the inverters 41 and 42 are output from the motor ECU 40 via the output ports. The motor ECU 40 is connected to the HVECU 70 via the communication port. The motor ECU 40 calculates the electrical angles θe1 and θe2 and the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotational position sensor.

[0025] The battery 50 is configured as a lithium-ion secondary battery or a nickel-metal hydride secondary battery, for example, and is connected to the inverters 41 and 42 via the power line 54 as described above. This battery 50 is managed by a battery electronic control unit (hereinafter referred to as "battery ECU") 52.

[0026] The battery ECU 52 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown in the figure. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input ports. Examples of the signals input to the battery ECU 52 include the voltage Vb of the battery 50 from a voltage sensor (not shown) attached between the terminals of the battery 50, the current Ib of the battery 50 from a current sensor (not shown) attached to the output terminal of the battery 50, and the 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 HV ECU 70 via the communication port. The battery ECU 52 calculates the state of charge SOC of the battery 50 based on the integrated value of the current Ib of the battery 50 from the current sensor. The state of charge SOC is the ratio of the amount of electric power that can be discharged from the battery 50 to the total capacity of the battery 50.

[0027] The HV ECU 70 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown in the figure. Signals from various sensors are input to the HV ECU 70 via the input ports. Examples of the signals input to the HV ECU 70 include the ignition signal from the ignition switch 80 and the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Also, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed V from the vehicle speed sensor 87 can be mentioned. As described above, the HV ECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

[0028] In the hybrid vehicle 20 of the embodiment configured in this way, through the coordinated control of the HVECU 70, the engine ECU 24, and the motor ECU 40, basically, there are a hybrid driving mode (HV driving mode) in which driving is accompanied by the operation of the engine 22 and an electric driving mode (EV driving mode) in which driving is performed without the operation of the engine 22, and the engine 22 is intermittently operated while switching between these two modes to drive the vehicle.

[0029] In the HV driving mode, basically, the HVECU 70 first sets the driving torque Td* required for driving (required for the drive shaft 36) based on the accelerator opening Acc and the vehicle speed V, and multiplies the set driving torque Td* by the rotational speed Nd of the drive shaft 36 (the rotational speed Nm2 of the motor MG2) to calculate the driving power Pd* required for driving. Subsequently, based on the driving power Pd* and the state of charge SOC of the battery 50, the target power Pe* of the engine 22 is set, and the target rotational speed Ne* and target torque Te* of the engine 22, and the torque commands Tm1*, Tm2* of the motors MG1, MG2 are set so that the target power Pe* is output from the engine 22 and the driving torque Td* is output to the drive shaft 36. The set target rotational speed Ne* and target torque Te* are transmitted to the engine ECU 24, and the torque commands Tm1*, Tm2* are transmitted to the motor ECU 40.

[0030] The engine ECU 24 performs driving 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 rotational speed Ne* and 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 126 or the in-cylinder injection valve 127 in the port injection mode, in-cylinder injection mode, or common injection mode. The ignition control is performed by controlling the ignition timing of the spark plug 130. 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 the torque commands Tm1*, Tm2*.

[0031] In the EV driving mode, the HVECU 70 sets the driving torque Td* in the same way as in the HV driving mode, sets the value 0 for the torque command Tm1* of the motor MG1, and 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.

[0032] In the HV driving mode, when the target power Pe* reaches less than the power threshold value Peref, etc., it is determined that the stop condition of the engine 22 is satisfied, the engine 22 is stopped, and the vehicle shifts to the EV driving mode. In the EV driving mode, when the target power Pe* calculated in the same way as in the HV driving mode reaches greater than or equal to the power threshold value (Peref + α), etc., it is determined that the start condition of the engine 22 is satisfied, and the engine 22 is started to shift to the HV driving mode.

[0033] In the hybrid vehicle 20 of the embodiment, catalyst warm-up is performed on the purification catalyst (three-way catalyst) 135a of the purification device 135 attached to the exhaust pipe 134 of the engine 22. The catalyst warm-up of the purification device 135 is performed when conditions such as a predetermined temperature or lower where the catalyst temperature Tc is less than the activation temperature and the accelerator-off condition are satisfied. As the catalyst warm-up, there are normal catalyst warm-up and rapid catalyst warm-up. In normal catalyst warm-up, the engine speed Ne of the engine 22 is maintained at a first predetermined speed (for example, 1300 rpm, etc.) Nset1, and fuel injection is performed 1 to 3 times from the in-cylinder injection valve 127 during the intake stroke to make the air-fuel mixture in the combustion chamber 129 homogeneous, and the ignition timing is set near the base ignition timing Tbase1 retarded from the normal timing to cause explosive combustion (homogeneous combustion). Rapid catalyst warm-up is performed by maintaining the engine speed Ne of the engine 22 at a second predetermined speed (for example, 1300 rpm, etc.) Nset2, performing fuel injection not only from the in-cylinder injection valve 127 during the intake stroke but also performing the final fuel injection during the compression stroke to increase the fuel concentration of the air-fuel mixture near the spark plug 130 in the combustion chamber 129, and setting the ignition timing near the base ignition timing Tbase2 further retarded from the base ignition timing of normal catalyst warm-up to cause explosive combustion (stratified combustion). When the ignition timing is retarded, the combustion efficiency decreases, so while maintaining the engine speed Ne of the engine 22 by increasing the intake air amount, the amount of combustion gas increases, and the absolute amount of emission components also increases, but the catalyst warm-up is promoted. Therefore, compared with normal catalyst warm-up, rapid catalyst warm-up can further promote catalyst warm-up by retarding the ignition timing even more. In rapid catalyst warm-up, fuel injection may be performed 1 to 3 times during the intake stroke or the compression stroke, the final fuel injection is performed during the expansion stroke, and ignition is synchronized with the fuel injection in this expansion stroke to cause explosive combustion (stratified combustion).

[0034] Next, the operation of the hybrid vehicle 20 of the thus configured embodiment will be described, particularly the operation when switching between normal control for operating the engine 22 according to the accelerator opening Acc, normal catalyst warm-up control, and rapid catalyst warm-up control. FIG. 3 is a flowchart showing an example of a control switching process executed by the engine ECU 24 when switching between normal control, normal catalyst warm-up control, and rapid catalyst warm-up control. As normal control, for example, control for idling the engine 22 at a predetermined normal rotational speed (e.g., 800 prm or 1000 prm, etc.) Nidl can be considered. Hereinafter, normal control will be assumed to control the engine 22 in this operating state.

[0035] When the control switching process is executed, the engine ECU 24 first identifies which control to switch from and to among normal control, normal catalyst warm-up control, and rapid catalyst warm-up control (step S100). This identification can be performed as a switch from the currently executed control to the control after the switching according to the switching instruction. As control switching, there are six types: switching from normal control to normal catalyst warm-up control, switching from normal control to rapid catalyst warm-up control, switching from normal catalyst warm-up control to rapid catalyst warm-up control, switching from rapid catalyst warm-up control to normal control, switching from rapid warm-up control to normal catalyst warm-up control, and switching from normal catalyst warm-up control to normal control. In step S100, it is to identify which of these is the case.

[0036] Subsequently, an intermediate transition control is selected based on the identified control switching (step S110), the selected intermediate transition control is executed (step S120), after waiting for the control transition by the intermediate transition control to be completed (step S130), the control after the switching is executed (step S140), and this process ends. Figure 4 is a list showing an example of control switching and selection of intermediate transition control. In step S110, as shown in the figure, in the switch from normal control to normal catalyst warm-up control, intermediate transition control (1) is selected; in the switch from normal control to rapid catalyst warm-up control, intermediate transition control (2) is selected; in the switch from normal catalyst warm-up control to rapid catalyst warm-up control, intermediate transition control (3) is selected; in the switch from rapid catalyst warm-up control to normal control, intermediate transition control (4) is selected; in the switch from rapid warm-up control to normal catalyst warm-up control, intermediate transition control (5) is selected; and in the switch from normal catalyst warm-up control to normal control, intermediate transition control (5) is selected.

[0037] Figures 5 to 10 are explanatory diagrams showing an example of the time changes in the engine speed, ignition timing, and intake valve timing in intermediate transition controls (1) to (6) executed when switching between normal control, normal catalyst warm-up control, and rapid catalyst warm-up control.

[0038] Intermediate transition control (1) is the control executed when switching from normal control to normal catalyst warm-up control, as shown in Figure 5. When a switch is instructed at time T1 during the execution of normal control, intermediate transition control (1) is executed, and for the engine speed Ne, throttle opening TH, and opening / closing timing VVT of the intake valve 128 of engine 22, they are immediately changed from the predetermined normal engine speed Nidl, throttle opening THidl, and opening / closing timing VVTidl in normal control to the first predetermined engine speed Nset1, throttle opening THset1, and opening / closing timing VVTset1 in normal catalyst warm-up control. For the ignition timing Tp, it is gradually retarded from the ignition timing Tpidl in normal control until it reaches the base ignition timing Tbase1 in normal catalyst warm-up control. Intermediate transition control (1) is terminated at time T2 when the change due to the gradual change of the ignition timing Tp is completed, and normal catalyst warm-up control is started.

[0039] The intermediate transition control (2) is the control executed when switching from the normal control to the rapid catalyst warm-up control, as shown in FIG. 6. When a switch is instructed at time T1 during the execution of the normal control, the intermediate transition control (2) is executed, and for the engine speed Ne, throttle opening TH, and intake valve opening / closing timing VVT of the engine 22, they are immediately changed from the predetermined normal engine speed Nidl, throttle opening THidl, and opening / closing timing VVTidl of the normal control to the second predetermined engine speed Nset2, throttle opening THset2, and opening / closing timing VVTset2 of the rapid catalyst warm-up control. For the ignition timing Tp, it is gradually retarded from the ignition timing Tpidl of the normal control until it reaches the base ignition timing Tbase2 of the rapid catalyst warm-up control. The intermediate transition control (2) is terminated at time T2 when the change due to the gradual change of the ignition timing Tp is completed, and the normal catalyst warm-up control is started.

[0040] The intermediate transition control (3) is a control executed when switching from normal catalyst warm-up control to rapid catalyst warm-up control as shown in FIG. 7. In the figure, the broken line shows, as a comparative example, the time change when switching from normal catalyst warm-up control to normal control and immediately switching from normal control to rapid catalyst warm-up control. When a switch is instructed at time T1 during the execution of normal catalyst warm-up control, the intermediate transition control (3) is executed, and for the engine speed Ne, throttle opening TH, and intake valve opening / closing timing VVT of the engine 22, they are immediately changed from the first predetermined engine speed Nset1, throttle opening THset1, and opening / closing timing VVTset1 of normal catalyst warm-up control to the second predetermined engine speed Nset2, throttle opening THset2, and opening / closing timing VVTset2 of rapid catalyst warm-up control. For the ignition timing Tp, it is gradually retarded from the base ignition timing Tbase1 of normal catalyst warm-up control until reaching the base ignition timing Tbase2 of rapid catalyst warm-up control. The intermediate transition control (3) is terminated at time T2 when the change due to the gradual change of the ignition timing Tp is completed, and the rapid catalyst warm-up control is started. In the comparative example, since the intermediate transition control (6) (see FIG. 10) from normal catalyst warm-up control to normal control is performed and then immediately the intermediate transition control (2) (see FIG. 6) from normal control to rapid catalyst warm-up is performed, there are many wasted operations for the engine speed Ne, throttle opening TH, intake valve opening / closing timing VVT, and ignition timing Tp of the engine 22, so the transition is completed at time T12 which is later than time T2, and the rapid catalyst warm-up control is started. Thus, by executing the intermediate transition control (3) when switching from normal catalyst warm-up control to rapid catalyst warm-up control, the switch from normal catalyst warm-up control to rapid catalyst warm-up control can be performed quickly and smoothly.

[0041] The intermediate transition control (4) is a control that is executed when switching from the rapid catalyst warm-up control to the normal control, as shown in FIG. 8. When a switch is instructed at time T3 during the execution of the rapid catalyst warm-up control, the intermediate transition control (4) is executed, and for the engine speed Ne, throttle opening TH, and intake valve opening / closing timing VVT of the engine 22, they are immediately changed from the second predetermined engine speed Nset2, throttle opening THset2, and opening / closing timing VVTset2 of the rapid catalyst warm-up control to the predetermined normal engine speed Nidl, throttle opening THidl, and opening / closing timing VVTidl of the normal control. For the ignition timing Tp, it is gradually advanced from the base ignition timing Tbase2 of the rapid catalyst warm-up control to the ignition timing Tpidl of the normal control. The intermediate transition control (4) is terminated at time T4 when the change due to the gradual change of the ignition timing Tp is completed, and the normal control is started.

[0042] The intermediate transition control (5) is a control executed when switching from the rapid catalyst warm-up control to the normal catalyst warm-up control as shown in FIG. 9. In the figure, the broken line shows, as a comparative example, the time change when switching from the rapid catalyst warm-up control to the normal control and immediately switching from the normal control to the normal catalyst warm-up control. When a switch is instructed at time T3 during the execution of the rapid catalyst warm-up control, the intermediate transition control (5) is executed, and for the engine speed Ne, throttle opening TH, and opening / closing timing VVT of the intake valve 128 of the engine 22, it is immediately changed from the second predetermined engine speed Nset2, throttle opening THset2, and opening / closing timing VVTset2 of the rapid catalyst warm-up control to the first predetermined engine speed Nset1, throttle opening THset1, and opening / closing timing VVTset1 of the normal catalyst warm-up control. For the ignition timing Tp, it is gradually advanced from the base ignition timing Tbase2 of the rapid catalyst warm-up control to the base ignition timing Tbase1 of the normal catalyst warm-up control. The intermediate transition control (5) is terminated at time T4 when the change due to the gradual change of the ignition timing Tp is completed, and the normal catalyst warm-up control is started. In the comparative example, since the intermediate transition control (4) (see FIG. 8) from the rapid catalyst warm-up control to the normal control is performed and then immediately the intermediate transition control (1) (see FIG. 5) from the normal control to the normal catalyst warm-up is performed, there are many wasted operations for the engine speed Ne, throttle opening TH, opening / closing timing VVT of the intake valve 128, and ignition timing Tp of the engine 22. Therefore, the transition is completed at time T34, which is later than time T4, and the normal catalyst warm-up control is started. Thus, by executing the intermediate transition control (5) when switching from the rapid catalyst warm-up control to the normal catalyst warm-up control, the switching from the rapid catalyst warm-up control to the normal catalyst warm-up control can be performed quickly and smoothly.

[0043] As shown in FIG. 10, the intermediate transition control (6) is a control executed when switching from the normal catalyst warm-up control to the normal control. When a switch is instructed at time T3 during the execution of the normal catalyst warm-up control, the intermediate transition control (6) is executed. Regarding the engine speed Ne, throttle opening TH, and intake valve opening / closing timing VVT of the engine 22, they are immediately changed from the first predetermined engine speed Nset1, throttle opening THset1, and opening / closing timing VVTset1 of the normal catalyst warm-up control to the predetermined normal engine speed Nidl, throttle opening THidl, and opening / closing timing VVTidl of the normal control. Regarding the ignition timing Tp, it is gradually advanced from the base ignition timing Tbase1 of the normal catalyst warm-up control to the ignition timing Tpidl of the normal control. The intermediate transition control (6) is terminated at time T4 when the change due to the gradual change of the ignition timing Tp is completed, and the normal control is started.

[0044] In the engine device mounted on the hybrid vehicle 20 of the embodiment described above, the intermediate transition control (1) is executed when switching from the normal control to the normal catalyst warm-up control, the intermediate transition control (2) is executed when switching from the normal control to the rapid catalyst warm-up control, the intermediate transition control (3) is executed when switching from the normal catalyst warm-up control to the rapid catalyst warm-up control, the intermediate transition control (4) is executed when switching from the rapid catalyst warm-up control to the normal control, the intermediate transition control (5) is executed when switching from the rapid warm-up control to the normal catalyst warm-up control, and the intermediate transition control (5) is executed when switching from the normal catalyst warm-up control to the normal control. Thereby, the switching with the control can be performed quickly and smoothly.

[0045] In the engine device mounted on the hybrid vehicle 20 of the embodiment, in the intermediate transition controls (1) to (6), the engine speed Ne, throttle opening TH, and intake valve opening / closing timing VVT of the engine 22 change relatively quickly, and the ignition timing Tp changes gradually. However, the engine speed Ne, throttle opening TH, and intake valve opening / closing timing VVT of the engine 22 may also change gradually.

[0046] In the engine device mounted on the hybrid vehicle 20 of the embodiment, regarding the intermediate shift control (1) to (6), the changes in the engine speed Ne, throttle opening TH, opening / closing timing VVT of the intake valve 128, and ignition timing Tp of the engine 22 have been described. In addition to these, the fuel injection mode, target air-fuel ratio, etc. are the same.

[0047] In the engine device mounted on the hybrid vehicle 20 of the embodiment, as the engine 22, one in which the in-cylinder injection valve 127 is arranged substantially at the center of the top of the combustion chamber 129 is used, but an engine in which the in-cylinder injection valve 127 is arranged on the side wall (side) of the combustion chamber 129 may also be used.

[0048] In the engine device mounted on the hybrid vehicle 20 of the embodiment, as the engine 22, one equipped with the port injection valve 126 and the in-cylinder injection valve 127 is used, but an engine equipped only with the in-cylinder injection valve without the port injection valve may also be used.

[0049] In the hybrid vehicle 20 of the embodiment, the battery 50 is used as the power storage device, but any power storage device may be used, and a capacitor or the like may also be used.

[0050] In the hybrid vehicle 20 of the embodiment, the engine ECU 24, the motor ECU 40, the battery ECU 52, and the HV ECU 70 are provided, but at least two of these may be configured as a single electronic control unit.

[0051] In the embodiment, the case where the present invention is applied to an engine device mounted on a hybrid vehicle 20 including an engine 22, motors MG1 and MG2, and a planetary gear 30 has been described. However, it may also be applied to an engine device mounted on an ordinary automobile.

[0052] A description will be given of the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems. In the embodiment, the purification device 135 corresponds to the "purification device", the engine 22 corresponds to the "engine", and the engine ECU 24 corresponds to the "control device".

[0053] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems is an example for specifically explaining the form for implementing the invention described in the column of means for solving the problems in the embodiment, and thus does not limit the elements of the invention described in the column of means for solving the problems. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the column of means for solving the problems.

[0054] As described above, the embodiments have been used to explain the forms for implementing the present invention. However, the present invention is not limited to such embodiments, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

Industrial Applicability

[0055] The present invention can be used in the manufacturing industry of engine devices and the like.

Explanation of Reference Numerals

[0056] 20 Hybrid vehicle, 22 Engine, 23 Crankshaft, 24 Engine ECU, 30 Planetary gear, 36 Drive shaft, 38 Differential gear, 39a, 39b Drive wheels, 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 Airflow meter, 123t Temperature sensor, 124 Throttle valve, 124a Throttle valve position sensor, 125 Surge tank, 125a Pressure sensor, 126 Port injection valve, 127 In-cylinder injection valve, 128 Intake valve, 129 Combustion chamber, 130 Spark plug, 132 Piston, 133 Exhaust valve, 134 Exhaust pipe, 135 Purification device, 135a Purification catalyst, 136 PM filter, 136a Differential pressure sensor, 137 Front air-fuel ratio sensor, 138 Rear air-fuel ratio sensor, 139 Variable valve timing mechanism, 140 Crank position sensor, 142 Water temperature sensor, 144 Cam position sensor, 150 Fuel supply device, 151 Fuel tank, 151t Fuel temperature sensor, 152 Feed pump, 152a Rotation speed sensor, 153 Low-pressure supply pipe, 153p Fuel pressure sensor, 154 Check valve, 155 Relief pipe, 156 Relief valve, 157 High-pressure pump, 157a Solenoid valve, 157b Check valve, 157c Plunger, 158 High-pressure supply pipe, 158p Fuel pressure sensor, MG1, MG2 Motors.

Claims

【Claim 1】 An engine having an in-cylinder injection valve with a purification device having a catalyst for purifying exhaust gas attached to an exhaust system, A control device for controlling the engine, An engine device comprising: The control device includes normal control for controlling the engine according to the accelerator opening, normal catalyst warm-up control for warming up the catalyst of the purification device by performing fuel injection in the intake stroke at a first predetermined rotational speed of the engine and retarding the ignition timing from the normal control, and rapid catalyst warm-up control for warming up the catalyst of the purification device by performing fuel injection in the compression stroke or expansion stroke at a second predetermined rotational speed of the engine and retarding the ignition timing from the normal catalyst warm-up control. When switching from the normal catalyst warm-up control to the rapid catalyst warm-up control, the rotational speed, throttle opening, and intake valve opening / closing timing of the engine are immediately switched from the state of the normal catalyst warm-up control to the state of the rapid catalyst warm-up control, and an intermediate transition control is executed in which the ignition timing is gradually retarded and switched from the state of the normal catalyst warm-up control to the state of the rapid catalyst warm-up control. When switching from the rapid catalyst warm-up control to the normal catalyst warm-up control, the rotational speed, throttle opening, and intake valve opening / closing timing of the engine are immediately switched from the state of the rapid catalyst warm-up control to the state of the normal catalyst warm-up control, and an intermediate transition control is executed in which the ignition timing is gradually advanced and switched from the state of the rapid catalyst warm-up control to the state of the normal catalyst warm-up control. An engine device characterized by the above.

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