JP2026011850A - Engine equipment - Google Patents

Abstract

To quickly resume EGR when the amount of change in required power increases immediately after the amount of change in required power temporarily decreases.
When the amount of change in engine power demand, calculated at a predetermined cycle, falls below a threshold, the control device prohibits exhaust gas recirculation in the exhaust recirculation system and sets the target opening of the EGR valve to 0. Immediately after that, when a predetermined condition is met in which one of a predetermined number of consecutive changes in the demand power reaches or exceeds the threshold, the control device immediately permits exhaust gas recirculation in the exhaust recirculation system and resumes EGR valve opening/closing control based on the target opening.
[Selected Figure] Figure 3

Description

This disclosure relates to an engine device, and more particularly to an engine device equipped with an engine equipped with an exhaust gas recirculation device having an EGR valve that adjusts the amount of exhaust gas recirculated back into the intake air.

Conventionally, engine systems of this type have been proposed that implement misfire prevention control when residual EGR gas flows into a cylinder during deceleration (see, for example, Patent Document 1). When the engine load is greater than a load determination value, first misfire prevention control is implemented, which suppresses misfire by increasing the fuel injection amount or retarding the ignition timing without changing the intake valve characteristics. When the engine load is less than the load determination value, second misfire prevention control is implemented, which suppresses misfire by changing the intake valve characteristics. As a result, when deceleration occurs during EGR, appropriate misfire prevention measures are implemented in stages according to the deceleration state, efficiently suppressing misfire.

JP 2016-014354 A

Such control during deceleration involves closing the EGR valve to completely remove EGR gas when the power demanded by the engine decreases and the change in power falls below a threshold, and then performing EGR stop/restart control, which gradually opens the EGR valve when EGR is restarted. In this case, even if the change in power demand temporarily decreases, and then immediately increases, EGR execution is delayed until EGR stop/restart control is complete, which can result in a deterioration in fuel economy.

The primary purpose of the engine device disclosed herein is to quickly restart EGR when the change in required power increases immediately after a temporary decrease in the change in required power.

The engine device disclosed herein employs the following measures to achieve the above-mentioned primary objective.

The engine device of the present disclosure comprises:
an engine equipped with an exhaust gas recirculation device having an EGR valve that adjusts the amount of exhaust gas recirculated to an intake;
a control device that controls the opening and closing of the EGR valve based on a target opening, and when a required power change amount calculated at a predetermined cycle as a change amount of required power required of the engine becomes less than a threshold value, prohibits exhaust gas recirculation in the exhaust gas recirculation device and controls the EGR valve with the target opening amount set to 0, and when exhaust gas recirculation is started thereafter, controls the EGR valve using a gradual change process so that the opening amount of the EGR valve changes gradually with respect to the target opening amount;
An engine device comprising:
When a predetermined condition is met in which one of a predetermined number of consecutive times of changes in the required power after the required power change amount has become less than the threshold value has become equal to or greater than the threshold value, the control device immediately permits exhaust gas circulation in the exhaust gas recirculation device and resumes opening/closing control of the EGR valve based on the target opening degree.
It is characterized by:

In the engine system disclosed herein, when the change in the required power required of the engine (required power change amount), calculated at a predetermined interval, falls below a threshold, exhaust gas recirculation in the exhaust gas recirculation system is prohibited and the EGR valve is controlled with the target EGR valve opening set to 0. When exhaust gas recirculation is subsequently initiated, the EGR valve is controlled using a gradual change process to gradually change the EGR valve opening relative to the target opening. When a predetermined condition is met, in which one of a predetermined number of consecutive required power changes exceeds the threshold after the required power change falls below the threshold, exhaust gas recirculation in the exhaust gas recirculation system is immediately permitted and EGR valve opening/closing control based on the target opening is resumed. In other words, when the required power change amount temporarily falls below the threshold and then immediately exceeds the threshold, EGR valve opening/closing control based on the target opening is immediately executed. This allows EGR to be resumed quickly when the required power change immediately increases after a temporary decrease in the required power change. As a result, deterioration in fuel economy can be suppressed.

In the engine system of the present disclosure, when the control device resumes control of the EGR valve based on the target opening degree when the predetermined condition is met, the control device may control the EGR valve without using the slow-change processing. This allows the EGR valve opening degree to be quickly adjusted to the target opening degree.

In the engine system of the present disclosure, when the control device prohibits exhaust gas recirculation in the exhaust gas recirculation system, it may store the immediately preceding target opening as an upper limit guard value, and when resuming control of the EGR valve opening based on the target opening, it may control the EGR valve by upper limiting the target opening with the upper limit guard value. In this way, it is possible to prevent the EGR valve from opening too suddenly.

1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device according to an embodiment of the present disclosure. FIG. 2 is a diagram showing the outline of the configuration of an engine 22. 4 is a flowchart showing an example of an EGR stop process executed by an engine ECU 24. FIG. 4 is an explanatory diagram illustrating an example of EGR stop processing.

Next, a mode (embodiment) for carrying out the present disclosure will be described. FIG. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with an engine device according to one embodiment of the present disclosure. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, an engine ECU 24, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50 serving as an electricity storage device, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

The engine 22 is a multi-cylinder (e.g., four-cylinder or six-cylinder) internal combustion engine that uses gasoline, diesel, or other fuel to output power. It is connected to the carrier of the planetary gear 30 via a damper 28. Figure 2 is a schematic diagram of the engine 22. As shown in the figure, the engine 22 draws air purified by an air cleaner 122 into an intake pipe 123, passes it through a throttle valve 124, and injects fuel from fuel injection valves 126 provided for each cylinder to mix the air and fuel. This mixture is then drawn into a combustion chamber 129 via an intake valve 128. The drawn mixture is then explosively combusted by an electric spark generated by an ignition plug 130 attached to each cylinder. The resulting energy pushes down a piston 132, and the reciprocating motion of the piston 132 is converted into rotational motion of the crankshaft 26. Because the engine 22 has a fuel injection valve 126 that injects fuel into each cylinder, fuel cutoff can be performed for each cylinder. Exhaust gas discharged from the combustion chamber 129 into an exhaust pipe 133 via an exhaust valve 131 is discharged into the outside air via a catalytic converter 134 and a PM filter 136, and is also supplied to the intake side via an exhaust gas recirculation system (hereinafter referred to as an "EGR system") 160, which recirculates the exhaust gas into the intake air. The catalytic converter 134 has a purification catalyst (three-way catalyst) 134a that purifies harmful components in the exhaust gas, such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The PM filter 136 is formed as a porous filter made of ceramics, stainless steel, or the like, and captures particulate matter (PM) such as soot in the exhaust gas. The EGR system 160 includes an EGR pipe 162 connected downstream of the catalytic converter 134 to supply exhaust gas to a surge tank on the intake side, and an EGR valve 164 disposed in the EGR pipe 162 and driven by a stepping motor 163. In the EGR system 160, the opening of the EGR valve 164 is adjusted to a target opening θ* according to the required power Pe* of the engine 22, thereby adjusting the amount of exhaust gas recirculated as unburned gas and recirculating it to the intake side.

The engine ECU 24 is configured as a microprocessor centered around a CPU 24a, and in addition to the CPU 24a, it also includes a ROM 24b that stores processing programs, a RAM 24c that temporarily stores data, and input/output ports and communication ports (not shown).

Signals from various sensors that detect the state of the engine 22 are input to the engine ECU 24 via input ports. Examples of signals input to the engine ECU 24 include crank position from a crank position sensor 140 that detects the rotational position of the crankshaft 26, and engine water temperature Thw from a water temperature sensor 142 that detects the temperature of the engine 22's coolant. Other signals include engine oil temperature Thoi from an oil temperature sensor 143 that detects the temperature of the engine oil, and cam position from a cam position sensor 144 that detects the rotational position of the intake valve 128 that intakes and exhausts air into the combustion chamber and the camshaft that opens and closes the exhaust valve. Other signals include throttle opening TH from a throttle valve position sensor 146 that detects the position of the throttle valve 124, intake air volume Qa from an air flow meter 148 attached to the intake pipe, intake air temperature Ta from a temperature sensor 149 also attached to the intake pipe, and intake pressure Pin from an intake pressure sensor 158 that detects the pressure within the intake pipe. Other examples include the catalyst temperature Tc from the temperature sensor 134a attached to the catalytic device 134, the air-fuel ratio AF from the air-fuel ratio sensor 135a, the oxygen signal O2 from the oxygen sensor 135b, and the differential pressure ΔP from the differential pressure sensor 136a that detects the differential pressure before and after the PM filter 136 (the differential pressure between the upstream and downstream sides). Also included is the EGR valve opening EV from the EGR valve opening sensor 165 that detects the opening of the EGR valve 164.

Various control signals for driving 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 drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, and a control signal to the ignition coil 138 integrated with the igniter. Other examples include a control signal to the variable valve timing mechanism 150 that can change the opening and closing timing of the intake valve 128, and a drive signal to the stepping motor 163 that adjusts the opening of the EGR valve 164.

The engine ECU 24 communicates with the hybrid electronic control unit 70, controls the operation of the engine 22 based on control signals from the hybrid electronic control unit 70, and outputs data regarding the operating state of the engine 22 as needed. The engine ECU 24 calculates the engine 22 rotation speed Ne based on the crank angle θcr from the crank position sensor 140, and calculates the load factor KL (the ratio of the volume of air actually taken in per cycle to the stroke volume per cycle of the engine 22) based on the intake air volume Qa from the air flow meter 148 and the engine 22 rotation speed Ne.

As shown in FIG. 1, the planetary gear 30 is configured as a single-pinion planetary gear mechanism and includes a sun gear 31, a ring gear 32, multiple pinion gears 33 that mesh with the sun gear 31 and ring gear 32, respectively, and a carrier 34 that supports the multiple pinion gears 33 so that they can rotate and revolve freely. The rotor of motor MG1 is connected to the sun gear 31 of the planetary gear 30. The ring gear 32 of the planetary gear 30 is connected to a drive shaft 36 that is connected to drive wheels 39a, 39b via a differential gear 38. As mentioned above, the crankshaft 26 of the engine 22 is connected to the carrier 34 of the planetary gear 30 via the damper 28.

Motor MG1 is configured, for example, as a synchronous generator motor, and as described above, its rotor is connected to the sun gear 31 of the planetary gear 30. Motor MG2 is configured, for example, as a synchronous generator motor, and its rotor is connected to the drive shaft 36. Inverters 41, 42 are used to drive motors MG1, MG2 and are connected to a battery 50 via a power line 54. A smoothing capacitor 57 is attached to the power line 54. Motors MG1, MG2 are rotated by a motor electronic control unit (hereinafter referred to as "motor ECU") 40 controlling the switching of multiple switching elements (not shown) of the inverters 41, 42.

Although not shown, the motor ECU 40 is configured as a microprocessor centered around a CPU. In addition to the CPU, it also includes a ROM for storing processing programs, a RAM for temporarily storing data, input/output ports, and communication ports. Signals from various sensors required for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input port. For example, rotational positions θm1 and θm2 are output from rotational position detection sensors 43 and 44, which detect the rotational positions of the rotors of the motors MG1 and MG2, and phase currents Iu1, Iv1, Iu2, and Iv2 are output from current sensors 45u, 45v, 46u, and 46v, which detect the currents flowing through each phase of the motors MG1 and MG2. The motor ECU 40 outputs switching control signals to multiple switching elements of the inverters 41 and 42 via the output port. The motor ECU 40 is connected to the HVECU 70 via the communication port. The motor ECU 40 calculates the electrical angles θe1, θe2, angular velocities ωm1, ωm2, 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 detection sensors 43, 44.

The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery, and is connected to a power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as "battery ECU") 52.

Although not shown, the battery ECU 52 is configured as a microprocessor centered around a CPU. In addition to the CPU, it also includes a ROM for storing processing programs, a RAM for temporarily storing data, input/output ports, and a communication port. Signals from various sensors required for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include the battery 50 voltage Vb from a voltage sensor 51a attached between the terminals of the battery 50, the battery 50 current Ib from a current sensor 51b attached to the output terminal of the battery 50, and the battery 50 temperature Tb from a temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via the communication port. The battery ECU 52 calculates the power storage percentage SOC based on the integrated value of the battery 50 current Ib from the current sensor 51b. The power storage percentage SOC is the ratio of the amount of power that can be discharged from the battery 50 to the total capacity of the battery 50.

Although not shown, the HVECU 70 is configured as a microprocessor centered around a CPU. In addition to the CPU, it also includes a ROM for storing processing programs, a RAM for temporarily storing data, input/output ports, and communication ports. Signals from various sensors are input to the HVECU 70 via the input ports. 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 operating position of a shift lever 81. Other signals 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 88. Another example is atmospheric pressure Pout from an atmospheric pressure sensor 89. As described above, the HVECU 70 is connected to the engine ECU 24, motor ECU 40, and battery ECU 52 via the communication ports.

The hybrid vehicle 20 of this embodiment configured in this manner runs (while operating the engine 22 intermittently) by switching between a hybrid driving mode (HV driving mode) in which the vehicle runs with the engine 22 operating, and an electric driving mode (EV driving mode) in which the vehicle runs with the engine 22 stopped.

In HV driving mode, the HV ECU 70 basically sets the driving torque Td* required for driving (required from the drive shaft 36) based on the accelerator pedal position Acc and the vehicle speed V, and then calculates the driving power Pd* required for driving by multiplying the set driving torque Td* by the rotation speed Nd of the drive shaft 36 (rotation speed Nm2 of the motor MG2). Next, the HV ECU 70 calculates the required power Pe* required for the engine 22 by subtracting the required charging/discharging power Pb* of the battery 50 (a positive value when discharging from the battery 50) from the driving power Pd*, and sets the target rotation speed Ne* and target torque Te* for the engine 22 and the torque commands Tm1* and Tm2* for the motors MG1 and MG2 so that the calculated required power Pe* is output from the engine 22 and the driving torque Td* is output to the drive shaft 36. The engine ECU 24 then transmits the target rotation speed Ne* and target torque Te* of the engine 22 to the engine ECU 24, and transmits torque commands Tm1* and Tm2* of the motors MG1 and MG2 to the motor ECU 40. Upon receiving the target rotation speed Ne* and target torque Te* of the engine 22, the engine ECU 24 controls the operation of the engine 22 so that the engine 22 operates based on the target rotation speed Ne* and target torque Te*. The operation control of the engine 22 includes intake air amount control, which controls the opening of the throttle valve 124, fuel injection control, which controls the amount of fuel injected from the fuel injection valve 126, and ignition control, which controls the ignition timing of the spark plug 130. In fuel injection control, a target injection amount Qf* is set to a basic fuel injection amount Qf, which is based on the engine 22 rotation speed and intake pipe pressure, multiplied by a correction coefficient based on various sensor values that detect the state of the engine 22, and the fuel injection valves 126 provided for each cylinder are controlled so that the amount of fuel injected from the fuel injection valves 126 becomes the target injection amount Qf*. When the motor ECU 40 receives torque commands Tm1* and Tm2* for the motors MG1 and MG2, it controls the switching of multiple switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1* and Tm2*.

In EV driving mode, the HV ECU 70 sets the driving torque Td* based on the accelerator opening Acc and the vehicle speed V, sets the torque command Tm1* for motor MG1 to a value of 0, and sets the torque command Tm2* for motor MG2 so that the driving torque Td* is output to the drive shaft 36. The torque commands Tm1* and Tm2* for motors MG1 and MG2 are sent to the motor ECU 40. The control of inverters 41 and 42 by the motor ECU 40 has been described above.

Next, we will explain the operation of the hybrid vehicle 20 configured in this manner, particularly the operation when the required power Pe* of the engine 22 decreases and the EGR is stopped. Figure 3 is a flowchart showing an example of the EGR stop process executed by the engine ECU 24. This EGR off stop process is executed repeatedly while the engine 22 is operating.

When the EGR stop process is executed, the engine ECU 24 first calculates the change amount dPe* in the required power Pe* (step S100). The required power change amount dPe* can be calculated as the difference between the current required power Pe* and the previous (previous cycle (period)) required power Pe* (current Pe* - previous Pe*). It then determines whether the calculated required power change amount dPe* is less than a threshold value dPeref (step S110). The threshold value dPeref is used to determine whether to stop EGR to prevent misfires and other problems due to a large decrease in required power Pe*, and can be determined through experimentation, etc. If it is determined that the required power change amount dPe* is equal to or greater than the threshold value dPeref, it determines to continue exhaust gas recirculation, and ends this process without stopping exhaust gas recirculation.

If it is determined in step S110 that the required power change amount dPe* is less than the threshold value dPeref, exhaust gas recirculation is prohibited and the target opening θ* as the target value for the opening of the EGR valve 164 is set to 0 (step S120), and the target opening θ* immediately before exhaust gas recirculation is prohibited is stored as the upper limit guard value θmax (step S130).

Next, the system waits until the next cycle (step S140), calculates the required power change dPe* (step S150), and determines whether the calculated required power change dPe* is less than the threshold dPeref (step S160). If it is determined that the required power change dPe* is less than the threshold dPeref, the system waits until the next cycle (step S170), calculates the required power change dPe* (step S180), and determines whether the calculated required power change dPe* is less than the threshold dPeref (step S190).

When it is determined in both step S160 and step S190 that the required power change amount dPe* is less than the threshold value dPeref, i.e., when it is determined that the required power change amount dPe* is less than the threshold value dPeref for three consecutive cycles (three periods) including the processing of step S110, the upper limit guard value θmax stored in step S130 is cleared (step S200), exhaust gas recirculation is permitted to resume after waiting for EGR gas to be completely removed (step S210), and when exhaust gas recirculation resumes, execution of a gradual change process is set to open the EGR valve 164 using a gradual change process when the opening of the EGR valve 164 is to be set to the target opening amount θ* (step S220), and this process ends. As a result, after waiting for EGR gas to be completely removed, the opening amount of the EGR valve 164 is controlled to the target opening amount θ* using the gradual change process.

On the other hand, if it is determined in either step S160 or step S190 that the required power change amount dPe* is equal to or greater than the threshold value dPeref, i.e., if it is determined in step S110 that the required power change amount dPe* is less than the threshold value dPeref but it is determined that the required power change amount dPe* is equal to or greater than the threshold value dPeref in one of the two consecutive cycles (two periods) immediately following that, exhaust gas recirculation is permitted (step S230), and restart control is set to be executed, in which the target opening degree θ* is upper-limit guarded using the upper limit guard value θmax and the opening degree of the EGR valve 164 is controlled to the target opening degree θ* (step S240), and this process ends. As a result, exhaust gas recirculation is immediately performed, and the EGR valve 164 is opened to the target opening degree θ* without undergoing slow-change processing, even though the upper limit is guarded by the upper limit guard value θmax.

Figure 4 is an explanatory diagram explaining EGR stop processing using the time change in the required power change amount dPe* for each cycle. In the figure, white circles indicate a state in which exhaust gas recirculation is permitted and performed, and black circles indicate a state in which exhaust gas recirculation is prohibited and not performed. In cycles C1 and C2, the required power change amount dPe* is greater than or equal to the threshold value dPeref, so exhaust gas recirculation is permitted and performed. In cycle C3, the required power change amount dPe* is less than the threshold value dPeref, so exhaust gas recirculation is prohibited and not performed. From cycle C3 to the black circle of cycle C4 with a solid arrow, and further from the black circle of cyclo C5 with a solid arrow, the required power change amount dPe* is less than the threshold value dPeref for three consecutive cycles (C3 to C5). Therefore, exhaust gas recirculation is permitted to resume after waiting for the EGR gas to be completely removed. When the EGR valve 164 is set to the target opening amount θ* upon resumption of exhaust gas recirculation, a slow-change process is executed. On the other hand, when the transition is made from cycle C3 to the white circle of cycle C4 with a dashed arrow, or from the black circle of cycle C4 to the white circle of cycle C5 with a dashed-dotted arrow, the required power change amount dPe* is equal to or greater than the threshold value dPeref in one of the two consecutive cycles (two periods) immediately following the black circle of cycle C3. Therefore, execution of exhaust gas recirculation is permitted, and the target opening amount θ* is upper-limit-guarded using the upper limit guard value θmax, and the opening amount of the EGR valve 164 is controlled to the target opening amount θ*. As a result, exhaust gas recirculation is immediately performed, and although the upper limit is guarded by the upper limit guard value θmax, the EGR valve 164 is opened to the target opening θ* without undergoing slow-change processing.

In the hybrid vehicle 20 of the embodiment described above, even if the required power change dPe* is determined to be less than the threshold value dPeref and exhaust gas recirculation is prohibited and the EGR valve 164 is closed, if the required power change dPe* is determined to be greater than or equal to the threshold value dPeref in one of the two consecutive cycles immediately following that, exhaust gas recirculation is permitted and restart control is executed to change the opening of the EGR valve 164 to the target opening θ*. This allows exhaust gas recirculation to be quickly restarted when the required power change dPe* immediately increases after a temporary decrease in the opening of the EGR valve 164. Moreover, the restart control does not perform a gradual change process when setting the opening of the EGR valve 164 to the target opening θ*, so exhaust gas recirculation can be quickly performed by setting the opening of the EGR valve 164 to the target opening θ*. Furthermore, in the restart control, the target opening θ* immediately before exhaust gas recirculation is prohibited is stored as an upper limit guard value θmax, and when the opening of the EGR valve 164 is set to the target opening θ*, the target opening θ* is upper-limit guarded by the upper limit guard value θmax, thereby preventing the opening of the EGR valve 164 from becoming excessive. As a result, more appropriate exhaust gas recirculation can be achieved.

In the hybrid vehicle of this embodiment, even if the required power change amount dPe* is determined to be less than the threshold value dPeref and exhaust gas recirculation is prohibited and the EGR valve 164 is closed, exhaust gas recirculation is resumed if the required power change amount dPe* is determined to be equal to or greater than the threshold value dPeref in any of the two consecutive cycles (two periods) immediately thereafter. However, after exhaust gas recirculation is prohibited and the EGR valve 164 is closed, exhaust gas recirculation may be resumed only if the required power change amount dPe* is determined to be equal to or greater than the threshold value dPeref in the immediately following cycle, or if the required power change amount dPe* is determined to be equal to or greater than the threshold value dPeref in any of three or four consecutive cycles (three periods).

In the hybrid vehicle of this embodiment, after exhaust gas recirculation is prohibited and the EGR valve 164 is closed, if it is determined that the required power change amount dPe* is equal to or greater than the threshold value dPeref in either of the immediately following two consecutive cycles (two periods), exhaust gas recirculation is resumed. However, the threshold value used to compare the required power change amount dPe* in the immediately following two consecutive cycles (two periods) may be a value different from the threshold value dPeref for prohibiting exhaust gas recirculation (for example, a value with an absolute value smaller than dPeref).

In this embodiment, the engine device is mounted on a hybrid vehicle in which the engine 22 and motor MG1 are connected to the drive shaft 36 via the planetary gear 30, the motor MG2 is connected to the drive shaft 36, and the battery 50 is connected to the motors MG1 and MG2 via power lines. However, the engine device may also be mounted on a so-called one-motor hybrid vehicle, a so-called series hybrid vehicle, or a so-called gasoline vehicle in which the engine 22 is connected to the drive shaft 36 via a transmission.

The following explains the correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section. In the embodiment, the EGR valve 164 corresponds to the "EGR valve," the exhaust gas recirculation device 160 corresponds to the "exhaust gas recirculation device," the engine 22 corresponds to the "engine," and the engine ECU 24 corresponds to the "control device."

The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, as the embodiments are examples used to specifically explain the form for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

The present disclosure has been described above using embodiments, but it goes without saying that the present disclosure is in no way limited to these embodiments and can be embodied in various forms without departing from the spirit of the present disclosure.

This disclosure can be used in the engine equipment manufacturing industry, etc.

20 Hybrid vehicle, 22 Engine, 24 Engine ECU, 26 Crankshaft, 28 Damper, 30 Planetary gear, 36 Drive shaft, 38 Differential gear, 39a, 39b Drive wheels, 40 Motor ECU, 41, 42 Inverter, 43, 50 Battery, 52 Battery ECU, 54 Power line, 57 Capacitor, 70 HV ECU, 80 Ignition switch, 81 Shift lever, 83 Accelerator pedal, 85 Brake pedal, 122 Air cleaner, 124 Throttle valve, 123 Intake pipe, 126 Fuel injection valve, 128 Intake valve, 129 Combustion chamber, 130 Spark plug, 131 Exhaust valve, 132 Piston, 133 Exhaust pipe, 134 Purification device, 134a Purification catalyst, 136 PM filter, 150 Variable valve timing mechanism, 160 EGR system, 162 EGR pipe, 163 stepping motor, 164 EGR valve, MG1, MG2 motors.

Claims (3)

an engine equipped with an exhaust gas recirculation device having an EGR valve that adjusts the amount of exhaust gas recirculated to an intake;
a control device that controls the opening and closing of the EGR valve based on a target opening, and when a required power change amount calculated at a predetermined cycle as a change amount of required power required of the engine becomes less than a threshold value, prohibits exhaust gas recirculation in the exhaust gas recirculation device and controls the EGR valve with the target opening amount set to 0, and when exhaust gas recirculation is started thereafter, controls the EGR valve using a gradual change process so that the opening amount of the EGR valve changes gradually with respect to the target opening amount;
An engine device comprising:
When a predetermined condition is met in which one of a predetermined number of consecutive times of changes in the required power after the required power change amount has become less than the threshold value has become equal to or greater than the threshold value, the control device immediately permits exhaust gas circulation in the exhaust gas recirculation device and resumes opening/closing control of the EGR valve based on the target opening degree.
An engine device characterized by: 2. The engine device according to claim 1,
When the control device resumes the opening/closing control of the EGR valve based on the target opening degree when the predetermined condition is satisfied, the control device controls the EGR valve without using the slow-change processing.
Engine equipment. 2. The engine device according to claim 1,
When the control device prohibits the recirculation of exhaust gas in the exhaust gas recirculation device, the control device stores the immediately preceding target opening degree as an upper limit guard value, and when the control device resumes the opening/closing control of the EGR valve based on the target opening degree, the control device controls the EGR valve by upper limit guarding the target opening degree with the upper limit guard value.
Engine equipment.