Engine device

Abstract

To quickly resume EGR when a change amount of required power increases immediately after the change amount of the required power temporarily decreases.SOLUTION: The control device prohibits circulation of exhaust gas in the exhaust gas circulation device and sets the target opening degree of the EGR valve to a value of 0 when a change amount of required power required for the engine calculated at a predetermined cycle becomes less than a threshold value. When a predetermined condition that one of the required power change amounts of a predetermined number of times continuing immediately thereafter reaches a threshold value or more is satisfied, the circulation of the exhaust gas in the exhaust circulation device is immediately permitted, and the opening / closing control of the EGR valve based on the target opening is restarted.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present 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 that is recirculated back into the intake air. [Background technology]

[0002] Conventionally, engine systems of this type have been proposed that perform misfire prevention control when residual EGR gas flows into a cylinder during deceleration (see, for example, Patent Document 1). The misfire prevention control involves a first misfire prevention control that suppresses misfires by increasing the fuel injection amount or retarding the ignition timing without changing the intake valve characteristics when the engine load is greater than a load determination value, and a second misfire prevention control that suppresses misfires by changing the intake valve characteristics when the engine load is less than the load determination value. This allows appropriate misfire prevention measures to be implemented in stages depending on the deceleration state when deceleration occurs during EGR, efficiently suppressing misfires. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-014354 Summary of the Invention [Problem to be solved by the invention]

[0004] As a control during deceleration, when the power demanded by the engine decreases and the change amount falls below a threshold, the EGR valve is closed to completely remove the EGR gas, and then the EGR valve is opened slowly when the EGR is restarted. In this case, even if the change amount of the power demand temporarily decreases, the execution of the EGR is delayed until the EGR stop / restart control is completed, which may result in a deterioration of fuel economy.

[0005] The engine device of the present disclosure has a main object to quickly restart EGR when the amount of change in the required power increases immediately after the amount of change in the required power temporarily decreases. [Means for solving the problem]

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

[0007] 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 the intake; a control device that controls the opening and closing of the EGR valve based on a target opening, and that prohibits exhaust gas recirculation in the exhaust gas recirculation device and controls the EGR valve with the target opening set to 0 when a required power change amount, which is a change amount of required power required of the engine calculated at a predetermined cycle, becomes less than a threshold value, and that subsequently controls the EGR valve using a gradual change process so that the opening of the EGR valve changes gradually with respect to the target opening amount when exhaust gas recirculation is started; 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 the exhaust gas to be circulated in the exhaust gas recirculation device and resumes the opening and closing control of the EGR valve based on the target opening degree. It is characterized by:

[0008] In the engine system disclosed herein, when the change in the required power (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 zero. 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, namely, when the required power change amount falls below the threshold and one of a predetermined number of consecutive required power changes reaches or exceeds 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. That is, 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 quickly resumed 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.

[0009] In the engine system of the present disclosure, when the control device resumes the opening / closing control of the EGR valve based on the target opening when the predetermined condition is satisfied, the control device may control the EGR valve without using the slow-change processing, thereby enabling the EGR valve opening to quickly reach the target opening.

[0010] In the engine system of the present disclosure, the control device may store the immediately preceding target opening as an upper limit guard value when prohibiting the recirculation of exhaust gas in the exhaust gas recirculation device, and when resuming control of the EGR valve opening based on the target opening, control the EGR valve by guarding the target opening with the upper limit guard value. In this way, it is possible to prevent the EGR valve from opening too quickly. [Brief explanation of the drawings]

[0011] [Figure 1] 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. [Figure 2] FIG. 2 is a diagram showing the outline of the configuration of an engine 22. [Figure 3] 4 is a flowchart showing an example of an EGR stop process executed by an engine ECU 24. [Figure 4] FIG. 4 is an explanatory diagram illustrating an example of EGR stop processing. 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 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 as an electricity storage device, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0013] 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, and is connected to a carrier of a planetary gear 30 via a damper 28. FIG. 2 is a schematic diagram illustrating the configuration 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 the air through a throttle valve 124, and injects fuel from fuel injection valves 126 provided for each cylinder to mix the air and fuel. The 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 a spark plug 130 attached to each cylinder, and the resulting energy pushes down a piston 132, causing reciprocating motion of the piston 132, which 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 cut can be performed for each cylinder. Exhaust gas discharged from combustion chamber 129 into exhaust pipe 133 via exhaust valve 131 is discharged into the outside air via catalytic converter 134 and PM filter 136, and is also supplied to the intake side via exhaust gas recirculation device (hereinafter referred to as "EGR (Exhaust Gas Recirculation) system") 160, which recirculates the exhaust gas into the intake air. 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). PM filter 136 is formed as a porous filter using ceramics, stainless steel, or the like, and captures particulate matter (PM) such as soot in the exhaust gas. EGR system 160 includes an EGR pipe 162 connected downstream of catalytic converter 134 to supply exhaust gas to a surge tank on the intake side, and an EGR valve 164 disposed in 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.

[0014] The engine ECU 24 is configured as a microprocessor centered around a CPU 24a, and in addition to the CPU 24a, includes a ROM 24b that stores processing programs, a RAM 24c that temporarily stores data, and input / output ports and communication ports (not shown).

[0015] Signals from various sensors that detect the state of the engine 22 are input to the engine ECU 24 via an input port. Examples of signals input to the engine ECU 24 include a crank position signal from a crank position sensor 140 that detects the rotational position of the crankshaft 26 and an engine water temperature signal Thw from a water temperature sensor 142 that detects the temperature of the engine 22's coolant. Other signals include an engine oil temperature signal Thoi from an oil temperature sensor 143 that detects the temperature of the engine oil, and a cam position signal from a cam position sensor 144 that detects the rotational position of a camshaft that opens and closes the intake valve 128 and exhaust valves that intake and exhaust air to and from the combustion chamber. Further signals include a throttle opening signal TH from a throttle valve position sensor 146 that detects the position of the throttle valve 124, an intake air amount Qa from an air flow meter 148 attached to the intake pipe, an intake air temperature Ta from a temperature sensor 149 also attached to the intake pipe, and an intake pressure signal Pin from an intake pressure sensor 158 that detects the pressure in the intake pipe. Other examples include a catalyst temperature Tc from a temperature sensor 134a attached to the catalytic device 134, an air-fuel ratio AF from an air-fuel ratio sensor 135a, an oxygen signal O2 from an oxygen sensor 135b, and a differential pressure ΔP from a differential pressure sensor 136a that detects a differential pressure (a differential pressure between the upstream side and the downstream side) across the PM filter 136. Another example includes an EGR valve opening EV from an EGR valve opening sensor 165 that detects the opening of the EGR valve 164.

[0016] The engine ECU 24 outputs various control signals via an output port for driving the engine 22. Examples of signals output from the engine ECU 24 include a drive signal to a fuel injection valve 126, a drive signal to a throttle motor 136 that adjusts the position of the throttle valve 124, and a control signal to an ignition coil 138 integrated with an igniter. Other examples of signals output from the engine ECU 24 include a control signal to a variable valve timing mechanism 150 that can change the opening and closing timing of the intake valve 128, and a drive signal to a stepping motor 163 that adjusts the opening of an EGR valve 164.

[0017] 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 relating to the operating state of the engine 22 as needed. The engine ECU 24 calculates the rotation speed Ne of the engine 22 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 during one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter 148 and the rotation speed Ne of the engine 22.

[0018] 1, the planetary gear 30 is configured as a single-pinion planetary gear mechanism and includes a sun gear 31, a ring gear 32, a plurality of pinion gears 33 meshing with the sun gear 31 and the ring gear 32, and a carrier 34 supporting the plurality of pinion gears 33 so that they can rotate and revolve. A rotor of a motor MG1 is connected to the sun gear 31 of the planetary gear 30. A drive shaft 36 is connected to the ring gear 32 of the planetary gear 30, and the drive shaft 36 is connected to drive wheels 39a, 39b via a differential gear 38. As described above, the crankshaft 26 of the engine 22 is connected to the carrier 34 of the planetary gear 30 via the damper 28.

[0019] The 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. The motor MG2 is configured, for example, as a synchronous generator motor, and its rotor is connected to the drive shaft 36. The inverters 41 and 42 are used to drive the motors MG1 and MG2, and are connected to a battery 50 via a power line 54. A smoothing capacitor 57 is attached to the power line 54. The motors MG1 and MG2 are rotationally driven 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 and 42.

[0020] Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU. In addition to the CPU, the motor ECU 40 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 an input port. For example, rotational positions θm1 and θm2 are detected by 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 detected by current sensors 45u, 45v, 46u, and 46v, which detect the currents flowing through the phases 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 an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the electrical angles θe1, θe2, angular velocities ωm1, ωm2, and rotational 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, .

[0021] 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.

[0022] Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU. In addition to the CPU, the battery ECU 52 includes a ROM for storing processing programs, a RAM for temporarily storing data, an input / output port, and a communication port. Signals from various sensors required for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include the voltage Vb of the battery 50 from a voltage sensor 51a attached between the terminals of the battery 50, the current Ib of the battery 50 from a current sensor 51b attached to the output terminal of the battery 50, and the temperature Tb of the battery 50 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 a power storage percentage SOC based on an integrated value of the current Ib of the battery 50 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.

[0023] Although not shown, the HVECU 70 is configured as a microprocessor centered around a CPU. In addition to the CPU, the HVECU 70 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 depression amount of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the depression amount of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 88. Another example of a signal input to the HVECU 70 is atmospheric pressure Pout from an atmospheric pressure sensor 89. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication ports.

[0024] 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.

[0025] In the HV driving mode, the HVECU 70 basically sets the driving torque Td* required for driving (required of the drive shaft 36) based on the accelerator opening Acc and the vehicle speed V, and calculates 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 HVECU 70 calculates the required power Pe* required of 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* of the engine 22 and the torque commands Tm1* and Tm2* of 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 to control the opening of the throttle valve 124, fuel injection control to control the amount of fuel injected from the fuel injection valve 126, and ignition control to control 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 based on the rotation speed and intake pipe pressure of the engine 22 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*, Tm2* for the motors MG1, MG2, it controls the switching of multiple switching elements of the inverters 41, 42 so that the motors MG1, MG2 are driven by the torque commands Tm1*, Tm2*.

[0026] In the EV driving mode, the HVECU 70 sets the driving torque Td* based on the accelerator opening Acc and the vehicle speed V, sets the torque command Tm1* of the motor MG1 to a value of 0, and sets the torque command Tm2* of the motor MG2 so that the driving torque Td* is output to the drive shaft 36. The HVECU 70 then transmits the torque commands Tm1* and Tm2* of the motors MG1 and MG2 to the motor ECU 40. The control of the inverters 41 and 42 by the motor ECU 40 has been described above.

[0027] Next, the operation of the hybrid vehicle 20 configured as described above will be described, 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 repeatedly executed while the engine 22 is operating.

[0028] 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*). Then, it is determined whether the calculated required power change amount dPe* is less than a threshold value dPeref (step S110). The threshold value dPeref is a threshold value used to determine whether to stop EGR to prevent problems such as misfires due to a large decrease in the required power Pe*, and can be determined through experiments, etc. If it is determined that the required power change amount dPe* is equal to or greater than the threshold value dPeref, it is determined to continue exhaust gas recirculation, and this process ends without stopping exhaust gas recirculation.

[0029] When 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).

[0030] Next, the process 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 process 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).

[0031] 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 continuously for three cycles (three periods) including the processing of step S110, the upper limit guard value θmax stored in step S130 is cleared (step S200), the EGR gas is completely removed and then restart of exhaust gas recirculation is permitted (step S210), and when the EGR valve 164 is restarted, the execution of a slow-change processing is set to open the EGR valve 164 by a slow change when the opening of the EGR valve 164 is to be set to the target opening amount θ* (step S220), and this processing ends. As a result, after waiting for the EGR gas to be completely removed, the opening of the EGR valve 164 is controlled to the target opening amount θ* by the slow-change processing.

[0032] On the other hand, when 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., when it is determined in step S110 that the required power change amount dPe* is less than the threshold value dPeref but the required power change amount dPe* is equal to or greater than the threshold value dPeref in either of the two consecutive cycles (two periods) immediately following that, execution of exhaust gas recirculation is permitted (step S230), and execution of resume control is set to control the opening of EGR valve 164 to target opening θ* by using upper limit guard value θmax to upper limit guard the target opening θ* (step S240), and this process ends. As a result, exhaust gas recirculation is immediately executed, and EGR valve 164 is opened to the target opening θ* while being upper-bound guarded by upper limit guard value θmax, without undergoing slow-change processing.

[0033] FIG. 4 is an explanatory diagram illustrating EGR stop processing using the time variation of the required power change amount dPe* per cycle. In the figure, open 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 equal to or greater than 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 cycle C4 (black circle with solid arrow), and further, from cycle C5 (black circle with 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 EGR gas to be completely removed, and a gradual change processing is performed when the opening of EGR valve 164 is set to the target opening amount θ* upon resumption of exhaust gas recirculation. On the other hand, When the cycle C3 transitions to the open circle of cycle C4 indicated by the dashed arrow or when the cycle C4 black circle transitions to the open circle of cycle C5 indicated by the dashed 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, so execution of exhaust gas recirculation is permitted, and the target opening degree θ* is upper-limit guarded using the upper limit guard value θmax, and the opening degree of EGR valve 164 is controlled to become the target opening degree θ*. As a result, exhaust gas recirculation is immediately executed, and although the upper limit is guarded by the upper limit guard value θmax, the EGR valve 164 is opened to the target opening degree θ* without being subjected to a slow-change process.

[0034] 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 equal to or greater than the threshold value dPeref in one of the two consecutive cycles (two periods) immediately thereafter, the execution of exhaust gas recirculation is permitted and restart control is executed so that the opening of the EGR valve 164 becomes 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 required power change dPe*. Moreover, in the restart control, the gradual change process is not performed when the opening of the EGR valve 164 is set to the target opening θ*, so that the opening of the EGR valve 164 can be quickly set to the target opening θ* and exhaust gas recirculation can be performed. Furthermore, in the restart control, the target opening θ* immediately before prohibiting exhaust gas recirculation is stored as an upper limit guard value θmax, and when the opening of 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 EGR valve 164 from becoming excessive. As a result, more appropriate exhaust gas recirculation can be performed.

[0035] In the hybrid vehicle of the embodiment, even if it is determined that the required power change amount dPe* is less than the threshold value dPeref and exhaust gas recirculation is prohibited and EGR valve 164 is closed, exhaust gas recirculation is resumed if it is determined that the required power change amount dPe* is equal to or greater than the threshold value dPeref in one of the immediately following two cycles (two periods). However, it is also possible to resume exhaust gas recirculation only if it is determined that the required power change amount dPe* is equal to or greater than the threshold value dPeref in the immediately following cycle after exhaust gas recirculation is prohibited and EGR valve 164 is closed, or to resume exhaust gas recirculation if it is determined that the required power change amount dPe* is equal to or greater than the threshold value dPeref in one of three or four consecutive cycles (three periods).

[0036] In the hybrid vehicle of the embodiment, after exhaust gas recirculation is prohibited and EGR valve 164 is closed, exhaust gas recirculation is resumed when it is determined that the required power change amount dPe* is equal to or greater than threshold value dPeref in either of the immediately following two consecutive cycles (two periods). However, the threshold value to be compared with the required power change amount dPe* in the immediately following two consecutive cycles (two periods) may be a value different from threshold value dPeref for prohibiting exhaust gas recirculation (for example, a value having an absolute value smaller than dPeref).

[0037] In the 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 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.

[0038] The correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problems" section will be described below. 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 "controller."

[0039] 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, since the embodiments are examples for specifically explaining the mode 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.

[0040] The present disclosure has been described above using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be embodied in various forms within the scope that does not deviate from the gist of the present disclosure. [Industrial Applicability]

[0041] The present disclosure is applicable to the engine device manufacturing industry and the like. [Explanation of symbols]

[0042] 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 HVECU, 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

1. 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. 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.

3. 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.

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