JP7768158B2 - Engine control device - Google Patents

Description

The present invention relates to an engine control device.

Conventionally, a control system for this type of engine has been proposed that controls a multi-cylinder engine that has a filter in the exhaust system that removes particulate matter (see, for example, Patent Document 1). This control system performs a partial cylinder fuel cut, which stops fuel supply to some of the multiple cylinders, thereby raising the temperature of the filter and regenerating the filter.

Japanese Patent Application Laid-Open No. 2022-90735

When the engine control device described above performs partial cylinder fuel cut, the torque output from the engine decreases compared to when fuel is supplied to all cylinders. One method of suppressing this decrease in engine torque is to increase the amount of fuel supplied to the remaining cylinders. However, because the amount of fuel cannot be increased indefinitely, if the engine requires greater power or torque, this demand cannot be met, resulting in shocks and other discomfort to the user.

The primary purpose of the engine control device of the present invention is to reduce the sense of discomfort felt by the user.

The engine control device of the present invention employs the following means to achieve the above-mentioned main object.
The first engine control device of the present invention is used in a multiple-cylinder engine having an exhaust system with a filter that removes particulate matter and a variable valve timing mechanism that can change the opening and closing timing of the intake valve, and when a request for filter regeneration is made, the engine control device performs a partial-cylinder fuel cut that stops fuel supply to some of the multiple cylinders.When the partial-cylinder fuel cut is performed, power increase is performed to control the engine so that a provisional required power that is greater than the required power to be output from the engine is output from the remaining cylinders excluding some of the cylinders.When a request for filter regeneration is made, at least one of a first condition that the opening and closing timing of the intake valve is the earliest possible timing within a range, and a second condition that the provisional required power exceeds a predetermined power when the partial-cylinder fuel cut is performed, the partial-cylinder fuel cut and the power increase are prohibited.

In the first engine control device of the present invention, the engine is mounted on a hybrid vehicle together with a first motor connected to the engine output shaft, a second motor capable of inputting and outputting power for driving, and an electric storage device capable of exchanging electric power with the first and second motors. When at least one of the first condition, the second condition, and a third condition is met, where the discharge power of the electric storage device required to increase the engine power that is transiently reduced due to the partial-cylinder fuel cut is greater than the output limit of the electric storage device, execution of the partial-cylinder fuel cut and the power increase may be prohibited. In this case, when at least one of the first condition, the second condition, the third condition, and a fourth condition is met, where the engine speed exceeds a predetermined speed when the partial-cylinder fuel cut and the power increase are executed, execution of the partial-cylinder fuel cut and the power increase may be prohibited.

The second engine control device of the present invention is used in a multiple-cylinder engine having a filter in the exhaust system that removes particulate matter, and when a request for filter regeneration is made, the engine control device performs partial cylinder fuel cut, which stops fuel supply to some of the multiple cylinders. When performing the partial cylinder fuel cut, the engine performs power increase, which controls the engine so that a provisional requested power greater than the requested power to be output from the engine is output from the remaining cylinders excluding some of the cylinders. When a request for filter regeneration is made, if performing the partial cylinder fuel cut and power increase would cause the provisional requested power to exceed a predetermined power, the execution of the partial cylinder fuel cut and power increase is prohibited.

FIG. 2 is a diagram showing the outline of the configuration of a hybrid vehicle 20. FIG. 2 is a diagram showing the outline of the configuration of an engine 22; 10 shows an example of an operating point of the engine 22 when power raising is performed. 10 is a flowchart showing an example of a first determination routine. 10 is a flowchart showing an example of a second determination routine.

Next, we will explain how to implement the present invention using examples.

Figure 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with an engine control device according to one embodiment of the present invention. Figure 2 is a schematic diagram showing the configuration of an engine 22. As shown, the hybrid vehicle 20 of the embodiment includes the engine 22, a planetary gear 30, motors MG1 and MG2 (first and second motors), inverters 41 and 42, a battery (electrical storage device) 50, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

The engine 22 is configured as a multi-cylinder internal combustion engine. The engine 22 draws air purified by an air cleaner 122 into an intake pipe 125 via a throttle valve 124, and injects fuel from a fuel injection valve 126 to mix the air and fuel. This mixture is then drawn into a combustion chamber 129 via an intake valve 128a, where it is explosively combusted by an electric spark from an ignition plug 130. The resulting energy pushes down a piston 132, whose reciprocating motion is converted into rotational motion of a crankshaft 26. Exhaust gas discharged from the combustion chamber 129 through an exhaust valve 128b into an exhaust pipe 133 is purified by an exhaust purification device 134 equipped with a purification catalyst (three-way catalyst) 134a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx), and a gasoline particulate filter (GPF) 25. The GPF 25 is formed as a porous filter using ceramics, stainless steel, or the like, and captures particulate matter (PM) such as soot. The engine 22 is equipped with a variable valve timing mechanism 150. The variable valve timing mechanism 150 advances or retards the rotational position of an intake camshaft, which opens and closes the intake valve 128a relative to the crankshaft 26, within a predetermined range including a reference position (reference angle), thereby changing the opening and closing timing VTin of the intake valve 128a within a predetermined timing range. In this embodiment, by advancing the rotational position of the intake camshaft from the reference position (advancing the opening and closing timing VTin of the intake valve 128a), the engine 22 can be placed in an operating state capable of outputting high torque.

Although not shown, the engine ECU 24 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 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 a crank position sensor 140 that detects the rotational position of the crankshaft 26, and the coolant temperature Tw from a water temperature sensor 142 that detects the temperature of the engine 22's coolant. Other examples include cam angles θca and θcb from cam position sensors 144a and 144b that detect the rotational position of the intake camshaft that opens and closes the intake valve 128a and the exhaust camshaft that opens and closes the exhaust valve 128b. Other examples include a throttle opening 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 125, and an intake air temperature Ta from a temperature sensor 149 attached to the intake pipe 125. Other examples include an air-fuel ratio AF from an air-fuel ratio sensor 135a attached upstream of the exhaust purification device 134 in the exhaust pipe 133, an oxygen signal O2 from an oxygen sensor 135b attached downstream of the exhaust purification device 134 in the exhaust pipe 133, and a catalyst temperature Tsc from a temperature sensor 135c that detects the temperature of the three-way catalyst 134a. Other examples include a GPF temperature Tgpf from a temperature sensor 25c that detects the temperature of the GPF 25. The engine ECU 24 outputs various control signals for controlling the operation of the engine 22 via its output ports. Examples of signals output from the engine ECU 24 include a drive control signal to the throttle motor 136 that adjusts the position of the throttle valve 124, a drive control signal to the fuel injection valve 126, a drive control signal to the ignition coil 138 integrated with the igniter, and a control signal to the variable valve timing mechanism 150 that can change the opening and closing timing of the intake valve 128a. The engine ECU 24 calculates the rotation speed of the crankshaft 26, i.e., the rotation speed Ne of the engine 22, based on the crank angle θcr.

The planetary gear 30 is configured as a single-pinion planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is linked to the drive wheels (front wheels) 39a, 39b via a differential gear 38. As mentioned above, the crankshaft 23 of the engine 22 is connected to the carrier of the planetary gear 30.

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

The motor ECU 40 includes a microcomputer (not shown) with a CPU, ROM, RAM, flash memory, 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 ports. Examples of signals input to the motor ECU 40 include rotational positions θm1 and θm2 from rotational position sensors (not shown) that detect the rotational positions of the rotors of the motors MG1 and MG2, and phase currents Iu1, Iv1, Iu2, and Iv2 from current sensors (not shown) that detect the phase currents flowing through each phase of the motors MG1 and MG2. The motor ECU 40 outputs switching control signals and other signals to multiple switching elements (not shown) of the inverters 41 and 42 via the output ports. The motor ECU 40 is connected to the HVECU 70 via the communication ports. The motor ECU 40 calculates the electrical angles θe1, θe2 and rotation speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position sensors.

The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery, and as described above, is connected to the inverters 41, 42 via 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 equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. 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 from a voltage sensor 50a attached between the terminals of the battery 50 and the current Ib from a current sensor 50b attached to the output terminal of 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 50b. 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 includes a microcomputer with a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. Signals from various sensors are input to the HVECU 70 via 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, a vehicle speed V from a vehicle speed sensor 87, and a regeneration request signal from a regeneration request switch 88 that requests GPF regeneration. As described above, the HVECU 70 is connected to the engine ECU 24, motor ECU 40, and battery ECU 52 via communication ports.

In the hybrid vehicle 20 of this embodiment configured as described above, the HV ECU 70, engine ECU 24, and motor ECU 40 basically coordinate control to control the engine 22 and motors MG1 and MG2 (inverters 41 and 42) so that the vehicle travels at a required torque Td* based on the accelerator pedal position Acc and vehicle speed V in a hybrid driving (HV driving) mode in which the vehicle travels with the engine 22 operating, or in an electric driving (EV driving) mode in which the vehicle travels with the engine 22 stopped. Note that the EV driving mode is not central to the present invention, so a detailed description thereof will be omitted.

In HV driving mode, the HV ECU 70 sets the required torque Td* (required from the drive shaft 36) required for driving based on the accelerator pedal position Acc and the vehicle speed V, and then multiplies the set required torque Td* by the rotation speed Nd of the drive shaft 36 (rotation speed Nm2 of the motor MG2) to calculate the required driving power Pd* (required from the drive shaft 36). Next, the required driving power Pe* is set by subtracting the required charging/discharging power Pb* (a positive value when discharging from the battery 50) based on the battery 50's charge storage percentage SOC) from the required driving power Pd*. Next, the target rotation speed Ne* and target torque Te* of the engine 22 are set so that the required power Pe* is output from the engine 22. The target rotation speed Ne* and target torque Te* are set as operating points (rotation speed, torque) on the optimal operating line corresponding to the required power Pe*. The optimal operation line is set based on the vehicle speed V from among a plurality of operation lines determined for each vehicle speed V as an operation line that optimizes fuel economy while taking into account noise, vibration, and the like among the operating points of the engine 22. Then, a torque command Tm1* for the motor MG1 and a torque command Tm2* for the motor MG2 are set so that the engine 22 rotates at the target rotation speed Ne* and a required torque Td* is output to the drive shaft 36 within the range of the input/output limits Win, Wout of the battery 50 (maximum values of power that are allowed to be charged to and discharged from the battery 50). Then, the target rotation speed Ne* and target torque Te* for the engine 22 are sent to the engine ECU 24, and the torque commands Tm1*, Tm2* for the motors MG1, MG2 are sent to the motor ECU 40. The engine ECU 24 controls the intake air volume, fuel injection, ignition, and other aspects of the engine 22 based on the target rotation speed Ne* and target torque Te*, so that the engine 22 operates by supplying fuel to all cylinders. The motor ECU 40 controls the switching of the transistors in the inverters 41 and 42 so that the motors MG1 and MG2 are driven by torque commands Tm1* and Tm2*.

When the user turns on the regeneration request switch 88 to input a regeneration request signal and the execution of partial cylinder fuel cut (partial cylinder FC) is permitted in the determination routine described below, the HVECU 70 executes partial cylinder FC. In partial cylinder FC, fuel supply to some of the multiple cylinders (one cylinder in this embodiment) is stopped, and fuel is supplied to the remaining cylinders to operate the engine 22. Partial cylinder FC introduces more oxygen into the GPF 25 from the cylinders to which fuel supply is stopped, effectively combusting particulate matter accumulated in the GPF 25 and regenerating the GPF 25.

When partial cylinder FC is performed, power increase is performed. Figure 3 is an explanatory diagram illustrating an example of the operating point of the engine 22 when power increase is performed. In power increase, the required driving power Pd* is set using the same process as in the HV driving mode described above. The required driving power Pd* is then set by subtracting the required charging/discharging power Pb* from the set required driving power Pd* to set the required power Pe*. The required power Pe* is multiplied by an FF coefficient Cff greater than 1 (= Pe* · Cff), and the resulting value is subtracted by the required charging/discharging FB power Pbf*. The minimum power Pemin, which is the minimum value of power that can be output from the engine 22 when operating under load, is set as the provisional required power Petmp. Then, the intake air volume, fuel injection, ignition, and other controls of the engine 22 are performed so that the engine 22 operates at a target rotation speed Netag and a target torque Tetag on the optimal operating line corresponding to the provisional required power Petmp. If the engine 22 is operated at an operating point (point A in the figure) on the optimal operating line corresponding to the required power Pe* during partial cylinder FC, torque is not output from some cylinders during partial cylinder FC. Therefore, the torque actually output from the engine 22 is smaller than the torque at point A (point B in the figure), resulting in a decrease in power output from the engine 22. In power boosting, this decrease in power is taken into account and the provisional required power Petmp is set to a value greater than the required power Pe* without falling below the minimum power Pemin. Then, when the intake air amount, fuel injection, and ignition controls of the engine 22 are performed so that the engine 22 is operated at the target rotation speed Netag and target torque Tetag (point E in the figure) on the optimal operating line corresponding to the provisional required power Petmp, the torque actually output from the engine 22 is smaller than the target torque Tetag, and the actual operating point of the engine 22 becomes a point on the line where the required power Pe* is constant. This control prevents a decrease in power output from the engine 22 when partial cylinder FC is performed. Here, the FF coefficient Cff is the product of coefficient C1 and environmental correction coefficient Cc. Coefficient C1 is a coefficient for adjusting the power actually output from the engine 22 to the required power Pe* when partial cylinder FC is performed in an environment of 1013 hPa, and is determined through experiments, analysis, machine learning, etc. Environmental correction coefficient Cc is a coefficient for suppressing a decrease in power output from the engine 22 in places where the air pressure is low and the air is thin, and is set based on the air pressure detected by a barometric pressure sensor (not shown).

Next, the process for determining whether partial cylinder FC is permitted will be described. FIG. 4 is a flowchart illustrating an example of a first determination routine executed by the HVECU 70. FIG. 5 is a flowchart illustrating an example of a second determination routine executed by the HVECU 70. The first and second determination routines are executed in parallel at predetermined intervals (e.g., every few milliseconds). Partial cylinder FC is executed when both the first and second determination routines are permitted, and is prohibited when at least one of the first and second determination routines is prohibited. First, the first determination routine will be described, and then the second determination routine will be described. Note that when partial cylinder FC is permitted, partial cylinder FC and power boosting are executed, and when partial cylinder FC is prohibited, partial cylinder FC and power boosting are prohibited and not executed.

When the first determination routine is executed, the CPU of the HVECU 70 determines whether the intake valve 128a opening/closing timing VTin is fully advanced, i.e., whether the opening/closing timing VTin is the earliest timing within a predetermined timing range (step S100). If the opening/closing timing VTin is not the earliest timing, it is determined that the user is not requesting high power or torque, and partial cylinder FC execution is permitted (step S110). If the opening/closing timing VTin is the earliest timing (first condition), it is determined that the user is requesting high power or torque, and partial cylinder FC execution is prohibited (step S120), and the routine ends. Executing partial cylinder FC also increases power, but when the opening/closing timing VTin is the earliest, i.e., when the user is requesting high power or torque, the torque or power requested by the user cannot be output, which may cause a shock or other discomfort to the user. In this embodiment, when the opening/closing timing VTin is the earliest timing within a predetermined timing range, execution of partial cylinder FC is prohibited, which prevents the engine 22 from outputting the torque or power requested by the user, thereby preventing the user from feeling uncomfortable.

Next, the second determination routine will be described. When the second determination routine is executed, the CPU of the HVECU 70 determines whether the prohibition flag F is set to a value of 1 (step S200). The prohibition flag F is set in steps S250 and S270, which will be described later. The prohibition flag F is set to a value of 0 when partial cylinder FC is permitted, and to a value of 1 when partial cylinder FC is prohibited.

When the prohibition flag F is set to 0, i.e., when partial-cylinder FC operation is permitted, the routine then determines whether the prohibition conditions for prohibiting partial-cylinder FC operation are met (step S210). Details of the prohibition conditions will be described later. If the prohibition conditions are not met, partial-cylinder FC operation is permitted (step S240), the prohibition flag F is set to 0 (step S250), and the routine ends. If the prohibition conditions are met in step S210, partial-cylinder FC operation is prohibited (step S260), the prohibition flag F is set to 1 (step S270), and the routine ends.

If the prohibition flag F is set to 1 in step S200, i.e., if partial-cylinder FC execution is prohibited, the routine determines whether a post-prohibition permission condition, which is a condition for permitting partial-cylinder FC execution after prohibition, is satisfied (step S230). The post-prohibition permission condition is a different condition from the prohibition condition and will be described in detail later. If the post-prohibition permission condition is not satisfied, partial-cylinder FC execution is prohibited (prohibition of partial-cylinder FC execution) continues (step S260), and the prohibition flag F is set to 1 (step S270). This routine ends. If the post-prohibition permission condition is satisfied, partial-cylinder FC execution is permitted (step S240), and the prohibition flag F is set to 0 (step S250). This routine ends. Once partial-cylinder FC execution is prohibited through this process, the prohibition of partial-cylinder FC execution continues even if the prohibition condition is no longer satisfied as long as the post-prohibition permission condition is not satisfied. This prevents a short-term change between allowing and prohibiting partial cylinder FC operation, and a change between allowing and stopping partial cylinder FC operation.

At least one of the following conditions may be used as the prohibition condition in step S210, and if at least one of the following conditions is met, it is determined that the prohibition condition is met. The post-prohibition permission condition in step S230 is determined according to the prohibition condition in step S210. The prohibition condition in step S210 and the post-prohibition permission condition in step S230 are explained below.

The prohibition condition for step S210 can be that the execution of partial-cylinder FC causes the required power Pe* to exceed a predetermined upper limit power (predetermined power) Pemax as the upper limit of the power output to the drive shaft 36 (second condition). This prevents a power shortage that occurs when the power output to the drive shaft 36 is insufficient, causing the user to feel uncomfortable. In this case, the post-prohibition permission condition for step S230 can be that the required power Pe* is equal to or less than the upper limit power Pemax, and that the required running power Pd* is equal to or less than a determination power Pdth. The determination power Pdth is a threshold used to determine whether partial-cylinder FC is permitted, and is set based on experiments, analysis, machine learning, etc.

Another prohibition condition for step S210 is that the required torque Td* becomes greater than the upper limit torque Tdmax when partial cylinder FC is executed. The upper limit torque Tdmax is the upper limit of torque that can be output from the engine 22 and motor MG2 to the drive shaft 36 when partial cylinder FC is executed. The upper limit torque Tdmax is calculated as the sum of the upper limit direct torque Temax, which is the upper limit of torque that can be output from the engine 22 and motor MG1 to the drive shaft 36 via the planetary gear 30, and the upper limit motor torque Tm2max, which is the upper limit of torque that can be output from motor MG2 to the drive shaft 36. The upper limit direct torque Temax is the smaller of the torque Te output from the engine 22 when partial cylinder FC is executed and the upper limit motor torque Tm1max, which is the torque that can be output from motor MG1 to the drive shaft 36 via the planetary gear 30. Torque Te is determined by experimentation, analysis, machine learning, etc., using provisional required power Petmp and target rotation speed Netag when partial cylinder FC is executed. Upper limit motor torques Tm1max and Tm2max are the upper limits of torque that can be output from motors MG1 and MG2 based on their specifications. This prevents partial cylinder FC from causing a shortage of torque output from the engine 22 and motors MG1 and MG2 to the drive shaft 36 relative to required torque Td*, which can cause discomfort to the user. In this case, post-prohibition permission conditions in step S230 include required torque Td* being equal to or less than upper limit torque Tdmax and required running power Pd* being equal to or less than determination power Pdth.

Another prohibition condition for step S210 is that the discharge power Wdc of the battery 50 when restoring engine 22 power, which has transiently decreased from required power Pe* due to partial-cylinder FC (moving from point A to point B in Figure 3), to the required power Pe* exceeds the battery 50 output limit Wout (condition 3). The discharge power Wdc can be calculated as the sum of the amount of power reduction ΔPe of the engine 22 and the inertia power Pina when the motor MG1 increases the engine 22 rotation speed Ne to the target rotation speed Netag. The amount of reduction ΔPe is calculated by subtracting the required power Pe* multiplied by the reciprocal of the FF coefficient Cff (= 1/Cff) from the required power Pe*. The inertia power Pina is determined by experiment, analysis, machine learning, etc., using the provisional required power Petmp and the target rotation speed Netag when partial-cylinder FC is executed. In this case, the post-prohibition permission condition in step S230 is that the discharge power Wdc is equal to or less than the determination threshold Wth, which is slightly smaller than the output limit Wout.

Furthermore, a prohibition condition for step S210 may be that the target rotation speed Netag when partial cylinder FC is performed exceeds an upper limit rotation speed (predetermined rotation speed) Nemax that is determined in advance through experiments, analysis, machine learning, etc. as the upper limit value for the rotation speed Ne of the engine 22 during partial cylinder FC. This prevents the rotation speed Ne of the engine 22 from exceeding the upper limit rotation speed Nemax due to the execution of partial cylinder FC. In this case, a post-prohibition permission condition for step S230 may be that the target rotation speed Netag is equal to or less than the upper limit rotation speed Nemax and the required driving power Pd* is equal to or less than the determination power Pdth.

In a hybrid vehicle 20 equipped with the engine control device of the embodiment described above, when a filter regeneration request is made and at least one of the following conditions is met: the intake valve 128a opening/closing timing VTin is the earliest possible timing within the range (first condition); and the execution of partial cylinder FC would cause the provisional required power Petmp to exceed the upper limit power Pemax (second condition), execution of partial cylinder FC is prohibited, thereby preventing the user from feeling uncomfortable.

Furthermore, the engine 22 is mounted on the hybrid vehicle 20 together with the motors MG1 and MG2 and the battery 50, and when at least one of the first condition, the second condition, and the third condition, under which the discharge power Wdc of the battery 50 exceeds the output limit Wout when partial cylinder operation FC is performed, is met, the execution of partial cylinder operation FC is prohibited, thereby preventing the user from feeling uncomfortable.

Furthermore, when at least one of the first, second, third, and fourth conditions is met, whereby execution of partial cylinder FC would cause the engine 22 rotation speed Ne to exceed the upper limit rotation speed Nemax, execution of partial cylinder FC is prohibited, thereby preventing the user from feeling uncomfortable.

The hybrid vehicle 20 equipped with the engine control device of the embodiment is equipped with a variable valve timing mechanism 150, but it may not be equipped with a variable valve timing mechanism 150. In this case, the first determination routine illustrated in FIG. 3 is not executed. The present invention may also be applied to hybrid vehicles that include an engine 22, motors MG1 and MG2, and a motor MG3 attached to wheels (rear wheels) different from the drive wheels (front wheels) 39a and 39b, or to automobiles that run on power from the engine without a motor that outputs power for running. Furthermore, the engine may be installed in trains, airplanes, or stationary equipment.

The above describes the form for carrying out the present invention using examples, but the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention.

This invention can be used in industries such as the engine control device manufacturing industry.

22 engine, 70 hybrid electronic control unit (HVECU).

Claims (4)

1. An engine control device used in a multiple cylinder engine having an exhaust system with a filter that removes particulate matter and a variable valve timing mechanism that can change the opening and closing timing of an intake valve, wherein when a regeneration request for the filter is made, a partial cylinder fuel cut is performed to stop fuel supply to some of the multiple cylinders,
When the partial cylinder fuel cut is performed, a power boost is performed to control the engine so that a provisional required power greater than a required power to be output from the engine is output from the remaining cylinders excluding some of the cylinders,
When a request for regeneration of the filter is made, if at least one of a first condition that the opening/closing timing of the intake valve is the earliest timing within a possible range and a second condition that the temporary requested power exceeds a predetermined power when the partial cylinder fuel cut is executed, the engine control device prohibits the partial cylinder fuel cut and the power increase. 2. The engine control device according to claim 1,
the engine is mounted on a hybrid vehicle together with a first motor connected to an output shaft of the engine, a second motor capable of inputting and outputting power for running, and an electricity storage device capable of exchanging electric power with the first motor and the second motor,
When at least one of the first condition, the second condition, and a third condition that the discharge power of the power storage device required to increase the engine power that is transiently reduced due to the partial cylinder fuel cut is greater than an output limit of the power storage device is satisfied, the engine control device prohibits the partial cylinder fuel cut and the power increase. 3. The engine control device according to claim 2,
When at least one of the first condition, the second condition, the third condition, and a fourth condition that the engine speed exceeds a predetermined speed when the partial cylinder fuel cut and the power increase are performed is satisfied, the engine control device prohibits the partial cylinder fuel cut and the power increase. 1. An engine control device used in a multiple cylinder engine having a filter in an exhaust system that removes particulate matter, the engine control device executing a partial cylinder fuel cut that stops fuel supply to some of the multiple cylinders when a regeneration request for the filter is made,
When the partial cylinder fuel cut is performed, a power boost is performed to control the engine so that a provisional required power greater than a required power to be output from the engine is output from the remaining cylinders excluding some of the cylinders,
When a request for regeneration of the filter is made, if the execution of the partial cylinder fuel cut and the power increase would cause the provisional requested power to exceed a predetermined power, the engine control device prohibits the execution of the partial cylinder fuel cut and the power increase.