Control device for internal combustion engine

Abstract

Control device for an internal combustion engine (22), wherein the internal combustion engine (22) includes a port injection valve (125) which injects fuel into an intake air port and a cylinder injection valve (126) which injects fuel into a cylinder, wherein the control device comprises: an electronic control unit (24) configured to control the port injector (125) and the cylinder injector (126) such that, upon return from a fuel cut-off that stops fuel injection from the port injector (125) and the cylinder injector (126), a value of a port increase quantity correction (Q) kp ), which is a fuel increase quantity correction, in which a fuel quantity is adjusted after a period of time (T). aft ) during port injection is greater than a value of a cylinder increase quantity correction (Q kd), which is a fuel increase quantity correction, in which a fuel quantity is adjusted after a period of time (T). aft ) is reduced during cylinder injection, wherein the fuel is injected by the port injector (125) during port injection and by the cylinder injector (126) during cylinder injection, where the port increase quantity correction (Q kp ) based on a port increase quantity correction initial value (Q kps ) is determined by applying the duration (T cut ) the fuel cut-off on a port characteristic curve and the elapsed time (T aft ) is obtained after returning from fuel cut-off, and the cylinder increase quantity correction (Q kd ) based on an initial cylinder increase quantity correction value (Q kds ) is determined by applying the duration (T cut) the fuel cut-off on a cylinder characteristic curve that differs from the port characteristic curve, and the elapsed time (T aft ) is received after returning from fuel shutdown, and where the difference between the initial port increase quantity correction value (Q kps ) and the initial cylinder increase quantity correction value (Q kd ) with increasing duration (T cut ) the fuel interruption tends to increase.

Description

Background of the invention 1. Field of the invention

[0001] The present invention relates to a control device for an internal combustion engine and in particular to a control device for an in-vehicle internal combustion engine with a port injection valve and a cylinder injection valve. 2. Description of the related prior art

[0002] A control device for this type of internal combustion engine has been proposed which, upon termination of fuel cut-off and execution of fuel injection, sets an increase quantity coefficient relative to a base injection quantity such that the increase quantity coefficient is lower in cases where the fuel cut-off duration is short than in cases where the fuel cut-off duration is long (see, for example, patent application JP 2016-151261A). Since a machine or intake air opening cools down when the fuel cut-off duration is long, it is necessary to increase the fuel quantity for injection after the return from fuel cut-off. Because the machine or intake air opening cools down as the fuel cut-off duration increases, the amount of fuel increase becomes large.From US patent 2018 / 0230928 A1, a control device for an internal combustion engine is known, wherein the internal combustion engine includes a port injector that injects fuel into an intake air port and a cylinder injector that injects fuel into a cylinder. The control device has an electronic control unit configured to control the port injector and the cylinder injector such that, after the internal combustion engine is started, a port increase quantity correction and a different cylinder increase quantity correction are performed. A method for operating an internal combustion engine with port injection and direct injection as injection types is the subject of German patent DE 102015214813 A1.In this process, a fuel correction quantity is determined for at least one of the two injection types, which is intended to correct the amount of fuel to be supplied to the internal combustion engine due to a load requirement, as required by the build-up or breakdown of a fuel film on the engine wall, when the relevant injection type is switched on or off, wherein the amount of fuel to be supplied to the internal combustion engine due to the load requirement is only corrected by the fuel correction quantity for a predetermined period of time when the relevant injection type is switched on or off. Summary of the invention

[0003] In a control unit for an internal combustion engine with a port injector and a cylinder injector, an intake air port becomes cooler than a cylinder as a result of fuel shut-off. For this reason, combustion during port injection, combustion during cylinder injection, or combustion during both injections can become unstable if the fuel injection quantity after the return from fuel shut-off is the same for both port and cylinder injection.

[0004] Starting from the prior art, the object of the invention is to provide a control device for an internal combustion engine that enables more stable combustion after a return from a fuel cut-off. This object is achieved with the control device having the features of claim 1; advantageous embodiments are the subject of the dependent claims.

[0005] The control device of the internal combustion engine according to the present invention uses the following configurations.

[0006] One aspect of the present invention is a control device for an internal combustion engine. The internal combustion engine includes a port injection valve, which injects fuel into an intake air port, and a cylinder injection valve, which injects fuel into a cylinder.The control device includes an electronic control unit designed to control the port injector and the cylinder injector such that, upon returning from a fuel cut-off that stops fuel injection from both the port and cylinder injectors, the value of the port increase quantity correction (a fuel increase quantity correction that reduces the amount of fuel injected over time during port injection) is greater than the value of the cylinder increase quantity correction (a fuel increase quantity correction that reduces the amount of fuel injected over time during cylinder injection). Fuel is injected from the port injector during port injection and from the cylinder injector during cylinder injection.

[0007] When the control device of the internal combustion engine according to the present invention returns from a fuel cut-off, the value of a port boost correction, which is a fuel boost correction where the amount of fuel injected from the port injector is reduced over time during a port injection, differs from the value of a cylinder boost correction, which is a fuel boost correction where the amount of fuel injected from the cylinder injector is reduced over time during a cylinder injection. In other words, a more appropriate port boost correction and cylinder boost correction are set and used. As a result, combustion after returning from a fuel cut-off can be more stable.

[0008] In the aspect described above, the values ​​of the port increase quantity correction and the cylinder increase quantity correction can increase with a longer fuel cutoff duration. This is because the intake air port or cylinder becomes cooler the longer the fuel cutoff lasts.

[0009] When returning from fuel cut-off, the electronic control unit can control the port and cylinder injectors such that, after a certain time, the port boost correction switches to the cylinder boost correction when port injection switches to cylinder injection, and vice versa. Consequently, combustion can become more stable when boost correction is applied after returning from fuel cut-off, both when switching from port injection to cylinder injection and vice versa. Brief description of the drawings

[0010] Features, advantages, and the technical and economic significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and in which: Fig. 1 is a configuration diagram that schematically illustrates a configuration of a hybrid vehicle as an embodiment of the present invention; Fig. 2 a configuration diagram that schematically illustrates a configuration of a machine or fuel supply device; Fig. 3 is a flowchart illustrating an example of a calculation routine executed by a machine ECU for an increase quantity correction after returning from a fuel shutdown; Fig. 4 is an explanatory diagram illustrating examples of a port characteristic curve and a cylinder characteristic curve; Fig. 5 is an explanatory diagram illustrating a port increase quantity correction and a cylinder increase quantity correction in relation to an elapsed time after returning from fuel shutdown; Fig. 6 is a configuration diagram that schematically illustrates a configuration of a hybrid vehicle of a modified example; Fig. 7 is a configuration diagram that schematically illustrates a configuration of a hybrid vehicle of another modified example; and Fig. Figure 8 is a configuration diagram that schematically illustrates a configuration of a hybrid vehicle or another modified example. Detailed description of embodiments

[0011] Next, a form in which the present invention is implemented will be described with reference to embodiments.

[0012] Fig. Figure 1 is a configuration diagram that schematically illustrates a configuration of a hybrid vehicle 20 as an embodiment of the present invention, and Fig. Figure 2 is a configuration diagram that schematically illustrates a configuration of a machine 22 or a fuel supply device 60. As shown in Fig. As illustrated in Figure 1, a hybrid vehicle 20 according to the embodiment includes the machine 22, the fuel supply device 60, a planetary gear 30, motors MG1, MG2, inverters 41, 42, a battery or accumulator 50 and an electronic hybrid control unit (hereinafter referred to as an “HVECU”) 70. At least one machine ECU 24 is included as a control device for an internal combustion engine.

[0013] Machine 22 is designed as an internal combustion engine that delivers power using fuel such as gasoline or light oil. As in Fig. As illustrated in Figure 2, the machine 22 includes a port injector 125, which injects fuel into an intake air port, and a cylinder injector 126, which injects fuel into a cylinder. Because it has the port injector 125 and the cylinder injector 126, the machine 22 can be operated in either port injection mode or cylinder injection mode. In port injection mode, air cleaned by an air purifier 122 is introduced via a throttle valve 124, and fuel is injected by the port injector 125 such that the air and fuel are mixed. The air-fuel mixture is then introduced into a combustion chamber via an intake air valve 128 and explosively combusted by an electric spark from a spark plug 130.The reciprocating motion of a piston 132, which is pushed downwards by the energy generated by the explosive combustion, is then converted into a rotary motion of a crankshaft 26. In cylinder injection mode, air is introduced into the combustion chamber in the same way as in port injection mode, and fuel is injected by the cylinder injector 126 during the intake stroke or at the beginning of the compression stroke. The fuel is then explosively combusted by an electric spark from the spark plug 130, and the rotary motion of the crankshaft 26 is maintained. Switching between these injection modes is based on the drive condition of the engine 22. Exhaust gas discharged from the combustion chamber is passed through an exhaust control device 134 with an exhaust gas control catalyst (a three-way catalyst), which removes harmful components such as carbon monoxide (CO), hydrocarbons (HC), or nitrogen oxides (NO).x ) removed, released to the outside.

[0014] As in Fig. As illustrated in Figure 2, the fuel supply device 60 is designed to supply fuel to the port injector 125 and the cylinder injector 126 of the machine 22. The fuel supply device 60 includes a fuel tank 61, a supply pump (a first pump) 62, which supplies fuel from the fuel tank 61 to a low-pressure-side flow path (a first flow path) 63 connected to the port injector 125, a check valve 64 provided on the low-pressure-side flow path 63, and a high-pressure fuel pump (a second pump) 65, which pressurizes fuel on the port injector 125 side of the check valve 64 in the low-pressure-side flow path 63 and supplies the fuel to a high-pressure-side flow path (a second flow path) 66, to which the cylinder injector 126 is connected.

[0015] The feed pump 62 and the check valve 64 are located in the fuel tank 61. The feed pump 62 is designed as an electric pump, driven by receiving electrical power supplied by the battery or accumulator 50. The check valve 64 opens when the fuel pressure on the feed pump 62 side is higher than the fuel pressure on the port injector 125 side in the low-pressure-side flow path 63, and it closes when the fuel pressure on the feed pump 62 side is less than or equal to the fuel pressure on the port injector 125 side.

[0016] The high-pressure fuel pump 65 is driven by power from the machine 22 (rotation of a camshaft) to pressurize the fuel in the low-pressure-side flow path 63. The high-pressure fuel pump 65 has an electromagnetic valve 65a connected to an inlet, which opens / closes when the fuel is pressurized, and a check valve 65b connected to an outlet, which prevents backflow of fuel and maintains fuel pressure in the high-pressure-side flow path 66.During operation of the machine 22, the high-pressure fuel pump 65 receives fuel from the supply pump 62 when the electromagnetic valve 65a opens. When the electromagnetic valve 65a closes, it pressurizes the fuel supplied to the high-pressure flow path 66 by intermittently feeding the fuel, which has been compressed by a piston (not shown) driven by the machine 22, to the high-pressure flow path 66 via the check valve 65b. During operation of the high-pressure fuel pump 65, the fuel pressure in the low-pressure flow path 63 or the fuel pressure in the high-pressure flow path 66 is pulsated according to the rotation of the machine 22 (the rotation of the camshaft).

[0017] The drive of the machine 22 and the fuel supply device 60 is controlled by an electronic control unit for a machine (hereinafter referred to as a "machine ECU") 24. The machine ECU 24 is designed as a microprocessor (not shown) which has a CPU as its main unit and includes a ROM that stores a processing program, a RAM that temporarily stores data, input / output ports and a communication port in addition to the CPU.

[0018] Signals from various sensors, necessary for controlling the drive of machine 22 and the fuel supply device 60, are input into the machine ECU 24 via the input port. Examples of signals input into the machine ECU 24 may include: a crank position θ cr from a crank position sensor 140, which detects a rotational position of the crankshaft 26, a coolant temperature T wfrom a coolant temperature sensor 142, which detects the temperature of the coolant of the machine 22, a cam position θ ca from a cam position sensor 144, which detects a rotational position of an intake camshaft opening / closing the intake air valve 128 or an exhaust camshaft opening / closing an exhaust valve, a throttle opening degree TH from a throttle valve position sensor 146, which detects a position of the throttle valve 124, an intake air quantity Q a from an air flow meter 148, which is attached to an intake air pipe, an intake air temperature T a from a temperature sensor 149, which is attached to the intake air pipe, an air-fuel ratio AF; from an air-fuel ratio sensor 135a, which is attached to an exhaust pipe, an oxygen signal O2; from an oxygen sensor 135b, which is attached to the exhaust pipe, a rotational speed N fpthe feed pump 62 from a rotational speed sensor 62a, which is attached to the feed pump 62 of the fuel supply device 60, a fuel pressure P fp of the fuel supplied to the port injector 125 by a fuel pressure sensor 68, which is located near the port injector 125 in the low-pressure side flow path 63, and a fuel pressure P fd of the fuel supplied to the cylinder injector 126 by a fuel pressure sensor 69, which is located near the cylinder injector 126 in the high-pressure side flow path 66.

[0019] Signals from various sensors, necessary for controlling the drive of the machine 22 and the fuel supply device 60, are output to the machine ECU 24 via the output port. Examples of signals output by the machine ECU 24 include a drive signal to the port injector 125, a drive signal to the cylinder injector 126, a drive signal to a throttle motor 136 that adjusts the position of the throttle valve 124, a control signal to an ignition coil 138 integrated with an ignition device, a drive control signal to the supply pump 62, and a drive control signal to the electromagnetic valve 65a of the high-pressure fuel pump 65.

[0020] The machine ECU 24 is connected to the HVECU 70 via the communication port. The machine ECU 24 calculates based on the crank angle θ. cr from the crank position sensor 140 a rotational speed N eof machine 22. Furthermore, the machine ECU 24 calculates based on the intake air quantity Q a from the air flow meter 148 and the rotational speed N e The machine 22 has a volumetric efficiency (a ratio of a volume of air actually drawn in during a cycle to a stroke volume of the machine 22 per cycle) KL.

[0021] As in Fig. As illustrated in Figure 1, the planetary gear 30 is designed as a single-pinion planetary gear mechanism. A rotor of the motor MG1 is connected to a sun gear of the planetary gear 30. A drive shaft 36, which is connected via a differential 38 to drive gears 39a, 39b, is connected to a ring gear of the planetary gear 30. The crankshaft 26 of the machine 22 is connected via a damper 28 to a carrier of the planetary gear 30.

[0022] Motor MG1, for example, is designed as a synchronous motor-generator and, as described above, has a rotor connected to the sun gear of the planetary gear set 30. Motor MG2, for example, is also designed as a synchronous motor-generator and has a rotor connected to the drive shaft 36. Inverters 41 and 42 are connected to motors MG1 and MG2, respectively, and to the battery 50 via power lines 54. Motors MG1 and MG2 are driven by controlling the switching of a plurality of switching elements (not shown) of inverters 41 and 42 using an electronic motor control unit (hereinafter referred to as a "motor ECU") 40.

[0023] The motor ECU 40 is designed as a microprocessor (not shown) with a CPU as its main unit. In addition to the CPU, it includes a ROM for storing a processing program, a RAM for temporary data storage, input / output ports, and a communication port. Signals from various sensors, necessary for controlling the drive of motors MG1 and MG2, are input to the motor ECU 40 via the input port. Examples of these signals include rotational positions θ. m1 , θ m2 of rotary position sensors 43, 44, which detect rotary positions of the rotors of the motors MG1, MG2, and a temperature t m2The motor MG2 includes the temperature sensor that detects the temperature of motor MG2. A signal for controlling the switching of the majority of switching elements (not shown) of inverters 41, 42, and the like is output via the output port from the motor ECU 40. The motor ECU 40 is connected to the HVECU 70 via the communication port. The motor ECU 40 calculates based on the rotational positions θ m1 , θ m2 of the rotors of motors MG1, MG2 from the rotational position sensors 43, 44 rotational speeds N m1 , N m2 the MG1 and MG2 engines.

[0024] The battery 50, for example, is designed as a lithium-ion secondary battery or a nickel-hydrogen secondary battery and is connected to the inverters 41, 42 via the power lines 54. The battery 50 is managed by an electronic control unit for a battery (hereinafter referred to as a "battery ECU") 52.

[0025] The battery ECU 52 is designed as a microprocessor (not shown) with a CPU as its main unit. It includes a ROM for storing a processing program, a RAM for temporary data storage, input / output ports, and a communication port in addition to the CPU. Signals from various sensors necessary 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 a battery voltage (V). b from a voltage sensor 51a installed between terminals of battery 50, a battery current I b from a current sensor 51b attached to an output terminal of the battery 50 and a battery temperature T bfrom a temperature sensor 51c attached to battery 50. The battery ECU 52 is connected to the HVECU 70 via the communication port. The battery ECU 52 calculates based on the integrated value of the battery current I b The current sensor 51b provides a state-of-charge (SOC) power storage ratio. The SOC power storage ratio is the ratio of the capacity of electrical power that can be discharged from battery 50 to the total capacity of battery 50.

[0026] The HVECU 70 is designed as a microprocessor (not shown) with a CPU as its main unit. In addition to the CPU, it includes a ROM for storing a processing program, a RAM for temporary data storage, input / output ports, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. Examples of signals input to the HVECU 70 include an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 detecting the operating position of a shift lever 81, and an accelerator pedal opening degree A. cc from an accelerator pedal position sensor 84, which detects a depressor pedal 83, a brake pedal position BP from a brake pedal position sensor 86, which detects a depressor pedal 85, a vehicle speed V from a vehicle speed sensor 88 and an outside air temperature T outfrom an outside air temperature sensor 89. As described above, the HVECU 70 is connected to the machine ECU 24, the engine ECU 40 or the battery ECU 52 via the communication port.

[0027] In the hybrid vehicle 20 of the embodiment designed in this way, a required drive force of the drive shaft 36 is determined based on the accelerator pedal opening degree A. cc and the vehicle speed V is set, and the drive of the machine 22 and the motors MG1, MG2 is controlled such that a required power, corresponding to the required driving force, is output to the drive shaft 36. Drive modes of the machine 22 and the motors MG1, MG2 include the following modes (1) to (3). (1) Torque conversion drive mode: A mode in which the drive of the machine 22 is controlled such that power corresponding to the required drive force is output by the machine 22 and the drive of the motors MG1, MG2 is controlled such that all the power output by the machine 22 is converted into torque by the planetary gear 30 and the motors MG1, MG2 and the required power is output to the drive shaft 36. (2) Charging / discharging drive mode: A mode in which the drive of the machine 22 is controlled such that a power corresponding to the sum of the required power and the electrical power necessary to charge / discharge the battery 50 is output by the machine 22, and the drive of the motors MG1, MG2 is controlled such that the power output by the machine 22 is converted wholly or partly into torque by the planetary gear 30 and the motors MG1, MG2 according to the charging / discharging of the battery 50, and the required power is output to the drive shaft 36. (3) Motor drive mode: A mode in which the drive of the motor MG2 is controlled such that the drive of the machine 22 is stopped and the required power is delivered to the drive shaft 36.

[0028] Furthermore, in the hybrid vehicle 20 according to the embodiment, the ECU 24 controls the intake air quantity, the fuel injection or the supply pump 62 or the high-pressure fuel pump 65 of the fuel supply device 60 during the operation of the machine 22.

[0029] The intake air volume of machine 22 is controlled by first setting a target intake air volume Q. a* based on a target torque T e* The machine 22 is set, followed by a target throttle opening degree TH. * is set in such a way that the intake air quantity Q a the target intake air quantity Q a* is, and then the throttle motor 136 is controlled in such a way that the throttle opening degree TH is the target throttle opening degree TH * becomes.

[0030] Fuel injection is controlled by selecting between the port injection mode and the cylinder injection mode based on the rotational speed N. eand the volumetric efficiency KL of machine 22 is first determined to determine an injection mode to be executed, then based on the target intake air quantity Q a* and the injection mode to be executed, a target injection quantity Q fp* of the port injector 125 and a target injection quantity Q fd* of the cylinder injection valve 126 is set such that the air-fuel ratio AF is a target air-fuel ratio AF * (for example, the stoichiometric air-fuel ratio), and then a target injection time. τfp* of the port injector 125 or a target injection time τfd* of the cylinder injector 126 based on the target injection quantities Q fp* and Q fd* and the fuel pressures P fp , P fd is determined. If the target injection times τfp* , τfd*Once these values ​​are set, the cylinder injector 126 or the port injector 125 is controlled such that the fuel is injected by the cylinder injector 126 or the port injector 125 at the target injection times. τfp* , τfd* is injected.

[0031] The feed pump 62 is controlled by first setting a target fuel pressure P fp* of the fuel supplied to port injector 125 and a target delivery quantity Q pp* the feed pump 62, which operates on a target injection quantity Q fp* of the port injector 125 or a target injection quantity Q fd* the cylinder injection valve 126 is set. In this embodiment, the target fuel pressure P is determined. fp* to a predetermined fuel pressure P fp1 fixed, which is relatively high at the start of the engine's operation 22, and into a predetermined fuel pressure P fp2, which is lower than the predetermined fuel pressure P fp1 , switched on when a predetermined time T1 elapses. When the predetermined fuel pressure P fp1 For example, approximately 500 kPa to 550 kPa are usable, and as the predetermined fuel pressure P fp2 For example, approximately 380 kPa to 420 kPa can be used. For the predetermined time T1, for example, approximately 5 seconds to 7 seconds can be used. Furthermore, in this embodiment, the target delivery quantity Q pp* set in such a way that it increases when the target fuel pressure P fp* It increases. If the target delivery quantity Q pp* Once this value is set, the feed pump 62 is controlled such that the delivery quantity (the amount of fuel) from the feed pump 62 is equal to the target delivery quantity Q. pp* becomes.

[0032] The high-pressure fuel pump 65 is controlled by first setting a target delivery quantity Q. pd*the high-pressure fuel pump 65 based on a target fuel pressure P fd* of the fuel supplied to the cylinder injector 126. The target fuel pressure P is defined as follows: fd* For example, several MPa to a dozen MPa can be used. In this embodiment, the target output quantity Q pd* set in such a way that it increases when the target fuel pressure P fd* increases, and then increases when the target injection quantity Q fd* It increases. If the target delivery quantity Q pd* Once this value is set, the electromagnetic valve 65a of the high-pressure fuel pump 65 is controlled such that the delivery quantity (the fuel quantity) of the high-pressure fuel pump 65 is equal to the target delivery quantity Q. pd* becomes.

[0033] Next, the operation of the hybrid vehicle 20 of this embodiment is described, in particular fuel injection control after returning from a fuel cut-off. During fuel injection after returning from the fuel cut-off, the machine ECU 24 calculates an increase quantity correction based on a duration T. cut the fuel cut-off and an elapsed time T aft after returning from fuel shutdown, and the increase quantity correction to the target injection quantity Q fp* Q fd* of the port injector 125 or the cylinder injector 126 is carried out. Fig. Figure 3 is a flowchart illustrating an example of a calculation routine executed by the machine's ECU 24 for the increase quantity correction after returning from fuel cut-off. The machine's ECU 24 repeats this routine at predetermined time intervals.

[0034] When executing the calculation routine for the increased quantity correction after returning from fuel shutdown, the machine ECU 24 first outputs the duration T. cut the fuel cut-off and the elapsed time T aft After returning from fuel cut-off (step S100), the machine ECU 24 then applies a port increase quantity correction Q as an increase quantity correction. kp fixed when the fuel is injected from port injector 125 (steps S110 and S120) and sets a cylinder increase quantity correction Q in parallel as an increase quantity correction. kd fixed when the fuel is injected by cylinder injector 126 (steps S130 and S140).

[0035] The port increase quantity correction Q kp can be set as follows. First, the machine ECU 24 forwards a port increase quantity correction initial value Q. kpsand sets this by determining the duration T cut applies the fuel cut-off to a port characteristic curve (step S110). Fig. Figure 4 illustrates examples of a port characteristic curve and a cylinder characteristic curve. Fig. 4. Solid lines represent the port characteristic curve and the cylinder characteristic curve. In this embodiment, the port characteristic curve represents a relationship between the duration T obtained through experiments or the like. cut the fuel cut-off and the port increase quantity correction initial value Q kps The machine ECU 24 then sets the port increase quantity correction Q. kp based on the elapsed time T aft after returning from fuel shutdown and the port increase quantity correction initial value Q kps fixed (step S120). In this embodiment, the port increase quantity correction Q kp obtained by setting the initial port increase quantity correction value Q kpswith a damping coefficient obtained from experiments or the like, in relation to the elapsed time T aft is multiplied after returning from fuel cut-off. In Fig. 4 represents a dashed line in relation to the initial port increase quantity correction value Q. kps a change in the port increase quantity correction Q kp over time, which is determined by multiplying the damping coefficient and the port increase quantity correction Q. kp is obtained when the fuel cut-off ends at time T1.

[0036] The cylinder increase quantity correction Q kd can be set as follows. First, the machine ECU 24 initiates a cylinder increase quantity correction initial value Q. kds and sets this by determining the duration T cut applies the fuel cut-off to a cylinder characteristic curve (step S130). In Fig. Figure 4 shows the cylinder characteristic curve represented by the lower solid line. In this embodiment, the cylinder characteristic curve represents a relationship between the duration T cut the fuel cut-off and the cylinder boost correction initial value Q kds which is obtained through experiments or the like. As from Fig. As can be seen in section 4, the initial value Q for the cylinder increase quantity correction is... kds smaller than the initial port increase quantity correction value Q kps This is because the temperature of the intake air port is lower than inside the cylinder, as it is difficult to cool the cylinder interior using intake air during fuel cut-off with a coolant or similar device, whereas it is easy to cool the intake air port using intake air during fuel cut-off. Subsequently, the engine ECU 24 sets the cylinder boost quantity correction Q. kdbased on the elapsed time T afc after returning from fuel shutdown and the port increase quantity correction initial value Q kds fixed (step S140). In this embodiment, the cylinder increase quantity correction Q kd obtained by setting the initial cylinder increase quantity correction value Q kds with a damping coefficient in relation to the elapsed time T aft The value obtained from experiments or similar methods is multiplied after returning from fuel shutdown. Fig. 4 represents a dashed line in relation to the cylinder increase quantity correction initial value Q kds a change in the cylinder increase quantity correction Q kd over time, which is represented by multiplying the damping coefficient and the cylinder increase quantity correction Q kd is obtained when the fuel cut-off ends at time T1.

[0037] After the port increase quantity correction Q kp and the cylinder increase quantity correction Q kd Once these parameters have been set, the machine ECU 24 determines whether the injection mode to be executed is port injection mode or cylinder injection mode (step S150). If the machine ECU 24 determines that the injection mode to be executed is port injection mode, the fuel is injected by port injector 125 using the port boost correction Q. kp Fuel is injected (step S 160) and this routine is completed. However, if the machine ECU 24 determines that the injection mode to be executed is the cylinder injection mode, the fuel is injected by the cylinder injector 126 using the cylinder increase quantity correction Q. kd injected (step S 170) and this routine is completed.

[0038] Now, consider a case where the injection mode to be executed switches from port injection mode to cylinder injection mode before the fuel quantity increase correction is completed after returning from fuel shutdown. In this case, according to the calculation routine for the fuel quantity increase correction after returning from fuel shutdown, the Fig. 3 the increase quantity correction from the port increase quantity correction Q kp , which using the initial port increase quantity correction value Q kps based on the duration T cut the fuel cut-off and the elapsed time T afc calculated after returning from fuel cut-off, into the cylinder increase quantity correction Q kd switched, which is based on the initial cylinder increase quantity correction value Q kds based on the duration T cut the fuel cut-off and the elapsed time T afcis calculated after returning from fuel shutdown. Fig. Figure 5 is an explanatory diagram showing the port increase quantity correction Q kp and the cylinder increase quantity correction Q kd according to the elapsed time T aft The following is illustrated after returning from fuel shutdown. A solid line represents a change in the port boost quantity correction Q. kp over time, and a dashed line represents a change in the cylinder elevation quantity correction Q. kd over time. Considering a case where the port injection mode switches to the cylinder injection mode at time T2, the increase quantity correction is determined by the port increase quantity correction Q. kp , which have a value Q kp1 exhibits, in the cylinder increase quantity correction Q kd switched, which has a value Q kd1exhibits. Conversely, if we consider a case in which the cylinder injection mode is switched to the port injection mode at time T2, the increase quantity correction is determined by the cylinder increase quantity correction Q. kd , which have the value Q kd1 exhibits, in the port increase quantity correction Q kp switched, which has the value Q kp1 This indicates that if, before the end of the increase quantity correction after returning from fuel shutdown, the injection modes to be executed are switched, the combustion itself can become more stable before and after switching between the injection modes to be executed, by performing the increase quantity correction according to each injection mode.

[0039] If, in a machine mounted on the hybrid vehicle 20 of the embodiment described above, an increase quantity correction is performed in the port injection mode after returning from fuel shutdown, the port increase quantity correction Q kp based on the port increase quantity correction initial value Q kps , which is achieved by applying the duration T cut the fuel cut-off is obtained on the port characteristic curve, and the elapsed time T aft fixed after returning from fuel cut-off. In cylinder injection mode, the cylinder increase quantity correction Q is set. kd based on the cylinder increase quantity correction initial value Q kds , which is achieved by applying the duration T cut the fuel cut-off is based on the cylinder characteristic curve, which differs from the port characteristic curve, and the elapsed time T. aftThe increase quantity correction is set after the fuel cut-off. Since the increase quantity correction is performed by setting an initial value using a characteristic curve that varies depending on the injection mode being executed, combustion can become more stable after the fuel cut-off, regardless of the injection mode. Furthermore, because the increase quantity correction is executed according to each injection mode, even if the system switches between the injection modes before the end of the increase quantity correction after the fuel cut-off, combustion can become more stable both before and after switching between the injection modes.

[0040] In the hybrid vehicle 20 according to the embodiment, the battery 50 is used as a power storage device, but any device capable of storing power, such as a capacitor, can be used.

[0041] The hybrid vehicle 20 according to the embodiment includes the machine ECU 24, the motor ECU 40, the battery ECU 52 and the HVECU 70, but at least two of these can be designed as a single electronic control unit.

[0042] In the hybrid vehicle 20 according to the embodiment, the machine 22 and the motor MG1 are connected via the planetary gear 30 to the drive shaft 36, which is connected to the drive wheels 39a, 39b, and the motor MG2 is connected to the drive shaft 36, so that the motors MG1, MG2 are connected to the battery 50 via power lines. As in a hybrid vehicle 220 of a modified example of the Fig. As illustrated in Figure 6, the vehicle can, however, be designed as a so-called single-engine hybrid vehicle, in which an engine MG is connected via a transmission 230 to the drive shaft 36, which is connected to the drive wheels 39a, 39b, and the machine 22 is connected to the engine MG via a clutch 229, so that the battery 50 is connected to the engine MG via a power line. Furthermore, as in a hybrid vehicle 320 of another modified example of the Fig. As illustrated in Figure 7, the vehicle can be configured as a so-called series hybrid vehicle, in which a motor MG1 for power generation is connected to the machine 22, and a motor MG2 for propulsion is connected to the drive shaft 36, which is connected to the drive wheels 39a, 39b, so that the battery 50 is connected to the motors MG1, MG2 via power lines. Furthermore, as in a hybrid vehicle 420 of another modified example of the Fig.As illustrated in Figure 8, the vehicle can be designed as a so-called gasoline vehicle, in which the engine 22 is connected via a gearbox 430 to the drive shaft 36, which is connected to the drive wheels 39a, 39b.

[0043] The following is a description of the correspondence between the main elements in the embodiment and those of the invention described in the ABSTRACT OF THE INVENTION. In the embodiment, the port injector 125 corresponds to the “port injector”, the cylinder injector 126 corresponds to the “cylinder injector”, the machine 22 corresponds to the “internal combustion engine”, and the machine ECU 24 corresponds to the “control device”.

[0044] The present invention is applicable to the manufacturing industry of a control device for an internal combustion engine and the like.

Claims

[1] Control device for an internal combustion engine (22), wherein the internal combustion engine (22) includes a port injector (125) which injects fuel into an intake air port and a cylinder injector (126) which injects fuel into a cylinder, wherein the control device comprises: an electronic control unit (24) configured to control the port injector (125) and the cylinder injector (126) such that, upon return from a fuel cut-off that stops fuel injection from the port injector (125) and the cylinder injector (126), a value of a port increase quantity correction (Q) kp ), which is a fuel increase quantity correction, in which a fuel quantity is adjusted after a period of time (T). aft ) during port injection is greater than a value of a cylinder increase quantity correction (Q kd), which is a fuel increase quantity correction, in which a fuel quantity is adjusted after a period of time (T). aft ) is reduced during cylinder injection, wherein the fuel is injected by the port injector (125) during port injection and by the cylinder injector (126) during cylinder injection, where the port increase quantity correction (Q kp ) based on a port increase quantity correction initial value (Q kps ) is determined by applying the duration (T cut ) the fuel cut-off on a port characteristic curve and the elapsed time (T aft ) is obtained after returning from fuel cut-off, and the cylinder increase quantity correction (Q kd ) based on an initial cylinder increase quantity correction value (Q kds ) is determined by applying the duration (T cut) the fuel cut-off on a cylinder characteristic curve that differs from the port characteristic curve, and the elapsed time (T aft ) is received after returning from fuel shutdown, and where the difference between the initial port increase quantity correction value (Q kps ) and the initial cylinder increase quantity correction value (Q kd ) with increasing duration (T cut ) the fuel interruption tends to increase. [2] Control device according to claim 1, wherein the values ​​of the port increase quantity correction (Q kp ) and the cylinder increase quantity correction (Q kd ) with an increasing duration (T cut ) the fuel cut-off will increase. [3] Control device according to claim 1 or 2, wherein the electronic control unit (24) is configured to control, when fuel is injected after fuel shut-off, the port injector (125) and the cylinder injector (126) such that the port increase quantity correction (Q kp ) with the passage of time (T aft ) into the cylinder increase quantity correction (Q kd ) is switched when port injection is switched to cylinder injection, and the cylinder increase quantity correction (Q kd ) with the passage of time (T aft ) into the port increase quantity correction (Q kp ) is switched when cylinder injection is switched to port injection.

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