JP2012136959A - Control apparatus of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control apparatus of an internal combustion engine that reduces particulates in exhaust gas and satisfies both low-fuel consumption and low emission, in an internal combustion engine controlling an intake valve to be retarded.SOLUTION: The control apparatus performs the retard control of the intake valve and controls an injection condition so as to allow a port injection valve for performing intake asynchronous injection and intake synchronous injection into an intake port to change an intake asynchronous injection ratio. The apparatus includes: a separately-injection controller for performing the asynchronous injection of the port injection valve during an intake asynchronous injection period Taup1 in which the asynchronous injection ends further on an exhaust top dead center (TDC) side than an intake-valve opening period tp3 and for performing the injection of an uninjected remaining amount during an intake synchronous injection period Taup2 which starts from the intake-valve opening period tp3, the injection of the uninjected remaining amount exceeding an injection quantity during the intake asynchronous injection period Taup1 by the port injection valve in a required injection quantity; and a separately-injection injection-quantity setting device for each setting the injection quantity during the intake asynchronous injection period Taup1 and the uninjected remaining amount according to a temperature of the internal combustion engine.

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine suitable for retarding an intake valve and generating an in-cylinder vortex flow in an internal combustion engine having a fuel injection valve for port injection.

  In internal combustion engines for vehicles such as automobiles, pumping loss is reduced by slow closing control of the intake valve (retarding control that retards the valve closing timing) in response to highly demanding fuel efficiency. By executing the delay opening control that opens the intake valve after passing the dead center (retarding control that delays the valve opening timing), the means for generating vortex flow in the cylinder such as tumble air flow (intake flow control valve, intake port identification) In some cases, control is performed to improve combustion by improving the action of the inclination, shape, and valve lift amount.

  As a control device for a conventional internal combustion engine that executes retard control of an intake valve and control of vortex flow in a cylinder, for example, in a port injection type engine equipped with a variable valve lift (two-stage switching) mechanism, the intake valve is opened. The timing is retarded from the exhaust top dead center and the valve lift amount of the intake valve is decreased to increase the flow rate of intake air. When the fuel is a fuel that is difficult to evaporate, the port injection valve of the required injection amount It is known that the amount of fuel adhering to the inner wall surface of the intake port is suppressed by reducing the ratio of the fuel that is asynchronously injected from the intake air (see, for example, Patent Document 1).

  The threshold for switching the opening and closing of the tumble control valve is set to a relatively low load / low rotation side during warm-up of the internal combustion engine, and to a relatively high load / high rotation side after the internal combustion engine is warmed up. By setting each, during warm-up, the valve opening area of the tumble control valve (operating area where the tumble is suppressed) is expanded, and the output fluctuation due to the opening and closing of the tumble control valve is known. (For example, refer to Patent Document 2).

  In addition, select any combustion method from stratified combustion and uniform combustion according to the engine speed and load, and stop the generation of tumble air flow by opening the tumble control valve in the low and medium load operation region where stratified combustion is performed. In addition, there is also known a technique that prevents the dense air-fuel mixture around the plug from being diffused by the tumble airflow (see, for example, Patent Document 3).

JP 2007-332936 A Japanese Patent Application Laid-Open No. 08-165929 JP 07-293304 A

  However, in the conventional internal combustion engine control apparatus in which the valve opening timing of the intake valve is retarded and the valve lift is reduced, the intake port and the wall surface temperature in the cylinder are cold when the internal combustion engine is cold. When the intake valve opens, droplets of fuel adhering around the intake valve may enter the cylinder all at once with the intake air flow when the intake valve is opened. There is a concern that the particulate matter in the exhaust gas is generated or the oil on the cylinder inner wall surface is diluted.

  That is, when port injection is performed so that the air and fuel in the intake port are in the required mixed state before the intake valve opens, when the intake port wall surface temperature is low, such as during cold start, the intake air Since the atomization of the fuel injected into the port is difficult to proceed, when the intake valve is controlled to be retarded, a droplet of fuel that is not sufficiently atomized flows from the intake port into the cylinder of the intake stroke. End up. In addition, when the intake valve is retarded, the compression end temperature in the cylinder also decreases, making it difficult to evaporate the liquid fuel adhering to the wall surface of the bore. For example, it may fly to the wall surface of the cylinder bore on the exhaust port side and adhere to it, and the oil on the bore wall surface may be diluted, or it may become nonflammable and generate particulate matter in the exhaust gas. There is.

  In particular, when the fuel injection amount is corrected to be increased when it is cold, or when the intake port has an inclined posture that can generate a high tumble airflow, droplet-like fuel tends to adhere to the inner wall surface of the cylinder, In addition, since it is difficult to evaporate, there is a possibility that problems such as increase in particulate matter (particulate matter mass (PM) and particle number concentration (PN)) in exhaust gas and dilution of oil for lubrication / cooling may occur. It was high.

  In addition, even in a conventional internal combustion engine control device that suppresses the tumble air flow during warm-up or low / medium load, the valve opening timing of the intake valve is retarded, so that the intake valve opens prior to valve opening. When the amount of fuel injected into the intake port increases, the fuel easily adheres to the inner wall surface of the intake port and becomes droplets, which may cause the same problem as described above.

  Therefore, the present invention aims to reduce particulate matter in the exhaust gas and prevent dilution of the lubricating / cooling oil in an internal combustion engine that generates vortex flow in the cylinder such as a high tumble airflow and retards the intake valve, The present invention provides a control device for an internal combustion engine that can achieve both low fuel consumption and low emission.

  In order to solve the above problems, the control apparatus for an internal combustion engine according to the present invention executes (1) retard control for opening the intake valve of the internal combustion engine during a valve opening period set after exhaust top dead center. In addition, intake asynchronous injection for injecting fuel into the intake passage of the internal combustion engine outside the valve opening period of the intake valve and intake synchronous injection for injecting fuel into the intake passage during the valve opening period of the intake valve A control device for an internal combustion engine that controls an injection condition so as to change a ratio of a fuel amount by the intake asynchronous injection of a required fuel amount with respect to a feasible port injection valve, wherein the asynchronous injection of the port injection valve Is executed during the intake asynchronous injection period that ends on the exhaust top dead center side from the opening timing of the intake valve, and exceeds the injection amount during the intake asynchronous injection period by the port injection valve of the required injection amount Uninjected Injection control means for executing an amount of fuel injection during an intake synchronous injection period starting from the opening timing of the intake valve, and an injection amount and an uninjected remaining amount during the intake asynchronous injection period, respectively, And an injection-divided injection amount setting means which is set according to the above.

  With this configuration, the fuel injected into the intake passage by the port injection valve is controlled to be divided into intake asynchronous injection and intake synchronous injection, so that the fuel injected into the intake passage adheres to the inner wall surface of the intake passage. As a result, it is possible to reduce the amount of fuel injection asynchronous to intake air so that it does not liquefy, and even if the intake valve is retarded, the fuel injected into the intake passage is less likely to adhere around the intake valve and the fuel adhering to the wall surface This effectively suppresses the phenomenon that the liquid drops into the cylinder. Therefore, it is possible to prevent the particulate fuel in the exhaust gas from being generated by the liquid fuel that has entered the cylinder and the oil on the cylinder inner wall surface from being diluted. In an internal combustion engine that generates a vortex and delays the intake valve, it is possible to reduce particulate matter in the exhaust gas and prevent dilution of the lubricating / cooling oil. The temperature of the internal combustion engine mentioned here can be grasped by, for example, the cooling water temperature of the internal combustion engine, but other temperature detection information that changes depending on the intake port or the wall temperature in the cylinder may of course be used.

  In the control apparatus for an internal combustion engine according to the present invention, (2) the injection divided injection amount setting means increases the injection amount during the intake asynchronous injection period by the port injection valve when the temperature of the internal combustion engine is high. When the temperature of the internal combustion engine is low, it is desirable to set it to a small amount. Thereby, depending on whether the temperature of the internal combustion engine is high and the fuel easily evaporates, or the temperature of the internal combustion engine is low and the fuel is difficult to evaporate, the fuel injection amount during the intake asynchronous injection period is increased or decreased, The fuel injected into the intake passage is less likely to adhere to the wall surface around the intake valve.

  In the control device for an internal combustion engine according to the present invention, preferably, (3) when the temperature of the internal combustion engine is lower than a preset temperature, than when the temperature is higher than the preset temperature. The apparatus further includes feed pressure variable means for changing the supply pressure of the fuel supplied to the port injection valve to a high pressure. In this case, the fuel injection pressure is increased in addition to the fuel injection amount being reduced during the intake asynchronous injection period, and the fuel atomization is promoted by the increase in the fuel penetration force.

  In the control apparatus for an internal combustion engine according to the present invention, (4) the injection divided injection amount setting means changes the asynchronous injection start timing in the intake asynchronous injection period on the advance side from the exhaust top dead center of the internal combustion engine. Preferably, the intake synchronous injection period is variably set by changing the synchronous injection end timing on the retard side from the exhaust top dead center. This ensures the required atomization time for all of the fuel that is port-injected during the intake asynchronous injection period. In this case, it is preferable that the end timing of the intake asynchronous injection period is a timing at which the internal combustion engine (piston) becomes the exhaust top dead center.

  More preferably, in the control device for an internal combustion engine according to the present invention, (5) an in-cylinder eddy current generating mechanism for generating an in-cylinder vortex flow in the internal combustion engine when the intake valve is opened, and a temperature of the internal combustion engine are preset. Eddy current limiting means for limiting the generation of the in-cylinder eddy current by the in-cylinder eddy current generating mechanism when the temperature is lower than the set temperature. With this configuration, combustion can be improved by generating vortex flow in the cylinder such as tumble airflow, and generation of vortex flow in the cylinder can be limited when the vortex flow in the cylinder is not desirable, and pumping loss is reduced by slow closing of the intake valve. Combustion can be improved by reducing the effect of the vortex flow in the cylinder such as the tumble air flow by timely delaying the intake valve opening control. The in-cylinder vortex generating mechanism mentioned here may be an intake flow control valve such as a tumble control valve, or an intake passage shape, a slow-open intake valve, or a valve effective for generating an in-cylinder vortex such as a tumble air flow. A timing variable mechanism or the like may be used. Further, the cold time is a time when the temperature of the internal combustion engine, for example, the coolant temperature is equal to or lower than a predetermined value, and may be at the time of starting or operating the internal combustion engine.

  In the control apparatus for an internal combustion engine according to the present invention, (6) the injection divided injection amount setting means includes the injection amount during the intake asynchronous injection period by the port injection valve and the intake synchronous injection period by the port injection valve. The ratio with the injection amount may be held at a fixed value. In this case, it becomes easy to set the injection amount.

  (7) The injection divided injection amount setting means variably sets a ratio between an injection amount during the intake asynchronous injection period by the port injection valve and an injection amount during the intake synchronous injection period by the port injection valve. It may be a thing. In this case, it is possible to set finely divided injection amounts. As the temperature of the internal combustion engine increases, the port injection limit amount increases. On the other hand, the required fuel injection amount decreases as the temperature of the internal combustion engine decreases. It increases as it becomes. Therefore, the divided injection amount required to be synchronously injected as the difference between the two decreases as the temperature of the internal combustion engine increases.

  In the control apparatus for an internal combustion engine according to the present invention, (8) the injection divided injection amount setting means sets the fuel injection amount corresponding to the uninjected remaining amount to an injection amount during the intake synchronous injection period by the port injection valve. And an injection amount by an in-cylinder injection valve capable of injecting fuel into the cylinder of the internal combustion engine. In this case, when port injection is the preferred operating state and the remaining amount of uninjected fuel increases, the fuel injection by the port injection valve is mainly used, but the in-cylinder injection valve is used in the operating state where fuel adhesion is a concern. The required fuel injection amount can be secured. In this case, the injection amount by the in-cylinder injection valve is set within a small amount of in-cylinder injection amount that does not adversely affect the cold operation of the internal combustion engine.

  In the control apparatus for an internal combustion engine according to the present invention, (9) when the divided injection amount setting means is such that a supercharging pressure of a supercharger equipped in the internal combustion engine is lower than a preset threshold supercharging pressure. It may be one that operates. In this way, for example, when the supercharging pressure of the supercharger increases and the compression end temperature of the internal combustion engine rises, and the relationship between the cooling water temperature and the cylinder inner wall surface temperature falls outside the normal range, It is possible to change the ratio between the intake asynchronous injection amount and the intake synchronous injection amount, or to temporarily suspend injection into the intake asynchronous injection and the intake synchronous injection.

  According to the present invention, the fuel injection into the intake passage by the port injection valve is controlled to be divided into intake asynchronous injection and intake synchronous injection, and the fuel injected into the intake passage adheres to the wall surface and becomes liquefied. The amount of fuel for intake asynchronous injection is limited to such an extent that even if the intake valve is retarded, the fuel injected into the intake passage hardly adheres around the intake valve, and the fuel droplets form into the cylinder at a stroke. Such a phenomenon is effectively suppressed, so that liquid fuel entering the cylinder prevents particulate matter in the exhaust gas from being generated and the oil on the cylinder inner wall surface from being diluted. can do. As a result, in an internal combustion engine that generates vortex flow in the cylinder such as a high tumble air flow and retards the intake valve, the particulate matter in the exhaust gas is reduced and the lubrication / cooling oil is prevented from being diluted. It is possible to provide a control device for an internal combustion engine that can achieve both low emissions.

1 is a schematic configuration diagram of an internal combustion engine and a control device thereof according to a first embodiment of the present invention. 1 is a block diagram showing a schematic configuration of a control device for an internal combustion engine according to a first embodiment of the present invention. FIG. 3 is a graph showing a map for setting the injection divided injection amount according to the engine coolant temperature in the control apparatus for an internal combustion engine according to the first embodiment of the present invention, where the vertical axis indicates the fuel injection amount and the horizontal axis indicates the cooling. Indicates water temperature. It is explanatory drawing of the timing of intake asynchronous injection and intake synchronous injection in case the injection of port injection is requested | required in the control apparatus of the internal combustion engine which concerns on 1st Embodiment of this invention. It is a flowchart which shows the general | schematic control procedure in the control apparatus of the internal combustion engine which concerns on 1st Embodiment of this invention. It is explanatory drawing of the timing of intake asynchronous injection and intake synchronous injection in case the injection of port injection is requested | required in the control apparatus of the internal combustion engine which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the general | schematic control procedure in the control apparatus of the internal combustion engine which concerns on 2nd Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1 to 5 show an internal combustion engine and its control device according to a first embodiment of the present invention.

  Note that the internal combustion engine of the present embodiment is mounted on an automobile (vehicle), and a fuel injection valve for port injection and an in-cylinder engine are able to meet advanced demands for improvement in fuel consumption, output, exhaust purification performance, and the like. This is a dual injection method using a fuel injection valve for injection, and a dual VVT method equipped with a variable valve timing mechanism (hereinafter referred to as VVT) for intake and exhaust.

  First, the configuration will be described.

  As shown in FIG. 1, the internal combustion engine of the present embodiment is mounted on an engine 10 that is a spark ignition type V-type 6-cylinder (multi-cylinder) internal combustion engine.

  Although not shown in detail, the engine 10 includes a piston 12 housed in each cylinder 11c of the pair of left and right banks 11, a combustion chamber 11d is defined, and an intake valve 13 and an exhaust valve 14 are mounted. is there. Further, a direct ignition type ignition device 15 having an ignition plug 15a exposed in the combustion chamber 11d and an ignition coil (not shown) for igniting the plug is provided. Further, the plurality of pistons 12 in the pair of left and right banks 11 are respectively connected to a crankshaft 17 (not shown in detail) via connecting rods 16, and water is placed around each cylinder 11 c of the pair of left and right banks 11. A jacket 11w is formed.

  In this engine 10, the valve timings of the intake valves 13 and the exhaust valves 14 of the plurality of cylinders 11c are variable to the intake timing and the exhaust timing according to the operating state of the engine 10 by the known intake side VVT 18 and exhaust side VVT 19, respectively. The intake side VVT 18 is controlled based on a control signal from an ECC (engine control computer) 100 serving as a control means, which will be described later, and in accordance with the operating state of the engine 10, the intake valve 13 of each cylinder 11c. Is opened during a valve opening period set after the exhaust top dead center of the piston 12 in the cylinder 11c (top dead center when shifting from the late exhaust stroke phase to the early intake stroke) (retard angle control). And the intake valve 13 of each cylinder 11c is opened before the exhaust top dead center of the piston 12 in the cylinder 11c. Usually it has to be able to run and control that. The exhaust-side VVT 19 closes the exhaust valve 14 at the exhaust top dead center position, for example, when cold, based on a control signal from the ECC 100 described later, and sets the closing timing of the exhaust valve 14 from the exhaust top dead center position during normal operation. It is set to the retard side.

  Although not shown in detail, a plurality of intake ports 11a are provided on one wall surface side of the pair of banks 11 that are close to each other, and a plurality of exhaust ports 11b are provided on the other wall surface side of the pair of banks 11 that are separated from each other. Between the upper ends of the pair of banks 11 formed on one wall surface side, an intake manifold 25 capable of distributing intake air to the plurality of intake ports 11a of the pair of banks 11 is provided. On the other wall surface side of the bank 11, exhaust manifolds 31A and 31B for collecting exhaust gases discharged from the plurality of exhaust ports 11b are mounted.

  The intake manifold 25 constitutes a known intake device 20 together with an air cleaner 21, an intake pipe 22, an electronically controlled throttle valve 23, a surge tank 24, and the like, and the exhaust manifolds 31A and 31B are exhaust purifications such as a three-way catalyst. First catalytic converters 32A and 32B, intermediate exhaust pipes 33A and 33B, a downstream exhaust pipe 34 that collects exhaust gas from the exhaust gas that has passed through these exhaust pipes 33A and 33B, and this downstream exhaust pipe A known exhaust device 30 is configured with second catalytic converters 35A, 35B provided between the exhaust pipe 34 and the exhaust pipes 33A, 33B, and an exhaust muffler (not shown) mounted in the middle of the downstream exhaust pipe 34. is doing.

  The plurality of intake ports 11a are provided with a plurality of first injectors 41 (port injection valves, low-pressure fuel injection valves) for port injection corresponding to the plurality of cylinders 11c. Are connected to a feed pump 45 for supplying fuel via a pair of low-pressure delivery pipes 43. Although not shown in detail, the feed pump 45 pumps up the fuel in the fuel tank 46, for example, gasoline, discharges it at the first fuel pressure level, and passes a pair of fuel through the discharge check valve 42a, the fuel filter 42b, and the fuel passage 47. It feeds to each of the low pressure delivery pipes 43. The feed pump 45 is ON / OFF-driven and rotational speed controlled via a pump drive circuit 44 based on a pump control signal from the ECC 100 described later. For example, the rotational speed of the pump rotor driven by a motor is used. This is a low-pressure-side variable discharge pressure fuel pump that can change the discharge flow rate and the feed fuel pressure by changing. The feed pump 45 is not a variable pump, but a back pressure or the like of a variable pressure regulator 48 connected to the fuel passage 47 is set to a solenoid valve 49 (in FIG. 1, the discharge port of the feed pump 45 and the variable pressure regulator 48). The feed pressure may be controlled so that at least two stages of high pressure and low pressure can be switched by a three-way valve connected to the surplus fuel discharge port.

  On the other hand, the plurality of cylinders 11c of the engine 10 are provided with a plurality of in-cylinder injection second injectors 51 (in-cylinder injection valves, high-pressure fuel injection valves) that inject high-pressure fuel directly into the respective combustion chambers 11d. These second injectors 51 are connected to a plunger-type high-pressure fuel pump 55 mounted on the upper part of the bank 11 on one side via a pair of high-pressure delivery pipes 53 and a high-pressure fuel pipe 54. Although not shown in detail, the high-pressure fuel pump 55 has a pressurizing chamber for introducing fuel fed from the feed pump 45, and the fuel in the pressurizing chamber has a feed pressure level higher than the first fuel pressure level. A plunger capable of being pressurized to a high pressure second fuel pressure level, and the high pressure fuel pump 55 has a valve opening operation and a pressure chamber for opening the pressure chamber to the fuel passage 47 on the feed pump 45 side. Is mounted with an electromagnetic spill valve 56 that can be closed from the fuel passage 47 on the feed pump 45 side. The electromagnetic spill valve 56 is closed when a drive signal is input, and a check valve that prevents high-pressure backflow at the fuel inlet of the pressurizing chamber of the high-pressure fuel pump 55 connected to the fuel passage 47 on the feed pump 45 side. While performing the function, when the drive signal input is stopped and the valve is opened, the high-pressure fuel in the pressurizing chamber can be leaked to the low-pressure side. Accordingly, by driving the plunger in the fuel pressurizing direction when the electromagnetic spill valve 56 is closed, the high pressure fuel pressurized to the second fuel pressure level is discharged from the high pressure fuel pump 55 to the pair of high pressure delivery pipes 53. The discharge flow rate of the high-pressure fuel pump 55 can be controlled by controlling the closing time of the electromagnetic spill valve 56.

  The first injector 41, the second injector 51, and the electromagnetic spill valve 56 described above are each connected to an injector driver circuit 50, and are controlled by the ECC 100 via the injector driver circuit 50. Here, when the injector driver circuit 50 receives a control signal (an injector drive signal, a fuel injection request signal, a high pressure fuel injection amount signal, etc.) from the ECC 100, it converts the control signal into a high voltage / high current drive signal. The control object corresponding to the control signal from ECC100 among the 1st injector 41, the 2nd injector 51, and the electromagnetic spill valve 56 is each drive-controlled.

  Sensors such as an intake air temperature sensor 26, an air flow meter 27, and a throttle opening sensor 28 are attached to the intake device 20, and a resonator 29 is attached. Further, the exhaust device 30 includes an air-fuel ratio sensor 36 that detects the state of the air-fuel ratio in the exhaust gas upstream of the first catalytic converters 32A and 32B, the first catalytic converters 32A and 32B, and the second catalyst. An oxygen sensor 37 that detects the oxygen concentration in the exhaust gas is mounted between the converters 35A and 35B. Further, the engine 10 includes a pair of a water temperature sensor 71 that detects the temperature of the coolant passing through the water jacket 11 w (engine temperature), intake and exhaust cam angle sensors 72 and 73, and a high-pressure fuel pump 55. A high pressure fuel pressure sensor 74 that detects the fuel pressure supplied to the high pressure delivery pipe 53, a crank angle sensor (rotational speed sensor) 75 that detects an angular position and a rotational speed for each predetermined rotational angle of the crankshaft 17, and a knock control sensor (No code) etc. are attached. Sensor information from these sensor groups is taken into the ECC 100. In addition to the injector driver circuit 50, the ECC 100 includes oil control valves 81 and 82 for controlling an ignition drive circuit, a fuel pump drive circuit, an intake side VVT 18 and an exhaust side VVT 19 (VVT operated by oil supply / discharge control). A drive circuit or the like for the electromagnetic control valve to be controlled (hereinafter referred to as OCV in the figure) is connected, but since these configurations are the same as those in the prior art, they will not be described in detail here.

  Although the detailed hardware configuration is not shown, the ECC 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a nonvolatile backup memory, and further includes an A / D. An input interface circuit including a converter, an output interface circuit including a driver and a relay switch, a constant voltage circuit, and a communication interface circuit with another on-vehicle ECU (Electronic Control Unit) ing. The ECC 100 is based on sensor information or preset value information stored in a ROM or a backup memory in accordance with a plurality of control programs stored in advance in the ROM, and further while communicating with other in-vehicle ECUs. For example, the fuel injection amount corresponding to the operating state of the engine 10 or the acceleration request is calculated, and the injection command signal and the electromagnetic spill valve 56 to the first injector 41 for port injection and the second injector 51 for in-cylinder injection are set. A control signal, such as a command signal to the injector driver circuit 50 for driving, is output in a timely manner, and a plurality of functions are provided so as to perform a plurality of functions for performing port injection division control, which will be described later. Includes maps.

  As shown in FIG. 2, the input interface circuit of the ECC 100 includes an intake air temperature sensor 26, an air flow meter 27, a throttle opening sensor 28, an air-fuel ratio sensor 36, an oxygen sensor 37, a water temperature sensor 71, and intake and exhaust air. In addition to the cam angle sensors 72 and 73, the high pressure fuel pressure sensor 74, and the crank angle sensor 75, an accelerator opening sensor 76, an ignition relay switch 77, an ECT select switch 78, and the like are connected. Another ECU 105 such as a transmission control computer (TCC) is connected. Further, the output interface circuit of the ECC 100 includes a plurality of ignition coils (for the first to sixth cylinders) 15c of the ignition device 15 corresponding to the number of cylinders (for example, 6) of the engine 10 and an electronically controlled throttle valve 23. The electronically controlled throttle motor 23m, the injector driver circuit 50, each pair of the intake side VVT OCV 81 and the exhaust side VVT OCV 82, and the pump drive circuit 44 are connected.

  The ECC 100 adjusts the amount of fuel leakage from the pressurizing chamber by the electromagnetic spill valve 56 (or further by adjusting the driving speed of the high-pressure fuel pump 55), so that the high-pressure fuel pump 55 is connected to the high-pressure delivery pipe 53. The pressure of the supplied fuel can be controlled to an optimum fuel pressure according to the operating state of the engine 10 and the injection characteristics of the second injector 51 for in-cylinder injection (in-cylinder injectors # 1 to 6 in FIG. 2). It has become. For example, the ECC 100 can set an ON time during which the electromagnetic drive coil of the electromagnetic spill valve 56 is in an excited state and an OFF time during which the excitation state is released within a predetermined signal cycle. By changing the ratio (0% to 100%; hereinafter referred to as the duty ratio), the leakage amount of fuel from the pressurizing chamber by the electromagnetic spill valve 56 can be adjusted.

  Further, the ECC 100 reduces the pumping loss of the engine 10 by the slow closing control that retards the closing timing of the intake valve 13 and further opens the intake valve 13 after passing the exhaust top dead center of the piston 12. , The in-cylinder vortex generating mechanism 60 having the intake port 11a and the intake valve 13 having a specific shape set to an inclination that easily generates a tumble airflow (in-cylinder vortex) is generated (the intake port 11a is narrowed when the valve is closed). An intake flow control valve that generates an in-cylinder vortex flow while increasing an intake flow velocity, for example, a tumble control valve that generates a tumble airflow (hereinafter also referred to as a TCV) is enhanced to improve the combustion effect in the engine 10. It is like that. Furthermore, the ECC 100 eliminates the so-called valve overlap when cold, thereby suppressing the amount of exhaust gas that blows back into the intake port 11a and the combustion chamber 11d, and the closing timing of the intake valve 13 according to the engine speed. By retarding, the volumetric efficiency can be improved as the closing timing of the intake valve 13 according to the inertia of the intake air. The ECC 100 incorporates a map M1 for executing such valve timing control.

  In addition, the ECC 100 performs fuel injection by, for example, the first injector 41 for port injection (port injectors # 1 to # 6 in FIG. 2) when the engine 10 is started according to the control program stored in the ROM. When the fuel pressure in the high-pressure delivery pipe 53 detected by the high-pressure fuel pressure sensor 74 exceeds a predetermined pressure value, the output of the injection command signal to the second injector 51 for in-cylinder injection is started. ing.

  Further, the ECC 100 operates the engine 10 in a port injection operation region in which only port injection is performed, a mix injection operation region in which port injection and in-cylinder injection are used in combination, and in-cylinder injection operation in which only in-cylinder injection is performed. A map M2 that is divided into regions is built in, and for example, when the engine 10 is warmed up or when the engine speed is low and high, port injection or mixed injection is executed.

  Further, the ECC 100 is based on the coolant temperature detected by the water temperature sensor 71 (engine temperature; other detection information indicating the inner wall temperature of the intake port 11a). When the cooling water temperature is lower than the predetermined temperature as at the start or when the cooling water temperature is lower than the predetermined temperature even during steady running, fuel injection into the intake port 11a by the first injector 41 for port injection (port injection) Is divided into an intake asynchronous injection period preceding the opening of the intake valve 13 and an intake synchronous injection period during the opening of the intake valve 13, and is executed as port injections a plurality of times, for example, two times before and after. .

  That is, the ECC 100 performs asynchronous intake injection in which fuel is injected into the intake port 11a of the engine 10 outside the opening period of the intake valve 13 and intake air synchronization in which fuel is injected into the intake port 11a during the opening period of the intake valve 13. The ECC 100 is a control device that controls the injection condition so as to change the ratio of the fuel amount by the intake asynchronous injection of the required fuel amount with respect to the first injector 41 that can perform the injection. The ECC 100 is a first injector. Asynchronous injection 41 is executed during the intake asynchronous injection period that ends on the exhaust top dead center side with respect to the opening timing of the intake valve 13 and can be injected during the intake asynchronous injection period by the first injector 41 of the required injection amount. Injection division control means for executing fuel injection of the uninjected remaining amount exceeding the injection amount during the intake synchronous injection period starting from the valve opening timing of the intake valve 13 And it functions to, and also serves as a divided injection injection amount setting means for setting in accordance with the temperature of the injection quantity and non-injected residual each engine 10 in intake-asynchronous injection period.

  Further, the ECC 100 functions as a divided injection amount setting means so that the injection amount during the intake asynchronous injection period by the first injector 41 is large when the temperature of the engine 10 is high, and small when the temperature of the engine 10 is low. , Each is set. Note that when the temperature of the engine 10 is low, for example, when the engine 10 is warmed up, and when the temperature of the engine 10 is high, for example, during operation after the engine 10 is warmed up.

  Specifically, the ECC 100 has a built-in injection injection amount setting map M3 as shown in the graph of FIG. 3, and the cooling water temperature of the engine 10 or the inner wall temperature of the intake port 11a is below a predetermined temperature. When tumble (in-cylinder vortex) is likely to occur in each cylinder 11c set in advance, and / or when the compression end temperature in the cylinder 11c decreases due to the slow closing of the intake valve 13. In order to avoid problems such as an increase in particulate matter in the exhaust gas and dilution of oil for lubrication / cooling, the required injection according to the operating state of the engine 10 using the setting map M3 for the divided injection amount At least a portion of the remaining uninjected amount that cannot be port-injected during the intake asynchronous injection period by the first injector 41 of the quantity is started from the opening timing of the intake valve 13. It is adapted to set as the divided injection injection amount is performed during morphism period.

  The setting map M3 for the divided injection amount is a limit port injection amount that can absorb so-called port wet (more than the port injection amount) according to the cooling water temperature (temperature detected by the water temperature sensor 71) representing the temperature of the engine 10. Increases the port injection amount at which the fuel wall adhesion and liquefaction in the intake port 11a suddenly progress (hereinafter referred to as the port injection limit amount). The difference from the required injection amount exceeding the above is set as an uninjected remaining amount (split injection amount) that should be injected separately into the fuel injection different from the intake asynchronous port injection, for example, the intake synchronous port injection. The setting condition is such that the lower the cooling water temperature at which the limit amount is smaller, the higher the injection amount is. Note that the divided injection amount here is indicated by a white bidirectional arrow in FIG. 3 and also changes depending on the transition (increase / decrease) in the required injection amount according to the cooling water temperature and other operating conditions. In addition, the injection amount during the intake asynchronous injection period when performing the port injection division can be set to an arbitrary injection amount equal to or less than the port injection limit amount.

  As to the setting map M3 for the divided injection amount, the port injection during the intake asynchronous injection period by the first injector 41 is in a state where the air and fuel in the intake port 11a are in a required mixed state before the intake valve 13 is opened. Thus, since the piston 12 is executed a certain period before the exhaust top dead center, when the wall surface temperature of the intake port 11a is low, such as during cold start, it is injected into the intake port 11a. Fuel atomization is difficult to proceed. Therefore, as indicated by a dotted line in FIG. 3, the port injection limit amount generally becomes smaller as the cooling water temperature is lower, and the cooling water temperature is decreased until the cooling water temperature becomes a relatively high temperature after warming up. The lower the value, the larger the rate of decrease, and after the cooling water temperature reaches a relatively high temperature after warming up, the rate of increase decreases even if the cooling water temperature rises. However, under certain conditions such as when a turbocharger is provided in the intake system, the conditions as shown in FIG. 3 can be lost, so under such specific conditions, the map shown in FIG. Or a ratio between the injection amount during the intake asynchronous injection period by the first injector 41 and the injection amount during the intake synchronous injection period by the first injector 41 is set in advance as a fixed value. Can be held in.

  As shown in FIG. 4, the ECC 100 serving as the divided injection quantity setting means is configured such that the end timing tp2 of the intake asynchronous injection period Taup1 by the first injector 41 is set so that the piston 12 in the target cylinder 11c of the asynchronous injection is exhausted. On the other hand, the start timing tp1 of the intake asynchronous injection period Taup1 is advanced from the exhaust top dead center (left side of TDC in FIG. 4) while being set to the time point of reaching the dead center (position of TDC in FIG. 4). By changing, the intake asynchronous injection period Taup1 is variably set. Further, the ECC 100 matches the start timing tp3 of the intake synchronous injection period Taup2 by the first injector 41 with the valve opening timing of the intake valve 13 in the target cylinder 11c of the synchronous injection, while being retarded from the exhaust top dead center. The intake synchronous injection period Taup2 is variably set by changing the end timing tp4 of the intake synchronous injection period Taup2 that is further retarded than the opening timing (tp3) of the intake valve 13 of the intake valve.

  Here, the start timing tp1 of the intake asynchronous injection period Taup1 by the first injector 41 is, for example, at the compression top dead center (the top dead center when the piston 12 in the target cylinder 11c shifts from the late stage of the compression stroke to the early stage of the expansion stroke). It is set to a time point after the time point about 400 ° before (B400 ° CA) and before the exhaust top dead center (B360 ° CA) with respect to the time point reached. Further, the end timing tp4 of the intake synchronous injection period Taup2 by the first injector 41 is, for example, delayed by an opening timing tp3 of the intake valve 13 of the target cylinder 11c (for example, a crank angle of about 20 ° from the exhaust top dead center at the time of slow opening). Is set to a time point that is about 290 ° before the crank angle (about B290 ° CA) from the time point when the piston 12 in the target cylinder 11c reaches the compression top dead center. . The restriction on the retard side of the end timing tp4 of the synchronous injection period Taup2 is to suppress the discharge amount of unburned hydrocarbon (HC).

  In the present embodiment, the ECC 100 serving as the injection divided injection amount setting means includes the fuel injection amount during the intake asynchronous injection period Taup1 by the first injector 41 and the fuel injection amount during the intake synchronous injection period Taup2 by the first injector 41. 3 is variably set based on the setting map of the divided injection quantity as shown in FIG. 3, but the ratio to the fuel injection quantity is a fixed value (for example, the intake synchronous injection with respect to the intake asynchronous injection quantity 7). The ratio may be a ratio of 7: 3 where the amount is 3, or a 1: 1 ratio where the intake synchronous injection amount is 5 with respect to the intake asynchronous injection amount 5).

  Further, the intake synchronous injection period Taup2 by the first injector 41 is shortened by the slow opening of the intake valve 13, and the uninjected remaining fuel that cannot be injected within the intake asynchronous injection period Taup1 of the required injection amount is taken into the intake synchronous injection period Taup2. In the case where all of the port injection cannot be performed, the remaining fuel amount is injected into the intake-synchronized port injection amount that is the injection amount during the intake-synchronized injection period Taup2 by the first injector 41 and into the cylinder 11c of the engine 10. You may make it set separately with the injection amount by the 2nd injector 51 which can inject a fuel. However, when the cooling water temperature is low, there is almost no fuel injection by the second injector 51 other than the injection amount by the second injector 51 of a part of the remaining uninjected amount here, and the engine 10 is cold. The in-cylinder injection at the time is executed only in a small amount at the time of the injection division request.

  The ECC 100, together with the pump drive circuit 44 and the feed pump 45, has a first injector when the temperature of the engine 10 is lower than a preset temperature, than when the temperature of the engine 10 is higher than the preset temperature. The feed pressure variable means is configured to change the supply pressure of the fuel supplied to 41 to a high pressure.

  When the temperature of the engine 10 is lower than a preset temperature with respect to the in-cylinder eddy current generating mechanism 60 that generates an in-cylinder eddy current in the engine 10 when the intake valve 13 is opened, the ECC 100 It also functions as eddy current limiting means for limiting the generation of eddy current in the cylinder by the eddy current generating mechanism 60. For this purpose, the cooling water temperature that is a threshold value for determining whether or not cooling is performed, and its determination processing program are stored. Yes.

  In addition, between the fuel tank 46 and the intake pipe 22, the evaporated fuel generated in the fuel tank 46 is adsorbed and held by the canister 91, and released from the canister 91 into the intake pipe 22 when the engine 10 is inhaled. A known evaporative fuel processing device 90 is provided. The evaporative fuel processing device 90 adjusts the opening of the purge passage 92 between the canister 91 and the intake pipe 22 via the vacuum solenoid valve 93 by the ECC 100, and purges the evaporated fuel sucked into the intake pipe 22 from the canister 91. The amount can be adjusted.

  Next, the operation will be described.

  FIG. 5 shows a schematic processing procedure of the injection division control program executed at predetermined time intervals during the operation of the engine 10 in the control apparatus for an internal combustion engine according to the first embodiment of the present invention.

  First, various sensor information including the cooling water temperature thw detected by the water temperature sensor 71 and the required injection amount calculated by the ECC 100 according to the operating state of the engine 10 and the vehicle every predetermined time are used as the injection dividing control means. It is taken in by ECC100.

  Next, when the cooling water temperature thw representing the temperature of the engine 10 is compared with a predetermined threshold temperature T1 for determining whether or not it is cold, it is determined that the cooling water temperature thw is equal to or higher than the determination threshold temperature T1. (NO in step S12), the current process is terminated.

  On the other hand, when it is determined that the coolant temperature thw is lower than the determination threshold temperature T1 (in the case of YES at step S12), an operation in which the intake side VVT 18 performs the late closing control (retarding angle control) of the intake valve 13 is then performed. It is determined whether or not it is in a state (step S13).

  In the present embodiment, the in-cylinder vortex generating mechanism 60 has the intake port 11a having a specific shape that easily generates a tumble airflow, and when the intake valve 13 is controlled to be closed slowly by the intake side VVT 18, the intake valve 13 is delayed. Opening increases the flow velocity of the intake air flowing into the cylinder 11c when the intake valve 13 is opened, and a strong tumble airflow can be generated. Moreover, the compression end temperature in the cylinder 11c also falls by the late closing of the intake valve 13, and the inner wall temperature of the cylinder 11c can be lowered. Accordingly, if the intake valve 13 is controlled to be closed late by the intake side VVT 18 when the engine 10 is cold when it is difficult to atomize the fuel injected into the port and the injection amount is increased, etc., particulates in the exhaust gas are particularly generated. Problems such as increase of substances and dilution of oil for lubrication / cooling are likely to occur.

  Therefore, whether or not such a problem is likely to occur is determined by the above-described two determination steps, and an operation in which an increase in particulate matter in the exhaust gas or dilution of oil for lubrication / cooling is a concern. If it is determined that the state is in the state (YES in step S13), the following processing is executed.

  First, the feed fuel pressure to the low pressure delivery pipe 43 is increased by increasing the rotational speed of the feed pump 45 via the pump drive circuit 44 or switching the pressure regulation level of the pressure regulator 48 to the high pressure side. The fuel pressure (port injection fuel pressure) of the port injection by the injector 41 is increased (step S14). When the in-cylinder vortex generating mechanism 60 has a TCV or the like, in addition to the step of increasing the port injection fuel pressure, the cylinder eddy current generating mechanism 60 further executes a process for suppressing the generation of the in-cylinder vortex. Is preferred.

  Next, it is determined whether or not port injection needs to be divided based on the required injection amount according to the operating state of the engine 10 and the port injection limit amount according to the coolant temperature (step S15).

  If it is determined that the required injection amount is relatively small and port injection is not required to be divided (NO in step S15), then the start timing of the intake asynchronous injection period and the intake asynchronous injection period are determined. (Step S17).

  On the other hand, if it is determined that the required injection amount is relatively large and port injection needs to be divided (YES in step S15), the engine is then used by using the injection divided injection amount setting map M3. The ratio between the intake asynchronous port injection amount and the intake synchronous port injection amount among the required injection amounts corresponding to the ten operating states is determined (step S16), and then the start timing of the intake asynchronous injection period and the intake asynchronous injection are determined. The end time of each period is determined (step S18).

  The ECC 100 can execute fuel injection during the injection period of the first injector 41 of each cylinder 11c according to the start timing of the intake asynchronous injection period and the end timing of the intake asynchronous injection period set in this way. The electromagnetic drive unit or the piezo element (not shown) is energized, and the port injection from the first injector 41 of each cylinder 11c is executed during the intake asynchronous injection period and the intake asynchronous injection period.

  In the present embodiment in which the above-described injection division control is executed, fuel injection into the intake pipe 22 (in the intake passage) by the first injector 41 that is a port injection valve is injected into intake asynchronous injection and intake synchronous injection. By performing the split control, it is possible to reduce the amount of asynchronous fuel injection so that the fuel injected into the intake pipe 22 does not adhere to the inner wall surface of the intake pipe 22 and liquefy, and the intake valve 13 is retarded. However, it becomes difficult for the fuel injected into the intake pipe 22 to adhere around the intake valve 13, and the phenomenon that the fuel adhering to the wall surface drops into the cylinder 11c is effectively suppressed. . Accordingly, it is possible to prevent the particulate fuel in the exhaust gas from being generated by the liquid fuel that has entered the cylinder 11c and the oil on the inner wall surface of the cylinder 11c from being diluted. In the engine 10 that generates the in-cylinder vortex and controls the intake valve 13 to be retarded, it is possible to reduce particulate matter in the exhaust gas and prevent dilution of the lubricating / cooling oil.

  Further, the ECC 100 as the divided injection amount setting means sets the injection amount during the intake asynchronous injection period by the first injector 41 as the port injection valve when the temperature of the engine 10 is high and when the temperature of the engine 10 is low. Since the engine 10 is set to a small amount, the fuel injection amount during the intake asynchronous injection period Taup1 increases depending on whether the temperature of the engine 10 is high and the fuel easily evaporates, or conversely, whether the temperature of the engine 10 is low and the fuel does not easily evaporate. Therefore, the fuel injected into the intake pipe 22 is less likely to adhere to the wall surface around the intake valve 13 or the like.

  Further, when the temperature of the engine 10 is lower than a preset set temperature, the ECC 100 as the feed pressure variable means and the pump drive circuit 44 are more effective than when the temperature is higher than the preset temperature. Since the supply pressure of the fuel supplied to 41, that is, the feed fuel pressure is changed to a high pressure, the fuel injection pressure is increased in addition to the reduction of the fuel injection amount during the intake asynchronous injection period. Fuel atomization is encouraged.

  Further, the ECC 100 as the injection divided injection amount setting means variably sets the intake asynchronous injection period Taup1 by changing the asynchronous injection start timing on the advance side from the exhaust top dead center of the engine 10, and the intake synchronous injection period Taup2 is set. Since the synchronous injection end timing is changed on the retard side from the exhaust top dead center and is variably set, the required atomization time is secured for all of the fuel injected into the port during the intake asynchronous injection period Taup1.

  In addition, in the present embodiment, the in-cylinder vortex generating mechanism 60 that causes the engine 10 to generate an in-cylinder vortex flow when the intake valve 13 is opened and the cooling water temperature of the engine 10 are set in advance by the ECC 100 as the vortex limiting means. When the temperature is lower than the above temperature, the generation of the in-cylinder vortex by the in-cylinder vortex generating mechanism 60 is limited. Occasionally, the generation of vortex flow in the cylinder can be stopped, and the pumping loss is reduced by the slow closing control of the intake valve 13, and the action of the vortex flow in the cylinder such as a tumble air flow is enhanced by the slow opening control of the intake valve 13 at an appropriate time Can improve combustion.

  Further, the ratio between the injection amount during the intake asynchronous injection period Taup1 by the first injector 41 and the injection amount during the intake synchronous injection period Taup2 by the first injector 41 is variably set using the setting map M3 of the divided injection amount. This makes it possible to set finely divided injection amounts. Of course, the ratio of the injection amount during the intake asynchronous injection period Taup1 by the first injector 41 and the injection amount during the intake synchronous injection period Taup2 by the first injector 41 is held at a fixed value, and the injection divided injection amount is set. Can also be made easier.

  As described above, according to the control apparatus for an internal combustion engine of the present embodiment, the control for dividing the fuel injection into the intake passage by the first injector 41 into the intake asynchronous injection and the intake synchronous injection is executed. The amount of fuel for asynchronous injection is limited so that the fuel injected into the wall does not adhere to the wall and liquefy, and even if the intake valve is retarded, the fuel injected into the intake passage adheres around the intake valve 13 However, the phenomenon that the fuel drops into droplets and enters the cylinder 11c at a stroke is effectively suppressed, so that the particulate matter in the exhaust gas is generated by the liquid fuel entering the cylinder 11c. It is possible to prevent the oil on the inner wall surface of the cylinder 11c from being diluted. As a result, in an internal combustion engine that generates vortex flow in the cylinder such as a high tumble airflow and retards the intake valve 13, the particulate matter in the exhaust gas is reduced and the lubrication / cooling oil is prevented from being diluted. Further, it is possible to provide a control device for an internal combustion engine that can achieve both low emission and low emission.

(Second Embodiment)
6 and 7 are diagrams showing a control device for an internal combustion engine according to the second embodiment of the present invention.

  Note that the present embodiment has an overall configuration substantially similar to that of the first embodiment described above, and a part of the control program of the ECC 100 serving as the control means is different from the first embodiment. Therefore, here, for the same configuration as in the first embodiment, reference numerals of corresponding components in FIGS. 1 to 5 are used, and differences from the first embodiment will be described.

  As shown in FIG. 6, in the control apparatus for an internal combustion engine in the present embodiment, the ECC 100 as the injection divided injection amount setting means does not completely inject fuel due to port injection in the intake asynchronous injection period Taup1. The injection amount is determined by the first injector 41 during the intake synchronous injection period Taup2 and the injection during the injection period Taup3 by the in-cylinder second injector 51 capable of injecting fuel into the cylinder 11c of the engine 10. The amount is set separately. In this case, the injection period Taup3 of the in-cylinder injection by the second injector 51 may be either intake air synchronous or intake air asynchronous, but the injection amount by the second injector 51 has an adverse effect on the cold operation of the engine 10. It is set within a range of a small amount of in-cylinder injection without any.

  Further, the ECC 100 as the injection divided injection amount setting means is a threshold supercharging in which the supercharging pressure of the supercharger is set in advance when the engine 10 is equipped with a supercharger (for example, a turbocharger). When the pressure is lower than the pressure, the spray dividing control is executed.

  In addition, under the specific high wall temperature state, the cooling water temperature and the intake port 11a under the specific high wall temperature state are determined by a pre-test so that the setting map of the spray injection amount other than the map shown in FIG. 3 can be used. The port injection limit amount changes according to the coolant temperature of the engine 10 while the difference between the port injection limit amount and the required injection amount exceeding the port injection limit amount is clarified. Another map that can be set as an uninjected remaining amount (split divided injection amount) to be divided into different fuel injections, for example, intake-synchronized port injection is prepared. In this case, the ratio between the injection amount during the intake asynchronous injection period by the first injector 41 and the injection amount during the intake synchronous injection period by the first injector 41 may be held at a preset fixed value.

  It should be noted that the specific high wall temperature state mentioned here means that when the turbocharger is provided in the intake device 20, the cooling of the engine 10 is performed at the time of high boost pressure operation in which the boost pressure is higher than a predetermined boost pressure. Even when the water temperature is relatively low, a state may occur in which the inner wall temperature of the intake port 11a is relatively high. Of course, in the case where the relationship between the cooling water temperature and the inner wall temperature of the intake port 11a is different from normal due to other equipment of the engine 10, and an operation state occurs in which the inner wall temperature of the intake port 11a is relatively high, The operation state may be a specific high wall temperature state.

  In the injection division control in the present embodiment, as shown in FIG. 7, in addition to executing the processes in steps S11 to S18 similar to those in the first embodiment, the processes in steps S21 to S24 are further executed.

  That is, if it is determined in step S15 that the required injection amount is relatively large and port injection needs to be divided (YES in step S15), it is then determined whether or not a specific high wall temperature state is present. (Step S21).

  If it is determined that the specific high-wall temperature state is present (YES in step S21), the operating state of the engine 10 is determined using another injection-split injection amount setting map different from the spray-split injection amount setting map M3. The ratio of the intake asynchronous port injection amount and the intake synchronous port injection amount among the requested injection amounts according to the above is determined according to a specific high wall temperature state (step S22). At this time, the feed fuel pressure to the low pressure delivery pipe 43 depends on whether the rotational speed of the feed pump 45 is reduced via the pump drive circuit 44 or the pressure regulator 48 is switched to the low pressure side. May be returned to the normal pressure, and the fuel pressure (port injection fuel pressure) of the port injection by the first injector 41 may be reduced.

  Next, based on the ratio obtained in the previous step and the required injection amount according to the operating state of the engine 10, a fuel injection amount corresponding to the remaining uninjected amount is generated by the port injection in the intake asynchronous injection period Taup1. Is determined (step S23).

  When it is determined that the fuel injection amount corresponding to the remaining uninjected amount is generated due to the port injection in the intake asynchronous injection period Taup1 (when it is determined that there is a shortage in step S23), during the intake synchronous injection period Taup2 by the first injector 41 And the injection amount during the injection period Taup3 by the second injector 51 for in-cylinder injection capable of injecting fuel into the cylinder 11c of the engine 10 are set (individual injection amount). Steps S24 and S18).

  Then, the ECC 100 determines the first injector 41 and the first injector 41 of each cylinder 11c according to the start timing tp1 of the intake asynchronous injection period Taup1 and the end timing tp4 of the intake synchronous injection period Taup2, and the in-cylinder injection execution period Taup3. In order that fuel injection can be executed by the two injectors 51 during the injection periods Taup1 to Taup3, the electromagnetic drive unit or the piezo element (not shown) is energized, and the port injection and the first injection from the first injector 41 of each cylinder 11c are performed. 2. In-cylinder injection from the injector 51 is executed.

  Also in the present embodiment, the fuel injection into the intake pipe 22 (in the intake passage) by the first injector 41 that is a port injection valve is controlled to be divided into intake asynchronous injection and intake synchronous injection, whereby the intake pipe 22 is controlled. As a result, the fuel injection amount asynchronous to intake air can be reduced so that the fuel injected into the intake wall 22 does not adhere to the inner wall surface of the intake pipe 22 and liquefy, and even if the intake valve 13 is retarded, it is injected into the intake pipe 22 This makes it difficult for the deposited fuel to adhere to the periphery of the intake valve 13, and the phenomenon that the fuel adhering to the wall surface forms droplets and enters the cylinder 11c is effectively suppressed. Accordingly, it is possible to prevent the particulate fuel in the exhaust gas from being generated by the liquid fuel that has entered the cylinder 11c and the oil on the inner wall surface of the cylinder 11c from being diluted. In the engine 10 that generates the in-cylinder vortex and controls the intake valve 13 to be retarded, it is possible to reduce particulate matter in the exhaust gas and prevent dilution of the lubricating / cooling oil.

  Further, in the present embodiment, when the port injection is a preferable operation state and the remaining uninjected amount is increased, the fuel injection by the port injection valve is mainly performed, and the in-cylinder operation is performed in the operation state in which fuel adhesion is a concern. The required fuel injection amount can be ensured by utilizing the second injector 51 for injection.

  Further, in the present embodiment, since the injection division control is executed when the supercharging pressure of the supercharger is lower than a preset threshold supercharging pressure, for example, the supercharging pressure of the supercharger increases and the engine 10 When the relationship between the cooling water temperature indicating the temperature of the intake port 11a or the inner wall surface temperature of the cylinder 11c deviates from the normal range, the ratio of the intake asynchronous injection amount and the intake synchronous injection amount is changed from normal. Thus, the maps can be switched, and the injection division into the intake asynchronous injection and the intake synchronous injection can be temporarily stopped.

  In each of the above-described embodiments, the temperature of the engine 10 is represented by the cooling water temperature. However, other temperature detection information such as the intake wall temperature of the intake port 11a and the cylinder 11c may be used. Instead of determining whether or not the spray distribution control is necessary, it may be determined whether the warm-up operation or the operation after the warm-up operation is being performed. The in-cylinder vortex flow generation mechanism 60 includes a specific shape of the intake port 11a and the intake valve 13 set to have an inclination that easily generates a tumble airflow. When the valve is closed, the intake port 11a is throttled to increase the intake flow velocity. While an intake flow control valve that generates an in-cylinder vortex may be used, it is needless to say that any known means for generating an in-cylinder vortex may be used. Furthermore, although the port injection is divided into two in the front-rear direction, it is also conceivable to make it more than three times. However, for example, dividing the intake-synchronized injection into a plurality of times while ensuring the necessary injection time requires the first injector 41 to have high responsiveness. In addition, the specific high wall temperature state is not limited to the case where the turbocharger is installed, and if there is a state in which the correlation with the cooling water temperature is lost due to the combination of the equipment to be provided and the high wall temperature is high, this is the state. May be.

  As described above, the present invention executes the control for dividing the fuel injection into the intake passage by the port injection valve into the intake asynchronous injection and the intake synchronous injection, and the fuel injected into the intake passage adheres to the wall surface. Even if the intake valve is retarded, the amount of fuel injected into the intake passage is difficult to adhere around the intake valve, and the fuel drops into droplets. As a result, the phenomenon of entering the cylinder at a stroke is effectively suppressed, so that the liquid fuel entering the cylinder generates particulate matter in the exhaust gas and the oil on the cylinder inner wall is diluted. As a result, in an internal combustion engine that generates vortex flow in the cylinder such as a high tumble airflow and controls the retarded angle of the intake valve, the particulate matter in the exhaust gas is reduced and the lubricating / cooling oil Dilution It is possible to provide a control device for an internal combustion engine that can achieve both low fuel consumption and low emissions, and exhausts an intake valve in an internal combustion engine having a fuel injection valve for port injection. The present invention is useful for general control devices for internal combustion engines that execute retard control for opening the valve after the top dead center and generate vortex flow in the cylinder.

10 Engine (Internal combustion engine)
11a Intake port (intake passage)
11b Exhaust port 11c Cylinder 13 Intake valve 18 Intake side VVT (Intake side variable valve timing mechanism)
22 Intake pipe (intake passage)
31A, 31B Exhaust manifold 41 First injector (port injection valve, low pressure fuel injection valve)
43 Low pressure delivery pipe 44 Pump drive circuit (feed pressure variable means)
45 Feed pump (low pressure fuel pump, variable feed pressure)
50 Injector driver circuit 51 Second injector (in-cylinder injection valve, high-pressure fuel injection valve)
53 High Pressure Delivery Pipe 55 High Pressure Fuel Pump 60 In-Cylinder Vortex Generation Mechanism 71 Water Temperature Sensor 74 High Pressure Fuel Pressure Sensor 75 Crank Angle Sensor (Rotation Speed Sensor)
81 Oil control valve for intake side VVT (OCV for intake side VVT)
82 Oil control valve for exhaust VVT (OCV for exhaust VVT)
100 ECC (Engine control computer, injection division control means, injection division injection amount setting means, feed pressure variable means, eddy current limiting means)
M3 Map for Injecting Separate Injection Amount Taup1 Intake Asynchronous Injection Period Taup2 Intake Synchronous Injection Period Taup3 Injection Period (Period of In-Cylinder Injection)
tp1 start time tp2 end time tp3 start time (opening timing of intake valve)
tp4 end time

Claims (9)

Delay angle control is performed to open the intake valve of the internal combustion engine during the valve opening period set after exhaust top dead center, and fuel is supplied into the intake passage of the internal combustion engine outside the valve opening period of the intake valve. For the port injection valve capable of executing the intake asynchronous injection to be injected and the intake synchronous injection to inject fuel into the intake passage during the opening period of the intake valve, the fuel by the intake asynchronous injection out of the required fuel amount A control device for an internal combustion engine for controlling an injection condition so as to change a ratio of an amount,
The asynchronous injection of the port injection valve is executed during the intake asynchronous injection period that ends on the exhaust top dead center side from the opening timing of the intake valve, and the intake asynchronous by the port injection valve of the required injection amount An injection dividing control means for executing fuel injection of an uninjected remaining amount exceeding an injection amount during an injection period during an intake synchronous injection period starting from a valve opening timing of the intake valve;
A control device for an internal combustion engine, comprising: a divided injection amount setting means for setting an injection amount during the intake asynchronous injection period and a remaining uninjected remaining amount according to the temperature of the internal combustion engine.   The injection divided injection amount setting means sets the injection amount during the intake asynchronous injection period by the port injection valve to a large amount when the temperature of the internal combustion engine is high and to a small amount when the temperature of the internal combustion engine is low. The control apparatus for an internal combustion engine according to claim 1.   When the temperature of the internal combustion engine is lower than a preset temperature, the fuel supply pressure supplied to the port injection valve is changed to a higher pressure than when the temperature is higher than the preset temperature. The control apparatus for an internal combustion engine according to claim 1, further comprising a feed pressure varying unit.   The injection divided injection amount setting means variably sets the intake asynchronous injection period by changing the asynchronous injection start timing on the advance side from the exhaust top dead center of the internal combustion engine, and the intake synchronous injection period is set to the intake synchronous injection period. The control device for an internal combustion engine according to any one of claims 1 to 3, wherein the synchronous injection end timing is changed and set variably on the retard side from the exhaust top dead center. An in-cylinder vortex generating mechanism for generating an in-cylinder vortex in the internal combustion engine when the intake valve is opened;
The eddy current limiting means for limiting the generation of the in-cylinder eddy current by the in-cylinder eddy current generating mechanism when the temperature of the internal combustion engine is lower than a preset temperature. The control device for an internal combustion engine according to any one of claims 4 to 4.   The injection-divided injection amount setting means holds a ratio of an injection amount during the intake asynchronous injection period by the port injection valve and an injection amount during the intake synchronous injection period by the port injection valve at a fixed value. The control apparatus for an internal combustion engine according to any one of claims 1 to 5.   The injection divided injection amount setting means variably sets a ratio between an injection amount during the intake asynchronous injection period by the port injection valve and an injection amount during the intake synchronous injection period by the port injection valve. The control apparatus for an internal combustion engine according to any one of claims 1 to 5.   The injection-divided injection amount setting means may inject fuel into the uninjected remaining fuel amount into an injection amount during the intake synchronous injection period by the port injection valve and into the cylinder of the internal combustion engine. The control device for an internal combustion engine according to any one of claims 1 to 7, wherein the control device is set separately for an injection amount by the in-cylinder injection valve.   9. The injection-divided injection amount setting means operates when a supercharging pressure of a supercharger equipped in the internal combustion engine is lower than a preset threshold supercharging pressure. The control apparatus of the internal combustion engine according to any one of claims.

Images