JP6326934B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device including an in-cylinder injection valve and a port injection valve.

  Conventionally, an in-cylinder injection valve that directly injects fuel into a cylinder (hereinafter, in-cylinder injection is referred to as “direct injection”, and an in-cylinder injection valve is referred to as “direct injection valve”), and fuel is injected into an intake port. 2. Description of the Related Art An engine equipped with a port injection valve that performs such a process is known.

  In this type of engine, the direct injection valve and the port injection valve are selected according to the operating conditions, such as fuel injection using only the port injection valve, fuel injection using only the direct injection valve, or fuel injection using both. A control device and a control method that are used in combination or in combination are employed.

  If a direct injection valve is used, an air-fuel mixture having an air-fuel ratio close to the stoichiometric air-fuel ratio is locally formed around the spark plug, etc., so that ignition is possible even with a lean air-fuel ratio as a whole in the cylinder chamber. . As a result, the CO and HC emissions can be reduced, and the fuel efficiency at low loads such as during steady running can be improved. In addition, there is no time lag in the increase / decrease of the fuel injection amount supplied into the cylinder chamber, and the fuel controllability is good, so there is an advantage that the acceleration / deceleration response is good.

  However, when the engine is started in the cold state, if the fuel pressure is insufficient or the fuel is insufficiently vaporized, the engine may not be started smoothly only by fuel injection by the direct injection valve.

  Therefore, in Patent Document 1, based on the coolant temperature of the engine at the time of start-up, fuel injection is performed only by the direct injection valve during the warm period, and fuel injection is performed only by the port injection valve during the cold period. Taking advantage of the jet valve.

Japanese Patent Laying-Open No. 2006-258017 (see page 5-6, paragraphs 0028-0032)

  In the technology of Patent Document 1, at the time of starting, fuel injection by a direct injection valve and fuel injection by a port injection valve are performed based on whether or not the water temperature exceeds a predetermined threshold based on the coolant temperature of the engine. Switching.

  By the way, in recent years, an idling stop function that automatically stops the engine while the vehicle is stopped by a signal, etc., or a coast that automatically stops the engine before the vehicle stops when the vehicle falls below a predetermined speed during deceleration or coasting. An increasing number of vehicles have a stop function.

  In vehicles with this type of function, when starting and restarting the engine, it is necessary for a smooth start depending on the driving situation up to that point, the driving situation when actually starting the engine, and the state of the engine. The fuel supply conditions are considered to be different.

  For this reason, as in Patent Document 1, not only the fuel injection mode at the time of starting is determined only by the temperature of the engine cooling water, but also fine control of fuel supply is required.

  Therefore, an object of the present invention is to realize a smooth start by controlling the fuel supply at the time of starting the engine more finely based on the operation state and the state of the engine.

  In order to solve the above problems, the present invention includes a direct injection valve that directly injects fuel into a cylinder, a port injection valve that injects fuel into an intake port that communicates with the cylinder, and an intake valve that opens and closes the intake port. And an operating state detection means for detecting whether the engine is in an ignition stop state where the engine is stopped based on an ignition operation or an idle stop state where the engine is automatically stopped based on an idle stop function when the engine is started And valve control means for controlling the opening / closing timing of the intake valve at the start based on the engine operating state detected by the operating state detecting means, and at the time of starting based on the operating state detected by the operating state detecting means The ratio of the fuel injection amount by the direct injection valve and the fuel injection amount by the port injection valve and the injection timing are determined. A fuel injection determining means that, to a control device for an engine and a fuel injection execution means for executing the fuel injection based on the timing of the determined ratio and injected by the fuel injection determination means.

  At this time, it is provided with a water temperature detecting means for detecting the temperature of the cooling water of the engine, and the valve control means, when the operating state is not an idle stop state, based on the water temperature detected by the water temperature detecting means, A configuration for controlling the opening / closing timing of the intake valve can be employed.

  Further, the fuel injection determining means is configured such that when the operating state is not the idle stop state, the fuel injection amount by the direct injection valve at the time of start and the fuel by the port injection valve based on the water temperature detected by the water temperature detecting means It is possible to employ a configuration that determines the ratio of the injection amount to the injection amount and the injection timing.

  In each of these aspects, the idle stop function includes a stop idle stop function that automatically stops the engine when the vehicle is stopped and a coast stop function that automatically stops the engine when the vehicle is decelerated or coasted. The means has a function of detecting whether the engine is stopped by the idle stop function or when stopped by the coast stop function when the operating state is an idle stop state, and the valve control means detects the operating state Adopting a configuration for controlling the opening / closing timing of the intake valve at the start based on whether the stop state detected by the means is a stop state by an idle stop function at the time of a stop or a stop state by a coast stop function Can do.

  At this time, the fuel injection determining means is based on whether the stop state detected by the operating state detecting means is a stop state by a stop-time idle stop function or a stop state by a coast stop function. It is possible to adopt a configuration that determines the ratio between the fuel injection amount by the direct injection valve and the fuel injection amount by the port injection valve and the injection timing.

  According to the present invention, when the engine is started, it is determined whether the engine is stopped by the idle stop function or based on the ignition operation, and the determined operating state and engine state are determined. Based on this, the ratio between the fuel injection amount by the direct injection valve and the fuel injection amount by the port injection valve and the injection timing are determined, so that smoother starting can be realized.

It is a flowchart of control by the engine control apparatus of one Embodiment of this invention. It is a schematic diagram which shows the structure of the control apparatus of the engine of this invention. It is a schematic diagram which shows examples, such as the opening / closing timing of the intake valve of an engine, the start timing of fuel injection.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart of control by the engine control device of this embodiment, and FIG. 2 is a schematic diagram conceptually showing the engine control device.

  As shown in FIG. 2, the engine is provided with a spark plug 4 for igniting the fuel in the combustion chamber 3 at the top of the cylinder 1. An in-cylinder injection valve (direct injection valve) 10 that directly injects fuel into the combustion chamber 3 is provided slightly on the side of the upper part of the cylinder. In this embodiment, a multi-cylinder engine having a plurality of cylinders is assumed, and FIG. 2 shows one of them. However, the present invention can also be applied to a single-cylinder engine.

  An intake port 5 that leads to the upper part of the cylinder is provided on the side of the spark plug 4. The intake port 5 is provided with a port injection valve 9 for injecting fuel and an intake valve 6 for opening and closing the outlet on the combustion chamber 3 side. Further, on the opposite side of the intake port 5, an exhaust port 7 is also provided that leads to the upper part of the cylinder. The exhaust port 7 is provided with an exhaust valve 8 that opens and closes the outlet on the combustion chamber 3 side.

  The fuel is fed into the port injection valve 9 and the direct injection valve 10 by using a pump 9 a provided in the fuel tank 11. The pump 9 a sends the fuel in the fuel tank 11 toward the port injection valve 9 and the direct injection valve 10. Here, since the fuel injection pressure of the direct injection valve 10 is higher than that of the port injection valve 9, a high-pressure direct injection pump 10 a is used in the middle of the supply route to the direct injection valve 10.

  The fuel injection from the port injection valve 9 and the direct injection valve 10 can be switched between fuel injection and injection stop by opening and closing the electromagnetic valves provided in the port injection valve 9 and the direct injection valve 10 respectively. Adjustment of increase / decrease in the injection amount is performed.

  A vehicle equipped with this engine includes an electronic control unit 20 for controlling the engine. The electronic control unit 20 includes an operating state detection unit 21 that determines the operating state of the engine.

  The operating state detecting means 21 stops various operating conditions such as whether the vehicle is accelerating, decelerating, coasting, or stopping, and whether the engine is operating. It is possible to grasp the overall operating state of the engine, including the state of the engine such as whether or not the engine is stopped.

  The operating state detection means 21 acquires information on the temperature of cooling water from the engine, information on the rotational speed of the engine, information on the engine load, and the like, and uses the information for engine control. The operating state detection means 21 acquires information on the engine speed based on information from a crank angle sensor or the like. Further, information on the load on the engine is acquired based on information such as the opening degree of the throttle valve linked to the accelerator pedal, the fuel injection amount, the engine speed, and the vehicle speed.

  In addition, the fuel pump 9a or the direct injection that sends fuel to the fuel injection device through the intake valve 6, the exhaust valve 8, the ignition plug 4, the port injection valve 9 as the fuel injection device, the direct injection valve 10, and the fuel pipes 9b and 10b. The high-pressure fuel pump 10a that sends fuel to the valve 10 and other devices necessary for the operation of the engine are controlled by control means provided in the electronic control unit 20 through cables. In this embodiment, a part of the computer of the electronic control unit 20 is used as control means.

  Further, the operating state detecting means 21 is in an ignition stop state in which the engine is stopped based on an ignition operation performed by a driver or is automatically stopped based on an idle stop function when the engine is started. It has a function of detecting whether it is in an idle stop state.

  In the ignition operation, the driver supplies the necessary fuel and air to the engine by turning the ignition key from OFF to ON, or by pressing the ignition start button, and the intake and exhaust valves are supplied at a predetermined timing. The engine can be started by operating 6, 8 and the spark plug 4. Further, the engine can be stopped by turning the ignition key from ON to OFF, or by pressing the ignition start button. The engine is started and stopped based on the ignition operation while the vehicle is stopped.

  In this embodiment, the idle stop function includes a stop idle stop function that automatically stops the engine when the vehicle stops, and a coast idle stop function that automatically stops the engine during deceleration or coasting (hereinafter referred to as a coast stop function). And).

  The operating state detection means 21 has a function of detecting whether the engine is stopped by the idle stop function when the vehicle is stopped or stopped by the coast stop function when the engine is in the idle stop state.

  When the vehicle is stopped, the idle stop function automatically stops the engine when the vehicle temporarily stops at a signal installation place or an intersection. That is, the engine is stopped based on the idle stop function when the vehicle is stopped while the vehicle is stopped. The operating state detection unit 21 can detect that the engine is stopped by the idle stop function when the vehicle is stopped based on information from the control unit included in the electronic control unit 20. At this time, determination may be made using vehicle speed information and the like together.

  The coast stop function automatically stops the engine when the vehicle speed is lower than a predetermined value when the vehicle is decelerating or coasting. This vehicle speed is set to be 5 km / h or less, 10 km / h or less, for example. That is, the engine is stopped based on the coast stop function while the vehicle is running. The operating state detection means 21 can detect that the engine is stopped by the coast stop function based on information from the control means provided in the electronic control unit 20 or vehicle speed information.

  In addition, when the engine is stopped by the ignition operation performed by the driver, the operating state detection unit 21 indicates that the engine has been stopped by the ignition operation, such as information from the control unit included in the electronic control unit 20 It can be detected by vehicle speed information or the like.

  As shown in FIG. 2, the electronic control unit 20 includes valve control means 22 that controls the opening / closing timing of the intake valve 6 and the exhaust valve 8 at the start based on the operating state of the engine detected by the operating state detection means 21. Prepare.

  Also, the electronic control unit 20 is based on the operating state of the engine detected by the operating state detecting means 21, and the ratio between the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 at the start, And the fuel-injection determination means 23 which determines the timing of the injection is provided.

  Further, the electronic control unit 20 determines the ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 determined by the fuel injection determining means 23 and the fuel injection from each injection valve. Fuel injection execution means 24 is provided for executing fuel injection based on the timing.

  The electronic control unit 20 includes water temperature detection means 25 that detects the temperature of engine coolant. A temperature sensor is provided in one of the cooling water flow paths, and temperature information acquired by the temperature sensor is transmitted to the water temperature detection means 25 by an electrical signal. The operating state detection unit 21 acquires information about the temperature of the cooling water from the water temperature detection unit 25.

  Based on the water temperature detected by the water temperature detection means 25 when the engine is not in the idle stop state, the valve control means 22 opens and closes the intake valve 6 and the exhaust valve 8 at the start of the engine. To control.

  In this engine, a variable valve timing mechanism is employed, and the valve opening timing and the valve closing timing of the intake valve 6 and the exhaust valve 8 can be arbitrarily set by the control of the valve control means 22. The operation of the variable valve timing mechanism is preferably performed by an electric motor or an electric oil pump. Thereby, the operation | movement independent of the hydraulic pressure of an engine is possible.

  Furthermore, when the engine operating state detected by the operating state detecting unit 21 is an idle stop state, the valve control unit 22 determines whether it is a stop state by an idle stop function when the vehicle is stopped, or a coast stop function. The valve opening timing and valve closing timing of the intake valve 6 and the exhaust valve 8 at the time of starting are controlled based on whether or not the engine is stopped.

  At this time, in the fuel injection determination means 23, the stop state (idle stop state) detected by the operating state detection means 21 is a stop state by the idle stop function when the vehicle is stopped, or a stop state by the coast stop function. Based on this, the ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 at the time of start-up and the timing of the injection are determined. The fuel injection determining means 23 may determine the ratio of the injection amounts on the assumption that both the direct injection valve 10 and the port injection valve 9 are used, or the fuel injection or port injection by the direct injection valve 10 alone. In some cases, fuel injection by only the valve 9 is determined.

  The fuel injection execution unit 24 has a function of instructing and executing fuel injection by the direct injection valve 10 and the port injection valve 9 based on these determinations.

  Further, the electronic control unit 20 includes ignition timing adjusting means for setting the ignition timing for each cylinder. The ignition timing adjusting means determines the optimal ignition timing for each cylinder based on the injection timing and injection amount of the fuel supplied to each cylinder, and the presence or absence of knocking occurrence by the knock detection means. Command can be issued.

  The operation of this engine control device and its control method will be described based on the flowchart of FIG.

  In step S1, start fuel control accompanying engine start is started. This start is performed based on an engine start signal issued by the electronic control unit 20 by an ignition operation performed by the driver, or based on an engine start signal issued by the electronic control unit 20 by an idle stop function.

In step S2, it is determined whether the engine operating state (stopped state) is an idle stop state or an ignition stop state.
In this step S2, when the engine is in the idle stop state, it is not yet determined whether it is a stop state by the idle stop function when the vehicle is stopped or a stop state by the coast stop function.

  When the operating state of the engine is the ignition stopped state, the process proceeds to step S3. Here, it is determined whether the temperature of the engine coolant is greater than or less than a predetermined value.

  In step S3, when the water temperature is equal to or higher than a predetermined value, it is determined that the water temperature is high, that is, it is warm, and the process proceeds to step S4.

  In step S4, the opening timing and closing timing of the intake valve 6 are retarded in response to the engine warm start. In this embodiment, the opening timing of the intake valve 6 is set immediately after top dead center. At this time, the closing timing of the intake valve 6 may be the bottom dead center or the timing at which the compression stroke starts from the bottom dead center. However, in this embodiment, it is retarded from the normal valve closing timing (intermediate position described later) (see FIG. 3A). The opening timing and closing timing of the exhaust valve 8 are determined at appropriate timings through the combustion stroke and the exhaust stroke.

  In FIG. 3, the symbol a indicates the intake stroke, the symbol b indicates the compression stroke, and the symbol e indicates the exhaust stroke. Symbol c indicates the period during which the intake valve 6 is open, symbol d indicates the start timing of fuel injection by the direct injection valve 10, and symbol p indicates the start timing of fuel injection by the port injection valve 9.

  Next, the process proceeds to step S5. In step S5, fuel injection is executed based on the ratio of the fuel injection amount determined based on the operating state of the engine and the timing of fuel injection. Here, since it is a warm start, fuel injection by only the direct injection valve 10 is executed. The ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 is 100: 0. The start timing of the fuel injection is the first half of the intake process, a little later than the top dead center (the period after the start of the intake stroke from the exhaust stroke). Note that the end timing of fuel injection varies depending on the fuel injection amount.

  The fuel injection by the direct injection valve 10 has good controllability of fuel injection and has a short interval until ignition, which is advantageous for starting the engine when it is warm. Although the degree of mixing of fuel and air is inferior to that of port injection, there is no problem in startability if it is a warm start. In addition, the fuel injection by the direct injection valve 10 at the time of cold tends to increase the fuel adhesion to the inner wall of the combustion chamber 3.

  Further, the actual compression ratio can be reduced by retarding the opening timing and closing timing of the intake valve 6. Thereby, vibration and noise can be reduced.

  As described above, in the warm start, since the engine is sufficiently warm and the startability is good, the fuel is injected only by the direct injection valve 10 to ignite early and the vibration of the intake valve 6 is delayed and vibration and noise are caused. To achieve a start-up with reduced Further, by adopting fuel injection by the direct injection valve 10 and bringing the air-fuel mixture to a state close to the stoichiometric air-fuel ratio, deterioration of exhaust gas is prevented and fuel efficiency is improved.

  In step S3, if the water temperature is lower than the predetermined value, it is determined that the water temperature is low, that is, it is cold, and the process proceeds to step S6.

  In step S6, the opening timing of the intake valve 6 is advanced in response to the cold start of the engine. In this embodiment, the opening timing of the intake valve 6 is slightly before top dead center (hereinafter referred to as an intermediate position). At this time, the closing timing of the intake valve 6 may be the bottom dead center or the timing at which the compression stroke starts from the bottom dead center. However, in this embodiment, the valve is closed at an intermediate position similarly to the valve opening timing, that is, the valve is closed slightly earlier than in the case of the above-described warm start (see FIG. 3B). The opening timing and closing timing of the exhaust valve 8 can be the same as in the case of the warm start. At this intermediate position, an intermediate effect between the retard angle and the advance angle can be expected, that is, the occurrence of vibration and noise and the fuel vaporization effect can be expected in a balanced manner.

  Next, the process proceeds to step S7. In step S7, fuel injection is performed based on the ratio of the fuel injection amount determined based on the operating state of the engine and the timing of fuel injection. Here, since it is a cold start, fuel injection by only the port injection valve 9 is executed. The ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 is 0: 100. The fuel injection start time is immediately after the exhaust stroke is started.

  The fuel injection by the port injection valve 9 has a long interval until ignition, so the degree of mixing of fuel and air is good. For this reason, it is advantageous for cold start. In the fuel injection by the port injection valve, in order to ensure the startability, considering that the fuel is likely to adhere to the inner surface of the port, the controllability of the fuel injection is inferior to that of the direct injection, and the variation in the fuel properties, etc. It is desirable to make the starting fuel rich.

  Further, by advancing the valve opening timing and valve closing timing of the intake valve 6, the intake air amount increases and the starting torque increases. As a result, drivability can be improved although vibration and noise are slightly increased. Further, by expanding the overlap period with the valve opening period of the exhaust valve 8, it is possible to expect the fuel vaporization promoting effect of the port injection by blowing back the combustion gas to the intake side.

  Thus, in cold start, since the engine is in a cold state and it is desired to ensure startability, stable fuel supply by the port injection valve 9 and the intake valve 6 are suppressed while minimizing an increase in vibration and noise. Achieving a smooth start with advance angle. In addition, stable combustion suppresses deterioration of fuel consumption and exhaust gas.

  Next, when the engine operating state (stop state) is the idle stop state in the above-described step S2, the process proceeds to step S8.

  In step S8, it is determined whether the idle stop state of the engine is a stop state by the coast stop function (coast stop state) or a stop state by the idle stop function when stopped (idle stop state when stopped). .

  When it is in the coast stop state, the process proceeds to step S9. Here, in the case of restart from the coast stop state, that is, restart in which the vehicle has not stopped yet and is traveling due to inertia, the process proceeds to step S10.

  In step S10, the valve opening timing of the intake valve 6 is further advanced. In this embodiment, the opening timing of the intake valve 6 is further on the exhaust stroke side than the intermediate position just before top dead center. At this time, the closing timing of the intake valve 6 may be the bottom dead center or the timing of entering the compression stroke from the bottom dead center, but in this embodiment, the valve closing timing is earlier than the intermediate position as in the valve opening timing. (See FIG. 3C). The opening timing and closing timing of the exhaust valve 8 may be the same as those described above.

  Next, the process proceeds to step S11. In step S11, fuel injection is performed based on the ratio of the fuel injection amount determined based on the operating state of the engine and the timing of fuel injection. Here, since the restart is from the coast stop state and corresponds to the warm start, fuel injection by only the direct injection valve 10 is executed. The ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 is 100: 0. The start timing of the fuel injection is the timing immediately after the intake stroke starts from the exhaust stroke, that is, the first half of the intake stroke.

  In the case of restart from the coast stop state, the vehicle is still running, so it is necessary to accelerate the vehicle immediately. For this reason, response is emphasized.

  On the other hand, when the engine idle stop state is the idling stop state when the vehicle is stopped in step S8, the process proceeds to step S12.

  In step S9, although the vehicle is stopped by the coast stop function, when the vehicle is restarted from the already stopped state, the process proceeds to step S12 according to the idle stop state when the vehicle is stopped.

  In step S12, the opening timing of the intake valve 6 is retarded. In this embodiment, the opening timing of the intake valve 6 is on the intake stroke side with respect to the top dead center. At this time, the closing timing of the intake valve 6 may be the bottom dead center or the timing when it enters from the bottom dead center in the compression stroke. However, in this embodiment, the valve is closed later than the intermediate position shown in FIG. 3B (see FIG. 3D). The opening timing and closing timing of the exhaust valve 8 may be the same as those described above.

  Next, the process proceeds to step S13. In step S13, fuel injection is performed based on the ratio of the fuel injection amount determined based on the operating state of the engine and the timing of fuel injection. Here, the restart is from the idle stop state when the vehicle is stopped, and corresponds to the warm start, so that the fuel injection only by the direct injection valve 10 is executed. The ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 is 100: 0. The fuel injection start time is slightly before top dead center and in the latter half of the compression stroke.

  In the case of restart from the idle stop state when the vehicle is stopped, there is some time until the vehicle actually starts, and therefore control is performed with emphasis on reduction of vibration and noise.

  After the engine is started and restarted, it shifts to a normal engine operating state. The control means of the electronic control unit 20 performs normal fuel control, valve control, ignition timing control, and the like according to the operating conditions.

  As described above, according to the present invention, when the engine is started, it is determined whether the engine is stopped by the idle stop function or based on the ignition operation, and the determined engine Since the ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 and the injection timing are determined based on the operating state, a smoother start can be realized.

  Since the friction is small when starting at a high water temperature, the actual compression ratio can be lowered by retarding the valve timing, and the occurrence of noise and vibration can be suppressed. Further, by adopting fuel injection by the direct injection valve 10 with good fuel controllability and bringing the air-fuel mixture to a state close to the stoichiometric air-fuel ratio, exhaust gas and fuel consumption can be improved.

  Further, when starting in a low water temperature state, the valve timing is advanced to ensure torque and promote fuel vaporization, and to improve exhaust gas by stable fuel injection by the port injection valve 9. be able to.

  In the above embodiment, the idle stop function is composed of an idle stop function when the vehicle is stopped automatically when the vehicle is stopped and a coast stop function that automatically stops the engine when the vehicle is decelerated or coasted. Depending on the specifications of the engine, it is possible to adopt one without the coast stop function. In this case, in the flowchart of FIG. 1, steps S8 to S11 are omitted, and if “N” is determined in step S2, the process proceeds to step S12.

  In the above embodiment, the ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 is set to 100: 0 or 0: 100, respectively, depending on the operating state of the engine. It is not limited to this embodiment.

  For example, in the control of FIGS. 3A, 3C, and 3D mainly for the direct injection, the ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 is changed to 100: 0. You may set the function of the fuel-injection determination means 23 so that it may become 90:10 or 80:20. At this time, it is desirable that the fuel injection amount by the direct injection valve 10 is relatively large.

  Further, for example, in the control of FIG. 3B in which the port injection is mainly performed, the ratio of the fuel injection amount by the direct injection valve 10 and the fuel injection amount by the port injection valve 9 is changed to 10:90 instead of the ratio 0: 100. You may set the function of the fuel-injection determination means 23 so that it may be set to 20:80. At this time, it is desirable that the fuel injection amount by the port injection valve 9 is relatively large.

  In each of the above embodiments, a four-cycle gasoline engine for automobiles has been described as an example. However, the present invention is not limited to this embodiment, and the present invention can be applied to, for example, a two-cycle gasoline engine. The present invention can also be applied to reciprocating engines used in various transportation equipment other than automobiles and industrial machines.

1 Cylinder 2 Piston 3 Combustion chamber 4 Spark plug 5 Intake port 6 Intake valve 7 Exhaust port 8 Exhaust valve 9 Port injection valve 9a Fuel pump 9b Fuel pipe 10 Direct injection valve 10a High pressure fuel pump 10b Fuel pipe 11 Fuel tank 20 Electronic control unit 21 Operating state detection means 22 Valve control means 23 Fuel injection determination means 24 Fuel injection execution means 25 Water temperature detection means

Claims (4)

A direct injection valve that directly injects fuel into the cylinder;
A port injection valve for injecting fuel into the intake port leading to the cylinder;
An intake valve for opening and closing the intake port;
An operating state detecting means for detecting an operating state of whether the engine is in an ignition stop state in which the engine is stopped based on an ignition operation or in an idle stop state in which the engine is automatically stopped based on an idle stop function when starting the engine;
Valve control means for controlling the opening and closing timing of the intake valve at the start based on the operating state of the engine detected by the operating state detecting means;
Fuel injection determining means for determining a ratio between the amount of fuel injected by the direct injection valve and the amount of fuel injected by the port injection valve at the time of start and the timing of injection based on the operating state detected by the operating state detecting unit; ,
Fuel injection execution means for executing fuel injection based on the ratio determined by the fuel injection determination means and the timing of injection;
Bei to give a,
The idle stop function consists of an idle stop function when stopping to automatically stop the engine and a coast stop function that automatically stops the engine when decelerating or coasting,
The operating state detecting means has a function of detecting whether the engine is stopped by the idle stop function or stopped by the coast stop function when the operating state is the idle stop state,
The valve control means is configured to determine whether the intake valve at the time of starting is based on whether the stop state detected by the operating state detecting means is a stop state by an idle stop function when stopped or a stop state by a coast stop function. Engine control device that controls opening and closing timing . Equipped with a water temperature detection means for detecting the temperature of the engine cooling water,
2. The engine control device according to claim 1, wherein when the operating state is not an idle stop state, the valve control unit controls the opening / closing timing of the intake valve at the start based on the water temperature detected by the water temperature detecting unit. .   The fuel injection determining means, when the operating state is not an idle stop state, the fuel injection amount by the direct injection valve and the fuel injection by the port injection valve at the start based on the water temperature detected by the water temperature detecting means 3. The engine control device according to claim 2, wherein a ratio to the quantity and an injection timing are determined. The fuel injection determining means is configured to detect the direct injection at the time of starting based on whether the stop state detected by the operating state detecting means is a stop state by an idle stop function at a time of stopping or a stop state by a coast stop function. The engine control device according to any one of claims 1 to 3, wherein a ratio between a fuel injection amount by a valve and a fuel injection amount by the port injection valve and an injection timing are determined.

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