FR3076862A1 - FUEL INJECTION CONTROL DEVICE AND FUEL INJECTION CONTROL SYSTEM - Google Patents

Abstract

A fuel injection control device is provided. The fuel injection control device is configured to stop injecting fuel into an engine (2) in response to automatic engine shutdown. A quantity of fuel injection during engine restart is changed according to a time elapsed after the fuel cut attributable to the automatic engine stop until the start of fuel injection attributable to the engine restart . Fig. 1

Description

The present invention relates to a fuel injection control device and a fuel injection control system.

PRIOR ART In certain vehicles such as four-wheeled cars, a standby and start stop control is carried out (see for example Patent Document 1). In Patent Document 1, in order to suppress the occurrence of a hesitation at the time of a sudden acceleration after restart, after an engine has been restarted from an automatic stop state, if an action is performed during a predetermined period in order to increase the degree of opening of the throttle valve, the amount of fuel injection is increased.

Technical problem [0003] However, in the case where the fuel injection is interrupted if the standby stop starts, the fuel in an intake port is atomized until the engine is restarted. In this case, since the quantity of fuel injected into the cylinders during the restart decreases, a delay may occur during the increase in the rotation speed after the restart. Thus, in Document Patent 1, a good restart capacity is not always obtained and it is necessary to further improve the restart capacity.

Summary of the invention [0004] Consequently, one of the objects of the present invention is to provide a fuel injection control device and a fuel injection control system capable of improving the restartability after an automatic engine stop. Disclosure of the invention According to one aspect of the embodiments of the present invention, there is provided a fuel injection control device configured to stop the injection of fuel into an engine in response to the automatic stop. of the engine, in which a quantity of fuel injection during restarting of the engine is modified as a function of a time elapsed after the fuel cut off attributable to the automatic stopping of the engine until the start of fuel injection due to restarting the engine.

According to one embodiment, the quantity of fuel injection during the restarting of the engine is modified as a function of a fuel cut-off period until an engine speed decreasing due to the cut of fuel reaches zero, included in the elapsed time.

According to one embodiment, the quantity of fuel injection during the restarting of the engine is modified as a function of an automatic stopping period when the engine speed is maintained at zero, comprised in the elapsed time.

According to one embodiment, the automatic stopping of the engine is determined according to the depressing of a brake pedal, and the restarting of the engine is determined according to the release of the depressing of the brake pedal , and the quantity of fuel injection during the restarting of the engine is modified according to whether an accelerator pedal is actuated or not after the release of the depressing of the brake pedal.

According to one embodiment, in the case where no action on the accelerator pedal has been carried out, the quantity of fuel injection during the restarting of the engine is modified according to a first card which is defined according to the elapsed time.

According to one embodiment, in the case where an action on the accelerator pedal has been carried out, the quantity of fuel injection during the restarting of the engine is modified according to a second card which is defined in dependent on engine speed and intake air pressure.

According to one embodiment, the quantity of fuel injection during the restarting of the engine is modified as a function of an amount of air circulating during a period following the interruption of the fuel injection of the engine until the engine is restarted.

According to another aspect of the embodiments of the present invention, there is provided a fuel injection control system comprising an engine having a fuel injection device of the indirect injection type and a control device d fuel injection configured to control the fuel injection of the fuel injection device, wherein the fuel injection control device comprises: a standby stop control unit configured to control the stop automatic and engine restart; a time measurement unit configured to measure a time elapsed after the fuel cut off attributable to the automatic stopping of the engine until the engine is restarted; and an injection amount control unit configured to increase the amount of fuel injection from the fuel injection device during engine restart, as the elapsed time which is measured by the time measuring unit elongates.

According to the present embodiment, it is possible to improve the restarting capacity after the automatic stopping of an engine.

Brief description of the drawings In the accompanying drawings:

Fig.l [fig.l] is a view illustrating the general configuration of a fuel injection control system according to one embodiment;

Fig. 2 [fig-2] is a comparative diagram illustrating the temporal variations of the engine speed after a restart of the engine according to the embodiment and the prior art;

Fig. 3 [fig.3] is a schematic diagram illustrating the temporal variation of the engine speed after an automatic engine stop until restart;

Fig. 4 [fig-4] is a flowchart illustrating an example of fuel injection control according to the embodiment;

Fig. 5 [Fig.5] is a view illustrating a flow of elapsed time calculation according to a variant.

Description of the embodiments Below, an embodiment of the present invention is described in detail with reference to the appended figures. Similarly, below, by way of example of a vehicle on which a fuel injection control system according to the present invention is implemented, a four-wheeled automobile is described; however, the purpose of the implementation is not limited to it and may be changed. For example, the present invention can also be implemented on other types of vehicles such as motorcycles and motor tricycles of buggy type.

Referring to FIG. 1, a fuel injection control system according to the present embodiment is described. Fig. 1 is a view illustrating the general configuration of the fuel injection control system according to the present embodiment. However, the fuel injection control system is not limited to the configuration described below and can be modified as appropriate.

As illustrated in FIG. 1, a fuel injection control system 1 according to the present embodiment is configured to control the operations of an engine 2 which is an internal combustion engine and its peripheral components by an ECU 3 (Electronic Control Unit or in English Electronic Control Unit or ECU). The ECU 3 constitutes a fuel injection control device of the present invention, as described in detail below. Engine 2 is configured with, for example, a double overhead camshaft (in English Double OverHead Camshaft or DOHC) of direct action type. The engine 2 is configured to include a crankshaft 20 housed in a casing (not shown in the drawings), a cylinder 21, a cylinder head 22, etc.

In the cylinder 21, a piston 23 is housed so as to be able to move back and forth in a predetermined direction (in Fig. 1, in the up-down direction). The crankshaft 20 and the piston 23 are connected by a connecting rod 24. In the engine 2, the piston 23 moves back and forth in the predetermined direction, the crankshaft 20 being driven in rotation via the connecting rod 24.

The internal space of the cylinder head 22 constitutes a combustion chamber 25. At an upper part of the combustion chamber 25, a spark plug 26 which is an ignition device is provided. The spark plug 26 ignites the air-fuel mixture in the combustion chamber 25 at a predetermined time as a function of an ignition signal which is emitted by the ECU 3.

The cylinder head 22 has an intake port 27a and an exhaust port 27b connected to the combustion chamber 25. In addition, the cylinder head 22 has an intake valve 28a and an exhaust valve 28b corresponding to the intake port 27a and the exhaust port 27b. The upper ends of the intake valve 28a and the exhaust valve 28b have an intake camshaft 29a and an exhaust camshaft 29b.

On the crankshaft 20, the intake camshaft 29a and the exhaust camshaft 29b, a chain for cams (not shown in the drawings) is installed. The rotation of the crankshaft 20 is transmitted to the intake camshaft 29a and to the exhaust camshaft 29b via the cam chain. If the intake camshaft 29a and the exhaust camshaft 29b are rotated, the intake valve 28a and the exhaust valve 28b move back and forth with respect to the combustion chamber 25 at predetermined times.

An intake pipe 10 is connected to the upstream end of the intake port 27a via an intake manifold (not shown in the drawings). The passage in the intake pipe 10 and the intake orifice 27a constitute an intake air intake passage. On certain parts of the intake pipe 10, an air filter 11, a throttle valve 12 and a balancing tank 13 are provided from the upstream side. On the part of the intake pipe 10 between the air filter 11 and the throttle valve 12, an air quantity sensor 40 is provided. The air quantity sensor 40 detects the quantity of intake air (mass flow) flowing in the intake pipe 10 through the air filter 11 and transmits the detection value to the ECU 3.

The throttle valve 12 is configured to include, for example, a butterfly valve, and is opened and closed according to the commands of the ECU 3 to adjust the flow of intake air flowing in the intake pipe 10. The balancing tank 13 has a sufficiently large volume and is intended to prevent pulsations of the intake air. On the balancing tank 13, an intake air pressure sensor 41 is provided. The intake air pressure sensor 41 detects the intake air pressure (the intake air pressure) in the balancing tank 13 and transmits the detection value to the ECU 3.

In the intake pipe 10 (or the intake port 27a) on the downstream side of the balancing tank 13, an injector 14 which is a fuel injection device for injecting fuel is provided. The injector 14 injects a predetermined quantity of fuel into the intake pipe 10 (or the intake orifice 27a) in accordance with a command from the ECU 3. In other words, the engine 2 according to this mode embodiment is configured with a so-called indirect injection type engine (in English port injection type engine).

At the downstream end of the exhaust port 27b, an exhaust pipe 15 is connected via an exhaust manifold (not shown in the drawings). The exhaust port 27b and the passage in the intake pipe 10 constitute an exhaust passage for the exhaust gases. On a part of the exhaust pipe 15, a catalytic converter 16 intended to purify the exhaust gases is provided. The catalytic converter 16 is configured with, for example, a three-way catalytic converter and converts pollutants (such as carbon monoxide, hydrocarbons, nitrogen oxides, etc.) contained in the exhaust gases into substances harmless (such as carbon dioxide, water, nitrogen, etc.).

Before and after (on the upstream side and on the downstream side) the catalytic converter 16, air-fuel ratio sensors 42 and 43 are provided. The air-fuel ratio sensors 42 and 43 detect the air-fuel ratios of the exhaust gases before and after the catalytic converter 16 and transmit the detection values to the ECU 3.

In the engine 2 which is configured as described above, the intake air having passed through the air filter 11 is subjected to an adjustment of the flow rate of the throttle valve 12, then flows into the inlet 27a through the balancing tank 13. At this time, the fuel is injected from the injector 14 at a predetermined time, so that the intake air and fuel are mixed in the intake port 27a. The air-fuel mixture of the intake air and the fuel enters the combustion chamber 25 at a time when the intake valve 28a is open and is compressed in the combustion chamber 25, then is ignited by the spark plug. ignition 26 at a predetermined time. The ignited and burnt exhaust gases are evacuated from the exhaust port 27b to the outside by the exhaust pipe 15. At this time, the exhaust gases are purified by the catalytic converter 16, then the noise exhaust these are reduced by a silencer (not shown in the drawings).

Similarly, in the engine 2, a water temperature sensor 44 for detecting the temperature of the engine water and a crankshaft sensor 45 for detecting the phase of the crankshaft 20 are provided.

The detection values of the water temperature sensor 44 and the crankshaft sensor 45 are transmitted to the ECU 3. From the data of the crankshaft sensor 45, the engine speed can be calculated.

In addition, in the vehicle, a vehicle speed sensor 46 for detecting the vehicle speed, a brake pedal 47 and an accelerator pedal 48 are provided. The detection value of the vehicle speed sensor 46 is transmitted to the ECU 3. The brake pedal 47 constitutes a braking means for generating a braking force in the vehicle and transmits a predetermined electrical signal as a function of the intensity of the depressing force (the depressing force) applied thereto to the ECU 3. The accelerator pedal 48 constitutes an acceleration means for generating an acceleration force in the vehicle and transmits a predetermined electrical signal as a function of the intensity of the penetration (the penetration force) applied to it at the ECU 3.

The ECU 3 generally controls the operation of the entire vehicle, including various components in addition to the engine 2. The ECU 3 is configured with a processor to perform various processes, a memory, etc. The memory is configured with storage media such as read-only memory (ROM), random access memory (RAM), etc. for its use. In memory, a control program for controlling the various components mentioned above, etc., is stored.

For example, the ECU 3 determines the state of the vehicle from various sensors provided in the vehicle and performs a control on the piloting of the spark plug 26, of the injector 14, of the valve d 12, etc. The ECU 3 controls the fuel injection from the injector 14 as a function of the time elapsed after the automatic shutdown of the engine 2 and of the detection values received from the water temperature sensor 44, from the crankshaft sensor 45, from the vehicle speed sensor 46, brake pedal 47, etc. which are described in detail later. In addition, the ECU 3 stores cards (a first card and a second card described below) defining predetermined conditions for correcting the amount of fuel injection in advance.

For example, the ECU 3 comprises a plurality of functional blocks as a function of components which are objects to be checked. In particular, the ECU 3 comprises a standby stop control unit 30 for controlling the automatic stopping and restarting of the engine 2, a time measurement unit 31 for measuring the time elapsed after the automatic stopping of the engine 2 until restarting, and a unit for controlling the injection quantity 32 for controlling the piloting of the injector 14 as a function of the elapsed time which is measured by the time measurement unit 31.

However, these functional blocks are only examples for practical reasons, and the ECU 3 is not limited to these functional blocks and may include other functional blocks. In addition, the ECU 3 can globally perform the following various checks without including these functional blocks. For example, the standby stop control unit 30 can have the functions of the time measurement unit 31 and of the injection quantity control unit 32.

The standby stop control unit 30 performs a so-called stop and start standby control (automatic stop-restart control) to automatically stop the engine 2 if the vehicle s temporarily stops, for example to wait for a signal at an intersection and to restart engine 2 from the automatic stop state (the standby stop state).

More specifically, the standby stop control unit 30 determines whether an automatic stop condition is met, depending on whether or not the brake pedal 47 is actuated, the speed of the vehicle , engine water temperature, etc. In the case where the predetermined automatic stop condition is fulfilled, the standby stop control unit 30 stops the injection of fuel from the injector 14 (fuel cut).

In addition, the standby stop control unit 30 determines whether a restart condition is met, depending on the release of the depressing on the brake pedal 47, etc. In the case where the predetermined restart condition is fulfilled, the standby stop control unit 30 restarts the engine 2 by driving a starting engine (not shown in the drawings) while restarting the fuel injection from the injector 14.

The time measurement unit 31 measures the time after the fuel cut due to the automatic shutdown of the engine 2 until restart, as described above. In addition, the injection quantity control unit 32 controls the quantity of fuel injection of the injector 14 during the restarting of the engine 2, as a function of the time which is measured by the time measurement unit 31 , and controls the amount of fuel injection from the injector 14 as a function of a predetermined parameter. The time measurement unit 31 and the injection quantity control unit 32 are described below.

By the way, in a vehicle which performs an automatic stop-restart control in an engine of the indirect injection type, the fuel injection is interrupted in response to the automatic engine stop. For this reason, it can be considered that the fuel present on the interior surface of the intake port is atomized until the engine is restarted and the interior surface of the intake port dries up. If fuel injection is restarted in this state, since part of the injected fuel adheres to the internal surface of the intake port, the amount of fuel introduced into the combustion chamber decreases significantly. Consequently, when the engine is restarted, a slowness, that is to say a hesitation, occurs.

In the prior art, there is a technology for making a correction to increase the amount of fuel injection depending on the degree of opening of the throttle during restart; however, good restartability is not always achieved and there is a need to further improve restartability.

Referring now to FIG. 2, the temporal variations in the speed of the engine after restarting the engine according to the prior art and the present invention are described. Fig. 2 is a comparison diagram illustrating the temporal variations in the speed of the engine after a restart of the engine according to the present invention and the prior art. In Fig. 2, a horizontal axis represents time and a vertical axis represents the speed of the motor. Furthermore, in FIG. 2, a dotted line represents an example according to the prior art, and a solid line represents an example according to the present invention.

As shown in FIG. 2, in the prior art, due to the phenomenon described above (the hesitation), after restarting the engine, the engine speed increases and decreases repeatedly, and the increase in the engine speed becomes stagnant.

On the contrary, in the present invention, taking into account the time elapsed after the fuel cut-off until restarting, the quantity of fuel injection during the restarting of the engine is modified as a function of this elapsed time. In the present embodiment, the ECU 3 modifies the quantity of fuel injection during the restarting of the engine 2 as a function of the period of time (elapsed time) after the interruption of the fuel injection attributable to the automatic stopping of the engine 2 until the start of the fuel injection attributable to the restarting of the engine 2. More precisely, after the fuel injection has been interrupted by the standby stop control unit 30, the time elapsed until restart is measured by the time measurement unit 31. Then, as a function of this elapsed time, the injection quantity control unit 32 controls (increases) the quantity of fuel injection of the injector 14.

In general, during the automatic shutdown of the engine 2, the fuel from the intake orifice is atomized and the amount of fuel introduced into the combustion chamber during the restart of the engine 2 decreases. As a result, the air-fuel ratio may weaken. According to the configuration described above, since the quantity of fuel injection during the restart is corrected (increased) as a function of the time during which the fuel injection was interrupted due to the automatic stopping of the engine 2, a an appropriate amount of fuel including atomized fuel can be introduced into the combustion chamber. Consequently, as shown by the solid line in FIG. 2, after restarting the engine, it is possible to quickly stabilize the engine at a predetermined speed without causing the engine speed to stagnate. In other words, it is possible to prevent the air-fuel ratio during restarting from weakening, thereby improving the restartability of engine 2.

Referring now to FIG. 3, the temporal variation of the motor speed after the automatic stop of the motor of the present embodiment until its restart is described. Fig. 3 is a schematic diagram illustrating the temporal variation of the engine speed after an automatic engine stop until restart. In Fig. 3, a horizontal axis represents time and a vertical axis represents the speed of the motor.

As described above, if the vehicle stops temporarily, for example to wait for a signal at an intersection, and the automatic engine 2 shutdown condition is met, the ECU 3 (the unit of standby stop control 30) cuts the fuel at an instant Tl shown in FIG. 3. At this time, the time measurement unit 31 begins the measurement of time (counting by timer).

After T1, since the fuel cut continues, the engine speed decreases and, at an instant T2, the engine speed reaches zero. Here, the time between T1 and T2 is called the fuel cut-off period. In other words, the fuel cutoff period refers to the time elapsed after the fuel cutoff begins until the engine drive stops completely (rotation of the camshaft). However, even at this time, the time measurement unit 31 continues the measurement of time.

After T2, if the engine 2 restart condition is met at an instant T3, the standby stop control unit 30 restarts the engine 2 by driving the starting engine (not shown in the drawings ) while restarting the injection of fuel from the injector 14. Here, the time between T2 and T3 is called the automatic shutdown period. In other words, the automatic stop period means the time after the drive of motor 2 has been completely stopped until the start of restarting (the time during which the motor speed has been kept at zero). Similarly, the release of the depressing of the brake pedal 47 can be taken as an example in which the condition for restarting the motor 2 is fulfilled.

In addition, at time T3, the time measurement of the time measurement unit 31 ends. The duration measured by the time measurement unit 31, that is to say the time elapsed after the interruption of the fuel injection attributable to the automatic stopping of the engine 2 until the start of the injection of fuel attributable to restarting engine 2 is a period including both the fuel cut-off period and the automatic shutdown period described above.

After T3, the injection quantity control unit 32 calculates the quantity of fuel injection as a function of the elapsed time measured by the time measurement unit 31. For example, the control unit of injection amount 32 increases the amount of fuel injection as the elapsed time becomes longer.

The method for calculating the quantity of fuel injection is now described. For example, after T3, during a period elapsing up to an instant T4 when the depressing of the accelerator pedal 48 begins, the injection quantity control unit 32 calculates (corrects) the amount of fuel injection by multiplying a correction coefficient (called for convenience first card), which increases as the elapsed time becomes longer, by the elapsed time. Thus, the injection amount control unit 32 determines the amount of fuel injection so that the amount of fuel injection increases as the elapsed time becomes longer, and performs the fuel injection at from the injector 14 with the determined quantity of fuel injection.

In addition, after T4, since the engine speed gradually increases, taking into account the engine load, the injection quantity control unit determines the quantity of fuel injection according to a second card. different from the first card. More specifically, the injection quantity control unit 32 calculates (corrects) the quantity of fuel injection by multiplying a correction coefficient (the second map), which is defined as a function of the engine speed and the intake air pressure, by the time elapsed. In addition, the second map is defined as a function of the intake air pressure, which increases as the engine speed increases. Thus, after T4, the injection quantity control unit 32 changes the reference card, from the first card to the second card, and determines the quantity of fuel injection so that the quantity of fuel injection increases as the engine load increases. Then, the injection quantity control unit injects fuel from the injector 14 with the determined fuel injection quantity.

As described above, by switching between a card (the first card) based on the fact that the accelerator pedal 48 has been actuated, that is to say the time elapsed, and a card (the second map) based on the engine load which is defined as a function of the engine speed and the intake air pressure as a function of the degree of opening of the throttle valve, it is possible to modify the amount of fuel injection depending on the engine load. Therefore, it is possible to improve the increase in engine speed after restarting engine 2.

For example, in the case of a restart of the engine 2 without depressing the accelerator pedal 48, by injecting a defined quantity of fuel during the restart, the amount of fuel injection during the restart is modified as a function of the elapsed time described above. In general, in the case of restarting the engine 2 which is carried out in the case where the accelerator pedal 48 is not depressed, the restarting of the engine 2 is carried out with the quantity of fuel injection which is the defined quantity , and the quantity of fuel injection is increased as a function of the elapsed time, which makes it possible to improve the restartability of engine 2.

In addition, in the case where the accelerator pedal 48 is depressed and the degree of opening of the throttle reaches or exceeds a predetermined value, the quantity of fuel injection which is determined as a function of the pressure d The intake air is increased as a function of the time elapsed. In other words, in the case where the degree of opening of the throttle valve after the release of the depressing of the brake pedal 47 reaches or exceeds the predetermined value, the transition to a fuel injection control based on the intake air pressure is performed. Consequently, it is possible to carry out a fuel injection control as a function of the acceleration actions by the occupant. Likewise, the case where the degree of opening of the throttle reaches or exceeds the predetermined value indicates the case where an occupant depresses the accelerator pedal 48 in order to make the vehicle accelerate.

Similarly, in the calculation of the elapsed time described above, the amount of air flowing from the engine 2 (the intake port) during the elapsed time can be taken into account, which is described in detail later. By considering the amount of air flowing from engine 2, it is possible to estimate the amount of fuel to be extracted from the intake port, which makes it possible to appropriately adjust the amount of fuel injection during the restarting the engine 2. Alternatively, the amount of circulating air can be calculated from the total number of engine revolutions in the elapsed time. In addition, the quantity of circulating air can be acquired from the air quantity sensor 40. The quantity of circulating air can also be calculated as a function of the intake air pressure detected by the pressure sensor intake air 41. For example, as the intake air pressure increases, the amount of circulating air increases.

Referring now to Lig. 4, a control flow according to the present embodiment is described. The Lig. 4 is a flow chart illustrating an example of fuel injection control according to the present embodiment. Likewise, in the control flow described below, unless expressly indicated, the subject of operations (calculation (computer calculation), determination, etc.) is the ECU.

As shown in Lig. 4, if the control starts, at ΓΕΤΑΡΕ ST101, it is determined whether the condition of automatic stop of motor 2 is fulfilled. If the automatic stop condition of motor 2 is not fulfilled (NO at ΓΕΤΑΡΕ ST101), the process in ΓΕΤΑΡΕ ST101 is repeated. In the event that the automatic stopping condition of engine 2 is fulfilled (“YES” at ΓΕΤΑΡΕ ST101), the fuel is cut and control passes to the process of ΓΕΤΑΡΕ ST102.

At ΓΕΤΑΡΕ ST102, the measurement of time is started. Then control passes to the process of ΓΕΤΑΡΕ ST 103.

At ΓΕΤΑΡΕ ST103, it is determined whether the condition for restarting the motor 2 is fulfilled. If the restart condition of motor 2 ("NO" at ΓΕΤΑΡΕ ST 103) is not fulfilled, the process of ΓΕΤΑΡΕ ST 103 is repeated. If the restart condition of motor 2 ("YES" at ΓΕΤΑΡΕ ST103) is fulfilled, control passes to the process of ΓΕΤΑΡΕ ST 104.

At ΓΕΤΑΡΕ ST104, the measurement of time is finished. In this way, it is possible to measure the time elapsed after the fuel cut-off until the engine 2 is restarted. At this moment, while the fuel injection is restarted, the starting engine is driven, the engine 2 being then restarted. Then, control passes to the process of ΓΕΤΑΡΕ ST 105.

At ΓΕΤΑΡΕ ST105, the quantity of injection is modified as a function of the measured elapsed time. For example, the amount of fuel injection increases as the elapsed time becomes longer. Then the control ends.

As described above, in the present embodiment, the quantity of fuel injection during the restarting of the engine 2 is modified as a function of the time elapsed after the fuel has been cut off until restarting, which makes it possible to '' improve restarting capacity after automatic engine shutdown 2.

Likewise, although the case in which the quantity of fuel injection during restarting is modified as a function of the elapsed time measured in the control flow described above has been described, the present invention is not there not limited. The elapsed time can be calculated (corrected) according to a predetermined condition. Referring now to FIG. 5, an elapsed time calculation flow is described. Fig. 5 is a view illustrating an elapsed time calculation flow according to a variant.

As indicated in FIG. 5, in the elapsed time calculation flow, at ΓΕΤΑΡΕ ST201, the time elapsed after the fuel cut-off until the engine speed reaches zero, i.e. the fuel cut-off period shown in Fig. 3, is calculated. In addition, the amount of air circulating during the fuel cut-off period is calculated.

At ΓΕΤΑΡΕ ST202, the fuel cut-off period calculated at ΓΕΤΑΡΕ ST201 is corrected as a function of the amount of circulating air. For example, since the amount of atomized fuel is expected to increase as the amount of circulating air increases, in order to increase the amount of fuel injection, the fuel cut-off period is corrected so that it lengthens.

At ΓΕΤΑΡΕ ST203, the time during which the motor speed has been kept at zero, that is to say the automatic stopping period shown in FIG. 3 is calculated.

At ΓΕΤΑΡΕ ST204, the fuel cut-off period corrected at ΓΕΤΑΡΕ ST202 and the automatic stop period calculated at ΓΕΤΑΡΕ ST203 are added.

The duration calculated as described above can be used as elapsed time, and the injection quantity control (STEP ST 105) illustrated in FIG. 4 can be carried out as a function of this elapsed time. In addition, the elapsed time calculation flow shown in Fig. 5 can be performed at any time within a range in which no contradiction occurs in the control. For example, the elapsed time calculation flow can be performed after ΓΕΤΑΡΕ ST 104 in FIG. 4. However, depending on the duration that is calculated, the elapsed time calculation flow can be performed before ΓΕΤΑΡΕ ST 103. In addition, all the individual processes of the elapsed time calculation flow need not be executed and some processes can be executed. In addition, the order of the processes can be appropriately changed within a range in which no contradiction occurs.

Furthermore, in the embodiment described above, the description has been made using the engine 2 of the indirect injection type. The present invention is not however limited to this configuration. For example, an engine 2 of the direct injection type can be used.

In addition, in the embodiment described above, the case where the second card is defined as a function of the engine speed and the intake air pressure has been described. The present invention is not however limited to this configuration. The second map can be defined according to the intake air pressure and the engine water temperature. For example, it is better to decrease the correction coefficient when the engine water temperature increases. In other words, when the temperature of the engine 2 increases, the amount of fuel injection during restarting decreases, while, when the intake air pressure increases, the amount of fuel injection increases. The reason is that if the temperature of the engine 2 is high, the atomization of the fuel injected by the injector 14 is favored and the amount of fuel injection introduced into the engine increases. In addition to the engine water temperature, the engine oil temperature, the transmission oil temperature, etc. can also be used.

In addition, the embodiment of the present invention is not limited to the embodiment described above, and various changes, replacements and modifications can be made without departing from the spirit of the idea. technique of the present invention. Furthermore, if the technical idea of the present invention can be implemented in a different way, due to advances in technology or by another derived technology, the present invention can be realized in a different way. The claims therefore cover all embodiments which may fall within the scope of the technical idea of the present invention.

As described above, the present invention has the effect of allowing the improvement of the restarting capacity after the automatic stopping of an engine and is particularly useful in fuel injection control devices and fuel injection control systems.

List of documents cited

Patent documents For all practical purposes, the following patent document is cited:

- Patent Document 1: Publication of the Japanese Patent Application ri 2015-004346 A.

Claims (1)

A fuel injection control device configured to stop fuel injection into an engine (2) in response to automatic engine shutdown, in which an amount of fuel injection during engine restart is changed as a function of a time elapsed after the fuel cut off due to the automatic engine shutdown until the start of fuel injection due to the engine restart. The fuel injection control device according to claim 1, in which the amount of fuel injection during restarting of the engine is varied according to a fuel cut-off period until an engine speed decreasing due to the fuel cut reaches zero, inclusive in the past time. The fuel injection control device according to claim 1 or 2, wherein the amount of fuel injection during engine restart is changed in accordance with an automatic shutdown period when the engine speed is maintained at zero, included in the elapsed time. The fuel injection control device according to any one of claims 1 to 3, wherein the automatic stopping of the engine is determined according to the depressing of a brake pedal, and the restarting of the engine is determined as a function of the release of the depressing of the brake pedal, and in which the quantity of fuel injection during restarting of the engine is modified according to whether an accelerator pedal is actuated or not after the release of the depressing of the brake pedal. The fuel injection control device according to claim 4, in which, in the case where no action on the accelerator pedal has been carried out, the amount of fuel injection during restarting of the engine is changed to function of a first card which is defined as a function of the elapsed time. The fuel injection control device according to claim 4 or 5, in which, in the case where an action on the accelerator pedal has been carried out, the amount of fuel injection during restarting of the engine is changed to function of a second card which is defined as a function of the engine speed and of an air pressure [Claim 7] [Claim 8]. The fuel injection control device according to any one of claims 1 to 3, in which the amount of fuel injection during the restarting of the engine is modified according to an amount of air circulating during a period following the interruption of the fuel injection of the engine until the engine is restarted. A fuel injection control system comprising an engine having an indirect injection type fuel injection device, and a fuel injection control device configured to control the fuel injection of the fuel injection device fuel, wherein the fuel injection control device comprises: a standby stop control unit (30) configured to control automatic stopping and restarting of the engine; a time measurement unit (31) configured to measure an elapsed time after a fuel cut due to automatic engine shutdown until the engine is restarted; and an injection amount control unit (32) configured to increase the amount of fuel injection from the fuel injection device during restart of the engine, as the elapsed time measured by the measurement unit of time is getting longer.