JPH0666228A - Fuel injector for internal combustion engine - Google Patents

Abstract

PURPOSE:To secure a predetermined quantity of air to be introduced without deteriorating an engine brake effect by providing a means for setting an air supply rate and the like at a speed reduction fuel cut timing in order to reduce the air supply rate with a lapse of time. CONSTITUTION:An air flow from an air assist passage 3 is supplied to a fuel injection flow from a fuel injection valve 34. An air control valve 36 opens or closes the air assist passage 3, and a fuel injection controller 1 controls a fuel injection rate from the fuel injection valve 34. Furthermore, an air supply controller 2 controls an air supply rate from the air control valve 36. Meanwhile, a detector 4 detects a speed reduction fuel cut timing of an internal combustion engine. At the speed reduction fuel cut timing, a setter 5 sets an air rate from the air supply controller 2 in order to reduce the air supply rate from the air control valve 36 with a lapse of time. Consequently, it is possible to secure a predetermined quantity of air to be introduced without deteriorating an engine brake effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for an internal combustion engine, and more particularly to a device intended to improve drivability during deceleration.

[0002]

2. Description of the Related Art In a so-called air-assist type fuel injection device, an air control valve is provided for controlling the introduction of assist air, and a high-speed air flow from the air control valve is introduced into the fuel flow from the fuel injection valve to generate air. It is known to inject an air-fuel mixture formed by mixing with fuel from a nozzle into an intake port. The injection of the fuel injection valve is performed in the intake stroke of the cylinder, and the valve opening time of the fuel injection valve is set to the time for injecting the amount of fuel determined by the engine load and the rotational speed at that time. During deceleration, fuel is cut to prevent afterburn and the fuel injection valve is kept closed. On the other hand, the air control valve is kept open during deceleration fuel cut. This is intended to prevent backflow of the exhaust gas by supplying air at the time of fuel cut, and to prevent carbon in the exhaust gas from adhering to the nozzle and the fuel injection valve. See JP-A-63-268971.

[0003]

In the prior art, the air control valve is continuously opened during the deceleration fuel cut to introduce the air. Due to such continuous introduction of air, the engine braking effect during deceleration becomes weak. An object of the present invention is to make it possible to introduce the required amount of air without weakening the engine braking effect.

[0004]

An air-assisted fuel injection system according to the present invention is shown in FIG.
An air assist passage 3 for supplying an air flow to the injected fuel flow from the fuel injection valve 34, an air control valve 36 for opening and closing the air assist passage 3, and a fuel injection for controlling the fuel injection amount from the fuel injection valve 34. The control means 1, the air supply control means 2 for controlling the amount of air supplied from the air control valve 36, the means 4 for detecting the deceleration fuel cut time of the internal combustion engine, and the air control valve 36 for the deceleration fuel cut time. Means 5 for setting the air amount by the air supply control means so as to decrease the air supply amount with time.

[0005]

The air flow from the air control valve is introduced at high speed into the fuel injection flow from the fuel injection valve 34 through the air assist passage 3, and the air mixed with the fuel injection flow is injected into the internal combustion engine. The fuel injection control means 1 controls the amount of fuel injected from the fuel injection valve 34 according to the engine operating conditions, and the air supply control means 2 controls the air supply amount from the air control valve 36 according to the engine operating conditions. Control. Deceleration fuel cut detection means 4
However, when the deceleration fuel cut time of the internal combustion engine is detected, the fuel cut air amount setting means 5 controls the air supply amount by the air supply control means 2 to decrease the air supply amount from the air control valve 36 with time after the deceleration fuel cut. To set.

[0006]

1 and 2, 10 is a cylinder head, 11 is a cylinder block, 12 is an intake manifold,
14 is a cylinder bore, 15 is a piston, 16 is an intake valve,
18 is an exhaust valve. In this embodiment, the engine is a so-called four-valve type in which two intake valves 16 and two exhaust valves 18 are provided. The number of cylinders is 4, for example. The cylinder head 10 forms an intake port 20 to each intake valve 16 and an exhaust port 22 from each exhaust valve 18. The intake port 20 is connected to the intake manifold 12. 23 is a distributor.

Reference numeral 24 is an air cleaner, and the air from the air cleaner 24 is measured by an air flow meter 26 and introduced into an intake manifold 12 via an intake pipe (illustrated by an arrow) 30 via a throttle valve 28. To be done.
Reference numeral 31 is an idle speed control valve (ISC valve) provided in a bypass passage 32 that bypasses the throttle valve 28, and as is well known, it obtains a predetermined engine speed during idle operation.

The fuel injection valve 34 and the air control valve 36 are attached by a mounting body 38 to the mounting portion 12a of the intake manifold 12.
Is attached to. The mounting body 38 is composed of an upper member 38-1 and a lower member 38-2, as shown in FIG.
An O-ring 40 for sealing is arranged on these mating surfaces. An air assist adapter 42 is arranged at the tip of the fuel injection valve 34, and an elongated cylindrical nozzle 44 is arranged in series with the air assist adapter 42. The tip of the nozzle 44 projects from the lower member 38-2 and opens to the intake port 20 as shown in FIG. As is well known, a solenoid (not shown) is provided inside the fuel injection valve 34, and fuel injection can be controlled by selectively energizing this solenoid. A fuel receiving port 54 is provided at the upper end of the fuel injection valve 34, and a delivery pipe 56 is provided.
Fuel from (FIGS. 1 and 4) is supplied to the fuel injection valve 34. The delivery pipe 56 extends in the direction in which the cylinders are arranged, and can supply fuel to the fuel injection valve of each cylinder.

The air control valve 36 has an air nozzle 58 at the lower end and an air receiving port 60 at the upper end. Air receptacle 6
0 is connected to the delivery pipe 56 and the air pump 62
Air from (FIG. 1) is introduced. The air control valve 36 is
Although not shown in the other detailed configuration, a solenoid for controlling the air injection from the air nozzle 58 is provided.

Air assist adapter 4 for fuel injection valve 34
2 is inserted in the upper member 38-1. On the other hand, the nozzle 44
Is inserted into the lower body 38-2. An injection fuel hole 64 extending in the axial direction is formed in the air assist adapter 42. The injection fuel hole 64 receives fuel injected from the fuel injection valve 34, and receives assist air from the air control valve 36 on the way. Mix the fuel and air. On the other hand, the nozzle 44 is formed with an air-fuel mixture injection hole 66 that extends in the axial direction and is aligned with the injection fuel hole 64. The air-fuel mixture injection hole 66 receives the air-fuel mixture from the air assist adapter 42 and sucks air from its tip. The mixture is injected into the port 20 as indicated by the arrow F in FIG.

A PTC heater 70 is arranged on the outer surface of the nozzle 44, and the PTC heater 70 is operated at a low temperature of the internal combustion engine to heat the air-fuel mixture passing through the air-fuel mixture injection hole 66 in the nozzle to atomize it. Make a promotion. Upper member 38-1
An air communication chamber 80 is formed between the lower member 38-2 and the lower member 38-2. On the other hand, the air assist adapter 42 has a groove 82 having a V-shaped cross section extending in the circumferential direction on the outer periphery thereof. Opens to the air communication chamber 80. An assist air hole 84 is formed in the air assist adapter 42 so as to be inclined downward, and one end of the assist air hole 84 has the V-shaped groove 82.
And the other end is opened to the injection fuel hole 64, and the air from the assist air hole 84 is mixed with the fuel from the fuel injection valve 34 in the injection fuel hole 64.

In FIGS. 1 and 4, the delivery pipe 56 is shared by air and fuel, and the fuel delivery passage 92 and
An air delivery passage 94 is formed, a hole 96 into which the fuel receiving port 54 of the fuel injection valve 34 of each cylinder is inserted is opened in the fuel delivery passage 92, and an air receiving port of the air control valve 36 of each cylinder is opened in the air delivery passage 94. Hole 9 into which 60 is inserted
8 is opened. One end of the fuel delivery passage 92 is closed, and the other end is connected to a fuel tank (not shown) via a fuel injection pump (not shown). Fuel from the fuel tank is fed to each cylinder via the fuel delivery passage 92 by the fuel injection pump. It is supplied to the injection valve 34. Air delivery passage 9
4 has one end closed and the other end connected to the discharge side of an air pump 62 via an air delivery conduit 100. Air pump 6
The suction side of No. 2 is connected to an intake pipe downstream of the air flow meter 26 and upstream of the throttle valve 28 via an air extraction conduit 102. The air pump 62 is a piston pump in this embodiment, and includes a piston 62a, a crank disk 62b connected to a crankshaft (not shown) of the internal combustion engine, and a connecting rod connecting the piston 62a and the crank disk 62b. 62c, a suction control reed valve 62d, and a discharge control reed valve 62e are basic constituent elements. Air pump 62
Introduces the air bypassed from the intake pipe into the air control valve 36 of each cylinder through the air delivery passage 94.

The pressure control valve 104 is an air delivery passage 94.
The pressure of the air introduced into the
Diaphragm 104a, spring 104b, diaphragm
And a valve 104c connected to 104a, the valve 104c,
A return passage 10 connected to a portion of the intake pipe downstream of the air flow meter 26 and upstream of the throttle valve 28.
6 open / close control is performed. That is, when the discharge air pressure from the air pump 62 becomes larger than a predetermined value, the diaphragm 104a moves to the left against the spring 104b to open the valve 104c, and a part of the air passes through the return passage 106 to generate air. It is returned to the intake pipe downstream of the flow meter 26. As a result, when the pressure drops, the spring 104b causes the diaphragm 10 to
By moving 4a to the right, the valve 104c is closed, and the air pressure to the air delivery passage 94 is controlled to be constant by repeating such operations.

The control circuit 110 controls the operation of the fuel injection valve 34 and the air control valve 36, and is constructed as a microcomputer system. The control circuit 110 also controls other engines, for example, controls the operation of the ISC valve 31. Various sensors are connected to the control circuit 110, and various engine state signals are input. The air flow meter 26 detects the total amount Q of air introduced into the engine, including the air taken out for air assist from the air pump 62. The distributor 23 is provided with crank angle sensors 114 and 116, and the first crank angle sensor 114 uses the crankshaft 72 that serves as a reference signal.
A pulse signal is generated every 0 ° (that is, one cycle of the engine), and the second crank angle sensor 116 generates a pulse signal every 30 ° of the crankshaft, which is the timing of fuel injection start and the interval between the pulses. It is used to know the engine speed as is well known by the interval of. The water temperature sensor 120 measures the temperature of the cooling water in the cooling water jacket of the engine.
Used to know TW, the intake air temperature sensor 122 is used to know the temperature Ta of the intake air. Control circuit 110
Generates the operating signals of the fuel injection valve 34, the air control valve 36 and the heater 70 according to a program from these sensors. It also controls the operation of other engine control devices such as the ISC valve 31. The control circuit 110 is powered by the battery 132 via the ignition key switch 130.

FIG. 5 shows the connection to the control circuit 110 and the fuel injection valve 34 and the air control valve 36 of each cylinder. Gate 140-
1,140-2,140-3,140-4 control the fuel injection valves 34 of the first, second, third, and fourth cylinders, respectively, and gates 142-1, 142-2, 142-3,
142-4 is the air control valve 3 of the first, second, third, and fourth cylinders, respectively
Control 6 The port CRF of the control circuit 110 is connected to a fuel injection control compare register (not shown) in the control circuit 110, and this port CRF is set from the fuel injection start time to the fuel injection end time. The port CRA is connected to an air supply control compare register (not shown) in the control circuit 110, and this port CRA is set from the start to the stop of the air supply. Ports F1, F2, F3, F4 are set only during fuel injection for that cylinder, respectively. This allows gates 140-1,140-2,140-3,140-4 and 142-1,142-2,142-3,
It becomes possible to set only the gate of the cylinder that injects fuel among 142-4, and the fuel injection valve 34 and the air control valve 3 of that cylinder can be set.
Only 6 is controlled to open. For example, at the time of injection in the first cylinder, F
Gate 140-while 1 is set and port CRF is 1
1 is turned on, the fuel injection valve 34 is opened, and the port CRA
Gate 142-1 is turned on while is 1, and the air control valve 36
Is opened. The same operation is performed during the injection of the other cylinders.

The air control valve 36 is opened prior to the fuel injection valve 34, and the air branched from the intake pipe is the air pump 6
2 through the air delivery passage 94, from the air nozzle 58 of the air control valve 36 into the injection fuel hole 64 through the air communication chamber 80 and the assist air hole 84, and from the mixture injection hole 66 of the nozzle 44 through the intake port 20. Is jetted toward. When the flow of assist air is formed in this way, the fuel injection valve 34 is opened, fuel is injected into the injection fuel hole 64, and the injected fuel is already formed in the injection fuel hole 64. The air is ejected to the intake port 20 in the state of being well atomized through the air-fuel mixture injection hole 66 in the nozzle 44. After the calculated amount of fuel is injected, the introduction of the assist air is continued for some time because of the scavenging of the fuel remaining in the air fuel passage. The fuel injection amount from the fuel injection valve 34 and the air supply amount from the air control valve 36 are changed depending on the load and the rotation speed of the engine. As will be described later, the time from the opening of the air control valve 36 to the opening of the fuel injection valve 34 does not change much with respect to the engine load and the rotational speed, but the fuel injection valve 34 closes. Therefore, the time until the air control valve is closed is changed depending on the engine load and engine speed.

Further, at the time of cold start, a signal for energizing the heater 70 is output from the control circuit 110 when the engine temperature is low, so that the mixing property of air and fuel can be improved and the combustibility at low temperature can be maintained. However, the effect of the heater 70 immediately after the start is not good, so that the fuel adheres to the liquid surface a lot and there is a problem in the mixing property of the air and the fuel. Therefore, the opening time of the air control valve at the time of start, particularly the fuel injection valve 34 The time from the closing of the valve to the closing of the air control valve is extended, the fuel adhering to the wall surface is blown away, and the aim is to improve the mixing property of air and fuel at the time of starting.

Hereinafter, the operation of the control circuit 110 will be described in detail with reference to the flow charts of FIGS. 6 to 10. In FIG. 6, the crank angle from the second crank angle sensor 116 is 3 degrees.
This is a crank angle interruption routine executed every 0 °.
In step 200, it is determined whether or not it is time to execute the fuel injection calculation for the first cylinder. Since the fuel injection is executed in the intake stroke as described above, the fuel injection calculation of each cylinder (calculation of the opening and closing times of the fuel injection valve 34) is performed at a predetermined timing prior to that, for example, 60 ° before the intake top dead center. ) Is performed (see (b) in FIG. 11). This timing can be determined by the counter value which is cleared by the pulse signal every 720 ° CA from the first crank angle sensor 114 and incremented by the pulse signal every 30 ° CA from the second crank angle sensor 116. Similarly, at steps 202, 204 and 206, it is judged if it is the fuel injection calculation timing for the second, third and fourth cylinders. The timing of this 30 ° CA routine is
For example, when it is determined to be the calculation timing for the fourth cylinder, the routine proceeds from step 206 to step 208, and the basic fuel injection amount Tp is calculated from the intake air amount-rotational speed ratio Q / NE and the engine rotational speed NE that are load factors of the engine. It is calculated. The basic fuel injection amount Tp is the intake air amount-rotational speed ratio Q / NE.
And the fuel amount for obtaining the theoretical air-fuel ratio at the rotational speed NE. In step 210, the air supply amount Ta is calculated. This air supply amount Ta is also the intake air amount-rotational speed ratio Q / N.
It is calculated according to E and the rotational speed NE.

Step 212 is the fuel cut flag F._cut
It is determined whether or not = 1. F_cut= 1 is deceleration fuel cut
Sometimes set (1). Not in deceleration fuel cut state
(F _cut= 0), the steps in and after step 218
The usual fuel injection and assist air supply processing is executed.
In step 218, the valve opening start time t1 of the fuel injection valve 34
And the valve opening end time t2 is calculated. In this example
Is fuel injection in the intake stroke, near the intake bottom dead center
The valve closing time t2 is determined so that the fuel injection ends at
Then, the valve opening start time t1 for obtaining the fuel injection amount Tp
Is calculated back. In step 220, from the air supply amount Ta
Valve opening start time t1 ′ and valve opening end time of the air control valve 36
Calculation of t2 'is performed. At the start of opening the air control valve 36
The time t1 ′ is prior to the valve opening start time t1 of the fuel injection valve 34.
Enough air to flow into the air assist passage
The time required to keep the air control valve fully open
Is set as a constant value and is a constant value regardless of load and rotation speed.
It Further, at the valve closing time t2 ′ of the air control valve 36, fuel injection is performed.
Sufficiently after the closing time t2 of the valve 34, the fuel injection
Completely scavenges the fuel adhering to the wall of the air fuel passage after shooting
It is set as a time that can be done. That is, load, rotation
The larger the number, the longer the time to close the valve. Figure 11
See (c) and (d).

In step 222, the fuel injection valve opening start time t1 is set in the fuel injection control compare register (not shown) of the control circuit 110. The port CRF connected to the fuel injection control compare register is turned on at the arrival of the fuel injection start time t1, and at the arrival of the fuel injection end time t2.
It is turned off (see Figure 11 (h)). In step 224, the air control valve opening start time t1 ′ is set in the assist air control compare register (not shown) of the control circuit 110. The port CRA connected to the air supply control compare register is turned on at the arrival of the air supply start time t1 'and turned off at the arrival of the air supply end time t2' (see FIG. 11 (re)). .

In step 226, the injection control port F4 of the fourth cylinder is set, and the switching flag FF of the fuel injection control time coincidence routine and the switching flag FA of the air supply control time coincidence routine are set. The set time of the compare register for controlling the air control valve, that is, the air control valve start time t1 'comes first (FIGS. 11 (c) and 11 (d)), and the port C
RA is turned on, gate 142-4 is turned on, the air control valve 36 of the fourth cylinder is turned on, and air is injected from the air control valve 36 into the injection fuel hole 64 via the air communication chamber 80 and the assist air hole 84. Will be introduced first. At the same time, the time coincidence interrupt routine shown in FIG.
It is determined whether or not = 1, and Yes is initially set (step 226).
Therefore, the routine proceeds to step 228, and the air injection end time t
2'is set in the compare register for the air control valve. In step 229, FA = 0 is set.

When the fuel injection start time t1 arrives after the opening of the air control valve 24, the port CRF is turned on, the gate 140-4 is turned on, and the fuel injection valve 34 of the fourth cylinder is turned on.
Then, fuel injection is started from the injection port 50 of the fuel injection valve 34, and at the same time, the time coincidence interrupt routine of FIG. 9 is started,
At step 230, it is determined whether or not FF = 1, and the first is Yes.
Since it is (step 226), the process proceeds to step 232,
The fuel injection end time t2 is set in the compare register for the fuel injection valve. In step 233, FF = 0 is set.

Since the closing time t2 of the fuel injection valve 34 comes next and the port CRF = 0, the gate 140-4 is turned off, and a valve closing signal is sent to the fuel injection valve 34, and at the same time, FIG.
The time coincidence interrupt routine is started, and since FF = 0 (step 233) in step 230, the determination is No, and step 232 is bypassed. Finally air control valve 3
When the valve closing time t2 'of 6 arrives, the port CRA is turned off, the gate 142-4 is turned off, a valve closing signal is sent to the air control valve 36, and at the same time, the time / time coincidence interrupt routine of FIG. 10 is started. , At step 227, FA = 0 (step 2
Since it is 29), the determination is No, the step 228 is bypassed, and the port F4 for the fourth cylinder injection control is cleared in the step 235.

When F _cut = 1 is determined in step 212 of FIG. 6, the process proceeds to step 217, where Tp = 0,
The fuel injection valve 34 is not opened, that is, the fuel cut is performed. In step 219, the air supply amount Ta = f × T
It is calculated by a. The detailed meaning of this equation will be described later, but after fuel cut, f (<1) gradually decreases toward zero.

FIG. 10 shows a fuel cut flag control routine, which is a time interruption routine executed at regular time intervals (for example, 50 milliseconds). Step 30
At 0, it is determined whether or not the throttle valve 28 is in the idle position. If the throttle valve is not in the idle position, bypass the routine below. When the throttle valve is at the idle position, the _routine proceeds to step 302, where it is judged if F _cut = 1 (that is, if fuel cut is being executed). When not in the fuel cut state, the routine proceeds to step 304, where it is judged if the engine speed NE is higher than the fuel cut start speed NE1. When NE ≦ NE1, the routine does not go into the fuel cut and the following routine is exited. When NE> NE1, it is determined that the deceleration fuel cut start condition is reached, and the routine proceeds to step 306,
Fuel cut flag F _cut = 1 is set, and step 3
At 08, the initial value of the attenuation rate K of the air supply amount after the fuel cut is started is calculated. This damping factor K is, for example, the engine water temperature.
It is configured as a map of (THW) and is determined as shown in the following table, for example.

[0026] That is, the larger the water temperature (THW), the more the damping rate is set. In step 310, the initial value f _{0 of the} damping coefficient is set to f.
The value of this f ₀ is set to an appropriate value smaller than 1, and Ta = f × Ta in step 219 of FIG. 7, so a smaller amount of air than before the fuel cut is supplied immediately after the fuel cut.
In step 312, the current value of f is stored in f'and used as the previous value in the next step.

In this way, when the deceleration fuel cut operation is started, as long as it continues, in step 302, F _{cut is performed.}
Since = 1, the routine proceeds from step 302 to step 316, where the engine speed NE is the fuel return speed NE2 (<N
It is determined whether or not E2). If NE ≧ NE2, it is determined that the fuel cut condition continues, and step 318
Then, the air supply amount attenuation coefficient f is calculated by f = f ′ × (1-k). That is, the damping coefficient this time becomes smaller by the amount obtained by multiplying the damping coefficient k ′ of the previous time by 1-k. Therefore, the air supply amount Ta gradually decreases every time the process of step 219 of FIG. 7 is performed after the fuel cut. In FIG. 10, in step 320, it is determined whether or not f ≦ 0. If f> 0, the process proceeds to step 312.
If f ≦ 0 is determined in step 320, step 3
The process proceeds to step 22, and f = 0, so the air supply amount after fuel cut becomes zero at this point.

FIG. 12 shows the relationship between the fuel injection signal (corresponding to (c) in FIG. 11) and the air supply signal ((d) in FIG. 11) at the time of fuel cut. If the fuel cut condition is satisfied at time x in FIG. 12, the fuel cut is immediately executed as shown in (a), but the air supply is continued for a while after the fuel cut as shown in (b). However, the opening interval of the air control valve is shown in Fig. 10.
According to the equation of step 318 of t ₁ ...
It becomes short like t _n , and finally becomes zero.

The control of the valve opening time of the air control valve after the fuel cut is not limited to the calculation formula of step 318 in FIG. 10, but may be an optional item as long as it is an appropriate setting that gradually decreases with time. is there. For example, a calculation formula such as Ta = Ta′−n × k Ta = k ₁ × Ta′−n × k ₂ may be used.

[0030]

According to the present invention, the engine brake performance is prevented from being sharply lowered by gradually reducing the air supply amount after the fuel is cut, and it may occur if the air supply is suddenly stopped. It is possible to eliminate the shock at the time of deceleration.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram of an internal combustion engine of an embodiment.

2 is a longitudinal sectional view of a combustion chamber portion of the internal combustion engine of FIG.

FIG. 3 is a partial cross-sectional view of a fuel injection valve and an air control valve.

FIG. 4 is a cross-sectional view of a fuel and air delivery pipe.

FIG. 5 is a block diagram of a portion of a control circuit that operates a fuel injection valve and an air control valve in the control circuit.

FIG. 6 shows a part of a flowchart of a crank angle interrupt routine.

FIG. 7 shows the remaining portion of the crank angle interrupt routine flowchart.

FIG. 8 is a flowchart of a time coincidence interrupt routine of an air injection control comparison register.

FIG. 9 is a flowchart of a time coincidence interrupt routine of a fuel injection control comparison register.

FIG. 10 is a flowchart of a fuel cut routine.

FIG. 11 is a timing chart explaining operation timings of the air control valve and the fuel injection valve.

FIG. 12 is a diagram for explaining a series of operations of the fuel injection valve and the air control valve at the time of fuel cut.

FIG. 13 is a diagram showing a functional configuration of the present invention.

[Explanation of symbols]

 10 ... Cylinder head 12 ... Intake manifold 16 ... Intake valve 18 ... Exhaust valve 20 ... Intake port 26 ... Air flow meter 28 ... Throttle valve 31 ... ISC valve 34 ... Fuel injection valve 36 ... Air control valve 38 ... Mounting body 42 ... Air assist Adapter 44 ... Nozzle 64 ... Injection fuel hole 66 ... Mixture injection hole 80 ... Air communication chamber

Claims (1)

[Claims] 1. A fuel injection valve, an air assist passage for supplying an air flow to an injected fuel flow from the fuel injection valve, an air control valve for opening and closing the air assist passage, and a fuel injection amount from the fuel injection valve. Fuel injection control means, air supply control means for controlling the amount of air supplied from the air control valve, means for detecting when deceleration fuel cut of the internal combustion engine, and air supply from the air control valve during deceleration fuel cut A fuel injection device for an internal combustion engine, comprising means for setting an air amount by an air supply control means so as to decrease the amount with time.