JP3395643B2 - Fuel injection device for internal combustion engine - Google Patents

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 fuel injection device including fuel supply means for distributing and supplying fuel to each cylinder.

[0002]

2. Description of the Related Art Conventionally, there is provided a nozzle having an injection port opening to a combustion chamber and directly injecting fuel into the combustion chamber of each cylinder, while a fuel supply means for supplying fuel to an intake port portion of each cylinder is provided. At least the fuel is supplied by the nozzle when the load is low, the fuel is supplied by the fuel supply means when the load is high, and both the nozzle and the fuel supply means are operated at the time of startup and during warm-up after startup, and There is known a fuel injection device configured to gradually reduce the ratio of the amount of fuel injected by the fuel supply means (JP-A-61-2503).
54 publication).

[0003]

However, according to the fuel injection device having the above structure, a fuel injection valve for injecting fuel into the combustion chamber and a fuel injection valve for injecting fuel into the intake port portion are provided for each cylinder. However, there is a problem in that the number of fuel injection valves installed is large and the cost is high.

Further, when the fuel is injected from the fuel injection valve of the intake port during start-up, the distance from the injection position to the intake valve is short, and the space where the fuel is injected is narrow, so the spray is a wall flow. However, there is a problem that it is difficult to obtain good startability especially at low temperature. On the other hand, there is known a fuel injection device having a fuel injection valve for each cylinder and an auxiliary fuel injection valve provided in an intake collector portion to distribute and supply fuel to each cylinder.

According to the fuel injection device having such a structure, it is possible to reduce the number of fuel injection valves to be installed, and if the structure is such that fuel is injected into the intake collector portion, sufficient vaporization time can be secured, and further, relatively comparatively. Since the fuel is injected into a wide space, it is possible to prevent the spray from forming a wall flow. However, in the case where the fuel is injected into the intake collector as described above, the fuel is uniformly sucked into each cylinder both at the time of starting and at the time of high load due to the difference in the intake airflow at the time of starting and at the time of high load. Is difficult to do,
There is a problem that it is difficult to achieve both low temperature startability and high load performance.

The present invention has been made in view of the above problems, and in a fuel injection device having a structure in which fuel is distributed from a common fuel supply means to each cylinder, the fuel is used both at low temperature starting and at high load. An object of the present invention is to enable good distribution of fuel from the supply means.

[0007]

Therefore, according to the invention of claim 1, the intake passage connected to each cylinder is formed in a branched manner, and the collector into which intake air flows from one end side is extended in the cylinder row direction, and The fuel supply means is disposed on the intake air inflow side of the collector and injects fuel at least in the downstream direction with respect to the intake airflow at startup and injects fuel at least with respect to the intake airflow at a predetermined high load operation. .

At the time of starting, especially immediately after the start of cranking, the air originally existing in the collector is sucked into each cylinder, so fuel is injected from the upstream side to the downstream side of the collector, that is, in the collector. Good startability can be obtained by mixing the fuel spray with the entire air present in the. In this case, it does not matter if the fuel is injected in the upstream direction at the same time as the injection in the downstream direction, but the fuel injected in the upstream direction rides on the very slow intake airflow during cranking and is carried to each cylinder. Since it takes some time, injection in the downstream direction is important to obtain good startability.

On the other hand, during high-load operation, the fuel can be dispersed in a wide range on the cross section of the flow of the intake air by injecting it in the upstream direction so as to face the intake air, and the intake air and the fuel spray can be dispersed. Mixing with the fuel is promoted and the fuel distribution to each cylinder is improved. Further, in order to further improve the fuel distribution to each cylinder both at the time of starting and at the time of high load, as shown in the invention of claim 2, the fuel supply means is arranged at the most upstream side of the collector. It may be arranged upstream of the opening position of the intake passage opening at.

According to the third aspect of the present invention, the fuel supply means is constituted by a fuel injection valve having an injection port extending upstream with respect to the intake air flow and an injection port extending downstream with respect to the intake air flow. According to this configuration,
With one fuel injection valve, it is possible to perform injection in the direction corresponding to the start and the high load operation.

According to a fourth aspect of the invention, the fuel injection valve is
The injection rate in the injection in the upstream direction with respect to the intake airflow was set to be higher than the injection rate in the injection in the downstream direction with respect to the intake airflow. According to this configuration, if the fuel corresponding to the air corresponding to the collector volume can be supplied, the fuel is sufficiently injected in the downstream direction, and the intake air amount is large and the required fuel amount is large in the upstream direction for high load operation. The fuel injection can be rationally performed by one fuel injection valve. Also, when setting the injection rate by the size of the injection port,
Since the diameter of the downstream injection port, which has a low injection rate, becomes smaller and the atomized spray becomes more advanced, the effect of further improving the startability can be expected.

In the invention of claim 5, the fuel injection valve is
It is configured to eject in two directions at the same time. With such a configuration, it is possible to improve the startability and the fuel distribution during high load operation with a very simple configuration. It should be noted that the fuel injected in the upstream direction at the time of start-up will ride on the intake airflow from the middle of the cranking and flow into each cylinder.Therefore, after the initial explosion quickly obtained by the injection in the downstream direction, it is certain that Can lead the engine to a complete explosion.

In the invention of claim 6, the fuel injection valve is
It is configured to be switchable between a state of injecting in a downstream direction with respect to the intake airflow and a state of injecting in both a downstream direction and an upstream direction with respect to the intake airflow. With such a configuration, the fuel supplied at the time of starting can be injected only in the downstream direction, which is important for improving the startability, and the fuel consumption at the time of starting can be reduced.

In the invention of claim 7, the fuel injection valve is
An injection valve configured to lift a valve body by a magnetic attraction force of an electromagnetic coil, wherein the magnetic attraction force is switched to at least two types, ie, the strength of the valve body and the lift amount of the valve body is switched to a downstream direction with respect to an intake air flow. The injection state and the injection state in both the downstream direction and the upstream direction with respect to the intake airflow can be switched.

According to such a configuration, by switching the magnetic attraction force of the valve body, it is possible to easily switch between the injection of the intake airflow only in the downstream direction and the injection in the downstream direction and the upstream direction. In the invention of claim 8, the fuel supply means is
The first auxiliary fuel injection valve has an injection direction directed upstream with respect to the intake airflow, and the second auxiliary fuel injection valve has an injection direction directed downstream with respect to the intake airflow.

According to this structure, by providing the two fuel injection valves whose injection directions are opposite to each other, it is possible to inject the intake airflow in the upstream direction and / or the downstream direction, and in the upstream direction and the downstream direction. The injection amount control can be performed individually and accurately. In the invention of claim 9, the fuel supply means rotates the auxiliary fuel injection valve having an injection direction in a direction substantially orthogonal to the central axis around the central axis so that the injection direction becomes the upstream direction with respect to the intake air flow. It is configured to switch to either the downstream direction.

According to this structure, one of the fuel injection valves can switch between the injection directed toward the downstream side of the intake airflow and the injection directed toward the upstream direction.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
It will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing a system configuration of a vehicle internal combustion engine in an embodiment.
In FIG. 1, intake air whose flow rate is adjusted by a throttle valve 2 is supplied to each cylinder of the engine 1 (four cylinders # 1 to # 4) from a collector 3 extending in the cylinder row direction to each cylinder. Are distributed and supplied through the intake passages 3a to 3d.

Each cylinder is provided with electromagnetic fuel injection valves 4a to 4d for directly injecting fuel into the combustion chamber, and an ignition plug (not shown) for igniting and burning the air-fuel mixture in the combustion chamber. There is. The fuel injection valves 4a-4d
Detection signals from various sensors are input to the control unit 5 that controls the. The various sensors include an air flow meter 6 that detects the intake air flow rate Qa of the engine 1, a rotation sensor 7 (crank angle sensor) that outputs a detection signal in synchronization with the rotation of the engine 1, and a cooling water temperature Tw of the engine 1. A water temperature sensor 8 or the like for detecting the water temperature is provided. still,
The engine rotation speed Ne is calculated based on the detection signal from the rotation sensor 7.

The control unit 5 determines the combustion method and the target air-fuel ratio based on the detection signal, and calculates the fuel injection amount and the injection timing according to the determination. As the combustion method, stratified charge combustion is performed by forming a stratified combustible mixture around the spark plug by injecting fuel in the compression stroke by the fuel injection valves 4a to 4d, and by the fuel injection valves 4a to 4d. Switching between the homogeneous combustion, which is performed by injecting the fuel in the intake stroke to form an air-fuel mixture having a substantially uniform air-fuel ratio in the entire cylinder, is controlled.

Further, the engine 1 in the present embodiment includes
The auxiliary fuel injection valve 9 (fuel injection shared by each cylinder is provided upstream of the branch portion of the collector 3, that is, upstream of the connection position of the intake passage 3d of the # 1 cylinder located at the most upstream side with the collector 3. A supply unit) is provided, and the control unit 5 controls the auxiliary fuel injection valve 9 as shown in the flowchart of FIG.

In the flowchart of FIG. 2, in S1, the engine speed Ne, the intake air flow rate Qa, the cooling water temperature Tw, etc. are read. At S2, the current engine speed N
Based on whether or not e is equal to or higher than a preset reference speed NeL, it is determined whether or not the engine 1 is in the complete explosion state.
When it is determined that the engine rotation speed Ne is less than the reference speed NeL and the complete explosion has not been reached, the process proceeds to S3, and it is determined whether or not the current cooling water temperature Tw is equal to or lower than a preset reference temperature TwL. .

When it is determined in S3 that the cooling water temperature Tw exceeds the reference temperature TwL, it is satisfactory even if the auxiliary fuel injection valve 9 is not used for fuel injection at the time of normal starting. Since the startability can be obtained, the process proceeds to S4, and the auxiliary fuel injection valve 9 is not used. On the other hand, S
If the cooling water temperature Tw is determined to be equal to or lower than the reference temperature TwL at the time of low temperature starting in 3, the process proceeds to S5 in order to perform the fuel injection by the auxiliary fuel injection valve 9 that can sufficiently secure the vaporization time. The setting for using the auxiliary fuel injection valve 9 is performed.

Further, at the next S6, the starting injection amount is calculated from the operating conditions read at S1. The starting injection amount is calculated as the sum of the fuel amount injected by the fuel injection valves 4a and 4b and the fuel amount injected by the auxiliary fuel injection valve 9. Further, in the next S7, the injection ratio of the auxiliary fuel injection valve 9 at the current cooling water temperature Tw is obtained by referring to the table shown in FIG. Then, the portion corresponding to the injection ratio of the starting injection amount calculated in S6 is
As the fuel amount injected by the auxiliary fuel injection valve 9, the remaining fuel amount is set as the fuel amount injected by the fuel injection valves 4a to 4b.

When it is determined in S2 that the state of complete combustion is complete, the process proceeds to S8, and it is determined whether or not it falls within a preset high load operation region. Specifically, as shown in FIG. 4, when the actual engine load is larger than the threshold value of the engine load set for each engine rotation speed Ne (when it corresponds to the hatched area shown in FIG. 4), the high Judge that it is under load.

When it is determined in S8 that the load is not high,
That is, when it is in the low / medium load region, the process proceeds to S9,
The setting is made so that the auxiliary fuel injection valve 9 is not used. on the other hand,
When it is determined in S8 that the engine is under heavy load, the process proceeds to S10 and the setting for using the auxiliary fuel injection valve 9 is performed. Then, in S11, the fuel injection amount is calculated in the same manner as in S6, and in the next S12, as shown in FIG. 5, the injection ratio by the auxiliary fuel injection valve 9 is increased as the engine load at that time increases. The setting is performed so that the injection ratio of the fuel injection amount calculated in S11 is injected from the auxiliary fuel injection valve 9, and the rest is injected by the fuel injection valves 4a to 4b.

By the way, the auxiliary fuel injection valve 9 is constructed so as to be capable of injecting in two directions of the upstream side and the downstream side of the intake airflow. FIG. 6 shows a first embodiment of the injection characteristics of the auxiliary fuel injection valve 9, in which fuel is injected only in the downstream direction of the intake air flow at low temperature start, and only in the upstream direction of the intake air flow at high load. To spray.

That is, immediately after the start of cranking at the start,
Since each cylinder inhales the air originally in the collector 3, it is necessary to mix fuel spray into the entire air in the collector 3 simultaneously with the start of cranking in order to obtain good startability. Fuel is injected from the upstream side to the downstream direction. On the other hand, when using the auxiliary fuel injection valve 9 after the complete explosion, that is, after shifting to the normal operation,
If the fuel spray is dispersed over the entire intake airflow passing through the auxiliary fuel injection valve 9, the fuel can be evenly distributed to each cylinder. Therefore, the fuel should be injected upstream so as to face the intake airflow. ing.

Here, the first auxiliary fuel injection valve is installed so that the injection port is directed toward the downstream side of the intake airflow, and the second auxiliary fuel injection valve is installed where the injection port is directed toward the upstream direction of the intake airflow. If the auxiliary fuel injection valve 9 is constituted by two of the above, the injection directions shown in FIG. 6 can be switched. Further, an auxiliary fuel injection valve 9 having an injection direction substantially orthogonal to the central axis is rotatably supported around the central axis and is rotationally driven by an actuator such as a motor so that the injection direction is upstream of the intake air flow. The direction may be switched to either the direction or the downstream direction.

FIG. 7 is a diagram showing the structure of the auxiliary fuel injection valve 9 that can be used in the first embodiment. Figure 7
The auxiliary fuel injection valve 9 shown in FIG. 2 includes an electromagnetic coil 22 whose energization is controlled via a connector 21, a needle valve 23 which is lifted from a valve seat by a magnetic attraction force of the electromagnetic coil 22, and the needle valve 23 in a seating direction. On the other hand, a nozzle portion 25 continuous with the valve seat is provided extending in the axial direction while being constituted by a coil spring 24 for urging, and the closed distal end portion of the nozzle portion 25 has a direction orthogonal to the axial direction. The jet port 26 is opened at.

With this structure, when the needle valve 23 is lifted against the closing force of the coil spring 24 by energizing the electromagnetic coil 22, fuel flows out to the nozzle portion 25 and is injected from the injection port 26. When the auxiliary fuel injection valve 9 (fuel supply means) is configured by using two fuel injection valves shown in FIG. 7, the axial direction of each auxiliary fuel injection valve becomes a direction orthogonal to the direction of the intake air flow, and The two auxiliary fuel injection valves are fixed so as to be arranged along the direction of the intake air flow, and one auxiliary fuel injection valve (the first auxiliary fuel valve interposed on the upstream side is provided.
Of the other auxiliary fuel injection valve (the second auxiliary fuel injection valve interposed on the downstream side) is directed toward the downstream side of the intake air flow. It should be directed to.

If only one fuel injection valve shown in FIG. 7 is used as the auxiliary fuel injection valve 9 and the switching of the injection direction is realized by the rotation of the auxiliary fuel injection valve, the auxiliary fuel injection valve 9 The actuator that is supported by the intake passage wall and is composed of a combination of a motor and a reduction gear, etc., is so that its axial direction is orthogonal to the direction of the intake airflow and is rotatable at least in the range of 180 °. The auxiliary fuel injection valve 9 may be rotated around its axis so that the injection direction can be switched between the upstream direction and the downstream direction.

FIG. 8 shows a second embodiment of the injection characteristic of the auxiliary fuel injection valve 9, both in the upstream direction and in the downstream direction of the intake air flow at both the low temperature start and the high load. It is configured to be injected into. As described above, the auxiliary fuel injection valve 9 capable of simultaneously performing the downstream injection and the upstream injection is as shown in FIG.
As shown in FIG. 2, two nozzles 26a and 26b whose injection directions are different from each other by 180 ° are formed at the tip of the nozzle portion 25, and the auxiliary fuel injection valve 9 is arranged such that one of the nozzles 26a and 26b faces the upstream direction of the intake air flow The other side may be installed so as to face the downstream side of the intake airflow.

If the auxiliary fuel injection valve 9 as shown in FIG. 9 is used to perform injection in both directions at both low temperature start and high load, one auxiliary fuel injection valve 9 is used. The structure can be simplified because it is composed of only the injection valve and there is no need to provide a rotating mechanism or the like. FIG. 10 shows a third embodiment of the injection characteristic of the auxiliary fuel injection valve 9,
Also in this case, as in the second embodiment, the injection is performed in both the upstream direction and the downstream direction of the intake air flow at both the low temperature start and the high load, but the injection is performed in the downstream direction. The hole diameter ratio of the injection ports 26a and 26b shown in FIG. 9 is set so that the fuel amount injected in the upstream direction is larger than the injection amount injected.

Since the required injection amount at the time of cold start is smaller than the required injection amount at the time of high load, the atomization performance is restricted by limiting the fuel injection amount toward the downstream direction, which contributes to the improvement of the startability at the time of low temperature start. While increasing the fuel injection amount, the injection amount toward the upstream direction, which exclusively contributes to the fuel distribution under high load, is increased to ensure the required injection amount under high load.

FIG. 11 shows a fourth embodiment of the injection characteristic of the auxiliary fuel injection valve 9, in which the injection is performed only in the downstream direction of the intake airflow at low temperature start, but in the downstream direction of the intake airflow at high load. And the upstream direction. As described above, as the auxiliary fuel injection valve 9 (fuel supply means) capable of switching the injection only in the downstream direction and the injection in the downstream direction and the upstream direction, the first auxiliary fuel injection valve with the injection port directed in the downstream direction. And a second auxiliary fuel injection valve having an injection port directed to the upstream direction may be provided. However, if a fuel injection valve having a structure as shown in FIG. 12 is used, it is possible to switch the injection direction by one. .

The fuel injection valve shown in FIG. 12 has two electromagnetic coils 22, a first coil 22a and a second coil 22b. Either one of the first coil 22a and the second coil 22b is provided. The magnetic attraction force generated when only the first coil is energized and the larger magnetic attraction force generated when both coils are energized can be switched between two stages.

As the coil spring 24 for urging the needle valve 23 in the valve closing direction, two coil springs 24a and 24b having a different diameter are used, and a second coil spring 24b having a smaller diameter is used. It is provided so as to be inserted into the first coil spring 24a having a large diameter. When the needle valve 23 is seated, the first coil spring 24a is connected to the needle valve 23 and the spring adjuster 27.
While being compressed between and to generate a biasing force in the valve closing direction,
The free length of the second coil spring 24b is shorter than the distance between the needle valve 23 and the spring adjuster 27 in the seated state, so that the load is not applied.

A disc-shaped stroke adjusting shim 28 is provided on the side opposite to the needle valve 23 side of the second coil spring 24b, until the stroke adjusting shim 28 comes into contact with the spring adjuster 27. In the meantime, the needle valve 23 receives the biasing force in the valve closing direction only by the first coil spring 24a. Therefore, the stroke adjusting shim 28
The first coil spring 24a during the stroke until the spring comes into contact with the spring adjuster 27.
It suffices if the magnetic attraction force is sufficient to resist the valve closing biasing force.

On the other hand, when the stroke adjusting shim 28 comes into contact with the spring adjuster 27, the urging force in the valve closing direction is applied from both the first coil spring 24a and the second coil spring 24b. When the needle valve 23 is lifted against the valve closing urging force, the needle valve 23 is stroked to a position where the central portion of the Newle valve 23 contacts the stopper 29. Therefore, in order to make the central portion of the Newle valve 23 stroke to a position where it abuts on the stopper 29, a magnetic attraction force sufficient to resist the valve closing urging force of both the first coil spring 24a and the second coil spring 24b. Will be needed.

From the valve closed state, the stroke adjusting shim
Let st1 be the stroke amount until 28 comes into contact with the spring adjuster 27, and st2 be the stroke amount from the closed state until the central portion of the newle valve 23 comes into contact with the stopper 29. <St2, figure
The gap d shown by 12 is set to be st2 <d so as not to affect the stroke.

As described above, the injection valve shown in FIG.
The magnetic attraction force can be switched between large and small by controlling the energization of the coil 22a and the second coil 22b, and the stroke adjusting shim 28 causes the spring adjuster 27 to move.
When it is desired to make a stroke up to the position where the first coil spring 24a comes into contact with the first coil 22a and the second coil 22b, it is possible to resist the valve closing biasing force of the first coil spring 24a. Coil springs 24a, 24b
A relatively weak magnetic attraction force that cannot lift the needle valve 23 against the valve closing biasing force is generated.

On the other hand, the central portion of the Newdle valve 23 is a stopper.
When it is desired to make a stroke to a position where it abuts on 29, both the first coil 22a and the second coil 22b are energized to lift the needle valve 23 against the valve closing urging force of both coil springs 24a and 24b. It is possible to generate a relatively large magnetic attraction force. Further, in the nozzle portion 25 of the fuel injection valve shown in FIG. 12, two injection ports 26a, 26b whose injection directions are different by 180 ° are opened so that the injection air can be injected both in the upstream direction and the downstream direction. , The jet port 26a directed in the downstream direction is the jet port 26b directed in the upstream direction
The nozzle portion 25 is opened to the upstream side.

Then, the injection port 26 in the fuel passage of the nozzle portion 25
A step portion 30 whose inner diameter is enlarged toward the downstream side is provided on the downstream side of a and on the upstream side of the ejection port 26b, and the ejection port 26b is opened in the portion whose inner diameter is enlarged via the step portion 30. , A disk-shaped spool valve 31 in the portion where the inner diameter is enlarged.
A (coil valve) is provided and a coil spring 32 is provided for urging the spool valve 31 in the direction of contacting the step portion 30 (upstream side).

That is, unless the spool valve 31 is pushed downward in FIG. 12 by the fuel, the injection port 26b is closed, so that the fuel is injected only from the injection port 26a directed in the downstream direction, and the spool valve 31 When the fuel is pushed downward in FIG. 12 by the fuel, the fuel is injected from the nozzle 26a together with the nozzle 26a, and the downstream and upstream injections are simultaneously performed.

As described above, the fuel injection valve shown in FIG.
The stroke of the needle valve 23 can be controlled in two steps. When the stroke adjusting shim 28 is moved to a position where the stroke adjusting shim 28 contacts the spring adjuster 27, the lift amount is compared. Since the fuel flow rate in the nozzle portion 25 is small due to the small amount, the spool valve 31 keeps the injection port 26b closed, but the coil 29 is energized so that the center portion of the newdle valve 23 contacts the stopper 29. When it is stroked to, the lift amount increases and the fuel flow rate in the nozzle portion 25 increases, and the spool valve 31 is pushed down by such a large fuel flow rate, and fuel injection is also performed from the injection port 26b.

That is, at the time of low temperature starting, when it is desired to perform the injection from the injection port 26a only in the downstream direction, it suffices to energize only one coil, and at the time of high load, both injection ports 26a. , 26b, when it is desired to perform the injection in both the downstream direction and the upstream direction, it suffices to energize both coils. Incidentally, in the fuel injection valve shown in FIG.
The hole diameters of the injection holes 26a, 26b may be different so that the upstream direction becomes larger, and the hole diameters of the injection holes 26a, 26b may be the same.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an engine according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a state of injection control of an auxiliary fuel injection valve in the embodiment.

FIG. 3 is a diagram showing characteristics of an injection ratio according to water temperature in the embodiment.

FIG. 4 is a diagram showing a high load region in which fuel injection is performed by an auxiliary fuel injection valve in the embodiment.

FIG. 5 is a diagram showing a characteristic of an injection ratio according to an engine load in the embodiment.

FIG. 6 is a state diagram showing a first embodiment of the injection characteristic of the auxiliary fuel injection valve, (A) shows the injection characteristic at low temperature start,
FIG. 3B is a state diagram showing injection characteristics at high load.

FIG. 7 is a sectional view showing an example of an auxiliary fuel injection valve used in the first embodiment.

FIG. 8 is a state diagram showing a second embodiment of the injection characteristic of the auxiliary fuel injection valve, FIG.
FIG. 3B is a state diagram showing injection characteristics at high load.

FIG. 9 is a sectional view showing an example of an auxiliary fuel injection valve used in the second embodiment.

FIG. 10 is a state diagram showing a third embodiment of the injection characteristic of the auxiliary fuel injection valve, (A) shows the injection characteristic at low temperature start,
FIG. 3B is a state diagram showing injection characteristics at high load.

FIG. 11 is a state diagram showing a fourth embodiment of the injection characteristic of the auxiliary fuel injection valve, FIG. 11A is an injection characteristic at low temperature start,
FIG. 3B is a state diagram showing injection characteristics at high load.

FIG. 12 is a cross-sectional view showing an example of an auxiliary fuel injection valve used in the fourth embodiment.

[Explanation of symbols]

1 Internal combustion engine 2 Throttle valve 3 collectors 3a-3d intake passage 4a-4d Fuel injection valve 5 control unit 6 Air flow meter 7 Rotation sensor 8 Water temperature sensor 9 Auxiliary fuel injection valve 22 Electromagnetic coil 23 Needle valve 24 coil spring 25 nozzle 26 nozzle

Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI F02M 69/04 F02M 69/04 Q (72) Inventor Go Taniyama 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (56) Reference Documents JP-A-2-9948 (JP, A) JP-A-60-249665 (JP, A) JP-A-4-66774 (JP, A) JP-A-4-292572 (JP, A) JP-A-7- 133753 (JP, A) JP 62-288368 (JP, A) JP 61-250354 (JP, A) Actually open flat 2-39567 (JP, U) Actually open 60-102467 (JP, U) 62-56762 (JP, U) JP 45-28443 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02D 41/00-41/40 F02M 61/00 -69/04

Claims (9)

(57) [Claims] 1. An intake passage connected to each cylinder is formed in a branched manner, a collector into which intake air flows from one end side is extended in a cylinder row direction, and the intake passage is arranged on the intake air inflow side of the collector. A fuel injection device for an internal combustion engine, comprising: a fuel supply unit that injects fuel at least in a downstream direction with respect to the intake airflow and injects fuel at least in an upstream direction with respect to the intake airflow during a predetermined high load operation. 2. The fuel injection for an internal combustion engine according to claim 1, wherein the fuel supply means is arranged on the upstream side of an opening position of the intake passage opening on the most upstream side of the collector. apparatus. 3. A fuel injection valve, wherein said fuel supply means is constituted by a fuel injection valve having an injection port directed upstream with respect to the intake airflow and an injection port directed downstream with respect to the intake airflow. A fuel injection device for an internal combustion engine according to item 1. 4. The fuel injection valve is set such that the injection rate in the upstream injection with respect to the intake airflow is higher than the injection rate in the downstream injection with respect to the intake airflow. 3. The fuel injection device for an internal combustion engine according to item 3. 5. The fuel injection device for an internal combustion engine according to claim 3, wherein the fuel injection valve is a fuel injection valve that simultaneously injects in two directions. 6. The fuel injection valve is configured to be switchable between a state of injecting in a downstream direction with respect to the intake airflow and a state of injecting in both a downstream direction and an upstream direction with respect to the intake airflow. Item 5. A fuel injection device for an internal combustion engine according to Item 3 or 4. 7. The fuel injection valve is an injection valve configured to lift a valve body by a magnetic attraction force of an electromagnetic coil,
By switching the magnetic attraction force to at least two types, the lift amount of the valve body, the injection is performed in the downstream direction with respect to the intake airflow, and the injection is performed in both the downstream direction and the upstream direction with respect to the intake airflow. 7. The fuel injection device for an internal combustion engine according to claim 6, wherein the fuel injection device is configured to be switchable to. 8. The fuel supply means comprises a first auxiliary fuel injection valve whose injection direction is directed upstream with respect to the intake airflow, and a second auxiliary fuel injection valve whose injection direction is directed downstream with respect to the intake airflow. The fuel injection device for an internal combustion engine according to claim 1 or 2, comprising: 9. The fuel supply means rotates an auxiliary fuel injection valve having an injection direction in a direction substantially orthogonal to a central axis about the central axis so that the injection directions are upstream and downstream with respect to an intake air flow. 3. The fuel injection device for an internal combustion engine according to claim 1, wherein the fuel injection device is configured to switch to either of the above.