JP2762848B2 - Fuel supply 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 supply system for an internal combustion engine which has an intake port in each cylinder and injects fuel from a fuel injection valve provided for each cylinder toward the intake port. In particular, the present invention relates to a technique for preventing fuel injected from a fuel injection valve from flowing into a wall.

[0002]

2. Description of the Related Art As a conventional fuel supply device for an internal combustion engine, for example, there is one as shown in FIG. That is, in this embodiment, a fuel injection valve 1 is mounted on an upper wall portion 2a of an intake pipe 2, and a swirl control valve 3 is provided in an intake port 4 for the purpose of enhancing intake swirl.

When the swirl control valve 3 is closed in a low load region of the engine, the intake air flow rate is increased and a strong swirl is generated in the combustion chamber 5 to improve combustion efficiency, while the swirl control valve 3 is opened in a high load region. The intake passage area is increased so that the efficiency of charging the intake air into the combustion chamber 5 is improved (for example, see Japanese Utility Model Laid-Open No. 61-190439).

[0004]

By the way, in such a conventional fuel supply device for an internal combustion engine, in order to further enhance the intake swirl in the combustion chamber, a swirl control valve 3 is provided.
Should be mounted on the combustion chamber 5 as much as possible. on the other hand,
Usually, the fuel injection valve 1 is mounted on the intake manifold side for manufacturing reasons or the like. Therefore, there is a considerable distance between the injection port 1a of the fuel injection valve 1 and the swirl control valve 3. Become.

Therefore, when fuel is injected from the fuel injection valve 1 in a state where the swirl control valve 3 is closed, the injected fuel 6 adheres to the surface of the swirl control valve 3 and the fuel wall flow 6
a and flows through the inner surface of the intake port 4 and flows into the combustion chamber 5,
There is a problem that not only the fuel transport is delayed, the operability is reduced, the transient response is deteriorated and the combustion becomes unstable, but also the fuel consumption and the exhaust are impaired.

In particular, during a cold operation, the rich operation is performed so as to ensure the drivability, so that the generation of unburned HC is increased. The present invention has been made in view of such a conventional problem, and an internal combustion engine capable of injecting and supplying fuel from a fuel injection valve to a combustion chamber without adhering to a swirl control valve surface and causing a wall flow. It is an object to provide a fuel supply device.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has an intake port communicating with an intake port in each cylinder, and a fuel injection valve provided for each cylinder is directed toward the intake port. In a fuel supply device for an internal combustion engine that injects and supplies fuel, a swirl control valve having a spray passage hole through which a fuel spray passes when the valve is closed, while generating a swirl by changing an intake passage shape upstream of the intake port. And a pipe-like extension having an injection hole is provided at the tip of the fuel injection valve, and the tip of the extension extends to the spray passage hole position of the swirl control valve that is closed. .

Further, the invention according to claim 2 is characterized in that the engine
The swirl control valve is provided with two intake ports, and a cutout is provided on a side of the swirl control valve facing either one of the two intake ports so as to allow intake air to pass therethrough. Further, the invention according to claim 3 is characterized in that the spray passage hole has a Venturi shape.

Further, the invention according to claim 4 is characterized in that an assist air supply means for supplying assist air for promoting atomization of fuel is connected to the fuel injection valve.

[0010]

According to this structure, the following (1)
To (4). (1) The fuel spray injected and supplied from the injection hole provided at the tip of the extension portion extending to the position of the spray passage hole formed in the closed swirl control valve adheres to the surface of the swirl control valve. Never. Therefore, the fuel spray does not become a wall flow, so that the fuel spray directly flows into the combustion chamber through the opening of the intake valve to stabilize combustion, thereby improving fuel efficiency and reducing unburned HC. .

(2) When the swirl control valve is fully closed, the intake air passes through the notch and is introduced into the combustion chamber through only one intake port side. Therefore, for example, a strong swirl optimal for a low load region is provided. And the combustion efficiency is improved. On the other hand, for example, in a high load region, the swirl control valve is fully opened, and intake air passes through the two intake ports, so that sufficient intake charging efficiency can be obtained.

(3) The fuel spray injected and supplied from the injection hole provided at the tip of the extension portion extending to the position of the venturi-shaped spray passage hole adheres to both the upstream and downstream surfaces of the swirl control valve. Therefore, since the flow does not become a wall flow, it flows directly into the combustion chamber through the intake valve opening to stabilize combustion, thereby further improving fuel efficiency and reducing unburned HC. .

(4) The assist air and the fuel are sufficiently mixed while passing through the extending portion, so that atomization of the fuel can be promoted, and the combustion efficiency can be further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, referring to FIGS. 1 and 4, the overall configuration of a fuel supply apparatus according to a first embodiment of the present invention will be described. The internal combustion engine has two intake ports 12 and two exhaust ports 13 for each cylinder 11. A fuel injection valve 15 is mounted on an upper wall 14a of an intake pipe 14 that communicates with the intake port 12 for each cylinder.

The fuel injection valve 15 is an electromagnetic fuel injection valve that is energized by a drive pulse signal output from a control unit (not shown) and is opened by being energized, and is deenergized and closed by a drive pulse signal. At its tip, a pipe-shaped extending portion 16 having a nozzle hole 16a with a tip branched into two is provided. The fuel injection valve 15 has an assist air supply means as shown in FIGS. 2 and 3. Specifically, the fuel injection valve 15 is provided with an assist air, which is air for promoting atomization of the injected fuel, and a fuel. The mixing is configured to take place at a location before the extension branches off. That is, the air that has flowed into the air pump 22 from the downstream of the air flow meter is accumulated and stored in the pressure accumulating vessel 23. The flow rate of the fuel is adjusted by the assist air adjusting valve 26 to reach the inside of the main body of the fuel injection valve 15 and is ejected from a large number of injection holes 27 provided in the fuel passage wall to be mixed with fuel.

The fuel injection valve 15 is of a large flow rate type (having a large fuel passage area of the injection valve control unit) because the fuel is supplied during the suction process by the assist air. Thus, while passing through the extension portion 16, the fuel and the assist air are sufficiently mixed,
The atomization of the fuel is improved and the combustion efficiency is improved.

A tip of the extension 16 is provided with a spray passage hole 17 formed in a swirl control valve 17 in a closed state.
The injection hole 16a, which extends to the position a and is provided at the tip, is directed toward the center side of the combustion chamber with respect to the intake valve stem 18, and the extension 16 allows the direction of fuel spray and the straight traveling. It has excellent properties. On the other hand, if the size of the spray passage hole 17a is large, the air flow rate on the intake valve closing side increases, and the effect of the swirl control valve 17 is reduced. At the position where the fuel spray of
Since the injection hole 16a provided at the tip of the nozzle is close to the spray passage hole 17a, it is formed by a small spray passage hole 17a, and allows sufficient fuel spray to pass without reducing the effect of the swirl control valve 17. It is configured to be able to.

As shown in FIG. 5, when the fuel is injected while the intake valve 19 is open regardless of the amount of injected fuel, the fuel is injected into the extending portion 16 which is branched into two. The fuel is injected from the injection hole 16a provided at the tip, passes through the intake valve opening A, and flows directly into the combustion chamber 20.
The fuel injection amount can be controlled by adjusting the injection period around the time when the intake valve 19 reaches the maximum lift.

The swirl control valve 17 is provided at a position close to the upstream end 21b of the partition wall 21a between the intake ports in the intake port 21 so as to open and close the intake ports simultaneously for the purpose of strengthening the intake swirl. Rotatable shaft 1
7b, and a cutout 17c is formed on the side facing one intake port 21 so as to allow intake air to flow even when the valve is closed.

The swirl control valve 17 is configured so as to close in a low load region B of the engine shown by oblique lines in FIG. 6. The swirl control valve 17 increases the intake air flow rate, generates a strong swirl in the combustion chamber 20, and improves the combustion efficiency. On the other hand, in other high load regions, the opening is formed so that the area of the intake passage is increased by opening, so that the efficiency of charging the intake air into the combustion chamber 20 is improved.

As a result, the extension portion 16 extending to the spray passage hole position 7a formed in the swirl control valve 7 which is closed is provided.
The fuel spray is injected and supplied from the injection hole 16a provided at the tip of the swirl control valve 17 and does not adhere to the surface of the swirl control valve 17. Therefore, since there is no wall flow, the fuel spray directly flows into the combustion chamber 20 through the intake valve opening A, thereby stabilizing combustion and improving fuel efficiency and reducing unburned HC. Can be planned.

Next, another embodiment will be described with reference to FIG. This is basically the first type shown in FIGS. 1 and 4.
As in the first embodiment, the spray passage hole 17a formed in the swirl control valve 17 in the closed state of the first embodiment is formed in a venturi shape. As a result, the fuel spray injected and supplied from the injection hole 16a is sucked and discharged at the surface of the swirl control valve 17 by the high flow velocity of the venturi portion, so that the fuel spray adheres to both the upstream and downstream surfaces of the swirl control valve 17. In addition, since the flow does not form a wall flow, the air flows directly into the combustion chamber 20 through the intake valve opening A, and the combustion is stabilized, so that the fuel efficiency can be improved and the unburned HC can be further reduced.

FIG. 8 shows an example in which the venturi shown in FIG. 7 is press-formed integrally with a plate-like member forming the swirl control valve 17, whereby the number of working steps and the number of assembling steps are increased. , Which leads to a reduction in cost. In each of the above embodiments, the fuel supply device for an internal combustion engine according to the present invention has been described having two intake ports. However, the present invention is not limited to this, and one or three or more Naturally, the present invention can also be applied to a device having the above-described intake port.

[0024]

As described above, according to the present invention,
A swirl control valve having a spray passage hole through which fuel spray passes when the valve is closed is provided upstream of the intake port, and a pipe-shaped extension having an injection hole is provided at the tip of the fuel injection valve. The fuel spray injected from the injection hole does not adhere to the surface of the swirl control valve and does not become a wall flow because the tip of the nozzle extends to the spray passage hole position of the closed swirl control valve. Then, the fuel flows directly into the combustion chamber through the opening of the intake valve to stabilize combustion, thereby improving fuel efficiency and reducing unburned HC.

Further, since the notch is provided on the side of the swirl control valve facing either one of the two intake ports, the intake air passes through the notch when the swirl control valve is fully closed. Is introduced into the combustion chamber only through the intake port side, so that, for example, a strong swirl optimal for a low load region is obtained, and the combustion efficiency is improved. On the other hand, for example,
In the high load region, the swirl control valve is fully opened, and the intake air passes through the two intake ports, so that sufficient intake charging efficiency can be obtained.

Further, since the spray passage hole has a Venturi shape, the fuel spray injected and supplied from the injection hole provided at the tip of the extension portion extending to the position of the spray passage hole is supplied to the upper part of the swirl control valve. Since it does not adhere to either downstream surface and does not become a wall flow, it flows directly into the combustion chamber through the intake valve opening, stabilizing combustion, improving fuel efficiency and reducing unburned HC. It can be achieved even more.

Further, since the assist air supply means for supplying the assist air to the fuel injection valve is connected, the assist air and the fuel are sufficiently mixed while passing through the extending portion, and the fuel is sufficiently finely divided. And the combustion can be made closer to complete combustion in the combustion chamber, and the combustion efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an assist air supply unit of the fuel injection valve according to the present invention.

FIG. 3 is a partial longitudinal sectional view showing the fuel injection valve of FIG. 2;

4A is a longitudinal sectional view of FIG. 1, and FIG. 4B is a view of the swirl control valve as viewed from an arrow S.

FIG. 5 is an explanatory diagram showing an injection period of the fuel supply device according to the present invention.

FIG. 6 is an explanatory diagram showing an operation operation region of the swirl control valve.

FIG. 7A is a longitudinal sectional view showing another embodiment of the present invention, and FIG. 7B is a view of the swirl control valve as viewed from an arrow S.

FIG. 8A is a longitudinal sectional view showing another embodiment of the present invention, and FIG. 8B is a view of the swirl control valve as viewed from an arrow S.

FIG. 9 is a longitudinal sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Cylinder 12 Intake port 13 Exhaust port 14 Intake pipe 14a Intake pipe upper wall 15 Fuel injection valve 16 Extension part 16a Injection hole 17 Swirl control valve 17a Spray passage hole 17c Notch 18 Intake valve stem 19 Intake valve 20 Combustion chamber 21 Intake port 21a Partition wall 22 Air pump 23 Pressure storage container 24 Ventilation pipe 25 Assist air introduction port

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F02M 69/00 F02M 69/04 F02M 61/18 F02B 31/02

Claims (4)

(57) [Claims] 1. A fuel supply device for an internal combustion engine, wherein each cylinder has an intake port communicating with an intake port, and supplies fuel from a fuel injection valve provided for each cylinder toward the intake port. A swirl control valve having a spray passage hole through which fuel spray passes when the valve is closed is provided, and a swirl control valve is provided upstream of the fuel injection valve. A fuel supply device for an internal combustion engine, comprising: a pipe-shaped extension portion; and a tip of the extension portion extending to a position of the spray passage hole of the swirl control valve that is closed. 2. A fuel for an internal combustion engine according to claim 1, wherein the engine has two intake ports, and a cutout is provided on a side of the swirl control valve facing one of the two intake ports so as to allow intake air to pass therethrough. Feeding device. 3. The fuel supply device for an internal combustion engine according to claim 1, wherein the spray passage hole has a Venturi shape. 4. The fuel supply for an internal combustion engine according to claim 1, wherein an assist air supply means for supplying assist air for promoting atomization of fuel is connected to the fuel injection valve. apparatus.