JPH05164025A - Fuel injection device for engine - Google Patents

Abstract

PURPOSE:To secure a stable combustion state by way of letting a mixed air current injected and supplied from a mixed air injection passage flow in a combustion chamber to generate a vertical vortex and to secondarily save fuel consumption and improve exhaust gas purifying performance. CONSTITUTION:An air intake passage 12 and an air intake valve 20 to communicate with each other through an air intake port 16 are provided on a combustion chamber 18 of a multi point type engine 2, and a mixed air injection passage 24 is provided so that a mixed air current injected from an injector 22 generates a vertical vortex in the combustion chamber 18. A central axis C of this mixed air injection passage 24 is provided in parallel with a straight line extended from the inner wall surface of the air intake port 16 in the neighbourhood of the air intake valve 20. Additionally, an air guide part the injection directing direction of which points to the side of an ignition plug and which is projected in the air intake port 16 is provided in the mixed air injection passage 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection system for an engine, and more particularly to a fuel injection system for a multi-point engine in which injectors are provided in respective combustion chambers of the engine and a mixed air flow is injected from the injectors. Regarding the device.

[0002]

2. Description of the Related Art An engine fuel injection system is provided with an injector for injecting fuel into the engine.
In this injector, the multi-point type in which the number of injectors corresponding to the number of cylinders is arranged to supply the mixed air flow to each combustion chamber which is each cylinder of the engine, or the mixed air flow from one injector is supplied to each combustion chamber There is a single point formula that branches to.

As a fuel injection device for the engine, there is one disclosed in Japanese Unexamined Patent Publication No. 62-162770. The fuel supply device for an internal combustion engine disclosed in this publication is
While forming the first and second intake ports in the internal combustion engine,
First and second intake valves are provided in the first and second intake ports, respectively, and a fuel injection valve for injecting fuel toward a valve hole of the first intake valve is provided. Is provided with an on-off valve that opens and closes in accordance with the engine operating state, the distance from the injection hole of the fuel injection valve to the valve hole is L, the diameter of the valve hole is D, and the spread angle of the fuel injected from the fuel injection valve is When θ is set, the equation tan ⁻¹ (2 ^1/2 D / 2L) ≦ θ ≦ tan ⁻¹ (D / L) is set to be satisfied.

Further, there is one disclosed in Japanese Utility Model Laid-Open No. 60-32562. The fuel injection device disclosed in this publication is provided with a fuel injection nozzle for injecting fuel into an intake passage of an internal combustion engine, and is inclined in the intake passage in front of the fuel injection nozzle with respect to the injection direction axis and in the intake direction. And a deflection plate that is substantially parallel to.

Further, there is one disclosed in Japanese Utility Model Laid-Open No. 60-183272. A fuel supply device for an internal combustion engine disclosed in this publication is provided with a plurality of fuel injection nozzles for injecting fuel of a predetermined pressure by energization, and a cross-sectional area in front of each fuel injection nozzle in the fuel injection direction is provided. A plurality of divergent nozzles that increase after being reduced are provided, an air introduction path for introducing air is provided between each divergent nozzle and the injection port, and a main throttle valve that controls the intake air amount is arranged in the collecting pipe that collects the branch manifolds. A plurality of sub-throttle valves are provided in the branch manifold upstream of the fuel injection nozzle, and the sub-throttle valves are opened / closed in conjunction with the main throttle valve. The amount is supplied to the air introduction path.

Furthermore, there is one disclosed in Japanese Utility Model Publication No. 61-122374. A fuel injection device for an internal combustion engine disclosed in this publication is provided with a fuel injection valve on an upper wall of an intake port of a cylinder head, and one end is fixed to the upper wall and the other end is provided on the upstream side of the fuel injection valve. Is provided with a guide member that is directed toward the center of the intake valve.

[0007]

By the way, in the conventional fuel injection system for an engine, as shown in FIG. 9, the intake port 116 is provided in the cylinder head 104 of the engine 102.
The intake port 116 communicates with a combustion chamber 118 which is a cylinder formed by the cylinder head 104 and the cylinder block 106.

The intake passage 11 formed in the intake manifold 110 is located upstream of the intake port 116.
2 are connected to each other, and an intake valve 120 is provided on the downstream side of the intake port 116.

Further, an injector 122 is arranged in the cylinder head 104, and a mixture injection passage 124 which connects the injector 122 and the intake port 116 is provided, and a throttle not shown in the drawing is provided in the middle of the mixture injection passage 124. An air introduction passage 126 that communicates with the intake passage on the upstream side of the valve and introduces air is connected.

At this time, the injector 122 and the air-fuel mixture injection passage 124 have the umbrella portion 120 of the intake valve 120.
It is arranged so as to be directed toward the center of b,
Intake valve 12 which is a direction different from the flow direction of the main intake air of 2
The mixed airflow was jetted toward the center of the umbrella portion 120b of 0.

As a result, when the engine is operating, for example, in the low load range, the mixture air flow impedes the main intake air flow because the direction of the mixed air flow injected from the injector is different from the direction of the main intake air flow of the engine. This means that a stable combustion state cannot be secured, which is disadvantageous in practical use.

Further, in the case where the intake port of the engine is formed in a shape effective for the vertical vortex flow, the mixed air flow cannot be utilized for the enhancement of the vertical vortex flow in the low load region, and as described above, it is stable. However, there is a disadvantage in that the above combustion state cannot be secured, which is disadvantageous in practical use.

[0013]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides a fuel injection system for a multi-point engine in which an injector is provided to inject and supply a mixed air flow to each combustion chamber. An intake valve that opens and closes a downstream side of the intake port is provided with an intake passage that communicates with the combustion chamber through an intake port, and the mixed air flow injected from the injector is an injector to generate a vertical vortex flow in the combustion chamber. A mixture injection passage communicating with the intake port is provided, and at least a central axis of the mixture injection passage is provided in parallel with a straight line extending an inner wall surface of the intake port near the intake valve. Further, in a fuel injection device of a multi-point type engine in which an injector is arranged to inject and supply a mixed air flow to each combustion chamber, an intake passage communicating with the combustion chamber via an intake port is provided, and a downstream of the intake port is provided. An intake valve that opens and closes the side, and a mixture injection passage that connects the injector and the intake port to generate a vertical vortex in the combustion chamber by the mixture airflow injected from the injector, at least the central axis of the mixture injection passage. Is provided in parallel with a straight line extending the inner wall surface of the intake port near the intake valve, and the air-fuel mixture injection passage is provided with an air guide portion protruding into the intake port so that the injection direction is directed to the ignition plug side. It is characterized by

[0014]

According to the invention as described above, the mixed airflow injected and supplied from the air-fuel mixture injection passage flows into the combustion chamber to generate a vertical vortex flow, and the mixed airflow enhances the vertical vortex flow in the combustion chamber and stabilizes it. The combustion state is secured, and the vertical vortex flow is enhanced to achieve rapid combustion, improving the stability of combustion. Further, the mixed airflow that is injected and supplied from the air guide portion projecting in the intake port so that the injection direction is directed to the spark plug side in the mixture injection passage, flows into the combustion chamber to generate a vertical vortex, and the air guide The vertical vortex flow in the combustion chamber is enhanced by the mixed airflow from the section to secure a stable combustion state, and the vertical vortex flow is enhanced to achieve rapid combustion, thereby improving the combustion stability.

[0015]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. 1, 2 is an engine, 4 is a cylinder head, 6 is a cylinder block, 8 is an air cleaner, 10 is an intake manifold, 12 is an intake passage, 14 is a throttle valve, 16
Is an intake port, and 18 is a combustion chamber.

An intake manifold 10 is connected to a cylinder head 4 of the engine 2, and an intake passage 12 and an intake port 1 are connected.
6 will be established in contact with.

Further, the intake port 16 is provided so as to communicate with the combustion chamber 18, and the intake port 16 is provided downstream of the intake port 16.
An intake valve 20 for opening and closing the downstream side opening 16z is provided.

An injector 22 is attached to the cylinder head 4.
The injector 2 is arranged so that the mixed airflow injected from the injector 22 causes a vertical vortex flow in the combustion chamber 18.
2 and the intake port 16 are provided with a mixture injection passage 24, and at least the central axis C of the mixture injection passage 24 is parallel to a straight line L extending from the inner wall surface 16f of the intake port 16 near the intake valve 20. The configuration is provided.

More specifically, as shown in FIG. 1, when the injector 22 and the mixture injection passage 24 are arranged in the cylinder head 4, they are formed to have the same central axis C, and the intake valve 20 is provided. The central axis C is formed parallel to the straight line L extending from the inner wall surface 16f of the upper portion of the intake port 16 in the vicinity, for example, the distance S1 is formed between the lines L and C.

Further, an air introduction passage 26 having a starting end opening is provided in the air-fuel mixture injection passage 24 in communication with the intake passage 12 upstream of the throttle valve 14.

Next, the operation will be described.

When the engine 2 is operating, air is introduced into the combustion chamber 18 from the air cleaner 8 through the intake passage 12 and the intake port 16 successively.

Then, the fuel injected from the injector 22 is mixed with the air in the air introduction passage 26 in the air-fuel mixture injection passage 24 to generate an air-fuel mixture, and from the air-fuel mixture injection passage 24 through the intake port 16, It is injected and supplied to the combustion chamber 18.

At this time, the central axis C and the straight line L extending from the inner wall surface 16f of the upper portion of the intake port 16 in the vicinity of the intake valve 20 are formed parallel to each other, so that the mixture flowing into the combustion chamber 18 flows as a mixture. The air flow is flowing so as to generate a vertical vortex in the same direction without hindering the air flow.

As a result, the combustion chamber 18 is generated by the mixed air flow.
The vertical vortex flow in the inside can be enhanced, a stable combustion state can be secured, and it is practically advantageous.

Further, since the vertical vortex flow is enhanced, the combustion becomes quicker than that of the conventional one, the combustion stability can be improved, and the lean combustion is also possible.

Further, by enhancing the vertical vortex flow, fuel efficiency and exhaust gas purification performance can be secondarily improved, which is economically and practically advantageous.

FIG. 2 shows a second embodiment of the present invention. In the second embodiment, the portions having the same functions as those in the first embodiment will be described with the same reference numerals.

The feature of this second embodiment is that the upper inner wall surface 30f of the mixture injection passage 30 is provided on a straight line L extending from the upper inner wall surface 16f of the intake port 16. It is in.

That is, the distance S2 between the straight line L and the central axis C is made equal to the radius of the air-fuel mixture injection passage 30, and the inner wall surface 16f at the upper portion of the intake port 16 and the inner wall surface 30f at the upper portion of the air-fuel mixture injection passage 30 are connected. Are formed flush with each other.

As a result, the state of the mixed airflow injected from the air-fuel mixture injection passage 30 into the intake port 16 can be made smoother, and like the first embodiment described above,
The vertical vortex flow in the combustion chamber 18 can be enhanced by the mixed air flow, a stable combustion state can be ensured, and the vertical vortex flow is enhanced, resulting in faster combustion than in the conventional one, and stability of combustion. Can be improved, and lean combustion is also possible.

Further, by enhancing the vertical vortex flow, fuel efficiency and exhaust gas purification performance can be secondarily improved, which is economically and practically advantageous.

3 and 4 show a third embodiment of the present invention.

The feature of the third embodiment is that the mixed airflow from the injector 22 is introduced into the intake port 16 so that the direction of injection of the mixed airflow is directed to the spark plug 42 side. The point is that an air guide portion 44 protruding into the port 16 is provided.

More specifically, an air guide portion 44 having an inner diameter smaller than that of the mixture injection passage 40 is provided in the mixture injection passage 40, and the injection direction by the air guide portion 44 is set to the spark plug 42 side. For example, it is provided so as to be directed to the central portion of the combustion chamber 18.

Further, the tip end of the air guide portion 44 is cut out in parallel with the intake passage 12, and is formed so as to protrude into the intake port 16 by a distance S3.

As a result, the mixed air flow from the mixed gas injection passage 40 passes through the air guide portion 44 and the intake port 16
Is injected and supplied into the inside of the container, and like the first and second embodiments described above,
The vertical vortex flow in the combustion chamber 18 can be enhanced by the mixed air flow, a stable combustion state can be secured, and the vertical vortex flow is enhanced, resulting in quicker combustion than the conventional one, and stability of combustion. Can be improved, and lean combustion is also possible.

Further, by enhancing the vertical vortex flow by the air guide portion 44, fuel efficiency and exhaust gas purification performance can be improved secondarily, which is economically and practically advantageous.

5 to 8 show a fourth embodiment of the present invention.

The feature of this fourth embodiment is that the tip portion 50a of the air guide portion 50 disposed in the air-fuel mixture injection passage 40 is partially removed.

That is, as shown in FIG. 6, the tip end of the air guide portion 50 is cut out in parallel with the intake passage 12, and the distance S4 within the intake port 16 is increased.
Formed by protruding only.

Then, as shown in FIG. 5, when the ignition plug 52 is arranged at the front side portion on the left side of the downstream side opening 16z of the intake port 16 formed in the cylinder head 4, as shown in FIG. As shown in FIG. 8, the air guide portion 5
The part of the spark plug 52 on the side of the spark plug 52 is cut off from the central axis C (see FIG. 5) that passes through the center of the combustion chamber 18 and the center of the air guide part 50 at the end portion 50a of 0, which protrudes into the intake port 16. .

As a result, the mixed airflow reaching the air guide portion 50 from the mixture injection passage 40 is directed to the ignition plug 52 by the tip portion 50a of the air guide portion 50 when flowing into the intake port 16. Similarly to the above-described first to third embodiments, the vertical vortex flow in the combustion chamber 18 can be enhanced by the mixed air flow, a stable combustion state can be ensured, and the vertical vortex flow is enhanced so that the conventional Compared with the above, the combustion becomes faster, the stability of combustion can be improved, and lean combustion is also possible.

Further, by enhancing the vertical vortex flow by the air guide portion 50, fuel efficiency and exhaust gas purification performance can be secondarily improved, which is economically and practically advantageous.

The present invention is not limited to the above-mentioned first to fourth embodiments, and various application modifications are possible.

For example, in the first to fourth embodiments of the present invention, the description has been made of the case where one intake valve is provided in each combustion chamber of the engine, but two or more intake valves are provided in each combustion chamber. It is also possible to use an engine having

[0048]

As described in detail above, according to the present invention, the intake passage communicating with the combustion chamber of the multipoint engine through the intake port is provided, and the intake valve for opening and closing the downstream side of the intake port is provided. An air-fuel mixture injection passage that connects the injector and the intake port is provided so that a mixed air flow injected from the injector causes a vertical vortex flow in the combustion chamber. Since the inner wall surface is provided parallel to the extended straight line, the mixed airflow injected and supplied from the air-fuel mixture injection passage flows into the combustion chamber to generate a vertical vortex flow,
The vertical vortex flow in the combustion chamber can be enhanced by the mixed air flow, a stable combustion state can be ensured, and the vertical vortex flow can be enhanced for rapid combustion to improve combustion stability. In addition, by enhancing the vertical vortex flow, it is possible to improve fuel efficiency and exhaust gas purification performance secondarily, which is economically and practically advantageous.

Further, an intake passage communicating with the combustion chamber of the multi-point engine via an intake port is provided, and an intake valve opening / closing the downstream side of the intake port is provided so that the mixed air flow injected from the injector is in the combustion chamber. A mixture injection passage that connects the injector and the intake port to generate a vertical vortex, and at least the center axis of the mixture injection passage is provided parallel to the straight line extending the inner wall surface of the intake port near the intake valve. , The air-fuel mixture injection passage is provided with an air guide portion projecting into the intake port so that the injection direction is directed to the spark plug side. The mixed airflow that is injected and supplied from the protruding air guide part flows into the combustion chamber to generate a vertical vortex, and the mixed airflow from the air guide part It is possible to enhance the vertical swirl shrink chamber, together may ensure the stable combustion state, and rapid combustion by enhancing Tateuzuryu, can improve the stability of combustion. Furthermore, by enhancing the vertical vortex flow by the air guide portion, fuel efficiency and exhaust gas purification performance can be secondarily improved, which is economically and practically advantageous.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a fuel injection device for an engine showing a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of an engine fuel injection device showing a second embodiment of the present invention.

FIG. 3 is a plan view of a cylinder head in a fuel injection system for an engine showing a third embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of a fuel injection device for an engine.

FIG. 5 is a plan view of a cylinder head in an engine fuel injection device showing a fourth embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view of a fuel injection device for an engine.

FIG. 7 is an enlarged plan view of an air guide portion.

FIG. 8 is an enlarged front view of an air guide portion.

FIG. 9 is a schematic cross-sectional view of an engine fuel injection device showing a conventional technique of the present invention.

[Explanation of symbols]

 2 Engine 4 Cylinder Head 6 Cylinder Block 12 Intake Passage 16 Intake Port 16f Inner Wall 16z Downstream Opening 18 Combustion Chamber 20 Intake Valve 22 Injector 24 Mixture Injection Passage C Central Axis L Straight Line Extending Inner Wall of Intake Port 26 Air Introduction Passage 30 Mixture injection passage 30f Inner wall surface 40 Mixture injection passage 42, 52 Spark plug 44, 50 Air guide part 50a Tip part

Claims (2)

[Claims] 1. A fuel injection device for a multi-point engine in which an injector is arranged to inject and supply a mixed air flow to each combustion chamber, and an intake passage communicating with the combustion chamber via an intake port is provided. An intake valve that opens and closes the downstream side of the port is provided, and a mixture injection passage that connects the injector and the intake port is provided so that the mixture airflow injected from the injector causes a vertical vortex flow in the combustion chamber. At least the mixture injection passage A fuel injection device for an engine, wherein a central axis line of the engine is provided parallel to a straight line extending an inner wall surface of an intake port near the intake valve. 2. A fuel injection device for a multi-point engine in which an injector is arranged to inject and supply a mixed airflow to each combustion chamber, and an intake passage communicating with the combustion chamber via an intake port is provided. An intake valve that opens and closes the downstream side of the port is provided, and a mixture injection passage that connects the injector and the intake port is provided so that the mixture airflow injected from the injector causes a vertical vortex flow in the combustion chamber. At least the mixture injection passage Is provided parallel to a straight line extending the inner wall surface of the intake port near the intake valve, and an air guide portion protruding into the intake port so that the injection direction is directed to the spark plug side in the mixture injection passage. A fuel injection device for an engine, characterized by being provided with.