JP2004183593A - Air intake device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constantly allow atomization of fuel independent of operating conditions of an internal combustion engine. <P>SOLUTION: An air intake device comprises an injector 3 disposed to an air intake passage 6 to inject the fuel. The air intake device further comprises a dynamical pressure intake port 5 projecting into the air intake passage 1 to take inflow air in the air intake passage 1 in the dynamical pressure intake port 5, and a dynamic pressure passage 13 guiding the inflow air taken from the dynamical pressure intake port 5 to around a fuel injection port 3a of the injector 3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an intake device for an internal combustion engine, and more particularly to an intake device for making fuel spray finer.
[0002]
[Prior art]
By reducing the particle size of the fuel spray, the fuel spray is easily vaporized in the combustion chamber, the ignitability of the air-fuel mixture in the combustion chamber and the stability of flame propagation in the low-speed low-load region are improved, and the ignition , The air-fuel ratio can be made leaner, the exhaust gas temperature can be raised, the time for raising the temperature of the catalyst can be shortened, and the emission of unburned HC can be greatly reduced.
[0003]
In medium-, high-speed, and medium-to-high load ranges, the latent heat of vaporization improves knock resistance, increases compression ratio, improves torque, improves fuel efficiency in the partial range of the throttle, and improves torque when the throttle is fully opened due to improved volumetric efficiency. The effect of is obtained.
[0004]
Therefore, the smaller the particle size of the fuel spray injected from the injector, the better.
[0005]
As a method of atomizing the fuel spray, there is a method of using a multi-hole injector, but this has not been sufficient.
[0006]
On the other hand, Japanese Patent Application Laid-Open No. H11-163,087 discloses an apparatus that provides a bypass passage communicating from an intake passage to a portion near an injector injection port and collides air passing through the bypass passage with fuel spray to atomize fuel spray. I have.
[0007]
[Patent Document 1]
JP-A-9-228931
[Problems to be solved by the present invention]
However, the device described in Patent Literature 1 is provided with an intake flow control valve that controls an opening degree in accordance with an operation state downstream of the bypass passage opening of the intake passage, and an upstream and downstream of the intake flow control valve is provided. This is a device for introducing intake air into the bypass passage using a differential pressure.
[0009]
Therefore, when the opening degree of the intake flow control valve is small, that is, in the low-speed low-load region, air is injected from the bypass passage outlet toward the fuel spray using the differential pressure generated upstream and downstream of the intake flow control valve. However, when the opening degree of the intake flow control valve is large, that is, when the throttle is fully opened, almost no intake air is introduced into the bypass passage due to the small differential pressure between the upstream and downstream of the intake control valve, and the fuel The spray could not be atomized.
[0010]
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to enable atomization of fuel spray in almost the entire operation range of an engine.
[0011]
[Means for Solving the Problems]
The intake device of the present invention includes an injector for injecting fuel into an intake passage, and injects air to the fuel spray to atomize the fuel spray. In order to take in the air, a protruding dynamic pressure intake is provided in the intake passage to take in the inflow air in the intake passage, and the inflow air taken in from the dynamic pressure intake is brought into the vicinity of a fuel injection port of the injector. And a leading dynamic pressure passage.
[0012]
[Action / Effect]
According to the present invention, the assist air that collides with the fuel spray is taken in from the intake passage by using the dynamic pressure, and the dynamic pressure of the intake air is also used when injecting the fuel toward the fuel spray. Irrespective of this, the assist air can always be injected. As a result, it is possible to atomize the fuel spray in almost the entire operation range.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a sectional view of the present embodiment, and FIG. 2 is a top view of the same.
[0015]
The intake passage 6 branches downstream into two intake ports 7 and communicates with the combustion chamber 1. An opening of the intake port 7 on the combustion chamber 1 side is provided with an intake valve 2 which opens and closes in synchronization with the rotation of the engine. When the intake valve 2 is closed, the communication between the intake port 7 and the combustion chamber 1 is cut off. Then, in the opened state, the intake air is communicated from the intake passage 6 to the combustion chamber 1 through the intake port 7.
[0016]
The injector 3 facing the intake port 7 is attached to the intake passage wall 8. The injector 3 is driven to open by a signal output from a control unit (not shown), and injects fuel toward the two intake ports 7. Note that the injector 3 used in the present embodiment is a multi-hole injector that is advantageous for atomizing fuel spray, and is injected in an intake process of an internal combustion engine.
[0017]
An assist air device 4 is mounted on the inner wall of the intake passage 6 near the injection port 3a of the injector 3.
[0018]
FIG. 3 is a three-view drawing (a front view, a side view, and a top view) of the assist air device 4. FIG. 4 is a sectional view taken along line AA of FIG. 3, FIG. 5 is a sectional view taken along line BB, and FIG. 6 is a sectional view taken along line CC of FIG.
[0019]
As shown in FIG. 3, the assist air block 4a of the assist air device 4 has an injector mounting port 10 into which the injection port 3a of the injector 3 is inserted, and a movement opening substantially at right angles to the intake air flow toward the intake upstream side. The pressure inlet 5 is open. The dynamic pressure intake 5 protrudes into the intake passage 6.
[0020]
As shown in FIGS. 4 and 6, a fuel injection passage 14 that penetrates through the assist air block 4 a from the injector mounting port 10 and communicates with the intake passage 6 is provided.
[0021]
The fuel injection passage 14 has two ends 14 a and 14 b so as to face the injector mounting port 10 and the two intake ports 7 at one end, and has two passages inside the assist air block 4 a. Has branched to.
[0022]
Further, two assist air injection ports 12a and 12b facing each other are symmetrically opened on the wall surface of the fuel injection passage 14 with respect to the center line F of the fuel spray. A straight line G connecting the two assist air injection ports 12a and 12b is substantially perpendicular to the center line F of the fuel spray.
[0023]
As shown in FIG. 5, a dynamic pressure passage 13 that connects the dynamic pressure intake port 5 and the fuel injection passage 14 is provided inside the assist air block 4a. The dynamic pressure passage 13 is branched into two on the way, and each of the branch passages 13a and 13b is connected to the assist air injection ports 12a and 12b, respectively. The branch paths 13a and 13b are symmetric with respect to a line H connecting the centers of the dynamic pressure intake port 5 and the injector mounting port 10.
[0024]
Next, the operation of the present embodiment will be described.
[0025]
Part of the intake air flowing through the intake passage 6 is taken into the assist air device 4 from the dynamic pressure intake port 5 and is injected from the assist air injection ports 12 a and 12 b toward fuel spray injected from the injector 3.
[0026]
At this time, the fuel spray collides with the assist air to atomize the fuel spray. Further, the two assist air injection ports 12a and 12b are located symmetrically with respect to the center line F of the fuel injection, and the passages from the dynamic pressure intake port 5 to the assist air injection ports 12a and 12b are also symmetrical. The pressure of air injected from the assist air injection ports 12a and 12b is substantially equal. Therefore, the direction of the fuel spray is not biased toward any of the intake ports 7 by the injection of the assist air.
[0027]
Since the dynamic pressure intake 5 protrudes into the intake passage 6 and opens substantially at right angles to the intake flow toward the intake upstream, the intake of the intake at the dynamic pressure intake 5 causes the assist air injection port 12a, Until the injection at 12b, all are performed by the dynamic pressure of the intake air. For this reason, unlike the conventional case, sufficient assist air cannot be obtained at the time of a high load, and the dynamic pressure increases in a high load region where the intake flow rate of the intake passage 6 increases, so that the assist air can be supplied effectively.
[0028]
Also, by setting the injection timing of the injector 3 to the intake process, the intake valve 2 is opened when the injector 3 performs fuel injection, that is, when assist air injection is required, and the combustion chamber 1 is provided in the intake port 7. , A dynamic pressure is secured.
[0029]
Therefore, it is possible to always inject the assist air regardless of the degree of the throttle opening, and as a result, it is possible to always atomize the fuel spray.
[0030]
The assist air device 4 has an opening 5 provided near the injector injection port 3, and assist air taken in by utilizing dynamic pressure is supplied from the assist air injection ports 12 a and 12 b to the fuel from the injection port 3 a of the injector 3. Since the injection is performed toward the spray, the dynamic pressure passage 13 can be shortened, and the assist air can be efficiently supplied with a small pressure loss.
[0031]
As described above, in the present embodiment, the assist air that collides with the fuel spray is taken in from the intake passage 6 using the dynamic pressure, and the dynamic pressure of the intake air is also used when injecting the fuel toward the fuel spray. The assist air can always be injected regardless of the operation state.
[0032]
It is needless to say that the present invention is not limited to the above embodiment, and various changes can be made within the scope of the technical idea described in the claims.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of the present invention.
FIG. 2 is a top view of the embodiment of the present invention.
FIG. 3 is a three side view of the assist air device.
FIG. 4 is a cross-sectional view (AA cross-sectional view of FIG. 3) of the assist air device.
5 is a cross-sectional view of the assist air device (a cross-sectional view taken along the line BB in FIG. 3).
6 is a sectional view of the assist air device (a sectional view taken along line CC in FIG. 3).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Intake valve 3 Injector 4 Assist air device 5 Dynamic pressure intake 6 Intake passage 7 Intake port 8 Intake passage wall 10 Injector attachment port 12 Assist air injection port 13 Dynamic pressure path 14 Fuel injection path

Claims (3)

In an intake device including an injector that injects fuel into an intake passage,
A dynamic pressure intake port protruding into the intake passage for taking in the inflow air in the intake passage;
An intake device for an internal combustion engine, comprising: a dynamic pressure passage for guiding inflow air taken in from the dynamic pressure intake port to a vicinity of a fuel injection port of the injector. 2. The intake device for an internal combustion engine according to claim 1, wherein the dynamic pressure intake has an opening facing upstream of the intake passage and substantially perpendicular to a flow direction of the inflow air. 3. An assist air block is attached to an inner wall of the intake passage near the injector, and an injector mounting port into which the injection port of the injector is inserted into the assist air block; and While providing an open fuel injection passage, the assist air block is provided with the dynamic pressure intake port, and connected to the dynamic pressure intake port to eject assist air to fuel spray from the injection port. 3. The intake device for an internal combustion engine according to claim 2, wherein an assist air injection port of the pressure passage is opened to the fuel injection passage.

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