JPS62162766A - Intake manifold for gasoline engine - Google Patents

Abstract

PURPOSE:To atomize the fuel adhering onto a suction passage by the air stream which flows on the inner and outer surfaces of an inner cylinder, at the downstream edge of the inner cylinder, by installing the inner cylinder having a gap between the inner wall of the suction passage on the upstream side of the branched part of each suction passage and forming a communication hole which communicates to each gap. CONSTITUTION:A large part of the fuel which is jetted in synchronization with the intake stream from a fuel feeding part 16 is atomized, and reaches a branched part 5, passing through the both sides of a throttle valve 17, and inflows into any of the first, third, and fifth cylinders which is in suction cycle. An intake passage 6 similarly communicates to the second, fourth, and sixth cylinders through a branched part 8. For example, when the first cylinder is in suction cycle, no cylinder on the suction passage 6 side is in the suction cycle. The air stream directed towards the suction passage 3 from the suction passage 6 is generated in a communication hole 9. The air stream flows in the gap 20 on the outer surface of an inner cylinder 18, and splashes out the fuel adhering at the lower edge of the inner cylinder 18 by the cooperation with the air stream inside the inner cylinder 18, and flows into the first cylinder from a branched part 5.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an intake manifold for a multi-cylinder gasoline engine, and is particularly suitable for improving the distribution of fuel between cylinders of a fuel injection device that injects fuel into a gathering part of an intake passage. related to intake manifolds for gasoline engines.

[Conventional technology]

Conventionally, as a method of improving fuel distribution in a multi-cylinder gasoline engine, there was a method shown in Japanese Utility Model Publication No. 56-66054, in which a cylindrical heating element was provided downstream of the throttle valve of the carburetor to evaporate the fuel adhering to the a-plane. was known.

[Problem that the invention seeks to solve]

However, this method has problems such as the expensive heating element and the need for a large-capacity generator because it uses a large amount of electricity, making it difficult to use in vehicles.

SUMMARY OF THE INVENTION An object of the present invention is to provide an intake manifold for a multi-cylinder gasoline engine with good fuel distribution between cylinders.

[Means for solving problems]

A feature of the present invention is that an inner cylinder is provided upstream of the branch part of the intake passage in order to reduce fuel flowing unevenly into each cylinder along the wall surface of the branch part of the intake passage. This is achieved by providing a communicating hole.

[Effect]

The fuel adhering to the intake passage flows along the inner wall of the inner cylinder, and is atomized at the downstream end of the inner cylinder by the air flow flowing on the inner and outer surfaces of the inner cylinder.

Furthermore, by utilizing the phase difference between the intake air of each cylinder, it is possible to improve the distribution performance of the air flow flowing on the outer surface of the inner cylinder simply by using a communication hole that communicates the gap between the intake passage and the inner cylinder.

[Embodiments of the invention]

An embodiment in which the present invention is applied to a six-cylinder gasoline engine will be described below with reference to FIG. 1.2.3.

Figures 1 and 2 show the structure and cylinder arrangement of the intake manifold of this embodiment.The cylinder arrangement of one engine 1 is such that the 1st, 3rd, and 5th cylinders are on one side of the intake manifold 2, and the 2nd and 4th cylinders are on the opposite side. ．．
It has 6 cylinders. The intake passage 3 connected to the 1st, 3rd and 5th cylinders is divided at a branch 5 immediately below the vertical shaft A4 forming a part of the intake passage 3 and connected to each cylinder. Similarly, the intake passage 6 that connects to the second 4.6 cylinder is divided at a branch part 8 just below the vertical shaft B7 that forms part of the intake passage 6.
Connect to each cylinder. The vertical shaft A4 and the vertical shaft B7 communicate with each other through a communicating hole 9.

The intake passage 3 upstream of the shaft A4 has an injection body 1 fixed to the intake manifold 2 via a spacer 10.
It communicates with the space 12 within 1. A fuel supply 15.16 consisting of a fuel injection valve 13.14 is arranged in the space 12. In the intake passage 3 between the fuel supply section 15 and the shaft A4, there is provided an inner cylinder 18 that is attached to a throttle valve 17 and a spacer 10 and projects into the shaft A4. A ring-shaped gap 2 is formed between the outer wall of the inner cylinder 18 and the inner wall 19 of the intake passage made up of the inner wall of the vertical shaft A.
0 is set. Similarly, the intake passage 6 also communicates with the space 12,
A throttle valve 21 and an inner cylinder 2 are provided between the fuel supply section 16 and the vertical hole B7.
2. An intake passage inner wall 23 and a gap 24 are provided.

The upstream ends of the gaps 20, 24 are closed by the spacer 1o, and the downstream ends are open toward the intake passages 4, 6, respectively.

The downstream end of internal information 18.22 extends to the lower end of shaft A, B, 4.7 or shaft A, B, in order not to increase the flow path resistance in branch 5.6.

It is set in the middle of 4.7. The opening position of the communication hole 9 is provided upstream from the lower ends of the inner cylinders 18 and 22.

Therefore, the intake passages 3 and 6 form independent intake passages downstream of the space 12. The fuel supply sections 15 and 16 are arranged such that the most upstream positions of the fuel adhesion sections 26 and 27, where the discharged fuel adheres to the wall surface, are downstream from the connection points of the intake passages 3 and 6 with the space 12, respectively.

Space 12 communicates with the atmosphere via an air flow meter and an air cleaner (not shown).

Most of the fuel injected from the fuel supply section 16 in synchronization with the intake air flow is atomized and passes through both sides of the throttle valve 17 to the branch section 5.
The air then flows into the 1st, 3rd, and 5th cylinders that are in the intake stroke along with the intake air flow. - If some of the fuel adheres to the wall surface of the intake passage 3 and flows, it reaches the lower end of the inner cylinder 18. On the other hand, the firing order of each intake cylinder is set to 1.2, 3, 4.5.
6, the intake timing will be as shown in FIG. (The numbers surrounded by circles in the figure indicate the numbers of each cylinder during intake.) Therefore, when the intake speed of the first cylinder is the highest, no cylinder on the intake path 6 side is in the intake stroke. Therefore, at this time, as shown by the arrow in FIG.
An air flow from the intake passage 6 toward the intake passage 3 is generated within the intake passage. This air flow flows in the gap 20 on the outer surface of the inner cylinder 18, and blows off the fuel adhering to the lower end of the inner cylinder 18 together with the air flow inside the inner cylinder 18, causing it to flow into the first cylinder from the fifth branch portion 5.

Therefore, this occurs when the inner cylinder 18 is not present. Since the fuel adhering to the inner wall of the intake passage 3 flows along the wall surface without riding the airflow, it tends to flow into any one cylinder easily.
Even with the inner cylinder 18, there is no air on the outer wall surface of the inner cylinder, so it is possible to prevent the fuel caught in the gap 2o from flowing into the cylinders along the wall surface of the intake passage, which improves the distribution of fuel to each cylinder. It becomes possible to make it uniform.

In general, the distribution of fuel between cylinders is particularly deteriorated when the fuel is operated at low speed and the throttle valve is fully open. When applied to a fuel injection device, the fuel injection time is short compared to the intake stroke at low speed and full throttle, so the air flowing in from the non-intake side intake passage contains almost no fuel, and exhibits an ideal effect. When fuel continuously flows in from a fuel supply section, such as in a carburetor, some fuel is mixed into the air flow passing through the communication hole 9, so the effect is reduced to some extent, but it is not impossible to use.

The material for the inner walls 18 and 22 is preferably fluoride or ethylene resin, to which fuel does not easily adhere, or the fully curved surface is coated with the same resin.

FIG. 4 shows another embodiment of the invention.

The downstream end of the inner cylinder 18.22 is widened toward the inner wall 19.23 of the intake passage, and by narrowing the outlet of the air gap 20.24, the air passing through the communication hole 9 and flowing on the outer surface of the inner cylinder 18.22 is directed to the inner cylinder 1.
This has the effect of making the flow uniform around the outer circumferences of 8 and 22.

Further, although the communication hole 9 is provided on the lower surface of the spacer 10 instead of the intake manifold 2, the effect is the same as if it were provided on the intake manifold 2.

Furthermore, an auxiliary passage 25 is provided for circulating exhaust gas into the intake passage in order to reduce NOx in the exhaust gas, and for introducing air into the intake passage to bypass the throttle valve 17.21 to increase the idle speed at low temperatures. By opening in the communication hole 9, uneven distribution of fuel and air to each cylinder can be prevented, which is caused by the exhaust gas flow and air flow flowing through the intake passage 36 being biased to one side of the intake passage. It has the effect of

Furthermore, due to the difference in the amount of fuel that adheres to the wall surface before reaching the branch part, which occurs when there is a difference in the distance between the first branch parts 5 and 8 and the fuel supply part 15.16 due to the arrangement of the intake passage,
The difference in fuel distribution between the two classes of air passages 3 and 6 can be achieved by making the distances between the branch parts 5 and 8 and the lower ends of the inner cylinders 18 and 22 almost the same.
This can be prevented by making the amount of atomized fuel attached to the branch wall surface uniform at the lower end of the inner cylinder 18°22.

It should be noted that the present invention is effective not only for the ■-shaped six-cylinder engine shown in the embodiment, but also for 4- and 6.8-cylinder engines having two independent intake passages, regardless of the cylinder arrangement.

〔Effect of the invention〕

Therefore, according to the present invention, it is possible to improve the uneven distribution of fuel between the cylinders of a multi-cylinder gasoline engine with an inexpensive method of simply adding WNm passages and cylindrical parts. It has the effect of improving.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the present invention, FIG. 2 is a top view showing the cylinder and intake manifold arrangement of the embodiment of FIG. 1, and FIG. 3 is a top view of the embodiment of FIG. 1. FIG. 4 is a schematic diagram showing the intake timing of FIG. 4, and FIG. 4 is a longitudinal sectional view showing another embodiment. 1... Engine, 2... Intake manifold, 3... Intake path. 4... Vertical shaft A, 5... Branch, 6... Intake path, 7
...Vertical shaft B, 8...branch, 9...communicating hole, 1o...
... Spacer, 11 ... Injection body, 1
2... Space, 13... Fuel injection valve, 14... Fuel injection valve, 15... Fuel supply section, 16... Fuel supply section,
17... Throttle valve, 18... Inner cylinder, 19... Intake path inner wall, 20... Gap, 21... Throttle valve, 22 Inner cylinder, 2
3...Inner wall of intake passage, 24...Gap, 25...Auxiliary passage, 26...Fuel adhesion part, Agent: Patent Attorney Yoshio Ogawa\, -゛・Yu l Figure 3 j

Claims (1)

[Scope of Claims] 1. A multi-purpose intake manifold with a flow path consisting of a plurality of independent intake passages from upstream of the fuel supply section or the fuel adhesion part to the inner wall of the intake passage downstream of the fuel supply section to each cylinder. In a cylinder gasoline engine, an inner cylinder having a gap between it and the inner wall of the intake passage is provided upstream of the branch part of the intake passage downstream of the fuel supply part or the fuel adhesion part of each intake passage, and the upstream side of the intake passage of the gap is closed, and the downstream side is open to the intake path,
An intake manifold for a gasoline engine, characterized in that a communication hole is provided to communicate each gap. 2. The intake manifold for a gasoline engine according to claim 1, characterized in that an auxiliary passage is opened in the communication hole.