JPS6115237Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Field of Industrial Application> The disclosed technology belongs to the technical field of mixing and feeding fuel and bleed air from the float chamber of a carburetor attached to an automobile engine to the main nozzle of the bench lily.

Therefore, in this invention, the main nozzle passage connected to the main nozzle provided in the bench lily part of the carburetor is connected via the dead space part formed on the outside of the inner tube connected to the air bleed jet. This invention relates to a main well structure of a carburetor in which the dead space part is connected to the main jet of a float chamber, and in particular, the dead space part is squeezed into a tapered shape from the downstream side to the upstream side, and
This invention relates to a main well structure for a carburetor that reduces the dead space and increases the fuel supply flow rate.

<Prior Art> As is well known, a carburetor is attached to an internal combustion engine installed in an automobile.The general structure of a carburetor 1 is shown in FIG. Lily 5 is attached, and throttle valve 6 is downstream.
However, a chiyoke valve 7 is provided upstream.

A main nozzle 8 opening into the small bench lily 5 is connected to a main well 10 via a main nozzle passage 9, and a main jet 11 communicates the main well 10 with a float chamber 12.

When the engine is running, the fuel 13 in the float chamber 12 is sucked in by the vent valve negative pressure that is generated depending on the opening degree of the throttle valve 6, is metered in the main jet 11, and is transferred to the main well 10 as shown in FIG. The bleed air enters the inside through the fuel hole 15 of the outer tube 14, and is mixed with fuel by jetting out from the emulsion hole 18 of the inner tube 17 of the bleed air supplied from the air bleed jet 16 to form an emulsion flow. The liquid is agitated in the upper dead space part 19 and is ejected from the main nozzle 8 to the bench lily part.

<Problems to be solved by the invention> However, as shown in FIG. 2, in the conventional structure of the main well 10, the main well 10 is formed by the inside of the outer tube 14 connected to the main nozzle passage 9 and the outside of the inner tube 17. Since the dead space 19 is too wide as a mere ring-shaped intersection, the fuel 13 and the blade air are not mixed well, and emulsion formation by the bleed air is not good.

Therefore, there is a problem that the air-fuel ratio of the air-fuel mixture ejected from the main nozzle 8 tends to fluctuate, and therefore, for example, vibrations in the longitudinal direction due to torque fluctuations,
That is, there were also problems such as the so-called surge phenomenon.

The purpose of this invention is to solve the technical problem of the dead space part of the main well of the carburetor based on the above-mentioned conventional technology, and to increase the flow velocity of the air-fuel mixture in the dead space part to create a fuel mixture with a stable air-fuel ratio. It is an object of the present invention to provide an excellent main well structure of a carburetor that can be used to supply fuel from the main nozzle to the bench lily section and effectively take measures against surges, thereby benefiting the field of application of fuel system technology in the automobile industry. .

<Means/effects for solving the problem> In accordance with the above-mentioned purpose, the structure of this invention, which is summarized in the scope of the above-mentioned utility model registration claim, is to solve the above-mentioned problem by applying negative pressure to the bench lily during engine operation. The fuel to be sucked in is metered by the main jet of the float chamber, enters the main well, and the flow rate of the bleed air from the emulsion hole of the inner tube to be sucked in is increased due to the high flow rate in the dead space section. The fuel is made into a small particle size and emulsion is effectively carried out, and the emulsified fuel is accelerated at a squeezing part with no dead space in the dead space part, flows through without stagnation, and flows from the main nozzle to the bench lily part without fluctuation. Technical measures have been taken to prevent fluctuations in the air-fuel ratio from occurring.

<Example> Next, an example of this invention will be described below with reference to FIG. 1 and the drawings from FIG. 3 onwards. Note that the same parts as in FIGS. 1 and 2 will be described using the same reference numerals.

In the embodiment shown in FIGS. 3 and 4, the main well 10' constitutes the gist of this invention, and is provided in the same carburetor as the embodiment shown in FIG. 12 and the main jet 11.

The gap between the inner tube 17' and the outer tube 14' is narrower than that of the conventional one shown in FIG. 2 in order to improve the response of the fuel.

The outer tube 14' is connected to the inside and outside as well as to the main nozzle passage 9 via the lower fuel hole 15, and the dead space 19' formed on the inside with respect to the main nozzle passage 9 is connected from the downstream side. A tapered portion 20 is provided that tapers toward the upstream side.

On the other hand, an inner tube 17' coaxially installed inside the outer tube 14' has an emulsion hole 18 and an air bleed jet 16 at the upper end, and a portion that takes part in forming a dead space 19' on the outside thereof. forms a tapered portion 21 having a taper degree greater than that of the tapered portion 20 of the outer tube 14', and therefore, the dead space portion 19' is squeezed upward toward the top as shown in FIG. It is ensured that there is no

In the above configuration, when the engine is operated, the throttle valve 6 or it and the throttle valve 7
The fuel 13 is sucked from the float chamber 12 by the negative pressure created in the bench lily part 3 in cooperation with the main jet 11, and enters the main well 10', where it enters the fuel hole 15.
From there, enter the outer tube 14'.

On the other hand, the bleed air entering from the air bleed jet 16 is ejected from the emulsion hole 18 of the inner tube 17' and flows into the fuel hole 15.
However, due to the high flow velocity of the squeezed portion of the inner tube 17' and outer tube 14', the jetted bleed air is made into fine particles, and the fuel 13 is also made into fine particles, forming an emulsion. is carried out well.

The emulsified fuel mixture sucked up from between the outer tube 14' and the inner tube 17' is formed by the tapered part 20 of the outer tube 14' and the tapered part 21 of the inner tube 17'. Mixing and agitation is further promoted in the squeezing part, and the mixture is ejected and supplied from the main nozzle passage 9 to the main nozzle 8.

Since the dead space 19 is squeezed in this process, the air-fuel mixture does not stagnate. Therefore, the emulsified fuel-air mixture is supplied in a stable state, and as a result, surge phenomena and the like are almost never caused. It will no longer occur.

In addition, the embodiment shown in FIG.
The tapered portions 21 and 20 that form a dead space portion 19'' of 7'' are formed in two stages, which further enhances the stirring effect.

In the embodiment shown in FIG. 6, the part of the outer tube 14'' that is connected to the dead space part 19 is a right-angled part 23 with respect to the tapered part 21 of the inner tube 17', so that the pinched part is sharpened. , there is no difference in practical effects.

However, if the well volume is large, the bubbles generated at high temperatures will push up the fuel inside the well, intensifying the occurrence of percolation, so there are well designs that omit the outer tube to reduce the internal volume of the well and prevent the occurrence of percolation. The embodiments shown in Figures 7 and 8 correspond to the above Figures 3 and 4 and Figures 5 and 6 and are well configurations in which the outer tube is omitted, and have the same substantial effects.

It goes without saying that the embodiments of this invention are not limited to the above-mentioned embodiments; for example, the inner tube may be made straight in the dead space portion, and when an outer tube is provided, it may be made into an inside taper shape. Various aspects can be adopted.

Various types of carburetors, such as a compound two-barrel type carburetor, can also be used.

<Effects of the invention> As described above, according to this invention, in the main well structure of the carburetor which is connected to the main jet of the float chamber and the main nozzle of the bench lily part, the dead space part formed by the inner tube connected to the air bleed jet in the well is By squeezing the fluid into a tapered shape that tapers from the downstream side to the upstream side, the dead space basically becomes narrower toward the upstream side, eliminating the dead space, increasing the flow rate, and eliminating stagnation. The air-fuel mixture of the emulsified fuel flowing through the air does not fluctuate, so the air-fuel ratio is stabilized.
This provides an excellent effect of preventing vehicle surge phenomena and the like.

In addition, since the flow velocity in the dead space is increased, the supply condition of bleed air from the inner tube becomes better, and the particle size of the fuel mixed with this becomes smaller, which has the advantage of improving the emulsion effect. .

Furthermore, since the dead space is squeezed into a tapered shape to prevent stagnation, the fine air bubbles in the emulsified fuel mixture do not combine and become larger in diameter, thereby reducing the amount of fuel supplied. This also has the effect of avoiding fluctuations in the value.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of a carburetor, Fig. 2 is a sectional view of the main well structure based on the prior art, Fig. 3 and the following are explanatory views of embodiments of this invention, and Fig. 3 is a sectional view of one embodiment. , FIG. 4 is an enlarged sectional view of the same part, FIG. 5 is a sectional view of another embodiment, FIG. 6 is a sectional view of another embodiment, and FIGS. 7 and 8 are sectional views of another embodiment. It is a diagram. 1... Carburetor, 3, 4, 5... Bench lily section, 8... Main nozzle, 9... Main nozzle passage, 12... Float chamber, 11... Main jet, 10', 10''... Main well, 16 ...Air bleed jet, 17', 17''...Inner tube, 19', 19'', 19...Dead space section.

Claims (1)

[Scope of utility model registration request] In a structure in which the main well, which is connected to the main nozzle passage communicating with the main nozzle of the bench lily of the carburetor and also connected to the main jet of the float chamber, has an inner tube connected to the air bleed jet, from the outside of the inner tube. A main well structure for a carburetor, characterized in that a dead space portion connected to the main nozzle passage is formed in a tapered shape from the downstream side to the upstream side.