JPH08319890A - Carburettor - Google Patents

Abstract

PURPOSE: To reduce bubbling when the inflowing fuel to a float chamber has intruded under the fuel liquid surface. CONSTITUTION: The fuel flowing into a float chamber 1 diverges to a side hole 3. Fuel flowing down inside a needle seat 2 passes a flow path 12, proceeds to the lower part, and flows into the fuel liquid surface H aslant from a flow path 13 in trumpet form. Therein the summerging to under the liquid surface H remains shallow, and bubbling is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a carburetor used in an internal combustion engine of a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, in order to reduce the generation of bubbles due to the fuel submerged in the fuel level H of the float chamber 1, a lateral hole 3 is provided in the needle seat 2 to secure the fuel. Vaporizers that split the flow are known.

Reference numeral 4 is a float chamber cover, 5 is a float, 6 is a float lever, 7 is a float lip, 8 is a pin for swingably supporting the float lever 6, 9 is a needle valve, 10 is Needle valve 9
A push rod inserted into the upper and lower parts so as to be slidable relative to each other, and 11 is a needle valve 9 and a push rod 1.
It is a spring interposed between zero.

[0004]

SUMMARY OF THE INVENTION In the above conventional technique,
When the fuel flow rate is large and the flow velocity of the fuel flowing between the needle seat 2 and the needle valve 9 is large, a negative pressure is generated inside the needle seat 2, and the atmosphere is sucked through the lateral hole 3 and the needle seat 2 Mixes with fuel inside to generate a large amount of bubbles.

Thus, the fuel containing a large amount of bubbles flows right below through the cylindrical flow passage 12 between the cylindrical portion 2a of the needle seat 2 and the cylindrical portion 9a of the needle valve 9 to reach the fuel level H. There was a problem that it crawls into and creates a large amount of foam.

Bubbling causes so-called spewing and causes engine malfunction. This large amount of bubbling occurs even when the lateral hole 3 is not provided in the needle seat 2, which is a problem.

Therefore, an object of the present invention is to provide a carburetor capable of solving the above problems by reducing a large amount of bubbling due to the infiltration of the fuel into the liquid surface H of the fuel.

[0008]

In order to achieve the above-mentioned object, the invention of claim 1 is such that the lower outer diameter of the needle valve (9) and the lower inner diameter of the needle seat (2) are respectively lowered downward. The vaporizer is characterized in that it is provided with tapered portions (9b) and (2b) whose diameter increases.

According to the present invention, the fuel flowing into the float chamber obliquely flows into the liquid surface of the fuel, so that the fuel penetration is shallow and the bubbling due to the fuel penetration is reduced.

According to a second aspect of the invention, in the carburetor according to the first aspect, the needle valve (2) has a tapered portion (2).
It is characterized by having a lateral hole (3) above b).

According to the present invention, since the amount of fuel flowing in is increased and the atmosphere is sucked in through the lateral holes 3 to contain bubbles, the depth of fuel penetration is reduced, so that foaming due to fuel penetration is reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, and portions of the same reference numerals as those in the prior art shown in FIG.

The embodiment of FIG. 1 differs from the prior art of FIG. 2 in that the outer diameter of the lower portion of the needle valve 9 and the inner diameter of the lower portion of the needle seat 2 are tapered toward the lower portions 9b and 2b, respectively. It is the only point where and are provided.

By doing so, the flow passage 12 between the needle seat 2 and the needle valve 9 becomes a trumpet-like flow passage 13 that gradually expands in diameter in the lower portion, and from this flow passage 13 the inside of the float chamber 1 is increased. Since the fuel flowing into the tank flows obliquely into the liquid surface H of the fuel, the submersion below the liquid surface becomes shallow and bubbling is reduced.

In particular, as in the embodiment of FIG.
When the lateral hole 3 is formed in the seat 2, the air is sucked from the lateral hole 3 when the flow rate is large, and the fuel mixed with the bubbles flows into the fuel level H, so that the fuel flows into the fuel level H. Although the amount of foaming when it sneaks in is further increased, since it flows in obliquely from the trumpet-shaped channel 13 and sunk therein, the foaming is reduced to such an extent that it does not pose a practical problem.

[0016]

Since the carburetor of the present invention is constructed as described above, there is an advantage that the fuel flowing into the fuel liquid surface of the float chamber becomes shallower and the bubbling is reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a conventional technique.

[Explanation of symbols]

 1 ... Float chamber 2 ... Needle seat 2b ... Tapered part 3 ... Side hole 5 ... Float 9 ... Needle valve 9b ... Tapered part

Claims (2)

[Claims] 1. A carburetor, characterized in that a taper portion is provided on a lower outer diameter of a needle valve and a lower inner diameter of a needle seat, the taper portions increasing in diameter downward. 2. The carburetor according to claim 1, wherein the needle valve has a lateral hole above the tapered portion.