JPS6136765Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a float type carburetor used in motorcycles and the like.

In this type of vaporizer, an overflow passage and an air vent passage that communicate with the float chamber of the carburetor body are connected to a merging chamber outside the float chamber, and the merging chamber has an atmosphere opening passage and an air vent passage that can flow even when this passage is blocked. A system in which a chamber is connected to a preliminary passage for communicating with the atmosphere is conventionally known (Utility Model Opening in 1983).
(See Publication No. 104750). However, in the above-mentioned conventional device, there is no special means for preventing blockage of the reserve passage, and therefore, if the reserve passage becomes blocked by dust, muddy water, etc., it is impossible to connect the float chamber to the atmosphere. It may not be possible to do so.

The purpose of the present invention is to provide a float type carburetor with a simple structure that does not have the above-mentioned problems, and its features include an overflow passage and an air vent passage that communicate with the float chamber of the carburetor body, respectively, in a confluence chamber outside the float chamber. In a float type vaporizer in which an atmosphere opening passageway communicating with the atmosphere is connected to the merging chamber, the tip of the branch pipe forming a branch passage branching from the atmosphere opening passageway is connected to the outside of the vaporizer main body. It is inserted into a recess formed on the side surface with a clearance, and the branch passage is opened to the atmosphere through the clearance.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a synthetic resin carburetor body, and a float chamber 4 is defined by a lower cylinder body and a synthetic resin cup-shaped member 3 joined to the lower cylinder body. ing.
The carburetor body 1 has a hook-shaped overflow passage 6 and an air vent passage, each having one end opened in a large-diameter recess 5 formed on the upper outer surface of the carburetor body 1 and the other end opened in the top surface of the float chamber 4. 7 are bored in parallel.

The joint member 9 connecting each passage 6, 7 and the drain pipe 8 is molded from synthetic resin, and includes a cup-shaped main body 10, a main pipe 11 protruding from the main body 10, and a joint member 9 that connects each passage 6, 7 with the drain pipe 8.
The cup-shaped body 10 is fitted into the large diameter recess 5 of the carburetor body 1 with the main pipe 11 facing downward, and the tip of the branch pipe 12 is connected to the carburetor body. 1 cylinder 2
It is inserted into a small diameter recess 1 formed on the outer surface with a clearance S. Therefore, the cup-shaped main body 10
Inside, there is a merging chamber 14 between the overflow passage 6 and the air vent passage 7, and inside the main pipe 11, there is an atmosphere opening passage 15 communicating with the merging chamber 14.
However, inside the branch pipe 12, there are formed branch passages 16 into which the atmosphere opening passage 15 branches, and a drain pipe 8 communicating with the atmosphere is connected to the lower end of the main pipe 11. The channel 16 is constantly open to the atmosphere via the clearance S.

In the figure, 17 is an intake path, 18 is a synthetic resin throttle valve, 19 is a main fuel jet, 20 is a main fuel nozzle, 21 is a needle valve that increases pressure integrally with the throttle valve 18,
22 is a float.

In the above configuration, the lower part of the atmosphere opening passage 15 and the drain pipe 8 connected thereto are blocked by dust, etc., and the inside of the float chamber 4 is leaked through the air vent passage 7, the merging chamber 14, the upper part of the atmosphere opening passage 15, and the branch passage 16. Can be communicated with the atmosphere at all times,
As a result, the fuel supply from the carburetor to the engine can always be stabilized, and the engine can be operated properly.
In this case, the tip of the branch pipe 12 has a small diameter recess 1
3 with a play space S, and the play space S can function as a labyrinth that effectively prevents the passage of intruders such as dust. Intrusion into the chamber 4 can be prevented, and therefore, the opening of the float chamber 4 to the atmosphere via the branch passage 16 can be maintained reliably. Furthermore, even if the lower part of the atmosphere opening passage 15 or the drain pipe 8 is blocked as described above, the overflow passage 6 can maintain its function of overflowing excess fuel through the branch passage 16. When the oil level in the overflow passage 4 rises to the bent portion of the overflow passage 6, the excess fuel overflows to the outside from the branch passage 16 through the upper part of the overflow passage 6, the merging chamber 14, and the atmosphere opening passage 15.

Furthermore, when a motorcycle is running, if a pressure difference occurs between the atmosphere-side openings of the atmosphere-opening passage 15 and the branch road 16 due to the influence of the running wind, etc., the atmosphere-opening passage 1
5 and the branch passage 16, but since the overflow passage 6 and the air vent passage 7 merge in the merging chamber 14, there is no air flow in both passages 6 and 7 regardless of the generation of the air flow. The pressure is maintained at the same level, thus suppressing the generation of air flow in the overflow passage 6, the float chamber 4 and the air vent passage 7, or the reverse path, and reducing the release of evaporated fuel from the float chamber 4 to the outside. Can be done.

As described above, according to the present invention, the overflow passage 6 and the air vent passage 7 communicating with the float chamber 4 of the carburetor main body 1 are connected to the confluence chamber 14 outside the float chamber 4.
In a float type vaporizer in which an atmosphere opening passage communicating with the atmosphere is connected to the merging chamber 14, the tip of the branch pipe 12 forming a branch passage 16 branched from the atmosphere opening passage 15 is connected to the atmosphere opening passage 15. The carburetor body 1 is inserted into the recess 13 formed on the outer surface thereof with a clearance S, and the branch passage 16 is opened to the atmosphere through the clearance S, so that the atmosphere side end of the atmosphere opening passage 15 and Drain pipe 8 connected to it
Even if the float chamber 4 is blocked by dust or the like, the inside of the float chamber 4 can always be communicated with the atmosphere through the branch passage 16, and thereby the fuel supply from the carburetor to the engine combustion chamber can always be stabilized. The overflow passage 6 can always perform the function of overflowing excess fuel.

Furthermore, the recess 1 at the tip of the branch pipe 12
The clearance S formed at the insertion part into the interior of the passageway 3 can function as a passageway that effectively prevents the passage of intruders such as dust, so that the intruders may clog the branching path 16 or cause the branching. Intrusion into the float chamber 4 through the channel 16 can be prevented, and there is no need to provide special members or complicate the structure of the branch pipe 12 to form the labyrinth. Since it is sufficient to simply form the concave portion 13 with a simple shape on the outer surface of the carburetor main body 1, the structure is simple and can contribute to cost reduction and improved assemblability.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a main part of an embodiment of the present invention, and FIG. 2 is a partially enlarged view thereof. 1... Carburetor body, 4... Float chamber, 6...
Overflow passage, 7...Air vent passage, 14
...merging room, 15...atmosphere open passage, 16...branching path, 13...recess, S...play space.

Claims (1)

[Scope of utility model registration request] An overflow passage 6 and an air vent passage 7 communicating with the float chamber 4 of the carburetor body 1 are connected to a merging chamber 14 outside the float chamber 4, and an atmosphere opening passage 15 communicating with the atmosphere is connected to the merging chamber 14. In this float type vaporizer, a gap S is provided in a recess 13 formed on the outer surface of the vaporizer main body 1 at the tip of the branch pipe 12 forming a branch path 16 branching from the atmosphere opening path 15. A float type vaporizer characterized in that the branch passage 16 is opened to the atmosphere through the play space S.