JPH0413404Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an intake system structure for a carburetor-equipped engine.

[Conventional technology]

Conventionally, an intake passage 2 that communicates with an engine body 1 (see FIG. 1; refer to the same figure for reference numbers of members to be described later).
Various types of air cleaners have been proposed in which an air cleaner 10, a choke valve 6, a bench lily portion 3a of a carburetor 3, and a throttle valve 4 are arranged from the upstream side.

For example, there are "air cleaners" shown in Japanese Utility Model Publication No. 55-22182 and "air cleaners" shown in Japanese Utility Model Publication No. 61-2289.

[Problem that the invention attempts to solve]

However, in such a conventional engine with a carburetor, especially in the case of a kerosene engine, the fuel blown back toward the air cleaner 10 due to the blowback of intake air collides with the partition wall 9 of the air cleaner 10, becomes liquid, and flows outside the air cleaner 10. There is a problem with leakage.

That is, at the end of the intake stroke of the engine, an air flow (blown back air) from the engine body 1 toward the carburetor 3 is generated due to the inertia of the intake air or the incompatibility of the intake valve closing timing.

On the other hand, due to the inertia of the fuel, even if the intake valve closes,
Fuel is still flowing out from main nozzle 5.

Therefore, the fuel is blown back from the vaporizer 3 toward the air cleaner 10 by the above-mentioned blowback air, collides with the partition wall 9 of the air cleaner 10, becomes liquid, flows downward, and leaks to the outside of the air cleaner 10.

The present invention is intended to solve these problems, and aims to provide an intake system structure for an engine with a carburetor that can prevent fuel from leaking to the outside of the air cleaner.

[Means for solving problems]

Therefore, the intake system structure of the engine with a carburetor of the present invention includes a carburetor installed horizontally in the intake passage of the engine, an air cleaner disposed in the intake passage upstream of the carburetor, and an air cleaner installed in the intake passage on the upstream side of the carburetor. a rotary valve pivotally mounted on the intake passage between the carburetor and the air cleaner, a pivot portion of the rotary valve being provided at a lower part of the upstream side of the carburetor in close proximity to the carburetor; The tip of the Chiyork valve is arranged so as to contact or be close to the partition wall of the air cleaner when the Chiyork valve is fully open, and the upper surface of the Chiyork valve is transmitted along the partition wall of the air cleaner when the Chiyork valve is fully open. It is characterized in that it is formed as a guide surface that guides the return of liquid fuel to the vaporizer.

[Effect]

In the intake system structure of the engine with a carburetor of the present invention described above, when the intake air is blown back when the choke valve is fully open, liquid fuel adheres to the partition wall of the air cleaner and flows down the partition wall. Liquid fuel is guided from the partition wall to the carburetor side via the guide surface of the choke valve.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cutaway elevational view of a main part of an intake system structure of an engine with a carburetor as an embodiment of the present invention.

As shown in FIG. 1, an air cleaner 10, a choke valve 6, a bench lily portion 3a of a carburetor 3, and a throttle valve 4 are interposed in an intake passage 2 communicating with a fuel chamber of an engine body 1 from the upstream side. .

A main nozzle 5 is connected to the carburetor 3, and fuel is injected into the intake air contracted by the bench lily portion 3a.
3 is horizontal.

A chiyoke valve shaft 7 that pivotally supports the chiyoke valve 6 is located below the carburetor inlet 8, and when the chiyoke valve 6 is opened, one end of the chiyoke valve 6 is connected to the air cleaner 1.
It is configured to be in contact with the partition wall 9 of 0 or to have a small gap therebetween.

The shape of the check valve 6 may be square or circular, and the check valve 6 is arranged horizontally or inclined from the air cleaner side to the carburetor 3 side so that the liquefied fuel easily returns to the carburetor 3 side. In addition, an upper guide surface 6a is formed on the upper surface of the check valve 6.

Note that numerals 11 and 12 in the figure indicate an element and a lid of the air cleaner 10, respectively.

Since the intake system structure of the engine with a carburetor as an embodiment of the present invention is configured as described above,
When the fuel blows back from the carburetor 3, it first collides with the partition wall 9 of the air cleaner 10 and becomes liquid, and falls along the partition wall 9, but it collects on the upper guide surface 6a of the choke valve 6 in the state shown in the figure. is,
It is returned to the carburetor 3 side along the choke valve 6.

In addition, the yoke valve 6 may be formed as a gutter having a concave cross-sectional shape as shown by the two-dot chain line, or the tip portion on the partition wall 9 side may be bent upward by a predetermined angle θ.

Further, a recess 9a shown by a two-dot chain line may be formed in the partition wall 9 so that the liquid fuel tends to collect toward the choke valve 6.

In this way, according to this embodiment, the chiyoke valve 6
In the open state, the tip of the choke valve 6 contacts the partition wall 9 of the air cleaner 10 or is configured to have a small gap. The fuel that has become liquid due to the collision passes along the upper surface of the choke valve 6 and flows toward the carburetor 3 side.

[Effect of idea]

As detailed above, according to the intake system structure of the engine with a carburetor of the present invention, the carburetor is installed horizontally in the intake passage of the engine, and the carburetor is installed in the intake passage upstream of the carburetor. an air cleaner, and a chiyoke valve pivotally connected to the intake passage between the carburetor and the air cleaner, the pivoting portion of the chiyoke valve being located close to the carburetor and on the upstream side of the carburetor. provided at the lower part, the tip of the chiyoke valve is arranged so as to contact or be close to the partition wall of the air cleaner when the chiyoke valve is fully open; With a simple structure formed as a guide surface for guiding the return of liquid fuel to the vaporizer through the partition wall of the air cleaner, the following effects and advantages can be obtained.

(1) Since fuel does not leak to the outside, there is no fuel loss, which is economical, and is safe without causing fires.

(2) Since the chiyoke valve itself is used, there is no need to attach any special devices, resulting in low cost.

[Brief explanation of the drawing]

FIG. 1 is a cutaway elevational view of a main part of an intake system structure of an engine with a carburetor as an embodiment of the present invention. 1...Engine body, 2...Intake passage, 3...
Carburetor, 3a... Bench lily part, 4... Throttle valve, 5... Main nozzle, 6... Chyoke valve,
6a... Upper guide surface, 7... Chiyoke shaft as a pivot joint, 8... Carburizer inlet passage, 9... Partition wall, 9
a... recess, 10... air cleaner, 11... element, 12... lid.

Claims (1)

[Scope of utility model registration request] A carburetor is installed horizontally in the intake passage of the engine, an air cleaner is provided in the intake passage upstream of the carburetor, and the air cleaner is pivotally connected to the intake passage between the carburetor and the air cleaner. It is equipped with a chiyoke valve, and the pivoting part of the chiyoke valve is
It is provided in the lower part of the upstream side of the carburetor in close proximity to the carburetor, and the tip of the choke valve is arranged so as to come into contact with or be close to the partition wall of the air cleaner when the choke valve is fully open. An intake air intake for an engine with a carburetor, characterized in that an upper surface of the Chiyork valve is formed as a guide surface for guiding liquid fuel flowing through the partition wall of the air cleaner back to the carburetor when the Chiyork valve is fully open. System structure.