JPH11280556A - Cabureter of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cabureter previously preventing a fuel unavoidably remained from closing a slow caburetion system after an excess fuel in a float chamber is drained. SOLUTION: A venturi portion 2 is provided on an intake pipe 1, a float chamber 5 is provided at a lower portion of the venturi portion 2 and a drain valve 24 is provided on the float chamber 5. A float 6 and a float valve 7 are provided in the float chamber 5, a main nozzle 10 of a main caburetion system is projected on the venturi portion 2 and a slow port 17 of a slow caburetion system is opened at a neighboring portion of a throttle valve 4 at a downstream of the venturi portion 2. In this case, a slow passage 14 is suspendedly provided at an upstream side of a flow jet 15 constituting the slow caburetion system. A buffer space 20 for excess fuel is provided on the slow passage 14, a plug closing tool 21 is upwardly threaded to a lower end of the flow passage 14 and an auxiliary space 22 is provided on the plug closing tool 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carburetor for an engine, and more particularly to a technique for preventing fuel unavoidably remaining after draining excess fuel in a float chamber from blocking a slow vaporization system.

[0002]

2. Description of the Related Art As a carburetor of an engine, there is a conventional one as shown in FIG. In this carburetor, a venturi section 2 is provided in an intake pipe 1, a float chamber 5 is provided below the venturi section 2, and the float chamber 5 is provided.
, A drain valve (not shown) is provided, and a float 6 and a float valve 7 are provided in the float chamber 5.
The main nozzle 1 of the main vaporizing system is provided in the venturi section 2.
0, and a slow vaporization slow port 17 is opened in the vicinity of the throttle valve 4 on the downstream side of the venturi section 2. A rubber stopper 21a is screwed upward into the lower end of the slow passage 14 of the slow vaporizing system.

[0003]

In general, excess fuel in the float chamber 5 is drained by opening a drain valve (not shown) for long-term storage prior to a non-agricultural season or the like. About 1 cc of fuel unavoidably remains in the fuel oil chamber 8. While leaving it unattended, the working machine and the like are enlarged for maintenance (about 100
When tilted, the fuel unavoidably remaining in the fuel oil chamber 8 flows into the slow jet 15 via the slow passage 14 of the slow vaporization system, and it is turned into gum during the agricultural off season to close the slow jet 15. . For this reason, even when the engine is started and operated when the working machine or the like is restarted, fuel does not flow to the slow vaporization system, and low-speed operation such as idling cannot be performed.

In some cases, the fuel remaining in the slow jet 15 is removed by air blowing. However, the rubber plug 21a may come off and be lost due to the pressure of the air blowing. The present invention has been made in view of such circumstances, and after draining excess fuel in the float chamber,
It is an object of the present invention to provide a carburetor that prevents fuel unavoidably remaining in the fuel oil chamber 8 from blocking a slow vaporization system.

[0005]

According to a first aspect of the present invention, a venturi section 2 is provided in an intake pipe 1, and a float chamber 5 is provided below the venturi section 2. A drain valve 24 is provided in the float chamber 5, and a float 6 and a float valve 7 are provided in the float chamber 5.
The main vaporizer main nozzle 10 protrudes from the engine, and the slow vaporizer slow port 17 is opened in the vicinity of the throttle valve 4 downstream of the venturi section 2 to constitute the slow vaporizer. A slow passage 14 is provided vertically on the upstream side of the slow jet 15, and a buffer space 20 for surplus fuel is provided in the slow passage 14.

[0006] The invention described in claim 2 is the invention according to claim 1.
In the carburetor of the engine described in (1), a stopper 21 is screwed upward into the lower end of the slow passage 14, and an auxiliary pace 22 is provided in the stopper 21.

[0007]

According to the first aspect of the present invention, the slow passage 14 is provided vertically on the upstream side of the slow jet 15 constituting the slow vaporization system, and the excess fuel buffer space 20 is provided in the slow passage 14. Therefore, after the surplus fuel is drained, when the working machine or the like is greatly tilted for maintenance, the fuel unavoidably remaining in the fuel oil chamber 8 stops in the buffer space 20 and the slow jet on the downstream side thereof 15 is prevented from flowing into. Accordingly, it is possible to prevent the surplus fuel from becoming gummed in the slow jet 15 and blocking the slow jet 15.

According to the second aspect of the present invention, since the stopper 21 is screwed upward into the lower end of the slow passage 14 and the auxiliary pace 22 is provided in the stopper 21, maintenance of the working machine and the like is completed. At this time, the surplus fuel remaining in the buffer space 20 is collected in the auxiliary pace 22 of the stopper 21. This can prevent the fuel from remaining in the slow vaporization system. Further, by screwing the stopper 21, even when fuel remaining in the slow vaporization system is removed by air blow, there is no possibility that the stopper will fall off due to the pressure of the air blow.

[0009]

Embodiments of the present invention will be described below in more detail with reference to the drawings. 1A and 1B are longitudinal sectional views of a vaporizer according to an embodiment of the present invention.
The left half in (B) is a vertical sectional view taken along line BB in FIG. 1 (A), and the right half is a vertical sectional view taken along line CC in FIG. 1 (A). In this carburetor, a venturi section 2 is provided in an intake pipe 1, and a choke valve 3 is provided upstream of the venturi section 2.
A throttle valve 4 is provided on the downstream side, a float chamber 5 is provided below the venturi section 2, a drain valve 24 for closing a drain port 23 is provided in the float chamber 5, and a float is provided in the float chamber 5. 6
And a float valve 7 provided with a needle valve so as to keep the fuel oil level S in the float chamber 5 substantially constant.

A main nozzle 10 constituting a main vaporizing system is protruded from the venturi section 2 and ejects fuel to the venturi section 2 through the main nozzle 10 when the engine rotates at a high speed. Further, a slow port 17 and an idle hose (not shown) constituting a slow vaporization system are opened downstream of the venturi section 2 and in the vicinity of the throttle valve 4, and a slow jet 15 and the like described later when the engine is running at a low speed. The fuel is ejected to the slow port 17 and the idle hoat through the.

The main vaporizing system includes the main nozzle 10
A fuel oil chamber 8 provided in a lower portion thereof, a main jet 12 communicating the fuel oil chamber 8 with the inside of the float chamber 5, and a main air bleed chamber 11 formed around the middle of the main nozzle 10. And a main air bleed (not shown) communicating therewith. The main nozzle 1 mixes the air that has flowed into the main air bleed chamber 11 and the fuel that is sucked out by negative pressure when the engine is rotating at high speed.
It is configured to squirt into the venturi section 2 from the tip of the zero.

The slow vaporizing system includes an outlet passage 13 from the fuel oil chamber 8, a vertically disposed slow passage 14, a slow jet 15, a port passage 16 to a slow port 17 and an idle port (not shown). And a pilot air bleed (not shown), which mixes the air flowing into the pilot air bleed during low-speed rotation of the engine with the fuel sucked out by the negative pressure at the slow port 17 near the throttle valve 4. It is configured to blow out from the slow port 17 and the idle port. In addition,
Reference numeral 18 in FIG. 1B is an idling adjustment screw.

As shown in FIGS. 1A and 1B, the slow passage 14 is provided with a buffer space 20. This is because when the working machine or the like is largely tilted for maintenance after draining the surplus fuel, the fuel unavoidably remaining in the fuel oil chamber 8 stops in the buffer space 20 and the downstream slow jet 15 is intended to be avoided. As a result, it is possible to prevent the fuel from becoming gummed in the slow jet 15 and blocking the slow jet 15.

A bolt stopper 21 is screwed upward into the lower end of the slow passage 14, and an auxiliary pace 22 is provided in the stopper 21. This is because the buffer space 2
The purpose is to recover the fuel remaining in the space 0 into the auxiliary pace 22 of the stopper 21. This can prevent the fuel from remaining in the slow vaporization system. Further, by screwing the bolt stopper 21, the stopper 2 is air blown as in the conventional example.
There is no danger that 1 will fall off and be lost.

The present invention is not limited to the above-described embodiment.
The specific shape of the auxiliary pace 22 provided on the stopper 21 and the stopper 21 can be implemented with appropriate changes.

[Brief description of the drawings]

FIGS. 1A and 1B are longitudinal sectional views of a vaporizer according to an embodiment of the present invention, and the left half in FIG.
1A is a vertical sectional view taken along line BB in FIG.
(A) is a vertical sectional view taken along line CC in FIG.

FIG. 2 is a longitudinal sectional view of a vaporizer according to a conventional example.

[Explanation of symbols]

F ... fuel, 1 ... intake pipe, 2 ... venturi section, 4 ... throttle valve, 5 ... float chamber, 6 ... float,
7: float valve, 10: main nozzle, 14: slow passage, 15: slow jet, 17: slow port,
20: buffer space, 21: stopper, 22: auxiliary pace, 24: drain valve.

Claims (2)

[Claims] An intake pipe (1) is provided with a venturi portion (2), a float chamber (5) is provided below the venturi portion (2), and a drain valve (24) is provided in the float chamber (5). At the same time, a float (6) and a float valve (7) are provided in the float chamber (5), a main nozzle (10) of a main vaporizing system is protruded from the venturi section (2), and a In a carburetor of an engine having a slow vaporization system slow port (17) opened in the vicinity of the throttle valve (4) on the downstream side, a slow passage (14) is provided upstream of the slow jet (15) constituting the slow vaporization system. ), And an excess fuel buffer space (20) is provided in the slow passage (14). 2. A carburetor for an engine according to claim 1, wherein a stopper (21) is screwed upward into a lower end of said slow passage (14), and an auxiliary pace (2) is inserted into said stopper (21).
2) An engine carburetor provided with 2).