JP2002174144A - Air path for carburetor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the controllability of an air fuel ratio by preventing the influence of the intake operation of a slow air jet on the intake operation of a main air jet during light load operation of an engine. SOLUTION: A carburetor having air paths constituted by grooved portions formed in the surface of a carburetor body 2 and a cover comprises the plurality of independent air paths 15, 16 formed by the plurality of independent grooves 10, 11 and the main air jet 18 and the slow air jet 19 arranged in the respective air paths, the air paths 15, 16 having intake ports, 20, 21 independently open to the atmosphere on both sides of an intake path 3. Thus, the influence of the intake operation of the slow air jet 19 on the controllability of the main air jet 18 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an air passage for supplying air to a main air jet and a slow air jet of a carburetor.

[0002]

2. Description of the Related Art Conventionally, an air passage which comprises a groove formed on the surface of a carburetor body and a cover and supplies air to a main air jet and an air bleed jet is provided through a single air hole communicating with the air. The stream was distributed and supplied to a slow air jet and a main air jet. Therefore, when the engine is running at a low speed, the throttle valve is closed, the intake pipe negative pressure is large, and the air flow passing through the slow air jet increases, so that the air flow passing through the main air jet decreases and the fuel flow decreases. The main air bleed effect of mixing with the air to promote the flow cannot be exerted, resulting in a problem that the air-fuel efficiency is reduced. (See JP-A-64-35060)

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a carburetor which prevents the influence of the intake action of a slow air jet on the intake action of a main air jet during a light engine load operation, thereby stabilizing the controllability of air-fuel efficiency. The purpose of the present invention is to provide an air passage.

[0004]

SUMMARY OF THE INVENTION The present invention provides a carburetor having an air passage formed by a groove formed on the surface of a carburetor body and a cover, wherein a plurality of independent air passages are formed by a plurality of independent grooves. The main air jet and the slow air jet are disposed in each air passage, and the suction port of the air passage is independently opened to the atmosphere. You can prevent it from affecting you.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention forms a plurality of independent air passages by covering a plurality of independent grooves formed on the surface of a carburetor body, and forms a main air jet in each air passage. , A slow air jet is installed. Further, the suction ports of the respective air passages are independently opened to the atmosphere.

The intake ports of the air passages in which the main air jet and the slow air jet are disposed are opened to the atmosphere on both sides of the intake path, so that the intake air sucked into the slow air jet and the main air jet influence each other. Conflict can be completely prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. 1 is a carburetor, and the carburetor body 2 has an intake path 3
The upstream side of the intake passage 3 is connected to an air cleaner (not shown), and the downstream side is connected to an intake port of an engine (not shown) via an intake manifold (not shown). A venturi 5 is provided at the center of the intake path 3, and a throttle valve 6 is arranged downstream of the venturi 5.

The upper end 8 of the carburetor body 2 is provided with a plurality of independent grooves 10, 11, and 12.
・ 16 ・ 17 is formed. The grooves 10 and 11 respectively have a main air jet 18 and a slow air jet 1.
9 are provided. On the other hand, the other of the grooves 10 and 11 extends to both sides of the intake path 3 and is connected to the atmosphere on both sides of the intake path 3 by intake ports 20 and 21. That is, the main air jet 18 and the slow air jet 19 are disposed on the left side of the intake passage 3 in FIG.
And is connected to an atmosphere chamber 25 formed in the silencer side flange portion 24 by the suction port 20. Reference numeral 26 denotes an atmosphere port of the atmosphere chamber 25. The other end of the groove 11 in which the slow air jet 19 is disposed is extended to the right until it crosses the longitudinal center line LL of the intake passage 3 and then returned to the left side of the carburetor body 2 to be suctioned. 21 connects to the atmosphere. By circulating the grooves 10 and 11 in this manner, the air intake ports 20 and 2 connected to the main air jet 18 and the slow air jet 19 are formed.
1 is open to the atmosphere on the side of the carburetor body 2 with the intake path 3 interposed therebetween, so that the intake action of one air jet does not affect the other air jet, and each of the above-mentioned components is set when the carburetor rolls over. Suction port 2 for air passages 15 and 16
The fuel is prevented from flowing out of the fuel cell 0.21.

A fuel chamber 30 is provided below the intake passage 3. An upper space of the fuel chamber 30 is provided with an air vent passage 31.
Thus, it is connected to the groove 12 of the upper end 8 of the vaporizer body 2. The other side of the groove 12 is connected to the atmosphere by a suction port 32.

The carburetor body 2 is provided with the fuel chamber 3
A main nozzle boss 34 protruding to zero is provided, and a main nozzle 35 is housed in the boss 34. The upper end of the main nozzle 35 faces the intake passage 3, and the lower end communicates with the fuel chamber 30 below the oil level via the main jet 36. The main air bleed chamber 37 is provided around the main nozzle 35, and the main air bleed chamber 37 is communicated with an inner hole 39 of the main nozzle by a plurality of bleed holes 38 provided in the main nozzle 35. The main air bleed chamber 37 is connected to the main air jet 18 by a main air passage 40.

The main jet 36 and the main nozzle 3
5, a slow passage 41 is connected, and the other end of the slow passage 41 is connected to a slow jet 42. A slow air bleed chamber 43 is provided around the slow jet 42. The slow jet 42 is provided in the slow passage 4
4 connects the idle port 45 and the bypass port 46. Also, the slow air bleed chamber 43
The other end of the slow air passage 47 is connected to the slow air jet 19.

According to the above configuration, during the low-speed operation of the engine, the fuel controlled by the slow jet 42 is injected from the idle port 45 and the bypass port 46 into the intake passage 3, and at this time, the fuel passing through the slow jet 42 The air in the slow air bleed chamber 43 is mixed therein, and the fuel is emulsified to improve the flow of the fuel. The slow air supplied to the air bleed chamber 43 is controlled by the slow air jet 19, and its suction port 21 is guided to the left side of the carburetor body 2 in FIG. 1 by an air passage 16 formed upstream.

When the engine is running at a high speed, the fuel controlled by the main jet 36 is ejected from the main nozzle 35 into the intake passage 3, and the fuel passing through the main nozzle 35 is supplied to the main nozzle 35 through the bleed hole 38. The air in the air bleed chamber 37 is mixed and the fuel is emulsified.
The main air supplied to the air bleed chamber 37 is controlled by the main air jet 18,
0 is guided to the right side of the carburetor body 2 in FIG. 1 by an air passage 15 formed upstream.

As described above, the inlets 20 and 21 of the main and slow air passages 15 and 16 are independently opened on both sides of the carburetor body 2 with the intake passage 3 interposed therebetween.
Even when the flow rate of air passing through the slow air jet 19 increases during low-speed operation of the engine with a large intake pipe negative pressure, the controllability of the main air jet 18 is not affected,
The air bleed effect of the main system can be improved, and the start of the main system fuel can be improved. As a result, it is possible to prevent a problem that the air-fuel efficiency in the rotation range where the fuel of the main system starts to flow becomes low.

The air vent passage 31 is connected to the atmosphere by a groove 12 independent of the grooves 10 and 11 to which the main air passage 40 and the slow air passage 47 are connected. Affecting the air passage 40 and the slow air passage 47;
Or the main air passage 40 and the slow air passage 4
7 does not affect the pressure in the fuel chamber 30.

[0016]

As described in detail above, according to the present invention,
In a carburetor that forms an air passage with a groove formed on the surface of the carburetor body and the cover, a plurality of independent air passages are formed by a plurality of independent grooves, and a main air jet is formed in each air passage. By disposing the slow air jet and independently opening the suction port of the air passage to the atmosphere, it is possible to prevent the intake action of the slow air jet from affecting the controllability of the main air jet, thereby reducing the engine lightness. It is possible to prevent air-fuel consumption from decreasing during load operation, and as a result, it is possible to reduce the generation of hydrocarbons.

Further, since the suction ports of the air passages provided with the main air jet and the slow air jet are respectively opened on both sides of the intake passage, the suction action of the slow air jet affects the controllability of the main air jet. Can be reliably prevented from being given.

Further, the suction port of the air passage is disposed on the opposite side of the air jet with respect to the longitudinal center line of the suction path, or the air jet and the suction port are located on one side of the longitudinal center line of the suction path. When the carburetor is in the roll-over position, either the air jet or the suction port or the air The middle of the passage is higher than the longitudinal center line of the intake passage, and it is possible to prevent the fuel from flowing out from the intake port when the carburetor is in the rolled position.

[Brief description of the drawings]

FIG. 1 is a top view of a vaporizer having an air passage according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG. 1;

FIG. 5 is a front view of a carburetor provided with an air passage according to the present invention.

FIG. 6 is an air-fuel ratio characteristic diagram of a carburetor having an air passage according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 carburetor 2 carburetor body 3 intake path 6 throttle valve 10.11.12 groove 15.16.17 air passage 18 main air jet 19 slow air jet 20.21.32 intake port 30 fuel chamber 31 air vent passage 35 main nozzle 36 Main jet 37 Main air bleed chamber 40 Main air passage 42 Slow jet 43 Slow air bleed chamber 44 Slow passage 47 Slow air passage

Claims (2)

[Claims] In a carburetor comprising an air passage formed by a groove formed on a surface of a carburetor body and a cover, a plurality of independent air passages are formed by a plurality of independent grooves. To the main air jet,
An air passage for a carburetor, wherein a slow air jet is provided, and an intake port of the air passage is independently opened to the atmosphere. 2. An air inlet provided in the air passage provided with the main air jet and the slow air jet is opened to the atmosphere on both sides of the air intake passage.
4. The air passage of the carburetor according to 1.