JPH07101017B2 - Float chamber structure of car carburetor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a float chamber structure for a vehicle carburetor, and more particularly to a float chamber structure capable of preventing the air vent from being clogged with fuel or the like and the fuel from blowing out from the air vent. Regarding

[Conventional technology]

Generally, a carburetor for a vehicle is provided with a float chamber communicating with a fuel injection port in a mixture passage, and a float valve that moves up and down together with the float opens and closes a fuel supply port to the float chamber. It is configured to keep the surface constant. In such a carburetor, in order to smoothly flow the fuel from the float chamber to the mixture passage to obtain an appropriate mixing ratio, the atmospheric pressure in the float chamber or the air pressure in the air cleaner (hereinafter referred to as atmospheric pressure, etc.) An air vent is formed to introduce the above).

[Problems to be solved by the invention]

However, the above-mentioned conventional air vent is generally formed in an elongated hole shape, and for example, fuel, bubbles, dust, etc. in the float chamber are easily clogged in the air vent, so that atmospheric pressure and the like cannot be introduced into the float chamber, and In some cases, the original purpose of the air vent, which is to smooth the outflow into the air-fuel mixture passage, may not be achieved.

In order to prevent the clogging of the fuel and the like, conventionally, there has been one in which the air vent has a large diameter. In this case, although there is an effect of preventing clogging of fuel and the like, if the oil level fluctuates during posture change, vibration, or turning of the vehicle, the fuel easily flows out through the large-diameter air vent. was there.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems and to provide a float chamber structure of a vehicle carburetor in which the air vent is not clogged with fuel or the fuel does not flow out from the air vent.

[Means for solving problems]

The present invention, in the float chamber structure of a vehicle carburetor, at the upper part of the float chamber, a partition plate for vertically partitioning the float chamber is arranged with a slight gap between the peripheral edge and the inner surface of the side wall of the float chamber, It is characterized in that the upper chamber above the partition plate is opened to the atmosphere or the air cleaner by an air vent.

[Action]

According to the float chamber structure of the vehicle carburetor according to the present invention,
The float chamber side opening of the air vent is located in the upper chamber defined by the partition plate, and the gap between this partition plate and the inner surface of the float chamber side wall is small. When the fuel shakes, the fuel is blocked by the partition plate and does not flow out from the air vent. Further, although the gap between the partition plate and the inner surface of the side wall of the float chamber is narrow, since it is provided over the entire peripheral edge of this partition plate, even if a part of the partition plate is clogged with fuel or the like, the remaining part remains. Through this, atmospheric pressure is introduced into the float chamber, and the original function of the air vent of maintaining the inside of the float chamber at atmospheric pressure is secured.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 are views for explaining a float chamber structure of a vehicle carburetor according to an embodiment of the present invention. In the figure, reference numeral 1 is a carburetor connected to the downstream side of the air cleaner 9. A piston type throttle valve 4 is arranged in a venturi portion 3a of a mixture passage 3 formed in a body 2 of the carburetor 1 so as to be vertically movable, whereby the venturi diameter can be varied.

The float casing is attached to the lower surface of the body 2.
5a is bolted and fixed, and the casing 5a and the lower surface of the body 2 form a float chamber 5. The float chamber 5 has a substantially cubic shape, and a fuel ejection portion 3b integrally formed on the lower surface of the body 2 is inserted inside the float chamber 5. The float chamber 5 is formed so as to penetrate the ejection portion 3b. The air outlet 3c communicates with the mixture passage 3.

A pair of left and right floats 6 are supported by a support portion 3d integrally formed on the lower surface of the body 2 so as to be vertically swingable. An arm portion 6a of the float 6 moves a needle 6a up and down to supply fuel. The passage 3e can be opened and closed.

The portion on the fuel ejection portion 3b side of the lower surface of the body 2 is recessed above the portion on the support portion 3d side.
In the left and right portions in the direction of flow, concave left and right concave portions 2b are formed further upward. A partition plate is provided in the upper recess 2a.
10 is fixed by mounting bolts 11. This partition
Reference numeral 10 is a rectangular shape in which the notch 10a for the fuel ejection portion 3b is formed, whereby the left and right recesses 2b and the partition plate 10 are formed.
The part surrounded by and is the upper chamber 5b. A gap 12 is provided between the peripheral edge of the partition plate 10 and the peripheral edge of the upper recess 2a forming the side wall of the float chamber 5.

An air vent portion 7 is formed on the left and right side wall portions of the venturi portion 3a of the body 2. The air vent portion 7 is formed wide in the air-fuel mixture flow direction, and the lower end opening portion 7b thereof is open to the upper chamber 5b. In addition, the air vent 7
The tube connection portion 7a is formed in the upper end opening of the
The introducing tube 8 connected to the connecting portion 7a is opened in the element 9a of the air cleaner 9, whereby
The float chamber 5 includes the gap 12, the upper chamber 5b, the air vent portion 7,
It is released into the air cleaner 9 through the introduction tube 8.

Next, the function and effect of this embodiment will be described.

In the carburetor 1 of this embodiment, when the oil level in the float chamber 5 is lowered, the float 6 is lowered, whereby the needle 6b is lowered and the fuel supply passage 3e is opened to supply the fuel into the float chamber 5. When the predetermined oil level is reached, the needle 6b will move into the fuel supply passage.
3e is closed so that the oil level in the float chamber 5 is kept constant. Further, when a negative pressure is generated in the venturi portion 3a due to the circulation of air, the fuel is jetted into the air-fuel mixture passage 3 through the fuel jet port 3c due to the pressure difference with the float chamber 5.

At this time, in the conventional carburetor, since the air vent portion is a passage having a small diameter, there is a problem that fuel or dust is easily clogged in this passage. On the other hand, in this embodiment, since the air vent portion 7 has a shape having a sufficiently large passage area,
The clogging of fuel etc. can be prevented. Further, the partition plate 10 arranged on the upper part of the float chamber 5 narrows the gap with the inner surface of the side wall of the float chamber 5, but since this gap is provided over the entire peripheral edge thereof, it is assumed that a part of the gap is above. Even if the fuel or the like is clogged, the pressure in the air cleaner 9 is introduced into the float chamber 5 through the remaining portion, and the original function of the air vent can be sufficiently ensured.

Further, in the conventional structure in which the passage area of the air vent portion is increased, there is a problem that when the fuel sways due to a change in the posture of the vehicle, the fuel flows out from the air vent portion, but in the present embodiment, the partition plate 10 is used. Since the opening 7b of the air vent portion 7 on the side of the float chamber 5 is covered with this, and since the gap 12 between the partition plate 10 and the inner surface of the side wall of the float chamber 5 is small, the rocking will cause the air vent portion 7 to enter. This fuel is shielded by this partition plate 10, and as a result, the fuel can be surely prevented from flowing out.

In the above embodiment, the case where the air vent portion 7 has a large diameter to increase the passage area has been described. However, in the large invention, the air vent portion 7 does not necessarily have to have a large diameter.
It can also be applied when a small-diameter air vent is provided.

Further, in the above embodiment, the air vent portion 7 is open to the inside of the air cleaner, but of course, it may be opened directly to the atmosphere.

Furthermore, although the piston type throttle valve type carburetor has been described in the above embodiment, the present invention can be applied to a butterfly type throttle valve type carburetor as a matter of course.

〔The invention's effect〕

As described above, according to the float chamber structure of the vehicle carburetor according to the present invention, the float chamber is formed by disposing the partition plate having the gap between the peripheral edge and the inner surface of the float chamber side wall at the upper portion of the float chamber. Since the upper chamber is divided into the upper and lower parts and the upper chamber is opened to the atmosphere by the air vent, there is an effect that the clogging of the air vent due to fuel etc. can be prevented and an appropriate mixing ratio can be secured, and the outflow of the fuel can be ensured. There is an effect that can be prevented.

[Brief description of drawings]

1 to 4 are views for explaining a float chamber structure of a vehicle carburetor according to an embodiment of the present invention.
FIG. 2 is a partial sectional side view of the air vent portion, FIG. 2 is a sectional front view of the air vent portion, FIG. 3 is a partial sectional side view of the central portion, and FIG. 4 is a sectional bottom view of the float chamber. is there. In the figure, 1 is a vaporizer, 3 is a mixing passage, 3c is a fuel injection port, 5 is a float chamber, 5b is an upper chamber, 7 is an air vent part, and 9
Is an air cleaner, 10 is a partition plate, and 12 is a gap.

Claims (1)

[Claims] 1. A carburetor for a vehicle, comprising: a float chamber communicating with a mixture passage through a fuel injection port; and an air vent for introducing atmospheric pressure or air cleaner internal pressure to the float chamber. Above the oil level of the chamber, a partition plate is provided to vertically partition the float chamber with a slight gap between the peripheral edge and the inner surface of the side wall of the float chamber, and the upper chamber above the partition plate is exposed to the atmosphere or the atmosphere by the air vent. A float chamber structure for a vehicle carburetor, which is released into the air cleaner.