JPS6019979Y2 - automatic fuel kettle - Google Patents

Description

[Detailed description of the invention] This invention is an automatic system that uses negative pressure absorbed by the engine to pull a diaphragm, opens the fuel valve attached to the diaphragm, and connects the fuel passage between the fuel tank and the float chamber of the carburetor. Regarding improvements to fuel cocks.

A conventionally known automatic fuel cock is shown in FIG.

1 is a cock body, 2 is a diaphragm, 3 is a fuel chamber formed above the diaphragm 2, 4 is a fuel passage that communicates a fuel tank and a float chamber (not shown) of a carburetor through the fuel chamber 3; A fuel valve 5 is attached to the center of the diaphragm 2, and the fuel passage 4 is opened and closed by this fuel valve 5.

6 is a negative pressure chamber formed on the back (lower side) of the diaphragm 2; 7 is a spring that is contracted in the negative pressure chamber 6 and gives the fuel valve 5 a tendency to always close the fuel passage 4; 8 is a negative pressure chamber 6; A check valve 9 that is opened only by negative pressure is installed in this negative pressure passage 8.

9a is a check valve chamber provided in the middle of the negative pressure passage 8 and accommodates the check valve 9; 10 is a rubber tube (10) which constitutes the negative pressure passage 8 and connects one end to an intake pipe (not shown) of the engine; A tube joint 11 to which the other end (not shown) is fitted is a bypass passage that bypasses the check valve 9 and communicates the negative pressure passage 8 upstream of the check valve 9 with the negative pressure chamber 6;
By this bypass passage 11, after the engine is stopped, the negative pressure chamber 6
Negative pressure remaining within the fuel valve 5 is quickly dissipated, and the fuel valve 5 closes the fuel passage 4.

Generally, in order to improve engine startability, it is necessary that the oil level in the float chamber of the carburetor always reach a specified level.

However, according to the above conventional automatic fuel cock, when the engine is stopped, the fuel passage 4 leading from the fuel tank to the float chamber of the carburetor is completely shut off by the fuel valve 5, so the engine is stopped for a long period of time. If this happens, the oil level in the float chamber of the carburetor will drop below a specified level due to fuel evaporation, etc., which has the disadvantage of impeding engine startability.

That is, the fuel passage 4 of the fuel valve 5 when the engine is cranked once by the starter motor or kick pedal.
Since the opening time is very short and the amount of fuel supplied to the float chamber is small, the engine must be cranked many times in order to raise the oil level in the float chamber to the specified level. This means that it takes a long time to start.

The object of the present invention is to provide an automatic fuel cock that eliminates the above-mentioned drawbacks.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 2, in which the same parts as the conventional example are given the same reference numerals. A valve body 12 for opening and closing the bypass passage 11 is rotatably installed on a bypass passage 11 that communicates the upstream passage 8 with the negative pressure chamber 6.

This valve body 12 is pressed against the bypass passage opening surface 11a by the acting force of a spring 14 contracted on its back surface, and the contact surface 12a of the valve body 12 that contacts the bypass passage opening surface 11a is A groove 12b is provided so as to partially shape the bypass passage 11 and communicate the bypass passage 11 only when the opening position is rotated to the open position.

The back surface 12c of the valve body 12 is provided with a groove or notch 12b for engaging a driver or the like for rotating the valve body 12.

Further, an annular seal member 13 is attached to the circumferential sliding surface of the valve body 12.

15 is a member that prevents the spring 14 and the valve body 12 from being removed.

Next, to explain the operation of this embodiment, when starting the engine after it has been stopped for a long time, the valve body 12 is operated by a driver or the like, and the bypass passage 11 is closed, and the starter motor or kick pedal is used to start the engine. When the engine is cranked once, the negative pressure generated in the intake pipe of the engine passes through the negative pressure passage 8, opens the check valve 9, and is transmitted to the negative pressure chamber 6.

This negative pressure then pulls the diaphragm 2 against the spring 7, and accordingly, the fuel valve 5 opens the fuel passage 4, and fuel is supplied from the fuel tank to the float chamber of the carburetor.

Once negative pressure is introduced into the negative pressure chamber 6, this negative pressure does not disappear because the check valve 9 is closed and the bypass passage 11 is closed. Therefore, the fuel valve 5 keeps the fuel passage 4 open.

Therefore, by cranking the engine once using the starter motor or kick pedal, the automatic fuel cock can be maintained in an open state, and the oil level in the float chamber of the carburetor can be filled to a specified level.

Next, after the engine is started, continuous engine suction negative pressure acts on the negative pressure chamber 6, so even if the valve body 12 is rotated with a screwdriver or the like to open the bypass passage 11, the diaphragm 2 The fuel valve 5 maintains the open state of the fuel passage 4 and supplies fuel from the fuel tank to the float chamber.

Next, when the engine operation is stopped, the negative pressure in the suction pipe disappears, so the negative pressure in the negative pressure chamber 6 also disappears through the bypass passage 11, and the diaphragm 2 is moved upward by the spring 7 and the fuel valve 5 blocks the fuel passage 4.

Another embodiment of the present invention is shown in FIGS. 4 and 5.

In FIG. 4, the valve body 12 is provided with a lever portion A projecting to the outside of the fuel cock, and the valve body 12 is rotated by operating this lever portion A.

In FIG. 5, the bypass passage 11 is opened and closed by sliding the valve body in the axial direction. B is an operating rod that projects outside the fuel cock, and 16 is attached to the contact surface 12a of the valve body 12. This is a sealed seal member.

As described above, according to the present invention, a valve that is operated from outside the fuel cock to open and close the bypass passage is installed on the bypass passage that dissipates the negative pressure in the negative pressure chamber of the automatic fuel cock when the engine is stopped. By closing the passage,
Maintains the suction negative pressure in the negative pressure chamber when the engine is cranked once with the starter motor or kick pedal,
The diaphragm is pulled down to open the fuel valve and keep the fuel passage open, so even if the engine is stopped for a long time and the oil level in the float chamber of the carburetor drops below the specified level, the engine will continue to function. One cranking operation quickly raises the oil level in the float chamber to a specified level, and therefore the engine can be started immediately, which is extremely effective in improving engine startability.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a conventional automatic fuel cock, FIG. 2 is a vertical sectional view showing an embodiment of the automatic fuel cock of the present invention, and FIG. 3 is a partial vertical sectional view showing the operating state in FIG. 2. , FIG. 4 and FIG. 5 are longitudinal cross-sectional views showing only essential parts of other embodiments of the present invention. 1... Cock body, 2... Diaphragm, 6... Negative pressure chamber, 8... Negative pressure passage,
9...Check valve, 11...Bypass passage, 12...Valve body.

Claims (1)

[Scope of utility model registration request] In an automatic fuel cock, a diaphragm is pulled by the engine's suction negative pressure, the fuel valve attached to the diaphragm is opened, and the fuel passage connecting the fuel tank and the float chamber of the carburetor is communicated. A negative pressure passage connects to the pressure chamber via a check valve, and a bypass passage connects the negative pressure passage upstream from the check valve to the negative pressure chamber. An automatic fuel cock characterized by having a valve installed.