JPS6238859A - Overflow device of membrane type carburetor - Google Patents

Abstract

PURPOSE:To prevent the overflow of fuel into a cylinder and improve starting performance by cutting off the communication between a pressure adjusting chamber and a nozzle passage when an engine is in stop and installing an overflow valve for the communication between an overflow passage and a bypass passage. CONSTITUTION:When fuel is supplied into a membrane type carburetor 1 from a fuel tank 10 when an engine is in stop, if an overflow valve 31 is pressing- operated, the part between a pressure adjusting chamber 6 and a nozzle 3 is cut off. The pressure adjusting chamber 6 and an overflow passage 9 are allowed to communicate through a passage 33, and at the same time, the pressure adjusting chamber 6 and a bypass passage 35 are allowed to communicate through a passage 34. When a primer pump is operated, fuel is supplied into the pressure adjusting chamber 6 from an inlet 4a through the bypass passage 35. The overflow fuel in the pressure adjusting chamber 6 is returned into the fuel tank 10, passing through the overflow passage 9. Since the pressure adjusting chamber 6 and the nozzle 3 are cut off, overflow of fuel into a venturi 8 is prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an overflow device for a membrane vaporizer.

[Conventional technology]

FIG. 13 shows a conventional membrane vaporizer in cross section.

〉In the figure, 1 is the carburetor body, 2 is the model pump, and 3 is the carburetor body.
is the nozzle, 4 is the needle valve, 4a is the fuel inlet, 5 is the tickler,
6 is a pressure regulating chamber, 7 is an overflow valve, 8 is a venturi, and 9 is an overflow passage.

10 is a fuel tank, and 11 is a primer pump.

If the engine stops due to lack of fuel, etc.

There is no fuel in the membrane type carburetor 1, and even if fuel is supplied to the fuel tank 10, the fuel is not supplied to the membrane type carburetor 1 as it is. Therefore, in order to supply fuel to the membrane type carburetor 1, push up the tip □5 to push up the overflow valve, simultaneously lower the needle valve 4, operate the primer pump 11, and supply the fuel to the membrane type carburetor 2. It is necessary to supply the pressure to the pressure regulating chamber 6 through the air. At this time, when the pressure regulating chamber is filled with fuel, part of the excess fuel supplied by the primer pump 11 flows out through the overflow passage 9, and the rest passes through the nozzle 3 to the venturi 8, and then to the cylinder ( (not shown).

[Problem that the invention seeks to solve]

The conventional method described above has the following drawbacks.

The fuel that flows into the cylinder makes the air-fuel ratio too rich when starting the engine, which tends to cause starting problems.

[Means for solving problems]

The object of the present invention is to provide a membrane vaporizer that eliminates the above-mentioned drawbacks, and its features are as follows.

During operation, the pressure regulating chamber and nozzle passage are communicated, and the overflow passage and the piping passage provided between the model pump and the pressure regulating chamber are isolated, without the need for a Ticla attachment. The present invention includes an overflow valve configured to shut off the pressure regulating chamber and the nozzle passage and communicate the overflow passage and the bypass passage.

[Effect]

In this case, (1) the new overflow valve prevents fuel from flowing into the overflow passage and nozzle at the same time, and (2)
) Tickle is abolished, and fuel is supplied to the pressure regulating chamber by bypassing the fuel valve through the overflow valve pipe/gas passage.

[Embodiments] Examples according to the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a first embodiment of an overflow device according to the present invention, and FIG. 2 is an explanatory diagram showing its operating state.

In the figure, 31 is an overflow valve that is movable in the axial direction. 32 is a return spring of the overflow valve 32, 33 is a passage provided in the overflow valve connecting the pressure regulation chamber 6 and the overflow passage 9, and 34 is a bypass passage 35 for the pressure regulation chamber 6 and the nozzle 3 or the pressure regulation chamber 6 and fuel. 4a is a fuel inlet passage provided in the overflow groove connecting the two.

The operation in the case of the above configuration will be described.

When supplying fuel from the fuel tank 10 to the membrane carburetor 1 when the engine is stopped, the overflow valve 3
1, the pressure regulating chamber 6 and the nozzle 3 are shut off. Further, at this time, the pressure regulating chamber 6 and the overflow passage 9 are communicated through a passage 33, and at the same time, the pressure regulating chamber 6 and the pipe/gas passage 35 are communicated through a passage 34.

Next, when the primer pump 11 is operated, fuel is supplied from the fuel tank to the pressure regulating chamber 6 through the bypass passage 35 via the fuel port 4a. Furthermore, Primapon f 1.1
When the pressure regulating chamber 6 is operated, the pressure regulating chamber 6 is filled with fuel, and in the illustrated embodiment, overflowing fuel is returned to the fuel tank 10 through an overflow passage 9. At this time, pressure regulating chamber 6 and nozzle 3
Since it is cut off from the venturi 8, fuel will not overflow to the venturi 8.

When the bushing of the overflow valve 31 is stopped.

The overflow valve 31 is returned by the force of the return spring 32, as shown in FIG. At this time, the pressure regulating chamber 6 and the nozzle 3 are communicated through a passage 34, and an overflow passage 9. The bypass passage 35 and the pressure regulation chamber are cut off.

In this way, when the engine is operating, it is in a normal state, so the needle valve functions normally, and the function as a membrane type carburetor is the same as before.

A second embodiment is shown in FIGS. 3 and 4. In the figure, 41
can be rotated with a cock type overflow valve.

42 is a passage provided in the overflow valve that connects the pressure regulation chamber 6 and the overflow passage 9; 43 is a passage provided in the overflow valve that connects the pressure regulation chamber 6 and the nozzle 3; 44;
is a passage provided in an overflow valve that connects the pressure regulating chamber 6 and the piston passage 35.

In the case of the above configuration, when fuel is supplied by the membrane carburetor Hebrauma pump prior to starting the engine, if the overflow valve is rotated to the position shown in Fig. 4, the pressure regulating chamber 6
The pinox passage 35 and the overflow passage 9 communicate with each other, so that the carburetor is filled with fuel and excess fuel flows out from the overflow passage.

At this time, since the pressure regulating chamber 6 and the nozzle 3 are shut off, fuel does not flow out to the venturi 8. When the engine is running, the third
The overflow valve is rotated to the position shown in the figure, the pressure regulating chamber 6 and nozzle 3 are communicated, the bypass passage 35 and the overflow passage 9 are closed, and the engine can be operated normally.

FIGS. 5 and 6 show a third embodiment. Overflow valve 51 is similar to that shown in FIG.

Passages provided in the overflow valve 52, 53°5
4 is different. When the overflow valve 51 is pressed, as shown in FIG. 6, the pressure regulating chamber 6 and pi'? The flow passage 35 communicates with the passage 54 and the overflow passage 9 communicates with the passage 52, while the passage to the nozzle 3 is blocked. When the pressing pressure of the overflow valve 51 is stopped, the result is as shown in FIG. The overflow passage 9 is blocked and the passage to the nozzle 3 is opened by the passage 53.

FIG. 7 is an explanatory diagram showing an overflow device according to a fourth embodiment of the present invention, and FIG. 8 is an explanatory diagram showing its operating state.

In the figure, 61 is an overflow valve, which is movable in the axial direction. 62 is a passage provided in the overflow valve that connects the overflow passage 9 and the pressure regulation chamber 6, 63 is a passage provided in the overflow valve that connects the nozzle 3 and the pressure regulation chamber 6, and 64 is a return spring of the overflow valve. .

The operation in the case of the above configuration will be described.

When supplying fuel from the fuel tank 10 to the membrane carburetor 1 when the engine is stopped, the overflow valve 61 is pressed as shown in FIG. It communicates with the pressure regulation chamber 6.

Next, when the tickler 5 is pressed to open the needle valve 4 and the primer pump 11 is operated, fuel starts to be supplied from the fuel tank 10 to the pressure regulating chamber 6. In the one shown in this figure, when the pressure regulating chamber 6 is filled with fuel, the overflow valve 61
passage 62. The fuel then returns to the fuel tank 1 through the overflow passage 9. At this time, the fuel passage to the nozzle 3 is blocked, so no fuel enters the cylinder.

When starting the engine, if you stop the overflow valve 61 and the bushings of the tickler 5, the return valve will return as shown in Fig. 7.
Since the overflow valve 61 returns due to the force of the spring 64,
Since the nozzle 3 is connected to the pressure regulating chamber 6 through the passage 63 and the overflow passage is blocked, the membrane vaporizer 1 functions normally.

9 and 10 show a fifth embodiment. In the figure, 7
1 is a cock type overflow valve that can be rotated. 72 is a passage provided in an overflow valve that connects the pressure regulation chamber 6 and the overflow passage 9, and 73 is a passage provided in the overflow valve that connects the pressure regulation chamber 6 and the nozzle 3.

To describe the operation of the above configuration, 2. During normal operation, as shown in FIG. 9, the pressure regulating chamber 6 and the nozzle 3 communicate through a passage 73, and the characteristics are the same as those of a conventional carburetor. At this time, the pressure regulating chamber 6 and the overflow passage 9 are cut off. When supplying fuel from the fuel tank 10 to the pressure regulating chamber 6 when the engine is stopped, the overflow valve 71 is rotated 90 degrees (10th
), push up the ticker 5 to open the needle valve 4 and operate the priming pump 11. At this time, the pressure regulation chamber 6 and the nozzle 3 are cut off, and the pressure regulation chamber 6 and the overflow passage 9 are communicated through a passage 72.

Therefore, the fuel that has overflowed the pressure regulating chamber 6 flows out from the Onipah flow passage.

A sixth embodiment is shown in FIGS. 11 and 12. In the figure, 81 is an overflow valve similar to the overflow valve 61, and is movable in the axial direction. 82 is the pressure regulating chamber 6 and the nozzle 3. Alternatively, it is a passage provided in the overflow pulp that connects the pressure regulating chamber 6 and the overflow passage 9. 84 is a return spring.

The operation is the same as in the fourth embodiment.

〔Effect of the invention〕

The effects in the above case will be described.

1st. In the second and third embodiments, (1) When the Zoraima pump is operated at startup, the fuel does not overflow into the cylinder, so there is no problem with starting due to excessive fuel concentration. Only.

4th. In the fifth and sixth embodiments, (1) fuel does not flow into the cylinder when operating the Zoraima ponzo at startup;
There is no problem with starting due to excessive concentration, and (2) during normal operation, the carburetor characteristics are the same as conventional ones. In addition, there is no pai/gusu passage, but a teakura.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an overflow device according to a first embodiment of the present invention, and FIG. 2 is an explanatory diagram showing its operating state.
FIG. 3 is an explanatory diagram showing the overflow device of the second embodiment;
Figure 4 is an explanatory diagram showing the operating state, and Figure 5 is the third
An explanatory diagram showing the overflow device of the embodiment, FIG. 6 is an explanatory diagram showing the state during operation, and FIG. 7 is an explanatory diagram showing the overflow device according to the present invention.
FIG. 8 is an explanatory diagram showing the overflow device of the embodiment, FIG. 8 is an explanatory diagram showing the state in operation, FIG. 9 is an explanatory diagram showing the overflow device in the fifth embodiment, and FIG. 10 is the state in operation. FIG. 11 is an explanatory diagram showing the open low device of the sixth embodiment, FIG. 12 is an explanatory diagram showing its operating state, and FIG. 13 is a sectional view showing a conventional membrane vaporizer. be. 3... Nostle, 6... Pressure adjustment chamber, 9... Overflow passage, 31 Re-overflow pal 7'', 35...
・Hinox passage. 35-1-bye 0s 11b to 13 Fig. 4rlJ Fang J Fig. 2 Fig.'5t-9 Fig.lo Fig. Z Fang 11 Fig. z Fang 12 Fig.

Claims (1)

[Claims] 1. During operation, the pressure regulation chamber and nozzle passage are communicated, and the overflow passage and the bypass passage provided between the membrane pump and the pressure regulation chamber are blocked, without the need for a Ticla.
An overflow device for a membrane vaporizer, comprising an overflow valve configured to shut off the pressure regulating chamber and the nozzle passage and communicate the overflow passage and the bypass passage when stopped.