JPS6021486Y2 - Residual fuel discharge type carburetor - Google Patents

Description

[Detailed description of the invention] The present invention mainly relates to a carburetor attached to a gasoline engine, and in particular, the present invention is a residual fuel discharge type that makes it possible to discharge the fuel remaining in the carburetor when not in use before it deteriorates. Regarding vaporizers.

Conventionally, there is a carburetor commonly used as shown in Fig. 1, where the reference numeral 1 indicates the main body of the vaporizer, and 2 indicates the carburetor body.
is the fuel inlet, 3 is the needle valve, 4 is the fuel chamber, 5 is the float, 6
is the main nozzle, 7 is the air passage, 8 is the drain bolt, 9
indicates the oil level.

In such a carburetor, when draining the fuel in the carburetor, the drain bolt 8 is pulled out using a spanner.

However, such fuel discharge means has the following drawbacks.

(1) Since the drain operation is performed manually, it may be forgotten and it is difficult to perform it reliably.

(2) Since the degree of gasoline deterioration depends not only on the properties of gasoline but also on weather conditions such as temperature, humidity, and atmospheric pressure, it is virtually impossible to perform draining operations that match these conditions.

(3) In order to completely avoid artificially altering the quality of gasoline in the carburetor, a drain operation must be performed every time the engine is stopped, which is troublesome and uneconomical.

Here, deterioration of the gasoline in the vaporizer means that the low-temperature volatile components of gasoline evaporate and only the high-temperature volatile components remain. It causes a chemical reaction with the constituent materials and becomes gummy.

It is estimated that it usually takes 20 to 200 days to reach a gummy state.

Note that this occurs when the engine is stopped (gasoline stagnates) and does not occur while driving.

Engine troubles caused by this deterioration include the following.

(1) Starting becomes difficult because the main nozzle 6 and other fuel chamber passages in the carburetor are filled.

(2) Degenerate substances adhere to the main nozzle and other fuel passages in the carburetor, causing engine malfunction.

(3) Degenerate substances fall off during operation and block the main nozzle and other fuel passages, resulting in malfunction or engine stoppage.

(4) Corrosion of carburetor and fuel system parts reduces component life.

These engine troubles have been occurring sporadically in the past, but
Since the introduction of unleaded gasoline in the past few years, this problem has become more frequent, especially in small general-purpose engines that are used at varying frequencies and require long-term storage due to physical work during the distribution stage.

Therefore, a method of discharging the fuel remaining in the carburetor by the capillary action of a string-like member can be considered, but if the string-like member is simply inserted through the air passage 7, there is a risk that the air passage 7 will be blocked. Providing a fuel discharge path would complicate the work and increase costs.

The present invention solves the above-mentioned problems and makes it possible to quickly and automatically drain the fuel inside when the carburetor is left unused for a long period of time.
It is an object of the present invention to provide a device which has a simplified structure and which can maintain operation as a vaporizer with sufficient reliability during use.

Therefore, in the residual fuel discharge type carburetor of the present invention, the tip of a pipe with a wall that can guide the residual fuel upward by capillary action is placed at the bottom of the fuel chamber in the carburetor, and the pipe The base end of the fuel chamber communicates with the outside of the carburetor through the upper part of the fuel chamber, and a small hole is provided in the wall of the pipe for communicating the upper part of the fuel chamber with the outside space through the internal air passage of the pipe. It is characterized by the formation of

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
2 and 3 are longitudinal cross-sectional views showing a residual fuel discharge type carburetor as a first embodiment and a second embodiment of the present invention, respectively, and in the figures, the same symbols as in FIG. Similar parts are shown.

First, the first embodiment shown in FIG. 2 will be described. At the bottom of the fuel chamber 4 inside the carburetor body 1, the lower end of a pipe 11 has a wall that can guide residual fuel upward by capillary action. The upper end of the pipe 11 passes through the upper space 4a of the fuel chamber 4, passes through a hole 12 in the earthen wall of the carburetor body 1, and communicates with the outside.

Then, in the upper space 4a of the fuel chamber 4, the pipe 11
A small hole 14 is formed in the wall of the fuel chamber 4 so that the upper space 4a of the fuel chamber 4 is communicated with the outside space via the internal air passage 13 of the pipe 11.

The material of the pipe 11 is a flexible foamed resin that does not easily cause capillary action, or a foamed resin layer that easily causes capillary action is lined with something like woven fabric on the inner wall surface of a metal pipe. You can do it like this.

In any case, in the carburetor of the present invention, the pipe 11 is used as a member for sucking up residual fuel by capillary action when not in use, but during normal use, the internal air passage 13 of the pipe 11 passes through the small hole 14 to air passage (first
(see reference numeral 7 in the figure), so that it does not interfere with its use as a vaporizer at all times.

That is, the small hole 14 is provided to discharge the air in the upper space 4a of the fuel chamber to the outside through the internal passage 13 of the pipe 11, so that the fuel population 2 is normally drawn into the fuel chamber 4. The fuel entering through the fuel chamber 4 can be replaced with the air in the fuel chamber 4 without any problem.

If the fuel chamber 4 of the carburetor main body 1 is to be left unused for a long period of time with the fuel stored in the fuel chamber 4, the pipe 1
It is automatically discharged to the outside by capillary action in the wall.

In this way, the pipe 11 has both the function of a conventional air passage in a carburetor and the function of sucking up residual fuel.

Note that while the carburetor main body 1 is in use, a plug P with an air hole is fitted into the hole 12 to suppress the wall at the base end of the pipe 11 to prevent fuel from leaking through the wall of the pipe 11. It is desirable to allow air communication but not to cause fuel leakage.

In the second embodiment of the present invention shown in FIG. 3, in order to further improve the above points, a fuel return pipe 15 is provided which leads from the hole 12 in the upper wall of the carburetor body 1 to the fuel tank 16. The tip end is connected to a pipe-like mouthpiece 16a of the fuel tank 16.

The upper end extension of the pipe 11 is inserted into the base end of the fuel return pipe 15.

With this configuration, the fuel guided by capillary action through the wall of the pipe 11 is returned to the fuel tank without leaking to the outside, which has the advantage of greatly improving safety.

As detailed above, according to the residual fuel discharge type carburetor of the present invention, the tip of the pipe with a wall that can guide the residual fuel upward by capillary action is arranged at the bottom of the fuel chamber in the carburetor. At the same time, the base end of the pipe is communicated with the outside of the carburetor through the upper part of the fuel chamber, and the upper part of the fuel chamber is communicated with the outside space through the internal air passage of the pipe with the wall of the pipe. It has an extremely simple structure in which small holes are formed for communication, making it possible to prevent problems caused by deterioration of fuel during long periods of non-use. Since the pipe has small holes in it and also serves as an air passage, it not only simplifies the structure but also improves reliability.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional carburetor, and the second and third
The figures are longitudinal sectional views showing a residual fuel discharge type carburetor as a first embodiment and a second embodiment of the present invention, respectively. 1... Carburetor body, 2... Fuel inlet,
3...Needle valve, 4...Fuel chamber, 4a...
... Upper space of the fuel chamber, 5 ... Float,
6...Main nozzle, 9...Curved oil surface, 11...
... Pipe, 12 ... Hole, 13 ... Curved internal chamber air passage, 14 ... Small hole, 15 ... Fuel return pipe, 16 ...・・Fuel tank, 16a・・・・
...Fuel tank pipe-shaped mouthpiece, P...Plug.

Claims (1)

[Scope of utility model registration request] A lower end of a pipe with a wall that can guide residual fuel upward by capillary action is arranged at the bottom of the fuel chamber in the carburetor, and an upper end of the pipe vaporizes through the upper space in the fuel chamber. The residual fuel is connected to the outside of the vessel, and has a small hole formed in the wall of the pipe for communicating the upper space of the fuel chamber to the outside space through the internal air passage of the pipe. Discharge type vaporizer.