JPS593187Y2 - Air and water removal device for fuel system in internal combustion engine - Google Patents

Description

[Detailed description of the invention] This invention prevents the filter from rotting and fouling due to direct contact with water or drainage in the fuel sent to the fuel pump through the fuel delivery pipe, and improves the durability of the filter. The present invention relates to an air and water removal device for a fuel system in an internal combustion engine.

As a conventional air bleed device for the fuel system of this type of internal combustion engine, there is a known device equipped with a fuel filter having an air bleed pipe integrated into the fuel tank, as seen in, for example, Japanese Utility Model Publication No. 15064/1983. However, since such a device is equipped with a fuel filter inside the tank, the structure for filtering and sending fuel between the fuel tank and fuel pump becomes compact, and the fuel filter is not damaged. Although there are advantages, there is the inconvenience of not being able to visually check how dirty the fuel is or whether there are impurities in the fuel. It was not possible to visually confirm the situation.

Therefore, in order to overcome the above-mentioned defect, the present applicant has installed a fuel cock C that also serves as an air vent at the bottom of a fuel tank T that houses a fuel filter F with an air pipe P connected to its upper end, as shown in FIG. At the same time, we proposed an air venting device in which a cup S made of a transparent material is attached to the lower end of the cock C.

However, this air venting device visually checks the presence or absence of impurities in the fuel, separates the water mixed in the fuel, and visually checks the situation, eliminating the drawbacks of conventional devices. For example, when using a paper filter, an oil film is formed on the filter surface, making it difficult for water to pass through the filter, making it difficult to separate the water.

Therefore, the inventor of the present invention planned further improvements based on such knowledge, and in addition to the above structure, provided a water drain hole in the bottom plate of the fuel tank, and provided water in the fuel cock body so that it communicated with the water drain hole only when the cock was open. An extraction passage was formed.

However, if the filter is built-in like the one shown above, the water or drain in the tank comes into direct contact with the filter, so the water or drain can rot the filter, impairing its durability, and eventually causing damage to the filter. Force size 1 may cause damage or malfunction to the fuel injection system.
There was one.

In particular, such defects are noticeable when the drain in the tank is forgotten to be discharged during long-term storage, when poor quality fuel is used, and when the machine body is held in an inclined position, such as a tiller.

The present invention is proposed in view of the above-mentioned actual situation and circumstances, especially in order to prevent the filter from rotting due to water or drainage, and to improve its durability. A surrounding outer cylinder is provided inside the fuel tank to prevent direct contact between the water or drain in the tank and the filter, and an air vent pipe is also connected to the outer cylinder, while the fuel cock body is connected to the fuel that flows into the fuel tank. An inflow hole, a fuel passage that flows through the fuel filter, two fuel passages that communicate with the fuel passage that flows inside the outer cylinder, and a cup that is attached to the lower part of the cock body, and are attached to the cock body. A feature of the present invention is that the cock is provided with a fuel passage hole that communicates with the fuel inlet hole and the fuel passage when the cock is opened.

Hereinafter, the specific content of the present invention will be further explained based on the embodiment shown in the attached drawings. Fig. 2 shows an example of the device of the present invention, in which 1 is a fuel tank, and 2 is a fuel tank provided at the bottom of the fuel tank. A filter mounting hole 3 is a fuel cock body attached to the mounting hole 2 through a gasket 4 with ports 1-5;
6 is a fuel cock in the fuel cock body 3; 7 is a lever for opening and closing the fuel cock; this lever 7 has a spring 8 built therein, is sealed with a seal rubber 9, and is attached to the cock body 3;

Further, the reference numeral 10 in the figure is a fuel filter inserted into the mounting hole 2 in the fuel tank 1, and the bottom part thereof has a receiving part 1 fitted into a protruding part protruding from the fuel cock main body 3.
1, and an air vent pipe 1 is attached to the upper end of the pipe.
2 are connected in series, and the upper end of the pipe 12 protrudes above the fuel liquid level in the tank near the inner top surface of the fuel tank T, as shown in FIG.

On the other hand, 13 is an outer cylinder which is an important part of the present invention, and is installed to surround the fuel filter 10, and its lower end is interposed in the mounting part of the fuel cock main body 3, and is fixed integrally with the cylinder 5. are doing.

In this case, it is necessary to maintain an appropriate gap space 26 between the inner circumferential surface of the outer cylinder 13 and the outer circumference of the filter 10 in order to form a fuel path to be described later.

An air vent pipe 14 is connected to the upper end surface of the outer cylinder 13 in a double-pipe structure to surround the air vent pipe 12 and to remove air from within the outer cylinder.

15 is a fuel inlet port for sending the fuel oil in the fuel tank 1 through the fuel cock body 3 to the fuel outlet part 16, and from the fuel outlet part 16 there is a pipe joint for sending fuel to the fuel pump as is known in the art. 17 are connected as shown in FIGS. 3 and 4.

Next, 18 is a gasket 19 attached to the lower end of the fuel cock body 3.
The cup is removably screwed onto a ring 20 via a ring 20, and is made of an oil-resistant synthetic resin such as transparent cellulose acetate resin or a transparent material such as transparent glass, and is made of a transparent material such as transparent glass. A configuration is adopted that allows for visual confirmation of separation and impurity contamination status.

Of course, this cup is not limited to being transparent, and may be attached by screwing or fixed.

In the device having each of the configurations described above, the present invention provides a fuel cock body 3 with a fuel inlet hole 21 that communicates with the fuel tank 1 through the fuel inlet 15, a fuel passage 25 that communicates with the fuel filter 10, and the outer cylinder. 13 and the fuel filter 10 through a space 26, and a first fuel passage 23 and a second fuel passage that communicate with the cup attached to the lower part of the cock body 3. 23', respectively, and when the cock inserted into the fuel cock body 3 is opened, the fuel inlet hole 21 of the cock body 3 is connected to the first fuel passage 23, and the fuel inlet hole 21 of the cock body 3 is connected to the first fuel passage 23. The fuel passage 23' of the outer cylinder 18
The fuel filter 10 is connected to a fuel passage 24 that communicates with the fuel filter 10.
Fuel passages 22, 22', 22'' are drilled through which the fuel passages 25 communicating therein communicate with the fuel outlet 16, respectively.

In this case, it is preferable that the fuel passage be of a double type as shown in the figure, and the positions of the fuel holes 22, 22', 22'' are such that in the illustrated example, the fuel passage 22 is on one side 6a and the other fuel passage is on the other side. Although the holes 22', 22'' are provided on the other side 6b, this position is not necessarily limited to the illustrated example; for example, the fuel holes 22', 22'' are provided on the one side 6a.
” or a fuel vent 22' on the other side,
22" may be provided.

Thus, in each fuel path as described above, fuel flows from inside the fuel tank 1 into the cock body 3 and flows toward the fuel outflow portion 16 from the fuel inlet 15 to the fuel inlet hole 21 to the fuel when the cock is opened. Through hole 22 → first fuel passage 23 → cup IB → second fuel passage 23' → fuel passage 22' → fuel passage 24 → filter 10 → fuel passage 25
→Fuel passage 22''→Fuel outflow portion 16, and the fuel is sent to a fuel pump (not shown) through a fuel delivery pipe 17.

On the other hand, one of the air inside the cup 1B escapes to the upper part of the fuel tank 1 through the fuel vent 22 of the cock, and the other air escapes from inside the cup through the fuel vent 22' of the cock through the gap space 26 between the filter and the outer cylinder. The air escapes to the upper part through the air vent pipe 14 at the upper part.

Moreover, the air within the filter 10 flows upward through an air vent pipe 12 connected to the upper part thereof.

Further, the air in the pipe between the fuel pump and the fuel pump ascends through the center of the filter 10 from the fuel delivery pipe 17 through the fuel passage 22'' in the center of the cock, and escapes upward from the air vent pipe 12 together with the air in the filter.

When water gets mixed into the fuel in the cup 1B, the fuel separates into the upper part and the water in the lower part due to the difference in specific gravity.If there are impurities in the fuel, the condition can be visually checked through the cup 1B. , remove the cup from the cock body 3 as appropriate.

The drain in the fuel tank 1 also flows from the fuel inlet 15 through the fuel hole 22 and the first fuel passage 23 and collects at the bottom of the cup 18, and is removed at any time by removing the cup as described above.

During the flow of fuel, air removal, and water removal as described above, the fuel filter 10 does not come into direct contact with the water or drain in the tank.

Therefore, the filter is prevented from being contaminated by contact with water or drain, ensuring that the quality of the fuel flowing to the fuel pump is high, and the flow of the fuel system can be made extremely efficient.

As described above, according to the device of the present invention, the fuel in the fuel tank and the filter are separated by the outer cylinder, and the water or drainage in the fuel does not come into direct contact with the filter, thus preventing the filter from rotting. , the durability of the filter can be further improved compared to conventional filters.

In addition, as mentioned above, since water does not come into contact with the filter, there are no additional restrictions on the selection of filter materials, resulting in extremely high versatility.

Moreover, since the device of the present invention is equipped with a cup and has passages through which fuel, water, and air flow, not only can air and water be reliably separated from the fuel, but if the cup is made transparent, the inside of the cup can be The degree of contamination of the fuel and the state of water puddles can be easily checked from the outside, and it is also possible to improve the quality of the fuel.

In addition, when draining the fuel tank, it is sufficient to simply remove the cup and open the cock, and the cock can also serve as a drain plug, eliminating the need for a separate drain plug and reducing costs.

Furthermore, with the configuration of the present invention, inside the cock mechanism and the fuel pump,
Air bubbles in flow paths such as fuel pipes can be automatically expelled without the need for other tools, and air can be removed without leaking even a single drop of fuel, which greatly contributes to resource conservation. be.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an example of the air and water removal device for the fuel system proposed earlier, Fig. 2 is a longitudinal sectional view of the main part of the device of the present invention, and Fig. 3 is a plan view of the fuel cock main body. FIG. 4 is a right side view of the same. 1... Fuel tank, 3... Fuel cock body, 6... Cock, 10... Fuel filter, 12.14... Air vent pipe, 1
3... Outer cylinder, 15... Fuel inlet, 1
6...Fuel outflow part, 1B...Cup,
21... Fuel inlet hole, 22.22', 22''
・・・・・・Fuel hole, 23.23', 24゜25・
...Fuel passage.

Claims (1)

[Scope of utility model registration request] In a fuel system for an internal combustion engine, the fuel tank has a fuel filter connected to the upper end thereof, and a fuel cock body is attached to the bottom of the lower end of the fuel tank. an air vent pipe is connected to the upper end of the outer cylinder;
The fuel cock body has a fuel inlet hole communicating with the inside of the fuel tank, a fuel passage communicating with the inside of the fuel filter, a fuel passage communicating with the inside of the outer cylinder, and a first part communicating with the inside of the cup attached to the lower part of the cock body. , a second fuel passage and a fuel outlet communicating with the fuel pump are respectively provided, and when the cock attached to the cock body is opened, the fuel inlet hole is connected to the first fuel passage, and the second fuel passage is connected to the second fuel passage. A fuel system for an internal combustion engine, characterized in that a fuel passage that communicates a fuel passage with an outer cylinder is provided with a plurality of fuel passages that communicate a fuel passage that communicates with the inside of the fuel filter and a fuel outlet, respectively. Air and water removal device.