JPH066983Y2 - Float type fuel cutoff valve - Google Patents

Description

[Detailed Description of the Invention] Industrial field of application The present invention is installed inside the tank side outlet of the vapor flow path connecting the fuel tank and the canister. It relates to a fuel cutoff valve that closes the valve so that it does not rise to the vicinity of the outlet and flow out to the canister.

Conventional Technology Conventionally, in a fuel tank, as shown in FIG.
A vent hole (3) for introducing the vapor generated in the tank (1) and its pressure to the engine via the canister (2) is installed, but the fuel tank (1) of the vapor passage (4) is installed. ) Side vent of this vent hole (3)
Changes the liquid level (5) of the fuel liquid when the vehicle turns, suddenly brakes, suddenly starts, slurries, runs on uneven roads, etc., and the liquid level (5 ′) that reaches the vent hole (3) due to the change causes vaporization. Since the liquid will flow out to the vapor passage to the canister (2), which has passed only the pressure, the liquid is flown out, and the structure is so constructed as to prevent this.

As a conventional structure for preventing liquid from flowing out to the canister (2), as shown in FIG. 3 (B), a convex portion (6) having a convex shape in the vent hole (3) is provided, and Even if it is not a convex part, it is one that takes a lot of spatial layers,
Or, as shown in FIG. 3 (C), there is a plurality of vapor passages (8) equipped with vapor liquid separators (7).

By the way, in recent fuel tanks, a large number of convex portions (6) and space layers are taken, or a vapor liquid separator (7) and a plurality of vapor passages (8) are provided due to restrictions on the space for installing the fuel tank. It became difficult to provide.

Therefore, in order to eliminate these difficulties, a fuel cutoff valve (9) for closing the vent hole (3) when the liquid level (5) reaches the vent hole (3),
(10) has also been conventionally mounted.

As shown in FIG. 2 (A), the conventional fuel cutoff valve includes a fuel cutoff valve (9) that uses the buoyancy of the float (9a) to close the valve hole (9b).
As shown in FIG. 2 (B), the sway (1
There was a fuel cut-off valve (10) that utilized a ball (10a) going up and down 0c). A needle valve system is generally used for the fuel cutoff valve (9) utilizing the buoyancy of the float (9a), and a small diameter valve hole communicating with the vapor passage for opening and closing the float (9a) is used. It had (9b).

The problem to be solved by the invention is that the needle valve type fuel cut-off valve (9) using the float (9a) that has been generally used in the past has a small valve hole (9b) and a seal. The sealing surface of the part is a valve hole, and foreign matter is likely to adhere due to the sudden change in cross section, and further, the foreign matter adheres to clog the valve hole (9b), resulting in positive pressure in the fuel tank. For some occasions, emergency valves were also installed, but when installed, the installation position of the emergency valve had to be arranged in a parallel position other than the valve hole (9b), As a result, the plane space for mounting the emergency valves in parallel was increased, which made it difficult to install the fuel tank. In addition, an emergency valve dedicated flow channel other than the normal vapor flow channel is required, and in addition, a structure for joining these two flow channels is also required.
This causes inconvenience in processing and assembling work.

Therefore, the present invention is provided with a large-diameter sealing packing and a flat valve seat as the sealing surface in the seal portion that is opened and closed by a float, and further, a float in which an emergency valve is provided in series inside the float. The purpose is to provide a formula fuel cut-off valve.

The present invention is a float type fuel cut-off valve installed in the vent hole at the outlet of the fuel tank of the vapor passage that connects the fuel tank and the canister. A float for opening and closing is provided, and a seal packing is provided around the top surface of the float, and a flat valve seat is formed inside the valve case as a seal surface with the seal packing to form a seal portion. It is a float type fuel cutoff valve in which an emergency valve is provided in series inside.

Therefore, the fuel liquid in the fuel tank changes its level when the vehicle turns, suddenly brakes, suddenly starts, runs slalom, and runs on uneven roads, and the vapor and its pressure generated in the fuel tank pass through the canister. The float type fuel cut-off valve is installed in the vent hole part so that the liquid does not flow out to the canister when the liquid level reaches the vent hole of the fuel tank introduced to the engine.

When the liquid level reaches the fuel cutoff valve, the float of the fuel cutoff valve is pushed up by its buoyancy due to the change in the liquid level, and the seal packing around the top surface of the float is flattened. Push it against the valve seat to close it. Therefore, since the sealing portion between the sealing packing and the valve seat has a large diameter and is flat, foreign matter is less attached to the sealing surface. When the float in the normal state descends and is in the open state, the seal portion has a large diameter, so the cross section of the flow path is enlarged, and the supply of vapor and its pressure to the canister is easy with little resistance. To

In addition, an emergency valve is provided inside the float,
Since it is in series with the seal part that opens and closes with a float,
It does not require a space for installation and a flow path dedicated to the emergency valve, and eliminates the positive pressure generated in the fuel tank.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a cross section of the float type fuel cutoff valve (11) of the present invention.

Reference numeral (12) is a float, and a seal packing (13) is provided on a peripheral portion of a top surface of the float (12), and a flat seal surface in the valve case (14) is in contact with the seal packing (13). And a valve seat (15) made of the same form a seal portion. Furthermore, an emergency valve (16) in series with a fuel cut-off valve for opening and closing the vapor and its pressure at the seal portion is mounted at the center of the top surface of the float (12), and the emergency valve (16) is a positive pressure valve. Ball (16a) and positive pressure valve spring (1
6b).

Incidentally, (17) is a buoyancy assisting spring, and (18) is a nipple for attaching a vapor passage hose.

Therefore, when the liquid level of the fuel liquid in the fuel tank reaches the fuel cutoff valve (11) installed in the bend hole that supplies the vapor and its pressure to the engine, the float (12) causes the buoyancy assist spring ( It is pushed up with the help of 17) and is closed by the seal portion consisting of the seal packing (13) and the valve seat (15) so that liquid cannot flow out to the canister. However, when a positive pressure is generated in the fuel tank, the emergency valve (16) mounted at the center of the top surface of the float (12) balances the positive pressure with the positive pressure valve spring (16b). The valve ball (16a) is pushed up and opened to release the positive pressure. When the liquid level does not reach the float (12) of the fuel cutoff valve (11), the seal portion is opened, and the vapor and its pressure in the fuel tank are opened and the large-sized seal packing for sealing is opened. Because of the seal portion, the flow passage has a large cross section, the seal portion flows out, flows into the canister through the vapor passage, and is introduced into the engine.

Effect As a result of the above, the seal part of the fuel cutoff valve of the present invention has a seal packing around the top surface of the float and a flat valve seat in the valve case, which allows a large cross-section of the flow passage, and the fuel tank. The internal vapor and its pressure easily flow out, and since the seal portion is flat and has a large diameter, foreign matter is less likely to adhere to it, and therefore the flow path resistance is not increased. Also, by mounting the emergency valve in the center of the top surface of the float, the fuel cut-off valves will be arranged in series, and the plane space for mounting the emergency valve can be made small, so the mounting flexibility of the fuel tank is reduced. Since it is large and it is in series, it does not require a special flow path for the emergency valve and can share the vapor flow path, and since the seat part of the hose mounting nipple that connects to the canister is used as the valve room of the emergency valve. , Is made compact overall.

[Brief description of drawings]

FIG. 1 is a sectional view of the float type fuel cutoff valve of the present invention. FIG. 2 is a sectional view of a conventional fuel cutoff valve, where (A) is a float type sectional view and (B) is a ball type sectional view. FIG. 3 is a fuel tank structure explanatory drawing, (A) is an overall structure explanatory drawing, (B) is a 1-vent system structure explanatory drawing, (C) is a multi-vent system structure explanatory drawing. 1 ... Fuel tank, 2 ... Canister, 3 ... Vent hole, 4 ... Vapor flow path, 5, 5 '... Liquid level,
6 ... Convex part, 7 ... Vapor liquid separator, 8 ...
... Multiple vapor passages, 9 ... Float type fuel cut-off valve, 9a ... Float, 9b ... Valve hole,
10-ball type fuel cut-off valve, 10a
…… Ball, 10b …… Valve hole, 10c …… Slope, 1
1 ... Float type fuel cut-off valve, 12 ...
… Float, 13 …… Seal packing, 14 …… Valve case, 15 …… Valve seat, 16 …… Emergency valve, 16a …… Positive pressure valve ball, 16b …… Positive pressure valve spring, 17 …… Buoyancy auxiliary spring , 18 ... Nipple for hose mounting.

Claims (1)

[Scope of utility model registration request] 1. A fuel cutoff valve installed in a vent hole at an outlet of a fuel tank on a vapor passage connecting a fuel tank and a canister, wherein a float for opening and closing the vent hole by buoyancy is provided. A seal packing is provided on the peripheral portion of the top surface of the float, and a flat valve seat is formed inside the valve case as a seal surface with the seal packing to form a seal portion. Further, an emergency valve is provided in series inside the float. Float type fuel cut-off valve.