JPS603024Y2 - Anti-blowing device in fuel tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing sudden blowback of fuel that occurs when opening the filler cap when the tank is full in a closed type fuel tank for preventing fuel evaporation.

Conventionally, in this type of tank, an empty chamber is formed by a separator having a ventilation hole in the upper part of the closed tank body, and the inside is communicated with an external canister or other device through a conduit having a relief valve, and the inside is communicated with the external canister and other objects. Types with an upwardly opening injection port are known, but in this case, the injection port is generally configured as shown in Figure 1, and such a system is likely to cause the above-mentioned blowback. .

That is, in Fig. 1, a indicates the tank body, and b indicates the injection port on the top surface of the tank.The injection port has a cylindrical shape that extends approximately vertically in the vertical direction, and its lower end regulates the fuel level when the tank is full. A small hole C for ventilation is provided on the side surface of the upper part of the cap.If the small hole C is too large, it becomes difficult to regulate the liquid level, and if it is too small, the ventilation resistance becomes large and the liquid flows through the small hole C. It becomes difficult to quickly exhaust the air, and in both cases, the above-mentioned blowback is likely to occur.

In order to improve this, for example, Utility Model Application No. 51-141813
As described in the publication, the injection port is of the type that slopes laterally, and the internal pressure is controlled by the cap, and the tank is filled through the gap between the lower and upper mouth edges. There are some models in which a cavity formed inside is communicated with the outside through a passage with a relief valve, but since the exhaust port of the conduit that communicates from the cavity to the outside is provided on the side of the tank, the liquid level when the vehicle is tilted. This has the disadvantage that it easily reaches the exhaust port and causes the evaporated fuel to directly flow out.

The purpose of the present invention is to obtain a device that does not have such inconveniences, and an injection lower is opened on the side of the closed tank body 1, and the lower opening rim 8 of the injection lower is used to prevent fuel from flowing when the tank is full. The surface 9 is regulated and a gap 11 is formed above the regulated liquid level 9 with the upper mouth edge 10 of the injection lower, and the empty chamber 4 is formed in the gap 11 through a separator 3 having a ventilation hole 2. In a fuel tank in which the interior of the cavity 4 is communicated with an external canister and the like through a conduit 6 having a relief valve 5, the exhaust port of the conduit 6 communicating from the cavity 4 to the outside is located at the center of the tank when viewed from the front. It is characterized in that the ventilation hole 2 is opened below and near the exhaust port of the conduit 6 by penetrating the separator 3 vertically close to the earthen wall.

FIGS. 2 and 3 show an example of this, and the injection lower has a cylindrical shape similar to the conventional one, but it is inclined slightly upward to the left as shown in the figures.

To explain its operation, when injecting fuel, the inside of the injection lower is looked at and the liquid level 9 is regulated to the height of the lower mouth rim 8.Then, the cap is applied, and the next step is to ensure that the tank is fully filled. Considering the case where the cap is removed, the somewhat high-pressure air that should exist above the liquid level 9 is quickly discharged to the outside through the gap 11 that exists above the liquid level 9. There is no blowback as mentioned above.

In this way, according to the present invention, the sealed tank body 1
The lower mouth rim 8 of the injection lower opening on the side regulates the fuel level 9 when the tank is full, and the regulated liquid level 9
A separator 3 having a gap 11 formed above with the upper mouth edge 10 of the injection lower, and having a ventilation hole 2 in the gap 11.
In a fuel tank in which a cavity 4 is formed through a fuel tank, and the interior of the cavity 4 is communicated with an external canister or the like through a conduit 6 having a relief valve 5, a conduit 6 that communicates from the cavity 4 to the outside is provided. Since the exhaust port is placed close to the earthen wall at the center of the tank when viewed from the front, even if the liquid level changes when the vehicle is tilted, the liquid level will not reach the exhaust port of the conduit 6, which will cause liquid leakage. The internal pressure can be easily reduced without causing any problems, and since the vent hole 2 that opens in the separator 3 is opened below and near the exhaust port of the conduit 6 by penetrating the separator 3 vertically, the vehicle body tilts, vibrations, etc. This makes it difficult for fuel to enter the cavity 4 above the separator 3, and even if it does, it can be discharged very easily.
Since the liquid fuel does not enter the gas-liquid separation chamber without reaching the point where the liquid fuel reaches the canister etc. through the conduit 6, the function of the canister etc. can be fully utilized and its lifespan can be extended.

[Brief explanation of drawings]

FIG. 1 is a several-level plan view of the inlet portion of a conventional example, FIG. 2 is a sectional view of one example of the device of the present invention, and FIG. 3 is an enlarged sectional view of a portion thereof. 1...Tank body, 2...Vent hole, 3
... Separator, 4 ... Vacant room, 5 ...
... Relief valve, 6 ... Conduit, 7 ...
...Inlet, 8...Lower mouth rim, 9...
Liquid level, 10... Upper lip, 11... Gap.

Claims (1)

[Scope of utility model registration request] An injection lower is opened on the side of the closed tank body 1, and the lower lip 8 of the injection lower regulates the fuel liquid level 9 when the tank is full, and the injection lower is placed above the regulated liquid level 9. A gap 11 is formed between the upper lip 10 and a cavity 4 is formed in the gap 11 via a separator 3 having a ventilation hole 2, and the interior of the cavity 4 is connected with a conduit 6 having a relief valve 5. In a fuel tank that communicates with an external canister or the like, the exhaust port of a conduit 6 that communicates from the empty chamber 4 to the outside is disposed close to an earthen wall at the center of the tank when viewed from the front.
A blowback prevention device for a fuel tank, characterized in that the vent hole 2 is opened below and near the exhaust port of the fuel tank by vertically penetrating the separator 3.