JPH0241061Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a fuel evaporative emission suppressing device for an automobile gasoline engine.

In the fuel system of an automobile gasoline engine, such as a fuel tank, fuel evaporates and becomes evaporative gas, which causes air pollution if it is directly released into the atmosphere. For this reason, all vehicles are required to be equipped with a fuel evaporative gas emission control device to keep the amount of evaporative gas below a certain value.

Conventionally used devices separate liquid fuel from evaporated gas in the width direction of the vehicle above the fuel tank 1 (in the horizontal direction in the figure), as shown in FIG. A plurality of separator tanks 2 (two in the illustrated example) are provided, and pipes 3 are arranged to intersect from each separator tank 2 to communicate with the fuel tank 1. The evaporated gas is led from these separator tanks 2 to an activated carbon canister or the like.

In addition, in the one shown in FIG. 1b, instead of a separator tank, there are many holes 4 in the upper part of the fuel tank
A separator chamber 6 is formed in the fuel tank 1 by attaching a partition plate 5 having a perforation therein.
The evaporated gas is guided from the activated carbon canister to the activated carbon canister.

Furthermore, in the fuel tank 1 shown in FIG. Evaporated gas is led from the tank 2 to an activated carbon canister or the like.

However, in these conventional devices, when a plurality of separator tanks are provided, space is restricted and the number of parts is large, leading to an increase in cost. In addition, in the case where a separator chamber or a separator tank is installed inside the fuel tank, the surrounding environment is the same as inside the fuel tank, and the cooling effect due to airflow outside the fuel tank is small, making it possible to reduce the amount of evaporative gas. Moreover, it has the disadvantage that the manufacturing process is complicated.

The present invention aims to eliminate such conventional drawbacks and provide a fuel evaporative gas emission suppressing device that has a simple structure and a high cooling effect. The structure of the present invention to achieve such an object is to form a plurality of small holes communicating with the interior in the approximate center of the upper plate of the fuel tank, and to cover the small holes and form a separator chamber, a lid material is attached to the fuel tank. On the other hand, it is characterized in that the opening of the pipe for guiding the evaporated gas to the outside is located approximately at the center of the separator chamber and close to the upper plate and not directly facing the small hole.

Hereinafter, one embodiment of the present invention will be described in detail based on FIG. 2.

Approximately in the center of the upper plate 11 of the fuel tank 10,
A plurality of small holes 12 are bored, and a lid member 13 is hermetically fixed to the upper plate 11 so as to cover these small holes 12, thereby forming a separator chamber 14 corresponding to a separator tank. A pipe 15 guides the evaporated gas from inside the separator chamber 14 to an activated carbon canister or the like.
The opening at the tip thereof is located approximately at the center of the separator chamber 14 at a distance from the periphery of the separator chamber 14, and the upper plate 11
It is fixed to the lid member 13 so as to be close to the upper plate 11 without directly facing the small hole 12 .

Therefore, even if the fuel in the fuel tank 10 is scattered into the separator chamber 14 due to the shaking of the vehicle, it is unlikely to directly enter the pipe 15, and even if it does, it will not return to the fuel tank 10 through the many small holes 12. becomes.
This has good air circulation due to the large number of small holes 12.
This is because the fuel that has entered the separator chamber 14 is facilitated to return smoothly to the fuel tank 10.

Furthermore, since the upper plate 11 of the fuel tank 10 is used as the bottom plate of the separator chamber 14, the structure is simplified, and since the separator chamber 14 protrudes from the top of the fuel tank 10, the air flowing around the fuel tank 10 can The evaporated gas is cooled and the liquefaction of the evaporated gas is also promoted. Further, although the liquefied fuel flows down along the wall surface of the separator chamber 14, since the opening of the pipe 15 is located approximately at the center separated from the wall surface, it can be prevented from being directly discharged through the pipe 15.

As described above in detail with one embodiment, according to the present invention, the upper plate of the fuel tank is used to form the separator chamber, which simplifies the structure and reduces the number of parts. and,
Since the opening of the pipe for discharging evaporative gas is provided close to the upper plate and not directly facing the small hole, even if fuel is scattered due to the shaking of the vehicle, it can be prevented from entering the pipe.

Additionally, since the separator chamber is provided so as to protrude from the fuel tank, the airflow around the fuel tank has a high cooling effect.

[Brief explanation of the drawing]

FIGS. 1a, b, and c are schematic sectional views of a conventional fuel evaporative gas emission suppressing device, and FIG. 2 is a sectional view of an embodiment of the fuel evaporative gas emission suppressing device of the present invention. In the drawing, 10 is a fuel tank, 11 is an upper plate, 12
13 is a small hole, 13 is a cover material, 14 is a separator chamber, 15
is a pipe.

Claims (1)

[Scope of utility model registration request] A plurality of small holes communicating with the inside are formed in the approximate center of the upper plate of the fuel tank, and a lid material that covers these small holes and forms a separator chamber is attached to the fuel tank, while a cover material that covers the small holes and forms a separator chamber is attached to the fuel tank; A fuel evaporative gas emission suppressing device, characterized in that the opening of a pipe for guiding evaporative gas to the outside is located close to the upper plate and not directly opposed to the small hole.