Internal-combustion engines – Charge forming device – Fuel injection system
Reexamination Certificate
1999-06-04
2001-06-12
Yuen, Henry C. (Department: 3747)
Internal-combustion engines
Charge forming device
Fuel injection system
C123S509000
Reexamination Certificate
active
06244251
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an engine including a subsidiary tank for temporarily storing fuel to be supplied to a fuel injection valve, and an air vent pipe which has one end communicating with an upper space in the subsidiary tank and the other end communicating with an intake system, and particularly, to an air vent structure in the subsidiary tank.
BACKGROUND ART
There is an engine known from Japanese Patent Application Laid-open No. 3-64658, in which an upper space in a subsidiary tank for temporarily storing fuel to be supplied to a fuel injection valve is connected to a portion near a throttle valve through an air vent pipe.
In the known engine, there is a possibility that the vapor of fuel discharged from the subsidiary tank through the air vent pipe into an intake system may be liquefied within a throttle body, when the engine is stopped.
DISCLOSURE OF THE INVENTION
The present invention has been accomplished with the above circumstance in view, and it is an object of the present invention to provide an air vent structure in a subsidiary tank, wherein the treatment of the vapor of fuel discharged from the subsidiary tank into the intake system can be performed appropriately.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided an air vent structure in a subsidiary tank in an engine comprising a subsidiary tank for temporarily storing fuel to be supplied to a fuel injection valve, and an air vent pipe, which has one end communicating with an upper space in the subsidiary tank and the other end communicating with an intake system, characterized in that the other end of each of the air vent pipes communicates with an intake silencer which is mounted at a location upstream of a throttle body in a direction of flowing of intake air.
With the above arrangement, since the other end of the air vent pipe communicates with an intake silencer mounted at the location upstream of the throttle body in the direction of flowing of intake air, even if fuel discharged from the subsidiary tank into the intake silencer is liquefied when the engine is stopped, the fuel can be caught in the intake silencer having a sufficient volume and prevented from flowing to the outside.
According to a second aspect and feature of the present invention, in addition to the first feature, there is provided an air vent structure in a subsidiary tank in an engine including a pair of air vent passages are defined in an upper portion of the subsidiary tank to open at one end into the upper space in the subsidiary tank, the air vent passages being connected at the other end to a pair of the air vent pipes, the air vent passages being disposed to cross each other at intermediate portions thereof.
With the above arrangement, the pair of air vent passages are defined in an upper portion of the subsidiary tank to open at one end into an upper space in the subsidiary tank and to be connected at the other end to a pair of the air vent pipes, and disposed to cross each other at intermediate portions thereof. Therefore, even if the engine falls down sideways, the fuel is prevented from flowing out of the subsidiary tank due to the gravity, and moreover, the fuel in the subsidiary tank is prevented from being forced out into an intake system due to the internal pressure.
REFERENCES:
patent: 4809666 (1989-03-01), Baltz
patent: 4844043 (1989-07-01), Keller
patent: 5438963 (1995-08-01), Tsunoda et al.
patent: 5617821 (1997-04-01), Tsunoda et al.
patent: 5669358 (1997-09-01), Osakab
patent: 5783259 (1998-07-01), McDonald
patent: 5865160 (1999-02-01), Kato
patent: 41 06 012 A 1 (1991-09-01), None
patent: 43 03 713 A 1 (1993-09-01), None
patent: 724652 (1955-02-01), None
patent: 2 217 388 (1989-10-01), None
patent: 3-64658 (1991-03-01), None
patent: 5-86997 (1993-04-01), None
patent: 8-232765 (1996-09-01), None
Shidara Sadafumi
Wada Tetsu
Arent Fox Kintner & Plotkin & Kahn, PLLC
Gimie Mahmoud M
Honda Giken Kogyo Kabushiki Kaisha
Yuen Henry C.
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