Fluent material handling – with receiver or receiver coacting mea – Multiple passage filling means for diverse materials or flows – With valve
Reexamination Certificate
2000-11-01
2003-03-18
Maust, Timothy L. (Department: 3751)
Fluent material handling, with receiver or receiver coacting mea
Multiple passage filling means for diverse materials or flows
With valve
C141S044000, C141S046000, C141S059000, C141S082000, C141S198000
Reexamination Certificate
active
06533002
ABSTRACT:
INCORPORATION BY REFERENCE
The disclosures of Japanese Patent Application Nos. HEI 11-320667 filed on Nov. 11, 1999, HEI 11-329272 filed on Nov. 19, 1999, 2000-015957 filed on Jan. 25, 2000 and 2000-014465 filed on Jan. 24, 2000, including the specifications, drawings and abstracts are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel tank system and, more particularly, to a fuel tank system which is installed in a vehicle such as an automobile.
2. Description of the Related Art
Among fuel tank systems installed in a vehicle such as an automobile according to the related art, there is one employing a construction for reducing fuel vapor gas (vapor) generated from the interior of a fuel tank. Japanese Utility Model Publication No. SHO 57-168760 discloses one such example.
As shown in
FIG. 8
, in this fuel tank system, a conduit for communication between a fuel tank
210
and a canister
212
is provided with a check valve
216
for suitably maintaining a pressure in the fuel tank
210
. In addition, a cooling device
220
is assembled with a conduit
214
between an air chamber
218
of the fuel tank
210
and the check valve
216
. Thereby part of the vapor discharged from the fuel tank
210
through the conduit
214
is condensed by the cooling device
220
and returned to the fuel tank
210
. Thus, the amount of vapor introduced into the canister
212
can be reduced.
However, in a fuel tank system having such a construction, since the opening pressure for the check valve
216
is set regardless of operation of the cooling device
220
, it is difficult to efficiently condense vapor in accordance with the cooling capacity of the cooling device
220
.
Also, it is necessary to set a large capacity for the canister
212
in consideration of the case where a large amount of vapor has flown into the canister
212
with the check valve
216
open.
SUMMARY OF THE INVENTION
It is an object of the present invention to obtain a fuel tank system capable of reducing an amount of vapor fuel to be adsorbed in a canister and making the canister compact.
According to a first aspect of the present invention, there is provided a fuel tank system comprising a fuel tank which accommodates fuel, a canister which communicates with the fuel tank through an evaporation passage, a valve member which is provided in the evaporation passage and which is opened when the system assumes a predetermined state, and cooling means which is provided in the fuel tank or in the evaporation passage from the fuel tank to the valve member and which operates at least until the system assumes the predetermined state.
That is, in this fuel tank system, the valve member remains closed and the cooling means is in operation until the system assumes the predetermined state. Then, if the system assumes the predetermined state, the valve member is opened and vapor is introduced into the canister. Thus, generation of vapor can efficiently be inhibited in accordance with the cooling capacity of the cooling means.
Further, by activating the cooling means, the amount of vapor introduced into the canister is reduced. Thus, it is possible to make the canister compact and reduce the amount of emission substances.
The cooling means may be provided either in the fuel tank or in the evaporation passage from the fuel tank to the valve member. In addition, it is also possible to provide the cooling means in both of them. In the case where the cooling means is provided in the fuel tank, it is possible to directly inhibit evaporation of fuel by cooling liquid fuel. In the case where the cooling means is provided in the evaporation passage from the fuel tank to the valve member, it is possible to reduce the amount of vapor introduced into the canister.
In the aforementioned aspect of the present invention, the predetermined state for opening the valve member may be a state of a high temperature which exceeds a predetermined temperature that has been set in advance.
Thus, the valve member remains closed and the cooling means is in operation until a the temperature exceeds the predetermined temperature that has been set in advance. In a state of a high temperature exceeding the predetermined temperature, the valve member is opened. This makes it possible to efficiently inhibit generation of vapor.
In the aforementioned aspect of the present invention, the predetermined state for opening the valve member may be a state of a high pressure which exceeds a predetermined pressure that has been set in advance.
Thus, the valve member remains closed and the cooling means is in operation until the pressure exceeds the predetermined pressure that has been set in advance. In a state of a high pressure exceeding the predetermined pressure, the valve member is opened. This makes it possible to efficiently inhibit generation of vapor.
In the aforementioned aspect of the present invention, refueling detection means for detecting a refueling state of the fuel tank may be provided, and the predetermined state may be a refueling state detected by the refueling detection means.
Thus, the valve member is closed in a state where the refueling detection means has not detected a refueling state (a state where no fuel is being refueled). If the refueling detection means has detected a refueling state, the valve member is opened and vapor is introduced into the canister. Also in this case, the amount of vapor introduced into the canister is reduced by activating the cooling means. Thus, it is possible to make the canister compact and reduce the amount of emission substances.
In the aforementioned aspect of the present invention, the valve member may include a control valve which is controlled by control means and a vent valve which is set to an open-valve pressure higher than a minimum open-valve pressure of the control valve.
Thus, regardless of the predetermined state (the high-temperature state, the high-pressure state or the refueling state), the control valve can be controlled by the control means and closed. While the control valve is thus closed, even if the pressure in the fuel tank has become higher than a minimum open-valve pressure of the control valve, the open-valve pressure of the vent valve is set higher than the minimum open-valve pressure of the control valve. Therefore, the vent valve remains closed until it reaches its own open-valve pressure. For example, even if the interior of the fuel tank has reached a high pressure in a parked state of the vehicle, it is possible to prevent vapor from being discharged from the fuel tank.
According to a second aspect of the present invention, there is provided a vapor gas inhibiting device for a fuel tank comprising a control valve which is disposed in a communication passage by which a fuel tank communicates with a canister, a control device which performs open-close control of the control valve in accordance with a state of a vehicle, and pressure detection means which detects an internal pressure of the fuel tank, wherein the control device controls the control valve such that a speed of change in internal pressure of the fuel tank becomes equal to or smaller than a predetermined value, based on an output value of the pressure detection means.
Thus, the control device controls the control valve such that the speed of change in internal pressure of the fuel tank becomes equal to or smaller than a predetermined value, based on an output value of pressure detection means for detecting an internal pressure of the fuel tank. As a result, the speed at which vapor is discharged from the interior of the fuel tank can be limited to a value that enables vapor to be adsorbed effectively in the canister. Thus, it is possible to improve the efficiency in adsorbing vapor.
According to a third aspect of the present invention, there is provided a vapor gas inhibiting device for a fuel tank comprising a control valve which is disposed in a communication passage by which a fuel tank communicates with a canister, a control devic
Ishikawa Takashi
Kido Katsuyuki
Kobayashi Masahide
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Maust Timothy L.
Toyota Jidosha & Kabushiki Kaisha
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