U.S. patent application number 17/100126 was filed with the patent office on 2022-02-10 for fuel tank isolation solenoid valve for vehicle.
This patent application is currently assigned to HYUNDAI MOTOR COMPANY. The applicant listed for this patent is HYUNDAI MOTOR COMPANY, KIA MOTORS CORPORATION. Invention is credited to Hyun Do JEON, Tac Koon KIM, Bu Yeol RYU.
Application Number | 20220042481 17/100126 |
Document ID | / |
Family ID | 1000006104980 |
Filed Date | 2022-02-10 |
United States Patent
Application |
20220042481 |
Kind Code |
A1 |
RYU; Bu Yeol ; et
al. |
February 10, 2022 |
FUEL TANK ISOLATION SOLENOID VALVE FOR VEHICLE
Abstract
A fuel tank isolation solenoid valve for a vehicle includes: a
plunger disposed in the isolation solenoid valve to be vertically
moved and has first vent holes for releasing overpressure or
over-negative pressure; a valve body disposed in the isolation
solenoid valve to be vertically moved and has second vent holes for
releasing overpressure or over-negative pressure.
Inventors: |
RYU; Bu Yeol; (Hwaseong-si,
KR) ; KIM; Tac Koon; (Seoul, KR) ; JEON; Hyun
Do; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HYUNDAI MOTOR COMPANY
KIA MOTORS CORPORATION |
Seoul
Seoul |
|
KR
KR |
|
|
Assignee: |
HYUNDAI MOTOR COMPANY
Seoul
KR
KIA MOTORS CORPORATION
Seoul
KR
|
Family ID: |
1000006104980 |
Appl. No.: |
17/100126 |
Filed: |
November 20, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02M 2025/0845 20130101;
F16K 31/0655 20130101; F02M 25/0836 20130101 |
International
Class: |
F02M 25/08 20060101
F02M025/08; F16K 31/06 20060101 F16K031/06 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 4, 2020 |
KR |
10-2020-0097486 |
Claims
1. A fuel tank isolation solenoid valve for a vehicle, the fuel
tank isolation solenoid valve comprising: an upper case; a bobbin
mounted in the upper case; a coil wound around the bobbin; a core
mounted in the bobbin, the core having therein a plunger passage
that is open at a lower end thereof; a lower case coupled to the
upper case, the lower case including: a first passage configured to
communicate with a fuel tank, a second passage configured to
communicate with a canister, and a communication passage defined
between the first passage and the second passage; a plunger having
a lower open space formed therein and a plurality of first vent
holes configured to allow the first passage to communicate with the
lower open space, the plunger being disposed in the plunger passage
and configured to vertically move; a main seal mounted on a lower
surface of the plunger; a valve body disposed in the communication
passage to be vertically moved and having a plurality of second
vent holes, wherein the plurality of second vent holes are
vertically formed through the valve body and are configured to
allow the first passage to communicate with the second passage; a
sealing plate mounted on the lower case at an outer circumference
of the communication passage so as to be in airtight contact with
both a lower surface of the main seal and an upper surface of the
valve body; a first spring disposed between a lower surface of the
core and a lower end of the plunger; and a second spring disposed
between a lower surface of the valve body and a bottom surface of
the communication passage.
2. The fuel tank isolation solenoid valve of claim 1, further
comprising: a diaphragm disposed between and connected to an outer
surface of the plunger and an inner surface of the core.
3. The fuel tank isolation solenoid valve of claim 2, wherein the
plunger further has a vent hole formed therein, the vent hole
configured to allow an upper space in the diaphragm to communicate
with the lower open space in the plunger.
4. The fuel tank isolation solenoid valve of claim 1, wherein the
plunger has a first spring-holding groove formed in an outer
circumference of a lower end thereof, the first spring configured
to be fitted and held in the first spring-holding groove.
5. The fuel tank isolation solenoid valve of claim 1, wherein the
plunger includes a stopper on an upper surface thereof, and the
stopper is configured to contact with an upper end surface of the
plunger passage formed in the core while buffering the upper end
surface of the plunger.
6. The fuel tank isolation solenoid valve of claim 1, wherein the
valve body includes a sealing wall projecting from an upper surface
thereof at an inner circumference inwardly spaced apart from the
second vent holes, the sealing wall configured to come into
airtight close contact with the main seal.
7. The fuel tank isolation solenoid valve of claim 1, wherein the
valve body includes a vertical guide pin formed at a center of the
upper surface thereof, and the vertical guide pin is configured to
enter and come out of the lower open space in the plunger.
8. The fuel tank isolation solenoid valve of claim 1, wherein the
valve body has a second spring-holding groove formed in an outer
circumference of the lower surface thereof, and the second spring
is configured to be fitted and held in the second spring-holding
groove.
9. The fuel tank isolation solenoid valve of claim 1, wherein the
sealing plate includes a fitting wall formed on a lower surface
thereof, and the lower case has a fitting groove formed in an outer
circumference of the communication passage, the fitting wall
configured to be fitted and held in the fitting groove.
10. The fuel tank isolation solenoid valve of claim 1, wherein:
when an overpressure, which is a pressure higher than a reference
pressure, acts on the valve body through the first passage and the
first vent holes in the plunger from the fuel tank, the valve body
is lowered while compressing the second spring, the overpressure
sequentially passes through the first vent holes and the lower open
space in the plunger and the second vent holes in the valve body,
and acts on the second passage, and the overpressure is
released.
11. The fuel tank isolation solenoid valve of claim 1, wherein:
when an over-negative pressure, which is a pressure lower than a
reference pressure, acts on a lower portion of the plunger through
the second vent holes in the valve body from the canister, the
plunger is raised while compressing the first spring, the
over-negative pressure passes through the second vent holes in the
valve body and acts on the first passage communicating with the
fuel tank, and the over-negative pressure is released.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2020-0097486, filed on Aug. 4,
2020, the entire contents of which are incorporated herein by
reference.
FIELD
[0002] The present disclosure relates to a fuel tank isolation
solenoid valve for a vehicle in which a positive and negative
pressure relief valve is integrally incorporated.
BACKGROUND
[0003] The statements in this section merely provide background
information related to the present disclosure and may not
constitute prior art.
[0004] Referring to FIG. 1, a fuel tank 10 for a vehicle is
connected to a canister 20, which is configured to collect
evaporation gas of fuel and to purge the evaporation gas to the
combustion chamber in an engine 30 such that the evaporation gas is
burned in the combustion chamber.
[0005] To this end, the inlet 21 of the canister 20 and the fuel
tank 10 are connected to each other via a discharge line 13
disposed therebetween, and the outlet 22 of the canister 20 and an
engine intake duct are connected to each other via a purge line 14
disposed therebetween.
[0006] The canister 20 is provided therein with a collector (not
shown), configured to adsorb and collect evaporation gas, and is
provided with a discharge port 23 through which the remaining
purified air excluding the evaporation gas collected at the
collector is discharged to the outside.
[0007] Consequently, the fuel in the fuel tank 10 is supplied to
the engine 30 through a fuel supply line 12 so as to be burned by
operation of a fuel pump 11 mounted in the fuel tank 10, and the
evaporation gas from the fuel in the fuel tank 10 is collected in
the canister 20 through the discharge line 13, and is supplied to
the engine 30 through the purge line 14 so as to be burned due to
the negative intake pressure of the engine.
[0008] Hybrid vehicles, particularly plug-in hybrid electric
vehicles (PHEVs) travel in an EV traveling mode using a drive
motor. However, when evaporated gas is maximally collected in the
canister 20, the collection of the evaporation gas which is
continuously introduced from the fuel tank 10 is limited.
[0009] Although the evaporation gas collected in the canister 20 is
purged to the engine so as to be burned when the hybrid vehicle is
converted into an HEV traveling mode in which the engine is
operated, the evaporation gas is continuously introduced from the
fuel tank 10 beyond the collection capacity of the canister 20 in a
parked or stopped state or an EV traveling mode.
[0010] Accordingly, when the evaporation gas is continuously
introduced into the canister 20 from the fuel tank 10 in the state
in which the evaporation gas is maximally collected in the canister
20, the evaporation gas exceeding the collection capacity of the
canister 20 is not collected in the canister, but is discharged to
the atmosphere through the discharge port 23, thereby causing a
problem of air pollution.
[0011] A fuel tank isolation solenoid valve (FTIV) 200 is mounted
on the discharge line 13 connected both to the fuel tank 10 and to
the inlet 21 of the canister 20 such that isolation solenoid valve
200 is closed or opened so as to block or permit flow of the
evaporation gas to the canister 20 from the fuel tank 10, as
illustrated in FIG. 2.
[0012] The isolation solenoid valve 200, which is a solenoid-type
isolation solenoid valve configured to be opened upon application
of power, is normally maintained in the closed state but is opened
only when the engine is operated or the fuel tank is refueled.
[0013] More specifically, the isolation solenoid valve 200 is
maintained in the closed state in a normal situation, in which the
engine is not operated, as in a parked or stopped state or an EV
traveling mode. However, the isolation solenoid valve 200 is opened
by application of power in response to a signal from a controller
(for example, an engine control unit; ECU) upon operation of the
engine or by application of power in response to a signal from a
controller (for example, a body control unit; BCM) upon
refueling.
[0014] Consequently, when the isolation solenoid valve 200 is
maintained in the closed state, the evaporation gas in the fuel
tank 10 is hermetically stored in the fuel tank 10 without flowing
into the canister 20, thereby inhibiting the evaporation gas from
being discharged to the atmosphere through the canister 20.
[0015] Meanwhile, when the isolation solenoid valve 200 is opened
upon operation of the engine, the evaporation gas in the fuel tank
10 is collected in the canister 20 through the opened isolation
solenoid valve 200, and the evaporated gas collected in the
canister 20 is purged to the engine so as to be burned due to the
negative intake pressure of the engine.
[0016] In addition, when the isolation solenoid valve 200 is opened
upon refueling of the fuel tank, the evaporation gas in the fuel
tank 10 is collected in the canister 20 through the opened
isolation solenoid valve 200, and the internal pressure in the fuel
tank 10 is released, thereby allowing the fuel tank to be easily
refueled.
[0017] At this time, when a refueling button in the vehicle is
pushed by a user, the controller (for example, the body control
unit; BCM) performs control to check whether the isolation solenoid
valve 200 is opened for release of the internal pressure in the
fuel tank and to open an electrical fuel door 40.
[0018] As illustrated in FIG. 3, the isolation solenoid valve 200
is further provided at one side thereof with a positive and
negative pressure relief valve 210, which is a kind of safety
valve.
[0019] The relief valve 210 is normally maintained in the closed
state. However, when overpressure (positive pressure), which is
higher than a reference pressure, acts on the isolation solenoid
valve 200 from the fuel tank 10, the relief valve 210 operates to
open the bypass path provided therein toward the canister 20 so as
to release the overpressure. Furthermore, when over-negative
pressure, which is lower than the reference pressure, acts to the
isolation solenoid valve 200 from the canister 20, the relief valve
210 operates to cause the bypass path to be opened toward the fuel
tank 10 so as to release the over-negative pressure.
[0020] However, we have discovered that because the conventional
isolation solenoid valve is further provided with the relief valve,
the conventional isolation solenoid valve has the following
disadvantages.
[0021] First, because the relief valve is provided at one side of
the isolation solenoid valve so as to project laterally, the
overall size of the isolation solenoid valve is increased and
package layout to mount the isolation solenoid valve including the
relief valve to a vehicle body is desired.
[0022] Second, because the relief valve is additionally mounted on
the isolation solenoid valve, the number of components and
manufacturing costs increase.
[0023] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
present disclosure and therefore it may contain information that
does not form the prior art that is already known to a person of
ordinary skill in the art.
SUMMARY
[0024] The present disclosure provides a fuel tank isolation
solenoid valve for a vehicle. The fuel tank isolation solenoid
valve includes: an upper case, a bobbin mounted in the upper case,
around which a coil is wound, a core mounted in the bobbin, the
core having a plunger passage which is open at a lower end thereof,
a lower case coupled to the upper case, the lower case including a
first passage communicating with a fuel tank, a second passage
communicating with a canister, and a communication passage defined
between the first passage and the second passage, a plunger having
formed therein a lower open space and a plurality of first vent
holes, configured to allow the first passage to communicate with
the lower open space, the plunger being disposed in the plunger
passage to be vertically movable, a main seal mounted on a lower
surface of the plunger, a valve body disposed in the communication
passage to be vertically movable, the valve body having therein a
plurality of second vent holes, which are vertically formed through
the valve body so as to allow the first passage to communicate with
the second passage, a sealing plate mounted on the lower case at an
outer circumference of the communication passage so as to be in
airtight contact both with a lower surface of the main seal and
with an upper surface of the valve body, a first spring disposed
between a lower surface of the core and a lower end of the plunger,
and a second spring disposed between a lower surface of the valve
body and a bottom surface of the communication passage.
[0025] A diaphragm may be disposed between an outer surface of the
plunger and an inner surface of the core, and may be connected
thereto so as to inhibit foreign substances from entering the
valve.
[0026] The plunger may further have a vent hole formed therein to
allow an upper space in the diaphragm to communicate with the lower
open space in the plunger.
[0027] The plunger may have a first spring-holding groove formed in
an outer circumference of a lower end thereof, the first spring
being fitted and held in the first spring-holding groove.
[0028] The plunger may be provided on an upper surface thereof with
a stopper, which comes into contact with an upper end surface of
the plunger passage formed in the core while buffering the upper
end surface.
[0029] The valve body may include a sealing wall projecting from an
upper surface thereof at an inner circumference inwardly spaced
apart from the second vent holes, the sealing wall coming into
airtight contact with the main seal.
[0030] The valve body may include a vertical guide pin formed at a
center of the upper surface thereof, the vertical guide pin
entering and coming out of the lower open space in the plunger.
[0031] The valve body may have a second spring-holding groove
formed in an outer circumference of the lower surface thereof, the
second spring being fitted and held in the second spring-holding
groove.
[0032] The sealing plate may include a fitting wall formed on a
lower surface thereof, and the lower case may have a fitting groove
formed in an outer circumference of the communication passage, the
fitting wall being fitted and held in the fitting groove.
[0033] When overpressure, which is a pressure higher than a
reference pressure, acts on the valve body through the first
passage and the first vent holes in the plunger from the fuel tank,
the valve body may be lowered while compressing the second spring,
and the overpressure may sequentially pass through the first vent
holes and the lower open space in the plunger and the second vent
holes in the valve body and may act on the second passage, whereby
the overpressure is released.
[0034] When over-negative pressure, which is lower than a reference
pressure, acts on a lower portion of the plunger through the second
vent holes in the valve body from the canister, the plunger may be
raised while compressing the first spring, and the over-negative
pressure may pass through the second vent holes in the valve body
and may act on the first passage communicating with the fuel tank,
whereby the over-negative pressure is released.
[0035] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the
description and specific examples are intended for purposes of
illustration only and are not intended to limit the scope of the
present disclosure.
DRAWINGS
[0036] In order that the disclosure may be well understood, there
will now be described various forms thereof, given by way of
example, reference being made to the accompanying drawings, in
which:
[0037] FIG. 1 is a schematic view illustrating a procedure in which
the evaporation gas in a fuel tank is collected in a canister and
is then purged to an engine;
[0038] FIG. 2 is a schematic view illustrating a structure in which
an isolation solenoid valve is provided between the fuel tank and
the canister;
[0039] FIG. 3 is a perspective view illustrating the appearance of
the conventional isolation solenoid valve equipped with a relief
valve;
[0040] FIG. 4 is a perspective view illustrating the appearance of
a fuel tank isolation solenoid valve for a vehicle according to one
form of the present disclosure;
[0041] FIG. 5 is a cross-sectional view illustrating the fuel tank
isolation solenoid valve for a vehicle according to one form of the
present disclosure;
[0042] FIG. 6 is a perspective view illustrating a plunger among
the components of the fuel tank isolation solenoid valve for a
vehicle according to one form of the present disclosure;
[0043] FIG. 7 is a perspective view illustrating a valve body among
the components of the fuel tank isolation solenoid valve for a
vehicle according to one form of the present disclosure;
[0044] FIG. 8 is a perspective view illustrating the assembled
state of the internal components of the fuel tank isolation
solenoid valve for a vehicle according to one form of the present
disclosure, including the plunger and the valve body;
[0045] FIG. 9 is a cross-sectional view illustrating an operation
of opening the fuel tank isolation solenoid valve for a vehicle
according to one form of the present disclosure upon application of
power;
[0046] FIG. 10 is a cross-sectional view illustrating an operation
of releasing overpressure by the fuel tank isolation solenoid valve
for a vehicle according to one form of the present disclosure;
and
[0047] FIG. 11 is a cross-sectional view illustrating an operation
of releasing over-negative pressure by the fuel tank isolation
solenoid valve for a vehicle according to one form of the present
disclosure.
[0048] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present
disclosure in any way.
DETAILED DESCRIPTION
[0049] Hereinafter, reference will now be made in detail to various
forms of the present disclosure, examples of which are illustrated
in the accompanying drawings and described below. While the present
disclosure will be described in conjunction with exemplary forms,
it will be understood that the present description is not intended
to limit the present disclosure to those exemplary forms. On the
contrary, the present disclosure is intended to cover not only the
exemplary forms, but also various alternatives, modifications,
equivalents and other forms that may be included within the spirit
and scope of the present disclosure.
[0050] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various preferred features illustrative of the
basic principles of the disclosure. The specific design features of
the present disclosure as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes, will be
determined in part by the particular intended application and use
environment.
[0051] Hereinafter, a preferred form of the present disclosure will
be described in detail with reference to the accompanying
drawings.
[0052] FIGS. 4 and 5 illustrate a fuel tank isolation solenoid
valve for a vehicle according to one form of the present
disclosure.
[0053] As illustrated in FIGS. 4 and 5, the fuel tank isolation
solenoid valve 100 includes: an upper case 110 and a lower case
120, which are coupled to each other so as to define the appearance
of the valve 100.
[0054] The lower case 120 has formed therein a first passage 121 to
communicate with a fuel tank and a second passage 122 to
communicate with a canister. A communication passage 123 is defined
in the boundary portion between the first passage 121 and the
second passage 122.
[0055] A hollow bobbin 112, around which a coil 111 is wound and
which is of a solenoid type for raising and lowering the plunger,
is mounted on the inner wall of the upper case 110, and a core 113
is mounted in the bobbin 112.
[0056] The core 113 is provided therein with a plunger passage 114,
which is open at the lower end thereof.
[0057] A plunger 130 is disposed in the plunger passage 114 in the
core 113 so as to project downwards from the core 113.
Specifically, the upper end of the plunger 130 is inserted into the
plunger passage 114 to be vertically movable and the lower end of
the plunger 130 is positioned under the core 113.
[0058] As illustrated in FIGS. 5 and 6, the plunger 130 has the
form of a circular column in which the diameter of the lower
portion thereof is larger than the diameter of the upper portion
thereof. The plunger has formed therein a lower open space 131.
[0059] Particularly, the lower portion of the plunger 130 is
provided therein with a plurality of vent holes 132 for allowing
the lower open space 131 to communicate with the first passage 121
in the lower case 120.
[0060] As illustrated in FIGS. 5 and 8, a diaphragm 136 is disposed
between the outer surface of the plunger 130 and the inner surface
of the core 113, and is connected thereto. The diaphragm 136 serves
to inhibit foreign substances from entering the plunger passage 114
in the core 113.
[0061] More specifically, the diaphragm 136 serves to inhibit a
phenomenon in which the plunger 130 is jammed in the plunger
passage 114 and is thus incapable of being raised and lowered due
to foreign substances, which enter the plunger passage 114 in the
core 113.
[0062] The plunger 130 is further provided therein with vent holes
133 for allowing the upper space in the diaphragm 136 to
communicate with the lower open space 131.
[0063] Consequently, when the plunger 130 is raised, the air in the
upper space in the diaphragm 136 and in the plunger passage 114 is
discharged into the lower open space 131 through the vent holes
133, thereby enabling the plunger 130 to be easily raised without
resistance to air.
[0064] A first spring 140 is disposed between the lower surface of
the core 113 and the lower end of the plunger 130 so as to be
compressed. To this end, the lower end of the plunger 130 is
provided at the outer circumference thereof with a first
spring-holding groove 134 in which the first spring 140 is fitted
and held.
[0065] Accordingly, the first spring 140 is compressed while the
plunger 130 is raised, and provides elastic restoring force to the
plunger 130 when the plunger 130 is lowered.
[0066] Preferably, the plunger 130 is provided on the upper surface
thereof with a rubber stopper 135, which comes into contact with
the upper end surface of the plunger passage 114 formed in the core
113, thereby limiting the distance that the plunger 130 is raised
and buffering the plunger 130.
[0067] A main seal 150 is mounted on the lower surface of the
plunger 130. The main seal 150 is in close contact with a sealing
plate 170, which will be described later, in an airtightly sealed
manner, so as to block the first passage 121 communicating with the
fuel tank and the second passage 122 communicating with the
canister.
[0068] A valve body 160 is disposed in the communication passage
123 in the lower case 120 to be vertically movable.
[0069] Referring to FIGS. 5 and 7, the valve body 160 has formed
therein a plurality of second vent holes 161 for allowing the first
passage 121 to communicate with the second passage 122. The valve
body 160 is disposed in the communication passage 123 to be
vertically movable.
[0070] The upper surface of the valve body 160 is provided at a
circumferential location inwardly spaced apart from the second vent
holes 161 with a sealing wall 162, which projects upwards so as to
be in airtight close contact with the lower surface of the main
seal 150.
[0071] Furthermore, the center of the upper surface of the valve
body 160 is provided with a vertical guide pin 163, which projects
upwards and which enters and comes out of the lower open space 131
in the plunger 130.
[0072] A second spring 180 is disposed between the lower surface of
the valve body 160 and the bottom surface of the communication
passage 123 so as to be compressed. To this end, the lower surface
of the valve body 160 is provided on the outer circumference
thereof with a second-spring-holding groove 164 in which the second
spring 180 is fitted and held.
[0073] The second spring 180 is compressed while the valve body 160
is lowered, and provides elastic restoring force when the valve
body 160 is raised.
[0074] The lower case 120 is provided on the outer circumference of
the communication passage 123 with a circular ring-shaped sealing
plate 170, which is in airtight contact both with the lower surface
of the main seal 150 and with the upper surface of the valve body
160.
[0075] To this end, the lower surface of the sealing plate 170 is
provided with a fitting wall 171, and the lower case 120 is
provided in the outer circumference of the communication passage
123 with a fitting groove 124, in which the fitting wall 171 is
fitted.
[0076] Here, the sealing plate 170 is in airtight contact both with
the lower surface of the main seal 150 and with the upper surface
of the valve body 160, and is configured to have a circular ring
shape so as to inhibit the second vent holes 161 in the valve body
160 from being blocked by the sealing plate 170, as illustrated in
FIGS. 5 and 8.
[0077] The operation of the fuel tank isolation solenoid valve
according to one form of the present disclosure, which is
constructed in the above-described manner, will now be
described.
Closed State of the Isolation Solenoid Valve
[0078] As illustrated in FIG. 5, the isolation solenoid valve 100
is maintained in a closed state in a normal situation in which the
engine is not operated as in a parked or stopped state and an EV
traveling mode.
[0079] More specifically, when the isolation solenoid valve 100 is
closed, the plunger 130 is maximally raised due to the elastic
restoring force of the first spring 140, and the valve body 160 is
maximally raised due to the elastic restoring force of the second
spring 180. Consequently, the lower surface of the main seal 150
mounted on the plunger 130 is in airtight contact with the upper
surface of the sealing plate 170, and the upper surface of the
valve body 160 is in airtight contact with the lower surface of the
sealing plate 170.
[0080] Accordingly, since the communication passage 123, which is
defined between the first passage 121 communicating with the fuel
tank and the second passage 122 communicating with the canister, is
closed, the evaporated gas in the fuel tank cannot flow to the
canister.
[0081] When the isolation solenoid valve 100 is maintained in the
closed state, the evaporated gas in the fuel tank cannot flow to
the canister and is hermetically stored in the fuel tank, thereby
inhibiting the evaporated gas from being discharged to the
atmosphere through the canister.
Operation of Opening the Isolation Solenoid Valve
[0082] FIG. 9 is a cross-sectional view illustrating an operation
of opening the isolation solenoid valve for a vehicle according to
the form of the present when power is applied thereto.
[0083] The isolation solenoid valve 100 is opened at the time of
operation of the engine, refueling, checking of leakage of the fuel
tank and the like.
[0084] When power is applied to the coil 111, the plunger 130 is
raised along the plunger passage 114 in the core 113 due to the
magnetic attraction, and the first spring 140 is compressed.
[0085] When the plunger 130 is raised, the air present in the upper
space in the diaphragm 136 and the plunger passage 114 is
discharged into the lower open space 131 and the first vent holes
132 through the vent holes 133, as indicated by the arrow "A" in
FIG. 9, thereby allowing the plunger 130 to be easily raised
without resistance to air.
[0086] Furthermore, when the plunger 130 is raised, the main seal
150 mounted on the plunger 130 is separated and spaced apart from
the upper surface of the sealing plate 170.
[0087] Consequently, since the second vent holes 161 in the valve
body 160 are opened, the first passage 121 communicating with the
fuel tank communicates with the second passage 122 communicating
with the canister via the second vent holes 161, with the result
that the communication passage 123 defined between the first
passage 121 communicating with the fuel tank and the second passage
122 communicating with the canister is converted into the opened
state.
[0088] In other words, the first passage 121 communicating with the
fuel tank and the second passage 122 communicating with the
canister communicate with each other via the second vent holes 161,
as indicated by the arrow "B" in FIG. 9.
[0089] When the isolation solenoid valve 100 is opened during
operation of the engine, the evaporated gas in the fuel tank
sequentially passes through the first passage 121, the second vent
holes 161 in the valve body 160, and the second passage 122, and is
collected in the canister, and the evaporated gas collected in the
canister is purged to the engine so as to be burned due to the
negative intake pressure of the engine.
[0090] When the isolation solenoid valve 100 is opened during
refueling of the fuel tank, the evaporated gas in the fuel tank
sequentially passes through the first passage 121, the second vent
holes 161 in the valve body 160 and the second passage 122, and is
collected in the canister. At this time, the internal pressure in
the fuel tank is released, thereby allowing the fuel tank to be
easily refueled.
Operation of Isolation Solenoid Valve for Releasing
Overpressure
[0091] FIG. 10 is a cross-sectional view illustrating an operation
of releasing overpressure by the fuel tank isolation solenoid valve
for a vehicle according to the form of the present disclosure.
[0092] When the pressure in the fuel tank is increased to be higher
than a reference pressure due to the amount of evaporated gas
therein, the external temperature or the like, the overpressure in
the fuel tank acts on the first passage 121.
[0093] The overpressure, which is the pressure higher than the
reference pressure and which acts on the first passage 121, acts on
the valve body 160 through the first vent holes 132 in the plunger
130.
[0094] Consequently, the valve body 160 is lowered while
compressing the second spring 180 due to the overpressure, which is
higher than the reference pressure, and the upper surface of the
valve body 160 is separated and spaced apart from the lower surface
of the sealing plate 170 while the sealing wall 162 of the valve
body 160 is separated and spaced apart from the lower surface of
the main seal 150. Consequently, the first passage 121
communicating with the fuel tank and the second passage 122
communicating with the canister communicate with each other via the
second vent holes 161 in the valve body 160.
[0095] As a result, the overpressure in the fuel tank sequentially
passes through the first passage 121, the first vent holes 132 in
the plunger 130, the lower open space, and the second vent holes
161 in the valve body 160, and then acts on the second passage 122
communicating with the canister, whereby the overpressure is easily
released, as indicated by the arrow "C" in FIG. 10.
[0096] When the overpressure is released, the valve body 160 is
raised to the initial position thereof, and comes into airtight
contact both with the sealing plate 170 and with the main seal 150,
thereby closing the isolation solenoid valve 100.
[0097] FIG. 11 is a cross-sectional view illustrating an operation
of releasing over-negative pressure using the fuel tank isolation
solenoid valve for a vehicle according to the form of the present
disclosure.
[0098] When the pressure in the fuel tank is decreased below the
reference pressure, over-negative pressure acts on the second
passage 122 from the canister on which the negative pressure of the
engine acts.
[0099] The over-negative pressure in the second passage 122, which
is transmitted from the canister, acts on the lower portion of the
plunger 130 through the second vent holes 161 in the valve body
160.
[0100] Consequently, due to the over-negative pressure, the plunger
130 is raised while compressing the first spring 140, and the main
seal 150 mounted on the plunger 130 is separated and spaced apart
from the sealing plate 170, as illustrated in FIG. 11. Accordingly,
the first passage 121 communicating with the fuel tank and the
second passage 122 communicating with the canister communicate with
each other via the second vent holes 161 in the valve body 160.
[0101] As a result, the over-negative pressure in the canister
sequentially passes through the second passage 122 and the second
vent holes 161 in the valve body 160, and then acts on the first
passage 121 communicating with the fuel tank, whereby the
over-negative pressure is easily released, as indicated by the
arrow "D" in FIG. 11.
[0102] When the over-negative pressure is released as described
above, the plunger 130 is lowered to the initial position thereof
by the elastic restoring force of the first spring 140, and the
main seal 150 mounted on the plunger 130 comes into airtight
contact with the sealing plate 170 and the sealing wall 162,
thereby closing the isolation solenoid valve 100.
[0103] Therefore, since overpressure (positive pressure) or
over-negative pressure, which acts on the isolation solenoid valve
100, is easily released, it is possible to inhibit damage and
malfunction of the internal components of the isolation solenoid
valve, and it is possible to increase the durability of the fuel
tank and the isolation solenoid valve.
[0104] Comparing the conventional isolation solenoid valve 200
including the relief valve 210 shown in FIG. 3 with the isolation
solenoid valve 100 according to the form of the present disclosure
shown in FIG. 4, the size of the isolation solenoid valve 100 is
reduced to be smaller than the size of the conventional isolation
solenoid valve 200 because the relief valve is omitted from the
isolation solenoid valve 100. Consequently, the isolation solenoid
valve according to the present disclosure offers an advantage in
the design of a package layout, in which it is desirable to mount
the isolation solenoid valve to a vehicle body, and offers effects
of a reduced number of component, cost savings and reduced weight
by virtue of obviation of the relief valve.
[0105] By virtue of the above-described construction, the present
disclosure offers the following effects.
[0106] First, when overpressure (positive pressure), which is a
pressure higher than a reference pressure, acts on the isolation
solenoid valve from the fuel tank, since the valve body in the
isolation solenoid valve is lowered so as to define a path for
releasing the overpressure, it is possible to easily release the
overpressure.
[0107] Second, when overpressure (positive pressure) acts on the
isolation solenoid valve from the canister, since the plunger in
the isolation solenoid valve is raised so as to define a path for
releasing the overpressure, it is possible to easily release the
overpressure.
[0108] Third, since overpressure (positive pressure) and
over-negative pressure acting on the isolation solenoid valve, are
easily released, it is possible to inhibit malfunction of the
isolation solenoid valve and to increase durability of the
isolation solenoid valve.
[0109] Fourth, it is possible to ensure a function of inhibiting
evaporated gas from being discharged to the atmosphere since the
isolation solenoid valve is maintained in the closed state when the
engine is not operated, a function of collecting the evaporated gas
in the fuel tank into the canister and of purging the evaporated
gas to the engine so as to be burned since the isolation solenoid
valve is opened when the engine is operated, and a function of
releasing the internal pressure in the fuel tank for refueling
since the isolation solenoid valve is opened when the fuel tank is
refueled.
[0110] Fifth, the isolation solenoid valve according to the present
disclosure is able to reduce the overall size thereof, compared to
a conventional isolation solenoid valve including a relief valve,
and thus offers an advantage in the design of a package layout, in
which it is desirable to mount the isolation solenoid valve to a
vehicle body. Furthermore, it is possible to offer effects of a
reduced number of components, cost savings and reduced weight by
virtue of omission of the relief valve.
[0111] The present disclosure has been described in detail with
reference to preferred forms thereof. However, it will be
appreciated by those skilled in the art that changes may be made in
these forms without departing from the principles and spirit of the
present disclosure.
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