CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Patent Application No. 62/054,657
filed on September 24, 2014; U.S. Patent Application No. 62/056,063 filed on
September 26, 2014; U.S. Patent Application No. 62/061 ,344 filed on October 8, 2014;
U.S. Patent Application No. 62/1 14,548 filed on February 10, 2015; and U.S. Patent
Application No. 62/140,1 12 filed on March 30, 2015. The disclosures of the above
applications are incorporated herein by reference.
FIELD
[0002] The present disclosure relates generally to fuel tanks on passenger vehicles
and more particularly to a fuel tank having an electronically controlled module that
manages the complete evaporative system for the vehicle.
BACKGROUND
[0003] Fuel vapor emission control systems are becoming increasingly more
complex, in large part in order to comply with environmental and safety regulations
imposed on manufacturers of gasoline powered vehicles. Along with the ensuing
overall system complexity, complexity of individual components within the system has
also increased. Certain regulations affecting the gasoline-powered vehicle industry
require that fuel vapor emission from a fuel tank's ventilation system be stored during
periods of an engine's operation. In order for the overall vapor emission control system
to continue to function for its intended purpose, periodic purging of stored hydrocarbon
vapors is necessary during operation of the vehicle.
[0004] The background description provided herein is for the purpose of generally
presenting the context of the disclosure. Work of the presently named inventors, to the
extent it is described in this background section, as well as aspects of the description
that may not otherwise qualify as prior art at the time of filing, are neither expressly nor
impliedly admitted as prior art against the present disclosure.
SUMMARY
[0005] A fuel tank system constructed in accordance to one example of the present
disclosure includes a fuel tank and an evaporative emission control system. The
evaporative emissions control system is configured to recapture and recycle emitted
fuel vapor. The evaporative emissions control system further includes a manifold
assembly having a first solenoid and a second solenoid. The control module is
configured to regulate operation of the first and second solenoids to selectively open
and close pathways in the manifold assembly to provide over-pressure and vacuum
relief for the fuel tank.
[0006] According to additional features, the fuel tank system can further include a
first roller over valve pick up tube disposed in the fuel tank and fluidly connected to the
manifold assembly. A second roll over valve pick up tube can be disposed in the fuel
tank and is fluidly connected to the manifold assembly. A fuel line vent vapor (FLW)
pick-up tube can be disposed in the fuel tank and be fluidly connected to the manifold
assembly. A float level sensor assembly can be disposed in the fuel tank and be
configured to provide a signal to the control module indicative of a fuel level state.
[0007] According to other features, a first vent valve can be disposed in the fuel tank
and be fluidly connected to the manifold assembly. A second vent valve can be
disposed in the fuel tank and be fluidly connected to the manifold assembly. The fuel
tank system can further include a liquid trap. The liquid trap can further comprise a
venturi jet that is configured to drain liquid from the liquid trap by way of a vacuum. One
of the first and second vent valves can further comprise a liquid vapor discriminator.
One of the first and second vent valves comprises a solenoid activated vent valve. The
solenoid activated vent valve can further comprise a vent valve body that defines a first
opening and a second opening. The first opening communicates with a canister. The
second opening communicates with the manifold assembly. The solenoid activated
vent valve further includes a biasing member that biases a spring plate toward a seal.
The spring plate further comprises an overmolded diaphragm.
[0008] A fuel tank system constructed in accordance to additional features of the
present disclosure includes a fuel tank and an evaporative emissions control system.
The evaporative emissions control system can be configured to recapture and recycle
emitted fuel vapor. The evaporative emissions control system comprises a liquid trap, a
first solenoid, a second solenoid, a control module and a G-sensor. The first solenoid
can be configured to selectively open and close a first vent. The second solenoid can
be configured to selectively open and close a second vent. The control module can
regulate operation of the first and second solenoids to provide over-pressure and
vacuum relief for the fuel tank. The G-sensor can provide a signal to the control module
based on a measured acceleration.
[0009] According to other features, the fuel tank system can further include a jet
pump driven by the fuel pump. The liquid trap can signal the control module to actuate
the jet pump solenoid when the liquid trap fills to a predetermined point and run for a
specific period of time. A liquid trap level sensor can measure liquid level in the liquid
level trap. The fuel tank system can further include a fuel level sensor. The fuel level
sensor indicates a fuel level thereat. When the fuel level reaches a threshold, the first
and second solenoids close. The first solenoid is selectively opened and closed to
adjust the rate of pressure rise within the fuel tank.
[0010] A fuel tank system constructed in accordance to additional features includes a
fuel tank, a first and second vent tube, an evaporative emissions control system and a
cam driven tank venting control system. The first and second vent tubes are disposed
in the fuel tank. The evaporative emissions control system can be configured to
recapture and recycle emitted fuel vapor. The evaporative emissions control system
can have a controller. The cam driven tank venting control assembly can have a rotary
actuator that rotates a cam assembly based on operating conditions. The cam
assembly can have a first cam and a second cam. The first cam can have a first cam
profile configured to selectively open and close the first vent tube. The second cam can
have a second cam profile configured to selectively open and close the second vent
tube based on operating conditions.
[0011] According to other features, the first and second cam profiles have cam
profiles that correspond to at least a fully closed valve position, a fully open valve
position and a partially open valve position. The fuel tank system can further comprise
a third cam having a third cam profile and a fourth cam having a fourth cam profile. The
third cam profile cam be configured to selectively open and close a third vent tube
disposed in the fuel tank. The fourth cam profile can be configured to selectively open
and close a fourth vent tube disposed in the fuel tank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present disclosure will become more fully understood from the detailed
description and the accompanying drawings, wherein:
[0013] FIG. 1 is a schematic illustration of a fuel tank system having an evaporative
emissions control system including a manifold having two solenoids, a controller, an
electrical connector and associated wiring in accordance to one example of the present
disclosure;
[0014] FIG. 2 is a schematic illustration of a fuel tank system having an evaporative
emissions control system including a manifold having two solenoids, a controller and a
liquid trap according to another example of the present disclosure;
[0015] FIG. 2A is a schematic illustration of an exemplary solenoid activated vent
valve that may be used with the evaporative emissions control system of FIG. 2 ;
[0016] FIG. 3 is schematic illustration of the fuel tank system of FIG. 1 according to a
first implementation;
[0017] FIG. 4 is a schematic illustration of the fuel tank system of FIG. 1 according to
a second implementation;
[0018] FIG. 5 is a schematic illustration of the fuel tank system of FIG. 3 and shown
during initial onset of a refueling event;
[0019] FIG. 6 is a schematic illustration of the fuel tank system of FIG. 5 and shown
with the fuel tank at fill level during a refueling event;
[0020] FIG. 7 is a schematic illustration of the fuel tank system of FIG. 3 and shown
in a "purge off' state during a dynamic driving condition;
[0021] FIG. 8 is a schematic illustration of the fuel tank system of FIG. 7 and shown
in a "purge on" state during a dynamic driving condition;
[0022] FIG. 9 is a schematic illustration of the fuel tank system of FIG. 3 and shown
in a "power on" state during a static (parked) condition;
[0023] FIG. 0 is a schematic illustration of the fuel tank system of FIG. 9 and shown
in a "power off' state during a static (parked) condition;
[0024] FIG. is a schematic illustration of the fuel tank system of FIG. 3 and shown
during an on-board diagnostics leak check;
[0025] FIG. 12 is a schematic illustration of the fuel tank system of FIG. 3 and shown
during a roll-over or crash condition;
[0026] FIG. 13 is a schematic illustration of a pressurized fuel tank system according
to another example of the present disclosure and shown during the onset of a
depressurization or refueling event;
[0027] FIG. 14 is a schematic illustration of the pressurized fuel tank system of FIG.
13 and shown with the fuel tank at fill level during a refueling event;
[0028] FIG. 15 is a schematic illustration of the pressurized fuel tank of FIG. 13 and
shown with the fuel tank sealed and the canister open during a "power on" state;
[0029] FIG. 16 is a schematic illustration of the pressurized fuel tank of FIG. 15 and
shown with the fuel tank sealed and the canister open during a "power off' state;
[0030] FIG. 17 is a schematic illustration of the fuel tank of FIG. 13 and shown with
the fuel tank and the canister both sealed;
[0031] FIG. 18 is a schematic illustration of a fuel tank system having an over
pressure release valve according to another example of the present disclosure;
[0032] FIG. 19 is a schematic illustration of a fuel tank system having an onboard
vapor recovery valve according to another example of the present disclosure;
[0033] FIG. 20 are exemplary block diagrams for the fuel tank system according to
the present disclosure during a vehicle rollover according to various examples of the
present disclosure;
[0034] FIGS. 2 1A and 2 1B are exemplary block diagrams for the fuel tank system
according to the present disclosure during vehicle refueling according to various
examples of the present disclosure;
[0035] FIG. 22 is a schematic illustration of a fuel tank system having an evaporative
emissions control system in accordance to one example of the present disclosure;
[0036] FIG. 23A is a schematic illustration of a cam driven tank venting control
assembly constructed in accordance to one example of the present disclosure and
shown with the cam in a first position where all valves are in an open position;
[0037] FIG. 23B is a schematic illustration of the cam driven tank venting control
assembly of FIG. 23A and shown with the cam in a second position where one of the
valves is closed and the remaining three valves are open;
[0038] FIG. 24 is a schematic illustration of a cam driven tank venting control
assembly constructed in accordance to another example of the present disclosure; and
[0039] FIG. 25A is a schematic illustration of a cam driven tank venting control
assembly constructed in accordance to another example of the present disclosure and
shown with a valve in a partially open position;
[0040] FIG. 25B is a schematic illustration of the cam driven tank venting control
assembly of FIG. 25A and shown with the valve in a fully open position; and
[0041] FIG. 26 is a perspective view of a cam assembly of the cam driven tank
venting control assembly of FIGS. 25A and 25B and illustrating a table of exemplary
open and close sequences.
DETAILED DESCRIPTION
[0042] With initial reference to FIG. 1, a fuel tank system constructed in accordance
to one example of the present disclosure is shown and generally identified at reference
number 10. The fuel tank system 10 can generally include a fuel tank 12 configured as
a reservoir for holding fuel to be supplied to an internal combustion engine via a fuel
delivery system, which includes a fuel pump 14. The fuel pump 14 can be configured to
deliver fuel through a fuel supply line 16 to a vehicle engine. An evaporative emissions
control system 20 can be configured to recapture and recycle the emitted fuel vapor. As
will become appreciated from the following discussion, the evaporative emissions
control system 20 provides an electronically controlled module that manages the
complete evaporative system for a vehicle. The evaporative control system 20 provides
a universal design for all regions and all fuels. In this regard, the requirement of unique
components needed to satisfy regional regulations may be avoided. Instead, software
may be adjusted to satisfy wide ranging applications. In this regard, no unique
components need to be revalidated saving time and cost. A common architecture may
be used across vehicle lines. Conventional mechanical in-tank valves may be replaced.
As discussed herein, the evaporative control system 20 may also be compatible with
pressurized systems including those associated with hybrid powertrain vehicles.
[0043] The evaporative emissions control system 20 includes a manifold assembly
24, a control module 30, a purge canister 32, a fuel line vent vapor (FLW) pick-up tube
36, a first roll-over valve (ROV) pick-up tube 40, a second ROV pick up tube 42, an
electrical connector 44, a fuel delivery module (FDM) flange 46 and a float level sensor
assembly 48. In one example, the manifold assembly 24 can include a manifold body
including conventional worm tracks and further comprise first and second solenoid 50,
52 (FIG. 3). The first solenoid 50 can be a tank side solenoid. The second solenoid 52
can be a canister side solenoid. The control module 30 can be adapted to regulate the
operation of first and second solenoids 50, 52 to selectively open and close pathways in
the manifold assembly 24, in order to provide over-pressure and vacuum relief for the
fuel tank 12. The manifold 24 can additionally comprise a mechanical grade shut-off
valve 60 (FIG. 3).
[0044] The control module 30 can further include or receive inputs from a tank
pressure sensor, a canister pressure sensor, a temperature sensor and a vehicle grade
sensor. The control module 30 can additionally include fill level signal reading
processing, fuel pressure driver module functionality and be compatible for two-way
communications with a vehicle electronic control module (not specifically shown). The
manifold assembly 24 can be configured to control a flow of fuel vapor between the fuel
tank 2 and the purge canister 32. The purge canister 32 adapted to collect fuel vapor
emitted by the fuel tank 12 and to subsequently release the fuel vapor to the engine.
The control module 30 can also be configured to regulate the operation of evaporative
emissions control system 20 in order to recapture and recycle the emitted fuel vapor.
The float level sensor assembly 48 can provide fill level indications to the control
module 30. The control module 30 can close the first solenoid 50 when the float level
sensor assembly 48 provides a signal indicative of a full fuel level state. While the
control module 30 is shown in the figures generally adjacent to the solenoids 50 and 52,
the control module 30 may be located elsewhere in the evaporative emissions control
system 20 such as adjacent the canister 32 for example.
[0045] With continued reference to FIG. 1, additional features of the evaporative
emissions control system 20 will be described. In one configuration, the ROV pick-up
tube 40 and the ROV pick-up tube 42 can be secured to the fuel tank 2 with clips. By
way of non-limiting example, the inner diameter of the FLW pick-up tube 36 can be 12
mm. The inner diameter of the ROV pick-up tubes 40 and 42 can be 3-4mm. The ROV
pick-up tubes 40 and 42 can be routed to high points of the fuel tank 12. In other
examples, external lines and tubes may additionally or alternatively be utilized. In such
examples, the external lines are connected through the tank wall using suitable
connectors such as, but not limited to, welded nipple and push-through connectors.
[0046] As identified above, the evaporative emissions control system 20 can replace
conventional fuel tank systems that require mechanical components including in-tank
valves with an electronically controlled module that manages the complete evaporative
system for a vehicle. In this regard, some components that may be eliminated using the
evaporative emissions control system 20 of the instant disclosure can include in-tank
valves such as GW's and FLW's, canister vent valve solenoid and associated wiring,
tank pressure sensors and associated wiring, fuel pump driver module and associated
wiring, fuel pump module electrical connector and associated wiring, and vapor
management valve(s) (system dependent). These eliminated components are replaced
by the control module 30, manifold 24, solenoids 50, 52 and associated electrical
connector 44. Various other components may be modified to accommodate the
evaporative emissions control system 20 including the fuel tank 12. For example, the
fuel tank 12 may be modified to eliminate valves and internal lines to pick-up points.
The flange of the FDM 46 may be modified to accommodate the manifold 24, the control
module 30 and the electrical connector 44. In other configurations, the fresh air line of
the canister 32 and dust box may be modified. In one example, the fresh air line of the
canister 32 and the dust box may be connected to the control module 30.
[0047] Turning now to FIG. 2, a fuel tank system 110 constructed in accordance to
another example of the present disclosure will be described. The fuel tank system 110
includes an evaporative emissions control system 120. Unless otherwise described, the
evaporative emissions control system 20 can be configured similar to the evaporative
emissions control system 20 described above. The evaporative emissions control
system 120 can include a manifold assembly 124, a control module 130, a liquid trap
36, a drain valve 138, a first vent valve 140, and a second vent valve 142. The second
vent valve 142 can be a refueling vent valve. A mechanical LVD 144 can be provided at
the liquid trap 136. In one configuration, the liquid trap 136 can include a venturi jet that
drains liquid by way of a vacuum out of the liquid trap 136 when the fuel pump is on.
The manifold assembly 124 can include a first solenoid 150 and a second solenoid 152.
[0048] With reference to FIG. 2A, a solenoid activated vent valve 200 is shown. The
solenoid activated vent valve 200 can be configured for use at one of or both of the first
valve 140 and the second valve 142. The solenoid activated vent valve 200 can include
a vent valve body 202 that defines a first opening 210 and a second opening 212. The
first opening 210 can communicate with the canister (such as canister 32, FIG. 1). The
second opening 212 can communicate with the manifold assembly 124. The solenoid
activated vent valve 200 can further include a liquid vapor discriminator 220. In other
configurations, a baffle may be incorporated if a centralized liquid trap is used. The
solenoid activated vent valve 200 can additionally include a biasing member or spring
230 that biases a spring plate 232 toward a seal 240. A diaphragm 242 can be
overmolded to the spring plate 232. A heat staked membrane 248 can be positioned
proximate to the seal 240. n operation, if the first solenoid 150 is off (corresponding to
a closed position), the spring 230 biases the spring plate 232 against the seal 240 and
the diaphragm is forced shut. If the fuel tank pressure is higher than atmosphere, the
heat staked membrane 248 allows air to pass through. If the control module 130 is set
to vent, the first solenoid 150 is on (corresponding to an open position), the spring plate
232 moves away from the seal 240 against the spring 230 and the solenoid activated
vent valve 200 vents out to the canister (see canister 32, FIG. 1).
[0049] Turning now to FIG. 3, a system schematic of the fuel tank system 10
according to a first example is shown. The mechanical grade shut-off 60 can be
configured to close in the event of a roll-over or vehicle crash event. The mechanical
grade shut-off 60 does not require power to close. FIG. 4 illustrates a system schematic
of the fuel tank system 10 according to a second example. In FIG. 4 , the FLW pick-up
tube 36 and the ROV pick-up tube 40 are arranged according to another example as
shown.
[0050] With reference to FIG. 5, a system schematic is shown during an initial
refueling event. The FLW pick-up tube 36 is open for full flow. FiG. 6 shows a system
schematic during refueling when a full fill level is attained. A fuel level sensor signal
(such as from the level sensor assembly 48, FIG. 1) can trigger closure to stop fueling.
[0051] With reference to FIGS. 7 and 8, a system schematic is shown during
dynamic conditions such as driving. The fuel tank system 10 monitors fuel level, tank
pressure, and vehicle grade. The control module 30 opens the solenoid valves 50, 52
as needed to vent. In FIG. 7, purge is set to off. In FIG. 8 , purge is set to on. During a
purge event, fresh air is drawn through the canister 32.
[0052] FIGS. 9 and 10 show a system schematic during a static condition such as
parked. The control module 30 determines which of the ROV pick-up tubes 40, 42 to
open based on grade, fuel level and tank pressure. n FIG. 9, power is on whereas in
FIG. 10, power is off. When power is off, a bypass 310 can open to allow liquid to drain
back into the fuel tank 12.
[0053] With reference to FIG. 1 , a system schematic is shown during an on-board
diagnostics (OBD) leak check. During an OBD leak check, the canister air and engine
ports are closed. A pressure drop is monitored across the system. The ROV pick-up
tubes 40, 42 are opened or closed depending on the grade and fuel level. At least one
ROV pick-up tube 40, 42 is open.
[0054] FIG. 12 shows a system schematic during a roll-over or crash event. The first
and second solenoids 50 and 52 are shut if power is available. If no power is available,
the mechanical shut off valve 60 is triggered to close to seal the system.
[0055] FIGS. 13 and 14 show a system schematic during a depressurization or
refueling event for a pressurized system. FIG. 13 is a system schematic during initial
refueling. FIG. 14 is a system schematic during refueling when a full fill level is attained.
A fuel level sensor signal (such as from the level sensor assembly 48, FIG. 1) can
trigger closure to stop fueling.
[0056] FIGS. 15 and 16 show a system schematic during a tank sealed state. FIG.
15 shows a power on state. FIG. 16 shows a power off state. FIG. 17 is a system
schematic showing the tank and canister sealed. FIG. 18 is a system schematic
showing the OPR with the power on/off. FIG. 19 is a system schematic showing the
OVR with the power on/off.
[0057] FIG. 20 illustrates exemplary flow charts for a vehicle rollover event. The
sequence of events are aligned vertically between the vehicle, the evaporative emission
system, vehicle controls, the fuel tank and error states. A vehicle flow chart is shown at
410. At 412, the vehicle is in normal orientation. At 414, power is on. At 416, power is
off. At 418, the vehicle starts to roll. At 420, the vehicle roll stops in a non-normal
orientation. At 422, the roll stops and returns to normal operation. At 424 the vehicle
starts normal operation.
[0058] An evaporative emission system flow chart is shown at 430. At 432, the ports
are open to the canister. At 434, the ports are closed. At 436, the ports are kept
closed. At 440, the ports are closed to the canister. At 442, the ports are closed. At
444, the ports are opened according to normal operating processes (e.g. based on
pressure, orientation inputs, etc.). At 446, normal operation is continued. At 450, the
master mechanical rollover valve is opened. At 452, the master mechanical rollover
valve is closed. The valve can be spring and float driven. At 454, the master
mechanical rollover valve is opened. At 456 the master mechanical rollover valve is
opened.
[0059] An evaporative controls flow chart is shown at 460. The grade sensor senses
an orientation within normal limits at 462. The grade sensor senses an orientation
greater than a threshold degree at 464. The grade sensor senses an orientation greater
than a threshold degree at 466. At 468, the grade sensor senses an orientation in a
normal range for a threshold amount of time. At 470, the sensors are monitored per
normal process.
[0060] Various error states are shown at 480. At 482, with no power, a backup is the
master mechanical rollover valve. At 484, with a failed grade sensor, a backup is the
master mechanical rollover valve. At 486, with the mechanical rollover valve stuck
open, the same controls and failure modes are followed from a traditional valve system.
At 488, with the mechanical rollover valve stuck closed, the same controls and failure
modes are followed from a traditional valve system.
[0061] FIG. 2 1 illustrates exemplary flow charts for a vehicle rollover event. The
sequence of events are aligned vertically between the vehicle, the evaporative emission
system, vehicle controls, the fuel tank and error states. A vehicle flow chart is shown at
510. At 512, the vehicle is stopped at a gas station. At 514, the vehicle is keyed off. At
516, the vehicle is keyed on. At 520, the fuel fill door is opened. At 522, the fuel cap is
removed. 522 may also represent a cap-less fuel tank vehicle. At 526, the nozzle is
inserted. At 528, fuel is dispensed. At 530, a nozzle shut-off is triggered. At 532, the
nozzle is removed. At 534, the fuel cap is installed. At 536 the fuel door is closed. At
538, the vehicle drives off.
[0062] An evaporative emission system flow chart is shown at 540. At 542 a
refueling event is detected. At 544, the fuel level detected is less than full. At 546, the
fuel level is full. At 550, the FLW port is opened to the canister. At 552, vapor is
vented to the canister. At 554, full fuel level is reached on with the fuel level sensor. At
556 the FLW port is closed and the head valve port is opened. At 558 all venting is
closed after a predetermined time. At 560, all venting is closed to trigger a shut-off. At
562 refueling completion is detected. Detection can be satisfied with the fuel cap on,
vehicle movement or a change in the fuel level sensor. At 566, full ROV venting is
opened. At 570, the FLW port is kept closed. At 572, pressure builds in the fuel tank
and triggers a nozzle shut-off. At 574, the fuel level sensor is at or above full. At 576,
the tank pressure is monitored and the ROV port is triggered open at a pop point.
[0063] An evaporative controls flow chart is shown at 580. At 582, the fuel level is
read from the level sensor. At 584, solenoid movement is verified. In one example an
inductive charge can be used. At 586, a fuel level change is detected indicating a full
fuel level. At 588, solenoid movement is verified. Again, in one example, an inductive
charge can be used.
[0064] Various error states are shown at 590. At 592, a failed level sensor is
detected. The failed level sensor may be detected by satisfying a status of stuck, bad
resistance, no signal, or an intermittent signal. At 594, a solenoid failure may cause a
port not to open. At 596, a solenoid failure may cause a port not to close. At 598, the
ROV port is opened with a pressure trigger or head valve pop point. The vehicle is not
to drive off after refueling.
[0065] Turning now to FfG. 22, a fuel tank system constructed in accordance to
another example of the present disclosure is shown and generally identified at reference
number 610. The fuel tank system 610 can generally include a fuel tank 612 configured
as a reservoir for holding fuel to be supplied to an internal combustion engine via a fuel
delivery system, which includes a fuel pump 614. The fuel pump 614 can be configured
to deliver fuel through a fuel supply line 616 to a vehicle engine. An evaporative
emissions control system 620 can be configured to recapture and recycle the emitted
fuel vapor. As will become appreciated from the following discussion, the evaporative
emissions control system 620 provides an electronically controlled module that
manages the complete evaporative system for a vehicle.
[0066] The evaporative control system 620 provides a universal design for all
regions and all fuels. In this regard, the requirement of unique components needed to
satisfy regional regulations may be avoided. Instead, software may be adjusted to
satisfy wide ranging applications. In this regard, no unique components need to be
revalidated saving time and cost. A common architecture may be used across vehicle
lines. Conventional mechanical in-tank valves may be replaced. As discussed herein,
the evaporative control system 620 may also be compatible with pressurized systems
including those associated with hybrid powertrain vehicles.
[0067] The evaporative emissions control system 620 includes a manifold assembly
624, a fuel delivery module 628 having a control module 630, a purge canister 632, a Gsensor
636, a first roll-over valve (ROV) pick-up tube or vent 640, a second ROV pick
up tube or vent 642, a first fuel level sensor 644A, a second fuel level sensor 644B, a
third fuel level sensor 644C, a liquid trap 646, a liquid level sensor 648, a large vent
solenoid 650 and a small vent solenoid 652.
[0068] The control module 630 can be adapted to regulate the operation of a first
and second solenoids 650, 652 to selectively open and close pathways in liquid trap
646, in order to provide over-pressure and vacuum relief for the fuel tank 612.
[0069] The fuel delivery module 628 has an integral accelerometer or G-sensor 636
and a control module 630 that close any number of vent lines most likely two. One
larger (to manage refueling vapor flow) and one smaller (to manage grade venting).
The larger can also manage grade venting. The fuel delivery module 628 houses a
liquid trap 646 with a jet pump 660 driven by the main fuel pump 614 and turned off and
on via a solenoid valve.
[0070] During operation such as a refueling event, fuel is dispensed and rises toward
fuel level sensor 644c. When the sensor 644c indicates fuel level has reached this
point the large solenoid 650 closes and the small solenoid 652 also closes. Pressure
builds in the fuel tank 612 causing fuel to back up the fill pipe and turn off the dispensing
nozzle. The smaller solenoid can be used to adjust the rate of pressure rise by opening
and closing as needed. This activity will ensure a good fill without spit back at the filler
neck. Various pressure profiles are easily produced for system variations.
[0071] Running loss and liquid carry-over prevention will now be described. The
vehicle is quite dynamic and the liquid trap must not allow liquid fuel to pass into the
charcoal canister 632. The liquid trap 646 signals the control module 630 to actutate
the jet pump solenoid 660 to turn on the jet pump 6 6 when the liquid trap 646 fills to a
predetermined point and run for a specific period of time, such as long enough to drain
the liquid trap 646.
[0072] The control module 630 continuously monitors the bulk fuel level, the Gsensor
636, the vent solenoids 650, 652, the fuel tank pressure and the liquid trap level
sensor 648. The G-sensor can communicate a signal to the control module 630 based
on a measured acceleration. As the vehicle is driven this monitoring process is used to
optimize the vent process. The goal is to selectively open and close the vent solenoids
650, 652 and the jet pump solenoid 660 to maintain an acceptable fuel tank pressure,
ensure no liquid leave the liquid trap, and minimize the jet pump on time.
[0073] Grade venting will now be described. When the vehicle is stopped and the
engine is turned off, the fuel delivery module, G-sensor 636 and fuel level determine
which vent line is above fluid level and closes the solenoids 650, 652 including the jet
pump solenoid 660. This will allow the fuel tank 612 to vent. The solenoids are latching
so no power is required to keep them closed or open. During engine off, a watch dog
supervisory control will monitor the G-sensor 636. Should the vehicle attitude change,
the system will wake and adjust for proper venting and then go to sleep again.
Consider complete power failure or crash. The system has a main floated valve in the
fuel delivery module which floats closed when the liquid trap is over filled in any vehicle
orientation. Pressure build at this time will be released by the filler cap over pressure
relief.
[0074] With reference now to FIGS. 23A and 23B a cam driven tank venting control
assembly 670 constructed in accordance to another example of the present disclosure
will be described. The cam driven tank venting control assembly 670 includes one
rotary actuator 672 and a cam 674 to selectively open valves 676a, 676b, 676c and
676d. The valves 676a, 676b, 676c and 676d can be poppet valves that are configured
to open and close respective vents 680a, 680b, 680c and 680d located at discrete
positions in the fuel tank. The cam 674 can be rotated to a prescribed position where
the required valves 676a, 676b, 676c and 676d are open or closed. When the power is
off, the rotary actuator 672 and cam 674 remain in position so latching is inherent in the
design. The cam driven tank venting control assembly 670 can be used in the
evaporative emissions control systems described above when it may be desired to
provide multiple vents while avoiding multiple latching solenoids. The rotary actuator is
rotates to a desired position based on an input from the controller based on operating
conditions.
[0075] Turning now to FIG. 24, a cam driven tank venting control assembly 710
constructed in accordance to another example will be described. While the
configuration shown above with respect to FIGS. 23A and 23B discuss a cam and valve
arrangement that move valves between fully open and fully closed positions, other
configurations are contemplated. For example, the tank venting control configuration
710 includes a cam 712 that rotates a roller 714 resulting in a valve 720 moving
between a fully open position, a fully closed position and a partially open position. In
this regard, the cam 712 includes a first cam profile 1 that results in an orifice size being
closed (or the valve 720 being fully closed), a second cam profile 2 that results in an
orifice size being small (or the valve 720 being partially open), and a third cam profile 3
that results in an orifice size being large (or the valve 720 being fully open).
[0076] While three discreet positions are described, including two levels of "open"
and one closed position, more positions may be provided. For example it is possible to
rotate the cam 712 to a position between the cam profiles 1, 2 and 3 to offer a truly
variable orifice size. The cam driven tank venting control configuration 710 can be
configured such that during refueling the valve 720 is on the third cam profile 3 or the
valve 720 being fully open. The valves can be configured for various combinations
during vehicle operation. An additional benefit to this configuration is that the piece
costs and complexity of multiple solenoids opening and closing multiple vents can be
avoided in favor of the cam arrangement that opens valves to various levels of open.
[0077] With reference now to FIGS. 25A, 25B and 26, a tank venting control
assembly 750 constructed in accordance to additional features of the present disclosure
will be described. The tank venting control assembly 750 includes a cam assembly 752
that includes cams 754A, 754B and 754C. The cams 754A, 754B and 754C
independently rotate a roller (only one roller 760 shown in FIGS. 25A and 25B) resulting
in a valve (only one valve 762 shown) moving between a fully open position, a fully
closed position and a partially open position based on the cam profile. In this regard,
each cam 754A, 754B and 754C includes a specific cam profile that results in an orifice
size leading to a respective vent tube (780 shown) being closed (or the valve 762 being
fully closed), or various states of open.
[0078] Again, depending on the cam profile, the valve can be moved to many
degrees or levels of open. An arm 766 can be provided on each valve that is configured
to deflect toward and away from the valve opening. n the configuration shown, all of
the three valves (672) is achieved at an angle of 170 degrees. A fully open condition
(OL) provides 4.88 mm of clearance at the valve opening. An open position (O)
provides 2.13 mm of clearance at the valve opening. It is appreciated however that
these values are merely exemplary and may be changed within the scope of this
disclosure in the configuration shown a DC motor 784 is used to drive a worm gear
786 which in turn rotates the cam assembly 752 on a common axle. As the cam
assembly 752 rotates, a rotary potentiometer can be used to monitor position. With
three valve elements, there are eight positions to accommodate the eight states
possible for vent valves. The valves ensure that all three vent tubes can be opened or
closed as the fuel tank vent controller determines. As the DC motor 784 rotates, the
potentiometer indicates angular position and thus the cam positions and subsequently
which valve is open and which is closed.
[0079] The foregoing description of the examples has been provided for purposes of
illustration and description. It is not intended to be exhaustive or to limit the disclosure.
Individual elements or features of a particular example are generally not limited to that
particular example, but, where applicable, are interchangeable and can be used in a
selected example, even if not specifically shown or described. The same may also be
varied in many ways. Such variations are not to be regarded as a departure from the
disclosure, and all such modifications are intended to be included within the scope of
the disclosure.

CLAIMS
What is claimed is:
. A fuel tank system comprising:
a fuel tank; and
an evaporative emissions control system configured to recapture and
recycle emitted fuel vapor, the evaporative emissions control system comprising:
a control module; and
a manifold assembly having a first solenoid and a second solenoid,
wherein the control module is configured to regulate operation of the first and second
solenoids to selectively open and close pathways in the manifold assembly to provide
over-pressure and vacuum relief for the fuel tank.
2. The fuel tank system of claim , further comprising:
a first roll over valve pick up tube disposed in the fuel tank and fluidly
connected to the manifold assembly; and
a second roll over valve pick up tube disposed in the fuel tank and fluidly
connected to the manifold assembly;
3. The fuel tank system of claim 2, further comprising:
a fuel line vent vapor (FLW) pick-up tube disposed in the fuel tank and
fluidly connected to the manifold assembly.
4 . The fuel tank system of claim 3, further comprising a float level sensor
assembly disposed in the fuel tank and configured to provide a signal to the control
module indicative of a fuel level state.
5. The fuel tank system of claim , further comprising:
a first vent valve disposed in the fuel tank and fluidly connected to the
manifold assembly; and
a second vent valve disposed in the fuel tank and fluidly connected to the
manifold assembly.
6 . The fuel tank system of claim 5, further comprising a liquid trap.
7 . The fuel tank system of claim 6 wherein the liquid trap further comprises a
venturi jet that is configured to drain liquid from the liquid trap by way of a vacuum.
8. The fuel tank system of claim 6 wherein one of the first and the second
vent valves further comprises a liquid vapor discriminator.
9. The fuel tank system of claim 8 wherein one of the first and second vent
valves comprises a solenoid activated vent valve.
10. The fuel tank system of claim 9 wherein the solenoid activated vent valve
further comprises a vent valve body that defines a first opening and a second opening,
wherein the first opening communicates with a canister and wherein the second
opening communicates with the manifold assembly.
. The fuel tank system of claim 10 wherein the solenoid activated vent valve
further includes a biasing member that biases a spring plate toward a seal.
12. The fuel tank system of claim 11 wherein the spring plate further
comprises an overmolded diaphragm.
13. A fuel tank system comprising:
a fuel tank; and
an evaporative emissions control system configured to recapture and
recycle emitted fuel vapor, the evaporative emissions control system comprising:
a liquid trap;
a first solenoid configured to selectively open and close a first vent;
a second solenoid configured to selectively open and close a
second vent;
a control module that regulates operation of the first and second
solenoids to provide over-pressure and vacuum relief for the fuel tank; and
a G-sensor that provides a signal to the control module based on a
measured acceleration.
14. The fuel tank system of claim 13, further comprising a jet pump driven by
the fuel pump
15. The fuel tank system of claim 13 wherein the liquid trap signals the control
module to actuate the jet pump solenoid when the liquid trap fills to a predetermined
point and run for a specific period of time.
16. The fuel tank system of claim 15, further comprising a liquid trap level
sensor that measures liquid level in the liquid level trap.
17. The fuel tank system of claim 13, further comprising a fuel level sensor,
wherein the fuel level sensor indicates fuel level thereat, and wherein the first and
second solenoids close based on the fuel level reaching a threshold, and wherein the
first solenoid is selectively opened and closed to adjust the rate of pressure rise within
the fuel tank.
18. A fuel tank system comprising:
a fuel tank;
a first and second vent tube disposed in the fuel tank; and
an evaporative emissions control system configured to recapture and
recycle emitted fuel vapor, the evaporative emissions control system having a controller;
a cam driven tank venting control assembly having a rotary actuator that
rotates a cam assembly based on operating conditions, the cam assembly having (i) a
first cam having a first cam profile configured to selectively open and close the first vent
tube, and (ii) a second cam having a second cam profile configured to selectively open
and close the second vent tube based on operating conditions.
9. The fuel tank system of claim 18 wherein the first and second cam profiles
have cam profiles that correspond to at least a fully closed valve position, a fully open
valve position and a partially open valve position.
20. The fuel tank system of claim 18, further comprising a third cam having a
third cam profile and a fourth cam having a fourth cam profile, the third cam profile
configured to selectively open and close a third vent tube disposed in the fuel tank, the
fourth cam profile configured to selectively open and close a fourth vent tube disposed
in the fuel tank.