WO2021104671A2

WO2021104671A2 - Fuel tank system having cam actuated venting with position sensing

Info

Publication number: WO2021104671A2
Application number: PCT/EP2020/025537
Authority: WO
Inventors: Vaughn K. Mills; Jeffrey B. Smith; Steven AMBROSE; Max FRANKLIN; Nikhil NAHAR
Original assignee: Eaton Intelligent Power Limited
Priority date: 2019-11-25
Filing date: 2020-11-25
Publication date: 2021-06-03
Also published as: WO2021104671A3

Abstract

An evaporative emissions control system configured to manage venting on a fuel tank system configured to deliver fuel to an internal combustion engine includes a fuel tank, a first vent tube, a purge canister, a cam driven tank venting control assembly, a controller and a home feature. The first vent tube is disposed in the fuel tank. The cam driven tank venting control assembly has a rotary actuator that rotates a cam assembly based on operating conditions. The cam assembly has at least a first cam having a first cam profile configured to selectively open and close a first vent valve associated with the first vent tube based on operating conditions. The controller communicates with the cam driven tank venting assembly. The home feature is configured to send a signal to the controller indicative of a home position of the vent valve.

Description

FUEL TANK SYSTEM HAVING CAM ACTUATED VENTING WITH POSITION

SENSING

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/939,966 filed on November 25, 2019, the contents of which is 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 evaporative emissions control system that incorporates cam actuated venting having position sensing.

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] An evaporative emissions control system configured to manage venting on a fuel tank system configured to deliver fuel to an internal combustion engine includes a fuel tank, a first vent tube, a purge canister, a cam driven tank venting control assembly, a controller and a home feature. The first vent tube is disposed in the fuel tank. The purge canister is adapted to collect fuel vapor emitted by the fuel tank and to subsequently release the fuel vapor to the internal combustion engine. The cam driven tank venting control assembly has a rotary actuator that rotates a cam assembly based on operating conditions. The cam assembly has at least a first cam having a first cam profile configured to selectively open and close a first vent valve associated with the first vent tube based on operating conditions. The controller communicates with the cam driven tank venting assembly. The home feature is configured to send a signal to the controller indicative of a home position of the vent valve.

[0006] According to additional features, the home feature further includes a cam gear associated with the first cam. The cam gear includes a cam gear rotational stopper disposed thereon. A gear plate supports the cam assembly. The gear plate includes a gear plate stopper disposed thereon. The cam gear rotational stopper is configured to engage the gear plate stopper and inhibit further rotation of the cam gear corresponding to the home position. The home feature can alternatively include a first position sensor assembly having a first reed switch and a magnet. The first reed switch can be configured to send a first signal to the controller based on proximity to the magnet. The first position sensor assembly can further include a second reed switch. The second reed switch can be configured to send a second signal to the controller based on proximity to the magnet. The first signal can correspond to the vent valve having a small orifice and the second signal corresponds to the vent valve having a large orifice.

[0007] According to additional features, the first cam profile has profiles that correspond to at least a fully closed valve position, a fully open position and a partially open position. The evaporative emissions control system can further include a second vent tube disposed in the fuel tank. The cam assembly can further include a second cam having a second cam profile configured to selectively open and close the second vent tube based on operating conditions. The second cam profile can have profiles that correspond to at least a fully closed valve position, a fully open valve position and a partially open valve position. A second valve can selectively open and close based on rotation of the second cam. The first and second valves can be poppet valves. [0008] In other features, the home feature can include a hard stop comprising one of a potentiometer and rheostat. The home feature can include a hard stop comprising a stepper motor that senses a home position and keeps track of subsequent steps based on rotation. The stepper motor can be bidirectional. The home feature can comprise a hard stop configured on a cam shaft that supports the cam assembly. A switch can detect and calibrate a home position. The switch can include one of a reed switch, an optical switch and a push button switch.

[0009] A method of operating an evaporative emissions control system configured to manage venting on a fuel system is provided. The control system has a cam driven tank venting control assembly including a rotary actuator that rotates a cam assembly based on operating conditions. The cam assembly has a first cam configured to selectively open and close a first vent valve. A first signal is sent to the controller based on a magnet having proximity to a first reed switch. A position of the vent valve is determined based on the first signal. A second signal is sent to the controller based on the magnet having proximity to a second reed switch. A position of the vent valve is determined based on the second signal.

BRIEF DESCRIPTION OF THE DRAWINGS [0010] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0011] FIG. 1 is a schematic illustration of a fuel tank system having an evaporative emissions control system including a vent shut-off assembly, a controller, an electrical connector and associated wiring in accordance to one example of the present disclosure; [0012] FIG. 2 is a front perspective view of an evaporative emissions control system including a vent shut-off assembly configured with solenoids according to one example of the present disclosure;

[0013] FIG. 3 is an exploded view of the evaporative emissions control system of FIG.

2;

[0014] FIG. 4A is a table illustrating operating conditions for the poppet valve assembly shown in FIG. 4B; [0015] FIG. 4B is a cross-sectional view of the poppet assembly during the conditions shown in FIG. 4A;

[0016] FIG. 5A is a table illustrating operating conditions for the poppet valve assembly shown in FIG. 5B;

[0017] FIG. 5B is a cross-sectional view of the poppet assembly during the conditions shown in FIG. 5A;

[0018] FIG. 6A is a table illustrating operating conditions for the poppet valve assembly shown in FIG. 6B;

[0019] FIG. 6B is a cross-sectional view of the poppet assembly during the conditions shown in FIG. 6A;

[0020] FIG. 7A is a table illustrating operating conditions for the poppet valve assembly shown in FIG. 7B;

[0021] FIG. 7B is a cross-sectional view of the poppet assembly during the conditions shown in FIG. 7A;

[0022] FIG. 8A is a first cross-sectional view of the poppet assembly during the conditions shown in FIGS 4A and 4B;

[0023] FIG. 8B is a second cross-sectional view of the poppet assembly during the conditions shown in FIGS 4A and 4B;

[0024] FIG. 9A is a first cross-sectional view of the poppet assembly during the conditions shown in FIGS 5A and 5B;

[0025] FIG. 9B is a second cross-sectional view of the poppet assembly during the conditions shown in FIGS 5A and 5B;

[0026] FIG. 10A is a first cross-sectional view of the poppet assembly during the conditions shown in FIGS 6A and 6B;

[0027] FIG. 10B is a second cross-sectional view of the poppet assembly during the conditions shown in FIGS 6A and 6B;

[0028] FIG. 11A is a first cross-sectional view of the poppet assembly during the conditions shown in FIGS 7A and 7B;

[0029] FIG. 11 B is a second cross-sectional view of the poppet assembly during the conditions shown in FIGS 7A and 7B; [0030] FIG. 12A is a cross-sectional view of the vent shut-off assembly taken through a pump and shown with a push pin in an extended position;

[0031] FIG. 12B is a cross-sectional view of the vent shut-off assembly taken through the pump and shown with the push pin in a depressed position;

[0032] FIG. 13A is a perspective view of the pump;

[0033] FIG. 13B is an exploded perspective view of the pump of FIG. 13A;

[0034] FIG. 14A is a bottom view of a vent shut-off assembly constructed in accordance to another example of the present disclosure;

[0035] FIG. 14B is a cross-sectional view of the vent shut-off assembly of FIG. 14A taken along lines 14B-14B;

[0036] FIG. 15A is a front perspective view of the vent shut-off assembly of FIG. 14A;

[0037] FIG. 15B is a cross-sectional view of the vent shut-off assembly of FIG. 15A taken along lines 15B-15B;

[0038] FIG. 15C is a cross-sectional view of the vent shut-off assembly of FIG. 15A taken along lines 15C-15C;

[0039] FIG. 15D is a cross-sectional view of the vent shut-off assembly of FIG. 15A taken along lines 15D-15D;

[0040] FIG. 16 is a cross-sectional view of the vent shut-off assembly of FIG. 15A taken along lines 16-16;

[0041] FIG. 17 is an exploded perspective view of a plunger assembly of the vent shut off assembly of FIG. 14A;

[0042] FIG. 18 is an exploded perspective view of a camshaft assembly of the vent shut-off assembly of FIG. 14A;

[0043] FIG. 19A is a first perspective view of a plunger assembly of the vent shut-off assembly of FIG. 14A;

[0044] FIG. 19B is a second perspective view of the plunger assembly of FIG. 19A; [0045] FIG. 19C is a sectional view of the plunger assembly of FIG. 19A;

[0046] FIG. 20 is a schematic illustration of a fuel tank system having an evaporative emissions control system including a vent shut-off assembly, a controller, an electrical connector and associated wiring in accordance to one example of the present disclosure; [0047] FIG. 21 is a front perspective view of an evaporative emissions control system including a vent shut-off assembly configured with solenoids according to one example of the present disclosure;

[0048] FIG. 22 is an exploded view of the evaporative emissions control system of FIG. 21;

[0049] FIG. 23 is a perspective view of a fuel tank system having a vent shut-off assembly and configured for use on a saddle fuel tank according to another example of the present disclosure and shown with the fuel tank in section view;

[0050] FIG. 24 is a perspective view of the vent shut-off assembly of the fuel tank system of FIG. 23;

[0051] FIG. 25 is a top perspective view of a vent shut-off assembly constructed in accordance to additional features of the present disclosure;

[0052] FIG. 26 is a bottom perspective view of the vent shut-off assembly of FIG. 25;

[0053] FIG. 27 is a sectional view of the vent shut-off assembly of FIG. 25 taken along lines 27-27;

[0054] FIG. 28 is a sectional view of the vent shut-off assembly of FIG. 25 taken along lines 28-28;

[0055] FIG. 29 is a front perspective view of a vent shut-off assembly constructed in accordance to another example of the present disclosure;

[0056] FIG. 30 is a sectional view of the vent shut-off assembly of FIG. 29 taken along lines 30-30;

[0057] FIG. 31 is a sectional view of the vent shut-off assembly of FIG. 29 taken along lines 31-31 ;

[0058] FIG. 32 is an exploded view of the vent shut-off assembly of FIG. 29;

[0059] FIG. 33 is a schematic illustration of an evaporative emissions control system according to the present disclosure;

[0060] FIG. 34 is a schematic illustration of an exemplary reed switch configuration used according to the instant disclosure;

[0061] FIG. 35 is an exemplary reed switch configuration according to one example of the present disclosure having a first magnet and shown with the cam in a first position corresponding to the valve being closed; [0062] FIG. 36 is an exemplary reed switch configuration of FIG. 35 and shown with the cam in a second position and with the valve being moved to a position corresponding to a small orifice;

[0063] FIG. 37 is an exemplary reed switch configuration of FIG. 35 and shown with the cam in a third position and with the valve being moved to a position corresponding to a large orifice;

[0064] FIG. 38 is an exemplary reed switch configuration according to another example of the present disclosure having a second magnet, smaller than the first magnet of FIG. 35 and shown with the cam in a first position corresponding to the valve being closed;

[0065] FIG. 39 is an exemplary reed switch configuration of FIG. 38 and shown with the cam in a second position and with the valve being moved to a position corresponding to a small orifice;

[0066] FIG. 40 is an exemplary reed switch configuration of FIG. 38 and shown with the cam in a third position and with the valve being moved to a position corresponding to a large orifice;

[0067] FIG. 41 is a partial perspective view of a vent shut-off assembly and shown identifying various home features adapted for use with a direct current (DC) motor according to various examples of the present disclosure;

[0068] FIG. 42 is a perspective view of a cam gear, gear assembly and gear plate assembly having a stopper configuration according to one example of the present teachings;

[0069] FIG. 43 is a side perspective view of the cam plate and gear plate of FIG. 42; and

[0070] FIG. 44 is an exploded view of the cam plate and gear plate of FIG. 43.

DETAILED DESCRIPTION

[0071] 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. The fuel tank 12 can define a vapor dome 18 generally at an upper portion of the fuel tank 12. 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.

[0072] 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.

[0073] The evaporative emissions control system 20 includes a vent shut-off assembly 22, a manifold assembly 24, a liquid trap 26, a control module 30, a purge canister 32, a first vapor tube or vent line 40, a second vapor tube or vent line 42, a third vapor tube or vent line 43, an electrical connector 44, a fuel delivery module (FDM) flange 46 and a fuel fill level sensor assembly such as a float level sensor assembly 48. The first vapor tube 40 can terminate at a vent opening or liquid vapor discriminating (LVD) valve 41A arranged at a top corner of the fuel tank 12. Similarly, the second vapor tube 42 can terminate at a vent opening or LVD valve 41 B arranged at a top corner of the fuel tank 12. The third vapor tube 43 can terminate at a vent opening or LVD valve 41 C arranged at a top of the fuel tank 12. All of the vent openings 41A-41C can terminate at a vapor dome 18. Each of the LVD valves 41 A, 41 B and 41 C are configured to permit vapor to pass from the vapor space 18 to the vent shut-off assembly 22 while inhibiting liquid fuel from entering and passing into the vent shut-off assembly.

[0074] In one configuration, the first, second and third vapor tubes 40, 42 and 43 can merge at a union 47. From the union 47, a vent line connection 49 connects with vent line port 50 defined on the vent shut-off assembly 22. In other examples, some or all of the vapor tubes 41 , 42 and 43 can have a dedicated input port into the vent shut-off assembly 22. In one example, the manifold assembly 24 can be defined within the vent shut-off assembly 22 downstream of the vent line port 50 (or equivalent porting that accepts the respective vapor tubes 41 , 42 and 43).

[0075] As will become appreciated from the following discussion, the vent shut-off assembly 22 can take many forms. In the examples discussed herein, the vent shut-off assembly 22 has an actuator assembly that is configured as a cam actuated system. However, other configurations suitable to selectively open and close vent line port 50 are contemplated including, but not limited to, other mechanical systems, solenoid systems, hydraulic systems, magnetic systems and combinations thereof.

[0076] The control module 30 can further include or receive inputs from system sensors, collectively referred to at reference 60. The system sensors 60 can include a tank pressure sensor 60A that senses a pressure of the fuel tank 12, a canister pressure sensor 60B that senses a pressure of the canister 32, a temperature sensor 60C that senses a temperature within the fuel tank 12, a tank pressure sensor 60D that senses a pressure in the fuel tank 12 and a vehicle grade sensor and or vehicle accelerometer 60E that measures a grade and/or acceleration of the vehicle. It will be appreciated that while the system sensors 60 are shown as a group, that they may be located all around the fuel tank system 10. 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).

[0077] The vent shut-off assembly 22 can be configured to control a flow of fuel vapor between the fuel tank 12 and the purge canister 32. The purge canister 32 is 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. As will become appreciated from the following discussion, the control module 30 can send signals to the vent shut-off assembly 22 based on operating conditions such as provided by the sensors 60 to open and close venting from the fuel tank 12 to the purge canister 32. [0078] With additional reference to FIGS. 2 and 3, the vent shut-off assembly 22 will be further described. The vent shut-off assembly 22 generally comprises a main housing 70, a top housing 72 having a canister line port 73, a poppet valve assembly 74, a cam assembly 76, a motor 78 and a pump 80. The motor 78 and the cam assembly 76 can collectively define an actuator assembly 81. The main housing 70 and the top housing 72 can collectively define a chamber that includes the manifold assembly 24. The main housing 70 can define a poppet assembly receiving bore 84 and a pump outlet opening 88. The poppet assembly receiving bore 84 leads to the vent line port 50 and receives the poppet valve assembly 74. The pump outlet opening 88 generally mounts the pump 80 and provides an outlet for pumping liquid out of the main housing 70 as will be described in detail herein. A vent line 89 can be fluidly connected between the canister line port 73 of the vent shut-off assembly 22 and the canister 32.

[0079] The cam assembly 76 generally includes a first or poppet cam 90 and a second or pump cam 92. The first and second cams 90, 92 are mounted for rotation with a cam shaft 94. A gear 96 is meshingly engaged with a complementary gear (not shown) extending from the motor 78. In other examples the gear 96 can be directly coupled for rotation with a motor drive shaft. The first cam 90 (see FIG. 8A) generally includes a cam surface 100 having a generally high lift surface 102 and a low lift surface 104. The second cam 92 (FIG. 12A) generally includes lift lobes 112, 114 separated by a valley 116. As will become appreciated herein, movement of the cam 92 causes a push pin 118 extending from the pump 80 to translate along its axis as it slidably negotiates along the cam 92 between the lift lobes 112, 114 and the valley 116 causing the pump 80 to pump liquid fuel out of the main housing 70. The push pin 118 is urged into engagement with the cam 92 by a pin biasing member 119.

[0080] With additional reference now to FIG. 4B, the poppet valve assembly 74 will be further described. The poppet valve assembly 74 includes a poppet 120, a disk 122 that supports a seal member 124, a pin 130, a retainer 132 and a poppet carrier 136. A first biasing member 140 is biased between the poppet 120 and the carrier 136. A second biasing member 144 is biased between the disk 122 and the retainer 132. A third biasing member 146 is biased between the retainer 132 and a collar 150 on the pin 130. In some examples, the third biasing member 146 may be omitted as the first and second biasing members 140 and 144 may perform such function. The seal member 124 includes an inner lip seal 154 and an outer lip seal 156.

[0081] As will become appreciated from the following discussion, the poppet valve assembly 74 will be described as moving between fully open and closed positions for achieving various operating functions. However, the poppet valve assembly 74 and other components (such as the disk 122) can move to attain positions intermediate “fully open” and “fully closed”. In this regard, it may be desirable, based on operating conditions, to vent the fuel tank 12 to the carbon canister 30 a predetermined amount between fully open and fully closed.

[0082] In general, the poppet valve 74 allows the vent shut-off assembly 22 to operate in various states, depending on operating conditions, to allow vapor to flow along a first path A (from the fuel tank 12 to the carbon canister 32) or a second path B (from the carbon canister 32 to the fuel tank 12). In one operating condition, vapor that enters at least one of the LVD valves 41 A, 41 B, 41 C passes along at least one of the vapor lines 40, 42, 43 and enters the vent shut-off assembly 22. The operating state of the poppet valve 74, as described herein, allows the vapor to pass therethrough and out of the canister line port 73 to the carbon canister 32 (see flow path A, FIG. 2). Flow path A is desirable alleviate high pressure within the vapor space 18 of the fuel tank. Flow path A can also be desirable during a refueling event or other operating conditions that may cause pressure to rise above a threshold. As will become appreciated herein, the poppet valve 74 can be commanded to move (by the controller 30, FIGS. 4A, 4B) to achieve flow path A or, can automatically move to achieve flow path A (over pressure relief condition, FIGS. 6A, 6B). In another operating condition, fresh air is permitted to pass from the carbon canister 32, into the vent shut-off assembly 22. The operating state of the poppet valve 74 allows that fresh air to exit the vent shut-off assembly 22 through the vent line port 50 and backflow into the vapor space 18 through at least one of the LVD valves 41 A, 41 B, 41 C. Flow path B is desirable to alleviate an undesirable vacuum condition within the vapor space 18 of the fuel tank 12.

[0083] With specific reference now to FIGS. 4A, 4B, 8A and 8B the poppet valve assembly 74 is shown during normal operation in a fully open position. Explained further, the first cam 90 is rotated to a position wherein the high lift surface 102 urges the pin 130 to be depressed or translated leftward as viewed in the FIGS. Translation of the pin 130 causes the poppet 120 to be lifted off of sealing engagement with the inner lip seal 154 of the seal member 124 and into the bias of the first biasing member 140. When the poppet 120 is in the open position, the vapor flow is permitted along flow path A into the vent line port 50 and out of the canister port 73. Fuel vapor from the vapor space 18 is caused to be vented to the canister 32.

[0084] With specific reference now to FIGS. 5A, 5B, 9A and 9B the poppet valve assembly 74 is shown during normal operation in a fully closed position. Explained further, the first cam 90 is rotated to a position wherein the low lift surface 104 aligned with the pin 130 such that bias of the first biasing member 140 causes the pin to be translated rightward as viewed in the FIGS. Translation of the pin 130 rightward causes the poppet 120 to attain a sealing engagement with the inner lip seal 154 of the seal member 124. When the poppet 120 is in the closed position, the vapor flow is inhibited from flowing into the vent line port 50 and out of the canister port 73. Fuel vapor from the vapor space 18 is precluded from venting to the canister 32. Flow along either of flow paths A or B is inhibited.

[0085] With reference now to FIGS. 6A, 6B, 10A and 10B, the poppet valve assembly 74 is shown during an over pressure relief (OPR) condition. In an OPR condition, pressure within the vapor space 18 of the fuel tank 18 has exceeded a threshold wherein vapor pressure in the fuel tank 12 is great enough to cause the seal member 124 to be lifted off of a sealed position with the carrier 136. In one example, the threshold can be around 14kPa for a conventional fuel vehicle and around 37kPa for a pressurized/hybrid vehicle. Explained further, the seal member 124 is caused to translate rightward as viewed in the FIGS such that the outer lip seal 156 moves off of a sealed relationship with the carrier 136. The outer lip seal 156 acts as an OPR seal. In the OPR condition, fuel vapor from the vapor space 18 is caused to flow along flow path A and be vented to the canister 32. Notably, the seal member 124 can move rightward in an OPR condition without any command from the controller 30.

[0086] With reference now to FIGS. 7A, 7B, 11 A and 11 B, the poppet valve assembly 74 is shown during an over vacuum relief (OVR) condition. In an OVR condition, pressure within the vapor space 18 of the fuel tank 18 has dropped below a threshold wherein vapor pressure in the fuel tank is low enough to cause a vacuum wherein the poppet 120 is lifted off of sealing engagement with the inner lip seal 154 of the seal member 124 and into the bias of the first biasing member 140. When the poppet 120 is in the open position, the vapor flow is permitted to equalize pressures. In other words, vapor is permitted to flow along flow path B (from the canister 32 through the canister line 89) out of the vent line port 50 and into the vapor space 18. Notably, the poppet 120 can move leftward in an OVR condition without any command from the controller 30.

[0087] With reference now to FIGS. 12A - FIG. 14, the pump 80 will be further described. The pump 80 is configured to pump liquid fluid out of the vent shut off assembly 22. As will become appreciated, rotation of the cam assembly 76 (FIG. 3) ultimately actuates the pump 80. The pump 80 generally includes a piston housing 210, a piston 212, a check valve 220, a check valve housing 222 and a cap 226. The push pin 118 extends through a spring cap 230, a pump spring 232 and a bearing assembly 240 having bearings 242 and 244.

[0088] The push pin 118 further extends into the piston housing 210 and is coupled to the piston 212. In particular, the push pin 118 defines an annular recess 250 that receives a snap ring 252 thereat. The snap ring 252 can be inserted through a window 258 defined in the piston 212 to engage the push pin 118. The push pin 118 therefore engages the cam 92 on a first end and is fixed for translation with the piston on a second end. A seal 260 is received around an annular surface of the piston 212. The seal 260 slidably translates along an inner diameter 264 (FIG. 12A) of the piston housing 210 during pumping. An umbrella seal assembly 270 having an outer seal member 272 and an inner seal member 274 is disposed on an outboard end of the piston 212.

[0089] The piston housing 210 defines a housing window 266. The housing window 266 allows liquid fuel to enter the piston housing 210 where it can be pumped out of the vent shut off assembly 22. The window 266 can also be used to gain access to the pin 118 when assembling the snap ring 252 at the annular recess 250.

[0090] The check valve 220 can cooperate with the check valve housing 222 and the cap 224 to permit liquid fuel from exiting the check valve housing 222 (out of the vent shut off assembly 22) while inhibiting liquid fuel from entering the vent shut off assembly 22 (through the check valve housing 222). The check valve 220 can take many forms for accomplishing one way fluid flow. In this regard, the specific geometry shown in the FIGS is merely exemplary and other check valves may be used within the scope of this disclosure.

[0091] Operation of the pump 80 will now be described according to one exemplary method of operation. When the lift lobes 112 and 114 of the second cam 92 are aligned with the push pin 118 of the pump 80, fluid that may have passed through the LVD valves 41 A, 41 B and 41 C, to be pumped out of the housing 70. When the valley 116 is aligned with the push pin 118, the biasing member 232 urges the push pin 118 to retract. When the push pin moves from the location shown in FIG. 12A to the position shown in FIG. 12B, liquid fuel in the piston housing 210 is urged by the piston 212 to be expelled into the check valve housing 222 where the check valve 220 permits the liquid fuel to exit the check valve housing 222 and ultimately the vent shut off assembly 22. The pump 80 can be a piston pump or any pump suitable to pump liquid fuel out of the vent shut off assembly 22. By way of example only, the pump can be configured to pump 1-3 cubic centimeters of liquid fuel per cycle and have a maximum pump rate of around 8.3 cubic centimeters per minute.

[0092] 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 FLVV’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, vent shut-off assembly 22, manifold 24, 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 other components such as the control module 30 and/or the electrical connector 44. In other configurations, the fresh air line of the canister 32 and a 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. [0093] Turning now to FIGS. 14A-15A and 18, a vent shut-off assembly constructed in accordance to additional features of the present disclosure is shown and generally identified at reference 522. As will become appreciated from the following discussion, the vent shut off assembly 522 can be configured for use with a fuel tank for a hybrid vehicle. A fuel tank system for a hybrid vehicle can include a fuel tank isolation valve (FTIV) that includes built in OPR and OVR. The vent shut-off assembly 522 according to the present disclosure incorporates OPR and OVR. In this regard, the vent shut-off assembly 522 can be used on fuel tanks configured for use with hybrid powertrains. As will become appreciated from the following discussion, the vent shut-off assembly 522 is similar to the vent shut-off assembly 22 however the vent shut-off assembly 522 has dedicated cams and poppets for each of the LVD valves 41 A, 41 B and 41 C.

[0094] The vent shut-off assembly 522 includes a main housing 502 that at least partially houses an actuator assembly 510. A canister vent line (not shown but see canister vent line 89, FIG. 1) routs to the canister (see canister 32, FIG. 1). The vent shut-off assembly 522 includes a cam assembly 530. The cam assembly 530 includes a cam shaft 532 that includes cams 534, 536 and 538. The cam shaft 532 is rotatably driven by a motor 540 and can be supported in the housing 502 on opposite ends by grommets 542 (FIG. 18). In the example shown the motor 540 is received in the housing 502. The motor 540 is a direct current motor that directly drives the camshaft 532. Other configurations are contemplated. The cams 534, 536 and 538 rotate to interact with respective plunger assemblies (or poppet valve assemblies) 544, 546 and 548 to open and close valves 554, 556 and 558, respectively. The valves 554, 556 and 558 open and close to selectively deliver vapor through ports 564, 566 and 568, respectively. In one example the motor 540 can alternately be a stepper motor. An active drain liquid trap (ADLT) 570 can be provided on the housing 502.

[0095] As will be described herein, each of the plunger assemblies 544, 546 and 548 are configured as poppet valves with spring return. With spring return, these plunger assemblies 544, 564 and 548 provide a pressure relief function. In other words, if a pressure experienced on one side of the poppet valve is large enough to overcome a bias of an oppositely acting spring, the valve will open to relieve the pressure.

[0096] With reference now to FIG. 17, a plunger assembly 544 is shown in exploded view. Description of the plunger assembly 544 will now be explained with the understanding that the plunger assemblies 546 and 548 are similarly constructed. The plunger assembly 544 includes a stem assembly 600, a roller 606, an O-ring 610, a plunger housing 620, a first biasing member 624 and a collar 630. The stem assembly 600 can include a seal 632 disposed around a stem body 634.

[0097] As shown in FIGS. 19A-19C, the plunger sub-assembly 544 can also include an OPR check valve 640. The OPR check valve 640 can include a ball 644, a second biasing member 646 and a disk 648. During operation, the seal 632 of the plunger assembly 544 is normally sealed against a seat 652 on the plunger housing 620. No vapor can pass through plunger assembly 544 in the sealed position. The first biasing member 624 will urge the collar 630 upward (as viewed from FIG. 19C) urging the stem body 634 upward and the seal 632 against the seat 652. It is appreciated that the first biasing member 624 is permitted to urge the collar 630 when the cam 534 is not urging the roller 606 downward. In other words, the cam 534 is sufficiently in a no lift position. If enough pressure builds against an upper surface (as viewed in FIG. 19C) of the collar 630 to overcome the bias of the first biasing member 624, the plunger assembly 544 can open by moving the stem assembly 600 downward and urging the seal 632 off of the seat 652.

[0098] If a predetermined pressure is reached in the vapor dome within the fuel tank (see fuel tank 12, FIG. 1), the OPR check valve 640 will open. Specifically, the ball 644 will urge the second biasing member 646 upward. As the ball 644 moves upward, the ball 644 moves off of a ball seat 664 on the stem body 634 allowing fuel vapor to be relieved from the vapor dome of the fuel tank through passages 660 (FIG. 19B) of the stem body 634, around the ball 644 and through a corresponding passage 670 (FIG. 19C) in the disk 648. The passages 660 can be formed anywhere on the stem body 634. In sum, the plunger assembly 544 can incorporate an OPR/OVR relief function in both directions to relieve pressure on opposite ends of the plunger assembly 544. In other advantages, the OPR/OVR relief function is mechanically operable independent of power supply. In this regard, the OPR/OVR relief will work subsequent to power loss in the vehicle.

[0099] In some examples, the OPR check valve functionality can be incorporated on only the plunger assembly 544. In other examples, an OPR check valve can be additionally or alternatively incorporated on the plunger assemblies 546 and 548. In other arrangements the OPR/OVR functionality can be incorporated elsewhere on the vent shut-off assembly 522 such as through the housing 502. In yet other configurations, the OPR/OVR mechanism can be provided as a snorkel out of the housing 502. The snorkel can be routed to the center of the fuel tank and most likely to always see vapor. In another configuration, the OPR/OVR mechanism can be incorporated into a vapor line leaving the fuel tank downstream of the in-line liquid vapor discriminating (LVD) valve that is part of the vent shut-off assembly 522. The OPR/OVR can also be incorporated into the LVD that is part of the vent shut-off assembly 522. The OPR/OVR can be incorporated at the exit of the ADLT 570. As explained above, the vent shut-off assembly 522 provides an OVR function at each of the plunger assemblies 544, 546 and 548.

[00100] With reference to FIG. 20, a fuel tank system constructed in accordance to one example of the present disclosure is shown and generally identified at reference number 1010. The fuel tank system 1010 can generally include a fuel tank 1012 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 1014. The fuel pump 1014 can be configured to deliver fuel through a fuel supply line 1016 to a vehicle engine. An evaporative emissions control system 1020 can be configured to recapture and recycle the emitted fuel vapor. As will become appreciated from the following discussion, the evaporative emissions control system 1020 provides an electronically controlled module that manages the complete evaporative system for a vehicle.

[00101] The evaporative emissions control system 1020 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 1020 may also be compatible with pressurized systems including those associated with hybrid powertrain vehicles.

[00102] The evaporative emissions control system 1020 includes a vent shut-off assembly 1022, a manifold assembly 1024, a liquid trap 1026, a control module 1030, a purge canister 1032, an energy storage device 1034, a first vapor tube 1040, a second vapor tube 1042, an electrical connector 1044, a fuel delivery module (FDM) flange 1046 and a float level sensor assembly 1048. The first vapor tube 1040 can terminate at a vent opening 1041A that may include a baffle arranged at a top corner of the fuel tank 1012. Similarly, the second vapor tube 1042 can terminate at a vent opening 1041B that may include a baffle arranged at a top corner of the fuel tank 1012.

[00103] In one example, the manifold assembly 1024 can include a manifold body 1049 (FIG. 22) that routes venting to an appropriate vent tube 1040 and 1042 (or other vent tubes) based on operating conditions. As will become appreciated from the following discussion, the vent shut-off assembly 1022 can take many forms such as electrical systems including solenoids and mechanical systems including DC motor actuated cam systems.

[00104] Turning now to FIGS. 21 and 22, a vent shut-off assembly 1022A constructed in accordance to one example of the present disclosure is shown. As can be appreciated, the vent shut-off assembly 1022A can be used as part of an evaporative emissions control system 1020 in the fuel tank system 1010 described above with respect to FIG. 20. The vent shut-off assembly 1022A includes two pair of solenoid banks 1050A and 1050B. The first solenoid bank 1050A includes first and second solenoids 1052A and 1052B. The second solenoid bank 1050B includes third and fourth solenoids 1052C and 1052D. [00105] The first and second solenoids 1052A and 1052B can be fluidly connected to the vapor tube 1040. The third and fourth solenoids 1052C and 1052D can be fluidly connected to the vapor tube 1042. The control module 1030 can be adapted to regulate the operation of the first, second, third and fourth solenoids 1052A, 1052B, 1052C and 1052D to selectively open and close pathways in the manifold assembly 1024, in order to provide over-pressure and vacuum relief for the fuel tank 1012. The evaporative emissions control assembly 1020 can additionally comprise a pump 1054, such as a venturi pump and a safety rollover valve 1056. A conventional sending unit 1058 is also shown.

[00106] The control module 1030 can further include or receive inputs from system sensors, collectively referred to at reference 1060. The system sensors 1060 can include a tank pressure sensor 1060A that senses a pressure of the fuel tank 1012, a canister pressure sensor 1060B that senses a pressure of the canister 1032, a temperature sensor 1060C that senses a temperature within the fuel tank 1012, a tank pressure sensor 1060D that senses a pressure in the fuel tank 1012 and a vehicle grade sensor and or vehicle accelerometer 1060E that measures a grade and/or acceleration of the vehicle. It will be appreciated that while the system sensors 1060 are shown as a group, that they may be located all around the fuel tank system 1010.

[00107] The control module 1030 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 vent shut-off assembly 1022 and manifold assembly 1024 can be configured to control a flow of fuel vapor between the fuel tank 1012 and the purge canister 1032. The purge canister 1032 adapted to collect fuel vapor emitted by the fuel tank 1012 and to subsequently release the fuel vapor to the engine. The control module 1030 can also be configured to regulate the operation of evaporative emissions control system 1020 in order to recapture and recycle the emitted fuel vapor. The float level sensor assembly 1048 can provide fill level indications to the control module 1030.

[00108] When the evaporative emissions control system 1020 is configured with the vent shut-off assembly 1022A, the control module 1030 can close individual solenoids 1052A-1052D or any combination of solenoids 1052A-1052D to vent the fuel tank system 1010. For example, the solenoid 1052A can be actuated to close the vent 1040 when the float level sensor assembly 1048 provides a signal indicative of a full fuel level state. While the control module 1030 is shown in the figures generally remotely located relative to the solenoid banks 1050A and 1050B, the control module 1030 may be located elsewhere in the evaporative emissions control system 1020 such as adjacent the canister 1032 for example. [00109] With continued reference to FIGS. 20-22, additional features of the evaporative emissions control system 1020 will be described. In one configuration, the vent tubes 1040 and 1042 can be secured to the fuel tank 1012 with clips. The inner diameter of the vent tubes 1040 and 1042 can be 3-4mm. In some examples, the poppet valve assembly or cam lobes will determine smaller orifice sizes. The vent tubes 1040 and 1042 can be routed to high points of the fuel tank 1012. 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.

[00110] As identified above, the evaporative emissions control system 1020 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 1020 of the instant disclosure can include in-tank valves such as GW’s and FLVV’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 1030, vent shut-off assembly 1022, manifold 1024, solenoid banks 1050A, 1050B and associated electrical connector 1044. Various other components may be modified to accommodate the evaporative emissions control system 1020 including the fuel tank 1012. For example, the fuel tank 1012 may be modified to eliminate valves and internal lines to pick-up points. The flange of the FDM 1046 may be modified to accommodate other components such as the control module 1030 and/or the electrical connector 1044. In other configurations, the fresh air line of the canister 1032 and a dust box may be modified. In one example, the fresh air line of the canister 1032 and the dust box may be connected to the control module 1030.

[00111] Turning now to FIGS. 23 and 25, a fuel tank system 1010A constructed in accordance to another example of the present disclosure will be described. Unless otherwise described, the fuel tank system 1010A can include an evaporative emissions control system 1020A that incorporate features described above with respect to the fuel tank system 1010. The fuel tank system 101 OA is incorporated on a saddle type fuel tank 1012A. A vent shut-off assembly 1022A1 can include a single actuator 1070 that communicates with a manifold 1024A to control opening and closing of three or more vent point inlets. In the example shown, the manifold assembly 1024A routs to a first vent 1040A, a second vent line 1042A and a third vent line 1044A. A vent 1046A routs to the canister (see canister 1032, FIG. 20). A liquid trap and a drain 1054A are incorporated on the manifold assembly 1024A. The fuel tank system 1010A can perform fuel tank isolation for high pressure hybrid applications without requiring a fuel tank isolation valve (FTIV). Further, the evaporative emissions control system 1020A can achieve the highest possible shut-off at the vent points. The system is not inhibited by conventional mechanical valve shut-off or reopening configurations. Vapor space and overall tank height may be reduced.

[00112] Turning now to FIGS. 25 and 26, a vent shut-off assembly 1022B constructed in accordance to another example of the present disclosure will be described. The vent shut-off assembly 1022B includes a main housing 1102 that at least partially houses an actuator assembly 1110. A canister vent line 1112 routs to the canister (see canister 1032, FIG. 20). The actuator assembly 1110 can generally be used in place of the solenoids described above to open and close selected vent lines. The vent shut-off assembly 1022B includes a cam assembly 1130. The cam assembly 1130 includes a cam shaft 1132 that includes cams 1134, 1136 and 1138. The cam shaft 1132 is rotatably driven by a motor 1140. In the example shown the motor 1140 is a direct current motor that rotates a worm gear 1142 that in turn drives a drive gear 1144. The motor 1140 is mounted outboard of the main housing 1102. Other configurations are contemplated. The cams 1134, 1136 and 1138 rotate to open and close valves 1154, 1156 and 1158, respectively. The valves 1154, 1156 and 1158 open and close to selectively deliver vapor through ports 1164, 1166 and 1168, respectively. In one example the motor 1140 can alternately be a stepper motor. In other configurations, a dedicated DC motor may be used for each valve. Each DC motor may have a home function. The DC motors can include a stepper motor, a bi-directional motor, a uni-directional motor a brushed motor and a brushless motor. The home function can include a hard stop, electrical or software implementation, trip switches, hard stop (cam shaft), a potentiometer and a rheostat. [00113] In one configuration the ports 1164 and 1166 can be routed to the front and back of the fuel tank 1012. The port 1164 can be configured solely as a refueling port. In operation, if the vehicle is parked on a grade where the port 1166 is routed to a low position in the fuel tank 1012, the cam 1134 is rotated to a position to close the port 1164. During refueling, the valve 1154 associated with port 1164 is opened by the cam 1134. Once the fuel level sensor 1048 reaches a predetermined level corresponding to a “Fill” position, the controller 1030 will close the valve 1154. In other configurations, the cam 1134, valve 1154 and port 1164 can be eliminated leaving two cams 1136 and 1138 that open and close valves 1156 and 1158. In such an example, the two ports 1168 and 1166 can be 7.5mm orifices. If both ports 1168 and 1166 are open, refueling can occur. If less flow is required, a cam position can be attained where one of the valves 1156 and 1158 are not opened all the way.

[00114] Turning now to FIGS. 29-32, a vent shut-off assembly 1022C constructed in accordance to another example of the present disclosure will be described. The vent shut-off assembly 1022C includes a main housing 1202 that at least partially houses an actuator assembly 1210. A canister vent line 1212 routs to the canister (see canister 1032, FIG. 20). The actuator assembly 1210 can generally be used in place of the solenoids described above to open and close selected vent lines. The vent shut-off assembly 1022C includes a cam assembly 1230. The cam assembly 1230 includes a cam shaft 1232 that includes cams 1234, 1236 and 1238. The cam shaft 1232 is rotatably driven by a motor 1240. In the example shown the motor 1240 is received in the housing 1202. The motor 1240 is a direct current motor that rotates a worm gear 1242 that in turn drives a drive gear 1244. Other configurations are contemplated. The cams 1234, 1236 and 1238 rotate to open and close valves 1254, 1256 and 1258, respectively. The valves 1254, 1256 and 1258 open and close to selectively deliver vapor through ports 1264, 1266 and 1268, respectively. In one example the motor 1240 can alternately be a stepper motor. A drain 1270 can be provided on the housing 1202.

[00115] In one configuration the ports 1264 and 1266 can be routed to the front and back of the fuel tank 1012. The port 1264 can be configured solely as a refueling port. In operation, if the vehicle is parked on a grade where the port 1266 is routed to a low position in the fuel tank 1012, the cam 1236 is rotated to a position to close the port 1266. During refueling, the valve 1254 associated with port 1264 is opened by the cam 1234. Once the fuel level sensor 1048 reaches a predetermined level corresponding to a “Fill” position, the controller 1030 will close the valve 1254. In other configurations, the cam 1234, valve 1254 and port 1264 can be eliminated leaving two cams 1236 and 1238 that open and close valves 1256 and 1258. In such an example, the two ports 1268 and 1266 can be 7.5mm orifices. If both ports 1268 and 1266 are open, refueling can occur. If less flow is required, a cam position can be attained where one of the valves 1256 and 1258 are not opened all the way.

[00116] Turning now to FIG. 33, an evaporative emissions control system constructed in accordance to additional features of the present disclosure is shown and generally identified at reference 1520. The evaporative emissions control system 1520 can be used in place of and/or in conjunction with any of the evaporative emissions control systems described above. The evaporative emissions control system 1520 can be used in a fuel tank 1522 that is configured as a reservoir for holding fuel to be supplied to an internal combustion engine via a fuel delivery system. In this regard, the evaporative emissions control system 1520 can include a controller 1530 that communicates with electronically controlled solenoid vent valves or motor/cam shaft operated vent valves as described above. Such vent valves are referred to generically as “vent valve #1” 1540, “vent valve #2” 1542 and “vent valve #n” 1544.

[00117] It will be appreciated that vent valve #n 1544 is used to denote any combination of vent valves above two vent valves. The vent valves can be disposed at any desired location within the fuel tank 1522 according to application. A three axis accelerometer 1560 senses acceleration in an x, y and z axis. In one configuration, the accelerometer 1560 can be integrated within the plastic structure of the fuel tank 1522.

[00118] A fuel level sensor 1562 provides information indicative of an amount of fuel in the fuel tank. Other sensors collectively referred to at 1564 such as a pressure sensor 1564A, a temperature sensor 1564B and other sensors provide operating information to the controller 1530. A liquid trap 1570 can have a pump such as a piston pump that can selectively pump liquid from the liquid trap 1570. The liquid trap 1570 communicates a liquid level to the controller 1530. The controller 1530 can also receive operating information from each vent valve 1540, 1542 and 1544 such as current drawn and a position of each valve 1540, 1542 and 1544 as discussed herein.

[00119] The evaporative emissions control system 1520 includes a position sensing assembly collectively identified at reference 1600 (FIG. 33). The position sensing assembly 1600 includes a first position sensor assembly 1610 configured on the first vent valve 1540, a second position sensor assembly 1612 configured on the second vent valve 1542 and a third position sensor assembly 1614 configured on vent valve 1544. Each of the position sensor assemblies 1610, 1612 and 1614 provide valve position feedback for control and diagnostics to the controller 1530. In some other arrangements an encoder is used to determine a position of the valves. The position sensing assembly 1600 may be used instead of an encoder while realizing a cost savings.

[00120] In one example of the present disclosure, a hard stop may be implemented to determine valve position. Exemplary hard stop implementations are shown at FIGS. 42 - 44. In this regard, a mechanical stop can be used to calibrate a position at the beginning and thereafter keep track of the angle change (of the camshaft; see 1232, FIG. 30) with a stepper motor (see for example motor 1240, FIG. 31). Alternatively a brushless direct current (BLDC) motor can be run in step mode. For hard stop configurations, the motor is bidirectional. In another example of the present disclosure, a soft stop may be implemented to determine valve position. A switch can be used to detect and calibrate an initial or home position. The switch can be any suitable switch including, but not limited to, a reed switch, an optical switch, a push button switch. The count of steps or angle change can be determined. A motor with bidirectional motion can reduce the maximum travel time by half between positions as compared to a hard stop. In some examples, the overall current consumption in a soft stop configuration can be lower than a hard stop configuration to detect a home position.

[00121] With particular reference now to FIGS. 34-37, the position sensing assembly 1600 used with the evaporative emissions control system 1520 of the present disclosure will be described. FIG. 34 shows an exemplary circuit 1620 contemplated for use with the present disclosure. Those skilled in the art will appreciate however that the circuit 1620 shown in FIG. 34 is merely exemplary and other circuits may be used within the scope of the present disclosure. [00122] With initial reference to FIG. 35, the position sensor assembly 1610 will be further described. It will be appreciated however that the position sensor assemblies 1612 and 1614 are constructed similarly. The position sensor assembly 1610 includes a first reed switch 1630, a second reed switch 1632 and a magnet 1634. By way of example, the vent valve 1540 is shown to include valve 1254 (see also FIG. 30) that actuates based on rotation of cam 1234 (FIG. 30). In FIG. 35, the magnet 1634 is shown at a position offset from the reed switches 1630 and 1632 resulting in no feedback and an indication that the vent valve 1540 is closed. In general, as the magnet 1634 moves into alignment or proximity to the reed switches 1630 and 1632, feedback is sent to the controller 1530 indicative of a position of the vent valve 1540.

[00123] When the magnet 1634 moves into alignment or proximity to the reed switch 1632 (FIG. 36), a signal is sent to the controller 1530 indicating same and a valve first location is known. In the configuration shown, FIG. 36 corresponds to the vent valve being moved to a small orifice position. Similarly as the magnet 1634 moves into alignment or proximity to the reed switch 1630 a signal is sent to the controller 1530 indicating same and a valve second location is known. In the configuration shown, FIG. 17 corresponds to the vent valve being moved to a large orifice position.

[00124] Turning now to FIGS. 38-40, a position sensor assembly 1610A constructed in accordance to additional features will be further described. In general, the position sensor assembly 1610A includes a magnet 1634A having a reduced size as compared to the magnet 1634. It will be appreciated that the position sensor assemblies 1612 and 1614 can be constructed similarly. The position sensor assembly 1610A includes a first reed switch 1630A, a second reed switch 1632A and the magnet 1634A. By way of example, the vent valve 1540 is shown to include valve 1254 (see also FIG. 30) that actuates based on rotation of cam 1234 (FIG. 30). In FIG. 38, the magnet 1634A is shown at a position offset from the reed switches 1630A and 1632A resulting in no feedback and an indication that the vent valve 1540 is closed. In general, as the magnet 1634A moves into alignment or proximity to the reed switches 1630A and 1632A, feedback is sent to the controller 1530 indicative of a position of the vent valve 1540.

[00125] When the magnet 1634A moves into alignment or proximity to the reed switch 1632A (FIG. 39), a signal is sent to the controller 1530 indicating same and a valve first location is known. In the configuration shown, FIG. 39 corresponds to the vent valve being moved to a small orifice position. Similarly as the magnet 1634A moves into alignment or proximity to the reed switch 1630A a signal is sent to the controller 1530 indicating same and a valve second location is known. In the configuration shown, FIG. 40 corresponds to the vent valve being moved to a large orifice position.

[00126] Turning now to FIG. 41 , additional features of the present disclosure will be described. The DC motor 1140 can be configured for direct drive with the cam shaft 1132. In some examples, such as described above with respect to FIG. 26, intermediate gears may be employed between the motor 1140 and the cam shaft 1132. The position of the cam shaft 1132, and therefore the respective positions of the valves 1154, 1156 and 1158 are known by the controller 1030 after key off or loss of power. In this regard, the DC motor 1140 can be configured with one or more home features whereby the controller 1030 determines the respective open/closed/partially open states of each of the valves 1154, 1156 and 1158. In some examples, the controller 1030 can command the DC motor 1140 to achieve any rotational position of the cam shaft 1132. The DC motor can be a stepper motor, a bi-directional motor, a uni-directional motor a brushed motor or a brushed motor. One or more home features 1702 can include a hard stop on the DC motor 1140, electric software limits configured on the controller 1030, and trip switches. A hard stop can be additionally or alternatively arranged on the cam shaft 1132. A potentiometer or rheostat can be configured on the cam shaft 1132 and/or the DC motor 1140.

[00127] FIGS. 42-44 illustrate another home feature constructed in accordance to another example of the present disclosure and generally identified at reference 1810. The home feature 1810 includes a stopper configuration. The stopper configuration 1810 can be used to calibrate a position at the beginning and thereafter keep track of the angle change. FIG. 42 illustrates a cam gear 1820, a gear assembly 1824 and a gear plate 1830. A gear plate stopper 1834 is formed on the gear plate 1830. The gear plate 1830 supports the cam assembly (see also cam assembly 76, FIG. 3). A cam gear rotational stopper 1840 is formed on the cam gear 1820. A hard stop occurs upon engagement of the cam gear rotational stopper 1840 with the gear plate stopper 1834. Control can determine a homing position at the engagement. In this regard, rotational movement of the 1820, corresponding to engagement of the cam 1820 during opening of the valve can be known. In other words, the cam gear rotational stopper 1840 is configured to engage the gear plate stopper 1834 and inhibit further rotation of that cam gear 1820 corresponding to the home position for the controller. [00128] 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

CLAIMS What is claimed is:

1. An evaporative emissions control system configured to manage venting on a fuel tank system configured to deliver fuel to an internal combustion engine, the evaporative emissions control system comprising: a fuel tank; a first vent tube disposed in the fuel tank; a purge canister adapted to collect fuel vapor emitted by the fuel tank and to subsequently release the fuel vapor to the internal combustion engine; a cam driven tank venting control assembly having a rotary actuator that rotates a cam assembly based on operating conditions, the cam assembly having at least a first cam having a first cam profile configured to selectively open and close a first vent valve associated with the first vent tube based on operating conditions; a controller that communicates with the cam driven tank venting assembly; and a home feature configured to send a signal to the controller indicative of a home position of the vent valve.

2. The evaporative emissions control system of claim 1 wherein the home feature further comprises: a cam gear associated with the first cam, the cam gear including a cam gear rotational stopper disposed thereon; a gear plate that supports the cam assembly, the gear plate including a gear plate stopper disposed thereon; and wherein the cam gear rotational stopper is configured to engage the gear plate stopper and inhibit further rotation of the cam gear corresponding to the home position.

3. The evaporative emissions control system of claim 1 wherein the home feature includes a first position sensor assembly having a first reed switch and a magnet, the first reed switch configured to send a first signal to the controller based on proximity to the magnet.

4. The evaporative emissions control system of claim 3 wherein the first position sensor assembly further includes a second reed switch, the second reed switch configured to send a second signal to the controller based on proximity to the magnet.

5. The evaporative emissions control system of claim 4 wherein the first signal corresponds to the vent valve having a small orifice and the second signal corresponds to the vent valve having a large orifice.

6. The evaporative emission control system of claim 1 wherein the first cam profile has profiles that correspond to at least a fully closed valve position, a fully open position and a partially open position.

7. The evaporative emissions control system of claim 1 , further comprising: a second vent tube disposed in the fuel tank.

8. The evaporative emissions control system of claim 7 wherein the cam assembly further comprises: a second cam having a second cam profile configured to selectively open and close the second vent tube based on operating conditions.

9. The evaporative emissions control system of claim 8 wherein the second cam profile has profiles that correspond to at least a fully closed valve position, a fully open valve position and a partially open valve position.

10. The evaporative emissions control system of claim 9, further comprising a second valve, wherein the second valve selectively opens and closes based on rotation of the second cam.

11. The evaporative emissions control system of claim 10 wherein the first and second valves are poppet valves.

12. The evaporative emissions control system of claim 1 wherein the home feature includes a hard stop comprising one of a potentiometer and rheostat.

13. The evaporative emissions control system of claim 1 wherein the home feature includes a hard stop comprising a stepper motor that senses a home position and keeps track of subsequent steps based on rotation.

14. The evaporative emissions control system of claim 13 wherein the stepper motor is bidirectional.

15. The evaporative emissions control system of claim 1 wherein the home feature comprises a hard stop configured on a cam shaft that supports the cam assembly.

16. The evaporative emissions control system of claim 1 , further comprising a switch that detects and calibrates a home position.

17. The evaporative emissions control system of claim 16 wherein the switch comprises one of a reed switch, an optical switch and a push button switch.

18. A method of operating an evaporative emissions control system configured to manage venting on a fuel tank system, the control system having a cam driven tank venting control assembly including a rotary actuator that rotates a cam assembly based on operating conditions, the cam assembly having a first cam configured to selectively open and close a first vent valve, the method comprising: sending a first signal to a controller based on a magnet having proximity to a first reed switch; and determining a position of the vent valve based on the first signal.

19. The method of claim 18, further comprising: sending a second signal to the controller based on the magnet having proximity to a second reed switch; and determining a position of the vent valve based on the second signal.