WO2018009849A1

WO2018009849A1 - Electronic fuel tank system venting configuration

Info

Publication number: WO2018009849A1
Application number: PCT/US2017/041171
Authority: WO
Inventors: Vaughn Kevin Mills
Original assignee: Eaton Corporation
Priority date: 2016-07-07
Filing date: 2017-07-07
Publication date: 2018-01-11

Abstract

An evaporative emissions control system configured to recapture and recycle emitted fuel vapor on a vehicle fuel tank includes a liquid trap, a first vent tube, a second vent tube and a check valve. The first vent tube is disposed in the fuel tank and extends between a first vent opening and the liquid trap. The second vent tube is disposed in the fuel tank and has a p-trap disposed therein. The second vent tube has a first decreasing elevation portion from the second vent opening to the p-trap and the second increasing elevation portion from the p-trap to the liquid trap. The check valve is disposed at the p-trap trap and is configured to seal the second vent tube when liquid fuel rises above the p-trap and open when liquid fuel recedes below the p-trap.

Description

ELECTRONIC FUEL TANK SYSTEM VENTING CONFIGURATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Patent Application No. 62/475,584 filed on March 23, 2017 and U.S. Patent Application No. 62/359,262 filed on July 7, 2016. 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] An evaporative emissions control system configured to recapture and recycle emitted fuel vapor on a vehicle fuel tank includes a liquid trap, a first vent tube, a second vent tube and a check valve. The liquid trap is configured to drain liquid fuel back to the fuel tank. The first vent tube is disposed in the fuel tank and extends between a first vent opening and the liquid trap. The second vent tube is disposed in the fuel tank and has a p-trap disposed therein. The second vent tube extends between a second vent opening and the liquid trap. The second vent tube has a first decreasing elevation portion from the second vent opening to the p-trap and the second increasing elevation portion from the p-trap to the liquid trap. The check valve is disposed at the p-trap trap and is configured to seal the second vent tube when liquid fuel rises above the p-trap and open when liquid fuel recedes below the p-trap.

[0006] According to additional features, the check valve includes a valve float that moves relative to a valve body based on a fuel level in the fuel tank. The second vent tube defines a drain passage at the check valve. The valve float is caused to rise relative to the valve body and seal the drain passage when liquid fuel rises above the p-trap and is caused to fail relative to the valve body when liquid fuel recedes below the p-trap opening the drain passage allowing liquid fuel to drain through the drain passage into the fuel tank. The fuel tank incorporates a recessed portion in an outer geometry. The p-trap is positioned generally at the recessed portion.

[0007] According to additional features, the evaporative emissions control system includes a first vent valve and a second vent valve. The first vent valve is disposed on the first vent tube and is configured to selectively open and close a first port fluidly coupled to the first vent tube. The second vent valve is disposed on the second vent tube and is configured to selectively open and close a second port fluidly coupled to the second vent tube. A vent shut-off assembly selectively opens and closes the first and second valves to provide overpressure and vacuum relief for the fuel tank. A control module regulates operation of the vent shut-off assembly based on operating conditions. The vent shut-off assembly comprises a cam assembly having a cam shaft that includes a first cam and a second cam. The first and second cams have respective profiles that correspond to at least a fully opened valve position, a fully closed valve position and a partially open valve position. The first and second valves are caused to selectively open and close based on rotation of the respective first and second cams to deliver fuel vapor through the respective first and second vent tubes. An actuator assembly drives the cam assembly. The actuator assembly includes a motor.

[0008] An evaporative emissions control system constructed in accordance to additional features includes a fuel tank, a purge canister, a liquid trap, a first vent line and a baffle. The purge canister is adapted to collect fuel vapor emitted by the fuel tank and to subsequently release the fuel vapor to an engine. The liquid trap is configured to drain liquid from the liquid trap. The first vent line is disposed in the fuel tank and extends between a first vent opening and the liquid trap. The baffle has a tank mounting feature and a connection port. The tank mounting feature is configured to couple the baffle to the fuel tank.

[0009] According to other features, the baffle is one-piece. The baffle is formed of a similar material as the fuel tank. The baffle is formed of high-density polyethylene (HOPE). In another arrangement, the baffle can be formed of a dissimilar material as the fuel tank. The baffle can be formed of thermoplastic polyoxymethyiene (POM). In another configuration, the baffle is formed of polyamide (PA).

[0010] An evaporative emissions control system configured to recapture and recycle emitted fuel vapor on a vehicle fuel tank includes a liquid trap, a first vent tube, a first vent valve, a second vent valve, and a vent shut-off assembly. The liquid trap is configured to drain liquid fuel back to the fuel tank. The first vent tube is disposed in the fuel tank and extends between a first vent opening and the liquid trap. The first vent valve is disposed on the first vent tube and is configured to selectively open and close a first port fluidiy coupled to the first vent tube. The second vent valve is configured to selectively open and close a second port. A vent shut-off assembly selectively opens and closes the first and second valves to provide overpressure and vacuum relief for the fuel tank. The liquid trap, first vent valve, second vent valve and vent shut-off assembly are integrated as a single unit at the second port. The evaporative emissions control system can further include a control module that regulates operation of the vent shut-off assembly based on operating conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0012] 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;

[0013] 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;

[0014] FIG, 3 is an exploded view of the evaporative emissions control system of FIG. 2;

[001 S] FIG. 4 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;

[0016] FIG. 5 is a perspective view of the vent shut-off assembly of the fuel tank system of FIG. 4;

[0017] FIG, 6 is a top perspective view of a vent shut-off assembly constructed in accordance to additional features of the present disclosure;

[0018] FIG. 7 is a bottom perspective view of the vent shut-off assembly of FIG.

6;

[0019] FIG. 8 is a sectional view of the vent shut-off assembly of FIG. 6 taken along lines 8-8;

[0020] FIG. 9 is a sectional view of the vent shut-off assembly of FIG. 6 taken along lines 9-9;

[0021] FIG. 10 is a front perspective view of a vent shut-off assembly constructed in accordance to another example of the present disclosure;

[0022] FIG. 1 1 is a sectional view of the vent shut-off assembly of FIG. 10 taken along lines 1 1-1 1 ; [0023] FIG. 12 Is a sectional view of the vent shut-off assembly of FIG. 10 taken along lines 12-12;

[0024] FIG. 13 is an exploded view of the vent shut-off assembly of FIG. 10;

[0025] FIG. 14 is a schematic illustration of an evaporative emissions control system incorporating a check valve and p-trap constructed in accordance to another example of the present disclosure;

[0026] FIG. 14A is a schematic illustration of the check valve of FIG. 14 shown in an open position (solid line) permitting liquid fuel to drain from a drain passage in the p-trap and a closed position (phantom line) sealing the drain passage;

[0027] FIG. 15 is a side view of a one-piece evaporative baffle having an integrated internal tank mount and vent line connection; and

[0028] FIG. 16 is a schematic illustration of an evaporative emissions control system incorporating a vent shut-off assembly that includes a liquid trap, a vapor vent opening and a baffle thereon.

DETAILED DESCRIPTION

[0029] 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 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.

[0030] The evaporative emissions control system 1020 provides a universal design for ail 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,

[0031] 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 (FD ) flange 1048 and a float level sensor assembly 1048. The first vapor tube 1040 can terminate at a vent opening 1041 A 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 1041 B that may include a baffle arranged at a top corner of the fuel tank 1012.

[0032] in one example, the manifold assembly 1024 can include a manifold body 1049 (FIG. 3) 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.

[0033] Turning now to FIGS. 2 and 3, 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. 1 . 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.

[0034] 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,

[0035] 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 acceierometer 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 ail around the fuel tank system 1010,

[0036] 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,

[0037] 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. [0038] With continued reference to FIGS. 1 -3, 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.

[0039] 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 GVV'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 vaive(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 1048 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.

[0040] Turning now to FIGS. 4 and 5, a fuel tank system 101 OA constructed in accordance to another example of the present disclosure will be described. Unless otherwise described, the fuel tank system 101 OA 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. 1 ). A liquid trap and a drain 1054A are incorporated on the manifold assembly 1024A. The fuel tank system 101 OA 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.

[0041] Turning now to FIGS. 8-7, 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 1 102 that at least partially houses an actuator assembly 1 1 10. A canister vent line 1 1 12 routs to the canister (see canister 1032, FIG. 1 ). The actuator assembly 1 1 10 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 1 130. The cam assembly 1 130 includes a cam shaft 1 132 that includes cams 1 134, 1 136 and 1 138. The cam shaft 1 132 is rotatabiy driven by a motor 1 140. in the example shown the motor 1 140 is a direct current motor that rotates a worm gear 1 142 that in turn drives a drive gear 1 144. The motor 1 140 is mounted outboard of the main housing 1 102. Other configurations are contemplated. The cams 1 134, 1 136 and 1 138 rotate to open and close valves 1 154, 1 156 and 1 158, respectively. The valves 1 154, 1 156 and 1 158 open and close to selectively deliver vapor through ports 1 164, 1 166 and 1 168, respectively. In one example the motor 1 140 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.

[0042] in one configuration the ports 1 164 and 1 188 can be routed to the front and back of the fuel tank 1012. The port 1 164 can be configured solely as a refueling port. In operation, if the vehicle is parked on a grade where the port 1 166 is routed to a low position in the fuel tank 1012, the cam 1 134 is rotated to a position to close the port 1 184. During refueling, the valve 1 154 associated with port 1 164 is opened by the cam 1 134. Once the fuel level sensor 1048 reaches a predetermined level corresponding to a "Fill" position, the controller 1030 will close the valve 1 154. In other configurations, the cam 1 134, valve 1 154 and port 1 164 can be eliminated leaving two cams 1 138 and 1 138 that open and close valves 1 156 and 1 158. In such an example, the two ports 1 168 and 1 186 can be 7.5mm orifices, if both ports 1 188 and 1 186 are open, refueling can occur. If less flow is required, a cam position can be attained where one of the valves 1 156 and 1 158 are not opened all the way.

[0043] Turning now to FIGS. 10-13, 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. 1 ). 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 rotatabiy 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, 1286 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. [0044] In one configuration the ports 1264 and 1286 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 1286 is routed to a low position in the fuel tank 1012, the cam 1238 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 1288 and 1288 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,

[0045] FIG, 14 illustrates a top mount evaporative emissions control system 1310 constructed in accordance to additional features of the present disclosure and incorporated on a fuel tank 1312. Unless otherwise described herein, the evaporative emissions control system 1310 can include similar components as described above with respect to the evaporative emissions control systems described above. The top mount evaporative emissions control system 1310 can include a vent shut-off assembly 1314, such as described above that incorporates a liquid trap 1318. For simplicity, FIG. 14 includes the vent shut-off assembly 1314 and is used to genericaily represent both of the electronically controlled solenoid valve configuration and the motor/cam shaft operated vent valve configuration described above. In this regard, the evaporative emissions control system 1310 can include a controller (see controller 1030) that communicates with electronically controlled solenoid vent valves or motor/cam shaft operated vent valves as described above. The vent shut-off assembly 1314 is mounted generally on an upper portion of the fuel tank 1312 as compared to the vent-shut-off assemblies 1022, 1022A, 1022A1 , 1022B described above that are arranged near the bottom of the fuel tank. The fuel tank 1312 incorporates a recessed portion 1318 into an outer geometry. As is becoming more common, fuel tank geometries can have non-rectangular profiles in an effort to maximize fuel volume while not interfering with vehicle components such as those associated with powertrains including all-wheel-drive powertrains.

[0048] A first vent line or tube 1320 extends between a first vent opening 1322 to the vent shut-off assembly 1314 and liquid trap 1316. A second vent line or tube 1330 extends between a second vent opening 1332 to the vent shut-off assembly 1314 and liquid trap 1316. In one configuration, the first vent line 1320 generally includes a decreasing elevation from the first vent opening 1322 to the vent shut-off assembly 1314 and liquid trap 1316. The second vent line 1330 however includes a first decreasing elevation portion 1336 from the second vent opening 1332 to a check valve 1340, and a second increasing elevation portion 1344 from the check valve 1340 to the vent shut-off assembly 1314 and liquid trap 1316. The check valve 1340 positioned generally at a p-trap portion 1344 of the second vent line 1330. As used herein the term "p-trap" is used to denote a low elevation area of a vent line that has increasing elevation portions extending therefrom. The p-trap portion 1344 generally defines a low elevation portion of the second vent line 1330.

[0047] The check valve 1340 generally includes a valve float 1346 that moves relative to a valve body 1348. The check valve 1340 is configured to seal the second vent line 1330 when submerged. Explained further, when liquid fuel rises above the p-trap portion 1344, the valve float 1346 is caused to rise relative to the valve body 1348 and seal a drain passage 1350 defined in the second vent line 1330 (see phantom line position FIG. 14A). When liquid fuel fails below the p-trap portion 1344, the valve float 1346 is caused to fall relative to the valve body 1348 opening the drain passage 1350 and allowing liquid fuel to drain from the second vent line 1330 through the drain passage 1350 generally along path 1354 and back into the fuel tank 1312. The check valve 1340 therefore opens to clean out residual liquid in the p-trap 1344 when liquid fuel recedes below the p- trap 1344. Addition of the check valve 1340 and p-trap 1344 to a low point in any vent line can clean out the vent line when the fuel recedes and close to maintain the integrity of the vent line as fuel rises, actuating it dosed. In this regard, the geometry of the fuel tank 1312 shown in FIG. 14 is merely exemplary. The check valve 1340 and p-trap 1344 can be positioned at any low point in any vent line to facilitate liquid fuel draining of a vent line extending from the vent shut-off assembly 1314 and liquid trap 1316.

[0048] FIG. 15 illustrates a one-piece baffle 1370 configured for use in an eVap system, such as any of the evaporative emissions control systems described herein and constructed in accordance to additional features. The one-piece baffle 1370 combines the design functions of an eVap baffle into a one-piece molded component. The baffle 1370 includes a tank mounting feature 1352 and a connection port 1374. The connection port 1374 can include a barb or quick connect that couples to a vent line 1380 that leads to an eVap liquid trap (such as incorporated into a vent shut-off assembly described above). The one-piece baffle 1370 includes a vent opening 1382 and various wails and barriers that inhibit liquid fuel from entering the vent line 1380 through the vent opening 1382.

[0049] The baffle 1370 can be formed of high-density polyethylene (HDPE) or a common material as the fuel tank 1378. The mounting feature 1352 can have sacrificial ribs 1384 that are configured to melt to the molten HDPE tank material during a formation process. The baffle feature decreases liquid in-flow to the vent line 1380. The connection port 1374 can take any shape that facilitates coupling to the vent line 1380. in another configuration, the one-piece baffle 1370 can be formed of a dissimilar material from HDPE. Exemplary materials include thermoplastic poiyoxymethy!ene (POM), and/or nylon poiyamide (PA). The mounting feature 1352 can have weep holes that allow molten HDPE tank material to flow through and lock the baffle 1370 to the upper inner surface of the fuel tank 1378.

[0050] FIG. 16 illustrates an evaporative emissions control system 1410 constructed in accordance to additional features. The evaporative emissions control system 1410 includes a fuel tank 1414 having a vent shut-off assembly 1434 and liquid trap 1436. A vapor vent opening (port) 1422 and baffle 1442 can be integrated directly onto the vent shut-off assembly 1434 and liquid trap 1436. The eVap liquid trap 1436 (and vent shut-off assembly 1434) can be mounted on the fuel tank 1414 at any strategic area to act as a vent point. In this regard, the liquid trap 1436, first vent valve (see vent valve 1 156, FIG. 9), second vent valve (see vent valve 1 158, FIG. 9) and vent shut-off assembly 1436 are integrated as a single unit at the second port 1422 (see also port 1 168, FIG. 9). An additional vent line 1450 can lead to a secondary vent point 1452. By incorporating the vent shut-off assembly 1434 and liquid trap 1436 with the vapor vent opening 1422 and baffle 1442, a second vapor line can be eliminated,

[0051] 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 ail such modifications are intended to be included within the scope of the disclosure.

Claims

What is claimed is:

1 , An evaporative emissions control system configured to recapture and recycle emitted fuel vapor on a vehicle fuel tank, the evaporative emissions control system comprising:

a liquid trap configured to drain liquid fuel back to the fuel tank; a first vent tube disposed in the fuel tank and extending between a first vent opening and the liquid trap;

a second vent tube disposed in the fuel tank and having a p-trap disposed therein, the second vent tube extending between a second vent opening and the liquid trap, the second vent tube having a first decreasing elevation portion from the second vent opening to the p-trap and a second increasing elevation portion from the p-trap to the liquid trap; and

a check valve disposed at the p-trap that is configured to seal the second vent tube when liquid fuel rises above the p-frap and open when liquid fuel recedes below the p-trap.

2, The evaporative emissions control system of claim 1 wherein the check valve includes a valve float that moves relative to a valve body based on a fuel level in the fuel tank.

3. The evaporative emissions control system of claim 2 wherein the second vent tube defines a drain passage at the check valve.

4. The evaporative emissions control system of claim 3 wherein the valve float is caused to rise relative to the valve body and seal the drain passage when liquid fuel rises above the p-trap and is caused to fall relative to the valve body when liquid fuel recedes below the p-trap opening the drain passage allowing liquid fuel to drain through the drain passage into the fuel tank.

5. The evaporative emissions control system of claim 1 wherein the fuel tank incorporates a recessed portion in an outer geometry, wherein the p- trap is positioned generally at the recessed portion. 6. The evaporative emissions control system of claim 1 , further comprising:

a first vent valve disposed on the first vent tube that is configured to selectively open and close a first port fluidly coupled to the first vent tube;

a second vent valve disposed on the second vent tube that is configured to selectively open and dose a second port fluidly coupled to the second vent tube;

7. The evaporative emission control system of claim 8, further comprising:

a vent shut-off assembly that selectively opens and closes the first and second valves to provide overpressure and vacuum relief for the fuel tank; and

a control module that regulates operation of the vent shut-off assembly based on operating conditions.

8. The evaporative emissions control system of claim 7 wherein the vent shut-off assembly comprises a cam assembly having a cam shaft that includes a first cam and a second cam. 9. The evaporative emissions control system of claim 8 wherein the first and second cams have respective profiles that correspond to at least a fully opened valve position, a fully closed valve position and a partially open valve position, 10. The evaporative emissions control system of claim 9 wherein the first and second vent valves are caused to selectively open and close based on rotation of the respective first and second cams to deliver fuel vapor through the respective first and second vent tubes.

1 1 . The evaporative emissions control system of claim 10, further comprising an actuator assembly that drives the cam assembly, the actuator assembly including a motor.

12. An evaporative emissions control system comprising:

a fuel tank;

a purge canister adapted to collect fuel vapor emitted by the fuel tank and to subsequently release the fuel vapor to an engine;

a liquid trap that is configured to drain liquid from the liquid trap; a first vent line disposed in the fuel tank and extending between a first vent opening and the liquid trap; and

a baffle having a tank mounting feature and a connection port, the tank mounting feature configured to couple the baffle to the fuel tank.

13. The evaporative emissions control system of claim 12 wherein the baffle is one-piece,

14. The evaporative emissions control system of claim 13 wherein the baffle is formed of a similar material as the fuel tank.

15. The evaporative emissions control system of claim 14 wherein the baffle is formed of high-density polyethylene (HDPE). 18. The evaporative emissions control system of claim 13 wherein the baffle is formed of a dissimilar material as the fuel tank.

17. The evaporative emissions control system of claim 18 wherein the baffle is formed of thermoplastic polyoxymethylene (POM).

18. The evaporative emissions control system of claim 17 wherein the baffle is formed of polyamide (PA).

19. An evaporative emissions control system configured to recapture and recycle emitted fuel vapor on a vehicle fuel tank, the evaporative emissions control system comprising:

a second vent valve that is configured to selectively open and close a second port;

wherein the liquid trap, first vent valve, second vent valve and vent shut-off assembly are integrated as a single unit at the second port.

20. The evaporative emissions control system of claim 19, further comprising: