FIELD

[0001] 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

[0002] 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.

[0003] In some fuel vapor emission control systems, one or more roll over valves (ROV) are configured within the fuel tank and fluidly coupled to a liquid trap by way of one or more fill limit vent valve (FLVV) pick-up tubes. Typically the FLVV’s need to be placed at varying heights to meet refill volume control. Prior art ROV’s are designed to meet all requirements and call for a huge effort to customize for different fuel tanks. They prevent liquid fuel from leaving the tank through the canister port such as by closing the valve when parked at an incline. The FLW placement along with ROV in complex fuel tank shapes makes the task more difficult to provide good refueling performance. Also, there are different ROVs for different tanks adding to excess part numbers, manufacturing and management needs.

[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 first vent tube, a first electronically controlled roll over valve (ROV), and a control module. The first vent tube is disposed in the fuel tank. The first ROV is disposed on the first vent tube and has a first float that is configured to selectively move between an open position and a closed position and close a first vent fluidly coupled to the first vent tube. The control module regulates operation of the first electronically controlled ROV based on operating conditions.

[0006] According to additional features, the first electronically controlled ROV comprises a first solenoid having a coil and an armature. Energization of the first coil causes the armature to translate and the first float to move to the closed position. The electronically controlled ROV selectively and alternatively moves to a closed position in a first mode wherein liquid fuel rises to a predetermined level in the fuel tank causing the first float to rise to a position that closes the first vent. In a second mode the armature translates due to electrical actuation causing the first float to move to the closed position.

[0007] In other features, the evaporative emissions control system further includes a second vent tube disposed in the fuel tank. A second electronically controlled ROV is disposed on the second vent tube and has a second float that is configured to selectively open and close a second vent fluidly coupled to the second vent tube. The control module regulates operation of the second electronically controlled ROV based on operating conditions.

[0008] According to still other features, the first electronically controlled ROV is normally open. The first float comprises a first seal disposed thereon that engages a seat when the first float moves to close the first vent. The first float is configured to translate between the open and closed positions. In another configuration, an arm is coupled for rotation around a pivot axle. Energization of the first coil causes the armature to translate causing the arm to rotate about the pivot axle and urge the first seal into the closed position. The evaporative emissions control system can further include a liquid trap. The first and second vent tubes can be fluidly connected to the liquid trap. A third vent tube can be connected between a purge canister and the liquid trap. A valve can be arranged between the liquid trap and the third vent tube.

[0009] An evaporative emissions control system configured to recapture and recycle emitted fuel vapor on a vehicle fuel tank according to another example of the present disclosure includes a first vent tube, a first electronically controlled roll over valve (ROV), and a control module. The first vent tube is disposed in the fuel tank and fluidly connects to a liquid trap. The first ROV is disposed on the first vent tube and has a first float that is configured to selectively move between an open position and a closed position and close a first vent fluidly coupled to the first vent tube. The control module regulates operation of the first electronically controlled ROV based on operating conditions. The electronically controlled ROV selectively and alternatively moves to a closed position in a first mode wherein liquid fuel rises to a predetermined level within the fuel tank causing the first float to rise to a position that closes the first vent. In a second mode, the first float moves to the closed position due to electrical actuation of the ROV.

[0010] In other features, a canister vapor tube is fluidly connected between the liquid trap and a purge canister. A valve can be arranged between the liquid trap and the canister vapor tube. The valve is configured to open and close based on a signal from the control module. The first electronically controlled ROV is normally open. The first float comprises a first seal disposed thereon that engages a seat when the first float moves to close the first vent. The float is configured to translate between open and closed positions. In another configuration, an arm is coupled for rotation around a pivot axle. Energization of the first coil causes the armature to translate causing the arm to rotate about the pivot axle and urge the first seal into the closed position. A second vent tube can be disposed in the fuel tank and fluidly connected to the liquid trap. A second electronically controlled ROV can be disposed on the second vent tube and have a second float that is configured to selectively open and close a second vent fluidly coupled to the second vent tube. The control module can regulate operation of the second electronically controlled ROV 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 first electronically controlled roll over valve (ROV), a second electronically controlled ROV, a controller, a liquid trap, and a drain pump in accordance to one example of the present disclosure;

[0013] FIG. 2A is a detail view of the first electronically controlled roll over valve (ROV) of FIG. 1 and shown in a normally open position;

[0014] FIG. 2B is a detail view of the ROV of FIG. 2A and shown in a closed position in a first mode due to fuel level rising to a predetermined level;

[0015] FIG. 2C is a detail view of the ROV of FIG. 2A and shown in a closed position in a second mode due to electrical actuation;

[0016] FIG. 3A is a schematic illustration of an electronically controlled ROV constructed in accordance to another example of the present disclosure and shown in a normally open position;

[0017] FIG. 3B is a detail view of the ROV of FIG. 3A and shown in a closed position in a first mode due to fuel level rising to a predetermined level;

[0018] FIG. 3C is a detail view of the ROV of FIG. 3A and shown in a closed position in a second mode due to electrical actuation;

[0019] FIG. 4A is a schematic illustration of an electronically controlled ROV constructed in accordance to another example of the present disclosure and shown in a normally open position;

[0020] FIG. 4B is a detail view of the ROV of FIG. 4A and shown in a closed position in a first mode due to fuel level rising to a predetermined level; and

[0021] FIG. 4C is a detail view of the ROV of FIG. 4A and shown in a closed position in a second mode due to electrical actuation.

DETAILED DESCRIPTION

[0022] Turning now 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 (not particularly shown). The fuel pump can be configured to deliver fuel through a fuel supply line to a vehicle engine. An evaporative emissions control system 20 can be configured to recapture and recycle the emitted fuel vapor. As will become appreciated from the following discussion, the evaporative emissions control system 20 provides an electronically controlled venting that manages the complete evaporative system for a vehicle.

[0023] The evaporative emissions control system 20 includes a vent shut-off assembly 22, a liquid trap 26, a control module 30, a purge canister 32, an active drain 34, a first vapor tube 40 and a second vapor tube 42. The liquid trap 26 and active drain 34 can be collectively referred to as an active drain liquid trap or ADLT. The active drain 34 can be actuated by any suitable configuration such as a piston for example. The control module 30 receives input from a fuel level sensor, valve states, an accelerometer and level of the liquid trap 26 for making controls decisions.

[0024] A first electronically controlled ROV 50 is disposed on the first vapor tube 40 and located generally in a vapor space 44 of the fuel tank 12. Similarly, a second electronically controlled ROV 52 is disposed on the second vapor tube 42 and located in the vapor space 44. Both of the ROVs 50 and 52 are fluidly connected to the liquid trap 26 by way of the first and second vapor tubes 40 and 42. A third or canister vapor tube 56 connects between the purge canister 32 and the liquid trap 26. It is appreciated that more than two ROVs may be configured for use in the fuel tank 12.

[0025] The first ROV 50 includes a float 60 that moves from between a normally open position (FIG. 2A) and a closed position. A seal 62 is disposed on the float 60 and sealingly engages a seat 64 when the float 60 moves upward to seal a first vent opening 66. The float 60 is caused to move in a first mode into the closed position upon liquid fuel raising the float 60 such as during a refueling event, grade causing, sloshing or roll-over scenarios. The float 60 can also be caused to move in a second mode into a closed position by way of electrical actuation. In the example shown, a first solenoid 70 having a coil 72 and armature 74 causes the float to move to the closed position. Explained further, the control module 30 communicates a signal to the first solenoid 70 energizing the coil 72 and causing the armature 74 to translate (upward as viewed in FIG. 2C) ultimately closing the first vent 66. It will be appreciated that the solenoid can be configured to actuate at discrete intervals between completely open and completely closed in the event that a partial venting condition is desired.

[0026] The second ROV 52 includes a float 80 that moves from between a normally open position and a closed position. A seal 82 is disposed on the float 80 and sealingly engages a seat 84 when the float 80 moves upward to seal a second vent opening 86. The float 80 is caused to move in a first mode into the closed position upon liquid fuel raising the float 80 such as during a refueling event, grade causing, sloshing or roll- over scenarios. The float 80 can also be caused to move in a second mode into a closed position by way of electrical actuation. In the example shown, a second solenoid 90 having a coil 92 and armature 94 causes the float to move to the closed position. Explained further, the control module 30 communicates a signal to the second solenoid 90 energizing the coil 92 and causing the armature 94 to translate ultimately closing the second vent 86. It will be appreciated that the solenoid can be configured to actuate at discrete intervals between completely open and completely closed in the event that a partial venting condition is desired.

[0027] The ROV’s 50 and 52 provide both float based actuation and electronic based actuation. The response time can be faster for controlling vent closing for a dynamic situation. Liquid carryover can be prevented and/or limited to the liquid trap 26. Furthermore, refueling can be improved further on aspect of spit back, well back, premature shut offs (PSO’s) and fill volume accuracy. Moreover, the configuration also helps to reduce vapor space as a ROV’s can be of bigger orifices (as FLW) and can be placed at higher ends of the fuel tank 12, since the refueling volume can be electronically controlled. The system can also help with OBD-II diagnostics. The configuration provides a fallback action in case of power loss. In such cases, the ROV will mimic the present day operations with float based actuation. The present disclosure can satisfy upcoming auto regulations for redundancy compliance. The first and second ROV’s 50 and 52 can be universal with a single large orifice or can be of two sizing compared to traditional ROV/GVV and FLW, thus reducing the manufacturing and maintenance of huge part numbers overhead.

[0028] In one optional configuration, a valve 96 (FIG. 1 ) can be arranged between the liquid trap 26 and the third vapor tube 56 connected between the purge canister 32 and the liquid trap 26. The valve 96 can be configured to open and close by a signal from the controller 30. The valve 96 can be actuated by any mechanism such as solenoid based or a cam based configuration. The fuel tank system 10 can further be configured for use in pressurized fuel tanks such as in a hybrid vehicle application. In other configurations, the solenoid can be placed in series with a traditional ROV. In other words, the designs shown in the FIGS merge float based actuation and solenoid actuation into a single hardware package. In another option, a solenoid (such as normally open, energized to close) can be configured in series with ROVs. [0029] With particular reference to FIGS. 2A-2C, operation of the ROV 50 will be described in greater detail with the understanding that operation of the ROV 52 is similar. The ROV 50 is shown in FIG. 2A in a normally open position. In the normally open position a fuel level is not high enough to raise the float. Further, no electrical signal is sent to the solenoid 72. In this regard, the ROV 50 remains in the normally open position. The ROV 50 is shown in FIG. 2B in a closed position according to a first mode of operation. In the first mode of operation a fuel level F has risen to a predetermined level to raise the float 60 to a position where the seal 62 engages the seat 64. In the first mode, there is no electrical actuation of the armature 74 by the solenoid 72. The ROV 50 is shown in FIG. 2C in a closed position according to a second mode of operation. In the second mode of operation the control module 30 communicates a signal to the first solenoid 70 energizing the coil 72 and causing the armature 74 to translate upward thereby also moving the float 60 and seal 62. The seal 62 engages the seat 64 in the closed position shown in FIG. 2C. The control module 30 can communicate the signal to the first solenoid 70 based on one or a combination of operating inputs. The control module 30 can receive inputs from a tank pressure sensor, a canister pressure sensor, a temperature sensor and a vehicle grade sensor. The control module 30 can additionally include fill level signal reading processing, fuel pressure driver module functionality and be compatible for two-way communications with a vehicle electronic control module (not specifically shown).

[0030] With reference to FIGS. 3A - 3C, an electronically controlled ROV 150 constructed in accordance to other features is shown. The ROV 150 can be used in place of one or both of the ROV’s 50 and 52 described above in the evaporative emissions control system 20. The ROV 150 includes a float 160 that moves between a normally open position and a closed position. A seal 162 is disposed on the float 160 and sealingly engages a seat 164 when the float 160 moves upward to seal a vent opening 166. The float 160 is caused to move in a first mode into the closed position upon liquid fuel raising the float 160 such as during a refueling event, grade causing, sloshing or roll-over scenarios. The float 160 can also be caused to move in a second mode into a closed position by way of electrical actuation. In the example shown, a solenoid 170 having a coil 172 and armature 174 causes the float 160 to move to the closed position. Explained further, the control module (such as the control module 30) communicates a signal to the solenoid 170 energizing the coil 172 and causing the armature 174 to translate ultimately raising the float 160 upward and closing the vent 166. It will be appreciated that the solenoid 170 can be configured to actuate at discrete intervals between completely open and completely closed in the event that a partial venting condition is desired.

[0031] With particular reference to FIGS. 3A-3C, operation of the ROV 150 will be described in greater detail. The ROV 150 is shown in FIG. 3A in a normally open position. In the normally open position a fuel level is not high enough to raise the float. Further, no electrical signal is sent to the solenoid 172. In this regard, the ROV 150 remains in the normally open position. The ROV 150 is shown in FIG. 3B in a closed position according to a first mode of operation. In the first mode of operation a fuel level F has risen to a predetermined level to raise the float 160 to a position where the seal 162 engages the seat 164. In the first mode, there is no electrical actuation of the armature 174 by the solenoid 172. Notably, the float 160 moves upward along legs 182 relative to the armature 174. The armature 174 and legs 182 are fixed relative to each other. The ROV 150 is shown in FIG. 3C in a closed position according to a second mode of operation. In the second mode of operation the control module 30 communicates a signal to the first solenoid 170 energizing the coil 172 and causing the armature 174 to translate upward thereby also moving the float 160 and seal 162. The seal 162 engages the seat 164 in the closed position shown in FIG. 3C. The control module 30 can communicate the signal to the first solenoid 170 based on one or a combination of operating inputs such as, but not limited to, those discussed above. It will be appreciated that the configuration shown in FIGS. 3A-3C is exemplary and other arrangements may be used that permit the float 160 to move relative to the armature 174.

[0032] With reference to FIGS. 4A - 4C, an electronically controlled ROV 250 constructed in accordance to other features is shown. The ROV 250 can be used in place of one or both of the ROV’s 50 and 52 described above in the evaporative emissions control system 20. The ROV 250 includes a seal 262 that moves between a normally open position and a closed position. The seal 262 can be movably coupled to a float 260. The seal 262 sealingly engages a seat 264 to seal a vent opening 266. An arm 267 is pivotally coupled to a pivot axle 268.

[0033] The float 260 is caused to move upward into the closed position in a first mode upon liquid fuel raising the float 260 such as during a refueling event, grade causing, sloshing or roll-over scenarios. In the first mode, the float 260 urges the seal 262 into contact with the seat 264. The seal 262 can also be caused to move in a second mode into a closed position by way of electrical actuation. In the example shown, a solenoid 270 having a coil 272 and armature 274 causes the arm 267 to move (rotate clockwise) to the closed position. Explained further, the control module (such as control module 30) communicates a signal to the solenoid 270 energizing the coil 272 and causing the armature 274 to translate (leftward as viewed in FIG. 4) ultimately rotating the arm 267 (clockwise) into the seal 262 causing the seal 262 to raise against the seat 264. A nub 278 can be arranged at an end of the arm 267 that engages the seal 262. In some examples, the seal 262 can be slidably mounted to the float 260 by a push-pin mount 280. It will be appreciated that the solenoid 270 can be configured to actuate at discrete intervals between completely open and completely closed in the event that a partial venting condition is desired.

[0034] With particular reference to FIGS. 4A - 4C, operation of the ROV 250 will be described in greater detail. The ROV 250 is shown in FIG. 4A in a normally open position. In the normally open position a fuel level is not high enough to raise the float. Further, no electrical signal is sent to the solenoid 272. In this regard, the ROV 250 remains in the normally open position. The ROV 250 is shown in FIG. 4B in a closed position according to a first mode of operation. In the first mode of operation a fuel level F has risen to a predetermined level to raise the float 260 to a position where the seal 262 engages the seat 264. In the first mode, there is no electrical actuation of the armature 274 by the solenoid 272. The ROV 250 is shown in FIG. 4C in a closed position according to a second mode of operation. In the second mode of operation the control module 30 communicates a signal to the first solenoid 270 energizing the coil 272 and causing the armature 274 to translate lefttward (as viewed in FIG. 4C) thereby also moving the float 260 and seal 262. In the example shown, the armature 274 engages a bumper 290 configured on the arm 267. The nub 278 on the float 260 can ultimately engage the seal 262 and urge the seal 262 into the seat 264.

[0035] The seal 262 engages the seat 264 in the closed position shown in FIG. 4C. The control module 30 can communicate the signal to the first solenoid 270 based on one or a combination of operating inputs such as, but not limited to, those discussed above.

[0036] 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.