VAPOR VENT CONTROL VALVE

Abstract: A vapor vent control valve arrangement (l0) for a fluid tank (l2) is disclosed. The valve arrangement includes a solenoid operated valve (28) with a normally-open parallel switch assembly (l6) and a normally-closed switch (42) in an electrical circuit (ll) to activate the solenoid valve. An impact switch (70) may also be provided as a safety precaution in the series circuit. The valve assembly is spring-biased to provide an over-pressure check valve function and also includes a back-pressure relief valve (62).

Description: The present invention relates to a vapor vent control valve arrangement for a fluid tank. More specifically, a solenoid operable valve is disclosed, which valve utilizes a spring-biased actuation means and a resilient member to provide a safety function. A specific embodiment is taught for an automobile fuel tank application. A variety of control circuits and apparatus providing communication between a fuel tank and a vapor storage [cannister] system or vapor consumption equipment are taught in the prior art. Vapor consumption equipment generally refers to injection or aspiration of captured vapors into an air-fuel mixing device for an automobile engine. Indicative of a cannister storage system is that shown in the Chassis and Body Service Manual for the l982 Buick at page 6e l-l2 and l-l3. In the drawing illustrated therein, a vapor storage cannister is connected through a line to the top of a fuel tank. The single control ele­ ment illustrated in the schematic drawing is a vent restric­ tor in the conduit between the fuel tank and cannister. Vapors from the fuel tank are transmitted to the vapor storage cannister, which is subsequently evacuated or purged to the air-fuel mixer [carburetor] during engine operation. Purge of this vapor storage cannister, which is charcoal filled, is provided through a purge solenoid which may be responsive to engine temperature or other operating parameters. A diagramatic view of the charcoal cannister is provided at Fig. 6e l-l6a of the aforementioned manual. The vent restrictor does not provide a seal means as a precautionary measure and is continually evacuating the fuel tank. U.S. Patent No. 3,586,0l6-Meyn discloses a control valve for a tank filling and evaporation arrangement which includes a buoyant member for the fuel level having a per­ manent magnet available to actuate a reed switch. The reed switch is in series with a pressure switch and a solenoid valve controlling flow between the fuel tank and the vapor storage means. The pressure switch is closed when the buoyant member is in a lowered or rest position. The reed switch, which is in parallel with the fuel level and tank attitude sensing means, remains closed when the attitude sensing means is in the reference position. In addition, the pressure switch will close to complete the solenoid circuit only if the tank vapor pressure is high enough to actuate this pressure switch. A similar system is disclosed in U.S. Patent No. 3,586,0l5-Kitzner. However, the Kitzner patent includes a spherical weight movable on a ramp to open the reed switch in response to changes in tank attitude. U.S. Patent No. 3,200,2l4-Aubert discloses a magne­ tically-actuated reed switch. This reed switch is in a flow control device with a movable magnetic means therein. U.S. Patent No. 3,242,937-Morin teaches an air vent for a fuel tank with a set of adjustable floats which are raised by excess fuel to close a needle valve. The needle is also moved by an adjustable plate and lever assembly which rotates when the tank is tilted. The above-described art discloses valve closing means generally utilizing magnetic operators and float control means in alternative series and/or parallel circuits. The invention disclosed herein requires only a single magnet, utilizes a parallel switch circuit in the series circuit, has a solenoid operator providing a relief valve arrange­ ment in addition to a controllable valve, and a predeter­ mined pressure level in the tank is not required to com­ plete the circuit. A tank filling and evaporative control valve appara­ tus is disclosed including a solenoid operated vent valve, an attitude sensing means and a fluid level sensing means. The solenoid operator in the preferred embodiment provides a communication path from a fuel tank to a vapor storage or consumption system. The solenoid is energized when an ignition or a fill-opening switch is closed to complete an electrical circuit. A float or fluid level sensing means with a magnetic device opens the electrical circuit if the fuel level is above a proscribed level. A preferred embodiment utilizes a normally-closed solenoid operator, wherein opening the electrical circuit closes the solenoid valve to seal fluid communication through the vapor vent. In addition, a means is provided to open the circuit and close the vent valve for an attitude change of the fuel tank. An impact switch may also be provided in this series circuit to open the circuit in the event of a traumatic impact, which impact switch would open the circuit and close the vapor vent thereby sealing a potential fuel leak path. The solenoid valve is a spring biased, normally-closed valve which provides a pressure-relief function and will allow a back pressure to evacuate to the tank in the event of an over-pressure condition in the vapor recovery system. In the figures of the drawing, like reference numerals identify like components and in the drawing: Fig. l is a cross-sectional view of a preferred embodiment of the vent vapor valve; Fig. 2 is an electrical schematic of the basic electrical circuit of this valve; Fig. 3 illustrates an alternative embodiment of the electrical circuit; and Fig. 4 illustrates the structure of Fig. l including the impact inertia switch illustrated in Fig. 3. A vapor vent control valve arrangement l0 for a fuel tank l2 with a fill-opening l5 and a fill-door l3 therefor is illustrated in Figs. l and 4. Valve arrangement l0 is operably connected to an electrical circuit ll which is coupled to an energy source l4 through a conductor 2l. Circuit ll includes a first switch or switch means arrange­ ment l6, which is shown as a parallel arrangement of an ignition switch l8 and a fill-opening switch 20. As an example, fuel tank l2 may be considered as an automobile fuel tank associated with the electrical and fluid circuits of a vehicle. The vapor vent control valve l0 is illustrated as seated atop fuel tank l2 to evacuate vapors therefrom to a fuel vapor recovery system 22. Valve arrangement l0 broadly comprises a housing 24, a solenoid assembly 28 including a casing 27 defining an enclosure 29 with a solenoid operator 38 therein, a fuel level sensor means 30, an attitude sensor means 32, and a valve subassembly 34. Solenoid operator 38 is electrically operable by completion of circuit ll. Housing 24 defines a fuel chamber or fluid passage 26, a recovery or exhaust port 37, a fuel aperture or entry port 39 communicating between tank l2 and chamber 26, an opening 36 and a valve well 52. Solenoid 38 in enclosure 29 has a movable stem 40 extending from enclosure 29 through opening 36, passage 26 and port 37 into valve well 52. A reed switch or second switch means 42 in assembly 28 is in series with switch arrangement l6 and is operable to open electrical circuit ll and thus close solenoid 38. As shown in Figs. l and 4, reed switch 42 within assembly 28 extends into chamber 26. Positioned in chamber 26 in proximity to reed switch 42 is a fluid level sensor 30 which is illustrated as a hollow float-like device 44 with a magnet 48. Attitude sensing means 32, also in chamber 26, is shown as a spherical element 49 positioned between float 44 and fuel tank l2 on a ramp-like cavity defined by a ramp 50. Spheri­ cal ball 49 is freely movable in response to attitude changes of fuel tank l2 to move float 30 with magnet 48 to open reed switch 42 by magnetic attraction. Valve well 52 with a spring retainer means 54 positioned therein communicates with fluid passage 26 through exhaust port 37 and is directly coupled to vapor recovery means 22. Solenoid valve means 28 includes solenoid 38 and valve cap means 34, which contacts and is operable by stem 40 in well 52. Valve cap means 34 has a valve plate 56 which is biased to seal port 37 by a spring or bias means 58 positioned between spring retainer 54 and plate 56. Further, valve plate 56 defines a relief port 60 with a relief valve means 62 sealingly positioned over port 60 and operable to relieve back pressure in well 52. Solenoid valve means 28 including stem 40, valve 56 and bias means 58 cooperate to act as an exhaust port seal and valve means. Solenoid 38 is operable to move an armature, in this case stem 40, in response to an electro­ magnetic field imposed by closing or completing the elec­ tric circuit ll. Circuit ll is illustrated in Fig. 2 with energy source l4 connected to first switch means l6 by a conduit means or means for receiving energy 2l. Switch arrangement l6 is connected in series with normally closed reed switch 42 and normally closed solenoid operator 38. Closure of either normally-open switch l8 or 20 of switch means l6, will complete circuit ll to energize solenoid 38 and move stem 40 with valve plate 56 to open port 37. How­ ever, reed switch 42 may be opened, thus opening circuit ll, by attitude sensor 32 when the fuel tank attitude exceeds a predetermined angle from the reference position of Fig. l, or by fuel level sensor 30 in response to an elevated fuel level. In addition, valve subassembly 34 provides a check-valve function to relieve an over-pressure condition in the fuel tank, when such over-pressure is sufficient to overcome the bias force of spring 58 and the inertia of stem 40. In the alternative embodiment depicted in Figs. 3 and 4, an impact switch 70 is disclosed in series in circuit ll between switch means l6 and reed switch 42. Impact switch 70 is operable to open circuit ll and seal communication through well 52 to fuel vapor recovery system 22 when a disturbance of sufficient magnitude opens switch 70. Those skilled in the art will recognize that certain variations can be made in the illustrated embodiments. While only specific embodiments of the invention have been described and shown here, it is apparent that various alter­ natives and modifications can be made therein. It is, therefore, the intention in the appended claims to cover all such modifications and alterations as may fall within the true scope and spirit of the invention.

Claims: 1. A vapor vent control valve arrangement (l0) positioned between a fluid tank (l2) and a vapor recovery means (22), which valve arrangement comprises: a housing (24) defining a fluid passage (26) with an entry port (39) and an exhaust port (37) which cooperate to define a fluid flow path between said tank and vapor recovery means; a solenoid valve means (28) positioned to seal said exhaust port (37); a series circuit (ll), including means for receiving electrical energy (38), a first switch means (l6), a second switch means (42) and said solenoid valve means (28); a buoyant float (44) in said fluid passage, operable to open said second switch means; an attitude-responsive means (32), operable to move said buoyant float (44) and thus open said second switch means (42), wherein actuation of said first switch means (l6) com­ pletes said series circuit (ll) and opens said solenoid valve means (28), thus providing fluid communication between said fluid tank (l2) and said vapor recovery means (22). 2. A vapor vent control valve arrangement, as claimed in Claim l, wherein said solenoid valve means (28) is normally closed in a reference position and said valve arrangement further comprises a bias means (58) to maintain said valve means in said reference position. 3. A vapor vent control valve arrangement, as claimed in Claim 2, wherein said solenoid valve (28) is operable to open against said bias means (58) in response to a vapor pressure above a predetermined level. 4. A vapor vent control valve arrangement, as claimed in Claim l, and further comprising a relief valve means (62) in said solenoid valve means (28) to relieve a backpressure downstream of said solenoid valve (28). 5. A vapor vent control valve arrangement, as claimed in Claim 2, and further comprising a relief valve means (62) in said solenoid valve to relieve a backpressure downstream of said solenoid valve. 6. A vapor vent control valve arrangement, as claimed in Claim l, further comprising an impact switch means (70) in series with said second switch means (42), said impact switch means (70) being operable to open said circuit and close said solenoid valve (34). 7. A vapor vent control valve arrangement, as claimed in Claim 2, further comprising an impact switch means (70) in series with said second switch means (42), said impact switch (70) means being operable to open said circuit and close said solenoid valve (34). 8. A vapor vent control valve arrangement, as claimed in Claim 3, further comprising an impact switch means (70) in series with said second switch means (42), said impact switch means being operable to open said circuit and close said solenoid valve. 9. A vapor vent control valve arrangement (l0) for a fluid tank (l2) as claimed in Claim 4, and further comprising an impact switch means (70) in series with said second switch means (42), said impact switch means (70) being operable to open said circuit and close said solenoid valve. l0. A vapor vent control valve arrangement, as claimed in Claim 5, further comprising an impact switch means (70) in series with said second switch means (42), said impact switch means being operable to open said circuit and close said solenoid valve. 11. A vapor vent control valve arrangement, as claimed in Claim l, wherein said fluid tank (l2) is an auto­ mobile fuel tank defining a fill opening (l5) with a fill-door (l3) and said first switch means (l6) to energize said solenoid valve comprises a parallel arrangement of a fill-opening switch (20) and an ignition switch means (l8). 12. A vapor vent control valve arrangement for an automobile fuel tank as claimed in Claim ll, wherein said ignition switch means (l8) is an automobile ignition switch. 13. A vapor vent control valve arrangement for a fluid tank as claimed in Claim ll, wherein said fuel tank fill-opening switch means (20) is mounted in said fill-opening (l5) and operable by said fill-door (l3). 14. A vapor vent control valve arrangement for a fluid tank as claimed in Claim l2, wherein said fuel tank fill-opening switch means (20) is mounted in said fill-opening (l5) and operable by said fill-door (l3). 15. A vapor vent control valve arrangement for a fluid tank as claimed in Claim l wherein said second switch means (42) is a flexible reed switch and said buoyant float (44) bears a magnet (48) to actuate and open said reed switch to open said series circuit.

Inventors: DEVALL, JEFFREY EDWARD, REINKE, RONALD EDWARD
Applicants: BORG-WARNER AUTOMOTIVE, INC.
Application year: 1987
Main classification: F02M25
IPC codes: B60K15, F02M25