Combination overfill and tilt shutoff valve system for vehicle fuel tank

• US 5,036,823 A
• Filed: 08/17/1990
• Issued: 08/06/1991
• Est. Priority Date: 08/17/1990
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: MacKinnon, Donald T.
• Primary Examiner(s): MILLER, CARL STUART
• Application Number:
  US07/568,805
• Time in Patent Office: 354 Days
• Field of Search: 123/516, 123/518, 123/519, 123/520, 123/521, 137/43, 137/51, 137/154, 220/1 V, 220/85 F, 220/85 VR, 220/85 US, 220/86 R
• US Class Current: 123/520
• CPC Class Codes: B60K 15/03519 Valve arrangements in the vent line
• CPC Class Codes: F02D 33/006 depending on engine operating conditions, e.g. start, stop or ambient conditions
• CPC Class Codes: F02M 25/0836 Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
• CPC Class Codes: F02M 25/0872 Details of the fuel vapour pipes or conduits
• CPC Class Codes: F02M 37/0023 Valves in the fuel supply and return system
• CPC Class Codes: F02M 37/0082 Devices inside the fuel tank other than fuel pumps or filters electrical pumps submerged in fuel tanks F02M37/10, jet pumps F02M37/025

Abstract

A vapor storage canister protection system that prevents tank overfill and prevents canister contamination when the vehicle tilts significantly from the horizontal, using a single valve to perform both the overfill and tilt protection shut off functions. A series of switches sensitive to when vehicle is being filled block the canister vent line at the end of fill, and then reopen after a short, timed duration or when the vehicle is restarted.

Claims

1. In a vehicle that has an engine, a fuel tank adapted to be filled with liquid fuel, a vapor storage canister, and a vent line running from said canister and opening into said fuel tank, a combined overfill and shutoff valve system, comprising,

a valve including a magnetic weight supported beneath said vent line opening so as to be movable upwardly, under the force of gravity, from a normally open position to a closed position shutting off said vent line when said vehicle tilts sufficiently from horizontal,

electromechanical means adapted to lift said magnetic weight, when energized, from said open to said closed position independently of gravity, and,

sensor means adapted to energize said electromechanical means only when said fuel tank is being filled,

whereby, said blocking valve serves to shut off said vent line both when said vehicle tilts sufficiently and when said fuel tank is being filled.

2. In a vehicle that has an engine, a fuel tank adapted to be filled with liquid fuel, a vapor storage canister, a vent line running from said canister and opening into said fuel tank, and a sensor means adapted to be activated only when said fuel tank is being filled, the improvement which comprises,

a valve including a magnetic weight supported beneath said vent line opening so as to be movable upwardly, under the force of gravity, from a normally open position to a closed position shutting off said vent line when said vehicle tilts sufficiently from horizontal,

an electromechanical means adapted to lift said magnetic weight, when said sensor means is activated, from said open to said closed position independent of gravity,

whereby said valve performs the dual, independent functions of preventing liquid fuel from entering said vent line when said fuel tank is being filled and also when said vehicle tilts sufficiently from horizontal.

3. In a vehicle that produces oil pressure only when running, and that has a fuel tank, a vapor storage canister, and a vent line running from said canister and opening into a vapor pressure chamber at the top of said fuel tank, a combined overfill and shutoff valve system comprising,

a valve including an elongated magnetic weight supported on a spring aligned with and beneath said vent line opening, so as to be movable upwardly, under the force of gravity, from a normally open position to a closed position shutting off said vent line when said vehicle tilts sufficiently from horizontal,

a solenoid capable of lifting said magnetic weight, when energized, from said open to said closed position independently of gravity,

an oil pressure activated electrical switch that is open only when said vehicle is running,

a tank pressure activated electrical switch that moves from an open to a closed position when the pressure in said vapor pressure chamber rises above a predetermined threshold value,

a timed electrical switch that is set to stay closed and pass current for only a predetermined time after it is first energized, then to automatically open and interrupt any circuit of which it is a part, and,

a connecting circuit joining all of said switches in a series, so that current reaches said solenoid only when all three of said switches are closed,

whereby, when said vehicle is horizontally oriented, said magnetic weight is substantially vertically oriented and compresses said spring sufficiently but when said vehicle is oriented sufficiently away from horizontal, said magnetic weight moves away from vertical, so that less weight of said magnetic weight is supported by said spring, allowing said spring to extend and move said magnetic weight and to close said valve;

additionally, when said vehicle is not running and said tank is being filled, said oil pressure switch will be closed, so that when said fuel level rises to the point that the pressure in said vapor pressure chamber rises above said threshold value, said tank pressure switch will close as well, thereby energizing said timed switch and energizing said solenoid to lift said magnetic weight to close said valve.