Two-stage high flow purge valve
First Claim
1. A two-stage valve for a vehicle having an internal combustion engine comprising:
- a valve body defining an inlet port adapted for connection to a source of fluid and an outlet port adapted for connection to a source of vacuum;
a high flow orifice defining a first flow path through said valve body from said inlet port to said outlet port;
a low flow orifice defining a second flow path through said valve body from said inlet port to said outlet port in parallel with said first flow path;
first valve means responsive to the level of vacuum pressure at said outlet port for controlling the fluid flow through said high flow orifice; and
second valve means comprising a solenoid valve for controlling the fluid flow through said low flow orifice in response to an electrical signal supplied to said solenoid valve.
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Accused Products
Abstract
A two-stage high flow purge valve for an evaporative emission system of a vehicle. The valve body contains two valves for controlling fluid flow through separate parallel flow paths in the valve body. A fast-acting, pulse width modulated solenoid valve responsive to an electrical control signal from the engine control computer precisely controls flow through a low flow path, and a vacuum-responsive valve controls flow through a high flow path in accordance with the level of manifold vacuum at the engine intake. A third valve member is provided to block flow through the high flow path when the engine is off and the manifold vacuum is zero. Means for calibrating both the solenoid valve and the vacuum-responsive valves are also provided.
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Citations
28 Claims
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1. A two-stage valve for a vehicle having an internal combustion engine comprising:
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a valve body defining an inlet port adapted for connection to a source of fluid and an outlet port adapted for connection to a source of vacuum; a high flow orifice defining a first flow path through said valve body from said inlet port to said outlet port; a low flow orifice defining a second flow path through said valve body from said inlet port to said outlet port in parallel with said first flow path; first valve means responsive to the level of vacuum pressure at said outlet port for controlling the fluid flow through said high flow orifice; and second valve means comprising a solenoid valve for controlling the fluid flow through said low flow orifice in response to an electrical signal supplied to said solenoid valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In a vehicle evaporative emission control system including a charcoal canister for trapping fuel vapors emanating from the fuel tank of the vehicle and a purge system for drawing the fuel vapors out of the canister and feeding them into the intake system of the engine of the vehicle while the engine is running, the engine having an engine control computer for controlling the fuel/air mixture fed into the engine, a two-stage purge valve adapted for connection into the purge system for controlling the purge flow from the charcoal canister to the engine intake system, comprising:
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a valve body having an inlet port adapted for connection to the charcoal canister and an outlet port adapted for connection to the intake system of the engine; a high flow orifice defining a first flow path through said valve body from said inlet port to said outlet port; a low flow orifice defining a second flow path through said valve body from said inlet port to said outlet port in parallel with said first flow path; vacuum responsive valve means for controlling the flow through said high flow orifice, including a valve member for controlling the effective size of said high flow orifice and having a first position wherein said high flow orifice is closed and a second position wherein said high flow orifice is fully opened, bias means for biasing said valve member toward said second position, and a diaphragm connected to said valve member and responsive to the vacuum pressure at said outlet port for controlling the position of said valve member, such that at vacuum pressures above a predetermined level said valve member is in said first position and at vacuum pressures below said predetermined level said high flow orifice is opened; and solenoid valve means for controlling the flow through said low flow orifice including a solenoid having a coil adapted for electrical connection to the engine control computer and a valve member responsive to the energization of said solenoid coil by an electrical signal from the engine control computer for controlling the flow through said low flow orifice. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A two-stage valve for a vehicle having an internal combustion engine comprising:
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a valve body having a central axis, an inlet port adapted for connection to a source of fluid and an outlet port and adapted for connection to a source of vacuum and defining a first chamber in fluid communication with said inlet port and a second chamber in fluid communication with said outlet port, said first and second chambers being separated by a wall in said valve body; a low flow orifice concentric with said central axis and defining a first flow path through said wall from said first chamber to said second chamber; a high flow orifice concentric with said central axis and defining a second flow path through said wall from said first chamber to said second chamber in parallel with said first flow path; a solenoid valve having an axis aligned with said central axis for controlling the flow through said low flow orifice in accordance with an electrical signal supplied to said solenoid valve; and vacuum responsive valve means having an axis aligned with said central axis for controlling the flow through said high flow orifice in accordance with the level of vacuum pressure in said second chamber. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification