Claims
- 1. A vapor collection system for an internal combustion engine fuel system comprising:
- an intake manifold of an engine;
- a fuel vapor collection canister;
- a solenoid-operated canister purge valve in fluid communication with and disposed between said intake manifold and said fuel vapor collection canister, said purge valve including a valve element that is displaced relative to a valve seat by a
- a control system coupled to said solenoid for sensing current flow therethrough and for controlling said current flow to cause movement of said valve element to provide a displacement thereof which is relative to said purge control signal.
- 2. The vapor collection system of claim 1, wherein said control system controls said flow current in response to temperature-induced changes in resistance of a coil of said solenoid.
- 3. The vapor collection system of claim 1, wherein said control system controls said current flow by delivering thereto a DC component that establishes a desired displacement of said valve element and a fluctuating component that imparts dither to said valve element at such displacement position.
- 4. The vapor collection system of claim 1, wherein said solenoid and said valve element have displacement hysteresis, and said control system controls said current flow in response to a change of the purge control signal, so that the new current flow target is always approached from the same direction.
- 5. The vapor collection system of claim 1, wherein said control system controls said current flow in response to changes in magnitude of voltage across a coil of said solenoid.
- 6. The vapor collection system of claim 1, wherein said control system controls said current flow by delivering a PWM current thereto.
- 7. The vapor collection system of claim 1, wherein said control system compares said sensed current flow with a reference current flow, and adjusts the current delivered to the solenoid in a sense to reduce difference between said reference current flow and said sensed current flow.
- 8. A vapor collection system for an internal combustion engine fuel system comprising:
- an intake manifold of an engine;
- a fuel vapor collection canister;
- a solenoid-operated canister purge valve in fluid communication with and disposed between said intake manifold and said fuel vapor collection canister, said purge valve including a valve element that is displaced relative to a valve seat by a solenoid in response to a current flow therethrough that is related to a purge signal; and
- a control system coupled to said solenoid that includes a sensor for sensing current flow therethrough and for controlling said current flow in response to the sensed current to cause movement of said valve element to provide a displacement thereof which is relative to said purge control signal.
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation of Ser. No. 08/447,167 filed on May 19, 1995, now abandoned.
US Referenced Citations (19)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0015167 |
Jan 1982 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
447167 |
May 1995 |
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