Patent ID: 8931508
Filing Date: 2015-01-13
Classification: B60K,F02M,F16K,Y10T

Abstract:
1. A two-stage fuel tank vapor isolation valve, comprising: a first chamber; a second chamber opposite the first chamber, the second chamber comprising a bias spring and a first end of a pilot valve; a third chamber surrounding the first chamber and opposite the second chamber, the third chamber connected to a second end of the pilot valve; a valve movable between a first stage preventing fluid flow directly between the first chamber and the third chamber and a second stage permitting fluid flow directly between the first chamber and the third chamber, wherein the valve comprises: the pilot valve movable between a pilot open position, permitting vapor flow between the second chamber and the third chamber, and a pilot closed position, preventing vapor flow between the second chamber and the third chamber, in response to a control signal; and a control system connection for receiving electronic signals from a vehicle control device to selectively move the pilot valve between the pilot open position and the pilot closed position, wherein, in response to a fuel-fill event indication by the vehicle control device, the pilot valve is opened to permit vapor flow at a first rate from the second chamber to the third chamber while the valve is at the first stage, and then to permit vapor flow at a second rate from the first chamber directly to the third chamber when the valve moves to the second stage, and wherein, in response to a fuel level signal from the vehicle control device, the pilot valve is closed to permit vapor pressure to build and move the valve from the second stage back to the first stage, wherein the bias spring comprises a spring force such that, when the pilot valve is closed, when a vacuum is applied to the first chamber, and when atmospheric pressure is applied to the third chamber, the valve moves from the first stage to the second stage to relieve the vacuum.