US 5,857,446 A · Fuel vapor source

Abstract

A canister contains two cartridges of activated carbon for storing fuel in gasoline powered motor vehicles. A first cartridge operates to prevent release of hydrocarbons vaporized in the fuel tank while the vehicle is not operating. The second cartridge performs two functions. First, the second cartridge traps fuel in vapor displaced during refueling. Second, the second cartridge is charged with adsorbed fuel after the engine is stopped. Vaporous fuel from the first and second cartridges is supplied to fuel the engine upon startup. An air-fuel ratio sensor and a fuel vapor sensor are achieved by comparing the transit time of sound in two chambers, one containing air and the other containing a mixture of air and fuel. After the engine is stopped a solenoid valve is closed and an electrically energized air pump draws vapor from the fuel tank through the second cartridge to charge it with fuel. Charging is terminated when the fuel vapor sensor senses that fuel has passed through the second cartridge without being adsorbed. The air-fuel ratio sensor measures the ratio of air to fuel provided to the engine during initial startup for controlling a valve to maintain a desired air-fuel ratio. A vacuum actuated spool valve reconnects one sensor enabling it to perform both the vapor sensing function and air-fuel ratio sensing function as required.

Claims24

Dependent claims

A fuel vapor source (10) for supplying fuel vapor to a vehicle engine comprising a container containing a first fuel vapor adsorbing material (32) and also comprising:

fuel tank connection means (108) for connecting said fuel vapor source with a fuel tank of a vehicle,
fuel charging means comprising vapor drawing means (112, 192, 166, 168, 190, 204, 194,206, 209) adapted to draw air and fuel vapor from said fuel tank through said fuel tank connection means and through said first fuel vapor adsorbing material,
fuel supplying means comprising said first fuel vapor adsorbing material and combining means (142, 144, 146, 148, 150) for combining stored fuel from said first fuel vapor adsorbing material and combustion air and supplying said combination to said engine,
first sensing means (160) adapted to indicate the fraction of fuel in said combined fuel and combustion air, and
first valve means (12, 140) responsive to said first sensing means by controlling said fraction of fuel.

2 more elements

A sensor responsive to the fraction of fuel vapor in a mixture of air and fuel vapor comprising:

first sound generating means (224, 250) adapted for generating sound in said mixture of air and fuel vapor,
first sound reflecting means (218) adapted for reflecting said sound generated by said first sound generating means,
said first sound generating means being responsive to receipt of said reflection of said sound generated by said first sound generating means, and
signal processing means (250) adapted to provide an output signal responsive to the elapsed time between said sound generation by said first sound generation means and said sound receipt.

1 more element

Dependencies are inferred from the claim text.

Fuel vapor source

Life of this patent

Fuel vapor source

Life of this patent

Abstract

Claims24