Abstract: An evaporative emission control system for an internal combustion engine comprises a canister for adsorbing evaporative fuel generated in the fuel tank, and a first evaporative fuel passage extending between the canister and the tank main body of the fuel tank. A differential pressure-operated valve is arranged across the first evaporative fuel passage, which has a positive pressure chamber communicating through the first evaporative fuel passage with the interior of the tank main body of the fuel tank, and a back pressure chamber. The differential pressure-operated valve opens and closes the first evaporative fuel passage in response to a difference in pressure between the positive pressure chamber and the back pressure chamber.

Abstract: An evaporative emission control system for an internal combustion engine includes a canister for adsorbing evaporative fuel generated in the fuel tank, a communication passage connecting between first and second adsorbent chambers defined in the canister, a first introducing passage for introducing the generated evaporative fuel into the canister on an occasion other than at fueling, a purging passage for purging the evaporative fuel adsorbed into the canister to the intake passage, and an air-inlet passage communicating with the atmosphere. The first introducing passage, the second air-inlet passage and the purging passage are connected to the first adsorbent chamber. A second introducing passage is connected to the second adsorbent chamber, for introducing the evaporative fuel thereinto at refueling, and an additional passage having a cross sectional area larger than that of the air-inlet passage and communicating with the atmosphere is connected to the first adsorbent chamber.

Abstract: An evaporative fuel-processing system for an internal combustion engine includes a canister accommodating an adsorbent therein, for adsorbing evaporative fuel generated in a fuel tank of the engine, and a charging passage connecting between the canister and the fuel tank. A shutter valve is arranged in a fuel supply pipe of the fuel tank in the vicinity of an inlet end thereof, for isolating the interior of the fuel supply pipe from the atmosphere, and the shutter valve is disposed to be opened by the tip of a refueling gun when the latter is inserted into the fuel supply pipe. A pressure-intake port section is arranged in the fuel supply pipe at a side of the shutter valve closer to the main body of the fuel tank, for taking in pressure within the fuel supply pipe.

Abstract: An evaporative fuel-adsorbing device adsorbs evaporative fuel generated from a fuel tank of an internal combustion engine. A partition divides the interior of a casing at least into a first adsorbent chamber and a second adsorbent chamber. Adsorbents are charged in the first adsorbent chamber and the second adsorbent chamber, respectively, for adsorbing the evaporative fuel. The evaporative fuel from the fuel tank is permitted to flow into the first adsorbent chamber via a charging port provided therein. The evaporative fuel desorbed from the adsorbents in the adsorbent chambers are permitted to flow out of the first adsorbent chamber via a purging port provided therein. The second adsorbent chamber is communicated with the atmosphere via an air-inlet port.

Abstract: In an evaporative fuel processing device, a canister is divided into first, second, third and fourth chambers by partition walls. A control valve is provided in a communication passage which connects the second and third chambers to each other. A first charge passage is connected to an upper space in a fuel tank and to a port in the third chamber, and a second charge passage is connected to a fuel supply valve for the fuel tank and to a port in the first chamber. Further, a purge passage is connected to an intake passage of an internal combustion engine and to a port in the first chamber. The control valve is connected to an electronic control unit, and opened during refueling and during traveling of a vehicle and closed during parking of the vehicle. Thus, it is possible to reliably prevent an evaporative fuel from being released to the atmosphere, while the capacity of the canister to a minimum.

Abstract: An evaporative emission control system for an internal combustion engine includes a canister for adsorbing evaporative fuel generated in the fuel tank, a first introducing passage for introducing evaporative fuel generated in the fuel tank into the canister on an occasion other than at refueling, a purging passage for purging evaporative fuel adsorbed in the canister into the intake passage of the engine, and a first air-inlet passage communicating between the canister and the atmosphere. First and second adsorbent chambers are formed in the canister and each accommodating an adsorbent. The first introducing passage and the purging passage are connected to the first adsorbent chamber. The first air-inlet passage is connected to the second adsorbent chamber. A communication passage communicates between the first adsorbent chamber and the second adsorbent chamber.

Abstract: A vent passage communicated to an upper space of a fuel tank mounted on an automobile is connected to a canister. A two-way valve, which includes a pair of one-way valves disposed oppositely and in parallel to each other, is provided in the vent passage. One one-way valve is adjusted its valve opening pressure in a two-staged manner according to the operational state of an internal combustion engine. In another method, a bypass passage bypassing the two-way valve is provided in the vent passage. A solenoid valve and a one-way valve are interposed in the bypass passage. The above one one-way valve of the two-way valve is set at a first valve opening set-up pressure, and the other one-way valve is set at a second valve opening set-up pressure lower than the first valve opening set-up pressure. The solenoid valve is opened or closed according to the operational state of the internal combustion engine.

Abstract: A canister includes a casing, a fuel reserve well defined at the bottom of the casing, an adsorbent layer provided in the casing for adsorbing fuel vapor, the adsorbent layer communicating with the fuel reserve well at a region of its lower portion and communicating with an atmosphere at its upper portion, a first communication passage defined so that the fuel reserve well communicates with a fuel system of an engine, and a second communication passage defined so that the fuel reserve well communicates with an intake system o f the engine.

Abstract: A starting fuel supply control system for an internal combustion engine having a purging passage connecting between a canister and an intake passage for purging a mixture of evaporative fuel from a fuel tank and air therethrough into the intake passage, and a purge control valve arranged across the purging passage for controlling the flow rate of the evaporative fuel to be supplied to the intake passage. An ECU detects a flow rate of an evaporative fuel component in the mixture flowing in the purging passage, and sets an amount of fuel to be supplied to the engine at the start thereof, based upon the detected flow rate of the evaporative fuel component.

Abstract: A mass flowmeter outputs an output value indicative of the flow rate of a gaseous mixture containing evaporative fuel and being purged into the intake system of an internal combustion engine. A calculated value of the flow rate of the mixture is obtained based on a plurality of operating parameters of the engine. The actual flow rate of the mixture and/or the actual flow rate of the evaporative fuel are/is calculated based on the output value from the mass flowmeter and the calculated value based on the engine operating parameters. The concentration of the evaporative fuel is calculated from the calculated actual flow rates of the evaporative fuel and the mixture. The calculated actual flow rate is compared with a desired flow rate value, and a purge control valve is controlled based on results of the comparison. A basic amount of fuel supplied to the engine is corrected based on the calculated actual flow rate of the evaporative fuel.

Abstract: An evaporative fuel-purging control system for an internal combustion engine having a canister in which evaporative fuel from a fuel tank is absorped. Purge control valves are arranged between the canister and the intake system of the engine for controlling the flow rate of evaporative fuel supplied from the canister to the intake system. An ECU is responsive to an output from an exhaust gas ingredient concentration sensor arranged in the exhaust system of the engine for calculating an air-fuel ratio correction coefficient, based upon the output from the exhaust gas ingredient concentration sensor and controlling the air-fuel ratio of a mixture supplied to the engine by the use of the air-fuel ratio correction coefficient. The ECU calculates an average value of the air-fuel ratio correction coefficient, and is responsive to the calculated average value for controlling the purge control valves.