Abstract: In an evaporative emission control system, when an engine is running, a negative pressure generated in an air intake pipe of the engine is introduced into a fuel tank through a negative pressure intake line. When the engine halts, a purge valve provided on a purge line connecting the intake pipe and a canister is closed and defines a closed space between the purge valve and the fuel tank. After the negative pressure in the fuel tank is introduced into the closed space and the closed space is maintained under a continuous and uniform negative pressure, the system starts a leak check. Because the negative pressure intake line is provided with a negative pressure maintaining valve, the fuel tank is maintained under the negative pressure when the engine is running.

Abstract: An evaporated fuel adsorbed by an adsorbing member of a canister is compulsively desorbed by driving of a purge pump and is introduced into an intake passage of an internal combustion engine. In this instance, intake pulsation of the intake passage of an internal combustion engine is introduced into a driving chamber of the purge pump and a partition is moved, so that the capacity of a pump chamber is varied. In other words, the purge pump conducts its pump operation by utilizing the movement of the partition resulting from the introduction of intake pulsation of the intake passage of the internal combustion engine, and a power loss can be thus reduced. When a pressure difference is small between the intake pressure inside the intake passage of the internal combustion engine and the pressure on the canister side, too, a desired purge flow rate can be secured in accordance with the operating condition of the internal combustion engine.

Abstract: A fuel vapor purge system has a canister and a pump on a purge line arranged between the canister to the intake passage. The system further has a sub-canister on a branch passage of the purge line. The pump is driven when the engine is stopped, and reduces an inside pressure of the system. The vapor discharged from the pump is adsorbed in the sub-canister, therefore, no vapor is emitted to the atmosphere. The controller checks a leak by monitoring the inside pressure after the inside pressure is reduced. It is possible to improve an accuracy of the leak detection since a leak check is executed when the engine is stopped.

Abstract: In an evaporative emission control system, when an engine is running, a negative pressure generated in an air intake pipe of the engine is introduced into a fuel tank through a negative pressure intake line. When the engine halts, a purge valve provided on a purge line connecting the intake pipe and a canister is closed and defines a closed space between the purge valve and the fuel tank. After the negative pressure in the fuel tank is introduced into the closed space and the closed space is maintained under a continuous and uniform negative pressure, the system starts a leak check. Because the negative pressure intake line is provided with a negative pressure maintaining valve, the fuel tank is maintained under the negative pressure when the engine is running.

Abstract: A canister for a vehicular evaporative emission control system has activated carbon and heating means. The heating means heats the activated carbon particles. The activated carbon particles are characterized by the following properties. Pore volume is 0.28 ml/ml or more. Average pore radius is in a range of 10.5 Angstroms to 12.0 Angstroms. Particle diameter of the activated carbon is in a range of 1.0 mm to 1.6 mm. The activated carbon particles provide high performances on both of adsorption and desorption.

Abstract: A fuel adsorption layer formed in a canister is partitioned into an upper adsorption layer and a lower adsorption layer by a partition plate in which a heater is embedded. The relation between a heating value of the heater and thickness X of the upper and lower adsorption layers is set so that the temperature of a part closest to the heater heating face of the fuel adsorption layer is lower than a fire point of the fuel, and the temperature of a part farthest from the heater heating face is higher than the boiling point of the fuel. With the configuration, by heating the fuel adsorption layer by the heater, the desorption performance of activated carbon is improved, and almost all of the fuel vapors adsorbed can be desorbed. As a result, the fuel vapors do not remain in the canister, so that all of the fuel vapors which flow in at the time of adsorption can be adsorbed with reliability.

Abstract: A fuel vapor purge system has a canister and a pump on a purge line arranged between the canister to the intake passage. The system further has a sub-canister on a branch passage of the purge line. The pump is driven when the engine is stopped, and reduces an inside pressure of the system. The vapor discharged from the pump is adsorbed in the sub-canister, therefore, no vapor is emitted to the atmosphere. The controller checks a leak by monitoring the inside pressure after the inside pressure is reduced. It is possible to improve an accuracy of the leak detection since a leak check is executed when the engine is stopped.

Abstract: An evaporated fuel adsorbed by an adsorbing member of a canister is compulsively desorbed by driving of a purge pump and is introduced into an intake passage of an internal combustion engine. In this instance, intake pulsation of the intake passage of an internal combustion engine is introduced into a driving chamber of the purge pump and a partition is moved, so that the capacity of a pump chamber is varied. In other words, the purge pump conducts its pump operation by utilizing the movement of the partition resulting from the introduction of intake pulsation of the intake passage of the internal combustion engine, and a power loss can be thus reduced. When a pressure difference is small between the intake pressure inside the intake passage of the internal combustion engine and the pressure on the canister side, too, a desired purge flow rate can be secured in accordance with the operating condition of the internal combustion engine.

Abstract: A fuel pump suctions fuel from a fuel tank and discharges it into a pressure tank. Then, the fuel pump suctions the fuel from the pressure tank and pressurizes it. Then, the fuel pump discharges the pressurized fuel toward an engine side through a fuel discharge pipeline. A pressure control valve is opened to communicate an inside of the fuel tank and an inside of the pressure tank when a pressure in the pressure tank becomes equal to or greater than a predetermined pressure. A canister receives activated carbons for absorbing vapor fuel from the fuel tank. A pressurizing pump suctions the vapor fuel from the canister and pressurizes it. The pressurized vapor fuel is then discharged from the pressurizing pump into the pressure tank, so that the vapor fuel is dissolved into the fuel in the pressure tank.

Abstract: A fuel pump suctions fuel from a fuel tank and discharges it into a pressure tank. Then, the fuel pump suctions the fuel from the pressure tank and pressurizes it. Then, the fuel pump discharges the pressurized fuel toward an engine side through a fuel discharge pipeline. A pressure control valve is opened to communicate an inside of the fuel tank and an inside of the pressure tank when a pressure in the pressure tank becomes equal to or greater than a predetermined pressure. A canister receives activated carbons for absorbing vapor fuel from the fuel tank. A pressurizing pump suctions the vapor fuel from the canister and pressurizes it. The pressurized vapor fuel is then discharged from the pressurizing pump into the pressure tank, so that the vapor fuel is dissolved into the fuel in the pressure tank.

Abstract: A canister for use in an evaporative emission control system of an automotive vehicle is provided which includes a box-like casing, an inlet port formed in one end wall of the casing through which fuel vapors generated within a fuel tank are drawn into the canister, and a plurality of vapor-adsorbing passages each of which is filled with activated carbon and has a given length through which the fuel vapors drawn through the inlet port flow. The vapor-adsorbing passages are all arranged within said casing in parallel to each other. This arrangement allows the casing to be of a flat shape which facilitates easy installation of the canister within a flat space around a fuel tank.

Abstract: A canister which can control the diffusion of evaporated fuel to surely prevent the evaporated fuel from blowing through into the atmosphere has a main chamber having therein a first adsorbent layer for adsorbing evaporated fuel and including an evaporated fuel lead-in port and a purge port, a subchamber having therein a second adsorbent layer for adsorbing evaporated fuel and including an atmospheric air lead-in port, and an air chamber communicating with the main chamber and the subchamber are provided in a casing of a canister. The air chamber is divided into three parts: a first chamber at the side of the main chamber, a second chamber at the side of the subchamber and a third chamber between the first and second chambers. A nonlinear communication passage is formed inside of the third chamber by dividing the third chamber with a partition wall having its both ends opened to the first chamber and the second chamber respectively.

Abstract: When refueling is started, a purge valve is closed, and power is supplied to a coil of a solenoid so that a constant pressure operating valve of an atmospheric escape valve is opened. When the temperature of the fuel tank rises while an engine is at a stop, fuel evaporation gas generates and the pressure within the fuel tank increases. When the differential pressure between the in-tank pressure and the atmospheric pressure increases, a first communication passage is opened, and the pressure is released to the outside. Thus, the pressure within the fuel tank can be maintained at an appropriately high pressure level while the vehicle is at a stop, and the quantity of the fuel evaporation gas generating while the vehicle is at a stop can be controlled.

Abstract: A canister for preventing diffusion of fuel vapor to atmosphere is disclosed herein. The canister includes a first case having an adsorbent material, such as activated charcoal, therein and a second case also having an adsorbent material therein. The two cases are joined by a passage having a valve disposed therein. The valve regulates the airflow between the two cases. The first case is connected to the valve, a gas tank, and an engine, while the second case is connected to the valve and to atmosphere. During a refueling operation, the valve is operated so as to allow air to flow from the tank, through the first case and out to the atmosphere through the valve, without passing through the second case.

Abstract: A canister is provided between a fuel tank and an intake conduit of an engine so that fuel vapor generated in the tank and adsorbed in the canister is purged into the intake conduit. In correcting a fuel quantity in accordance with a purge quantity, the fuel quantity is compensated for by a canister piping condition such as a pressure loss and/or a purge delay. A first fuel correction coefficient is calculated from canister pressure, intake pressure and atmospheric pressure. The first coefficient may be calculated in association with an idling speed control value. A second fuel correction coefficient is calculated from changes in purge flow quantity and canister pressure. The second coefficient may be calculated in association with an air-fuel ratio feedback control value.

Abstract: Operation of a fuel vapor control apparatus having a canister and a fuel vapor purging passage is detected occasionally by a pressure sensor which is disposed in a fuel tank of an engine. The sensor detects pressure changes in the purging passage caused by closing or opening the passage between the canister and a suction pipe of the engine, and by introducing or by interrupting the air flowing into the canister. A computer calculates signals generated by the sensor and decides whether or not any failure has occurred in the fuel vapor control apparatus. An air intake unit which has an air filter and an air switching valve is detachably installed close to the canister. When the air switching valve is controlled to introduce the air into the canister, the air passes the filter before the switching valve so that the valve may not be subject to dust or foreign particles contained in the air and good sealing of the valve is ensured for long time.

Abstract: A fuel vapor purging system includes a container in which a set of divided chambers are formed by partition walls. Absorbent is disposed in the divided chambers. The divided chambers are sequentially connected to form a zigzag passage. Fuel vapor can enter the container from a fuel tank via a vapor line connecting the fuel tank and the container. In the container, an end of the vapor line faces the divided chamber which occupies an end of the set of the divided chambers. In the container, the fuel vapor is absorbed by the absorbent. Air can escape from the container via an opening in the container. The fuel vapor can be separated from the absorbent. The separated fuel vapor can be drawn into a suitable drawing device such as an engine air induction device via a purge line connecting the container and the drawing device. Fresh air can flow into the container via an air inlet provided on the container.

Abstract: A fuel vapor treatment apparatus for a vehicle for absorbing the fuel vapor emanating from a fuel tank has a diffusing chamber at the portion into which an inlet port opens. The fuel vapor introduced through the inlet port diffuses in this diffusing chamber, by which the component of the fuel vapor velocity in the direction in which the fuel vapor is adsorbed by the adsorbent is reduced. In consequence, the capability with which the canister adsorbs the fuel vapor is increased so as to allow a large volume of fuel vapor which flows at a high flow rate to be adsorbed.

Abstract: An apparatus for treating fuel vapor, such as in a motor vehicle fuel tank, by subjecting it to adsorption treatment to prevent its direct emission into the atmosphere. The apparatus according to the present invention comprises a fuel tank, a partitioning wall provided within the fuel tank to define a small fuel storage chamber within the fuel tank, a canister container housed in the small fuel storage chamber, the canister container storing therein a fuel adsorbing material. When fuel feeding takes place, feeding fuel is introduced into the small fuel storage chamber to cool the canister container. However, when the engine is operated, high temperature return fuel is introduced into the small storage chamber to heat the canister container thereby promoting the adsorbing and de-adsorbing action of fuel by the fuel adsorbing material.