Abstract: An air suction device is provided with an air suction system having at least one capacity-enlarged portion, a compression pump compressing air in synchronization with operation of an engine, a compression air control unit, and a vibration plate which is vibration-excited by air compressed by the compression pump and disposed in a connection passage connecting a discharge side of the compression pump with the capacity-enlarged portion. The compression air control unit controls the phase and amplitude of a pressure variation of compression air discharged from the compression pump, to provide compression air with the pressure variation having the phase opposite to a pressure variation of suction air sucked into the engine.

Abstract: A butterfly valve restricts flow passage areas of a purge passage and a blow-by gas passage by the same degree. A first pressure sensor detects variation in pressure of the purge gas, which is generated by the butterfly valve. A second pressure sensor detects variation in pressure of the blow-by gas, which is generated by the butterfly valve. Since a fuel vapor concentration of the blow-by gas is lower than that of the purge gas, the blow-by gas can be treated as air of 100%. Hence, the fuel vapor concentration is calculated based on the variations in pressure detected by the first pressure sensor and the second pressure sensor.

Abstract: A butterfly valve restricts flow passage areas of a purge passage and a blow-by gas passage by the same degree. A first pressure sensor detects variation in pressure of the purge gas, which is generated by the butterfly valve. A second pressure sensor detects variation in pressure of the blow-by gas, which is generated by the butterfly valve. Since a fuel vapor concentration of the blow-by gas is lower than that of the purge gas, the blow-by gas can be treated as air of 100%. Hence, the fuel vapor concentration is calculated based on the variations in pressure detected by the first pressure sensor and the second pressure sensor.

Abstract: A PCV valve is arranged in an outflow passage. An ECU controls rotation of a motor such that an opening degree of the PCV valve increases in response to an increase in an opening degree of a throttle valve. The outflow passage connects an interior of a head cover of an engine to a portion of an intake air passage located on a downstream side of the throttle valve. The outflow passage recirculates blow-by gas leaked from a combustion chamber into an interior of a crankcase to the portion of the intake air passage located on the downstream side of the throttle valve. An inflow passage connects the interior of the head cover to a portion of the intake air passage located on an upstream side of the throttle valve. The inflow passage conducts intake air from the intake air passage to the interior of the head cover.

Abstract: An air suction device is provided with an air suction system having at least one capacity-enlarged portion, a compression pump compressing air in synchronization with operation of an engine, a compression air control unit, and a vibration plate which is vibration-excited by air compressed by the compression pump and disposed in a connection passage connecting a discharge side of the compression pump with the capacity-enlarged portion. The compression air control unit controls the phase and amplitude of a pressure variation of compression air discharged from the compression pump, to provide compression air with the pressure variation having the phase opposite to a pressure variation of suction air sucked into the engine.

Abstract: A canister is connected to a fuel tank to adsorb fuel vapor vaporized in the fuel tank and includes a canister housing and a canister main body, which is received in the canister housing and communicates with the fuel tank at one end. The canister housing includes an atmospheric port and a filter chamber, and the filter chamber receives a filter and communicates between the other end of the canister main body and the atmospheric port, which in turn communicates with the atmosphere. The filter includes an active carbon part, an atmosphere-side unwoven fabric and a tank-side unwoven fabric. The active carbon part includes active carbon granules, which adsorb fuel vapor vaporized in the fuel tank. The atmosphere-side unwoven fabric and the tank-side unwoven fabric sandwich the active carbon part therebetween in a flow direction of air, which passes through the active carbon part.

Abstract: A controller for an engine including a fuel vapor processing mechanism. The controller determines the amount of fuel vapor drawn into an intake passage based on the concentration of fuel vapor purged into the purge passage. The controller corrects the fuel injection amount of a fuel injection valve in accordance with the determined amount of fuel vapor. The controller starts correcting the fuel injection amount from the cylinder that is undergoing an intake stroke when the crankshaft is rotated to a certain crank angle.

Abstract: A fuel vapor leakage inspection apparatus utilizes a fuel tank, an adsorption container which houses an adsorbent for adsorbing fuel vapor generated in the fuel tank, and an exhaust device for communicating between the adsorption container and an intake pipe. Furthermore, the apparatus utilizes a pressure means that pressurizes or depressurizes a fuel vapor path formed from the fuel tank through the adsorption container to the exhaust device. A leakage detection means detects leakage from the fuel vapor path after the fuel vapor path is pressurized or depressurized by the pressure means while a calculation means calculates an amount of fuel vapor adsorbed, and a control means determines if the pressure means should execute leakage inspection of the fuel vapor path in accordance with the amount of the fuel vapor calculated by the calculation means.

Abstract: An evaporated fuel adsorbing apparatus for an engine intake passage includes a layer of activated carbon disposed in the engine intake passage for adsorbing evaporated fuel. The activated carbon includes activated carbon pellets having pores. At least one of an average pellet size and an average pore size of the activated carbon is varied in an intake gas flow direction of the engine intake passage. More particularly, an average pore size of a first portion of the activated carbon located in an atmosphere side portion of the layer is greater than an average pore size of a second portion of the activated carbon located in an engine side of the layer. An average pellet size of the first portion of the activated carbon is smaller than an average pellet size of the second portion of the activated carbon.

Abstract: A controller for an engine including a fuel vapor processing mechanism. The controller determines the amount of fuel vapor drawn into an intake passage based on the concentration of fuel vapor purged into the purge passage. The controller corrects the fuel injection amount of a fuel injection valve in accordance with the determined amount of fuel vapor. The controller starts correcting the fuel injection amount from the cylinder that is undergoing an intake stroke when the crankshaft is rotated to a certain crank angle.

Abstract: An apparatus detects leak in a fuel vapor treatment system which is referred to as an evaporation system. The apparatus measures a required time T2 that is required for decreasing pressure in the evaporation system from P0 to P1 while opening a base leak hole that provides known amount of leak. Then, a required time T1 that is required for decreasing pressure from P0 to P1 is measured while closing the base leak hole. The apparatus compares the required times T1 and T2 in order to detect a leak other than the base leak hole. In this process, a specified coefficient that is defined in accordance with the base leak hole is taken into consideration. It is possible to detect the leak of the evaporation system with high accuracy even when the amount of remaining fuel is extremely large.

Abstract: A fuel vapor leakage inspection apparatus utilizes a fuel tank, an adsorption container which houses an adsorbent for adsorbing fuel vapor generated in the fuel tank, and an exhaust device for communicating between the adsorption container and an intake pipe. Furthermore, the apparatus utilizes a pressure means that pressurizes or depressurizes a fuel vapor path formed from the fuel tank through the adsorption container to the exhaust device. A leakage detection means detects leakage from the fuel vapor path after the fuel vapor path is pressurized or depressurized by the pressure means while a calculation means calculates an amount of fuel vapor adsorbed, and a control means determines if the pressure means should execute leakage inspection of the fuel vapor path in accordance with the amount of the fuel vapor calculated by the calculation means.

Abstract: A fuel vapor leakage inspection apparatus utilizes a fuel tank, an adsorption container which houses an adsorbent for adsorbing fuel vapor generated in the fuel tank, and an exhaust device for communicating between the adsorption container and an intake pipe. Furthermore, the apparatus utilizes a pressure means that pressurizes or depressurizes a fuel vapor path formed from the fuel tank through the adsorption container to the exhaust device. A leakage detection means detects leakage from the fuel vapor path after the fuel vapor path is pressurized or depressurized by the pressure means while a calculation means calculates an amount of fuel vapor adsorbed, and a control means determines if the pressure means should execute leakage inspection of the fuel vapor path in accordance with the amount of the fuel vapor calculated by the calculation means.

Abstract: An evaporated fuel adsorbing apparatus for an engine intake passage includes a layer of activated carbon disposed in the engine intake passage for adsorbing evaporated fuel. The activated carbon includes activated carbon pellets having pores. At least one of an average pellet size and an average pore size of the activated carbon is varied in an intake gas flow direction of the engine intake passage. More particularly, an average pore size of a first portion of the activated carbon located in an atmosphere side portion of the layer is greater than an average pore size of a second portion of the activated carbon located in an engine side of the layer. An average pellet size of the first portion of the activated carbon is smaller than an average pellet size of the second portion of the activated carbon.

Abstract: An apparatus detects leak in a fuel vapor treatment system which is referred to as an evaporation system. The apparatus measures a required time T2 that is required for decreasing pressure in the evaporation system from P0 to P1 while opening a base leak hole that provides known amount of leak. Then, a required time T1 that is required for decreasing pressure from P0 to P1 is measured while closing the base leak hole. The apparatus compares the required times T1 and T2 in order to detect a leak other than the base leak hole. In this process, a specified coefficient that is defined in accordance with the base leak hole is taken into consideration. It is possible to detect the leak of the evaporation system with high accuracy even when the amount of remaining fuel is extremely large.

Abstract: When purge control of fuel vapor, which is released from a fuel tank and is then adsorbed and retained in a fuel adsorption layer of a canister, is performed through ON/OFF control of a purge valve, ON/OFF of a heater plate received in the canister is controlled based on a purge fuel vapor concentration estimated through air-fuel ratio control operation of an engine. In this way, a sensor for measuring the purge fuel vapor concentration of the fuel vapor conducted from the canister to an intake passage of the engine can be eliminated.

Abstract: An apparatus detects leak in a fuel vapor treatment system which is referred to as an evaporation system. The apparatus measures a required time T2 that is required for decreasing pressure in the evaporation system from P0 to P1 while opening a base leak hole that provides known amount of leak. Then, a required time T1 that is required for decreasing pressure from P0 to P1 is measured while closing the base leak hole. The apparatus compares the required times T1 and T2 in order to detect a leak other than the base leak hole. In this process, a specified coefficient that is defined in accordance with the base leak hole is taken into consideration. It is possible to detect the leak of the evaporation system with high accuracy even when the amount of remaining fuel is extremely large.

Abstract: A shut off valve is provided in an intake line farther upstream than a throttle valve of the intake passage and farther downstream than an air cleaner. This shut off valve is opened by a signal or the like from an ECU when an engine is operating. Further, the shut off valve closes when the engine is stopped so as to suppress evaporative fuel inside the intake passage from flowing outside through the air cleaner. The evaporative fuel trapped inside the intake passage passes through a bypass passage that provides communication between the intake passage and the canister, and is then adsorbed with an adsorbent in the canister. A blow-by passage is also connected to the intake passage that is closed off by the shut off valve. Because the blow-by passage is closed off by a blow-by valve, which is closed during normal operation when the engine is stopped, sticking of the shut off valve and the throttle valve and the like due to the inflow of blow-by gas into the intake passage is inhibited.

Abstract: In a double-acting diaphragm pump, a diaphragm is provided to divide a pump body into two pump chambers. An electromagnetic-type reciprocating actuator is provided in a housing hermetically integrated with the pump body. Different from an electric-type pump, the actuator is integrally mounted on the double-acting diaphragm pump and an entire system is hermetically sealed. Therefore, even if the diaphragm is torn, fuel vapor is prevented from leaking outside. Additionally, four check valves are provided to control the discharge of vapor from a canister side to an engine side. These check valves may employ a reed to control vapor flow or a spring and plate to control flow. In addition, since the pump may be a double-acting type, a large discharge volume is obtained and the pump can be made smaller. The pump may also be a non double-acting type.

Abstract: A canister is connected to a fuel tank to adsorb fuel vapor vaporized in the fuel tank and includes a canister housing and a canister main body, which is received in the canister housing and communicates with the fuel tank at one end. The canister housing includes an atmospheric port and a filter chamber, and the filter chamber receives a filter and communicates between the other end of the canister main body and the atmospheric port, which in turn communicates with the atmosphere. The filter includes an active carbon part, an atmosphere-side unwoven fabric and a tank-side unwoven fabric. The active carbon part includes active carbon granules, which adsorb fuel vapor vaporized in the fuel tank. The atmosphere-side unwoven fabric and the tank-side unwoven fabric sandwich the active carbon part therebetween in a flow direction of air, which passes through the active carbon part.