An evaporated fuel treatment device is provided with an electric-operated valve, a positive-pressure relief valve mechanism and a negative-pressure relief valve mechanism. The electric-operated valve has a valve body for opening/closing a vapor passage allowing a fuel tank and a canister, and adjusts the flow rate by electrical control. The positive-pressure relief valve mechanism opens when the pressure at the fuel tank side has a value greater than or equal to a predetermined positive pressure value. The negative-pressure relief valve mechanism opens when the pressure at the fuel tank side has a value less than or equal to a predetermined negative pressure value. The electric-operated valve is configured such that the valve body is moved in the valve opening direction by the pressure at the fuel tank side that is higher, by a predetermined value, than the valve opening pressure for the positive-pressure relief valve mechanism.

The disclosed embodiments relate to a device for operating a tank ventilation system of an internal combustion engine. This device has a fuel tank, an activated carbon filter for collecting and buffering fuel vapors escaping from the fuel tank, a purge air pump and a control unit. The outlet of the purge air pump is connected to the intake tract of the internal combustion engine via a first tank venting valve and connected to the exhaust tract of the internal combustion engine via a second tank venting valve.

A controller has a leak determiner determining the presence or absence of an evaporative gas leak in a fuel evaporative gas emission suppressing device, based on a first pressure which is the pressure of a canister when a first predetermined period has elapsed in a state where a first opening/closing section and a second opening/closing section are closed, a third opening/closing section is opened, a fourth opening/closing section is closed, and a pressure generating section is operated; and a second pressure which is the pressure within the canister when, after a lapse of the first predetermined period, a second predetermined period has elapsed in a state where the third opening/closing section is closed.

An evaporated fuel processing device configured to supply purge gas into an intake passage through which air to be suctioned into an engine passes. The evaporated fuel processing device may include a canister in which the purge gas including evaporated fuel is generated; a purge pump configured to discharge the purge gas toward the intake passage from the canister; a measurement unit configured to measure a temperature of the purge gas discharged from the purge pump; an estimation unit configured to estimate a temperature of the purge gas to be discharged from the purge pump based on an index other than the temperature measured by the measurement unit; and a controller. The controller may be configured to compare the measured temperature measured by the measurement unit with a reference temperature that is higher by a predetermined degree than the temperature estimated by the estimation unit.

An engine device is provided with a fuel vapor processor comprising a first supply pipe configured to supply a vaporized fuel gas including fuel vapor generated in a fuel tank, to a downstream side of a compressor in an intake pipe; a first valve provided in the first supply pipe; a second supply pipe configured to supply the vaporized fuel gas to an upstream side of the compressor in the intake pipe; and a second valve provided in the second supply pipe. When a supercharger operates and the first valve is closed, the engine device performs abnormality diagnosis of the second valve, based on a control state of the second valve and a pressure in the fuel tank.

In a purge control valve device, a purge valve includes a first electromagnetic valve and a second electromagnetic valve which are provided inside a housing. The first electromagnetic valve has a first valve body that controls a flow rate of evaporative fuel flowing in the housing. The second electromagnetic valve has a second valve body that controls a flow rate of evaporative fuel flowing in the housing. The upstream passage and the downstream passage are arranged in series. The first electromagnetic valve switches a seated state and an unseated state of the first valve body. The purge valve has a narrowed passage in which a flow rate of the evaporative fuel is smaller in one of the seated state and the unseated state than in another of the seated state and the unseated state.

An evaporated fuel treatment apparatus includes a partition wall for dividing the inside of a canister into a first region located close to a purge passage and a fuel tank and a second region located close to an atmosphere passage, an electromagnetic valve provided in the partition wall and configured to open and close between the first and second regions, a small hole provided in the partition wall to release the pressure between the first and second regions, and a determination unit for performing a leak determination of the apparatus and a failure determination of a purge valve and the electromagnetic valve based on behaviors of the internal pressure of the canister according to opening and closing operations of the electromagnetic valve.

A pressure sensor malfunction determination device for a fuel tank includes a fuel tank that stores fuel, a canister that absorbs an evaporated fuel gas and includes a drain port opened to atmosphere, an evaporation path communicating with the canister and fuel tank, a purge gas path communicating with an engine inlet system and the canister, a pressure sensor that detects a pressure, a solenoid valve that opens/closes the evaporation path, and a control unit that controls an opening/closing state of the solenoid valve. When the fuel tank pressure is one of predetermined positive and negative pressure states, the control unit performs valve-opening control on the solenoid valve. The control unit includes a pressure sensor malfunction determination unit that, when an output value of the pressure sensor detected under an atmospheric pressure condition corresponds to a pressure other than the atmospheric pressure, determines that the pressure sensor is malfunctioning.

A control valve assembly includes a housing accommodating an electromagnetic coil unit which is disposed in an in-housing passage and drives a valve element to open and close the in-housing passage. An inflow-outflow member is coupled to the housing, and includes an inflow portion having an inflow passage through which evaporative fuel flows toward the in-housing passage, and an outflow portion having an outflow passage through which the evaporative fuel from the in-housing passage flows. The outflow passage in the outflow portion and the inflow passage in the inflow portion communicate with each other through the in-housing passage.

A vapor impermeable solenoid includes an outer housing fabricated from a vapor impermeable material configured to prevent fuel vapor molecules from passing therethrough; windings configured to generate a magnetic flux when energized, a flux collector configured to direct the magnetic flux, a pole piece, and a magnetic armature disposed within the housing and coupled to a seal configured to selectively seal a passage that allows fuel vapor to pass to a purge canister. The magnetic armature is configured to move from a first position to a second position when an electric current is applied to the windings.