Abstract: A leakage detector includes a pressure sensor for detecting the pressure in a detecting target area of the fuel vapor treatment system and a controller. The controller measures the pressure in the detecting target area at a certain point in time. The controller then determines whether the measured pressure satisfies a condition for leakage detection by a vapor pressure device. When the controller determines that the condition is satisfied, the controller selects the vapor pressure device. When the controller determines that the condition is not satisfied, the controller predicts the change in vapor pressure at a subsequent temperature based on a saturated vapor pressure characteristic of the fuel. If it is determined the pressure in the detecting target will satisfy a predetermined condition, the controller selects a pressure application device. If it is determined that the predetermined condition will be satisfied, the controller selects the vapor pressure device.

Abstract: An evaporated fuel treatment apparatus includes an electrically-operated valve disposed between a full tank control valve and an atmosphere open port and a control unit that controls the electrically-operated valve, and the control unit performs valve-closing control that fully closes the electrically-operated valve when a valve-closing condition is satisfied after the start of fuel supply, in which a value measured by a fuel volume measurement unit is equal to or greater than a first predetermined value determined in advance and a value detected by a pressure sensor is equal to or greater than a second predetermined value determined in advance.

Abstract: A failure diagnostic device is configured to determine saturated vapor pressures of a fuel within a fuel tank. In a fuel vapor processing apparatus, some or all of the passages and spaces into which the fuel vapor flows into the fuel vapor processing apparatus are closed to the atmosphere. In this condition, the failure diagnostic device determines a plurality of saturated vapor pressure characteristics over time. The failure diagnostic device is configured to diagnose whether or not a leakage or a blockage failure in the fuel vapor processing apparatus is present. The failure diagnostic device determines a Reid vapor pressure (RVP) based on each of the plurality of determined saturated fuel vapor pressure characteristic and diagnoses whether or not a failure is present in accordance with a change in these RVPs over time.

Abstract: A concentration measuring device includes a circulation passage, an aspirator, a differential pressure sensor, and a control unit. The aspirator is disposed in a fuel tank and is connected to the circulation passage. While a gas flows from a gaseous layer within a fuel tank through the circulation passage due to a negative pressure generated in the aspirator, the differential pressure sensor measures a pressure difference of the gas within the circulation passage between an upstream side of a narrowed part, having a narrower passage area than an adjacent portion of the circulation passage, and a downstream side of the narrowed part. The control unit is configured to calculate a density of the fuel vapor from the pressure difference of the gas and to calculate a concentration of the fuel vapor from the density of the fuel vapor.

Abstract: A leakage detector includes a pressure sensor for detecting the pressure in a detecting target area of the fuel vapor treatment system and a controller. The controller measures the pressure in the detecting target area at a certain point in time. The controller then determines whether the measured pressure satisfies a condition for leakage detection by a vapor pressure device. When the controller determines that the condition is satisfied, the controller selects the vapor pressure device. When the controller determines that the condition is not satisfied, the controller predicts the change in vapor pressure at a subsequent temperature based on a saturated vapor pressure characteristic of the fuel. If it is determined the pressure in the detecting target will satisfy a predetermined condition, the controller selects a pressure application device. If it is determined that the predetermined condition will be satisfied, the controller selects the vapor pressure device.

Abstract: A leakage detector for a fuel vapor processing system includes a pressure sensor and a control unit. The pressure sensor is configured to measure an internal pressure of the fuel vapor processing system. The control unit is configured to calculate changes of a fuel vapor pressure from a saturation vapor pressure curve of the fuel vapor, a fuel vapor concentration of the fuel vapor in a gaseous layer within the fuel vapor processing system, and a convective velocity in the gaseous layer, to correct a reference pressure for leakage detection based on the changes of the fuel vapor pressure so as to calculate a corrected reference pressure, and to compare the internal pressure measured by the first pressure sensor to the corrected reference pressure so as to determine whether any of the fuel vapor has leaked from the fuel vapor processing system.

Abstract: A concentration measuring device includes a circulation passage, an aspirator, a differential pressure sensor, and a control unit. The aspirator is disposed in a fuel tank and is connected to the circulation passage. While a gas flows from a gaseous layer within a fuel tank through the circulation passage due to a negative pressure generated in the aspirator, the differential pressure sensor measures a pressure difference of the gas within the circulation passage between an upstream side of a narrowed part, having a narrower passage area than an adjacent portion of the circulation passage, and a downstream side of the narrowed part. The control unit is configured to calculate a density of the fuel vapor from the pressure difference of the gas and to calculate a concentration of the fuel vapor from the density of the fuel vapor.

Abstract: A failure diagnostic device is configured to determine saturated vapor pressures of a fuel within a fuel tank. In a fuel vapor processing apparatus, some or all of the passages and spaces into which the fuel vapor flows into the fuel vapor processing apparatus are closed to the atmosphere. In this condition, the failure diagnostic device determines a plurality of saturated vapor pressure characteristics over time. The failure diagnostic device is configured to diagnose whether or not a leakage or a blockage failure in the fuel vapor processing apparatus is present. The failure diagnostic device determines a Reid vapor pressure (RVP) based on each of the plurality of determined saturated fuel vapor pressure characteristic and diagnoses whether or not a failure is present in accordance with a change in these RVPs over time.

Abstract: An accessory component mounting structure includes a tubular pump mounting portion provided in a canister and a purge pump having a motor unit that generates heat. The purge pump is inserted into the internal space of the pump mounting portion and is mounted by snap-fitting. A gap passage extending from an opening side of the pump mounting portion to the rear side thereof is provided between the pump mounting portion and the purge pump. A first communication hole in fluid communication with the gap passage and the outside is provided in the pump mounting portion.

Abstract: An evaporated fuel treatment apparatus includes an electrically-operated valve disposed between a full tank control valve and an atmosphere open port and a control unit that controls the electrically-operated valve, and the control unit performs valve-closing control that fully closes the electrically-operated valve when a valve-closing condition is satisfied after the start of fuel supply, in which a value measured by a fuel volume measurement unit is equal to or greater than a first predetermined value determined in advance and a value detected by a pressure sensor is equal to or greater than a second predetermined value determined in advance.

Abstract: A leakage detector for fuel vapor treatment device is configured to diagnose a leakage of a fuel vapor in a vapor path based on an internal pressure change of the vapor path with the vapor path functioning as a closed space. The leakage detector performs the leakage diagnosis of the vapor path by correcting the effect of the pressure of the fuel vapor with regards to the internal pressure change. The leakage detector comprises a vaporization promoting device and is configured to determine whether the fuel vapor in the gas space of a fuel pump has reached a saturated state.