Abstract: In a fuel property sensor, a pair of first and second electrodes is arranged in a fuel chamber to measure an electric capacitance, thereby detecting a mixing ratio of alcohol to gasoline in a fuel of the fuel chamber. An outer wall surface of the first electrode is exposed in the fuel, and a sensing portion contacts an inner wall surface of the first electrode to detect a temperature of the fluid via the first electrode. One end portion of a lead is connected to the sensing portion and the other end portion thereof is connected to a plate portion attached to a housing. Furthermore, an elastic deformation portion is provided as a part of the lead to be elastically deformed, and to cause the sensing portion to be biased in a direction on which the sensing portion contacts the inner wall surface of the first electrode.

Abstract: In a fuel property detection device, a fuel housing is made of a thin-plate metal member that can be elastically-deformed by a fuel pressure in a fuel chamber. Thus, if the fuel pressure in the fuel chamber is increased, the fuel housing expands and the pressure in the fuel chamber is decreased. Further, if the fuel pressure in the fuel chamber is decreased, the fuel housing contracts and the pressure in the fuel chamber is increased. That is, the fuel housing functions as a kind of damper. Therefore, in the fuel property detection device, generation of abnormal noise due to fuel pulsation or the like, and a positional change of the electrodes due to the fuel pulsation or the like can be prevented.

Abstract: A fuel property sensor, which is installed to a fuel tank of a fuel tank assembly, senses a property of fuel at the fuel tank. First and second electrodes of the fuel property sensor are made of an electrically conductive material and are exposed in a fuel flow passage in a housing of the fuel property sensor such that the first and second electrodes are generally parallel to a flow direction of fuel in the fuel flow passage and are spaced from each other by a predetermined distance. The fuel property sensor determines the property of the fuel based on a capacitance, which is generated between the first electrode and the second electrode.

Abstract: A microcomputer of an alcohol concentration sensor reads a first measurement value corresponding to a first frequency and reads a second measurement value corresponding to a second frequency. The microcomputer calculates a difference between the first and second measurement values. The microcomputer performs stuck failure abnormality determination when a state where the difference between the measurement values is equal to or smaller than a predetermined value continues. The microcomputer outputs a PWM signal of a specific frequency, which is different from a frequency in a case of a normality, to an engine ECU. Thus, a failure of the alcohol concentration sensor can be surely determined.

Abstract: A capacitance sensing section senses a capacitance between first and second electrodes. A temperature sensing section senses fuel temperature. A microcomputer functions as a concentration sensing section and senses a concentration of ethanol contained in fuel based on the capacitance sensed by the capacitance sensing section and the temperature sensed by the temperature sensing section. The microcomputer functions as an abnormality detecting section and performs abnormality determination to determine that an abnormality has occurred in the capacitance sensing section when the capacitance sensed by the capacitance sensing section does not change and the temperature sensed by the temperature sensing section changes. Since a dielectric constant has such a temperature characteristic that the dielectric constant changes with the temperature, the abnormality detecting section can detect occurrence of the abnormality in the capacitance sensing section.

Abstract: In a fuel property sensor, a pair of first and second electrodes is arranged in a fuel chamber to measure an electric capacitance, thereby detecting a mixing ratio of alcohol to gasoline in a fuel of the fuel chamber. An outer wall surface of the first electrode is exposed in the fuel, and a sensing portion contacts an inner wall surface of the first electrode to detect a temperature of the fluid via the first electrode. One end portion of a lead is connected to the sensing portion and the other end portion thereof is connected to a plate portion attached to a housing. Furthermore, an elastic deformation portion is provided as a part of the lead to be elastically deformed, and to cause the sensing portion to be biased in a direction on which the sensing portion contacts the inner wall surface of the first electrode.

Abstract: In a fuel property detection device, a fuel housing is made of a thin-plate metal member that can be elastically-deformed by a fuel pressure in a fuel chamber. Thus, if the fuel pressure in the fuel chamber is increased, the fuel housing expands and the pressure in the fuel chamber is decreased. Further, if the fuel pressure in the fuel chamber is decreased, the fuel housing contracts and the pressure in the fuel chamber is increased. That is, the fuel housing functions as a kind of damper. Therefore, in the fuel property detection device, generation of abnormal noise due to fuel pulsation or the like, and a positional change of the electrodes due to the fuel pulsation or the like can be prevented.

Abstract: A liquid concentration sensor includes an electrode capacitance conversion circuit, a stray capacitance conversion circuit and a difference calculation circuit. The electrode capacitance conversion circuit includes a detection electrode and a switching device. The detection electrode has a pair of opposing terminals and is partially located in a liquid fuel. The switching device is turned ON and OFF to switch between charging and discharging of the detection electrode. The electrode capacitance conversion circuit outputs a first measurement value determined by the charging and discharging of the detection electrode. The stray capacitance conversion circuit has the almost same configuration as the electrode capacitance conversion circuit so as to output a second measurement value corresponding to a stray capacitance of the electrode capacitance conversion circuit. The difference calculation circuit outputs a difference between the first and second measurement values.

Abstract: An object of the invention is to provide a fuel-aspect sensor having higher detection accuracy. A first electrode is inserted into a hole formed in a first housing member. A cylindrical second electrode is inserted into and firmly fixed to the first electrode by a cylindrical insulating member. A first elastic member, for example, made of rubber, is arranged between the first electrode and a second housing member. The first electrode has a large-diameter portion, which is biased by the first elastic member toward a sealing surface formed on an inner wall of the hole, so as to fluid-tightly seal a space between the first electrode and the second housing member.

Abstract: At the time of shifting a fuel property value associated with a first imaginary passage cell as a fuel property value associated with a second imaginary passage cell located on the downstream side thereof, the fuel property value associated with the second imaginary passage cell is corrected in a controller by computing a difference between the fuel property value associated with the first imaginary passage cell and the fuel property value associated with the second imaginary passage cell and multiplying the difference by a correction coefficient. A stoichiometric air/fuel ratio is computed in the controller based on the fuel property value, which is associated with a last one of the imaginary passage cells. Fuel injection of an injector is controlled by the controller based on a computed injection quantity of fuel, which is computed based on the stoichiometric air/fuel ratio.

Abstract: A fuel property detection device for detecting a property of fuel based on a detection signal output from a photoreceptor includes a light guiding member having a reflecting surface located in direct contact with the fuel. The light guiding member includes a light emitting surface through which measurement light from a light source is emitted from the light guiding member into the fuel, a light incident surface through which the measurement light emitted from the light emitting surface and passing through the fuel enters again the light guiding member, and the reflecting surface from which the measurement light incident from the light incident surface is reflected toward the photoreceptor. The light incident surface and the light emitting surface are opposite to each other to have a space therebetween in the light guiding member, and the space is provided to be filled with the fuel.

Abstract: A self-opened type valve is opened by motor torque of an electric motor. Therefore, a diaphragm is not necessary for opening the valve, and downsizing of a valve drive apparatus for opening the valve is possible. Since the valve is assembled to the motor shaft of the electric air pump via a motion-direction conversion mechanism, an opening action of the valve can start in a short time after a rotational action of the impeller of the electric air pump starts, so that control responsiveness is improved. At a rotation stop of the impeller of the electric air pump, the valve can be maintained in a fully closed condition by an urging force of the coil spring, thereby preventing exhaust gases or condensed water from entering into an inside of the electric air pump.

Abstract: A fuel property sensor, which is installed to a fuel tank of a fuel tank assembly, senses a property of fuel at the fuel tank. First and second electrodes of the fuel property sensor are made of an electrically conductive material and are exposed in a fuel flow passage in a housing of the fuel property sensor such that the first and second electrodes are generally parallel to a flow direction of fuel in the fuel flow passage and are spaced from each other by a predetermined distance. The fuel property sensor determines the property of the fuel based on a capacitance, which is generated between the first electrode and the second electrode.

Abstract: An alcohol density sensor for detecting an alcohol density in mixture fuel composed of petroleum-fuel and alcohol is installed in a fuel tank of an automotive vehicle. The alcohol density sensor includes a pair of electrodes immersed in the mixture fuel and a conductor portion for connecting the electrodes to a control unit having a circuit board. The conductor portion is composed of a first conductor portion integrally formed with the electrode and a second conductor portion connected to the first conductor portion. The first conductor portion is led out of a casing containing the electrodes and liquid-tightly sealed at a first through-hole formed in the casing. The second conductor portion is led out of the fuel tank through a second through-hole formed in the fuel tank. Since the first through-hole is sufficiently sealed to prevent pressurized mixture fuel in the casing from leaking into an inner space of the fuel tank, sealing of the second through-hole can be simplified.

Abstract: A fuel property detection device for detecting a property of fuel based on a detection signal output from a photoreceptor includes a light guiding member having a reflecting surface located in direct contact with the fuel. The light guiding member includes a light emitting surface through which measurement light from a light source is emitted from the light guiding member into the fuel, a light incident surface through which the measurement light emitted from the light emitting surface and passing through the fuel enters again the light guiding member, and the reflecting surface from which the measurement light incident from the light incident surface is reflected toward the photoreceptor. The light incident surface and the light emitting surface are opposite to each other to have a space therebetween in the light guiding member, and the space is provided to be filled with the fuel.

Abstract: In a detection of an alcohol concentration, a first light and a second light are irradiated to a mixed liquid including a fossil fuel, an alcohol, and water, and the alcohol concentration is calculated based on amounts of the first light and the second light permeated through the mixed liquid. In the detection, a difference of a transmittance of the fossil fuel with respect to the first light and each transmittance of the alcohol and water with respect to the first light is larger than a first value. In addition, a difference of a transmittance of water with respect to the second light and each transmittance of the fossil fuel and the alcohol with respect to the second light is larger than a second value.

Abstract: A canister is connected with a fuel tank to adsorb fuel vapor generated in the fuel tank. The canister is also connected to a downstream side point of an intake air pipe, which is on a downstream side of a supercharging device, through a first purge line. The canister is also connected to an upstream side point of the intake air pipe, which is on an upstream side of the supercharging device, through a second purge line. An ECU opens a first valve of the first purge line and a second valve of the second purge line to generate an air flow through the first connection passage, the canister and the second connection passage to desorb the fuel vapor from the adsorbent and to purge the desorbed fuel vapor into the intake air passage in an operational period of the supercharging device.

Abstract: A canister is connected with a fuel tank to adsorb fuel vapor generated in the fuel tank. The canister is also connected to a downstream side point of an intake air pipe, which is on a downstream side of a supercharging device, through a first purge line. The canister is also connected to an upstream side point of the intake air pipe, which is on an upstream side of the supercharging device, through a second purge line. An ECU opens a first valve of the first purge line and a second valve of the second purge line to generate an air flow through the first connection passage, the canister and the second connection passage to desorb the fuel vapor from the adsorbent and to purge the desorbed fuel vapor into the intake air passage in an operational period of the supercharging device.

Abstract: A fuel handling apparatus with a purge system, a first communication passage, and a second communication passage with a greater pressure loss than the first communication passage. A check device is coupled to the second communication passage for checking a leak of evaporative fuel from the purge system. A pump is included, and a selector device is included for switching fluid communication of the pump between one of the first communication passage and the second communication passage. A controller controls the selector device to allow fluid communication between the first communication passage and the pump and then controls the pump to produce the pressure difference for forcible purging. The controller further controls the selector device to allow fluid communication between the second communication passage and the pump, and then controls the pump to produce the pressure difference and controls the check device for leak checking.

Abstract: A fuel handling apparatus with a purge system, a first communication passage, and a second communication passage with a greater pressure loss than the first communication passage. A check device is coupled to the second communication passage for checking a leak of evaporative fuel from the purge system. A pump is included, and a selector device is included for switching fluid communication of the pump between one of the first communication passage and the second communication passage. A controller controls the selector device to allow fluid communication between the first communication passage and the pump and then controls the pump to produce the pressure difference for forcible purging. The controller further controls the selector device to allow fluid communication between the second communication passage and the pump, and then controls the pump to produce the pressure difference and controls the check device for leak checking.