Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Other

Kenji Nagasaki

Tokiji Ito

Hideki Miyahara

Masao Kano

Yasuo Kato

Nobuhiko Koyama

Mitsuyuki Kobayashi

Akira Ichikawa

Yoshichika Yamada

Shinsuke Kiyomiya

Koji Wada

Shuichi Hanai

Kenichi Nagase

When a coolant temperature is abnormal and alcohol concentration of a main fuel detected by an alcohol concentration sensor is in a high concentration region, an auxiliary fuel supply is conducted. Thus, when the actual coolant temperature is in a low temperature region and an alcohol concentration of the main fuel is in a high concentration region, that is, when a volatility of the main fuel is not sufficient, the auxiliary fuel supply is certainly conducted. Furthermore, when the coolant temperature sensor is abnormal, the pseudo coolant temperature is set lower than the standard coolant temperature. A warming increase coefficient is computed by use of the pseudo coolant temperature. Thereby, the main fuel injection quantity is increased sufficiently when the actual coolant temperature is in a low temperature region and the alcohol concentration of the main fuel is in high concentration region.

Controller for internal combustion engine

A drive control device of a fuel pump for sucking fuel in a fuel tank supplying the fuel to an internal combustion engine, and using a motor with a brush as a drive source thereof. The drive control device includes a starting current reduction control device that starts the fuel pump in a state where a drive current of the fuel pump is reduced.

Drive control device of fuel pump

A concentration-detecting unit detects concentration of fuel vapor flowing in a concentration-detecting passage branched from a purge passage. The concentration-detecting passage communicates with a communicating passage of a canister. Air including the fuel vapor of which concentration is detected by a concentration-detecting unit is returned to the communicating passage of the canister. The fuel vapor is adsorbed by an absorbent accommodated in a accommodating chamber to restrict a discharge of the fuel vapor into atmosphere.

Fuel vapor treatment apparatus

A suction pump introduces negative pressure into a reference-pressure-detecting portion. A driving voltage V of the suction pump is adjusted in such a manner that pressure Pr in the reference-pressure-detecting portion is within a target pressure range. When the pressure Pr is brought into the target pressure range, the driving voltage V of the suction pump is stored as a first driving voltage Vand the pressure Pr is stored as a reference pressure Pr. When pressure detection and leak detection process are conducted, the suction pump is driven at the first driving voltage Vto introduce the negative pressure. The computer compares the pressure Pr with a leak determination value to determine whether a leak exists.

Leak detector for fuel vapor purge system

After a reference pressure using a reference hole is measured, a pressure in an evaporation path is measured. An ECU conducts failure diagnosis using, as a determination pressure for diagnosing presence/absence of a failure, a value obtained by correcting the reference pressure using the reference hole in a manner lowering the same by a predetermined amount, taking into account pressure lowering in the evaporation path due to condensation of fuel vapor at the time of adsorption in a canister when a vapor concentration in the evaporation path is high.

Failure diagnostic apparatus for fuel vapor purge system and fuel vapor purge apparatus and combustion engine having failure diagnostic apparatus

When a purge amount while an engine is running is a first purge amount and the purge amount before failure diagnosis is larger than a required purge amount, an amount adsorbed in a canister before the failure diagnosis is executed is smaller than a predetermined determination value. Accordingly, an ECU executes the failure diagnosis. When the purge amount while the engine is running is a second purge amount and the purge amount before the failure diagnosis is equal to or smaller than the required purge amount, the amount adsorbed in the canister before the failure diagnosis is equal to or larger than the predetermined determination value. Accordingly the ECU does not execute the failure diagnosis. The required purge amount used for determining whether or not the failure diagnosis can be executed is determined according to the temperature before the failure diagnosis.

Pressure leakage in an evaporated fuel control system having a canister for absorbing evaporated fuel in a fuel tank is detected after an engine is stopped and a temperature in the system is stabilized. In the leakage detecting process, communication between the system and an atmospheric pressure is shut-off by closing an electromagnetic valve connected to the canister. The electromagnetic valve is closed by once supplying a full voltage thereto, and the closed-state is maintained by intermittently supplying a voltage in a duty-ratio-controlled manner or by supplying a lower voltage. Thus, power consumption for maintaining the closed-state is reduced.

Method of detecting pressure leakage in evaporated fuel control system for use in automobile

An evaporative emission leak detection system provides for detecting a leakage of a fuel vapor evaporating in a fuel tank by using a pressure difference between an inside and outside of the fuel tank. The system includes a pump for providing the pressure difference between the inside and outside of the fuel tank, a brushless motor for operating the pump, a first passage connecting to the fuel tank, a second passage connecting to the outside of the fuel tank, and a switching device for switching connections between the pump and at least one of the first passage and the second passage. The first passage has an adsorbent for adsorbing the fuel vapor. This system ensures a long life time and high accuracy of the leak detection.

Evaporative emission leak detection system with brushless motor

A fuel vapor purge system includes a fuel tank, a canister, and an evaporation route, and purges fuel vapor collected in the canister into an intake passage of an internal combustion engine. A failure diagnosis apparatus of the fuel vapor purge system includes a controller having a pressure difference applying unit for applying a pressure difference between the evaporation route and outside air. The controller also detects a level of an influence of the fuel vapor generated in the fuel tank on failure determination of the evaporation route, and detects both a pressure state obtained when the pressure difference applying unit communicates with a reference orifice communicating with the outside air and a pressure state obtained when the pressure difference applying unit communicates with the evaporation route. The failure diagnosis apparatus determines whether there is a failure in the evaporation route in view of the level of the influence by comparing the detected pressure states with each other.

Apparatus and method for failure diagnosis of fuel vapor purge system

When detection of an abnormality in a fuel vapor treating system is executed, a vapor zone including a fuel tank and a canister is sealed. The sealed vapor zone is pressurized. Whether fuel vapor is leaking from the vapor zone is determined based on the pressure in the sealed vapor zone. A canister valve selectively connects a canister with and disconnects the canister from the atmosphere. During the abnormality detecting procedure, an electronic control unit (ECU) shuts the canister valve. After the abnormality detecting procedure is ended, the ECU sends a control signal having a predetermined frequency to the canister valve, thereby gradually increasing the opening size of the canister valve. Accordingly, the pressure in the vapor zone is gradually lowered to the atmospheric pressure. This prevents fuel vapor adsorbed by the canister from being released to the atmosphere.

Growing community of inventors

Nagoya, Japan

Kenji Nagasaki