Toyota Jidosha Kabushiki Kaisha

Shuji Yuda

Akinori Osanai

Toshinari Nagai

Hiroshi Kanai

Kenji Harima

Kazuhiko Iwano

Nobuyuki Kobayashi

Tomohiro Nakano

Mitsuru Takada

Takayuki Demura

Takahiro Uchida

Koji Okawa

Masakatsu Nagai

Kazuhiro Iwano

In a hydraulic actuator control device, a changing tendency of responsiveness of a hydraulic actuator to changes in the oil control valve (OCV) drive duty of a virtual OCV is stored as model control characteristics. The ratio of an actual OCV dead zone width to a virtual OCV dead zone width is calculated as an OCV variation correction coefficient. A basic control amount is calculated based on a deviation between an operating amount and a target operating amount of the hydraulic actuator. An actual OCV in-dead-zone control amount is obtained by correcting a virtual OCV in-dead-zone control amount with the OCV variation correction coefficient, and an actual OCV out-of-dead-zone control amount is calculated based on a virtual OCV out-of-dead-zone control amount. The actual OCV control amount is the sum of the actual OCV in-dead-zone control amount and the actual OCV out-of-dead-zone control amount.

Hydraulic actuator control device and hydraulic actuator control method

The apparatus is arranged with a duty control valve 21 in a passage 19 for purged gas, connected between a canister 16 which temporarily traps fuel vapor and an air-intake passage 23 of an engine 1. The valve 21 is controlled to open and close at predetermined interval and supplies the purged gas to the air-intake passage 23. The apparatus comprises an interval changing means for changing an ON-OFF interval of the valve 21 shorter than normal at the particular engine operating condition. Another apparatus equipped with a multiple cylinder engine comprises a cylinder selecting means for selecting a cylinder sucking in the largest volume of the purged gas, and a torque fluctuation preventing means for equalizing the combustion pressure in all cylinders of the engine.

Apparatus for disposing of fuel vapor

This fuel injection control apparatus consists of a calculating device for calculating an air-fuel ratio correction factor FAF, a learning device for learning an air-fuel ratio learning factor KG in accordance with the deviation of FAF from the reference value, and a controller for controlling the amount of injected fuel in accordance with FAF and KG. When the start enrichment FASE and the warm-up enrichment FWL are added, KG is learned in accordance with the corrected deviation which is the deviation of FAF corrected by the correction factor f(FASE+FWL) which is concerned with FASE and FWL. The learning accuracy is improved because KG is learned at each region of FWL which is divided into plural regions in accordance with the engine driving conditions.

Fuel-injection control apparatus for an engine

Fuel-vapor evaporating from a fuel tank is led though a vapor pipe and absorbed in a charcoal canister. Though the evaporating rate is influenced by the altitude where the automobile operates, the air-fuel ratio must be controlled within the proper range. This apparatus controls a purge valve in accordance with the purge rate which is determined based on the standard atmospheric pressure and compensated in accordance with the present atmospheric pressure. Therefore, this apparatus can precisely control the amount of purged fuel and the air-fuel ratio.

Apparatus for disposing of fuel-vapor

Fuel-vapor evaporating from a fuel tank is led through a vapor pipe and absorbed in a charcoal canister. Fuel-vapor stored in the charcoal canister is supplied to an inlet pipe when a purge valve is opened when the engine is driven, because the pressure in the inlet pipe is low. Fuel-vapor is then burned as fuel in the engine. If the opening of the purge valve is suddenly increased at the start of the purge, the air fuel ratio control is disturbed. Therefore, the purge rate is gradually increased and the vapor concentration of the fuel-vapor purged from the charcoal canister is learned, and the change rate of the purge rate is made small because the air-fuel ratio control may be disturbed when the vapor concentration is not learned enough.

Fuel-vapor evaporating from a fuel tank 13 is led through a vapor pipe 133 and absorbed in a charcoal canister 14. When a large amount of fuel is trapped in the charcoal canister, the learning of the basic air-fuel ratio correction factor executed in the control system 15 is interrupted in order to avoid faulty learning and the purging of fuel from the charcoal canister to the engine is continued in order to ensure sufficient fuel-purging. Only when a small amount of fuel is trapped in the charcoal canister, and the engine is driving in the region where the basic air-fuel ratio correction factor has not been learned, its learning is executed.

An air-fuel ratio control apparatus includes: a determining part for determining a target purge ratio in accordance with operating conditions of an engine; a purge control part for controlling a flow rate of evaporated fuel, supplied from an evaporated fuel purge system into an intake passage of the engine, by actuating a purge control valve based on the target purge ratio, and for storing an evaporated fuel flow rate of the purge control valve; a fuel injection control part for generating a drive signal in accordance with a fuel injection time, and for controlling an air-fuel ratio of an air-fuel mixture to the intake passage by actuating a fuel injection valve in accordance with the drive signal; an estimating part for estimating the ratio of an evaporated fuel flow rate to an intake air flow rate based on sensed operating conditions of the engine and on the stored evaporated fuel flow rate of the purge control part; and a fuel injection time determining part for determining a fuel injection time based on the estimated ratio, and for supplying the fuel injection time to the fuel injection control part.

Growing community of inventors

Susono, Japan

Shuji Yuda