Nippondenso Co., Ltd.

Denso Corporation

Katsuhiko Nakabayashi

Noriaki Kurita

Hisashi Iida

Toshio Kondo

Shigenori Isomura

Eiichi Kurokawa

Tomoo Kawase

Junya Morikawa

Katsuhiko Kawai

Hideyuki Mori

Takahito Masuko

Kazushi Nakashima

Hiroaki Nakane

Koji Sugiura

Hiroaki Miyanaga

Tasunori Kato

A fuel supply system has an in-tank module. The in-tank module is provided with a pump, a filter, a pressure regulator and a pressure sensor detecting a fuel pressure. The pressure sensor is disposed on or at a vicinity of the fuel pump so that the pressure sensor easily detects a pulsation component due to the pump. A fuel pump controller includes a speed detection module which detects the rotation speed of the fuel pump based on a cycle of the pulsation component of the pressure detected by the pressure sensor. Thus, the rotation speed of the fuel pump can be indirectly detected by means of the pressure sensor.

Fuel supply system

An intake control device of an internal combustion engine in which an intake path of each cylinder is partitioned into an upper and a lower path and a tumble control valve and an intake pressure control valve are provided to open/close the upper path and lower path respectively. In a given driving condition, the intake air flow velocity in the lower path is increased by closing the tumble control valve, thereby generating a tumble flow in the combustion chamber. In this process, the intake pressure control valve is opened around start of an intake stroke and closed around its end to make intake pressure downstream of the intake pressure control valve higher than upstream of it to increase the difference between upstream and downstream intake pressures in the intake stroke. This increases the intake air flow velocity in the lower path and intensifies the tumble flow in the combustion chamber.

Intake control device for internal combustion engine

A correction apparatus for correcting an output of an oxygen sensor installed in an exhaust pipe of an internal combustion engine to measure the concentration of oxygen contained in exhaust gas. The apparatus works to execute a fuel cut operation to bring the pressure in the exhaust pipe to the atmospheric pressure and enters an under-atmosphere correction mode to sample an output of the oxygen sensor and determine a correction factor compensating for a deviation of the sampled output from a reference value representing an actual concentration of oxygen. The apparatus also works to calculate the pressure in the exhaust pipe after start of the fuel cut and determine whether the under-atmosphere correction mode is to be entered or not based on the pressure of exhaust gas, thereby ensuring the accuracy in correcting the output of the oxygen sensor regardless of a variation in the pressure of exhaust gas.

Oxygen sensor output correction apparatus for internal combustion engine

An evaporated fuel gas purging system performs breakdown analysis without deterioration of drivability and exhaust emission even when the amount of purged fuel gas is large. During introduction of negative pressure into the purge system, a control value DUTY sets opening of a purge control valve and a purge flow amount GPG is derived from a map based on differences in the control value DUTY, atmospheric pressure and intake pipe pressure. Thereafter, a purge ratio PGR is calculated from intake air GA and purge flow GPG (PGR=GPG/GA), and a fuel injection correction value FAFLEAK=PGR.times.(FGPGAV-1).times.K1 is calculated, with FGPGAV-1 being the air-fuel ratio feedback correction deviation per 1% purge ratio, and K1 being an error correction coefficient. Then, the fuel injection correction FAFLEAK is guard-processed to maintain it below an upper limit guard value KFLEAKMX.

Purging of evaporated fuel to engine intake with engine fuel correction

Speed control system for an internal combustion engine

Deterioration of a catalyst of a catalytic converter of an internal combustion engine is detected, during negative feedback control of the air-fuel ratio based on an output signal from at least one of a pair of O.sub.2 sensors disposed respectively upstream and downstream from the catalyst in the exhaust system. Detection is executed after changing the feedback period, which is the period of alternation of a feedback correction coefficient used to control the fuel injection quantity, with the change in period being such as to provide improved accuracy of detection of catalyst deterioration. The change may consist of a single step change, in which the feedback period is set to a specific predetermined value at which the output signal amplitude from the downstream sensor, or the phase difference between the two sensor output signals, should be within predetermined limits if the catalyst is in satisfactory condition.

Apparatus for detecting purification factor of catalyst in catalytic

An apparatus for detecting a purification factor of a catalyst for purifying an exhaust gas of an internal combustion engine comprises a catalyst disposed in an exhaust system of the internal combustion engine for purifying an exhaust gas, first and second air-fuel ratio sensors disposed upstream and downstream of the catalyst for detecting air-fuel ratios, respectively, a response delay time difference detecting device for detecting differences in response delay time between the first and second air-fuel ratio sensors in respective different operation states of the engine, a purification factor detecting device for detecting a purification factor of the catalyst on the basis of a deviation between the first and second response delay time differences detected in respective different operation states of the engine. Since the purification factor of the catalyst is detected on the basis of a deviation between the first and second response delay time differences detected in the respective different engine operation states, the purification factor of the catalyst can be detected with high accuracy independently of response characteristics of the first and second air-fuel ratio sensors themselves.

Apparatus for detecting purification factor of catalyst

Growing community of inventors

Handa, Japan

Katsuhiko Nakabayashi