Toyota Jidosha Kabushiki Kaisha

Toyoto Jidosha Kabushiki Kaisha

Kunihiko Nakata

Mamoru Yoshioka

Toshihisa Sugiyama

Toru Kidokoro

Takahiko Fujiwara

Hiroki Ichinose

Akira Kotani

Makoto Makino

Atsunori Hirata

Yuji Kanto

Yasuyuki Irisawa

Kenji Sakurai

Shigeru Yoshiyama

Masanobu Kanamaru

Takashi Miyake

Hiroaki Mizoguchi

Yoshiaki Atsumi

Masaaki Kawai

Hiroki Wada

Keizo Takahashi

Shunichi Ide

Yuuji Kantou

The combustion air-fuel ratio is made leaner than the stoichiometric air-fuel ratio at the time of engine startup and the combustion air-fuel ratio is made richer than the stoichiometric air-fuel ratio and the exhaust downstream part of the three-way catalyst apparatus is raised in temperature when it is judged that just the exhaust upstream part of the three-way catalyst apparatus arranged in the engine exhaust system has been raised to the catalyst activation temperature.

Air-fuel ratio control device of internal combustion engine

The exhaust gas purifying catalysts sometimes generate HS which emits exhaust odor under reducing atmosphere. However, in the ordinary air-fuel ratio control, it takes much time to establish sufficient oxygen atmosphere for suppressing HS emission when the maximum oxygen storage amount which the exhaust gas purifying catalyst can store is large. Thus, the fuel cut control apparatus of an internal combustion engine executes fuel cut to bring oxygen in the exhaust gas into an excessive state when the maximum oxygen storage amount is a predetermined amount or more. As a result, sufficient oxygen can be stored in the exhaust gas purifying catalyst. Even when the maximum oxygen storage amount of the exhaust gas purifying catalyst is smaller than the predetermined amount, if the temperature of the exhaust gas purifying catalyst is lower than predetermined temperature, fuel cut is executed. In this case, influence which is given to deterioration of the catalysts is small even if the fuel cut is executed and the inside of the catalysts is under the oxygen atmosphere. On the other hand, if the temperature of the exhaust gas purifying catalyst is the predetermined temperature or higher, the fuel cut is not executed. Since the deterioration of the catalyst is promoted when the catalyst is under the oxygen atmosphere at high temperature, priority is given to prevention of deterioration of the exhaust gas purifying catalyst.

Fuel cut control apparatus of internal combustion engine

In an emission control apparatus of an internal combustion engine in which an emission control catalyst is disposed in an engine exhaust passage, if fuel cut is performed during a decelerating operation of the engine when the temperature of the emission control catalyst is to be quickly reduced by a secondary air supply device supplying fresh air to the emission control catalyst during the decelerating operation of the engine, the supply of fresh air from the secondary air supply device to the emission control catalyst is started after a fuel cut executing condition is met but before the fuel cut is actually executed. Therefore, the temperature of the catalyst is reduced before the exhaust air-fuel ratio shifts to the lean side due to execution of the fuel cut. Thus, exposure of the catalyst to a deteriorating condition of high temperature and lean air-fuel ratio is prevented.

Emission control apparatus of internal combustion engine, and method for retarding deterioration of emission control catalyst

An engine control apparatus is disclosed, in which the combustion instability is improved regardless of the type of fuel supplied to the engine so that the idle state immediately after an engine start is stabilized for improving the fuel consumption rate, preventing the deterioration of emission and thereby improving the durability of catalysts. A counter counts the time elapsed from an engine start. A sensor detects the engine speed. A control circuit controls the timing of fuel injection into the engine. The intake-synchronous injection is carried out during a first predetermined time immediately after a cold engine start. The intake-asynchronous injection is carried out after the lapse of the first predetermined time. During the intake-asynchronous injection, the engine speed is monitored to determine whether it is reduced below a reference engine speed until the lapse of a second predetermined time. In the case where the engine speed is reduced below the reference engine speed, the intake-synchronous injection is temporarily carried out and the engine speed is increased for stabilizing the idle state. The control apparatus can store the idling characteristic for cold engine start for each type of fuel supplied so that temporary intake-synchronous injection may be carried out only for the heavy fuel.

Control apparatus, for internal combustion engine, for improving

A vehicular engine speed controller for keeping the engine speed constant while preventing the overrunning of the engine. The vehicle includes a propeller shaft connected to driving wheels and a torsional damper for connecting the propeller shaft with the engine drive shaft. The controller comprises a detector for detecting a value corresponding to engine speed, and an injection control device for controlling injectors, based on the detected value from the detector. The control device stores a first and second determining values (Da and Db). The control device halts fuel supply from the injector when the detected value exceeds the first value (Da), and resumes fuel supply when the detected value becomes below the second value (Db). The control device further causes the injector to execute the resumption and halt of fuel injection at least one time, when the detected value is changed to a smaller value than the first value (Da) from a larger value than the first value (Da), thereby extinguishing the torsional energy accumulated in the torsional member. The engine speed is not affected by the torsional damper.

Engine speed controller for a vehicle

A charging control apparatus including means for shortening a running-up period of the second turbocharger with an exhaust bypass valve when an instant engine speed is low, so that torque shock during the transition from one-turbocharger-operation to two-turbocharger-operation is decreased. During rapid acceleration at high engine speeds, an exhaust switching valve is opened at once. Further, the reference engine speed and the reference intake air quantity for switching to two-turbocharger-operation are varied in accordance with the gear shift position, so that an optimum switching to two-turbocharger-operation is obtained.

Charging control apparatus for an internal combustion engine with a dual

A charging control apparatus including means for shortening a running-up period of the second turbocharger with an exhaust bypass valve when an instant engine speed is low, so that torque shock during the transition from one-turbocharger-operation to two-turbocharger-operation is decreased. During rapid acceleration at high engine speeds, an exhaust switching valve is opened at once. Further, the reference engine speed and the reference intake air quantity for switching to two-turbocharger-operation are varied in accordance with the shift gear position, so that an optimum switching to two-turbocharger-operation is obtained.

A charging pressure control apparatus including a first duty control solenoid valve for controlling the opening degree of an exhaust bypass valve to thereby control a charging pressure during 'one-turbocharger-operation', and a second duty control solenoid valve for controlling the opening degree of a waste gate valve to thereby control a charging pressure during 'two-turbocharger-operation'. The operating conditions at high altitudes of the first duty control solenoid valve and the second duty control solenoid valve are made different from those at low altitudes so that the power characteristic of the turbocharged engine is as good at high altitudes as at low altitudes.

Charging pressure control apparatus for an internal combustion engine

An EGR apparatus includes an EGR conduit, an EGR valve, a first passage connecting a portion of an intake conduit downstream of a throttle valve and the EGR valve, and a second passage connecting a portion of the intake conduit upstream of the throttle valve and a medium portion of the first passage. A two-way solenoid valve is installed in the first passage between the intake conduit and a connecting portion where the first passage and the second passage join. Further, a fixed throttle is disposed in the second passage. By removing a VCV of a conventional EGR apparatus from the EGR apparatus and by replacing a three-way VSV of the conventional apparatus with a combination of the two-way solenoid valve and the fixed throttle, a problem of non-cutting of EGR, which can occur in the conventional apparatus, does not occur in the EGR apparatus of the invention.

EGR apparatus for an internal combustion engine

An internal combustion engine with a dual turbocharger system includes an air bypass conduit connecting a downstream portion of a first turbocharger compressor with an upstream portion of a second turbocharger compressor so that the length of the air bypass conduit is relatively long. When a throttle is rapidly closed, an air bypass valve installed in the air bypass conduit is opened and the compressed air downstream of the throttle valve is returned to the upstream of the turbocharger compressor to suppress occurrence of a surging at the turbocharger compressor. Since the air bypass conduit is relatively long, the compressed and circulated air is effectively cooled when flowing through the air bypass conduit and melting of an impeller of the turbocharger compressor is prevented.

Internal combustion engine with a dual turbocharger system

An evaporated fuel discharge suppressing apparatus includes a main purge conduit and a bypass purge conduit. The main purge conduit connects a canister and an intake conduit of an engine downstream of a throttle valve, and a purge control solenoid valve is installed in the main purge conduit. The bypass purge conduit bypasses the purge control solenoid valve. Even if the purge control solenoid valve sticks in a closed position, evaporated fuel adsorbed by the canister can flow into the intake conduit of the engine through the bypass purge conduit so that the evaporated fuel in the canister is not discharged into the atmosphere.

Evaporated fuel discharge suppressing apparatus for an internal

An internal combustion engine with a dual turbocharger system includes an engine, a first turbocharger and a second turbocharger arranged in parallel with each other, an intake switching valve located downstream of a compressor of the second turbocharger, and an exhaust switching valve located downstream of a turbine of the second turbocharger. At large intake air quantities, both turbochargers are operated, while at small to medium intake air quantities only the first turbocharger is operated. At 'one-turbocharger-operation', when the engine load is low, the intake switching valve is opened, while the exhaust switching valve is maintained closed. Thus, at small to medium intake air quantities and low engine loads, the intake flow can be introduced through both the compressor of the first turbocharger and the compressor of the second turbocharger. As a result, flow resistance is decreased and acceleration response from low engine loads is improved.

An internal combustion engine with a dual turbocharger system includes a first turbocharger and a second turbocharger arranged in parallel with each other. An exhaust switching valve is installed in an exhaust conduit downstream of a turbine of the second turbocharger and is actuated by a single diaphragm actuator. An exhaust bypass conduit is provided so as to bypass the exhaust switching valve, and an exhaust bypass valve is installed in the exhaust bypass conduit. Before the operation is changed from 'one-turbocharger-operation' to 'two-turbocharger-operation', the exhaust bypass valve is opened before the exhaust switching valve is opened, to suppress a shock which may occur at the transition from the 'one-turbocharger-operation' to 'two-turbocharger-operation'.

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Susono, Japan

Kunihiko Nakata