Nissan Motor Company Limited

Renault S.a.s.

Daisuke Takaki

Kenji Suzuki

Hirofumi Tsuchida

Takeshi Tsuyuki

Naozumi Katou

Takayuki Hamamoto

Kazuhiko Sugawara

Tomoyuki Takeda

Hitoshi Ishii

Masayuki Tomita

Akira Nakajima

Mitsuhiro Akagi

Katsuaki Uchiyama

Masatoshi Hidaka

Taizo Horikomi

Tomoyuki Shigefuji

Makoto Yasunaga

Takayuki Sui

Yuta Ishigaki

An EGR valve is provided in an EGR passage circulating a part of an exhaust gas of an exhaust pipe in an intake pipe as an EGR gas, the EGR valve adjusting an EGR gas amount flowing in the EGR passage when an engine is in an EGR region, a differential pressure device is provided in the intake pipe, the differential pressure device adjusting a differential pressure of the EGR valve, a control unit is provided to control the EGR valve and the differential pressure device, and the EGR control method includes switching whether to adjust the EGR gas amount using the EGR valve and the differential pressure device or to adjust the EGR gas amount using the EGR valve only on the basis of an exhaust gas pressure of an inlet portion of the EGR passage.

EGR control method and EGR controller

A controller, in shifting the state of the EGR system from the EGR operating state to the EGR non-operating state at the time of performing the deceleration of the vehicle, calculates a provisional EGR ratio that is a provisional value of the current EGR ratio, estimates the provisional EGR ratio as the actual EGR ratio when a fore-and-aft differential pressure of the EGR valve is equal to or more than a predetermined value, performs correction to make the provisional EGR ratio smaller, and estimates the corrected provisional EGR ratio as the actual EGR ratio when the fore-and-aft differential pressure of the EGR valve is less than the predetermined value.

Method of estimating actual EGR ratio in EGR system and EGR system

A catalytic converter is provided with: an inlet-side diffuser part; an outlet-side diffuser part; a case including an upstream-side cylindrical part and a downstream-side cylindrical part; an inner liner provided in the upstream-side cylindrical part; a first catalyst retained inside the inner liner; and a second catalyst retained inside the downstream-side cylindrical part. An end face of the second catalyst faces a peripheral surface of the inner liner. An annular flow path is provided between the upstream-side cylindrical part and the inner liner, and the first catalyst is insulated from heat by the annular flow path. A part of exhaust flows into the second catalyst via the annular flow path.

Catalytic converter

In a non-EGR region that is a light load operating region, an EGR control valve () is opened at a predetermined infinitesimal opening degree M that corresponds to such infinitesimal EGR ratio as not to affect an ignition timing. With this control, since an EGR passage () is basically in a state in which the EGR passage () is filled with EGR gas, when an operating condition is changed from the non-EGR region to an EGR region and the EGR control valve () is opened so as to gain a target EGR ratio, a desired quantity of the EGR gas is introduced into an intake passage () substantially at the same time as the opening of the EGR control valve (). An actual EGR ratio can thus follow the target EGR ratio with a good response.

Control device for internal combustion engine

An exhaust gas recirculation control device controls an exhaust gas recirculation device that includes an exhaust gas recirculation passage adapted to circulate a portion of exhaust gas of an internal combustion engine from an exhaust passage downstream of a turbine of a turbo supercharger along an exhaust flow to an intake passage upstream of a compressor of the turbo supercharger along an intake flow and downstream of an air flow meter along the intake flow, and a recirculation control valve adapted to adjust an amount of exhaust gas circulated to the intake passage. Furthermore, the exhaust gas recirculation control device includes recirculation ratio setting means adapted to set a lower target recirculation ratio for a smaller intake air amount of the internal combustion engine.

Exhaust gas recirculation control device and exhaust gas recirculation control method

An EGR control device includes an estimate EGR ratio calculating portion adapted to calculate an estimate EGR ratio from a fresh air flow amount at a joining portion with the EGR passage of an intake passage and an EGR gas amount passing through the EGR valve, and a joining portion EGR ratio estimating portion adapted to correct an estimate EGR ratio on the basis of a gaseous state inside the introduction passage when the EGR valve switches from a closed state to an open state, to calculate a joining portion EGR ratio being a proportion of an EGR gas amount with respect to fresh air in the joining portion.

EGR control device and EGR control method

An upper-limit threshold value and a lower-limit threshold value of a fore-and-aft differential pressure of an EGR control valve is calculated based on an intake-air quantity detected by an airflow meter. An actual fore-and-aft differential pressure of the EGR control valve is calculated from detected values of an upstream-side pressure sensor and a downstream-side pressure sensor. Then, these threshold values are compared with the actual fore-and-aft differential pressure, and when the actual fore-and-aft differential pressure exceeds the upper-limit threshold value or when the actual fore-and-aft differential pressure is less than the lower-limit threshold value, it is determined that the pressure loss of an intake and exhaust system has changed. If it is determined that the pressure loss of an intake and exhaust system has changed, EGR is inhibited, and if not so, EGR is permitted to be performed. These threshold values are varied depending on a target EGR rate.

Internal combustion engine

When an EGR control valve is fixed and a valve opening degree EGRVO of the EGR control valve is greater than a valve-opening threshold value EGRVOth, a limit value Qlim of the intake air amount is set to a prescribed amount Qlim1. Conversely when the EGR control valve is fixed and the valve opening degree EGRVO of the EGR control valve is less than or equal to the valve-opening threshold value EGRVOth, the limit value Qlim of the intake air amount is set to a prescribed amount Qlim2.

Exhaust gas recirculation control device and exhaust gas recirculation control method for internal combustion engine

Provided is a control device for a multi-cylinder internal combustion engine, including: a supercharger to be driven by exhaust gas energy; and a fuel injection control unit, in which the fuel injection control unit sets a fuel injection amount for one cylinder so that an air/fuel ratio in the one cylinder is richer than a theoretical air/fuel ratio, and exhaust gas exhausted when the one cylinder is in an exhaust stroke and scavenging gas scavenged during a valve overlap period from another cylinder which is in an intake stroke when the one cylinder is in the exhaust stroke are mixed in an exhaust pipe so as to attain an air/fuel ratio facilitating combustion.

Control device for multi-cylinder internal combustion engine

A control device for an internal combustion engine with a turbo-supercharger including a variable valve mechanism at least at either one of an intake side and an exhaust side includes a scavenging amount setting means for determining an upper limit value of a scavenging amount moving from an intake passage to an exhaust passage across the interior of a cylinder during a valve overlap period to satisfy a performance requirement for the internal combustion engine, and a variable valve control means for controlling the duration of the valve overlap period according to the scavenging amount.

Control device for internal combustion engine with turbo-supercharger

A compressor () of a turbo supercharger () is located between an air flow meter () and a throttle valve (). An EGR passage () is connected to an intake passage () at a joint () upstream of the compressor (). The following relationship (1) is satisfied between an intake passage volume (V) from the air flow meter () to the junction (), an intake passage volume (V) from the compressor () to the throttle valve () and a maximum boost pressure (P) under operating conditions in which the introduction of EGR gas is performed, in order to prevent a mixed gas of fresh air and EGR gas from flowing back to the air flow meter () even under the maximum boost pressure (P). 

Intake device for internal combustion engine with supercharger

Provided is a control device for an internal combustion engine equipped with a supercharger, including: operation state detection means for detecting an operation state of the internal combustion engine; overlap read means for reading a valve overlap period; collector pressure detection means for detecting a collector pressure; exhaust gas pressure estimation means for estimating an exhaust gas pressure on an upstream side of the supercharger; and scavenging amount estimation means for estimating a scavenging amount based on the operation state, the valve overlap period, the collector pressure, and the exhaust gas pressure.

Control device for internal combustion engine equipped with supercharger

In control apparatus and method for an inner cylinder spark ignited internal combustion engine having a fuel injection valve configured to directly inject fuel into an inside of an engine cylinder and a spark plug, a super retard combustion is executed to set an ignition timing after a compression stroke top dead center and to inject fuel before the ignition timing and after the compression stroke top dead center during a predetermined engine driving condition and at least part of fuel is injected before the compression stroke top dead center to decrease a fuel injection quantity after the compression stroke top dead center during an interval which is immediately after an engine start and in which a pressure of fuel is relatively low.

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Yokohama, Japan

Daisuke Takaki