Mazda Motor Corporation

Mitsubishi Denki Kabushiki Kaisha

Hirofumi Nishimura

Youichi Kuji

Junichi Taga

Tsuyoshi Goto

Wataru Yamamoto

Yuta Enokizono

Kentaro Furusho

Keiji Araki

Hiroyuki Yamashita

Michihiro Imada

Kiyotaka Mamiya

Tomomi Watanabe

Masayuki Kuroki

Seiko Kono

Masayuki Tetsuno

Yasuyuki Morita

Eiji Nishimura

Tadataka Nakazumi

Tadashi Kaneko

Kazunari Komatsu

Naoyuki Noguchi

Takahisa Ishihara

Kiyoshi Kuronishi

Akihide Takami

Hiroshi Yamada

Hiroyuki Oda

Hideharu Iwakuni

Kenji Okamoto

Noriyuki Ota

Makoto Kyogoku

Akira Kageyama

Nobuo Takeuchi

Masanori Misumi

Misao Fujimoto

Ken Umehara

Akira Takai

Takanobu Morimasa

Hiroshi Tokushige

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: identify a speed reduction ratio in a driving force transmission mechanism; estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that the average torque output by the engine and an engine speed are constant, to set the countertorque such that, as the speed reduction ratio becomes smaller, the absolute value of the countertorque becomes larger.

Driving force control method and device for hybrid vehicle

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that the average torque output by the engine is constant, to set the countertorque such that, as an engine speed of the engine becomes larger, the absolute value of the countertorque becomes larger.

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: identify a vehicle acceleration; estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that an engine speed and the average torque output by the engine are constant, to set the countertorque such that, as the absolute value of the vehicle acceleration becomes smaller, the absolute value of the countertorque becomes larger.

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that an engine speed is constant, to set the countertorque such that, as the average torque output by the engine becomes larger, the absolute value of the countertorque becomes larger.

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under the condition that the average torque output by the internal combustion engine is constant, to set a negative control gain such that, as an engine speed becomes higher, the absolute value of the control gain becomes smaller, and then to set the countertorque based on a product of the estimated torque fluctuation component and the control gain.

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that an engine speed is constant, to set the countertorque such that, as the average torque output by an engine becomes larger, the absolute value of the countertorque becomes smaller.

An exhaust purifying system includes switching between a stratified combustion state at a stratified combustion region (I) of low revolutions speeds and low loads and a homogeneous combustion state of substantially the theoretical air/fuel ratio at a warm &lgr;&equals;1 region (II) adjacent thereto with higher revolution speeds or loads, wherein a first oxygen concentration sensor is arranged upstream from the three-way catalyst, and when an engine shifts from the stratified combustion region (I) to the warm &lgr;&equals;1 region (II), the feedback control of the air/fuel ratio based on an output signal of that sensor begins, and the target air/fuel ratio A/F is set to a range of 14.0&lE;A/F<14.7, so that the target air/fuel ratio A/E is slightly richer than the theoretical air/fuel ratio, thus preventing a temporary deterioration of the exhaust gas state.

Exhaust gas purifying system for engine

In the case that an engine is operated in a state where an in-cylinder air/fuel ratio is lean in a stratified combustion region and a fuel cut control is performed under a predetermined condition, when catalysts are in a low temperature state where a purification performance is deteriorated or when a NOx absorptive amount of the lean NOx catalyst, a control procedure for exhaust air/fuel state at a recovery timing from the fuel cut control so that a driving sensation is improved while maintaining the exhaust purification performance by the catalysts. When the fuel cut control is terminated and the engine shifts into the stratified combustion region, if a catalyst temperature is at or below a set temperature or a NOx absorptive amount is at or above a set amount, the in-cylinder air/fuel ratio of the engine is correctively enriched and the exhaust air/fuel state is enriched.

Fuel control apparatus for an engine

An engine control system for a direct injection-spark ignition type of engine which is equipped with a fuel injector for spraying fuel directly into a combustion chamber and an exhaust system having a lean NOx conversion catalyst for lowering an emission level of nitrogen oxides (NOx) in exhaust gas at an air-fuel ratio of &lgr;>1 controls divides a given amount of fuel into two parts which are intermittently delivered through early and late split injection respectively in a intake stroke and controls a fuel injector such that a midpoint between points at which the early and late split injection are timed respectively to start is before a midpoint of a intake stroke while the engine is in a lean fuel charge zone.

Control system for a direct injection-spark ignition engine

In a direct injection engine including an injector ( ) for directly injecting fuel into a combustion chamber ( ) and a lean NOx catalyst ( ), an ECU ( ) changes the air-fuel ratio from that higher than the stoichiometric air-fuel ratio to that substantially equal to or lower than the stoichiometric air-fuel ratio. When the air-fuel ratio has changed from a air-fuel ratio higher than the stoichiometric air-fuel ratio to an air-fuel ratio substantially equal to or lower than the stoichiometric air-fuel ratio, the ECU controls to divisionally execute fuel injection from the injector ( ) in at least two injections, i.e., leading injection that starts within the intake stroke period and trailing injection that starts within the compression stroke period.

Control apparatus for direct injection engine

A direct injection engine of sparking ignition type has a catalyst in an exhaust passage and a fuel injection valve for directly spraying fuel into a combustion chamber. An ECU for controlling the engine is provided with a setter and an air-fuel ratio controller. The setter sets an enriched region where an air-fuel ratio is smaller than a stoichimetric air-fuel ratio in a high engine speed and load area of an operating region of the engine, a stoichimetric air-fuel ratio region where the air-fuel ratio is equal to the stoichimetric air-fuel ratio in an area of the operating region of the engine having lower engine speed or load than the enriched region, and a lean region where the air-fuel ratio is larger than the stoichimetric air-fuel ratio between the stoichimetric air-fuel ratio region and the enriched region. The air-fuel ratio controller controls the air-fuel ratio based on the setting by the setter. Accordingly, a rise in exhaust gas temperature can be suppressed in the operating region having high engine speed and load, thereby significantly improving fuel consumption at high speeds while ensuring reliability.

Control system for a direct injection engine of spark ignition type

A control system is adapted for a direct injection engine of spark ignition type provided with an exhaust gas purifying catalyst in an exhaust passage, a fuel injection valve for directly spraying fuel into combustion chambers, a sparking plug having an electrode projecting into the combustion chamber. The control system includes an intake air amount controller for controlling the amount of intake air to be admitted into the combustion chambers, and a fuel injection controller for carrying out stratified combustion in a stratified combustion region set in a low engine load region while carrying out uniform combustion in a uniform combustion region set in a high engine load region. When the intake air amount controller executes a control to reduce the amount of intake air in the stratified combustion region when the engine is warm, and the fuel control system advances the fuel injection starting timing within a compression stroke and sets a degree of advancement within such a range where stratified combustion can be maintained. Accordingly, deterioration of combustibility can be effectively prevented when the intake air amount controller executes the control to reduce the amount of intake air in the stratified combustion region.

A catalyst light-off device for a direct injection engine comprises a temperature state identifier ( ) for judging the temperature state of a catalyst ( ) for converting exhaust gases, a fuel injection controller ( ) for controlling fuel injection from an injector ( ), and an ignition timing controller ( ). When the catalyst is in its unheated state in which its temperature is lower than its activation temperature, the fuel injection controller ( ) causes the injector ( ) to make split injection during a period from an intake stroke to an ignition point including a later injection cycle which produces a mixture having local unevenness and an earlier injection cycle which produces a uniform and lean mixture, and the ignition timing controller ( ) retards the ignition point.

Catalyst light-off method and device for direct injection engine

To reduce the amounts of HC, NOx and other emissions from a direct injection engine when a catalyst is still in its unheated state, and to promote catalyst quick light-off operation by increasing the temperature of exhaust gases, a control device comprises a temperature state identifier (,) for judging the temperature state of a catalyst (,) and a fuel injection controller (,) for controlling fuel injection from an injector (,). The fuel injection controller (,) controls the injector (,) based on judgment results of the temperature state identifier (,) in such a way that the injector (,) makes at least two-step split injection during a period from an intake stroke to an ignition point including a later injection cycle performed in a middle portion of a compression stroke or later and an earlier injection cycle performed prior to the later injection cycle at least in a low-load range of the engine when the catalyst (,) is in its unheated state, in which its temperature is lower than its activation temperature, and either of the later injection cycle and earlier injection cycle injects fuel which contributes to main combustion during a main combustion period in which approximately 10% to 90% by mass of the injected fuel is burnt in a combustion process occurring in the combustion chamber.

Control device for direct injection engine

A control device for a direct injection engine includes an identifier for judging whether a catalyst is in its unheated state in which its temperature is lower than its activation temperature, an engine temperature state detector for sensing the temperature state of the engine, and a fuel injection controller for controlling fuel injection from the injector. The fuel injection controller controls an injector in such a way that it makes at least two-step split injection including an earlier injection cycle performed during an intake stroke and a later injection cycle performed in a middle portion of a compression stroke or later when the catalyst is in its unheated state, and the later injection cycle is retarded when the catalyst is still in its unheated state but the engine temperature has become higher than a specified temperature compared to a case where the temperature of the engine is equal to or lower than the specified temperature.

Growing community of inventors

Hiroshima, Japan

Hirofumi Nishimura