Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Aisan Kogyo Kabushiki Kaisha

Toshitake Sasaki

Kenji Kimura

Yoshihisa Oda

Hitoki Sugimoto

Kazuya Miyaji

Kiyohito Murata

Tsukasa Abe

Ikuo Ando

Takashi Suzuki

Takahiro Nishigaki

Osamu Harada

Koji Hayashi

Keisuke Nagakura

Masakazu Yamamoto

Masato Terashima

Kenya Maruyama

Hiroyasu Harada

Yuji Itoh

Yu Tamura

Shigemichi Ujiie

A grille shutter is a device configured to adjust a temperature of coolant water of an engine by adjusting an amount of outside air introduced into a radiator of the engine. An ECU performs a failure diagnosis for the engine based on a temperature of coolant water of the engine. When the grille shutter is immovable in an opened state of the grille shutter regardless of an operating command to the grille shutter, the ECU renders the failure diagnosis process for the thermostat valve not to be executed. As a result, an incorrect operation of various controls executed based on a temperature of coolant water of the engine can be suppressed.

Vehicle including shutter device for adjusting temperature of coolant water of engine

In a vehicle provided with an engine, an EGR cooler for cooling EGR gas recirculated from an exhaust channel of the engine to an intake channel thereof by using a coolant, an electric pump for supplying the coolant to the EGR cooler, and a gas temperature sensor for detecting the temperature of the EGR gas temperature at the downstream of the EGR cooler, an ECU acquires a first gas temperature in a normally stable state where the electric pump is rotating, thereafter performs a coolant amount suppressing process to suppress the rotational speed of the electric pump, acquires a second gas temperature in a suppressed stable state after a predefined time has elapsed from the start of the coolant amount suppressing process, and determines that the EGR cooler is abnormal if a difference between the first gas temperature and the second gas temperature is less than a threshold value.

Vehicle with an EGR-cooler and its diagnotic

An ECU sets a leakage flow rate flowing through a radiator circulation passage in a closed state of a thermostat valve, calculates an estimated temperature of coolant water in the radiator circulation passage based on a set leakage flow rate and a detected water temperature of an engine-side coolant water temperature sensor, and performs a failure diagnosis for the thermostat valve based on a difference between the calculated estimated temperature and the detected water temperature of the radiator-side coolant water temperature sensor. The leakage flow rate during operation of the electric pump is set to be a larger value as compared to the leakage flow rate during stopping of the pump. As a result, a diagnostic can be prevented by improving an accuracy of failure detection for the thermostat valve.

Cooling device for internal combustion engine and failure diagnosis method for cooling device for internal combustion engine

An internal combustion engine includes a port injection valve and a feed pump that pressurizes the fuel. An engine ECU performs a stuck abnormality diagnosis of the fuel pressure sensor based on detection values of the fuel pressure sensor in first processing and second processing. The first processing includes setting a target pressure of the fuel in the storage section to a first pressure, and detecting a pressure of the fuel with the fuel pressure sensor. The second processing includes setting the target pressure of the fuel in a low-pressure delivery pipe to a second pressure lower than the first pressure, and detecting a pressure of the fuel. The engine ECU causes the first processing to be performed in response to a start signal that starts an internal combustion engine, and causes the second processing to be performed subsequent to the first processing.

Control device for internal combustion engine

A learning unit learns a difference between a detected value ECT and a detected value RCT when it is determined that the detected value ECT and detected value RCT are stable while an engine is at a stop. A diagnostic unit performs a fault diagnosis for the engine based on the difference between the detected value ECT and detected value RCT having been corrected through use of a learned value learned by the learning unit. Accordingly, a fault diagnostic system for an internal combustion engine and a fault diagnostic method for an internal combustion engine can be achieved in which accuracy in fault diagnosis for the internal combustion engine can be improved and an erroneous diagnosis can be restrained.

Fault diagnostic system for internal combustion engine and fault diagnostic method for internal combustion engine

A hybrid vehicle including an engine having a catalyst in an exhaust passage, first and second motor generators, a battery and a power transmission mechanism coupling a drive shaft, the engine and the motor generators by a gear mechanism such that torque is transmittable, and its control method, are provided. When a coolant temperature is a threshold or below, catalyst warm-up operation for starting the engine and retarding an ignition timing by a retardation amount is executed. When a battery level is a threshold or below, forced charging operation for starting the engine and charging the battery by driving the first motor generator is executed. During the forced charging operation, an engine load is changed on the basis of the battery level. When the catalyst warm-up operation is executed during the forced charging operation, the retardation amount for facilitating warm-up of the catalyst is reduced as the engine load increases.

Hybrid vehicle and control method for hybrid vehicle

A controller for internal combustion engine includes a rotation number detecting section to detect engine rotation number and an air-fuel ratio detecting section to detect an air-fuel ratio (A/F) of air-fuel mixture and is configured to perform leaning control of the A/F. The controller further includes a rotation number difference calculating section to calculate a difference between a rotation number variation value of a worst cylinder specified as having largest rotation number variation based on the detected rotation number detected and an average value of rotation number variation values of remaining cylinders other than the worst cylinder; an estimated imbalance rate calculating section to calculate an estimated imbalance rate based on the A/F detected by the air-fuel ratio detecting section; and a lean abnormality detecting section to detect lean imbalance abnormality in a specific cylinder based on the calculated rotation number difference and the calculated estimated imbalance rate.

Controller for internal combustion engine

When an engine is in a predetermined steady operating state, a gradient accumulation average value &#x394;Aulsa corresponding to the amount of change in the air-fuel ratio AF, detected by an air-fuel ratio sensor, over the period of time from when an upper peak is reached, at which the direction of change in the air-fuel ratio AF is inverted to when a lower peak is reached, at which the subsequent inversion of the direction occurs, is calculated (Sto S) and, when the calculated gradient accumulation average value &#x394;Aulsa is greater than a predetermined threshold value &#x394;Arefthat is determined in advance as an upper limit (absolute value) of the range, in which it may be determined that the air-fuel ratio is even between the cylinders of the engine (Sto S), it is determined that the engine is in an air-fuel ratio imbalance state, in which there is an imbalance in air-fuel ratio between the cylinders of the engine.

Internal combustion engine system, method of determining occurrence of air-fuel ratio imbalance therein, and vehicle

An engine ECU diagnoses the presence or absence of abnormality during execution of the fuel cut. The engine ECU is configured to restrict the fuel cut according to the temperature of a catalyst when the temperature is higher than a fuel-cut-restriction temperature of the catalyst. The engine ECU is configured to set the fuel-cut-restriction temperature is lower when the diagnosis has been completed than when the diagnosis has not been completed. Furthermore, the engine ECU continues the fuel cut if the diagnosis is completed during execution of the fuel cut while the temperature of the catalyst is between the fuel-cut-restriction temperature set prior to the completion of the diagnosis and the fuel-cut-restriction temperature set after the completion of the diagnosis.

Control apparatus and control method for internal combustion engine

An ECU executes a program including the steps of: when a switching valve is controlled to be closed, comparing exhaust gas's temperature, as detected, with a map value; if the exhaust gas's temperature is larger than the map value, determining that the switching valve normally operates; and if the exhaust gas's temperature is smaller than the map value, determining that the switching valve has abnormality.

Exhaust heat recovery system abnormality detection device

A power output system that provides power to a driveshaft is provided which includes an internal combustion engine, an electric motoring mechanism, an electric storage device, a first exhaust gas channel that guides exhaust gas from the engine directly to an exhaust gas purifying catalyst, a second exhaust gas channel which guides the exhaust gas from the engine to the exhaust gas purifying catalyst via an unburned-component adsorber, a channel switching mechanism operable to switch a channel of the exhaust gas from the engine between the first exhaust gas channel and the second exhaust gas channel, a pressure accumulator operable to accumulate therein a negative pressure produced through rotation of the engine, a negative-pressure introducing/releasing mechanism that selectively permits and inhibits introduction of the negative pressure from the pressure accumulator into the channel switching mechanism, and a controller that controls the electric motoring mechanism and the negative-pressure introducing/releasing mechanism.

Power output system, vehicle including the same, and method of controlling power output system

An exhaust emission control system. A generator has a thermoelectric conversion element for achieving thermoelectric conversion by making use of heat of exhaust gas. An exhaust purifying catalyst disposed in the generator or on the exhaust downstream side of the generator, and a heat conduction varying device make heat conduction from the exhaust gas to the thermoelectric conversion element variable between a high conduction state and a low conduction state. When a temperature of the exhaust purifying catalyst is higher than a predetermined temperature, the heat conduction varying device varies the heat conduction from the exhaust gas to the thermoelectric conversion element into the high conduction state. This permits the system to efficiently re-collect thermal energy from the exhaust gas and convert it into electric energy, without increase in a time to arrival of the exhaust purifying catalyst at an activation temperature thereof.

Exhaust emission control system

The exhaust heat recovery system of the invention includes: a thermoelectric conversion element that generates electric energy by thermoelectric conversion using heat of exhaust gas discharged from an engine; and a heat pump including a heat recovery unit that absorbs the heat contained in the exhaust gas through an endothermic reaction using a heating medium, and a heat generation unit which generates heat through an exothermic reaction of the heating medium and which supplies the heat to the thermoelectric conversion element. With this configuration, the thermoelectric conversion element and the heat generation unit are movably attached to each other such that they can be placed in contact with and separated from each other, and the heat recovery unit is positioned in an exhaust gas passage in an exhaust gas downstream flow direction from the heat generation unit.

Exhaust heat recovery system

In an exhaust heat recovery system, electric power generation efficiency of a thermoelectric conversion element can be improved, and warming-up of a catalyst can be completed early, without using a complicated device. The exhaust heat recovery system according to the invention includes an exhaust pipe in which exhaust gas discharged from an internal combustion engine flows; a catalyst which purifies the exhaust gas; a heat recovery portion which is fitted to the exhaust pipe, and which recovers heat contained in the exhaust gas; a thermoelectric conversion element which generates electric power using thermoelectric conversion; and a heat pipe which connects the heat recovery portion to the thermoelectric conversion element, and which transfers the heat recovered in the heat recovery portion to the thermoelectric conversion element. An operation starting temperature of the heat pipe is set so as to be higher than an activation temperature of the catalyst.

Growing community of inventors

Toyota, Japan

Toshitake Sasaki