Honda Giken Kogyo Kabushiki Kaisha

Kei Machida

Masaki Ueno

Ken Ogawa

Hideharu Yamazaki

Tetsuo Endo

Shiro Takakura

Shusuke Akazaki

Yoshikazu Oshima

Yasunori Ehara

Norihito Watanabe

Masahiro Sato

Tadashi Sato

Takashi Haga

Kenichi Ohmori

Yasuyuki Miyahara

Atsushi Kato

Yuji Yasui

Yusuke Hasegawa

Hidetaka Maki

Isao Komoriya

Yoichi Nishimura

Hiroshi Sono

Kotaro Miyashita

Yoshihisa Hara

Eisuke Kimura

Satoru Abe

A temperature control apparatus for a humidity sensor is provided for preventing impurities from sticking on a sensor element, while protecting the sensor element from cracking due to the humidity sensor heated by a heater in the presence of condensation, to maintain a high detection accuracy of the humidity sensor. The temperature control apparatus is configured to control the temperature of a sensor element of a humidity sensor disposed in an exhaust passage of an internal combustion engine for detecting the humidity within the exhaust passage. The temperature control apparatus comprises a heater for heating the sensor element, a temperature sensor for detecting the temperature of the sensor element, and an ECU for controlling a heating amount of the heater to bring the detected temperature of the sensor element to a first predetermined temperature during an operation of the internal combustion engine.

Temperature control apparatus for humidity sensor

A humidity sensoris disposed downstream of an exhaust gas purifier comprising a hydrocarbon adsorbing catalyst, and an air-fuel ratio sensoris disposed at least downstream of the exhaust gas purifier. The hydrocarbon adsorbing ability of a hydrocarbon adsorbent of a hydrocarbon adsorbing catalyst(the exhaust gas purifier) is evaluated using output data of the humidity sensor. The unburned gas purifying ability based on a catalytic action of the hydrocarbon adsorbing catalystis evaluated using output data of the air-fuel ratio sensor. Based on the evaluated results, the overall deteriorated state of the exhaust gas purifier is evaluated. The overall deteriorated state of the exhaust gas purifier which has the hydrocarbon adsorbing catalystcan thus adequately be evaluated.

Deteriorated state evaluation device for exhaust emission control equipment

An exhaust gas purifying apparatus for an internal combustion engine is provided for switching a switching valve at an optimal timing in accordance with an actual activated state of a catalyzer and a heated state of an adsorbent to achieve an optimal exhaust gas characteristic. The exhaust gas purifying apparatus comprises a catalyzer disposed in an exhaust system of the internal combustion engine, an adsorbent filled in a second passage circumventing a first passage in the exhaust system for adsorbing hydrocarbons within exhaust gases, a switching valve operable to switch between an open position for opening the first passage and a close position for closing the first passage, an ECU for detecting an atmospheric pressure state, and a switching valve driver for driving the switching valve to the close position upon start of the internal combustion engine, and driving the switching valve to the open position in accordance with the detected atmospheric pressure state.

Exhaust gas purifying apparatus for internal combustion engine

A characteristic change of a humidity sensoris detected based on the transitional characteristics of output data of the humidity sensorwith respect to integrated moisture quantity data representative of an integrated amount of moisture that is supplied to an HG adsorbentby an exhaust gas after an enginehas started to operate. A parameter for grasping a state of the HC adsorbentis corrected. The state, such as a deteriorated state or the like, of a hydrocarbon adsorbent (HC adsorbent) is properly monitored while compensating for the effect of the characteristic change of the humidity sensor and the effect of variations of the characteristics of individual units of the humidity sensor.

Hydrocarbon adsorbent state monitoring device

A state determination apparatus for a humidity sensor is provided for accurately determining the state of the humidity sensor, including the responsibility, from a result detected by the sensor itself. The state determining apparatus is configured to determine a humidity sensor arranged in an exhaust system of an internal combustion engine for detecting a humidity within an exhaust pipe. The apparatus comprises an ECU which determines whether or not the internal combustion engine is in a predetermined operating condition, calculates a change state parameter indicative of a change state of a value detected by the humidity sensor based on the detected value of the humidity sensor detected when the internal combustion engine is in the predetermined operating condition, and determines the state of the humidity sensor in accordance with the calculated change state parameter.

State determining apparatus for humidity sensor

An adsorbent state determining apparatus is provided for accurately determining the state of an adsorbent including a deterioration while ensuring elimination of the influence of impurities sticking on a sensor element of a humidity sensor. The adsorbent state determining apparatus determines the state of an adsorbent disposed in an exhaust system of an internal combustion engine for purifying exhaust gases. The adsorbent is capable of adsorbing hydrocarbons and moisture within exhaust gases. The adsorbent state determining apparatus comprises a humidity sensor disposed near the adsorbent in the exhaust system for detecting a humidity of exhaust gases; a heater for executing cleaning for removing impurities sticking on a sensor element of the humidity sensor; and an ECU for determining whether or not the heater has completed the cleaning, and for determining the state of the adsorbent in accordance with the humidity of exhaust gases detected by the humidity sensor when the ECU determines that the cleaning is completed.

Adsorbent state determining apparatus

An exhaust emission control system for an internal combustion engine has an exhaust passage switching device for switching an exhaust gas flow path, an HC adsorbent material disposed within the main exhaust passage for adsorbing and releasing unburned constituents in exhaust gases, and a control device for controlling the switching device such that the exhaust gas flow path is switched to the main exhaust passage when the unburned constituents is adsorbed by the HC adsorbent material, that the exhaust gas flow path is switched to the bypass exhaust passage when the unburned constituents adsorbed by the HC adsorbent material is released from the HC adsorbent material, and that the exhaust gas flow path is switched to the main exhaust passage when the release of the unburned constituents from the HC adsorbent material is completed.

Exhaust emission control system for an internal combustion engine

A temperature sensor is disposed near an HC adsorbent in an exhaust system of an internal combustion engine. After the internal combustion engine is shut off, a deteriorated state of the HC adsorbent is evaluated based on a value of the humidity detected by a humidity sensor. The deteriorated state of the HC adsorbent is evaluated by comparing the detected value of the humidity with a threshold established depending on the temperature state near the HC adsorbent. In evaluating deteriorated state of the HC adsorbent, a change in the output characteristics of the humidity sensor depending on its temperature state is compensated for.

Method of evaluating deteriorated state of hydrocarbon adsorbent

There is provided a temperature control system for a humidity sensor, which is capable of eliminating impurities attached to a sensor element of the sensor efficiently and sufficiently while preventing the sensor element from being cracked due to heat generated by a heater in a state of condensation formed thereon, and suppressing attachment of impurities to the sensor element, thereby making it possible to preserve an excellent detection accuracy of the humidity sensor. The temperature control system controls the temperature of the sensor element of the humidity sensor arranged in an exhaust pipe for detecting humidity within the exhaust pipe. A heater heats the sensor element. The temperature of the sensor element is detected. When the detected temperature of the sensor element is higher than a predetermined temperature, said heater is operated.

Temperature control system for humidity sensor

In an internal combustion engine having a double-structure exhaust passage comprised of an inner (bypass) exhaust passage and an outer (main) exhaust passage arranged to surround the outside of the inner exhaust passage such that exhaust gases are discharged through one of the inner and outer exhaust passages, an exhaust gas characteristic detecting apparatus is capable of reliably detecting the characteristic of exhaust gases through the inner exhaust passage. The detecting apparatus comprises a guide pipe extending across the outer exhaust passage and having an exhaust gas introducing port facing the inner exhaust passage for introducing exhaust gases flowing into the inner exhaust passage into the guide pipe, and a sensor having a sensing unit for detecting the humidity of exhaust gases and arranged such that the sensing unit is positioned in the guide pipe.

Exhaust gas characteristic detecting apparatus for internal combustion engine

An exhaust gas purifying apparatus for an internal combustion engine is provided for simultaneously realizing sufficient recovery of the adsorbing capability of an adsorbent and limitation to an increase in exhaust resistance. The exhaust gas purifying apparatus for an internal combustion engine comprises a flow path switching valve for switching an exhaust gas flow path to a bypass exhaust passage or to a main exhaust passage, three-way catalysts, and an HC adsorbent arranged in the bypass exhaust passage for adsorbing hydrocarbons in exhaust gases and fully desorbing the adsorbed hydrocarbons when it is heated to a full desorption temperature or higher. A troidal passage of the main exhaust passage completely surrounds a portion of the bypass exhaust passage in which the HC adsorbent is arranged. A ratio S /S of the cross-sectional area S of the troidal passage to the cross-sectional area of a flow-in passage is set in a range from 1.0 at which the exhaust resistance begins gradually decreasing as the ratio S /S increases to 3.0 at which the HC adsorbent can be heated to the full desorption temperature or higher.

A system for discriminating degradation of an exhaust purification system of an internal combustion engine having an adsorbent installed at a bypass exhaust gas passage adsorbing unburned HC in exhaust gas generated by the engine. Based on the assumption that the degradation of the adsorbent made from zeolite progresses or advances depending on its temperature, the temperature is detected and if it exceeds a predetermined temperature, an index indicative of the degree of degradation progress is determined based on a surplus exceeding the predetermined temperature. The index is accumulated to be compared with a threshold value and the adsorbent is discriminated to be degraded when the accumulated index exceeds the threshold value, thereby enabling to discriminate the adsorbent degradation accurately with a simple configuration.

Degradation discrimination system of internal combustion engine exhaust gas purification system

A fuel injection control system for an internal combustion engine comprises an ECU which calculates a direct supply ratio and a carry-off ratio, and detects a predetermined operating condition of the engine in which an increased amount of fuel is to be supplied to the engine. When the predetermined operating condition is detected, a plurality of fuel injection amounts to be sequentially injected by at least one fuel injection valve are calculated based on operating conditions of the engine, the direct supply ratio and the carry-off ratio. Then, an amount of fuel adhering to the intake system of the engine is calculated based on the total sum of the calculated plurality of fuel injection amounts, as well as on the calculated direct supply ratio and the calculated carry-off ratio. At least one of the calculated plurality of fuel injection amounts is corrected based on the calculated amount of fuel adhering to the intake system. Then, at least one fuel injection valve is controlled to sequentially carry out a plurality of fuel injections in one operating cycle of the engine, based on the calculated plurality of fuel injection amounts including the at least one thereof corrected.

Fuel injection control system for internal combustion engines

An electromagnetically driven valve control system for an internal combustion engine having at least one intake valve and at least one exhaust valve, and a starter for starting cranking of the engine. A CPU controls an energization time/timing control circuit section to electromagnetically drive at least one of the at least one intake valve and the at least one exhaust valve. The CPU detects a starting signal indicative of starting of the cranking of the engine, and a timer measures a time period elapsed after the starting signal is detected. An inhibiting time period is set, over which the operation of the starter means is inhibited, and the at least one of the at least one intake valve and the at least one exhaust valve is driven in a valve closing direction when the starting signal is detected. The operation of the starter is permitted when the time period elapsed after the starting signal is detected exceeds the inhibiting time period.

Electromagnetically driven valve control system for internal combustion

A system for detecting air-fuel ratio of an internal combustion engine by sampling outputs of an air-fuel ratio sensor installed at an exhaust system confluence point of said engine. A timing map is prepared to be retrieved by the engine speed and manifold absolute pressure to determine one among sampled data which are successively stored in buffers. It is selected such that as the engine speed decreases or the manifold absolute pressure increases, a datum sampled at earlier crank angular position is selected. At an engine equipped with a variable valve timing mechanism, a datum sampled at earlier crank angular position is selected in the valve timing is controlled for high engine speed provided that the engine speed and manifold absolute pressure is constant. The sampled data stored in the buffers may be transferred to another buffers at a predetermined crank angular position. The sampled data is corrected by an environmental conditions including atmospheric pressure, a mixture or sensor degradation. Each buffer may have a plurality of sampled data.

Growing community of inventors

Saitama-ken, Japan

Kei Machida