摘要:
A state determining apparatus for an exhaust gas purifier is provided for accurately determining the state of the exhaust gas purifier including an adsorbent for adsorbing hydrocarbons, including a deterioration of the adsorbent, in accordance with an ignition time of an internal combustion engine. The state determining apparatus for an exhaust gas purifier is arranged in an exhaust system of the internal combustion engine for determining the state of the exhaust gas purifier including the adsorbent capable of adsorbing hydrocarbons and moisture in exhaust gas. The state determining apparatus has a humidity sensor arranged at a location downstream of the adsorbent in the exhaust system for detecting the humidity of exhaust gases, and an ECU for determining the state of the adsorbent in accordance with the humidity of exhaust gases detected by the humidity sensor, and the ignition time of the internal combustion engine.
摘要:
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.
摘要:
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 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 a temperature state of the exhaust system upon start of the internal combustion engine, and calculating the calory of exhaust gases discharged after the start of the internal combustion engine, 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 start-time temperature state of the exhaust system, and the calculated post-start exhaust gas calory.
摘要:
A failure determination device that detects the humidity of exhaust gases from an internal combustion engine and a control system for an exhaust passage changeover valve, which can switch the changeover valve with appropriate timing, thereby enabling sufficient purification of exhaust gases. An operating condition of the engine is detected. Based on the detected operating condition of the engine, it is determined whether the engine is in an operating condition in which failure determination of the humidity sensor can be executed. It is determined whether the humidity sensor has failed, based on a result of detection by the humidity sensor, when it has been judged that the failure determination of the humidity sensor can be executed.
摘要:
A hydrocarbon adsorbent state determining apparatus is provided for compensating the ability of a hydrocarbon adsorbent to adsorb moisture for fluctuations due to a change in the flow velocity of exhaust gases to accurately determine the state of the hydrocarbon adsorbent, including a deterioration thereof, irrespective of the change in the flow rate of exhaust gases. The hydrocarbon adsorbent state determining apparatus determines the state of a hydrocarbon adsorbent disposed in an exhaust system of an internal combustion engine for adsorbing hydrocarbons and moisture within exhaust gases. The hydrocarbon adsorbent state determining apparatus comprises a downstream humidity sensor for detecting the humidity of exhaust gases which have passed through the hydrocarbon adsorbent, a flow velocity parameter detector for detecting a flow velocity parameter indicative of a flow velocity of the exhaust gases, and an ECU for determining the state of the hydrocarbon adsorbent in accordance with the detected humidity of the exhaust gases and the flow velocity parameter.
摘要:
A state determining apparatus for an exhaust gas recirculation system is provided for appropriately determining the state of an exhaust gas recirculation system including an EGR passage. An exhaust gas recirculation system is arranged in an exhaust system of an internal combustion engine including an EGR passage for recirculating a portion of exhaust gases to an intake system in accordance with an operating state of the internal combustion engine. The state determining apparatus comprises a humidity sensor arranged in the EGR passage for detecting a humidity within the EGR passage, and an ECU for determining the state of the exhaust gas recirculation system based on a result detected by the humidity sensor.
摘要:
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.
摘要:
After an engine 1 has started to operate, a state in which a humidity represented by an output of a humidity sensor 19 downstream of a hydrocarbon adsorbent 7 takes a minimum value is sequentially searched for, and a timing at which the humidity changes from the minimum value to a monotonously increasing state is grasped as a timing at which the adsorption of moisture and hydrocarbons by the hydrocarbon adsorbent 7 is saturated. After the engine has started to operate, a parameter representing an integrated amount of moisture given to the hydrocarbon adsorbent 7 by the exhaust gas is sequentially generated, and a deteriorated state of the hydrocarbon adsorbent 7 is evaluated based on the value of the parameter at the timing at which the adsorption is saturated. The deteriorated state of the hydrocarbon absorbent can thus accurately be evaluated by an inexpensive arrangement which employs the humidity sensor 19 disposed downstream of the hydrocarbon adsorbent 7.
摘要:
An exhaust gas valve device in an internal combustion engine, including a first bearing member mounted between a valve shaft and a valve body with one end of the valve shaft turnably fitted into the first bearing member, a second bearing member mounted between the valve shaft and the valve body with the other end of the valve shaft turnably passed through the second bearing member, and an actuator connected to the other end of the valve shaft protruding from the second bearing member. The valve body, the valve shaft and the first and second bearing members are formed of metal materials having equivalent thermal expansion coefficients; the first and second bearing members are press-fitted into said valve body; and a skin of a graphite-based solid lubricant is formed on a surface of the valve shaft in regions corresponding to the first and second bearing members. The concentricity accuracy of the pair of bearing members supporting the opposite ends of the valve shaft is enhanced, while avoiding an increase in the number of parts, thereby preventing the generation of noise and reducing the friction.
摘要:
An exhaust gas purification system of internal combustion engine having a branch pipe coupled to the exhaust pipe through a flange and having a first cylindrical case constituting a bypass exhaust gas passage and a second cylindrical case constituting a main exhaust gas passage, whose flow are switched by a switch-over valve by selectively connecting the exhaust pipe to the main exhaust gas passage or the bypass exhaust gas passage, and an adsorbent installed in the bypass exhaust gas passage for adsorbing unburned components of the exhaust gas. The unburned exhaust gas components are recirculated to the air intake system through an EGR pipe. In the system, an inlet of the EGR pipe is formed integrally with the branch pipe flange, thereby enabling to prevent increase in fabrication step and cost and further to facilitate maintenance. Moreover, the first cylindrical case is made displace relative to the second cylindrical case. This can prevent the deformation due to the thermal stress which could occur when they are different in temperature.