Honda Giken Kogyo Kabushiki Kaisha

Masao Komine

Kenji Abe

Kenichi Ohmori

Yasuyuki Miyahara

Norihito Watanabe

Tadashi Sato

Kazuhiro Yamamoto

Tetsuo Endo

Takashi Haga

Mitsuru Sugimoto

Masakatsu Miyao

A humidity sensor is disposed near an HC adsorbent in an exhaust system of an internal combustion engine. After the internal combustion engine is shut off, it is detected whether or not the humidity sensor has failed based on the value of the humidity detected by the humidity sensor when the detected value of the humidity is substantially constant, by determining whether or not the detected value of the humidity falls in a range between upper and lower limit thresholds that are set depending on the temperature near the HC adsorbent. It is stably and easily detected whether or not the humidity sensor disposed near the HC adsorbent in the exhaust system of the internal combustion engine has failed.

Method of detecting failure of humidity sensor

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.

Exhaust gas valve device in internal combustion engine

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.

Exhaust gas purification system of internal combustion engines

A gas jacket is provided in a lower portion of a cylinder block, so that an exhaust gas in an exhaust gas passage is supplied to the gas jacket through an exhaust gas supply passage having an exhaust gas supply valve. Fresh air in an intake passage is supplied to an intake passage through a fresh-air supply passage having a fresh-air supply valve. The temperature of a lower cylinder wall is controlled in a feedback manner to a target temperature for the lower cylinder wall. The target temperature for the lower cylinder wall is set at a sufficiently high temperature in a range in which an oil film of lubricating oil, extending from an intermediate portion of the cylinder wall to a bottom dead center of a piston, can be ensured. Therefore, the viscosity of the lubricating oil can be decreased to minimize the friction loss at slide portions of the cylinder wall and the piston, thereby providing an increase in engine output, a reduction in amount of fuel consumed and a reduction in lubricating oil consumed.

System for controlling the temperature of a cylinder wall in an engine

Growing community of inventors

Wako, Japan

Masao Komine