| 摘要 |
PURPOSE:To make a tip end surface of a light guide member wipable clean and prevent an incident quantity of light from reducing, by installing a wiper piece, performing a deformational motion on the basis of temperature variations in an internal-combustion engine, in the tip of a flame sensor. CONSTITUTION:A light guide member 13 of a flame sensor part 11 is composed of a light transmission material having heat resistance, and inserted into a core part of a cylindrical heat-resisting box body 12 and locked thereinto. A wiper piece 30 is installed in a tip of the flame sensor part 11, and it performs a deformational motion on the basis of temperature variations between low temperature in time of engine stopping and high temperature in time of driving. With this deformational motion, the lower side edge 30c of the wiper piece 30 slidingly brushes over the whole surface on a tip end surface 13c, wiping clean combustion products sticking onto this tip end surface 13c. Thus, reduction in an incident quantity of light is preventable from occurring. |
