| 摘要 |
PURPOSE:To prevent a nonreturn valve being damaged by burned gas blown back via a secondary-air introduction port by providing a chamber extended forward via the nonreturn valve and facing the chamber almost tangentially on the outside of the secondary-air introduction port. CONSTITUTION:A chamber 11 is provided to be extended forward via a nonreturn valve 6 on the end of the downstream side of a passage 5 connected to a pressure air source 4. It is faced almost tangentially on the outside of a secondary-air introduction port 3, and connected into an introduction port 3 through an opening 12 on its side. In this construction, the burned gas blown back via the introduction port 3 is dashed to a wall 13 of another chamber via the opening 12, and prevented from being introduced directly into the nonreturn valve 6. |
