| 摘要 |
PURPOSE:To enhance the durability and facilitate manufacture by forming a joint surface consisting of a straight conical surface over the outside surface of the bevel part of the valve element, and by brazing the jointing inner surface of a ring-shaped sheet member consisting of a sintered alloy fast to said joint surface. CONSTITUTION:In manufacturing poppet valves, first a joint surface 1a is formed at the periphery of the bevel part 1b of the valve element 1 to serve for jointing with a sheet member 2. This sheet member 2 is provided separately from the valve element 1, consisting of a ring-shaped sintered sterite made preveously through sintering from powders. The valve element 1 and sheet member 2 are brazed together with their joint surfaces 1a, 2a. Then the final machining is made to the sheet member 2 to form the sheet surface 2b with the valve seat. Accordingly there is no fear of crack generation even though the hardness of sheet part is raised, so that the valve durability can be enhanced by increasing the hardness of the sheet part above that of a conventional type. |
