Spark plug for internal combustion engines and method for producing such a spark plug

摘要

A spark plug is proposed which serves to ignite mixtures of fuel vapour and air in internal combustion engines. The spark plug contains in the ignition-side section of the longitudinal hole of its electric insulator a metal core which is connected, remotely from the combustion space, to the connection bolt via an electrically conductive sealing means and on the combustion-space side either itself acts as a central electrode or is in contact with a separate central electrode in the bottom of the electric insulating element. In order to protect the ignition-side front part of the metal core against melting, it is produced from a mechanical mixture of materials whose first material component has a melting point of over 1000 DEG C and whose second material component has a melting point which lies below that of the first material component; the molten mass of the second material component is melted here into the not yet molten, or only partially molten first, powderous or granular material component. The shaft which adjoins the front part of the metal core remotely from the combustion space consists of the second material component of the mechanical mixture of materials and the melting point of the second material component of the mechanical mixture of materials corresponds approximately to the melting point of a meltable sealing means also loacted in the longitudinal hole of the electric insulating element. A method for producing such a spark plug is also described. <IMAGE>