Method for manufacturing corona ignition unit, involves providing inner tube made of material having higher electrical conductivity, and expanding housing after or during retraction of inner tube, where housing has increased outer diameter

摘要

The method involves providing a center electrode (5) that is inserted into an insulator (3) and is connected to a coil (7). A support (2) of the insulator is provided at a front end of a housing tube (1) with a conducting layer (1b). A closure piece (4) is secured to a rear end of the housing tube. An inner tube is retracted into an outer tube. The inner tube is made of a material having a higher electrical conductivity or a lower coercivity than a material of the outer tube. The housing is expanded after or during retraction of the inner tube, and the housing has increased outer diameter. The conducting layer is covered by a protecting layer e.g. paint layer.