Switching device i.e. start relay, for start device of internal combustion engine of vehicle, has switching surface of contact bridge or counter contact provided with non-metallic layer, where contact and bridge are made of contact metal

摘要

The device (20) has a counter contact (6) and a contact bridge (8) for switching electrical current and made of a contact metal e.g. electrolytic copper 57. A switching surface of the contact bridge or the counter contact is provided with a non-metallic layer (35). A core (4) form an electromagnetic circuit together with a housing (23) and an armature (1). The electromagnetic circuit is excitable by a pull-in winding (2) and a hold-in winding (3). A laminated spring is arranged between the core and a switch cover (12). The non-metallic layer is made of composite of the contact metal with boron, carbon, nitrogen, phosphorous, oxygen, fluorine, chlorine, bromine pr iodine. An independent claim is also included for a method for producing a non-metallic layer on a contact metal of a contact of a switching device.