METHOD FOR TIGHTENING A NOZZLE TENSIONING NUT OF AN INJECTOR FOR FUEL INJECTION, AND INJECTOR AND NOZZLE TENSIONING NUT

摘要

Generally, a nozzle tensioning nut (7) is used for a fuel injector during the connection of the injector housing (1) to the nozzle housing (6). Said nozzle tensioning nut (7) is slid over the nozzle housing (6) and screwed to the injector housing (1). As a result of the friction resistance on the contact surfaces (11) between the nozzle tensioning nut (7) and the nozzle housing (6), deformations are created, that, inter alia, can lead to loss of tightness on the high pressure sealing surface. According to the invention, a traction device (3,3a) is arranged between the injector housing (1) and the nozzle tensioning nut (7), by which means the friction resistance on the contact surfaces (11) can be reduced when the nozzle tensioning nut (7) is tightened. To this end, holding surfaces (8,9) are applied to the outer periphery of the nozzle tensioning nut (7) and/or the injector housing (1), and the traction device (3,3a), in turn, is applied to said holding surfaces. In this way, the two assembly parts are prevented from twisting, and the high pressure region remains sealed for a long time with the required press-on pressure.