ADAPTER BETWEEN A MILLIMETER SHAFT SENSOR AND A COMMERCIAL SPARK PLUG, IN PARTICULAR TO TEST MEASUREMENT FOR OTTO ENGINES

摘要

1. Adapter between a millimetre wave sensor (1) and a commercially usual sparking plug, wherein a millimetre wave energy radiated from the sensor (1) is coupled by way of the porcelain insulator (7) of the sparking plug into a combustion space and the millimetre wave energy reflected from the combustion space is detected by the sensor (1), in particular for the measurement of the upper dead centre in the case of Otto engines, wherein the adapter consists of a clamping head (8), which engages around the hexagonal nut (13) of the sparking plug, a metal cylinder (9), which displays a hollow space (5) for the reception of the upper part of the sparking plug, as well as of a tightening device (10) for the tightening of clamping head (8) around the hexagonal nut (13) of the sparking plug, characterised by the following features : - Adjoining the hollow space (5) for the reception of the upper part of the sparking plug is a bore (6), which leads obliquely out of the metal cylinder (9), for the feeding through of the ignition cable, - guided through the metal cylinder (9) is a millimetre wave waveguide train (2) ; which closely above the collar (12) of the sparking plug housing opens at an oblique incident radiation angle (3) into the hollow space (5) filled out by the upper part of the sparking plug ; the incident radiation angle (3) in that case forms about a Brewster angle with the axis of symmetry of the sparking plug ; - annular grooves (4) are applied as flux traps above the incident radiation angle (3) in the wall of the hollow space (5).