Displacement detection mechanism for tensioning device, tensioning device and slag conveyor

The utility model relates to a displacement detection mechanism used for a tensioning device, the tensioning device and a submerged chain conveyor, and the displacement detection mechanism comprises a connecting piece which is provided with a triggering piece; the detection assembly comprises a control module, a mounting plate, a first current loop and a second current loop, a plurality of resistors arranged at intervals are connected to the first current loop in series, and any two adjacent resistors are connected to the second current loop through a normally open proximity switch; the plurality of normally-open proximity switches are sequentially arranged on the mounting plate at intervals from bottom to top, the normally-open proximity switches are constructed to be closed when the trigger piece moves in the vertical direction and the trigger piece is detected, and the control module is used for detecting the current of the first current loop. Therefore, the displacement of the tensioning main shaft in the