Abstract: A stop system intended to engage with a tool for heating by direct contact for a machine for plastic welding of a component over an opening in a wall of a motor vehicle tank. The system contains a cam mechanism which includes a straight cam with a longitudinal axis and a follower coupled to the straight cam for converting a translational movement along the longitudinal axis of the follower into a straight or quasi-straight movement of a point of the follower in a direction non-parallel to the longitudinal axis. The cam mechanism of the follower is capable of moving from a rest position, where the stop system is configured to pass freely through an opening in a wall of a motor vehicle tank, to a working position. The stop system is configured to bear against an inner surface of the wall of the tank through which the straight cam passes.

Abstract: The tool for welding of a mounting bracket on a tube for a tank comprises means for gripping of the tube, which clear access to a surface on the tube which is designed to be welded, means for heating of the surface which are mobile relative to the means for gripping of the tube, between a position of heating of the surface and a retracted position, means for heating of the mounting bracket, and means for gripping of the bracket which are mobile relative to the means for heating of the bracket and relative to the means for gripping of the tube, between a position for heating of the mounting bracket and a position for welding of the mounting bracket on the surface of the tube.