METHOD FOR OPERATING A FILLING ADAPTER AND FILLING ADAPTER FOR FILLING REFRIGERANT R744 INTO VEHICLE AIR CONDITIONING SYSTEMS

摘要

The invention relates to a method for operating a filling adapter for filling refrigerant R744 into vehicle air conditioning systems as well as to a corresponding adapter. Said adapter comprises mechanical clamping elements actuated by a pneumatically or mechanically controlled clamping piston. The clamping elements are clamped by the clamping piston onto specifically designed sections of the vehicle air conditioning system for the filling process and are kept in the clamping position during the filling process. The aim of the invention is to create a technical solution that allows the locking action of such a clamping system to be securely maintained in case the filling valve or the vehicle valve is not closed or in case the control pressure drops below a predefined value. Said aim is achieved by subjecting the clamping piston to two different pressurization media i.e. first to the control pressure of the filling adapter and then to the filling pressure of the refrigerant. In order to be able do so the clamping piston (2) comprises at least two separate piston surfaces (5; 7) to be subjected to the pressure of two different pressurization media one piston surface (5) being effectively connected to the control pressure of the filling adapter and the other piston surface (7) being effectively connected to the filling pressure of the refrigerant.