HEATABLE PLASTIC TANK
<Fulltext not available> A plastic tank contains a heating coil, the ends (3) of which are attached to a metal fitting (2) that passes through the tank wall (1) and provides a connection (12) with a seal for a heating fluid supply. The connection fitting (2) is encased on the inside of the tank with plastic by sintering to protect and seal it. An independent claim is also included for the method of manufacture, consisting of welding the fitting (2) to the coil end (3) to give an oil-tight joint, inserting the coil and fitting into the tank with a metallic mold, filling the mold with plastic powder and sintering with heat while rocking the assembly. Heatable plastic tank (5), particularly one-piece plastic tank (5) for instance water-urea mixtures comprising at least one fuel inlet and one fuel outlet (4) respectively in at least one plastic tank wall (1) and one heating coil (6) connected inside of the plastic tank (5) to the fuel inlet and fuel outlet (4), characterized in that the heating coil (6) is essentially self-supporting and sintered in plastic on at least one bearing surface (10, 11) inside of the plastic tank (5) at the plastic tank wall (1), the fuel inlet and fuel outlet (4) are formed in sinter and having each an essentially cylindrical insert (2) receiving coaxially ends (3) of lines of the heating coil (6), and in that at least one reception (12) is provided in the plastic tank wall (1) for sealing with an adapter of a heating line to the fuel inlet and fuel outlet (4). Heatable plastic tank (5) according to claim 1, characterized in that the reception (12) is formed for at least one flat or radial sealing (13). Heatable plastic tank (5) according to claim 1, characterized in that the heating coil (6) is formed of stainless steel with preferably inserts (2) formed as inserted nuts welded to the ends (3) of lines. Heatable plastic tank (5) according to claim 3 characterized in that the inserted nuts (2) are welded or compressed in an oil tight manner. Heatable plastic tank (5) according to claim 3 characterized in that the inserted nuts (2) are heat insulated. Method for producing a heatable plastic tank (5) according to claim 1, characterized by
fixing and welding or compressing of an inserted nut (2) to ends (3) of lines of a heating coil (6) for fuel inlet and fuel outlet (4),
fixing of the heating coil (6) by means of specially formed inserts to a respective inserted nut (2) in a metallic molding tool supported on main and auxiliary rotary axis,
supplying of suitable plastic powder in the metallic molding tool,
driving the metallic molding tool to dumpling movements around the main and auxiliary rotary axis at predefined rotary speeds,
supplying heat to the metallic molding tool at the inner wall of the metallic molding tool und cooling of the plastic tank.