Pipe connecting structure

#The present invention relates to a pipe connecting structure, and more particularly to a pipe connecting structure in which a conductive tube is fitted onto a plastic coated metal tube obtained by coating the outside of a bare metal pipe with a nonconductive plastic film, to connect the conductive tube and the plastic coated metal tube.

#Pipes in vehicles which are exposed outside of the vehicle body such as fuel lines and pneumatic or hydraulic lines for brakes are made from sufficiently strong metal tubes for locations which are exposed to flying gravel or the like during driving, and are made from plastic tubes in other locations. Furthermore, metallic tubes and plastic tubes are connected together by fitting the end of the plastic tube onto the end of the metal tube (for example, refer to Japanese Patent Publication 2673418).

#Incidentally, the metal tubes which are used for automotive fuel lines are covered with a corrosion resistant nonconductive plastic such as polyamide to prevent salt damage and corrosion from battery fluid and cleaning liquids or the like.

#FIG. 1 is a partial half cut cross-section view showing an embodiment of the pipe connecting structure of the present invention;

#FIG. 2 is a partial half cut cross-section view showing another embodiment of the pipe connecting structure of the present invention; and

#FIG. 3 is a partial half cut cross-section view showing yet another embodiment of the pipe connecting structure of the present invention.

#The pipe connecting structure of the present invention will be described in detail based on preferred embodiments shown in the drawings, but the present invention is not restricted to these embodiments.

#FIG. 1 through FIG. 3 are partial half cross-section views showing various embodiments of the pipe connecting structure of the present invention, and the pipe connecting structures shown in FIG. 1 through FIG. 3 show a connection form comprising a plastic coated metal tube 3 made by coating a bare metal pipe 1 made of steel which has been coated by plating on the outside surface, and also coated with a nonconductive plastic film 2 such as polyamide, and a conductive plastic tube 4 made by mixing a conductive material such as carbon fiber or the like.

#With the connection structure of FIG. 1, beads 5a, 5b, 5c are formed in three locations around the whole circumference of the end of the plastic coated metal tube 3. In the plastic coated metal tube 3, the plastic film 2 at the tip of the bead 5a is cut off so that the bare metal pipe 1 is exposed in this area. Furthermore, sealing material 6 is stored between two beads 5a, 5b. Furthermore, the end of the conductive plastic tube 4 is fit over the end of the plastic coated metal tube 3.