Water pipe connection device

A water pipe connection device adapted for insertion of a water pipe therein, said water pipe connection device comprising:

• a connecting tube including a tube head and a tubular member, said tube head defining an installation space therein, and having a large tubular section and a small tubular section at two opposite ends thereof, a diameter of said tube head decreasing in a direction from said large tubular section to said small tubular section, said large tubular section being connected to said tubular member, said small tubular section having an opening adapted for insertion of the water pipe;
• a fastening member movably disposed in said installation space and adjacent to said large tubular section;
• and
• a fixing unit movably disposed in said installation space, and including a fixing ring, and a plurality of reverse toothed structures that are disposed around said fixing ring, each of said reverse toothed structures having a plurality of teeth portions that protrude toward a central axis of said fixing ring and that extend obliquely away from said opening;
• wherein said fixing unit and said fastening member are adapted for the water pipe to extend therethrough in sequence, said water pipe being clamped and positioned by said teeth portions of said reverse toothed structures, when said water pipe connection device is in use, water flowing into said installation space through a space between said tubular member and said water pipe, and said fastening member being pushed by the water to move said fixing unit towards said small tubular section, so that said fixing unit is pressed by said tube head to fix said water pipe.