Tube connecting structure

A tube connecting structure having an integrally formed cylindrical connecting member comprising:

• a first cylindrical section disposed at a first axial end;
• wherein said first cylindrical section comprises:
• a joining cylinder having a first end and a second end;
• said joining cylinder formed with engagement holes at a first end at a plurality of perimeter positions;
• a ring-shaped flange projected radially inward from said second end of said joining cylinder;
• an inner cylinder extending within said joining cylinder co-axially from said ring-shaped flange toward said first end of said joining cylinder and separated by a predetermined distance from said first end of said joining cylinder;
• an inner cylindrical member having a diameter identical to that of said inner cylinder and extending co-axially within said joining cylinder at a predetermined distance from a first end of said inner cylinder, one end being projected outward from said first end of said joining cylinder;
• and
• an elastic ring-shaped sealing member disposed co-axially between said inner cylinder and said inner cylindrical member;
• a second cylindrical section co-axially disposed at a second axial end;
• a first tube being connected to said first cylindrical section;
• wherein said first tube comprises:
• a large-diameter end spanning axially from one end to a predetermined distance;
• said large-diameter end having an inner diameter roughly identical to an outer diameter of said inner cylinder and said inner cylindrical member;
• and
• a small-diameter cylindrical section adjacent to said large-diameter end;
• said small-diameter cylindrical section having a diameter smaller than that of said large-diameter end;
• a second tube being connected to said second cylindrical section;
• said second tube comprising an insertion end extending in a straight manner and being formed with a ring-shaped projection projecting radially outward at a predetermined distance from an end;
• said second tube being inserted into said second cylindrical section so that said ring-shaped projection engages with an engaging means formed integrally or separately from said second cylindrical section;
• and
• an end of said insertion end extending to said inner cylindrical member in said first cylindrical section;
• a joining member formed as a cylindrical shape from a pair of half-cylindrical members;
• each said half-cylindrical member having a second axial end formed as a large-diameter section and a first axial end formed as a small-diameter section;
• engagement pieces being formed on said large-diameter section at positions aligned with said engagement holes on said joining cylinder;
• said engagement pieces being projected radially outward and being elastically deformable in a radial direction;
• said joining member supporting said first tube by placing said large-diameter end at said large-diameter section and placing said small-diameter section at said small-diameter cylindrical section;
• said joining member being inserted and integrally fitted with said first tube into a space formed between said joining cylindrical structure, said inner cylinder and said inner cylindrical member;
• and
• said engagement pieces of said large-diameter section engaging with said engagement holes so that said first tube is connected with said first cylindrical section;
• and
• said elastic ring-shaped sealing member forming a fluid-tight seal between an inner perimeter surface of said large-diameter end of said first tube and an outer perimeter surface of an insertion end of said second tube.