To raise service life by controlling the degradation of a packing 12 made of a rubber like elastic material prepared in the drain pipe joint 10 as much as possible.

The packing 12 made of a rubber like elastic material to seal the space between the drain pipe 20 and the joint main part 11 for connecting this drain pipe 20 is retained in the packing retaining groove 11a formed on the inner circumference face of the joint main part 11 and many unevenness 11c is formed on the inner circumference face of the joint main part 11 positioned on the outer circumference of the end 20a side of the drain pipe 20 rather than the packing 12. Even if some water W to flow through the inside of the drain pipe 20 comes into the cylindrical gap G2 between the joint main part 11 and the drain pipe 20 from the end of the drain pipe 20, the flow F of such invasion water is decreased by unevenness 11c and the dynamic contact is controlled to the packing 12.

COPYRIGHT: (C)2010,JPO&INPIT