PROBLEM TO BE SOLVED: To provide a greenhouse door structure assembled so as to be in a lattice structure which has a rectangular outer shape, made of a highly-strong and highly-rigid sheet-fitting material as a frame material, and provided with a fitting groove having a narrow opening part at its one surface and cross sectional surface shaped into an almost square tube. SOLUTION: The greenhouse door structure is as follows: four corner parts formed of the outer peripheral frame materials (a), B of the structure are joined with each other entirely via a nested L-shaped joint 1 bent into a right angle; the nested L-shaped joint 1 is formed at a nested part 11 where both end parts in right-angle two directions are closely engaged into a tube-state space (a)1 or b1 at the back surface side of a groove bottom wall g1 of the sheet fitting groove g at the outer peripheral frame materials (a), B; the nested part 11 is provided with an internally threaded part 12 at a position corresponding to a bolt hole 2 made at the groove bottom wall g1 of the sheet fitting groove g at the outer peripheral frame materials (a), B; and the nested part 11 engaged with the inside of the tube-state space (a)1 or b1 is connected to the outer peripheral frame materials (a), B via a bolt 3 screwed into the internally threaded part 12 of the nested part 11 through the bolt hole 2 made at the groove bottom wall g1 of the sheet fitting groove g. COPYRIGHT: (C)2009,JPO&INPIT
