NOVELTY - The tool has a hardening agent that is filled in an inside of a cylindrical pile (2) and fixes a fixing segment e.g. eyebolt (16). A supporting segment (38) supports the eyebolt which is inserted into cylindrical pile, in a perpendicular manner. A baffle plate (37) mounts the supporting segment so that sliding is possible. A securing segment e.g. latching board (33) is latched by a head (2a) of the cylindrical pile. An adjustment mechanism (36) is supported by the latching board and adjusts a height position and inclination of baffle plate.    USE - Tool for pile-head junction structure assemblies, used for assembling pile-head junction structure when installing various structures such as panel installation for solar cells used in solar power generation device.    ADVANTAGE - Since the inclination of a fixing segment and the difference of the orthogonal direction and a horizontal direction which are inserted into a cylindrical pile can be adjusted accurately and can be absorbed by easy structure by the adjustment segment and a supporting segment, the structure joined to these piles through a fixing segment can be installed and fixed precisely, even when the placed pile inclines or the position of the orthogonal direction or a horizontal direction has shifted. Since the number of segments of the tool for pile-head junction structure assemblies which adjusts the positioning accuracy of the fixing segment with respect to a pile is reduced to make a simple structure, the positioning operation of the fixing segment with respect to a pile can be rapid, and it can carry out easily. Since the adjustment mechanism fixed to a pile-head and the supporting segment which fixes a fixing segment are isolated and it enabled it to install separately, the position adjustment of a horizontal direction can carry out in the arbitrary range, and assembly and position adjustment of a tool can be performed easily.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for assembling method of pile-head junction structure.    DESCRIPTION OF DRAWING(S) - The drawing shows the side view illustrating the structure which attached the tool for pile-head junction structure assemblies.    Cylindrical pile (2)    Cylindrical pile head (2a)    Eyebolt (16)    Latching board (33)    Adjustment mechanism (36)    Baffle plate (37)    Supporting segment (38)