The invention belongs to the technical field of construction equipment and in particular relates to a
drill rod
assembly of a
pile driver, aiming at solving the problem of an existing
pile driver that a
grout spraying area is small and the like. The
drill rod
assembly comprises a hollow
drill rod body, wherein a
drill bit pointed-cone-shaped part is arranged at one end of the drill rod body; a spiral
drill bit blade, which is arranged in a spiral shape, is arranged at the circumferential outer side of one end, provided with the
drill bit pointed-cone-shaped part, of the drill rod body; one end of the spiral drill bit blade extends to the drill bit pointed-cone-shaped part and the other end of the spiral drill bit blade is connected with a
grout spraying seat which is arranged at the outer side of the drill rod body in the radial direction; at least one
grout spraying hole connected with the inner part of the drill rod body is formed in one side, toward the drill bit pointed-cone-shaped part, of the grout spraying seat; the hole
diameter of each grout spraying hole is gradually increased from inside to outside. The drill rod
assembly of the
pile driver has the advantages that a blocking phenomenon does not easily occur in a grout spraying process; the grout spraying area is large, and
slurry is sprayed out in a sector shape; the grout spraying effect is good; the drill rod has good stability when rotating in the
peripheral direction, and a swinging phenomenon does not easily occur; the efficiency of drilling the hole by the drill rod is improved and drill rods are not easy to be mutually interfered.