Patent ID: 7730647

Claim:
A construction machine, comprising: a lower traveling body having a crawler belt and a frame supporting the crawler belt; an upper slewing body which slews freely in relation to the lower traveling body; and a blade, which is rotatably supported by the lower traveling body; wherein the lower traveling body, includes: a center frame integrally casted by a cast steel; right and left truck frames, which are located on an outside of two side portions, respectively, of the center frame; right and left connecting members, which are fixed to both the center frame and the right and left truck frames, respectively; and a blade bracket joined to the center frame and the connecting members, wherein the center frame has, on a front side thereof, a joining flat face that joins the blade bracket, each of the connecting members has, on a front side thereof, a joining face that joins the blade bracket and has a prescribed width in a vehicle-width direction, the blade bracket comprising: a right fulcrum plate assembly that rotatably supports the blade, wherein the right fulcrum plate assembly comprises two plates, an outer fulcrum plate, which has a rear face, wherein an entirety of the rear face of the outer fulcrum plate of the right fulcrum plate assembly is joined to the joining face of the right connecting member, and an inner fulcrum plate, which has a rear face, wherein an entirety of the rear face of the inner fulcrum plate of the right fulcrum plate assembly is joined to the joining flat face of the center frame, and a left fulcrum plate assembly that rotatably supports the blade, wherein the left fulcrum plate assembly comprises two plates, an outer fulcrum plate, which has a rear face, wherein an entirety of the rear face of the outer fulcrum plate of the left fulcrum plate assembly is joined to the joining face of the left connecting member, and an inner fulcrum plate, which has a rear face, wherein an entirety of the rear face of the inner fulcrum plate of the left fulcrum plate assembly is joined to the joining flat face of the center frame, and a reinforcing plate that is joined to an upper face of the right fulcrum plate assembly and an upper face of the left fulcrum plate assembly, wherein the reinforcing plate has a rear face, and the rear face of the reinforcing plate is attached to the joining faces of the right and left connecting members and the joining flat face of the center frame.