In a crawler frame in which legs in a center frame are formed from cast
steel, a simple structure is achieved by reducing the number of
components. To this end, the crawler frame, which has a center frame
composed of a central frame section for supporting a swing bearing and
legs located on the right and left sides of the central frame section;
and track frames disposed on the sides of the distal ends of the legs,
respectively, of the center frame, is designed such that each of the legs
is bifurcated into front and rear leg sections and the front and rear leg
sections are respectively formed from cast steel.