US Patent 9103092 Hybrid construction machine

A electric storage device and a controller are disposed efficiently without obstructing ventilation, with a vehicle size equivalent to that of a normal shovel. A hybrid construction machine includes a device case which internally accommodates an electric storage device and a controller, and the device case is provided in a space above an upper frame, in a front portion of the upper frame and on the opposite side of two vertical plates from the cabin, and constitutes up-and-down steps which are formed in a rearward-ascending step shape so as to be able to be ascended and descended.