NOVELTY - The electric hydraulic engine (12) has rotary fluid machine (40) which drives rotary booster pump (44) by mechanical energy, accumulator (46) which stores high pressure liquid phase working fluid, switch control valve (50) which changes flow path of high pressure liquid phase working fluid to accumulator or supercritical fluid generator (42), generator (45) which drives mechanical energy, and outputs electric power, and rapid charge-and-discharge type electrical storage apparatus (26) which electrically stores generated electric power and supplies electric power to pulse power supply (28).    USE - Electric hydraulic engine for vehicle, such as plug-in hybrid vehicle. (all claimed). Uses include but are not limited to passenger-car type electric vehicle, agricultural-and-forestry-industries machines, construction machines, track, bus, two-wheeled motor vehicle, cycle car, electric locomotive, rail vehicle, special equipment vehicle, servomotor mounting locomotive, hydraulic shovel, bulldozer, tractor, combine, tank, ship, submarine, aircraft, and space shuttle.    ADVANTAGE - Utilization of rapid charge-and-discharge type electrical storage apparatus of small capacity is attained since a rapid charge-and-discharge type electrical storage apparatus performs quick charge of the generated electric power of a generator, thus, a pulse current can be continuously supplied to a supercritical fluid generator. Utilization of electrical storage apparatus of small capacity is enabled, and utilization of a small highly efficient clean electric fluid pressure engine is enabled. Utilization of accumulator of small capacity is enabled and enhancement of small performance electric fluid pressure engine is achieved. Very large output torque is obtained and electric fluid pressure engine with high clean energy efficiency can be provided. Number of components is reduced, thus, cost, weight and size of electrical fluid pressure are also reduced. Electric power can be exchanged between an external power supply and the interface for external power supplies. Electric power can be supplied outside on-demand, utilizing a plug-in hybrid vehicle also as moving type electric power generating apparatus, and convenience of plug-in hybrid vehicle improves. Environment-friendly small lightweight vehicle with improved flight range is provided.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for an electric fluid pressure energy conversion method for vehicle.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the plug-in hybrid vehicle incorporating the electric fluid pressure engine.    Electric hydraulic engine (12)    Rapid charge-and-discharge type electrical storage apparatus (26)    Pulse power supply (28)    Rotary fluid machine (40)    Supercritical fluid generator (42)    Rotary booster pump (44)    Generator (45)    Accumulator (46)    Switch control valve (50)