An Experimental Investigation of Energy Saving Hydraulic Control System Using Switching Type Closed Loop CPS

摘要

It is strongly requested to reduce fuel consumption because of high oil price and exhaust gases of road vehicles for environmental preservation. To solve these problems, several types of hybrid vehicles have been developed. Among them, flywheel hybrid vehicle using variable displacement pump/motor was already proposed as one of the feasible hybrid systems in place of hybrid vehicle by the conventional storage battery. The proposed flywheel hybrid vehicle is to keep constant pressure of high pressure line by control of swash plate angle of flywheel pump/motor as pressure compensator. The efficiency of the overall system depends severely on the efficiency of hydraulic pump/motor in the energy saving hydraulic control system. According to the control methods of swash plate angle of piston pump/motor, there remain several problems to be solved. In this paper, a switching type closed loop CPS is newly proposed in order to improve the energy efficiency and working condition of hydraulic pump/motor. Newly proposed switching type CPS is a closed loop system and switches the high pressure line according to the operating conditions of the vehicle. The proposed switching type closed loop CPS was verified experimentally to be effective in the energy saving and reduction of pressure fluctuations in the high pressure line, particularly between acceleration and deceleration.