Expansion of Application Range of Component Restricting Pressure Change Caused by Oil Temperature Change

One of the advantages of an oil-hydraulic system is that the system keeps the value of oil pressure when the pressurized oil is enclosed in a container. However, when the pressurized oil is enclosed in a head or a rod end chamber of an actuator by a check valve or a shut-off valve, the value of the oil pressure deceases gradually by the leakage from the check valve or the shut-off valve. Then, it is necessary to employ non-leakage valve which is expensive or to control the pressure by using a valve or a pump control. In pressure control, energy to compensate pressure is required. From the view point of cost reducing or especially energy saving, it seems to be desirable to develop a component which prevents this pressure drop without energy consumption. Authors had developed a component restricting pressure change caused by oil temperature change. This component has simple mechanism and hardly needs energy. In this study, the possibility of the component to prevent pressure drop due to leakage is investigated experimentally. Consequently, it makes clear that the component is effective to prevent pressure drop by leakage and the enclosed pressure decreases only about 3% in 3 min and about 7% in 60 min when the target enclosed pressure is 3.5 MPa.