油壓裝置의 設計에 있어서 效率的인 Relief Valve에 對한 硏究 = A Study on efficient Relief Valves in Hydraulic System

다국어 초록 (Multilingual Abstract)

The efficiency on Relief Valves in the hydraulic system was studied by experiment. More efficient Relief Valve had the most important role in hydraulic pressure control. In general, Relief valve had problems of pressure over-ride, Hysteresis, chattering by instability, and response.
In this paper, we intended to improve the above problems by comparing Balanced piston type Relief valves with Direct operation ones. The Balanced piston type Relief valve used in this paper, was hydraulic pressure, P=300㎏/㎠ and flowrate, Q=40ι/min of the cement mill shoe metal of cement plants.
We obtained results by experimental study as follows;
(l) Balanced piston type Relief valves was more efficient than Direct operation ones in over-ride characteristics.
(2) In the Relief Valve when self-vibration was more than 1 in its reflection-ratio of oil wave, it occured and the valves of dQ/dP became minus.
(3) Thermal expansion of valve spring and other elements cause the chattering by leakage of oil.
(4) In the period of stability-restoration from instability which cccured by valve popping pressure, Balanced piston type Relief valves were more efficient than Direct operation type ones.
(5) The Hysteresis of droping and rising pressure of the Balanced piston type Relief valves was 5% of full scale and the least control power was lo㎏/㎠ relatively more higher than Direct operation type ones.

목차 (Table of Contents)

• 1. 緖說
• 2. 油壓裝置 回路圖 및 릴리이프 밸브의 改造圖
• 3. 릴라이프 밸브를 設置한 油壓實驗系統圖
• 4. 릴리이프 밸브의 性能實驗 및 考察
• 1) 밸런스 피스톤型 릴리이프 밸브의 基礎理論
• 2) 壓力變化에 따른 밸브振動現象의 實驗結果월에 對한 考察
• 3) 溫度變化에 따른 實驗結果에 對한 考察
• 4) 流量變化에 따른 밸브의 Response에 對한 實驗結果의 考察
• 5. 結論
• 參考文獻