方坯连铸拉矫机液压系统设计与分析

Design and Analysis of Hydraulic System for Continuous Casting Machine Withdrawal Straightening Unit

方坯连铸拉矫机压下辊的工作压力对铸坯质量有非常重要的影响。为了提高拉矫机的铸坯生产质量和效率,以调节拉矫机工作压力满足生产要求为目的,以拉矫机液压系统为研究对象,针对拉矫机设备结构的特点,介绍了工作过程中压下辊压力的变化情况,提出了拉矫机液压系统的设计要求,并依此设计出多种形式的液压系统且在工程中广泛应用。结合工程设计经验,通过对比不同的液压系统,得出如下结论:用普通先导式减压阀的系统成本较低,但冷热坯压力不可调,只能适合生产单一断面的钢种;用比例减压阀的差动系统自动化较高,提高了铸坯了质量和生产效率,适用于生产多种断面的钢种;用比例减压阀和事故回路构成的系统,压力在线可调,且专门设置了事故应急动力源,生产安全系统提高。

The strengthen pressure of withdrawal straightening unit in billet continuous casting machine has great effect on the casting quality. In order to improve quality and efficiency of withdrawal straightening unit, aiming to adjusting the pushing roller pressure to meet the requirements of production, taking the hydraulic system as the research object, the pressure changing in the operation process were illustrated and the hydraulic system requirements were put forward,according to which several hydraulic systems were designed and these systems wildly used in projects. Basing on projects design experience and analyzing different hydraulic systems, the result shows that system with pilot operated reducing valve is suitable for single section dimension system, because the cold/hot pressure cannot be conditioned though it has a lower cost, while the proportional reducing valve with differential circuit can be used for several sections dimension iron steel with high quality and efficiency. The system with proportional reducing valve and emergency circuit can adjust pressure online, and improve safety reliability as it designs emergent power supply.