双折臂起重机起吊装置速度控制优化

Optimization of Speed Control for Double Folding Boom Crane Working Device

双折臂起重机起吊装置复合动作协调性小于安全性需求,考虑到阀后补偿较阀前补偿复杂,故采用阀前补偿型负载敏感液压系统控制其起吊装置动作。给出了双折臂起重机起吊装置起吊原理,搭建了其液压系统仿真模型,开展了双折臂起重机复合动作速度仿真。主要分析了不同开度和不同质量下的动臂和伸臂速度动态性能,基于动臂和伸臂液压缸活塞受负载影响明显,在动臂液压缸无杆腔油路增加了平衡阀。通过分析设置了动臂平衡阀开启压力20.5 MPa、先导比0.5、全开压降1.5 MPa,进行了相同开度和质量工况的动臂活塞速度仿真。研究表明:增加平衡阀后,动臂下降速度能限制在与负载质量无关的速度指令范围内。选取某双折臂式起重机为实车测试对象,验证了仿真结论的正确性。据此可在伸臂液压缸进回油路增加平衡阀,解决伸臂液压缸速度受负载的影响问题。该研究对提高双折臂起重机的起吊性能具有一定参考价值。

The lifting device action coordination of the double folding boom crane is less than the safety requirements.Considering that the post valve compensation is more complex than the pre valve compensation type,therefore,a load sensitive hydraulic system with compensation in front of the valve is used to control the movement of the lifting device.The lifting principle of the double folding arm crane lifting device is provided.The hydraulic system simulation model was established.This paper conducted a simulation of the composite action speed of a double folding boom crane and mainly analyzed the dynamic performance of the boom and extension speed under different openings and masses.Based on the significant impact of load on the piston of the boom and extension cylinder,a balance valve has been added to the rod less chamber oil circuit of the boom hydraulic cylinder.By analyzing and setting the opening pressure of the boom balance valve to 20.5 MPa,the pilot ratio to 0.5,and the fully open pressure drop to 1.5 MPa.The speed simulation of the boom piston was conducted under the same opening and mass conditions.The research has shown that by adding a balance valve,the lowering speed of the boom can be limited to a speed command range unrelated to the load mass.Finally,a double folding boom crane was selected as the actual vehicle test object to verify the correctness of the simulation conclusion.Based on this,a balance valve can be added to the inlet and outlet oil circuit of the boom cylinder,thus it can solve the problem of the speed of the boom cylinder being affected by the load.This study has certain reference value for improving the lifting performance of double folding boom cranes.