轴向冲液电解线切割50CrVA试验研究

采用轴向高速冲液电解线切割方法加工50CrVA弹簧钢,利用高速流动的电解液快速带走加工产物。通过对加工区域的流场进行仿真,选出合适的喷嘴直径,并对影响加工的重要因素(加工电压、占空比、频率、进给速度)进行单因素试验,研究各参数对加工缝宽的影响。最后,采用优化参数加工出缝宽约为1 mm的典型零件。

电解线切割加工技术试验研究

分析了应用电解线切割加工工艺在厚不锈钢板上加工高深宽比结构的可行性。为解决加工高深宽比结构时的排屑问题,在分析该工艺特点的基础上,采用了轴向冲液的方法。在自行搭建的加工系统中,进行了不同加工参数的一系列试验,以研究加工电压、电极丝进给速度、电解液浓度和冲液速度对该工艺的影响。最后,对电解线切割加工参数进行优化,加工出了缝宽为160μm、深宽比高达30的微型花键。

方形切缝扭簧电解线切割加工试验研究

方形切缝扭簧广泛用于各类战机、直升机配平舵机,其力学特性受制造精度影响显著。提出采用低速旋转+直线进给的组合运动方式进行方形扭簧电解线切割加工,分析其组合运动学特性,设计专用运动装置,建立了方形切缝扭簧电解线切割加工试验系统。首先开展穿丝孔管电极电解加工试验研究,探究进给速度和加工电压参数对穿丝孔孔径大小与孔型的影响,选择进给速度0.6mm/min、加工电压14V的加工参数加工出孔径为0.96mm的阵列穿丝孔。其次采用涂覆绝缘涂层的工艺,避免了电解线切割过程中扭簧非加工表面腐蚀现象,同时试验探究了加工电压对其进给速度的影响。最后,采用优化后的工艺参数和改进的工艺流程,加工出平均缝宽为1.006mm、尺寸偏差在±0.05mm内、表面质量较好的方形切缝扭簧样件。

Sensitivity Analysis and Optimization of Geometric Parameters of a New Fluid Bag Buffer Mechanism on Buffering Performance

A new fluid bag buffer mechanism,which can provide large axial stiffness under the small displacement,is designed.The dynamic change laws of the mechanism stiffness and the internal pressure of the fluid bag are studied when it is subjected to impact load.According to the protection performance for the flexible joint and the pressure change in the fluid bag during the impact process,the sensitivity of the geometric parameters of the fluid bag to the axial stiffness is analyzed by using the orthogonal experimental method,and the optimal parameter combination of the geometric parameters of the fluid bag under impact is obtained,leading to the displacement of the inner shell reduce by 41.4%.The results show that the internal pressure of the fluid bag is a rising process of oscillation and fluctuation.The sensitivity of the geometric parameters of the fluid bag to the displacement of the inner shell from high to low is as follows:Height H,radius r,wall thickness t,chamfer A.The correlation between the geometric parameters of the fluid bag and its internal pressure is:H is negatively correlated with the internal pressure,while the r,t,and A are positively correlated with the internal pressure.

Influence of Different Filling Materials on Stiffness of a New Buffer Bag

A buffer bag mechanism is designed,which can provide axial impact protection under small displacement.The stiffness characteristics of the structure under impact load are studied.The stiffness of the mechanism and the internal pressure change of the buffer bag are compared and analyzed,when the filling materials are liquid and gas respectively.Finally,the influence of initial fluid bag pressure,bulk modulus and shell thickness on the stiffness of the mechanism and the change of bag pressure are studied.The results show that the stiffness of the liquid bag is better than that of the gas bag when the filler is liquid and gas;the liquid bag has obvious pressure rise after the mechanism is subjected to axial force by 300 kN,and the gas bag has almost no pressure rise;the change of bulk modulus,which is1000,1500,2000 and 2500 MPa,has an obvious effect on the liquid bag,and it is positively correlated with the stiffness of the mechanism.The change of gas modulus,which is 28 and 44,has little effect on the stiffness of the mechanism;the thickness of the buffer bag,which is 5,10 and 15 mm,also has an obvious effect on the stiffness.The stiffness of the liquid bag is greater,and the protection for flexible joint is better in the same condition.