高速走丝线切割有关电极丝断丝的分析及处理

针对高速走丝电火花线切割加工中与电极丝相关断丝的原因,进行详细的分析,并分别就不同的原因提出了对策,这些对策能行之有效地减少断丝。     

中走丝线切割机床的上丝机构设计

针对中走丝线切割机床上丝过程中出现电极丝断丝、张紧力不均衡和大小不可调问题,设计了一种用于上丝的机构,将上丝与紧丝合二为一,提高上丝效率并均衡了电极丝的张紧力,提高了加工过程中机床的切削稳定性。结果表明:上丝效率提高60%以上,零件加工质量显著提高。     

探讨高速走丝电火花线切割机断丝的原因及解决方法

针对高速走丝线切割机易断丝的问题，从选择电极丝、运丝机构、绕丝方法、安装工件、选择工艺参数及操作等方面提出了减少断丝的方法。     

高速走丝线切割机的断丝原因及对策

断丝是线切割加工中的常见问题，造成断丝的原因也很多。针对高速走丝电火花线切割加工过程中的断丝问题，综述并补充分析了影响电火花切割中断丝的相关因素，并提出了切实有效的减少断丝现象的对策。     

线切割加工中断丝的原因及其解决办法

在模具加工制造中，线切割机床起到了较大的作用。而线切割中断丝故障是比较常见的故障之一。本文在探索快走丝线切割加工中断丝故障的基础上，分析了断丝的各种原因，并针对各种断丝原因分别给出了其有效的处理办法。     

快走丝线切割非正常断丝原因的探讨

探讨了快走丝线切割非正常断丝产生的原因，从线切割机床和工艺等方面，提出了消除或减小导致线切割加工过程不稳定的外界和内部干扰源的具体措施。     

低速走丝电火花线切割机走丝系统的现状和发展

阐述了低速走丝电火花线切割机走丝系统的组成、功能及原理，在分析现状的基础上，指出了其发展趋势。     

CN200510060848.4 即时更换砂布丝条的丝轮

本发明公开了即时更换砂布丝条的丝轮，包括具有轴孔的基盘，基盘外周背上环绕制有凹口，每个凹口对应设置有砂布丝条，采取的措施包括：凹口为外口径小于内口径的齿形槽，     

电极丝相关控制参数对单向走丝电火花线切割加工效果的影响

分析了单向走丝电火花线切割加工中,电极丝材质、运丝速度、运丝张力以及电极丝直径等相关控制参数对加工过程、加工结果以及加工成本的影响,论述了引起电极丝断丝的原因及其改善措施.     

单向走丝电火花线切割电极丝的分类及发展

正确选用单向走丝电火花线切割的电极丝,对高速切割和高精度加工起着至关重要的作用,对提高工艺稳定性和降低加工成本也有重要的影响。通过叙述单向走丝电火花线切割电极丝从紫铜丝到镀锌丝的发展过程,以及电极丝的性能、种类及优缺点等,进一步分析了电极丝的发展趋势,有助于加工时对各类电极丝的正确选用。     

双丝筒超长丝往复走丝电火花线切割加工技术

研发了双丝筒长丝往复走丝电火花线切割加工技术及工艺方法,提高了"中走丝"线切割加工的精度、降低了表面粗糙度。通过构建双丝筒恒张力可往复、变速运丝系统,使往复走丝和单向走丝线切割加工的工艺方法很好地结合在一起。基于该研发成果,采取先往复走丝切割、后单向走丝修整切割,实现修切时与单向走丝线切割相同的加工工艺,为"中走丝"线切割加工质量更接近单向走丝的加工水准创造了条件。同时,该方法实现了电极丝的循环使用,与单向走丝线切割加工方法相比,节约了电极丝资源。     

高速走丝电火花线切割机线架结构的改进

针对高速走丝电火花线切割机加工薄件时的倒向条纹问题，对比分析了低速走丝线切割机线架结构，经过反复实验，对线架结构进行了改进，取得了预期的效果。     

基于智能PID算法的WEDM电极丝恒张力控制

目前市场上慢走丝电火花线切割(WEDM)的电极丝运行机构基本为单向走丝系统,存在张力波动较大且难以被精确控制从而导致机床加工性能降低的问题。针对上述问题,分析电火花线切割加工过程中电极丝张力变化的主要因素;基于模拟退火与PID控制混合算法设计智能PID控制器;基于智能PID控制,采用压力式传感器测量电极丝张力为反馈信号,分别建立磁粉制动器和双电机转速差为执行元件控制电极丝的张力控制系统;并采用示波器采集压力式传感器的信号,比较两个不同控制系统的控制效果。结果表明:两个电极丝张力控制系统能够将电极丝的波动控制住1 N以内,双电机转速差控制系统各项指标略优于磁粉制动器控制系统。     

PCD、PCBN复合片的电火花线切割加工质量

选取几种典型的PCD、PCBN复合片,在慢走丝电火花线切割机床上对其进行了多次加工工艺试验;运用三维表面轮廓仪、超景深三维显微镜对线切割加工后的表面粗糙度、富钴界面层加工质量、刃口加工质量等进行测量。结果表明:超硬颗粒直径大小及含量对加工质量影响较大,PCD、PCBN复合片经多次电火花线切割加工,能够得到较好的加工质量;经WEDM加工后的PCD复合片刃磨量可控制在4～15μm左右,PCBN复合片BNX20刃磨量可控制在10μm以内,而BZN6000则需较大的刃磨量。     

高稳定性电弧喷涂刚性送丝机的设计

目的解决传统电弧喷涂送丝机的局限性,特别是柔性送丝结构存在的送丝速率低、送丝波动大等问题。方法设计了刚性送丝结构,进而成功研制了高稳定性电弧喷涂刚性送丝机,并通过送丝速率测试、喷涂电流测试及喷涂焰流观察等对比性试验,验证了设计的有效性和可行性。结果在无喷涂状态下,传统柔性送丝机和文中研制的刚性送丝机的送丝速率均随送丝电压的增大而增大,且刚性送丝速率呈近似线性变化趋势,而柔性送丝速率具有一定随机性。在相同送丝电压下,刚性送丝的速率高于柔性送丝,即具有更小的送丝阻力;且刚性送丝机两侧丝材送进平均速率的同步误差均小于3%,而柔性送丝机的同步误差为5%左右,说明刚性送丝机具有较好的送丝同步性。同时,柔性送丝机的送丝速率波动率为10%左右,而刚性送丝机的仅为2%左右,说明刚性送丝机在无喷涂状态下具有优异的送丝稳定性。在喷涂状态下,刚性送丝机和柔性送丝机的喷涂电流波动率分别为4.76%和29.36%,且刚性送丝机的喷涂焰流比柔性送丝机的更加集中稳定,说明刚性送丝机在喷涂状态下也能保持良好的送丝稳定性。结论刚性送丝结构可以有效减小送丝机的送丝阻力并保证两侧丝材送进的同步性,使送丝过程具有更高的稳定性。     

Fixed abrasive diamond wire machining—part I: process monitoring and wire tension force

The process monitoring and mechanics of fixed abrasive diamond wire saw machining are investigated in this study. New techniques to affix diamond particles to a steel wire core have advanced to make this process feasible for the machining of ceramics, wood, and foam materials. Developments in fixed abrasive diamond wire machining are first reviewed. Advantages of using fixed abrasive diamond wire machining are then introduced. The process monitoring and signal processing techniques for measuring the cutting forces, wire speed, down feed rate, and wire bow angle in diamond wire saw machining are developed. The application of a capacitance sensor to measure the wire bow and a procedure to convert the wire bow to vertical cutting force in a rocking motion wire saw machine are developed. The tension force of the wire during cutting is also derived and discussed.     

钼丝研究现状

钼丝作为一种重要的钼制品,拥有十分广阔的发展前景,主要应用于线切割行业、喷涂钼丝行业等,但是在制备和使用过程中存在着成丝率低、断丝率高、寿命短等问题,纯钼丝已经无法满足现代工业发展的要求,各种掺杂钼合金丝日益得到重视,对纯钼丝、TZM合金丝、Al-Si-K掺杂钼合金丝、Mo-Re合金丝、稀土掺杂钼丝、Mo-Al2O3合金丝及多元复合掺杂钼丝的制备方法和研究现状进行了综述,并对钼丝在研究过程中存在的问题进行了讨论、分析和展望。     

移动热源作用下电火花线切割加工电极丝三维温度场模拟

往复走丝和“中走丝”电火花线切割机床是中国独创的电加工设备,在模具制造等行业发挥着重要作用.由于其电极丝是重复使用的,因此电极丝损耗是普遍存在的问题.在电极丝与工件之间相对运动的情况下,建立了移动热源条件下的电极丝传热模型,通过有限元分析对单脉冲放电条件下电极丝表面温度场进行了三维仿真,发现当走丝速度增加时电极丝熔融区...     

Study on Heat Generation Mechanism and Melting Behavior of Droplet Transition in Resistive Heating MetalWiresEI北大核心CSCD

With the development of space technology, the ability of manufacturing in space is a necessary guarantee for a long-term space mission. To achieve the repair and maintenance of spacecraft structure in space, a metal additive manufacturing method named resistance heating metal wire additive manufacturing process has been proposed in this work. During the experiments, the wire and the base plate are short-circuited, the current output from the programmable power source flows through the wire and the base plate to generate resistance heat, and then the wire begins to melt and transfer to the base plate. A real-time synchronization system has been used to record the current, voltage and image of metal wire synchronously, to study the melting process of metal wire by resistance heating. The direct current and pulse current with different amplitudes which were supplied by programmable power source have been used to study the effect of the current style and value on the melting process and transition behavior of metal wire. The change characteristic of the resistance in the wire and base plate has been analyzed during wire melting, to study the relationship between the current resistance and the wire state. The effect of gravity on the wire melting process has been studied by the wire transfer experiments at different space locations. The results show that when the metal wire was heated by the constant current, the total heat of metal melt could be controlled by controlling the current value, but it was difficult to precisely control the heating speed and the heat input. When using pulse current heating, both the heating speed and the heat input could be precisely controlled by pulse frequency and pick value. In the melt transfer stage, the constant current provides a fixed force on the molten wire, but the pulse current makes the molten wire swing by the intermittent force. The real-time resistance of metal wire during heating could be used to reflect the melting state of wire in both current styles. On the ground environment, the surface tension and electromagnetic contraction force make the melting wire against the gravity and transfer to the base plate, which illustrated the feasibility of using this process in space environment.