电解扩孔成形加工装置的设计

目前对细长孔进行扩孔加工主要采用机械扩孔的加工方法,存在刀杆易振动、加工轴线易歪斜等问题;而采用电解扩孔方法,则加工精度高、表面质量好,能较好地解决上述问题。设计并搭建的细长孔脉冲电解扩孔成形加工装置为细长阶梯孔脉冲电解扩孔加工奠定了实验条件。     

便携式、多功能、模块化、小型数控电火花加工机床系列的开发研制

目前,电火花加工机床主要以大、中型为主,当加工尺寸较小以及要求加工后能在位测量工件时,会存在大材小用或加工不便的问题。为此,研制了两个系列的便携式、多功能、模块化、小型数控电火花加工机床。     

硬质合金和聚晶金刚石电火花加工用微能脉冲电源的研究

针对微细制造领域里微细铣刀制备困难的问题,探讨了微铣刀常用材料硬质合金、聚晶金刚石(PCD)的电火花加工机理,分析了微能脉冲电源的实现途径,并设计开发出了满足微细加工用的微能脉冲电源.     

钛合金叶栅套料电解加工表面质量研究

针对TC4钛合金叶栅套料电解加工易点蚀、表面质量差的问题,开展了直流和脉冲电解加工对比研究,设计了脉冲电解加工正交试验,优化了脉冲电压、频率、占空比和加工速度等参数。试验结果表明:脉冲电解加工能减少钛合金点蚀凹坑,提高表面质量,在22 V电压、80%占空比和1000 Hz频率时,加工叶型表面完整无点蚀,加工效率高。     

西门子840D系统多方式组多通道技术在机床上的运用

本文通过对西门子840D系统多方式组多通道技术运用和研究,以解决数控机床加工的同时性问题,即在同一时间能加工不同的零件、做不同的操作,且互相独立、互不影响。     

光学工件高效加工用铁笔结构设计

以现有光学零件常用的加工工艺为基础,分析总结这些工艺所存在的缺陷;针对所存在的问题进行分析,提出新的加工工艺方案,设计新型的加工结构装置。通过加工实验,验证新结构的使用性能和效果。实验结果证实:采用新结构的加工装置,能明显提高产品的生产效率1倍以上,并且能降低人工劳动强度和生产成本等。     

薄壁零件切削参数优化系统研究

针对薄壁零件自身强度低、加工易变形的问题,通过优化调整切削参数的大小,进而调整动态切削力大小和控制切削状态,使因切削力影响造成薄壁零件的加工变形量能满足公差要求,且使加工状态始终处于稳定,降低切削震动造成的变形,从而实现薄壁零件的高精、高速、高效加工.     

齿轮电跑合

从事齿轮加工的人都知道,不论用金刚石砂研磨跑合、机械加载跑合,还是采用人工铲刮等方法来提高齿轮的接触精度,既费工又费时,而且不能有效地解决齿轮的接触精度问题。但是,采用齿轮电跑合新工艺却能实现上述方法无法达到的加工效果。由于它为非接触加工,且具有能加工     

在车床上钻削多孔

分析了利用钻床或镗床加工主轴上多孔时存在的问题，利用车床及专用装置对其进行加工，能保证加工精度及效率，且操作方便、结构简单，扩大了机床的使用范围。     

电火花电解复合加工工作液浓度对电极损耗的影响研究

针对电火花电解复合加工的电极损耗问题,以模具钢为加工对象开展了电火花电解复合加工实验。分析了在不同极性和电极材料条件下,工作液浓度对电极相对损耗、电极形状变化规律及加工精度的影响。结果表明:合理控制工作液浓度能降低电极相对损耗及减小电极形状变化。     

干切削时切削参数的选择和使用

在干切削中,刀具遇到的突出问题是严重的摩擦和高温,只要合理地选择切削用量,减小切削热和摩擦对加工过程的影响,可以减轻干切削的不利条件,有效提高干切削刀具的耐用度,使干切削像湿切削一样在生产中顺利进行。论文通过试验的方法来证明干切削完全可以取得良好的加工效果。     

Force and specific energy in stone cutting by diamond mill

Cutting force and energy are often used as parameters for monitoring the stone cutting process. Empirical models are required to guide the selection of cutting conditions. In this paper, the effect of cutting conditions on cutting force and energy are reviewed. The effects of cutting conditions on cutting force and cutting energy are related to the shape of the idealized chip thickness. The empirical models developed in this paper can be used to predict the variation of the cutting energy. Therefore, the models can be used to guide the selection of cutting conditions. The chip generation and removal process has been quantified with the intention of assisting both the toolmaker and the stonemason in optimising the tool composition and cutting process parameters, respectively.     

切削参数对子午线轮胎模具侧板切削比能及表面粗糙度的影响研究

以子午线轮胎模具侧板为研究对象进行铣削试验,着重研究主轴转速、每齿进给量、切削深度对轮胎模具侧板切削比能、材料去除率和表面粗糙度的影响规律。分析试验结果可知:切削比能随着切削参数的增大而减小,说明适当增大切削参数可以提高切削效率并节约能量;表面粗糙度随主轴转速增大呈先增大后减小的趋势,随切削深度和每齿进给量的增加而增大。结果表明:提高主轴转速既有利于降低切削比能(节能)也有利于改善表面粗糙度,增大每齿进给量和切削深度会降低切削比能但会恶化表面质量。因此,为同时达到高效节能和良好表面质量的要求,应尽量提高主轴转速。     

激光切割表面质量比照判别与控制方法

提出了激光切割表面质量比照判别的方法与标准，通过调整激光切割参数，控制激光切割表面质量等级，解决了激光切割技术在更广泛范围内应用的技术关键，从而保证了在一定范围内实现激光切割加工一次性达到加工技术精度要求。     

Burr minimizing scheme in drilling

In conventional drilling, burr formation can be changed by varying the drill’s geometry, i.e. the step angle and point angle. To minimize burr formation, it is proposed that a step drill be used. The step drill performs front edge cutting before step edge cutting. The burr formed in first cutting by front cutting edge can be removed in second cutting by step edge. In particular, new burrs are formed through the second cutting. They can be minimized by changing the drill’s geometry. A laser sensor is used to measure the burr formed in the drilling.     

Design of hob cutters for generating helical cutting tools with multi-cutting angles

This paper studies the design of hob cutters for generating the multi-cutting angles (radial rake angle, relief angle, and clearance angle) of helical cutting tools in one hobbing process. The current manufacturing process can be greatly improved if the cutting edges in the normal section profile, the rack profile, of a hob cutter are designed with several cutting edges with different pressure angles, so that the helical cutting tools with multi-cutting angles can be formed in one generating process. This paper, therefore, designs a rack profile of a hob cutter consisting of three straight cutting edges with different pressure angles and a curved cutting edge. By applying the equations of designed rack profiles of hob cutters, the principle of coordinate transformation, the theory of differential geometry, and the theory of gearing, the mathematical models of the helical cutting tool can be derived. In addition, the formulas for the radial cutting angle, relief angle, and clearance angle can be derived. Meanwhile, solid modelling of the helical cutting tool can be carried out with computer graphics programming. The results of this paper will contribute to the improvement of the design technology of hob cutters, to enhance the manufacturing processes of helical cutting tools, and to assist tool-related industries in upgrading their technology and competitive abilities.     

An approach for on-line cutting edge stress estimation

Cutting edge deteriorations are attributed to higher mechanical and thermal stresses working on it during metal cutting. However, the stress estimation is a difficult task, especially when on-line estimation is desired. This paper presents a new approach for cutting edge mechanical stress estimation and load simulation. The approach can be applied in the implementation of on-line stress estimation to the study of stress state at the cutting edge and the strategy of real-time edge deterioration monitoring. The approach is based upon cutting force measurement and cutting edge load analysis. The concept of load function and related stress are introduced to estimate stresses working on the cutting edge. With multiple regression, the related stresses can be estimated on-line, from which the actual stresses can be estimated. The method for two-dimensional stress estimation of a cutting edge is illustrated and the principle can also be applied to three-dimensional stress estimation of a cutting edge. The experimental results, obtained with a developed real-time monitoring system and their analysis with respect to cutting edge stress estimation and analysis under different processing phenomena are also reported.     

陶瓷刀具高速干切削加工数值仿真研究

陶瓷刀具在高温作用下会产生自润滑现象,可起到减摩、抗磨作用.论文以Al2O3陶瓷刀具为例,在高温下刀具表面产生自润滑薄膜,利用有限元分析软件DEFORM-3D,建立高速切削AlSI——1045模型,分析Al2O3陶瓷刀具在高速切削加工时,产生自润滑现象所需切削速度,以及在高速切削时,刀具表面的主切削力、应力分布、温度分布和刀具的磨损状态等.研究表明:当切削速度为270m/min,时,刀具表面温度高达842℃,能够产生自润滑现象.     

激光切割过程辅助气体动力学性能的数值模拟

激光切割过程中辅助气体的动力学性能对切缝形成过程具有重要影响.利用VOF算法和深度自适应激光热源,建立了能反映切割过程中辅助气体和切缝之间相互作用的多相流模型,结合切割试验对模型的有效性进行了验证.采用多相流模型分析了从打孔到稳定切割过程中切缝形貌、辅助气体动力学性能和温度场分布.计算结果表明,在未切透阶段,受切割前沿形状和切割深度等的影响,辅助气体动力学性能不断发生变化;当切割过程稳定后,辅助气体流场几乎不发生变化,切缝形状和温度场也不再改变;所建模型能够有效反映辅助气体动力学性能对切割深度和切缝宽度的影响.     

便携式磨料水射流系统切割X60钢的试验研究

磨料水射流切割技术能够满足油气储运设备设施应急抢修切割的需求。通过切割试验研究了便携式磨料水射流切割系统对管线钢的切割特性,得到压力、靶距和横移速度对切割深度的影响关系,提出了切割深度预测模型。结果表明:切割深度与切割压力成正比,与靶距和横移速度成反比。切割深度模型对切割结果预测的最大误差为15.04%,最小误差为0.87%,平均误差为5.98%,表明切割深度模型在一定参数范围内能够有效指导切割工艺的制定。