基于SolidWorks的抛丸清理机仿真系统设计

由于目前一般的仿真软件无法实现对抛丸清理机工况分析以及对抛射区域检查,本文介绍了如何运用SolidWorks建立产品模型,以及运用SolidWorksAPI和VB进行开发,实现抛丸清理机工作过程的运动仿真,同时实现对抛丸清理机工况的分析和抛射区域的检查,体现了产品的优越性。     

喷丸与激光喷丸强化高强度钢对比试验

为了考察和对比喷丸(SP)和激光喷丸(LSP)2种表面强化技术对金属零件的强化效果,以30CrMnSiNi2A钢为试样,进行喷丸和激光喷丸强化处理试验。试验结果显示,2种强化试样的残余压应力和硬度都有较大的提高。分别测定了喷丸强化和激光喷丸强化试样在同一应力水平下的疲劳寿命,并运用扫描电镜分析了两者的疲劳断口。试验结果表明,激光喷丸强化试样中值疲劳寿命是喷丸强化试样的1.11~2.75倍,激光喷丸强化比喷丸强化在提高金属零件表面性能方面的效果更佳。     

济钢1750高炉气动开口机润滑系统的改造

济钢第二炼铁厂由于原设计润滑方式不合理,使用的气动开口机90％的故障来自润滑不良。通过重新设计润滑方案,润滑效果大大增强,开口机故障基本消除。     

Experimental investigation of shot peening: correlation of pressure and shot velocity to Almen intensity

The International Journal of Advanced Manufacturing Technology - Shot peening is a mechanical surface enhancement process that is extensively used in various industries to increase fatigue life of...     

Kinematic modeling and deformation mechanics in shot peening of functional ceramics

The applications of functional ceramics are significantly limited by the brittleness and low reliability. Recent studies have shown that compressive residual stress can be created in ceramics by shot peening, which improves the contact strength and fatigue of ceramic components. However, the formation mechanism of residuals stress in shot peening is yet to understand. In this study, a pressure-dependent plasticity model has been incorporated into a finite element simulation model of shot peening to understand the process mechanism underpinning the residual stress formation. Since shot velocity is the key process parameter to dominate the impact energy which determines the deformation state of the peened surface and the resultant residual stress, a new kinematic model of shots has also been developed by incorporating air drag and travel distance inside and outside the peening nozzle. The results have shown that the shot velocity model can be used to predict shot velocity. The experiment-based model may help understand the process mechanism underpinning the residual stress formation.     

The effects of laser peening and shot peening on fretting fatigue in Ti-6Al-4V coupons

This paper describes testing of Ti-6Al-4V coupons in fretting fatigue and compares the effects of mechanical surface treatments on performance. Fretting fatigue tests were performed using a proving ring for fretting load, bridge-type fretting pads, and applied tension-tension cyclic fatigue stress. As-machined (AM), shot peened (SP), and laser peened (LP) coupons were evaluated, and data generated to compare residual stress, surface condition, lifetime, and fractographic detail encountered for each. Near-surface residual stress in SP and LP coupons was similar. The layer of compressive residual stress was far deeper in LP coupons than in SP coupons and, consequently, subsurface tensile residual stress was significantly greater in LP coupons than in SP coupons. SP coupons exhibited a rough surface and had the greatest volume of fretting-induced wear. LP coupons exhibited a wavy surface and had a small volume of wear localized at wave peaks. SP coupons had the greatest fretting fatigue lifetime, with significant improvement over AM coupons. Lifetimes of LP coupons were similar to those for SP coupons at high fatigue stress, but fell between AM and SP coupons at lower fatigue stress. Fractographic evaluation showed that fractures of AM samples were preceded by initiation of fretting-induced cracks, transition of a lead fretting crack to mode-I fatigue crack growth, and crack growth to failure. SP and LP samples exhibited behavior similar to AM samples at high fatigue stress, but in coupons tested at low stress the lead crack initiated subsurface, near the measured depth of maximum tensile residual stress, despite the presence of fretting-induced cracks. The level of fatigue stress above which lead cracks were initiated by fretting was higher for LP than for SP, and was predicted with good accuracy using an analysis based on linear elastic fracture mechanics, the fatigue crack growth threshold stress intensity factor range, and superposition of measured residual stress and applied fatigue stress.     

激光喷丸用四轴机器人与脉冲激光器的联动方法

为实现对位置固定的、具有复杂形状表面的构件进行在线激光冲击强化,对四轴机器人和脉冲激光器等组成的激光喷丸系统的联动方法进行了研究。通过分析机器人与激光器之间所支持的通信方式、信号输出和接收方式,分析能够被设备识别的信号接收与发送的要求,提出采用RS232串口通信来实现激光喷丸系统的联动。根据四轴机器人对外进行交流的信号要求,设计出相应的信号转换电路、压降电路、单片机方波产生电路等,并编写出相应的IO接口开关控制程序和RS232串口异步通信程序,开发出相应的硬件电路和联接方法,实现了四轴机器人和脉冲激光器间的信号互动,达到了联动工作的效果。     

大吨位隧道混凝土管片真空吸吊翻转机的设计与研制

阐述了隧道施工用混凝土管片的结构特点及对管片吸吊翻转的要求,根据真空吸吊工作原理讨论了真空吸吊翻转机相关设计参数的确定.最后介绍了研制成功的真空吸吊翻转机的结构组成、功能及其应用情况.     

Empirical modeling of shot peening parameters for welded austenitic stainless steel using grey relational analysis

The attempt of this paper is to present an effective approach for the optimization of the shot peening process of welded AISI 304 austenitic stainless steel with multi performance characteristics using Grey relational analysis (GRA) based on Taguchi orthogonal array. Twenty-seven experimental runs are performed to determine best process parameters level. An analysis of variance (ANOVA) is carried out to identify significant peening parameters. The response tables are obtained for analyzing the optimal levels of shot peening parameters and major factors that affect the quality function. The multiple performance characteristics including tensile strength, surface hardness and surface roughness are the quality functions considered for the optimization. Further mathematical models are developed using regression analysis for the tensile strength, surface hardness and surface roughness. It will be very helpful to the engineers in deciding the levels of the shot peening parameters for desired performance characteristics.     

Evaluation of a wafer transportation speed for propulsion nozzle array on air levitation system

A transportation system of single wafer has been developed to be applied to semiconductor manufacturing process of the next generation. In this study, the experimental apparatus consists of two kinds of track, one is for propelling a wafer, so called control track, the other is for generating an air film to transfer a wafer, so called transfer track. The wafer transportation speed has been evaluated by the numerical and the experimental methods for three types of nozzle position array (i.e., the front-, face- and rear-array) in an air levitation system. Test facility for 300 mm wafer has been equipped with two control tracks and one transfer track of 1500 mm length from the starting point to the stopping point. From the present results, it is found that the experimental values of the wafer transportation speed are well in agreement with the computed ones. Namely, the computed values of the maximum wafer transportation speed Vmax are slightly higher than the experimental ones by about 15–20%. The disparities in Vmax between the numerical and the experimental results become smaller as the air velocity increases. Also, at the same air flow rate, the order of wafer transportation speeds is: V_max for the front-array > V_max for the face-array > V_max for the rear-array. However, the face-array is rather more stable than any other type of nozzle array to ensure safe transportation of a wafer.     

Some investigations into the optimal dimensional synthesis of parallel robots

In this paper, we will perform a comparison between two approaches of dimensional synthesis of parallel robots. The first one concerns the single-objective optimization approach; in this case, the dimensional synthesis is expressed by taking into account only one performance criterion but enables to get a final solution if it exists. The second one concerns the multi-objective optimization approach; it enables to simultaneously take into account several performance criteria. However, this approach appears to provide a set of solutions instead of a single expected final solution which should directly enable to carry out the structural synthesis. In fact, the search of a single final solution is postponed to a further step where the designers have to impose and/or restrict certain parameters. And we will establish if it is really necessary to make a multi-objective optimization approach or if a single-objective is sufficient to reach the objectives set in the specifications (user requirements). A discussion is proposed concerning the arising questions related to each approach and leading to the optimal dimensional synthesis. The PAR2 robot with two degree-of-freedom is used to exemplify the analysis and the comparison of the two approaches. The proposed comparison can be applied to any classes of parallel robots.     

分纸吸嘴机构反求设计方法

针对印刷机飞达分纸吸嘴高速输纸时的抖动问题,提供了一套分纸吸嘴机构反求设计的方法。根据实测凸轮廓线离散坐标,利用样条插值法得到了实际廓线的解析方程;构建了分纸机构运动反求的数学模型,得到了从动件及分纸吸嘴的运动规律。分析表明：分纸吸嘴抖动的根本原因在于运动过程中加速度的剧变;通过反求设计,吸嘴的加速度峰值降低了84％,显著改善了吸嘴的运动性能。该方法可用于其它机构的运动分析和反求设计。     

管桩成型机的电液系统设计与开发

给出了管桩成型机工艺流程,针对传统管桩成型机的电液系统不足之处,该文对该系统进行了设计与开发。新设计与开发的系统具有生产效率高,故障率低,操作方便等特点,从而在生产中取得了满意的效果。     

喷印机喷嘴易堵塞原因分析

喷印机是一种在热轧带钢钢卷上面打印标识的一种装置,但在使用时喷嘴易堵塞,容易对产品的包装形象造成影响,不符合产品的出厂包装。该文对喷嘴易堵塞的原因进行了分析,并提出相应的防范措施。     

喷丸残余应力场有限元模拟研究进展

喷丸强化处理工艺可以显著提高金属材料的抗疲劳和抗应力腐蚀等性能,这与喷丸后在金属表面层形成的残余应力场紧密相关,因此对喷丸残余应力的大小及分布进行预测具有重要意义.对近年国内外喷丸残余应力场的有限元模拟进行评述,总结出6种典型的残余应力分析模型,分别是二维轴对称模型、四对称面模型、三对称面模型、双对称面模型、单对称面模...     

空气炮清堵装置的研究与应用

介绍了空气炮清堵装置的工作原理、结构特点和设计分析，并根据其原理及特点简单介绍了在使用中的注意事项。     

工程机械制造企业集成化工艺系统的研究与开发

以工程机械制造企业集成化工艺系统的研究开发为背景,针对制造企业信息化中最为复杂和最具多变性的工艺系统集成环节,介绍了与之相关的各种工艺系统模型的构建、结构、相互关系以及工艺过程设计的方法;并分析了以模型为基础的工艺路线文件、工艺规程文件的编制策略.在此基础上,介绍了以模型驱动技术开发实现方法及制造企业工艺集成系统功能.     

内壁自动喷涂机控制系统的设计与研制

介绍了一种适合于圆形内表面喷涂的数控喷涂机的控制系统.首先,确定了喷涂工艺方案,接着,进行了控制系统的总体设计,包括元器件的选择、触摸屏的设计、传动部分的控制设计以及喷涂部分的控制设计,最后,确定了控制系统的流程.实际应用证明,该机具有结构紧凑、运动灵活、占用空间少、工作可靠、节能、装卸料容易等优点.     

全液压铣刨机铣刨系统速度刚度问题研究

为提高全液压铣刨机铣刨鼓切削速度稳定性,采用理论分析与试验相结合的方法,对影响铣刨鼓切削速度稳定性的因素及提高铣刨鼓切削速度稳定性的方法进行了研究.指出铣刨液压系统的速度刚度是影响铣刨鼓切削速度稳定性的重要因素,采用高性能元件、加大液压马达排量和合理配置液压元件的工作点是提高液压系统速度刚度的重要措施,其中液压系统的速度刚度与液压马达排量的平方呈正比关系.