汽车冲压零件的设备许用载荷分析

根据多连杆压力机的行程曲线特点,提出了以80%公称力作为公称力控制线,并据此绘制压力机载荷许用区间图,即将力-行程曲线划分为安全区、临界区和危险区。当成形力处于公称力控制线下方,则设备载荷能够满足成形要求;当成形力处于公称力控制线和公称力曲线之间的临界区,需要进一步对变形功进行校核。另一方面,采用数值积分的方法对成形力和作用距离进行积分,得到变形功,与压力机许用变形功进行比较,提出能量校核的前提和校核方法。最后提出了成形力和变形功校核流程图,并用于前门内板等零件的分析。结果表明,采用22500 k N压力机满足前门内板一模双件载荷要求。     

Influence of the connecting tube at the cold end in a U-shaped pulse tube cryocooler

In some special applications, the pulse tube cryocooler must be designed as U-shape; however, the connecting tube at the cold end will influence the cooling performance. Although lots of U-shape pulse tubes have been developed, the mechanism of the influence of the connecting tube on the performance has not been well demonstrated. Based on thermoacoustic theory, this paper discusses the influence of the length and diameter of the connecting tube, transition structure, flow straightener, impedance of the inertance tube, etc. on the cooling performance. Primary experiments were carried out in two in-line shape pulse tube cryocoolers to verify the analysis. The two cryocoolers shared the same regenerator, heat exchangers, inertance tube and straightener, and the pulse tube, so the influence of these components could be eliminated. With the same electric power, the pulse tube cryocooler without connecting parts obtained 31 W cooling power at 77 K; meanwhile, the other pulse tube cryocooler with the connecting parts only obtained 27 W, so the connecting tube induced more than a 12.9% decrease on the cooling performance, which agrees with the calculation quite well.     

SPS模式下物料消耗平准化的混流装配线车型排序

在混流生产过程中,针对零部件供应不能实现JIT的问题,提出在SPS物料配送模式下,提高零部件消耗平准化程度。在汽车混流装配线中最重要的目标是零部件消耗速率平准化,建立了混流装配线车辆排序模型。结合W公司实际案例,验证了车型排序在平准化物料消耗中的重要意义。     

Cloud-DPP for distributed process planning of mill-turn machining operations

Today, the dynamic market requires manufacturing firms to possess a high degree of adaptability to deal with shop-floor uncertainties. Specifically targeting SMEs active in the metal cutting sector who normally deal with intensive process planning problems, researchers have tried to address the subject. Among proposed solutions, Cloud-DPP elaborates a two-layer distributed adaptive process planning based on function-block technology and cloud concept. One of the challenges of companies is to machine as many part features as possible in a single setup on a single machine. Nowadays, multi-tasking machines are widely used due to their various advantages such as reducing setup times and increasing part accuracy. However, they also possess programming challenges because of their complex configuration and multiple machining functions. This paper reports the latest state of design and implementation of Cloud-DPP methodology to support parts with a combination of milling and turning features, and process planning for multi-tasking machining centers with special functionalities to minimize the number of setups. The contributions of this work are: representation of machining states and part transfer functionality, support of multi-tasking machines in adaptive setup merging, development of special function blocks to handle sub-setups and transitions, and finally generation of function-block network for the merged setups. The developed prototype is validated through a case study.     

Operation Assist by Vibration Suppression Control Using Impulse‐Shaped Signals for Power Assist Conveyance System

This paper presents an assist control method for a flexible parts conveyance task using a power assist conveyance system. The assist control method should be designed so as not only to suppress vibration but also to reduce the degradation of operating feel. For this purpose, multiple impulse‐shaped signals are used as feedforward signals in order to reduce the vibration of flexible parts during conveyance. In addition, the adjustment time is introduced to adjust the input timing of the impulse‐shaped signal and to suppress vibration. In order to improve the degradation of operating feel, the smaller amplitudes of the three impulse‐shaped signals are used and input repeatedly. The effectiveness of the proposed system was verified experimentally. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(2): 31–39, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22476     

同步预热焊接专机的应用

同步预热焊接专机在提高工程机械重要结构件的焊接加工效率和质量方面效果显著。文中主要对专机的工作原理、系统组成、工作特点、操作方法及现场应用情况进行了说明和介绍。生产实践表明：该专机适用范围广，操作性良好，预热效果理想，焊接质量可靠，可在大型机械制造中推广使用。     

机体挡圈装配研制工艺

挡圈两端面的平行度及切开后再加工是工艺上的难点,无法采用车间现有的通用设备加工。文中利用三套工装夹具,通过特殊的加工方法保证零件的技术要求,并给出了机体挡圈加工和装配的特殊工艺过程。     

一维波动方程Dirichlet问题解的结构

提出了一类常见一维波动方程Dirichlet问题解的结构，从而得到该问题的简捷算法。     

特种电机轴Cr17Ni2钢的兰脆

本文介绍了Cr17Ni2特种电机轴高温时出现的兰脆现象，并对兰脆断口进行了扫描电镜分析。     

关于复合材料加工技术的探析

由于机械加工复合材料能够划分成特种与常规。特种则是借助于刀具根本不接触工件,监控起来比较容易,而且磨损刀具程度小,这种方式适合自动化操作,可是受到不同种类复合材料特性的影响,导致特种加工通用性比较差,常规的则是将切削加工金属的一整套设备与工艺进行沿袭,相对来说显得工艺较成熟与简单,可是复杂形状工件加工比较难,磨损刀具比较快,切削粉末危害人们的身体健康与加工质量比较低,如今还是更多的使用常规加工。