双折U形件聚氨酯橡胶弯曲模

本分析了双折U形件的弯曲工艺,计算了工件的展开长度、落料力、冲孔力及弯曲力,制订了排样图,设计了冲孔——落料倒装复合模及聚氨酯橡胶弯曲模的模具结构。     

落料冲孔弯曲复合模设计

１引言图１是我厂为长春长铃摩托车有限公司加工零件，常用工艺是落料、冲孔复合→弯曲，需２副模具完成，并且根据该件弯曲高度要弯曲凹模和活动凸模有足够的强度。所以，根据零件特点作了改进，制造了１副落料、冲孔、弯曲复合模，经试制完全符合图纸要求，避免了传统方法难以解决的问题，并减少了模具的数量，降低了模具的生产成本，大大地提高了生产效率。图１零件图２模具结构特点模具结构如图２所示，设计的重点是落料凸模必须有部分成为弯曲凸模，并且成形工序须滞后于落料工序。为此，设计了一个活动凸模块和滚轮滑块机构，当上模下…     

精密垫圈落料冲孔复合模加工及装配

通过对精密垫圈冲孔落料工艺的分析,介绍了模具关键零件加工工艺的特点.根据垫圈零件的特点,提出了采用倒装复合模工艺,介绍了模具结构,同时对模具装配的关键过程作了介绍.     

外壳冲压件成形工艺分析与模具设计

为了保证弯曲时外壳零件多孔的形状,并降低模具的设计成本,通过对冲压工艺分析,对比不同工艺方案,设计了冲孔落料复合模与单工序弯曲模来实现零件的成形。冲孔落料复合模可一次实现多孔成形,保证多孔分布的均匀性及成形的高效性;弯曲模易于确定压力中心,可确保零件一次弯曲成形。该套模具可提高外壳冲压件的生产效率,保证产品质量。     

复合模的装配

<正> 装配是模具制造的最后工序,其质量的优劣不但影响模具的合格与否,而且关系到它的使用寿命。复合模装配的关键是间隙的调整。以落料冲孔式复合模为例,不论是正装式还是倒装式,都存在着保证两方面间隙的问题,往往是顾了冲孔间隙而落料间隙不能保证,尤其是在冲孔凸模较多且形状复杂的情况下,往往是顾此失彼。钳工装配合模     

三种垫圈同时冲孔——落料复合模

分析比较了用三种垫圈同时冲孔——落料复合模代替单只垫圈冲孔——落料复合模,计算了落料力、冲孔力、推件力及顶件力,设计了三种垫圈同时冲孔——落料复合模的模具结构。     

连接件五工位级进模

<正> 连接件(如图1)为车辆组装中一个重要零件,生产批量大,板料厚,形状较复杂。展开后的形状如图2。整个工艺过程为冲孔、落料、U型弯曲、V型弯曲。以往采用3副模具完成该零件,即冲孔落料复合模、U型弯曲模、V型弯曲模。由于工序复杂,使得定位精度低,生产效率低。为了提高该件的生产效率,将以往的3副模具合并为1副模具,设计成五工位级进模,既提高了生产效率,又提高了工件的精度。     

盖板落料冲孔弯曲复合模设计

分析了导板零件冲压成形的工艺特点,设计了一副包含落料、冲孔、弯曲的复合模,该模具结构紧凑,装、拆、修磨方便,模具使用性能良好,经济效益显著.     

卡座级进模设计

介绍了一种越野车中的卡座零件级进复合模设计,将落料、冲孔、翻边和弯曲设计在一副模具中,具有操作简便,生产效率高和操作安全性好的特点.阐述了该模具的结构设计.     

汽车后安全带固定座冲压模拟及模具设计

分析计算了汽车后安全带固定座的冲压工艺,确定了落料冲孔翻边复合模冲压方案。利用DYNAFORM软件得到了制件翻边前的落料形状并模拟了制件翻边成形过程,验证了落料冲孔翻边复合模冲压加工的可行性。设计了1副落料冲孔翻边复合模,并阐述了模具结构、工作过程及设计制造要点。生产实践表明,该模具能够一次完成落料、冲孔、翻边工序,操作方便可靠,保证了制件的形状和精度。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.