共查询到20条相似文献,搜索用时 140 毫秒
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提出了种称为双向充液变薄拉深的工艺方法,从理论上推导出变薄成形极限计算式,并采用三种毛坯进行了双向充液变薄拉深度试验。当液压达120MPa时,车削软铝毛坯的极限变薄拉深系数由0.5减小到0.3;二次拉深毛坯的极限变薄拉深系数由0.6减小到0.45;二次拉深化退火毛坯的极限变薄拉深系数由0.6减小到0.4。 相似文献
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不等壁厚带台阶锥形件冲压成形工艺与模具设计 总被引:2,自引:2,他引:0
分析了不等壁厚带台阶锥形件的冲压成形工艺,介绍了有色金属变薄拉深毛坯直径计算方法,采用合适的润滑剂及润滑方法和确定合理的模具间隙,经过多次拉深、变薄拉深和锥部拉深,成形出了表面质量理想的不等壁厚带台阶锥形件。 相似文献
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提出了一种能有效减小拉深件最大厚度变薄量,提高拉深成形极限及拉深件质量的夹紧式拉深模具结构,并已用于实际生产中。叙述了该模具结构特点及其工作原理,对有关工艺参数的影响进行了实验研究,并对实验结果进行了分析。 相似文献
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多道次变薄拉深机理分析 总被引:2,自引:1,他引:1
以多道次变薄拉深的刚塑性有限元法力学模型为基础,进一步阐明其变形机理。研究发现除后拉力效应外,变薄区出口速度减小也是提高多道次变薄拉深成形极限的一个原因。 相似文献
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以汽车发动机制动室缸体拉深成形为例,分析了厚壁筒形件拉深时筒壁产生变薄环的原因,介绍了采用变薄拉深工艺将其消除的方法。该方法对内壁质量要求较高的筒形件成形具有普遍的实用意义。 相似文献
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壁厚变薄直径缩小空心件的变薄拉深 总被引:2,自引:1,他引:1
通过薄壁、变壁厚、厚底、大高度的空心零件成形,介绍了变薄拉深工艺的特点,分析了壁厚变薄、直径缩小的变薄拉深变形过程,给出了变形程度的表示方法——加工率,提出了该类变薄拉深的工艺参数计算方法,可为同类型零件变薄拉深工艺计算提供参考。 相似文献
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圆筒形件充液拉深皱曲和破裂极限的研究 总被引:1,自引:0,他引:1
从充液拉深时零件变形的应力应变状态出发,根据普通拉深成形起皱和破裂的控制和预测,导出了圆筒形件充液拉深防皱曲和防破裂压边力的极限判据,作为其皱曲与破裂极限的预报及控制.同时还给出了圆筒形件充液拉深成形安全区域图,由此可以确定圆筒形件充液拉深成形的极限拉深系数和最小拉深系数,适用于无凸缘圆筒形件拉深、带凸缘圆筒形件拉深和刚性凸模的胀形.另外分析了在4组压边力的条件下液压力对零件成形的影响,为工艺参数确定、模具设计和设备选择提供依据. 相似文献
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The range of possible applications of ironing processes reaches from the production of cylindrical pressure tanks, shock absorber
pipes, battery and beverage cans to the production of flacons for the cosmetics industry. One goal of the finite element analyses
of ironing processes is to gain knowledge about process limits regarding maximized forming capacity and optimized surface
quality. The ironing process is characterized by parameters like friction, geometry of the ironing ring and anisotropic material
behavior. Due to the high complexity of this process, it is complicated to detect these effects on the basis of experimental
investigations only. Therefore, one of the aims of this study is to identify relevant process parameters by means of systematic
numerical analyses. The design of experiments was utilized to create a model of the ironing process. By means of this model
it was possible to reduce the punch load and to minimize the tensile stresses in the first stage of the analyzed ironing process. 相似文献
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Shrinidhi Chandrasekharan Hariharasudhan Palaniswamy Nitin Jain Gracious Ngaile Taylan Altan 《International Journal of Machine Tools and Manufacture》2005,45(4-5):379-388
Lubricants are employed in stamping operations in order to (a) improve the material flow into the die cavity, (b) reduce wear and galling in the die and (c) obtain good surface finish of the part. Process conditions such as high temperatures and pressures could cause the lubricant to fail, thus resulting in galling or tearing of the part, damage to the tooling, and lost production. Therefore, selection of an appropriate lubricant based on the process conditions is important in the stamping industry. Several benchmark tests emulating stamping operations have been developed and are used to evaluate the performance of candidate lubricants. The major drawback of most of these tests is their inability to emulate high contact pressures and sliding velocities, which are crucial parameters for lubricity, especially in the case of high-speed progressive or transfer die operations involving ironing. Moreover, most of these tests are conducted at room temperature, while in reality; the process temperature can reach as high as 200 °C. The ironing tribotest developed at the Engineering Research Center for Net Shape Manufacturing (ERC/NSM) induces high contact pressures and temperatures, thus emulating the conditions in a production environment. Application of the test to screen candidate lubricants for stamping operations involving the ironing process is discussed in this paper. 相似文献
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利用连续速度场解析了筒形件变薄拉深过程拉深力,并获得其上限解析解,通过相同条件下该解析解与实验结果比较表明,两者吻合较好。 相似文献
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通过对轴承环进行拉深工艺分析,找到了影响变薄拉深工艺的各种因素,论证了轴承环进行变薄拉深的可行性与优越性。采用有限元软件Dynaforrn及Deforrn对其进行数值模拟,获得了优化的工艺参数并得到生产实际检验。 相似文献
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Food and beverage containers are common in Western society, with over one billion beverage containers produced annually in the United States alone. One of the environmental concerns associated with the manufacture of these products is the production of volatile organic compounds during the coating of the can interior with a protective polymer. This issue can be resolved by using pre-laminated steels as a base stock, so long as the polymer coating is robust and can survive the can making operation. Recognizing that ironing is the most demanding metal forming operation in can making, a series of formability tests were conducted on novel laminated polymer-coated steel specimens using an ironing simulator. It was found that the laminate-coated steels could display good ironability with tin-free steel substrates. The surface quality was evaluated and related to process parameters, of which the ironing angle was determined as the most important factor. With proper tooling and layer design, polymer laminate base stocks have been demonstrated to be suitable for drawn and ironed containers. 相似文献
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S. Kuriyama Y. Yoshida T. Takahashi S. Kumagaya T. Aoki K. Miyauchi 《Journal of Materials Processing Technology》2003,140(1-3):13-18
A code of FEM for an elastic and plastic material has been developed to calculate a residual stress distribution in D-I can by both-sided ironing. It is possible for the code to simulate a forming process of deep drawing from a sheet to a can, an ironing process of both-sided of the can wall, and a deformation of the whole of the can under perfect unloading when the can is removed from an equipment of deep drawing and ironing. From these simulations, quite different and contrary distributions of residual stress are obtained according to mutual positions of dies for the ironing, which are considered to expand the wall of can as an ellipsoidal shape or shrink it to a hyperbolic shape. 相似文献
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李智宇 《特种铸造及有色合金》2009,29(11)
采用刚塑性有限元法对高强度钛合金缩径挤压过程进行模拟,获得了成形过程中的网格变化图和标记点的金属流动速度变化图;通过对各标记点速度变化的分析,发现坯料表面金属相对于中心金属的流动速度变化是端面凹陷形成的根本原因;在此基础上探讨了凹模锥面的形状和摩擦阻力对缩径挤压的影响. 相似文献
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工艺参数对减径挤压的影响 总被引:3,自引:0,他引:3
影响减径挤压的工艺参数主要包括凹模锥角、定径带长度、摩擦系数、高径比等。采用有限元模拟技术模拟了不同工艺参数条件下的减径挤压变形过程。以内缩量为评价标准,分析了这些工艺参数对减径挤压的影响规律。 相似文献