共查询到19条相似文献,搜索用时 187 毫秒
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现代冷挤压成形技术研究与应用 总被引:2,自引:0,他引:2
现代冷挤压技术已经从传统的冷挤压成形基本方法发展成复合挤压、复动挤压、闭塞挤压、分流挤压、控制流动挤压等多种形式,分别阐述了各种冷挤压新技术的成形原理、成形特点和基本方法,并对现代冷挤压模具也作了必要的论述。并根据冷挤压成形特点,对传统的冷成形与新技术成形特点与原理以及传统模具结构与现代模具结构等做了较详细的分析。 相似文献
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高频电液激振冷挤压数值模拟及其减载实验研究 总被引:1,自引:0,他引:1
针对冷挤压成形过程中流动应力大、零件成形所需压力高的问题,提出了一种新的挤压工艺,设计了一种新的电液高频轴向振动激励冷挤压试验平台及相应冷挤压模具。利用Deform-3D软件建立了有限元分析模型,分析了在轴向振动激励下该模型的成形过程降载效果,精确地模拟了万向节轴套的冷挤压成形过程的挤压力的变化,比较了传统挤压形式下和轴向振动激励形式下的成形压力值,通过挤压试验验证了模型模拟的准确性。试验结果表明,该新的挤压成形工艺能使万向节杯套成形压力降低21.78%,减载效果明显。研究结果表明,这种新的成形工艺可以为一些难成形零件的冷挤压成形加工打下良好基础。 相似文献
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内花键挤压成形的数值模拟分析 总被引:1,自引:0,他引:1
介绍了挤压成形的工艺特点,通过对内花键成形过程的数值模拟仿真,分析其成形的可行性,找出影响复合挤压的关键因素,针对其成形特点,设计合理的模具,对该零件的生产应用具有极大的指导意义. 相似文献
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铝型材等温挤压温度控制的研究 总被引:1,自引:0,他引:1
对温度进行有效控制是实现铝型材等温挤压的关键技术,结合传热学推导出铝型材挤压容室从室温加热到特定值所需的加热能量及加热功率的计算公式与空气冷却量的计算公式。在此理论基础上设计了用于等温挤压容室温度控制的加热与冷却系统,介绍了感应加热的优缺点。采用有限元模拟了挤压容室温度与应力分布情况,结果表明:加热时挤压容室温度分布均匀,由于挤压容室为过盈装配,必须缓慢加热,根据此模拟结果提出了实现铝型材等温挤压容室温度控制的技术路线。计算结果在100MN油压双动铝型材挤压机上得到了验证。 相似文献
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NUMERICAL DESIGN OF DIE LAND FOR SHAPE EXTRUSION 总被引:3,自引:0,他引:3
Hao Nanhai Department of Mechanical Engineering Taiyuan Heavy Machinery Institutex Li Kezhi Northwestern Polytechnical University 《机械工程学报(英文版)》2001,(1):91-93
0 INTRODUCTIONIntheextrusionofshapeswithflat faceddies ,asthebigdifferenceinsectionbetweentheextrudedshapeandthebillet ,theseriousfrictiononthematerial/toolinterface ,non uniformmetalflowispresentinthedeformationzone .Thismayresults ,dependingonthecomplexit… 相似文献
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通过对小模数花键冷挤轧成形过程分析,指出冷挤小模数花键的可行性,其工艺明显优于传统加工方法,加工精度、齿面强度和效率均得到很大提高。针对实际的成形条件,详述了滚轧轮的设计方法,为小模数花键零件的研究和生产提供了一种实用、高效、可靠的成形工艺。 相似文献
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In an extrusion plant, the die design procedure is very often a trial-and-error process which requires a number of extrusion trials before reaching a satisfactory design. If the die is not corrected or tuned appropriately, the product may be twisted and warped. In this work, a model is proposed which should guide the preliminary design of extrusion dies. The model is focused on the distortions of the extruded product due to exit velocity variations. The die design model is limited to the extrusion of thin sections through solid dies. Since the die opening is assumed to be long and slender, asymptotic approximations have been used in the analysis. Some die design examples are discussed. 相似文献
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ZHANG Jun College of Materials Science Engineering Northwestern Polytechnical University Xi’ an China China Heavy Machinery Research Institute Xi’ an China YANG He College of Materials Science Engineering Northwestern Polytechnical University Xi’ an China XIE Donggang HAN Bingtao China Heavy Machinery Research Institute Xi’ an China 《机械工程学报(英文版)》2007,20(2):36-40
A modern design method,in which traditional design formulas are conjoined with numerical simulation and optimization,is successfully used to design the out-size extrusion frame precisely so that the press cost can be saved. A new technology used for decompressing by a multi-steps dynamical mode is put forward,which makes it possible to decompress the large flow-volume high-pressure oil in the main cylinders. In addition,a method for realizing the fixed mandrel process by hydraulic support is proposed and its control equation is established. Pre-tightening frame tests are carried out by over-operating pressure on 100 MN aluminium extrusion press with oil-driven double action,which is developed based on the above key techniques and is the largest press so far in the world,and the results show that the frame structure designed is reasonable and reliable,and the modern design method used is an useful tool for designing large and out-size heavy plastic forming machinery. The results of decompressing curve in main cylinder and noise inspection indicate that multi-steps dynamical mode for decompressing the large flow-volume high pressure oil is valid and reliable. Meanwhile,the fixed mandrel process is well realized based on the control equation. These key techniques have been used in the development of 125 MN aluminium extrusion press with oil-driven double action. 相似文献
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L. X. Li K. P. Rao Y. Lou D. S. Peng 《International Journal of Mechanical Sciences》2002,44(12):2415-2425
Hot extrusion of Ti–6Al–4V alloy has been studied using finite element simulation and the results are compared with those obtained experimentally. First, the constitutive behavior of the material and friction at the extrusion temperatures are established based on the results obtained through cylindrical and ring compression tests, respectively. While the flow stress below β transus temperature is expressed as a strain-dependent function, it is taken as strain-independent one at higher temperatures. The distribution of strain, temperature and effective stress has been simulated under different design and processing conditions. Simulation results show that heat generation due to deformation is significant (as much as 160°C) in the hot extrusion of Ti alloys, and it mainly occurs at the beginning of the extrusion process. This leads to reduction in flow stress which, in turn, leads to enlarged deformation zone. A fair agreement has been found between the experimental results and those obtained through simulations. 相似文献
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锥齿轮冷挤压成形加工数值模拟研究 总被引:1,自引:0,他引:1
为了解决人工设计锥齿轮冷挤压模具过度依赖经验的问题,将数值模拟应用到锥齿轮模具设计中。设计了一套用于冷挤压加工锥齿轮的三层组合凹模,制定了相应的工艺措施,利用Deform-3D软件对锥齿轮的冷挤压加工过程进行了数值模拟,分析了加工过程中的载荷曲线、速度场、应力场和温度场,获得了有关锥齿轮变形规律的基本情况。研究结果表明,通过改善润滑条件、优化模具几何参数可以提高冷挤压加工锥齿轮的成形质量,并对锥齿轮冷挤压加工工艺流程定制、模具设计具有一定的指导意义。 相似文献