共查询到20条相似文献,搜索用时 15 毫秒
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针对齿轮坯闭式模锻模具设计,详细研究了其参数化设计过程及其二次开发的方法和技术,成功开发了齿轮坯闭式模锻模具参数化设计系统,实现了齿轮坯闭式模锻模具参数化绘图。 相似文献
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Forging processes in the past have primarily been developed based on empirical relationships or trial and error. The finite
element approach to forging process development and design has been found to be practically feasible and economical. The rigid-viscoplastic
finite element method (FEM) code “ALPID” developed by Battelle Columbus Laboratories, has been successfully utilized to simulate
metal forming processes. In the following paper, the application of finite element simulation to study deformation mechanics
in the forging of gear blanks and axle shafts is discussed. An underfill problem on the gear blank was overcome and tool life
was improved on the axle shaft hot heading process. 相似文献
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利用AutoCAD2002二次开发工具VBA,开发出了齿轮坯闭式模锻工艺CAD系统,并对其二次开发的方法和技术进行了研究。实践表明,该系统使用简单、可靠性高,能够极大提高齿轮坯闭式模锻工艺设计的效率和质量。 相似文献
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O. Eyercioglu M.A. Kutuk N.F. Yilmaz 《Journal of Materials Processing Technology》2009,209(4):2186-2194
The usual way to shrink fit design for precision forging of gear dies is to use thick wall cylinder theory (analytical approach) assuming that bore diameter is equal to pitch diameter by neglecting actual gear tooth shape. For more accurate determination, finite element method (FEM) can be used. The actual stresses predicted by FEM are much higher than the analytical approach, so that the design of the gear shaped die is beyond the capability of the analytical approach. In this paper, analytical approach for dies with gear teeth is modified using FEM solution sets. FEM analyses results are verified by experiments. During experiments cylinder approach is observed to be inadequate for forging loads. An easy to use set of formula and nomograms for determination of sizes of die and ring, and radial interference are presented. The solution set is verified with experiments. Proposed equations can safely be used for shrink fit design of precision forging gear dies. 相似文献
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滑动叉传统上采用开式模锻工艺生产,飞边大,材料浪费严重而且尺寸精度差。为了降低锻件成本,针对滑动叉的形状特征,提出一种无飞边模锻的新工艺,使预制毛坯在封闭的模腔内成形,实现净成形或近净成形。应用Deform 3D模拟研究了滑动叉无飞边锻造工艺过程,模拟验证结果表明,新工艺显著地提高了材料利用率和成形质量,降低了锻造载荷。 相似文献
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Guoqun Zhao Ed Wright Ramana V. Grandhi 《International Journal of Machine Tools and Manufacture》1997,37(9):1251-1271
A sensitivity analysis method for preform die shape design in net-shape forging processes is developed in this paper using the rigid viscoplastic finite element method. The preform die shapes are represented by cubic B-spline curves. The control points or coefficients of B-spline are used as the design variables. The optimization problem is to minimize the zone where the realized and desired final forging shapes do not coincide. The sensitivities of the objective function, nodal coordinates and nodal velocities with respect to the design variables are developed in detail. A procedure for computing the sensitivities of history-dependent functions is presented. The remeshing procedure and the interpolation/transfer of the history-dependent parameters, such as effective strain, are stated. The procedures of sensitivity analysis based preform die design are also described. In addition, a method for the adjustment of the volume loss resulting from the finite element analysis is given in order to make the workpiece volume consistent in each optimization iteration. The method developed in this paper is used to design the preform die shape of H-shaped forging processes, including plane strain and axisymmetric deformations. The results show that a flashless forging with a complete die fill is realized using the optimized preform die shape. 相似文献
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Workability domain without the onset of flow instability was developed by numerical simulation and response surface method(RSM) for complex-shaped straight spur gear forging. The processing map of AZ31 B alloys was calculated from flow stress curves and then integrated with the finite element model to simulate the distribution of flow instability in the straight spur gear undergoing isothermal forging process. Occurrence of flow instability depends on forging temperature, punch velocity and billet reduction. Taking forging temperature and punch velocity as design variables, while billet reduction as response variable, RSM of workability domain was established. Analysis of variance indicates that forging temperature is the most significant factor determining the appearance of flow instability in the forged gear. Flow instability is easier to take place at lower temperatures of 250 and 300 °C in the early stage of forging but at higher temperatures of 350 and 400 °C in the later stage of forging, which is attributed to different deformation mechanisms and dynamic recrystallization behaviors at different temperatures or deformation levels. Meanwhile, increasing punch velocity further reduces the workability of the forged gear.Four different processing paths were chosen to carry out the gear forging trials. Visual observations and metallographic examinations demonstrate that the developed workability domain contributes to optimization of forging parameters. 相似文献
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A new technique has been developed for the design of die shapes in the plane strain forging process. The objective of this research work is to develop a design procedure to obtain the number of stages and the shape of each die for manufacturing a desired product. Metal flow during the forging is considered in the design of the intermediate die shapes in multistage forgings. The two approaches developed for the preform shapes design are conformal mapping techniques and ideal material flow simulations. The forging process is simulated using a nonlinear rigid visco plastic finite element program ALPID (analysis of large plastic incremental deformation). Staging criteria is developed from the results of the forging simulation and the number of stages are based on the stress ratio parameterg (mean stress/effective stress) and strain rate gradient information. This paper presents two examples of forgings to demonstrate an optimal die shape design methodology. 相似文献
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通过对小锥角螺旋伞齿轮塑性成形金属流动的分析,设计了螺旋伞齿轮预制坯形状和在通用压力机上使用的复动闭式模锻模具,成形出小锥角螺旋伞齿轮锻件。揭示了使用复动闭式模锻模具成形小锥角螺旋伞齿轮的可行性。 相似文献
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Beom-Soo Kang Naksoo Kim S. Kobayashi 《International Journal of Machine Tools and Manufacture》1990,30(1)
This study attempts to establish systematic procedures for the preform design in forging of an airfoil section blade as a two-dimensional plane-strain problem. Forward loading and backward tracing simulations by the finite element method are used. A circular shape is selected as an original stock, and a side-pressed preform of the circular shape is adopted in view of preliminary simulations using rectangular preforms. The optimal slope angle of the die parting line and the position of the preform within the die, which satisfy the final design condition of flashless forging, are determined from the results of the simulations. 相似文献
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叙述了羊角锤新旧模锻工艺过程,介绍了活动模具的动作原理及模具结构,阐述了用闭式精密模锻工艺代替普通模锻的优点,提出了模具设计的基本要求,指出了目前使用活动模具闭式精密模锻中所存在的问题 相似文献
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Numerical simulation of thixoforming 总被引:3,自引:0,他引:3
Processing of alloys and composites in the solid plus liquid range has advantages over casting, forging, and powder metallurgy
techniques. The sensitivity of semisolid slurries to temperature variations and their history and rate dependent behavior,
however, make process design and control difficult. Precise selection of die velocity, process temperature, and die design
is necessary to produce satisfactory products. Therefore, a computational capability for the prediction of the rheological
behavior of semisolid materials would be an invaluable tool in process design. This work presents preliminary results on numerical
simulations of thixoforming operations. Constitutive models that are able to describe qualitatively the transient flow behavior
of semisolid materials are implemented in a finite element program. Simple but realistic thixoforming operations are simulated.
Weaknesses of currently available constitutive models and numerical techniques are identified and discussed.
This paper was originally presented at the Symposium “Paniculate Materials in Rheological Applications,” TMS 1993 Fall Meeting,
Materials Week Program. 相似文献