Metal Flowing of Involute Spline Cold Roll-beating Forming

The present research on involute spline cold roll-beating forming is mainly about the principles and motion relations of cold roll-beating,the theory of roller design,and the stress and strain field analysis of cold roll-beating,etc.However,the research on law of metal flow in the forming process of involute spline cold roll-beating is rare.According to the principle of involute spline cold roll-beating,the contact model between the rollers and the spline shaft blank in the process of cold roll-beating forming is established,and the theoretical analysis of metal flow in the cold roll-beating deforming region is proceeded.A finite element model of the spline cold roll-beating process is established,the formation mechanism of the involute spline tooth profile in cold roll-beating forming process is studied,and the node flow tracks of the deformation area are analyzed.The experimental research on the metal flow of cold roll-beating spline is conducted,and the metallographic structure variation,grain characteristics and metal flow line of the different tooth profile area are analyzed.The experimental results show that the particle flow directions of the deformable bodies in cold roll-beating deformation area are determined by the minimum moving resistance.There are five types of metal flow rules of the deforming region in the process of cold roll-beating forming.The characteristics of involute spline cold roll-beating forming are given,and the forming mechanism of involute spline cold roll-beating is revealed.This paper researches the law of metal flow in the forming process of involute spline cold roll-beating,which provides theoretical supports for solving the tooth profile forming quality problem.

MECHANICS ANALYSIS ON PRECISE FORMING PROCESS OF EXTERNAL SPLINE COLD ROLLING

According to the suitable assumption, the deformation process of external spline cold rolling is analyzed. By the graphing method, the slip-line field of plastically deforming area in process of external spline cold rolling is set up. Different friction-conditions are used in different contact areas in order to realistically reflect the actual situation. The unit average pressure on contact surface of the rolling process is solved according to the stress filed theory of slip-line. And the formulae of the rolling-force and rolling-moment are established. The theoretical result is well consistent with the finite element analysis. A theoretical basis is provided for the precise forming process of spline cold rolling and the production of external splined shafts.

TOOTH CURVES AND ENTIRE CONTACT AREA IN PROCESS OF SPLINE COLD ROLLING

In spline rolling process, the contact area between roller and workpiece plays an important role in calculating rolling-force and rolling-moment. For the purpose of studying the contact area, contact state between roller and workpiece in process of spline cold rolling based upon cross rolling is analyzed. According to the suitable hypothesis, the mathematic model of roller-tooth-curve in optional position of rolling process is established. Combing the theory of conjugate curves with the theory of envelope curve, the corresponding mathematic model of workpiece-tooth-curve is established. By utilizing establishing mathematic models, the algorithm of entire contact area in rolling process is created. On the basis of the algorithm, calculation-program is compiled under MATLAB program language environment. The calculation-program actualizes quantitative analysis and quantitative calculation of contact areas. Utilizing the calculation-program, the influence of parameters on contact area is analyzed, and the tendency is consistent with the manufacturing experience. In consideration of rolling-force optimization, the primary process parameters may be selected according to results of calculation. The result of the present study may provide basis for research on rolling-force and rolling-moment.

Rolling Force and Rolling Moment in Spline Cold Rolling Using Slip-line Field Method

Rolling force and rolling moment are prime process parameter of external spline cold rolling. However, the precise theoretical formulae of rolling force and rolling moment are still very fewer, and the determination of them depends on experience. In the present study, the mathematical models of rolling force and rolling moment are established based on stress field theory of slip-line. And the isotropic hardening is used to improve the yield criterion. Based on MATLAB program language environment, calculation program is developed according to mathematical models established. The rolling force and rolling moment could be predicted quickly via the calculation program, and then the reliability of the models is validated by FEM. Within the range of module of spline m=0.5-1.5 mm, pressure angle of reference circle α=30.0°-45.0°, and number of spline teeth Z=19-54, the rolling force and rolling moment in rolling process （finishing rolling is excluded） are researched by means of virtualizing orthogonal experiment design. The results of the present study indicate that： the influences of module and number of spline teeth on the maximum rolling force and rolling moment in the process are remarkable; in the case of pressure angle of reference circle is little, module of spline is great, and number of spline teeth is little, the peak value of rolling force in rolling process may appear in the midst of the process; the peak value of rolling moment in rolling process appears in the midst of the process, and then oscillator weaken to a stable value. The results of the present study may provide guidelines for the determination of power of the motor and the design of hydraulic system of special machine, and provide basis for the farther researches on the precise forming process of external spline cold rolling.

Numerical simulation of involutes spline shaft in cold rolling forming

Design of forming dies and whole process of simulation of cold rolling involutes spline can be realized by using of CAD software of PRO-E and CAE software of DEFORM-3D. Software DEFORM-3D provides an automatic and optimized remeshing function, especially for the large deformation. In order to use this function sufficiently, simulation of cold rolling involutes spline can be implemented indirectly. The relationship between die and workpiece, forming force and characteristic of deformation in the forming process of cold rolling involutes spline are analyzed and researched. Meanwhile, reliable proofs for the design of dies and deforming equipment are provided.

Transverse Distributions of Front and Back Tension Stresses in Cold Strip Rolling

In this paper,such a new lateral displacement function is proposed that the lateral flow velocity is con- tinuous at the entry and the exit of deformation zone.A new kind of finite strip method—the third power B-spline finite strip method—is put forward to simulate strip rolling process.Front and back tension stresses are formulated.The computed results of the transverse distributions of the front and back tension stresses are close to the experimental results.The paper lays a foundation for further analysing the three-dimensional stresses and deformations of strip rolling.

渐开线花键冷滚压精密成形工艺分析及试验研究

花键冷滚压精密成形技术是一种高效、精密、少无切削的先进制造技术,具有成形效率高、节能、节材和零件成形性能好等特点。分析渐开线花键冷滚压精密成形工艺过程及原理,对成形过程的单位平均压力、接触面积、滚压坯料直径、滚压力及滚压力矩等进行求解。对渐开线花键进行冷滚压精密成形试验,分析零件变形区的金属流动规律,组织形成机理及塑性变形对成形性能的影响。试验结果表明,在花键冷滚压精密成形过程中,工件表层发生剧烈的塑性变形,晶粒沿齿廓呈连续的流线型分布,塑性变形区为细长的纤维组织,齿形截面硬度分布具有一定的规律性。试验所得零件无缺陷,硬度、耐磨性等较传统的切削加工花键大大提高,可满足使用要求。

花键冷滚打和铣削加工的金属组织变形研究

本文针对冷滚打花键和铣削花键加工工艺特点,从微观组织分析角度,对两种加工方法得到工件金相组织和硬度分布进行分析比较。试验表明:铣削加工过程中,金属表面组织被切断,内部组织没有发生变化,对力学性能也没有影响;而冷滚打加工后的花键金属组织未被切断,晶粒破碎和细化,位错密度增加,最终被拉成条形纤维组织。相对于铣削,冷滚打加工改善了加工表面金属组织,硬度和强度有较大提高。从而为冷滚打花键成形技术的进一步研究奠定了基础。

冷滚轧滚轮设计理论及实验修正

通过对渐开线花键冷轧加工机床及工艺的分析 ,建立了滚轧轮设计的数学模型 ,用范成法解决了采用成形法设计轮廓不准的缺陷 ,并得到了实际验证。针对材料的弹塑性变形 ,通过对加工零件的误差测量 ,基于实验数据 ,反映到滚轧轮坐标系中 ,得到滚轧轮廓的修正量 ,使滚轧的花键齿形更接近于理想齿形 ,精度和寿命都得到进一步提高 ,实现了高精度花键轴的冷轧加工。

SCM435花键轴冷挤压过程工艺分析

针对花键轴生产中产生的中心凹陷等成形缺陷问题进行了系统的分析,并利用Deform-3D软件对花键轴冷挤压成形过程进行了数值模拟,揭示其变形过程中的金属流动规律,找到了成形缺陷产生的原因。通过优化模具结构和改进冷挤压工艺方案,在实际生产中有效地解决了该零件的质量问题,最终生产出了合格零件。

内花键齿形冷挤压成形工艺方案的研究

归纳并分析了内花键齿形成形工艺方式,运用DEFORM-3D有限元软件,采用直接成形、间接成形两种方式对其冷挤压过程进行了模拟。结果表明:增加一道预成形工序来间接成形内花键齿形能够大大提高生产效率、端面尺寸精度及模具使用寿命,最优成形孔尺寸为20.5mm。

基于数值模拟的渐开线花键件冷挤压工艺参数优化

基于弹塑性有限元数值模拟技术,使用MSC/SuperForm软件对传动轴渐开线花键冷挤压成形过程进行了数值模拟,通过改变工艺参数,分析了坯料直径、凹模入口半角和定径带宽度对挤压工艺的影响,并优化出最佳参数。根据优化结果进行冷挤压试验,得到质量合格的制件,为花键类汽车件冷挤压成形工艺的制定提供了依据。

6061铝合金花键壳体冷挤压工艺研究

针对冷挤压工艺生产6061铝合金花键壳体容易产生表面裂纹、拉伤等问题,进行了详细的工艺分析,并利用有限元法进行了成形模拟,揭示了缺陷产生的原因,优化了模具结构和成形方案。同时,从生产实际出发,改进了毛坯表面处理方法及润滑措施。结果表明,该改进措施能有效解决零件的质量问题,最终生产出合格产品。

花键轴开模冷挤压成形条件研究

针对花键轴开模冷挤压实际工艺中经常出现的坯料在入模口处局部镦粗的问题，在三维上限元分析的基础上，提出开模挤压应具有一定的成形条件，当αｃｒ１≤α≤αｃｒ２时，满足ｐ≤σｓ，具有开模挤压的可成形性，可避免局部镦粗问题的发生。其中α和σｓ是两个重要的可调参数。文中对１２５ｃ摩托车传动主花键轴进行了开模冷挤压实验，实验结果证明理论计算提供的工艺参数可行。

花键轴冷滚压成形的分齿条件

自由分度式花键冷滚压成形工艺,不具备分度装置,成形过程的分齿阶段对整个滚压过程的成败至关重要.为保证冷滚压加工的正确分齿,必须对影响冷滚压成形分齿阶段的花键参数和滚压模具几何参数给出限定条件.按照滚压成形前后工件(花键)体积不变的原则给出毛坯直径的计算公式;根据分齿阶段花键毛坯与滚压轮作等线速纯滚动的运动特征,推导保证正确分齿要求的滚压轮齿顶圆直径公式;根据滚压时的受力分析,给出旋转条件及滚压轮的齿数条件;分析主轴转速及径向速度对分齿时齿距累积误差的影响.对所得结论进行实验验证,按照理论计算的结构参数及工艺参数,可以滚压出4级精度的渐开线外花键轴.

传动轴渐开线花键冷挤压成形过程数值仿真

采用M SC/Superform软件对某型汽车传动轴渐开线花键冷挤压成形过程进行了三维数值模拟。通过数值仿真、实现了成形过程跟踪、力学量场再现和成形缺陷预测,探索了复杂高精度零件冷挤压成形规律,实现了毛坯和模具的优化设计,为花键类零件冷挤压工艺生产提供了依据。工艺试验表明,该冷挤压工艺与模具设计合理,数值模拟分析及计算准确。

小齿轮件的成形工艺及模具设计

针对小齿轮件(既有齿轮又有花键的小齿轮件)的花键和齿轮成形问题进行工艺分析。为了节约成本和使成形顺利进行,采用冷挤压工艺方案,并进行花键正挤和齿轮反挤的挤压组合模具设计。研究表明,小齿轮件采用冷挤压工艺方案是可行的,模具设计合理,可以获得准确的花键、齿轮齿形和较好的表面质量,节约材料,缩短辅助时间,降低生产成本。

冷滚打花键动力学分析与仿真

根据冷滚打花键的工艺特点和柔体动力学理论基础,建立柔体动力学数学模型;并依据有限元理论建立了冷滚打花键结构动力学模型;同时应用ADAMS和ANSYS进行动力学仿真。理论分析与仿真结果表明:花键毛坯在滚打过程中受到滚轮的滚打力由径向力FX、轴向力FY和FZ三个方向的分力合成。其中,径向力FX随滚打时间做近似于四边形的周期变化。同时得到了冷滚打加工中花键轴应变情况,精确找到加工中的辅助支撑点,可以大大提高冷滚打花键的加工精度。

矩形花键轴冷挤压的数值模拟分析

采用金属成形有限元分析软件DEFORM,模拟CG125摩托车发动机主轴的矩形花键冷挤压成形过程,得到挤压过程中的模具受力图及坯料的应力分布图。结合数值计算的结果,探讨冷挤压过程中的塌角与金属堆积现象。工艺实验表明,该冷挤压工艺与模具设计合理,数值模拟分析对冷挤压模具设计具有一定的指导意义。

矩形花键齿形成形研究

运用有限元数值模拟的方法,针对长轴类矩形花键成形时齿形充型不完整的缺陷进行研究,探讨凹模模面的具体参数和毛坯前端倒角对其产生的影响,最终找到最佳的组合,成功地解决了齿形角隅充不满的难题。为现实生产提供理论依据,模拟结果能够很好地指导生产实践。