DOI: 10. 3969 / j. issn. 1009-9492. 2020. 03. 001
夏琴香,赖学成,肖刚锋,等. 旋轮与芯模间隙对内外齿旋压缺陷的影响规律[J] . 机电工程技术,2020,49(03):1-4.
基金项目:国家自然科学基金资助项目(编号:50475097)
旋轮与芯模间隙对内外齿旋压缺陷的影响规律
夏琴香1,赖学成1,肖刚锋1,程秀全2
(1.华南理工大学机械与汽车工程学院, 广州510640;
2.广州民航职业技术学院飞机维修工程学院, 广州510403)
摘要:旋轮与芯模间隙是影响旋压件成形质量的重要工艺参数。离合器毂的内外齿形在旋压成形中易出现齿侧壁呈弧形、齿顶圆角不饱满等缺陷,提出采用齿侧壁弧形度? 、齿顶圆角不饱满度χ 等来定量表征上述缺陷的大小,并基于有限元软件ABAQUS对内外齿旋压成形过程进行了数值模拟,获得了旋轮与芯模间隙对齿侧壁呈弧形、齿顶圆角不饱满等缺陷的影响规律,并获得了特定条件下的旋轮与芯模间隙的最佳值。结果表明,随着旋轮与芯模间隙的减小,齿侧壁弧形度? 、齿顶圆角不饱满度χ 随之减小;当旋轮与芯模间隙值取齿顶壁厚的公称尺寸与下极限尺寸的中间值时,可满足齿形壁厚要求并最大限度改善成形缺陷。有限元模型结果与成形试验结果吻合度良好。
关键词:内外齿;旋压;旋轮与芯模间隙;成形缺陷;数值模拟
中图分类号:TG306 文献标志码:A 文章编号:1009-9492 ( 2020 ) 03-0001-04
Effect of the Clearance between the Roller and the Mandrel on Spinning Defects
for Internal and External Tooth
XIA Qinxiang1, LAI Xuecheng1, XIAO Gangfeng1, CHENG Xiuquan2
(1. School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640, China;2. School of Aircraft Maintenance Engineering, Guangzhou Civil Aviation College, Guangzhou 510403, China)
Abstract: The clearance between the roller and the mandrel is an important process parameter affecting the forming quality of spun parts. Some defects such as the arc-shaped side wall of tooth and insufficient filling of addendum fillet occur easily during spinning of clutch hub internal and external tooth. To evaluate the defects mentioned above quantitatively, evaluation indexes including curvature of tooth side wall ? and non fullness of addendum fillet χ were proposed.Based on the ABAQUS software, the numerical simulation of the spinning process for internal and external tooth was carried out. The influence of the clearance between the roller and the mandrel on the forming defects was discussed, and the optimal value of clearance under a given condition was obtained. The results show that the values of ? and χ both decrease with the decrease of the clearance between the roller and the mandrel, the obtained optimal clearance is the median value between the nominal size of addendum wall thickness and its lower limit size, which can meet the requirements of the wall thickness of tooth and improve the forming defects significantly. The simulated results agree well with those of the experiment.
Key words: internal and external tooth;spinning;clearance between the roller and the mandrel;forming defect;numerical simulation
引言
汽车离合器毂件是自动变速器中的重要动力传递部件,其形状复杂、尺寸精密,是自动变速器制造中最为困难的零件之一[1]。离合器毂件侧壁上的内外齿形在工作中起着传递扭矩及固定和支撑其他零部件的重要作用,因此对内外齿形部分的尺寸精度、表面粗糙度以及力学性能要求均较高[1]。
汽车离合器毂件内外齿形部分的成形一直是国内外材料成形所关注的重点,从最早的铸造和机械加工[1],直到最为先进的板料冲压[2]和旋压成形[3-4]。但采用冲压成形的方式,成形工序多、模具结构复杂,难以成形内外齿的小圆角部分,很难满足市场高精度、大批量、低成本化的需求。
采用旋压工艺成形内外齿具有能保证产品具有完整的金属流线,材料利用率高、模具寿命长等优点[5-6]。但在旋压成形内外齿的过程中,会出现齿侧壁呈弧形、齿顶圆角不饱满、齿形对称度较低等齿形缺陷。范酉根等[3]基于Deform-3D软件,研究了外毂零件内外齿的旋压成形过程。结果表明,外毂先接触旋轮一侧金属流动速度较大,且啮合的部位会发生向上的流动,流动速度较小,造成一侧齿壁发生翘曲齿形不对称,需要增加整形工序来提高零件的齿形对称度。王秀鹏等[4]基于成形实验,研究了QSTE420TM钢内外齿形件旋压成形工艺。结果表明,侧隙值及旋轮进给比是齿形精度的主要影响因素;且当坯料厚度选择合理时,侧隙值是齿形精度的最主要影响因素。合理地控制预制坯与侧隙值的匹配,可以获得齿形对称度较高的旋压件。以上文献指出了旋轮与芯模间隙值是保证齿形精度重要工艺参数,但对这一重要工艺参数对齿侧壁呈弧形、齿顶圆角不饱满齿形等缺陷的影响规律尚未见报道。
为定量研究旋轮与芯模间隙值对内外齿形件旋压成形时缺陷的影响规律,本文给出了内外齿形件旋压成形缺陷的表征指标;并基于ABAQUS软件建立了内外齿形旋压成形有限元数值模拟模型,分析了旋轮与芯模间隙对齿侧壁呈弧形、齿顶圆角不饱满缺陷的影响规律,为内外齿形件旋压成形时旋轮与芯模之间间隙的选取提供了理论依据。





结束语
本文基于有限元软件ABAQUS对离合器毂内外齿旋压成形过程进行了数值模拟,研究了旋轮与芯模间隙对齿侧呈弧形、齿顶圆角不饱满缺陷的影响规律,结论如下。
(1) 提出采用齿侧弧形度? 、圆角不饱满度χ 等来表征内外齿形件在旋压成形中出现的齿侧呈弧形、齿顶圆角不饱满等缺陷。
(2) 旋轮与芯模间隙对齿侧呈弧形、齿顶圆角不饱满等缺陷有重要影响。随着旋轮与芯模间隙的增大,齿侧弧形度? 、圆角不饱满度χ 也随之增大。
(3) 存在能最大程度改善齿侧呈弧形、齿顶圆角不饱满等缺陷的旋轮与芯模间隙最佳值,其最佳值为离合器毂齿顶或齿根壁厚公称尺寸与下极限尺寸的中间值。
(4) 在芯模转速n=150 r/min、旋轮进给速度v=1.7 mm/s、旋轮与芯模间隙为1.63 mm时,内外齿齿顶壁厚的模拟值与试验值的最大相对误差为6.0%,说明本文所建立的有限元模型和模拟结果具有较好的可靠性和准确性。