第42卷第12期 Vol. 42No.12
假压技木
FORGING & STAMPING TECHNOLOGY
基于数值模拟的局部变过盈量组合凹模研究
陈莹莹12，冯文杰13，杨创创3，刘吉3
2017年12月 Dec.2017
（1.重庆理工大学汽车零部件先进制造技术教育部重点实验室，重庆400054；2.重庆理工大学车辆工程学院，重庆400054；
3.重庆理工大学机械工程学院，重庆400054）
摘要：借助有限元软件分析了预紧力状态下，采用均勾变过盈量设计的组合凹模能有效减小消气带区齿根的切向压应力，以避免线切制时模具的破损，但模芯成形区齿根的切向压应力也相应减小，无法完全抵清挤压时在成形区产生的拉应力，从而影响了模具的使用寿命。为解决这一间题，提出局部变过盈量组合凹模的设计方法，即在模芯上部采用均勾过盈量，下部采
而只减小消气带齿根的切向压应力，有效提高
用变过盈量的设计，以保证预紧状态下模芯成形区齿根切向压应力不截减小，了模具寿命。以模数m=4的某齿轮为研究对象，
，确定了锥角"=1°，”=1.2°，均勾过盈量区高度h：
通过数值模拟，
21mm等参数进行实际生产
与均勾变过盈量模具寿命相比，提高了35%左右。
关键词：组合回模；均勾变过盈量；局部变过盈量；模具寿命；数值模拟
DOI: 10. 13330/j. issn. 1000-3940. 2017. 12. 020
中图分类号：TG376
文献标识码：A
文章编号：1000-3940（2017）12-0109-05
Research on combined die with local changeable interference based on
numerical simulation
Chen Yingying'-2, Feng Wenjie'-3, Yang Chuangchuang , Liu Ji
(1. Key Laboratory of Advanced Manufacturing Technology foe Autombile Parts, Ministry of Educatioen, Chongqing University of Technology, Chongqing 400054, China; 2. Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China:
3. Colloge of Mechanical Engineering, Chongqing University of Technology , Chongqing 400054, China)
Abstract : The combined die with uniform changeable interference under the preload condition was designed by the finite element soft-ware. This combined die could effectively reduce tangential compressive stress of gear root in the getter zone to avoid the die damage with wire cutting. But the tangential compressive stress of gear root in forming zone of die core reduced accordingly , which could not fully offset the tensile stress during extrusion forming, and the die life was affected. In order to solve this problem, the design method of local change-
able interference on combination die was put forward,
namely,
unifom interference was applied on the upper part of die core, while
changeable interference was used on the lower part of die core.
. Therefore, the tangential compressive stress of gear root in forming zone of
die core under the preload condition was not reduced, and the tangential compressive stress of gear root in the getter zone was only de-creased to improve the die life. Furthermore, for the gear with modulus of 4, the cone angle ° = 1° and y"* = 1. 2° as well as the height 21 mm of uniform interference zone were determined respectively by numerical analysis, and the actual production was caried out. Thus, for the combined die with uniform changeable interference, the die life was prolonged by obout 35% .
Key words : combined die; uniform changeable interference; local changeable interferenoe; die life ; numerical simulation
冷挤压成形是一种高效、节能、低成本的绿色加工方法，大模数齿轮因在冷挤压成形时会对模具收稿日期：20170728；修订日期：20171020
基金项目：重庆市教委科学技术研究资助项目（KJ1400944）；重庆市科委资项目（cste2014yykfA60001）
作者筒介：陈堂堂（1979-），女，颈士，副教授 E-mail: cheny@ equt. edu. cn
通讯作者：冯文杰（1964-），男，颈士，教授万方数据il：wjfeng@ equt.edlu.cn
型腔造成极大的切向拉应力，引起模具开裂失效，因此，通常采用多层组合凹模设计的方法[1-2]，使模具型腔在预紧状态下具有一定的压应力，以减小或消除挤压状态时的拉应力，从而达到提高模具使用寿命的目的。敬文刚等[3]运用统一强度理论、等强度分析和有限元模拟对齿形冷挤压回模进行优化设计：鲁志兵等[4]基于第四强度理论，推导了n层组合凹模承受内压的数学表达式，并结合数值模拟进行了3层组合凹模的设计；杨丰钰等[5]将自增强