球面滑履精密冷挤压大升角旋转脱模方法研究与实践  

Research and practice of big lead angle rotating unloading method for precise cold extrusion die of spherical slippery footstep

作　　者：郑伟刚[1] 束昊[1] 滕生磊[1] 何欣[1] 

机构地区：[1]贵州大学机械工程与自动化学院,贵阳550003

出　　处：《塑性工程学报》2009年第4期100-104,共5页Journal of Plasticity Engineering

基　　金：贵州省重大专项基金资助项目(黔科合重大专项字(2007)6015号)

摘　　要：球面滑履在冷挤成形后,由于球面和柱面回弹对模芯产生很大抱合力,加之凹模壁面摩擦阻力,导致脱模时滑履顶出端口发生变形,影响零件成形精度。考虑采用模芯和滑履相对旋转后顶出方式来消除模芯和滑履内表面微观机械咬合力进行脱模,从而达到减小脱模阻力目的,文章对大升角旋转顶出的脱模方法原理进行分析,并根据球面对称性特点,利用数值拟合方法获得回弹变形方程,然后利用回弹变形方程和与之变化相适合球面积分计算重要参数旋转脱模升角,从而实现通过大升角螺旋传动把顶杆直线运动转化模芯旋转运动,达到旋转脱模的效果,通过工艺实验证明,旋转顶出的脱模方式具有脱模阻力小,脱模精度高的优点。The spherical slippery footstep was in the cold extrusion, die core had great clinging power due to spherical and cylindrical resilience, additionally the frictional resistance of the die cavity wall, resulting in the slippery footstep port occurred deformation when die unloaded, which affected the forming parts accuracy. Considering making the die core and slippery footstep the relatively rotate to eliminate microcosmic mechanical biting force of the die core and the inner surface of slippery footstep to unload die, it is to reduce the resistance to unload die, this paper analyzed the principle of the rotating and pushing-out die unloading, and in accordance with the characteristic of the spherical symmetry, using numerical fitting method to obtain rebound deformation equation, and then using rebound deformation equation and suitable spherical integral to calculate the important die unloading lead angle, the big lead angle spiral motion can translate mandril＇s elinear motion into die core＇s rotary movement, releasing the rotating die unloading, finally the technical experiment proved the rotating and pushing-out die unloading has small resistance and high-precision forming.

关 键 词：球面滑履 精密挤压 旋转脱模 回弹变形方程 球面积分 脱模升角 

分 类 号：TG376[金属学及工艺—金属压力加工]