PRACTICAL APPLICATION OF PLANETARY CONICAL ROLLING

管子拉深过程中没有滑动摩擦，这是常规拉深过程中产生擦伤和破损的主要原因。在此过程中，多个滚子围绕圆锥体旋转，同时绕各自的轴旋转。行星圆锥滚压工艺称为PCR。该工艺具有以下优点：(1)滚子由无侧向力的轴支撑，(2)轴的直径与产品内径几乎相同，(3)轴的高刚性导致产品的高精度，(4)滚子倾斜不允许滚子与材料在径向滑动。结果表明，该工艺对镜面抛光的外表面可获得大于0.89的减薄效果。为了利用这些特性，通过将材料流动到模具上的凹面来形成具有表面特征的产品。在考虑其实际用途的情况下，选择螺纹作为表面特征。成形的螺纹质量很好，但对于薄壁管，用传统的轧制方法成形是困难的。本发明的方法是研究薄管的成形。结果表明，由进给速度控制的较高径向压力可以获得较高的充填率。聚合酶链式反应成功成丝的主要原因是通过聚合酶链式反应的一步一步递增过程填充凹陷。

The process of tube ironing is done without sliding friction which is the main cause for galling and breakage in conventional ironing. In this process a number of rollers rotate around the cone while revolving around their respective axis. The process "Planetary Conical Rolling" is termed PCR.This process has the following advantages : (1) rollers are supported by a shaft being free of lateral force, (2) the diameter of the shaft is almost the same as the inner diameter of the product, (3) high rigidity of the shaft results in high accuracy of products, (4) rollers inclination does not allow slide between roller and material in the radial direction. The results show this process can produce thickness reduction larger than 0.89 with mirror-finished outer surface. In order to make use of these characteristics, products having surface features were formed by flowing material into a concave on a die. A thread was chosen as the surface feature under the consideration of its practical uses. A formed thread has an excellent quality, but when it comes to thin tubes, forming by conventional rolling methods is difficult. The present method examine forming thin tubes. The results show that a higher filling rate of a material into the concave can be obtained by a higher radial pressure which is controlled by the feed speed. The main reason for the successful thread formation by PCR is that the concave is filled by a step by step incremental process of the PCR.