螺旋输送器的计算机制图参数化

螺旋输送器(又称绞龙)的叶片轮廓曲线为园柱螺旋线,其反映轴线的投影为正弦(或余弦)曲线。由于叶片与轴的相互遮蔽而产生了隐藏线的消除问题,从而使绞龙的各部轮廓线成为断续的曲线和直线。在粮食机械设计制图中常用直线(或直线与园弧的连接)示意性地画出,但这种图形过于失真。如果利用计算机技术,则可精确而迅速地绘出其图形。本文介绍了绞龙的参数化绘图程序的编制原理。该程序具有消隐、变比、平移等功能,适于各种尺寸的等螺距绞龙图形的绘制。

Parameterization of Drawing Screw Conveyors by Means of Computers

The flight outline of screw conveyors is a helix. The projection representing the axis is a sine curve ( or a cosine curve ) .The mutual obstruction of flight and axis results in the necessity of elimination of hidden lines, making the projection of the outline intermittent curves and straight lines. In the drawing of grain machinery the outline is often schematically drawn out as straight lines ( or straight lines and arcs ) . Certainly, such a sketch is not true to the object itself. If we use computers, the outline will be drawn out precisely and quickly. The present paper briefs us on the principles of programming of parameterized screw conveyors drawing. The programm, being able to eliminate hidden lines, scaling and translate, is fit for drawing of screw conveyors of all sizes, with constant pitches.