板件生产,其关键工序往往是下料,特别是具有空间角度的板件。下面就我厂生产的LJ150型载重汽车中的两个零件,介绍一下用球面三角学计算展开图的方法。1.图1是外托板左支架,图2是该件的展开。为下料需计算α和β角。分析:α角为H、F面的交线与G、H面交线之间的夹角,应在H面内侧量。M面为过BC Plate production, the key processes are often cutting, especially with a spatial perspective of the plate. Here I plant the LJ150-type truck in the two parts, introduce the use of spherical trigonometry calculated expansion method. 1. Figure 1 is the outer bracket left bracket, Figure 2 is the expansion of the piece. Calculate α and β angles for blanking. Analysis: α angle H, F surface of the line of intersection with the G, H surface intersection angle between the amount should be in the H surface. M surface is too BC