专注通风管道加工·排烟罩

Unfolding and blanking of ventilation pipe processing: in ventilation engineering, the shapes of pipes and parts made of metal and non-metallic sheet materials are various, and some parts must be processed and fabricated by the basic method of unfolding and blanking. The so-called unfolding is to lay the surface of pipe fittings on the sheet material according to the actual size according to the requirements of the pipe fitting construction drawing (or setting out drawing), Directly affects the quality and material efficiency of spiral ducts and components.

展开下料的步骤：展开下料的基本步骤是：熟悉图形，形体分析，求直线的实长或平面的实形，确定展开方法和画展开图等。

Steps for unfolding cutting: The basic steps for unfolding cutting include familiarizing oneself with graphics, analyzing shapes, finding the true length of a straight line or the true shape of a plane, determining the unfolding method, and drawing an unfolding diagram.

熟悉图纸展开下料前，要认真熟悉施工图纸，了解需要展开的管件或部件的内容，它在通风工程的部位、与何种管件相连接，它在图纸上尺寸的大小，用哪种材料制作等。对于复杂的管件和部件需要反复仔细地对施工图进行阅读和分析，必U型全部看懂，如果图纸有错误或看不懂或设计不合理，应向有关部门提出。

Be familiar with the drawings. Before unfolding and blanking, first of all, be familiar with the construction drawings carefully, understand the contents of the pipe fittings or components to be unfolded, the position of the ventilation project, the pipe fittings to be connected with, the size of its size on the drawings, and the material to be used. For complex pipe fittings and components, it is necessary to carefully read and analyze the construction drawings repeatedly, and all U-shaped parts must be understood. If there are errors in the drawings, or the design is unreasonable, it should be reported to the relevant departments.

形体分析通风和空调工程中的通风管件和部件都是由几何图形构成的，对形体的分析的目的就是把复杂的几何形体分解成简单的几何形体，通过分解，便能找到恰当的展开方法，一般需要展开的部件多为壳体，壳体有平面壳体和曲面壳体。

The ventilation pipes and components in ventilation and air conditioning engineering are all composed of geometric shapes. The purpose of analyzing shapes is to decompose complex geometric shapes into simple geometric shapes. Through decomposition, an appropriate unfolding method can be found. Generally, the components that need to be unfolded are mostly shells, which have flat shells and curved shells.

1)、平面壳体：它是由一组平面形成的壳体，主要有棱柱形和棱锥形两种。前者棱形相互平行，后者棱形丰交一点，通常按棱线的多少有三棱、四棱柱形及三棱、四棱锥形。正棱柱壳体：底部为正多边形，棱与底平面相垂直。正棱锥壳体：底部为多边形，而锥项投影与底部正多边形相重合，不重合者为锥形壳体。经过剖切，壳体可出现各种截体。棱柱形壳体（截体）的特点是：各棱对不同投影面相互平行或分别交于一点。棱锥形壳体（截体）的特点是：各棱的投影相交于一点。多面壳体，它的四棱延长线不相交于一点。

1) Flat shell: It is a shell formed by a set of planes, mainly consisting of two types: prism and pyramid. The former has parallel prisms, while the latter has more intersecting prisms. Usually, there are three prisms, four prisms, and three prisms and four pyramids according to the number of prisms. Regular prism shell: the bottom is a Regular polygon, and the edge is perpendicular to the bottom plane. Pyramid shell: the bottom is a polygon, and the cone projection coincides with the center of the bottom Regular polygon, otherwise it is a conical shell. After cutting, various types of cut bodies can appear on the shell. The characteristic of a prismatic shell (truncated body) is that the different projection surfaces of each pair of edges are parallel to each other or intersect at a point. The characteristic of a pyramid shaped shell (truncated body) is that the projections of each edge intersect at a point. A polyhedral shell with four extended edges that do not intersect at a point.

2)、曲面壳体：表面为曲面，或曲面、平面兼有的壳体称为曲面壳体。曲面壳体可分为：旋转或非旋转两种壳体。

2) Curved shell: A shell with a curved surface or both surfaces is called a curved shell. Curved shells can be divided into two types: rotating or non rotating shells.