摘  要:蚕沙就是蚕的粪便，它富含大量营养成分，也是提取叶绿素和维生素E、K果胶等化学品较为经济的原料，同时蚕沙也是一种常见的中药材。蚕沙的来源主要是依靠搜集家蚕的粪便，筛净杂质之后晒干所得。目前，蚕桑养殖户主要是通过人工对养蚕过程中所产生的蚕沙进行筛选，通过钉耙或者直接用手对大的桑叶杆进行清理，之后再用竹筛进一步筛选，这种方法耗时较长，消耗体力，工作效率低。因此选择设计一种可以代替人工来对新鲜蚕沙进行筛选的一种机器，从而提高筛选效率。

　　　本设计主要针对现有的人工筛选方式进行相对应的创新性设计，基于人工筛选的思路，设计了三重筛选机构，分别利用凸轮联动机构，高速凸轮机构，风扇等装置协调运动实现对蚕沙的三次筛选。本课题研究的主要内容基本包括实现三重筛选的机构设计、各类杂质的分类排出设计、电机的选择、传动零件和减速装置的设计、整机传动方案的选择等方面。首先根据设计需要，完成对实现运动的零部件设计，确定出各装置的结构，通过UG三维建模，把各个装置装配起来，最终完成蚕沙筛选机的设计。在论文的最后，对本次设计进行总结，简明说明设计中的优点与不足。

　　　本设计不仅能减轻人们的劳动强度，节约大量的时间，而且解决了蚕沙筛选过程中体力重复消耗大，工作效率低等一系列问题。

关键词： 新鲜蚕沙；替代人工；三重筛选；输出；机械

ABSTRACT:Silkworm excrement is the dung of the silkworm, which is rich in nutrients, is also the economical materials to extract of chlorophyll and vitamin E, K pectin chemicals, and it is one kind of the common Chinese herds. The sources of the silkworm excrement mainly rely on the collection of silkworm excrement, then sieve net impurity and dried. At present, the sericulture farmers mainly select the silkworm that produces in the process of rearing of the silkworm by hand, which cleans the big mulberry leaves by rakes or using the hands. After this, the people use the bamboo sieve to screen. This method will spend more time, more physical strength and the efficiency is low. Therefore, the author design one machine can take place human to screen the fresh silkworm, and improve the efficiency of screening.

　　　This study aims to make an innovative design to present artificial way of selecting the silkworm. Based on the idea that manual screening, the author designs the screening mechanism, which divides use the Cam linkage mechanism, High-speed cam mechanism and Electric fan to realize three screening of silkworm excrement. The aim content of this paper contain some aspects, such as, the realization of the three heavy screening mechanism design, Classification of all kinds of impurity exhaust design, Selection of the Motor, Design of Transmission parts and the reduction device, The selection of the transmission scheme, and so on. Firstly, the author finished the design of the move parts, certain the structures of these devices, combine all of the parts by UG 3D model and then finished the design of the silkworm screening machine. At the end of this study, the author summarizes this study, simply describe the advantage and disadvantage of this study. 

　　　 The machine is not only can reduces the labor intensity of people, save a lot of time, but also solve a series of the problems ,such as, the repeated physical consumption  in the silkworm screening process, low work efficiency.

Keywords: Fresh silkworm; Take place the manual work; Three screening machine; Output; Machinery