摘要：植树造林，绿化祖国，是我们国家的一项基本国策。植树造林能够美化环境，清除空气污染，使水土得到保持防风固沙，根除风沙灾害，此外，植树造林为人类提供各种有用的物品。截止2008 年，我国森林面积1.95 亿hm2，森林覆盖率达到20.36％，森林资源进入快速发展时期。国家“十二五”规划纲要草案提出了森林覆盖率提高到21.66％，森林蓄积量增加6 亿m3，达到143 亿m3 的目标。江苏省提出到2015 年实现森林覆盖率达到22%的目标，计划新增20 万hm2。南通市“十二五”期间预计完成3.53 万hm2 植树造林任务。

　　　本文的目的就是要设计出一种操作简便，经济环保的树苗挖坑机，提高树苗的种植效率，减轻劳动者的劳动强度。植树造林，绿化祖国，是我们国家的一项基本国策。然而，目前我国植树造林多为人海战术，劳动强度大、效率低，采用机械化作业可以提高工效几十倍甚至几百倍，也提高了经济效益。通过对现有挖坑机资料的整理和现有知识的总结，本文设计了三轮式挖坑小车。本次设计的小车能够高效率的种植树苗，同时，也是对现有挖坑机的一种创新和发展，为树苗挖坑机的研究提供了一种新的思路。

　　　第一章首先介绍了本设计的选题目的及意义，阐述了现在的发展状况；再分别介绍三种不同的设计方案，最后对三种方案进行优化对比，确定最后的设计方案。第二章是本设计的主体部分，包括挖坑机整体结构设计、动力的选择、总传动设计、防护罩设计、齿轮箱设计和最后的钻头设计。第三章简要说明本设计的不足和优点。

关键词：挖坑机；机械化；自动化；劳动效率；生产成本

Abstract：Afforestation, afforest motherland, is a fundamental state policy of our country.Planting trees to beautify the environment, clear the air pollution, the soil is maintained in windbreak and sand fixation, eradication of wind sand disaster, in addition, afforestation for mankind to provide a variety of useful articles.As of 2008, China's forest area of 195000000 Hm2, the forest coverage rate reached 20.36%, entered a period of rapid development of forest resources.Artificial afforestation of poor quality, low efficiency, slow speed, large labor intensity; mechanized planting can not only improve work efficiency, reduce labor intensity, but also ensure afforestation quality, reduce production costs, improve economic efficiency, is to represent the general trend.Digging machine is one of the main equipment of afforestation.As "in the strategy of sustainable development and should gift forestry is an important position in zoology construction, should gift forestry is the primacy of" put forward, afforestation upsurge is all-time and rising, the market demand will grow with each passing day digging machine.

　　　The first chapter introduces the design of the selected topic and its significance, elaborated the present development state of affairs; and then introduces three kinds of different design schemes, finally on three kinds of scheme comparison, determine the final design scheme.The second chapter is the design of the main body portion, including the digging machine the whole structure design, dynamic choice, total transmission design, winding design, gear box design and final bit design.The third chapter briefly explains the design defects and advantages.

Keywords: Digging machine;mechanization;automation;labor productivity;production cost