【作者】 俞国胜；

【导师】 顾正平；

【作者基本信息】 北京林业大学 ， 机械设计及理论， 2001， 博士

【摘要】 荒漠化是当今世界威胁人类生存的严重问题之一,世界各国对防治荒漠化都十分重视。我国是荒漠化较为严重的国家之一,荒漠化的面积占国土面积的27.32%。植树造林、种草恢复植被是目前防治荒漠化的最有效手段。对多年来采用深栽造林技术营造林木的调查发现,在科尔沁沙地杨树深栽造林深度在1.4m 以下时的成活率几乎达到100%,在栽植深度为70～80cm 时的造林成活率也在78%左右。深栽造林是一项在干旱沙地提高造林成活率和保存率的有效技术和方法。为了解决造林效率、降低造林成本,本课题研制了2 种适用于干旱沙地的新型深栽造林机械:一种是以小型农用拖拉机为动力底盘的钻孔机。这种机器采用全液压操纵与控制,具有与拖拉机挂接方便、操作简单等特点,深栽造林作业效率根据造林地土壤条件的不同可达到每小时造林60～120 棵,是一种具有广阔推广前景的深栽造林设备。另一种是以大型履带式拖拉机为牵引动力的插干造林设备-深松插干植树机用于中等深度的造林作业,该机每小时可插干造林1000～1500棵,是一种造林效率极高的设备,但受到其牵引动力-拖拉机功率的限制,在科尔沁沙地最大造林深度不大于80cm。本课题通过对用于深栽造林钻孔机的螺旋型钻头钻孔阻力矩进行的系统性理论分析,找出了钻头结构参数和运动参数对钻孔阻力矩的影响关系,为螺旋型钻头的设计提供了理论依据。通过对科尔沁沙地3 种典型造林地,即流动沙丘、固定沙地和道路两侧的实地试验研究,得出了钻头转速、进给速度之间的相互关系及对钻孔阻力矩的影响关系。在钻头转速为300～400rpm 范围时,进给速度为0.047m/s 具有最小的钻孔阻力矩和最好的综合钻孔造林效率。不同钻头钻尖结构,不同切刀刃角在3 种典型造林地的试验表明,这些因素对钻孔阻力矩的影响很小。在全部的实地测试还表明,在科尔沁沙地目前最广泛使用的钻孔直径为90mm,导程为75mm,长为1.7m 的深栽造林用钻头所需的钻孔驱动力矩不超过90Nm。这些实验研究所得出的结论,为今后同类设备的设计、动力的选型、液压元件的选购提供了可靠的依据。深松插干植树机进行的牵引阻力测试揭示了深松插干植树机的松土深度与牵引阻力几乎为一线性关系。随松土深度的增加,牵引阻力在空载运行阻力的基础上以0.79 倍松土深度(以cm 计)的速率增加。同时还得出了在科尔沁沙地,以东方红系列、功率为50～60kW 履带式拖拉机为牵引动力的深松插干植树机最大插干造林深度不超过80cm 的结论。这一试验结果为同类松土式和开沟式植树机的设计与正确使用提供了理论依据。通过对干旱地区机械化造林技术装备的研究,不仅在理论上为深栽造林设备的设计、研制提供了依据,而且所研制的深栽造林设备具有极好的适用性,现已开始推广,为加快我国防治荒漠化的进程提供一种高效、先进的技术装备。更多还原

【Abstract】 Desertification is the one of serious problems to human being’s alive. Most country paid a lot of attention to combat the desertification. China is one of the deserted countries on all over the world. The deserted land was up to 27.32% of total China’s cultivated land. Afforestation and recover vegetation on the deserted is most efficiency and practical method to combat the desertification. An investigation on tree deep planting in arid area showed that planted trees have had almost 100% survival rate when planting depth under 1.4m and 78% survival rate when planting depth in 70cm to 80cm. Tree deep planting is a remarkable technology and effective method to increase the tree planting survival rate and keep rate. Two equipments for tree deep planting were designed and manufactured in order to increase tree planting efficiency and decrease cost. One of them is the deep planting earth auger that powered with mini agricultural tractor. The machine was totally hydraulic driving, operating and controlling. It is easy to couple with tractor and simple operating. The efficiency of tree planting is 60 to 120 per hour according to different soil hardness. The deep planting earth auger will have a bright future to be distributed to arid area. Medium Depth Planter is another machine for tree deep planting. A crawl tractor with power of 50 to 60 kW towed the machine. It could plant 1000 to 1500 trees per hour. It is an effective tree planting equipment. Limited by tractor’s power, the maximum depth of tree planting is 80 cm in Keerqing sand area. The relations of resistant torque with the parameters of spiral auger’s structure and movement have been find out by theoretical research and analyzing in this thesis. It supplies a theoretical basis for spiral auger design. A test for deep planting earth auger reveal out the relationship between auger’s rotation speed, feeding speed with its drilling resistant torque in three typical tree planting land of moving dune, sand soil and road side in the area of Keerqing. It will have minimum drilling resistance torque and efficiency tree planting when the auger bit with 300 to 400 rpm rotation speed and 0.047m/s feeding speed. The test also shows that torque has not big change by using difference augers’tip and different angle of soil cutting blade on the end of auger’s spiral wing. The maximum drilling torque was less than 90Nm in all tests using the auger bits with diameter of 90mm, spiral wing throw of 75mm and hole length of 1.7m. The results of the tests supply reliable data for similar kind of machine design, power unit select and hydraulic components choosing. The test of traction resistance for Medium Depth Planter reveals almost a line relation between its tow resistance and depth of soil loose. The machine traction resistance would be 0.79 times its working depth and plus rolling resistance. The maximum working depth would be 80cm underground if DHF tractor with 50 to 60kW as power to tow the machine. The results of the test would be theoretical basis to design same machine and furrowed tree planter. The theoretical and test research of tree planting equipment used in arid area give out theoretical and reliable basis for afterwards machine design and manufacture. The developed two tree deep planting machines are suited local conditions and have been distributed in that area. The machines will act the role to speed up combat desertification by their tree planting efficiency.更多还原