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周家付 《林业机械与木工设备》2002,30(10):11-13
建立了剪枝机液压缸缸体的有限元力学模型,通过有限元分析得出液压缸缸体的危险点位置,为液压缸缸体的设计和计算提供了理论依据。 相似文献
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Weeds limit hazelnut productivity through competition and interference. Field experiments were conducted from spring 2010 through 2013 to evaluate string trimming alone or combined with herbicides in hazelnut orchards to control mugwort (Artemisia vulgaris L.), purple nutsedge (Cyperus rotundus L.), and burning nettle (Urtica urens L.). Treatments were mowing with a string trimmer (ST) alone, or ST followed by glyphosate, glyphosate + diflufenican, and glyphosate + carfentrazone-ethyl. These combinations also were applied with pendimethalin and oxyfluorfen as pre-emergence applications. The experiments were conducted in Fatsa-Ordu, Turkey, on a sandy clay soil with multi-stemmed trees (ocak). The combination treatments improved weed control compared to ST alone. Glyphosate plus carfentrazone-ethyl application 15 days after ST was the most effective treatment for control of these weeds. This combination was more effective in reducing seed bank reserves of A. vulgaris, C. rotundus and U. urens than herbicides applied alone or in mixtures throughout all seasons. Hazelnut yield was not significantly affected by herbicide treatments in 2010 or 2011. Hazelnut yield increased during the latter half of the experimental period, in 2012 and 2013. In a mixed population of A. vulgaris, C. rotundus and U. urens, 89 plants per m2 caused 12.1% yield loss. When the density increased to 256 plants per m2, yield losses increased to 29.7%. Hazelnut treated with ST followed by glyphosate plus carfentrazone-ethyl had the highest financial return. Post-emergence weed management systems in hazelnut should include ST followed by glyphosate plus carfentrazone-ethyl applications for maximum returns. 相似文献
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小型电动割草机刀盘变形试验分析与仿真 总被引:1,自引:0,他引:1
割草机刀盘的旋转变形是导致其产生机械振动噪声的主要因素之一。利用高速数码摄像机分别拍摄了割草机刀盘在无保护端盖和有保护端盖状态下的旋转变形图像,获得了刀盘的高速旋转变形曲线,分析了产生变形的原因;并在试验的基础上建立了刀盘的有限元模型,通过ANSYS分析软件,模拟了刀盘的径向变形情况,分析了径向变形与刀盘结构和电动机转速之间的关系。减小刀盘大孔面积能使刀盘最大径向位移减小(在12.000r/min时,减小约30%);维持电动机转速在8.000r/min左右,可使最大径向位移不超过0.2mm,刀盘运转平稳。 相似文献
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随着果园种植规模的扩大,果树修剪工作也越来越繁重,但传统修剪机智能化程度低,修剪质量不高,作业强度大,且工作效率低,导致果树修剪进度滞后,严重时会影响果蔬的产量。为克服这一难题、提高果蔬修剪效率,在自动修剪机中引入计算机控制技术、PLC技术等,对自动修剪机运行过程中的各类参数进行实时监控、实时共享和在线监测,完成了自动修剪机控制系统总体方案的设计。同时,对自动修剪机控制系统硬件进行了模块设计,完成了控制系统的I/O分配表设计,并对控制系统的软件运行流程进行优化设计。试验结果表明:基于计算机控制技术的自动修剪机具有远程控制和参数监控功能,能够实时掌握修剪机的运行状态,修剪效率高,果蔬修剪质量好,系统安全性和稳定性高,从而降低了劳动生产成本及生产强度,具有较大的推广价值。 相似文献
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针对当前柑橘果树一般采用交替结果模式从而需要对柑橘果树进行整行齐切的问题,设计了一种符合规范化果园修剪需要的空间可调双边齐切式柑橘修剪机。锯切台架试验表明,锯片转速为3 000 r/min、进给速度为0.6 m/s时,锯切能耗和修剪效果最佳。柑橘修剪机修剪宽度调节范围为1.6~2.4 m,修剪高度调节范围为2.0~2.5 m。功能展示表明,修剪机在不同修剪形状下进行齐切作业,修剪机最大漏割率为10.1%,最小漏割率为3.5%,修剪合格率高于88%,修剪树形和断面符合农艺要求。 相似文献
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