基于仿生微织构的电动修剪机刀具磨损性能研究

Wear Performance of Electric Pruning Scissors Based on Bionic Micro-structure

针对普通电动修剪机刀具易磨损、崩刃等情况,设计了一种蚯蚓仿生微织构刀具,以蚯蚓体表形貌为基础,利用激光成型技术加工刀具表面微织构,研究激光成型参数对成型沟槽几何尺寸的影响;通过摩擦磨损对比试验研究了仿生微织构刀具和普通刀具的摩擦因数和磨损情况,分析仿生刀具减磨机理;通过自制剪切试验平台对不同直径龙眼树枝进行刀具剪切试验,验证仿生刀具减磨特性。研究结果表明:优化后激光成型仿生刀具的工艺参数为:激光功率75 W、激光扫描速度4.8 mm/s;仿生刀具微织构实际尺寸为:沟宽138.3μm,沟深33.5μm;与普通刀具相比,载荷400 g下沟槽间距1.6 mm时微织构仿生刀具表现出最小摩擦因数0.2619和体积磨损量616.70 mm^3,具有明显减磨特性;随载荷增加磨损机制逐渐由黏着磨损、微切削磨损向磨粒磨损和氧化磨损的复杂磨损形式转变;磨损稳定时,沟槽间距1.6 mm微织构仿生刀具所需剪切次数50~55次,比普通刀具剪切次数(45~50次)高5~10次,沟槽间距1.6 mm微织构仿生刀具在剪切直径10、15、20 mm的树枝磨损面积稳定次数分别为35~40次、45~50次、50~55次,树枝直径越大微织构刀具抗磨效果越明显。

A biomimetic micro-texture tool for earthworm was designed.Based on the surface morphology of earthworm,the micro-texture of tool surface was processed by laser molding technology.The friction coefficient and wear of the bionic texture tool and the ordinary tool were studied through the comparative test of friction and wear,and the wear reduction mechanism of the bionic tool was analyzed.The cutting test of longan branches with different diameters was carried out by the self-made cutting test platform to verify the wear reduction characteristics of the bionic cutting tools.The results showed that the optimized process parameters of the bionic laser forming tool were as follows:laser power was 75 W,laser scanning speed was 4.8 mm/s;the actual size of the micro-texture of the bionic cutter was 138.3 m wide and 33.5 m deep.Compared with ordinary cutting tools,the texture bionic cutting tools showed the minimum friction coefficient of 0.2619 and the volume wear amount of 616.70 mm^3 when the groove spacing width was 1.6 mm under the load of 400 g,which had obvious wear reduction characteristics.With the increase of load,the wear mechanism was gradually changed from adhesive wear and micro-cutting wear to the complex wear forms of abrasive wear and oxidation wear.When the wear was stable,the required cutting times of 1.6 mm texture bionic tool were 50~55 times higher than that of ordinary tool(45~50)times,and the stable times of 1.6 mm texture bionic tool in cutting the wear area of branches with a diameter of 10 mm,15 mm and 20 mm were 35~40,45~50 and 50~55 respectively.The larger the diameter of the branch was,the more obvious the anti-wear effect of the texture tool was.