丘陵果园螺旋开沟机开沟刀耐磨损性能改进与试验

针对丘陵果园螺旋开沟机在土壤富含岩石等杂物环境下作业时出现的开沟刀破损和磨损严重的问题,基于原来开沟刀并借鉴隧道掘进机械刀具设计了硬质合金开沟刀。主要改进措施如下:将开沟刀磨损最严重的的刀齿部位的材料由H13替换为YG11C硬质合金并增大刃厚;在刀体上下表面使用氧乙炔火焰堆焊铸造WC焊条。3种开沟刀磨损台架试验与田间试验均表明耐磨损性能排序为硬质合金开沟刀>修补硬质合金开沟刀>原来开沟刀,验证了硬质合金开沟刀应用线切割—钎焊修补技术的可行性。台架磨损试验60min后,硬质合金开沟刀与修补硬质合金开沟刀磨损质量比原来开沟刀分别减少65.44%、62.65%。5种堆焊方式磨损台架试验结果表明:耐磨损性能排序为相邻法向堆焊>相邻切向堆焊>间隔网状堆焊>间隔法向堆焊>间隔切向堆焊。堆焊密度与堆焊方向对耐磨损性能均具有影响;相邻堆焊优于间隔堆焊,法向堆焊优于切向堆焊;间隔网状堆焊的综合性能较好,适合于大面积堆焊。田间试验4h后,磨损质量硬质合金开沟刀与修补硬质合金开沟刀比原来开沟刀分别减少60.53%、54.67%。

Improvement and Test of Abrase Resistance of Ditching Blades of Hill Orchard Spiral Ditcher

When hill orchard spiral ditcher is working,but there are rocks and foreign matters in orchard soil,its ditching blades will abrase quickly.The operation process of hill orchard spiral ditcher and shield machine is very similar.It is worth trying to replace the original ditching blades with carbide ditching blades.Because severe abrase at the teeth of blade,therefore replace its material with YG11C from H13 and blade thickness is increased.Using oxyacetylene flame for surfacing WC welding electrode on the upper and lower surfaces of blade body.Abrase bench test and field test show that in terms of abrase resistance,carbide blades are best,original blades are worst,and mending carbide blades are between carbide blades and original blades.It's feasible to repair carbide blades using wire cutting technology and Brazing technology.After 60 minutes of abrase bench test,abrase weight of carbide blades and mending carbide blades are 65.44%and 62.65%less than that of original blades.And differences of hardfacing types on abrase resistance are adjacent normal>adjacent tangent>spaced reticulum>spaced normal>spaced tangent.Density and direction have influence on abrase resistance.Density types of adjacent is better than spaced,and direction types of normal is better than tangent on abrase resistance.Spaced reticulum hardfacing has good comprehensive performance therefore it is suitable for large area surfacing.After 4 hours of field test,abrase weight of carbide blades and mending carbide blades are 60.53%and 54.67%less than that of original blades.The study provide a reference for optimizing the abrase resistance of ditching blades.