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仿形性能好的割晒机
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作者 于作林 《农业机械》 北大核心 1989年第6期8-8,共1页
现在普遍使用的东方红-54(75)拖拉机前悬挂割晒机因其仿形性能不太好,在收获小麦时,如地块不平,易造成割茬不齐,甚至掉穗(小麦株高为30厘米左右),致使收获损失增加。尤其在拖拉机高档作业时,表现更为突出。图1所示为改装的东方红-54(75... 现在普遍使用的东方红-54(75)拖拉机前悬挂割晒机因其仿形性能不太好,在收获小麦时,如地块不平,易造成割茬不齐,甚至掉穗(小麦株高为30厘米左右),致使收获损失增加。尤其在拖拉机高档作业时,表现更为突出。图1所示为改装的东方红-54(75)拖拉机前悬挂割晒机的结构型式。此机仿形性能良好。现在普遍使用的国产4.0前悬挂割晒机与东方红-54(75)拖拉机的挂接型式属单点铰链联接。由于这种机构不是四连杆机构,所以仿形性能差。 展开更多
关键词 割晒机 仿形性能 收获机
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Thickness distribution of multi-stage incremental forming with different forming stages and angle intervals 被引量:1
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作者 李军超 杨芬芬 周志强 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第3期842-848,共7页
Although multi-stage incremental sheet forming has always been adopted instead of single-stage forming to form parts with a steep wall angle or to achieve a high forming performance, it is largely dependent on empiric... Although multi-stage incremental sheet forming has always been adopted instead of single-stage forming to form parts with a steep wall angle or to achieve a high forming performance, it is largely dependent on empirical designs. In order to research multi-stage forming further, the effect of forming stages(n) and angle interval between the two adjacent stages(Δα) on thickness distribution was investigated. Firstly, a finite element method(FEM) model of multi-stage incremental forming was established and experimentally verified. Then, based on the proposed simulation model, different strategies were adopted to form a frustum of cone with wall angle of 30° to research the thickness distribution of multi-pass forming. It is proved that the minimum thickness increases largely and the variance of sheet thickness decreases significantly as the value of n grows. Further, with the increase of Δα, the minimum thickness increases initially and then decreases, and the optimal thickness distribution is achieved with Δα of 10°.Additionally, a formula is deduced to estimate the sheet thickness after multi-stage forming and proved to be effective. And the simulation results fit well with the experimental results. 展开更多
关键词 incremental forming multi-stage forming angle interval thickness distribution
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