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设计一双锥度模具来替代生物质常温液压成型机中的单锥度模具.对双锥度模具进行力学分析,并建立基于ANSYS的双锥度模具的有限元模型;对4种不同物料在同一双锥度模具下进行压缩试验,得出模具的锥度α、β,锥长l1、l2,保形长度l3以及出口直径d对物料的成型密度都有一定的影响;分析在挤压过程中物料(秸秆)的变形趋势及其摩擦应力分布,得到材料在双锥度模具中所受载荷的变化规律;在同一模具下,不同物料的压缩循环过程具有相同的变化规律,物料的压力均值与密度均值也有一定关系;对于同种材料,双锥度模具下的最大压力峰值要大于单锥度. 相似文献
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塑料模具在塑料成型加工中占有非常重要的地位。模具生产技术也是衡量一个国家制造工艺水平的重要标志之一。为了发展模具工业,一些国家制订了有关扶植政策,如日本在80至90年代制订了机械生产振兴法,把模具列为特定产品加以发展。美国现拥有模具专业厂家一万多个,90年代后期模具总产值达100多亿美元。 相似文献
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在冲压工艺设计中,对于成型工序来说,计算毛坯的尺寸是必要的环节,生产实际中。常采用经验公式法来进行计算。特别是卷圆类冲件毛坯展开尺寸的精确计算及在模具中的一次弯曲成形,具有一定的难度,无法计算出毛坯的精确尺寸,只能初步计算,在通过试模后,再进行修正。 相似文献
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硬质合金具有较高的强度、耐磨性和红硬性,在我国主要应用于刀具和刃具上。近年来随着科学技术的不断发展,各种用途的硬质合金材料及加工技术得到了长足的发展。硬质合金在冲裁模、拉伸模等冷作模具上也得到应用,并取得了可观的经济效益。 相似文献
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阐述了冲压件的基本特征及其常见问题,提出一种加工冲压件定位点的模具结构,不但能够将冲压件快速精确定位,省时省力。而且能提升加工工件加工精度。 相似文献
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弯曲成型钢板(8 mm以上)时,变形抗力大,出现弹性变形,致使工件的弯曲角度和圆弧半径难以准确控制。根据零件性能,合理高效的设计成型工艺。如何最经济,最适用地进行模具机构设计?针对这一问题,结合生产经验和最新技术对此进行深入的探讨和研究。 相似文献
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基于Solid Edge的不锈钢圆筒形件拉深模具设计的研究 总被引:1,自引:0,他引:1
分析了不锈钢在拉深中存在的工艺问题和如何选用模具材料以延长模具的寿命。并基于Solid Edge平台,采用参数设计技术和Visual Basic工具,开发了一个圆筒形零件拉深模具系统,该系统能够全参数化进行零件设计并生成零件图、模具虚拟安装并生成模具装配图。 相似文献
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ZhaoDong SunYanling 《中国林学(英文版)》2004,6(2):46-49
In order to study mechanical behaviors of com stalk powder during the compaction, the yield criterion for com stalk powder is proposed with a plasticity theory. From the stress-strain curves of uni-axial compaction test for com stalk powder, the constitutive model, in which the equations are modified by experiments on corn stalk powder, is adopted to describe plastic behaviors of powder, and is discussed based on the incremental theory and deformation theory. The numerical results agree well with the experimental ones. 相似文献
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Ajaye Babatunde 《林业研究》2011,21(1):111-115
Cement-bonded particleboards of 6 mm in thickness were manufactured using maize stalk (Zea mays) particles of uniform sizes at three levels of board density and additive concentrations respectively. The bending strength and dimensional properties were assessed. Increase in board density and additive concentration caused increase in Modulus of rupture (MOR), Modulus of elasticity (MOE), and decrease in Thickness swelling (TS) and Water absorption (WA). The MOR, MOE and TS of the boards were significantly affected by board density except for WA, but additive concentration affected all the boards’ properties examined at p ≥ 0.05. Strong and dimensional stable cement-bonded boards could be manufactured from maize stalk particles with Portland cement as the binder after hot water treatment. Although the dimensional stability and mechanical strength properties of the boards were affected by the board density and additive concentration, the study revealed that cement-bonded particleboards could be manufactured from maize stalk (Zea mays) particles. However, the increase in board density and additive concentration could cause the increase in MOR and MOE, and cause the decrease in TS and WA of boards. 相似文献
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The volatiles release behavior of poplar powder has been studied by TD-GC/MS online technique at different temperatures.The results show that the proportion of main harmful components was higher than that of beneficial in the volatiles of poplar powder at 40℃ and 90℃,the harmful components was 1.7 times higher than beneficial components. The proportions of main beneficial and harmful components were equivalent at 60℃,while the main beneficial components was 5.42 times higher than that of harmful.Taking poplar wood powder as substrate to prepare wood powder-based composites by high-pressure no-gel molding compaction between the temperature of lignin softening point and wood materials carbonization(about 150-180℃) can present a satisfactory environmental friendliness. 相似文献