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张登坪 《锻压装备与制造技术》2014,49(4):52-53
介绍一种数控分度冲槽卷绕机的钢带送进及控速装置,该装置可主动送进钢带,实时控制钢带的送进速度。解决了现有钢带送进速度无法精确控制而造成冲制槽型不齐的缺陷。 相似文献
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“应力集中控制爆破”开采石材由两个关键部分组成:方便易行的刻槽技术和安全廉价的低爆压炸药。 岩石呈脆性,在岩石上开槽的技术是人们十分关注的研究课题。根据格里菲斯断裂理论可知,在裂纹前缘尖端区域,应力场具有价的奇异性,也就是说具有高度应力集中的特性。在“应力集中控制爆破”开采石材中,开凿应力集中槽用手持式凿岩机完成,先钻孔后开槽,无论是在花岗岩或大理石上开槽,开槽时间仅只有钻孔时间的1/15~1/20。笔者认为机械开槽是今后发展的必然趋势,爆炸物质反应类型,即爆轰或爆燃,这在很大程度上取决于激发方式,而点火式正是石材开采中低爆压炸药的起爆方式。 相似文献
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Single-point turning of Inconel 718 alloy with commercially available Physical Vapour Deposition (PVD)-coated carbide tools under conventional and high-pressure coolant supplies up to 20.3 MPa was carried out. Tool life, surface roughness (Ra), tool wear, and component forces were recorded and analyzed. The test results show that acceptable surface finish and improved tool life can be achieved when machining Inconel 718 with high coolant pressures. The highest improvement in tool life (349%) was achieved when machining with 11 MPa coolant supply pressure at higher speed conditions of 60 m · min?1. Machining with coolant pressures in excess of 11 MPa at cutting speeds up to 40 m · min?1 lowered tool life more than when machining under conventional coolant flow at a feed rate of 0.1 mm · rev?1. This suggests that there is a critical coolant pressure under which the cutting tools performed better under high-pressure coolant supplies. Cutting forces increased with increasing cutting speed due probably to reactive forces introduced by the high-pressure coolant jet. Tool wear/wear rate increased gradually with prolonged machining with high coolant pressures due to improved coolant access to the cutting interface, hence lowering cutting temperature. Nose wear was the dominant tool failure mode when machining with coated carbide tools due probably to a reduction in the chip-tool and tool-workpiece contact length/area. 相似文献
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张士光 《锻压装备与制造技术》2014,49(4):40-41
高速冲槽机冲制硅钢片过程中,操作者需经常调整模具下模高度。为减轻劳动强度,提高劳动生产率,设计出一种可调工作台装置,可方便调节工作台高度,并且实现了无极调节。 相似文献
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采用示波冲击试验方法,研究了HQ785C钢的夏比V型缺口、线切割缺口和预疲劳裂纹3种类型试样在冲击断裂过程中各部分能量与温度的关系。分析了各部分能量随温度变化的规律。试验结果表明,预疲劳裂纹试样的脆性转变温度比线切割缺口试样和夏比V型缺口试样分别提高约20℃和40℃。 相似文献
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