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我厂从日本引进的一台1000t液压剪切机,已运行一年半左右。总的来说,液压系统稳定可靠,处理能力大,产量为25t/h。但是,该剪切机的剪切部分导板早期拉毛损伤严重(1986年发生了一次左侧前导板断裂事故),成为影响剪切机正常运行的一大隐患。 相似文献
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本文对唐钢二炼钢厂弧型方坯连铸造机用500t液压剪切机在使用中出现的问题进行了分析,找出了事故发生的原因,并对剪切机受力状态、下刀台导向装置及剪切机整体结构作了改进,效果显著。 相似文献
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本文是针对某厂1600吨浮动轴钢坯剪切机的机架振动问题,在先后三次测试分析的基础上写下的部分专题总结。对剪切机的液压平衡系统进行了动态过程分析,求得与实测示波图基本相符合的液压波动方程及计算公式。应用中值定理对减振效应作了验证;应用广义中值定理推导出冲击振动的公式。对剪切机存在的\ 相似文献
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剪切机是冷轧带钢生产中使用最广泛的单机设备之一。宝钢冷轧厂酸洗和轧机2条主作业线上使用的5台曲柄滑块机构的机械式剪切机,由于原设计的缺陷,在剪切4.5 ̄6.0mm的钢板时,经常发生故障。为此将其作彻底的设备改造,设计出新颖的直角双摇杆机构的液压剪切机,实施一年来效果良好。本文对新剪切机的特点、设计参数等作了概要介绍。 相似文献
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本文通过对T960剪切机液压系统的油温过高的原因分析,计算,介绍了洛钢针对其主要发热部位进行改进和预防的有效措施及取得的明显效果。 相似文献
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本文介绍了连铸坯剪切机液压源有用高低压组合泵传动。有效地节约了能量,减少发热,适应高压大流量,高频率剪切工况。使剪切、压紧、横移等环节,动作控制平稳可靠。 相似文献
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本文论述广钢3^#高炉炉顶大,小钟液压系统不能停泵检修的弊端,探讨在原有1^#,2^#液压系统基础加装第3系统,同时对1^#,2^#液压系统进行改造,实现不停泵检修。 相似文献
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轧三半连轧改造后,冷床上钢动作由电控系统发出信号控制电机来完成,不能满足高速生产要求,在全连轧改造中,采用电控系统控制液压缸来完成上钢动作,适应了16m/s轧制速度要求,解决了飞剪至冷床距离短的问题,满足了生产工艺要求,提高了产量,取得了经济效益。 相似文献
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酒钢一高线高速剪转辙器动作的稳定性,决定了其能否将高速剪分切后的倍尺成功导入分钢器内而不发生撞头堆钢。本文针对转辙器直线轴承润滑维护工作时,点检克服转辙器由于润滑油脂不当,冬季油脂不能满足使用要求,在低温下黏度过大造成转辙器电机电流过大不能正常工作,造成生产事故。 相似文献
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《钢铁冶炼》2013,40(5):333-338
AbstractHistorical analysis of metal cutting shows that metal removal rates have been increasing in the course of the century, predicated by the advancement in tool materials but the steel design has lagged behind. This paper examines the mechanisms of chip formation and tool wear as a function of cutting speed in metal cutting. Chemical wear is identified as the dominant mechanism of tool wear at high cutting speeds caused by temperature rise due to shear localisation in the primary and secondary shear zones of chip. Shear localisation in the primary shear zone is shown to be influenced by both microstructural parameters, i.e. matrix hardening and second phase particles, and metal cutting variables, i.e. cutting speed (strain rate) and feed (pressure). Shear localisation in the secondary shear zone is caused by the tribological conditions of seizure at the tool/chip interface. Chemical crater wear is caused by the dissolution of tool into the workpiece (chip) by diffusion mechanism and can be prevented by suppressing the tribological condition of seizure. The design of steel for high speed machining is based on engineering glassy oxide inclusions in steel, which are designed to form a viscous layer in situ at the tool/chip interface at high cutting speeds. The viscous layer lubricates the tool/chip interface and prevents the occurrence of seizure, thereby suppressing chemical crater wear. In comparison with the large volume fraction of inclusions required for promoting ductile fracture at low cutting speeds, the amount of inclusions required for lubricating the tool/chip interface is very small and is in the range that is typical of clean steel. Thermodynamic modelling is shown to be a powerful tool to engineer glassy oxide inclusions in steel 相似文献
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简要介绍某高线工程的工艺流程,重点描述其中轧线上的启停式飞剪控制系统的构成、特点和作用。该系统配置良好,投入运行后大大提高了生产率,完全满足生产的需要。 相似文献
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文章分析了热轧卷板横切机组液压剪结构特点及液控原理,对液压故障症状及排查进行了概述,通过系统分析、简约改进,防止类似故障重复发生,有效提高液压剪的安全性和可靠性。 相似文献
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为推动平面形状控制技术的工业推广应用,介绍了中厚板轧机平面形状控制技术的基本原理,论述了为实现平面形状控制技术现场应用,中厚板轧机机械系统、液压系统和自动化系统应具备的条件。以唐钢中厚板生产线为例,对液压系统进行改造,采用双伺服阀并联方式,达到20 mm/s的液压压下速度。自动化系统由基础自动化、过程控制系统和人机界面系统协调配合,实现平面形状控制功能。通过采用高次曲线控制模型、轧件长度精确跟踪功能以及高精度厚度计算模型,实现平面形状控制道次的精确厚度变化控制。实际应用表明,投入平面形状控制技术后,中厚板两切产品成材率提高超过0.7%,四切产品成材率提高超过1%,可以显著提升中厚板产品成材率,创造可观的经济效益。 相似文献
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The effect of the laser beam on chip formation when machining Ti6Al4V alloy has been investigated at different cutting speeds
and laser powers. The characteristics of the segmented chip produced by laser-assisted machining (LAM) in terms of the tooth
depth and tooth spacing were strongly dependent on the cutting speed and laser power. Two types of segmented chip formation
processes were observed, one at low and the other at high cutting speeds with a continuous chip occurring between these two
types of segmented chips. The critical cutting speed at which the transition from the sharp, segmented chip to the continuous
chip occurred increased with laser power. To obtain the continuous chip, plastic deformation at the shear zone to match the
deformation strain introduced by the cutting tool is required. This can be achieved by laser heating the material in front
of the cutting tool. A physical model is proposed to explain qualitatively the chip segmentation in conventional machining
and the continuous chip transition at high cutting speed with the application of a laser beam. 相似文献
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介绍柳钢1550mm冷连轧飞剪控制系统的控制数学模型,包括飞剪剪切角计算模型、飞剪剪切距离计算模型和飞剪速度目标值计算和速度转矩调节模型等。采用该数学模型实现飞剪自动剪切、定位和制动,将轧件的平均剪切误差控制在15cm以内。 相似文献