Ultra-large plate forgings are foundation of heavy machinery,but many parts of the type cannot be made by conventional technologies due to the characters of extreme manufacturing in terms of size and quality requireme...Ultra-large plate forgings are foundation of heavy machinery,but many parts of the type cannot be made by conventional technologies due to the characters of extreme manufacturing in terms of size and quality requirements.This paper introduced a systematically method called cylinder unfolding method(CUM)for producing large plate forgings,by using a serial of operations including“splitting”,“unfolding”,and“flattening”of a thick cylinder obtained from saddle forging.The technological route of CUM was presented in detail with an example of plate forging with the horizontal sizes of 6100 mm and thickness of 300 mm.The deformation features of saddle forging for fabricating transitional cylinders were analyzed,and then the subsequent handling steps including splitting,unfolding and flattening of the cylinder,as well as the auxiliary processing,were addressed.The practice proved that CUM can provide an efficient way for manufacturing ultra-large plate forgings and meet the strict requirements in geometry and mechanical performance,without highly increasing the investments of forming equipment and tooling.展开更多
Purpose： Scarf is a long loose piece of cloth worn around the neck and shoulder. Despite cultural asso- ciation of this apparel, it is part of numerous injury episodes of varying enormity. Entanglement of loose scarf...Purpose： Scarf is a long loose piece of cloth worn around the neck and shoulder. Despite cultural asso- ciation of this apparel, it is part of numerous injury episodes of varying enormity. Entanglement of loose scarf in spoke wheels of bike, tricycle, belt driven machines like sugarcane juice machine, thresher, grinding machines, etc is observed both in social and industrial milieu. This study aims to investigate the scarf-related injuries at a major trauma center in northern India. Methods： From June 2013 to May 2015, a hospital-based prospective observational study was done in patients who presented to a level 1 trauma center in northern India with the mode of injury involving scarf around the neck. Demographic profile, mode of trauma, contributing factors, injury pattern, and the early management as well as early complications were recorded. Results： There were 76 injuries directly related from scarf with the mean age of patients being 32.4 years. The most common primary factor involved was rotating wheel of motorbike/tricycle （46.1%）, followed by belt driven machines （28.970）. The spectrum of injuries was diverse, including minor abrasions or lac- erations （53.9%）, large lacerations （15.8%）, fractures and spine trauma （18.4%）, mangled extremity and amputations （7.9%） and death （3.9%）. More severe injury patterns were noted with belt driven machines. Conclusion： Scarf-related injuries constitute a sizable proportion of trauma, with varying degrees of severity. Devastating consequences in significant proportion of cases dictate the call for a prevention plan comprising both educational and legislative measures. Urgent preventive measures targeting scarf- related injuries will help reduce mortality and morbidity.展开更多
基金Project(cstc2018jcyjAX0159)supported by the Natural Science Foundation of Chongqing,ChinaProject(51575066)supported by the National Natural Science Foundation of China。
文摘Ultra-large plate forgings are foundation of heavy machinery,but many parts of the type cannot be made by conventional technologies due to the characters of extreme manufacturing in terms of size and quality requirements.This paper introduced a systematically method called cylinder unfolding method(CUM)for producing large plate forgings,by using a serial of operations including“splitting”,“unfolding”,and“flattening”of a thick cylinder obtained from saddle forging.The technological route of CUM was presented in detail with an example of plate forging with the horizontal sizes of 6100 mm and thickness of 300 mm.The deformation features of saddle forging for fabricating transitional cylinders were analyzed,and then the subsequent handling steps including splitting,unfolding and flattening of the cylinder,as well as the auxiliary processing,were addressed.The practice proved that CUM can provide an efficient way for manufacturing ultra-large plate forgings and meet the strict requirements in geometry and mechanical performance,without highly increasing the investments of forming equipment and tooling.
文摘Purpose： Scarf is a long loose piece of cloth worn around the neck and shoulder. Despite cultural asso- ciation of this apparel, it is part of numerous injury episodes of varying enormity. Entanglement of loose scarf in spoke wheels of bike, tricycle, belt driven machines like sugarcane juice machine, thresher, grinding machines, etc is observed both in social and industrial milieu. This study aims to investigate the scarf-related injuries at a major trauma center in northern India. Methods： From June 2013 to May 2015, a hospital-based prospective observational study was done in patients who presented to a level 1 trauma center in northern India with the mode of injury involving scarf around the neck. Demographic profile, mode of trauma, contributing factors, injury pattern, and the early management as well as early complications were recorded. Results： There were 76 injuries directly related from scarf with the mean age of patients being 32.4 years. The most common primary factor involved was rotating wheel of motorbike/tricycle （46.1%）, followed by belt driven machines （28.970）. The spectrum of injuries was diverse, including minor abrasions or lac- erations （53.9%）, large lacerations （15.8%）, fractures and spine trauma （18.4%）, mangled extremity and amputations （7.9%） and death （3.9%）. More severe injury patterns were noted with belt driven machines. Conclusion： Scarf-related injuries constitute a sizable proportion of trauma, with varying degrees of severity. Devastating consequences in significant proportion of cases dictate the call for a prevention plan comprising both educational and legislative measures. Urgent preventive measures targeting scarf- related injuries will help reduce mortality and morbidity.
