Abstract:To solve the problem of existing sticky mold in punch pressing upstream pumping grooves on sealing rings of SiC, the study was carried out in the aspects of mold structure, selection of mold release agent, speed of compression and depressurization, et al. The single factor analysis method was used, and lots of test with hydraulic forming machine was conducted for parameters optimization. The results show that the most available structure of mold is a draft angle of 11°-15°on the two sides of the small spiral pieces with a radius of transition fillet with 0.1-0.2 mm on the areas of the bottom corners. Two kinds of combinations were chosen on the selection of mold release agent with their properties and experimental results, one is the combination of molybdenum disulfide of solid lubricant and vaseline, and the other is the combination of lithium base grease and anti-wear hydraulic oil. The appearance of former method is better than latter one, but the process of application is more complicated while the productivity is lower. Pressing speed and holdup time hardly impacts demolding, while depressurization rate has obvious impacts. The optimum depressurization rate is 2-5 MPa/s. In addition, according to the property of SiC and appearance of pumping grooves, the reasons that other kinds release agent cannot meet the requirements were analyzed.
符永宏, 袁志超, 华希俊, 肖开龙, 杨烨刚. 机械密封环上游泵送槽凸模压制脱模工艺试验[J]. 排灌机械工程学报, 2014, 32(6): 500-504.
Fu Yonghong, Yuan Zhichao, Hua Xijun, Xiao Kailong, Yang Yegang. Experimental research on technique of demolding with punch pressing of upstream pumping grooves on sealing rings. Journal of Drainage and Irrigation Machinery Engin, 2014, 32(6): 500-504.
[1]Etsion I. State of the art in laser surface texturing [J]. Journal of Tribology, 2005, 127(1): 248-253.[2]Noel B, Bernard T. Numerical analysis of a surface-textured mechanical seal operating in mixed lubrication regime[J]. Tribology International, 2012,49: 80-89.[3]符永宏,纪敬虎,华希俊,等.端面规则凹坑造型机械密封综合性能的数值分析[J].排灌机械工程学报,2010,28(2):169-173. Fu Yonghong, Ji Jinghu, Hua Xijun, et al. Numerical analysis of integrated performance of mechanical seals with regular micro-surface structure [J]. Journal of Drainage and Irrigation Machinery Engineering, 2010, 28(2):169-173.(in Chinese)[4]华希俊,符永宏,袁润,等.激光表面微造型工艺试验与应用[J]. 农业机械学报,2007, 38(12): 177-180. Hua Xijun, Fu Yonghong, Yuan Run, et al. Experimental investigation on laser surface micro-texturing technology[J]. Transactions of the Chinese Society for Agricultural Machinery, 2007, 38(12): 177-180.(in Chinese)[5]Ali A. Up-stream pumping: New developments in mechanical seal design[C]//Proceedings of the Sixth International Pump Users Symposium,1989: 55-58.[6]Miller B A, Green I. Numerical formulation for the dynamic analysis of spiral-grooved gas face seals[J]. Journal of Tribology, 2001, 123(2): 395-403.[7]Antoszewski B. Mechanical seals with sliding surface texture-model fluid flow and some aspects of the laser forming of the texture[J]. Procedia Engineering, 2012(39): 51-62.[8]Zhang Jinfeng, Yuan Shouqi, Fu Yonghong, et al. A numerical simulation of 3-D inner flow in up-stream pumping mechanical seal [J]. Journal of Hydrodyna-mics, 2006, 18(5): 572-577.[9]符永宏,华希俊,黄骞.一种机械密封环表面动压泵送槽的成型方法:中国,101592225[P]. 2011-06-01.[10]梁国正,顾媛娟.模压成型技术[M].北京:化学工业出版社,1999:285-290.[11]李昂.脱模剂及其作用机理[J].特种橡胶制品,2002,23(4):26-29. Li Ang. Mold release agent and their function mechanism[J]. Special Purpose Rubber Products, 2002, 23(4):26-29.(in Chinese)[12]王德广,吴玉程,焦明华,等.不同压制工艺对粉末冶金制品性能影响的有限元模拟[J].机械工程学报,2008,44(1):205-211. Wang Deguang, Wu Yucheng, Jiao Minghua, et al. Finite element simulation of influence of different compacting processes on powder metallurgic products properties [J]. Chinese Journal of Mechanical Engineering, 2008, 44(1): 205-211.(in Chinese)