【作者】 王新；

【导师】 肖建斌；

【作者基本信息】 青岛科技大学 ， 材料工程（专业学位）， 2021， 硕士

【摘要】 近年来,汽车业发展迅速,排放法规逐渐收紧,随着电子燃油喷射装置、涡轮增压技术及排气后处理系统在汽车发动机系统中得到推广和应用,燃油效率、发动机转速设计的不断提高,发动机内部温度、压力也不断增加,由此带来更高的内磨加剧的风险,再加上合成机油的普及使用和品级升高,如此“恶劣”的工况给车用油冷器密封圈的密封可靠性提出更高的要求,鉴于此,该类产品用橡胶材料除了满足更高的机械强度等力学性能指标之外,还须在长期高温空气和高温机油的环境中,能够保持各项性能的损失在产品使用工况的可受范围内,特别是压缩永变性能,这些对于产品的可靠性至关重要。氢化丁腈橡胶(HNBR)在机械物性方面表现突出,不但具备高强度、高撕裂,而且耐磨强,同时又耐高温、耐臭氧和耐高温形变性能,并且在苛刻条件下对于含极性添加剂的润滑油也有很好的耐受型,因而,相对于丁腈橡胶(NBR)、氯丁橡胶(CR)、氟橡胶(FKM)等材料更加适用于该类产品的制造,并在国内外得到推崇。本研究工作以“发动机全速全负荷1000h耐久性试验油冷器密封圈泄露事件”的客户“痛点”为切入点,经过工况条件的仔细调研之后,从HNBR材料的性能特点出发,对HNBR主体材料化学结构、分子链段类型和技术指标,过氧体系用交联助剂品类,过氧体系用量对其未硫化胶的硫化特性和硫化胶的常规力学性能、耐高温空气、机油压缩永变性能、耐长期高温空气、高温机油老化性能的影响规律的进行深入的探究,并结合以往的研发经验完成了对其配合体系的系统优化,在满足产品工艺性能的前提下,进一步提高了材料的常规力学性能,同时实现了其耐高温空气老化、高温油老化,特别是高温、机油压缩永久变形性能的较大改善。在油冷器密封圈制造方面,本研究工作从混炼胶制备、胶坯成型、一次硫化成型、二次硫化定型等工艺方面对其生产过程进行了工艺优化。从成本和效率出发,采用密炼机制备混炼胶;从质量和成本考虑,采用胶片裁切工艺;从降低废品率的角度考虑,一次硫化成型采用抽真空硫化机,二次硫化成型采用自动控温系统控制高温烘箱。最终经过产品性能的验证,使用优化后配方制备的HNBR材料各项性能指标满足产品用料的技术标准指标的要求,所制造的两款油冷器密封圈通过了客户全速全负荷1000h耐久性测试,并且对产品耐高温机油压缩永久变形的研究成果为后续油冷器密封圈耐久性、可靠性试验的时效性的标定提供了有效的参照指标,为客户后期快速判定产品质量提供了依据。更多还原

【Abstract】 In recent years,with the rapid development of the automobile industry and the continuous tightening of emission regulations,as electronic fuel injection devices,turbocharging technology and exhaust gas aftertreatment systems have been promoted and applied in automobile engine systems,the design of fuel efficiency and engine speed has improved With the continuous increase,the internal temperature and pressure of the engine also continue to increase,which brings a higher risk of aggravated internal friction.Coupled with the popular use of synthetic engine oil and the increase in grade,such "bad" working conditions are cooling the vehicle oil.The sealing reliability of the seal ring of the device puts forward higher requirements.In view of this,in addition to meeting higher mechanical strength and other mechanical performance indicators,the rubber used in this type of product must also have stronger heat aging performance and high temperature oil aging resistance.Performance,especially lower reliability requirements such as compression set resistance.HNBR has excellent heat resistance,ozone resistance and high temperature compression permanent deformation properties;at the same time,in terms of mechanical properties,it also has high strength,high tear performance and excellent wear resistance.Lubricating oils with polar additives also have a good resistance type.Therefore,compared to materials such as NBR,CR,FKM,etc.,they are more suitable for the manufacture of such products and are highly regarded at home and abroad.This research work is based on the customer’s "pain point" of the "engine full-speed and full-load 1000 h durability test oil cooler sealing ring leakage event".After careful investigation of the working conditions,starting from the performance characteristics of the HNBR material,the main body of the HNBR Material chemical structure,molecular chain type and technical indicators,peroxide system cross-linking aid category,peroxide curing agent dosage for its unvulcanized rubber characteristics and vulcanization characteristics and conventional mechanical properties of vulcanized rubber,high temperature air resistance,In-depth research on the influence rules of oil compression set performance,heat-resistant air aging performance,and high-temperature oil aging performance,combined with previous research and development experience,completed the system optimization of its matching system,under the premise of meeting product process performance,To further improve the conventional mechanical properties of the material,and at the same time to achieve a greater improvement in its resistance to high temperature air aging,high temperature oil aging,especially high temperature,oil compression permanent deformation performance.In the aspect of oil cooler seal ring manufacturing,this research work optimizes its manufacturing process from the aspects of compound rubber preparation,rubber blank molding,primary vulcanization molding,and secondary vulcanization shaping.From the perspective of cost and efficiency,an internal mixer is used to prepare the rubber compound;from the perspective of quality and cost,the film cutting process is used;from the perspective of reducing the scrap rate,the vacuum vulcanizing machine is used for the primary vulcanization molding,and the secondary vulcanization molding is automatically controlled.The temperature system controls the high temperature oven.Finally,after product verification,the performance indicators of the HNBR material prepared with the optimized formula meet the requirements of the technical standard indicators of the product materials.The two oil cooler seals manufactured have passed the customer’s full-speed full-load 1000 h durability test,and The research results on the long-term high-temperature oil compression permanent deformation of the product provide an effective reference index for the timeliness of the subsequent oil cooler seal durability reliability test,and provide a basis for the customer to quickly determine the product quality in the later period.更多还原