车用橡胶件行业现状与用材趋势分析

车用橡胶件是指除轮胎以外的各种橡胶制品,主要包括橡胶胶管、减震橡胶、密封橡胶、传动皮带等。随着我国汽车工业的稳步发展,车用橡胶件的市场前景也得到进一步扩大,但也存在技术力量薄弱、专业化程度有待提高等问题。通过分析世界车用橡胶件的发展特点、以及主流橡胶件的用材现状,对车用橡胶件的用材趋势进行预测分析,并提出行业发展建议。     

长城汽车股份公司建设车用橡胶件项目

为实现车用橡胶件的自用需求，长城汽车股份有限公司决定投资建设年产50万套汽车橡胶件项目。该项目位于保定市徐水县大王店产业园区，     

低温和频率对橡胶弹性元件刚度性能的影响

介绍橡胶弹性元件静刚度和动刚度的测试原理,设计一种新型低温刚度试验工装以对橡胶弹性元件进行静态和模态试验,研究温度对橡胶弹性元件静刚度和动刚度的影响,以及频率对橡胶弹性元件动刚度的影响。结果表明:本试验工装结构合理,满足试验要求,随着温度的降低,橡胶弹性元件静刚度和动刚度增大;随着频率的增大,橡胶弹性元件的动刚度在低频段增大,在一定频率后变小,最后趋于稳定;温度低于-40℃时橡胶弹性元件的动刚度-频率曲线的变化拐点前移。     

汽车减震器动刚度测定仪

介绍研究开发的汽车减震器金属-橡胶件动刚度测定仪的结构、原理及测试方法.该仪器包括无预加应力和有预加应力两种装置,能够准确测定不同频率下制品的动剐度,并绘出曲线.与传统电-液伺服疲劳试验台相比,该测定仪振动位移更大,测量精度更高.     

退役汽车塑料材料NIRS识别技术及设备研究

基于近红外塑料识别技术具有操作简单、稳定性好、效率高、环保清洁、成本低等特点,开发了一套退役车用塑料近红外识别试验系统。该系统的硬件部分包括BTC261E阵列型近红外光谱仪、BIP2.0积分球、光纤探头、钨丝灯光源、测试台架等,软件部分包括样品采集单元、模型建立和校正单元、样品检测单元。系统的应用测试结果表明,车用塑料的识别准确率超过95%,满足车用塑料识别的要求,为进一步工业化开发和应用做好了铺垫,同时为开展退役汽车塑料的回收利用奠定了坚实的基础。     

汽车用橡胶件的技术开发动向

介绍了汽车用橡胶软管、车体用橡胶件、汽车密封垫等车用橡胶件的生产现状及开发动向,指出企业应紧跟市场变化,不断改进汽车用橡胶件,改善配套性能,把握产品质量,才能在竞争中立于不败之地。     

阻尼硅橡胶的高温动态性能研究

将阻尼硅橡胶在20~150℃下进行动静态性能试验,研究了阻尼硅橡胶的高温动态性能。结果表明,阻尼硅橡胶的损耗角、动刚度均随着试验的进行逐渐减小,最后趋于稳定。阻尼硅橡胶稳定后的损耗角、动刚度均随着温度的升高而下降,其中,150℃下的损耗角、动刚度是20℃的0.43倍和0.67倍。在周期性外力下,再施加缓慢的静态力后,阻尼硅橡胶的静刚度随着温度的升高而降低,动静比随着温度的升高逐渐降低。     

测试条件对微孔橡胶垫板动刚度及动静比的影响

建立了微孔橡胶垫板结构简化模型,对动静比与能量损耗的关系进行了定性分析,并考察了测试频率和加载力值对动刚度和动静比的影响。结果表明,在外力作用下,橡胶垫板的内耗越大,则动刚度和动静比越大;随着测试频率和加载力值的增加,动刚度和动静比均增大。     

受损伤HMPE系缆动刚度演变的试验研究

深海绷紧式系泊系统采用合成纤维缆绳作为系泊缆绳,由于材料属性和安装、使用等因素造成缆绳带损伤服役,因此有必要研究受损伤的缆绳在复杂海况下的非线性动力特性尤其是动刚度演变规律。详细介绍了国内首台合成纤维系缆循环加载试验系统,论述了终端所采用的缆绳插编方式,试样磨合处理的流程以及通过减小缆绳有效承载面积制造定量损伤的方法。对直径6 mm和8 mm的高相对分子质量高密度聚乙烯(HMPE)缆绳试样进行试验研究,验证了小比尺HMPE受损伤缆绳的动刚度模型试验可以反映大比尺HMPE受损伤缆绳的动刚度特性。分别考察了损伤度、平均载荷、应变幅值和循环周次对HMPE缆绳动刚度的影响,为今后更为复杂的全尺寸受损伤缆绳的动刚度研究提供了方法和依据。     

轨道车辆转向架橡胶止挡试验设计与研究

本文分析了垂向、横向及纵向3种止挡的结构与原理,设计了止挡静刚度、动刚度和疲劳性能试验方案,介绍了一种新型的压剪偏复合加载试验方案,并与传统试验方案进行比对,研究了不同止挡垂向静态和载荷拐点特性、不同频率对止挡动态性能的影响,不同加载方式对疲劳性能的影响。研究表明:试验设计与实际工况一致,止挡垂向静刚度呈非线性、载荷拐点与刚度特性相关、动刚度随频率增加而递增,损耗角、阻尼随频率增加而减小,疲劳性能均满足要求,研究成果对橡胶止挡及同类产品的研发和试验起到了一定的指导作用。     

橡胶衬套静刚度有限元分析与测试技术的应用现状

当前我国国民经济飞速发展,随着人们对于出行要求的不断提高,汽车的数量也在快速增加。橡胶衬套广泛应用于汽车悬架,其能够很好的起到减震的作用,也能够大大提高汽车悬架的使用寿命。作为汽车悬架的重要部件,橡胶衬套的静刚度很大程度上会影响汽车的NVH性能,刚度越小减震效果越好,但容易引起共振带来抖动,反之,静刚度过大不利于隔离震动,因而对于橡胶衬套静刚度的测试分析十分有必要。合适的静刚度能够最大限度地提高车辆行驶的舒适性,也能够在一定程度上保证行车安全。以下就橡胶衬套静刚度的有限元分析与测试技术进行简要的分析研究。     

中心销板式牵引装置的试验设计与研究

介绍中心销板式牵引装置的结构和原理,设计新型系统加载试验方案,研究牵引装置的纵向刚度、垂向刚度、横向刚度和耐疲劳性能,并与传统牵引橡胶堆组对试验进行分析对比。试验结果表明:试验设计与实际工况一致,系统加载试验能准确反映出牵引装置的力学性能;牵引装置的刚度小于牵引橡胶堆组对,且各项性能满足要求;试验研究成果可为牵引装置类产品的设计和试验提供参考。     

Rubber injection molding: Applying multivariate statistics to identify quality issues solely from process signals

Injection-molded rubber parts are widely used in automotive, aeronautical, and industrial engineering applications Therefore, such rubber parts are often critical to the safe operation of the entire system, and part failure can result in significant human or environmental damage. To avoid shipping any parts of subpar quality, manufacturers need to continuously monitor the quality of their product. xIn this work, we apply a principal component analysis (PCA) based process monitoring method. This method is able to detect process fluctuations (faults) in real-time solely from sensor data features, only requiring pretraining on data from about 10 in-control cycles. Specific faults were set to critically affect the dynamic performance of the manufactured NBR rubber parts. Fisher discriminant analysis (FDA) was employed to automatically cluster individual molding cycles into those of being in control, those of defectives caused by unfavorable raw material storage and those of out-of-tolerance induced by an overheated mold, again solely from sensor data. Both PCA fault detection and FDA fault identification decisions were validated by oscillatory rheology and dynamic compression testing of the manufactured parts. This combined method approach is scalable, transferable, and can be implemented on standard industrial injection molding equipment.     

Effect of types of carbon black and cure conditions on dynamic mechanical properties of elastomers

The dynamic mechanical properties of natural rubber and bromobutyl rubber (used in automotive suspension parts) were investigated to determine the effect of particle size of carbon black filler and state of cure of the rubber matrix. The results indicate that state of cure has little effect on storage modulus (hardness and stiffness). However, elastomers with a desirable storage modulus, with low sensitivity to temperature change, can be developed using a filler with a small particle size.     

Morphology and mechanical properties of layered silicate reinforced natural and polyurethane rubber blends produced by latex compounding

Natural rubber (NR), polyurethane rubber (PUR), and NR/PUR‐based nanocomposites were produced from the related latices by adding a pristine synthetic layered silicate (LS; sodium fluorohectorite) in 10 parts per hundred parts rubber (phr). The dispersion of the LS latices in the composite was studied by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Further information on the rubber/LS interaction was received from Fourier transform infrared spectroscopy (FTIR) and dynamic mechanical thermal analysis (DMTA). Tensile and tear tests were used to characterize the performance of the rubber nanocomposites. It was found that LS is more compatible and thus better intercalated by PUR than by NR. Further, LS was preferably located in the PUR phase in the blends, which exhibited excellent mechanical properties despite the incompatibility between NR and PUR. Nano‐reinforcement was best reflected in stiffness‐ and strength‐related properties of the rubber composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 543–551, 2004     

橡胶球铰应力作用下的刚度变化研究

通过测试预压缩、多次刚度试验后的橡胶物理性能、动态机械性能和核磁共振交联密度等,分析了橡胶球铰在不同应力作用下的刚度变化。结果表明,应力作用可使橡胶球铰的刚度下降。预压缩过程中的剪切力可使橡胶分子链发生滑移,并有部分分子链发生断裂。在刚度测试过程中主要发生了交联网络内部重排现象,但没有分子链断裂现象发生。炭黑聚集体的破碎效应也是导致球铰产品刚度下降的因素之一。     

橡胶减摆器的环境适应性研究

采用电液伺服试验机进行了橡胶减摆器高低温动态特性测试,研究了橡胶减摆器在不同温度环境下动态特性的变化规律,为其在高寒和热带地区的应用提供依据;同时对其湿热、霉菌和盐雾环境适应性进行了测试,为其在潮湿和海洋环境中的应用提供了依据。研究结果表明,当温度在-55~20℃之间时,橡胶减摆器的低温动态刚度与室温下的比值在1~1.7之间;当温度在20~70℃之间时,橡胶减摆器的高温动态刚度与室温下的比值在0.86~1之间;橡胶减摆器具有较好的高低温动态性能;湿热、霉菌和盐雾试验结果表明,橡胶减摆器的环境适应性优良。     

受压与不受压条件对铁路扣件系统减震垫板的静刚度及动静比的长期影响研究

对比研究了长期室外受压与室内不受压存放条件对60-10-17橡胶垫板、WJ7-B橡胶垫板、WJ8-B弹性垫板静刚度及动静比的影响。结果表明,三种试验垫板在室内存储27个月,其静刚度与动静比均满足铁标要求;在长期室外受压模拟试验中,WJ8-B弹性垫板静刚度保持率良好,60-10-17橡胶垫板与WJ7-B橡胶垫板静刚度在受压两个月后超出标准,三者动静比均满足要求。对于影响弹性垫板老化的关键性因素,需要进一步探讨验证。     

On the potential of organoclay with respect to conventional fillers (carbon black,silica) for epoxidized natural rubber compatibilized natural rubber vulcanizates

Onium modified montmorillonite (organoclay) was compounded with natural rubber (NR) in an internal mixer and cured by using a conventional sulfuric system. Epoxidized natural rubber with 50 mol % epoxidation (ENR 50) in 10 parts per hundred rubber (phr) was used as a compatibilizer in this study. For comparison purposes, two commercial fillers: carbon black (grade N330) and silica (grade vulcasil‐S) were used. Cure characteristics were carried out on a Monsanto MDR2000 Rheometer. Organoclay filled vulcanizate showed the lowest values of torque maximum, torque minimum, scorch, and cure times. The kinetics of cure reaction showed organoclay could behave as a cocuring agent. The mechanical testing of the vulcanizates involved the determination of tensile and tear properties. The improvement of tensile strength, elongation at break, and tear properties in organoclay filled vulcanizate were significantly higher compared to silica and carbon black filled vulcanizates. In terms of reinforcing efficiency (RE), organoclay exhibited the highest stiffness followed by silica and carbon black filled vulcanizates. Scanning electron microscopy revealed that incorporation of various types of fillers has transformed the failure mechanism of the resulting NR vulcanizates compared to the gum vulcanizates. Dynamic mechanical thermal analysis (DMTA) revealed that the stiffness and molecular relaxation of NR vulcanizates are strongly affected by the filler–rubber interactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2438–2445, 2004