中美缺陷汽车轮胎召回分析与对比研究

对历年来中美汽车轮胎产品投诉与缺陷召回数据进行分析。研究表明:中美两国汽车轮胎投诉与召回的品牌、缺陷分布比较接近;而平均每年的轮胎召回次数、召回量及轮胎制造商主动召回率差异较大,美国远高于中国。美国汽车轮胎召回已较成熟,中国汽车轮胎召回尚处于起步阶段,建议中国应尽快完善汽车轮胎召回制度、加强对汽车轮胎召回的宣传教育、完善汽车轮胎行业标准体系等。     

巨型工程机械轮胎热修补胶的研制

介绍巨型工程机械轮胎热修补胶的研制。结果表明,配方为NR100,炭黑N32645,白炭黑10,间接法氧化锌10,粘合剂RE／RH2．5,增粘树脂2．4,松焦油3．5,不溶性硫黄IS-603,促进剂1．6,其它3的热修补胶与胎面粘合性能好、存放时间长、实际使用效果良好,修补轮胎寿命长,在满足使用要求的前提下,与进口热修补胶相比可降低生产成本。     

Effect of ZnO nanoparticles doped graphene on static and dynamic mechanical properties of natural rubber composites

In this work, effect of ZnO nanoparticles doped graphene (Nano-ZnO–GE) on static and dynamic mechanical properties of natural rubber composites were studied. Nano-ZnO–GE was synthesized by sol–gel method and thermal treatment. With the incorporation of nano-ZnO–GE into the matrix, the mechanical properties of NR nanocomposite significantly improved over that of NR composite containing with 5 phr of conventional-ZnO. The results demonstrated that the presence of nano-ZnO on the surface of graphene sheets not only conduces to suppressing aggregation of graphene sheets but also acts as a more efficient cure-activator in vulcanization process, with the formation of excellent crosslinked network at low nano-ZnO–GE content. This work also showed that NR/Nano-ZnO–GE nanocomposites exhibited higher wet grip property and lower rolling resistance compared with NR/Conventional-ZnO composite, which makes nano-ZnO–GE very competitive for the green tire application as a substitute of conventional-ZnO, enlarging versatile practical application to prepare high-performance rubber nanocomposites.     

轮胎侧向刚度试验研究

采用轮胎室内静态刚度测量装置测量轮胎的侧向刚度,考察充气停放时间、滑板运行速度、冠带层帘线材料弹性模量、垂直负荷和充气压力对轮胎静态侧向刚度的影响,并研究静态和动态侧向刚度数据之间的关系,得到轮胎充气停放时间是影响侧向刚度数据重复性的重要因素及冠带层帘线材料弹性模量增大可以有效提高轮胎侧向刚度等结论。     

Design optimization of backup seal for sodium cooled fast breeder reactor

Design optimization of static, fluoroelastomer backup seals for the 500 MWe, Prototype Fast Breeder Reactor (PFBR) is depicted. 14 geometric variations of a solid trapezoidal cross-section were studied by finite element analysis (FEA) to arrive at a design with hollowness and double o-ring contours on the sealing face. The seal design with squeeze of 5 mm assures failsafe operation for at least 10 years under a differential pressure of 25 kPa and ageing influences of fluid (air), temperature (110 °C) and γ radiation (23 mGy/h) in reactor. Hybrid elements of 1 mm length, regular integration, Mooney–Rivlin material model and Poisson’s ratio of 0.493 were used in axisymmetric analysis scheme. Possible effects of reduced fluoroelastomer strength at 110 °C, ageing, friction, tolerances in reactor scale, testing conditions during FEA data generation and batch-to-batch/production variations in seal material were considered to ensure adequate safety margin at the end of design life. The safety margin and numerical prediction accuracy could be improved further by using properties of specimens extracted from seal. The approach is applicable to other low pressure, moderate temperature elastomeric sealing applications of PFBR, mostly operating under maximum strain of 50%.     

考虑高阶剪切的轮胎Gough刚度模型

轮胎是一种帘线增强橡胶复合材料结构,Gough刚度是表征轮胎侧向变形与磨耗的一个重要参数,但缺乏理论推导。本文基于高阶剪切复合材料梁理论,研究子午线轮胎带束层角度对轮胎侧向变形的影响及Gough刚度的理论基础。在Fiala横梁模型的基础上,将轮胎简化为弹性基础上的复合材料梁。胎侧及胎面胶简化为弹性基础,带束和胎体简化为复合材料梁。考虑高阶剪切位移场及帘线-橡胶材料的各向异性,利用虚功原理建立模型方程,得到了复合材料梁在侧向载荷作用下的小挠度理论解,与有限元结果和已有文献结果对比验证了其合理性。算例分析表明,当胎体等效梁结构的高宽比固定时,对应Gough刚度极大值带束角度是固定的;不同的帘线模量和橡胶模量也会对Gough刚度极大值所对应的带束角度产生不同的影响;带束层厚度对Gough刚度极大值对应的带束角度影响较小。根据Gough刚度极大值准则得到了不同高宽比下的轮胎最佳带束角度,利用实际轮胎解剖结构进行了验证。本文提出的模型为子午线轮胎带束角度优选和磨耗设计提供了理论指导。      

19.5L-24 14PR R-4无内胎大型农业轮胎的设计

介绍19.5L-24-14P.R.(R-4)无内胎大型农业轮胎的设计。结构设计：外直径 1300mm,断面宽 500mm,着合直径 612mm,行驶面宽度 440mm,行驶面弧度高 22mm,断面水平轴位置(H1/H2) 0.8495,花纹深度 27mm,花纹周节数 18,花纹饱和度 40%。施工设计：胎体采用6层1870dtex/2尼龙帘线,钢丝圈结构12根×13排×1个,机头直径 800mm,机头宽度 993mm,立式硫化罐水胎硫化。成品试验结果表明,外缘尺寸符合美国TRA标准要求,成品轮胎物理性能符合国家标准要求。     

Effect of ball milling on the structure of Na+-montmorillonite and organo-montmorillonite (Cloisite 30B)

The effect of high energy ball milling under different conditions on the structure of Na⁺-montmorillonite (Na-MMT), and the organo-montmorillonite (Cloisite 30B) was investigated. Ball milling increased the structural disorder: peeling off of layers from the particles was observed, followed by the exfoliation of the particles, indicated by the disappearance of the (001) reflection. X-ray diffraction and infrared spectra revealed that the exfoliated layers did not show deteriorated structures. The presence of the alkylammonium ions seemed to stabilize the structure by reducing exfoliation.     

汽车轮胎的突出质量问题与解决措施建议

以轿车和全钢载重子午线轮胎为例,介绍近年来轮胎使用过程中暴露出的主要质量问题。轮胎突出质量问题包括带束层脱层、胎面/胎侧龟裂、胎圈上方周向裂口、胎圈上方脱层、胎里凹陷和胎侧爆破,缺陷产生的原因包括原材料质量、生产工艺条件控制和操作技术以及轮胎结构设计等方面。对轮胎质量共性问题的解读可为轮胎企业提高轮胎制造水平和产品质量提供参考。     

轿车轮胎的固有频率及振型的研究

用加速度计测量悬置轿胎的固有频率和振型，得知斜交轮胎与子午线轮胎两者的固有频率和振型不相同的。不同气压，不同轮胎规格对其固有频率有影响。经实测证明轿车斜交胎也具有多于两个的固有频率及振型。用实测得到的不与地面接触的轮胎固有频率，可用于计算与地面接触的轮胎固有频率。由于斜交轮胎与子午线轮胎的振动特性及固有频率的不同，子午线轮胎在较低速度下的行驶舒适性不如斜交轮胎，故原为斜交轮胎设计的车辆换装子午线轮