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汽车行业中,钢丝圈的作用是赋予胎圈必要的强度和刚性,使轮胎牢牢固着于轮辋上,其质量直接影响轮胎的使用寿命及汽车的安全。本文主要介绍了基于单片机的钢丝圈内周长测长仪的机械结构、测量原理及电控单元的硬件和软件系统,其测量精度可达到±0.1mm,且稳定可靠。 相似文献
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The cause of the ICE train derailment, which occurred in 1998 at Eschede, was fatigue failure originating on the inside of the wheel tire. Rubber-sprung resilient wheels were used for the trailer cars. The wheel tire is mounted on the wheel disc. Thirty-four rubber pads were arranged between the wheel disc and the wheel tire. It was postulated that fretting fatigue between the rubber block and the inner side of the tire might have an influence on the initiation of the incipient crack. In order to clarify the influence of the rubber contact on the fatigue strength of the tire, fretting fatigue experiments under rubber contact conditions were performed. During the fundamental fretting fatigue test using bridge pads and small size carbon steel specimens, no typical fretting damage such as fretting wear and minute cracks were observed due to contact of the rubber. Stress conditions of the rubber-sprung wheel under vertical and lateral wheel loads were evaluated by a three-dimensional elastic stress analysis. Since the rubber is a super-elastic material, the Mooney-Rivlin model was used in the FEM calculation. It was found that the wheel tire is subjected to a cyclic stress during one revolution of the wheel and the maximum stress occurred at the center of the inner surface of the tire where the fatigue crack initiated. Fatigue strength of the wheel tire was determined by the rotating bending fatigue testing of specimens taken from the tire. It was found that the tire with an 862 mm diameter at a wheel load of 80 kN had a safety factor more than 3.5 from a fatigue limit diagram with a failure probability of 0.01. To confirm the fretting damage under the rubber contact and the result of the fatigue strength evaluation, fatigue tests of a full size wheel were made. After 20 million cycles at the wheel load of 280 kN, which was just below the endurance limit estimated by the endurance limit diagram, no fretting damage and no fatigue cracks were observed. The wheel was, however, fractured at 1.56 million cycles under the maximum load of 308 kN, which was just above the endurance limit. The estimation of the safety factor of 3.5 estimated from the endurance diagram was confirmed by the full size fatigue testing. It was concluded that there was no effect of fretting due to the rubber contact on the fatigue strength of the rubber-sprung single-ring railway wheel. 相似文献
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This new utility model relates to a vehicle tire, especially to the multi-cavity tire which the inside of tire is divided into many cavities. The feature of this new utility model is that, several interlayers are provided in the direction of the tire's circumferential cross section, which divides the tire into many cavibies. The center of the tire cavity is provided with the ring-like rubber pipe, which passed through each interlayer of the cavity. There is an air hole on the rubber pipe. If this tire is punctured during the vehicle runing, the air is leaked from the fracted cavity, but the air in other cavities would flow out through the hole on the rubber pipe, so the flpw is very slow, therefore it can play the cushion role, and it also can reduce the burst power, because the air in each small cavity is little. 相似文献
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铝合金车轮13°冲击试验仿真分析 总被引:5,自引:0,他引:5
为了减少铝合金车轮性能检测的试验次数以提高车轮的设计研发效率,建立铝合金车轮13°冲击试验的数值模型进行仿真试验非常必要。在充分考虑冲击试验台静态与动态效果的基础上,建立包括冲头、车轮总成和试验台架的铝合金车轮冲击试验有限元模型,其中试验台架上的橡胶支座采用弹簧—阻尼单元进行模拟,且将轮胎安装所产生的车轮预应力作为初始条件,使用非线性有限元动力分析软件LS-DYNA对铝合金车轮冲击过程进行仿真分析。通过对车轮上若干测量点应变值的有限元仿真结果与试验结果的比较,确认与铝合金车轮实际台架试验相等效的计算机模拟试验平台的有效性。该计算机模拟试验平台的建立对铝合金车轮的前期设计开发具有重要的指导意义及应用价值。 相似文献
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轮胎稳态侧倾力学特性理论建模 总被引:6,自引:3,他引:3
研究了轮胎侧倾建模机理,并在此基础上导出了轮稳仿而倾的侧向力、回正力矩、纵向阻力和翻转力矩特性表达式。讨论了车轮定位时侧倾角与前束角的关系,引入了有效侧倾角概念,并基于此给出了子午线轮胎比斜交轮胎侧倾侧向力小的理解解释。 相似文献
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Monitoring tire pressure of cars and signaling abnormal conditions is an important means to prevent deadly accidents. Large achievements have been gained, especially in direct tire pressure monitoring system(TPMS). But there has been rarely research on indirect TPMS in the world. In China, the research on indirect TPMS is almost lacking. The international research on the indirect monitoring tire pressure method is mainly based on measuring and comparing the rotating speed of wheels. But it is very difficult to measure wheel rotating speed accurately because of the influence of many random factors. In this paper, the authors propose a new method in which the tire pressure can be monitored indirectly. This method can be used for tire calibration, wheel speed frequency standardization, wheel speed frequency comparison, and abnormal tire pressure determination. The pulse frequencies from wheel speed sensors of ABS are used to indicate tire deformation. Because the frequency has a relationship with tire deformation, the tire deformation reflects the tire pressure. Small sample statistics is used in the new method to increase the accuracy, and the experimental samples using the principle of the new method have been made and tested. The result of vehicle tests on road demonstrates that the method is efficient and accurate to monitor tire pressure. The research has positive potential for developing products. 相似文献
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Xiaohui Shen Jun Yan Tao An Zhangze Xu Jing Zhang 《The International Journal of Advanced Manufacturing Technology》2014,72(1-4):179-191
Rolling is one of the key stages of railway wheel hot forming process. In this work, a three-dimensional finite element analysis on wheel vertical rolling process based on some strategies proposed has been carried out by using FE code SuperForm. In modeling, a virtual mandrel is exploited in the hub hole to keep the wheel central instead of the guide rolls and centering rolls. Some features of the wheel forming are deeply investigated such as the rim diameter expanding, the rim lateral spreading, the metal flow in the circumferential direction, and the stresses distribution. The results show that (1) the rim radius expanding mainly occurs in the two affected zones before and after the back roll deformation zone; (2) the rim metal has flow trend in the circumferential direction during rolling, the metal of the intersection area, between the tread and the rim external side surface has the largest relative angular displacement; and (3) the tensile stresses of the web both in radial and circumferential directions during rolling result in the web thickness decreasing by about 3 mm for the investigated wheel. The simulations results reveal the forming mechanisms of wheel rolling, laying the basis for designing and optimizing railway wheel forming process. 相似文献
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高锰钢前导轮内腔结构复杂,需要合理的铸造工艺以避免填内部产生铸造缺陷。为此,采用商业软件ProCAST对导轮轴孔处设一个明冒口的单冒口工艺(SR)和两个明冒口的双冒口艺艺(DR)进行缺陷预测、计算发现,单冒口工艺(SR)的缺陷形成倾向低于双冒口的工艺(DR)。进而,通过调整单冒口工艺(SR)的冷铁形状、位置及增大轮缘处暗冒口体积.提出优化工艺M1;在M1基础上,通过减小轴孔处明冒口体积,并加大该处冒口保温砖厚度,提出优化工艺M2,模拟计算表明,采用M1和M2工艺均可消除导轮轮缘处的缩孔缩松缺陷;以M2的热裂倾向最小,热裂纹主要出现在前导轮内腔垂直拐角处和轴孔附近。 相似文献
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汽车轮力传感器串接在轮胎轮辋和车桥轮毂之间,用于在汽车实车道路试验和室内台架试验时测量由地面或激振器作用于轮胎的六分力。轮力传感器研制的关键技术包括可靠且准确的信号和能量传输、信号的解耦、强度和结构安装要求等。详细介绍了轮力传感器的研究进展、设计原理、性能评价和误差分析等,最后对其在汽车道路试验中的具体应用做了介绍。 相似文献
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Experimental results are presented for the effects of coil diameter, system pressure and mass flux on dryout pattern of two-phase
flow in helically coiled tubes. Two tubes with coil diameters of 215 and 485 mm are used in the present study. Inlet system
pressures range from 0.3 to 0.7 MPa, mass flux from 300 to 500 kg/m2s, and heat flux from 36 to 80 kW/m2. A partial dryout
region exists because of the geometrical characteristics of the helically coiled tube. The length of the partial dryout region
increases with coil diameter and system pressure. On the other hand, it decreases with increasing mass flux. The critical
quality at the tube top side increases with mass flux, but decreases with increasing system pressure. This tendency is more
notable when the coil diameter is larger. When the centrifugal force effect becomes stronger, dryout starts at the top and
bottom sides of the tube. However, when the gravity effect becomes stronger, dryout is delayed at the tube bottom side. In
some cases when the mass flux is low, dryout occurs earlier at the outer side than at the inner side of the tube because of
film inversion. 相似文献
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This new utility model is related to a modified tire bead building structure which mainly consists of a major body and a few pieces of components to form the tire bead. The outside of the main body is an combined open space. The two side walls and the bottom of the combined space forms a straight angle or an obtuse angle, so it facilitates for mold stripping after the main body is formed. The assembly is curving and a complete circle can be formed by several assemblies. The outside of the assembly is corresponding to the combined space and its inner side is formed a channel. A few curving assemblies could be applied to the combined space of the main body to form acomplete tire bead body. After assembly, the bead could be put into the tire body from this channel. 相似文献
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Hyae Kyung Yi Eun-Hwa Kim Sung-Pil Park Chester J. Van Tyne Young-Hoon Moon 《Journal of Mechanical Science and Technology》2013,27(5):1279-1285
The thermal expansion of pipes depends on both the temperature of the pipe and the expansion coefficient of the piping material at the operating temperature. In the case of a double-layered tube consisting of two different tube materials, the thermal deformation behaviors are dependent on the relative tube sizes, thermal expansion coefficients, and the mechanical properties of the inner and outer tubes. For the safe and reliable application of double-layered tubes that are fabricated by hydroforming, the thermal stress in circumferential direction and the gap between the inner and outer tubes need to be analyzed over a wide range of temperatures (?50°C~200°C). As it is difficult to measure the thermal stress and the gap between tubes at operating temperature, this study has analytically investigated the thermal deformation behavior of a double-layered tube. From the analytical model, the effect of hydraulic pressure, residual stress, and the relative sizes of the inner and outer tubes on the resultant thermal deformation, such as the circumferential thermal stress and the gap between inner and outer tubes, has been analyzed. The analytical results provide a theoretical basis for determining the reliable operating temperature of double-layered tubes. 相似文献
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Tanit Tangsri Somchai Norasethasopon Kazunari Yoshida 《The International Journal of Advanced Manufacturing Technology》2014,70(9-12):1923-1930
This paper is concerned with the development of ultra-small inner spiral ribbed copper tubes with high-quality heat transfer. Since the demand for the ultra-small tubes in electrical appliances is currently high and will be greater in the future, the technology employed must enable the production of inner spiral ribbed fine tubes with various features, such as small size, high quality, high functionality, and low processing cost so as to meet the increasing demand. The conventional production method is suitable for large tubes with high drawability but is unsuitable for fabrication of long ultra-small tubes because of the difficulty to manufacture both an ultra-small spiral ribbed mandrel and a floating plug. This research paper has proposed four drawing methods as follows: tube sinking, water, oil, and wax as mandrels and presented the comparison of seven parameters, i.e., drawing stress ratio, wall thickness ratio, ribbed base width ratio, ribbed tip width ratio, ribbed height ratio, ribbed pitch ratio, and ribbed spiral angle ratio. It was found that tube sinking was unfit for making the ultra-small inner spiral ribbed copper tubes due to the resulting high ratio of wall thickness. The results of all the parameters were similar in the cases of oil and wax. Despite less impressive outcomes, water was easily removed from the inner spiral ribbed copper tube compared to oil and wax. Thus, the tube drawing using water as mandrel was most suitable for the production of the inner spiral ribbed copper tube. 相似文献