子午线轮胎活络模花纹块精铸模具型腔曲面构造

采用加权曲面参数方程拟合型腔侧壁曲面的算法,实现了子午线轮胎活络模模具型腔曲面的构造。研究了从轮胎平面图提取出花纹块模具轮廓的方法及模具型腔的设计和调整方法。根据花纹平面轮廓沿周向和轴向投影时展开长度不变的原理,计算得到了弯曲后的胎顶和胎底花纹轮廓。根据精度要求,通过将胎顶、胎底轮廓和花纹沟槽侧壁斜截线离散为若干点,并应用加权BSC曲面拟合算法,构造出了型腔侧面参数方程。造型过程和试验结果表明,该曲面拟合算法可以控制加工精度,适用于构造和加工花纹型曲面。     

基于灵敏度方法的白车身扭转刚度提升研究

白车身扭转刚度是车身性能非常重要的指标之一,对整车的耐久性,舒适性和操稳性有着直接的影响。一般情况下,白车身扭转刚度与车身结构、型腔断面和材料厚度有着直接关系。文章在某车型车身结构和型腔断面受限的情况下,采用重量灵敏度分析的方法提升白车身扭转刚度,总结出两条重量灵敏度随零件料厚变化的规律,研究了如何合理分配料厚来提升白车身扭转刚度。     

康明斯曲轴锻模型腔电火花加工工艺

在电火花成形机床上采用电火加工工艺，加工康明斯曲轴锻模型腔，大幅度地提高了型腔的加工精度和生产能力。     

基于ProCAST低压铸造汽车车轮模具型腔有限元分析

通过实例论述了运用ProCAST软件分析低压铸造铝合金车轮模具设计过程中模具的型腔尺寸对铸造件凝固的影响,从而为获得高品质的铸件提供了保证。     

DB76A压铸模修复及表面强化

本文主要对引进的压铸模具，经使用产生型腔的磨损及蚀坑后，如何对模具进行维护，修补，使其延长寿命，进行了介绍。     

巧辨气缸盖气道容积

在四冲程发动机上，气缸盖上布置有进气道和称为排气道的废气通道，并分别设有进气门和排气门。气缸盖系铝合金低压铸造，其进、排气道的凸型模定型后，除非凸型腔磨损，进、排气道的内腔基本不会改变。而市场上伪劣气缸盖的进、排气道内腔偏小，且型腔内表面非常粗糙，使进、排气的气流不顺畅，甚至形成阻力，影响发动机功率的正常发挥，该如何有效鉴别呢？笔者经过多年的实践和经验积累，摸索到一个切实可行又简便的辨别方法，供大家参考。     

NH缸体毛坯渗漏的改进

ＮＨ缸体毛坯前端水泵凹入处因气孔造成的渗漏一度成为工厂的重大质量隐患者从加大型腔排气及严格操作着手，并应用铸造理论重新设计浇注系统，从而从根本上解决了缸体渗漏问题。     

汽车用塑料件及模具开发新技术

综述了汽车塑料件近年来的应用状况，介绍了CAD／CAE／CAM，激光快速成型，激光测量及模量型腔数控加工等几种用于高效开发汽车塑料件的新技术，并指出了今后的发展趋势及采取的措施。     

满足现在和未来要求的机体曲轴箱轻型结构

KS铝合金技术有限公司年产百万台铝合金机体曲轴箱,其中柴油机占有很高的份额,同时铸造工艺的革新引起了普遍的重视.模块化压铸工艺应对发动机小型化的挑战,型腔翻转重力浇铸工艺满足了柴油机对铝合金机体曲轴箱最高强度的要求,PTWA公司的工艺技术提高了气缸工作表面的工作能力.     

转向拉杆球头销一次冷挤成型

阐述了CA141载货汽车转向拉杆环头销挤压工艺与模具结构。这种球头销采用一冷挤成型工艺，上模采用浮动式的套料结构，增加了毛坯在模具型腔中的稳定状态，得到了上球头与林部的最佳同轴度，解决了现生产中的偏头问题，伺时减少了工序，节约了材料，提高了刀具耐用度和产品质量。     

The bricycle: a bicycle in zero gravity can be balanced or steered but not both

A bicycle or inverted pendulum can be balanced, that is kept nearly upright, by accelerating the base. This balance is achieved by steering on a bicycle. Simultaneously one can also control the lateral position of the base: changing of the track line of a bike or the position of hand under a balanced stick. We show here with theory and experiment that if the balance problem is removed, by making the system neutrally stable for balance, one cannot simultaneously maintain balance and control the position of the base. We made a bricycle, essentially a bicycle with springy training wheels. The stiffness of the training wheel suspension can be varied from near infinite, making the bricycle into a tricycle, to zero, making it effectively a bicycle. The springy training wheels effectively reduce or even negate gravity, at least for balance purposes. One might expect a smooth transition from tricycle to bicycle as the stiffness is varied, in terms of handling, balance and feel. Not so. At an intermediate stiffness, when gravity is effectively zeroed, riders can balance easily but no longer turn. Small turns cause an intolerable leaning. Thus there is a qualitative difference between bicycles and tricycles, a difference that cannot be met halfway.     

汽车排气催化转化装置气流特性分析

运用计算流体动力学对汽车排气污染物控制装置———催化转换器进行了研究。通过对 4种不同引流区结构的速度场、压力场的计算 ,证明引流区的结构对催化转化装置的气流分布影响很大 ,应尽量避免采用直壁无引流过渡的结构 ,采用平滑过渡的引流区 ,不仅可减少涡流损失 ,而且压力损失大大小于其它结构。对实际汽车用催化转化器在不同排气流量下的速度场和压力损失进行了计算和对比。采用Ansys/FlotranCFD计算流体动力学软件 ,其计算结果与试验结果吻合较好 ,证明采用的方法是可靠的。     

Roll stabilisation of road vehicles using a variable stiffness suspension system

A variable stiffness architecture is used in the suspension system to counteract the body roll moment, thereby enhancing the roll stability of the vehicle. The variation of stiffness concept uses the ‘reciprocal actuation’ to effectively transfer energy between a vertical traditional strut and a horizontal oscillating control mass, thereby improving the energy dissipation of the overall suspension. The lateral dynamics of the system is developed using a bicycle model. The accompanying roll dynamics are also developed and validated using experimental data. The positions of the left and right control masses are sequentially allocated to reduce the effective body roll and roll rate. Simulation results show that the resulting variable stiffness suspension system has more than 50% improvement in roll response over the traditional constant stiffness counterparts. The simulation scenarios examined is the fishhook manoeuvre.     

汽车转弯制动性能的模拟计算

本文是一篇研究汽车转弯制动性能模拟计算方法的专题论文。首先建立了11自由度的汽车动力学模型,模拟转弯制动开环试验方法,建立了非线性微分方程组,其初始条件通过计算汽车作圆周运动时的稳态转向特性求出。文中详细地介绍了各有关参量的计算方法,然后用四阶龙格-库塔法求出微分方程组的数值解,因此能够详尽地描述和研究各重要参数的变化情况及其对转弯制动性能的影响。最后给出四个典型算例,用以说明计算的可信程度。     

山区高速公路爬坡路段车辙变形的有限元分析

针对坡面的荷载特性和路面的结构组合，采用3种典型车型和3种典型路面结构对路面响应应力与蠕变变形进行了三维有限元分析，研究结果表明，坡面荷载合力明显高于常规平直路段荷载；荷载接地压力的非均布效应非常显著；坡面上发生车辙变形的可能性比常规平直路段高25％以上，需要单独设计以防止车辙的发生。     

A model of driver steering control incorporating the driver's sensing of steering torque

Steering feel, or steering torque feedback, is widely regarded as an important aspect of the handling quality of a vehicle. Despite this, there is little theoretical understanding of its role. This paper describes an initial attempt to model the role of steering torque feedback arising from lateral tyre forces. The path-following control of a nonlinear vehicle model is implemented using a time-varying model predictive controller. A series of Kalman filters are used to represent the driver's ability to generate estimates of the system states from noisy sensory measurements, including the steering torque. It is found that under constant road friction conditions, the steering torque feedback reduces path-following errors provided the friction is sufficiently high to prevent frequent saturation of the tyres. When the driver model is extended to allow identification of, and adaptation to, a varying friction condition, it is found that the steering torque assists in the accurate identification of the friction condition. The simulation results give insight into the role of steering torque feedback arising from lateral tyre forces. The paper concludes with recommendations for further work.     

拥塞控制算法三例

拥塞是由通信量和资源之间的矛盾引起的，在象因特网这样的大型互联网络中，通信高峰时，容易出现拥塞。因为拥塞具有恶性循环的特点，因此避免拥塞一直是学者和工程技术人员探讨的问题。文章从理论上提出了三种简单易行的拥塞控制算法，其算法中所体现的思路可借鉴。     

汽车覆盖件冲压成型过程中常见的缺陷分析

本文主要介绍了汽车覆盖件的关键加工技术——板料冲压成型,说明了其重要地位,详细地叙述了钣金冲压过程中出现缺陷的原因及影响因素,并通过某型号汽车的发动机蜗壳进行参数模拟分析,使之更直观的了解各因素对冲压成型的影响,最后提出了一些解决冲压成型缺陷的意见、方法。     

浮动式汽车离合器助力装置及其设计

汽车离合器踏板沉重是目前国产汽车普遍存在的问题之一。文中介绍了一种浮动式离合器助力装置,它不仅结构简单、助力效果好,其助力效果可达５０%以上,而且无论采用何种踏板布置形式,这种结构在整车上布置都很容易实现。提出了离合器助力装置的匹配设计原则和可行性方案设计。     

汽车车架中的铆钉结构应力分析研究

针对某汽车在行驶过程中铆钉脱落的现象,基于有限元分析技术,对其车架连接铆钉的应力进行深入研究。先建立整个车架的有限元模型,以梁单元离散铆钉,作线性静态计算,得到代表铆钉的梁单元的应力情况;然后再通过子模型的方式建立铆钉的接触模型,进行非线性求解,得到更加详细的铆钉应力情况。通过对比线性与非线性两次分析中铆钉的应力,得到两种分析铆钉应力的对应关系,为汽车车架整体分析中估计连接铆钉的应力提供参考。