基于专利的中信戴卡与立中集团技术创新研究

我国汽车轮毂产业作为一个发展迅速的汽车零部件产业,专利申请量也迅速上升。选取中信戴卡和立中集团两家汽车轮毂制造企业,从专利申请概况、技术布局、重点专利、创新战略分析、专利价值分析等方面,运用Patsnap专利分析工具和失效模式与影响分析等方法,从专利对比的角度对其进行分析,从中得到技术方向和创新策略,并对两家企业提出一些建议,为我国汽车轮毂产业的创新发展提供参考。     

镁合金汽车轮毂挤压成形工艺研究

通过对镁合金汽车轮毂成形难点的分析,制定出一套合理的成形方案.重点介绍了正挤压工序.通过分析坯料预热、模具预热及挤压速度等对正挤压的影响来合理控制坯料预热温度、模具预热温度、挤压速度以实现镁合金轮毂产品的成形,从而获得力学性能优于铸造成形的汽车轮毂.该工艺的提出为汽车轮毂的发展提供了有价值的参考依据.     

铝合金汽车轮毂淬火过程温度场有限元分析

在对A356铝合金汽车轮毂热处理工艺分析的基础上,采用ANSYS有限元软件对铝合金汽车轮毂淬火过程中温度场及热应力场的分布进行数值模拟与分析。研究表明:在淬火过程中,轮毂在47 s时完全冷却到70℃,与实际较为吻合。轮毂受到的最大热应力为180.507 MPa,小于A356铝合金的强度极限。轮毂在淬火过程中会发生微量的变形,距离轮辐最远处的变形量最大,其值为0.127341 mm,建议在热处理后对汽车轮毂进行精密校核。     

基于Taguchi的轮毂套管热挤压工艺优化

热挤压工艺参数对汽车轮毂套管的锻造性能和服役寿命具有重要的影响.首次采用Taguchi理论对EQ153汽车轮毂套管的热挤压工艺进行最优化处理.以不同工艺下的损伤、应变和应力作为目标值,通过灰关联分析和方差分析得到初锻温度、挤压速度和摩擦系数的最佳水平.优化结果良好,对轮毂套管的热挤压具有指导意义.     

低压铸造铝合金轮毂的研究现状

在轻量化和节能趋势下,铝合金轮毂已成为汽车轮毂的首要选择,其成型的主流方式为低压铸造。简要介绍了低压铸造在铝合金轮毂生产上的应用,重点对低压铸造铝合金轮毂的缺陷进行了综述,分析了模具、风冷和水冷、充型工艺等因素对轮毂缺陷的影响,并提出了今后需要重点研究的方向。     

德国汽车铝轮毂的生产情况

大量使用铝轮毂是汽车工业发展的趋势。如何提高铝轮毂的质量是铝轮毂生产厂家的首要问题，介绍了德国汽车铝轮毂生产情况。     

汽车轮毂铸锻一体化制造工艺

为生产高性能、低成本、重量轻的汽车轮毂,铝合金材料得到广泛应用;为降低部件的重量,结构轻量化技术被普遍应用于产品设计阶段。传统轮毂铸造工艺对零件性能有所提高,但对其内部组织的改善并不明显。铸锻一体化成形工艺则可以减少甚至消除铸造缺陷,提高工件性能,与铸造工艺相比,该工艺成形出的铝合金轮毂性能接近锻造的铝合金轮毂,质量高,重量轻,且比锻造工艺成本低、工艺简单。文章以17in.铝合金汽车轮毂为对象,采用拓扑优化方法对轮毂进行轻量化设计,并采用有限元仿真与实验相结合的方法,对铝合金轮毂的铸锻一体化成形工艺进行深入研究。通过FORGE软件对铝合金汽车轮毂铸锻一体化成形工艺的主要影响因素,即模具温度、活塞压射压力、锻造速度进行有限元仿真,得到不同参数对成形过程的影响规律。     

汽车轮毂曲面的精确重构技术

汽车轮毂因其形状复杂,故正向设计周期较长,且精度不易满足要求.利用逆向工程技术,采用Surfacer软件对汽车轮毂进行曲面精确重构.根据自由曲面的几何特性,对原始点云数据进行合理分块,利用NURBS曲面拟合技术得到轮毂曲面造型,最后对拟合曲面进行了误差分析,结果显示,重构的轮毂曲面符合实际工程要求.     

汽车镁合金轮毂铸造工艺设计与研究

依据汽车镁合金轮毂铸件结构,在分析镁合金工艺特性的基础上,提出采用真空高压铸造技术进行镁合金轮毂的生产工艺,并利用计算机模拟分析方法,设计了汽车镁合金轮毂真空高压铸造工艺,以AM60B镁合金为例,对该铸造工艺进行分析。结果显示,汽车镁合金轮毂真空高压铸造工艺的最佳工艺参数为:浇注温度680℃,模具预热温度250℃,快、慢压射速度分别为0.2、3.0 m/s。     

汽车铝合金轮毂技术与设备引进可行性研究

汽车铝合金轮毂技术与设备引进可行性研究机械部济南铸造锻压机械研究所沈少敏１一个热点─—汽车轮毂上马热全国汽车铝轮毂已形成上马热区不断升温，大有当年冰箱、彩电上马热之势，究其原因如下：（１）铝轮毂明显地优于钢轮毂铝的导热能力是钢的５倍，随着车速不断提高...     

The effect of runout on the milling tool vibration and surface quality

When milling with tools of a high length to diameter ratio, there is often a non negligible runout. Since those tools tend towards chatter because of their low stiffness, the effect of runout on the dynamic behavior of the tool must be considered. Runout adds an additional dynamic component to the tool vibration and thus to the dynamicly changing cutting forces. Furthermore runout affects the surface quality even in stable machining. This paper analyzes the effect of runout by simulation of the dynamic milling process and compares the results to experimental data. One aspect is the difference of the vibration patterns with and without runout. Furthermore, a method for the analysis of timeseries is presented in order to distinguish between chatter and runout. Another topic is the expected surface quality resulting from stable processes with runout. This surface is modeled, examined and compared to the one produced by a process without runout.     

2024铝合金搅拌摩擦连接作用力幅值及周期性

利用八角环测力仪和高速摄像对2024铝合金搅拌摩擦连接过程作用力和搅拌头轴肩径向跳动量进行测量研究.结果表明,作用力具有周期振动的特性,通过试验证明了周期大小只与旋转速度有关,且为旋转速度的倒数.分析了作用力周期性振动的主要原因是连接过程中主轴的径向跳动和金属材料的流动,通过研究作用力幅值和搅拌头径向跳动量的关系,表明作用力幅值随搅拌头径向跳动量线性增加,搅拌头径向跳动是作用力产生周期振动的主因,同时,在搅拌头径向跳动量及其它工艺相同的情况下,作用力振幅会随着连接速度的增大而增大.     

Efficient calibration of instantaneous cutting force coefficients and runout parameters for general end mills

This paper aims at developing a unified approach to identify the cutting force coefficients together with the cutter runout parameters for general end mills such as cylindrical, ball, bull nose ones, etc. The cutting forces that are modeled using the instantaneous cutting force coefficients are analyzed and separated into two terms: a nominal component independent of the runout and a perturbation component induced by the runout. The nominal component enables the calibration of the instantaneous cutting force coefficients whereas the runout parameters are determined from the perturbation component. The validity of the present method is demonstrated with simulation and experimented data.     

Runout effects in milling: Surface finish, surface location error, and stability

This paper investigates the effect of milling cutter teeth runout on surface topography, surface location error, and stability in end milling. Runout remains an important issue in machining because commercially-available cutter bodies often exhibit significant variation in the teeth/insert radial locations; therefore, the chip load on the individual cutting teeth varies periodically. This varying chip load influences the machining process and can lead to premature failure of the cutting edges. The effect of runout on cutting force and surface finish for proportional and non-proportional tooth spacing is isolated here by completing experiments on a precision milling machine with 0.1 μm positioning repeatability and 0.02 μm spindle error motion. Experimental tests are completed with different amounts of radial runout and the results are compared with a comprehensive time-domain simulation. After verification, the simulation is used to explore the relationships between runout, surface finish, stability, and surface location error. A new instability that occurs when harmonics of the runout frequency coincide with the dominant system natural frequency is identified.     

New procedures for calibration of instantaneous cutting force coefficients and cutter runout parameters in peripheral milling

In this paper, new procedures are proposed to calibrate the instantaneous cutting force coefficients and the cutter runout parameters for peripheral milling. By combining with optimization algorithm, i.e., the Nelder–Mead simplex method, detailed calibration schemes are derived for a mechanistic cutting force model in which the cutting force coefficients are described as the exponential functions of the instantaneous uncut chip thickness. Three different cutter runout models are considered in the calculation of instantaneous uncut chip thickness. Only one or two tests are required to perform the calibration. Experimental verifications are also conducted to validate the proposed procedures, and the results show that they are efficient and reliable. To see the effect of different runout models on milling process, comparisons among the predicted results under a wide range of cutting parameters are made to study the consistency and limitations of different models. It is found that the radial cutter runout model is a recommendable one for cutting force modelling.     

Numerical simulation and prediction of cutting forces in five-axis milling processes with cutter run-out

Radial cutter runout is a common issue in milling processes and has a direct effect on milling stability due to variations of resulting chip load and forces. This paper presents a new method to effectively model and predict the instantaneous cutting forces in 5-axis milling processes with radial cutter runout based on tool motion analysis. First, the undeformed chip thickness model taking runout effect into account is established under continuous change of cutter axis orientation by means of the sweep traces of cutter edges. Second, the engaged cutting edge is determined and cutting coefficients are subsequently calibrated. Finally, the method of identifying runout parameters from the measured cutting forces is proposed, and mechanistic method is then applied to predict the cutting force. Since this method is completely based on the relative motion analysis of tool-part, it can reduce the prediction errors of cutting forces effectively and is suitable for generic rotation cutters. Several validation examples are given under different cutting conditions to prove its effectiveness and accuracy. The results reveal that the developed method can predict the cutter forces with a high accuracy and has the ability to be used in simulations and optimizations of five-axis machining.     

Dynamic analysis of runout correction in milling

Tool runout and its effects is an important area of research within modelling, simulation, and control of milling forces. Tool runout causes tool cutting edges to experience uneven forces during milling. This fact also affects tool life and deteriorates workpiece surface quality. In this article a procedure, in order to diminish the effects of tool runout, is presented. The procedure is based on chip thickness modification by means of the fast correction of the tool feed rate. Dynamic feed rate modification is provided by superposing our own design of a fast feed system driven by a piezoelectric actuator to the conventional feed drive of the CNC machine tool. Previously, a model of the dynamic behaviour of the system was developed to analyze the influence of fast feed rate modification on cutting forces. The model incorporates the piezoelectric actuator response as well as the structural dynamics of the tool and the designed Fast Feed Drive System (FFDS). Simulated and experimental results presented in this paper show the effectiveness and benefits of this new tool runout correction procedure.     

Process geometry modeling with cutter runout for milling of curved surfaces

Prediction of cutting forces and machined surface error in peripheral milling of curved geometries is non-trivial due to varying workpiece curvature along tool path. The complexity in this case, arises due to continuously changing process geometry as workpiece curvature varies along tool path. In the presence of cutter runout, the situation is further complicated owing to changing radii of cutting points. The present work attempts to model process geometry in machining of curved geometries and in the presence of cutter runout. A mathematical model computing process geometry parameters which include cutter/workpiece engagements and instantaneous uncut chip thickness in the presence of cutter runout is presented. The developed model is more realistic as it accounts for interaction of cutting tooth trajectory with that of preceding teeth trajectories in computing process geometry. Computer simulation studies carried for this purpose has shown that it is essential to account for teeth trajectory interactions for accurate prediction of process geometry parameters. This aspect is further confirmed with machining experiments, which were conducted to validate this aspect. From the outcomes of present work, it is clearly seen that the computation of process geometry during machining of curved geometries and in presence of cutter runout is not straightforward and requires a systematic approach as presented in this paper.     

跳动公差与其它形位公差的关系研究

跳动公差是所有公差项目中应用最为灵活的一种，在设计使用过程中容易出现标注不当或重复标注现象。为此，本文在明确各种跳动公差基本概念的基础上，重点论述跳动公差与其它形位公差的关系及其取代应用，为避免上述错误标注现象提供理论依据。     

前轮毂压铸模具跑水的处理

以前轮毂压铸模具跑水导致的滑块卡死、斜导柱弯曲为例，通过对模具2次修改的过程表明，对于采用常规方式不能解决的模具问题，就要对模具的相关问题部位采用逐件分解、逐个确认的方法，去寻找问题产生的原因，针对原因采取适当的措施，才能从根本上解决模具的跑水。