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带轮旋压成形原理及工艺分析 总被引:1,自引:0,他引:1
通过对钣制皮带轮旋压成形过程的运动及应力应变分析,指出预成形槽的形状,顶压座的轴向送进速度及旋轮的径向进给速度等是带轮正确成形的主要影响因素。 相似文献
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快速成形的成形精度和速度往往是一对矛盾体 ,自适应分层方法是解决这一矛盾很好的方法之一。本文通过分析和比较切片轮廓信息 ,提出了一种简单而实用的适用于STL及PIC文件格式的自适应分层方法 ,并介绍了该自适应分层的算法。该方法在保证制件成形精度的前提下能极大地提高制件的成形速度 相似文献
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回弹和变形是影响高强度装载机覆盖件冲压成形形状精度的主要因素,通过22MnB5合金板热冲压成形实验,考察了热冲压成形的传热特征,推导出的热冲压成形传热数学模型的基本方程,提出热冲压成形模具冷却系统设计相关技术问题.研究表明,当冷却速度达到或超过临界冷却速度,才能使奥氏体直接转变为均匀马氏体;在模具结构、冷却系统、冷却介质等因素确定的情况下,冷却速度只与板材自身条件有关,可以通过控制最佳水流速度实现对最佳冷却速度的控制,达到减少和消除热冲压成形中变形和回弹等缺陷,提高装载机覆盖件热冲压成形质量. 相似文献
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《机械设计与制造》2016,(8)
金属件熔融堆积3D打印过程中,制件的层间结合性能主要取决于热作用过程,因此对成形过程温度变化进行研究显得尤为重要。该研究基于熔融堆积3D打印成形特点,建立了成形过程有限元分析数学及物理模型,并使用ANSYS有限元软件对不同熔融金属温度、基板温度及堆积速度条件下成形过程温度场变化进行模拟研究。结合相同参数条件下的对比工艺试验,研究了这些参数对最终成形金属实体层间结合性能的影响。研究结果表明:随着熔融金属温度、基板温度的升高,以及堆积速度的增加,成形实体温度上升速度加快,高温热影响区增大,温度梯度减小,实体层间结合及拉伸性能提高,并在熔融金属温度160℃,基板温度90℃,堆积速度16mm/s参数条件下打印出了层间结合良好的铋锡合金实体。 相似文献
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AZ31B镁合金板材旋压成形工艺研究 总被引:1,自引:0,他引:1
采用摩擦旋压成形工艺,研究了AZ31B挤压板材供应态试样在不预热的条件下直接进行旋压成形的可行性。结果表明,摩擦升温效应能迅速将坯料温度提高到200~450℃,从而提高镁合金板料的塑性变形能力,可旋压成形出最小直径为31.5mm、高度为9.22mm的镁合金碟形件。实验发现旋压成形的旋轮轴向进给量、旋轮运动轨迹、坯料旋转速度和润滑剂等对镁合金板材的旋压成形有较大的影响。当旋轮采用梳形运动轨迹、轴向进给量为0.22mm、坯料转速ω=900r/min时,采用MoS2钙基脂润滑,可获得较好的旋压成形效果。 相似文献
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本文研究金属带无级变速器带-带轮的机械损失。根据功率流观点把全部功率损失归因于转矩损失,开发了一个耦合图模型。由实验求得功率损失模型系数。由仿真和实验可以看到,稳态带-带轮损失取决于管压,输入转矩和转速。而瞬态损失则取决于转速,换档速度和惯性矩。 相似文献
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Q. X. Xia Z. Y. Lai Hui Long X. Q. Cheng 《The International Journal of Advanced Manufacturing Technology》2013,68(9-12):2461-2470
The noncircular spinning is one of the recent breakthroughs of the traditional spinning processes. The spinning force is one of the important parameters for designing the spinning equipment and one of the main factors influencing the forming quality of spun parts. The variation of spinning force during noncircular spinning is considerably different from that of the conventional spinning due to the high-speed reciprocating movement of the roller induced by the variable spun workpiece profile. This paper presents an experimental investigation of spinning force characteristics of a hollow part with triangular cross sections using an octagon ring transducer based on electrical measuring method. A series of experiments using profiling driving spinning method was carried out to study the effects of the main process parameters, such as the roller feed rate, blank thickness–diameter ratio, and mandrel rotational speed, on the spinning force characteristics. The important characteristics of the force components of noncircular spinning were discussed based on the electrical measuring results. Furthermore, the variations of force components were compared with those obtained in the cases of conventional spinning and 3D non-axisymmetrical spinning. The results show that different from the conventional spinning and similar to the 3D non-axisymmetrical spinning, the three components of spinning force along the axial, radial, and tangential direction of roller vary periodically with the mandrel rotational angle. Different from the conventional and the 3D non-axisymmetrical spinning, the maximum spinning force is related to the mandrel rotational speed, even if the feed rate of roller remains constant, and increases with the increase of the mandrel rotational speed. 相似文献
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The problem of controlling the load speed of a mechanical transmission system consisting of a belt-pulley and gear-pair is considered. The system is modeled as two inertia (motor and load) connected by a compliant transmission. If the transmission is assumed to be rigid, then using either the motor or load speed feedback provides the same result. However, with transmission compliance, due to belts or long shafts, the stability characteristics and performance of the closed-loop system are quite different when either motor or load speed feedback is employed. We investigate motor and load speed feedback schemes by utilizing the singular perturbation method. We propose and discuss a control scheme that utilizes both motor and load speed feedback, and design an adaptive feedforward action to reject load torque disturbances. The control algorithms are implemented on an experimental platform that is typically used in roll-to-roll manufacturing and results are shown and discussed. 相似文献
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《Measurement》2014
Due to unpredictable noises, there are plenty of health problems on human. This paper is focused on neural networks (NNs) based prediction analyzer for two types drive schemes of washing machines that are direct drive and belt-pulley drive, for vibration and fault diagnosis of motors bearings. Furthermore, eight different cases including, during washing with direct drive and belt-pulley, squeezing during washing with direct drive and belt-pulley for noises and acceleration of the washing machines systems are investigated using the proposed algorithm of NNs. An Intelligent Data Acquisition (IDA), a microphone and PC are used to measure the system noise. For the case of different working conditions of the system, three types of NN are used to investigate the noise levels. The results show that NN with quick propagation algorithm gives superior performance for predicting and evaluating the noise of washing machine systems. 相似文献
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等离子弧焊直接金属成形技术的工艺研究 总被引:4,自引:0,他引:4
提出了一种基于等离子弧焊的直接金属成形新方法,通过对成形工艺的试验研究,确定了焊接电流、成形速度与成形轨迹宽度之间的对应关系;针对成形轮廓的表面质量问题,实施了根据轮廓矢量进行切向送丝的填充方案;并采用循环水冷的温控措施解决了成形过程的过热问题。 相似文献