尾桨叶梁成型设备关键技术研究

【作者】 胡鹏；

【导师】 高殿斌；

【作者基本信息】 天津工业大学 ， 机械电子工程， 2008， 硕士

【摘要】 叶梁(树酯基复合材料)热压成型过程中,存在着许多复杂的环节,其中两大关键技术对产品质量造成很大的影响,即温度和压力控制。对它们进行完善的计算机控制和仿真是成型过程安全可靠、产品质量合格的保障。在温度系统中,通过系统需求分析,首先从热学性能、可加工性和机械性能三个方面对热压模具的材料进行了选择,确定热压模具的材料为模具钢(5CrMnMo),然后根据项目需求和现有的技术条件,确定了温控系统的加热/制冷方案。最后根据热压设备几个关键部位处对隔热材料的不同需求,选择了聚四氟乙烯作为隔热材料。同时对温度控制系统的硬件电路进行了设计和配置。利用ANSYS分析了叶梁热压后的温度分布情况,分析结果表明叶梁温差为6.398℃,与实际测量一致,但是距离要求温差在2%以内的要求相差太大。本课题要求温度均匀一致,这样大的温差显然不符合要求。之后对影响热压面温度均匀性的原因进行分析。首先分析了热压模具和周围环境之间的热损失对热压面稳态温度均匀性的影响,给出了在热压头侧面加隔热材料和调节加热功率的解决方案;其次从热压头材料的热扩散率的角度出发,分析了热扩散率对热压面动态温度均匀性的影响,并分别从保持现有热压头结构不变和改变热压头结构两个方面,给出了增大热压模具热扩散率的解决方案。最后采用在叶梁两端温度较低的区域并联两个管排式结构加热器来解决温度分布不均匀的问题。方案选定好后,采用ANSYS软件进行改进实验,有规律的改变管路在模具内的分布进行瞬态温度场分析,得到的分析结果温差为0.187℃,满足温差要求。在压力控制系统的设计上,本课题设计了热压系统的液压回路包括前后回路、出口节流调速回路、主蓄能器回路、增压蓄能器回路和增压控制回路,继而对压力控制系统做了总体设计,采用工控机与可编程控制器(PLC)构成的两级控制模式,负责热压机的动作顺序控制和压力的控制。建立了压力控制系统的数学模型,利用MATLAB的SIMULINK工具箱对其进行了仿真,建模、仿真和分析,得到了系统在常规PID控制器作用下对不同控制信号的响应曲线和特性参数,定量地分析了系统的动态指标。得到了阶跃信号下的响应曲线。在参数为Kp=10,Ki=0.8,Kd=0.3的PID控制下,系统的速度响应能较好地跟随控制信号,建压时间可以满足要求。更多还原

【Abstract】 In molding process of resinous matrix composites by hot-pressing, many complicated physical and chemical changes exist and many intricate factors affect quality of the products. The most important element is temperature and pressure. Computer control system for its formation process is the guarantee of high quality of final products, and it also makes the whole process much reliable.The scheme of system is investigated. According to the diathermancy and the mechanical ability, the material of hot-pressing block is decided. The conduction oil as heat element and the circulating-oil cooling as cooling method are employed in temperature system by comparing several heat/cooling projects. The heat insulation material is selected.Using ANSYS simulate the distribution of temperate. The result shows that the temperature difference is 6.398"C.But the range is out of the demanding. Then I am analysis the impact on the distribution of temperate. First the thermal loss between the mould and surrounding environments is explained and the solution is given. Secondly, considering diffusion rate of material, the analysis of this is given. Finally, parallel two tubes in temperature lower region to solve the temperature distribution non-uniformity problem. The plan is carried on by ANSYS software to improve the temperature non-uniformity problem, through the changing of pipeline and then obtains the result that the temperature difference is 0.187℃, so satisfied the request.Then, the blue print of injection system of pressing, which includes hydraulic circle design, control scheme design, hardware choose, software structure design, is presented. The fact that the injection process is a process with high speed and high pressure requires the control valves and sensors to have rapid response and fine precision, sampling plate to has high Sampling frequency, control software to has better real-time property. In this paper, the principle of injection system of pressing machine based on electro-hydraulic proportional control is introduced in detail. In order to get a in-depth and visual understanding of the performance of real-time controlled injection system, MTALB and its SIMULINK toolbox is used to build model, simulation and analyze for velocity control system and pressure control system of injection process. As result, response curves and dynamic characteristic parameters, which roundly represent the system performance, are obtained under various control signals during common PID control.更多还原