摘要在难加工材料的加工过程中,由于所消耗的能量大部分以热能的形式积聚在加工区,若不能及时将这些热量疏导出去,将导致加工区温度的急剧升高,对工具和零件具有很大的影响。
本文完成了低温喷雾射流冷却条件下的钛合金的磨削温度场仿真。通过对不同冷却方式下的加工效果对比研究发现,低温喷雾射流冷却具有更强的换热能力,可以更有效地降低切削区温度。研究主要步骤如下:首先确定了平面磨削时的热源形式,介绍了有限元法在热分析中应用的理论基础,对有限元分析软件ANSYS的热分析功能及分析的主要步骤作了简要说明,为后期工作做好准备;然后运用ANSYS有限元分析软件建立了平面磨削区温度场的几何模型、划分网络、定义边界条件,运用ANSYS软件的参数化设计语言实现了热源的移动。通过仿真分析,得出了在不同换热系数下工件表面温度场的分布状况,以及不同换热系数对磨削区温度场的影响作用。 49057
总之,低温喷雾射流具有较强的换热优势,可获得更好的加工效果,这进一步确证了其在难加工材料高效加工中的巨大应用潜力。
毕业论文关键词:磨削区温度场;低温喷雾射流冷却;有限元法;对流换热系数
Abstract During the machining of difficult-to-machine materials, most of the consumed energy converts to heat and accumulates in the machining zone. If the heat cannot be transferred out in time, the temperature in the machining zone will rise quickly and have a large impact on the tools and parts.
Machining effects of CPMJI have been studied compared with other two cooling methods in the turning of titanium alloy. Lower cutting temperature can reach employing with CPMJI. This thesis has determined the form of heat source in surface grinding situation. And also introduced the application of Finite Element in temperature field and simply introduced the function and main step of thermal analysis of finite element analysis software ANSYS. This thesis has also established the geometry model of temperature field in surface grinding area, meshing and defines the boundary conditions by ANSYS, Finally we have realized the moving of the heat source by ANSYS Parameterization Design Language (APDL). Then we have carried the simulation on the model, and obtained distributed condition of the temperature field and acquired influence which various convection heat transfer coefficient to the temperature field of grinding area.
Finally, The application results indicate that CPMJI have greater applied potentialities in high efficiency machining of difficult-to-machine materials compared with other two cooling methods.
Key Words: Temperature field of grinding area; Cryogenic pneumatic mist jet impinging cooling; Finite element method; convection heat transfer coefficient
目 录
第1章 绪 论 1
1.1 磨削加工过程 1
1.3 磨削温度的计算方法 3
1.4 本文研究的意义和内容 4
第2章 磨削温度场的分析 5
2.1 磨削过程中磨削热的产生 5
2.2 平面磨削区温度场的计算 5
2.3 热流密度和能量分配比例的确立 9
第3章 温度场有限元法分析理论 12
3.1 有限元法应用简介 12
3.2 有限元软件ANSYS简介