数控机床三明治复合结构进给系统设计

Design of Sandwich Composite Structure Feed System for CNC Machine Tool

在数控机床的直线电机进给系统运行中，绕组线圈发热、铁心磁滞发热及其他机械摩擦发热，会导致温升过高，产生热变形，从而影响工件加工精度。添加相变材料的高孔隙率泡沫金属三明治复合结构不仅能有效地减轻结构的质量，而且具有良好的热特性。将三明治复合结构形式应用于对数控机床的直线电机进给系统的改进设计中，通过对多孔金属和相变材料的分析，动子底板采用铝金属泡沫为基体、并填充石蜡（熔点为27～28℃）的三明治复合结构，在金属泡沫芯的外围通过钢板进行覆盖及密封。该结构在受热情况下在一定的时间范围内可保持在恒温状态不发生变化，有利于减小机床的热变形，提高加工精度。

When the linear motor feed system of Computer Numerical Control （CNC） machine tool was in the operation process, its temperature rise may he too high and thermal deformation produced because of the winding coil heated, iron core hysteresis heated and other mechanical friction heated and so on, thereby the machining accuracy of workpiece was affected. The weight of the structure could not only be reduced by the sandwich composite structure with high porosity rate metal foam filled with phase change materials （ PCM）, but also had excellent thermal characteristic. The sandwich composite structure form was applied to the improvement design of linear motor feed system for CNC machine tool. By analyzing of the porous metal and phase change materials, the mover baseboard used a sandwich composite structure which took aluminum metal foam as base and filled with wax （ melting point was at 27 ~ 28 ~C ）, and the periphery of metal foam core was covered and sealed by steel plates. The structure will keep unchanged in a constant tempera- ture condition for a certain period of time while heated, which is in favor of reducing the thermal deformation of the machine tool and improving the accuracy of machining.