利用预应力原理提升龙门机床横梁的抗弯强度 Promoting the Bending Strength of the Beam of Gantry Machine Tool by the Principle of Prestress

横梁是龙门机床的重要部件之一，与其他部件相比，它所承受的力及弯矩较大且方向较为复杂。如果横梁的自身抗弯强度不足，会产生明显的向下变形，将给龙门机床的加工精度产生一定的影响。本文利用预应力原理提升横梁的抗弯强度，建立预应力横梁的受力模型，分析横梁挠度与预应力的关系，并利用有限元方法对预应力横梁进行验证。结果表明应用预应力原理提升横梁抗弯性能是切实可行的，中部挠度减小了约80%，有效的增加了龙门机床的加工精度。 Beam is one of the important parts of gantry machine tool; compared with other parts, it bears the force and bending moment that is larger and has more complex direction. If a beam of its bending strength is insufficient, it will produce obvious deformation down and bring about the processing precision of gantry machining center with a great influence. In this paper, based on the principle of prestressing, the bending strength of the beam is promoted, the force model of the prestressed beam is established, the relationship between the deflection of the beam and the prestress is analyzed, and the finite element method is used to verify the prestressed beam. The results show that it is feasible to apply the principle of prestress to improve the bending resistance of beams, and the deflection reduced about 80%, increasing the machining precision of the gantry machine tool effectively.