缠绕式弯管组合模具

Combined Wind Bending Dies

在管零件制造行业中,弯管是最常用的加工方式之一。管件在弯曲过程中,当弯曲变形程度过大时,弯曲中性层的外层管壁会产生过度变薄,甚至导致破裂;最内侧管壁将增厚,甚至失稳起皱;同时,断面会产生畸变,呈椭圆形。因此外侧减薄量、内侧的波浪度、截面的椭圆度是必须严格控制的3个加工缺陷。通过对管件在绕弯方式下受力变形的理论分析与研究,提出并设计了适用于绕弯加工管件的组合模具,通过该组合模具来控制上述的3个变形。最后,采用装配了该组合模具的CNC(Computerized Numerical Control,电脑数值控制)弯管机进行试验,试验结果显示,该组合模具有效地解决了弯管过程中的缺陷,取得了良好的效果。

Pipe bending is one of the common processes for pipe part. During pipe bending, the outboard wall will be thinned excessively even to be split, and the inboard wall will be thickened even to be draped, meanwhile the cross-section will be distorted to form ellipse（ Brazier effect） when the pipe is deformed too large. So, the thinning ratio of outboard wall, the draping ratio of inboard wall and the distorting ratio of cross-section are three processing defects which must be controlled strictly. A set of combined wind bending dies to control the three deformations mentioned above is proposed and designed after studying the force and the deformation under bending. Finally experiments is made with a CNC pipe-bender which is equipped with the combined wind bending dies, and the result shows that the combined wind bending mould not only overcomes the defects but also increases the efficiency.