Effect of Active Deflection on the Forming of Tubes Manufactured by 3D Free Bending Technology
Effect of Active Deflection on the Forming of Tubes Manufactured by 3D Free Bending Technology
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DOI：
10.3390/met12101621
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发表时间：
2022-09
期刊：
影响因子：
2.9
通讯作者：
Hao Zhang;A. A. El-Aty-A.;J. Tao;Xunzhong Guo;Shuo Zheng;Cheng Cheng-Cheng
中科院分区：
文献类型：
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作者：
Hao Zhang;A. A. El-Aty-A.;J. Tao;Xunzhong Guo;Shuo Zheng;Cheng Cheng-Cheng
在三维自由弯曲成形技术中，复杂管件成形时，管件容易与设备发生干涉。因此，为了解决干涉现象，提出了一种避免干涉的主动变形法(ADM)，通过控制弯曲模具来驱动变形管绕轴线运动。该方法在不增加运动轴系的情况下，扩大了设备的活动自由度。然而，在ADM的实施过程中，经常出现严重的截面变形、表面划痕等成形缺陷，降低了管材的结构强度和抗压能力。建立了一个力学模型来分析管子的受力状态，结果表明，主动挠曲的驱动力主要由弹道半径决定。所采用的钟形过渡结构的曲线比圆形结构更接近管子的弯曲曲率，使导轨与管子由线接触转变为面接触。仿真和实验结果表明，增加轨迹半径可以增强转动力矩。采用钟形过渡结构后，管内应力集中得到缓解。
The formed parts of tubes easily interfere with the equipment when forming complex tubes in 3D free bending forming technology. Consequently, to solve the interferential phenomenon, an active deflection method (ADM) to avoid interference was proposed to drive the deformed tube around its axis by controlling the bending die. The method extended the activity freedom of the equipment without installing the additional motion shafting. However, severe section distortion, surface scratches and other forming defects frequently occurred during the implementation of ADM, which reduced the structural strength and pressure resistance of the tubes. A mechanical model was developed to analyze the force state of the tube, and the results showed that the driving force of active deflection was mainly determined by the trajectory radius. The curve of the adopted bell-shaped transition structure was closer to the bending curvature of the tube than the rounded structure, which transformed the guider and the tube from linear contact to surface contact. The simulation and experiment results indicated that adding the trajectory radius could strengthen the rotation torque. The stress concentration in the tube was alleviated after applying the bell-shaped transition structure.