The wire-cutting machine tool is a kind of wire-cut electric discharge machine. Its working principle is to use the continuously moving molybdenum wire (called electrode wire) as the electrode to perform pulse spark discharge ablation and cutting on the workpiece. The consumables of the wire-feeding machine can be used repeatedly, but during the processing, abnormal wire breakage may occur, which requires the operator to check and maintain.

  If the molybdenum wire is always broken during the operation of the wire-feeding machine, what will you do? Today, the editor will summarize the reasons for the broken wire.

  1、Internal factors:

  1、The parameter setting is unreasonable. When the machining current is large, the molybdenum wire is easy to break.

  2、The ratio of cutting fluid is inappropriate. Too little flushing fluid will make the discharge conditions worse, and it will not be able to effectively flush into the slit. In addition, the cutting fluid should be checked regularly to keep the circulation channel unobstructed.

  3、The precision of the guide wheel is abnormal (especially the support guide wheel). When the precision of the guide wheel is reduced, the molybdenum wire is likely to break.

  4. The conductive block is worn with grooves. The grooves caused by wear are easy to clamp the molybdenum wire. It is necessary to adjust the position of the conductive block frequently and replace the conductive block in time to prevent wear.

  5、The accuracy of the wire feed mechanism is reduced. The wire feeding mechanism is mainly composed of a wire storage drum, a wire feeding frame and a guide wheel. When the accuracy of the wire feeding mechanism (mainly the transmission bearing) is reduced, the radial runout and axial movement of the wire storage drum will be caused, and the diameter of the wire storage tube will be reduced. The jumping will reduce the tension of the electrode wire, causing the wire to become loose, and in severe cases, the molybdenum wire will fall out of the guide wheel groove and break, which requires frequent inspection of the wire transmission mechanism.

  2、External cause:

  1、Whether the quality of molybdenum wire is qualified, molybdenum wire with uneven thickness and poor material is easy to break.

  2. Whether the workpiece is deformed or not, the product will sometimes deform during the processing process, and the molybdenum wire will be pinched off. In order to avoid the deformation of the material during the cutting process, it is necessary to optimize the processing technology and pre-processing procedures. Threaded holes and pre-cuts reduce stress and optimize cutting paths.

  3、The surface of the workpiece material is oxidized or there are impurities inside that lead to non-conductivity, which requires inspection of the material to be processed and removal of non-conductive impurities in the material before machining.

  4、Is the installation tightness appropriate? If the molybdenum wire is installed too loosely, the molybdenum wire will vibrate violently, which will not only cause wire breakage, but also directly affect the surface roughness of the workpiece due to the vibration of the molybdenum wire, but it should not be installed too tightly, because it will increase the internal stress. It will also cause wire breakage. Generally speaking, the newly installed molybdenum wire must be tightened before processing.

  5、The workpiece is not clamped in place. If the workpiece is not clamped in place during processing, it is likely to cause displacement and cause wire breakage. Therefore, during the clamping process, the workpiece must be fixed.