建筑行业使用的插入式混凝土振动器长中管两头的M42×1.5的左旋细牙螺纹,常因砂浆渗入造成损坏,影响其再次使用,因装拆不当,也会碰伤丝口。对于损坏了的螺纹,最初我们是在车床上进行修整,但对刀较困难,修整后的螺纹常常超差,达不到使用要求,而且工效太低。为了保证维修质量,降低修理成本,我们设计制作了两种回螺纹简易丝攻,如图所示。经过近一年的使用,修整了100多根长中管,节省了二千多元修理费。 Plug-in concrete vibrators used in the construction industry have M42 × 1.5 left-handed fine thread on both ends of the long-middle pipe, which often causes damage due to mortar infiltration, which affects its re-use. Due to improper assembly and disassembly, it can also cause bruising. For the damaged thread, we were initially repaired on a lathe, but it was difficult to set the knife. The threads after dressing were often out of tolerance, not meeting the requirements for use, and the work efficiency was too low. In order to ensure the quality of maintenance and reduce the cost of repairs, we designed two kinds of simple thread taps with thread back, as shown in the figure. After nearly a year of use, more than 100 long and middle tubes were repaired, saving more than 2,000 yuan in repair costs.