大冶铁矿有KY—310和45—R两种型号的牙轮钻机,分别备有φ219mm和φ273mm两种规格的钻杆,每根钻杆长9m,由上接头、钢管(φ219、φ273×25×8000mm)和下接头组成,它们之间是用螺纹连接,扭紧后再将螺纹连接端面焊死(图1),图1为改进前的结构。这种钻杆在钻孔中,常常发生脱焊和断裂。修复方法是用气割枪将焊缝吹掉和割去钢管的螺纹部分,然后重新加工螺纹,再焊上、下接头。一次断杆影响生产再加修理费要损失1万多元,而且钢管有8m长,运输修复都很不方便。现作了如下改进。 Daye iron ore has KY-310 and 45-R two types of cone-type drilling rig, respectively, with φ219mm and φ273mm two specifications of the drill pipe, each drill pipe length 9m, by the connector, steel pipe (φ219, φ273 × 25 × 8000mm) and the lower connector, the thread between them is connected, after tightening the threaded end face welding (Figure 1), Figure 1 is to improve the structure before. Such drill pipe in the drilling, often occurs desoldering and fracture. The repair method is to use a gas torch to blow off the weld and cut off the threaded part of the pipe, and then rework the thread, and then welded on the next joint. A broken bar affect production plus repair costs to loss of more than 10,000 yuan, and the pipe is 8m long, transport and repair are very inconvenient. Now made the following improvements.