Research on mechanism of combined milling cutter cutting double-bevel groove of pipe

In order to cut the bevel groove of ocean oil and gas pipe, an underwater beveling machine, which was composed of radial feed mechanism, circumferential feed mechanism and milling mechanism, was desinged. The device could cut the double-bevel groove of large-diameter pipe in water and on land by adopting a combined milling cutter, which was composed of one disc milling cutter and two angle cutters. Experiential formula of general milling cutter was able to match with the combined milling cutter. According to its technique process, parameter design, force analysis, modeling and finite-element checking of the combined cutter were finished. A new theoretical formula of milling force of the combined cutter was educed. In order to validate and amend the formula, the experiment was carried out and the data were recorded. Results show that the formula is correct and the difference between theory result and actual result is in the scope of 0~9.6%. Meanwhile, the experiment shows that there is high efficiency, smooth surface and little tool wear by using the device to cut the bevel groove.