After the modification of step feed mechanism of deep drillcombined machine tool, simplifying structure, convenient adjustment and reducing fault rate have been proved.
对深孔钻屑组合机床分级进给机构进行改进后，达到了简化结构、方便调整、减少故障的目的。
2
Combined with engineering example the characteristics of auger drill and construction defects for special strata are discussed.
结合工程实例，论证了旋挖钻机的特点及在特殊地层的施工缺陷。
3
Combined with theory, we thought of the respond work principle to emergency, pre - arranged planning, drill and related policy.