抄録
The drilling capability of abrasive water suspension jets (AWSJs) under a submerged condition decreases steeply with the increase of the standoff distance, and the effective working distance for drilling and cutting is restricted in a small standoff distance region. When the standoff distance is small, the nozzle may be damaged by the reflected jet. In narrow environments, the nozzle sometimes cannot be set closer to the workpiece. Accordingly, we need methods that extend the effective working distance for submerged AWSJs. In this paper, a sheathed nozzle for AWSJs is proposed as a means of extending the effective working distance in submerged environments. Experiments are conducted to clarify the drilling capability of the jet delivered by this sheathed AWSJ nozzle using specimens of stainless steel at an injection pressure of 12MPa. A favorable nozzle shape for the sheathed AWSJ nozzle is discussed from the points of view of drilling capability and lifetime of the sheath.
