Development of Rock Excavation Method Assisted by High Pressure Water Jet

通过室内试验，研究了高压水射流对尖齿钻头切削力的影响。在不同的水压和切削速度下，对三城目安山岩进行了约400次切削试验，以确定钻头切削力的减小情况，切削力随钻头磨损而连续变化。咬合力的最大减少是严重磨损的钻头;在100 MP水压下，拖曳力减少约25%，法向力减少约40%。结果表明，在切削力降低的同时，水射流能有效地延长钻头寿命，钻头寿命提高了3倍左右。一个重要的好处可能是水射流的冷却和润滑作用。

A laboratory investigation was made of the effests of high pressure water jets on the cutting force of point asstack bit. About 400 cuts using Sanjome-andesite were carried out at different water pressures and cutting speeds to determine the reduction of cutting forces on the bit.The cutting forces shoewed continuous change with wear of bit. The greatest reduction in cugging force were with severely worn bits; the drag force was reduced about 25% and the normal force about 40% at 100MP water pressure. The method was less effective in case of sharp bit.Together with the reduction of cutting force, the water jet was found gto be effective to prolong the bit life; the bit life becoms about 3 times. An important benefit may be the cooling and lubricationg action of the water jet.