泥水盾构刮刀刃型与安装角对刮刀切削性能的影响

Influence of blade shape and installation angels on cutting performance for scrapers of slurry shield

基于在大直径泥水盾构机掘进过程中,刮刀起主要切削作用,为了获得刮刀刃型和安装角对其切削性能的影响,采用有限元方法,模拟刮刀切削土体过程,并以比能耗以及载荷波动系数作为评价刮刀切削性能的指标,研究大直径泥水盾构机中锯齿型、羊角型、平刃这3种刃型以及不同水平、垂直安装角对刮刀切削性能的影响规律。研究结果表明:刮刀刃型和安装角都会对刮刀切削性能产生重要影响;锯齿型刮刀与羊角型和平刃刮刀相比,比能耗分别减小52.2%和23.8%,水平载荷波动系数分别减小21.0%和13.4%,垂直载荷波动系数分别减小6.22%和2.63%;比能耗和载荷波动系数均随着刮刀水平安装角的增大而减小,随着垂直安装角的增大先减小后增大;当水平安装角为90°,垂直安装角为55°时,刮刀切削性能较优。

Considering that during the large diameter slurry shield driving, the scrapers play a major role, to obtain the influence of blade shape and installation angels on the cutting performance for scrapers, the specific energy consumption and load fluctuation coefficient were used to evaluate the cutting performance, the simulation model of cutting process for scrapers was established with finite element method and the effects of blade shape, horizontal and vertical installation angle on cutting performance were investigated. The results show that the blade shape and installation angles of scrapers all have important influence on its cutting performance. Compared with the horn scraper and the flat blade scraper, the sawtooth scraper reduces the specific energy consumption by 52.2% and 23.8%, respectively, the horizontal load fluctuation coefficient decreases by 21.0% and 13.4% and the vertical load fluctuation coefficient decreases by 6.22% and 2.63%, respectively. Both of the specific energy consumptions and load fluctuation coefficients decrease gradually with the increase of horizontal installation angle, and decrease firstly and then increase with the increase of vertical installation angle. When the horizontal installation angle is 90° and the vertical installation angle is 55°, the scraper has better cutting performance.