大型艉跳板铰链对中及其测量技术研究

Study on Hinge Alignment and Its Measurement Technique in Large Quarter Ramp Installation

艉跳板是滚装船舶滚动式货物和装卸车辆的进出通道,其主体一般通过一排铰链与船体活络地连接在一起。艉跳板制造厂家对铰链的同轴度有严格规定,必须在铰链安装期间予以控制和测量,以实现艉跳板铰链的完好对中。对此,借鉴琴钢丝测量主机机座挠度法,根据钢丝的连续下沉特性研究大型铰链同轴度的测量方法,即通过琴钢丝将无形的铰链中心线近似地显现出来,并建立钢丝下沉曲线模型,计算钢丝因自身重力下沉引起的与铰链中心线之间的位置偏移。设计同轴度控制和测量的对中工具,使用该工具将激光经纬仪找到的铰链中心线在工具的靶心上投射出2个端点,布置钢丝并使其穿过这2个端点,在工具上固定并张紧钢丝。研究的主要成果已成功应用到系列45 000 t集装箱滚装船艉跳板的铰链安装过程中,对提升工作效率和保证设备质量有很好的促进作用。

Quarter ramp is the passage for cargos and vehicles rolling on/off the Ro-Ro ship. It is usually connected to the ship by a number of hinges. The manufactory of the quarter ramp has strict regulations on the coaxiality of the hinges,which means the hinges must be measured and controlled in the installation to realize a precise alignment. In this paper,the measurement method of the coaxiality for large size hinges is studied by measuring the deflection of the main enginefoundation on the basis of the sagging of a piano wire, and thus the approximate center line of the hinges is obtained.Then a model for the sagging curve of the piano wire is established in accordance with the gravitation, and the offsetbetween the sagging and the center line of the hinges is calculated. In addition to this, an alignment tool to measure andcontrol coaxiality is designed, which have two points flashing on the center. These two points indicate the center line ofthe hinges found by the laser theodolites, and the piano wire is fixed and strained on the tool with the two points as the scale mark. The result of the study has been successfully applied to the hinge installation of the quarter ramps on the 45 000 t Con-Ro ship series, which plays an active role both in raising work efficiency and in improving the quality of the equipment.