塔式起重机臂架腹杆的加工

在塔式起量机臂架钢结构生产中,腹杆大多采用无缝钢管两端压扁焊接,腹杆形状如图1所示。传统的加工工艺流程是:下料——压扁——划线——切角度——校直。加工时几何尺寸均由手工控制,这样既浪费人力,劳动强度又大。为此我们设计制作了一套靠模工装,利用Q11—13×2500剪床采取压扁、切头一次成形的加工方法,工艺流程为:下料——校直——压扁切角度。其结构及安装方法如图2所示。     

塔机变截面变模数臂架焊接工装

目前,塔机技术发展已进入一个新阶段,尤其是在结构设计制造方面,已广泛采用变截面、变模数设计取代过去的等截面、等模数设计,使整机重量降低,受力情况大为改善。由此给制造工艺提出了更高的要求,要求工艺对变截面、变模数结构制造的精度、经济性及适应性必须给予保证。对此,我厂在制造QTZ60型变截面、变模数的45m长臂架塔机过程中,研制出一套经     

Study on passive compensation of temperature induced thermal lenses

The thermal lens problem of optical system caused by high temperature environment is a common problem. Athermal design of lenses based on optical calculation software is an effective passive compensation method. But it is difficult to determine its accuracy and measure it experimentally. We describe an athermal design technology and propose a simulated scheme to verify the accuracy of this design. Three materials with negative dn/dT have been selected to compensate for the thermal lenses produced by a fused silica lens. The results show that the compensation effect of N-PSK53A is the best.     

Simulated and experimental study on temperature induced lens focal shifts

Optical lenses used in high temperature environment are usually affected by thermal lenses problems, but it is difficult to evaluate their focal shifts in practical applications. A three-dimensional single-lens model based on finite element solver was built to evaluate the focal shift in this study, when the temperature of surface was raised from the initial temperature to the specified temperature. An experimental method based on a Hartmann-Shack wavefront sensor was proposed to verify the rationality of the model. The nearly same results between simulations and experiments for N-BK7 and fused silica were obtained, which proves that it is feasible to analyze focal shifts of optical lenses by simulation methods.