我国进口了一些液压汽车起重机,如芬兰的A351NS型,日本的NK-400E型等。起重臂是起重机吊装重物的主要执行机构,材质多采用具有较大抗弯刚性的低合金高强度钢板拚焊制成箱形薄壁结构,负载能力很大,套装在基本臂内的臂杆可由液压缸控制自由伸缩,满足不同吊装高度的需要。国内生产同类型起重臂的生产工艺要求高,起重臂截面上的两侧平面同底面不垂直度<5/1000,上挠度及旁弯度均≤1/1500,全长范围内≤4毫米。起重臂 China imported some hydraulic truck cranes, such as Finland’s A351NS type, Japan’s NK-400E type. The boom is the main crane carrying heavy lifting body, the material is more rigid with high bending strength of low-alloy high-strength steel tailored welded box-shaped thin-walled structure, load capacity, the arm set in the basic arm The rod can be freely scaled by the hydraulic cylinder to meet the needs of different hoisting heights. Domestic production of the same type of boom requires high production technology, the boom on both sides of the plane on both sides of the plane with the bottom of the non-perpendicularity <5/1000, the deflection and side camber are ≤ 1/1500, the whole length ≤ 4 mm . Boom