遵照伟大领袖毛主席“农业的根本出路在于机械化”的教导,宁波跃进农机厂于1973年下半年开始,组织三结合班子,通过走访农村,对旧的1.5吨挂车进行改革。在此基础上,于1974年初,接受一机部下达的7 CB——2吨农用半挂车和7 CBH——2型二吨后向自卸农用半挂车的新产品试制任务,为东方红—20型拖拉机提供较为合理的配套半挂车。在批林批孔运动普及、深入、持久发展的大好形势推动下,在各级党委的领导下,在一机部机械院农机所和省内外农用挂车系列设计单位具体帮助支持下,跃进农机厂发动群众,克服困难,设计试制出两种二吨挂车,并经过一万公里行车装运和五千次倾卸试验,测试有关数据。并 Following the teachings of Chairman Mao, the great leader, “The fundamental road to agriculture lies in mechanization,” Ningbo Yuejin Agricultural Machinery Factory started the second half of 1973 and organized three integrated teams to carry out reforms in the old 1.5-tonne trailers by visiting rural areas. On this basis, in early 1974, the pilot project of accepting the new product trial of 7 CB - 2 ton agricultural trailer and 7 CBH - 2 type 2 ton backward dumping semi - trailer for agricultural use, 20 tractors provide a more reasonable matching semi-trailer. Under the leadership of the party committees at all levels and with the specific help and support of the agricultural machinery institute of the Machinery and Machinery Department of the Ministry of Machinery Industry and the agricultural trailer series design units inside and outside the province, under the great situation of popularization, thorough and sustained development of the " Mobilize the masses to overcome difficulties, design and trial production of two two-ton trailer, and after ten thousand kilometers of motor transport and 5,000 dumping tests to test the data. and