随着国内汽车市场竞争的日趋激烈，为了满足市场的不同需求，各种性能和用途的车型不断推陈出新，尤其对三厢车的开发更为青睐。从市场的销售数据显示，节能与新能源汽车的研制也倾向于三厢车的开发与制造，三厢车的顶盖相比于两厢车顶盖增加了尾部流水槽的造型，尤其是带天窗结构的三厢车顶盖，在模具开发过程中，需要制定更多的工序和复杂的模具结构。目前流水槽的成形质量已经成为整个顶盖模具设计的关键。
With the increasingly fierce competition in the domestic automobile market, in order to meet the different needs of the market, the models with various performances and uses are constantly innovated, especially for the development of three compartment cars. According to the sales data of the market, the research and development of energy-saving and new energy vehicles also tend to the development and manufacture of three compartment cars. Compared with the two compartment roof, the top cover of the three compartment car has increased the shape of the tail water channel, especially for the roof of the three compartment car with skylight structure. In the process of mold development, it is necessary to formulate more processes and complex mold structure. At present, the forming quality of the water trough has become the key to the design of the whole top cover die.
目前各个主机厂开发出的流水槽造型在功能和用途上基本相同，只是形状和尺寸有所区别，根据AUTOFROM成形分析、工艺方案规划、模具结构设计、加工和钳工调试以及开发成本方面综合考虑，总结出以下4种针对流水槽的成形方案，分别为：流水槽下整形、流水槽斜楔侧翻、流水槽斜楔上翻与整形、流水槽下压料器上翻与整形。
At present, the function and use of the flow channel developed by each main engine factory are basically the same, but the shape and size are different. According to the autofrom forming analysis, process planning, die structure design, processing and fitter debugging and development cost, the following four forming schemes for the flow channel are summarized, which are: shaping under the water channel and slanting the flow channel It includes the following parts: wedge overturning, chute wedge turning up and shaping, downflow chute pressing device turning up and shaping.