Abstract: With the rapid development of new energy in the field of trucks, the lightweight and appearance quality of commercial vehicles are also paid more and more attention. Magnesium alloy has many advantages, such as low density and excellent casting performance, and has been widely used in structural parts such as cross car beam of passenger cars, but it is still blank in the field of heavy trucks. In this paper, by using casting magnesium alloy and aluminum alloy stamping parts, a heavy truck cross car beam of magnesium alloy is designed and developed to replace the original steel cross car beam. The results show that compared with steel, the weight of cross car beam of magnesium alloy is reduced by 53%, the strength safety factor of the cross car beam is increased by 10%, 30% and 50% respectively under braking, turning and vertical impact conditions, and the stiffness is increased by 30%.

Key words: Magnesium alloy; Lightweight; Commercial vehicle; Cross car beam

摘要： 随着新能源在卡车领域的迅速发展，商用车车身轻量化以及外观品质也越来越受到重 视。镁合金具有密度低、压铸性能优良等众多优点，在乘用车仪表板管梁等结构件已规模应 用，但是在重卡领域仍是空白。文章通过采用压铸一体成型镁合金配合使用铝合金冲压件的 方式，设计开发了一款重卡镁合金仪表板管梁取代原钢制管梁。结果表明，与钢制材料相比， 镁合金仪表板管梁重量减少了 53%，在制动、转弯及垂向冲击工况下仪表板强度安全系数分 别提高了 10%、30%、50%，刚度提升了 30%。

关键词: 镁合金；轻量化；商用车；仪表板管梁