某铝合金前防撞梁端板与吸能盒装配公差设计

Design of Assembly Tolerance of End Plate and Energy Absorption Box of an Aluminum Alloy Front Bumper

新型7系铝合金前防撞梁端板与吸能盒连接结构,提升连接强度及稳定性的同时,带来了装配间隙对焊缝质量影响的问题。旨在研究插接结构的铝合金前防撞梁端板与吸能盒装配公差设计,探讨如何制定名义尺寸及设计公差以获得满足焊接工艺要求的装配间隙。通过运用计算机辅助公差设计(CAT)技术,对依靠经验获得的零件制造公差进行分析,仿真结果输出装配公差贡献因子及贡献率,以此为依据制定零件合理的精度提升方案。依照方案对原有零件制造公差通过工艺手段进行加严,再次通过仿真分析获得优化后的装配间隙公差范围。修改吸能盒宽度名义尺寸,使得装配间隙的名义值覆盖公差值,达到实际装配既保证间隙公差符合目标范围又不产生装配干涉的效果。通过运用CAT技术,解决了插接结构的铝合金前防撞梁端板与吸能盒装配,几何公差、尺寸公差和定位公差非线性叠加的问题,最终零件设计公差满足装配公差要求。

The new 7-series aluminum alloy front bumper end plate and energy absorption box connection structure could improve the strength and stability of the connection,at the same time,it would bring the problem of the influence of assembly clearance on the weld quality.It was studied that the assembly tolerance design of aluminum alloy front bumper end plate and energy absorption box with plug-in structure,and was discussed that how to make nominal dimension and design tolerance to obtain the assembly clearance meeting the welding process requirements.Through using computer aided tolerance design(CAT)technology,the assembly tolerance analysis of the part manufacturing tolerance obtained by experience was carried out.The contribution factor and contribution rate of assembly tolerance were output from the simulation results,and the reasonable accuracy improvement scheme of parts was formulated based on the simulation results.According to the scheme,the original part manufacturing tolerance was tightened by production process means,and then the optimized assembly clearance tolerance range was obtained through simulation analysis.The nominal dimension of the width of the energy absorbing box was modified to make the nominal value of the assembly gap cover the tolerance value,so that the actual assembly could ensure that the gap tolerance meets the target range without assembly interference.By using CAT technology,the problems were solved such as non-linear superposition of geometric tolerance,dimensional tolerance and positioning tolerance in the assembly of aluminum alloy front bumper end plate and energy absorption box with plug-in structure,so the final part design tolerance met the requirements of assembly tolerance.