关键词: 轻客车型；安全带支架；结构优化；乘员保护；碰撞安全

Abstract: Regarding the issue of excessive head injury values in a dummy caused by insufficient strength of the seat belt pretensioner lap plate (PLP) bracket during the frontal collision test of a light passenger vehicle model exported to Europe under the ECE R137 regulation, this article studies the impact of bracket strength optimization on dummy injuries. Three sets of seat belt PLP brackets are selected, two of which are strengthened through local thickening and material reinforcement according to the optimized design, while the third maintained the original structure as the initial design. According to the ECE R137 regulation standards, a sliding platform system verification is conducted, with comparative tests performed while keeping other key components of the vehicle restraint system consistent. The center of gravity of the head is successfully reduced from the excessive 82.95g to the standard 73.99g by the continuous composite acceleration of more than 3 ms. The injury criterion values for the head continued to decline; the neck load significantly reduced, with the neck bending moment decreasing by 59.2%, and the chest and thigh injury indicators both met the regulatory requirements with minimal changes. The strength optimization of the PLP bracket can effectively control collision energy, improve the motion posture of the dummy, and significantly enhance the protection performance of the head and neck, providing practical evidence for solving similar restraint system design issues.

Key words: light commercial vehicle; seat belt bracket; structural optimization; occupant protection; crash safety