王昊，江佳廉，张泰

摘  要：在某车型开发的寒地试验中，发生了一起燃油箱开裂的故障。分析是静电放电引起了燃油箱爆炸。根据燃油箱内静电放电的原理，制定出燃油箱静电电压测试方法和静电放电路径测试方法。通过试验调查出故障原因是燃油箱汽油里的静电累积到油泵油位计上发生放电，放电能量大于点燃汽油最小能量0.2mJ的要求，点燃燃油箱内汽油蒸气引发爆炸。本文提出了静电对策方案且进行了试验验证，结果表明：将油泵油位计弹片基座改为导电材料，可以有效降低燃油箱内汽油静电电压和放电能量，解决静电放电燃烧问题。

关键词：静电放电;表面电位;放电路径;放电能量

中图分类号：U467.3      文献标识码：A     文章编号：1005-2550（2021）05-0047-06

Test Evaluation And Prevention Research Of

Electrostatic Level In Fuel Tank

WANG Hao， JIANG Jia-lian， ZHANG Tai

（ Dongfeng Nissan Technical Center， Guangzhou 510800， China）

Abstract： In the developing test of some vehicle in cold weather， a cracking failure occurred in the fuel tank. The analysis result is that the electrostatic discharge caused the fuel tank explosion. According to the principle of electrostatic discharge in the fuel tank， we worked out the electrostatic voltage test method and the electrostatic discharge path test method of the fuel tank. The cause of the fault was investigated through tests. The static electricity in the gasoline of fuel tank was accumulated to the fuel gauge of fuel pump and a discharge occurred. The discharge energy is more than the minimum energy requirement of 0.2 mJ for igniting gasoline， so the ignited gasoline vapor in the fuel tank caused an explosion. The countermeasure against static electricity is proposed and tested. The results show that changing the wiper retainer material of fuel gauge in fuel pump to conductive material can effectively reduce the electrostatic voltage of gasoline in the fuel tank and solve the problem of electrostatic discharge.

1    前言

在某車型开发的寒地试验中，发生了一起燃油箱开裂的故障。晚上车辆停车熄火以后，第二天早上试验员闻到浓烈的汽油味，点检车辆发现燃油箱泵口边缘出现了裂缝（如图1）。油泵上有被熏黑的痕迹，但油泵本身没有损坏和烧融，可以正常工作。燃油箱壳体也没有烧融痕迹。车辆位于燃油箱上方的地板出现了变形，车辆其余部位没有任何损坏。由于夜晚车辆熄火后油泵已经断电，推测燃油箱内部发生静电放电引起了爆炸，巨大的压力导致燃油箱开裂和车体变形。为了查明故障原因，接下来我们将编制两套试验方法，分别测试放电电压和放电路径，最后制定对策方案并验证。

2    燃油系统介绍

在搞清故障车油箱内静电放电机理之前，首先介绍一下汽车燃油系统的功能。……