发动机铸铝件气密检测方法的可靠性研究

肖培发^1，2，李正现^1，2，郭永强^1，2，王志磊^1，2，魏红玲^1，2

1.内燃机与动力系统全国重点实验室，山东 潍坊  261061；2.潍柴动力股份有限公司，山东 潍坊  261061

摘要：为提高发动机铸铝零部件气密检测的可靠性并降低试车泄漏故障率，设计试验方案，通过试验分析水检法与差压测试法协同气密检测、高温水检法的可靠性。结果表明：合格铸铝件的首测压差范围为336～354 Pa，复测压差范围为260～281 Pa，二者差异较大；根据压差判断的泄漏结果与观察结果存在不一致的情况，水检法与差压测试法协同气密检测的可靠性较低，不适用于铸铝件气密检测；水温升高后，铸铝件的泄漏现象加剧，并识别出新漏点，高温水检法有效提高了铸铝件气密检测的可靠性。

关键词：铸铝件；水检法；差压测试法；可靠性

Reliability study on airtightness testing methods in cast aluminum engine components

XIAO Peifa^1,2, LI Zhengxian^1,2, GUO Yongqiang^1,2, WANG Zhilei^1,2, WEI Hongling^1,2

1.State Key Laboratory of Engine and Powertrain System, Weifang 261061, China; 2. Weichai Power Co., Ltd., Weifang 261061, China

Abstract: In order to enhance the reliability of airtightness testing for engine cast aluminum components and reduce the leakage failure rate during test runs, a test plan is designed to analyze the reliability of collaborative airtightness testing using water inspection and differential pressure testing methods, as well as high-temperature water inspection method. The results show that the initial pressure difference range for qualified cast aluminum parts is 336-354 Pa, and the retest pressure difference range is 260-281 Pa, with a significant difference. There are inconsistencies between the leakage results determined based on pressure difference and the observed results. The collaborative airtightness testing using water inspection and differential pressure testing methods had low reliability and is not suitable for airtightness testing of cast aluminum parts. As the water temperature increased, the leakage phenomenon of cast aluminum parts intensified, and new leakage points are identified, effectively improving the reliability of airtightness testing for cast aluminum parts.

Keywords: cast aluminum components; water immersion method; differential pressure testing method; reliability