火箭推进

某发射场进行火箭发动机气瓶充气时出现充气卸荷开关关闭后泄漏故障,分解卸荷开关后发现卸荷开关阀芯导向部位存在异常磨损,且阀芯非金属密封面周向密封压痕深度不均匀,结合故障形貌,采用有限元仿真计算压痕深度,对泄漏故障的根本原因进行深入剖析。分析结果表明:卸荷开关阀芯导向部位存在微小原始缺陷,多次动作后在阀芯与壳体导向部位产生粘着磨损,阀芯在壳体导向孔中回位发生偏斜,造成阀芯非金属密封面出现不均匀压痕,最终导致卸荷开关在测试时漏率超标。

When inflating gas to a gas vessel of rocket engine at a launching site,a leakage phenomenon occurred after the unloading valve was closed.Abnormal wear of the spool's guiding part and an uneven indentation on non-metallic sealing surface were found by integrating the macro observation and micro morphology after breaking the valve.The finite element method is used to establish the model of spool and valve seat.It has verified that the calculated indentation depth is close to the measured depth.The analysis results indicate that there exists some tiny original defects in the spool's guiding part of unloading valve,and adhesive wear appears due to the repeated motion between the spool's guiding part and the guiding hole,which caused the return deflection of the spool in the guide hole and uneven indentation in non-metallic sealing surface,eventually led to leakage of unloading valve during the test.

引言
1 卸荷开关工作原理
2 卸荷开关泄漏现象
3 零组件损伤形貌分析
4 压痕有限元分析
5 泄漏机理分析
6 结论

图1 卸荷开关结构原理示意图<br/>Fig.1 Structure diagram of unloading valve

图1 卸荷开关结构原理示意图
Fig.1 Structure diagram of unloading valve

图2 卸荷开关阀芯非金属压痕<br/>Fig.2 Indentation on non-metallic sealing surface of spool

图2 卸荷开关阀芯非金属压痕
Fig.2 Indentation on non-metallic sealing surface of spool

图3 阀芯及壳体配合导向面损伤形貌<br/>Fig.3 Damage morphology of spool's guiding part and its guiding hole

图3 阀芯及壳体配合导向面损伤形貌
Fig.3 Damage morphology of spool's guiding part and its guiding hole

图4 导向面损伤微观形貌<br/>Fig.4 Damage micromorphology of guiding valve plug and its guiding hole

图4 导向面损伤微观形貌
Fig.4 Damage micromorphology of guiding valve plug and its guiding hole

表1 非金属(聚酰亚胺)邵氏D硬度测试结果<br/>Tab.1 Hardness test results of non-metallic (polyimide)Shore D

表1 非金属(聚酰亚胺)邵氏D硬度测试结果
Tab.1 Hardness test results of non-metallic (polyimide)Shore D

表2 非金属压痕深度计算结果<br/>Tab.2 Calculated results of non-metallicindentation depth

表2 非金属压痕深度计算结果
Tab.2 Calculated results of non-metallicindentation depth

图5 阀芯偏斜示意图<br/>Fig.5 Schematic diagram of valve plug deflection

图5 阀芯偏斜示意图
Fig.5 Schematic diagram of valve plug deflection

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备注

引言

1 卸荷开关工作原理

2 卸荷开关泄漏现象

3 零组件损伤形貌分析

4 压痕有限元分析

5 泄漏机理分析

6 结论

期刊信息