发明名称 |
Method and system for aggressive cycling of leak detection pump to ascertain vapor leak size |
摘要 |
<p>A system and method for detecting leakage from a evaporative emission space of an automotive vehicle fuel system. A reciprocating pump is operated in a pressurizing mode to build pressure in the space toward a nominal test pressure. The pressurizing mode involves operating the pump in a repeating cycle wherein the pump operates alternately in an accelerated pumping mode and a natural frequency pumping mode. During the pressurizing mode, a characteristic of successive occurrences of the natural frequency pumping mode indicative of pressure in the space is measured. The number of times the cycle repeats is counted and compared to a predefined reference. When the cycle count exceeds the predefined reference, the test continues at a lower resolution for detecting leakage, and when the cycle count does not exceed the predefined reference and a measurement of the characteristic of successive occurrences of the natural frequency pumping mode indicative of pressure in the space exceeds a predetermined reference pressure, the test continues at a higher resolution for detecting leakage. The invention is useful when overall test time is limited. <IMAGE></p> |
申请公布号 |
EP1108879(A2) |
申请公布日期 |
2001.06.20 |
申请号 |
EP20000204269 |
申请日期 |
2000.11.30 |
申请人 |
SIEMENS VDO AUTOMOTIVE INC. |
发明人 |
WELDON, CRAIG;RASOKAS, RAY;COOK, JOHN EDWARD |
分类号 |
F02M25/08;(IPC1-7):F02M25/08 |
主分类号 |
F02M25/08 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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