发明名称 |
Thermal-type air flow measuring instrument with fluid-direction judging capability |
摘要 |
There is disclosed a thermal-type air flow measuring instrument which judges whether the direction of flow of a fluid, ranging from a static flow to a pulsating flow involving a reverse flow, is forward or reverse, and outputs a signal corresponding to the flow rate of the fluid, thereby measuring the flow rate with high precision. An auxiliary passage is provided in a fluid passage, and is constituted by first, second and third passageways. Two temperature sensing resistors are mounted respectively at an upstream side and a downstream side within the first passageway in close proximity to each other. Most of the fluid, flowed into the first passageway in a forward direction, flows through the second passageway. The third passageway serves to direct a reverse flow of the fluid toward the temperature sensing resistors. Results of measurement of the flow rate of intake air in an internal combustion engine indicate that a minus error due to a pulsating flow, experienced in the conventional construction, is eliminated almost completely, and that a plus error due to a reverse flow is reduced to about +E,fra 1/10+EE .
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申请公布号 |
US5696321(A) |
申请公布日期 |
1997.12.09 |
申请号 |
US19950544648 |
申请日期 |
1995.10.18 |
申请人 |
HITACHI, LTD.;HITACHI CAR ENGINEERING CO., LTD. |
发明人 |
IGARASHI, SHINYA;KOBAYASHI, CHIHIRO;MOURI, YASUNORI;ISHIKAWA, HITOSHI;UCHIYAMA, KAORU |
分类号 |
G01F1/68;F02D35/00;G01F1/684;G01F1/69;G01F5/00;(IPC1-7):G01F1/68;G01M15/00 |
主分类号 |
G01F1/68 |
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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