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US 7,726,187 B2Granted
Thermal type flow meter and engine control system using the same
AssigneeHitachi, Ltd.
InventorsYoshihiro Sukegawa, Noboru Tokuyasu, Hiroaki Hoshika
Life of this patent
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Abstract
A thermal type flow meter has a first heating resistor, a second heating resistor for blocking heat transfer from the first heating resistor to a console, a temperature measuring resistor interposed between the two heating resistors, and a controller for calculating a flow rate unrelated to temperatures of fluid from temperatures of the resistors and currents supplied to the heating resistors.
Claims9
A heating resistor type flow rate measuring apparatus comprising:
- a first heating resistor arranged in a passage;
- a support member projecting from a console for supporting said first heating resistor and said support member includes a plurality of lead line members;
- a second heating resistor connected to said support member;
- temperature detection means including a temperature measuring resistor connected to said plurality of lead line members and interposed between said first heating resistor and said second heating resistor;
- and
- control means for controlling heat generation by said second heating resistor such that temperatures detected by said temperature detection means fall into a predetermined temperature range inclusive of temperatures of said first heating resistor,
- wherein each of said first heating resistor, said second heating resistor, and said temperature measuring resistor is electrically connected to said plurality of lead line members, and
- wherein the temperature measuring resistor is arranged between the first heating resistor and the second heating resistor, with the first heating resistor mounted adjacent a top of said support member and said second heating resistor is disposed adjacent said console.
5 more elements
An engine control system which comprises:
- a heating resistor type flow rate measuring apparatus including:
- a first heating resistor arranged in a passage;
- a support member projecting from a console for supporting said first heating resistor and said support member includes a plurality of lead line members;
- a second heating resistor connected to said support member;
- temperature detection means including a temperature measuring resistor connected to said plurality of lead line members and interposed between said first heating resistor and said second heating resistor;
- and
- control means for controlling heat generation by said second heating resistor such that temperatures detected by said temperature detection means fall into a predetermined temperature range inclusive of temperatures of said first heating resistor,
- wherein each of said first heating resistor, said second heating resistor, and said temperature measuring resistor is electrically connected to said plurality of lead line members,
- wherein the temperature measuring resistor is arranged between the first heating resistor and the second heating resistor, with the first heating resistor mounted adjacent a top of said support member and said second heating resistor is disposed adjacent said console, and
- wherein said engine control system further comprises:
- combustion control means for controlling a combustion state of an engine;
- and means for controlling said combustion control means based on an EGR gas flow rate signal and an EGR gas temperature signal.
9 more elements
Dependencies are inferred from the claim text.