THERMAL AIR FLOWMETER

• Main Authors: OGATA KIMITOSHI, ISHIZUKA NORIO, TOKUYASU NOBORU, MORINO TAKESHI, TASHIRO SHINOBU
• Format: Patent
• Language: English; Japanese
• Published: 02.02.2015
• Subjects: MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a thermal air flowmeter which secures high accuracy in positioning a flow rate detection part, and furthermore has high measurement accuracy by reducing an influence of thermal stress caused in a resistor within an LSI (Large Scale Integration).SOLUTION: The thermal air flowmeter includes: a sensor assembly 100 constituted in such a way that an LSI 3 having a resistor 7 and a flow rate detection part 4a are insert-molded so as to expose at least a portion of the flow rate detection part 4a; and a housing 301 having sub-passages 305i, 305o, and 305s and housing the sensor assembly 100 in such a manner as to dispose the flow rate detection part 4a inside the sub-passage 305s. In the thermal air flowmeter, the sensor assembly 100 is molded of a first resin, and the housing 301 is molded of a second resin. The sensor assembly 100 is fixed to the housing 301 with the second resin, and provided with resin structures 20 and 21 which cause in the sensor assembly 100 tensile stress parallel to an exposed surface of the flow rate detection part 4a. 【課題】本発明の目的は、流量検出部の高い位置決め精度を確保しつつ、ＬＳＩ内の抵抗体に発生する熱応力の影響を低減することで、計測精度の高い熱式空気流量計を提供することである。【解決手段】抵抗体７を有するＬＳＩ３と流量検出部４ａとを、流量検出部４ａの少なくとも一部が露出するようにインサートモールドして構成したセンサアセンブリ１００と、副通路３０５ｉ，３０５ｏ，３０５ｓを有し流量検出部４ａを副通路３０５ｓ内に配置してセンサアセンブリ１００を収容する筐体３０１とを備え、センサアセンブリ１００が第一の樹脂でモールド成形され、筐体３０１が第二の樹脂でモールド成形された熱式空気流量計において、センサアセンブリ１００は第二の樹脂で筐体３０１に固定されており、センサアセンブリ１００に対して流量検出部４ａの露出面に平行な引張応力を生じさせる樹脂構造２０，２１を備える。【選択図】図４