公开(公告)号：US20200326217A1

公开(公告)日：2020-10-15

申请号：US16757614

申请日：2018-12-14

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Tomoaki SAITO ,  Masayuki SATOU ,  Akira TAKASAGO ,  Noboru TOKUYASU

IPC: G01F1/684 ,  G01F1/696

Abstract: Provided is a thermal flowmeter that can achieve both measurement accuracy and antifouling performance with a simple and space-saving passage structure. In the thermal flowmeter of the invention, a housing is disposed in a main passage through which a gas to be measured flows, and the gas to be measured is taken from the main passage into an auxiliary passage provided in a housing, and a flow rate detection unit disposed in the auxiliary passage measures a flow rate of the gas to be measured. The auxiliary passage includes an inlet opening that opens to be inclined with respect to the main flow direction of the gas to be measured flowing through the main passage, and an inclined passage that extends in a direction inclined with respect to the main flow direction of the gas to be measured flowing from the inlet opening through the main passage.