公开(公告)号：US20190323871A1

公开(公告)日：2019-10-24

申请号：US16464867

申请日：2017-09-27

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Akira UENODAN ,  Masashi FUKAYA ,  Tomoaki SAITO ,  Shinobu TASHIRO ,  Tsubasa WATANABE

IPC: G01F1/684 ,  G01F15/04 ,  G01K13/02 ,  G01F5/00 ,  F02D41/18

Abstract: A thermal flowmeter includes a plurality of measuring units for stabilizing air flowing in a sub-passage, and improves noise performance or a pulsation characteristic of a flow rate sensor. The thermal flowmeter includes a flange fixed to an attachment part of a main passage, a sub-passage takes in a part of measured gas flowing in the main passage, a flow rate measuring unit measures a flow rate of the measured gas in the sub-passage, a circuit component controls the flow rate measuring unit, and the flow rate measuring unit and an electronic component are mounted on a circuit substrate. The sub-passage is formed in a substrate of the circuit substrate, the sub-passage on a surface side of the circuit substrate and a second space on a rear surface side are separated by the circuit substrate, and a pressure measuring unit and the circuit component are arranged in the second space.

公开(公告)号：US20190162570A1

公开(公告)日：2019-05-30

申请号：US16092025

申请日：2017-04-20

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Akira UENODAN ,  Tomoaki SAITO ,  Naoki SAITO ,  Masashi FUKAYA ,  Shinobu TASHIRO

IPC: G01F1/684 ,  F02M35/10

Abstract: Provided is a thermal flowmeter capable of reducing a measurement error during pulsation of a fluid as compared with that in the related art.The thermal flowmeter includes: a sub-passage 307 that takes a part of a gas 30 to be measured flowing through a main passage; and a flow measurement unit 451 disposed inside the sub-passage 307. The sub-passage 307 includes: a first passage 351 provided on a measurement surface 451a side of the flow measurement unit 451; a second passage 352 provided on a back surface 451b side of the flow measurement unit 451; and an inclined passage 361 provided on an upstream side of an inlet 351a of the first passage 351 in a forward flow direction F of the gas 30 to be measured in the first passage 351. The inclined passage 361 includes a first inclined surface 371, which is inclined from the second passage 352 side toward the first passage 351 side with respect to the forward flow direction F, to be closer to the second passage 352 side than the flow measurement unit 451.

公开(公告)号：US20180313680A1

公开(公告)日：2018-11-01

申请号：US15771007

申请日：2016-10-19

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Masashi FUKAYA ,  Shinobu TASHIRO ,  Akira UENODAN ,  Tomoaki SAITO ,  Naoki SAITO

IPC: G01F1/684

Abstract: The objective is to provide a thermal flowmeter that prevents a backflow generated from a trailing vortex downstream of the thermal flowmeter from inhibiting a flow flowing out from a dust discharge port. An opening surface of a dust discharge port is formed in a position that is displaced at least with respect to the direction of a backflow of air resulting from a trailing vortex generated as a result of the flow of air at a lower end surface in which the dust discharge port is formed. The main flow in an intake pipe flows from an upstream side to a downstream side, it is possible to avoid the flow from the dust discharge port opposing head-on a backflow from a trailing vortex on the lower end surface side, and suppress a reduction in the dust discharging effect and a worsening of mass flow rate measurement errors.

公开(公告)号：US20190120674A1

公开(公告)日：2019-04-25

申请号：US15765939

申请日：2016-10-05

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Takeshi MORINO ,  Shinobu TASHIRO ,  Akira UENODAN ,  Tomoaki SAITO ,  Masashi FUKAYA

IPC: G01F1/684 ,  G01F1/696

Abstract: The present invention addresses the problem of obtaining a thermal flow meter capable of reducing a pulsation error by preventing a discharge port and a main outlet from being blocked by a vortex during a transient period and reducing a difference between flow speed distributions in normal and pulsation states. This thermal flow meter is provided with a housing disposed in a main passage; and a sub passage provided in the housing. In addition, in the housing, a first outlet and a second outlet of the sub passage are disposed in a downstream end portion of the housing, and a curved surface section is provided adjacent to the first and second outlets.

公开(公告)号：US20200326218A1

公开(公告)日：2020-10-15

申请号：US16090656

申请日：2017-04-13

Applicant: Hitachi Automotive Systems, Ltd.

Inventor： Masashi FUKAYA ,  Shinobu TASHIRO ,  Akira UENODAN ,  Naoki SAITO ,  Tomoaki SAITO

IPC: G01F1/684

Abstract: Provided is a thermal flowmeter enabling a measurement error while fluid is pulsating, to fall below that of a conventional one. The thermal flowmeter includes a sub-passage configured to take in part of the fluid flowing in a main passage; and a flow-amount measuring unit disposed in the sub-passage. The sub-passage has a first passage provided on a measurement face side of the flow-amount measuring unit; a second passage provided on a back face side of the flow-amount measuring unit; and a slope passage provided on a downstream side in a forward direction of the fluid in the second passage with respect to an outlet of the second passage. The slope passage has a first slope face on a first passage side with respect to the flow-amount measuring unit, the first slope face sloping from a second passage side to the first passage side with respect to the forward direction.

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.

公开(公告)号：US20190137311A1

公开(公告)日：2019-05-09

申请号：US16307318

申请日：2017-06-14

Applicant: Hitachi Automotive Systems, Ltd.

Inventor： Tomoaki SAITO ,  Shinobu TASHIRO ,  Naoki SAITO ,  Masashi FUKAYA ,  Akira UENODAN

IPC: G01F1/684 ,  F02D41/18 ,  G01F1/688 ,  G01F1/696

Abstract: The object of the invention is to obtain a thermal flowmeter which effectively causes water droplets to be directed to a discharge port when the water droplets adhered to a wall surface of a first passage are drawn into a third passage portion. A thermal flowmeter of the present invention includes a sub-passage that takes a measurement gas flowing through a main passage; and a flow detection unit that measures a flow rate of the measurement gas by performing heat transfer with the measurement gas flowing through a sub-passage. Further, the sub-passage includes a first passage, a second passage portion branching in the middle of the first passage portion to be directed toward the flow detection unit; and a third passage portion branching in the middle of the second passage portion to be directed toward a third outlet, and a pressure loss generation means is provided between a third inlet and the third outlet of the third passage portion.