THERMAL FLOW METER
    1.
    发明申请
    THERMAL FLOW METER 审中-公开

    公开(公告)号:US20190120674A1

    公开(公告)日:2019-04-25

    申请号:US15765939

    申请日:2016-10-05

    IPC分类号: G01F1/684 G01F1/696

    摘要: 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.

    THERMAL FLOWMETER
    2.
    发明申请
    THERMAL FLOWMETER 审中-公开

    公开(公告)号:US20180313680A1

    公开(公告)日:2018-11-01

    申请号:US15771007

    申请日:2016-10-19

    IPC分类号: G01F1/684

    摘要: 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.

    THERMAL FLOWMETER
    3.
    发明申请
    THERMAL FLOWMETER 审中-公开

    公开(公告)号:US20190323871A1

    公开(公告)日:2019-10-24

    申请号:US16464867

    申请日:2017-09-27

    摘要: 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.

    THERMAL FLOWMETER
    4.
    发明申请
    THERMAL FLOWMETER 审中-公开

    公开(公告)号:US20190162570A1

    公开(公告)日:2019-05-30

    申请号:US16092025

    申请日:2017-04-20

    IPC分类号: G01F1/684 F02M35/10

    摘要: 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.

    Thermal Flowmeter
    5.
    发明申请
    Thermal Flowmeter 审中-公开

    公开(公告)号:US20200326218A1

    公开(公告)日:2020-10-15

    申请号:US16090656

    申请日:2017-04-13

    IPC分类号: G01F1/684

    摘要: 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.

    Thermal Flowmeter
    6.
    发明申请
    Thermal Flowmeter 审中-公开

    公开(公告)号:US20190137311A1

    公开(公告)日:2019-05-09

    申请号:US16307318

    申请日:2017-06-14

    摘要: 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.

    THERMAL FLOWMETER
    7.
    发明申请
    THERMAL FLOWMETER 审中-公开

    公开(公告)号:US20170276525A1

    公开(公告)日:2017-09-28

    申请号:US15505703

    申请日:2015-07-10

    IPC分类号: G01F1/684 G01F1/69

    摘要: The present invention provides a thermal flowmeter having good measurement accuracy by reducing deviation in the flow velocity distribution of a gas under measurement flowing through an auxiliary passage. An auxiliary passage 330 for taking in a portion of a gas under measurement IA flowing through a main passage 124 has a curved passage 32a that bends toward a flowrate measurement element 602. The curved passage 32a has a resistance portion 50 formed therein that applies resistance to the flow of the gas under measurement IA flowing through the outer peripheral side CO of the curved passage 32a so that the pressure loss of the gas under measurement IA flowing through the outer peripheral side CO is high compared to that of the gas flowing through the inner peripheral side CI of the curved passage 32a.