Abstract: To obtain a low-pressure-loss physical quantity detection device that can detect a plurality of physical quantities of intake air. A physical quantity detection device of the present invention that detects a plurality of physical quantities of a measured gas flowing in a main passage, the physical quantity detection device includes: a circuit board on which a sensor that detects the plurality of physical quantities and an electronic component that controls the physical quantities are mountable; a circuit board accommodating unit that accommodates the circuit board; and a sub-passage in which a flow sensor is disposed. The circuit board is accommodated in the circuit board accommodating unit on an upstream side of the sub-passage, and disposed in parallel with the measured gas flowing through the main passage.

Abstract: To obtain a physical quantity detection device that can prevent a thermal influence on a sensor due to downsizing. A physical quantity detection device 20 of the present invention includes a measuring unit 213 protruding from an inner wall of a main passage 22 toward a passage center of the main passage. The physical quantity detection device 20 includes at least one of a flow sensor 205 that detects a flow rate of a measured gas 2, an intake air temperature sensor 203 that detects temperature, a pressure sensor 204 that detects pressure, and a humidity sensor 206 that detects humidity, and the sensors are disposed along a protruding direction of the measuring unit 213.

Abstract: A flow meter includes: a flat substrate; a housing that houses the substrate and has an open in at least one surface; a cover that covers the substrate and covers an open surface of the housing; a support that supports the substrate and is in contact with the cover and the substrate; and a fixing unit that connects the substrate and the housing, in which, in a first region and a second region formed by dividing the substrate into two parts at a center in a longitudinal direction, the support is disposed in the first region, and the fixing unit is disposed in the second region.

Abstract: Provided is a thermal-type flowmeter which can prevent a reduction of flow rate accuracy and reliability, and an increase of cost of the thermal-type flowmeter compared to the related art, and can add a function of an electrostatic scattering mechanism. The thermal-type flowmeter of the present invention includes a sub-passage into which part of a measurement target gas flowing in a main passage is taken, a flow rate detection element of a flow measurement unit which is disposed in the sub-passage, a circuit package which supports the flow rate detection element, and a substrate to which the circuit package is fixed. The flow rate detection element includes a detection surface to detect a flow rate of the measurement target gas. The detection surface is disposed to face the circuit substrate.

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.

Abstract: Provided is a thermal-type flowmeter which can prevent a reduction of flow rate accuracy and reliability, and an increase of cost of the thermal-type flowmeter compared to the related art, and can add a function of an electrostatic scattering mechanism. The thermal-type flowmeter of the present invention includes a sub-passage into which part of a measurement target gas flowing in a main passage is taken, a flow rate detection element of a flow measurement unit which is disposed in the sub-passage, a circuit package which supports the flow rate detection element, and a substrate to which the circuit package is fixed. The flow rate detection element includes a detection surface to detect a flow rate of the measurement target gas. The detection surface is disposed to face the circuit substrate.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

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.

Abstract: A flow meter includes: a flat substrate; a housing that houses the substrate and has an open in at least one surface; a cover that covers the substrate and covers an open surface of the housing; a support that supports the substrate and is in contact with the cover and the substrate; and a fixing unit that connects the substrate and the housing, in which, in a first region and a second region formed by dividing the substrate into two parts at a center in a longitudinal direction, the support is disposed in the first region, and the fixing unit is disposed in the second region.

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.

Abstract: To obtain a flow meter with which it is possible to facilitate establishing an electrical connection with a conductor exposed in a location through which a gas to be measured passes. A flow meter that is provided with a lead and a circuit component placed on the lead, and that has a package in which part of the lead is molded from a resin, wherein the package is provided with an exposure portion for exposing part of the lead from the resin member, the exposure portion being electrically connected to a conductor that constitutes part of an auxiliary passage.

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.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

Abstract: A 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 in a forward flow direction F of the gas (30) to be measured in the first passage (351).

Abstract: To obtain a low-pressure-loss physical quantity detection device that can detect a plurality of physical quantities of intake air. A physical quantity detection device of the present invention that detects a plurality of physical quantities of a measured gas flowing in a main passage, the physical quantity detection device includes: a circuit board on which a sensor that detects the plurality of physical quantities and an electronic component that controls the physical quantities are mountable; a circuit board accommodating unit that accommodates the circuit board; and a sub-passage in which a flow sensor is disposed. The circuit board is accommodated in the circuit board accommodating unit on an upstream side of the sub-passage, and disposed in parallel with the measured gas flowing through the main passage.

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.

Abstract: In order to provide a flow measuring device high in thermal responsiveness, the flow measuring device includes a temperature detecting element 2 for temperature detection, and a conductive metal lead frame 3 that supports and fixes the temperature detecting element. Of the metal lead frame, a part of the metal lead frame mounted with the temperature detecting element has a portion which is thinner than the thickness of the other metal lead frame or narrower than the width of the other metal lead frame.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

Abstract: To obtain a physical quantity detection device that can prevent a thermal influence on a sensor due to downsizing. A physical quantity detection device 20 of the present invention includes a measuring unit 213 protruding from an inner wall of a main passage 22 toward a passage center of the main passage. The physical quantity detection device 20 includes at least one of a flow sensor 205 that detects a flow rate of a measured gas 2, an intake air temperature sensor 203 that detects temperature, a pressure sensor 204 that detects pressure, and a humidity sensor 206 that detects humidity, and the sensors are disposed along a protruding direction of the measuring unit 213.

Abstract: 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.