To obtain a physical quantity detection apparatus that can reduce the outer shape of a housing in size. A physical quantity detection apparatus 300 detects a plurality of physical quantities of gas 30 to be measured flowing in a main passage 124. The physical quantity detection apparatus 300 has a housing 302 disposed in the main passage 124, a circuit substrate 400 insert molded in the housing 302, and a plurality of detection sensors 452, 453, 454, 455, and 456 each mounted on each of one face and the other face of the circuit substrate 400.

A physical quantity measurement device measures a physical quantity of a fluid. The device includes a passage flow channel, a branch flow channel, a flow channel partition portion that separates the passage flow channel and the branch flow channel to have the branch flow channel branch off from the passage flow channel, and a physical quantity detector. The flow channel partition portion has a partition top portion as an upstream-side end that is not exposed through the inflow port.

An engine system includes: an engine main body; an intake pipe; a mass flow sensor that is provided in the intake pipe and outputs a measurement value of an amount of air passing through the intake pipe; an exhaust pipe; a removal device that is provided in the exhaust pipe and removes an air pollutant included in an exhaust gas passing through the exhaust pipe; a recirculation pipe; a recirculation valve that controls a flow rate of the exhaust gas flowing from the recirculation pipe to the intake pipe; a regeneration control unit that closes the recirculation valve; an air amount calculation unit that calculates a theoretical value of an amount of air flowing to the intake side of the engine main body on the basis of a quantity of state of the engine main body during the regeneration process; and a correction unit.

A flowmeter is disposed in a passage through which a fluid flows. The flowmeter includes a first passage and a second passage. The first passage defines a first opening through which at least a part of the fluid flows into the first passage from the passage. The second passage branches off from the first passage and includes a flow rate detector configured to detect a flow rate of the fluid flowing through the second passage from the first passage. The first passage includes a vortex reducer configured to restrict a vortex from generating.

A device which measures a physical quantity of a gas flowing through a main passage is described. The device includes a flange for fixing to the main passage; a housing that protrudes toward an inside of the main passage from the flange; and a printed circuit board fixed to the housing on which a measuring element that measures the physical quantity is mounted. Wiring of the printed circuit board has a plurality of irregularities formed along one direction of a surface, and the wiring is arranged such that a formation direction of the irregularities is oriented along a protruding direction of the housing toward an inside of the main passage. The irregularities may be polishing marks formed using a cylindrical polishing wheel or rolling marks of the wiring of the printed circuit board.

A marine outboard motor is provided with an internal combustion engine comprising an engine block defining at least one cylinder, an air intake configured to deliver a flow of air to the at least one cylinder; and an air intake duct forming part of an air intake path for delivering the flow of air to the air intake. The engine further includes a flow sensing arrangement located in the air intake duct and comprising a flow meter configured to generate a signal indicative of a flow rate of the flow of air through the air intake duct, and a bluff body located in the air intake duct upstream of the flow meter, wherein the flow meter is a vortex shedding flow meter.

A physical quantity measurement device includes a physical quantity detector and a support plate part superposed on a back surface of the physical quantity detector to support the physical quantity detector. The physical quantity detector includes a recessed part on the back surface, and a membrane part defining a bottom surface of the recessed part and being provided with a detection element for detecting a physical quantity of a fluid in a measurement low path. An area of the support plate part covering the recessed part includes a communication hole communicating with the recessed part. A peripheral edge portion of a hole opening, which is an end of the communication hole adjacent to the recessed part, is spaced apart, toward the inside, from a peripheral edge portion of a recess opening, which is an end of the recessed part adjacent to the support plate part.

The physical quantity measurement device for measuring the physical quantity of the fluid has a measurement flow passage through which the fluid flows; a detection element for detecting the physical quantity of the fluid; a plate-shape physical quantity detector that detects the physical quantity of the fluid by the detection element in the measurement flow passage; a protection body that protects the physical quantity detector; a body recess arranged on the outer surface of the protection body at a position separated from the physical quantity detector in the orthogonal direction, which is orthogonal to a thickness direction of the physical quantity detector.

A precleaner system for an air intake system. The precleaner system includes precleaners each having flow paths that induce a rotation to air flow and separate out particulate matter. The particulate matter is ejected from an outlet port in each of the flow paths and out of a dust ejector. The precleaned air is collected into a plenum from each of the precleaners. The precleaned air can flow from the plenum to a precleaner system outlet and the precleaned air can be received by an air intake system. A cover can be used to block air flow through one of the precleaners to tune the precleaner system to the desired airflow.

A physical quantity measurement device includes a physical quantity detector that detects a physical quantity of a fluid in a measurement flow path, a physical quantity processor that receives a detection result of the physical quantity detector, and a support plate part that supports the physical quantity detector and the physical quantity processor. The support plate part includes a detector support portion to which the physical quantity detector is attached, and a processor support portion that is located at a position spaced apart from the detector support portion and to which the physical quantity processor is attached. Between the detector support portion and the processor support portion, a heat transfer regulation portion is provided to regulate heat transfer from the processor support portion to the detector support portion.