Abstract: A Mass Flow Sensor (MFS) is provided and includes an MFS housing, a mounting structure, having a mounting structure top and a mounting structure bottom, wherein the MFS housing is associated with the mounting structure top, a first sensor leg, wherein the first sensor leg extends away from the mounting structure bottom and includes a first temperature measurement device and a heating element. The MFS further includes a second sensor leg, wherein the second sensor leg extends away from the mounting structure and includes a second temperature measurement device and an airfoil structure, wherein the airfoil structure defines an airfoil cavity and is associated with the mounting structure bottom to contain the first sensor leg and the second sensor leg.

Abstract: An object is to improve measurement accuracy of a flow rate measurement device. A flow rate measurement device including: a first void which is formed of one surface of the support body and one surface of the circuit board; a second void which is formed of a surface opposite to the one surface of the circuit board and the housing; and a third void which is formed of a surface opposite to the one surface of the support body and a cover.

Abstract: A system has a first temperature sensor located at a first location. A second temperature sensor is located at a second location. A control is configured to determine a difference between voltages indicated of a temperature sensed by each of the first and second sensors. A method is also disclosed.

Abstract: A Molded Air Intake System and Method for Internal Combustion Engines. The method of the present invention permits the single-shot molding of an air intake system, such as by roto-molding. The resultant air intake system has an internal pipe element and an external element, both of which are formed with superior molding tolerances. The internal pipe element is defined by an inner mold form that is insertable and removable from an external mold form. The final molded part defines an outer wall and an inner wall and an MAFS mounting pad having inner and outer apertures formed therethrough.

Abstract: In a measurement control device that measures an airflow, an amplitude calculator calculates, by use of an output value of a sensor, a pulsation amplitude that is a difference between a pulsation maximum and an average airflow or a difference between the pulsation maximum and a pulsation minimum. The pulsation maximum is a maximum value of pulsation generated in the airflow, the average airflow is an average value of the pulsation, and the pulsation minimum is a minimum value of the pulsation. A correction parameter acquirer acquires a correction parameter corresponding to the calculated pulsation amplitude by use of a correction characteristic. An airflow corrector corrects the airflow by use of the acquired correction parameter.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path in which a sensor support supports a physical quantity sensor. The measurement flow path includes a sensor path in which the physical quantity sensor is disposed, an upstream curved path between the sensor path and an inlet, and a downstream curved path between the sensor path and an outlet. The housing includes a measurement narrowed portion that gradually narrows the measurement flow path in a direction from the inlet toward the physical quantity sensor. An upstream end of the sensor support is provided upstream of the measurement narrowed portion in an arrangement cross section along an imaginary straight line passing through the physical quantity sensor and extending in an arrangement direction in which the upstream curved path and the downstream curved path are arranged.

Abstract: A physical quantity measuring device is configured to measure a physical quantity of a fluid. The physical quantity measuring device includes: at least two humidity detection parts configured to output a humidity signal corresponding to a humidity of the fluid; and an abnormality determination part configured to determine that an abnormality has occurred in the humidity detection parts in response to that a difference between the humidity signals obtained from the two humidity detection parts exceeds an abnormality determination threshold.

Abstract: A physical quantity measurement device includes a housing forming a through flow path, and a measurement flow path branching from the through flow path. A physical quantity sensor is provided in the measurement flow path. An inner surface of the housing includes an inlet ceiling surface and an inlet floor surface which face each other and define an inlet through path that is between and connects an inlet of the through flow path and an inlet of the measurement flow path, The inlet ceiling surface includes a ceiling inclined surface that extends from the inlet of the through flow path and is inclined with respect to the inlet floor surface. A distance between the ceiling inclined surface and the inlet floor surface gradually decreases in a direction from the inlet of the through flow path toward an outlet of the through flow path.

Abstract: Mass flow controllers and methods for controlling mass flow controllers are disclosed. A method includes providing a gas through a thermal mass flow sensor of the mass flow controller and processing a flow sensor signal from the thermal mass flow sensor of the mass flow controller to produce a measured flow signal. The measured flow signal is corrected to produce a corrected flow signal by gradually changing non-linearity correction to the measured flow signal when a flow rate of the gas changes. A valve of the mass flow controller is controlled using the corrected flow signal and a setpoint signal.

Abstract: A flow rate measurement system outputs a measurement value which represents a magnitude of a flow rate and a flow direction of a fluid that flows through a particular main passage. The system includes a bypass passage disposed in the main passage, a detection unit disposed in the bypass passage that outputs a detection value corresponding to a magnitude of a flow rate and a flow direction of the fluid flowing through the bypass passage, and a calculation unit that, by using the detection value, calculates the measurement value by compensating as needed for a delay in the change in flow rate in the bypass passage with respect to the change in flow rate in the main passage. The compensation is based on whether a change of flow direction has occurred in the main passage or the bypass passage.

Abstract: 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.

Abstract: A gas appliance includes a burner, a gas valve, and a control device, wherein the gas valve includes a valve body, a flow regulator, a hot film anemometer, and a stepper motor. The valve body communicates with the burner and a gas source. The flow regulator is driven by the stepper motor to change a gas flow rate supplying to the burner. The hot film anemometer is disposed in the valve body and includes a probe exposed to the outlet passage. The control device executes a control method for the gas valve: sensing the gas flow rate in the outlet passage with the hot film anemometer; comparing the gas flow rate sensed by the hot film anemometer with a predetermined gas flow rate, and controlling the stepper motor to drive the flow regulator based on the comparison result, whereby to stabilize the gas flow rate.

Abstract: Provided is a flow rate measuring device including a connector portion, a main body portion, an internal flow passage, and a flow rate detection element. The internal flow passage includes a main flow passage and a sub-flow passage. The sub-flow passage includes a flow rate detection element-side flow passage and connection flow passages. The main flow passage includes an introduction portion, a small flow passage sectional area portion, and an exit portion. The connection flow passages include an upstream-side connection flow passage and a downstream-side connection flow passage. The main flow passage and the flow rate detection element-side flow passage are formed so as to be symmetric with respect to a plane having a flow direction of the fluid to be measured flowing through the pipe as a normal. The main flow passage has a portion at the plane of symmetry as the small flow passage sectional area portion.

Abstract: There is provided an air cleaner including: an outlet pipe through which air is discharged; an airflow meter that is inserted toward an interior of the outlet pipe through a wall of the outlet pipe; and a flow-regulating member that is formed projecting from an inner surface of the outlet pipe at a side of the airflow meter, the flow-regulating member including an edge that is formed with a peaked shape with respect to the inner surface and that runs along a direction of flow of air, a rear end that is formed at a downstream end of the edge in the direction of flow, and that is shaped cut sharply toward the inner surface and a width-narrowing portion that decreases in width in a circumferential direction of the outlet pipe on progression downstream in the direction of flow.

Abstract: A purification method comprises providing a purification device comprising at least one exhaust gas purification member having an upstream surface through which the exhaust gas enters the purification member and a downstream surface through which the exhaust gases exit the purification member. The method further includes, in the absence of forced circulation of the exhaust gas through the purification member by an engine of the vehicle, heating radiatively at least either the upstream zone or the downstream zone, for example before starting the engine of the vehicle.

Abstract: An air flow measurement device that measures an air flow rate based on an output value of a sensing unit attached in an environment in which air flows, the air flow measurement device is provided. The air flow measurement device may calculate an average air amount, which is an average value of the air flow rate, from the output value. The air flow measurement device may calculate a pulsation maximum value, which is a maximum value of the air flow rate, from the output value.

Abstract: An air flow rate measurement device capable of suppressing disturbance of a flow of measured gas and reducing a characteristic influence due to water droplets flowing with intake air is realized. An edge 800 of the upstream side where air flows in a circuit board 400 on which a flow rate detection portion 602 is mounted is provided with a segmentation portion 801 to be a semicircular notch structure to segment the edge 800. Water droplets flowing with measured gas 30 can be captured by the segmentation portion 801 to inhibit the water droplets from arriving at the flow rate detection portion 602.

Abstract: There is provided an air cleaner including: an outlet pipe through which air is discharged; an airflow meter that is inserted toward an interior of the outlet pipe through a wall of the outlet pipe; and a flow-regulating member that is formed projecting from an inner surface of the outlet pipe at a leading end side of the airflow meter, the flow-regulating member including an edge that is formed with a peaked shape with respect to the inner surface and that runs along a direction of flow of air, a rear end that is formed at a downstream end of the edge in the direction of flow, and that is shaped cut sharply toward the inner surface and a width-narrowing portion that decreases in width in a circumferential direction of the outlet pipe on progression downstream in the direction of flow.

Abstract: A case is equipped to an intake passage where a mainstream of air flows toward an engine. The case has a bypass passage which draws a part of the mainstream. A sensor is equipped to the bypass passage. The case has an external wall as a side wall extending along the mainstream direction in which the mainstream flows. The bypass passage has an outlet port formed in the side wall as an opening which opens in a direction substantially perpendicular to the mainstream direction. The airflow measuring device further includes a throttle located on the upstream side in the mainstream direction than a center of the opening to throttle a stream of air which flows outside the case along the side wall. The throttle throttles the stream of air to flow toward a downstream side and to merge with air flowing out from the opening.

Abstract: The present disclosure aims to stabilize, in an engine with a supercharger, a detection result of an intake air temperature sensor interposed between the supercharger and an intercooler. A gas outlet of a supercharger and a gas inlet of an intercooler are connected together via a second passage. The second passage includes, in its middle position, a narrow region with a smaller cross-sectional area than the part of the second passage extending from an upstream end of the second passage to the middle position. The narrow region is provided with the intake air temperature sensor configured to detect the gas temperature in the narrow region.

Abstract: In some examples, a mass airflow sensor apparatus includes a housing having a tubular bore for passage of air, with an airflow sensor disposed at least partially within the tubular bore. The airflow sensor may be configured to measure a flow rate of air flowing past the airflow sensor. A focus component may be disposed upstream of the mass airflow sensor, the focus component including a cylindrical tubular focus member suspended within the bore. Further, a nozzle may be disposed upstream of the focus component. The nozzle may include a conical inner surface angled toward a center of the bore. In addition, a grid component may be disposed upstream of the focus component. The grid component may include a mesh grid including a plurality of openings for smoothing a flow of air flowing toward the airflow sensor.

Abstract: This signal processing unit includes: a comparison signal output unit which outputs a comparison signal on a negative side that corresponds to a negative side portion, of a second amplitude-increased signal, which is on the negative side with respect to the comparison threshold TH; an averaging processing unit which outputs an average signal obtained by averaging the comparison signal; a coefficient multiplication processing unit which outputs a coefficient-multiplied signal obtained by multiplying the average signal by an adjustment coefficient set in advance; and a signal correction processing unit which outputs, as a flow rate signal, a value obtained by correcting a first amplitude-increased signal so as to be decreased by use of the coefficient-multiplied signal, wherein the comparison threshold TH is set on the basis of an output characteristic of a sensor measured in advance with respect to at least a forward flow direction of an intake air.

Abstract: A control system for use in a fluid flow application is provided. The control system includes a heater having at least one resistive heating element. The heater is adapted to heat the fluid flow. The control system further includes a control device that uses heat loss from at least one resistive heating element to determine flow characteristics of the fluid flow.

Abstract: A flow measuring device includes a sub-bypass passage arranged to precede a bypass passage which is linked to a flow detecting element. Bypass passage wall surfaces, which are positioned adjacent the sub-bypass passage, are inclined toward a direction of a sub-inflow opening, and an inner-circumference-side wall surface and an outer-circumference-side wall surface of the sub-bypass passage are inclined toward a direction of a sub-outflow opening. The described structure minimizes variations in the size of the bypass passage due to build-up of foreign material, and results in a more stable flow velocity of measured fluid past the flow detecting element.

Abstract: To prevent a circuit board and circuit board wiring from being damaged at the time of assembling a physical quantity detection device. A physical quantity detection device of the present invention is characterized by having, on a circuit board, a sensor unit wherein a flow rate detection unit is disposed, a circuit unit wherein a circuit element is disposed, and a partitioning wall that partitions the sensor unit and the circuit unit from each other. The physical quantity detection device is also characterized in that an internal layer conductor for electrically connecting the flow rate detection unit and the circuit unit to each other is provided on a circuit board internal layer where the partitioning wall is positioned.

Abstract: A proportional flow meter includes a processor, a measurement channel including a measurement device and a first flow comparison sensor, a bypass channel including a second flow comparison sensor, the measurement and bypass channels operably coupled to an input. The processor may obtain a first measurement from the measurement device and a second measurement from the first flow comparison sensor, where the first and second measurements represent a flow volume of a first portion of a fluid flowing through the measurement channel, and also a third measurement from the second flow comparison sensor, representing a flow volume of a second portion of the fluid flowing through the bypass channel. The processor may determine a ratio of the third measurement to the second measurement, and may determine a total flow volume of the fluid through the measurement and bypass channels collectively based on the first measurement and the determined ratio.

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.

Abstract: A change amount per unit time of an engine output command for controlling engine output of an internal combustion engine is calculated as an engine output increasing rate, and a power supply device is controlled so that power corresponding to the calculated engine output increasing rate is supplied to a combustion promoter generation device. The combustion promoter generation device generates a combustion promoter through the power supplied from the power supply device to supply the combustion promoter to a combustion chamber of the internal combustion engine, and a generation amount of the combustion promoter increases as the supplied power increases. In this manner, the generation amount of the combustion promoter is adjusted.

Abstract: The present disclosure provides an air flow rate measuring device disposed in an intake air passage. The air flow rate measuring device measures a flow rate of the intake air flowing through the intake air passage. The air flow rate measuring device includes a casing, a flow rate sensor, and a sensor module. The casing defines a bypass passage to take in a portion of the intake air. The flow rate sensor is disposed in the bypass passage. The flow rate sensor generates an output signal according to a flow rate of the intake air. The sensor module protrudes from an outer wall of the casing. The sensor module includes a multi-sensor unit that has a relative humidity sensor and a temperature sensor. The relative humidity sensor is exposed to an inside of the intake air passage to detect a relative humidity of the intake air flowing through the intake air passage. The temperature sensor detects a temperature of the intake air flowing through the intake air passage.

Abstract: A sensor for determining at least one parameter of a fluid medium flowing through a measuring channel, in particular an intake air mass flow of an internal combustion engine. The sensor includes a sensor housing, in particular a plug-in sensor which is inserted or is insertable into a flow tube, in which a channel structure is formed, which includes the measuring channel, and at least one sensor chip situated in the measuring channel for determining the parameter of the fluid medium. The sensor housing includes an inlet into the channel structure, which is oriented away from a main flow direction of the fluid medium, and at least one outlet from the channel structure. The channel structure is delimited by wall sections. The wall sections have at least partially electrically insulating properties. Areas of the sensor housing adjoining the wall sections have electrically conductive properties.

Abstract: A flow rate measuring device measures a flow rate of a main flow flowing through a duct. The flow rate measuring device includes a bypass passage, a flow rate sensor, and a measurement body. The measurement body includes a measurement flow inlet opening toward an upstream side of the duct and a cylindrical portion opening toward a downstream side of the duct. The cylindrical portion is disposed to cover the measurement flow outlet. The cylindrical portion includes an outer circumferential surface guiding the main flow and an inner circumferential surface guiding the measurement flow. The cylindrical portion includes a waveform portion formed in an edge side of an opening of the cylindrical. The waveform portion divides the main flow guided by the cylindrical portion into a plurality of main flows and divides the measurement flow guided by the cylindrical portion into a plurality of measurement flows.

Abstract: In one example embodiment, a filter condition measurement device features an engine data repository, one or more sensor units, and a measurement unit. The measurement system is configured to identify a first flow value corresponding to a sensed engine power value from the engine data repository, determine a filter coefficient for the filter as a function of the first flow value and the sensed delta-pressure value; identify a second engine power value from the plurality of stored engine power values and a second flow value corresponding to the second engine power value; and determine a second delta-pressure value for the air filter as a function of the filter coefficient and the second flow value.

Abstract: An intake air heating system for a vehicle includes an electrical switching device configured to selectively connect a battery of the vehicle to a heater coil in contact with intake air of the vehicle. The intake air heating system includes a control circuit configured to, in response to an enable signal from an engine controller, drive the electrical switching device to connect the battery to the heater coil at full current. The control circuit is configured to measure a resistance of the heater coil indicative of an initial temperature of the heater coil and, in response to an estimated temperature of the heater coil exceeding a desired temperature value, modulate the electrical switching device to reduce current from the battery of the vehicle to the heater coil.

Abstract: A sensor assembly includes a sensor portion and a sensor circuit, which are integrated with each other and configured to measure an air flow quantity. A thermistor is configured to measure an air temperature. A metal plate includes a grounding end terminal. One lead wire of the thermistor is joined electrically with the grounding end terminal. The sensor circuit is disposed on the metal plate. The sensor circuit is entirely overlapped with the plate shape portion in a direction perpendicular to the metal plate.

Abstract: A thermal flow meter capable of measuring flow rates of a gas flowing in a forward direction and a backward direction with a high degree of accuracy is provided. A thermal flow meter 300 according to the present invention includes a bypass passage configured to retrieve and flow a measurement target gas 30 received from a main passage 124 and a flow rate measurement circuit 601 configured to measure a flow rate by performing heat transfer with the measurement target gas flowing in the bypass passage.

Abstract: An intake air heating system for a vehicle includes an electrical switching device configured to selectively connect a battery of the vehicle to a heater coil in contact with intake air of the vehicle. The intake air heating system includes a control circuit configured to, in response to an enable signal from an engine controller, drive the electrical switching device to connect the battery to the heater coil at full current. The control circuit is configured to measure a resistance of the heater coil indicative of a temperature of the heater coil. The control circuit is configured to, in response to the temperature of the heater coil exceeding a desired temperature value, modulate the electrical switching device to reduce current from the battery of the vehicle to the heater coil.

Abstract: A measuring sensor for a motor vehicle, including a body and an electronic measurement module having an integrated circuit for measurement management and a plurality of connection pins that are able to be linked to an electrical communication network of a motor vehicle. The sensor includes an electrical component carrier to which an electrical component is fastened, the component having a first connection wire, connected electrically to a first portion of a first connection pin of the plurality of connection pins of the electronic measurement module and a second connecting wire, connected electrically to a second portion of a second connection pin of the plurality of connection pins of the electronic measurement module.

Abstract: A filter box assembly for a branched intake system in a vehicle includes an air filter and a filter box housing the air filter. The air filter has a downstream face. The filter box defines an airflow path between a dirty air intake opening and multiple clean air output openings, has a clean air section at the downstream face of the air filter from which each of the clean air output openings open, and includes an interior wall in the clean air section that branches the airflow path to each of the clean air output openings at the downstream face of the air filter.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: In a thermal flow meter that can simplify a manufacturing process and that has high measurement accuracy, a circuit package includes a passage portion, in which an air flow sensing portion is arranged, and a processing unit, in which a circuit is arranged. The circuit package is fixed to a fixing portion integrally formed with the circuit package, and the passage portion of the circuit package is held in a bypass passage. At least a portion of an end spaced apart from a fixing wall of the passage portion of the circuit package is exposed in the bypass passage.

Abstract: Provided is a thermal flow meter through which a measurement with high accuracy and has a discharge function. In a thermal flow meter 300 of the invention, a part of a measurement target gas 30 flowing through the main passage 124 flows into a bypass passage. A drainage passage 3528 is provided in the bypass passage to communicate a bypass passage 4232 on the inlet port (between the inlet port 350 and the measurement surface 430 serving as the air flow sensing portion) and a bypass passage 4234 on the outlet port (between the measurement surface 430 serving as the air flow sensing portion and the outlet port 352). The drainage passage 3528 includes a through hole 3512. The through hole 3512 includes an inlet port 3542 which penetrates a wall surface 4212 forming the bypass passage 4232 on the inlet port and is opened in the bypass passage 4232 on the inlet port, and an outlet port 3544 which is opened in a rear surface 4213 of the wall surface.

Abstract: A heat-ray type of airflow meter has a signal processor for converting a detected intake air quantity into a frequency signal. An engine controller has a conversion table for converting the frequency signal into an air quantity. The signal processor and the conversion table have features such that the frequency increases as the magnitude of a positive air quantity increases, and the frequency decreases as an absolute value of a negative air quantity increases. In the conversion table, a prescribed positive air quantity value is assigned a dummy output for frequencies lower than a prescribed threshold value. Under normal circumstances, frequencies lower than a minimum value are not used. The frequency decreases to near 0 Hz when there is a disconnection or a short circuit, the dummy output is therefore output, and an injection quantity equal to or greater than a misfire limit is ensured.

Abstract: In one example embodiment, an engine flow measurement device features an engine data repository, one or more sensor units, and a measurement unit. The measurement system is configured to identify, from performance data, a maneuver performed during operation of the aircraft and to measure, for the identified maneuver, a plurality of maneuver flow values achieved during performance of the maneuver. The plurality of maneuver flow values correspond to a plurality of maneuver engine power values. Each of the plurality of maneuver flow values represent a volume of air flow through the air filter at a particular moment during performance of the maneuver.

Abstract: In order to provide a thermal flow meter for improving workability of a flow rate measurement device having a temperature measurement function for the measurement target gas and measurement accuracy for measuring a temperature, the thermal flow meter is structured such that a flow rate measurement circuit package having a protrusion for measuring a gas temperature is formed through resin molding. An inlet port opened to the upstream side of the measurement target gas is formed, a protrusion is arranged inside the inlet port, an inlet port and an outlet port are formed in the front and rear covers along the protrusion, and the measurement target gas received from the inlet port flows along the protrusion. Since the measurement target gas subjected to the measurement flows along the protrusion, it is possible to reduce influence of the heat from other heat resources and improve measurement accuracy.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flowmeter 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: Provided is a thermal type flowmeter in which contamination of a sensor element is reduced. The flowmeter includes a sensor element including a heating resistor formed in a thin film part, the thin film part being provided on a diaphragm formed on a substrate; a support member to locate the sensor element thereon; a secondary channel that includes part of the support member and takes in part of intake air flowing through an air intake pipeline; and a guide member provided on the support member or the sensor element that lies on a line L that extends along an air flow in the secondary channel and passing over the thin film part, the guide member allowing fine particles to be guided in a direction away from the line L, the fine particles coming together with an air flow along the surface of the support member or the sensor element.

Abstract: A sensor system is provided for determining at least one parameter of a fluid medium flowing through a channel, in particular an intake air mass flow of an internal combustion engine. The sensor system includes a sensor housing, in particular a plug-in sensor which is introduced or is introducible into a flow tube, in which the channel is formed, and at least one sensor chip which is situated in the channel for determining the parameter of the fluid medium. The sensor housing has an inlet into the channel which points counter to a main flow direction of the fluid medium, and at least one outlet from the channel in a surface of the sensor housing. The surface of the sensor housing has multiple recesses upstream from the outlet viewed in the main flow direction.

Abstract: To improve measurement accuracy of a thermal flow meter. The present invention provides a thermal flow meter, in which a protrusion 356 having an orifice surface 503 and a recovery surface 505 is provided on a wall surface 501 of a bypass passage, an intersection line 506 between the orifice surface 503 and the wall surface 501 is arranged in an upstream side from an upstream side end 401 of a circuit package 400, an intersection line 507 between the recovery surface 505 and the wall surface 501 is arranged in a downstream side from a downstream side end 402 of the circuit package 400, and an apex 504 of the protrusion 356 is arranged in a downstream side from a heat transfer surface of an air flow sensing portion 602 and in an upstream side from the downstream side end 402 of the circuit package 400.

Abstract: A method of modifying an engine after the engine has been initially sold by the manufacturer of the engine, wherein the engine has an air intake pipe and an air flow sensor, wherein the air intake pipe has an exterior wall surface and an interior wall surface, and wherein the air flow sensor has a sensing head disposed at a first location within the air intake pipe spaced apart from the interior wall surface of the air intake pipe, includes the step of: repositioning the sensing head from the first location to a second location, wherein the second location is closer to the interior wall surface of the air intake pipe than the position of the sensing head at the first location.

Abstract: A second sensor includes a lead wire and is exposed to intake air flowing through a passage outside a housing. A conduction body is conductively-joined to the wire. A lead hole opens on an exposed surface, and the wire or the conduction body is pulled out of the passage through the hole. A predetermined terminal is conductively-joined to the wire or the conduction body which is pulled out through the hole. A mold part is provided by injection-molding from resin fluid to seal a conductively-joined part between the wire or the conduction body and the predetermined terminal. The hole is filled up with a filler material to limit leakage of intake air from the passage. A high resilient part has higher resilience than the filler material and is located between the filler material and the mold part to receive injection pressure at time of the injection-molding of the mold part.