In an engine control device, a saturated water vapor pressure Ps is calculated from an intake temperature detected by an intake air temperature sensor. A water vapor partial pressure is worked out from the saturated water vapor pressure and humidity detected by a humidity sensor. A specific humidity q and a molar fraction are worked out from the water vapor partial pressure and an atmospheric pressure detected by an atmospheric pressure sensor. A moist air amount is calculated from an intake air amount detected by an AFS on the basis of the molar fraction, and a dry air amount is calculated from this moist air amount on the basis of the specific humidity. A fuel injection amount, an ignition timing, and a target throttle opening are then calculated on the basis of various operation information, using the moist air amount, the dry air amount, and the specific humidity.

A flow measuring device includes a housing including a bypass passage and a flow sensing chip located in the bypass passage and including a sensing surface portion. A throttle portion that is a part of a flowing passage wall facing a sensing surface portion throttles a cross-sectional area of a bypass passage. A position where the throttle portion starts is referred to as a start point position, and a position of the throttle portion where a distance between a gravity center of the sensing surface portion and the throttle portion is shortest is referred to as an end point position. The start point position and the end point position define an imagination line, and the imagination line and the flowing direction define an angle that is in a range from 0 degrees to 20 degrees.

The present disclosure provides a method for measuring air mass flow using an air mass flow meter. The air mass flow meter comprises a sensor element for detecting an air mass flow (Q) and for generating a signal (S), and an electronic circuit for processing the signal (S) from the sensor element, wherein the sensor element generates a non-linear signal characteristic. The method may include converting the non-linear signal into a correcting, non-linear signal characteristic, then filtering the correcting, non-linear signal characteristic, then converting the filtered non-linear signal characteristic into a non-linear signal characteristic, and then generating an output signal relaying the signals (S) detected by the sensor element and processed by the linearization element, the filter element, and the conversion element.

Provided is a thermal flow meter that can be prevented from being eroded due to adhesion of water or like to a cut end portion of the lead exposed from the mold resin of the circuit package. A thermal flow meter 300 of the present invention is a thermal flow meter having a circuit package 400 formed by mounting a detection element 518 on leads 544 and 545 supported by a support frame 512, sealing with a mold resin, and cutting off the support frame 512, wherein cut end portions 544a and 545a of the leads 544 and 545 exposed from the mold resin of the circuit package 400 by cutting off the support frame 512 is covered by a covering portion 371.

For diagnosing a proper functioning of an auxiliary heater in an air mass sensor in an engine system including an internal combustion engine, the auxiliary heater being used for preventing contamination of a sensor area, the air mass sensor communicating air mass information via a signal line during a sensor operating mode and, if a specified state on the signal line is detected, activating the auxiliary heater, the following are performed: setting the state of the signal line to the specified state for a predefined time period in an auxiliary heater operating mode; transmitting a first temperature information before the activation of the auxiliary heater operating mode and a second temperature information via the signal line after expiration of the predefined time period; and detecting the proper functioning of the auxiliary heater depending on the difference between the first temperature information and the second temperature information.

The present invention provides a thermal flow meter 300 which reduces a stress applied from a fixing portion 3721, which is used to hold and fix a circuit package 400 with respect to a housing 302, to the circuit package 400 and has high reliability. In the thermal flow meter of the invention, the circuit package 400 embedded with a flow rate measurement circuit is formed through a first resin molding process, the fixing portion 3721 is formed along with the housing 302 through a second resin molding process, and the circuit package 400 is enveloped by the fixing portion 3721, whereby the circuit package 400 is held by and fixed to the housing 302. In order to reduce the influence of a stress, generated based on a temperature change of the fixing portion 3721, on the circuit package 400, the fixing portion 3721 is constituted of a thick portion 4714 and a thin portion 4710. Since thickness of a resin of the thin portion 4710 is small, the stress to be generated is small, and a force applied to the circuit package 400 can be reduced.

An air flow measuring device is adapted to be attached to a duct. The device includes a first housing, a second housing, and a flow sensor. The first housing defines a bypass flow passage which takes in a part of air flowing in the duct, and includes a hollow part and a recess. The bypass flow passage is formed in the hollow part. The recess is formed on an upper side of the hollow part in a vertical direction of the device, and at the recess, an outer surface of the first housing is recessed inward of the first housing. The second housing is formed through secondary formation with the first housing as a primary formed part. The first housing is held on a lower side of the second housing in the vertical direction. The flow sensor is disposed in the bypass flow passage.

Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector provided in a thermal flow meter is a thermal flow meter to improve the measurement accuracy of a temperature detector provided in a thermal flow meter. The thermal flow meter includes a bypass passage through which a measurement target gas 30 flowing through a main passage flows, and a circuit package 400 which includes a measurement circuit for measuring a flow rate of the measurement target gas 30 flowing through the bypass passage and a temperature detecting portion 452 for detecting a temperature of the measurement target gas. The circuit package 400 includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion 424 molded by the resin. The temperature detecting portion 452 is provided in the leading end portion of the protrusion 424, and at least the leading end portion of the protrusion protrudes to the outside from a housing 302.

Provided is a thermal flow meter that can be prevented from being eroded due to adhesion of water or like to a cut end portion of the lead exposed from the mold resin of the circuit package. A thermal flow meter 300 of the present invention is a thermal flow meter having a circuit package 400 formed by mounting a detection element 518 on leads 544 and 545 supported by a support frame 512, sealing with a mold resin, and cutting off the support frame 512, wherein cut end portions 544a and 545a of the leads 544 and 545 exposed from the mold resin of the circuit package 400 by cutting off the support frame 512 is covered by a covering portion 371.

A flow rate measuring apparatus includes: a flow rate detecting device placed in an intake passage; a detection circuit for outputting an analog signal varying depending on the flow rate; a conversion circuit for converting the analog signal to a digital signal; a temperature detecting device for detecting an ambient temperature; and a correction circuit for primarily correcting the digital signal using a gain and/or an offset (correction coefficient) that can set the temperature coefficient in any appropriate way. The gain and/or the offset vary depending on the temperature coefficient set in any appropriate way and the ambient temperature detected by the temperature detecting device. Also, a plurality of the gains and/or the offsets are set depending on the flow rate, allowing the temperature characteristic error in flow rate measurement to be reduced.