Abstract: Disclosed here is a control unit employed for an internal combustion engine and provided with air flow sensor output correcting element capable of correcting a detected voltage error to occur in the air flow sensor according to a surge voltage and a supply voltage at each actuation of the thermal type air flow sensor. The thermal type air flow sensor output correcting element includes surge time measuring element for measuring a surge time in a value detected in the thermal type air flow sensor at the time of the sensor power on and supply voltage detecting means. The output correcting element thus calculates a warming-up characteristic correction amount for the thermal type air flow sensor according to the measured surge time and the detected supply voltage.

Abstract: Disclosed here is a control unit employed for an internal combustion engine and provided with air flow sensor output correcting means capable of correcting a detected voltage error to occur in the air flow sensor according to a surge voltage and a supply voltage at each actuation of the thermal type air flow sensor. The thermal type air flow sensor output correcting means includes surge time measuring means for measuring a surge time in a value detected in the thermal type air flow sensor at the time of the sensor power on and supply voltage detecting means. The output correcting means thus calculates a warming-up characteristic correction amount for the thermal type air flow sensor according to the measured surge time and the detected supply voltage.

Abstract: An air flow rate measuring apparatus having an air flow sensor and a temperature sensor which are disposed in a passage for intake air formed in the vicinity of a main air flow guide chamber in an internal combustion engine. The electric characteristics of the air flow sensor vary with the flow rate of air flowing by the sensors. The air flow sensor and temperature sensor have the same shape and the same construction. The temperature sensor is used to compensate the temperature of the air flow sensor so as to maintain the air flow sensor at a predetermined temperature. These sensors are arranged in the same plane that is at right angles to the direction in which said intake air flows. The sensors are extended parallel to each other in symmetrical relationship with respect to the center line in the above-mentioned plane. Conductor support pins to which the sensors are fixed are also arranged symmetrically with respect to the center line in the mentioned plane.

Abstract: An intake barrel connected to an intake pipe of an internal combustion engine is provided therein with a venturi member. Openings are formed in the wall of the intake barrel at the upstream and downstream sides of the venturi member. A bypass passage forming member provided with a groove of a length greater than the distance between said openings is fixed to the outside of the intake barrel. A bypass passage is formed by these openings and the groove. A spacer is interposed between the intake barrel and the bypass passage forming member. The cross-sectional area of the bypass passage can be varied by varying the thickness of the spacer.

Abstract: An air flow rate sensor including a resistor the characteristic of which depends on temperature for operation mounted in a suction conduit of an internal combustion engine. The air flow rate sensor includes a tube of inorganic material, a platinum wire wound in convolutions on the surface of the tube, and a glass coating applied at least to the surface of the resistor while allowing a part of the surface to be exposed. The glass coating has a thickness smaller than the diameter of the resistor wire and enables equalization of pulsations of the sensor output to be obtained because of the thermal capacity of the glass coating.

Abstract: An air intake apparatus for the internal combustion engine is disclosed comprising a heating resistor placed in a bypass for passing the air of an amount in a predetermined ratio to the amount of the air passing through a main air path communicating with the internal combustion engine, the bypass circumventing or detouring the main air path. The bypass body for defining the bypass is made of a synthetic resin material in order to prevent heat conduction to the heating resistor from an external source.