Abstract: A method and apparatus are disclosed for measuring atmospheric pressure in conjunction with an air-fuel ratio sensor of the type comprising a concentration cell with atmospheric air and exhaust electrodes on opposite sides of a solid-state electrolyte having oxygen ion conductivity. During an atmospheric pressure measuring cycle, oxygen ions are pumped from the atmospheric air electrode to the exhaust electrode, in a quantity which is either predetermined at a fixed value, or is sufficient to bring the cell to an equilibrium state. Atmospheric pressure is then calculated from measured emf of the cell, using an experimentally derived functional relationship. In a second embodiment, ions are pumped until a predetermined change of the concentration cell emf is achieved, and atmospheric pressure is determined based on the amount of time required to achieve such change. The atmospheric pressure measuring mode is operated on a time shared basis with the air-fuel ration detection mode.

Abstract: A semiconductor acceleration sensor is formed by a cantilever having a conductive movable electrode of predetermined mass at one end, at least one pair of fixed conductive electrodes which are stationary with respect to the movable electrode located on opposing sides of the movable electrode, and gaps provided between the movable electrode and the fixed electrodes. To prevent the movable electrode becoming fused to the contacted fixed electrode, in a first aspect of this invention, an insulating layer is provided between the movable electrode and fixed electrodes, the layer being either on the movable electrode or on the fixed electrodes and in a second aspect the movable electrode or, preferably, the fixed electrodes, are formed of a high melting point material. In such a second aspect, to improve adhesion between the high melting point material and a substrate to which the fixed electrodes are mounted, a lower melting point material is firstly coated on the substrates.

Abstract: An air fuel ratio detecting arrangement using a diffusion suppressing type air fuel ratio sensor applicable to an air fuel ratio control unit for an internal combustion engine incorporating an atmospheric air pressure correction circuit in a signal processing and outputting device for correcting an output voltage signal processed therein based on a change in atmospheric air pressure which is detected when a predetermined operating condition of an internal combustion engine is satisfied. A secular change correction circuit included in the signal processing and outputting device detects a change in electromotive force of a concentration cell portion of the air fuel ratio sensor when a predetermined rich air fuel ratio is reached and corrects a reference voltage for the air fuel ratio sensor based on the detected change in electromotive force of the concentration cell portion in addition to an air calibration circuit.

Abstract: Disclosed is a non-contact type throttle angle sensor sensing and converting angular rotation of a throttle valve of an internal combustion engine into an electrical signal. The sensor comprises a magnetic field generating element disposed on one end of a rotatable throttle shaft, a magneto-sensitive element disposed opposite to the field generating element at a position fixed relative to a throttle body and spaced apart from the field generating element, the magneto-sensitive element generating an output whose level changes with the rotation of the throttle valve shaft relative to the throttle body, a housing forming an integral part of the throttle body to accommodate the field generating element and the magneto-sensitive element, and an electrical circuit converting the output of the magneto-sensitive element into an electrical signal, the electrical circuit including a circuit adjusting the zero level and maximum level of the output of the magneto-sensitive element.

Abstract: A resistor main body of a hot film exothermic resistor includes a ceramic body with leads bonded to both end portions thereof, a platinum film body formed on a ceramic body, a spiral trimming groove formed in the platinum film body, and a glass material overcoated on the platinum film body and the ceramic body. The resistor main body projects in the upstream direction of the flow of such that the ratio of a length l.sub.1 of the resistor main body to the diameter d.sub.1 of the resistor main body is 25>l.sub.1 /d.sub.1 >14, and the leads are bent adjacent both end portions. The response speed characteristics, contamination preventing capability and temperature dependency of the hot film exothermic resistor is improved over conventional devices, and the level of noise in the output signal therefrom can be reduced over conventional devices.

Abstract: Apparatus for sensing oxygen concentration using a solid electrolyte of cylindrical shape, with a heater disposed within the solid electrolyte, is disclosed. The member supporting the heater, and the leads for the heater, are integrally bonded to the heater through an inorganic bonding member such as glass. By integrally bonding the support member and leads through an inorganic bonding member, the heater length can be reduced.

Abstract: A thermal air flow meter is equipped with a flow rate detector utilizing the phenomenon that heat is carried away in proportion to flow rate. The flow rate detector comprises a support, a heat-sensitive resistor formed on the support and leads attached to both ends of the support. To make the temperature distribution uniform, the heat-sensitive resistor is formed in such a manner that the resistance per unit length of the heat-sensitive resistor at either end of the support is greater than the resistance per unit length of the heat-sensitive resistor at the center of the support. This arrangement can provide a thermal air flow meter which has a rapid response to changes in flow rate.

Abstract: Air flowing through an air cleaner is passed through a main passage and drawn into an internal-combustion engine, with a part of the air flowing through the main passage flowing into a by-pass passage having an air flow sensor mounted therein. A length of the by-pass passage is substantially three or more times longer than that of a part of the main passage corresponding thereto. Accordingly, even when the internal-combustion engine is operated with a throttle nearly totally open and the air in the main passage is pulsated, the average flow rate in the by-pass passage increases due to the inertial lag effect obtained by lengthening the by-pass passage, so that it is possible to prevent the output of the flow sensor from being undesirably lowered.

Abstract: An air flow rate measuring apparatus in which an air flow sensor whose electric characteristic varies with the rate of air flowing by the sensor is supported on a heat-insulating support member and located in a bypass tube provided in the vicinity of the main venturi of an internal combustion engine, whereby the air flow sensor is isolated from adverse thermal influences so as to reduce an error in measuring air flow rate.

Abstract: A thermal air flow meter consists essentially of a hollow cylindrical support made of an insulating material, a heat-sensitive resistor formed on top of the support, and lead wires inserted into the hollow part of the support from either end and bonded thereto by glass. This flow meter measures the flow rate from changes in the resistance of the heat-sensitive resistor with temperature. The ratio of the inner diameter d.sub.2 of the support to the outer diameter d.sub.3 of the lead wires (d.sub.2 /d.sub.3) is at least 1.7. This arrangement can provide a thermal air flow meter with a quick response to changes in flow rate.

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.

Abstract: A sensor for detecting a fluid flow velocity or flow amount with high precision and high reliability is made by applying a conductor paste comprising platinum powder and an organic vehicle to the outer surface of a fine inorganic insulating tube, followed by drying and firing, thereby forming a platinum film, processing the platinum film into a spiral band form by laser application, inserting a lead wire into the insulating tube, applying a platinum conductor paste to between the spiral platinum band and the lead wire, followed by drying and baking, thereby connecting the spiral platinum band film to the lead wire.

Abstract: A first cylindrical member formed of an ion-conducting solid electrolyte is sealed at one end thereof by a discal plate and inserted at the other end thereof into an axial central bore, formed in a supporting member, in such a manner that the other end of the first cylindrical member is in airtight contact with an offset portion formed in an inner wall surface of the supporting member defining the axial central bore. The first cylindrical member has a first electrode formed on its inner wall surface and a second electrode formed on its outer wall surface. First and second conductors are formed at upper end portions of the first and second electrodes respectively. A second cylindrical member closed at its bottom and housing therein the first cylindrical member in enclosing relationship supports the latter at its bottom and is rigidly secured at its upper end to the supporting member.

Abstract: A protective layer of zirconia particles having particle sizes of 0.5-5 .mu.M is provided on a surface of an electron-conducting layer of an oxygen sensor at a side of a gas whose oxygen concentration is to be detected to a thickness of 4-100 .mu.M by bonding zirconia particles to one another and the first electron-conducting layer by 10-30% by weight of a high melting point adhesive, such as powders of borosilicate glass, based on total weight of the zirconia particles.