Abstract: An air intake system for an internal combustion engine which does not impair detection performance of a flow sensor without impairing intrinsic function thereof even when a distance between the flow sensor (4) and as inlet port (80) for a recirculating air is dimensioned short. The air intake system includes a recirculating air passage (8) for recirculating a blow-by gas (B) leaking into a crankcase (13) connected to an engine cylinder (1) to an intake air passage (2a).

Abstract: A Karman vortex flow meter has a detection passages located along a fluid flow in a duct 1. Flow outlets of the detection passage are disposed on an end face of a vortex generation element and flow inlets 3 are disposed upstream from the flow outlets. Heating coils for detecting flow velocity change of a fluid caused by a negative pressure of a Karman vortex are mounted in the detection passage, and swell portions are formed upstream from the heating coils in the detection passage. The flow meter that can prevent water drops, bubbles, etc., from adhering to heating coils, etc., and detect Karman vortexes stably.

Abstract: An object of the present invention is to obtain a highly accurate thermosensitive flowmeter in which flow rate characteristic errors and temperature characteristic errors of a flow rate signal voltage are small. According to the present invention, flow rate characteristic errors and temperature characteristic errors of a thermosensitive resistor caused by trimming adjustment made on the thermosensitive resistor can be reduced by providing unvaried profile of heating area on the thermosensitive resistor. Bridge balance is adjusted so that the heat value of the thermosensitive resistor correspond with predetermined value, and gain of amplifier is adjusted so that the flow rate signal voltage correspond with predetermined value.

Abstract: A pyroelectric IR-sensor in which a pyroelectric light receiving element is mounted on a MID substrate or a ceramic substrate having a thermal conductivity less than 0.02 cal/cm.sec..degree.C. Both ends of the pyroelectric light receiving element are supported by the substrate, with the central portion of the pyroelectric light receiving element being spaced from the substrate. Chip parts are mounted on the substrate.

Abstract: In a thermal flow sensor comprising a cylindrical housing, a straight-pipe-shaped detecting tube, and a heat-sensitive resistor provided in the detecting tube, the housing has a net at its one end opening through which fluid to be measured flows therein, and no net is provided at the other end opening. Instead, an insertion preventing member is provided downstream of the heat-sensitive resistor and inside the detecting tube to prevent the insertion of an unwanted object such as the finger into the detecting tube.

Abstract: A pyroelectric IR-sensor in which a pyroelectric light receiving element is mounted on a MID substrate or a ceramic substrate of which thermal conductivity is less than 0.02 cal/cm.sec..degree. C. in a manner that both end portions of the pyroelectric light receiving element are supported by the substrate with the central portion of the pyloelectric light receiving element being spaced from the substrate, and chip parts are further mounted on the substrate.

Abstract: A pyroelectric IR-sensor in which a pyroelectric light receiving element is mounted on a MID substrate or a ceramic substrate having a thermal conductivity less than 0.02 cal/cm.multidot.sec.multidot..degree.C. Both ends of the pyroelectric light receiving element are supported by the substrate, with the central portion of the pyroelectric light receiving element being spaced from the substrate. Chip parts are mounted on the substrate.

Abstract: A semiconductor pressure sensor device that improve the measuring accuracy without providing a silicon base in attaching a semiconductor pressure sensor chip to a lead frame, and a method of manufacturing thereof is disclosed. The semiconductor pressure sensor device includes a die-bond adhesive 10 formed of a resilient material for fixing a semiconductor pressure sensor chip 50 to a lead frame 100, a wire bond receiving projection 4 provided in the diepad where the semiconductor pressure sensor chip 50 is attached for receiving pressure application force from the bottom of the semiconductor pressure sensor chip 50 at the time of wire bonding, and a supporting projection 11 for preventing distortion stress by the wire bond receiving projection 4 from being transmitted. Thermal distortion of the semiconductor pressure sensor chip 50 and the lead frame 100 is absorbed by die-bond adhesive 10.

Abstract: A pressure sensor comprising a hollow main body (11) defining a bore (14) extending therethrough and having a detection end and an output end. A pressure sensing assembly is disposed within said bore (14) to divide it into a detection cavity (17) and an output cavity (18) through which output signal lines from said pressure sensing assembly extend. A flexible diaphragm (19) is attached to the detection end of the bore to define a sealed detection cavity (17) in which a pressure transmitting liquid is filled. The pressure sensing assembly comprises support plate (24) welded to said main body (11) and supporting a pressure sensing element (26) within said detection cavity (17) through a mounting bed (4). The signal lines sealingly extend through said support plate (24) from said detection cavity (17) to said output cavity (18).

Abstract: A pressure sensor comprising a case, a diaphragm provided within the case, a pressure detecting part provided within the case for detecting pressure applied to the diaphragm, and a pressure transmission chamber formed between the diaphragm and the pressure detecting part for sealingly accommodating therein liquid through which the pressure is transmitted from the diaphragm to the pressure detecting part. The pressure transmission chamber is arranged to cope with the volume changes of the liquid due to the temperature changes thereof.

Abstract: A fuel supply system including an evaporated fuel gas purge system measuring a purge gas quantity in purging which comprises: evaporated fuel gas adsorption means having at least a suction port, an exhaust port, a purge port, a chamber in which an adsorption agent that adsorbs an evaporated fuel gas is filled, and detecting means for detecting a quantity of adsorption by the adsorption agent; purge means for purging an adsorbed gas; pressure detecting means for detecting a pressure at a purge gas exhaust part; and suction air temperature detecting means for detecting a temperature of suction air which flows in purging the adsorbed gas. By using the measured value of the purge gas quantity, a fuel injection quantity is corrected, which is determined by an air quantity for suction of the engine corresponding with the purge gas quantity.

Abstract: A semiconductor pressure sensor device that can improve the measuring accuracy without providing a silicon base in attaching a semiconductor pressure sensor chip to a lead frame, and a method of manufacturing thereof is disclosed. The semiconductor pressure sensor device includes a die-bond adhesive 10 formed of a resilient material for fixing a semiconductor pressure sensor chip 50 to a lead frame 100, a wire bond receiving projection 4 provided in the diepad where the semiconductor pressure sensor chip 50 is attached for receiving pressure application force from the bottom of the semiconductor pressure sensor chip 50 at the time of wire bonding, and a supporting projection 11 for preventing distortion stress by the wire bond receiving projection 4 from being transmitted. Thermal distortion of the semiconductor pressure sensor chip 50 and the lead frame 100 is absorbed by die-bond adhesive 10.

Abstract: A fuel control system for an internal combustion engine calculates a first air-fuel ratio based on the output of an air-flow sensor and the injection time of an injector, a second air-fuel ratio based on the suction air quantity from outputs of a throttle opening degree sensor and an engine revolution sensor, and on the injection time of the injector, and a third air-fuel ratio based on the output of an oxygen concentration sensor. A malfunction determiner detects a malfunction of a sensor by comparing the calculated values of the three ratios, and specifies the abnormal sensor when the calculated value based thereon disagrees with those of the other sensors. The throttle opening degree sensor can be replaced with a boost pressure sensor.

Abstract: A Karman vortex generating member is made integral with a sensor portion and supported elastically by a wall of a fluid conduit through a pair of elastic holding members so that externally produced pressure is prevented from being transmitted to the sensor portion.

Abstract: An evaporated fuel gas purging system comprises a chamber having a case and a cap, the chamber being divided into a plurality of sub-chambers by partitioning plates each having through holes; a pair of electrodes provided in one of the sub-chambers, the one of sub-chambers being filled with an adsorbent and communicating with the other sub-chambers having an inlet port, an outlet port and a purge port, respectively; and a control circuit for detecting changes in electrical characteristics between the electrodes so that the amount of a fuel gas adsorbed by the adsorbent is detected. An evaporated fuel gas purging system further comprises a purging unit for purging the adsorbed gas, a control unit for controlling the purging unit, and a display unit operating in response to quantitative changes in the amount of the adsorbed gas.

Abstract: A vortex flowmeter for measuring the flow rate of a fluid flowing into a conduit, wherein a member 5a for disturbing the flow of the fluid is disposed upstream of a vortex generating column 3 for generating vortexes in the fluid to be measured, and upstream of a straightener 4 for uniforming the flow of the fluid into the conduit. The fluid flow is disturbed in both the flow direction and its orthogonal direction, and the generation of vortexes by the vortex generating column is facilitated, while the fluctuation of the generated vortexes is prevented.

Abstract: A vortex flowmeter including a shell member having an inlet and an outlet which are opened in the side wall thereof, a filter element provided in the shell member to define two, upper and lower, chambers inside the shell member and also isolate the inlet and the outlet from each other, a duct connected to the shell member in such a manner as to communicate with the outlet, and a vortex generating device provided inside the duct. A tubular projection is provided at the outlet in such a manner as to extend into the shell member, the projection being tapered toward the outlet, thereby correcting the flow of air flowing into the outlet so that the velocity distribution of air streams inside the duct becomes uniform.

Abstract: A semiconductor pressure sensor comprising two pressure sensing diaphragms attached to a support frame embedded within a bonding agent joining two parts of a housing which defines therein fluid passages in communication with two pressure sensing diaphragms. The support frame includes a support plate portion and terminal portions having the inner ends embedded within the bonding agent and the outer ends projecting outwardly of the bonding agent for external connections. The support frame is formed by cutting a lead frame, which has a support frame portion, terminal portions and a surrounding frame integrally connected together, substantially along the outer contour of the housing except for the terminals. A method for manufacturing the pressure sensor is also disclosed.

Abstract: A vortex flow meter comprises a first diaphragm which divides first and second pressure chambers from each other; a second diaphragm which divides third and fourth pressure chambers from each other and is disposed in such a manner that the direction in which the second diaphragm is movable is coincident with that in which the first diaphragm is movable, and that the direction is not coincident with that of the maximum component of an external force which acts on the diaphragms; first and second bridge circuits which make outputs in response to the action of the first and second diaphragms, respectively; and differential amplifiers which perform the differential amplification of the outputs from the first and second bridge circuits.

Abstract: A vortex flow meter comprises a first diaphragm which divides a first and a second pressure chamber from each other; a second diaphragm which divides a third and a fourth pressure chambers from each other; a first and a second bridge circuits which receive the action of the first and the second diaphragms, respectively; a first and a second variable amplifiers which amplify the outputs from the first and the second bridge circuits, respectively; and a differential amplifier which receives the outputs made by the first and the second variable amplifiers, inverse to each other in polarity and nearly equal to each other in magnitude.