Abstract: An air conditioning system including a refrigerant circulation route, a compressor, a condenser, an expansion valve, an evaporator and a pressure sensor for detecting pressure in the circulation route comprises a refrigerant phase detecter provided on the circulation route between the condenser and the evaporator where the refrigerant should be in a liquid phase for detecting whether the refrigerant is in a liquid phase or in a vapor phase and a control for determining whether the compressor is in a locked state in accordance with the signals from the refrigerant phase detecter and the pressure sensor. The air conditioning system can precisely determine and detect both compressor lock up and refrigerant leakage without providing a rotation detecting sensor for the compressor.

Abstract: An air conditioning system including a refrigerant circulation route, a compressor, a condenser, an expansion valve, an evaporator and a pressure sensor for detecting pressure in the circulation route comprises a refrigerant phase detector provided on the circulation route between the condenser and the evaporator where the refrigerant should be in a liquid phase for detecting whether the refrigerant is in a liquid phase or in a vapor phase and a control for determining whether the compressor is in a locked state in accordance with the signals from the refrigerant phase detector and the pressure sensor. The air conditioning system can precisely determine and detect both compressor lock up and refrigerant leakage without providing a rotation detecting sensor for the compressor.

Abstract: A refrigerant overcharge prevention system is applied to a refrigerant charging apparatus which has a refrigerant supply source and a refrigerant supply pipe connected to a refrigerant circuit of a cooling apparatus. The charging apparatus charges refrigerant into the refrigerant circuit while activating a compressor provided in the refrigerant circuit. The system comprises a refrigerant flow suppressing mechanism provided in the refrigerant supply pipe for preventing an excessive flow of refrigerant being charged, a refrigerant charge determining sensor provided in a high-pressure side path of the refrigerant circuit for determining whether the amount of charged refrigerant reaches a desired level by sensing a change of the state of refrigerant present in the refrigerant circuit, and a compressor deactivating circuit for deactivating the compressor in response to the determination of the refrigerant charge determining sensor.

Abstract: A refrigerator having a refrigerant circulating circuit for circulating a mixture of a refrigerant and a refrigerating machine oil. The refrigerator includes a compressor with a bypass circuit or a variable displacement compressor, a state detecting sensor for sensing the degree of separation of the refrigerant mixture, determining circuit for determining whether the detected degree of separation is in a two phase separation area, and a control unit for controlling the amount of the refrigerant passing through the bypass circuit or the displacement of the variable displacement compressor. When the refrigerant mixture enters into the two phase separation area, the amount of discharge or the displacement of the compressor is decreased. The temperature of refrigerant mixture is lowered accordingly and the phase changes from the two phase separation area. The refrigerating machine oil is maintained in a uniformly mixed state with the refrigerant and circulates with the refrigerant to the compressor.

Abstract: An apparatus for controllably sucking intake air into each cylinder of an internal combustion engine and method for controlling the intake air quantity of the internal combustion engine are disclosed in which, in an intake air passage, a first throttle valve associated with an acceleration element (accelerator pedal) is installed in a portion of the intake air passage located upstream of an intake manifold and a plurality of second throttle valves are installed in intake ports branched from the intake manifold whose opening angle is controlled by means of an actuator in response to a control signal input thereto. In addition, a bypass passage is connected between the intake air passage upstream of the first throttle valve and exits of the intake ports downstream of the second throttle valves to provide a swirl stream of the intake air sucked into each combustion chamber and a bypass intake air quantity control valve is installed in the bypass passage.

Abstract: An air conditioning system having a circuit for determining whether sufficient refrigerant is present in the system by detecting a phase state of the refrigerant. The circuit comprises a comparison circuit for comparing a detection signal of a state detecting sensor with a first reference value and a second reference value lower than the first reference value. An indication signal is output after the detection signal exceeds the first reference value until the detection signal is less than the second reference value. When the amount of refrigerant in the system is proper, even if the detection signal varies due to translucent lubricating oil in the refrigerant, the indication signal is continued to be output unless the detection signal drops below the second reference value. The amount of refrigerant in the refrigerant circuit can be accurately determined and maintained within a proper range.

Abstract: An air/fuel mixture ratio learning control system for an internal combustion engine using a mixed fuel employs a learnt correction coefficient which is used both in a FEEDBACK mode air/fuel ratio control and in an OPEN LOOP mode air/fuel ratio control. The learnt correction coefficient is derived based on a FEEDBACK air/fuel ratio dependent correction coefficient per one of preselected engine driving ranges and per one of preselected concentration ranges of one fuel component contained in the mixed fuel. The learnt correction coefficient is cyclically derived in a preselected stable engine driving condition during the FEEDBACK mode air/fuel ratio control for updating a previously derived and stored one to minimize a deviation of the FEEDBACK correction coefficient from a reference value.

Abstract: When the engine throttle valve is closed or very nearly closed, the induction vacuum assumes a level whereat the flow of exhaust gas through the EGR conduit can be induced to assume a sonic level and maximize. Under these conditions, by opening the EGR control valve and checking the change in induction pressure, the amount of recirculation can be monitored in a manner which enables partial EGR conduit blockage and/or similar types of malfunctions to be detected.

Abstract: A system for identifying a misfired cylinder of a multiple cylinder internal combustion engine is provided. The system comprises a sensor which monitors revolutional cycles of cylinders respectively to determine a parameter associated with a variation in an average effective pressure of the cylinder in a preselected relation to the revolutional cycles. When the parameter is less than a preselected level, the system corrects the parameter by a correction factor to provide a second parameter in order to prevent reduction in the average effective pressure due to wavering of engine speed after misfire occurs from causing erroneously detection of the misfire cylinder. The system then compares the second parameter with a slice level to detect occurrence of misfire and identifies the misfired cylinder.

Abstract: An air/fuel ratio control system derives a air/fuel ratio dependent correction value for correcting a basic fuel delivery amount as a proportional-integral control value composed of a proportional component and an integral component. The proportional component is derived on the basis of an air/fuel ratio indicative signal which varies the signal level when the air/fuel ratio varies across a predetermined stoichiometric value. The integral component is derived on the basis of a basic fuel delivery amount which is derived on the basis of engine speed and an engine load.

Abstract: In a fuel supply control system for an internal combustion engine, a voltage value to be applied to a fuel pump is controlled depending on a monitored alcohol concentration contained in a fuel to allow the fuel pump to supply a controlled amount of the fuel which is determined based on the monitored alcohol concentration contained in the fuel.

Abstract: An engine control system derives a basic fuel supply amount on the basis of preselected parameters including an intake air volume associated value and modifies the derived basic fuel supply amount in such a manner that the modified fuel supply amount becomes equal to the basic fuel supply amount derived on the basis of the preselected parameters when the engine is not in an acceleration state satisfying a predetermined first condition, and the modified fuel supply amount varies at a greater rate than variation rate of the basic fuel supply amount derived on the basis of the preselected parameters when the engine is in the accelerating state satisfying the predetermined first condition. The basic fuel supply amount as modified may be further modified with a correction value during the engine accelerating state satisfying a predeermined second condition.

Abstract: A fuel supply control system introducing the feature of learning in assuming or projecting an intake air flow rate while an engine driving condition is maintained in a sonic flow range, in which intake air path area is maintained substantially constant and intake air flow rate is varied linearly according to variation of an engine speed. The system also detects the engine driving condition in the sonic flow range and the engine speed maintained substantially constant to derive a basic fuel supply amount on the basis of boost pressure. The assumed intake air flow rate is derived on the basis of the basic fuel supply amount and the engine speed. The system derives the basic fuel supply amount on the basis of the assumed intake air flow rate and the engine speed when the engine speed varies within the sonic flow range.

Abstract: A fuel injection control system derives a correction coefficient for compensating overshooting component in measurement of an engine load indicative parameter, such as an intake air flow rate. The correction coefficient may be variable in such a manner that it increases according to increasing of the engine load. The correction coefficient may be used for correcting either the measured engine load parameter or the fuel injection amount derived taking the measured engine load.

Abstract: An engine control system introduces a technology of assuming actually required fuel amount to be delivered to each engine cylinder at opening timing of an intake valve of the engine cylinder. In order to derive the assumed fuel demand, a basic fuel supply amount is derived on the basis of a basic fuel supply control parameter including an engine speed data and an intake air amount representative data, an air induction path area variation ratio data and a lag time data from derivation of the air induction path area variation ratio data to opening of the intake valve. The assumed fuel demand data can be used not only for controlling fuel supply but also for spark ignition timing control, air/fuel ratio control and so forth so that the engine operation control may precisely follow the actual engine driving condition for optimizing the engine performance.

Abstract: A rotary turbine fluid pump employs unique configurations of turbine vane receptacle opening and turbine vanes. The turbine vane receptacle is connected to a circumferentially extending fluid path, in which free ends of turbine vanes are inserted for pressurization of the fluid therein. The turbine vane receptacle operation has pair of surfaces opposing and spaced apart to each other. Each surface is radially tapered toward the center at a first inclination rate. Each turbine vane is provided edges opposing the surfaces of the turbine vane receptacle operation. The edges are correspondingly tapered at a second rate which is determined so that the spacing between the surface and the edge is gradually increased toward the rotation center of the turbine. This construction minimizes friction increasing when the pressure balance in floating seal formed between the surface and the edge is destroyed.

Abstract: An air/fuel ratio control system employs an altitude dependent learnt uniform correction coefficient which is applicable for all engine driving range and another engine driving range based correction coefficient learnt with respect to responsive engine driving range. The uniform correction coefficient is cyclically updated on engine driving range based correction coefficient. The control system performs FEEDBACK mode air/fuel ratio control with the learnt uniform correction coefficient and the engine driving range based correction coefficient. On the other hand, the control system performs OPEN LOOP mode air/fuel ratio control with the learnt uniform correction coefficient.

Abstract: A fuel injection control system is directed a sequential injection type fuel injection internal combustion engine for injecting fuel to each engine cylinder at different timings. Acceleration enrichment asynchronous fuel injection is initiated in response to an acceleration demand. Acceleration enrichment is further performed for subsequent injection cycles to compensate for engine load indicative sensor signals which differ from actual engine load due to errors in an air flow meter.

Abstract: An apparatus for use with a multi-cylinder internal combustion engine including a plurality of fuel injectors, each being operable in its open position for injecting fuel into an intake port with which an intake valve is in cooperation for regulating the entry of combustion ingredients into the corresponding cylinder. The apparatus includes a control circuit for operating the fuel injectors in a predetermined sequence. The control circuit determines a length of time one fuel injector to be operated is in its open position in response to selected engine operating conditions. The control circuit opens the one fuel injector at a time to terminate the determined time length substantially at the same time when the corresponding intake valve opens. In addition, the control circuit prolongs the determined time length in response to a demand for engine acceleration produced when the one fuel injector is in its open position.

Abstract: An air/fuel ratio control system is designed for detecting small deceleration and subsequently detecting small magnitude acceleration. When small magnitude acceleration is detected, a LAMBDA control correction value which is utilized for deriving fuel injection amount, is fixed at a predetermined value for a predetermined period. The air/fuel ratio utilized during the aforementioned period is set at a value greater than the instantaneous value at a timing at which a demand for small magnitude acceleration is detected.