Abstract: The present invention relates to a fuel cell operation method in which a fuel cell 11 that generates power using hydrogen gas and oxidant gas as reaction gas is operated at an operating pressure that corresponds to a required power generation state. A hydrogen sensor 54 that detects hydrogen density is provided in a vicinity of the fuel cell 11, and based on values detected by the hydrogen sensor 54 and on the amount of hydrogen leakage at the current operating pressure and on the characteristics of the fuel cell 11, an operating pressure is predicted at which the hydrogen leakage amount from the fuel cell will not exceed a predetermined value, and the fuel cell 11 is operated while limiting the operating pressure to below the predicted operating pressure.

Abstract: The present invention relates to a fuel cell operation method in which a fuel cell that generates power using hydrogen gas and oxidant gas as reaction gas is operated at an operating pressure that corresponds to a required power generation state. A hydrogen sensor that detects hydrogen density is provided in a vicinity of the fuel cell, and based on values detected by the hydrogen sensor and on the amount of hydrogen leakage at the current operating pressure and on the characteristics of the fuel cell 11, an operating pressure is predicted at which the hydrogen leakage amount from the fuel cell will not exceed a predetermined value, and the fuel cell is operated while limiting the operating pressure to below the predicted operating pressure.

Abstract: Selectively operable first and second exhaust valves are provided for every combustion chamber in an engine. Branch pipes of a first intake manifold are connected to first exhaust ports opened and closed by the first exhaust valves, and branch pipes of a second exhaust manifold are connected to second exhaust ports opened and closed by the second exhaust valves. An adsorbing trap is provided in an aggregated pipe of the first exhaust manifold and a catalytic converter is provided in a common exhaust pipe connected to the aggregated pipes of the first and second exhaust manifolds. Only the first exhaust valves are operated to open and close at a low temperature of the adsorbing trap to permit the exhaust gas to flow into the first exhaust manifold. Thus, hydrocarbons (HCs) in the exhaust gas are adsorbed into the adsorbing trap at the low temperature and the heat of the exhaust gas is effectively utilized to promote the activation of the catalytic converter.

Abstract: A supercharging pressure control system for supercharged internal combustion engines includes a supercharging pressure control valve for controlling supercharging pressure of intake air, supplied by a supercharger. A desired value of the opening of the supercharging pressure control valve is determined depending on operating conditions of the engine. When the supercharging pressure detected has reached the desired value of the supercharing pressure, a feedback control mode is selected, in which the opening of the supercharging pressure control valve is controlled so as to make the supercharging pressure detected equal to the desired value of the supercharging pressure.

Abstract: A supercharged internal combustion engine includes an intake passage, a supercharger arranged in the intake passage, an exhaust passage, and a catalytic converter arranged in the exhaust passage. A supercharging pressure control system for the engine controls the opening of a supercharging pressure control valve for controlling supercharging pressure of intake air supplied to the engine by the supercharger. When the temperature of the catalytic converter falls outside a predetermined range, the opening of the control valve is controlled in a manner such that the temperature of the catalytic converter is brought into the predetermined range.

Abstract: A fuel supply control system for an internal combustion engine, wherein when the engine is at idle, a correction value is determined based on a difference between a desired idling engine rotational speed and an actual engine rotational speed, and an amount of fuel to be supplied to the engine is corrected by the determined correction value. Correction value-changing means sets a rate of change in the correction value relative to a change in the difference to a greater value when the detecting means detects that the engine means is not engaged with the transmission of an automotive vehicle, and to a smaller value when the detecting means detects that the engine is engaged with the transmisison.

Abstract: An exhaust gas circulation control method for an internal combustion engine in which an exhaust gas recirculating valve is arranged across an exhaust gas recirculating passage extending between the exhaust and intake passages. The opening of the valve is controlled in response to operating conditions of the engine. The exhaust gas circulation is inhibited when the engine load exceeds a predetermined value set in response to the engine temperature such that it is set to a smaller value as the engine temperature is lower.

Abstract: An air-fuel mixture heating device for heating an air-fuel mixture supplied from a carburetor to an intake manifold includes an insulator mounted between the carburetor and the intake manifold and having a first air-fuel mixture passage communicating with the primary air-fuel mixture passage in the carburetor, an electric heater disposed in the first air-fuel mixture passage of the insulator for heating the air-fuel mixture, and a plurality of conductors embedded in the insulator and having portions connected to the electric heater and an electric power supply. The insulator has access holes extending to the portions of the conductors for allowing said portions to be joined to the electric heater therethrough. The access holes are filled up with masses of sealing resin after said portions are joined to the electric heater.

Abstract: A flow control honeycomb structure for use in an intake passage of an engine for producing turbulent flow in an air-fuel mixture flowing through the intake passage, which structure includes a short cylindrical peripheral wall defining therein a circular passage having a substantially circular cross section, a plurality of substantially crisscross partitions joined to and disposed in the peripheral wall and dividing the circular passage into a first group of square passageways each having a substantially square cross section and a second group of four triangular passageways each having a substantially triangular cross section and a relatively large cross-sectional area, and a plurality of ribs extending obliquely from joints of those of the passageways which define the triangular passageways radially outwardly to the peripheral wall through the triangular passageways to divide each of the triangular passageways into a plurality of subpassageways of substantially the same cross-sectional area as the square pass