Abstract: A fuel injection system in which a fuel injector having a fuel pressure control chamber formed therein to create a pressure which forces a needle valve in the closing direction to open and close the nozzle hole, an accumulator to retain fuel discharged from the nozzle hole, and a fuel injector provided at each of the cylinders of the engine, are connected to the fuel injection pump by a single piping system without utilizing a special distribution mechanism. The volume of the fuel pressure control chamber in the fuel injector can be changed by a piezo-actuator. A check valve is provided at a half way point of the piping which leads the fuel fed under pressure from the fuel injection pump to the fuel injector into the fuel pressure control chamber and the accumulator, so that the fuel is fed through the check valve into the fuel pressure control chamber and the accumulator.

Abstract: A method and apparatus for driving a capacitive-type load using a direct current power source, a charging circuit connected in series to the load, a discharging circuit connected in parallel to the load, and an electric circuit for controlling the charging and discharging circuits, and wherein at least one of the charging and discharging circuits has a primary coil, and a secondary coil coupled to the primary coil restores energy, generated when the charging or discharging is turned OFF, to the power source. This provides a highly efficient driving by a restoration of energy.

Abstract: A color apparatus includes an electroexpansive actuator, a unit for supplying a charge to the electroexpansive actuator, and a unit for controlling an amount of charge discharged from the electroexpansive actuator, and a stroke of the electroexpansive actuator is controlled in accordance with the amount of charge discharged therefrom. When such an electroexpansive actuator is applied to a control apparatus for a fuel injection valve, a fuel injection amount per ON/OFF operation of the fuel injection valve or a fuel injection rate can be freely controlled.

Abstract: A piezoelectric fuel injector for use in fuel injection systems of spark-ignition engines is provided with a normally closed valve assembly in the form of a reed valve. The valve assembly includes a valve plate having one or more outlet ports having an overall cross-sectional flow area sufficient to ensure an unobstructed flow path therethrough. The valve assembly also includes a generally flat, thin, resilient closure member cooperating with the valve set of the valve plate. The pressure wave created in the fuel in the pumping chamber upon excitation of the piezoelectric actuator propagates into the outlet ports to directly reach the thin closure member, which readily resiliently yields to permit a desired amount of fuel to be injected into the engine cylinders. The fuel injector is particularly suitable to be operated by a high-frequency drive signal in order to ensure precise metering of fuel quantity over a wide range of engine operating conditions.

Abstract: A concrete breaker, in which in breaking a concrete structure, the inclination of the main chisel is maintained within a desired angle by a limit switch to prevent the chisel receiving bed and the ram from being damaged at least two mini-chisels disposed opposite the main chisel are slidably arranged and driving means for these chisels are encased in a machine frame provided with machine beds so that the machine body may be formed smaller and lighter in weight.