Abstract: Disclosed is a piezoelectric control valve which is arranged midway in a passage for supplying a high-pressure fuel to a fuel injection valve, and opens and closes this passage according to expansion and contraction of a piezoelectric element laminate. The valve body of the piezoelectric control valve is slidably held in a bore into which a high-pressure fuel passage connected to the fuel injection valve and a low-pressure fuel passage communicating with a fuel storage portion are opened. An annular groove is formed on the peripheral surface of the valve body, and the high-pressure fuel passage and the low-pressure fuel passage can communicate with each other through this annular groove. A piston moving reciprocatively according to expansion and contraction of the piezoelectric element laminate is provided, and a pressure chamber is formed between the piston and the valve body.

Abstract: A device for driving a load reactance element, such as a piezoelectric actuator for a fuel injection system, including a series reactance element connected in series with the load reactance element, and a resonance circuit formed by the load reactance and the series reactance. First and second switching elements are connected between the resonance circuit and the power source or ground potential. Each of the first and second switching elements is rendered conductive only during a half cycle of resonance. The directions of the load current flowing through the load reactance element are switchable by making alternately the first and second switching elements conductive.

Abstract: An electronically controllable, ultra-high pressure fuel injector comprises a differential pressure type injection nozzle which is opened and closed by an actuating element operated by a hydraulic power cylinder including a piston received in a working chamber. Working fuel to the working chamber of the power cylinder is ON/OFF controlled by an electronically controllable solenoid valve which when energized releases the pressure in the working chamber to open the injection nozzle. In order to ensure that the power cylinder is controlled by a compact, high response solenoid valve, the construction of the power cylinder and the injection nozzle is such that the force applied to the power cylinder piston by the working fuel pressure in the working chamber is substantially greater than the force applied to the actuating element by the fuel pressure in the pressure chamber in the injection nozzle or the fuel pressure in the passage for supplying the working fuel.

Abstract: A system for control of the amount of fuel to be injected in an internal combustion engine uses a high-pressure pump and a fuel control valve mechanism for spill having an electromagnetic valve and an oil-pressure valve. A predetermined delay time is added to the control timing of the current supply to the fuel control valve mechanism for spill, thus achieving the injection of the required amount of fuel at the most appropriate timing.

Abstract: A fuel injector for an internal combustion engine, the injector being actuated by a piezoelectric actuator. The piezoelectric actuator operates a piston, which changes the volume of a pump chamber formed between the piston and a nozzle needle. The nozzle needle moves up and down in response to a pressure in the pump chamber to open and close a port for injecting fuel. The piston is pressed toward the pump chamber by a fluidic force or a spring force and so on.

Abstract: A fuel injection apparatus for an internal combustion engine, which comprises an accumulator for storing therein pressurized fuel while maintaining the pressure thereof at a predetermined high level. A fuel injection valve is arranged to inject the pressurized fuel in the accumulator into a combustion chamber of the engine. The injection valve is controlled to open and close by an output signal from an external control unit. A pressurizing pump is arranged to pressurize the fuel delivered from a fuel-feed pump and to supply it into the accumulator through a check valve.

Abstract: A piezoelectric actuator comprises a housing having an inside cavity in which is mounted a column of piezoelectric elements having interleaved electrodes. The column of piezoelectric elements is mounted within a sealed enclosure which divides the inside cavity of the housing into an inner space receiving the column of piezoelectric elements and an outer space. The inner space is filled with a flowable, electrically insulative, thermally conductive material such as silicone oil held in direct contact with and in a heat transfer relationship with the column of piezoelectric elements. The silicone oil serves to isolate the column of piezoelectric elements and the electrodes from moisture and other foreign materials that would otherwise affect an insulation breakdown voltage. A cooling liquid is adapted to be circulated through the outer space surrounding the enclosure to absorb heat transferred thereto from the column of piezoelectric elements through the flowable thermally conducting material.

Abstract: A hydraulic control valve having a piezoelectric actuator comprises an expansible sleeve loosely received within a bore of the valve housing, with one end thereof being fixedly or stationarily mounted relative to the housing and the other end thereof being expansibly mounted within the bore. A slidable first piston is mounted within the bore of the valve housing and is urged against the other end of the expansible sleeve. This first piston floatingly supports one end of the piezoelectric actuator, the other end of which is supported by a second piston which is slidably mounted within the sleeve and is coupled to a valve member operable to cooperate with a valve seat to open and close an inside fuel passage communicating an inlet port with an outlet port.

Abstract: In a fuel injection apparatus for an internal combustion engine, the fuel injection is ended by a spill mechanism provided in a spill passage communicating with a pumping chamber. A piston opening and closing the spill passage is a free piston, and a solenoid valve to open and close a cylinder in which the free piston is disposed, is also provided. As the solenoid valve closes the cylinder, the free piston closes the spill passage, thus enabling the fuel feed to the fuel injection valve. When the solenoid valve opens the cylinder, the free piston opens the spill passage. Thus, the fuel flows through the spill passage to the fuel reservoir.

Abstract: A fuel injection apparatus for an internal combustion engine comprising: a nozzle body; a nozzle formed at the bottom of the nozzle body; an electroexpansive actuator having the electroexpansive effect; a valve member, slideably mounted within the nozzle body; and a fuel chamber formed between the electroexpansive actuator and the valve member. When the electroexpansive actuator expands to reduce the volume of the fuel chamber, the valve member is moved in the closed direction of the nozzle. When the electroexpansive actuator contracts to increase the volume of the fuel chamber, the valve member is moved in the open direction of the nozzle.

Abstract: A piezo-type valve with piezo-elements as a valve actuator. The piezo-elements are interposed by two freely movable pistons. A pressure chamber is formed on the outer side of one of the pistons to limit its outward movement. Thus, the substantial part of the expansion of the piezo-elements is transmitted to the other piston. The other piston is connected to a valve element. At least one flow port and a relief port are formed in the valve body. When voltage is applied to the piezo-elements, the at least one flow port and the relief port are communicated.

Abstract: A fuel injection system for an internal combustion engine includes a unit injector for compressing the fuel and injecting a predetermined amount of the fuel and an electronic control device. The unit injector includes a piezoelectric actuator, a piston, and an injection valve. The piezoelectric actuator comprises a columnar laminated body of disk-shaped piezoelectric elements. The laminated body is expanded or compressed in the axial direction of the column according to the application of positive or negative high voltage. The electronic control device controls the frequency of the voltage supplied to the actuator and controls accordingly the amount of fuel injection in accordance with the frequency of the voltage supplied to the actuator.

Abstract: A flow control device advantageously used in a fuel injection system for a diesel engine. The flow control device includes a spool valve defining on its sides first and second chambers which are connected with each other by means of a throttle. The second chamber is connected to a high pressure pipeline connecting a fuel pump with a fuel injector, while the first chamber is selectively opened to a relief line by means of an electrically operated valve. A cylinder has an annular groove opened to the relief line. When the valve is opened, the first chamber is opened to the relief line. A pressure difference is thus created between the first and the second chambers so as to move the spool valve to open. Thus fuel injection is stopped.

Abstract: A piezoelectric actuator comprising a tubular casing and an elongated piezoelectric member disposed in the casing. The piezoelectric member has axially spaced ends, one of which abuts the shoulder of the casing. The piezoelectric member expands and contracts in response to an applied voltage, another end effecting a pumping operation. The piezoelectric member forms first and second longitudinal surfaces extending along substantially the entire length of axis. The piezoelectric member is formed as a lamination of a plurality of piezoelectric plates, to each of which is applied an electrode element on one of lateral surfaces. The electrode elements protrude on the first or second surfaces, alternately. First and second electrode members are located at the first and second surfaces, respectively. The first surface may be a surface of an opening which extends through the piezoelectric member, and the second surface may be a surface of an outer cylindrical surface of the piezoelectric member.

Abstract: A method of driving a solenoid-operated proportional control valve is disclosed. The solenoid-operated proportional control valve is of the kind in which a valve member is displaced in proportional relation to current supplied to a solenoid under control of a control signal, and the method comprises adding a predetermined value to the control signal when the valve member starts to move to open the solenoid-operated proportional control valve from its full-closed position or subtracting a predetermined value from the control signal when the valve member starts to move to close the solenoid-operated proportional control valve from its full-open position.

Abstract: A multiitem indicating device for indicating a title of a desired item, its units and a detected electrical value corresponding to the desired item comprises a pair of drums around which a plurality of titles and their units are indicated respectively, and which are coaxially connected by a connecting shaft so as to be rotated integrally about an axis thereof. An angular position detecting means includes a code plate and a code sensor for detecting an angular position of the two drums and producing electric signals corresponding to said angular position and a figure indicator disposed in a groove surrounded by the two drums and the connecting shaft. Since the title and the detected value and the unit which correspond to the title can be detected on the same straight line on the same plane, the obtained data can be easily and precisely observed.

Abstract: A display apparatus for displaying two-dimensionally on a plane the correlation between two parameters, such as the acceleration of an automobile and the fuel consumption rate in its engine, which vary in association with the running of the automobile. The displaying portion includes a plurality of light-emitting elements which are arranged in rows and columns on the same plane so as to be given their respective co-ordinates, or ordinates and abscissas. The acceleration of an automobile is calculated corresponding to the counted value of speed pulses having a frequency proportional to the speed of revolution of the wheels so that the calculated acceleration value may be discriminated to show to which of a plurality of acceleration ranges the acceleration value belongs.

Abstract: A system for warning the driver of an acceleration or deceleration of a vehicle. A wheel sensor detects wheel rotational speeds N.sub.i and N.sub.i + 1 during two predetermined time intervals T.sub.i and T.sub.i + 1. The absolute value of the difference .vertline.N.sub.i - N.sub.i + 1 .vertline. between the rotational speeds is computed by a computing circuit. Indicating means gives an indication of acceleration when the difference is greater than a predetermined value and when the speed difference is negative, whereas an indication of deceleration is given when the speed difference is positive.

Abstract: A method and apparatus for displaying the brake stopping distance of a running vehicle by computing and displaying in a very short period of time the brake stopping distance of the running vehicle in response to its running speed and the surface conditions of the road. The displayed brake stopping distance varies by quickly responding to changes in the running speed of the vehicle and the surface conditions of the road. The brake stopping distance displaying apparatus comprises a vehicle speed detecting circuit for generating a signal corresponding to the running speed of the vehicle, a setting circuit for generating a signal corresponding to the friction coefficient of the road on which the vehicle runs, a computing circuit responsive to the two signals to generate a signal proportional to the square of the running speed and inversely proportional to the friction coefficient, and a display circuit for displaying the result of the computation in the computing circuit.