Abstract: An internal combustion engine fuel injection system includes a temperature sensor for detecting the temperature of the fuel or cooling water in the engine. When the detected temperature is higher than a given value, e.g., 50.degree. C., a pressure regulator for controlling the pressure of fuel supplied to a fuel injection valve is controlled so as to increase the fuel pressure irrespective of the intake pipe negative pressure and thereby increase the quantity of fuel supplied to the engine. In the case of an electronically controlled fuel injection control system, a predetermined correction quantity corresponding to the detected temperature from the temperature sensor is added to the basic fuel injection quantity calculated in accordance with given operating parameters of the engine, thereby increasing the quantity of fuel supplied to the engine.

Abstract: A spark plug for spark ignition type internal combustion engines includes an earth electrode formed of a heat-resisting metal, a central electrode, and a supplementary electrode provided on the earth electrode or the tip end of the central electrode. The supplementary electrode cooperates with one of the other electrodes to define therebetween a spark gap which is smaller in dimension than the normal spark gap defined between the earth and central electrodes. The supplementary electrode has a higher specific resistance than that of the earth electrode.

Abstract: A fuel quantity control apparatus of a supercharged diesel engine with safety measures comprises a fuel injection pump capable of increasing the fuel quantity according to the degree of supercharging, a detector for detecting the temperature in a combustion chamber or the temperature of the exhaust gas, a control circuit receiving an output of the detector, and a three-way valve driven by the control circuit to control the amount of the increase of the fuel quantity. Through the use of the apparatus when the detected temperature reaches a predetermined abnormal temperature, the amount of increase of the fuel quantity can be made zero or decreased and accidents such as melting or damage of the engine by abnormal rise of the temperature in the combustion chamber or of the temperature of the exhaust gas can be prevented.

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 multi-gap spark ignition device to be installed in a spark ignition engine, is disclosed. The device comprises a metallic base member provided with a hole which forms one portion of the combustion chamber of the engine. Within the wall defining the hole, a high voltage electrode, a plurality of intermediate electrodes and an earth electrode are embedded at regular intervals so that each end of the electrodes project into the hole to form a plurality of spark gaps between the adjacent ends of the electrodes. Each of the intermediate electrodes is composed of an electrode member and an insulating member for covering one end of the electrode member, and is closely inserted into a groove formed in one end surface of the base member along the hole thereof at regular intervals.

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 device for atomizing the fuel for an internal-combustion engine comprising a fuel pump, an electromagnetic fuel-injection valve connected to said fuel pump, an air-injection port adjoining the injection port of said electromagnetic fuel-injection valve, an electromagnetic air flow-controlling valve connected to said air-injection port, and an air pump for feeding air to said air flow-controlling valve, wherein said air flow-controlling valve is controlled in such a manner that the injection of air from said air-injection port takes place simultaneously with the injection of fuel from said fuel-injection valve, whereby the air pump and the driving circuit thereof are of a comparatively small size and the amount of power necessary for driving the air pump is of comparatively small.

Abstract: An EGR device for an internal combustion engine, including an EGR valve body in an EGR pipe for changing the opening degree of the EGR pipe for regulating the amount of the recirculated exhaust gas, a diaphragm supported by casing of the EGR valve and connected to the EGR valve body for forming a negative pressure chamber, and a solenoid fixed to a sleeve of one of the casing for driving a spool valve in the direction to the diaphragm when the solenoid is excited. The excitation of the solenoid is controlled by a control circuit in accordance with the running conditions of the internal combustion engine.

Abstract: In an EGR control system for a diesel engine, the EGR amount is controlled by controlling the pressure in a diaphragm chamber of an EGR valve using the output signal of a computer, responsive to signals from a plurality of engine running condition sensors, for calculating the EGR amount with corrections according to the engine running conditions and the excess air rate. In some cases, the EGR is carried out only when the rotational speed of the engine is higher than a predetermined rotational speed. Also, in some cases, the EGR is carried out when an occurrence of idling is detected, even if the rotational speed of the engine is lower than the predetermined rotational speed.

Abstract: A fuel evaporator for an internal combustion engine, which is provided with a ceramic heater, is disclosed. The fuel evaporator comprises a plurality of layered thin PTC ceramic plates, each of which has a plurality of open holes, electrodes which are provided on an upper surface, an under surface and between adjacent ceramic plates, and an insulator for securing the outer periphery of the layered PTC ceramic plates to the wall defining an air-fuel passage of an engine. The ceramic plates are electrically connected to one another in parallel so that each ceramic plate is rapidly heated by consuming only a small amount of electric power.

Abstract: A method and an apparatus for controlling EGR in a diesel engine according to the present invention used an EGR valve having a diaphragm chamber, a pressure supplying device for supplying air pressure to the diaphragm chamber, an adjusting device for adjusting the air pressure corresponding to the rotation angle of a rotary shaft for controlling the amount of fuel injected, a rotation rate detector of the engine, and a pressure releasing device for releasing a portion of the negative pressure in said diaphragm chamber. In the method and apparatus, a portion of the negative pressure in the diaphragm chamber is released to an atmospheric pressure corresponding to the rotation rate of the engine. Thus, the rate of EGR is decreased in accordance with an increase in the rotation rate in an operating condition higher than a predetermined rotation rate.

Abstract: In an apparatus for controlling the EGR in a diesel engine, a single pressure control valve adjusts the control pressure from a pump automatically when the pressure changes, and supplies the control pressure in response to the command signal of a control circuit to an EGR valve and a waste-gate valve of a turbocharger. The pressure control valve includes an electric actuator, a spool valve, a sleeve, a diaphragm, and a spring. By using this apparatus, a diesel engine which has a high response speed, high control precision, simple constitution, less nitrogen oxides in the exhaust gas, and low manufacturing cost is obtained.

Abstract: The degree of opening of the choke valve in a carburetor for an internal combustion engine is controlled in accordance with the temperature of at least one predetermined position of temperature adjustment devices in the air intake manifold portion of the engine, whereby emission of harmful exhaust gas is reduced and the rated fuel consumption of the engine is maintained.

Abstract: In an ignition system for an internal combustion engine in which the flow of a primary winding energizing current is switched on and off in synchronism with the rotation of the engine and a high voltage is induced in the secondary winding upon switching off of the energizing current, an energizing current is supplied again at around the top dead center of each cylinder and then decreased gradually and interrupted in accordance with a sawtooth waveform whose voltage attains a predetermined potential at around the top dead center and then decreases gradually.

Abstract: In a method for controlling the EGR in an internal combustion engine, the fuel amount detected by a sensor is used as the basis for the control of an EGR valve in line with a predetermined EGR rate equation.

Abstract: An ignition system for internal combustion engines of the type in which after the energizing current flow to the primary winding of an ignition coil has been interrupted and an ignition spark generating high voltage has been produced in the secondary winding, the primary winding is energized again to interrupt the ignition spark. The ignition spark is interrupted at around the TDC only when the engine is at high speed operating conditions and the deenergizing current in the primary winding is not interrupted in a moment but decreased gradually. Also, the ignition spark is interrupted only when the ignition spark is to continue beyond the top dead center.

Abstract: An ignition system for the internal combustion engine comprising a high voltage circuit for generating a spark, having the primary and secondary windings. In response to a first signal, the current in the primary winding is cut off thereby to generate a high voltage at the secondary winding. In response to a subsequent second signal, the primary winding is shorted thereby to cut off the high voltage thus far generated in the secondary winding, thus properly regulating the duration of the spark generated.

Abstract: A suction heating device for an internal combustion engine including a first metal member having a planar portion and a cylindrical portion extending from the flat portion for defining a passage for a fuel-air mixture, and a second metal member having a planar portion and a cylindrical portion extending from the planar portion and arranged outside the cylindrical portion of the first metal member with a predetermined spacing. The two cylindrical portions are joined to each other at the end to provide a casing for mounting therein a ceramic heater of positive temperature coefficient characteristic having a specific Curie point.

Abstract: A flexible barium titanate ceramic PTC heater for use in, for example, an intake pipe of an internal combustion engine to heat the air-fuel gas mixture is formed as a thin disc-shaped ceramic sheet constituted by a plurality of individual coplanar ceramic segments having interior edges positioned in spaced side-by-side relationship. The juxtaposed edges of the ceramic segments are united to each other by a flexible, heat-resistant, electrically non-conductive rubber band disposed in the space between the segments and bonded thereto by an electrically non-conductive adhesive to form the segments into a thin disc-shaped sheet which can be flexed without causing flexing of any of the individual segments. The ceramic heater is positioned in a metallic casing with one planar face thereof bonded to the inner surface of the casing by an electrically conductive adhesive. A stainless steel wool cushioning member engages the other planar face of the ceramic heater to support the heater in the metallic casing.