摘要:
A multi-gap spark ignition system is disclosed. The system comprises a plurality of spark gaps which are formed in series. The length of the spark gaps increases from the high voltage power source side towards the earth side. According to the present invention, necessary voltage to be applied to the spark ignition system can be decreased.
摘要:
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.
摘要:
A fuel injection pump including a valve opening and closing an overflow passage formed in a body of the pump to connect a high pressure chamber to a low pressure chamber. The low pressure chamber is provided for reserving low pressure fuel, and the high pressure chamber is provided for pressurizing fuel sent from the low pressure chamber and for discharging the pressurized fuel to fuel injectors. A plunger has intake grooves which open the feed passage to communicate the high pressure chamber with the low pressure chamber on an intake action of the pump. The body of the pump has a feed passage formed therein which connects the high pressure chamber to a control chamber. The pressure in the control chamber is changed by the expansion and contaction of a piezoelectric actuator, and the pressure in the control chamber urges the valve in a direction in which the valve closes the overflow passage. A start and end of a fuel injection period, and a fuel injection ratio (a pilot fuel injection), can be controlled by the opening and closing of the valve.
摘要:
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. The pressure in the pressure chamber is increased and decreased by the reciprocative movement of the piston, and by this increase and decrease of the pressure in the pressure chamber, the valve body is moved to connect the high-pressure fuel passage and the low-pressure passage to each other or to disconnect these passages from each other.
摘要:
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. The linear expansion of the sleeve due to a change in the ambient temperature causes the first piston to displace in one direction together with the piezoelectric actuator supported thereby so that the linear expansion of the piezoelectric actuator occurring in the opposite direction due to a similar ambient temperature change is counterbalanced whereby the second piston, serving as an output member of the piezoelectric actuator, is maintained at a constant distance with respect to the valve member regardless of change in the ambient temperature. Such a temperature compensation structure enabling precise positioning of the second piston ensures improved injection timing and injection quantity control of a fuel injection system for an internal combustion engine.
摘要:
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.
摘要:
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. Preferably, the fuel injector is provided with an injection rate control arrangement such as a flow control arrangement for limiting the flow rate of working fuel as it enters the working chamber and for increasing the flow rate of the working fuel as it is released therefrom, so that the rate of injection increases gradually at the outset of fuel injection but rapidly drops at the completion of the injection.
摘要:
An ignition system for a spark-ignition engine includes an ignition coil for applying a high voltage to each spark plug, a switch device connected in series with the secondary of the ignition coil for preventing in response to its conduction the supply of the high voltage to the spark plug, and a control circuit for turning on the switch device at a predetermined time after the generation of the high voltage, whereby the discharging at the spark plug is prevented under the combustion condition.
摘要:
A spark-ignition type internal combustion engine has a fuel injection valve for supplying fuel directly to a cylinder and a spark plug arranged near the fuel injection valve for igniting fuel in the cylinder. Auxiliary fuel injection is performed in the vicinity of the top dead center of the compression stroke, the subsequent main fuel injection is performed after the auxiliary fuel injection is terminated, and concurrently, the spray produced by auxiliary fuel injection is ignited by the spark plug.
摘要:
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.