A fuel injection device for an internal combustion engine is subjected to the action of two spring units mounted in a suction chamber connected to the suction inlet leading to the engine such that the first spring unit becomes inoperative when the engine is under high load while the resilient action of the second spring unit varies with atmospheric pressure change. The suction chamber has front and rear diaphragm walls against which the second spring unit permanently bears, whereas the first spring unit is fixedly supported at its back end while its front end bears against the front wall when the suction pressure is high during low engine load and loses contact therewith when the suction pressure is low during high engine load. At the back of the suction chamber is a further chamber acting on the rear diaphragm wall and selectively connected by a changeover valve to the atmosphere or to the suction inlet depending on atmospheric pressure.
A fuel pressure regulator includes a valve member 18 supported by a diaphram 16 which serves to receive fuel pressure supplied by a fuel pump, first and second cylindrical valve seats 15a, 22 associated with the valve member to perform on-off operations, and a spring 30 for moving the second valve seat together with the diaphram according to an engine operating condition to vary fuel pressure.
A controller for mechanically setting a diesel engine's air/fuel ratio at a stoichiometric value to reduce black smoke emissions by regulating the quantity of fuel injected into a diesel engine's combustion chamber in response to the quantity of air flow to the engine's cylinder consists of an air flow sensor device and a modulator. The air flow sensor device has a venturi tube located along the engine's air intake conduit, and the modulator is in air communication with the venturi tube via a hollow hose. The modulator is located between a fuel control device, such as an automobile's accelerator pedal, and the engine's fuel injection pump. The modulator consists of an outer shell, internal diaphragm, return spring, push-pull rod and air valve system. The diaphragm divides the modulator's interior cavity into a front chamber and a rear chamber which communicates with the venturi tube. The return spring is located in the rear chamber and urges the diaphragm forwardly so as to expand or enlarge the rear chamber and to contract or diminish the size of the front chamber. One end of the push-pull rod, which is generally axially aligned with the return spring, passes through the front of the modulator's outer shell and connects to the diaphragm; and, the other end of the push-pull rod is operatively connected to control levers for the fuel injector and the accelerator pedal. The air valve system is located between the rear chamber and the outer shell of the front chamber, and is operatively connected to the control levers. The air valve system includes a front valve seat, rear valve seat and an air duct which provides air communication between the ambient and the front and rear chambers.
A flow control unit for controlling liquid fuel pressure supplied to a supercharged internal combustion engine fuel injector or injectors, comprising housing structure having fuel inlet and outlet ports, and a first chamber through which fuel flows in flowing to and through the ports, and through a valving port in the chamber; the housing structure also defining a second chamber spaced from the first chamber; a diaphragm assembly extending between the chambers and movable relative thereto, the assembly including a first diaphragm having a first side exposed to the first chamber, and a second diaphragm having a first side exposed to the second chamber; structure for communicating engine manifold pressure to the second diaphragm, whereby a decrease in the manifold pressure results in a reduced liquid fuel pressure delivered to the injector or injectors; and a control structure associated with the assembly to allow adjustment of the effective cross sectional area of the second diaphragm.
There is provided a pneumatic governor system for fuel injection pumps comprising a pneumatic governor having a vacuum chamber and an atmospheric pressure chamber, an electrically operated throttle means, an atmospheric pressure inlet pipe for admitting atmospheric pressure into the atmospheric pressure chamber, a control unit for operating the throttle means in accordance with the acceleration of the engine and an acceleration detector for detecting the acceleration of the engine to apply an acceleration signal to the control unit.
A boost compensator has a valve operative in response to a boost pressure. When the boost pressure is equal to or lower than a setting pressure, the valve intercepts communication between first and second chambers of the boost compensator which are partitioned by a diaphragm. When the boost pressure exceeds the setting pressure, the valve brings the first and second chambers into communication with each other. By the communication, pressure within the second chamber is raised so that the diaphragm and a push rod operatively connected to the diaphragm are moved toward the first chamber. As a result, a control member of a fuel injection pump is caused to be moved in a fuel decreasing direction.
