Abstract: A fuel supply system of an internal combustion engine includes, a fuel return branch connection positioned downstream of a fuel filter. The branch connection returns part of the fuel which passed the fuel filter back into the fuel tank. An end of the fuel return connection is extended to the bottom of the fuel tank. A throttle part for controlling returned fuel flow is positioned in the branch connection. Because part of fuel which passed the fuel filter is returned into the fuel tank, fuel in the fuel tank is repeatedly filtered by the fuel filter. Thus, removal of dust in the fuel is improved and total fuel flow passing through the fuel pump is increased. This improves cooling of the fuel pump and thus helps prevent vapor generation while also improving durability of the pump.

Abstract: In a fuel supply system of an internal combustion engine, an actual fuel pressure Pf is measured by a differential pressure sensor and the actual fuel pressure Pf is averaged in a different degree to determine two kinds of values Pfs and Pft. The value Pfs is used to control the fuel pressure, while the value Pft is used to correct a pulse width. Then, a correction value Vfpci is determined according to the load applied to the engine and used in a feedback control to adjust a fuel discharge pressure of a fuel pump.

Abstract: According to the present invention, a fuel supply apparatus includes a fuel pump, a delivery pipe to distribute the fuel to each injector of the engine by receiving fuel supply by the fuel pump, a pressure sensor to detect the fuel pressure supplied to the delivery pipe, and a check valve disposed in the fuel discharge pipe of the fuel pump to prevent counterflow of the fuel from the delivery pipe. The amount of fuel discharged from the fuel pump is controlled to maintain the fuel pressure in the delivery pipe at a set value during fuel injection. At the stop of the engine, the amount of fuel discharged from the fuel pump is substantially reduced to zero, and the pressure of the fuel from the fuel pump is gradually reduced. After the pressure of the fuel discharged from the fuel pump reaches a predetermined value, the fuel pump stops. In this way the internal pressure of the delivery pipe is prevented from excessively rising without exterior parts such as a relief valve disposed outside of the fuel pump.

Abstract: A fuel supplying apparatus controls fuel pressure according to engine operating conditions to prevent blow-through of injected fuel into the exhaust system and hyper-vaporization of fuel. When the engine is being started and the fuel temperature is high, or when the engine has just started and the fuel temperature is high, a target fuel pressure is determined according to the fuel temperature. When a predetermined time has elapsed following the starting of the engine, or when the fuel temperature is not high (even if the predetermined time has not elapsed), it is determined whether fuel vapor is being purged from a canister into an intake pipe. The canister traps fuel vapor from a fuel tank. If the fuel purging is being performed, the apparatus determines whether the current engine operation is in a low-load region. If the fuel purging is being performed and the engine operation is in the low-load region, the apparatus computes a target fuel pressure according to the fuel purging conditions.

Abstract: An improved fuel injection control apparatus, in which a reference pressure is provided to a pressure regulator, for simplifying the fuel supply system by preventing the fuel quantity injected from injection valves into an engine from being influenced by variations in the air intake pressure. A pressure regulating device disposed in a fuel supply pipe between a fuel pump and the fuel injection valve regulates the pressure of fuel supplied from the fuel pump to the fuel injection valve so that the pressure is proportional to the predetermined pressure, without returning fuel from the injection valve to the fuel tank. An intake pressure detecting device detects the pressure in the intake pipe, and a fuel injection quantity correcting device corrects the fuel injection quantity according to deviations of the fuel pressure regulated by the pressure regulating device from a proper value due to the differential pressure between the pre-determined pressure of the pressure regulating means and the intake pressure.

Abstract: A fuel control system for internal combustion engines is disclosed in which a high temperature re-start state is determined based on a physical volume detecting device and a starting state detected by a start state detecting device. A compensation value is determined so as to compensate the amount of fuel supplied during re-start under high temperatures. The compensation value is determined by routines performed within a central processing unit. Variables that affect the compensation value include the physical volume, an internal pressure of a suction pipe, and the starting state of the engine. The compensation value ensures that fuel injection in the engine occurs over an appropriate timing.

Abstract: The present invention relates to a fuel supplying device for an internal combustion engine having multiple cylinder.The present invention comprises a plurality of fuel injection valves, a fuel pipe through which fuel flows, and a plurality of holder means on the fuel pipe so that the fuel from the fuel pipe is supplied to the holder means. The holder means accommodates the fuel injection valve so that the fuel is supplied to the fuel injection valve, and a start timing of the fuel supplied from the fuel pipe to at least one of the holder means is different from the start timing of the fuel supplied from the fuel pipe to the remaining holder means.

Abstract: In a fuel pressure regulator, the interior of a housing is divided into an air chamber and a fuel chamber by a diaphragm. A throttle portion is made up of a movable valve and a valve seat provided in the fuel chamber. The valve seat includes a fuel passage in communication with a fuel outflow pipe acting as an outflow passage for the fuel. The fuel passage is formed in such a shape that its cross-sectional area is gradually increased from the inlet side toward the outlet side.A valve seat holder includes an end face diposite to the movable valve, which end face is disposed on the same plane as an end face of the valve seat on the inlet side. The valve seat holder also includes a shoulder portion provided with a smoothly curved surface extending from the end face opposite to the movable valve to an outer peripheral side surface of the valve seat holder.

Abstract: A bypass air flow rate control apparatus has an idle speed control valve for continuously adjusting an air flow rate and an on-off control valve for allowing and shutting off an air flow passing therethrough. When an atmospheric pressure sensor detects that the atmospheric pressure is lower than a predetermined value, in other words, the density of intake air is lower than a predetermined value, the on-off control valve and the idle speed control valve are switched over. The air flows through the on-off control valve by an amount corresponding to the air flow rate reduced in the idle speed control valve. The valve switching over operation is performed when one of the following three conditions is satisfied: the engine is generating no torque, in other words, the engine is in a fuel cut operation; a load larger than a predetermined load value is applied; and the engine is accelerated at a rate equal to or greater than a predetermined value.

Abstract: A fuel system of an internal combustion engine comprises a fuel tank for storing fuel, a fuel injection valve disposed on the internal combustion engine, a fuel supply pipeline connecting between the fuel tank and the fuel injection valve, a fuel pump for supplying the fuel in the fuel tank to the fuel injection valve through the fuel supply pipeline, a fuel injection pressure regulator for regulating the fuel injection pressure of the fuel injection valve to a predetermined pressure, a fuel return pipeline through which surplus fuel from the fuel injection pressure regulator is returned into the fuel tank, and a pressure increasing device disposed in the fuel return pipeline and serving to increase the pressure in the fuel return pipeline above the pressure in the fuel tank while maintaining fuel pressure regulating function of the fuel injection pressure regulator.

Abstract: The present invention comprises a plurality of fuel injection valves, a fuel pipe through which fuel flows, and a plurality of holder means on the fuel pipe so that the fuel from the fuel pipe is supplied to the holder means. The holder means accommodates the fuel injection valve so that the fuel is supplied to the fuel injection valve, and a start timing of the fuel supplied from the tuel pipe to at least one of the holder means is different from the start timing of the fuel supplied from the fuel pipe to the remaining holder means.

Abstract: The present invention relates to a fuel supplying device for an internal combustion engine having multiple cylinder. The present invention comprises a plurality of fuel injection valves, a fuel pipe through which fuel flows, and a plurality of holder means on the fuel pipe so that the fuel from the fuel pipe is supplied to the holder means. The holder means accommodates the fuel injection valve so that the fuel is supplied to the fuel injection valve, and a start timing of the fuel supplied from the fuel pipe to at least one of the holder means is different from the start timing of the fuel supplied from the fuel pipe to the remaining holder means.

Abstract: A system for suppressing discharge of evaporated fuel gas is adapted to introduce the evaporated fuel gas generated in a fuel tank of an internal combustion engine into an intake passage, to suppress the discharge of the evaporated fuel gas into the atmosphere. The system comprises an evaporated fuel gas passage allowing the evaporated fuel gas within the fuel tank to be introduced into the intake passage and a controller variably controlling a cross-sectional area of the evaporated gas passage depending upon an operating condition of the engine. The cross-sectional area of the evaporated gas passage is controlled according to an amount of fuel supplied to the engine. In addition, the cross-section area of the evaporated gas passage may be controlled in response to the operating condition of the engine and may be controlled according to a preliminarily set comparative rotational speed in an idling condition of the engine.

Abstract: A detector for detecting amount of suction air or rotating speed of an internal combustion engine supplies the detection signal to a control circuit, which supplies a drive signal to an air control valve mounted in a suction pipe of the internal combustion engine in accordance with the detection signal from the detector so that an idling rotating speed of the internal combustion engine is increased to a predetermined speed.

Abstract: An internal combustion engine control apparatus which infers opening and closing of a throttle valve upon failure of throttle detecting switch. A programmed computer calculates basic fuel injection amount in accordance with detected rotational speed and air flow and discriminates failure of the throttle detecting switch when output of the throttle detecting switch does not correspond to the calculated basic fuel injection amount and the detected rotational speed. When the computer discriminates failure of the switch, the computer infers opening and closing of the throttle valve by comparing the calculated basic fuel injection amount with a reference value indicative of normal fuel injection amount closed throttle. The reference value is a function of the rotational speed and updated by the calculated basic fuel injection amount under closed throttle condition.

Abstract: Apparatus for controlling the operating state of an internal combustion engine (M1), has a demand amount detecting an unit (M2) for detecting amount of demand to the engine, an operating condition varying unit (M3) for varying a condition of operation of the engine, an operating state detecting an unit (M4) for detecting operating state of the engine, a target value setting unit (M5) for determining target values of variables of the operating condition, a control unit (M6) for controlling the operating condition varying unit (M3) by determining feedback amount of the operating condition variables so that detected values equal to the target values.