US 4,378,775 A · Method and apparatus for fuel injection in internal combustion engines in particular diesel engines

Abstract

In the method according to the invention, the inlet pressure and the inlet cross section of the fuel pre-stored in the pump work chamber is constant, and it is solely the opening duration of an inlet valve which is electrically regulated. In addition, a shift in the instant of supply onset controlled in accordance with operating characteristics is attained by means of a variation in the return-flow fuel quantity. A shift in the instant of supply onset, which is undesired when there is a change in the quantity of fuel to be injected, is prevented by means of a simultaneously-effected correction of the return-flow fuel quantity. A fuel injection apparatus suitable for performing the method has, as the inlet valve, a magnetic valve which determines the quantity of fuel pre-stored in the pump work chamber. The rotary position of the pump piston is variable in order to shift or correct the instant of supply onset by means of an adjacent device actuated by an electromechanical adjustment element. An electric control device emitting the metering pulse and a control pulse is connected with a set-point transducer and an adjustment-path transducer of the adjustment device. The apparatus can be equipped with either a pump/nozzle or a normal piston injection pump supplying the injection nozzle via a pressure line, or with a distributor injection pump.

Claims29

Dependent claims

A method of injecting fuel by a fuel injection assembly into an internal combustion engine, in particular a Diesel engine, having a fuel supply with an instant of onset, an inlet line, an inlet valve, a piston injecting pump with a pump work chamber, a relief means, a fuel metering means, an electrical regulating means, and a fuel return means the steps including:

metering a quantity of fuel to be injected with the fuel metering means, before the engine compression stroke,
injecting the metered quantity of fuel into the engine with the piston injection pump,
regulating the flow of fuel in the inlet line with the inlet valve having an opening duration, which leads to the pump work chamber,
pre-storing the metered quantity of fuel in the pump work chamber,
fixing the end of fuel supply by relieving the pump work chamber with the relief means, wherein
metering of the quantity of fuel prestored in the pump work chamber with the fuel metering means occurs while:
keeping the pressure of the fuel constant in the inlet line;
and
keeping the inlet cross-section of the inlet valve constant;
and wherein regulating the supply of fuel to be injected into the internal combustion engine occurs by
regulating the opening duration of the inlet valve with the electrical regulating means,
correcting the quantity of fuel in the fuel return means in accordance with the metered fuel quantity during changing of the quantity of fuel prestored in the work chamber.

9 more elements

An apparatus for regulating fuel injection in an internal combustion engine having a fuel supply pump which provides an inlet pressure, in particular a Diesel engine, having a piston injection pump which includes:

a piston;
a pump work chamber;
an adjusting device connected to the piston injection pump to alter the end of a piston supply stroke;
a diversion opening in the wall of the piston injection pump;
a control face on the piston which controls the diversion opening;
an inlet line provided with an inlet valve;
a pressure regulating valve connected to regulate the inlet pressure;
wherein the inlet valve is a magnetic inlet valve and is connected to the pump work chamber to regulate a fuel quantity which is prestored in the pump work chamber;
the piston injection pump also including:
an electromechanical adjusting element connected to actuate the adjusting device;
a pulse generating means which is connected to generate a control pulse to the electromechanical adjusting element to alter the piston position;
a set-point transducer which generates set-point information to the adjusting device;
an adjustment-path transducer which generates adjustment path information to the adjusting device;
an electrical control device connected to generate a signal to the electromechanical adjusting element such that the electromechanical adjusting element is dependent on the electrical control device, and wherein the electrical control device is connected to the set-point transducer to receive the set-point information and to the adjustment path transducer to receive the adjustment path information, and wherein the electrical control device is also connected to generate a metering pulse to the magnetic inlet valve to determine duration of the magnetic valve opening.

11 more elements

Dependencies are inferred from the claim text.

Method and apparatus for fuel injection in internal combustion engines in particular diesel engines

Life of this patent

Method and apparatus for fuel injection in internal combustion engines in particular diesel engines

Life of this patent

Abstract

Claims29