US 4,223,643 AGranted

Method and apparatus for fuel mixture enrichment during acceleration

AssigneeRobert Bosch GmbH

InventorsOtto Glockler, Harro Herth, Thomas Wilfert, Bernd Kraus

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Abstract

The fuel mixture preparation system of an internal combustion engine, especially a continuous fuel injection system, is engaged during intended engine accelerations by a pressure sensor in the induction manifold which responds to increasing manifold pressure to close a switch. The switch closure affects a pressure control valve that changes the control pressure in the fuel injection system and thereby causes temporary fuel enrichment until the differential pressure in the pressure sensor has returned to equilibrium. The signal from the pressure sensor may be extended arbitrarily by interposition of an electronic timing circuit which is constructed as an integrating circuit so that its output signal, when processed by a comparator, will produce a proportionally extended actuation signal for the control valve.

Claims9

Dependent claims

An apparatus for changing the ratio of the fuel-air mixture fed to an internal combustion engine, said engine including an induction tube and a continuous fuel injection system in which a fuel metering mechanism responds to the pressure of a control fluid maintained by a control valve, said control valve being actuated by circuit means responsive to induction tube pressure and the rotational speed of the engine, the improvement which comprises:

a differentiating pressure switch disposed in said induction tube, an electrical switch coupled to said differentiating pressure switch for generating an electrical signal in response to increases in induction tube pressure,
an oscillator connected to a source of power to provide a wave shaped output signal,
a comparator circuit responsive to the wave shaped output signal of the oscillator and having an output,
a first transistor connected to said source of power to provide a current path and responsive to said comparator, said electrical switch being disposed in said current path and
a power transistor controlled by said first transistor for actuating said control valve so that upon acceleration of the engine, the fuel-air mixture is enriched.

2 more elements

Dependencies are inferred from the claim text.