Correction device for a fuel metering system in an internal combustion engine

• US 4,426,980 A
• Filed: 03/28/1983
• Issued: 01/24/1984
• Est. Priority Date: 03/26/1980
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Stumpp, Gerhard, Wessel, Wolf, Eisele, Hermann, Flaig, Ulrich, Piwonka, Fridolin
• Primary Examiner(s): Neill, Raymond A.
• Application Number:
  US06/479,769
• Time in Patent Office: 302 Days
• Field of Search: 123/478, 123/480, 123/511, 123/512, 123/445, 123/446, 123/350, 123/352, 123/357, 123/359
• US Class Current: 123/478
• CPC Class Codes: F02D 41/28 Interface circuits
• CPC Class Codes: F02D 43/00 Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment

Abstract

A device is proposed for drift compensation in fuel metering systems, in which it is not the metered quantity as such which is controlled in closed-loop fashion, but rather only the position of a quantity-determining member. The object of the invention is to maintain or re-obtain the original association between the fuel quantity and the position signal of the quantity-determining member for the purpose of providing a correct indication of the load state existing at a particular time. The drift compensation is intended to be capable of being performed manually, semi-automatically, or automatically, in an additive and/or multiplicative manner. It can furthermore be realized via a preferably rpm-dependent characteristic curve. The various values may be ascertained, for instance, in connection with running-out and running-up tests.

Claims

1. A drift-compensation correction device for controlling a fuel metering system having a fuel pump in an internal combustion engine in which there is an incorrect relationship between a fuel metering signal and metered fuel quantity due to fuel pump aging, comprising:

means for generating set-point data signals responsive to operating parameters of said engine, said data signals including a drift signal corresponding to said incorrect relationship,

means responsive to a final control element in said fuel metering system for generating actual data signals,

a comparator means for comparing said actual and set-point signals,

a regulating means responsive to said comparator means for providing said fuel metering signal to said final control element via an output circuit means for determing said quantity of fuel to be metered to said pump, and

means supplying a correction intervention signal to said fuel metering signal corresponding to said drift signal, whereby the effect of drift in said set-point generating means due to aging of said pump is compensated for and said set-point generating means is restored to its original output rating value.

2. A correction device as defined by claim 1, wherein said corrective intervention signal being effected semiautomatically.

3. A device according to claim 1, wherein said correction intervention signal means comprises a potentiometer.

4. A device according to claim 1, wherein said correction intervention signal means comprises a characteristic curve generator, preferably rpm-dependent.

5. A device according to claim 1, wherein said fuel metering signal is additively corrected by said comparator means.

6. A correction device according to claim 1, wherein said correction intervention signal is applied to said fuel metering signal at said comparator means.

7. A correction device according to claim 1, wherein said correction intervention signal is applied to said fuel metering signal at said set-point generating means.