Robert Boschgmbh

Dieter Mayer

Ernst Wild

Albrecht Clement

Werner Jundt

Manfred Mezger

Martin Zechnall

Rolf Daumer

Claus Ruppmann

Gunther Kaiser

Rudiger Jautelat

Michael Kirschner

Egbert Perenthaler

Walter B Hersel

Heinz Bohmler

Klaus-Gerd Meyer

Siegfried Hertzler

Helmut Breitkreuz

Dieter Walz

Michael Henn

To prevent change of data in a non-volatile programmable, ready-only memory (25) forming, together with a microprocessor (23) a control unit, for example for an automotive vehicle, while permitting programming of the memory from an external programming unit (P, 1), an interface (3, 11, 12) is provided through which a release-enable bus (13) also passes, data being transmitted in accordance with a predetermined characteristic--even or odd parity--, the parity correctness being checked. If the parity is correct, an 'enter' signal is provided on the release-enable bus for storing the data; if not, retransmission is attempted for a predetermined number of time, and if it cannot be correctly effected, a malfunction indication output signal is generated.

Externally reprogrammable vehicular microcomputer with hardware lock-out

Device for determining angular position of a rotating part

An apparatus is disclosed for venting a fuel tank of internal combustion engines or the like, wherein fuel vapors developing in the tank are received in an intermediate storage unit containing an activated carbon filter and are delivered to the induction area of the engine in dependence upon operating conditions. The delivery is accomplished by an electrically controlled tank venting valve having a pass-through opening the cross section of which is continuously changed. This is achieved by changing the pulse duty factor of the drive pulse train for this valve. The pulse duty factor may be determined in the sense of a pure control using a family of characteristic fields in dependence on rotational speed and load of the engine, or by taking into account preferably averaged Lambda values with a reduction in the cross section of the pass-through opening of the tank vent valve as the mixture becomes richer. Further, an adaptive anticipatory control is provided which enters into the calculation of the fuel quantity to be supplied or of the fuel injection signal with a correction value (ATE) and switches over to a limit control when predetermined mixture proportions are reached. The basic adaptation in the Lambda control system for calculating the fuel supply is released only if the fuel quantities originating from tank venting are negligible.

Apparatus for venting a fuel tank

The invention is directed to a mixture metering arrangement for an internal combustion engine and includes an exhaust-gas sensor which is exposed to the exhaust gas of the internal combustion engine. The exhaust-gas sensor indicates the air ratio lambda and preferably has a two-level characteristic. The sensor output signals are acted upon by a follow-on controller which is preferably a PI-controller. The controller output quantity acts upon the mixture composition in a corrective fashion. In this arrangement, the control oscillation of the controller output quantity is adjusted to a predetermined amplitude by means of a superposed control. In particular, the integral component of the control oscillation is influenced in a manner causing it to have the same amplitude as the proportional component while in the steady operating condition. Thus, it is possible to maintain the maximum control frequency in any operating range of the internal combustion engine so that the controller always operates at its optimum. In addition, the effects of deviations occurring from one engine to another or from one exhaust-gas sensor to another as well as of long-term variations are suppressed.

Lambda-controlled mixture metering arrangement for an internal

The invention is directed to an arrangement for a fuel metering system for an internal combustion engine. The arrangement includes a computer unit for generating a fuel metering signal in dependence on the operating parameters of the internal combustion engine. The arrangement includes an oxygen sensor and a filter to which the sensor signal is applied, and a subsequent evaluation circuit for additionally influencing the fuel metering signal, preferably in a multiplicative manner. The filter output quantity and engine speed information are utilized together for an additional additive speed-dependent and an additive speed-independent influencing of the fuel metering signal via at least one control function. This arrangement permits a nearly ideal anticipatory control of the fuel metering signal which has an advantageous effect on the engine operating behavior and the exhaust gas quality, in particular with the internal combustion engine in a state of transition and the lambda control circuit deactivated.

Arrangement for a fuel metering system for an internal combustion engine

Growing community of inventors

Stuttgart, Germany

Dieter Mayer