Apparatus for venting a fuel tank

Apparatus for venting a fuel tank of an internal combustion engine or the like comprising:

• intermediate storage means for receiving the fuel vapors in the tank;
• an electrically-controlled tank venting valve having a pass-through opening and being arranged between said intermediate storage means and the fuel tank;
• and,
• control means for continuously changing the cross section of said opening in dependence upon selected operating conditions so as to control the delivery of the tank ventilating mixture to said engine;
• the tank ventilating being adaptively undertaken with a consideration of the Lambda control factor F.sub.R or together with the load (t.sub.L) and rotational speed (n) by influencing the computed value of the fuel quantity to be supplied to the engine;
• and,
• with a utilization of long-term deviations (mean-value formation) of the Lambda-control output as a measure for a correction of an adaptive, computed fuel-metered anticipatory control quantity, the controller output being switchable between the basic adaptation block 32 for the corrective influence of the computed fuel quantity and the tank venting adaptation block 35 for an adaptive value (ATE) of the tank vent at least at certain values of air quantity throughput and rotational speed such that basic adaptation is not influenced by the tank ventilation.

Apparatus for venting a fuel tank of an internal combustion engine or the like comprising:

• intermediate storage means for receiving the fuel vapors in the tank;
• an electrically-controlled tank venting valve having a pass-through opening and being arranged between said intermediate storage means and the fuel tank;
• control means for continuously changing the cross section of said opening in dependence upon selected operating conditions so as to control the delivery of the tank ventilating mixture to said engine;
• said intermediate storage means being an active-carbon filter container;
• said tank venting valve being a solenoid valve;
• and, said control means including means for supplying said solenoid valve with a clocked drive pulse train changeable with respect to its pulse duty factor for changing said cross section;
• Lambda-control-dependent control means for controlling said pulse duty factor of said drive pulse train of said solenoid valve thereby controlling the cross section of said opening;
• a characteristic field anticipatory control block being provided containing pulse duty factor values stored for the drive pulse train of the tank ventilating valve, said characteristic field anticipatory control block providing predetermined values of the pulse duty factor, in dependence upon load (t.sub.L) and rotational speed (n) and supplying said values to a multiplication stage 15;
• and,
• said multiplication stage 15 being supplied with a further output signal of a characteristic block 24, which makes available predetermined values of the pulse duty factor in dependence upon the course of the mean value F.sub.R of the Lambda control factor for general evaluation or in combination with the values of the anticipatory characteristic field.

Apparatus for venting a fuel tank of an internal combustion engine or the like comprising:

• intermediate storage means for receiving the fuel vapors in the tank;
• an electrically-controlled tank venting valve having a pass-through opening and being arranged between said intermediate storage means and the fuel tank;
• and,
• control means for continuously changing the cross section of said opening in dependence upon selected operating conditions so as to control the delivery of the tank ventilating mixture to said engine;
• said control means including means for supplying said venting valve with a clocked drive pulse train changeable with respect to its pulse duty factor for changing said cross section;
• said pulse duty factor (TVTE) of the drive pulse train being subjected to a limit-value control with said pulse duty factor with the pulse duty factor being changed to effect a reduction of said cross section when the means value of the Lambda control factor F.sub.R exceeds a predetermined limit value F.sub.RGW and with the pulse duty factor being changed to effect an increase in said cross section when the mean value of the Lambda control factor F.sub.R drops beneath a predetermined limit value F.sub.RGW ;
• and,
• a comparator location 25 to which are applied a limit value F.sub.RGW of the means value of the Lambda control factor and the Lambda control factor;
• a comparator 26 connected to the output of said comparator location for determining the sign, and an integrator 27 for generating a changing pulse duty factor for the drive pulse train and for supplying the same to the multiplier stage 15 alternatively to the characteristic dependent displacement and, if required, supplementary to the evaluation of the anticipatory control characteristic field, said integrator being containously altered with predetermined constants.

Apparatus for venting a fuel tank of an internal combustion engine or the like comprising:

• intermediate storage means for receiving the fuel vapors in the tank;
• an electrically-controlled tank venting valve having a pass-through opening and being arranged between said intermediate storage means and the fuel tank;
• and,
• control means for continuously changing the cross section of said opening in dependence upon selected operating conditions so as to control the delivery of the tank ventilating mixture to said engine;
• the tank ventilating being adaptively undertaken with a consideration of the Lambda control factor F.sub.R ;
• and,
• a sequential control circuit 34 for the adaptive anticipatory control for ventilation, a tank ventilating adaptation block 35 driven by said sequential control circuit 34, said adaptation block 35 making an anticipatory adaptation value (ATE) available by evaluating an averaged value of the Lambda control factor F.sub.R, said adaptation block 35 determining the computed sequence for the fuel quantity to be metered to the engine such that a constant fuel quantity or air quantity per unit of time is compensated for independently of load and rotational speed.

Apparatus for venting a fuel tank of an internal combustion engine or the like comprising:

• intermediate storage means for receiving the fuel vapors in the tank;
• an electrically-controlled tank venting valve having a pass-through opening and being arranged between said intermediate storage means and the fuel tank;
• and,
• control means for continuously changing the cross section of said opening in dependence upon selected operating conditions so as to control the delivery of the tank ventilating mixture to said engine;
• the tank ventilating being adaptively undertaken with a consideration of the Lambda control factor F.sub.R ;
• with a utilization of long-term deviations (mean-value formation) of the Lambda-control output as a measure for a correction of an adaptive, computed fuel-metered anticipatory control quantity, the controller output being switchable between the basic adaptation block 32 for the corrective influence of the computed fuel quantity and the tank venting adaptation block 35 an adaptive value (ATE) of the tank vent at least at certain values of air quantity throughput and rotational speed such that the basic adaptation is not influenced by the tank ventilation.