Internal-combustion engines – Engine speed regulator – Open loop condition responsive
Patent
1989-11-15
1991-05-14
Argenbright, Tony M.
Internal-combustion engines
Engine speed regulator
Open loop condition responsive
123489, F02D 4114
Patent
active
050146688
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a method and a system for adjusting a lambda value of the air/fuel mixture supplied to an internal combustion engine during the transition from a lower load range to a upper load range.
Such a method and such an adjusting system are known from DE-C2-33 41 720. The system includes an adjusting means which outputs, in dependence on a respective value of a accelerator pedal position signal supplied to it, an adjusting signal to a throttle flap actuator for adjusting the air volume supplied to the internal combustion engine in such a manner that a lean air/fuel mixture is obtained below a position threshold value of the accelerator pedal position signal which marks the boundary between the lower and upper load range. The system operates in such a manner that shortly before the threshold value is reached, the throttle flap is completely open. If, finally, correspondence between the threshold value and the value of the accelerator pedal position signal is achieved, the throttle flap is reset by a predetermined value which can depend on the rotational speed and the accelerator pedal position. The resetting occurs to such an extent that a rich mixture is obtained in the upper load range, even if the throttle flap is again opened further with further increase in the value of the accelerator pedal position signal past the position threshold value.
Operating at a lambda value of less than 1 in the upper load range results in an increased pollutant emission.
SUMMARY OF THE INVENTION
The object of the invention is a method and a system for adjusting the lambda value of an air/fuel mixture supplied to an internal combustion engine during the transition from the lower load range to the upper load range and conversely, which lead to a lower pollutant emission. The object of the invention is achieved by providing a method and a system which enable a throttle flap adjustment, at least at a steady-state operation, in such a manner that a lambda value equal to 1 is obtained for values of the accelerator position exceeding the position threshold value.
The method according to the invention and the adjusting system according to the invention differ from the prior art in that, for values of the accelerator pedal position signal above the position threshold value, at least during steady-state operation, adjusting signals of such a magnitude are output that an essentially stoichiometric mixture is obtained. In the lower load range, that is to say below the position threshold value of the accelerator pedal position signal, lambda values of greater than 1 are thus obtained whilst the lambda value is set to be equal to 1 in the upper load range. Thus, low pollutant values are also achieved in the upper load range in an internal combustion engine which is equipped with a catalytic converter.
The restriction, "at least during steady-state operation" is mentioned with respect to the adjustment of the lambda value. The reason for this restriction lies in the fact that it is possible, in the upper load range just as, incidentally, also in the lower load range, that the accelerator pedal is kept unchanged over relatively long time intervals whilst it is just as well possible that acceleration or deceleration occurs without leaving the range. The former is called steady-state operation and the latter is called non-steady-state operation. As a rule, the period within which several revolutions of the engine occur is considered to be the time interval within which no change in accelerator pedal position should occur and thus steady-state operation is referred to. In the case of non-steady-state operation, the adjustment to lambda equal to 1 can be conveniently disregarded because of the smooth running characteristics usually required.
To achieve good smooth running, the adjusting means according to an advantageous further development includes a transition means which during the transition from an adjusting signal for lean operation to one for stoichiometric operation or conversely produc
REFERENCES:
patent: 4434768 (1984-03-01), Ninomiya
patent: 4594984 (1986-06-01), Raff et al.
patent: 4771752 (1988-09-01), Nishimura et al.
Patent Abstracts of Japan, vol. 10, Nr. 311 (M528) (2367), Oct. 23, 1986 & JP, A, 61123735 (Toyota) 6-11-86.
Patent Abstracts of Japan, vol. 11, Nr. 321 (M633) (2768), Oct. 20, 1987 & JP, A, 62103447 (Mazda) 5-13-87.
Patent Abstracts of Japan, vol. 12, Nr. 315 (M735) (3162), Aug. 26, 1988 & JP, A, 6388236 (Nissan) 4-19-88.
Klenk Martin
Linder Ernst
Moser Winfried
Argenbright Tony M.
Robert & Bosch GmbH
Striker Michael J.
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