1534288-A is referenced by 28 patents.
1534288 Automatic control of fuel/air ratio in IC engines BROWN BOVERI & CIE AG 19 Dec 1975 [19 Dec 1974] 52151/75 Heading G3R A control system for the air/fuel mixture supplied to a combustion chamber includes means to change the constituents of the hot exhaust products before their oxygen content is sensed whereby the control system alters the air/fuel ratio of the supplied mixture until the sensed quantity reaches a desired value. In the arrangement shown in Fig. 4, the burners 38 of a boiler are controlled by a controller 2 which is responsive to the oxygen content of a sample of exhaust gases 18 passing through tube 11. An electrolytic unit 5 is used to produce an oxidizing and reducing gas which selectively can be fed by valve 31 into the tube 18 to mix with the exhaust gas.; By supplying additional oxygen the probe will provide a signal to cause the amount of air supplied for combustion to be reduced. Alternatively if hydrogen is added the sensed oxygen content will correspond to a weak combustion mixture and the supplied air/fuel mixture will be made richer. The reference signal for the probe by design corresponds to the oxygen content of the exhaust gases resulting from combustion of a mixture having #=1 and the arrangement described is used for continuous operation witb # # 1. For an I.C. engine the quantity of auxiliary gas added is controlled by an engine operating parameter e.g. speed or temperature and the control may be applied to a carburetter or fuel injection arrangement, Fig. 1 (not shown).; The exhaust gas mixing and sensing element is described, Fig. 2 (not shown) as consisting of a cell including a mixing (catalytic) section and a solid electrolyte oxygen sensor and includes a heater to ensure that the cell temperature exceeds 300 C. In the cell shown in Fig. 3 the sample of exhaust gas enters at 11 and passes through a solid electrolyte cell which extracts or adds oxygen to the gas as determined by the strength and polarity of the current through screen electrodes 39, 40. The changed gas then has its oxygen content sensed by means of the electrodes 1 before it is exhausted through valve 19.