AIR-FUEL RATIO SENSOR CONTROL DEVICE

摘要

An air-fuel ratio sensor control device, connected with two-cell type air-fuel ratio sensor having electromotive force and oxygen pump cells with first to third two-cell terminals or a one-cell type air-fuel ratio sensor having a single cell with first and second one-cell terminals, includes: first to third connection terminals for connecting the one-cell or two-cell type air-fuel ratio sensor; a control circuit that is switchable between a two-cell circuit configuration for controlling the two-cell type air-fuel ratio sensor through the first to third connection terminals and a one-cell circuit configuration for controlling the one-cell type air-fuel ratio sensor through the first and second connection terminals; and a control unit that sets a circuit configuration of the control circuit to the one-cell or two-cell circuit configuration.

主权项

1. An air-fuel ratio sensor control device that is connected with one of: a two-cell type air-fuel ratio sensor having an electromotive force cell and an oxygen pump cell, which are oxygen concentration cells in such a manner that a pump current flowing in the oxygen pump cell is controlled so that an output voltage of the electromotive force cell reaches a target value, and the pump current becomes a current corresponding to an air-fuel ratio; and a one-cell type air-fuel ratio sensor having a single cell, in which a current corresponding to the air-fuel ratio flows under a state where a voltage is applied to the single cell,
wherein the two-cell type air-fuel ratio sensor includes: a first two-cell terminal that is connected to one of a pair of electrodes in the oxygen pump cell; a second two-cell terminal that is connected to both of the other of the pair of electrodes in the oxygen pump cell and one of a pair of electrodes in the electromotive force cell; and a third two-cell terminal that is connected to the other of the pair of electrodes in the electromotive force cell, as terminals for controlling the air-fuel ratio sensor, and wherein the one-cell type air-fuel ratio sensor includes: a first one-cell terminal that is connected to one of a pair of electrodes in the single cell; and a second one-cell terminal that is connected to the other of the pair of electrodes in the single cell, as terminals for controlling the air-fuel ratio sensor, the air-fuel ratio sensor control device comprising: a first connection terminal, a second connection terminal, and a third connection terminal, as terminals for connecting one of the two-cell type air-fuel ratio sensor and the one-cell type air-fuel ratio sensor; a control circuit that is switchable, by turning on and off at least one changeover switch, between a one-cell circuit configuration and a two-cell circuit configuration, the two-cell circuit configuration controlling the two-cell type air-fuel ratio sensor through the first, second, and third connection terminals, and the one-cell circuit configuration controlling the one-cell type air-fuel ratio sensor through the first and second connection terminals; and a control unit that sets a circuit configuration of the control circuit to one of the one-cell circuit configuration and the two-cell circuit configuration, by controlling the at least one changeover switch.