| 摘要 |
A resistance adjusting type heater (14) for use as an element of a catalytic converter comprises a honeycomb structure (10) with at least two electrodes (13) provided thereon to supply a current to the honeycomb structure (10) and with a resistance adjusting means such as a plurality of slits (11) provided in the honeycomb structure between the electrodes. The heater (14) is formed such that the cross-section of its heating portion is substantially the same as that of a main monolithic catalyst (15). The catalytic converter includes a first flow passage (20) with a honeycomb heater (14) and a second flow passage (23) to bypass the heater (14). At the beginning of the operation, the exhaust gases of an internal combustion engine whose temperature is low is caused to flow through the first flow passage (20). When the temperature of the exhaust gases exceeds a predetermined value, the flow passage is switched over from the first flow passage (20) to the second flow passage (23). In one embodiment a honeycomb heater (14) is disposed downstream of the main monolithic catalyst (15) or between two monolithic catalysts (15). In another embodiment two honeycomb heaters (14) are respectively disposed upstream and downstream of a main monolithic catalyst (15). <IMAGE> |
