AUTOMOBILE EXHAUST EMISSION SYSTEM AND SECONDARY AIR INJECTION DEVICE THEREOF

摘要

An automobile exhaust emission system and a secondary air injection device thereof. The secondary air injection device comprises an electric pump (6) that is controlled to be opened or closed through an electric control unit (4). An intake port (65) of the electric pump (6) is communicated with an air source, an exhaust port (63) of the electric pump (6) is communicated with an intake port of a combined valve (5), and an exhaust port of the combined valve (5) is communicated with an exhaust pipe or an exhaust manifold. The control end of the combined valve (5) is connected to a control valve (3), the control valve (3) is in signal connection to the electric control unit (4) and controls the combined valve (5) to be opened or closed, and the control valve (3) is communicated with an intake manifold through a negative pressure pipe (9). According to the system, by using the combination of the electric pump, the combined valve and the control valve and controlling the electric pump to be opened or closed through the electric control unit, automatic control over the secondary air injection device is realized.