| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent backflow of exhaust gas, even if a reed valve is eliminated. <P>SOLUTION: This secondary air supply device (30) is equipped with secondary air passages (21, 22, 23a to 23d) taking out secondary air and supplying it to an upstream side from an exhaust emission control device (5) provided on an exhaust passage (7) of an internal combustion engine (1), a pump (9) provided on the secondary air passages (21, 22, 23a to 23d) and supplying secondary air, a secondary air passage opening/closing means (V1) provided in the downstream side of the pump (9) and opening/closing the secondary air passages (21, 22, 23a to 23d), and a pressure sensor (33) provided between the secondary air passage opening/closing means (V1) and the pump (5) and measuring pressure of the secondary air passages (21, 22, 23a to 23d). In this secondary air supply device (30), only when the pressure of the secondary air passages (21, 22, 23a to 23d) measured by the pressure sensor (33) exceeds a predetermined value (A) during operation of the pump (5) and closing of the secondary air passage opening/closing means (V1), the secondary air passage opening/closing means (V1) is opened to supply secondary air. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
