| 摘要 |
<p>PURPOSE:To provide the proper supply of secondary air and the reduction of drive loss by adjusting supercharging pressure in a supercharging path such that the super charging pressure in the secondary air supply is lower than thet in the non-supply. CONSTITUTION:When the running condition of an engine E is in the secondary air supply range, a secondary air cut valve 27 and a secondary air relief cut valve 32 are opened simultaneously by the operation of a three-way solenoid valve 36 to supply secondary air. Then, pressure in a secondary air supply path 26, i.e. supercharging pressure in a supercharging path 18 is reduced with a portion of pressured air being relieved to the upstream side by a secondary air relief path 31 and this pressure is maintained at a set pressure in a second relief valve 34. On the other hand, in the supercharging range to which secondary air is not supplied, the supercharging pressure is maintained at a high set pressure by the relief valve 23 so that sufficient supercharging amount is provided even in high load to improve the output.</p> |
