| 摘要 |
PURPOSE:To make the output load of the control valve changeable in accordance with the kind of vehicle and an operating condition to purify exhaust gas by a method wherein an orifice is provided in a vacuum path at the downstream side of the vacuum control valve and at least one vacuum path, comprising the orifice, is provided in parallel to the vacuum path at the downstream of the vacuum control valve. CONSTITUTION:In the multi-satage VRV EGR system, in which an EGR valve 3 is controlled by a VRV1 cooperating with an accelerating lever, is provided with the orifices 5a, 5b in the vacuum path 4 at the downstream side of said VRV1 and with at least one vacuum path B comprising the orifices 5a, 5b in parallel to the vacuum path A comprising said VRV1 and the orifices 5a, 5b, in order to make the output load of the VRV1 changeable easily in accordance with the kind of vehicle and the operating cndition. Accordingly, the output characteristic of the VRV1 moves in parallel, an EGR lift or an EGR rate may be changed so as to be capable of contriving further pulification of the exhaust gas while the EGR system, into which the VRV1 is incorporated, may be used commonly by utilizing said vacuum path B even when the kind of vehicle is changed. |
