| 摘要 |
PURPOSE:To improve the power characteristic in the super thin region and to suppress the torque variation and the lowering of the output by turning off the EGR control even in the intermediate load region. CONSTITUTION:An electromagnetic valve 4 having a three-way air path is provided between a BPT valve 3 and a negative pressure port 12. The movable contacts 56, 57 which move in accordance with the mechanical deformation of a diaphragm 52 are provided in a control switch 5. The excitation coil for the electromagnetic valve 4 is conducted during the low and heavy load operation to constitute the conventional EGR control system. During the intermediate load operation, the pressure applied on the diaphragm 52 is balanced with the spring 55 while when the load is further increased the contact 56 is departed from the contact 58 to make the electromagnetic valve non-conductive thereby the atmospheric air is fed from the port (c) to the port (b) to turn off the EGR control. Consequently the deterioration of the power performance in the super thin region can be prevented. |
