| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a braking servo system capable of improving fuel consumption. <P>SOLUTION: A braking servo unit 40 is connected with a branch pipe 20 connected with one of four cylinders by a negative pressure pipe 42, and introduces the negative pressure in the branch pipe 20 to assist a braking leg-force as a driving pressure. The negative pressure pipe 42 is connected with the branch pipe 20 downstream of a valve member 30. When the negative pressure Pb in the braking servo unit 40 is not less than a required negative pressure Pc, opening of a throttle is fully closed or fully opened repeatedly in all of the cylinders, so as to suck a required volume of air. When the volume of sucked air reaches a required value, the opening of the throttle is changed from full opening to full closing. When the negative pressure Pb in the braking servo unit 40 is not more than the required negative pressure Pc, the opening of the throttle of a throttle device installed to the branch pipe 20 connected with the negative pressure pipe 42 is throttled according to the opening of an accelerator. The opening of the throttle is throttled according to the opening of the accelerator, so as to generate the negative pressure in the branch pipe 20. <P>COPYRIGHT: (C)2003,JPO |
