| 摘要 |
PURPOSE:To provide a vacuum boosting device for vehicle which performs the always superior controlling boosting action and has a compact shape. CONSTITUTION:A vacuum tank 6 is divided into a negative pressure chamber 6a and a variable pressure chamber 6b by a movable wall 61, and the negative pressure chamber 6a communicates to the constant pressure chamber 1a of a brake booster 1 by an air piping 41, and the variable pressure chamber 6b is opened on the side wall of the brake booster 1 by an air piping 43. When a brake pedal 2 is stepped ON frequently, a large quantity of air is introduced into the variable pressure chamber 1b, and the negative pressure in the constant pressure chamber 1a lowers, and the brake boosting action is lightened. If the brake pedal 2 is stepped ON in this state, until a piston 11 passes through the opened port part of the air piping 43, the atmosphere is introduced into the variable pressure chamber 6b of the vacuum tank 6 from the variable pressure chamber 1b of the brake booster 1, and the movable wall 61 is advanced by the atmospheric pressure, and the negative pressure chamber 6a contracts. Each negative pressure is restored speedily in the contracted negative pressure chamber 6a and the constant chamber 1a which communicates to the negative pressure chamber because of the exhaust by a vacuum pump 5, and the sufficient boosting action is enabled again. |
