Patent ID: 7125085
Filing Date: 2006-10-24
Classification: B60T

Abstract:
1. A braking force retaining unit for a hydraulic brake system in a vehicle, the hydraulic brake system comprising: a hydraulic brake circuit; a master cylinder in fluid communication with the circuit; at least one wheel cylinder in fluid communication with the circuit; and a break pedal operatively connected to the master cylinder; the brake force retaining unit comprising: a cut-off valve provided in the circuit disposed between the master cylinder and the at least one wheel cylinder; and a control unit for controlling opening and closing of the cut-off valve, wherein the cut-off valve retains a predetermined brake hydraulic pressure at the at least one wheel cylinder until a predetermined releasing condition is established even after the depression of the brake pedal is released when a vehicle is stopped, such that when the depression of the brake pedal is released, the control unit controls the cut-off valve so as to continue to retain the retained brake hydraulic pressure at the at least one wheel cylinder while gradually reducing the retained brake hydraulic pressure at a first reduction rate, and when the predetermined releasing condition is established, the retained brake hydraulic pressure is released such that the control unit controls the cut-off valve so as to gradually reduce the retained brake hydraulic pressure at the at least one wheel cylinder at a second reduction rate to thereby release the retained brake hydraulic pressure, wherein the second reduction rate is faster than the first reduction rate.