Patent ID: 9533663
Date: 2017-01-03
CPC Classifications: B60T

Claim:
1. A hydraulic brake system, comprising: a first hydraulic-pressure generating device including a manual hydraulic pressure source which is configured to generate hydraulic pressure by operation of a brake operating member by an operator; a second hydraulic-pressure generating device including a power hydraulic pressure source which is activatable by supply of electric energy thereto and which is configured to generate hydraulic pressure by activation thereof; a plurality of hydraulic brakes provided for a plurality of wheels of a vehicle, and activatable by hydraulic pressures in respective brake cylinders thereof so as to restrain rotations of the respective wheels; a manual-operation-associated brake line including (i) a communicating device which is communicable with said manual hydraulic pressure source and which is communicable at least one of said brake cylinders of said plurality of hydraulic brakes, (ii) said first hydraulic-pressure generating device, and (iii) said at least one of said brake cylinders; an output hydraulic-pressure control device and a flow restraining device disposed in parallel with each other between said manual-operation-associated brake line and said second hydraulic-pressure generating device, said output hydraulic-pressure control device being configured to control the hydraulic pressure outputted from said second hydraulic-pressure generating device, said flow restraining device being configured to restrain flow of a working fluid away from said second hydraulic-pressure generating device toward said manual-operation-associated brake line; a power hydraulic pressure source control device configured to activate said power hydraulic pressure source such that the hydraulic pressure is supplied from said power hydraulic pressure source to said manual-operation-associated brake line via said flow restraining device, when said hydraulic brake system is in a failure state disabling said output hydraulic-pressure control device from controlling the hydraulic pressure outputted by said second hydraulic-pressure generating device; a front-wheel common passage to which said brake cylinders of said hydraulic brakes provided for respective front right and left wheels as ones of the plurality of wheels are connected via respective two front-wheel individual passages, wherein said manual hydraulic pressure source is constituted by each of two pressurizing chambers of a tandem master cylinder which includes two pressurizing pistons and which is configured to generate the hydraulic pressures in said two pressurizing chambers by operation of said brake operating member, said two pressurizing chambers being connected to said respective two front-wheel individual passages via respective two front-wheel individual connection passages, and wherein said communicating device includes (i) said front-wheel common passage, (ii) one of said two front-wheel individual passages, and (iii) one of said two front-wheel individual connection passages which is connected to said one of said two front-wheel individual passages; a front-wheel individual control valve provided in said one of said two front-wheel individual passages, and constituted by a normally-open electromagnetic valve which is switchable between an open state and a closed state by control of supply of an electric current to a solenoid thereof and which is to be placed in the open state when the electric current is not being supplied to the solenoid thereof; and another from-wheel individual control valve provided in another one of said two front-wheel individual passages, and constituted by a normally-closed electromagnetic valve which is switchable between an open state and a closed state by control of supply of an electric current to a solenoid thereof and which is to be placed in the closed state when the electric current is not being supplied to the solenoid thereof, wherein said one of said two front-wheel individual connection passages is connected to a portion of said one of said two front-wheel individual passages which is located on a downstream side of said front-wheel individual control valve constituted by said normally-open electromagnetic valve, while another one of said two front-wheel individual connection passages is connected to a portion of said another one of said two front-wheel individual passages which is located on a downstream side of said another front-wheel individual control valve constituted by said normally-closed electromagnetic valve.