Patent ID: 7213892
Filing Date: 2007-05-08
Classification: B60T

Abstract:
1. A vehicle motion control apparatus comprising: wheel brake cylinders operatively associated with wheels of a vehicle, respectively; a master cylinder connected to said wheel brake cylinders through a dual hydraulic circuit with a pair of wheel brake cylinders included in each hydraulic circuit, said master cylinder discharging a hydraulic braking pressure into each hydraulic circuit in response to operation of a brake pedal; normally open switching valves each disposed between said master cylinder and each of said pair of wheel brake cylinders, each of said normally open switching valves supplying the hydraulic braking pressure discharged from said master cylinder into each of said pair of wheel brake cylinders when each of said normally open switching valves is placed in an open position thereof; normally closed switching valves each connected to a passage between each of said normally open switching valves and each of said pair of wheel brake cylinders, each of said normally closed switching valves reducing the hydraulic braking pressure in each of said pair of wheel brake cylinders when each of said normally closed switching valves is placed in an open position thereof; proportional pressure difference valve means disposed between said master cylinder and said normally open switching valves in each hydraulic circuit, said valve means regulating a pressure difference between the hydraulic pressure at the side of said master cylinder and the hydraulic pressure at the side of said normally open switching valves to be of a desired value; automatic hydraulic pressure generating means for generating a hydraulic braking pressure independently of said master cylinder and irrespective of operation of said brake pedal, and supplying the hydraulic braking pressure into a passage between said valve means and said normally open switching valves in each hydraulic circuit; vehicle state monitor means for monitoring state variable of said vehicle; and control means for controlling said pressure generating means and said valve means, and regulating the hydraulic braking pressure in one of said wheel brake cylinders in one hydraulic circuit of said dual hydraulic circuit, on the basis of the state variable of said vehicle monitored by said vehicle state monitor means, said control means controlling at least said normally open switching valve connected to the other one of said wheel brake cylinders in said one hydraulic circuit, in response to the hydraulic pressure regulated in said one of said wheel brake cylinders, when said brake pedal is operated while said pressure generating means is being controlled on the basis of the state variable of said vehicle monitored by said vehicle state monitor means.