Patent ID: 6238019
Filing Date: 2001-05-29
Classification: B60T

Abstract:
A brake control apparatus for a vehicle comprising:a master cylinder producing pressure of a brake fluid when braking the vehicle;a first and a second wheel cylinder receiving the pressure of the brake fluid from said master cylinder pressure to apply braking efforts to a first and a second wheel, respectively;a third and a fourth wheel cylinder receiving the pressure of the brake fluid from said master cylinder to applying braking efforts to a third and a fourth wheel, respectively;a first hydraulic line connecting said master cylinder and said first and second wheel cylinders;a second hydraulic line connecting said master cylinder and said third and fourth wheel cylinders;a first pressure elevation/reduction actuator set disposed between said master cylinder and said first and second wheel cylinders in said first hydraulic line to selectively elevate and reduce the pressure of the brake fluid applied to said first and second wheel cylinders;a second pressure elevation/reduction actuator set disposed between said master cylinder and said third and fourth wheel cylinders in said second hydraulic line to selectively elevate and reduce the pressure of the brake fluid applied to said third and fourth wheel cylinders;a first differential pressure control valve disposed between said master cylinder and said first pressure elevation/reduction actuator set in said first hydraulic line, regulating flow of the brake fluid between a first portion of said first hydraulic line connecting with said master cylinder and a second portion of said first hydraulic line connecting with said first pressure elevation/reduction actuator set to control a difference in pressure of the brake fluid between the first and second portions;a second differential pressure control valve disposed between said master cylinder and said second pressure elevation/reduction actuator set in said second hydraulic line, regulating flow of the brake fluid between a first portion of said second hydraulic line connecting with said master cylinder and a second portion of said second hydraulic line connecting with said second pressure elevation/reduction actuator set to control a difference in pressure of the brake fluid between the first and second portions of said second hydraulic line;a first pump disposed in said first hydraulic line, delivering pressure of the brake fluid to said first and second wheel cylinders and returning an amount of the brake fluid equivalent to a required reduction in pressure of the brake fluid applied to said first and second wheel cylinders to said master cylinder;a second pump disposed in said second hydraulic line, delivering pressure of the brake fluid to said third and fourth wheel cylinders and returning an amount of the brake fluid equivalent to a required reduction in pressure of the brake fluid applied to said third and fourth wheel cylinders to said master cylinder;a first suction branch line connecting the first portion of said first hydraulic line and an inlet of said first pump;a second suction branch line connecting the first portion of said second hydraulic line and an inlet of said second pump;a first discharge branch line connecting an outlet of said first pump and the second portion of said first hydraulic line;a second discharge branch line connecting an outlet of said second pump and the second portion of said second hydraulic line;a connecting line connecting the second portion of said first hydraulic line between said first differential pressure control valve and said first pressure elevation/reduction actuator set and the second portion of said second hydraulic line between said second differential pressure control valve and said second pressure elevation/reduction actuator set; anda fluid pressure difference regulator disposed in said connecting line to regulate a difference between the pressure of the brake fluid in the second portion of said first hydraulic line delivered by said first pump and the pressure of the brake fluid in the second portion of said second hydraulic line delivered by said second pump so as to fall within a given allowable pressure range.