Anti-skid control apparatus for a vehicle braking system

Claim 2

In an anti-skid control apparatus for a vehicle braking system including: (A) a pair of front wheels, and a pair of rear wheels; (B) wheel speed sensors associated with said wheels, respectively; (C) a first fluid pressure control valve device for controlling the brake fluid pressure of the wheel cylinder of one of said front wheels, arranged between a first fluid pressure generating chamber of a tandem master cylinder and said wheel cylinder of the one front wheel; (D) a second fluid pressure control valve device for controlling the brake fluid pressure of the wheel cylinder of another of said front wheels, arranged between a second fluid pressure generating chamber of said tandem master cylinder and said wheel cylinder of the other front wheel; and (E) a control unit receiving outputs of said wheel speed sensors for measuring or judging the skid conditions of said front and rear wheels and for generating instructions for controlling said first and second fluid pressure control valve devices and in which said control unit discriminates the frictionally lower one (designated as "low side") of the sides of the road on which said wheels are running, on the basis of the measuring or judging results of the skid conditions of said rear and/or front wheels, combines logically the measuring or judging result of the skid condition of the one rear wheel running on said low side of the road, with that of the one front wheel running on the same side as said low side, for generating the instruction for controlling said first or second fluid pressure control valve device for the corresponding front wheel, and generates the instruction for controlling said second or first fluid pressure control valve device for the other front wheel, on the basis of the measuring or judging result of the skid condition of the other front wheel running on the high side (frictionally higher side) independently of those of said rear wheels, the improvements in which a brake relieving instruction for decreasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one of the front wheel and rear wheel on the low side which generates a brake relieving signal for decreasing the brake fluid pressure, sooner than the other thereof.

Claim 3

An anti-skid control apparatus according to claim 1, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one of the front wheel and rear wheel on the low side which has reached the stable region of the μ-slip characteristics, sooner than the other.

Claim 4

An anti-skid control apparatus according to claim 2 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 5

An anti-skid control apparatus according to claim 2 which is applied to a car of the four-wheel drive type.

Claim 6

An anti-skid control apparatus according to claim 1, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one of the front wheel and rear wheel on the low side which generates a brake increasing signal for increasing the brake fluid pressure, sooner than the other thereof.

Claim 7

An anti-skid control apparatus according to claim 5 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 8

An anti-skid control apparatus according to claim 5 which is applied to a car of the four-wheel drive type.

Claim 9

An anti-skid control apparatus according to claim 1, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one of the front wheel and rear wheel on the low side which has reached the stable region of the μ-slip characteristics, later than the other.

Claim 10

An anti-skid control apparatus according to claim 8 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 11

An anti-skid control apparatus according to claim 8 which is applied to a car of the four-wheel drive type.

Claim 12

An anti-skid control apparatus according to claim 1, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one of the front wheel and rear wheel on the low side which generates a brake increasing signal for increasing the brake fluid pressure, later than the other thereof.

Claim 13

An anti-skid control apparatus according to claim 11 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 14

An anti-skid control apparatus according to claim 11 which is applied to a car of the four-wheel drive type.

Claim 15

An anti-skid control apparatus according to claim 1, in which, in the lapse of a predetermined time after said brake relieving instruction disappears, a further brake relieving instruction is formed on the basis of the judging result of said other of the front wheel and rear wheel on the low side, when said other wheel continuously still generates a brake relieving signal.

Claim 16

An anti-skid control apparatus according to claim 14, in which the time of said further brake relieving instruction is limitted to a predetermined time.

Claim 17

An anti-skid control apparatus according to claim 15 which is applied to a car of the four-wheel drive type.

Claim 18

An anti-skid control apparatus according to claim 14 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 19

An anti-skid control apparatus according to claim 14 which is applied to a car of the four-wheel drive type.

Claim 20

An anti-skid control apparatus according to claim 14 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 21

An anti-skid control apparatus according to claim 1 which is applied to a car of the four-wheel drive type.

Claim 22

An anti-skid control apparatus according to claim 1 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 23

An anti-skid control apparatus according to claim 21 which is applied to a car of the four-wheel drive type.

Claim 24

In an anti-skid control apparatus for a vehicle braking system including: (A) a pair of front wheels, and a pair of rear wheels; (B) wheel speed sensors associated with said wheels, respectively; (C) a first fluid pressure control valve device for controlling the brake fluid pressure of the wheel cylinder of one of said front wheels, arranged between a first fluid pressure generating chamber of a tandem master cylinder and said wheel cylinder of the one front wheel; (D) a second fluid pressure control valve device for controlling the brake fluid pressure of the wheel cylinder of another of said front wheels, arranged between a second fluid pressure generating chamber of said tandem master cylinder and said wheel cylinder of the other front wheel; and (E) a control unit receiving outputs of said wheel speed sensors for measuring or judging the skid conditions of said front and rear wheels and for generating instructions for controlling said first and second fluid pressure control valve devices and in which said control unit discriminates the frictionally lower one (designated as "low side") of the sides of the road on which said wheels are running, on the basis of the measuring or judging results of the skid conditions of said rear and/or front wheels, combines logically the measuring or judging results of the skid conditions of said rear wheels with the measuring or judging result of the skid condition of the one front wheel running on the low side for generating the instruction for controlling said first or second fluid pressure control valve device for the corresponding front wheel, and generates the instruction for controlling said second or first fluid pressure control valve device for the other front wheel, on the basis of the measuring or judging result of the skid condition of the other front wheel running on the high side (frictionally higher side) independently of those of said rear wheels, the improvements in which a brake relieving instruction for improvements in which a brake relieving instruction for decreasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one or ones of the rear wheels both and front wheel on the low side which generates a brake relieving signal for decreasing the brake fluid pressure, sooner than the other or others thereof.

Claim 25

In an anti-skid control apparatus for a vehicle braking system including: (A) a pair of front wheels, and a pair of rear wheels; (B) wheel speed sensors associated with said wheels, respectively; (C) a first fluid pressure control valve device for controlling the brake fluid pressure of the wheel cylinder of one of said front wheels, arranged between a first fluid pressure generating chamber of a tandem master cylinder and said wheel cylinder of the one front wheel; (D) a second fluid pressure control valve device for controlling the brake fluid pressure of the wheel cylinder of another of said front wheels, arranged between a second fluid pressure generating chamber of said tandem master cylinder and said wheel cylinder of the other front wheel; and (E) a control unit receiving outputs of said wheel speed sensors for measuring or judging the skid conditions of said front and rear wheels and for generating instructions for controlling said first and second fluid pressure control valve devices and in which said control unit discriminates the frictionally lower one (designated as "low side") of the sides of the road on which said wheels are running, on the basis of the measuring or judging results of the skid conditions of said rear and/or front wheels, combines logically the measuring or judging results of the skid conditions of said rear wheels with the measuring or judging result of the skid condition of the one front wheel running on the low side for generating the instruction for controlling said first or second fluid pressure control valve device for the corresponding front wheel, and generates the instruction for controlling said second or first fluid pressure control valve device for the other front wheel, on the basis of the measuring or judging result of the skid condition of the other front wheel running on the high side (frictionally higher side) independently of those of said rear wheels, the improvements in which a brake relieving instruction for improvements in which a brake relieving instruction for decreasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one or ones of the rear wheels both and front wheel on the low side which generates a brake relieving signal for decreasing the brake fluid pressure, sooner than the other or others thereof.

Claim 26

An anti-skid control apparatus according to claim 23, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one or ones of the rear wheel both and front wheel on the low side which has reached the stable region of the μ-slip characteristics, sooner than the other.

Claim 27

An anti-skid control apparatus according to claim 24 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 28

An anti-skid control apparatus according to claim 24 which is applied to a car of the four-wheel drive type.

Claim 29

An anti-skid control apparatus according to claim 23, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one or ones of the rear wheels both and front wheel on the low side which generates a brake increasing signal for increasing the brake fluid pressure, sooner than the other or others thereof.

Claim 30

An anti-skid control apparatus according to claim 27 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 31

An anti-skid control apparatus according to claim 27 which is applied to a car of the four-wheel drive type.

Claim 32

An anti-skid control apparatus according to claim 23, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or second fluid pressure control valve device, is formed on the basis of the judging result of the one or ones of the rear wheels both and front wheel on the low side which has reached the stable region of the μ-slip characteristics, later than the other or others thereof.

Claim 33

An anti-skid control apparatus according to claim 30 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 34

An anti-skid control apparatus according to claim 30 which is applied to a car of the four-wheel drive type.

Claim 35

An anti-skid control apparatus according to claim 23, in which, after said brake relieving instruction disappears, a brake increasing instruction for increasing the brake fluid pressure, of the instructions for controlling the first or said fluid pressure control valve device, is formed on the basis of the judging result of the one or ones of the rear wheels both and front wheel on the low side which generates a brake increasing signal for increasing the brake fluid pressure, later than the other or others thereof.

Claim 36

An anti-skid control apparatus according to claim 33 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 37

An anti-skid control apparatus according to claim 33 which is applied to a car of the four-wheel drive type.

Claim 38

An anti-skid control apparatus according to claim 23, in which, in the lapse of a predetermined time after said brake relieving instruction disappears, a further brake relieving instruction is formed on the basis of the judging result of said other or other of the rear wheels both and front wheel on the low side, when said other wheel continuously still generates a brake relieving signal.

Claim 39

An anti-skid control apparatus according to claim 36, in which the time of said further brake relieving instruction is limited to a predetermined time.

Claim 40

An anti-skid control apparatus according to claim 37 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 41

An anti-skid control apparatus according to claim 37 which is applied to a car of the four-wheel drive type.

Claim 42

An anti-skid control apparatus according to claim 36 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 43

An anti-skid control apparatus according to claim 36 which is applied to a car of the four-wheel drive type.

Claim 44

An anti-skid control apparatus according to claim 23 in which a pressure selecting means for generating a pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with said first and second fluid pressure control valve devices is arranged between the wheel cylinders of the front wheels and those of the rear wheels.

Claim 45

An anti-skid control apparatus according to claim 42 which is applied to a car of the four-wheel drive type.

Claim 46

An anti-skid control apparatus according to claim 23 which is applied to a car of the four-wheel drive type.