Brake control apparatus

• US 6,132,014 A
• Filed: 05/20/1998
• Issued: 10/17/2000
• Est. Priority Date: 05/21/1997
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sawada, Mamoru, Yogo, Kazutoshi, Kiso, Takahiro
• Primary Examiner(s): SCHWARTZ, CHRISTOPHER P
• Application Number:
  US09/081,205
• Time in Patent Office: 881 Days
• Field of Search: 303/140, 303/146, 303/166, 701/83
• US Class Current: 303/146
• CPC Class Codes: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/3275 Systems with a braking assistant function, i.e. automatic full braking initiation in dependence of brake pedal velocity
• CPC Class Codes: B60T 8/442 the booster being a fluid return pump, e.g. in combination with a brake pedal force booster
• CPC Class Codes: B60T 8/4872 pump-back systems

Abstract

A turning state of a vehicle is detected to specify an outer side front wheel and an inner side rear wheel of a turning circle. A controlling device controls the brake fluid pressures of wheel cylinders of the specified wheels so that the brake fluid pressure of the wheel cylinder of one of the specified wheels is made smaller than a master cylinder pressure while substantially simultaneously the brake fluid pressure of the wheel cylinder of the other wheel of the specified wheels is made larger than the master cylinder pressure.

Claims

1. A brake control apparatus in a vehicle comprising:

wheel braking force producing devices for producing wheel braking force in front and rear wheels during braking of the vehicle;

a brake fluid pressure producing device for producing brake fluid pressure applied to the wheel braking force producing devices;

specifying means for detecting a turning state of the vehicle and specifying one of a front wheel and a rear wheel of the vehicle, the front wheel being the outer side wheel of the vehicle relative to a turning direction of the vehicle and the rear wheel being an inner side wheel of the vehicle relative to the turning direction of the vehicle; and

turning control means for controlling, when the turning state of the vehicle satisfies a predetermined condition, the brake fluid pressure producing device to reduce the applied brake fluid pressure to the wheel braking force producing device of a first wheel of the specified front wheel and rear wheel and substantially simultaneously controlling the brake fluid pressure producing device to increase the applied brake fluid pressure to the wheel braking force producing device of the second wheel of the specified front wheel and rear wheel;

wherein, the brake fluid pressure of the wheel braking force producing device of said first wheel is decreased by reducing a predetermined amount of brake fluid therefrom and the brake fluid pressure of the wheel braking force device of said second wheel is increased by adding thereto an amount of brake fluid equivalent to the predetermined amount of brake fluid reduced from the wheel braking force producing device of said first wheel.

3. A brake control apparatus according to claim 1 or 2, further comprising,

slip state detecting means for detecting respective slip states of the first and second wheels;

and

anti-skid controlling means for adjusting respectively the brake fluid pressure of the braking force producing devices of the first and second wheels based on brake fluid pressure initially applied by the brake fluid pressure producing device when the slip states of the first and second wheels satisfy respective predetermined conditions for executing anti-skid control; and

wherein, when the turning control means is controlling the brake fluid pressure producing device, the anti-skid control execution by the anti-skid controlling means is suspended.

4. A brake control apparatus according to claim 3, wherein the anti-skid control is suspended with respect to the outer side front wheel.

6. A brake control apparatus according to any one of claims 1, 2 and 5, wherein said wheel braking force producing devices comprise:

a first wheel braking force producing device for producing a wheel braking force in a front right wheel on vehicle braking;

a second wheel braking force producing device for producing a wheel braking force in a front left wheel on vehicle braking;

a third wheel braking force producing device for producing a wheel braking force in a rear right wheel on vehicle braking; and

a fourth wheel braking force producing device for producing a wheel braking force in a rear left wheel on vehicle braking, and further comprising;

a first pipe system which connects the brake fluid pressure producing device to both the first wheel braking force producing device and the second wheel braking force producing device; and

a second pipe system which connects the brake fluid pressure producing device to both the third wheel braking force producing device and the fourth wheel braking force producing device.

7. A brake control apparatus according to any one of claims 1, 2, and 5, wherein said wheel braking force producing devices comprise:

a first wheel braking force producing device for producing a wheel braking force in a front right wheel on vehicle braking;

a second wheel braking force producing device for producing a wheel braking force in a front left wheel on vehicle braking;

a third wheel braking force producing device for producing a wheel braking force in a rear right wheel on vehicle braking; and

a fourth wheel braking force producing device for producing a wheel braking force in a rear left wheel on vehicle braking, and further comprising;

a first pipe system which connects the brake fluid pressure producing device to both the first wheel braking force producing device and the fourth wheel braking force producing device; and

a second pipe system which connects the brake fluid pressure producing device to both the second wheel braking force producing device and the third wheel braking force producing device.

2. A brake control apparatus for a vehicle comprising:

wheel braking force producing devices for producing wheel braking force in front and rear wheels during braking of the vehicle;

a brake fluid pressure producing device for producing brake fluid pressure applied to the wheel braking force producing devices;

specifying means for detecting a turning state of the vehicle and specifying one of a front wheel and a rear wheel of the vehicle, the front wheel being the outer side wheel of the vehicle relative to a turning direction of the vehicle and the rear wheel being an inner side wheel of the vehicle relative to the turning direction of the vehicle; and

turning control means for controlling, when the turning state of the vehicle satisfies a predetermined condition, the brake fluid pressure producing device to hold constant the applied brake fluid pressure to the wheel braking force producing device of a first wheel of the specified front wheel and rear wheel and substantially simultaneously controlling the brake fluid pressure producing device to increase the applied brake fluid pressure to the wheel braking force producing device of the second wheel of the specified front wheel and rear wheel.

5. A brake control apparatus of a vehicle comprising:

wheel braking force producing devices for producing wheel braking force in front and rear wheels during braking of the vehicle;

a brake fluid pressure producing device for producing a first brake fluid pressure applied to the wheel braking force producing devices;

specifying means for detecting a turning state of the vehicle and specifying one of a front wheel and a rear wheel of the vehicle, the front wheel being the outer side wheel of the vehicle relative to a turning direction of the vehicle and the rear wheel being an inner side wheel of the vehicle relative to the turning direction of the vehicle; and

slip state detecting means for detecting respectively slip states of a first wheel of the specified front and rear wheels and a second wheel of the specified front and rear wheels;

anti-skid controlling means for adjusting respectively the brake fluid pressure of the braking force producing devices of the first and second wheels based on the first brake fluid pressure applied thereto when the slip states of the first and second wheels satisfy respective predetermined conditions for executing anti-skid control; and

a turning control means for controlling the brake fluid pressure producing device to increase the applied brake fluid pressure to the wheel braking force producing device of the second wheel to a brake fluid pressure larger than the first brake pressure immediately after the anti-skid controlling means starts reducing the brake fluid pressure of the wheel braking force producing device of the first wheel.

8. A brake control apparatus according to claim 5, wherein, when the brake fluid pressure of the wheel braking force producing device of the second wheel is increased by the turning control means, a threshold of the predetermined conditions for executing anti-skid control with respect to said second wheel is changed to a larger value so that starting the anti-skid control is delayed.

9. A brake control apparatus according to claim 5, wherein the turn controlling means operates to continue to increase brake fluid pressure of the wheel braking force producing device of said second wheel during a time period when the anti-skid controlling means is reducing the brake fluid pressure of the wheel braking force producing device to said first wheel.

10. A brake control apparatus according to claim 5, wherein the turn controlling means operates to increase the applied brake fluid pressure to the wheel braking force producing device of said second wheel when the predetermined condition for executing the anti-skid control is based on one of a brake fluid pressure holding and reducing modes of the wheel braking force producing device of said second wheel.

11. A brake control apparatus according to claim 5, wherein the turn controlling means controls the anti-skid control means to increase the brake fluid pressure of the wheel braking force producing device of said second wheel when the predetermined condition for executing the anti-skid control is based on one of a brake fluid pressure holding and reducing modes of the wheel braking force producing device of said second wheel.