US 6,598,946 B2Granted

Vehicular brake control apparatus and vehicular brake control method

AssigneeToyota Jidosha Kabushiki Kaisha

InventorAkira Nagae

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Abstract

A vehicle is equipped with a coupling such as, for example, a center differential or a variable clutch, that transmits a driving force from an engine to a front-wheel drive shaft and a rear-wheel drive shaft while allowing a difference in rotational speed therebetween and a brake controller that individually controls braking forces to be applied to wheels in accordance with a running state of the vehicle. A vehicular brake controller prohibits braking force control from being started if the coupling is in its locked state or when the coupling causes a relatively great connecting strength to exist between the front-wheel and rear-wheel drive shafts. While braking force control is being performed by the brake controller, braking force control is continued even if there is a command to cause the coupling to be locked or to achieve the great coupling strength.

Claims16

Dependent claims

A vehicular brake control apparatus comprising:

a connecting state coupling interposed between a front-wheel drive shaft that transmits a driving force to a front-wheel side and a rear-wheel drive shaft that transmits a driving force to a rear-wheel side, and that changes a connecting state between the front-wheel drive shaft and the rear-wheel drive shaft;
brakes, each of which is provided in a corresponding one of wheels to apply a braking force to the corresponding one of the wheels;
and
a brake controller that performs operation control of the brakes in accordance with a running state of the vehicle and that controls braking forces to be applied to the wheels individually, wherein the brake controller:
(a) prohibits brake control if conditions for starting brake control by the brake controller have been fulfilled during a period in which the coupling causes a great connecting strength to act between the front-wheel drive shaft and the rear-wheel drive shaft, and
(b) continues brake control if the connecting state between the front-wheel drive shaft and the rear-wheel drive shaft has been changed during perfoarmance of the brake control such that the great connecting strength acts between the front-wheel drive shaft and the rear-wheel drive shaft while brake control is being performed by the brake controller.

3 more elements

A brake control method for a vehicle having (a) a connecting state coupling interposed between a front-wheel drive shaft that transmits a driving force to a front-wheel side and a rear-wheel drive shaft that transmits the driving force to a rear-wheel side, and that changes a connecting state between the front-wheel drive shaft and the rear-wheel drive shaft, (b) brakes, each of which is provided in a corresponding one of wheels to apply a braking force to the corresponding one of the wheels, and (c) a controller that performs operation control of the brakes in accordance with a running state of the vehicle and that controls braking forces to be applied to the wheels individually, comprising the steps of:

prohibiting brake control if conditions for starting brake control by the brake controller have been fulfilled during a period in which the coupling causes a great connecting strength to act between the front-wheel drive shaft and the rear-wheel drive shaft;
and
continuing brake control by the brake controller if the connecting state between the front-wheel drive shaft and the rear-wheel drive shaft has been changed during performance of the brake control such that the great connecting strength acts between the front-wheel drive shaft and the rear-wheel drive shaft, while brake control is being performed by the brake controller.

Dependencies are inferred from the claim text.

Facts

Application: 09/907,757Filed 19 Jul 2001
Priority: JP 2000-23198931 Jul 2000
Published: US 2002/0014799 A17 Feb 2002
Granted: 29 Jul 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

B60K 23/0808
For changing number of driven wheels , for switching from driving one axle to driving two or more axles: for varying torque distribution between…
B60T 8/1769
Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS: specially adapted for vehicles having…
B60T 8/322
Deceleration: systems specially adapted for vehicles driven by more than one axle, e.g. Four Wheel-Drive vehicles
B60K 17/3462
The transfer gear being a differential gear: with means for changing distribution of torque between front and rear wheels