Brake system dig feature

Patent metadata

Field	Value
Publication number	US-9908408-B2
Application number	US-201615228053-A
Country	US
Kind code	B2
Filing date	Aug 4, 2016
Priority date	Dec 18, 2015
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A dig system which allows for a vehicle to perform a dig maneuver, without sacrificing drivability. An actuator places the dig system in one of four different modes of operation, where the front wheels are placed in either a first configuration or a second configuration, where the front wheels are positioned at a desired steering angle, and one of the front or rear wheels is braked and prevented from rotating. The transfer case transfers power to one or more of the non-braked wheels, and disconnects from the remaining wheels. One or more of the non-braked wheels are rotated such that the vehicle pivots about an axis which extends through one of the wheels. One of the rear wheels is braked when performing a front dig maneuver, and one of the front wheels is be braked when performing a reverse dig maneuver.

First claim

What is claimed is:

1. A dig system, comprising:
a vehicle;
at least one front wheel being part of the vehicle;
at least one rear wheel being part of the vehicle;
a braking system being part of the vehicle, the braking system operable for selectively preventing the rotation of the at least one front wheel and the at least one rear wheel;
a transfer case being part of the vehicle, the transfer case operable for transferring power to the at least one front wheel and the at least one rear wheel;
a plurality of axes; and
an actuator operable for placing the dig system in a first mode of operation, a second mode of operation, a third mode of operation, and a fourth mode of operation;
wherein during the first mode of operation, the at least one front wheel is placed in a first configuration, the transfer case is configured to transfer power to the at least one front wheel and disconnect from the at least one rear wheel, and the braking system is configured to prevent rotation of the at least one rear wheel, such that when the at least one front wheel is rotated by the transfer case, the vehicle pivots about one of the plurality of axes extending through the at least one rear wheel, during the second mode of operation, the at least one front wheel is placed in a second configuration, the transfer case is configured to transfer power to the at least one front wheel and disconnect from the at least one rear wheel, and the braking system is again configured to prevent rotation of the at least one rear wheel, such that when the at least one rear wheel is rotated, the vehicle pivots about the one of the plurality of axes extending through the at least one rear wheel, during the third mode of operation, the at least one front wheel is placed in the first configuration, the transfer case is configured to transfer power to the at least one rear wheel and disconnect from the at least one front wheel, and the braking system is configured to prevent rotation of the at least one front wheel, such that when the at least one rear wheel is rotated by the transfer case, and the vehicle pivots about one of the plurality of axes extending through the at least one front wheel, during the fourth mode of operation, the at least one front wheel is placed in the second configuration, the transfer case is configured to transfer power to the at least one rear wheel and disconnect from the at least one front wheel, and the braking system is again configured to prevent rotation of the at least one front wheel, such that when the at least one rear wheel is rotated, the vehicle pivots about the one of the plurality of axes extending through the at least one front wheel.

2. The dig system of claim 1 , further comprising:
a first front wheel rotationally driven by the transfer case; and
a second front wheel rotationally driven by the transfer case;
wherein during the first mode of operation, the first front wheel and the second front wheel are placed in the first configuration and are rotationally driven by the transfer case, during the second mode of operation, the first front wheel and the second front wheel are placed in the second configuration, and are rotationally driven by the transfer case, during the third mode of operation, the second front wheel is prevented from rotating by the braking system such that the vehicle pivots about one of the plurality of axes extending through the second front wheel, and during the fourth mode of operation, the first front wheel is prevented from rotating by the braking system such that the vehicle pivots about one of the plurality of axes extending through the first front wheel.

3. The dig system of claim 2 , the braking system further comprising:
a first front brake unit operable for selectively preventing rotation of the first front wheel; and
a second front brake unit operable for selectively preventing rotation of the second rear wheel;
wherein during the first mode of operation and the second mode of operation, the first front brake unit and the second front brake unit are deactivated such that first front wheel and the second front wheel are rotated by the transfer case, during the third mode of operation, the first front brake unit is deactivated, and the second front brake unit is activated to prevent the rotation of the second front wheel, and during the fourth mode of operation, the second front brake unit is deactivated, and the first front brake unit is activated to prevent rotation of the first front wheel.

4. The dig system of claim 1 , further comprising:
a first rear wheel rotationally driven by the transfer case; and
a second rear wheel rotationally driven by the transfer case;
wherein during the first mode of operation, the transfer case is disconnected from the first rear wheel and the second rear wheel, the braking system is configured to prevent the second rear wheel from rotating, such that the vehicle pivots about the one of the plurality of axes extending through the second rear wheel, during the second mode of operation, the transfer case is disconnected from the first rear wheel and the second rear wheel, the braking system is configured to prevent the first wheel from rotating such that the vehicle pivots about the one of the plurality of axes extending through the first rear wheel, and during the third mode of operation and the fourth mode of operation, the first rear wheel and the second rear wheel are rotationally driven by the transfer case.

5. The dig system of claim 4 , the braking system further comprising:
a first rear brake unit operable for selectively preventing rotation of the first rear wheel; and
a second rear brake unit operable for selectively preventing rotation of the second rear wheel;
wherein during the first mode of operation, the first rear brake unit is deactivated, and the second rear brake unit is activated such that the second rear wheel is prevented from rotating, during the second mode of operation, the second rear brake unit is deactivated, and the first rear brake unit is activated such that the first rear wheel is prevented from rotating, and during the third mode of operation and the fourth mode of operation, the first rear brake unit and the second rear brake unit are deactivated.

6. The dig system of claim 5 , the first rear brake unit further comprising a first parking brake unit.

7. The dig system of claim 5 , the second rear brake unit further comprising a second parking brake unit.

8. A dig system, comprising:
a vehicle;
a first front wheel;
a second front wheel;
a front axle, the first front wheel and the second front wheel connected to the front axle;
a first rear wheel;
a second rear wheel;
a rear axle, the first rear wheel and the second rear wheel connected to the rear axle;
a transfer case for distributing power between the front axle and the rear axle;
a first front brake unit operable for selectively preventing rotation of the first front wheel;
a second front brake unit operable for selectively preventing rotation of the second front wheel;
a first rear brake unit operable for selectively preventing rotation of the first rear wheel;
a second rear brake unit operable for selectively preventing rotation of the second rear wheel;
a hydraulic control unit operable for controlling the first front brake unit, the second front brake unit, the first rear brake unit, and the second rear brake unit;
a first axis extending through the first rear wheel;
a second axis extending through the second rear wheel;
a third axis extending through the first front wheel;
a fourth axis extending through the second front wheel; and
an actuator operable for placing the dig system in a first mode of operation, a second mode of operation, a third mode of operatio

Assignees

• Continental automotive systems inc

Inventors

• Baker David Leigh

Classifications

• B60T2201/16

  Curve braking control, e.g. turn control within ABS control algorithm · CPC title

• B60T11/21

  with two pedals operating on respective circuits, pressures therein being equalised when both pedals are operated together, e.g. for steering (steering non-deflectable wheels or endless tracks by differentially driving ground-engaging elements on opposite vehicle sides using brakes as main steering effecting means B62D11/08) · CPC title

• B60K23/08

  for changing number of driven wheels {, for switching from driving one axle to driving two or more axles (B60K17/3515 takes precedence)} · CPC title

• B60T8/246

  Change of direction · CPC title

• B60K17/344 Primary

  having a transfer gear · CPC title