Traction control device

• US 8,352,145 B2
• Filed: 07/01/2011
• Issued: 01/08/2013
• Est. Priority Date: 12/26/2008
• Status: Active Grant

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Uematsu, Koji, Hatake, Kazuhiro, Kusumoto, Yuya
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): LOUIE, WAE LENNY
• Application Number:
  US13/175,107
• Publication Number:
  US 20110257861A1
• Time in Patent Office: 557 Days
• Field of Search: 701/44, 701/48, 701/88, 701/50, 180/197, 180/235, 180/233, 180/245, 180/244
• US Class Current: 701/88
• CPC Class Codes: B60K 17/35 including arrangements for suppressing or influencing the power transfer, e.g. viscous clutches differential gearing with locking devices F16H48/20
• CPC Class Codes: B60T 10/00 Control or regulation for continuous braking making use of fluid or powdered medium, e.g. for use when descending a long slope
• CPC Class Codes: B60T 2201/14 Electronic locking-differential
• CPC Class Codes: B60T 2210/16 Off-road driving conditions
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60T 8/4809 Traction control, stability control, using both the wheel brakes and other automatic braking systems
• CPC Class Codes: B60W 10/14 Central differentials for dividing torque between front and rear axles
• CPC Class Codes: B60W 10/16 Axle differentials, e.g. for dividing torque between left and right wheels
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2510/0233 of torque converter lock-up clutch
• CPC Class Codes: B60W 2520/263 Slip values between front and rear axle
• CPC Class Codes: B60W 2520/266 Slip values between left and right wheel
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 2720/406 between left and right wheel
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels

Abstract

A traction control device includes: rotation speed detectors provided to wheels; a control-start determiner that determines whether or not to control a braking mechanism and a differential adjusting mechanism based on rotation speeds; a braking mechanism controller that controls the braking mechanism based on a result of the determination of the control-start determiner; and a differential adjusting mechanism controller that controls the differential adjusting mechanism based on the result of the determination of the control-start determiner, in which the control-start determiner includes: a right-left-wheel rotation speed difference calculating section; a front-rear-wheel rotation speed difference calculating section; and a control-start determining section that determines whether or not to start controlling at least one of the braking mechanism and the differential adjusting mechanism when one of rotation speed differences reaches or exceeds a predetermined threshold.

Claims

1. A traction control device of a construction machine comprising a braking mechanism provided to each of wheels and a differential adjusting mechanism for adjusting a differential between front and rear wheels, the traction control device controlling the differential adjusting mechanism, the traction control device comprising:

a rotation speed detector that detects a rotation speed of each of the wheels; and

a controller having a processor, the controller being configured to access at least a first and second threshold, the first threshold corresponding to a rotation speed difference between the right and left wheels, the second threshold corresponding to a rotation speed ratio between the right and left wheels, and the controller comprising;

a control-start determiner that determines whether or not to control the differential adjusting mechanism based on the detected rotation speed of each of the wheels; and

a differential adjusting mechanism controller that controls the differential adjusting mechanism based on a result of the determination of the control-start determiner, wherein the control-start determiner comprises;

a right-left-wheel rotation speed difference calculating section that calculates a rotation speed difference between right and left wheels;

a right-left-wheel rotation speed ratio calculating section that calculates a rotation speed ratio between the right and left wheels; and

a control-start determining section that determines to start controlling the differential adjusting mechanism for adjusting the differential between the front and rear wheels when the rotation speed difference between the right and left wheels reaches or exceeds the first threshold for right-left-wheel rotation speed difference or when the rotation speed ratio between the right and left wheels reaches or exceeds the second threshold for right-left-wheel rotation speed ratio.

2. The traction control device according to claim 1, wherein

the construction machine is an articulated construction machine having separate front and rear vehicle body frames, and

the control-start determiner further comprises a control threshold setting section that adjusts the first threshold for right-left-wheel rotation speed difference and the second threshold for right-left-wheel rotation speed ratio in accordance with an articulate angle between the front and rear vehicle body frames.

3. The traction control device according to claim 1, further comprising

a braking mechanism controller that controls the braking mechanism provided to each of the wheels, the braking mechanism controller starting controlling the braking mechanism when the control-start determiner determines to start controlling the differential adjusting mechanism.