Hydraulic circuit for traveling

• US 20030085615A1
• Filed: 12/20/2002
• Published: 05/08/2003
• Est. Priority Date: 10/02/2000
• Status: Abandoned Application

• Current Assignee: Teijin Seiki Co., Ltd. (Nabtesco Corporation)
• Original Assignee: Teijin Seiki Co., Ltd. (Nabtesco Corporation)
• Inventors: Tanabe, Sadayuki
• Application Number:
  US10/324,675
• Publication Number:
  US 20030085615A1
• Time in Patent Office: Days
• US Class Current: 303/139
• CPC Class Codes: B60K 17/10 of fluid gearing of fluid clutches B60K17/02
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60T 13/686 in hydraulic systems or parts thereof
• CPC Class Codes: B60T 2270/203 hydraulic system components
• CPC Class Codes: B60T 8/4809 Traction control, stability control, using both the wheel brakes and other automatic braking systems
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: F16H 2059/6876 the motor speed
• CPC Class Codes: F16H 2063/3033 the brake is actuated by springs and released by a fluid pressure
• CPC Class Codes: F16H 61/4157 Control of braking, e.g. preventing pump over-speeding when motor acts as a pump
• CPC Class Codes: F16H 61/421 Motor capacity control by electro-hydraulic control means, e.g. using solenoid valves
• CPC Class Codes: F16H 61/44 with more than one pump or motor in operation

Abstract

If a hydraulic motor (23) (traveling wheel (27)) is rotated (or skidding) at high rate, and a hydraulic motor (24) is hardly rotated, a detection controller (68) compares the rotational speeds of both hydraulic motors (23, 24). Then the rotation detected by the rotation detectors (66, 67) to detect the traveling wheel (27) to be skidding, and moves a piston (71) to allow a negative brake (40) to give a braking force to the hydraulic motor (23), and rotate the hydraulic motor (24). In this way, this invention can release the traveling wheel from skidding without the use of a flow dividing valve.

Claims

1. A traction control system for a traveling vehicle having at least two traveling wheels driven by a single hydraulic pump through respective hydraulic motors, comprising:

rotation detectors for respectively detecting rotation speeds of the traveling wheels;

a computer connected to the rotation detectors for comparing the rotational speeds of the traveling wheels; and

computer-controlled brake units respectively provided to the traveling wheels, and independently controlled by the computer.

2. The traction control system according to claim 1, wherein when the computer detects that one of the traveling wheels skids, the associated computer-controlled brake unit applies a braking force to the skidding traveling wheel.

3. The traction control system according to claim 2, wherein the computer is connected to a steering system for inputting a steering angle of the steering system into the computer, so as to detect the skidding traveling wheel based on the detected rotation speeds and the steering angle.

4. The traction control system according to claim 1, wherein the computer is connected to a foot brake, and controls the computer-controlled brake units according to an operation of the foot brake.

5. The traction control system according to claim 1 further comprising a parking brake for applying braking force to both of the traveling wheels when the hydraulic pump is not driven or the hydraulic pump does not provide sufficient hydraulic pressure to the hydraulic motors.

6. The traction control system according to claim 5, wherein the computer controls the computer-controlled brake units based on the difference between the rotation speeds of the traveling wheel.