Method for the automatic operation of a tire inflation device for motor vehicles

• US 6,594,566 B1
• Filed: 10/02/2001
• Issued: 07/15/2003
• Est. Priority Date: 05/17/1999
• Status: Expired due to Fees

• Current Assignee: Steyr-Daimler-Puch Spezialfahrzeug AG & Company KG (General Dynamics Corporation)
• Original Assignee: Steyr-Daimler-Puch Spezialfahrzeug AG
• Inventors: Skoff, Gerhard
• Primary Examiner(s): Zanelli, Michael J.
• Assistant Examiner(s): Gibson, Eric M
• Application Number:
  US09/958,083
• Time in Patent Office: 651 Days
• Field of Search: 701/29, 701/36, 340/442, 340/443, 340/444, 152/415, 152/416, 152/417, 152/418, 731/462
• US Class Current: 701/36
• CPC Class Codes: B60C 2200/14 for off-road use
• CPC Class Codes: B60C 23/002 by monitoring conditions other than tyre pressure or deformation

Abstract

Tire pressure is automatically checked when the motor vehicle is started. At the same time, the type of operation, either off-road operation or on-road operation, is detected. According to the inventive method, in the on-road operation of the motor vehicle, the speed of all four wheels is measured and it is made sure whether or not there is an inadmissible difference in wheel speed. If the wheel speeds do not differ, the theoretical tire pressure is determined. If the actual tire pressure differs from the theoretical pressure, the inflation or deflation valves of the tires are actuated until the theoretical value is achieved, thereby adjusting the theoretical value. If the wheel speeds differ, as for example, during the operation state of the off-road mode, the vehicle speed is measured and is compared with a threshold value.

Claims

1. A method for automatic operation of an inflation device for motor vehicle tires, comprising the steps of:

(a) measuring a tire pressure of a vehicle automatically when the vehicle is started and monitoring a driving condition, whether on-road or off-road, automatically by monitoring at least one unit selected from a reduction gear switch, level sensor, wheel revolution sensor, differential lock, and a manually operated traction selection switch;

(b) measuring under road driving conditions, speeds of all four wheels of the vehicle and performing a check to ensure that a difference between the speed of the wheels is within a certain tolerance;

(c) if the difference between the wheel speeds is within the certain tolerance, calculating a tire pressure setpoint, and if an actual value of tire pressure deviates from the setpoint, activating respective inflation or deflation valves of the tire until the setpoint is reached and established,

(d) if the difference between the wheel speeds is not within the certain tolerance, measuring a driving speed of the vehicle as for off-road driving conditions comparing a measured driving speed with a threshold value, and if the threshold value is not exceeded, activating deflation valves of the tires and establishing therein tire pressures that have been preset for off-road driving; and

(e) measuring the tire pressure each time steps (a)-(d) are completed, and repeating a cycle of steps (a)-(d).

2. The method according to claim 1 wherein a loading condition of the vehicle is measured while the vehicle is stationary.

3. The method according to claim 2 wherein the setpoint for the tire pressure is corrected by the addition of an application factor based on the loading condition.

4. The method according to claim 1 wherein, if a loss of pressure not associated with steps c) or d) is detected, a warning signal is triggered or the driving speed is governed to a value that is permissible.