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EP-4737231-A1 - A METHOD AND A CONTROL UNIT FOR CONDITIONING OF A FRICTION PAIRING OF A TRAILER BRAKING SYSTEM

EP4737231A1EP 4737231 A1EP4737231 A1EP 4737231A1EP-4737231-A1

Abstract

A method for conditioning a friction pairing of a brake system of a vehicle (10, 11) is disclosed, wherein the brake system is adapted to show a predetermined brake performance in a standard mode of operation, when the friction pairing has at least a minimum level of actuation. The method comprises the steps: obtaining a level of actuation applied to the friction pairing; comparing the level of actuation applied to the friction pairing with the minimum level of actuation and based on a result of the comparing switching from the standard operation mode to a reconditioning operation mode, when the level of actuation is above the minimum level of actuation , wherein in the reconditioning operation mode a minimum pressure (p0) in a brake chamber (16) utilized to actuate the braking is higher than that in the standard mode of operation.

Inventors

  • FRY, MATTHEW
  • PHAL, Stefan

Assignees

  • KNORR-BREMSE Systeme für Nutzfahrzeuge GmbH

Dates

Publication Date
20260506
Application Date
20241104

Claims (14)

  1. A method for conditioning a friction pairing of a brake system of a vehicle (10), the brake system is adapted to show a predetermined brake performance in a standard mode of operation by applying pressure to a brake chamber (16), when a minimum level of actuation is applied to the friction pairing, the method comprising: - obtaining (S110) a level of actuation applied to the friction pairing; - comparing (S120) the level of actuation applied to the friction pairing with the minimum level of actuation; and - based on a result of the comparing, switching (S130) from the standard operation mode to a reconditioning operation mode, when the level of actuation is above the minimum level of actuation, wherein in the reconditioning operation mode a minimum pressure (p0) in the brake chamber (16) utilized to actuate the braking is higher than that in the standard mode of operation.
  2. The method of claim 1, wherein the level of actuation applied to the friction pairing is derived from at least one of the following: - an actuation energy; - a braking force; - a braking pressure; - a degree of actuation of the brake pedal.
  3. The method of claim 1 and 2, further comprising: - during the reconditioning operation mode, comparing (S140) the level of actuation applied to the friction pairing with a sufficient level of actuation; and - based on a result of the comparing, switching (S150) from the reconditioning operation mode to the standard operation mode, when the level of actuation is below the sufficient level of actuation .
  4. The method according to any of claims 1 to 3, where the step of obtaining the level of actuation applied to the friction pairing includes at least one of the following: - receiving sensor data of a sensor adapted to measure the level of actuation; - determining an average level of actuation applied to the friction pairing based on an averaging of the level of actuation.
  5. The method of claim 4, the step of determining an average includes one or more of the following: - averaging based on a predetermined time, - averaging based on a predetermined distance, - averaging based on a predetermined number of measurements.
  6. The method according to any of claims 1 to 5, wherein in the standard operation mode the pressure level of the brake chamber (16) is being reduced to 0 bar as minimum pressure (p0).
  7. The method according to any one of claims 1 to 6, wherein, in the reconditioning operation mode, the pressure level of the brake chamber (16) is being reduced between 0.4 to 1 bar as minimum pressure (p0).
  8. The method according to any of the claim1 to 7, further comprising repeating the step of obtaining the level of actuation applied to the friction paring and during the reconditioning operation mode it is repeated more frequently than during the standard operating mode.
  9. The method according to any of claims 1 to 8, further comprising: - testing a brake performance for different level of actuation applied to the braking pairing; and - determining the minimum level of actuation based on the testing.
  10. A computer-readable storage device having instructions stored thereon designed to cause an apparatus to carry out the method as claimed in claim 1 when the software code is executed on a data processor.
  11. A control unit (14) of a vehicle (10) including a data processor and a memory with stored instructions that, when executed on the data processor, cause to carry out the steps of the method of any of claims 1 to 10.
  12. The control unit (14) of claim 11, wherein the vehicle (10) includes a towing vehicle (11) and a trailer (12) and wherein the brake system is a trailer brake system and the control unit (14) is designed to control a vehicle operation of the towing vehicle (11).
  13. A vehicle (10) with a service brake system including a brake chamber (16) to actuate a brake action, characterized by: a control unit (14) according to claim 11 or claim 12.
  14. The vehicle according to claim 13, which is a trailer (12), towing vehicle (11), or a combination thereof.

Description

The present invention relates to a method and a control unit for conditioning a friction pairing of a brake system of a vehicle and, in particular, to a method for conditioning of friction pairing on an O3/O4 trailer (trailer with gross weight exceeding 3.5/10 tons). Modern commercial motor vehicles are fitted with auxiliary braking systems such as hydraulic or electric retarders and engine brakes. Auxiliary brakes are used, where appropriate, to recover braking energy as useful energy and to prolong the life of service brakes. On the other hand, vehicles comprise a service brake for regular braking actuation. The braking actuation of the service brake utilizes friction pairings that rotate relative to each other and dissipate kinetic energy of the vehicle into heat. However, when frequently using the auxiliary brake system, less energy will be imposed into the friction pairing of the wheel brakes of both the motor vehicle as well as the trailer. If those friction pairing are not regularly used as such, the friction pairing will never be confronted with a significant amount of energy being imposed into the friction pairing and will therefore not be heated up but rather stay cold (<100°C). As a result, their friction coefficient will change which then results in a deterioration of the braking performance. There are some conventional methods known to overcome this problem and to maintain the optimal friction of the brake components. For example, EP 2159117B1 discloses a method for reconditioning the friction pairing of a transport vehicle using five operating modes to prioritize the different braking systems. Another example is disclosed in US 10,654,462 B2, where the temperature of the brake component of a trailer is monitored after braking operation. A thermal overloading is avoided by distributing brake actions among the axles or between the trailer and the towing vehicle. These technologies are based on static measurements. Static measurements have several disadvantages, for example the system to perform the reconditioning has to be permanently activate or has to be activated for a certain period of time or distance, and if the automatic activation is not successful, it has to be manually activated. Therefore, the known systems are not able to provide a reliable conditioning method for the friction pairing that are occasionally used during the brake, in particular of a heavy-duty vehicle with a trailer. Therefore, there is a demand for a method for reconditioning the friction pairing of vehicles and for a reliable reconditioning method. At least some of the problems as described before are overcome by a method for reconditioning according to claim 1 and the using of the control unit of claim 11. The dependent claims refer to further advantageous realization of the subject matters defined in the independent claims. The present invention relates to a method for conditioning a friction pairing of a brake system of a vehicle. The brake system is adapted to show, in a standard mode of operation, a predetermined brake performance when a minimum level of actuation is applied to the friction pairing. The method for conditioning a friction pairing comprises the following steps: obtaining a level of actuation applied to the friction pairing,comparing the level of actuation applied to the friction pairing with the minimum level of actuation, andbased on a result of the comparing, switching from the standard operation mode to a reconditioning operation mode, when the level of actuation is above the minimum level of actuation. It is understood that the (minimum) level of actuation depends on the desired deceleration and of other external parameters (load, slope of road, tires etc.). However, for a desired deceleration and for given external parameters the brake system - when the brake system operates correctly (normal mode of operation) - needs a particular brake actuation to achieve the desired deceleration. If the brake system has to be actuated more strongly for the desired deceleration, the friction provided by the friction pairing might be insufficient. This should be corrected. One reason for the insufficient friction is the insufficient temperature of the friction pairing. According to embodiments, this correction is provided by the reconditioning mode. In the reconditioning operation mode a minimum pressure in a brake chamber utilized by the braking system to actuate the braking is higher than that in the standard mode of operation (which may be zero in normal driving condition). By this, a small friction effect will be caused to apply energy into the friction pairing and therefore generate heat which in turn increases the temperature of the friction pairing. Optionally, the level of actuation applied to the friction pairing may represent a degree of actuation and may be derived from at least one of the following: an actuation energy;a braking force;a braking pressure (e.g. in the brake actuator);a degree of a