Method for electronically regulating the braking force distribution in a pressure medium-activated brake system of a vehicle and pressure medium-activated brake system of a vehicle having such a regulating means

• US 10,377,357 B2
• Filed: 06/02/2016
• Issued: 08/13/2019
• Est. Priority Date: 06/16/2015
• Status: Active Grant

• Current Assignee: Knorr-Bremse Systeme Fur Nutzfahrzeuge GMBH (Estate of Heinz Hermann Thiele)
• Original Assignee: Knorr-Bremse Systeme Fur Nutzfahrzeuge GMBH (Estate of Heinz Hermann Thiele)
• Inventors: Wieder, Gerhard, Mustapha, Adnan, Schaefers, Andreas, Hecker, Falk, Weber, Christian
• Primary Examiner(s): Dager, Jonathan M
• Application Number:
  US15/580,491
• Publication Number:
  US 20180170330A1
• Time in Patent Office: 1,167 Days
• Field of Search: None
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/1766 Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle
• CPC Class Codes: B60T 8/268 using the valves of an ABS, ASR or ESP system
• CPC Class Codes: B60T 8/34 having a fluid pressure regulator responsive to a speed condition

Abstract

A method and computer program for electronically regulating the brake force distribution in a pressure medium-operated brake system of a vehicle having at least one front axle brake circuit, associated with a front axle, and at least one rear axle brake circuit, associated with at least one rear axle, in which when the brake system is operated, a rear axle brake pressure, acting in the at least one rear axle brake circuit, is regulated to prevent locking of the rear wheels before locking of the front wheels, and in which the brake pressure at the rear axle is limited only while a pressure value which acts in the rear axle brake circuit is below a prespecified pressure threshold value, but the brake pressure at the rear axle is not limited if the pressure value acting in the rear axle brake circuit is not less than the prespecified pressure threshold value.

Claims

1. A method for electronically regulating the brake force distribution in a pressure medium-operated brake system of a vehicle having at least one front axle brake circuit, which is associated with a front axle, and at least one rear axle brake circuit, which is associated with at least one rear axle, the method comprising:

regulating, when the brake system is operated, a rear axle brake pressure, which acts in the at least one rear axle brake circuit, to prevent locking of the rear wheels before locking of the front wheels;

wherein the brake pressure at the rear axle is limited only while a pressure value which acts in the rear axle brake circuit is below a prespecified pressure threshold value, and wherein the brake pressure at the rear axle is not limited if the pressure value which acts in the rear axle brake circuit is equal to or greater than the prespecified pressure threshold value.

2. The method of claim 1, wherein the brake system has at least one brake light switch and operation of the brake system is identified by a brake light switch signal, wherein the brake pressure at the rear axle is limited only when a brake light switch signal which represents operation of the brake system is present, and wherein the brake pressure at the rear axle is not limited if a brake light switch signal which represents operation of the brake system is not present.

3. The method of claim 1, wherein an electronic regulating device for providing the brake force distribution is regulated depending on a differential slip or differential speed between at least one wheel of the front axle and at least one wheel of the rear axle, wherein, when the brake system is operated and when a differential slip threshold value or a differential speed threshold value is exceeded by the differential slip or the differential speed, the brake pressure at the rear axle is limited.

4. A non-transitory computer readable medium having a computer program, which is executable by a processor, comprising:

a program code arrangement having program code for electronically regulating the brake force distribution in a pressure medium-operated brake system of a vehicle having at least one front axle brake circuit, which is associated with a front axle, and at least one rear axle brake circuit, which is associated with at least one rear axle, the by performing the following;

regulating, when the brake system is operated, a rear axle brake pressure, which acts in the at least one rear axle brake circuit, to prevent locking of the rear wheels before locking of the front wheels;

wherein the brake pressure at the rear axle is limited only while a pressure value which acts in the rear axle brake circuit is below a prespecified pressure threshold value, and wherein the brake pressure at the rear axle is not limited if the pressure value which acts in the rear axle brake circuit is equal to or greater than the prespecified pressure threshold value.

11. The non-transitory computer readable medium of claim 4, wherein the brake system has at least one brake light switch and operation of the brake system is identified by a brake light switch signal, wherein the brake pressure at the rear axle is limited only when a brake light switch signal which represents operation of the brake system is present, and wherein the brake pressure at the rear axle is not limited if a brake light switch signal which represents operation of the brake system is not present.

12. The non-transitory computer readable medium of claim 4, wherein an electronic regulating device for providing the brake force distribution is regulated depending on a differential slip or differential speed between at least one wheel of the front axle and at least one wheel of the rear axle, wherein, when the brake system is operated and when a differential slip threshold value or a differential speed threshold value is exceeded by the differential slip or the differential speed, the brake pressure at the rear axle is limited.

5. A pressure medium-operated brake system of a vehicle having at least one front axle brake circuit, which is associated with a front axle, and at least one rear axle brake circuit, which is associated with at least one rear axle, comprising:

an electronic regulating device for providing a brake force distribution, so that when the brake system is operated, a rear axle brake pressure, which acts in the at least one rear axle brake circuit, is regulated to prevent locking of the rear wheels before locking of the front wheels; and

at least one pressure switch, which is is provided in a brake circuit, which pressure switch generates an activation signal for activating the electronic regulating device for providing the brake force distribution depending on a pressure value, which acts in the brake circuit, in relation to a prespecified pressure threshold value;

wherein the electronic regulating device is configured so that the brake pressure at the rear axle is limited only while the activation signal is generated or is present, and wherein the brake pressure at the rear axle is not limited if an activation signal is not generated or is not present,

wherein the brake circuit in which the pressure switch is provided is the rear axle brake circuit, and

wherein the pressure switch is configured so that it delivers the activation signal when a pressure value, which acts in the rear axle brake circuit, falls below its switching pressure and which otherwise does not deliver an activation signal of this kind.

6. The pressure medium-operated brake system of claim 5, further comprising:

at least one brake light switch;

wherein the electronic regulating device for providing the brake force distribution is configured so that it identifies operation of the brake system by a brake light switch signal, wherein the brake pressure at the rear axle is limited only when a brake light switch signal which represents operation of the brake system is present, and wherein the brake pressure at the rear axle is not limited when a brake light switch signal which represents operation of the brake system is not present.

7. The pressure medium-operated brake system of claim 5, wherein the electronic regulating device for providing the brake force distribution is configured so that the brake force distribution is regulated depending on a differential slip or differential speed between at least one wheel of the front axle and at least one wheel of the rear axle, wherein, when the brake system is operated and a differential slip threshold value or a differential speed threshold value is exceeded by the differential slip or the differential speed, the brake pressure at the rear axle is limited.

8. The pressure medium-operated brake system of claim 7, further comprising:

a sensor to measure wheel rotation speeds of the wheel of the front axle;

another sensor to measure wheel rotation speeds of the wheel of the rear axle;

an electronic control device to determine a differential slip or a differential rotation speed between the at least one wheel of the front axle and the at least one wheel of the rear axle;

wherein the electronic control device is configured so that, when a differential slip threshold value or a differential speed threshold value is exceeded by the differential slip or by the differential speed, the brake pressure at the rear axle is limited.

9. The pressure medium-operated brake system of claim 8, wherein the electronic control device is further configured so that, when excessive brake slip is present, it executes a brake slip regulation operation (ABS), wherein the brake pressure at the rear axle is limited by at least one ABS pressure control valve which is arranged in the rear axle brake circuit.

10. The pressure medium-operated brake system of claim 5, wherein the pressure threshold value of the pressure switch is approximately 3 bar.