METHOD FOR ADJUSTING BRAKE PRESSURES OF A VEHICLE VIA CONTROL OF A PRESSURE CONTROL VALVE, BRAKE SYSTEM FOR CARRYING OUT THE METHOD AND MOTOR VEHICLE

• US 20190084542A1
• Filed: 02/03/2016
• Published: 03/21/2019
• Est. Priority Date: 02/07/2015
• Status: Active Grant

• Current Assignee: ZF CV Systems Europe BV (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Wabco GmbH (Wabco Holdings Incorporated)
• Inventors: Eckert, Horst
• Granted Patent: US 11,198,421 B2
• Time in Patent Office: Days
• CPC Class Codes: B60T 13/683 in pneumatic systems or parts thereof in vacuum systems B60T13/72
• CPC Class Codes: B60T 2270/10 ABS control systems
• CPC Class Codes: B60T 8/36 including a pilot valve responding to an electromagnetic force
• CPC Class Codes: B60T 8/3605 wherein the pilot valve is mounted in a circuit controlling the working fluid system

Abstract

A method for adjusting brake pressures of a motor vehicle includes actuating, by a control unit, while taking into account determined dynamic state variables of wheels that are to be braked, a pressure control valve with an inlet valve for ventilating and with an outlet valve for venting the brake pressure line that is controlled by the pressure control valve. The control times of the outlet valve are determined depending on control of the inlet valve.

Claims

1. :

A method for adjusting brake pressures of a motor vehicle, the method comprising;

actuating, by control unit, while taking into account determined dynamic state variables of wheels that are to be braked, a pressure control valve with an inlet valve for ventilating and with an outlet valve for venting the brake pressure line that is controlled by the pressure control valve,

wherein control times of the outlet valve are determined depending on control of the inlet valve.

2. :

The method as claimed in claim 1, wherein in an external braking mode provided for a case where an external braking demand is received that is independent of a driver'"'"'s braking demand, the control unit, adjusts the brake pressure in the brake pressure line according to the external braking demand by determining control times of the outlet valve depending on control of the inlet valve.

3. :

The method as claimed in claim 1, wherein control times of the inlet valve and the control times of the outlet valve at least partly overlap.

4. :

The method as claimed in claim 1, wherein a number of actuations of the inlet valve during a build-up of brake pressure are counted and the control times of the outlet valve are determined depending on a number of already completed actuations of the inlet valve.

5. :

The method as claimed in claim 1, wherein the control times of the outlet valve are determined as a function of control times of the inlet valve.

6. :

The method as claimed in claim 5, wherein during a braking process a correction factor is determined, with which the control times of the inlet valve are weighted for determining the control times of the outlet valve.

7. :

The method as claimed in claim 6, wherein the correction factor is constantly determined as a function of a measured deceleration of the vehicle according to predetermined determination instructions.

8. :

The method as claimed in claim 6, wherein the correction factor is determined according to a predetermined characteristic curve as a function of a sum of the control times of already completed actuations of the inlet valve and control times of the outlet valve that were previously determined in connection with a reduction of the brake pressure.

9. :

The method as claimed in claim 8, wherein a predetermined time constant is subtracted from the control times of the inlet valve and the control times of the outlet valve that are to be summed.

10. :

The method as claimed in claim 1, wherein a brake cylinder is vented or ventilated via a brake pressure line on a side of a pressure control valve lying on another side of a pressure reservoir.

11. :

The method as claimed in claim 1, wherein a brake system of a trailer vehicle can be indirectly activated via a brake pressure line for the trailer vehicle and a pressure control valve disposed in the brake pressure line.

16. :

A motor vehicle with a brake system as claimed in claim 12 for carrying out a method as claimed in claim 1.

12. :

A brake system of a motor vehicle, the brake system comprising, for each wheel;

a brake cylinder; and

a pressure control valve, the pressure control valve comprising an inlet valve for ventilating and an outlet valve for venting a brake pressure line that is directly or indirectly connected to the brake cylinder,

wherein the inlet valve and the outlet valve can be actuated by a control unit while taking into account determined dynamic state variables of the wheels that are to be braked,

wherein the control unit is configured to determine control times of the outlet valve depending on control of the inlet valved.

13. :

The brake system as claimed in claim 12, wherein the control unit is configured to receive an external braking demand that is independent of the driver'"'"'s braking demand.

14. :

The brake system as claimed in claim 12, wherein the brake pressure lines are connected to a brake cylinder on a side of a pressure control valve lying on a side of a pressure reservoir.

15. :

The brake system as claimed in claim 12, wherein a brake pressure line for a trailer vehicle with a pressure control valve disposed in the brake pressure line is connected to a pneumatic coupling head, to which a brake system of the trailer vehicle can be coupled and can be activated via the brake pressure line for the trailer vehicle.