Brake valve, compressed-air brake system having the brake valve, and method for producing the brake valve

Patent metadata

Field	Value
Publication number	US-11325575-B2
Application number	US-201816755885-A
Country	US
Kind code	B2
Filing date	Sep 6, 2018
Priority date	Oct 17, 2017
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

A brake valve for a compressed air brake system of a utility vehicle includes a compressed air input configured to connect to a system pressure, a compressed air output configured to connect a brake control line, and at least one sensor configured to determine a brake valve actuation travel of an actuating element of the brake valve with a working interconnection to the brake pedal. The brake valve further includes a characteristic curve memory storing two stored characteristic curves and/or dependences and at least one determination device. The brake valve is configured to output at least two useful sensor signals, a first of which represents a brake valve output pressure and a second of which represents a percentage actuation position of the actuating element. The at least one sensor is configured to generate an actuating signal depending on the brake valve actuation travel of the actuating element.

First claim

The invention claimed is:

1. A brake valve for a compressed air brake system of a utility vehicle, wherein the brake valve can be actuated by a brake pedal and is provided for the output of an analog brake valve output pressure and of useful electrical sensor signals depending on the actuation of the brake pedal, the brake valve comprising:
a compressed air input configured to connect to a system pressure;
a compressed air output configured to connect a brake control line; and
at least one sensor configured to determine a brake valve actuation travel of an actuating element of the brake valve with a working interconnection to the brake pedal;
a characteristic curve memory storing two stored characteristic curves and/or dependences; and
at least one determination device,
wherein the brake valve is configured to output at least two useful sensor signals,
wherein a first useful sensor signal represents a brake valve output pressure and a second useful sensor signal represents a percentage actuation position of the actuating element,
wherein the at least one sensor is configured to generate an actuating signal depending on the brake valve actuation travel of the actuating element, and
wherein the at least one determination device is configured to generate the at least two useful sensor signals from the actuating signal depending on the at least two characteristic curves and/or dependences stored in the characteristic curve memory,
wherein the at least one determination device is configured to generate the first useful sensor signal from the actuating signal depending on a brake valve pressure characteristic curve and/or a pressure-travel dependence stored in the characteristic curve memory and to generate the second useful sensor signal from the actuating signal depending on a brake valve position characteristic curve and/or a position dependence stored in the characteristic curve memory,
wherein the at least one determination device is designed, by means of the stored brake valve pressure characteristic curve or the pressure-travel dependence, to assign the first useful sensor signal to the actuating signal, wherein the first useful sensor signal represents the controlled analog brake valve output pressure, and
wherein the stored brake valve pressure characteristic curve and/or the pressure-travel dependence represent a non-linear relationship between the brake valve output pressure and the brake valve actuation travel and the stored brake valve position-characteristic curve and/or the stored brake valve position-travel dependency represent a linear relationship between the percentage actuation position and the brake valve actuation travel.

2. The brake valve as claimed in claim 1 , wherein the at least one determination device is configured to produce the first useful sensor signal as a linear dependence of the brake valve output pressure on the brake valve actuation travel and to output the first useful sensor signal.

3. The brake valve as claimed in claim 1 , wherein the at least one determination device is configured, via the stored brake valve position characteristic curve or the position-travel dependence, to assign the second useful sensor signal to the actuating signal, wherein the second useful sensor signal represents the percentage actuation position of the brake pedal.

4. The brake valve as claimed in claim 3 , wherein the at least one determination device is configured to generate the second useful sensor signal as a linear dependence of the percentage actuation position on the brake valve actuation travel and to output the second useful sensor signal.

5. The brake valve as claimed in claim 1 , wherein the at least one determination device is configured to generate the useful sensor signals by proportional variation of a signal width and to output the useful sensor signals.

6. The brake valve as claimed in claim 1 , wherein the brake valve pressure characteristic curve or the pressure-travel dependence have at least two linear regions with different gradients, wherein the gradients are assigned to the spring stiffnesses of two springs of a spring device of the brake valve or the brake pedal or replicate a non-linear spring characteristic curve in linear sections.

7. The brake valve as claimed in claim 1 , wherein the characteristic curves have fixed points or travel points as pairs of values for interpolation of the characteristic curves.

8. The brake valve as claimed in claim 1 , wherein the brake valve has only one sensor and one determination device, wherein the at least one sensor is configured to generate the actuating signal depending on the brake valve actuation travel and to output it to the determination device and the only one determination device is configured to produce and output two different useful sensor signals from the one actuating signal depending on the at least two characteristic curves and/or dependences stored in the characteristic curve memory.

9. The brake valve as claimed in claim 1 , wherein the brake valve has two sensors and two determination devices, wherein a first sensor is configured to generate a first actuating signal depending on the brake valve actuation travel and to output it to a first determination device and a second sensor is configured to output a second actuating signal to a second determination device,
wherein the first determination device is configured to generate the first useful sensor signal from the first actuating signal depending on the characteristic curves and/or dependences stored in the characteristic curve memory and the second determination device is configured to generate the second useful sensor signal from the second actuating signal depending on the characteristic curves and/or dependences stored in the characteristic curve memory.

10. The brake valve as claimed in claim 1 , wherein the characteristic curves and/or dependences stored in the characteristic curve memory are formed by calibration of the brake valve and measurement of the output brake valve output pressure and the percentage actuation position.

11. The brake valve as claimed in claim 1 , wherein the at least one sensor is a travel sensor for determining the brake valve actuation travel of the actuating element with a working interconnection to the brake pedal for adjusting a passage cross-section of the brake valve.

12. A compressed air brake system for a commercial vehicle, the compressed air brake system comprising:
a brake pedal;
the brake valve as claimed in claim 1 , the brake valve being configured to be controlled by the brake pedal;
at least one brake circuit with at least one wheel brake and an ABS valve device;
a brake pressure control line configured to convey or conduct the analog brake valve output pressure to the brake circuit; and
a brake control device configured to receive the at least two useful sensor signals and configured to output control signals, wherein the useful sensor signals are configured to be output from the brake valve via an electrical control line.

13. A vehicle with a compressed air brake system as claimed in claim 12 .

14. A method for calibrating the brake valve as claimed in claim 1 , the method comprising:
connecting the system pressure to the compressed air input and a pressure sensor to the compressed air output;
successively adjusting an actuator, wherein the actuator acts on an actuation element of the brake valve;
measuring multiple brake valve actuation travel values as actuating signals of the at least one sensor and determining, via the pressure sensor, brake valve output pressure values output by the brake valve at the compressed air output

Assignees

• Wabco Gmbh
• Zf Cv Systems Europe Bv

Inventors

• Wallbaum Torsten
• Berroth Malte
• Gaulke Arnd

Classifications

• B60T15/14

  influencing electric control means · CPC title

• B60T13/683 Primary

  in pneumatic systems or parts thereof (in vacuum systems B60T13/72) · CPC title

• B60T2270/413

  Plausibility monitoring, cross check, redundancy · CPC title

• B60T8/327 Primary

  Pneumatic systems · CPC title

• B60T2270/10

  ABS control systems · CPC title