Operationally reliable parking valve

Patent metadata

Field	Value
Publication number	US-11577710-B2
Application number	US-201917251430-A
Country	US
Kind code	B2
Filing date	Jun 11, 2019
Priority date	Jun 13, 2018
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

A parking valve for manually actuating a spring-loaded parking brake, includes: a housing with a port that can be fluidically connected to a release chamber of a spring-loaded brake cylinder, a port that can be fluidically connected to a brake supply reservoir, and a ventilation port; a slide for manual actuation and which can be moved along a full section between two end positions inside the housing. The slide assumes positions along the full section, in which, as a result of at least one seal, there is no fluidic connection between the port to the release chamber and the ventilation port, and assumes other positions along the full section, in which, as a result of the at least one seal, there is no fluidic connection between the port of the release chamber and the port to the brake supply reservoir. A blocking device acts on the slide during movement at least along a partial section of the full section in at least one direction, with a continuously variable counterforce dependent on the position of the slide on the partial section.

First claim

What is claimed is:

1. A parking valve for manually actuating a spring-loaded parking brake, comprising:
a housing with a port that is fluidically connectable to a release chamber of a spring-loaded brake cylinder, a port that is fluidically connectable to an air reservoir, and a vent port;
a slide configured for manual actuation and being movable along an overall path between two end positions inside the housing, wherein the slide is configured to assume positions along the overall path in which, as a result of at least one seal, there is no fluidic connection between the port to the release chamber and the vent port, and to assume other positions along the overall path in which, as a result of the at least one seal, there is no fluidic connection between the port to the release chamber and the port to the air reservoir; and
an inhibiting device, which, during movement at least along a partial path of the overall path, is configured to act on the slide in at least one direction with a continuously variable counterforce dependent on the position of the slide on the partial path,
wherein
the inhibiting device is configured to subject the slide, over a path section of the overall path which does not form part of the partial path, to an assisting force, dependent on the position of the slide on the path section, in the direction of the movement, or to no force,
the inhibiting device is designed to exert the counterforce and/or the assisting force on the slide via magnetic force,
the inhibiting device has two first magnets and a counterpart located between the two first magnets, which is designed to be attracted by the first magnets, and
the counterpart is a second magnet or a magnetic element.

2. The parking valve as claimed in claim 1 , wherein at least one of:
the partial path includes at least one end position of the slide,
the counterforce is not produced on the basis of mechanical friction between two components,
the inhibiting device has a latch, which is configured to hold the slide at least in one position or in a limited region of the overall path, and
the at least one seal is provided on the slide or in the housing.

3. The parking valve as claimed in claim 1 , wherein
the partial path comprises at least two sections of the overall path which do not adjoin one another directly.

4. The parking valve as claimed in claim 1 , wherein
the counterforce on the slide has a maximum value which is increased by at least 25% relative to a force to which, owing to the design of the slide, said slide is subject during a movement.

5. The parking valve as claimed in claim 1 , wherein
the counterforce on the slide has a maximum value which is increased by at least 50% relative to the force, which force is owing to the friction of the at least one seal in the housing.

6. The parking valve as claimed in claim 1 , wherein
the assisting force is designed to bring about a movement of the slide into the end position which is in the direction of the movement, even without manual actuation.

7. The parking valve as claimed in claim 1 , wherein
the inhibiting device is designed to ensure that the counterforce and/or the assisting force are/is formed from the minimum to the maximum value thereof over a path whose length is at least 2% of the overall path.

8. The parking valve as claimed in claim 1 , wherein
the inhibiting device is designed to ensure that the counterforce and/or the assisting force are/is formed from the minimum to the maximum value thereof over a path whose length is at least 8% of the overall path.

9. The parking valve as claimed in claim 1 , wherein at least one of:
the first magnets are provided on or in the slide and the counterpart is provided on or in the housing, or the first magnets are provided on or in the housing and the counterpart is provided on or in the slide, and
the first magnets and the counterpart are arranged such that the force of attraction thereof becomes a maximum in one end position of the slide, at least relative to all other possible positions of the slide.

10. The parking valve as claimed in claim 1 , wherein
the inhibiting device has a further first magnet or a further counterpart on or in the housing or on or in the slide.

11. A parking valve for manually actuating a spring-loaded parking brake, comprising:
a housing with a port that is fluidically connectable to a release chamber of a spring-loaded brake cylinder, a port that is fluidically connectable to an air reservoir, and a vent port;
a slide configured for manual actuation and being movable along an overall path between two end positions inside the housing, wherein the slide is configured to assume positions along the overall path in which, as a result of at least one seal, there is no fluidic connection between the port to the release chamber and the vent port, and to assume other positions along the overall path in which, as a result of the at least one seal, there is no fluidic connection between the port to the release chamber and the port to the air reservoir; and
an inhibiting device, which, during movement at least along a partial path of the overall path, is configured to act on the slide in at least one direction with a continuously variable counterforce dependent on the position of the slide on the partial path,
wherein
the inhibiting device is configured to subject the slide, over a path section of the overall path which does not form part of the partial path, to an assisting force, dependent on the position of the slide on the path section, in the direction of the movement, or to no force,
the inhibiting device has a chamber having an equalization channel, the chamber being
fluidically closed by the slide and a part of the housing when the slide is moved over the partial path, and
connected to the atmosphere or to a venting device via the equalization channel only when the slide is moved beyond the partial path,

the chamber is designed to change volume in accordance with the movement of the slide, and
the inhibiting device is designed to subject the slide to a counterforce which is formed by a vacuum and which increases in a first direction of movement since a volume of the chamber increases or which is formed by an excess pressure and which increases in a second direction of movement since air in the chamber is compressed giving rise in the chamber to the excess pressure.

12. The parking valve as claimed in claim 11 , wherein
the closure of the chamber is accomplished by a seal of the slide and/or of the housing.

13. The parking valve as claimed in claim 12 , wherein
the chamber is formed in the slide and/or the housing.

14. The parking valve as claimed in claim 11 , wherein
the chamber is formed in the slide and/or the housing.

15. The parking valve as claimed in claim 11 , wherein
the chamber is designed to be connected to atmosphere or to the venting device when the slide is moved beyond the partial path and/or the path section.

16. The parking valve as claimed in claim 11 , wherein
the chamber is designed to be connected to an equalization chamber when the slide is moved beyond the partial path and/or the path section.

17. The parking valve as claimed in claim 11 , wherein
the chamber undergoes a change in volume of at least 5% when the slide is moved over the partial path.

Assignees

• Knorr Bremse Systeme Fuer Nutzfahrzeuge Gmbh

Inventors

• Koncz Laszlo

Classifications

• F16K21/10

  with hydraulic brake cylinder acting on the closure member · CPC title

• B60T15/226

  Trailer brake valves · CPC title

• B60T17/221

  Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems (hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M) · CPC title

• B60T15/206

  Trailer brake valves (B60T15/226 takes precedence) · CPC title

• B60T13/261

  systems with both indirect application and application by springs or weights and released by compressed air · CPC title