PRESSURE MAINTAINING VALVE FOR A REVERSIBLE CONNECTION TO AN AIR LINE

Abstract

A pressure-maintaining valve for a reversible connection to an air line, having a basic body with an inlet opening, an outlet opening for accommodating the air line, and a fluid chamber which connects the inlet opening to the outlet opening in a fluid-communicating manner. A piston which is mounted movably between a sealing position, an equalizing position and a release position is arranged in the inlet opening, and the piston has an annular groove with a piston sealing surface and a piston release surface. In the sealing position, a sealant is arranged in a sealing manner between the piston sealing surface and a basic body sealing surface. In the equalizing position an equalizing line arranged in the sealing piston bypasses the sealant in a fluid-communicating manner. In the release position, the piston release surface lifts off the sealant from the basic body sealing surface.

Claims

1. A pressure-maintaining valve for a reversible connection to an air line, said valve comprising: a basic body with an inlet opening, an outlet opening for accommodating the air line, and a fluid chamber which connects the inlet opening to the outlet opening in a fluid-communicating manner, a piston arranged in the inlet opening and mounted movably between a sealing position, an equalizing position and a release position, the piston having an annular groove with a piston sealing surface and a piston release surface, wherein, in the sealing position, a sealant is arranged in a sealing manner between the piston sealing surface and a basic body sealing surface, in the equalizing position an equalizing line arranged in the sealing piston bypasses the sealant in a fluid-communicating manner, and, in the release position, the piston release surface is lifted off the sealant from the basic body sealing surface.

2. The pressure-maintaining valve as claimed in claim 1, further comprising a spring device arranged on the basic body which acts upon the piston with a spring force in a direction of the sealing position.

3. The pressure-maintaining valve as claimed in claim 1, wherein the equalizing line has at least one line inlet in the annular groove.

4. The pressure-maintaining valve as claimed in claim 1, wherein the equalizing line has at least one line outlet on a head surface of the piston.

5. The pressure-maintaining valve as claimed in claim 1, wherein the annular groove has an axial length which is greater than or equal to twice an axial extent of the sealant.

6. The pressure-maintaining valve as claimed in claim 1, wherein an area enclosed by the piston sealing surface lies either completely or substantially completely within an area enclosed by the basic body sealing surface.

7. The pressure-maintaining valve as claimed in claim 1, wherein the piston has a cylindrical or substantially cylindrical basic shape for a translatory movement along a straight line, between the sealing position, the equalizing position and the release position.

8. The pressure-maintaining valve as claimed in claim 1, wherein the piston has at least one sliding surface on an outer side for a sliding mounting in the inlet opening.

9. The pressure-maintaining valve as claimed in claim 1, wherein the outlet opening has a latching device for latching the air line in an inserted position which corresponds to the release position of the piston.

10. A method for inserting an air line into a pressure-maintaining valve, said method comprising: introducing an air line into an outlet opening of a basic body of the pressure-maintaining valve, moving the air line together with a piston of the valve in the direction of a release position of the piston, equalizing a pressure between an inlet opening of the basic body and the outlet opening using an equalizing line of the piston, moving the air line together with the piston into the release position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] By means of a method, the same advantages are obtained as have been explained in detail with regard to a pressure-maintaining valve. Further advantages, features and details of the invention will become apparent from the description below, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention in each case individually by themselves or in any combination. In the drawings, schematically:

[0032] FIG. 1 shows an embodiment of a pressure-maintaining valve in a sealing position,

[0033] FIG. 2 shows the embodiment according to FIG. 1 in an equalizing position, and

[0034] FIG. 3 shows the embodiment of FIGS. 1 and 2 in a release position.

DETAILED DESCRIPTION OF THE INVENTION

[0035] An embodiment of a pressure-maintaining valve 10 according to the present invention, a method and the manner of operation therewith are described with reference to FIGS. 1 to 3.

[0036] FIG. 1 illustrates the sealing position DP, i.e. with the air line 100 removed or not yet completely inserted. In this position, a positive pressure is present on the inlet side, i.e. at the inlet opening 22 of the basic body 20, in comparison to the outlet opening 24. In principle, a fluid-communicating connection is provided between the inlet opening 22 and the outlet opening 24 via the fluid chamber 26. In the current case according to FIG. 1, i.e. in the sealing position DP, said fluid-communicating connection is, however, sealed and therefore interrupted. The sealing is ensured by the sealant 40 which is clamped here between a basic body sealing surface 28 and a piston sealing surface 34 of a piston 30 and is therefore arranged in a sealing manner. The sealant 40 therefore seals said described pressure difference.

[0037] If an air line 100 is then pushed in further, the air line 100 indirectly pushes the piston 30 in FIG. 1 via a driver 54 of a spring device 50 into a position to the right according to FIG. 2. The spring force of the spring element 52, inter alia, is overcome here. However, it is crucial that the counterforce from the pressure difference between the inlet opening 22 and the outlet opening 24 also has to be overcome here. Said counterforce is calculated from the pressure difference and the correspondingly effective area which here is the inner area with respect to the piston sealing surface 34. Since said inner area with respect to the piston sealing surface 34 is smaller than the comparable area with respect to the basic body sealing surface 28, a smaller counterforce than would be the case in pressure-maintaining valves equipped as standard will accordingly also be present. As soon as said pressure counterforce has been able to be overcome to such an extent that the equalizing position AP according to FIG. 2 has been able to be reached, an equalizing line 38 bypasses the sealant 40 such that the pressure between the inlet opening 22 and outlet opening 24 can be equalized, as shown in FIG. 2. For said bypassing, i.e. the bypass, the equalizing line 38 is provided with line inlets 38a in the annular groove 32 in which the sealant 40 is also arranged.

[0038] The corresponding line outlet 38b is provided on the opposite side, on the head surface 30a of the piston 30. From the time according to FIG. 2, a counterforce due to a pressure difference is no longer effective since said pressure difference has been equalized. For the further movement into the release position FP according to FIG. 3, only the spring force of the spring element 52 is then still overcome. In order then to release a sufficient flow cross section, from the equalizing position AP the sealant 40 is then in contact with the piston release surface 36 and is carried along by the piston 30 during the further movement into the position of the release position FP according to FIG. 3.

[0039] The above-described steps of inserting the air line 100 take place, of course, in the reverse direction when the air line 100 is pulled out, and therefore, at the end, the pressure-maintaining valve 10 is again in its closed and therefore sealing position DP.

[0040] The above explanation of the embodiments describes the present invention exclusively within the context of examples. Of course, individual features of the embodiment can be freely combined with one another, if technically expedient, without departing from the scope of the present invention.