Switching Membrane for a Pressure Control Valve and a Pressure Control Valve

Abstract

A switching membrane for a pressure control valve has a plate-shaped flat body with a central area and a bending area surrounding the central area. The central area is provided with a closure area. For switching the switching membrane, the central area can be moved back and forth by a bending movement of the bending area in a direction transverse to an extension of the central area. At least the bending area is made of fluorocarbon rubber. A pressure control valve, especially for crankcase ventilation, is provided with a valve housing that has a housing cover and further is provided with a valve seat. A switching membrane as described above is disposed in the valve housing and switches at pressure differences of at most 500 mbar to release or shut off a flow of fluid at the valve seat.

Claims

1. A switching membrane for a pressure control valve, the switching membrane comprising; a plate-shaped flat body comprising a central area and a bending area surrounding the central area, wherein the central area comprises a closure area; wherein, for switching the switching membrane, the central area is configured to be moved back and forth by a bending movement of the bending area in a direction transverse to an extension of the central area; wherein at least the bending area comprises fluorocarbon rubber.

2. The switching membrane according to claim 1, wherein the central area is comprised at least partially of plastic material.

3. The switching membrane according to claim 1, wherein the plate-shaped flat body further comprises a clamping area extending radially outside of the bending area, wherein the clamping area is comprised of plastic material.

4. The switching membrane according to claim 1, wherein the closure area comprises a sealing area and the sealing area is comprised at least partially of fluorocarbon rubber.

5. The switching membrane according to claim 4, wherein the sealing area has an annular shape.

6. The switching membrane according to claim 1, wherein the bending area extends in a radial direction as a corrugation about the central area.

7. The switching membrane according to claim 1, wherein the closure area is a cup-shaped protuberance of the central area.

8. The switching membrane according to claim 1, wherein the plate-shaped flat body has a diameter measuring between 40 mm and 100 mm.

9. The switching membrane according to claim 8, wherein the diameter measures between 50 mm and 80 mm.

10. The switching membrane according to claim 1, produced by two-shot injection molding.

11. A pressure control valve for control or regulation of a fluid pressure, the pressure control valve comprising: a valve housing comprising a housing body and a housing cover, wherein the housing body comprises a valve seat; a switching membrane disposed inside the valve housing and configured to switch at pressure differences of at most 500 mbar to release or shut off a flow of fluid at the valve seat; the switching valve comprising a plate-shaped flat body, wherein the plate-shaped flat body comprises a central area and a bending area surrounding the central area, wherein the central area comprises a closure area, wherein, upon switching of the switching membrane, the bending area by a bending movement moves the central area relative to the valve seat in a direction transverse to an extension of the central area toward the valve seat or away from the valve seat, and wherein at least the bending area comprises fluorocarbon rubber.

12. The pressure control valve according to claim 11, further comprising a spring element supported on the valve housing and exerting a force on the central area of the switching membrane.

13. The pressure control valve according to claim 12, wherein the spring element is supported on the central area.

14. The pressure control valve according to claim 12, wherein the closure area is a cup-shaped protuberance of the central area, wherein the spring element is arranged about the cup-shaped protuberance.

15. The pressure control valve according to claim 11, wherein a chamber of the valve housing is loadable with atmospheric pressure as control pressure.

16. The pressure control valve according to claim 11, wherein the switching membrane is configured to switch at pressure differences of at most 200.

17. The pressure control valve according to claim 16, wherein the switching membrane is configured to switch at pressure differences of at most 100.

18. The pressure control valve according to claim 11, configured for crankcase ventilation of an internal combustion engine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further advantages result from the following description of the drawings.

[0036] In the drawings, embodiments of the invention are illustrated. The drawings, the description, and the claims contain numerous features in combination. A person of skill in the art will consider the features expediently also individually and combine them to other meaningful combinations.

[0037] FIG. 1 shows a switching membrane according to an embodiment of the invention with a central area of plastic material in a section illustration.

[0038] FIG. 2 shows a switching membrane according to a further embodiment of the invention additionally provided with a clamping area of plastic material, in a section illustration.

[0039] FIG. 3 shows in section illustration a switching membrane according to a further embodiment of the invention with a central area of plastic material in which radially inwardly a sealing area of fluorocarbon rubber is arranged as a closure area.

[0040] FIG. 4 shows a switching membrane according to a further embodiment of the invention with a flat bending area in section illustration.

[0041] FIG. 5 shows in section illustration a switching membrane according to a further embodiment of the invention with a cup-shaped protuberance closure area.

[0042] FIG. 6 shows, in section illustration, a switching membrane according to a further embodiment of the invention with a sealing area arranged in an annular shape in the closure area.

[0043] FIG. 7 shows a pressure control valve with a switching membrane according to an embodiment of the invention in a section illustration.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0044] In the Figures, same or same type components are identified with same reference characters. The Figures show only examples and are not to be understood as limiting.

[0045] FIG. 1 shows a switching membrane 22 for a pressure control valve 10 according to an embodiment of the invention with a central area 24 of plastic material in section illustration. The pressure control valve 10 is illustrated in an exemplary fashion in FIG. 7.

[0046] The switching membrane 22 comprises a plate-shaped flat body 16 with a bending area 18 surrounding a central area 24, wherein the central area 24 comprises a radial inner closure area 25. The central area 24 is movable back and forth for switching of the switching membrane 22 by a bending movement of the bending area 18 in the direction L transverse to the extension of the central area 24. The bending area 18 is formed of fluorocarbon rubber. The central area 24 is formed as a flat plate of plastic materials such as PA, in particular glass fiber reinforced, or PP or a similar plastic material. The bending area 18 extends in a corrugation shape in radial direction and forms a corrugation about the central area 24.

[0047] Manufacture of the switching membrane 22 can be realized advantageously by a 2K (two-shot) injection molding method wherein fluorocarbon rubber and a plastic material such as PA, in particular glass fiber reinforced PA, or PP are employed as material components.

[0048] The flat body 16 has in particular a diameter 54 between 40 mm and 100 mm, preferably between 50 mm and 80 mm. In this way, it is ensured that the switching membrane 22 reliably seals a valve seat 32 of the pressure control valve 22 and provides a reliable switching behavior in this way.

[0049] FIG. 2 shows in section illustration a switching membrane 22 according to a further embodiment of the invention in addition provided with a clamping area 60 of plastic material. The clamping area 60 which is extending radially outside of the bending area 18, can be made, for example, of plastic materials such as PA or PP. In this way, the clamping area 60 can be fixedly compressed by the housing body 12 and housing cover 14 of the valve housing of the pressure control valve 10 for sealing in order to generate a reliable sealing action over the service life.

[0050] FIG. 3 shows in section illustration a switching membrane 22 according to a further embodiment of the invention with a central area 24 of plastic material in which radially inwardly a sealing area 62 of fluorocarbon rubber is arranged as a closure area 25. Since the inner sealing area 62 is formed of a relatively flexible fluorocarbon rubber, a reliable sealing action on a tubular valve seat 32 (see FIG. 7) is ensured. With such a sealing action with a soft material such as fluorocarbon rubber, also the noise level upon switching of the pressure control valve 22 can be decisively reduced because a soft pressure application is realized when the closure area 25 contacts the valve seat 32.

[0051] FIG. 4 shows a switching membrane 22 according to a further embodiment of the invention with a flat bending area 18 in section illustration. In this way, a particularly flat configuration of a pressure control valve 10 can be realized in which the switching membrane 22 carries out relatively minimal strokes in the direction of axis L. Despite of this, a reliable control behavior can be achieved in this way with such a switching membrane 22.

[0052] In FIG. 5, a switching membrane 22 according to a further embodiment of the invention with a cup-shaped protuberance 20 of the closure area 25 is shown in section illustration. Due to the cup-shaped protuberances 20 a stable shape of the central area 24 is achieved so that a reliable sealing action upon contacting of the closure area 25 on the valve seat 32 can be ensured. The protuberance 20 itself is not affected in its shape by the bending movement of the switching membrane 22 and maintains the shape for the reliable sealing effect.

[0053] In FIG. 6, in section illustration, a switching membrane 22 according to a further embodiment of the invention is illustrated with a sealing area 62 arranged in annular shape in the closure area 25. Such a sealing area 62 for a tubular valve seat 32 can be realized in a beneficial way by configuration of the sealing area 62 in the form of a ring in the closure area 25. In this way, the proportion of the relatively expensive high performance material fluorocarbon rubber for the sealing area 62 can be reduced so that the switching membrane 22 can be manufactured at low cost. In this way, a sealing area 62 can advantageously be designed with precise fit for the valve seat 32.

[0054] FIG. 7 shows in a section illustration a pressure control valve 10 with a switching membrane 22 according to an embodiment of the invention. The pressure control valve 10 serves for control or regulation of a fluid pressure, in particular for use for crankcase ventilation of an internal combustion engine. The pressure control valve 10 comprises a valve housing with a housing body 12 and a housing cover 14 wherein the valve housing comprises an inlet 28 embodied as an inlet socket and an outlet 30 for the fluid designed as an outlet socket. The switching membrane 22 can be moved with pressure differences of at most 500 mbar, preferably of at most 200 mbar, particularly preferred of at most 100 mbar, and serves for releasing or shutting off a flow of the fluid between the inlet 28 and the outlet 30.

[0055] The switching membrane 22 comprises a plate-shaped flat body 16 with a bending area 18 surrounding a central closure area 24, wherein the central area 24 comprises a radial inner closure area 25. Upon switching of the switching membrane 22, the bending area 18 moves by a bending movement the central area 24 relative to the valve seat 32 in axial direction L transverse to the extension of the central area 24 toward the valve seat 32 or away from the valve seat 32.

[0056] The switching membrane 22 has for this purpose at least in the bending area 18 a thickness of at most 1.0 mm, preferably of at most 0.7 mm, particularly preferred of at most 0.5 mm. In this context, the diameter of the switching membrane 22 is, for example, between 40 mm and 100 mm, preferably between 50 mm and 80 mm.

[0057] The switching membrane 22 is formed in the bending area 18 of fluorocarbon rubber and is clamped with a clamping area 60 between housing body 12 and the housing cover 14 of the valve housing. The switching membrane 22 separates a first chamber 36 from a second chamber 38, wherein the first chamber 36 is in communication (not illustrated) with the environment, i.e., the atmospheric pressure. In the situation of use, the inlet 28 of the pressure control valve 10 is connected fluidically, for example, with the crankcase of an internal combustion engine, while the outlet 30 is fluidically connected with the intake manifold.

[0058] The bending area 18 extends in radial direction in a corrugation shape, in the illustrated embodiment forms a corrugation about the central area 24, wherein a depression on one flat face corresponds to an elevation on the other flat face of the switching membrane 22. The closure area 25 closes off the valve seat 32 fluid-tightly when it is resting against the valve seat 32.

[0059] A spring element 26 is provided which is supported on the housing body 12 and which exerts a force on the central area 24 of the switching membrane 22 and in this way compensates the atmospheric pressure in the first chamber 36. The closure area 25 is formed as a cup-shaped protuberance 20 of the switching membrane 22. The spring element 26, surrounding the cup-shaped protuberance 20 that is extending into the interior of the spring element 26, is supported on the central area 24. Also, the end face of the spring element 26 which is facing the protuberance 20 may be embedded by injection molding for protection of the switching membrane 22 so that embedding protects the central area 24 from abrasion or other wear.

[0060] Advantageously, the pressure control valve can be used for crankcase ventilation of an internal combustion engine.

[0061] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.