Electronic air pressure regulator with a double diaphragm

Abstract

The invention relates to an electronic compressed air regulator (1) having a control head (3) and having a first diaphragm (10) and a second diaphragm (12), wherein the effective diameter of the first diaphragm (10) is greater than the effective diameter of the second diaphragm (12), wherein an input pressure P1 loads a valve cone (48), and the valve cone (48) interacts loosely with a valve pin (7), and the relative position of the valve pin (7) is able to be changed by a double diaphragm system (14), wherein the double diaphragm system (14) consists substantially of the first diaphragm (10) and of the second diaphragm (12), wherein the second diaphragm (12) is in the form of a beaded diaphragm or roller diaphragm, wherein a pressure pot (16) is arranged between the first diaphragm (10) and the second diaphragm (12), which pressure pot (16) loads the second diaphragm (12) with a planar underside, wherein a control pressure PST of a pressure piece (11) is loaded by the first diaphragm (10), which pressure piece (11) has a centring projection (15) on its underside, which centring projection (15) passes into internal centring means (36) of the pressure pot (16), the second diaphragm (12) centrally has a bore (32) and the underside of the pressure pot (16) is interrupted centrally by a bore (34), the corresponding bores (32, 34) are closed via an insert (33), the insert (33) has a bore, against which a head (53) of the valve pin (7) is sealingly placed, and an output pressure P2 is applied below the second diaphragm (12).

Description

[0001] Electronic air pressure regulator with a double diaphragm

[0002] The invention relates to an electronic compressed air regulator, comprising a first diaphragm and a second diaphragm, wherein the first diaphragm is subjected to a control pressure and the second diaphragm to an output pressure.

[0003] DE 499 725 C describes a gas pressure regulator with an automatic shut-off device for a gas line to the gas container. For this purpose, a second, larger auxiliary diaphragm, positively connected to a valve, is arranged above the regulating diaphragm of a diaphragm gas pressure regulator. The space between the two diaphragms is connected by a line, via a 3-way valve controlled by a gas container bell, either to the atmosphere or to the gas supply line upstream of the regulator.

[0004] EP 2 921 924 A1 discloses a device for providing a fluid with a controlled outlet pressure by means of a pilot pressure-controlled pressure control unit, in which an inlet chamber for the fluid under an inlet pressure, an outlet chamber for the fluid having the controlled outlet pressure, and a first valve unit acting between the inlet chamber and the outlet chamber are provided. The pressure control unit has a first diaphragm on which the pilot pressure acts and a second diaphragm, mechanically coupled to the first diaphragm, on which the outlet pressure of the fluid acts.

[0005] DE 870 654 C describes a pressure regulator for the automatic control of air supply for hose divers. This air supply valve has the advantage that, as the diver descends, it ensures the required constant volume of supplied air for any set amount of air. Furthermore, the pressure regulator operates independently of the pressure of the supplied compressed air.

[0006] With conventional compressed air regulators, it is not possible to equalize the inlet and outlet pressures. Typically, the pressure loss on the outlet side is up to 0.5 bar. Such a pressure difference is unacceptable in certain applications.

[0007] It is therefore an object of the invention that an output pressure P2 of a compressed air regulator to be regulated corresponds to the preset input pressure Pi in its absolute value.

[0008] The object of the invention is achieved by the features of claim 1. The dependent claims following the main claim contain a further embodiment of the inventive concept.

[0009] An electronic pneumatic pressure regulator with a double diaphragm is presented, in which the first diaphragm is a flat diaphragm and the second is a crimped Z-shaped diaphragm. The effective diameter of the first diaphragm is larger than that of the second. Both diaphragms are pre-tensioned in their mounting positions when the regulator's valve cone is closed. This design prevents disruptive internal stresses in the diaphragms. Furthermore, the two diaphragms do not have the same thickness; a thinner-walled version is chosen for the second diaphragm to minimize its own resistance to movement. This type of diaphragm system is ideally suited to eliminating the initial dip in the pressure characteristic curve.Due to the design of the electronic air pressure regulator, all pressure chambers within the regulator, such as the inlet pressure chamber, control pressure chamber, and outlet pressure chamber, have the same inlet pressure. In addition to an inlet pressure port for the inlet pressure Pi and an outlet pressure port P2, the electronic air pressure regulator also features an electrical connection for inputting and adjusting the control pressure PST, even from a remote location. The control pressure PST can also be continuously adjusted using a keypad on the regulator.

[0010] The operating principle of the electronic compressed air regulator is that a set control pressure PST is lower than the input pressure Pi, which acts on the upper, larger diaphragm area of ​​the first diaphragm. According to the principle of force equilibrium in dual-diaphragm systems, a higher pressure than the control pressure PST itself is generated on the lower, smaller, second diaphragm area. One could say that the differential areas provide a certain control pressure reserve.

[0011] Thus, the membrane system consists of the first membrane, which is designed as a flat membrane, and a pressure piece with a flat contact surface, which rests against the underside. The underside of this pressure piece dips into a pressure pot, which loads the second membrane below it with its effective diameter. In a first preferred embodiment, the pressure piece dips into the pressure pot below with only minimal clearance, ensuring reliable load transfer to the corrugated or rolling membrane. In another embodiment, a one-piece design of the pressure piece and pressure pot is also possible. It is important that the membrane system moves freely to avoid unwanted pressure losses. The use of a very thin-walled rolling membrane also contributes to this, as such a design results in very low resistance to movement.

[0012] The control pressure PST can be displayed on a gauge in the control head and adjusted via a keypad. In addition to the keypad on the front of the control head, a display can also show the selected and simultaneously achieved output pressure P2. Below the control head is the double diaphragm system with a pressure piece and pressure pot positioned between them. Both the flat diaphragm and the corrugated or rolled diaphragm are clamped laterally between the control head and the housing of the compressed air regulator below, using their edges. The housing of the compressed air regulator has an inlet pressure connection and an outlet pressure connection.

[0013] Both the flat membrane and the rolled or corrugated membrane are made of a chemically resistant, organic synthetic plastic.

[0014] The invention is explained in more detail below using a possible embodiment as an example.

[0015] Figure 1 shows a perspective view of the design of an electronic compressed air regulator;

[0016] Figure 2 shows a section through the electronic compressed air regulator according to Figure 1;

[0017] Figure 3 shows a section through the structure of the double-membrane system used; Figure 4 shows a section through a pressure piece with a pressure pot underneath;

[0018] Figure 5 shows a section through a roller or corrugated membrane and a pressure ring to be arranged above it;

[0019] Figure 6 shows a detailed cross-sectional view of the placement of the flat membrane and the underlying rolled or corrugated membrane;

[0020] Figure 7 shows a sectional view of an intermediate element located between a control head of the compressed air regulator and the housing below it.

[0021] Figure 1 shows a perspective view of a possible embodiment of a complete electronic compressed air regulator 1. This compressed air regulator 1 consists of a control head 3, an electrical connection 4, and a keypad 5, via which a desired output pressure P2 can be set. The desired output pressure P2 can then be displayed directly on a display 6 on the control head 3.

[0022] Below the control head 3 is an intermediate element 38 into which a double diaphragm system 14 is inserted, which will be discussed in more detail below; a housing 2 is also shown. The housing 2 has an inlet pressure port 23 for an inlet pressure Pi, as well as an outlet pressure port 24 for the desired outlet pressure P2.

[0023] Figure 2 shows a cross-section through the electronic compressed air regulator 1, without detailing the internal function of the control head 3. A cable can be connected to the electrical connection 4 to supply the control head 3 with electrical energy, enabling the setting and adjustment of a control pressure PST. The intermediate element 38 is shown below the control head 3 in the cross-sectional view, as are the inlet pressure port 23 and the outlet pressure port 24. The double diaphragm system 14 actuates a pressure pin 7, which is positioned at its end against a valve cone 48. A change in the position of the double diaphragm system 14 causes a change in the opening of the valve cone 48. The valve cone 48 is sealed at its upper side against a valve seat in the housing 2 by a seal (not specified).On its underside, the valve cone 48 is sealed in a chamber 49 of a closure 35 in the housing 2 or directly in the housing 2 by a lip seal or a sealing ring 50. The valve cone 48 is biased by a compression spring 8. The compressive force of the compression spring 8 should be designed to be as low as possible to ensure that the valve seat closes reliably. At the same time, however, the spring force must not oppose the opening movement of the push pin, as an excessively large counterforce would cause undesirable pressure losses. There is no fixed connection between the push pin 7 and the valve cone 48, in order to compensate for manufacturing tolerances, for example, in the line of action. The chamber 49 is operatively connected to the pressure chamber 42 of the outlet pressure P2 via a channel in the push pin.

[0024] To illustrate the double-diaphragm system 14 used, reference is made to the illustration in Figure 3. A cross-sectional view shows the upper first diaphragm 10 and the lower second diaphragm 12 in their functional assembly. A pressure piece 11 is used between the first diaphragm 10 and the second diaphragm 12, in contact with the first diaphragm 10, and this pressure piece is immersed in a pressure pot 16. The pressure pot is in direct contact with the second diaphragm 12. The second diaphragm 12 is subjected to pressure at its outer edge by a pressure ring 13, which is simultaneously clamped via the intermediate element 38. In a further preferred embodiment, the pressure ring 13 can also be formed integrally with the intermediate element 38. An outer edge of the first diaphragm 10 is clamped between a projection 37 and the intermediate element 38.To guarantee a secure clamping position of the first membrane 10, notches or ridges may be included, for example, on the clamping surface of the intermediate element 38.

[0025] The first diaphragm 10 is subjected to pressure from below by a flat surface 22 of the pressure piece 11. This pressure piece 11 has centering projections 15 on its underside, which extend into the pressure pot 16 located below it. The pressure pot 16 has a flat pressure surface 17 facing the second diaphragm 12. As shown in Figure 4, the pressure pot 16 is designed such that it is provided with projecting centering features 26 in the direction of an interior space (not specified here), which have a small clearance relative to the centering projections 15 of the pressure piece 11. The pressure pot 16 is closed off externally by a side wall 18. The side wall 18 transitions into the radius 31 located on the underside between a pressure surface 17 and the side wall 18. For easy centering of the pressure piece 11 in the pressure pot 16, a circumferential relief 25 is located on the inside of the centering projection 15. This can be seen in particular in Figure 4.The second diaphragm 12 is located below the pressure surface 17 of the pressure pot 16. The pressure pot 16 is inserted into a flat area between the circumferential groove 19. This is easily achieved because the flat pressure surface 17, with the outer radius 31 of the pressure pot 16, fits into the inner area of ​​the second diaphragm 12. The second diaphragm 12 is clamped externally between the intermediate element 38 by the pressure ring 13. The pressure ring 13 rests on a clamping edge 21 of the second diaphragm 12. The bottom of the pressure pot 16 has a bore 34. An insert 33, which may have a protruding rim on its upper side, is inserted into this opening of the bore 34. The insert 33 can also be sealed in the bore 34 by another form-fit connection. The second diaphragm 12 has a bore 32 in this area to allow the insert 33 to pass through.The attachment of the insert 33 also simultaneously clamps the second membrane 12.

[0026] The second membrane 12 is shown in a sectional view with the pressure ring 13 located above it, as shown in Figure 5. This section reveals that the second membrane 12 has a lateral clamping edge 21, which includes a chamfer 29 adjacent to the rising wall 20 of a groove 19. This gives the clamping edge 21 a substantially triangular shape. This substantially triangular shape corresponds to a chamfer 30 on the pressure ring 13, which transitions into the radius 31 on its underside. The substantially complementary shape of the clamping edge 21 ensures a secure fit of the pressure ring 13 on the second membrane 12. To further enhance this secure fit, the clamping edge 21 has small projections 28 on its underside.These projections 28 ensure precise positioning of the second membrane 12 when it is attached to the intermediate element 38. Projections 28 are also formed on the underside of the pressure surface 27 next to the bore 32; these are also necessary for a precise fit of the insert 33.

[0027] The placement of the insert 33 can also be seen in Figure 7. A seal 36 is inserted into the insert 33, which provides a secure closure for the pressure pin 7 against a bore 44 located above it. To ensure that the first diaphragm 10 can continuously transmit the control pressure PST present in a control pressure chamber 9 to the pressure piece 11, a chamfer 41 with an inward radius 40 has been formed in the intermediate element 38. The area between the end of the chamfer 41 and the inward radius 40 ensures the longevity of the first diaphragm 10, as there is no sharp edge in the area of ​​movement. This design can be seen in particular in Figure 6.

[0028] Figures 2 and 6 show an outlet pressure chamber 39 located below the second diaphragm 12, which supplies the outlet pressure P2. The outlet pressure P2 is conveyed to the outlet pressure port 24 via channels (not specified) and a connecting bore 43. This outlet pressure P2 is also present in a pressure chamber 42 of the housing 2. This can be seen particularly clearly in Figure 2, where the pressure pin 7 is subjected to pressure against the seal 36 from below by the compression spring 8. The compression spring 8 is mounted in the removable closure 35. The pressure pin 7 is positioned relative to the seal 36 by means of a convex end. The pressure pin 7 is guided by a head 53, which is guided by a sliding bearing 47 surrounding the head 53.

[0029] Above the intermediate element 38 is the attachment 37, in which the control pressure chamber 9 is located. The control pressure PST preselected by the control head 3 entered this control pressure chamber 9 via a bore 46.

[0030] The section of the double diaphragm system 14, comprising the first diaphragm 10 and the second diaphragm 12, including the lateral attachments via the attachment 37 and the intermediate element 38, is also shown in Figure 7. Here it becomes clear that the control pressure PST is directed via the bore 46 into the control pressure chamber 9 and onto the first diaphragm 10. In Figure 7, the first diaphragm 10 is shown in its rest position with a certain preload relative to the control pressure chamber 9. Such a preload is typical and does not impair the function of the flat diaphragm. Below the first diaphragm 10, the chamber has a lateral compensating bore 45. The control pressure PST simultaneously changes the shape of both the first diaphragm 10 and the second diaphragm 12. The second diaphragm 12 also acts via the insert 33 on the pressure pin 7, which in turn causes a change in the output pressure P2.The control pressure PST acts directly on the first diaphragm 10, which has a larger effective diaphragm area than the second diaphragm 12. According to the principle of force equilibrium, the pressure on the smaller, second diaphragm 12 is simultaneously increased, resulting in a higher output pressure P2 than the control pressure PST. Due to the force equilibrium of the double diaphragm system 14, the otherwise typical pressure drop is compensated for.

[0031] Reference sign

[0032] 1 Electronic compressed air regulator

[0033] 2 cases

[0034] 3 Steering head

[0035] 4 Electrical connection

[0036] 5 keyboard

[0037] 6 ads

[0038] 7 pressure pen

[0039] 8 compression spring

[0040] 9 Control pressure chamber

[0041] 10 First membrane

[0042] 11 Printed piece

[0043] 12 Second membrane

[0044] 13 Pressure ring

[0045] 14 Double membrane system

[0046] 15 hundredweight approach

[0047] 16 Pressure pot

[0048] 17 printing area

[0049] 18 side wall

[0050] 19 groove

[0051] 20 wall

[0052] 21 Clamping edge

[0053] 22 area

[0054] 23 Inlet pressure port Pi

[0055] 24 Outlet pressure port P2

[0056] 25 Clearing

[0057] 26 Centering

[0058] 27 printing area

[0059] 28 projections 29 slopes

[0060] 30 Bevel

[0061] 31 radius

[0062] 32 bore

[0063] 33 deployment

[0064] 34 bore

[0065] 35 Closure

[0066] 36 Seal

[0067] 37 Essay

[0068] 38 Intermediate element

[0069] 39 Outlet pressure chamber

[0070] 40 radius

[0071] 41 Slopes

[0072] 42 Printing room

[0073] 43 Connecting hole

[0074] 44 bore

[0075] 45 Compensating bore

[0076] 46 bore

[0077] 47 Bearing ring

[0078] 48 valve cones

[0079] Room 49

[0080] 50 Seal

[0081] 51 Connecting hole

[0082] 52 Seal

[0083] 53 heads

[0084] Pi input pressure

[0085] P2 initial pressure

[0086] PST control pressure

Claims

Claims 1. Electronic compressed air regulator (1) with a control head (3), as well as with a first diaphragm (10) and a second diaphragm (12), wherein the diaphragms (10, 12) are designed as flat diaphragms, the effective diameter of the first diaphragm (10) being larger than the effective diameter of the second diaphragm (12), characterized in that an inlet pressure Pi loads a valve cone (48), wherein the valve cone (48) loosely interacts with a valve pin (7), wherein the relative position of the valve pin (7) is changeable by a double diaphragm system (14), wherein the double diaphragm system (14) essentially consists of the first diaphragm (10) and the second diaphragm (12), wherein the second diaphragm (12) is designed as a corrugated or rolling diaphragm, wherein a pressure pot (16) is arranged between the first diaphragm (10) and the second diaphragm (12), which loads the second diaphragm (12) with a flat underside.wherein the first diaphragm (10) applies a control pressure PST to a pressure piece (11) which has a centner's extension (15) on its underside that engages with inner centerings (36) of the pressure pot (16), the second diaphragm (12) has a bore (32) in its center and the underside of the pressure pot (16) is penetrated in its center by a bore (34), the corresponding bores (32, 34) are closed by an insert (33), the insert (33) has a bore against which a head (53) of the valve pin (7) is positioned to seal, an output pressure P2 is present below the second diaphragm (10).

2. Compressed air regulator according to claim 1, characterized in that the diaphragms (10) and (12) of the double diaphragm system (14) are pre-tensioned when the valve cone (48) is closed.

3. Compressed air regulator according to claim 1, characterized in that the diaphragms (10) and (12) have different wall thicknesses.

4. Compressed air regulator according to claim 1, characterized in that the double diaphragm system (14) is arranged below a control head (3) in an attachment (37) and an intermediate element (38), wherein the intermediate element (38) is connected on its underside to a housing (2) of the electronic compressed air regulator (1) in which an inlet pressure port (23) for the inlet pressure Pi and a port (24) for the outlet pressure port (24) P2 are located.

5. Compressed air regulator according to claim 5, characterized in that the first diaphragm (10) is clamped at the edge between the attachment (37) and the intermediate element (38), the intermediate element (38) having a sloping incline (41) over a radius (40) towards an inner bore.

6. Compressed air regulator according to one or more of the preceding claims, characterized in that the second diaphragm (12) has on its outer side a circumferential, thickened clamping edge (21) which is loaded by a pressure ring (13) which has a complementary inclined plane (29) of the projection (21).

7. Pressure regulator according to claim 1, characterized in that the valve cone (48) is sealed against the housing (2) or a closure (35) in the housing (2) by a lip seal or a sealing ring (50).

8. Pressure regulator according to claim 1, characterized in that there is no fixed connection between the pressure pin (7) and the valve cone (48).

9. Pressure regulator according to claim 1, characterized in that the head of the pressure pin (7) is guided in a sliding bearing (47).

10. Pressure regulator according to claim 1, characterized in that the head (53) of the valve pin (7) is convex.

11. Compressed air regulator according to one or more of the preceding claims, characterized in that the first diaphragm (10) and the second diaphragm (12) consist of chemically resistant, organic, synthetic plastics.

12. Compressed air regulator according to claim 5, characterized in that the control head (3) has an electrical connection (4) and is provided with a display (6) and a keypad (5).

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