Membranventil

Abstract

The invention relates to a diaphragm valve (1) for controlling fluidic media, with a magnetic armature (10) which is arranged to be longitudinally displaceable in an interior space (31) of a pole tube (30) closed by means of a diaphragm (20) and is coupled to the diaphragm (20) in such a way that the diaphragm (20) can be moved by a longitudinal displacement of the magnetic armature (10) between a closed position, in which the magnetic armature (10) forces the diaphragm (20) onto a sealing seat (41) and closes a fluid channel (42), in particular a fluid inlet (43), and an open position, in which the magnetic armature (10) lifts the diaphragm (20) from the sealing seat (41) and opens the fluid channel (42), in particular the fluid inlet (43). The invention is characterized in that the interior (31) of the polar tube (30) contains a liquid (32) with a liquid volume and a gas (33) with a gas volume, wherein the liquid volume is larger than the gas volume.

Description

[0001] The invention relates to a diaphragm valve, in particular for controlling fluidic media according to the preamble of claim 1. Such diaphragm valves are known from practice.

[0002] Known diaphragm valves feature a magnetic armature that is longitudinally displaceable within a pole tube. The interior is sealed by a diaphragm, which structurally and hermetically separates the interior of the pole tube from a valve chamber or flow chamber. The magnetic armature is coupled to the diaphragm in such a way that the diaphragm can be moved from a closed to an open position by longitudinal displacement of the magnetic armature. In the closed position, the magnetic armature forces the diaphragm onto a sealing seat, thereby closing a fluid channel, particularly a fluid inlet. In the open position, the magnetic armature lifts the diaphragm from the sealing seat, thus opening the fluid channel, particularly the fluid inlet.

[0003] The fluid inlet of a diaphragm valve is typically arranged coaxially with the magnetic armature. This allows a central sealing section of the diaphragm to be effectively pressed against the sealing seat, reliably closing the fluid inlet. An outlet is usually positioned eccentrically to the fluid inlet, also opening into the valve flow chamber. The fluid in the inlet exerts a first pressure on the diaphragm in the area of ​​the sealing seat. The fluid in the outlet exerts a second pressure on the diaphragm in the area surrounding the sealing seat. Ambient air, which enters the pole tube during assembly at atmospheric pressure, is typically enclosed within the pole tube.

[0004] In the closed position of the diaphragm valve, a return element acting on the magnetic armature prevents the diaphragm from lifting away from the sealing seat. Such a return element can, for example, be a compression spring acting on the magnetic armature, thus ensuring that the closed position is maintained. The return force applied by the return element is designed to be greater than the force exerted on the diaphragm by the initial fluid pressure at the fluid inlet. A relatively small return force is required for this purpose, as the contact area between the fluid at the fluid inlet and the diaphragm is comparatively small. However, if the fluid pressure at the fluid outlet is greater than in the interior of the pole tube, this additional fluid pressure acts on a larger area of ​​the diaphragm, thereby generating a greater force that counteracts the return force of the return element.Relatively low pressures at the fluid outlet can cause the valve to open unintentionally. To prevent this, the return element must be designed to apply a correspondingly higher preload force to the magnetic armature. However, this means that a stronger magnetic force is required to open the valve, which increases the energy required to actuate the solenoid valve.

[0005] Against this background, the object of the invention is to provide a diaphragm valve that enables reliable operation with low energy consumption. In particular, the diaphragm valve should exhibit reduced sensitivity to pressure changes outside the sealing seat, especially in the area of ​​the fluid outlet.

[0006] This problem is solved by a diaphragm valve with the features of claim 1.

[0007] The invention provides a diaphragm valve for controlling fluidic media, comprising a magnetic armature which is longitudinally displaceable within the interior of a pole tube sealed by a diaphragm and coupled to the diaphragm in such a way that the diaphragm can be moved between a closed and an open position by longitudinal displacement of the magnetic armature. In the closed position, the magnetic armature forces the diaphragm onto a sealing seat and closes a fluid channel, in particular a fluid inlet. In the open position, the magnetic armature lifts the diaphragm from the sealing seat and opens the fluid channel, in particular the fluid inlet. According to the invention, the interior of the pole tube contains a liquid with a liquid volume and a gas with a gas volume, wherein the liquid volume is greater than the gas volume.

[0008] Unlike previously known diaphragm valves, in which the interior of the pole tube is filled exclusively with ambient air, i.e., a gas, the invention provides for filling the interior of the pole tube predominantly with a liquid. This reduces the gas volume within the interior. In this way, the pressure inside the pole tube can adapt more quickly to the pressure in the fluid channel due to a comparatively small deformation of the diaphragm and the resulting change in volume of the enclosed gas. This reduces the resulting pressure force on the diaphragm and thus the restoring force required by the return element to hold the valve in the closed position, so that a comparatively small force is required to open the diaphragm valve. This reduces the energy consumption of the diaphragm valve.Specifically, this reduces the pressure difference between the fluid pressure at the fluid inlet or outlet and the interior of the pole tube, thereby reducing the effective pressure force on the diaphragm and thus the influence of pressure changes on the valve function. The diaphragm valve according to the invention is therefore very efficient and comparatively insensitive to pressure differences.

[0009] The insensitivity of the diaphragm valve to pressure differences is directly related to the size of the remaining gas volume in the interior of the pole tube. A minimal gas volume is preferred. At the same time, the gas volume should be large enough to compensate for volume changes when the diaphragm moves from the closed to the open position, and vice versa, as well as for thermal expansion effects of the liquid due to temperature changes. In this context, it has proven particularly advantageous for the liquid volume and the gas volume to together form a single total volume, with the liquid volume comprising at least 50%, in particular at least 60%, in particular at least 70%, and in particular at least 80% of the total volume.The liquid volume can occupy at most 98%, in particular at most 95%, in particular at most 90%, in particular at most 85%, of the total volume. The total volume can correspond to the entire free internal volume of the pole tube, i.e., the internal volume of the pole tube less the volume of components located within the pole tube. These components can include, for example, the magnetic armature, the return element, and / or guide elements, in particular spring guide elements, for the return element.

[0010] To ensure the intended effect in all operating states and situations of the diaphragm valve, it is advantageous if the fluid remains liquid and has a low viscosity in all expected operating conditions, particularly at varying ambient temperatures. In this respect, the fluid is preferably incompressible. The fluid thus largely fills the interior of the pole tube, leaving a relatively small gas volume, which constitutes the compressible portion.

[0011] In a preferred embodiment of the diaphragm valve according to the invention, the magnetic armature has a through-channel that fluidically connects a diaphragm-side section of the interior with a return spring-side section of the interior. For efficient operation of the diaphragm valve, it is advantageous to have a uniform pressure in the interior of the pole tube. Since the magnetic armature is arranged to be longitudinally displaceable within the pole tube, there is a risk that, when the magnetic armature is displaced, different pressures will arise in a diaphragm-side area of ​​the interior and in a return spring-side area of ​​the interior, i.e., on both sides of the magnetic armature. The through-channel is provided to equalize this pressure. The through-channel is preferably dimensioned such that it can conduct both liquid and gas from one side of the magnetic armature to the other.

[0012] The magnetic armature can be operatively connected to a magnetic coil that extends around the pole tube. The pole tube can essentially be designed as a type of containment shell, which, in conventional containment shell motors, separates the magnetic armature from the magnetic coil. The magnetic coil can be energized to generate an electromagnetic field that moves the magnetic armature longitudinally through the interior of the pole tube. Due to the fluid inside the pole tube and the associated effect of requiring less force to open the diaphragm valve, the magnetic coil can be comparatively small. This not only improves the energy efficiency of the diaphragm valve operation but also reduces the material requirements and costs for the magnetic coil.In particular, this can reduce costs for copper wires, as the wire thickness or the number of windings for the magnet coil can be chosen to be comparatively low.

[0013] In the invention, a return spring is preferably used as the return element. The magnetic armature can be supported on one side opposite the diaphragm by such a return spring on an axial end flange of the pole tube. The return spring can, in particular, be designed as a helical compression spring. This allows for a particularly cost-effective and simple design. Furthermore, such a return spring is particularly reliable and can be easily adapted to the expected pressures.

[0014] In a preferred embodiment of the invention, the membrane hermetically separates the interior of the pole tube from a valve flow chamber. The valve flow chamber can essentially correspond to a valve chamber. Thus, the membrane simultaneously seals the interior of the pole tube. In this context, it is advantageous if the membrane is made of a flexible material, for example, a plastic, particularly an elastomer. The membrane can additionally have a curved, in particular at least partially hat-shaped, cross-sectional contour to facilitate movement from the open position to the closed position, and vice versa.

[0015] Furthermore, the fluid channel, in particular the fluid inlet, can open into the valve flow chamber and be closable by a sealing section of the diaphragm. The diaphragm can have a sealing section, preferably circular, particularly in a central area. The sealing section is preferably coaxial with the fluid inlet, and in particular also coaxial with the magnetic armature and / or pole tube. In the sealing section, the diaphragm can have an increased wall thickness to ensure a sufficient and reliable seal against the sealing seat.

[0016] The fluid channel, in particular the fluid inlet, preferably opens coaxially into the valve flow chamber. The valve flow chamber can therefore also have a geometry with a central longitudinal axis. In this respect, the valve flow chamber can have a rotationally symmetrical shape. The fluid inlet is preferably arranged coaxially with this rotationally symmetrical shape. This ensures a uniform pressure distribution within the valve flow chamber or valve chamber.

[0017] In the diaphragm valve according to the invention, a further fluid channel, in particular a fluid outlet, can also be provided for opening eccentrically into the valve flow chamber. This further fluid channel can be permanently connected to the valve flow chamber, regardless of the position of the diaphragm. The further fluid channel is thus permanently open. The diaphragm of the diaphragm valve only opens and closes the first fluid channel or fluid inlet. When the fluid inlet opens, fluid can flow from the fluid inlet through the valve flow chamber into the fluid outlet. This fluid flow is stopped when the diaphragm is forced against the sealing seat by the restoring force of the restoring element, thereby closing the fluid inlet.Against this restoring force, the magnetic armature, which is actuated by the magnetic coil, lifts the diaphragm from the sealing seat and opens the flow path from the fluid inlet via the valve flow chamber to the fluid outlet.

[0018] The invention is explained in more detail below using an exemplary embodiment with reference to the accompanying schematic drawings. These show Fig. 1 a longitudinal sectional view through a diaphragm valve according to the invention in a closed position; and Fig. 2 a longitudinal section view through the diaphragm valve according to Fig. 1 in an open position.

[0019] The accompanying drawings each show a diaphragm valve 1, which has a magnetic armature 10 arranged to be longitudinally displaceable within a pole tube 30. The magnetic armature 10 is rigidly connected to a diaphragm 20, which closes off an interior space 31 of the pole tube 30. The diaphragm 20 separates the interior space 31 from a valve flow chamber 45. The diaphragm 20 thus provides a hermetic seal, forming a hermetic barrier between the interior space 31 of the pole tube 30 and the valve flow chamber 45.

[0020] The pole tube 30 is connected to a valve housing 40, in which the valve flow chamber 45 is formed. Furthermore, the pole tube 30 extends into a drive housing 16, the drive housing 16 additionally comprising a magnetic coil 15 that is operatively connected to the magnetic armature 10. When energized with an electric current 47, the electromagnetic coil 15 generates a magnetic field that causes the longitudinal movement of the magnetic armature 10 through the interior 31 of the pole tube 20.

[0021] The pole tube 30 further comprises an end flange 34 in its interior 31, wherein a return spring 12 is located between the end flange 34 and the magnetic armature 10 as a return element. In the illustrated embodiment, the return spring 12 is designed as a helical compression spring.

[0022] The return spring 12 is aligned coaxially with the magnetic armature 10. To maintain this alignment, spring guide elements 13 are provided on the pole tube 30 and on the magnetic armature 10, which are essentially cylindrical and extend coaxially into the interior of the return spring 12.

[0023] The magnetic armature 10 further comprises a through-channel 11, which runs eccentrically through the magnetic armature 10. The through-channel 11 connects a resetting-element-side sub-compartment of the interior space 31 with a membrane-side sub-compartment of the interior space 31.

[0024] The magnetic armature 10 is connected to the diaphragm 20 via a connecting bolt 14, which is positively engaged with the diaphragm 20 by means of a bolt head. The diaphragm 20 can be formed by overmolding the bolt head. Alternatively, the bolt head can be vulcanized into the diaphragm 20. The connecting bolt 14 also has a bolt extension with an external thread, which is screwed into an internal thread located in the armature 10. In this way, the diaphragm 20 is firmly coupled to the magnetic armature 10. Furthermore, the outer edge of the diaphragm 20 is clamped between the pole tube 30 and the valve housing 40. This clamping action can additionally include a positive-locking component, whereby the outer edge of the diaphragm 20 forms an undercut that engages in a corresponding groove in the valve housing 40.

[0025] The membrane 20 includes a central sealing section 21, which in the closed position is Fig. 1 is shown, rests on a sealing seat 41 and thus closes a fluid channel 42, specifically a fluid inlet 43.

[0026] The fluid channel 42, or fluid inlet 43, extends coaxially to the magnetic armature 10 through the valve housing 40. The fluid inlet 43 opens into the valve flow chamber 45. In addition to the fluid inlet 43, another fluid channel 42, in particular a fluid outlet 44, is formed in the valve housing. The fluid outlet 44 runs essentially obliquely through the valve housing 40 and opens eccentrically into, or originates from, the valve flow chamber 45.

[0027] To enable the diaphragm valve to be integrated into a fluid flow system, external seals 46 are also provided on the valve housing 40, which can seal the diaphragm valve 1 against a valve block. This allows the diaphragm valve 1 to be easily and reliably integrated into suitable fluid flow systems.

[0028] In the prior art, the interior 31 of the polar tube 30 is usually filled with air, particularly at atmospheric pressure. This presents a challenge, especially when the pressure at the fluid outlet 44 is greater than the pressure in the interior 31. The fluid pressure at the fluid outlet 44 acts on the diaphragm 20 over a relatively large surface area. This is due to the design and the Fig. 1 and Fig. Figure 2 clearly shows that while the pressure from the fluid inlet 43 acts on a relatively small area of ​​the diaphragm 20, the pressure from the fluid outlet 44 is present throughout the entire valve flow chamber 45 and thus acts on a much larger area of ​​the diaphragm 20. This results in a relatively large force acting on the diaphragm 20 even at a relatively low fluid pressure in the fluid outlet 44, with this force having a main component opposite to the restoring force of the return spring 12. A relatively low fluid pressure in the fluid outlet 44 can therefore easily cause movement of the diaphragm 20, so that the seal between the diaphragm 20 and the sealing seat 41 is no longer guaranteed. This is usually compensated for by a correspondingly higher preload force of the return spring 12.However, the increased preload force of the return spring 12 means that the electromagnetic force for moving the magnetic armature 10 must be correspondingly large in order to open the diaphragm valve 1, i.e. to lift the diaphragm 20 from the sealing seat 41 against the return force of the return spring 12.

[0029] The liquid 32 provided in the invention solves this problem. In particular, in the diaphragm valve 1 according to the invention, the interior 31 of the pole tube 30 is mainly filled with a liquid 32. Furthermore, a gas 33 is also arranged in the interior 31 of the pole tube 30. Crucially for the functionality and efficiency of the invention, the liquid volume 32 must be greater than the gas volume 33 in the interior 31 of the pole tube 30.

[0030] When the magnetic armature 10 moves against the restoring force of the return spring 12, the total volume of the interior 31 of the pole tube 30 is reduced. However, since a liquid is hardly or not at all compressible, the gas 33 contained in the interior 31 of the pole tube must accommodate this change in volume. If the gas volume is relatively small, a rapid pressure increase occurs, so that the pressure in the interior 31 of the pole tube 30 adjusts more quickly to the pressure in the valve flow chamber 45. Thus, the restoring force of the return spring 12 can be chosen to be smaller in order to move the magnetic armature 10 with relatively little effort, thereby increasing the overall efficiency of the diaphragm valve 1. Overall, this significantly reduces the influence of the pressure change on the valve function.This increases the reliability of the valve function, especially in the event of pressure fluctuations that may result from changes in the ambient temperature and / or changes in the fluid temperature of the fluidic medium to be controlled.

[0031] The Fig. 1 and Fig. Figure 2, taken together, illustrates the operating states of the diaphragm valve 1. The representation according to Fig. Figure 1 shows the diaphragm valve 1 in a closed position. This means that the sealing section 21 is in a sealing position against the sealing seat 41, thus closing the fluid inlet 43. The solenoid coil 15 is preferably de-energized in this position, so that the seal between the diaphragm 20 and the sealing seat 41 is primarily achieved by the return spring 12, which pushes the magnetic armature 10 towards the fluid inlet 43. If a pressure increase occurs in the fluid inlet 43, the return spring 12, with its preload force, continues to ensure that the seal between the diaphragm 20 and the sealing seat 41 is maintained. A relatively small return spring force is required for this, since the pressure from the fluid inlet 43 acts on a relatively small area of ​​the diaphragm 20. Fig. 1).

[0032] In the event that the pressure in the fluid outlet 44 increases, a relatively higher force acts on the diaphragm 20, since the pressure in the fluid outlet 44 is distributed over a larger area of ​​the diaphragm 20 and thus exerts a greater force on it. This hydraulic pressure also pushes the magnetic armature 10 against the preload force of the return spring 12. At the same time, however, the relatively small gas volume within the interior 31 of the pole tube 30, in conjunction with the predominant liquid 32, ensures that this pressure is distributed within the pole tube 30, thus reducing the load on the return spring 12. In other words, the return spring 12, which has a relatively low preload force, can still exert sufficient force to tightly close the fluid inlet 43.

[0033] In Fig. Figure 1 clearly shows that the gas 33 occupies a gas volume that forms between the liquid 32 and the diaphragm 20. When the magnetic armature 10 is moved towards the end flange 34 of the pole tube 30, the gas 33 is compressed, thus reducing its gas volume. The liquid volume remains largely unchanged, as the liquid 32 is incompressible. This allows the diaphragm 20 to be lifted from the sealing seat 41, enabling fluid flow from the fluid inlet 43 through the valve flow chamber 45 to the fluid outlet 44. Fig. 2) This requires relatively little force, so the magnetic coil 15 and / or the magnetic armature 10 can be made smaller. This contributes in particular to energy efficiency, but can also lead to a more compact design.

[0034] In general, for all embodiments, the fluid 32 used is preferably liquid at all temperatures and under all other ambient conditions occurring during the operation of the diaphragm valve 1. Furthermore, the fluid 32 should exhibit low viscosity in all conceivable operating conditions. It is also advantageous if the fluid 32 has a relatively low coefficient of thermal expansion to prevent temperature changes from impairing the operation of the diaphragm valve 1. Additionally, it may be advantageous if the fluid has corrosion-inhibiting and / or friction-reducing properties. In all cases, it has proven particularly advantageous if the fluid 32 is chemically compatible with the other materials within the pole tube 30. Reference symbol list 1 diaphragm valve 10 magnetic anchors 11 Through channel 12 Return spring 13 spring guide elements 14 connecting bolts 15 Magnetic coil 16 drive housings 20 Membran 21 Sealing section 30 Polaring tube 31 Interior 32 Liquid 33 Gas 34 End flange 40 valve housings 41 Sealing seat 42 Fluid channel 43 Fluid inlet 44 Fluid outlet 45 Valve flow chamber 46 Outer seal

Claims

[1] Diaphragm valve (1) for controlling fluidic media, with a magnetic armature (10) which is arranged to be longitudinally displaceable in an interior space (31) of a pole tube (30) closed by means of a diaphragm (20) and is coupled to the diaphragm (20) in such a way that the diaphragm (20) can be moved by a longitudinal displacement of the magnetic armature (10) between a closed position, in which the magnetic armature (10) forces the diaphragm (20) onto a sealing seat (41) and closes a fluid channel (42), in particular a fluid inlet (43), and an open position, in which the magnetic armature (10) lifts the diaphragm (20) from the sealing seat (41) and opens the fluid channel (42), in particular the fluid inlet (43), characterized by , that the interior (31) of the polar tube (30) contains a liquid (32) with a liquid volume and a gas (33) with a gas volume, wherein the liquid volume is greater than the gas volume. [2] Diaphragm valve (1) according to claim 1 characterized by that the liquid volume and the gas volume together form a total volume, wherein the liquid volume occupies at least 50%, in particular at least 60%, in particular at least 70%, in particular at least 80%, of the total volume. [3] Diaphragm valve (1) according to claim 1 or 2 characterized by , that the liquid (32) is approximately incompressible compared to the gas volume. [4] Diaphragm valve (1) according to one of the preceding claims characterized by , that the magnetic armature (10) has a through channel (11) which fluidically connects a membrane-side section of the interior (31) with a return spring-side section of the interior (31). [5] Diaphragm valve (1) according to one of the preceding claims characterized by , that the magnetic armature (10) is operatively connected to a magnetic coil (15) which extends around the pole tube (30). [6] Diaphragm valve (1) according to one of the preceding claims characterized by , that the magnetic armature (10) is supported on a side opposite the diaphragm (20) via a return spring (12) on an axial end flange (34) of the pole tube (30). [7] Diaphragm valve (1) according to one of the preceding claims characterized by , that the membrane (10) hermetically separates the interior (31) of the pole tube (30) from a valve flow chamber (45). [8] Diaphragm valve (1) according to claim 7 characterized by , that the fluid channel (42), in particular the fluid inlet (43), opens into the valve flow chamber (45) and can be closed by a sealing section (21) of the diaphragm (20). [9] Diaphragm valve (1) according to claim 8 characterized by , that the fluid channel (42), in particular the fluid inlet (43), opens coaxially into the valve flow chamber (45). [10] Diaphragm valve (1) according to any one of the preceding claims characterized by, that a further fluid channel (42), in particular a fluid outlet (44), opens eccentrically into the valve flow chamber (45).

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