Position detection for valves

Abstract

Valve (10) with a first closing element (20) and a second closing element (22), which can assume a flow position and a closed position, so that the valve (10) can assume different valve positions, wherein the first closing element (20) and the second closing element (22) are electrically insulated from each other and the first closing element (20) is connected to a first sensor (40) and the second closing element (22) to a second sensor (42), characterized in that an electrical capacitance is measured between the first sensor (40) and the second sensor (44).

Description

Field of the invention

[0001] The present invention relates to valves and, in particular, to a position detection system for valves. This position detection system can detect whether a valve is open or closed. For certain valve types, other positions can also be detected. Background of the invention

[0002] EP 0 911 609 A1 discloses a valve with a spindle and a device for detecting the valve position. Two magnets are used to determine their relative positions. One magnet is glued to the spindle.

[0003] This device is only suitable for a specific valve type. It requires the assembly of additional components, and easy and accurate determination of the valve position appears difficult.

[0004] European patent EP 1 996 851 B1 discloses a connection status sensor for a coupling device. The coupling device is typically a simple valve. This valve can be used together with a plurality of similar valves in a larger system, for example, a system for mixing liquids. The valve has a simple shut-off element that can assume an open and a closed position. A magnet is provided on this element. A sensor is provided outside the shut-off element. This allows it to be determined whether the valve is open or closed. Again, additional components are required, and furthermore, an exact valve position cannot be determined.

[0005] The present invention aims to provide improved position detection and a corresponding device. The device should be suitable for a variety of differently constructed valves. Furthermore, it should enable precise detection of a valve position, particularly for valves that have multiple positions beyond an open and closed position, such as throttle positions. The control of multi-port valves is also considered. Position detection should be possible reliably with very few components.

[0006] This object is achieved by a valve according to claim 1. Advantageous further developments are specified in the subclaims. Further description

[0007] The present invention relates to a valve with a first closing element and a second closing element. These closing elements can assume a flow position and a closed position. In the flow position, the flow of a medium, usually a liquid, sometimes a gas or liquefied petroleum gas, should be possible. In the closed position, this flow is suppressed. The closing elements can also assume intermediate positions, for example, a throttle position. The valve can therefore assume various valve positions, in particular, be open and closed.

[0008] The locking elements should be electrically insulated from each other. Typically, the locking elements are conductive and usually made of metal. However, they should not be electrically connected to each other, so at least one insulator is placed between the two elements. Often, a direct or indirect mechanical connection between the locking elements is unavoidable because they are installed in a valve. In such cases, care must be taken to ensure that a suitable insulating material, such as plastic, is provided.

[0009] The first closing element should be connected to a first sensor, and the second closing element should be connected to a second sensor. It should be possible to measure an electrical capacitance between the first and second sensors. This capacitance is typically actually measured during valve operation.

[0010] By measuring the electrical capacitance, a statement can be made about the valve position.

[0011] For this purpose, the sensors can be connected directly or indirectly to the closing elements. For example, it might be possible to connect the first sensor directly to the first closing element, but connect the second sensor to a component, perhaps the valve housing, that is electrically connected to the second closing element.

[0012] In this arrangement, the first closing element and the second closing element are used as electrodes of a capacitor. Due to the electrical insulation of the two closing elements from one another, the capacitor can store charge and has an electrical capacitance. This electrical capacitance can be easily measured. Since capacitors play a major role in electronics, measuring devices for capacitors are numerous and even inexpensive measuring devices achieve a very high level of accuracy. This means that the electrical capacitance of the valve (or more precisely its closing elements), which depends on the valve position, can be used to derive an indication of the valve position. This often requires standardization and perhaps a conversion. A direct specification of a capacitance value (usually in Faradays) or a modified one, for example related to the valve position, e.g. open, closed, half open, is conceivable.

[0013] The present invention can be advantageously used in a valve through which flow passes in the direction of flow and in which the first closing element is a shut-off body that can move toward the second element substantially in the direction of flow. This situation is typical for a seat valve. For example, the first closing element can be a disc, and the second closing element can be a housing section toward which the disc moves to close. The capacitance can then be measured between the disc and the housing section. For this purpose, a first measuring sensor can be connected directly or indirectly to the disc, and a second measuring sensor can be connected directly or indirectly to the housing section.

[0014] The present invention can also be used in a valve through which flow passes in one direction and in which the first closing element is a shut-off body, but which can move essentially transversely to the flow direction toward the second closing element. Such a valve can be designed as a slide valve. The second element can in turn be a housing. The capacitance can then be measured between the shut-off body and the housing. For this purpose, a first measuring sensor can be connected directly or indirectly to the shut-off body, and a second measuring sensor can be connected directly or indirectly to the housing.

[0015] The present invention can also be used in a multi-way valve. A multi-way valve can, for example, comprise a distribution element that can assume multiple positions, for example, to direct a medium to a first channel, a second channel, or a third channel. For this purpose, the distribution element is generally movable relative to the housing. The position of the distribution element can be detected by capacitance differences between the distribution element and the housing.

[0016] The distribution element is often designed as a disc. The position of the distribution element can then be detected in a similar way to a throttle or shut-off valve with discs and openings in these discs.

[0017] The present invention can also be used in a valve which comprises a first disc with at least one opening as the first closing element and a second disc with at least one opening as the second closing element. The opening in the first disc can be regarded as the inflow opening and the opening in the second disc can be regarded as the outflow opening, although the flow direction in such a valve can usually be reversed. By changing the relative position of the discs to one another, it is possible for the valve to assume an open position because the corresponding openings overlap completely or at least partially. It is also possible to bring the valve into a closed position if the openings do not overlap and are usually also closed by sections of the disc.

[0018] The capacitance can then be measured between the first and second discs. A first sensor can be connected directly or indirectly to the first disc, and a second sensor can be connected directly or indirectly to the second disc.

[0019] It is advantageous if the first disc and the second disc can be rotated about a common central axis and the valve can be moved from the flow position to the closed position by rotating about this axis.

[0020] Such a valve has generally proven to be advantageous within the scope of the present invention, even if it is used without a first and / or second sensor.

[0021] A suitable valve can be designed, in particular, as a shut-off valve and especially as an emergency valve. It can have an inlet-side outer disc, an outlet-side outer disc, and a center disc arranged between the inlet and outlet outer discs.

[0022] These discs should each have at least one flow opening. By changing the relative position of the discs, it should be possible to either allow flow through the valve or suppress this flow. The valve can therefore assume a flow position and a blocking position. Intermediate positions in which the flow is throttled are also conceivable.

[0023] The inflow-side outer pane expediently comprises at least one first inflow-side flow opening, and the outflow-side outer pane expediently comprises at least one first outflow-side flow opening. The center pane expediently comprises at least one first central flow opening (center here describes the arrangement of the flow opening in the center pane, not the position of the flow opening relative to the center pane). Expediently, the panes each comprise a plurality of flow openings, for example, more than two, three, or four flow openings. Six flow openings each in the inflow-side outer pane, the outflow-side outer pane, and the center pane have proven expedient.

[0024] It is expedient if the valve is transferred from the flow position to the blocking position by rotating at least one disc about a rotational axis that runs essentially (or exactly) in the main flow direction. It is particularly expedient if either both outer discs or the center disc are rotated about this axis. The rotational axis can be a virtual axis, but it can also be a physical axis (or shaft). A physical axis can, for example, be firmly connected to the two outer discs. The center disc can have a central passage for this axis.

[0025] The relative rotation of at least two discs is advantageously achieved by a lever. This lever can be connected to at least one disc or to an axle supporting the disc. The lever end is generally located outside the shut-off valve and also outside the associated flow component. The lever runs transversely to the flow direction and typically perpendicular to the flow direction. The lever advantageously has a length that exceeds the disc diameter of the central disc; advantageously, it is at least twice or three times as long as this diameter.

[0026] It has also proven advantageous to provide an identical number of airflow openings, particularly in the outer panes, but frequently also in the center pane. It is advantageous if the airflow openings are arranged point-symmetrically or mirror-symmetrically on the panes. In particular, it is advantageous if the airflow openings are distributed symmetrically across circular sectors of the panes.

[0027] The discs extend along a main plane of extension and, when viewed perpendicular to this plane, are at least substantially circular. The corresponding circles can be divided into equal-sized sectors, which are arranged around the center point and each cover specific angular segments. The discs are advantageously manufactured so that a flow opening is arranged in each of four or six sectors (preferably of the same size).

[0028] It is advisable for the flow openings to be arranged at the same angle to each other. For this purpose, the geometric center of gravity of the flow opening and the center of the disk's rotational axis can be used as a reference line for measuring the angles.

[0029] It is advantageous to provide flow openings of the same shape in different discs. It is also practical to provide flow openings of the same shape and size. This allows a particularly high and turbulence-free flow to be achieved in the flow position of the valve. The outer discs are expediently arranged at a short distance from the center disc, for example at a distance of less than five, three, or two millimeters. In the flow position, flow then takes place through completely or partially overlapping flow openings. The described shape and arrangement of the flow openings ensures that the capacity changes in a way that is easy to predict and calibrate when the valve moves from one position to another.

[0030] The discs are conveniently made of metal, usually stainless steel. For typical applications, a disc diameter in the range of 10 to 100 cm and preferably in the range of 15 to 40 cm is suitable. The discs conveniently have a thickness of 5 to 50 mm, typically a thickness of 10 to 20 mm. Discs with a diameter in the range of 3 to 30 times, conveniently in the range of 8 to 10 times, the disc thickness are often suitable. The advantages of the invention include that both the disc diameter and the disc thickness, as well as the number, dimensions, and positioning of the openings, can be easily changed. The basic design of the valve can be retained.

[0031] It is also advisable to connect the actuating lever for the closing valve to weights. This preloading with weights allows for easy and reliable closing, especially in emergency situations. The weights are generally sized so that their weight alone ensures the safe closure of the closing valve. In the flow position, the movement of the weights is prevented by a suitable mechanism / emergency release mechanism. This emergency release mechanism can be a mechanical switch or a magnetic switch, which prevents the closing movement otherwise caused by the weights.

[0032] The emergency release mechanism can be connected to the weights and / or the valve's operating lever by a rod, preferably a jointed rod. The rod preferably has a plurality of links. It is conceivable to provide the emergency release mechanism outside a tank, but the valve inside the tank. The weights can be provided outside or inside the tank. The rod length can be easily adjusted to suit the situation.

[0033] Further features, as well as advantages of the invention, will become apparent from the following drawings and the accompanying description. In the figures and the accompanying descriptions, features of the invention are described in combination. However, these features can also be encompassed by an inventive subject matter in other combinations. Each disclosed feature is therefore also to be considered as disclosed in technically reasonable combinations with other features. Some of the figures are slightly simplified and schematic. Fig. 1 shows a side sectional view of the emergency valve according to the invention Fig. 2 shows a perspective sectional view of the emergency valve. Fig. 3 shows a schematic representation of the valve in the closed state Fig. 4 shows a schematic representation of the valve in the open state

[0034] Fig. Figure 1 shows the shut-off valve 10 according to the invention in a sectional view. The valve 10 is installed with a flow component 12. This has a valve-side flange 14 to which the shut-off valve 10 can be mounted. The flow component has a flow cross-section that tapers away from the valve; in particular, it provides the inlet opening 16. This represents a type of lower funnel opening. The valve 10 is further equipped with the mounting flange 18, with which it can be connected, for example, to additional pipes.

[0035] The shut-off valve 10 according to the invention allows liquid or gas flow in both directions. In this case, it is used so that the flow goes from the right side of the image to the left side. For example, a gas or liquid tank could be located on the right. The shut-off valve 10 can be inserted into such a tank together with the connected flow component 12. Using the mounting flange 18, it is then connected to a piping system for removing the fluid from the tank. In view of this exemplary assumption, the terms "inflow side" and "outflow side" are used.

[0036] The shut-off valve 10 accordingly has an inlet-side outer disc 20. A center disc 22 is arranged behind it. An outlet-side outer disc 24 is arranged behind it. The three discs are connected to one another by a central pin 26. The discs can rotate relative to one another about this pin 26 and can thus be moved from an open position to a closed position (and back to an open position).

[0037] A variety of mounting options for the closing valve 10 are conceivable, the connection of the center disc 22 for mounting, ie for connection to the flow component 12, is expedient and has been chosen here. For this purpose, the center disc 22 has a projecting edge which serves as a supporting flange 28 with the valve-side flange 14 of the flow component 12.

[0038] Due to its connection to the flow component 12, the center disk 22 in this embodiment is not rotatable (relative to the flow component). However, the two outer disks 20 and 24 are rotatable relative to the center disk 22. As indicated in the illustration, it is useful for this purpose if both outer disks are connected to the bolt 26 in a rotationally fixed manner. This can be achieved, for example, by pins protruding from the bolt 26 and suitably mounted in the disks. The bolt 26 is expediently mounted in the center disk 22 by a pivot bearing, for example a bolt or ball bearing. A plain bearing is also expedient. If the bearing is made of plastic, the plastic can insulate the disks between which a capacitance measurement is to be carried out.

[0039] Fig. Figure 2 shows the same closing valve 10 in perspective, in a sectional view. The valve is shown in the open position, and it can be seen how the first inlet-side flow opening 30 can be positioned exactly above the first central flow opening 32 (and also above the first outlet-side flow opening 34).

[0040] The figure also shows how capacitance measurement can be conveniently provided for this valve type. The first disc of the valve, the inflow-side outer disc 20, is connected to a first measuring sensor 40. This is placed on the disc. Fixing to the disc by mechanical fasteners, gluing, soldering, or welding would be conceivable. A second measuring sensor 42 is also provided. This measuring sensor is provided on the flow component 12 connected to the valve. It can also be fixed there in a similar manner. The flow component 12 offers the valve-side flange 14, to which the center disc 22 is mounted with the support flange 28. This second valve disc rotates relative to the first disc of the inflow-side outer disc. The capacitance between the discs 20 and 22 changes during rotation. This change in capacitance can be measured with the measuring sensors 40 and 42.Other placements of the sensors are easily conceivable.

[0041] In order to build up electrical capacitance between these discs, insulation of the discs is important. For this purpose, insulators 44 are provided on the bolt 26. If the bolt 26 is made of metal, as is usually the case, such insulation is important. If the bolt were made of plastic, insulation would not be necessary. A plastic element, such as a plain bearing or a plastic guide strip, can be used as the insulating body 44. More generally, the use of an insulating bearing is advisable.

[0042] Alternatively, with the valve shown, it would also be possible to measure the capacitance differences between the center disc 22 and the outflow-side outer disc 24. Since the discs 20 and 24 rotate at the same angle, the information obtained from the capacitance would be identical to the valve position.

[0043] Fig. Figure 3 shows the closing valve 10 in a schematic diagram in the closed position. The inflow-side outer disc 20 faces the viewer. The center disc 22 is indicated behind it. The inflow-side outer disc 20 has a plurality of flow openings, in particular the first inflow-side flow opening 30. The center disc 22 also has a plurality of flow openings, in particular the first central flow opening 32. By rotating the inflow-side outer disc 20 relative to the center disc 22, the flow openings 30 and 32 are rotated relative to each other such that no flow is possible.

[0044] The first inflow-side flow opening 30 and the second inflow-side flow opening 30' are spaced apart from one another such that a closed circular segment is formed between these two flow openings 30 and 30', which is large enough to completely cover the first central flow opening 32 and, moreover, creates a web section 46 next to the first central flow opening 32. In the area of ​​this web section 46, the flow openings in the outer pane and in the center pane do not overlap, so that a particularly secure seal is achieved here. The provision of such web sections, in particular web sections in the area of ​​which there are no flow openings in the direction of the main axis in the closed position, is generally a useful concept within the scope of the present invention. It is generally useful if such web sections cover an angular range between 3° and 20°.

[0045] The twisting of the sheets produced in this way causes a capacitance difference between the (electrically insulated) discs, essentially depending on the overlap of the through-holes.

[0046] Fig. Figure 4 shows the same arrangement in the open state. Here, the first inflow-side flow opening 30 and the first central flow opening 32 are positioned in a precisely overlapping position.

[0047] The valve can also be used as a flow-limiting valve. For this purpose, the discs are rotated relative to each other so that a partial overlap of the flow opening is achieved, for example a partial overlap of the first inflow-side flow opening 30 and the first central flow opening 32. Compared to Fig.3 clearly shows that the different valve position and in particular the different position of the flow openings relative to each other has a significant influence on the capacitance of the capacitor formed by the two discs.

[0048] Overall, it is clear how reliable and versatile position detection can be achieved using simple means. List of reference symbols 10 Closing valve 12 Flow component 14 valve-side flange 16 Inlet opening funnel end 18 Mounting flange 20 inflow-side outer pane 22 center disc 24 drain-side outer pane 26 bolts 28 Support flange 30 first inflow-side flow opening 32 first central flow opening 34 first outflow-side flow opening 36 nut on bolt 38 flange nuts 40 first sensor 42 second sensor 44 Insulator 46 bridge section QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 0 911 609 A1

[0002] EP 1 996 851 B1

[0004]

Claims

[1] Valve (10) with a first closing element (20) and a second closing element (22), which can assume a flow position and a closed position, so that the valve (10) can assume different valve positions, wherein the first closing element (20) and the second closing element (22) are electrically insulated from each other and the first closing element (20) is connected to a first measuring sensor (40) and the second closing element (22) is connected to a second measuring sensor (42), characterized by that an electrical capacitance is measured between the first measuring sensor (40) and the second measuring sensor (44). [2] Valve (10) according to the preceding claim, wherein an indication of the valve position is derived from the measured electrical capacitance. [3] Valve (10) according to one of the preceding claims, wherein the first closing element (20) and the second closing element (22) serve as electrodes of a capacitor. [4] Valve (10) according to one of the preceding claims, through which flow passes in one flow direction and in which the first closing element is a shut-off body which can move substantially in the flow direction towards the second closing element. [5] Valve (10) according to one of claims 1 to 3, through which flow passes in one flow direction and in which the first closing element is a shut-off body which can move substantially transversely to the flow direction towards the second closing element. [6] Valve (10) according to the preceding claim, wherein the first closing element comprises a first disc (20) with at least one first inflow opening (30) and the second closing element comprises a second disc (22) with at least one first outflow opening (32). [7] Valve (10) according to the preceding claim, wherein the first disc is rotatable relative to the second disc (22) about a common central axis and the valve (10) can be transferred from the flow position to the closed position by rotating the first disc (20) relative to the second disc (22). [8] Valve (10) according to one of claims 1 to 3 or 5 to 7, wherein the flow can pass through the valve (10) from an inflow side to an outflow side in a main flow direction through a passage plane perpendicular thereto, wherein the valve (10) has an inflow-side outer disc (20), an outflow-side outer disc (24) and a central disc (22) arranged between the inflow-side outer disc (20) and the outflow-side outer disc (24), and the inflow-side outer disc (20) has a first inflow-side throughflow opening (30), the outflow-side outer disc (24) has a first outflow-side throughflow opening (34) and the central disc (22) has a first central throughflow opening (32), wherein the discs (20, 22, 24) can assume a flow position,in which a flow from the first inflow-side flow opening (30) via the first central flow opening (32) to the first outflow-side flow opening (34) is possible and wherein the discs (20, 22, 24) can assume a blocking position in which this flow is not possible. [9] Valve (10) according to the preceding claim, in which the inflow-side outer disc (20) has a second inflow-side through-flow opening, the outflow-side outer disc (24) has a second outflow-side through-flow opening and the middle disc (22) has a second central through-flow opening and wherein a flow is possible from the second inflow-side through-flow opening via the second central through-flow opening to the second outflow-side through-flow opening. [10] Valve (10) according to the preceding claim, wherein the inflow-side outer disc (20) is fixedly connected to a bolt (26) and this bolt (26) is rotatably guided through the central disc (22).

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