Contactless sensor arrangement with magnet holder

Abstract

A valve (1) with a position-measuring system, comprising a control valve for regulating a flow of a process fluid and comprising a drive (60) and also a yoke (30) for connecting the drive (60) to the valve (1), comprising a control rod (50), which is linearly movable within the yoke (30), and comprising a measuring device (10) having at least one magnet-sensitive sensor (22) and at least one magnet (102). The magnet (102) is fastened to the control rod (50) by means of a magnet holder (100) and the sensor (22) is fastened to the yoke (30) by means of a sensor module (20). The magnet holder (100) has an adjusting element (104), which is of a shape that complements a receiving portion on the control rod in such a way that a magnet holder (100) arranged on the control rod (50) by means of the adjusting element (104) and the receiving portion is axially fixed, with the sensor (22) and the magnet (102) being in line, wherein the magnet holder (100) has two opposing legs (105), which span an opening width corresponding to the diameter of the control rod, so as to allow the control rod to be introduced radially into the magnet holder (100).

Description

[0001] SAMSON AG, Frankfurt / Main Non-contact sensor arrangement with magnetic holder The invention relates to control valves for regulating process fluids with a position measuring device and to such measuring devices, in particular non-contact sensor assemblies. Control valves usually have a valve element which regulates a flow cross-section inside a valve housing, between an inlet and an outlet. The valve element is connected to an actuating stem and is usually moved by a pneumatic actuator. The actuator is usually located outside the valve housing. The actuating stem extends sealingly from the valve housing. The invention further relates to a position measuring device for determining the position of a valve stem of an actuating element for a valve. Control valves usually require position sensors to detect the position of the valve element so that the positioner can adjust a precise position.Absolute measurement methods are preferred for this purpose, as a reference measurement is not possible in a process plant, and the valve position must be adjusted immediately for the desired opening cross-section after a malfunction or when starting up the plant. Due to the difficult environmental influences in process plants, non-contact measurement methods are preferred. Furthermore, it is preferable to install the measuring arrangement as far away from the process fluids as possible. Different valves, actuators, and positioners are usually combined, with the valve stroke ranges also varying. The actuator position is usually sensed via the actuator stem and a sensor fixed to the yoke. Magnetic or optical stroke measurement methods are particularly used as position sensors.EP 3161361 A1 and EP 1282798 B1 disclose position sensors that are located within a yoke between an actuator and a valve housing. This arrangement has the advantage that the sensor is located entirely outside the valve housing, i.e., in an area protected from the process fluid. NC-2024-0960 1 Furthermore, the position controller can be easily mounted in this area of ​​the yoke. The sensor is connected to the position controller via a short path. Such an arrangement is particularly suitable for a modular design. Actuators with different stroke forces and stroke lengths can be combined with different control valves using the yoke. The position sensor is located inside the yoke.A disadvantage of existing systems is that the sensors reduce the maximum possible stroke lengths of the actuators, and retrofitting existing valves with improved sensors requires a high level of adjustment effort. On the other hand, existing systems offer little flexibility for changing the position of the sensors on the valve. The object of the invention is therefore to improve the state of the art and to provide a position sensor for control valves that is suitable for different, particularly long, stroke lengths and that can be fixed in a modular manner with reduced adjustment effort and at different positions on the control valve. This object is achieved by the devices according to the independent claims. Advantageous further developments are the subject of the dependent claims.In a preferred embodiment, a position sensor comprises a sensor module with a sensor for detecting the position of a magnet relative to the sensor, a housing, in particular a yoke, and a fastening means for fastening the sensor module to the housing. The housing in turn has a central region for receiving a movable component, in particular an actuating rod of a valve. In particular, the housing projects around a central region. The housing is essentially a cuboid, with the central region representing an axis of the cuboid, which runs perpendicular and centered to two opposite sides of the housing. In an installed form of the position sensor, the actuating rod of a control valve preferably runs parallel or concentrically to the central region.As described later, the housing can be designed in particular as a yoke of a control valve, which is used to connect an actuator and a valve housing. The fastening means has a first fastening interface. The housing has at least one, preferably a plurality of, second fastening interfaces. The second fastening interfaces are designed to be complementary to the first fastening interface, such that the first fastening interface and the second fastening interface can be connected to one another. When the first and a second fastening interface are connected, the relative position, in particular the distance and the inclination, of the sensor module to the central region of the housing is the same, regardless of which second fastening interface the sensor module is fastened to.This means that the sensor module can basically be attached to all sides of the housing using the first mounting interface, and the position.

[0002] NC-2024-0960 2 of the sensor module to the central area in which the valve control rod is provided during use, on which in turn a magnet is provided for position determination, is always the same. The fastening means itself can be implemented in different ways. On the one hand, the fastening means can be an integral part of the sensor housing. On the other hand, the fastening means can be a separate component such as a plate, or the fastening means is part of another peripheral component, for example a wall of a positioner of a control valve. For all designs, it is relevant that the magnetic sensor or the sensor module is connected to a fastening means in such a way that the sensor, in an assembled state, is arranged close to a magnet for detecting the magnetic field. In this way, the definition of the interfaces can reduce the adjustment effort required to position the sensor module.In addition, it is possible for the sensor module to be arranged in different positions, for example on a yoke of a control valve. This in turn increases flexibility, particularly when retrofitting a valve with such a sensor arrangement. In at least one embodiment, the fastening means of the position sensor has a plate that closes the housing on one side. It is also conceivable for the sensor or the sensor module to be connected to a fastening or intermediate plate. In this way, the housing, for example the yoke of a control valve, can be closed by attaching the sensor module on the attachment side. As mentioned, the fastening means can, for example, be a separate plate provided with bores and / or threads that represent the interface for connection to the housing.The plate can, for example, be a plate that is arranged for fastening between a valve yoke and a positioner. This can enable the position sensor to be retrofitted without having to change any existing components. In this way, the design of a positioner, for example, can preferably remain unchanged. Only fastening options must be created on the positioner and / or the housing or yoke for attaching the intermediate plate. In particular, the intermediate plate can be a plate that is already commonly used for attaching the positioner. This plate can be reused by modifying or adding fastening holes and ensuring they are positioned precisely according to the interface to be defined. In this way, the sensor used can be converted in a material-saving manner. Alternatively, the fastening means can be a side panel of a positioner.Positioners are often located in close proximity to the valves to be controlled and are often directly connected to the yoke of a control valve. By using one of the positioner's walls as a support for the sensor, the number of components is reduced and existing mounting hardware can be reused.

[0003] NC-2024-0960 3 In this case, the mounting interface is defined by highly precise positioning of holes and / or threads in the wall of the positioner. One embodiment of such a measuring device is designed for a control valve, wherein the control valve is constructed with an actuator, an actuating rod, and a yoke extending around the actuating rod to connect the valve to the actuator. It is advantageous if the control valve is constructed as described below. Furthermore, the measuring device can comprise at least one magnetically sensitive sensor and at least one magnet, as well as a magnet holder for receiving the at least one magnet. The magnet holder further comprises a receiving opening for receiving an actuating rod of a control valve. The sensor is provided in a sensor module.The sensor module is designed such that it is suitable for direct or indirect attachment to a positioner and / or a yoke of the control valve, and, when attached, protrudes into the yoke. The sensor module is also designed or connected to a fastening means such that, when attached, the fastening means closes the yoke on the side equipped with the sensor module. The control valve can be designed as described below.In conjunction with the features described above or independently thereof, the magnet holder may comprise an adjusting element which is complementary in shape to a receiving section, in particular a groove, on the actuating rod, such that a magnet holder arranged on the actuating rod by means of the adjusting element and receiving section is positively fixed axially and the sensor, in particular a magnetic sensor, and the magnet are aligned, wherein the magnet holder comprises two opposing limbs which span an opening width corresponding to the actuating rod diameter, so that the actuating rod can be inserted radially into the magnet holder. The principle behind such magnet-sensitive sensor systems is that the electrical resistance changes when the sensor element is exposed to a magnetic field.If the valve's control rod, to which the magnet is attached, is moved relative to the sensor, the magnetic field induced in the sensor changes and the sensor module can therefore detect the valve position without contact and regulate it accordingly. A valve with a position measuring system according to one embodiment comprises a control valve for regulating a process fluid flow and a drive as well as a yoke for connecting the drive to the valve, a control rod that is linearly movable within the yoke, also referred to as a control shaft, and a measuring device. The measuring device has at least one magnet-sensitive sensor and at least one magnet. The magnet is attached to the control rod by means of a magnet holder and the sensor is attached to the yoke by means of a sensor module, as described in detail later. The sensor module is provided with at least one.

[0004] NC-2024-0960 4 fastening means which is designed for arranging the sensor module in a yoke of the control valve. The at least one fastening means forms a defined interface which can be complementary to a plurality of fastening points on the yoke, so that the sensor module can be arranged at different points in the yoke without any loss of function. In some embodiments, a plurality of fastening points can also be formed on the yoke as a defined interface, all of which are designed and provided for arranging the sensor module such that the sensor module is aligned with the magnet arrangement after assembly and are functionally connected to one another. This makes it possible for the user to be flexible in arranging the measuring device. It is understood that this interface is only formed for those fastening points which are actually intended to receive orarrangement of the sensor module are provided or designed. This makes it possible to arrange the sensor module and the magnets in alignment, regardless of the fastening point chosen. In the simplest version, exactly one fastening point on the yoke is designed to hold the sensor module. The actuating rod of the control valve has a receiving section, preferably a recess in the surface of the actuating rod, for fixing the magnet holder. The fastening means, the magnet holder and the receiving section of the actuating rod are designed and coordinated with one another in such a way that the sensor and the magnet are aligned relative to one another at each of the provided fastening points on the yoke. Due to the defined interface, the function of the sensor is therefore independent of the fastening point chosen for the sensor module on the yoke in each individual case. The magnet holder is attached to the actuating shaft orThe actuating rod is fixed. The fixation is achieved, for example, by means of a recess, specifically a groove, on the actuating shaft so that the magnet position is coordinated with the sensor position. "Aligned with each other" means that a fixed sensor module has a position relative to the yoke and the actuating rod that corresponds to a magnet attached to a predefined position on the actuating rod. In concrete terms, this means that a magnet arranged at the predefined position of the actuating rod has no lateral offset transverse to the main extension direction of the actuating rod relative to the sensor, within tolerances, but can be brought into alignment with the sensor by simple rotation around the actuating rod. In at least one embodiment, the magnet-sensitive sensor is a TMR sensor, or tunnel magnetoresistive sensor. TMR sensors have very low power consumption and high magnetic field sensitivity.Due to the high sensitivity of TMR technology, the measuring range can be increased compared to other sensor types, such as a Hall effect sensor or an AMR sensor, or anisotropic magneto-resistance sensor, with the same magnet length. Due to the TMR effect, a 360 degree magnetic vector rotation can be clearly recorded, instead of the usual 180 degree rotations with known AMR technologies, a much larger measuring length with the same magnet length.

[0005] NC-2024-0960 5 can be achieved. This is particularly advantageous when setting up an absolute value measuring system. TMR sensors can thus help measure longer stroke lengths without having to change the size or length of the magnet. In this way, the measurable stroke length, at which point a conventional, more complex incremental or vernier-based, 2- or multi-track measuring system would have to be used, can be shifted. This can enable improved use of the installation space, particularly when using short actuating rods and / or yokes with a low overall height. In at least one embodiment of the valve, the fastening means is a wall of a positioner. Alternatively, the fastening means can be designed as an intermediate plate. Advantageously, the fastening means can be mounted directly on the yoke.Using such an intermediate plate, the sensor module can be attached to different positioners on the one hand, and to different yoke designs on the other. The intermediate plate can thus serve as an adapter for different configurations of positioners and control valve designs. The intermediate plate is also suitable for being arranged independently of the positioner for fixing the sensor module at other defined positions on the yoke. In some yoke designs, the intermediate plate is already present to provide conventional positioner attachments for a mechanical stroke reading of the actuating rod. Such existing systems can therefore be adapted for use with the magnetic sensor system described herein by slight modification. The fastening means, in particular the intermediate plate and / or the wall of the positioner, and / or another closing plate which serves to close the yoke, can orcan contain a magnetically shielding material. This allows the yoke to be closed and magnetically shielded using the mounting components already required. This closure or shielding can be achieved on multiple sides using fastening elements, in particular an intermediate plate and / or the wall of the positioner, and / or a cover plate. The shape of the yoke is often rectangular, with two sides of the yoke open and the remaining sides enclosed by material. Materials with ferritic components are typically used to enclose the interior of the yoke.For example, if one of the open sides of the yoke is enclosed by a positioner and the other open side of the yoke is enclosed by a sensor module with an intermediate plate, the sensor module arranged in the yoke and the magnet mounted on the actuating rod can be completely enclosed by a ferrite sleeve and thus largely or completely shielded from external magnetic fields. This can improve the measurement accuracy or sensitivity of the sensor. In designs where the

[0006] NC-2024-0960 6 If the sensor module is mounted on a wall of the positioner and thus the yoke is only equipped on one side, an additional cover plate can close the still open yoke part. In at least one advantageous development, the sensor module can have a plug connection for directly contacting the magnetic sensor with the positioner. In designs in which the sensor module is connected directly to the positioner, without the intermediate plate, a direct electrical plug connection can thus be made between the sensor module and the positioner. In this way, cable routing can be made obsolete. The actual valve elements of such control valves usually consist of a valve housing and an axially movable valve cone installed within the valve housing for regulating a process fluid. The valve cone can be moved by a pneumatic actuator using a valve rod.The valve stem of the valve element is sealed off from the interior of the valve housing at the cover of the valve housing. The actuator has an actuator stem, previously referred to as the control rod. The actuator stem and the valve stem can be connected within the yoke by means of a coupling. Alternatively, as chosen here for simplicity of description, only one rod, namely the control rod, can be used, which is then coupled directly to the valve cone. The valve cone is exposed to high process pressures during operation. With asymmetric cone geometries, this can lead to a torque on the actuator stem. The actuator stem, for example of a pneumatic diaphragm actuator, is fixed to a plate of the diaphragm, and the diaphragm itself is attached to the actuator housing, so that any twisting of the actuator stem depends on the elasticity of the diaphragm's free length.This rotation influences the measurement accuracy of the position measuring system, since the magnet can rotate by up to 5° relative to the magnetic sensor during operation. It is therefore a further object to provide a measuring device for a control valve, and in particular a magnet holder and a valve, with increased tolerance to rotation of the magnet relative to a magnetic sensor. A magnet holder suitable for such a control valve according to one embodiment for attachment to an actuating rod of a control valve has a holder with a support section and two legs. The support section can be geometrically based on the shape of a half-cylinder, with outer surfaces and inner surface arranged concentrically to one another. The inner surface has a radius of curvature that corresponds to the radius of curvature of a control rod to be accommodated.The legs of the bracket extend radially from the support section and are configured opposite one another. The legs define an opening of a predefined size. This opening, as well as the inner contours of the support section, are designed to be predefined.

[0007] NC-2024-0960 7 dimensioned so that the magnet holder can accommodate an actuating rod of a valve. The shape of the magnet holder formed in this way can in particular resemble the shape of a horseshoe. The magnet holder also has a fixing element on its inner contour, which can be the adjusting element. This adjusting element or fixing element can improve the hold of the magnet holder on the actuating rod. On an outer side, the magnet holder has at least one magnet, preferably two magnets arranged next to one another in a row as seen in the circumferential direction of the magnet holder. This allows the magnet or magnets to be positioned close to a magnetic sensor. A magnet receptacle can be formed for the magnet or magnets. The magnets can also be integrated into the holder, for example, cast in the material of the magnet holder during the manufacturing process.It is particularly advantageous to arrange two or more magnets next to one another, in particular parallel to one another, along a circumferential direction of the magnet holder arranged around a control rod. It has been shown that this arrangement on the magnet holder results in favorable magnetic field lines, so that rotation of the shaft and the magnet holder has almost no influence on the measurement signal. In this way, the tolerance of the sensor system with regard to rotation of the magnet holder relative to the sensor during operation can be increased. In summary, the magnet holder is open on one side so that it can be subsequently attached to the control rod after the control valve, consisting of an actuator, a yoke, a valve and a control rod, has been completely assembled. A recess, for example in the form of a groove as a receiving section on the control rod orAn elevation, for example in the form of a projection as a fixing element, as well as a complementary design of the fixing element on the magnet holder allow improved, preferably exact, axial positioning of the magnet holder on the actuating rod and thus of the magnet system relative to the magnetic sensor. It goes without saying that the projection can also be formed on the actuating rod and the groove can also be formed on the magnet holder. All components have dimensions that lie within a defined dimensional accuracy and tolerance. In this way, it can be ensured that, after assembly, the distance between the magnet system and the magnetic sensor lies within the permissible tolerance range for the required measurement accuracy. By using a magnetic sensor and such a magnet holder, a measuring device is created that can be both electrically and mechanically contactless and wear-free.In this way, a measuring device for a control valve can be provided, wherein the measuring device has at least one magnetically sensitive sensor and at least one magnet, as well as a magnet holder for receiving the at least one magnet. The magnet holder further has a receiving opening for receiving an actuating rod of a control valve. The sensor is in a

[0008] NC-2024-0960 8 sensor module is provided, which can be arranged in the yoke and, at least indirectly, fastened to the yoke. The magnet holder has a self-adjusting adjusting element. This preferably has at least one inclined surface which is designed to fit with a predefined receiving section, in particular on an actuating rod of a control valve, and which, in an assembled state, engages or can be brought into engagement with this receiving section. At least one opening for receiving at least one clamping screw is formed in the adjusting element. The magnet holder can therefore be clamped to the actuating rod by means of at least one screw for attachment to the actuating rod. This is particularly advantageous since the angular position of the magnet holder can be adapted to the exact position of the magnetic sensor before clamping to the actuating rod.This is particularly advantageous because the control rod is rotationally symmetrical, meaning the actual angular position of the control rod in the valve can only be determined once the control valve has been fully assembled. In at least one design, the magnet holder is secured using a clamping screw arranged transversely through the two legs of the magnet holder. This has the advantage that a high clamping force can be generated and the clamping screw does not come into direct contact with the control rod. Compared to designs in which the recess of the clamping screw acts directly on the control rod, a transversely running screw does not damage the control rod, in particular the recess, i.e. the receiving section or groove.When using plastic for the magnet holder, it can also be advantageous to use a clamping screw that is not supported on the leg, since otherwise, expansion of the legs of the magnet holder cannot be ruled out and the clamping force on the actuating rod can decrease over time. Thus, the use of such a transverse clamping screw can improve the maintenance of the clamping force. If the clamping screw runs through both legs, with the legs being pulled towards each other by a corresponding clamping screw, a clamping force can be exerted on the actuating rod that will remain largely unchanged over time. In one embodiment of a valve with a position measuring system, a control valve for regulating a process fluid flow has an actuator and a yoke for connecting the actuator to the valve, an actuating rod that is linearly movable within the yoke, and a measuring device.The measuring device has at least one magnetically sensitive sensor and at least one magnet, wherein the magnet is arranged on the actuating rod by means of a magnet holder and the sensor is arranged in the yoke by means of a sensor module and is fastened, at least indirectly, to the yoke.

[0009] NC-2024-0960 9 The magnet holder, in turn, has an adjusting element that is complementary in shape to a receiving section on the actuating rod, such that a magnet holder, which is arranged on the actuating rod by means of the adjusting element and receiving section, is axially fixed, and the magnetic sensor and the magnet are aligned with each other. Complementarity is understood, in particular, to mean an opposing but complementary configuration.The fact that the adjusting element is complementary in shape to the receiving section should be understood in particular to mean that a shape of the adjusting element is at least partially complementary, in particular complementing each other via an external shape, to at least part of a shape of the receiving section, preferably in such a way that the magnet holder, which is arranged on the adjusting rod by means of the adjusting element and receiving section, is axially fixed and the magnetic sensor and the magnet are arranged in alignment with one another. Preferably, two objects which are at least partially complementary in shape to one another are arranged or can be arranged together in a form-fitting manner. The adjusting rod and the magnet holder can be connected to one another in a form-fitting manner.The positive connection between the actuating rod and the magnet holder ensures that the magnet holder moves together with the actuating rod and that no relative movement can occur between the magnet holder and the actuating rod, particularly in the axial direction. This ensures reliable detection of the position of the actuating rod, which, for example, cannot be fully guaranteed with a frictional connection between the actuating rod and the magnet holder, especially over longer periods of use, due to the risk of relative movement. The magnet holder also has two opposing legs that span an opening width corresponding to the actuating rod diameter, so that the actuating rod can be inserted radially into the magnet holder or, when installed, is inserted through the opening. This makes it possible to provide a control valve with a non-contact and wear-free measuring system.In particular, a valve can be retrofitted with such a measuring device without having to disassemble the valve structure. In at least one embodiment of the valve, at least two magnets arranged next to one another, in particular parallel to one another, are fixed to the magnet holder. This can contribute to a higher tolerance in the event of a possibly twisted arrangement of the magnets during initial assembly as well as in the event of twisting of the actuating rod during operation. The magnet(s) can be designed as bar magnets. The length and dimensions of the magnets can be easily adapted to different drive strokes. In addition, different actuating rod diameters can be easily realized, for example by using a differently dimensioned magnet holder, for example with a larger or smaller diameter.

[0010] NC-2024-0960 10 In at least one embodiment, a valve with a position measuring system has a magnet holder that is fixed to the actuating rod by means of a clamping screw. This can improve the hold of the magnet holder and reduce unintentional twisting of the magnet holder on the actuating rod. In alternative embodiments, the valve has a magnet holder in which a clamping screw is arranged transversely through the two legs of the magnet holder and fixes the magnet holder by pulling the legs towards each other. The clamping screw can advantageously also be designed as a fitting screw and fix the magnet holder radially to the actuating rod. This can reduce play of the magnet holder on the actuating rod and thus allow improved measuring accuracy of the sensor. The fitting screw can be designed such that it also forms a positive connection with the valve rod groove.Such a form-fitting assembly can further reduce axial slippage. The magnet holder of a valve with a position measuring system can advantageously have at least one locking lug on an inner circumference, in which the actuating rod is accommodated, for radial fixation on the actuating rod. In this way, the magnet holder can be arranged at the designated location on the actuating rod and secured against accidental removal of the magnet holder from the rod by engaging the locking lug. The locking lugs also serve for rough pre-adjustment. Once the magnet holder has engaged, it can no longer slip in the radial direction. The magnet holder can comprise a plastic or be made of a plastic. In particular, the magnet holder can be made of PEEK and can be thermoplastically or mechanically manufactured.A control valve with a position measuring system can also have a magnet holder that comprises or is made from a non-magnetically conductive metal. This can be a magnet holder manufactured using an MIM process, for example. This can reduce interference with the magnetic field of the magnets during measurement. Embodiments, developments, and examples of the invention are explained in more detail below with reference to the accompanying drawings. The figures show: Fig. 1 a sensor module and a magnet holder; Fig. 2 a perspective view of an embodiment of a measuring device in a disassembled state; Fig. 3 a perspective view of the measuring device according to Fig. 2 in an assembled state.

[0011] NC-2024-0960 11 Fig. 4 is a sectional view of a control valve with a measuring device according to one embodiment. Fig. 5 is a sectional view of a control valve with a measuring device according to a further embodiment. Fig. 6 is a sectional view of a control valve with a measuring device according to a further embodiment. Fig. 7 is a perspective view of the magnet holder according to one embodiment. Fig. 8 is a perspective view of a magnet holder according to a further embodiment. Fig. 9 is a perspective view of the magnet holder from Fig. 8 in the assembled state. In the figures, the same reference numerals designate the same or similarly acting components. For reasons of clarity and better readability, the description of such components is only repeated where necessary. Fig. 1 shows an embodiment of a sensor module 20 and a magnet holder 100 for a control valve 1. The sensor module 20 has a sensor housing 21.The basic structure of the sensor housing 21 forms a cuboid, which on one side, also referred to below as the fastening side, has two projections 23 which have two openings 26 for fastening. The openings 26 are provided as holes which enable the sensor module 20 to be fastened to a fastening means. In the embodiment shown, the fastening means is an intermediate plate 24, as will be described in more detail later. In alternative embodiments discussed later, the fastening means is designed as a wall 41 of a position controller 40. In this respect, the projections 23 represent a fastening means of the sensor module (20) in this and other embodiments. The projections can in particular also be flat, so that an intermediate plate 24 or the use of a position controller 40 as a module carrier can be dispensed with.On a side of the sensor housing 21 facing away from the fastening side, a recess is formed in the sensor housing 21. The magnetic sensor 22 is arranged on an inner wall of the recess at the distal end of the sensor housing 21, starting from the fastening side. The magnetic sensor is fastened to a circuit board 27, which is connected to the sensor housing 21. The fastening of the magnetic sensor 22 or the circuit board to the sensor housing 21 can be achieved by screwing, as shown in Fig. 1. This makes it possible to precisely define the position of the fastening holes. Likewise, in the embodiment shown, the fastening of the sensor housing 21 to the fastening means 24 is realized by screwing. The sensor module 20 has a cable feedthrough (not shown here) or, alternatively, a connector for contacting external components, such as a position controller.

[0012] NC-2024-0960 12 The intermediate plate 24 is formed with a plurality of through holes 25. The position of the through holes 25 is precisely predefined. The through holes 25 allow the intermediate plate 24 to be fastened to other components, for example to a housing of a position controller 40 or a housing or yoke 30 of a valve, as will also be described in more detail later. In addition, the intermediate plate 24 has a plurality, here two, fastening holes 28, which are designed to fasten the intermediate plate 24, for example to a valve yoke, or generally to a housing. Fig. 1 further shows a magnet holder 100. The magnet holder 100 is arranged on an actuating rod 50. For this purpose, the magnet holder 100 has a holder 101. The holder 101 has an opening which essentially corresponds to the circumference of the actuating rod 50, around which the magnet holder 100 is provided.In the embodiment shown, the magnet holder 100 has an adjusting element 104 designed as an adjusting web along a surface of the inside of the holder 100. The adjusting web is designed to engage with a groove 54 designed as a receiving section, which is formed at a predefined position along the surface of the adjusting rod 50. The adjusting web is preferably designed such that it has a positive connection to the groove 54. When the magnet holder 100 is mounted on an adjusting rod 50, for example of a valve 1, at least one magnet 102, two magnets 102 in the embodiment shown in Fig. 1, is arranged on a side facing the sensor module. The magnets 102 are arranged in the circumferential direction and, in the embodiment shown, parallel to one another.Furthermore, the magnet holder 100 is provided on the actuating rod such that the magnets 102 are aligned with the sensor housing 21 and specifically with the magnetic sensor 22. In the context of the embodiment according to Fig. 1, "alignment" means that the magnets arranged on an actuating rod move past the magnetic sensor at a minimum possible distance within tolerances during a vertical displacement of the actuating rod, as occurs when a valve is adjusted by a valve actuator, i.e., they are not rotated or offset relative to the position sensor 22 along the actuating rod 50. The magnet holder 100 further comprises a clamping screw 106. The clamping screw 106 is arranged on a side of the actuating rod opposite the magnets 102. The clamping screw allows the adjustment bar to be clamped in the groove 54.In alternative embodiments, the clamping screw 106 can be replaced by another fastening method, or even omitted entirely. The actuating rod 50 has a drive connection 56 at a first end for connecting the actuating rod to a valve actuator. At an opposite end of the actuating rod, it has a valve connection 52 for connecting to the valve element controlling the process fluid. The valve connection of the actuating rod can also be a connection to a valve rod, with the valve rod being guided into a valve housing and coupled therein to the actual valve element.

[0013] NC-2024-0960 13 Fig. 2 shows a perspective view of a measuring device 10 for a control valve. The components already described in connection with Fig. 1 are also provided, even if they are concealed by other components and therefore not visible. Fig. 2 also shows a sensor module 20. The sensor module 20 is in turn fastened to an intermediate plate 24. A valve drive 60 is arranged on the drive connection 56 of the actuating rod 50 (not visible in Fig. 2). A housing 30, designed in particular as a yoke and also referred to as a yoke in the context of valves, is formed around the actuating rod 50 and on the valve drive 60. The housing 30 is essentially cuboid-shaped. The valve drive 60 is arranged on an upper side of the housing 30. The valve rod protrudes centrally through the center of the housing 30, concentric with the surface normal of the upper and lower sides of the housing 30.On the underside of the housing, a cover plate 35 is formed, through which the actuating rod 50 protrudes from the housing. According to the embodiment shown in Fig. 2, two opposing lateral surfaces of the housing are closed with housing plates 36, which are formed with openings according to the intended functions. The number and type of openings can vary depending on the function. For fastening the plates, a plurality of fastening holes 32 are formed on the housing. The exact position of the fastening holes 32 on the housing 30 is again precisely predefined. As indicated in Fig. 2 and evident in Fig. 3, the intermediate plate 24 serves both to accommodate the sensor module 20, for fastening it to the position controller 40, and for fastening it to the housing 30.Previously known mounting plates in prior art devices are used to attach conventional position controllers, which are already designed, for example, for connection to a valve yoke, and can be easily modified or reused for use with a magnetic sensor. The intermediate plate 24 closes off one of the open sides of the housing 30. Thus, in this embodiment, one side of the housing 30 is open. As previously described, the plates closing off the housing 30 can have properties for shielding magnetic fields. Thus, with the appropriate choice of material, magnetic shielding of five of the six housing sides can be achieved using the embodiment shown in Fig. 2 or Fig. 3 with the commonly used components. It goes without saying that the remaining open side can also be closed off with a plate.This enables complete magnetic shielding.

[0014] NC-2024-0960 14 A position controller 40 is provided on a surface of the intermediate plate 24 facing away from the sensor housing 21. The wall of the position controller facing the intermediate plate 24 has a plurality of through-holes 42, of which only one is visible due to the representation in the figure. The through-hole 42(s) of the position controller 40 is / are congruent with the through-holes 25 provided in the intermediate plate 24 in an assembled state. Fig. 3 shows the measuring device according to Fig. 2 in the assembled state from a slightly different perspective. The position controller and intermediate plate are connected by screws that are screwed through the through-holes 42 of the position controller and the through-holes 25 of the intermediate plate (not visible in Fig. 3). The positioner 40 has a screw channel 43 to access the through holes 42.The through holes 43 and / or the through holes 25 can also have a thread. In this way, the play with which the components are fastened to one another can be minimized. Fig. 4 shows a cross-sectional view of a control valve 1 with a measuring device. Fig. 4 shows an embodiment of the measuring device as shown in Figs. 2 and 3. In addition, the control rod 50 is connected to a valve housing 70 on the valve connection side or is coupled to the actual valve element that regulates the process fluids. The position controller 40 is coupled via the intermediate plate 24 to the sensor module 20 and the valve yoke 30, previously also referred to as the housing. Starting from the valve housing 70, the control rod 50 runs through the central region of the yoke 30 to the valve actuator 60. A side of the yoke 30 opposite the position controller 40 is closed with a closure plate 34.The attachment of the position controller 40 or the intermediate plate 24 and the closure plate 34 to the yoke 30 cannot be seen in the figure due to the selected sectional plane. As described in the context of Fig. 1, the actuating rod 50 in the preferred embodiment shown here has a groove 54. The groove 54 is formed at a predefined position on the actuating rod, at which a magnet holder 100 is arranged. The magnets 102 are arranged on a side of the actuating rod 50 facing the sensor module. The position of the magnet holder 100 or of the magnets 102 held by the magnet holder 100 can be precisely predefined by using such a groove 54 and thus can take place without calibrating the sensor measurement, or can allow an essentially adjustment-free absolute measurement. As previously described, this allows the precise positioning of the sensor module relative to the magnet holder, or relative to the magnets. Fig.Figure 5 shows an alternative embodiment of a control valve 1 with a position measuring device. The sensor module 20 is mounted directly on the side wall 41 of the position controller 40. In this embodiment,

[0015] NC-2024-0960 15, the sensor module 20 has a connector 29. The connector 29 can be used for direct electrical coupling to the position controller 40. For this purpose, the position controller 40 in turn has a connector 44. The connectors 29 on the sensor housing 21 and the connector 44 on the position controller 40 are aligned and are automatically coupled and connected when the sensor housing 21 is attached to the position controller 40. In alternative embodiments, such as according to Fig. 4 or Fig. 6, the sensor module 20 can have a cable guide. In this way, a connecting cable can be guided from the sensor module 20 to the position controller 40. This cable guide can in particular also run through the interior of the yoke 30. Fig. 6 shows a further embodiment of a control valve 1 with a position measuring device. The sensor module 20 is arranged on a mounting plate corresponding to the intermediate plate 24.The fastening plate is therefore provided with the same reference numeral 24, in particular because it can explicitly be the same plate, which also enables fastening between yoke 30 and positioner 40. The fastening plate 24 is arranged on a side of the yoke 30 facing away from or opposite the positioner 40, as shown in Fig. 6. As previously mentioned, a cable outlet is optionally provided on the sensor module 20, which is not shown in Fig. 6. This makes it possible to fasten the sensor module 20 in a position facing away from the positioner 40 and to contact it with the positioner 40. Valves and associated components such as actuators, yokes or positioners are generally highly standardized due to the associated development costs. The individual components of the sensor module 20, including the intermediate orThe mounting plate 24, as well as the holes in the wall 41 of the positioner, therefore also have standardized dimensions with regard to their mountings. For this reason, it is possible to define the exact position of mounted components. This allows a mounting interface to be defined if the position of the necessary mounting elements, for example the through holes 25 or mounting holes 28 of the intermediate plate 24, the through holes 42 of the positioner 40, or the mounting holes 32 of the housing 30, is known. By appropriately designing the sensor housing 21, the magnetic sensor 22 can thus be arranged in a precisely predefined position. Likewise, the dimensions of the actuating rod 50 and the position of the groove 54, as already mentioned, are also standardized.precisely known, so that the magnet holder 100 is positioned at a precisely predetermined position on the actuating rod 50 and relative to the magnetic sensor 22. Thus, after installation of the magnet holder 100, only a rotation of the magnets 102 about the longitudinal axis of the actuating rod, which are held by the magnet holder 100, can occur. Compensation for the position of the magnets rotated in this way can easily be carried out during installation. For this purpose, for example, a marking applied to the magnet holder 100 and / or the sensor housing can be aligned with one another or relative to one another, or another aid can be used to measure the alignment of the magnets.

[0016] NC-2024-0960 16 Assembly The adjusted position of the magnet holder 100 is fixed in the embodiments shown in Fig.4, Fig.5 and Fig.6 by means of the clamping screw 106. Fig.7 shows a magnet holder corresponding to the embodiment in Fig.1 in an enlarged, perspective view without the adjusting rod. The holder 101 of the magnet holder 100 has essentially a horseshoe shape, with a semicircular bearing section 103, which is provided for positioning directly in an adjusting rod, and two legs 105 extending tangentially from the bearing section 103. The clamping screw 106 is designed such that it projects into a threaded bore through one of the legs 105 into or through the holder 101. When used with an adjusting rod, the screw shaft is pressed against the adjusting rod by turning the clamping screw 106, which leads to a jamming and thus to a firm fit of the magnet holder 100.The adjustment web is formed in the magnet holder 100 along an inner contour of the holder 101. In particular, the adjustment web has a wedge or prism shape, the width and flank shape of which enables a positive connection with the groove provided in the adjusting rod. The magnets 102 are arranged at a position opposite the clamping screw 106. In the embodiment shown in Fig. 7, the magnets 100 are partially enclosed by the material of the magnet holder 100. In alternative embodiments, the magnets 102 can be provided as an integral component in the magnet holder 100, i.e., completely enclosed by the holding material. Magnetization of the magnets can take place before or after the magnets are installed in the magnet holder or the magnet holder 100. Fig. 8 shows a further embodiment of a magnet holder 110. The magnet holder 110 according to Fig. 8 differs substantially from that shown in Fig.7 is that instead of a clamping screw, which is intended to come into direct contact with the adjusting rod, a clamp is provided which does not have a screw, but rather the legs of the holder 101 itself as the clamping element. For this purpose, a through-hole is formed through one of the legs 105 of the holder 101 as a screw receptacle 112 for a head section of a clamping screw, and a threaded hole 114 is formed in the other leg for receiving a threaded end of a screw and for screwing the screw into the threaded hole 114. The screw receptacle 112 and the threaded hole 114 are arranged in the fixing element or run through the fixing element. A center point of the through-opening of the screw receptacle 112 is further away from a free end of the leg 105 than the center point of the threaded hole 114. This leads to, as shown in Fig.9 shows that an inserted screw runs diagonally from one leg to the other. It is understood that this is only one possible embodiment. The screw can also have a straight path without deviating from the spirit of the invention. Furthermore, it is possible that the

[0017] NC-2024-0960 17 threaded hole is replaced by a through hole and another type of fastening of the screw is carried out, for example by means of a nut or a bolt lock. As previously described, the holder 101 is essentially a half-cylinder whose open ends merge into the legs 105. In the region of the transition from the curved bearing section 103 to the legs 105, a locking lug 118 is provided. The locking lug is a projection on the inner contour of the magnet holder, which is dimensioned and designed such that an adjusting rod with a defined diameter can pass past the locking lug when the adjusting rod is inserted into the magnet holder by elastically pushing the legs 105 apart. Due to the restoring force of the legs, however, the locking lug fixes the adjusting rod in the holder 101.As a result, the position of the adjusting rod is already roughly adjusted and only the magnets 102 need to be aligned during assembly. A sensor would ideally be arranged along axis A in Fig. 9 in order to detect the most symmetrical course of the magnetic field lines and the strongest possible magnetic field in the sensor. Fig. 9 further shows a clamping screw 116, which in this case is designed as a fitting screw engaging in the groove 54 - not visible in Fig. 9. The clamping screw 116 has a tangential course to the adjusting rod 50 received in the magnet holder 100. During use, the adjusting rod 50, in particular the groove 54 of the adjusting rod 50, is brought into engagement with the adjustment section of the magnet holder 100 through the opening of the legs 105 in the magnet holder 100.

[0018] NC-2024-0960 18 LIST OF REFERENCE SYMBOLS 1 Valve with position measuring system 10 Measuring device for control valve 20 Sensor module 21 Sensor housing 22 Magnetic sensor 23 Projection 24 Intermediate plate 25 Through hole 26 Opening 27 Circuit board 28 Mounting hole 29 Connector 30 Valve yoke / housing 32 Mounting hole 34 Cover plate 35 End plate 36 Side plate 40 Positioner 41 Positioner wall 42 Through hole 43 Screw channel 44 Connector 50 Control rod 52 Valve connection 54 Groove 56 Actuator connection 60 Valve actuator

[0019] NC-2024-0960 19 70 Valve housing 100 Magnet holder 101 Bracket 102 Magnet 103 Support section 104 Adjusting element 105 Leg 106 Clamping screw 112 Screw receptacle 114 Threaded hole 116 Clamping screw 118 Locking lug

[0020] NC-2024-0960 20

Claims

PATENT CLAIMS 1. Valve (1) with a position measuring system, comprising a control valve for regulating a process fluid flow and a drive (60) as well as a yoke (30) for connecting the drive (60) to the valve (1), an actuating rod (50) which is linearly movable within the yoke (30) and a measuring device (10) having at least one magnetically sensitive sensor (22) and at least one magnet (102), wherein the magnet (102) is fastened to the actuating rod (50) by means of a magnet holder (100) and the sensor (22) is fastened to the yoke (30) by means of a sensor module (20), characterized in that the magnet holder (100) has an adjusting element (104) which is complementary in shape to a receiving section on the actuating rod (50), such thatthat a magnet holder (100) arranged on the actuating rod (50) by means of an adjusting element (104) and a receiving section is axially fixed and the sensor (22) and the magnet (102) are aligned, wherein the magnet holder (100) has two opposite legs (105) which span an opening width corresponding to the actuating rod diameter, so that the actuating rod (50) can be inserted radially into the magnet holder (100).

2. Valve (1) with a position measuring system according to claim 1, characterized in that at least two magnets (102) arranged in series are fixed to the magnet holder (100).

3. Valve (1) with a position measuring system according to one of claims 1 or 2, characterized in that the magnet holder (100) is fixed to the actuating rod (50) by means of a clamping screw (106, 116).

4. Valve (1) with a position measuring system according to one of the preceding claims, characterized inthat the magnet holder (100) is fixed by means of a clamping screw (116) arranged transversely through the two legs (105) of the magnet holder (100).

5. Valve (1) with a position measuring system according to claim 4, characterized in that the clamping screw (116) is designed as a fitting screw and fixes the magnet holder (100) radially to the actuating rod.

6. Valve (1) with a position measuring system according to one of the preceding claims, characterized in that the magnet holder (100) has at least one locking lug (118) for radial fixation to the actuating rod (50).

7. Valve (1) with a position measuring system according to one of the preceding claims, characterized in that the magnet holder (100) is made of plastic, in particular PEEK. NC-2024-0960 21 8. Valve (1) with a position measuring system according to one of the preceding claims, characterized in that the magnet holder (100) comprises a non-magnetically conductive metal. 9.A measuring device (10) for a control valve with a drive, a control rod, and a yoke surrounding the control rod for connecting the valve to the drive, wherein the measuring device (10) has a housing (30), at least one magnetically sensitive sensor and at least one magnet (102), as well as a magnet holder (100) for receiving the at least one magnet (102). Furthermore, the magnet holder (100) has a receiving opening designed to receive a control rod (50) of a control valve (1), and the sensor (22) is provided in a sensor module (20) arranged in the yoke (30). The magnet holder (100) has an adjusting element (104) that has at least one inclined surface for fitting with a predefined receiving portion and can be engaged therewith, and the adjusting element has an opening for receiving a clamping screw (106, 116).Magnet holder (100) for fastening to an actuating rod (50) of a valve (1), in particular a control valve, comprising a holder (101) with a bearing section (103) and two legs (105) which extend radially from the bearing section and opposite one another, wherein the legs (105) span an opening of predefined size which is suitable for receiving an actuating rod of a valve, and wherein the magnet holder (100) has a fixing element on an inner side and at least one magnet (102) on an outer side, preferably two magnets (102) arranged in series. NC-2024-0960 22

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