EP4252262A2

EP4252262A2 - Device and method for actuating a control element in an environment at risk of explosion or fire, and, based thereon, current-to-pressure converters, solenoid valves, position controllers, control valves and systems

Info

Publication number: EP4252262A2
Application number: EP21820157.2A
Authority: EP
Inventors: Stefan Kolbenschlag
Original assignee: Samson AG
Current assignee: Samson AG
Priority date: 2020-11-26
Filing date: 2021-11-24
Publication date: 2023-10-04
Also published as: WO2022112317A2; WO2022112317A3; DE102020131398B3; CN220873342U

Abstract

The invention relates to devices (100) for actuating a control element (110), which devices can be safely and reliably operated in an environment at risk of explosion or fire. For this purpose, a device (100) is proposed in which the control element (110) is actuated by means of a magnetic field of an electromagnet (130), which is located in a flameproof housing (120). The magnetic field of the electromagnet (130) is conducted out of the housing (120) by means of a flux-conducting piece, which extends through the housing (120) in such a way that flameproofing is ensured. In this way, the magnetic force which the electromagnet (130) applies to the control element (110) of the device (100) can be transmitted to the control element (110) nearly without loss. The proposed device (100) is suitable for use in solenoid valves, current-to-pressure converters, position controllers or control valves in process systems or power plants.

Description

Device and method for actuating an actuating element in an explosive or fire-hazardous environment and IP converters, solenoid valves, positioners based thereon,

control valves and systems

description

field of invention

The invention relates to electromagnetic drives, in particular devices and methods for actuating a control element, which can be operated safely in an environment where there is a risk of explosion or fire, and IP converters, solenoid valves, position controllers, control valves and systems based thereon.

Electromagnetic drives convert electrical signals into mechanical movement. They are often made up of a magnetic coil or an electromagnet and a movable armature or actuating element. The electrical power introduced into the coil body determines the position of the armature or actuating element. The power consumption of electromagnetic drives can be very high, at least in the short term. The same applies to the currents and/or voltages that occur.

Electromagnetic drives are used in the positioners of control valves, solenoid valves or current-to-pressure converters (IP converters) to control pneumatic or hydraulic components and are therefore in many cases part of a process plant or a power plant. They can be exposed to a variety of operating conditions. These include conditions where a spark, e.g. from a contact on an electromagnetic drive, can ignite explosive vapors. Under such conditions, the operation of electromagnetic drives requires special protective measures. These measures can be distinguished based on their effect:

1. prevent sparks, flames or explosions; or

2. Contain any sparks, flames or explosions that may occur.

The first group includes protective measures in which the current intensities used and voltages in an electromagnetic drive are limited to values at which the generation of sparks or heat can be ruled out. In many cases, the intrinsic safety of the drive created in this way is associated with a more complex structure and more expensive circuit components, for example in order to prevent or intercept faults caused by broken wires or short circuits. In addition, certain voltage or current ranges are no longer available. This represents a restriction with regard to the forces that can be transmitted to the armature or the actuating element of the drive, the dimensioning of the magnets and/or the speed at which the armature or the actuating element can be moved. In order to be considered intrinsically safe, electromagnetic drives must also meet the DIN standard EN 60079-11 - in addition to the general requirements for explosion protection specified in the DIN standard EN 60079-0.

The second group of measures includes flameproof housings or capsules for the electrical contacts and components of an electromagnetic drive. The housing or capsules are designed in such a way that they prevent a spark, a flame or an explosion from spreading out of the housing. The pressure resistance of the housing or the capsule can be established by appropriate wall thicknesses and minimum requirements for connecting surfaces or gaps in the housing or the capsule. Both the general requirements of DIN standard EN 60079-0 and the special requirements of DIN standard EN 60079-1 must be observed for a flameproof housing or capsule.

Alternatively, the contact of ignitable mixtures of substances or vapors with the electrical contacts or components can be prevented by using inert gas, such as argon, as well as liquid or solid insulating materials. These measures are usually expensive and complex. They also justify certain minimum requirements for the geometric structure and the dimensions of the housing (cf. e.g. the requirements for encapsulation specified in DIN standard 60079-18).

In addition, the protective measures often disrupt the transmission of magnetic forces to the armature or the actuating element. The weakening is due to the larger distances that result from the required wall thicknesses, layer thicknesses or other geometric specifications and have to be overcome in order to transmit the magnetic forces. The materials used for the housing and the protective measures can additionally shield or diffuse the magnetic field. In addition, the control element is often restricted in its freedom of movement. As a result, the actuating element can be operated less reliably or only with reduced responsiveness or longer switching times. Additional mechanical components are often necessary to compensate for the limitations in the freedom of movement of the control element. This increases the effort for production, commissioning and maintenance, and also affects the reliability of the drives or with the drives equipped devices.

State of the art

The prior art offers various options for designing explosion-proof electromagnetic drives. This includes the use of encapsulated electromagnets, such as those known from DE 29 26 549 A1 or DE 19843 519 A1. By casting or encasing the electromagnet with an insulating material, including the electrical con tacts and the associated switching elements, contact with flammable vapors or gases is prevented. In addition to the additional costs for the insulating material, the housing that surrounds the insulating material and the encapsulation of the electromagnet, this type of protection requires additional volume both for the insulating material and for the housing. The use of such electromagnets in a drive, as described in patent specification DE 10 2012 003 175 B4, for example, generally requires an adaptation of the geometric structure of the drive, in particular the size, and/or the use of smaller and therefore in usually also less powerful electromagnets.

The published application EP 1 138 994 A2 provides for the use of pressure-resistant housings or capsules, specifically in order to accommodate an electromagnetic drive or a positioner controlled by the drive. The mechanical movement of the actuator or the positioner must be guided out of the housing. However, this is usually only associated with friction losses and wear and has a negative effect on the accuracy and speed with which the actuating element can be moved. In addition, the mechanical passage through the housing restricts the freedom of movement of the actuating element.

In addition to positioners, electromagnetic drives are also used in IP converters, such as those described in DE 198 18 336 C1 or DE 102018 123 166 B3. In this case, the mechanical movement of the actuating element is used to open an outlet opening of a nozzle in a controlled manner. The nozzle is used to vent a chamber that is supplied with compressed air via a restrictor. The pressure in the chamber can be controlled or regulated by opening the nozzle or venting the chamber in a controlled manner. This pressure represents the working pressure of the IP converter. The working pressure is determined by the current fed into the coil body of the electromagnetic drive. An IP converter is therefore a current(I)-pressure(P) converter and has a current-pressure characteristic.

US Pat. No. 5,464,041 A describes a system with multiple valves, the valves being controlled electromagnetically by a single electrical winding in order to realize simultaneous actuation for each of the valves. The permanently magnetized Part of the magnetic circuit involved is used to lock both valves in the operating state in which they have been actuated.

US Pat. No. 5,450,871 A describes an electromagnetically actuated valve construction in which a single magnetic circuit magnetically connects multiple valve elements so that a single electrical excitation coupled to the single magnetic circuit can control multiple valves simultaneously.

The publication US 5,139,226 describes an electromagnetic fluid control valve with a valve body with an internal cavity and at least two openings through which a fluid can be selectively directed. The cross-sectional areas of the core, in which a magnetic flux can be generated, and of the movable magnet armature are selected in such a way that the flux lines are efficiently limited. The resulting high flux density serves to maximize the force exerted on the armature and minimize the mass of the armature, which in turn maximizes the speed of the armature.

A flameproof version of the three valve designs just described could also be achieved by casting or encasing the electromagnet, including the electrical contacts and the associated switching elements, with an insulating material. The published specification US Pat. No. 5,464,041 A mentions epoxy resin as an example. In addition to the additional costs for the insulating material and the encapsulation of the electromagnet, this type of protection requires additional volume for the insulating material.

task

The object of the invention is to safely and reliably actuate an actuating element using simple means with the aid of an electromagnet in an environment at risk of explosion or fire.

solution

This object is solved by the subject matter of the independent claims. Advantageous developments of the subject matter of the independent claims are characterized in the dependent claims. The wording of all claims is hereby made part of the content of this description by reference.

The use of the singular is not intended to exclude the plural, which also applies in reverse, unless otherwise disclosed. Individual method steps are described in more detail below. The steps do not necessarily have to be carried out in the order given, and the method to be described can also have further steps which are not mentioned.

To solve the problem, a device for actuating an actuating element in an environment that is at risk of explosion or fire is proposed. The device includes a first housing having a wall and an electromagnet, with the electromagnet being disposed within the first housing. A second housing is arranged on the wall outside of the first housing in which the electromagnet is located. The actuating element is arranged on the second housing. In addition, the device has at least one flux-conducting piece, with at least one of the flux-conducting pieces being arranged in such a way that it can be magnetized by a magnetic field inside the electromagnet. The at least one flux conducting piece, which can be magnetized by the magnetic field inside the electromagnet, is guided through the wall of the first housing and the second housing. The first housing and the passage of the flux guide piece through the wall of the first housing are designed to be flameproof. The part of the at least one flux guide piece that is routed through the wall of the first housing and the second housing is designed in one piece. The actuating element is arranged outside of the first housing and is designed in such a way that it can be actuated by means of the magnetic field that is conducted out of the first housing with the aid of the at least one flux-conducting piece.

Due to this structure, the electromagnet and any existing contact points for the energy supply of the electromagnet are in an ignition-proof space and thus the components of the device that absorb the highest electrical power or the highest current intensities and may generate sparks or heat up. The control element and any other mechanical, pneumatic and/or hydraulic components are located outside the flameproof room (e.g. a pneumatic or fluid control or switching unit, which is actuated by means of the control element or the magnetic field conducted from the first housing). This not only simplifies the installation and maintenance of these components, but also makes it possible to reduce the size of the first housing. In addition, there are no restrictions with regard to the voltages and/or currents that can be used to generate the magnetic field for an intrinsically safe design.

The at least one flux conducting piece optimizes and/or amplifies the force that can be exerted on the actuating element with the aid of the electromagnet through the first housing or the second housing. Disturbing influences such as, for example, due to friction in the guidance of the adjusting element or impacts on the adjusting element (for example due to pressure fluctuations in a compressed air supply that may be controlled by the adjusting element) can be better compensated for in this way. In addition, the actuating element can be positioned more precisely. It can also be accelerated and moved more quickly from one position to another. The actuating element can thus be actuated more reliably, more quickly and with greater accuracy, with the flameproof design of the first housing and the implementation of the flow guide piece ensuring safe operation of the device in the explosion or fire risk environment.

The actuating element can consist of a magnetizable or magnetically conductive material or only comprise one or more magnetizable parts. The magnetizable part or parts of the actuating element are preferably located as close as possible to the at least one flux conducting piece, in particular the part of the flux conducting piece that is led out of the first housing and is therefore in the area outside of the first housing, which - at least in preferred embodiments - is can be most strongly influenced by the electromagnet.

The passage of the at least one flux guide piece can be designed in such a way that the flux guide piece ends flush with the wall of the second housing to the outside. Alternatively, the flux guide piece can protrude beyond the wall of the second housing. In this case, it can be carried out, for example, using drill holes in the wall of the first housing and the second housing. The boreholes in the first housing must be made with a precise fit so that the wall or the first housing remains unaffected by ignition. The flux guide or a part of the flux guide can also be equipped with an adjusting device or a fine thread in order to be able to set or vary the distance between the flux guide and the actuating element.

The flux conducting piece can also only be guided into the wall of the first housing and/or into the second housing so far that the magnetic field generated by the electromagnet can exit or be led out of the first housing and/or the second housing without significant losses. In this way, continuous gaps can be avoided when the at least one flux guide piece is fed through, i.e. the guidance of the flux guide piece in the wall of the first housing and/or the second housing is closed to the outside.

The at least one flux guide piece or a part thereof can form the core of the electromagnet. It can be a straight cylindrical rod. It can also have a pole shoe. The pole piece can be either flattened or rounded. Its shape can be designed in such a way that it interacts with a corresponding shape of the actuating element. In this way, the transmission of the magnetic force of the electromagnet to the actuating element can be improved. The part of the at least one flux conducting piece that is routed through the wall of the first housing and the second housing is designed in one piece in order to avoid an interruption in the magnetic conductors and the associated To avoid losses in the transmission of the magnetic force of the electromagnet on the actuator.

The actuating element can consist of a magnetically conductive material. The adjusting element and the at least one flux conducting piece can be arranged in such a way that the adjusting element can close the magnetic circuit, which is formed by the at least one flux conducting piece and the adjusting element, at least in one position. The closing of the magnetic circuit can be complete, i.e. the control element is in contact with both flux guide pieces at the same time or touches them. The greatest force can usually be exerted on the actuating element in or near this position. In many cases, however, it can be advantageous if the control element does not completely close the magnetic circuit, but instead a gap remains between the control element and at least one of the flux conducting pieces, specifically in every intended position of the control element. In this way, non-linear effects, which are often associated with a complete closure of the magnetic circuit, can be avoided. The control of the actuating element can thus take place in every position with the same or at least a similar or comparable accuracy. As a result, the entire stroke range is available for precise actuation of the control element.

The first housing with the flux conducting piece running through it forms a flameproof room. It can be designed to be pressure-resistant or meet DIN standard 60079-1. Wei direct measures to secure the device can thus often be omitted. This applies in particular to measures that prevent explosive vapors and/or flammable mixtures of substances from penetrating into the first housing. Finally, the flameproof design not only ensures that a spark occurring inside the first housing does not spread beyond the first housing and the passage of the flux conducting piece, but also that a flame or explosion occurring inside the first housing remains trapped. The wall thickness to be selected for the first housing or the wall of the first housing depends on the material used, the volume enclosed by the first housing and the type of flammable or explosive substances. Typical wall thicknesses range from 9 to 12 mm (see DIN standard EN 60079-1).

The first housing and/or the wall of the first housing and/or the second housing can be made of a magnetically non-conductive material, in particular a paramagnetic or diamagnetic material such as aluminum, brass, copper, a magnetically non-conductive material, e.g Austenitic stainless steel or a magnetically non-conductive plastic such as polyethylene or acrylic glass. In this way, it is possible to prevent the magnetic field of the electromagnet, in particular the part that is to be guided through the flux conducting piece from the first housing or the second housing, through the first housing and/or the wall of the first housing and/or the second housing is deflected, weakened or shielded.

The at least one flow guide piece guided through the first housing and the second housing can be secured against slipping out of the first housing and/or the second housing. This can be achieved by anchoring the flux guide. For this purpose, the flux guide piece can also have a conically shaped area with a correspondingly shaped recess in the wall of the first housing or the second housing. It may alternatively have a projection or step which engages the wall of the first housing or the second housing when a force acts on the flux guide which would push it out of the first housing or the second housing respectively. Likewise, helical configurations of the flux guide (with corresponding counter-windings in the wall of the first housing or of the second housing) or abutments can be provided.

The actuating element can be mounted such that it can tilt or rotate and/or can be held in a position above the at least one flux guide piece guided through the first housing and the second housing with the aid of springs. However, the flux guide piece can also be designed in such a way that it protrudes from the second housing and is used to mount the actuating element. In this way it can be ensured that the actuating element closes the magnetic circuit in at least one position either completely or except for a (residual) gap. The storage can be configured differently. For a tiltable control element that rests on the flux guide, it is typically sufficient if the flux guide projects 0.5 to 1 mm out of the second housing, in order to achieve a movement of a typical control element of 1 to 2° or a stroke of approx. 50 to allow until 60 pm.

The device or the flux guide can also be equipped with means (e.g. a (fine) thread for axial adjustment) with which it is possible to set how far the flux guide protrudes from the wall of the first housing or the second housing. In this way, the distance between the actuating element and the flow guide piece can be optimally set or readjusted.

The actuating element can have a window-shaped cutout which is designed in such a way that it only rests at two points on the flux guide piece, which is used to mount the actuating element. If the flux guide piece has a circular cross-section of the support surface at the upper end, this can be achieved, for example, by a rectangular or stadium-shaped cutout, and vice versa. In this way, complex and/or expensive components for the articulated mounting of the actuating element can be avoided. The device can have guide pins for fixing the actuating element at the two previously mentioned support points on the flux guide piece. For this purpose, the actuating element can have incisions or openings corresponding to the guide pins, for example a circular hole and a slot for guiding cylindrical guide pins. The fixation can be done by nuts that are screwed onto the guide pins, or include other elements such as a cap. Likewise, the actuating element can be fixed by a spring which depresses the actuating element. Advantageous developments also have a counterweight for balancing the actuating element mounted on the flux guide piece.

In the first housing of the proposed device are all the electrical com ponents, switches and controls and contacts that rule with the flammable mixtures of explosive or explosive environment can come into contact. Accordingly, these components, elements and contacts do not have to be designed to be intrinsically safe (e.g. in the sense of standard 60079-11). This does not apply to feed lines for control signals or the supply of electrical energy. They can usually be made intrinsically safe or explosion-proof with little effort and routed through the first housing in a flameproof manner.

In preferred embodiments, the device includes a controller for the Elek romagneten, which is also located in the first housing. For a self-sufficient energy supply of the device, a battery can also be provided in the first housing, so that the device can be operated reliably even in the event of a malfunction. If the controller is designed in such a way that it can be addressed wirelessly (e.g. via a WLAN, radio and/or Bluetooth interface), it is possible in many cases to dispense with feeding lines through the first housing. This also applies to a wireless power supply for the control unit and/or the battery, e.g. via an interface that can be inductively coupled to external power supply units.

Outside of the first housing is the control element and possibly other mechanical elements of the device niche. In further expansion stages, the device can have an outlet opening for a fluid, the actuating element being designed and arranged such that the flow of a fluid through the outlet opening can be controlled or regulated by actuating the actuating element. The actuating element can be a baffle plate in the region of the outlet opening, which can be pressed onto the outlet opening to close it with the aid of the electromagnet. The baffle plate can be lifted to open. In addition to opening and closing, the flow of fluid through the outlet opening can also be regulated in this way, with the help of the coil body of the device introduced electrical power.

The outlet opening can be the outlet opening of a nozzle. The nozzle can be equipped with a fine thread for setting and readjusting the distance between the nozzle and the actuating element of the device, in particular the baffle plate. Among other things, this allows the tightness to be adjusted when the baffle plate is closed.

The proposed device can include a further flow guide. The further flux conducting piece is guided through the wall of the first housing and the second housing, with the part of the further flux conducting piece that is guided through the wall of the first housing and the second housing being made in one piece and the passage of the further flux conducting piece through the wall of the first housing being designed to be flameproof . The further flux conducting piece is also connected in the first housing to the at least one flux conducting piece, which can be magnetized by the magnetic field inside the electromagnet. In this way, together with the actuating element, a magnetic circuit can be constructed which has fewer interruptions, in particular fewer parasitic air gaps, or in which the number of interruptions in the circuit is reduced.

For the same purpose, only a single, one-piece flow guide piece can be arranged in the first housing. This is typically U-shaped and is guided with the two free ends of the U, ie twice, through the wall of the first housing and the second housing. In this case, the parts of the at least one flux conducting piece that are routed through the wall of the first housing and the second housing are designed in one piece and the two passages of the flux conducting piece through the wall of the first housing are designed to be flammable. Due to the one-piece design, there are even fewer parasitic and thus potentially disruptive air gaps.

The device can be part of a solenoid valve, e.g. a 2/2-way valve, an IP converter, a positioner, a control valve or a system. It can be designed both as an integral and as a modular component. The first housing or the second housing can accommodate further contacts and control elements of the solenoid valve, IP converter, position controller, control valve or the system and enclose them in a flameproof manner. Additional or further measures to protect the further contacts and control elements can thus be dispensed with.

The object is also achieved by a method for actuating an actuating element in an environment where there is a risk of explosion or fire, the method comprising the following steps: 1. A device according to the invention for actuating an actuating element in an environment at risk of explosion or fire is provided;

2. a manipulated variable is specified;

3. The electrical power fed into the electromagnet is adjusted in such a way that the actuating element moves into a position corresponding to the specified manipulated variable.

The specified control variable can be an open/close position, i.e. the control element is only moved back and forth between two positions in the application, e.g. to open or close an outlet opening. The manipulated variable can also be a position of the control element between an open and a closed position, e.g. to regulate the flow through an outlet opening. The predetermined position can be reached by a lifting, rocking and/or rotating movement of the actuating element. Depending on the application, the manipulated variable can also be a position of a valve member, a pressure, a temperature and/or a flow rate.

As a rule, there is a clear connection between the electrical power that is fed into the electromagnet and the manipulated variable or the position that the actuating element assumes with this power, at least after a transient phase and/or as long as the actuating element is not subjected to any other forces and/or or is exposed to disturbances that force the actuator out of its equilibrium position. The relationship can be measured, for example, during the installation or initialization of the device and stored for the purposes of the method, for example in a control unit of the device. It can also be preset and/or the result of simulations and/or an automated calibration. The latter can be performed at installation and/or maintenance, and/or periodically to account for wear and changing environmental conditions that may affect the context.

Depending on the application, the electromagnet of a device according to the invention can be operated with direct current. In many cases, operation with direct current leads to non-linear force-displacement or force-stroke characteristics. This can be used to adapt the precision with which the actuating element can be positioned to the application, e.g. to be able to control or regulate the actuating element close to a closed position with greater precision than in other positions in which precise positioning of the Control element is less critical. Changing the operating mode, e.g. from operation with direct current to operation with alternating current, is also conceivable. As a result, the various force-displacement characteristics resulting from the two operating modes can be combined as required.

A method according to the invention for actuating an actuating element of an inventive This device can be used to control or regulate an IP converter, a solenoid valve, a positioner, a control valve and/or a system. Due to the flameproof design of the device, the control or regulation can take place in areas where there is a risk of explosion or fire.

Further details and features result from the following description of a preferred exemplary embodiment in conjunction with the figures. The respective features can be implemented individually or in combination with one another. The ways to solve the problem are not limited to the embodiment.

The embodiment is shown schematically in the figures. The same reference numerals in the individual figures designate elements that are the same or have the same function, or elements that correspond to one another in terms of their functions. In detail shows:

1 shows a device according to the invention for actuating an actuating element;

FIG. 2 shows a cover of the device from FIG. 1; FIG.

FIG. 3 shows a detail of the device from FIG. 1; FIG.

FIG. 4 shows a further view of the detail of the device from FIG. 1 ;

FIG. 5 shows a flow chart of a method for actuating an actuating element; FIG.

6 shows a further embodiment of a device according to the invention for actuating an actuating element;

7 shows a detail of an alternative embodiment of a device according to the invention for actuating an actuating element; and

8 shows a detail of a further alternative embodiment of one according to the invention

Device for operating an actuator.

1 shows a device 100 according to the invention for actuating an actuating element 110 in an IP converter. The device 100 comprises a first housing 120 with a wall 125. The wall 125 forms a cover of the first housing 120 which can be removed for installation or maintenance of the device 100. FIG. Accordingly, there are connecting gaps 127 between the wall 125 and the remaining part of the first housing 120. The first housing 120, the wall 125 and the connecting gaps 127 are designed to be flameproof.

Inside the first housing 120 is an electromagnet 130. The electromagnet 130 is connected via a connecting line 140 to a controller 150. The control 150 supplies the electromagnet 130 via the connecting line 140 with electrical Energy. The control unit 150 can control the electromagnet 130, in particular the strength of the magnetic field generated by the electromagnet 130, via the electrical power introduced into the electromagnet 130 in this way. The electrical energy required for this is provided via a supply line (not shown). The supply line is routed through the first housing 120 in a flameproof manner. In a similar way, commands or sensor data are transmitted to the control unit 150 via a data line (not shown), which is also passed through the first housing 120 in a flameproof manner.

The electromagnet 130 has a core 162 which is formed by a flux guide piece 160 . The flux conducting piece 160 has a pole shoe 161 . The pole shoe 161 is guided through the wall 125 in an impact-proof manner. The device 100 has a further flux-conducting piece 165 with a further pole shoe 166 and a magnetically conductive connecting piece 167 . The further flux conducting piece 165 is arranged parallel to the flux conducting piece 160 next to the electromagnet 130 . Its pole shoe 166 is also guided through the wall 125 in a flameproof manner. The magnetically conductive connector 167 is either lightly pressed onto the flux guides 160 and 165 (as shown) or connected to the flux guides 160 and 165 by means of locking devices. In addition, the flux guide pieces 160 and 165 have adjusting devices 163 and 168 . The adjusting devices 163 and 168 can be used to set how far the pole shoe 161 of the flux-conducting piece 160 and/or the pole shoe 166 of the flux-conducting piece 165 protrude from the first housing 120 or the wall 125.

The actuating element 110 is mounted on the pole shoe 161 like a rocker. It does not lie centrally on the pole shoe 161 but at a point that is close to one end of the actuating element 110 . A counterweight 170 is used to balance this asymmetrical position. The bearing is carried out with the aid of a spring, the spring being fixed to a cap 180 by means of a bolt 182 . The spring presses the counterweight 170 against the actuating element 110 and the actuating element 110 against the point at which the actuating element 110 rests on the pole shoe 161 . The cap 180 with the bolt 182 also has a set screw 185 . The adjusting screw 185 limits the freedom of movement of the adjusting element 110, wherein the range of motion can be varied using the adjusting screw 185 as required.

The actuating element 110 can be pressed onto an outlet opening 195 of a nozzle 190 with the aid of the electromagnet 130 . In this case, the outlet opening 195 of the nozzle 190 can be completely covered by the actuating element 110 .

The nozzle 190 has a chamber 197 . The chamber 197 is formed by a second housing 198 Ge. The second housing 198 is on the wall 125 of the device 100 is introduced. The nozzle 190 and the second housing 198 can be considered part of the device 100 in this embodiment. In other embodiments, however, they can also be formed as part of the IP converter in which the device 100 is used. The pole shoe 161 of the flux conducting piece 160 is used to mount the actuator 110 like a rocker. The other pole piece 166 closes flat with the second housing 198 Ge. In this way it can be ensured that there is an air gap between the actuating element 110 and the further pole shoe 166 in every position of the actuating element 110 . However, the size of the air gap can be varied using the adjustment device 168 .

Due to the structure of the device 100, the electrical coil or the electromagnet 130 and its control 150 are located in a completely flameproof encapsulated space, i.e. precisely the components that require the highest electrical power within the system or the environment at risk of explosion or fire , record and/or distribute via contact points are located in the completely flameproof encapsulated room. The mechanical or pneumatic components, in particular the actuating element 110 and the nozzle 190, are located outside of the flameproof encapsulated space. This not only facilitates the installation and maintenance of these components, but also enables the size of the first housing 120 to be reduced.

The flux conducting piece 160, the further flux conducting piece 165 and the magnetically conductive connecting piece 167 can be magnetized using the electromagnet 130. The magnetization is proportional to the current applied to the electromagnet 130 . The magnetization is transmitted to the actuating element 110 by the pole shoe 161 . The actuating element 110, the flux conducting piece 160, the further flux conducting piece 165 and the magnetically conductive connecting piece 167 form a magnetic circuit which is only interrupted by an air gap between the further pole shoe 166 and the actuating element 110. The force that the electromagnet 130 can exert on the actuating element 110 depends on the size of the air gap and is greatest when the distance between the actuating element 110 and the further pole shoe 166 is at its smallest. The air gap is dimensioned in such a way that the covering of the outlet opening 195 by the actuating element 110 can be controlled or regulated in any position with almost the same accuracy and with only slight delays or switching times.

In this embodiment, the flux conducting piece 160 is formed by the core 162 of the electromagnet 130 and by the pole piece 161 . In other embodiments, the core of the electromagnet 130 can also be formed by the additional flux conducting piece 165 . In principle, the position of the electromagnet 130 plays no role in the case of magnetically ideally conducting flux guide pieces.

Fig. 2 shows a view of a cover 200 of the device 100. The cover 200 includes the actuating element 110, the wall 125, the electromagnet 130 and the nozzle 190. The view 12 illustrates that the lid 200 can be lifted or pulled out of the first housing 120 as a whole. The view also shows that the adjusting element 110 covers the nozzle 190 according to the baffle plate principle. For this purpose, the adjusting element 110 is designed as a baffle plate at the end that is located above the nozzle 190 .

In operation, the actuator 110 is controlled by the current through the electromagnet 130 and the force exerted by the electromagnet 130 on the actuator 110 magnetic force. You can completely close the outlet opening 195 of the nozzle 190 (closed position). When the electromagnet 130 is switched off, i.e. when no current is flowing through the electromagnet 130 and the flux conducting piece is not magnetized, and provided that the chamber 197 is supplied with compressed air, the actuating element 110 is activated by the dynamic pressure exerted by the compressed air between the outlet opening 195 and the actuating element 110 raised to the position which is determined by the position of the adjusting screw 185 (open position). However, the actuating element 110 can also assume any position in between.

Fig. 3 shows a detail 300 of the lid 200 or the device 100, wherein the counterweight 170 and the cap 180 have been removed to allow a plan view of the storage of the Stel lelements 110, in particular on a rectangular provided for this purpose window-shaped cutout 305. Detail 300 includes a section 310 of pole shoe 161 and a section 320 of pole shoe 166. Sections 310 and 320 are those parts of pole shoes 161 and 166 that are guided through wall 125 in device 100. Both sections taper gradually. The actuating element 110 can be mounted on the pole shoe 161 at two points with the aid of the cylindrical section 310 projecting beyond the cover 125 and the rectangular window-shaped cutout 305 . Two guide pins 370 are provided for fixing the actuating element 110 at the two points. The guide pins 370 can be guided through a circular hole 350 and a slot 360 in the actuating element 110 . The guide pins 370 and the window-shaped cutout 305 are arranged in such a way that the actuating element 110 is mounted on the pole shoe 161 in the manner of a seesaw or rotatably about the axis formed by the support points.

The sections 310 and 320 also have steps 330 . The steps 330 are formed through the use of different radii in the cylindrical design of sections 310 and 320 . The passage of the pole shoes 161 and 166 through the wall 125 of the first housing 120 takes place with the aid of two boreholes, which are also designed with different radii, so that the steps 330 can engage in corresponding steps of the boreholes. In this way, the pole shoes 161 and 166 are secured against slipping out of the first housing 120 .

Figure 4 shows another view of detail 300. The view illustrates the situation of the circular hole 350 and the elongated hole 360 with respect to the support points of the actuating element 110 on the pole shoe 161. In this view, the centers of the guide pins (370) lie on an axis formed by the support points. The positioning element 110 is thus fixed via a linear support and thus allows tilting like a seesaw.

The circular hole 350 and the slot 360 are slightly larger in diameter or slot width than the outer diameter of the guide pins 370. This prevents rubbing or jamming and ensures the necessary freedom of movement for tilting the adjusting element 110.

FIG. 5 shows a flow chart of a method 500 for actuating an actuating element 110 by means of the device 100. In a first step 510, the IP converter with the device 100 is provided. In step 520, a (working) pressure is specified, and thus also a specific position of actuating element 110. In step 530, controller 150 of device 100 then controls the current through electromagnet 130 in order to generate a magnetic field that Actuating element 110 is moved into the position determined by the predetermined pressure, so that the predetermined pressure in chamber 197 is established.

In this exemplary embodiment, the position determined in step 520 by the specified pressure is a position between the closed and the open position of the actuating element 110, including the closed or open position. The magnetic field generated by the electromagnet 130 exerts a force on the actuating element 110 in step 530, which moves the actuating element into the position determined by the predetermined pressure or, if the actuating element 110 is already in this position, holds it there. The actuating element 110 is caused to perform a tilting movement about the axis defined by the two support points if the actuating element 110 is not already in the predetermined position or position.

The current strength required to reach or hold the position of the actuating element 110 can be determined by the controller 150 using a current-pressure characteristic curve that was measured before the IP converter or the device 100 was provided and stored in a memory unit of the controller 150 . However, it is often operated in a control mode in which it changes the current strength based on a feedback signal until the desired pressure is reached.

FIG. 6 shows a device 600 according to the invention, which is constructed very similarly to the device 100 . The device 600 has a wall 625 . The wall 625 represents a one-piece design of the wall 125 and the second housing 198 of the device 100. Additional steps for assembling the second housing 198 can thus be omitted. In addition, the 625 wall can withstand greater loads than the 125 wall. This also applies if the second housing 198 is fixed to the wall 125, and in particular for the connection of the second housing 198 to the wall 125.

FIG. 7 shows a detail 700 of an alternative embodiment of a device according to the invention for actuating an actuating element. The detail 700 includes a wall 725. A flux conducting piece 760 with a pole shoe 761 and a flux conducting piece 765 with a pole shoe 766 are guided through the wall 725 in a flameproof manner. In contrast to the flux guides 160 and 165, the flux guide pieces 760 and 765 are not connected via a magnetically conductive connection piece 167, but directly to one another. In this way, the number of parasitic air gaps between the magnetically conductive components of the device can be reduced.

Fig. 8 shows a detail 800 of a further alternative embodiment of a device according to the invention for operating an actuator. The detail 800 also includes a wall 825. A flux guide piece 860 with a pole shoe 861 and a pole shoe 866 is guided through the wall 825 in a flameproof manner. The pole shoes 861 and 866 are directly connected to one another by the one-piece, U-shaped design of the flux guide piece 860, i.e. there are no parasitic air gaps between the pole shoes 861 and 866.

glossary

Flameproof / flameproof enclosure

Pressure-resistant or pressure-resistant encapsulation refers to the design of devices according to a type of protection whose function is based on the containment of an explosion that may occur inside the housing. This is achieved through an explosion-proof design of the housing together with flameproof gaps at all housing openings, e.g. at the shaft bushing in a motor. Furthermore, the surface temperature must be limited below the ignition temperature of the surrounding potentially explosive atmosphere even if an expected fault occurs. The requirements of this type of protection are described in the standard EN 60079-1.

electromagnet

An electromagnet is a magnet that contains a coil in which a magnetic field can form as a result of an electrical current. In many cases, electromagnets have a core that guides and strengthens the magnetic field created by the current flow. The core is usually formed by a flux guide. Electromagnets are used as actuating magnets in tension, folding or plunger armatures, in relays or fuses. Other applications relate to electric motors, separators or Helmholtz coils.

explosion

An explosion is a process of rapid outward expansion in volume combined with the release of large amounts of energy, usually generating high temperatures and releasing pressure and kinetic energy. Supersonic explosions produced by high explosives are called detonations and occur via shock waves. Subsonic explosions are created from low explosives by a slower combustion process called deflagration.

flow guide

A flux guide is a component made of a soft magnetic material which, as a result of this property, concentrates (increases) or (further) conducts a magnetic flux of a magnetic field acting on the flux guide. Flux guides are used, for example, in electromagnets, electric motors or generators. Flux guides can be rod-, cylinder- or horseshoe-shaped. IP converter

An IP converter is an electric-pneumatic converter. IP converters have an electromagnet, a magnetic yoke and a tiltable or longitudinally movable adjusting element. An outlet nozzle can be closed and released again by the actuating element, this taking place as a function of the pneumatic force repelling the actuating element and the magnetic force attracting the actuating element. IP converters are supplied with compressed air with a pre-pressure Pv. The outlet air pressure Pa is set by opening or closing the outlet nozzle.

pole shoe

A pole shoe is a component made of a soft magnetic material that is used to allow the magnetic field lines of a permanent or electromagnet or a flux guide to emerge and distribute them in a defined form.

actuator

An actuator is an element that is used to actuate and release mechanical, pneumatic, hydraulic or electrical devices, e.g. to open or close an outlet opening or to switch fuses or relays.

Soft magnetic

Soft magnetic materials are materials with high permeability that can be magnetized and demagnetized easily. They amplify magnetic fields by their permeability and are characterized by low coercive and/or remanent field strengths. The soft magnetic materials include the so-called soft iron, electrical or dynamo sheets and steels with a low carbon content or added silicon (FeSi), iron alloys such as FeNi, FeCo, FeAl or FeAlSi and ferrites. flameproof implementation

A flameproof feedthrough is a feedthrough of a component through a housing in which gaps and openings between the component passed through and the housing are designed or constructed in such a way that sparks or flames are prevented or not possible from spreading through the gaps or openings is. Ignition safety can be achieved by casting or plugging the gaps or openings with an insulating material that prevents the spread of sparks or flames through the gaps or openings. It can also be made by reducing the gaps and openings to a level that allows penetration of a spark or flame prevent or in which a spark and/or a flame penetrating into the gap or opening is extinguished due to the geometric dimensions and/or shape. type of protection

A type of protection designates design principles in the field of explosion protection. The basic idea behind every type of protection is to minimize the risk of the simultaneous presence of an explosive atmosphere and ignition sources.

Reference sign device control element first housing wall connecting gap electromagnet connecting line control flux conducting piece pole shoe core adjusting device further flux conducting piece further pole shoe magnetically conductive connecting piece adjusting device counterweight cap bolt adjusting screw nozzle outlet opening chamber second housing cover detail window-shaped cutout section section step circular hole long hole guide pin Method providing a device 100 specifying a position of the actuating element 110 adjusting the position of the actuating element 110 method wall detail wall flux guide pole shoe flux guide pole shoe detail of wall flux guide pole shoe pole shoe

literature cited patent literature cited

DE 2926549 A1 DE 19843519 A1 DE 102012 003 175 B4 EP 1 138994 A2 DE 198 18336 C1 DE 102018 123 166 B3 US 5,464,041 A US 5,450,871 A US 5,139,226 A

DIN standard EN 60079-0 DIN standard EN 60079-1 DIN standard EN 60079-11 DIN standard EN 60079-18

Claims

patent claims

1. Device (100) for actuating an actuating element (110) in an explosive or fire-hazardous environment, the device (100) having the following components:

1.1 a first housing (120) with a wall (125; 725; 825);

1.2 an electromagnet (130),

1.2.1 wherein the electromagnet (130) is disposed within the first housing (120);

1.3 a second housing (198);

1.3.1 the second housing (198) being arranged outside of the first housing (120) and the adjusting element (110) being arranged on the second housing (198);

1.4 at least one soft magnetic flux guide piece (160, 165; 760, 765; 860);

1.4.1 wherein at least one of the flux guide pieces (160, 165; 760, 765; 860) is arranged in such a way that it can be magnetized by a magnetic field inside the electromagnet (130);

1.4.2 wherein the at least one flux guide piece (160, 165; 760, 765; 860), which can be magnetized by the magnetic field inside the electromagnet (130), through the wall (125; 725; 825) of the first housing ( 120) and passed through the second housing (198);

1.4.3 wherein the part of the at least one flux guide piece (160, 165; 760, 765; 860) that is guided through the wall (125; 725; 825) of the first housing (120) and through the second housing (198) is made in one piece;

1.4.4 wherein the first housing (120) and the passage of the flux guide (160, 165; 760, 765; 860) through the wall (125; 725; 825) of the first housing (120) are designed to be flameproof;

1.5 the actuating element (110),

1.5.1 wherein the actuating element (110) is designed in such a way that it can be actuated by means of the magnetic field that is conducted out of the first housing (120) with the aid of the at least one flux conducting piece (160, 165; 760, 765; 860). .

2. Device (100) according to the preceding claim, characterized in that the wall (125; 725; 825) and the second housing (198) are made in one piece.

3. Device (100) according to any one of the preceding claims, characterized in that that the first housing (120) is a pressure-resistant housing (120).

4. Device (100) according to any one of the preceding claims, characterized in that the first housing (120) and / or the wall (125; 725; 825) of the first housing (120) and / or the second housing (198). are made of a paramagnetic or diamagnetic material.

5. Device (100) according to one of the preceding claims, characterized in that the at least one through the wall of the first housing (120) and through the second housing (198) guided flux guide (160, 165; 760, 765; 860) against slipping out of the first housing (120) and/or the second housing (198) is secured.

6. Device (100) according to one of the preceding claims, characterized in that the at least one through the first housing (120) and the second housing (198) guided flux guide (160; 760; 860) to the outside of the second housing (198) protrudes and serves to support the actuating element (110).

7. Device (100) according to the preceding claim, characterized in that

7.1 that the actuating element (110) has a window-shaped cutout (305); and

7.2 that the window-shaped cutout (305) on the flux guide piece used for storage

(160; 760; 860) rests at only two points.

8. Device (100) according to the preceding claim, characterized in that

8.1 that the device (100) has guide pins (370) for the actuating element (110);

8.2 wherein the adjusting element (110) can be fixed to the two support points on the flow guide piece (160; 760; 860) with the aid of the guide pins (370).

9. Device (100) according to any one of the preceding claims, characterized in that

9.1 that the device (100) has a controller (150) for the electromagnet (130); and 9.2 that the controller (150) is located in the first housing (120).

10. Device (100) according to any one of the preceding claims, characterized in that

10.1 that the device (100) has an outlet opening (195) for a fluid; and

10.2 that the actuating element (110) is designed and arranged such that the flow of a fluid through the outlet opening (195) can be controlled or regulated by actuating the actuating element (110).

11. Device (100) according to any one of the preceding claims, characterized in that

11.1 that the device comprises a further flow guide piece (165; 765);

11.2 the further flow guide piece (165; 765) being guided through the wall (125; 725; 825) of the first housing (120) and the second housing (198);

11.3 wherein the through the wall (125; 725; 825) of the housing (120) and the second housing

(198) guided part of the further flux guide piece (165; 765) is made in one piece;

11.4, the passage of the further flow guide piece (165; 765) through the wall (125; 725;

825) of the first housing (120) is designed to be flameproof;

11.5 wherein the further flux guide in the first housing (120) with the at least one

Flux guide (160, 760, 860) is connected, which can be magnetized by the magnetic field inside the electromagnet (130).

12. Device (100) according to any one of the preceding claims, characterized in that

12.1 that only a single, one-piece flux guide piece (860) is arranged in the first housing (120);

12.2 that the flow guide piece (860) is guided twice through the wall (825) of the first housing (120) and the second housing (198);

12.3, the two passages of the flux guide piece (860) through the wall (825) of the first housing (120) being designed to be flameproof.

13. IP converter with a device (100) according to any one of the preceding claims.

14. Solenoid valve with a device (100) according to any one of the preceding claims.

15 position controller with a device (100) according to any one of the preceding claims. 16 control valve with a device (100) according to any one of the preceding claims.

17. Plant with a device (100) according to any one of the preceding claims.

18. Method (500) for actuating an actuating element (110) in an explosive or fire-hazardous environment, the method comprising the following steps:

18.1 a device (100) according to one of the preceding claims 1 to 12 is provided (510);

18.2 a manipulated variable is specified (520);

18.3 the electrical power fed into the electromagnet (130) is adjusted (530) in such a way that the actuating element (110) moves into a position corresponding to the specified manipulated variable or remains in this position so that the specified manipulated variable is reached or remains unchanged remains.

19. The method (500) according to the preceding claim, wherein the actuating element (110) for

Control and / or regulation of an IP converter, a solenoid valve, a position controller, a control valve and / or a system is used.