Automation field device

Abstract

The invention relates to an automation field device (1) comprising: - a sensor (MA), the sensor (MA) having a sensor housing (MAG) with a sensor housing opening (15) for routing electric connectors (EV), the sensor housing (MAG) having a sensor housing interior (2) in which at least one sensor unit (SE) is arranged; - a measuring transducer (MU), the measuring transducer (MU) comprising a measuring transducer housing (MUG) with a measuring transducer housing opening (3) for routing the electric connectors (EV), the measuring transducer housing (MUG) having a measuring transducer housing interior (4) in which measuring electronics (ME) are arranged, the measuring transducer housing (MUG) being mechanically coupled to the sensor housing (MAG); - a separating body (5) for separating the measuring transducer housing interior (4) from the sensor housing interior (2), the separating body (5) having at least one guide (6) for the electric connectors (EV), and the separating body (5) being air-permeable.

Description

[0001] Field device in automation technology

[0002] The invention relates to a field device in automation technology and a product family of field devices in automation technology.

[0003] In automation technology, particularly in process automation technology, field devices are often used to record and / or influence process variables. Sensors integrated into, for example, level measuring devices, flow meters, pressure and temperature measuring devices, pH-redox potential measuring devices, conductivity measuring devices, etc., are used to record process variables. These sensors record the corresponding process variables: level, flow, pressure, temperature, pH value, or conductivity. Actuators such as valves or pumps are used to influence process variables; they can be used to change the flow of a liquid in a pipe section or the fill level in a container. Field devices are essentially all devices that are used close to the process and that supply or process process-relevant information.In the context of the invention, field devices also include remote I / Os, radio adapters or generally electronic measuring components that are arranged at the field level.

[0004] A field device is in particular selected from a group consisting of flow measuring devices, level measuring devices, pressure measuring devices, temperature measuring devices, point level measuring devices and / or analytical measuring devices.

[0005] Flow meters include, in particular, Coriolis, ultrasonic, vortex, thermal and / or magnetic-inductive flow meters.

[0006] Level measuring devices include, in particular, radar-based level measuring devices, microwave level measuring devices, ultrasonic level measuring devices, time-domain reflectometric level measuring devices, radiometric level measuring devices, capacitive level measuring devices, inductive level measuring devices and / or temperature-sensitive level measuring devices.

[0007] Pressure measuring instruments are in particular absolute, relative or differential pressure devices.

[0008] Temperature measuring devices are in particular measuring devices with thermocouples and / or temperature-dependent resistors.

[0009] Point level measuring devices include, in particular, vibronic point level measuring devices, ultrasonic point level measuring devices and / or capacitive point level measuring devices.

[0010] Analytical measuring devices include, in particular, pH sensors, conductivity sensors, oxygen and active oxygen sensors, (spectro)photometric sensors, and / or ion-selective electrodes. These field devices typically comprise a sensor and a transmitter, which is directly or indirectly connected to the sensor. The electrical connection between the sensor unit of the sensor and the measuring electronics of the transmitter is established via electrical connectors. Typically, a connector is located in a transmitter or sensor housing opening for easier installation. Such connectors are customized for each field device and therefore costly.

[0011] The invention is based on the object of remedying the problem.

[0012] The problem is solved by the field device according to claim 1.

[0013] The field device of automation technology according to the invention comprises:

[0014] - a measuring sensor, wherein the measuring sensor has a measuring sensor housing with a measuring sensor housing opening for the passage of electrical connectors, wherein the measuring sensor housing has a measuring sensor housing interior in which at least one sensor unit is arranged;

[0015] - a measuring transducer, wherein the measuring transducer comprises a measuring transducer housing with a measuring transducer housing opening for passing through the electrical connectors, wherein the measuring transducer housing has a measuring transducer housing interior in which a measuring electronics is arranged, wherein the measuring transducer housing is mechanically coupled to the sensor housing,

[0016] - a separating body for separating the interior of the measuring transducer housing from the interior of the measuring sensor housing, wherein the separating body has at least one guide for the electrical connectors, wherein the separating body is designed to be permeable to air.

[0017] Advantageous embodiments of the invention are the subject of the subclaims.

[0018] One embodiment provides that the separating body has a cellular structure which is made of a plastic or a rubber.

[0019] One embodiment provides that the separating body has a pressure between 0.011 and 0.11 N / mm 2 , especially between 0.028 and 0.042 N / mm 2 One embodiment provides that the separating body is designed to create a pressure equalization between the interior of the sensor housing and the interior of the transmitter housing.

[0020] One embodiment provides that the field device has an overpressure device.

[0021] One embodiment provides that the interior of the sensor housing is cast with a, in particular expanding, casting compound, and / or wherein the interior of the transmitter housing is cast with a, in particular non-expanding, casting compound.

[0022] One embodiment provides that the guide is designed as a slot.

[0023] One embodiment provides that the guide has a first separating body slot through which two signal cables are guided, wherein the guide has a second separating body slot through which two sensor cables are guided, wherein the first separating body slot is separated from the second separating body slot.

[0024] One embodiment provides that the separating body is held in position by a retaining plate.

[0025] One embodiment provides that the retaining plate has two retaining plate slots, wherein the retaining plate covers the first and / or second separating body slot at least in sections.

[0026] One embodiment provides that an adapter with an adapter housing and an adapter housing opening is arranged between the measuring sensor and the measuring transmitter, wherein the separating body is arranged in the adapter housing opening.

[0027] The invention is explained in more detail with reference to the following figures. They show:

[0028] Fig. 1 : a sectional view through a field device according to the prior art;

[0029] Fig. 2: a partial view of a cross section of an embodiment of a field device according to the invention;

[0030] Fig. 3: a view of a separator, retaining plate and electrical connectors;

[0031] Fig. 4: a view of a separating body, retaining plate, and electrical connectors; and Fig. 5: a partial cross-sectional view of an embodiment of a field device according to the invention;

[0032] Some embodiments of the present disclosure are described in more detail below with reference to the accompanying figures. The figures illustrate some, but not all, embodiments of the disclosure. Indeed, these disclosures may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Different embodiments, each illustrating individual details of the inventive subject matter, may be combined with one another to form new embodiments not shown in the figures. Like numbers refer to like elements throughout.

[0033] The components illustrated in the figures represent components that may or may not be present in various embodiments of the present disclosure described herein, so that the embodiments may include fewer or more components than those illustrated in the figures without departing from the scope of the present disclosure. Some components may be omitted or shown in phantom in one or more figures to reveal underlying components.

[0034] The phrases "in an exemplary embodiment," "some embodiments," "various embodiments," and the like generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure and may be included in more than one embodiment of the present disclosure. Such phrases do not necessarily refer to the same embodiment.

[0035] The word "example" or "exemplary" is used herein to mean "serving as an example or illustration." Any implementation described herein as "exemplary" is not necessarily to be understood as preferred or advantageous over other implementations.

[0036] If the description of the figures states that a component, part, or feature is "preferably," "possibly," "typically," "optionally," or "for example" (or another such formulation) included, or that a feature "may" be included, or that a feature "could" or "should" have a property, it is not necessary that a specific component or feature be included or have the feature. Such components or features may be optionally included in some embodiments, but they may also be excluded. An embodiment not included in the figures may also contain all features—provided they do not contradict each other—of the embodiments shown. Fig. 1 shows a sectional view through a field device 1 according to the prior art. The field device 1 of the automation technology comprises a sensor MA and a transmitter MU.

[0037] The measuring sensor MA has a measuring sensor housing MAG with a measuring sensor housing opening 15 for the passage of electrical connectors for connecting the measuring sensor MA to the measuring transducer MU, so that both are in communication. The measuring sensor housing MAG has a measuring sensor housing interior 2 in which at least one sensor unit SE is arranged. The components of the sensor unit SE depend on the measuring principle. In a thermal flow meter, the sensor unit SE comprises at least two temperature sensors (e.g. PT1000 or PT1000 resistance thermometer). In a magnetic inductive flowmeter, the sensor unit SE comprises a magnetic field generating device 21 and at least two measuring electrodes 22, which are inserted in a measuring tube opening of a measuring tube 20. In an ultrasonic flowmeter, the sensor unit SE comprises at least two ultrasonic transducers.In a vortex flow meter, the sensor unit SE includes a vortex paddle that protrudes into the measuring tube.

[0038] The measuring transducer MU has a measuring transducer housing MUG with a measuring transducer housing opening 3 for the passage of the electrical connectors. The measuring transducer housing MUG further comprises a measuring transducer housing interior 4 in which measuring electronics ME are arranged, which are designed to determine the process variable to be monitored as a function of the measurement signal provided by the measuring sensor. The measuring transducer housing MUG is indirectly mechanically connected to the measuring sensor housing MAG. An adapter AD is arranged between the measuring transducer MU and the measuring sensor MA, which adapter housing AG has an adapter housing opening 30. A plug connector SV is arranged in the adapter housing opening 30 and is connected to the electrical connector or connectors originating from the sensor unit SE and also to the electrical connector or connectors originating from the measuring electronics ME.

[0039] Fig. 2 shows a partial view of a cross-section of an embodiment of a field device according to the invention, in particular of the contact point between the measuring sensor, the measuring transducer and the adapter.

[0040] A sensor housing MAG of the sensor has a sensor housing opening 15 for the passage of electrical connectors EV, which electrically connect the sensor unit of the sensor to the measuring electronics of the transmitter. For this purpose, the transmitter has a transmitter housing MUG, which also has a transmitter housing opening 3 for the passage of the electrical connectors EV.

[0041] In the illustrated embodiment, an adapter AD with an adapter housing AG is arranged between the transmitter housing MUG and the sensor housing MAG. The adapter housing AG has an adapter housing opening 30, which also serves the purpose of passing the electrical connectors EV. The adapter housing AG is designed such that it extends at least partially through the transmitter housing opening 3.

[0042] In the embodiment, a separating body 5 for separating the measuring transducer housing interior 4 from the measuring sensor housing interior 2 is arranged in the adapter housing opening 30. Alternatively, the separating body 5 can also be arranged in the measuring sensor housing opening 15 and / or in the measuring transducer housing opening 3. The separating body 5 is designed such that it completely fills the housing opening in which it is arranged. According to the invention, the separating body 5 is designed to be permeable to air. However, the material of the separating body 5 can be selected such that the separating body 5 is permeable to gases, but not permeable to a liquid potting compound made of plastic or resin. Thus, the separating body 5 has sealing properties with respect to any potting compound but at the same time is also permeable to gas or air.

[0043] At the same time, the separating body 5 can be configured to create a pressure equalization between the interior of the sensor housing 2 and the interior of the transmitter housing 4. This is the case when the interior of the sensor housing 2 and the interior of the transmitter housing 4 are free of encapsulation. If the field device also has a, in particular precisely one, overpressure device 7, a leak test (e.g., an ATEQ leak test) can be performed simultaneously for the sensor and transmitter via the overpressure device 7. In the illustrated embodiment, the overpressure device 7 is located in or on the sensor housing MAG and the adapter housing AG. It comprises a connection 40 to which a leak tester can be connected, a channel 41 which connects the connection 40 to the interior of the adapter AD and a pressure compensation element 42, in particular a membrane, which is arranged in a receptacle 43 in the sensor housing MAG.The diaphragm can be a Teflon diaphragm, for example. The pressure compensation element 42 is located in the sensor housing MAG. Alternatively, the pressure compensation element 42 can be located in the adapter housing AG or the transmitter housing MUG.

[0044] According to the invention, no plug connector is provided in the sensor housing opening 15, the transmitter housing opening 3, or the adapter housing opening 30. Instead, the electrical connectors EV run directly and without separation from the sensor unit to the measuring electronics.

[0045] Fig. 3 shows a view of a separator 5, a retaining plate 12, and electrical connectors. The separator 5 is fixedly arranged in an adapter housing opening AG.

[0046] The separating body 5 has at least one guide 6 for electrical connectors. The guide 6 can be designed as a slot. This simplifies the attachment of the electrical connectors. In the illustrated embodiment, the guide has two slots, namely a first separating body slot 14a, through which at least two signal cables 10a, 10b are guided, and a second separating body slot 14b, through which two sensor cables 11a, 11b, in particular four sensor cables 11a, 11b, 11c, 11d are guided. The slots each extend from the edge of the separating body 5 towards the center. The first separating body slot 14a is separated from the second separating body slot 14b, in particular positioned opposite one another, in order to minimize influences and interference caused by the signals. The signal cable 10a, 10b is configured to guide an operating signal generated by the measuring electronics to the sensor unit.The operating signal can be a time-varying voltage or current signal. Alternatively, the operating signal can also be a digital signal. The sensor cable 11a, 11b, 11c, 11d is designed to conduct measurement signals from the sensor unit to the measurement electronics. The measurement signal can be a time-varying voltage or current signal. Alternatively, the measurement signal can also be a digital signal. If the field device is a magnetic-inductive flowmeter, the signal cables 10a, 10b are coil cables that connect the measurement electronics to the coils of the magnetic field-generating device. In this case, the sensor cables 11a, 11b, 11c, 11d are electrical connectors that connect the measurement electronics to the at least two measuring electrodes and optionally to the level monitoring electrode and reference electrode.

[0047] The separating body 5 is secured via the retaining plate 12. The retaining plate 12 is fastened in or to the adapter housing opening 30 via at least one fixing element, for example a screw. The fixing elements extend through openings in the retaining plate 12, which are located in partial areas that do not cover the separating body 5. This has the advantage of preventing a rotational movement from acting on the separating body 5 during fastening.

[0048] Alternatively, the retaining plate 12 can be integrally connected to the adapter housing AG. The retaining plate 12 has two openings through which the signal cables 11a, 11b and the sensor cables 10a-d extend, respectively. The two openings are each designed as retaining plate slots 13a, 13b to facilitate assembly. The slots extend from the edge of the retaining plate 12 to a round or oval opening in the west. The retaining plate 12 is designed to withstand the mechanical resistance acting on the separating body 5 of an expanding encapsulation in the sensor.

[0049] Fig. 4 shows a view of an alternative embodiment of the retaining plate 12. The guide 6 also comprises a first separating body slot 14a and a second separating body slot 14b. The retaining plate 12 has two retaining plate slots 13a, 13b, each extending from the edge of the retaining plate to an oval opening. The retaining plate 12 conceals the first and / or second separating body slots 14a, 14b at least in sections.

[0050] Fig. 5 shows a partial cross-sectional view of an embodiment of a field device 1 according to the invention with a measuring transducer MU and a measuring sensor MA. An adapter AD is arranged between the measuring transducer MU and the measuring sensor MA. The adapter AD is connected to the measuring sensor MA, and the measuring transducer MU is connected to the adapter AD. The measuring sensor MA has a measuring sensor housing MAG with a measuring sensor housing opening 15 for the passage of electrical connectors. The measuring transducer MU comprises a measuring transducer housing MUG with a measuring transducer housing opening 3 for the passage of the electrical connectors.

[0051] The adapter AD is designed as shown in Fig. 3 or Fig. 4 and has a separating body 5 for separating the transmitter housing interior 4 from the sensor housing interior 2. The separating body 5 is gas-permeable, in particular air-permeable, but does not allow liquid encapsulation to pass through.

[0052] The interior of the sensor housing 2 is cast with an expanding potting compound 8, which is added in liquid form during production and then expands. The potting compound 8 is used to fix the individual components of the sensor MA and to provide resistance to water and moisture. The potting compound 8 is advantageous if the sensor housing MAG and / or seal is damaged and water would enter. The potting compound 8 can, for example, be a curable foam (e.g. PUR foam). The potting compound 8 also extends at least partially into the adapter opening 30 as far as the separator 5. When the potting compound 8 expands, it can happen that it presses against the separator 5. The holding plate 12 is designed such that it absorbs the acting force and the separator 5 thus remains stationary. The separating body 5 can have a pressure between 0.011 and 0.11 N / mm 2 , especially between 0.028 and 0.042 N / mm 2This means that the separating body 5 itself is deformable when a mechanical force acts on it.

[0053] The interior of the transmitter housing 4 is encapsulated with a non-expanding encapsulant 9. Encapsulant 9 can be a gel, particularly a SIL gel. Encapsulant 9 serves to enclose the measuring electronics ME, thus preventing it from coming into contact with a liquid (e.g., water).

Claims

PATENT CLAIMS 1. Field device (1) of automation technology, comprising: - a measuring sensor (MA), wherein the measuring sensor (MA) has a measuring sensor housing (MAG) with a measuring sensor housing opening (15) for the passage of electrical connectors (EV), wherein the measuring sensor housing (MAG) has a measuring sensor housing interior (2) in which at least one sensor unit (SE) is arranged; - a measuring transducer (MU), wherein the measuring transducer (MU) comprises a measuring transducer housing (MUG) with a measuring transducer housing opening (3) for passing through the electrical connectors (EV), wherein the measuring transducer housing (MUG) has a measuring transducer housing interior (4) in which a measuring electronics (ME) is arranged, wherein the measuring transducer housing (MUG) is mechanically coupled to the measuring sensor housing (MAG), - a separating body (5) for separating the interior of the measuring transducer housing (4) from the interior of the measuring sensor housing (2), wherein the separating body (5) has at least one guide (6) for the electrical connectors (EV), wherein the separating body (5) is designed to be permeable to air.

2. Field device (1) according to claim 1, wherein the separating body (5) has a cellular structure which is made of a plastic or a rubber.

3. Field device (1) according to claim 1 or 2, wherein the separating body (5) has a pressure between 0.011 and 0.11 N / mm 2 , especially between 0.028 and 0.042 N / mm 2 has.

4. Field device (1) according to one of the preceding claims, wherein the separating body (5) is designed to form a pressure equalization between the interior of the sensor housing (2) and the interior of the transmitter housing (4).

5. Field device (1) according to one of the preceding claims, wherein the field device (1) has an overpressure device (7).

6. Field device (1) according to one of the preceding claims, wherein the sensor housing interior (2) is provided with a, in particular expanding, potting (8) is cast, and / or wherein the transmitter housing interior (4) is cast with a, in particular non-expanding, casting (9).

7. Field device (1) according to one of the preceding claims, wherein the guide (6) is designed as a slot.

8. Field device (1) according to one of the preceding claims, wherein the guide (6) has a first separating body slot (14a) through which two signal cables (10a, 10b) are guided, wherein the guide (6) has a second separating body slot (14b) through which two sensor cables (11a, 11b) are guided, wherein the first separating body slot (14a) is separated from the second separating body slot (14b).

9. Field device (1) according to one of the preceding claims, wherein the separating body (5) is held in position by a holding plate (12).

10. Field device (1) according to claim 9, wherein the holding plate (12) has two holding plate slots (13a, 13b), wherein the holding plate (12) covers the first and / or second separating body slot (14a, 14b) at least in sections.

11. Field device (1) according to one of the preceding claims, wherein an adapter (AD) with an adapter housing (AG) and an adapter housing opening (30) is arranged between the measuring sensor (MA) and the measuring transducer (MU), wherein the separating body (5) is arranged in the adapter housing opening (30).

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