Display unit for an automation field device

Abstract

Display unit for an automation field device, at least having: - a display for displaying information (19); -a display frame (30) having a main body (31), the display frame (30) also having a plurality of press-on elements (34) which are formed on a second side (33) of the main body, the second side facing away from the first side (32), and are designed in such a way that the press-on elements extend or protrude from the second side in the opposite direction to the first side; - a carrier plate (50) having a plurality of spring elements (51), the spring elements and the press-on elements being matched to each other and designed in such a way that the spring elements push or press the projecting press-on elements in the direction of a normal vector (70) of the planar receiving surface (37) of the display frame in a clamped state, so that the display (19) located in the receiving surface (37) is moved in the direction of the normal vector (70); - the display holder (40), which has a receptacle for mechanically fixing at least the carrier plate (50) within the display holder (40).

Description

[0001] Display unit for a field device in automation technology

[0002] The invention relates to a display unit for a field device in automation technology, as well as a field device in automation technology with such a display unit.

[0003] Field devices used in industrial plants are known from the state of the art. Field devices are widely used in process automation technology as well as in manufacturing automation technology. In principle, field devices are all devices that are used close to the process and that provide or process-relevant information. Field devices are used to record and / or influence process variables. Measuring devices or sensors are used to record process variables. These are used, for example, for pressure and temperature measurement, conductivity measurement, flow measurement, etc. and record the corresponding process variables pressure, temperature, conductivity, pH value, fill level, flow rate, etc. Actuators are used to influence process variables. These are, for example, pumps or valves that can influence the flow of a liquid in a pipe or the fill level in a container.In addition to the measuring devices and actuators mentioned above, field devices also include remote I / Os, radio adapters and, in general, devices that are arranged at the field level.

[0004] A large number of such field devices are produced and distributed by the Endress+Hauser Group.

[0005] Hygienic processes place particularly high demands on processing and / or cleanliness. Examples of such hygienic processes include applications in the food industry, where there is a risk that deposits and / or impurities can impair the shelf life and / or lead to harmful contamination of food.

[0006] To meet these requirements, the housings of field devices are specially designed. For example, they are made of a metallic material such as 316L stainless steel and / or are designed to minimize the number of places where deposits and / or contaminants can accumulate.

[0007] Furthermore, field devices are often designed as hermetically sealed devices for this application. This means that operating and display elements are usually located behind a viewing window inside the field device and are hermetically sealed from the outside by the viewing window. Such operating and display elements can not only have means for displaying information but also means for enabling operation. For example, capacitive buttons are used for operation, which can be implemented as part of the operating and display element, e.g., using a suitable film. In the following, such operating and display elements are also referred to as displays.

[0008] The disadvantage of this is that the operation of such capacitive buttons on the display and / or good readability is only possible if the display, which is arranged behind the viewing window due to the hermetic encapsulation, lies as flat as possible and without any gap against the viewing window.

[0009] The invention is based on the object of showing a possibility of how a display can be arranged as flat as possible and without any gap on the viewing window of a field device in automation technology.

[0010] The object is achieved according to the invention by the display unit for a field device of automation technology according to patent claim 1 and the field device of automation technology according to patent claim 10.

[0011] The display unit according to the invention for a field device in automation technology comprises at least: a display for displaying information; a display frame with a preferably planar base body, wherein the base body provides a planar receiving surface for the display on a first side, so that the display frame receives the display and preferably partially surrounds it at least in the edge region and is connected to it, wherein the display frame further comprises a plurality of, preferably four, particularly preferably rod-shaped pressing elements, which are formed on a second side of the base body facing away from the first side and are designed in such a way that the pressing elements extend from the second side in the opposite direction to the first side.protrude; a carrier plate which has a plurality, preferably four spring elements 34, wherein the spring elements and the pressing elements are matched to one another and designed in such a way that the spring elements press or press the protruding pressing elements of the display frame in a clamped state in which the carrier plate and the display frame are introduced into a display holder and positioned relative to one another in the direction of a normal vector which is orthogonal to the planar receiving surface of the display frame, so that the display located in the receiving surface is moved in the direction of the normal vector; the display holder, which has a receptacle for the mechanical fixing of at least the carrier plate within the display holder.

[0012] According to the invention, a display unit is proposed in which additional spring elements are eliminated by the support plate itself having spring elements. The spring elements integrated into the support plate, together with the protruding pressure elements, ensure that a spring force is generated in the direction of the normal vector (and thus in the direction of an operating or viewing panel), so that the display, inserted into the receiving surface of the display frame, is pressed against an operating or viewing panel.

[0013] An advantageous embodiment of the display unit according to the invention can provide that the spring elements of the carrier plate are designed in the form of webs which, in a non-clamped state, lie in a plane of the carrier plate.

[0014] A further advantageous embodiment of the display unit according to the invention can provide that the carrier plate is a printed circuit board, and wherein the spring elements are part of the printed circuit board and are preferably cut out of the printed circuit board. For example, the spring elements can be cut out of the printed circuit board by milling, laser cutting, punching, or even by 3D printing.

[0015] A further advantageous embodiment of the display unit according to the invention can provide that the display holder comprises several, preferably two locking elements, which are designed such that the carrier plate can be locked or clipped into the locking elements, so that the carrier plate is mechanically fixed in the display holder.

[0016] A further advantageous embodiment of the display unit according to the invention can provide that the display holder has a base surface and a peripheral edge protruding from the base surface. In particular, the embodiment can provide that the locking elements of the display holder are designed such that they extend from the peripheral edge in the opposite direction to the base surface and / or that the base surface has a transparent operating or viewing panel, which is preferably designed such that the operating or viewing panel partially protrudes from the base surface.

[0017] A further advantageous embodiment of the display unit according to the invention can provide that several, preferably two, guide pins are formed on the second side of the base body of the display frame and the support plate for the guide pins has corresponding guide receptacles which are designed to enable axial guidance / alignment or positioning of the display frame relative to the support plate.

[0018] A further advantageous embodiment of the display unit according to the invention can provide that several, preferably two, locking elements are provided on the second side of the base body of the display frame, which are designed to be able to mechanically detachably fasten the display frame to the carrier plate.

[0019] The invention further relates to a field device of automation technology at least comprising: a field device housing which encloses an interior space; a transparent operating and / or viewing window for a display which is integrated or introduced into the field device housing; a display unit according to one of the previously described embodiments, wherein the display unit is arranged in the interior space of the field device housing in such a way that the display is located in the interior space behind the operating and / or viewing window and is pressed or pressed in the direction of the normal vector by the carrier plate introduced into the display holder and the display frame, so that the display located in the receiving surface moves in the direction of the normal vector.

[0020] An advantageous embodiment of the field device according to the invention can provide that, in the case that the transparent operating and / or viewing window is introduced into the field device housing, the field device housing has a recess for receiving the operating or viewing panel formed in the base area of ​​the display holder, in which the operating and / or viewing window is arranged.

[0021] The invention is explained in more detail with reference to the following drawings. It shows:

[0022] Fig. 1 : a schematic sectional view through a field device of automation technology, which is designed for use in hygienic applications and which has a display unit according to the invention,

[0023] Fig. 2: an exemplary sectional view through such a display unit,

[0024] Fig. 3: a rear view of a display holder in which a carrier plate is mechanically fixed,

[0025] Fig. 4: a display frame attached to the carrier plate, in which the display is inserted into the receiving surface, and Fig. 5: a carrier plate with integrated spring elements.

[0026] Figure 1 shows a schematic sectional view through an automation technology field device 10. The field device 10 comprises a field device housing 12 enclosing an interior space 13. The field device housing 12 has an at least partially rotationally symmetrical region 17 into which the field contact plug 21 is to be or is integrated. The field device 10 further comprises a sensor assembly arranged at the end of the field device housing 12, comprising a sensor and / or actuator element 14 for setting and / or detecting a process variable, and a process connection 28. The process connection 18 can be a threaded design or a screwable or clampable flange.

[0027] In the present embodiment, the sensor and / or actuator element 14 comprises a fill level sensor element for detecting a fill level as a process variable. Nevertheless, the invention is not limited to the type or specific design of the sensor and / or actuator element as a fill level sensor element, but can in principle be applied to any other sensor or actuator principle.

[0028] An electronic circuit 15, which is installed in an interior space 13 of the field device housing and is designed to operate the sensor and / or actuator element 14, serves to provide and / or process a sensor and / or actuator signal.

[0029] In the present embodiment, the electronic circuit comprises three circuit boards, two of which are arranged in the longitudinal direction of the housing, 15a and 15b, and one circuit board 15c is arranged transversely to the housing. The circuit boards 15a, 15b, and 15c are plugged into one another via corresponding plug connectors and mating connectors 15d, thus establishing electrical contact. The plug connectors and mating connectors can be designed as either rigid or flexible connectors. Plug and mating connectors can also be interchanged.

[0030] The electronic circuit further comprises connection electronics 20 with at least one first printed circuit board 25 with a field contact connector 21, which is arranged along a longitudinal axis of the printed circuit board 25 and soldered to a printed circuit board edge. Data, in particular measured values, and / or energy are transmitted from the field device 10 to an external unit, e.g., a higher-level unit or another field device, via the field contact connector 21.

[0031] The field contact connector 21 can, in particular, be a circular connector, e.g., an M12 circular connector. However, it can also be other common connectors suitable for transmitting data and / or power. For example, it can also be an Ethernet connector. Furthermore, the field contact connector 21 can also be a cable gland through which a cable for electrical contact is routed into the interior of the field device.

[0032] The connection electronics 20 further comprises at least one mating connector 22, which can be arranged and attached on the first circuit board 25 such that a plug-in axis 23 is inclined or tilted relative to a main plane in which the first circuit board 25 is formed. The connection electronics is connected to one of the circuit boards of the electronic circuit via the mating connector 22 of the connection electronics via a matching plug-in connector 15e present there. The plug-in connector and mating connector can be designed as either rigid or flexible connectors. Likewise, the plug-in and mating connectors can be interchanged. Furthermore, electronic components for EMC and / or explosion protection measures 24 can be mounted on the first circuit board 25.

[0033] The electronic circuit 15 located in the field device 10 is at least partially arranged in an electronics housing 16, which is firmly seated in the field device housing and, if necessary, also serves to secure the circuit boards of the electronic circuit. The electronics housing 16 can be substantially adapted to an outer contour of the field device housing. Furthermore, the electronic circuit components located in the electronics housing can be encapsulated using a potting compound 27.

[0034] The field device housing 12 further has a housing opening 18 through which the field contact plug is led to the outside. For mechanical fixing and / or alignment or positioning, a precisely fitting plug sleeve 26 is attached in or on the field device housing over the field contact plug. The plug sleeve is welded to the outside of the field device housing. In order to fix the plug sleeve during the welding process, it can be fastened to the electronics cup by means of a fastening device. This can be done, for example, via a locking mechanism on the electronics cup arranged in the field device housing. For example, a first fastening element can be realized by a locking geometry molded onto the electronics cup, e.g. in the form of a locking lug. To enable locking or clipping in, a circumferential groove is implemented on the plug sleeve as a second fastening element.The interaction of the two fastening elements prevents the field contact plug from being affected during the welding process, for example, by the dynamics of the welding system or the influence of shielding gas flows, as the plug sleeve is fixed to the electronics housing. Furthermore, a laser beam has free access to the weld.

[0035] At an upper end of the field device 10, the field device housing 12 has a display unit 60. Fig. 2 shows an example of a cross-sectional view of such a display unit. In the present exemplary embodiment, the display unit 60 comprises a carrier plate 50, the actual display for display and / or operation 19, capacitive buttons for operation 19a, a display frame 30 surrounding the display 19 and connected to it, and a display holder 40. The display unit 60 is arranged in the interior 13 of the field device, preferably in the region of a housing cover behind a transparent operating or viewing panel 11.

[0036] Fig. 3 shows a rear view of a display holder 40. The display holder 40 is designed to accommodate the carrier plate 50, the display, optionally with the capacitive buttons 19a, and the display frame 30, and to mechanically fix or connect them, so that a compact unit or assembly is created. For this purpose, the display holder 40 can have a U-shaped configuration in section with a base area 42 and a circumferential edge 43 protruding from the base area. The base area 42 can be round or oval, for example. However, other geometric configurations of the base area 42 are also conceivable. For inserting and / or positioning or aligning the carrier plate, the display holder can have corresponding locking elements 41. The locking elements 41 can be implemented, for example, in the form of locking hooks, by means of which the carrier plate 50 can be clipped in or on. The locking hooks 41 mechanically fix the carrier plate in the display holder.Furthermore, the display holder 40 can also include the transparent operating or viewing panel 11. For example, the operating or viewing panel 11 can be implemented as part of the base surface 42 and / or protrude from the base surface. In this case, the field device housing, preferably the housing cover, has a corresponding receptacle, e.g., in the form of an opening, into which the operating or viewing panel 11 can be inserted. However, it is also conceivable for the operating or viewing panel 11 to be integrated directly into the field device housing, preferably the housing cover.

[0037] The display unit or assembly formed by the display holder 40 can be integrated into the field device 10 during production by means of a corresponding receptacle in the field device housing 12, preferably in the housing cover. For example, the display unit 60 can be integrated into the field device housing 12 in such a way that the display holder 40 is first inserted into the receptacle of the field device housing 12 and fixed in place, for example by gluing. Subsequently, the prefabricated carrier plate 50, to which the display frame 30 including the display 19 is already mechanically fastened, is inserted into the display holder by snapping or clipping it in. The display 19 can be a TFT display, for example. A capacitive film 19a, for example, can be applied to the display in order to implement the buttons for operation using a touch function.

[0038] Fig. 4 shows a display frame 30 fastened to the carrier plate 50, in which the display (optionally with the capacitive film on it) is inserted into the receiving surface. The display frame 30 has a substantially planar, preferably cuboid-shaped base body 31 with a receiving surface 37 formed on a first side (front side) 32 of the base body 31 for receiving a display. Furthermore, the display frame has a plurality of locking elements 36 on a second side (rear side) 33 facing away from the first, which locking elements are designed to mechanically releasably fasten the display frame 30 to a carrier plate 50. For example, the locking elements can be designed in the form of locking hooks that engage or lock into place on a rear side of the carrier plate facing away from the display frame. Furthermore, the locking elements 36 can be arranged diagonally to one another on the rear side 33 of the base body 31.According to the invention, the display frame further comprises a plurality of protruding pressure elements 34 on the rear side 33 of the base body 31 as supports for spring elements of the carrier plate 50, which will be described in more detail later. The pressure elements 34 can, for example, be rod-shaped and / or extend or protrude from the rear side 33 of the display frame in the opposite direction to the front side 32 of the display frame. The display frame 30 can be made of a plastic, in particular by an injection molding process.

[0039] Additionally, the display frame 30 can further comprise a plurality of guide pins 35 on the rear side 33 of the base body 31, and the support plate can comprise corresponding guide receptacles 52, e.g., in the form of holes, for the guide pins. These guide receptacles are designed to ensure axial guidance / alignment or positioning of the display frame relative to the support plate and thus of the display 19 arranged in the receiving surface relative to the support plate 50. The guide pins 35 can also be arranged diagonally to one another on the rear side 33 of the base body 31. Preferably, they are arranged diagonally opposite to the locking elements 36 on the rear side 33 of the base body.

[0040] Fig. 5 shows a carrier board. The carrier board 50 can be a printed circuit board, for example, containing electronic components for controlling the display. Additionally or alternatively, the printed circuit board 50 can also contain electronic components for implementing a wireless connection, such as Bluetooth.

[0041] According to the invention, the carrier plate 50 has several, preferably four, spring elements 51. The spring elements 51 serve to press or push the protruding pressing elements 34 of the display frame 30 in the clamped state in the direction of a vector (normal vector) 70 orthogonal to the display, so that the display 19 located in the receiving surface is pressed or pushed against the operating or viewing panel 11. The clamped state is understood to mean the state in which the display frame 30 is fixed to the carrier plate 50 and the carrier plate 50 has been inserted into the display holder 40. The spring elements 51 can, for example, be designed in the form of webs, which are preferably produced by appropriate milling, laser cutting, punching of the circuit board 50, or by means of 3D printing. The spring elements are preferably arranged in the edge region of the circuit board.In principle, the spring force generated by the spring elements can be individually adjusted or adapted by the width and / or length of the webs and a thickness of the carrier plate in combination with a length of the pressure elements 34 of the display frame 30. Webs with a width in the range of 0.25 - 4 mm, preferably in the range of 0.3 - 3.5 mm, particularly preferably in the range of 0.5 - 3 mm and / or a length in the range of at least 3 mm to a maximum of 20 mm, preferably from at least 5 mm to a maximum of 18 mm, particularly preferably from at least 7 mm to a maximum of 16 mm, with a typical thickness of the carrier or circuit board of 1 - 2 mm, have proven particularly suitable.

[0042] List of reference symbols

[0043] Field device in automation technology

[0044] Operating or viewing window

[0045] Field device housing

[0046] Interior

[0047] Sensor and / or actuator element

[0048] Electronic circuit a-15c Printed circuit boards d Plug and mating connectors e Connectors

[0049] Electronic cup

[0050] Rotationally symmetric area

[0051] Housing opening

[0052] Display a Capacitive buttons or foil

[0053] Connection electronics

[0054] Field contact plug

[0055] Mating connector of the connection electronics

[0056] Electronic components, e.g. for EMC and / or explosion protection measures

[0057] First circuit board of the connection electronics

[0058] Plug sleeve for field contact plug

[0059] Potting compound

[0060] Process connection

[0061] Display frame

[0062] Base or fixture body

[0063] Front of the display frame

[0064] Back of the display frame

[0065] Pressure elements

[0066] Guide pins

[0067] Locking element of the display frame

[0068] Mounting area for the display

[0069] Display holder

[0070] Locking elements of the display holder

[0071] Base area of ​​the display holder

[0072] Circumferential edge of the display holder

[0073] Carrier board or circuit board

[0074] Spring elements of the carrier plate

[0075] Guide mounts of the carrier plate

[0076] Display unit 70 Normal vector to the recording surface

Claims

Patent claims 1. A display unit (60) for a field device in automation technology (10), at least comprising: a display for displaying information (19); a display frame (30) with a preferably planar base body (31), wherein the base body (31) provides a planar receiving surface (37) for the display (19) on a first side (32), so that the display frame (30) receives the display (19) and preferably partially surrounds it at least in the edge region and is connected to it, wherein the display frame (30) further comprises a plurality of, preferably four, particularly preferably rod-shaped pressing elements (34) which are formed on a second side (33) of the base body (30) facing away from the first side (32) and are designed such that the pressing elements (34) extend from the second side (33) in the opposite direction to the first side (32).protrude; a carrier plate (50) having a plurality of, preferably four, spring elements (51), wherein the spring elements (51) and the pressing elements (34) are matched to one another and designed in such a way that the spring elements (51) press or press the protruding pressing elements (34) of the display frame (30) in a clamped state in which the carrier plate (50) and the display frame (30) are introduced into a display holder (40) and positioned relative to one another in the direction of a normal vector (70) which is orthogonal to the planar receiving surface (37) of the display frame (30), so that the display (19) located in the receiving surface (37) is moved in the direction of the normal vector (70); the display holder (40), which has a receptacle for mechanically fixing at least the carrier plate (50) within the display holder (40).

2. Display unit according to claim 1, wherein the spring elements (51) of the carrier plate (50) are designed in the form of webs which, in a non-clamped state, lie in a plane of the carrier plate (50).

3. Display unit according to one or more of the preceding claims, wherein the carrier plate (50) is a printed circuit board and wherein the spring elements (51) are part of the printed circuit board and are preferably prepared from the printed circuit board.

4. Display unit according to one or more of the preceding claims, wherein the display holder (40) comprises a plurality of, preferably two, locking elements (41) which are designed such that the carrier plate (50) can be locked into the locking elements or can be clipped in so that the carrier plate (50) is mechanically fixed in the display holder (40).

5. Display unit according to one or more of the preceding claims, wherein the display holder (40) has a base surface (42) and a peripheral edge (43) protruding from the base surface (42).

6. Display unit according to claims 4 and / or 5, wherein the locking elements (36) of the display holder are designed such that they extend from the peripheral edge in the opposite direction to the base surface.

7. Display unit according to claim 5 and / or 6, wherein the base surface (42) has a transparent operating or viewing panel (11), which is preferably designed such that the operating or viewing panel (11) partially protrudes from the base surface (42).

8. Display unit according to one or more of the preceding claims, wherein a plurality of, preferably two, guide pins (35) are formed on the second side (33) of the base body (31) of the display frame (30) and the support plate (50) has corresponding guide receptacles (52) for the guide pins (35), which are designed to enable axial guidance / alignment or positioning of the display frame (30) relative to the support plate (50).

9. Display unit according to one or more of the preceding claims, wherein on the second side (33) of the base body (31) of the display frame (30) several, preferably two locking elements (36) are provided, which are designed to be able to mechanically releasably fasten the display frame (30) to the carrier plate (50).

10. A field device in automation technology, comprising at least: a field device housing (12) enclosing an interior space (13); a transparent operating and / or viewing window (11) for a display, integrated or incorporated into the field device housing (12); a display unit according to one of the preceding claims, arranged in the interior space (13) of the field device housing (12) in such a way that the display is located in the interior space behind the operating and / or viewing window (11) and is pressed or pressed in the direction of the normal vector (70) by the carrier plate (50) inserted into the display holder (40) and the display frame (30), so that the display (19) located in the receiving surface (37) moves in the direction of the normal vector (70).

11. Field device of automation technology according to the preceding claim and display unit according to claim 7, wherein in the case that the transparent operating and / or viewing window (11) is introduced into the field device housing (12), the field device housing (12) has a recess for receiving the operating or viewing panel (11) formed in the base area (42) of the display holder (40), in which the operating and / or viewing panel (11) is arranged.

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