Protective cover for a field device and field device for measuring / automation technology

Description

[0001] The invention relates to a protective cover for a field device and a field device for measurement / automation technology.

[0002] Field devices used in measurement and automation technology are frequently deployed in harsh environments, necessitating the use of protective covers designed to safeguard them from damage. An example of such a cover is found in EP2105715B1, where the cover attaches to the field device via a hinged locking mechanism, featuring two hinged sections. However, this type of cover is not particularly robust, and the locking tabs, which are exposed to the environment, are susceptible to damage. While it is also known to screw protective covers onto field device housings, this requires the use of tools, which is generally undesirable.

[0003] German patent DE102011004447A1 discloses a sensor arrangement with a sensor unit comprising a base carrier, wherein an elastic cap is provided which can be at least partially slid over the base carrier, which is designed as a housing, and seals a receiving pocket. The cap can be inverted by elastic deformation, so that after deformation it engages the housing by means of a fastening device.

[0004] The object of the invention can be seen as proposing a robust protective cover and a field device with such a protective cover, which can be easily mounted and dismounted.

[0005] The problem is solved by a protective hood according to the invention as defined in independent claim 1 and by a field device according to the invention as defined in independent claim 7.

[0006] A protective hood according to the invention, designed for a field device of measurement / automation technology, has a longitudinal axis and a hood wall which forms a hood chamber with an open first end and a closed second end. wherein the hood chamber is configured to receive an electronics housing of the field device via the open first end along the longitudinal axis, wherein the protective hood has at least one fastening device which is specifically configured to be mechanically contacted with the electronics housing, wherein the fastening device has a projection, wherein the protective hood is elastically deformable, wherein the protective hood has a first shape without the application of force in which the fastening device has a first distance to the longitudinal axis, wherein the protective hood is elastically deformable into a second shape by the application of force in which the fastening device has a second distance to the longitudinal axis which is greater than the first distance, wherein the fastening device is integrally formed in the hood wall.that, through the elastic deformation of the protective cover into the second shape, the protective cover can be slipped onto the electronic housing in such a way that, upon returning to the first shape, the protective cover engages the electronic housing by means of the fastening device, wherein the projection has a first surface, wherein a normal vector of the first surface faces the second end, wherein an interior angle between the normal vector and the cross-section of the protective cover is greater than 45 degrees, and in particular greater than 55 degrees, and preferably greater than 60 degrees, wherein the interior angle is less than 85 degrees, and in particular less than 80 degrees, and preferably less than 75 degrees, wherein the projection has a second surface, wherein a normal vector of the second surface faces the first end, and wherein the interior angle between the normal vector and the cross-section of the protective cover is less than 45 degrees, and in particular less than 35 degrees.

[0007] The invention has the advantage of preventing the protective cover from being removed by pulling along a longitudinal axis of the protective cover.

[0008] Furthermore, the advantage is that the protrusion, when the protective cover is mounted, exerts a force towards the first open end, thus ensuring that the protective cover is firmly attached to the electronics housing.

[0009] Furthermore, the protective cover has the advantage that it can be easily mounted by simply attaching it to a corresponding electronics housing.

[0010] In one embodiment, the hood cross-section in the first form follows a circle, while the hood cross-section in the second form follows an oval.

[0011] In an embodiment wherein the protective hood has at least one spacer device in the area of ​​the second end, which is designed to ensure a minimum distance between the second end and the electronic housing.

[0012] In one design, the protective cover is made of plastic or metal.

[0013] In one embodiment, a force of at most 100 Newtons, and in particular at most 50 Newtons, is required to transform the protective hood into the second form.

[0014] In this way, the protective cover can be removed and / or installed without tools, solely by manual operation.

[0015] In one embodiment, the second distance is at least 5% larger than the first distance, and preferably at least 10% larger than the first distance, or wherein the second distance is at least 1 millimeter and preferably at least 2 millimeters larger than the first distance.

[0016] A field device according to the invention for measurement / automation technology comprises: an electronic housing with a housing wall forming a housing chamber; a sensor configured to generate a measurement signal of a measured quantity; an electronic measuring / operating circuit for providing measured values ​​of the measured quantity by means of the measurement signal, wherein the electronic measuring / operating circuit is arranged in the housing chamber, wherein the field device has a protective hood according to the invention, wherein the electronic housing is arranged in the hood chamber and carries the protective hood.

[0017] The housing can include one or more housing covers, which close openings to the housing chamber. At least one housing cover thus forms part of the housing wall.

[0018] In one embodiment, the hood wall in the first form has a distance of at most 30 millimeters and / or at least 5 millimeters to the housing, at least outside an area of ​​the at least one first fastening device and the spacer device.

[0019] In one embodiment, the at least one first fastening device rests with the hood wall in the first form on the housing wall, in particular on a tip, edge or on a surface of the housing wall, and exerts a force on the protective hood with a force component in the direction of the open first end.

[0020] The invention will be described below using exemplary embodiments. Fig. 1shows a longitudinal section through an exemplary protective hood according to the invention; Fig. 2 sketches two different shapes of a cross-section through the protective hood; Fig. 3 sketches a schematic, exemplary field device according to the invention.

[0021] Fig. 1 Figure 1 shows a longitudinal section through an exemplary protective hood 10 according to the invention for a field device 1 for measurement / automation technology, wherein the protective hood has a longitudinal axis 10.1 and a hood wall 11. The hood wall has a first open end 11.1 and a second closed end 11.2, forming a hood chamber 11.3. The protective hood is designed to accommodate an electronics housing 20 along the longitudinal axis via the open first end, see Figure 1. Fig. 3, of the field device. The protective cover has at least one fastening device 12, here for example two, by means of which the protective cover can be attached to the electronics housing. As shown here, the protective cover can also have a spacer device 15, which is designed to ensure a minimum distance between a mounted electronics housing and the cover wall in the area of ​​the second end.

[0022] The fastening device can, as shown here, comprise a projection 12.1 with one of the first surfaces 12.11, in which a normal vector 12.111 of the first surface faces the second end. An interior angle 16 between the normal vector and a hood cross-section 10.2 of the protective hood is greater than 45 degrees, and in particular greater than 55 degrees, and preferably greater than 60 degrees. This makes it difficult or impossible to remove the protective hood by applying force along its longitudinal axis. In one embodiment, the interior angle is less than 85 degrees, and in particular less than 80 degrees, and preferably less than 75 degrees. In this way, the protective hood attached to an electronics housing exerts a preload against the second end of the hood wall, ensuring a firm and secure fit.

[0023] The projection can, as shown here, comprise a second surface 12.12, wherein a normal vector 12.111 of the second surface faces the first end 11.1, and wherein an interior angle 16 between the normal vector and the hood cross-section 10.2 of the protective hood is less than 45 degrees and, in particular, less than 35 degrees. In this way, the protective hood can be easily mounted by simply snapping it onto a corresponding electronics housing.

[0024] The fastening device can be integrally formed in the hood wall, the hood wall being manufactured, for example, by an injection molding process or a pressure forming process.

[0025] The hood wall can be made of plastic or metal.

[0026] Fig. 2outlines an essential aspect of the invention. According to the invention, the protective hood is elastically deformable, wherein the protective hood, without the application of force, has a first form 13.1 in which the fastening device has a first distance 14.1 from the longitudinal axis, wherein the protective hood is elastically deformable into a second form 13.2 by the application of force, in which second form the fastening device has a second distance 14.2 from the longitudinal axis, which is greater than the first distance. The hood cross-section 10.2 when as in Fig. 2 The first form, 13.1, shows a circle, and the second form, 13.2, shows an oval.

[0027] In this way, by elastically deforming the protective cover into the second shape, the protective cover can be placed onto an electronics housing and, upon returning to the first shape, engage with the electronics housing by means of the fastening device.

[0028] In one embodiment, the second distance is at least 5% larger than the first distance, and preferably at least 10% larger than the first distance, or wherein the second distance is at least 1 millimeter and preferably at least 2 millimeters larger than the first distance.

[0029] To enable the protective cover to be attached to an electronics housing manually without tools, it can be designed such that a force of no more than 100 Newtons, and in particular no more than 50 Newtons, is required to transfer the protective cover into the second form 13.2. A person skilled in the art can use simulation programs or relevant formulas or expertise in technical mechanics to accomplish this.

[0030] Fig. 3Figure 1 sketches a longitudinal section through an exemplary field device 1 according to the invention for measurement / automation technology, comprising an electronics housing 20, a sensor 30 configured to generate a measurement signal of a measured quantity, and an electronic measurement / operating circuit 40 arranged in the electronics housing for providing measured values ​​of the measured quantity by means of the measurement signal, as well as a protective cover 10 according to the invention, which is supported by the electronics housing. The exemplary electronics housing shown here has a housing wall 21, which includes a housing pot 21.13 with a housing opening 21.12, which is closed by a housing cover 21.11. The protective cover can, as shown here, engage an edge of the electronics housing, in this case an edge of the housing cover, and thus be attached to the electronics housing. Alternatively, the housing pot can also provide attachment points for the protective cover.

[0031] In the first form 13.1, the cover wall 11 can have a distance of at most 30 millimeters and / or at least 2 and, in particular, at least 5 millimeters from the electronic housing 20, at least outside the area of ​​the at least one first fastening device 12 and the spacer device 15. This provides sufficient clearance for disassembling the protective cover in the second form and good protection against adverse conditions. Reference symbol list

[0032] 1 Field device 10 Protective cover 10.1 Longitudinal axis 10.2 Cover cross-section 11 Cover wall 11.1 Open first end 11.2 Closed second end 11.3 Cover chamber 12 Mounting device 12.1 Projection 12.11 First surface 12.111 Normal vector 13.1 First shape 13.2 Second shape 14.1 First distance 14.2 Second distance 15 Spacing device 16 Internal angle 20 Electronic housing 21 Housing wall 21.11 Housing cover 21.12 Housing opening 21.13 Housing pot 22 Housing chamber 30 Sensor 40 Electronic measuring / operating circuit

Claims

1. Protective hood (10) configured for a field device (1) of measurement and / or automation technology, wherein the protective hood comprises a longitudinal axis (10.1) and a hood wall (11) having an open first end (11.1) and a closed second end (11.2), the hood wall forming a hood chamber (11.3), wherein the hood chamber is configured in particular to receive an electronics housing (20) of the field device via the open first end along the longitudinal axis, wherein the protective hood comprises at least one fastening apparatus (12) configured in particular to come into mechanical contact with the electronics housing, wherein the fastening apparatus (12) comprises a projection (12.1), wherein, without application of force, the protective hood has a first shape (13.1), in which the fastening apparatus has a first distance (14.1) from the longitudinal axis, characterized in that the protective hood can be elastically deformed, by application of a force, into a second shape (13.2), in which the fastening apparatus has a second distance (14.2) from the longitudinal axis, which is greater than the first distance, in that, by the elastic deformation into the second shape, the protective hood can be slipped over the electronics housing such that, upon return to the first shape, the protective hood engages the electronics housing by means of the fastening apparatus, wherein the fastening apparatus is integrally formed in the hood wall. wherein the projection (12.1) has a first surface (12.11), a normal vector (12.111) of the first surface being directed towards the second end (11.2), wherein an interiorangle (16) between the normal vector and a hood cross-section (10.2) is greater than 45°, in particular greater than 55°, preferably greater than 60°, and less than 85°, in particular less than 80°, preferably less than 75°, wherein the projection (12.1) has a second surface (12.12), a normal vector of the second surface being directed towards the first end (11.1), wherein the interior angle between this normal vector and the hood cross-section is less than 45°, in particular less than 35°.

2. Protective hood according to claim 1, wherein the hood cross-section (10.2) in the first shape (13.1) is circular and in the second shape (13.2) is oval.

3. Protective hood according to claim 1 or 2, wherein the protective hood (10) comprises, in the region of the second end, at least one spacing aparatus (15) configured to ensure a minimum distance between the second end and the electronics housing.

4. Protective hood according to any of the preceding claims, wherein the protective hood (10) is made of a plastic material or a metal.

5. Protective hood according to any of the preceding claims, wherein a force of at most 100 N, in particular at most 50 N, is required to deform the protective hood into the second shape (13.2).

6. Protective hood according to any of the preceding claims, wherein the second distance (14.2) is at least 5%, preferably at least 10%, greater than the first distance (14.1), or is at least 1 mm, preferably at least 2 mm, greater than the first distance.

7. Field device (1) of measurement and / or automation technology, comprising: - an electronics housing (20) having a housing wall (21) forming a housing chamber (22); - a sensor (30) configured to generate a measurement signal representing a measured variable; - an electronic measuring / operating circuit (40) configured to provide measured values of the measured variable based on the measurement signal, the circuit being arranged in the housing chamber, characterized in that the field device comprises a protective hood (10) according to any of the preceding claims, wherein the electronics housing is arranged in the hood chamber (11.3) and supports the protective hood.

8. Field device according to claim 7, wherein the hood wall (11) in the first shape (13.1) has, at least outside a region of the fastening apparatus (12) and the spacing apparatus (15), a distance from the electronics housing (20) of at most 30 mm and / or at least 5 mm.

9. Field device according to claim 7 or 8, wherein the at least one fastening apparatus (12), in the first shape, engages the housing wall (21), in particular at a tip. rests on an edge or on a surface of the housing wall and exerts a force on the protective cover (10) with a force component directed toward the open first end.

10. Field device according to any one of claims 8 through 9 wherein the protective cover can be mounted on the field device by applying a force along the longitudinal axis of the protective cover, and wherein the protective cover can be removed by deforming it into the second shape and pulling it off.