Automation field device

Abstract

The invention relates to an automation field device (1) comprising a housing (1.1) for receiving field device electronics (4) of the field device, said housing comprising a substantially cup-like housing body (1.4) which forms an interior (1.3). The housing body (1.4) has a lateral wall (1.5) which runs circumferentially in a preferably cylindrical manner and which forms at least one part of the interior (1.3) for receiving the field device electronics (4). The field device electronics (4) are introduced into the interior (1.3) such that an at least partly circumferential gap (1.6) is produced between the field device electronics (4) and the circumferential lateral wall (1.5), wherein a heat conducting body (3) is introduced at least into the at least partly circumferential gap (1.6), said heat conducting body connecting the field device electronics (4) to the circumferential lateral wall (1.5) of the housing (1.2) in a thermally conductive manner such that the heat conducting body (3) dissipates heat input into the housing (1.2), in particular heat input on a housing lower face, to the circumferential lateral wall (1.5).

Description

[0001] Field device in automation technology

[0002] The invention relates to a field device in automation technology with a housing for accommodating field device electronics of the field device.

[0003] In automation technology, particularly in process automation technology, field devices are often used in so-called automation systems to record and / or influence process variables. Sensors such as level gauges, flow meters, pressure and temperature gauges, pH and redox potential meters, conductivity meters, etc., are used to record process variables, measuring the corresponding process variables: level, flow, pressure, temperature, pH value, or conductivity. Actuators such as drives, units, valves, and pumps are used to influence process variables; these can be used to change the flow of a liquid in a pipe section or the fill level in a container.

[0004] In principle, field devices are all devices that are used close to the process and that supply or process process-relevant information, i.e. essentially process measurement or process control values.

[0005] A large number of such field devices are developed, manufactured and distributed by the Endress + Hauser Group.

[0006] Such field devices are often designed so that their housing consists of a lower housing section and a housing cover. Both sections are essentially cup-shaped and arranged in such a way that their cup openings face each other, so that the housing section is closed by the housing cover. The housing cover can have a recess in its cup base for a transparent viewing window insert, for example, made of plastic or glass. Such housings are usually made of a metal, such as stainless steel. However, plastic housings are also available.

[0007] To ensure that field devices can also be used in processes with high process temperatures (>100°C), so-called temperature spacers are used today. These temperature spacers are attached to the base of the housing and represent the connection to the process whose process variable is to be measured. The temperature spacers are designed to increase the distance between the process, which continuously releases heat that is introduced into the housing, and the housing. The design of the temperature spacers is intended to prevent damage to field device electronics located in the housing due to excessively high temperatures.

[0008] The disadvantage of this is that the temperature spacer makes the field device longer and therefore protrudes further during installation in the automation system, meaning the required installation space is larger. This, in turn, can mean that the use of a field device with a temperature spacer cannot be guaranteed in every installation situation in the automation system.

[0009] The invention is based on the object of remedying this situation.

[0010] The object is achieved according to the invention by the field device of automation technology according to patent claim 1.

[0011] The field device of automation technology according to the invention comprises a housing for accommodating field device electronics of the field device, wherein the housing comprises a substantially cup-like housing body which forms an interior space, wherein the housing body has a preferably cylindrical circumferential side wall which forms at least part of an interior space for accommodating the field device electronics, wherein the field device electronics is introduced into the interior space in such a way that a gap which is at least partially circumferential is produced between the field device electronics and the circumferential side wall, wherein a heat conducting body is introduced at least into the gap which is at least partially circumferential, which heat conducting body connects the field device electronics to the circumferential side wall of the housing in a heat-conducting manner, so that the heat conducting body prevents heat from being introduced into the housing, in particulara heat input on the underside of the housing, to the surrounding side wall of the housing.

[0012] According to the invention, the use of a heat-conducting element, which establishes a heat-conducting contact between the field device electronics and a side wall of the housing, is proposed for dissipating heat via the side wall. In contrast to the temperature spacers described above, the use of a heat-conducting element offers the advantage that the field device requires less installation space in the automation system.

[0013] An advantageous embodiment of the field device according to the invention provides that an inner cup is arranged in the interior of the housing and the field device electronics are at least partially incorporated into the inner cup, and wherein the heat-conducting body is designed such that it thermally connects the inner cup to the side wall of the housing. In particular, the embodiment can provide that the heat-conducting body is adapted in its shape to the at least partially circumferential gap and, in particular, is tubular and further comprises at least two spring elements, wherein at least a first spring element of the at least two spring elements is designed such that the at least one first spring element presses the heat-conducting body against the inner cup at a first contact surface, so that the heat-conducting body is thermally connected to the inner cup, and wherein at least a second spring element of the at least two spring elements is designed such thatthat the at least one second spring element presses the heat-conducting body against the side wall at a second contact surface, so that the heat-conducting body is thermally connected to the side wall of the housing and / or the at least one first spring element is formed by a plurality of individual first spring elements and the individual contact surfaces of the respective individual first spring elements in total form the first contact surface and / or that the at least one second spring element is formed by a plurality of individual second spring elements and the individual contact surfaces of the respective individual second spring elements in total form the second contact surface.

[0014] A further advantageous embodiment of the field device according to the invention provides that the at least one first spring element or the plurality of individual first spring elements are formed by raised points which extend on an inner surface of the, in particular, tubular heat conducting body in the direction of a central axis of the heat conducting body and / or the at least one second spring element or the plurality of individual second spring elements are formed by raised points which extend on an outer surface of the heat conducting body in the opposite direction to the central axis of the heat conducting body.

[0015] Yet another advantageous embodiment of the field device according to the invention provides that the heat conducting body is designed such that an outer contour, in particular an outer diameter of the, in particular tubular, heat conducting body has an excess in comparison to an inner contour, in particular an inner diameter of the, in particular cylindrical, side wall of the housing.

[0016] A further advantageous embodiment of the field device according to the invention provides that the plurality of individual first and / or second spring elements are arranged distributed radially around the heat conducting body and the raised areas extend in the axial direction of the heat conducting body.

[0017] An alternative embodiment of the field device according to the invention provides that the plurality of individual first and / or second spring elements are arranged distributed in the axial direction on the heat conducting body and the raised areas are formed at least partially radially circumferential.

[0018] A further advantageous embodiment of the field device according to the invention provides that the spring elements are designed such that the ratio of the first contact surface to the second contact surface is: 0.5 < A1 / A2 < 2; preferably 0.7 < A1 / A2 < 1.3; particularly preferably 0.9 < A1 / A2 < 1.1.

[0019] A further advantageous embodiment of the field device according to the invention provides that the heat-conducting body is made of a material with a thermal conductivity of at least 1.5 W / (m*K), preferably of at least 50 W / (m*K), particularly preferably of at least 100 W / (m*K), very particularly preferably of at least 150 W / (m*K).

[0020] A further advantageous embodiment of the field device according to the invention provides that the heat conducting body and / or the inner cup is / are made of aluminum.

[0021] An alternative embodiment of the field device according to the invention provides that at least one thermally conductive pad is introduced as a thermally conductive body at least into the at least partially circumferential gap.

[0022] Yet another alternative embodiment of the field device according to the invention provides that a thermally conductive casting compound is introduced as a heat-conducting body at least partially into the at least partially circumferential gap.

[0023] The invention is explained in more detail with reference to the following drawings. It shows:

[0024] Fig. 1 : a schematic representation of a field device in automation technology,

[0025] Fig. 2: a heat conducting body designed according to the invention,

[0026] Fig. 3a: a cross-sectional and a longitudinal section through a first variant of the heat-conducting body designed according to the invention, in which the heat-conducting body comprises a plurality of first and a plurality of second spring elements,

[0027] Fig. 3b: a cross-sectional and a longitudinal section through a second variant of the heat-conducting body designed according to the invention, in which the heat-conducting body comprises only a first and a second spring element, Fig. 4a: a cross-sectional and a longitudinal section through the first variant of the heat-conducting body designed according to the invention, in which the plurality of first and second spring elements are arranged distributed in the axial direction on the heat-conducting body,

[0028] Fig. 4b: a cross-sectional and a longitudinal section through the second variant of the heat conducting body designed according to the invention, in which the heat conducting body comprises only a first and a second spring element,

[0029] Fig. 5: a cross-sectional and a longitudinal section through the first variant of the heat-conducting body designed according to the invention, in which the heat-conducting body comprises a plurality of first and a plurality of second spring elements,

[0030] Fig. 6a: a cross-sectional and a longitudinal section through a variant of the heat-conducting body designed according to the invention, in which the heat-conducting body comprises a heat-conducting pad or a casting compound, and

[0031] Fig. 6b: a cross-sectional and a longitudinal section through a further variant of the heat-conducting body designed according to the invention, in which the heat-conducting body comprises a heat-conducting pad or a casting compound.

[0032] Figure 1 outlines a typical structure of a field device in automation technology 1. The field device 1 has a housing 1.1 with a housing body 1.4 and a housing cover 1.2. The housing body 1.4 is made in the present case from a metal sheet, preferably a steel sheet, particularly preferably a stainless steel sheet, such as 316L. In the present exemplary embodiment, the housing body 1.4 has a substantially cup-like shape with a base 1.7 and an opening through which an interior space 1.3 is accessible. The opening can be substantially round in cross-section, which in this case is defined or formed by a cylindrical side wall of the housing 1.5. Even if the housing is shown as a substantially cylindrical housing in the present exemplary embodiment, the invention is not limited to this, but can nevertheless be applied to any other housing shapes, in particularrectangular housing shapes can also be transferred.

[0033] In addition, the field device 1 further comprises a sensor and / or actuator element 5 arranged on or in the housing base 1.7 for setting and / or detecting a process variable. As an example, the usual heat input by the process into the housing via the housing base 1.7 is shown in Fig. 1 by means of a thick arrow. In order to enable operation / parameterization of the field device 1 and / or to display information, e.g. relating to the process variable to be detected or set, the field device 1 can have an operating and / or display element 2. The operating and / or display element 2 can, as sketched in Fig. 1, be integrated into the housing cover 1.2 of the field device or embedded in a housing wall of the housing body 1.4.

[0034] Alternatively, the control and / or display element 2 can also be mounted on an outer side of the housing wall. If the field device 1 has a control and / or display element 2, the field device electronics 4 can also be configured to control or operate the control and / or display element 2 accordingly.

[0035] In addition, the field device 1 comprises an electronic field device electronics unit 4 which is introduced into the interior of the housing. The field device electronics unit 4 is designed, among other things, to operate the sensor and / or actuator element 5 and for this purpose comprises conventional electrical and / or electronic components such as resistors, capacitors, coils, microcontrollers, etc. which have a certain temperature sensitivity. The field device electronics unit is introduced or arranged in the interior in such a way that a circumferential gap results between the field device electronics unit and the side wall of the housing. The circumferential gap can be completely circumferential, i.e. circumferential by 360°, or only partially circumferential.

[0036] In the embodiment shown in Fig. 1, an inner cup 4.1 is also provided, into which the field device electronics are at least partially inserted, approximately two-thirds in the figure. The inner cup can also have a cup-like shape in order to accommodate the field device electronics 4. Furthermore, the inner cup can be made of a metal, especially aluminum.

[0037] According to the invention, a heat-conducting body 3 is introduced into the at least partially circumferential gap 1.6. The heat-conducting body 3 is designed such that it is adapted to the circumferential gap and connects the field device electronics 4 to the side wall of the housing 1.5 in a heat-conducting manner, so that any unwanted heat input due to the process on the underside of the housing is dissipated via the heat-conducting body 3 and the side wall of the housing 1.5.

[0038] In the case where the housing 1.1 has a side wall that is at least partially cylindrical, the heat-conducting body 3 can have a tubular shape that is adapted to the circumferential gap 1.6 between the field device electronics 4 and the cylindrical side wall of the housing 1.5. The tubular molded part can also be designed such that it has a wall that is not completely circumferential by 360°, but rather has a wall that is circumferential by less than 360°.

[0039] In order to be able to press the heat conducting body against the housing inner wall in the inserted state, it can optionally be designed in such a way that an outer diameter of the tubular shaped part has an oversize compared to an inner diameter of the cylindrical side wall of the housing 1.5, so that the heat conducting body is pressed against the housing inner wall in the inserted state.

[0040] In addition, the heat-conducting body 3 can have at least two spring elements 3.1, 3.2, with which it is pressed internally against the field device electronics 4 or the inner cup 4.1 at a first contact surface A1 and externally against the side wall of the housing at a second contact surface A2. The spring elements 3.1,

[0041] 3.2 are preferably designed such that the first and / or second contact surface A1, A2 is / are designed to have the largest possible area, ie that the heat-conducting body 3 connects the field device electronics 4 or the inner cup 4.1 in a heat-conducting manner with the largest possible first contact surface A1 and / or connects the circumferential side wall 1.5 of the housing in a heat-conducting manner with the largest possible second contact surface A2. The following has proven particularly advantageous for the ratio of the first contact surface A1 to the second contact surface A2: 0.5 < A1 / A2 < 2; preferably 0.7 < A1 / A2 < 1.3; particularly preferably 0.9 < A1 / A2 < 1.1.

[0042] The heat conducting body 3 and in particular the first and / or second spring elements 3.1,

[0043] 3.2 can be designed in different ways. For this purpose, Figs. 3a, 3b, 4a, 4b, 5 as well as 6a and 6b each show a schematic cross-section (in the upper area of ​​the corresponding figure) and a longitudinal section (in the lower area of ​​the corresponding figure) through correspondingly designed heat conducting bodies. Figs. 2, 3a, 4a and 5 show a first variant, according to which the first spring element 3.1 is formed by several individual or further first spring elements 3.11 and / or the second spring element 3.2 is formed by several individual or further second spring elements 3.21, wherein in this case the sum of the respective individual first or further contact surfaces A11 results in the first contact surface A1 and / or the sum of the respective individual second or further second contact surfaces A21 results in the second contact surface A2.

[0044] Figs. 3b, 4b show a second variant, according to which the heat conducting body 3 comprises only one (single) first spring element 3.1 and / or one (single) second spring element

[0045] 3.2. The first spring element 3.1 or the plurality of individual first spring elements 3.11 can, for example, be formed by raised points or raised contours that extend on an inner surface 3.4 of the, in particular, tubular, heat-conducting body in the direction of a central axis 3.3 of the heat-conducting body. Additionally or alternatively, the second spring element 3.2 or the plurality of individual second spring elements 3.21 can be formed by raised points or raised contours that extend on an outer surface 3.5 of the heat-conducting body 3 in the opposite direction to the central axis 3.3 of the heat-conducting body 3.

[0046] The plurality of individual first spring elements 3.11 and / or a plurality of second spring elements 3.21 can, as shown in Figs. 2, 3a and 5, be designed such that the raised contours are arranged distributed radially around the heat conducting body 3 and extend in the axial direction of the heat conducting body 3.

[0047] Alternatively, the plurality of individual first and / or plurality of second spring elements, as shown in Fig. 4a, can be designed such that the raised contours are arranged distributed in the axial direction on the heat conducting body 3 and are at least partially radially circumferential.

[0048] The heat-conducting body 3 is made of a material with a thermal conductivity of at least 1.5 W / (m*K), preferably at least 50 W / (m*K), particularly preferably at least 100 W / (m*K), and most preferably at least 150 W / (m*K). Aluminum has proven to be a particularly preferred material.

[0049] Alternatively, the thermally conductive body 3 can also comprise a thermally conductive pad or a thermally conductive potting compound, which is introduced into the circumferential gap. The thermally conductive pad or potting compound can be completely introduced into the circumferential gap, as shown in Fig. 6a, so that the thermally conductive body 3 completely fills the circumferential gap 1.6. Alternatively, as shown in Fig. 6b, the thermally conductive pad or potting compound can be only partially introduced into the circumferential gap 1.6.

[0050] List of reference symbols

[0051] 1 field device

[0052] 1.1 Housing

[0053] 1 .2 Cover of the housing

[0054] 1.3 Interior of the field device housing

[0055] 1.4 Housing body

[0056] 1 .5 Circumferential side wall of the housing

[0057] 1 .6 At least partially circumferential gap

[0058] 2 Control and / or display element

[0059] 3 heat conducting bodies

[0060] 3.1 First spring element of the heat conducting body

[0061] 3.11 Further first spring elements of the heat conducting body

[0062] 3.2 Second spring element of the heat conducting body

[0063] 3.21 Additional second spring elements of the heat conducting body

[0064] 3.3 Central axis, especially pipe axis

[0065] 3.4 Inner surface

[0066] 3.5 Exterior surface

[0067] 4 Field device electronics or electronic circuit

[0068] 4.1 Inner cup

[0069] 5 Sensor and / or actuator element

[0070] A1 First contact surface

[0071] A11 Individual contact surfaces of the other first spring elements

[0072] A2 Second contact surface

[0073] A21 Individual contact surfaces of the other second spring elements

Claims

Patent claims 1 . Field device of automation technology (1) with a housing (1.1) for accommodating field device electronics (4) of the field device, wherein the housing comprises a substantially cup-like housing body (1.4) which forms an interior space (1.3), wherein the housing body (1.4) has a preferably cylindrical circumferential side wall (1.5) which forms at least part of an interior space (1.3) for accommodating the field device electronics (4), wherein the field device electronics (4) is introduced into the interior space (1.3) in such a way that an at least partially circumferential gap (1.6) is formed between the field device electronics (4) and the circumferential side wall (1.5), wherein at least in the at least partially circumferential gap (1.6) a heat-conducting body (3) is introduced, which connects the field device electronics (4) in a heat-conducting manner to the circumferential side wall (1.5) of the housing (1.2), so that the Heat conducting body (3) a heat input into the housing (1.2), in particulara heat input on the underside of the housing, to the circumferential side wall (1.5) of the housing.

2. Field device of automation technology according to claim 1, wherein an inner cup (4.1) is arranged in the interior (1.3) of the housing and the field device electronics (4) is at least partially introduced into the inner cup (4.1) and wherein the heat conducting body (3) is designed such that it connects the inner cup (4.1) to the side wall of the housing (1.5) in a heat-conducting manner.

3. Field device of automation technology according to the preceding claim, wherein the heat conducting body (3) is adapted in its shape to the at least partially circumferential gap (1 .6) and in particular is tubular and further comprises at least two spring elements (3.1, 3.2), wherein at least one first spring element (3.1) of the at least two spring elements is designed such that the at least one first spring element (3.1) presses the heat conducting body (3) against the inner cup (4.1) at a first contact surface (A1), so that the heat conducting body (3) is thermally conductively connected to the inner cup (4.1), and wherein at least one second spring element (3.2) of the at least two spring elements is designed such that the at least one second spring element (3.2) presses the heat conducting body (3) against the side wall (1 .5) at a second contact surface (A2), so that the heat conducting body (3) is thermally conductively connected to the side wall of the housing (1.5) is connected.

4. Field device of automation technology according to the preceding claim, wherein the at least one first spring element (3.1) is formed by several individual first spring elements and the individual contact surfaces (A11) of the respective individual first spring elements (3.11) in total result in the first contact surface (A1) and / or that the at least one second spring element (3.2) is formed by a plurality of individual second spring elements (3.21) and the individual contact surfaces (A21) of the respective individual second spring elements in total result in the second contact surface (A2).

5. Field device of automation technology according to one of claims 3 or 4, wherein the at least one first spring element (3.1) or the plurality of individual first spring elements (3.11) are formed by raised points which extend on an inner surface (3.4) of the, in particular, tubular heat conducting body in the direction of a central axis (3.3) of the heat conducting body and / or the at least one second spring element (3.2) or the plurality of individual second spring elements (3.21) are formed by raised points which extend on an outer surface (3.5) of the heat conducting body (3) in the opposite direction to the central axis (3.3) of the heat conducting body (3).

6. Field device of automation technology according to one or more of claims 3 to 5, wherein the heat conducting body (3) is designed such that an outer contour, in particular an outer diameter of the, in particular tubular, heat conducting body has an excess in comparison to an inner contour, in particular an inner diameter of the, in particular cylindrical, side wall of the housing (1.5).

7. Field device of automation technology according to one or more of claims 3 to 6, wherein the plurality of individual first and / or second spring elements are arranged distributed radially around the heat conducting body (3) and the raised points extend in the axial direction of the heat conducting body (3).

8. Field device of automation technology according to one or more of claims 3 to 6, wherein the plurality of individual first and / or second spring elements are arranged distributed in the axial direction on the heat conducting body (3) and the raised areas are formed at least partially radially circumferential.

9. Field device of automation technology according to one or more of claims 3 to 8, wherein the spring elements are designed such that the ratio of the first contact area (A1) to the second contact area (A2) is: 0.5 < A1 / A2 < 2, preferably 0.7 < A1 / A2 < 1.3, particularly preferably 0.9 < A1 / A2 < 1.

1.

10. Field device of automation technology according to one or more of the preceding claims, wherein the heat conducting body is made of a material with a thermal conductivity of at least 1.5 W / (m*K), preferably of at least 50 W / (m*K), particularly preferably of at least 100 W / (m*K), most particularly preferably of at least 150 W / (m*K).

11. The automation technology field device according to one or more of the preceding claims, wherein the heat-conducting body (3) and / or the inner cup is / are made of aluminum.

12. The automation technology field device according to claim 1, wherein at least one heat-conducting pad is inserted as a heat-conducting body (3) at least into the at least partially circumferential gap (1.6).

13. Field device of automation technology according to claim 1, wherein at least in the at least partially circumferential gap (1 .6) a thermally conductive casting compound is introduced as a heat conducting body (3).

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