Modular field device

The invention relates to a modular field device, which is simply and safely assemblable. For this, the field device comprises: a housing having an electrical plug contact arranged in a housing interior, a mechanical securement, which is embodied to secure a first electronic component in the housing interior, a second electronic component, which is arrangeable in the housing interior and which is electrically contactable with the plug contact, and an elastic connection, which is embodied to connect the first electronic component elastically with the second electronic component. A division of tasks between two electronic components enables a modular design of the field device with universally applicable electronic components. In addition, the elastic connection provides a simple, mechanical securement of the first electronic component in the housing with simultaneous, safe, electrical connection of the second electronic component with the plug contact.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims the priority benefit of German Patent Application No. 10 2017 119 358.8, filed on Aug. 24, 2017 and International Patent Application No. PCT/EP2018/072527, filed on Aug. 21, 2018, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a modular field device, which is simply and safely assemblable.

BACKGROUND

In automation technology, for example, for large industrial process plants, field devices are often applied, which serve for registering relevant process parameters of process media. Suitable measuring principles are applied for registering the process parameters. Corresponding sensors are applied in, among others, fill level measuring devices, flowmeters, pressure- and temperature measuring devices, pH, redox potential, measuring devices, conductivity measuring devices, etc. They register relevant process parameters in containers or tubes, in which a process medium is located, parameters such as fill level, flow, pressure, temperature, pH value, redox potential, conductivity or dielectric constant. A large number of these field devices are produced and sold by the firm, Endress+Hauser.

Increasingly, field devices are being modularly designed. This means for field devices that different field device types, types such as, for example, pressure measuring devices and fill level measuring devices, are partially constructed from the same components. Advantageously, the application of equal components in different field device types concerns, above all, electronic components, which perform higher functions, such as, for example, communication or measurement data processing. A modular design of individual components can bring about significant cost reduction in the development and manufacturing logistics of new field device types.

However, the modular design of a field device type can make its assembly more difficult, since the number of components, especially electronic components, increases while the space available in the housing interior of the field device remains unchanged. At the same time, the individual electronic components must be electrically and/or mechanically contacted both with one another, as well as also with the housing interior. Thus, a more complex, installed situation makes the assembling more difficult.

SUMMARY

An object of the invention, therefore, is to provide a modular field device, which is simply and safely assemblable.

The invention achieves this object with a field device, comprising:A housing havingan electrical plug contact arranged in a housing interior,a mechanical securement, which is embodied to securea first electronic component in the housing interior,a second electronic component, which is arrangeable in the housing interior and which is electrically contactable with the plug contact, andan elastic connection, which is embodied to connect the first electronic component elastically with the second electronic component.

A division of tasks between two electronic components enables a modular design of the field device with universally applicable electronic components. In addition, the elastic connection enables a mechanical securement of the first electronic component in the housing with simultaneous electrical connection of the second electronic component with the plug contact. Inherently, the electrical plug contact and the mechanical securement of the first electronic component additionally mechanically secures the second electronic component in the housing interior, without requiring that the second electronic component must be directly accessible. In such case, the elastic connection offers the special advantage that the force, which acts during the assembly on the electrical plug contact, is reduced. In this way, danger of damage is reduced and, thus, the assembling is, as a whole, safer, especially in the case of component tolerance related, geometrical deviations of the housing and/or the electronic components.

In order to reduce the force on the plug contact during the securement of the electronic components in the housing sufficiently, the elastic connection is advantageously so designed that it permits a spring movement between the first electronic component and the second electronic component of at least 2 mm. The particular design of the elastic connection of the invention is not limited. The elasticity can be achieved, for example, by providing that the elastic connection comprises, arranged between the first electronic component and the second electronic component, at least one elastic component, for example, a suitable elastomeric material having a defined geometry, or a spring element such as, for example, a leaf spring, helical spring or Belleville spring having an appropriate spring constant.

A first possibility for implementing the securement function of the mechanical connection provides that the elastic connection includes at least one headed stud on the first electronic component or on the second electronic component, and a corresponding engagement opening for the stud on the other electronic component. Advantageously, there are especially at least three studs. In such case, the engagement openings can be embodied, such that the first electronic component is connected to and/or released from the second electronic component either by means of a rotational movement or a translatory movement.

An alternative opportunity for implementing the securement function provides that the elastic connection comprises at least one snap fit hook on the first electronic component or on the second electronic component, and a corresponding engagement protrusion for the snap fit hook on the other electronic component. In such case, the at least one snap fit hook and the corresponding engagement protrusion are preferably designed releasably, in order in the case of a defective electronic component to enable replacement.

The danger of damage to the plug contact can further be reduced, when at least one portion of the housing interior, and an outer contour of the first electronic component and/or an outer contour of the second electronic component, are designed as a guide of the first electronic component and/or as a guide of the second electronic component, in order to contact the second electronic component to the plug contact. In such case, another possible further development provides that the guide comprises an end stop for the first electronic component or the second electronic component. The end stop can especially be embodied as a ledge in the housing inner wall. In this way, it can be enabled that the guide and the end stop are designed with accurate fit for mechanical securement of the first electronic component (with simultaneous contacting of the second electronic component with the plug contact).

DETAILED DESCRIPTION

FIG. 1shows a housing2for a modularly constructed field device1having two electronic components3,4. In such case, a typical construction of the electronic components3,4provides, as a rule, that each includes at least one electronics printed circuit board, which, in turn, is encapsulated, for example, in an appropriate (plastic-) box and/or potting material.

Housing2of the field device1includes in the housing interior20a plug contact21, which serves for electrical connection of the second electronic component4arranged in the housing interior20. Thus, via the plug contact21, an electrical connection of the second electronic component4to the outside of the housing2can be implemented. Especially in the case of embodiment of the plug contact21as a high frequency capable, coaxial plug, such can be utilized, for example, in order, in the case of radar based, fill level measurement, to drive an antenna arranged outside of the housing2by means of the second electronic component4. Likewise, the plug contact21can, however, also be applied as a data interface of the field device1to a superordinated unit, such as a process control station. In such case, of course, the second electronic component4is to be designed with a socket appropriate for the particular design of the plug contact21.

As a result of the modular design, the field device1shown inFIG. 1includes, besides the second electronic component4, also a first electronic component3. In such case, the first electronic component3is connected with the second electronic component4via an elastic connection50,52,53. A mechanical securement22,23provided for securing the first electronic component3in the housing interior20as well as an electronic contacting between the first electronic component3and the second electronic component4are not shown in detail inFIG. 1. A possible design of the mechanical securement22,23can be based on a ledge23on the inner wall of the housing2. In such case, the ledge23can function as an end stop for the first electronic component3, and the first electronic component3can be secured to the ledge23by suitable means, for example, by means of a screwed connection22(seeFIG. 3).

The assembly of the field device1is simplified by the elastic connection50,52,53of the invention between the two electronic components3,4. In such case, a first variant of the assembly provides that the first electronic component3is connected with the second electronic component4via the elastic connection50,52,53before installation in the housing interior20, and then the two electronic components3,4are introduced into the housing interior20via a housing opening24. In such case, the second electronic component4is first contacted with the plug contact21and then the first electronic component3is mechanically secured in the housing interior20.

In a second variant of the assembly, first, the second electronic component4is introduced separately, without the first electronic component, via the housing opening24into the housing interior20and contacted with the plug contact21. Then, the first electronic component3is brought into the housing interior20via the housing opening24and, with appropriate design of the elastic connection50,52,53, connected mechanically with the second electronic component4. Also in the case of this variant, lastly, the first electronic component3is mechanically secured in the housing interior20(for example, by means of the screwed connection ofFIG. 3).

In the case of both variants of assembly, the elastic connection50,52,53of the invention provides the advantage that force acting on the sensitive plug contact21during the securement of the first electronic component3to the housing interior20is reduced, above all in cases where the mechanical securement22of the first electronic component3is, due to component- and production tolerances, not arranged exactly at its preferred position. This especially reduces the danger of damaging the plug contact21during the assembly. This provides, as a whole, a simplified assembly. After the assembly, the elastic connection50,52,53provides during operation, moreover, the advantage that the plug contact21contacts with a defined, steady prestress, due to the elastic connection50,52,53. Thus, a possible loose connection is prevented. This increases the operational safety of the field device1.

The danger of damage to the plug contact21during assembly can be further reduced, when at least one portion of the housing interior20, the corresponding outer contour of the first electronic component3and/or the corresponding outer contour of the second electronic component4are/is designed as a guide25of the first electronic component3and/or the second electronic component4. In such case, the guide25is preferably so designed that the second electronic component4during the assembly after entering into the guide25is compelled to correctly engage with the plug contact21. In such case, the ledge23can serve not only as part of the mechanical securement22of the first electronic component3, but, also, with appropriate arrangement also as an end stop23of the guide25.

FIG. 1indicates a first design of the elastic connection50,52,53. As shown inFIGS. 2a, 2band 2cin further detail, this design of the elastic connection50,52,53is based on three, headed studs52on the first electronic component3and corresponding engagement openings53on the second electronic component4. This combination of studs and engagement openings provides the actual mechanical securement. An opposite arrangement of the studs52on the second electronic component4would likewise be an option. Also the application of more or less than three studs52is, of course, not excluded. For assuring the elasticity of the elastic connection50,52,53, an elastic component50(for example, an elastomeric washer) is provided around each stud52. In such case, the length of each stud52relative to the thickness of the elastic component50is so dimensioned that a corresponding spring movement of the elastic connection50,52,53(as regards the separation between the two electronic components3,4) is preferably greater than 2 mm. As can be seen fromFIGS. 2band 2c, implementing the elastic connection50,52,53based on studs53provides the opportunity for designing the engagement openings53such that the first electronic component3is connectable with, or releasable from, the second electronic component4either by translation (FIG. 2b) or by rotation (FIG. 2c).

An alternative design of the elastic connection51,54,55is shown inFIG. 3. In the case of the design ofFIG. 3, the mechanical connection between the first electronic component3and the second electronic component4is effected via three snap fit hooks54. In the case of the embodiment shown inFIG. 3, three snap fit hooks54are arranged on the second electronic component4and so oriented relative to the first electronic component3that the snap fit hooks54engage on corresponding engagement protrusions55on the outer contour of the first electronic component3. Three spring elements51, which are arranged between the two electronic components3,4, provide resilience in the connection51,54,55. For allowing the spring movement, the snap fit hooks54have corresponding openings for the engagement protrusions55, which enables a shifting of the engagement protrusions55within the openings by at least the desired spring movement.

The embodiment shown inFIG. 3shows an additional variant of the invention, in the case of which the spring elements51and snap fit hooks54are implemented as one, continuous, plastic component, wherein this plastic component is pushed as a cap onto the second electronic component4.

FIG. 4shows that at least in the case of application of snap fit hooks54also a Belleville spring can be applied as spring element51.

LIST OF REFERENCE CHARACTERS