DE102016015726B4 - Method of manufacturing a housing and such a housing - Google Patents

Abstract

Method for producing housings for electronic components, in particular temperature controllers, in which a one-piece, closed housing block is extruded, which has a front side (24) and a rear side (25) with a holding profile (26) for connection to a top-hat rail,- the housing block is divided transversely to form a plurality of housings (11) and receiving spaces (27) for electronic components are introduced into the housing (11) or the housing block, one receiving space (27) then being introduced into a housing (11).

Description

The invention relates to a method for manufacturing a housing and such a housing

Special requirements must be observed when controlling the temperature of heaters in potentially explosive atmospheres. The controllers or thermostats used for this must be protected or designed accordingly to prevent an explosion from contact sparks when switching under load or from electrostatic discharge. The ATEX directive of the European Union specifies the requirements for the respective devices and systems that may be used in potentially explosive atmospheres. In the case of controllers or heaters approved for this purpose, so-called EX controllers or EX heaters, it is necessary, for example, for the outer housing to have a grounding connection to prevent the housing from becoming electrostatically charged. The electrical components arranged in the housing require an additional ground connection. In the case of the temperature control devices usually available on the market in potentially explosive atmospheres, the temperature controller arranged in the housing is often protected by a ground connection in the housing. However, this complicates the manufacture and assembly of the device. In addition, the switching accuracy of such a known device is unsatisfactory, especially when controllers with a high switching capacity are used, which enables direct control of the heating devices connected to the controller. If the temperature controller is subjected to high currents, it heats up due to the physical internal resistance. The resulting drift in the switching point or the hysteresis behavior of the controller is disadvantageous.

In addition, electrical equipment used in hazardous areas must be hermetically sealed to prevent explosive mixtures from entering the equipment.

DE 195 40 339 A1 discloses an outlet box for a power distribution system, which has a housing with a base profile element and a cover profile element. Cover end parts are provided for closing the end faces of the housing. The two profile elements are manufactured using an extrusion process. According to DE 195 40 339 A1 thus the housing has two extruded profile elements.

In DE 20 2004 019 381 U1 describes a device for snap-mounting low-voltage electrical equipment. The device has a device housing that is attached to a top-hat rail. The device housing is made by injection molding.

According to DE 102 43 383 B3 discloses a device for fastening installation devices, for example electrical switching devices, which has a housing with an injection-molded carriage for mounting on a mounting rail.

The invention is based on the object of specifying a method for producing a housing which, with low production costs, allows the production of housings which can be used, inter alia, in connection with electronic components, specifically temperature controllers, in potentially explosive areas. The invention is also based on the object of creating such a housing.

According to the invention, the object is achieved with regard to the manufacturing method by the subject matter of claim 1 and with regard to the housing by the subject matter of claim 4.

The invention is based on the idea of specifying a method for producing housings for electronic components, in particular temperature controllers, in which a one-piece, closed housing block is extruded, which has a front side and a rear side with a holding profile for connection to a top-hat rail. The housing block is divided transversely to form a plurality of housings. Accommodating spaces for the electronic components are introduced into the housing or into the housing block. It is therefore possible to introduce receiving spaces before cutting to length, ie before dividing the connected, one-piece, closed (solid) housing block. Alternatively, the accommodation spaces can be introduced into the individual housings after they have been divided, in which case one accommodation space is then introduced into a housing in each case.

The invention has the advantage that the housing produced in this way is particularly suitable for use with a device for temperature control in areas at risk of explosion, since such housings are in one piece and thus enable optimal hermetic sealing of the temperature controller arranged in the housing. It is also possible to use the housing produced according to the invention in other technical areas where it is important to seal the temperature controller or the electronic component in general as hermetically as possible, such as in environments with high humidity where high IP protection classes are required.

Another advantage of the method according to the invention is that the manufacturing costs are significantly reduced.

The receiving spaces are preferably introduced by a machining process, in particular by drilling.

More preferably, a groove is introduced in the direction of extrusion in one side, in particular in the underside of the housing block, which groove has internal teeth for a retaining screw. The retaining screw can be connected to a line for the potential equalization of the housing in order to avoid electrostatic charging of the housing. The internal toothing of the groove is preferably formed during extrusion. It is also possible to introduce the groove with the internal toothing into the housing in some other way, for example by means of a machining process such as milling.

According to the independent claim 4, the invention relates to a housing for an electronic component, in particular a temperature controller, with a front and a rear which has a holding profile for connection to a top-hat rail. The housing is designed in one piece and is extruded and has a receiving space for the electronic component.

The housing is preferably produced by the method according to the invention.

One-piece means that the housing walls merge continuously, i.e. are not composed of individual parts. In addition, there are no openings, apart from the opening for the cable bushing, which pass through the housing walls, as is often the case for rivet connections in the prior art.

In a particularly preferred embodiment, the housing is made of a conductive material, in particular aluminum or an aluminum alloy. This reduces the risk of electrostatic charging of the housing. In addition, the use of aluminum or an aluminum alloy improves the heat transfer properties of the housing, so that the heat transfer to the temperature controller is improved in the case of a contact controller.

The housing preferably has other functionalities such as screw attachments oriented in different directions, i.e. lateral and rear screw attachments, a DIN clip and a grounding connection. The front of the housing can be designed with a visually appealing design.

The receiving space preferably has an opening which forms a cable bushing for the electronic component. The opening is also used to mount the electronic component, specifically the temperature controller.

The holding profile can have a receiving slot and a latching edge arranged parallel thereto with a run-in bevel, between which the top-hat rail can be locked. A retaining clip for the top-hat rail is preferably arranged in the receiving slot.

The terms "front, back, bottom and top" refer to the orientation or position of the housing when installed. The back of the housing is connected to a DIN rail.

Also described is a device for temperature control in potentially explosive areas, which has a temperature controller and a housing in which the temperature controller is arranged. The housing has a sealed opening through which electrical leads of the temperature controller are routed. The temperature controller has a measurement surface which is in direct contact with an inner wall of the housing, at least in some areas, and is electrically connected to a grounding lug. The grounding lug is electrically connected to another lead which is routed through the opening and preferably forms a unit.

Due to the direct contact of the measuring surface with the inner wall of the housing, an optimal heat transfer from the temperature controller to the environment and vice versa is possible. In other words, the bi-directional heat transfer between the temperature controller and the environment is significantly improved.

This has advantages for various possible uses of the device described.

When the temperature controller is subjected to high currents, it is desirable to dissipate the resulting heat as quickly and effectively as possible. The direct attachment of the temperature controller or its measuring surface to the inner wall of the housing avoids the formation of an insulating layer of air between the housing and the temperature controller and improves the cooling of the temperature controller. This increases the measuring and thus the control accuracy and the stability of the switching points. Due to the direct temperature exchange with the environment, a temperature equilibrium is established, which supports the controller in its accuracy. In this case, it makes sense to use the device described as a room controller, because then the outside of the housing is freely accessible in the area of the measuring surface, so that good cooling of the housing and thus of the temperature controller located directly on the inner wall of the housing is possible.

The good heat transfer properties can also be used in the other direction, i.e. with a heat gradient that drops towards the temperature controller, because the heat flow is then transferred quickly and efficiently via the housing wall to the temperature controller. In this case, the device described is particularly well suited as a contact sensor, in which the housing wall is connected in the area of the measuring surface to or contacts a component whose temperature is to be measured.

The grounding lug that is electrically connected to the measuring surface has the advantage that the ground connection cannot be made via the housing, but rather by another line that is electrically connected to the grounding lug. Together with the existing electrical lines of the temperature controller, this transmission is routed to the outside through the opening in the housing. This facilitates the manufacture of the device described. The grounding lug also has the advantage that the temperature controller can be placed well in the housing, so that the measurement surface can be placed directly against the inner wall of the housing.

Another advantage of the device described is that the grounding lug and the temperature controller, or the components of the temperature controller, such as the controller and the measuring surface (sensors), form a unit that can be handled together during assembly. This offers a significant simplification over the prior art, in which the controller is grounded through electrical contact with the housing.

For example, the grounding lug can extend along a side wall of the temperature controller and protrude beyond its end face. In this embodiment of the device described, the compact and space-saving design of the temperature controller is advantageous since the grounding lug can be guided closely to the side wall of the temperature controller or bears directly against the side wall of the temperature controller. The ground lug is therefore routed in the direction of the electrical connections of the temperature controller, which are connected to the cables. The controller, which forms a unit with the grounding lug, is therefore particularly compact and easy to assemble. The grounding lug protruding over the face is easily accessible for the connection to the further electrical line.

In a further embodiment of the device described, the free end of the grounding lug is angled towards the temperature controller, as a result of which the connection to the further electrical line is further facilitated.

The measurement surface preferably forms a lateral step that is electrically connected to the grounding lug. This also improves the compact form of the temperature controller, because the grounding lug is flush with the measuring surface on the side due to the offset.

The device described preferably has a device for strain relief of the lines, which is arranged in the opening. The device for strain relief also serves to seal the opening.

In a further preferred embodiment of the device described, the temperature controller is designed to be rotationally symmetrical. It is particularly advantageous if the temperature controller is designed in the form of a knob thermostat. The rotationally symmetrical temperature controller helps to simplify the manufacture of the device because the receiving space in the housing for the temperature controller can be produced by a simple blind hole. In addition, the grounding lug eliminates the connection of the ground to the housing, since this is directly connected to the live part.

The temperature controller can be connected to the inner wall of the housing in a materially bonded manner, for example by a contact connection, such as by a thermal paste. Additionally or alternatively, a heat conducting sheet can be arranged between the measuring surface and the inner wall. This is a particularly simple way of directly connecting the temperature controller to the inner wall of the housing.

Additionally or alternatively, a mechanical preload can be applied to the temperature controller, for example by a compression spring, which presses the measurement surface against the inner wall.

The temperature controller features a bimetallic switch, which has proven to be particularly reliable in connection with controlling the temperature in potentially explosive atmospheres.

The device described can be used as a contact controller or as a room controller. If the device used as a contact regulator the good heat transfer properties come into play when measuring the temperature of the contacted component. The device can be used as a room controller if the device is used to control a heater, specifically if the device is used with high currents for direct control of the heater, because the heat generated in the temperature controller is then easily dissipated to the outside.

The device can also be referred to as a device or product.

The invention is explained in more detail below using an exemplary embodiment with reference to the attached schematic drawings.

• 1 eine perspektivische Ansicht einer Vorrichtung zur Temperaturregelung in explosionsgefährdeten Bereichen mit einem Gehäuse nach einem erfindungsgemäßen Ausführungsbeispiel;
• 2 einen Schnitt durch die Vorrichtung nach 1;
• 3 eine perspektivische Darstellung des Temperaturreglers gemäß 1 mit angeschlossenen elektrischen Leitungen;
• 4 einen Schnitt durch das Gehäuse gemäß 1 ohne Einbauten;
• 5 eine Rückansicht der Vorrichtung nach 1 mit einer an der Vorrichtung befestigten Hutschiene; und
• 6 eine Seitenansicht der Vorrichtung nach 1 mit einer an der Vorrichtung befestigten Hutschiene.

In these show

• 1 a perspective view of a device for temperature control in potentially explosive atmospheres with a housing according to an embodiment of the invention;
• 2 a section through the device 1 ;
• 3 a perspective view of the temperature controller according to 1 with connected electrical lines;
• 4 according to a section through the housing 1 without internals;
• 5 a rear view of the device 1 with a top-hat rail attached to the device; and
• 6 a side view of the device 1 with a top-hat rail attached to the device.

The device for temperature control, as in the 1 and 2 shown, is intended for use in potentially explosive atmospheres where a temperature measurement is to be carried out, for example, in a flammable gas atmosphere or in a dusty environment. The device is therefore sealed against gases or dust.

For this purpose, the device has a temperature controller 10 which is arranged in a housing 11 . The housing 11 has an opening 12 through which electrical lines 13, 14 of the temperature controller 10 are routed to the outside. The opening 12 is sealed in a manner known per se so that gases or other substances cannot get into the housing. The opening 12 is sealed by a strain relief device 23 which is screwed into the opening 12 or otherwise connected to it. The connection between the device for strain relief 23 and the housing 11 is sufficiently tight to be used in potentially explosive atmospheres. In particular, the connection satisfies valid ATEX standards.

The housing 11 has an inner bore which forms a hollow space or receiving space 27 for the temperature controller 10 . The temperature controller 10 is rotationally symmetrical, in particular essentially cylindrical, so that it fits into the cavity. In general, the shape and size of the temperature controller 10 and the shape and size of the receiving space 27 are matched to one another. The temperature controller does not necessarily have to be round. Angular temperature controllers are also possible.

In order to control a device, for example a heating device, the temperature controller is connected in a manner known per se to electrical lines 13, 14, which are led to the outside through the opening 12 and the strain relief device 23. The electrical lines 13, 14 are sheathed. In concrete terms, the electrical lines 13, 14 are connected to corresponding contact terminals which are arranged on a first end face 20 of the temperature controller.

The electrical lines 13, 14 are connected to a bimetallic switch (not shown), which is arranged inside the temperature controller 10 and forms the temperature sensor of the temperature controller. As in 2 clearly visible, the temperature controller 10 has a measuring surface 15 . The bimetallic switch is arranged inside the temperature controller behind the measuring surface 15 .

During operation of the temperature controller 10, a flow of heat is transported through the measurement surface 15 into its interior, ie to the bimetallic switch, which closes or opens when the switching point is exceeded. The measurement surface 15 is formed on a second end face of the temperature controller 10 . As in 2 clearly visible, the area of the measuring surface 15, which forms the second end face of the temperature controller 10, is directly connected to an inner wall 16 of the housing 11 and rests against it. This improves the heat transfer from the temperature controller 10 to the housing and vice versa.

Direct contact means, on the one hand, direct contact without intermediate layers, so that the measurement surface 15 touches the inner wall 16 directly. On the other hand, a combination of the measuring surface 15 with the inner wall 16 by means of heat-conducting paste and/or heat-conducting plates is also understood as direct contact, because this is the case is a material connection between the measuring surface 15 and the inner wall 16, which causes good heat transfer.

The measurement surface 15 is not only limited to the end face of the temperature controller 10, but forms a peripheral ring which is arranged concentrically to a side wall 19 of the temperature controller. In other words, the measuring surface 15 forms a cap or hood at the end, which surrounds the wall of the temperature controller 10 at least in certain areas. The ring-shaped section of the measuring surface and the straight, end-side section of the measuring surface 15 are connected to one another in one piece.

The device has, as in the 2 , 3 to recognize a grounding lug 17 which is electrically connected to the measurement surface 15. Specifically, the grounding tab 17 is connected to the annular portion of the measurement surface 15 . This can be produced by a soldered, welded or glued connection or in one piece. The grounding lug 17 extends, as well in 3 to recognize parallel to the side wall 19 of the temperature controller 10 and thus along the side wall 19. The grounding lug 17 is located on the side wall 19 and is on the front side 20 of the temperature controller 10 before. The free end 21 of the grounding lug 17 is angled inwards, ie toward the temperature controller 10, and forms a fork for receiving the additional electrical line 18. As in FIG 2 , 3 As can further be seen, the measuring surface 15, specifically the annular section of the measuring surface 15, forms a shoulder 22 which merges into the grounding lug 17 and is therefore electrically connected to it. This is a direct, fixed connection with the electrically conducting contacts.

The above-described connection of the grounding lug 17 to the measuring surface 15 enables direct contact of the measuring surface 15, specifically the end section of the measuring surface 16, with the inner wall 16 of the housing 11. For this purpose, the temperature controller 10 is subjected to a contact pressure. In the simplest case, this is generated by the lines 13, 14, 18, which have an excess length between the strain relief device 23 and the end face 20 of the temperature controller 10, so that the lines 13, 14, 18 press the temperature controller 10 against the inner wall 16 . Alternatively or additionally, a compression spring can be used. Furthermore, an integral connection between the temperature controller 10 and the inner wall 16 of the housing 11 is possible by means of a heat-conducting paste or a heat-conducting sheet.

The housing 11 is described both in connection with the temperature control device, ie in combination with the temperature controller 10 arranged in the housing 11 .

In addition, the housing 11 is disclosed and claimed as such, ie without the temperature controller 10 arranged in the housing 11, since the housing 11 as such is also suitable for accommodating electronic components other than temperature controllers. The housing 11 is in 4 shown in section. This in 4 Housing 11 shown and the following explanations in connection with the housing 11 are also disclosed in connection with the device for temperature control in potentially explosive atmospheres. It's about the 1 until 6 for one and the same housing.

The housing 11 is made of a conductive material, which limits the risk of the housing 11 becoming electrostatically charged. Concretely, the case is made of aluminum or an aluminum alloy.

As per average 4 clearly visible, the housing 11 is in one piece. This means that the housing 11 is not assembled from several individual parts, but forms a single monolithic component with continuous walls. This applies not only to the in 4 shown sectional plane, but for the entire housing 11.

The housing 11 has a receiving space 27 in which the temperature controller, such as in 2 shown, or another electronic component can be arranged. The receiving space 27 is designed as a cylindrical blind hole. Other versions are possible.

The receiving space 27 has an opening 12 formed on the underside 28 of the housing 11 . On the one hand, the opening 12 forms the access to the receiving space for the assembly of the temperature controller 10. On the other hand, after the assembly of the temperature controller 10, the device for the strain relief 23 is inserted, in particular screwed, which seals the opening 12 from the environment, so that the opening 12 Cable bushing forms. Alternatively, a potting compound can be used to seal the opening 12 .

The holding profile 26 is used to connect the housing 11 to a top-hat rail, as shown in FIGS 5 , 6 shown. For this purpose, the holding profile 26, as in the 1 , 2 and 6 shown, has a receiving slot 31 and a latching edge 32 arranged parallel to the receiving slot 31 . The receiving slot 31 and the latching edge 32 extend substantially parallel to the underside 28 of the housing 11. The latching edge 32 is provided with a one running slope 33 connected to which the lower edge of the rail when clipping the housing 11 is performed. The top-hat rail is guided over the locking edge 32 and snaps into the gap between the locking edge 32 and the rear wall 35 of the housing 11, as in FIGS 5 , 6 to recognize.

A retaining clip 34 or retaining clip or tension spring or spring clip is arranged in the receiving slot 31 and rests on the bottom of the receiving slot 31 on the one hand and on the top-hat rail on the other hand. The retaining clip 34 serves to latch the housing 11 to the top-hat rail when the top-hat rail is passed over the latching edge 32 . When locking, the retaining clip 34 is pressed together and thus allows the latching edge 32 to be overcome. When the latching edge 32 is arranged in the gap between the rear wall 35 and the latching edge 32, the retaining clip 34 exerts a spring force on the top-hat rail, which securely holds the housing 11 with it this fixed.

A groove 29 is formed on the underside 28 of the housing 11 and has internal teeth 30 . The groove 29 extends parallel to the underside 28 across the entire width of the housing 11. The groove 29 serves to receive a retaining screw 36, as shown in FIGS 2 and 6 shown. The retaining screw 36 serves to connect the housing 11 to a ground wire. The retaining screw 36 is arranged in the groove 29 in a laterally displaceable manner.

In the rear area, the housing has screw openings 37A, 37B for lateral attachment. A further opening, in particular a drilled hole 39, is formed at the rear of the housing for a standard screw attachment.

The case 11 is manufactured as follows.

The basic shape of the housing 11 is formed by extrusion. A one-piece closed (solid) housing block with the in 1 shown outer profile made. The outer profile includes the retaining profile 26 on the back 25 of the housing 11, a curved surface on the front 24 and the groove 29 with the internal teeth. The cavity 37 at the back 25 of the housing 11 is also formed during extrusion.

The receiving spaces 27 are introduced into the one-piece, closed, linear housing block on the underside 28, for example by drilling. Then the housing block is cut to length, ie divided transversely. This results in several housing, one of which in the 1 until 6 is shown.

All edges and surfaces of the housing 11 extend in the extrusion direction, i.e. also the locking edge 32, the inlet bevel 33, the receiving slot 31 and the groove 29. Only the side surfaces 38 of the housing 11, which are created during transverse dividing, and the receiving space 27 are in a different one Direction oriented as these are not formed during extrusion.

The receiving spaces 27 can be introduced into the housing block before the transverse division or individually in the housing after the transverse division. As in 4 shown, each housing has a single receiving space 27 in the illustrated embodiment.

reference list

10

temperature controller

11

Housing

12

opening

13, 14

Electric lines

15

measuring surface

16

inner wall

17

grounding flag

18

Another line

19

Side wall

20

face

21

free end

22

Unit volume

23

Device for strain relief

24

front

25

back

26

holding profile

27

recording rooms

28

bottom

29

groove

30

internal teeth

31

receiving slot

32

locking edge

33

inlet slope

34

holding clamp

35

back panel

36

retaining screw

37

cavity

37A, 37B

Lateral screw fastening

38

side faces

39

Drill hole for standard screw attachment

Claims (8)

Process for the production of housings for electronic components, in particular temperature controllers, in which - a one-piece, closed housing block is extruded, which has a front (24) and a rear (25) with a retaining profile (26) for connection to a top-hat rail, - the housing block is divided transversely to form a plurality of housings (11) and - Receiving spaces (27) for electronic components are introduced into the housing (11) or the housing block, one receiving space (27) then being introduced into a housing (11). procedure after claim 1 , characterized in that the receiving spaces (27) are introduced by a machining process, in particular by drilling. procedure after claim 1 or 2 , characterized in that in one side, in particular the underside (28) of the housing block, a groove (29) is introduced in the extrusion direction, which has internal teeth (30) for a retaining screw. Housing for an electronic component, in particular a temperature controller, with a front (24) and a rear (25), the rear (25) having a retaining profile (26) for connection to a top-hat rail, characterized in that the housing (11) is formed in one piece and extruded and has a receiving space (27) for the electronic component. housing after claim 4 , characterized in that the housing (11) is formed from a conductive material, in particular from aluminum or an aluminum alloy. housing after claim 4 or 5 , characterized in that the receiving space (27) has an opening (12) which forms a cable bushing for the electronic component. Housing after one of Claims 4 until 6 , characterized in that the holding profile (26) has a receiving slot (31) and a latching edge (32) arranged parallel thereto with a run-in bevel (33), between which the top-hat rail can be locked. housing after claim 7 , characterized in that a holding clamp (34) for the top-hat rail is arranged in the receiving slot (31).

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