AU2008200646A1

AU2008200646A1 - Casing for an electric house technology device and electric house technology device

Info

Publication number: AU2008200646A1
Application number: AU2008200646A
Authority: AU
Inventors: Ralf Briese; Michael Ewen; Hubert Nolte
Original assignee: Stiebel Eltron GmbH and Co KG
Current assignee: Stiebel Eltron GmbH and Co KG
Priority date: 2007-02-10
Filing date: 2008-02-11
Publication date: 2010-03-18
Anticipated expiration: 2028-02-11
Also published as: AU2008200646B2; DE102007006692B3

Description

2 Housing for an electrical building service equipment as well as an electrical building service equipment This application concerns a housing for an electrical building service equipment 5 as well as an electrical building service equipment. A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the 10 common general knowledge as at the priority date of any of the claims. To increase the efficiency of heat pumps, a suitable heat insulation should be provided. As heat pumps are mounted, inter alia, in residential buildings, a sound insulation of the heat pump is also required. 15 In this connection the housing of a heat pump or of an electrical building service equipment is typically manufactured from sheet metal. Sound insulating mats as well as insulating mats are used for sound insulation and for thermal insulation. In addition, the prerequisites for a housing of an electrical building service 20 equipment intensify when it is installed in the open air. For this purpose typically the ends of a cylindrical thin sheet metal casing are joined with one another by spot-welding along the development of the casing. By doing so the ends of the casing are spot-welded at right angles to its circumference. The metal casings are joined and subsequently lacquered. A storage container for the heat pump is 25 introduced into the sheet metal casing and filled with foam. Since the metal casing is lacquered only after joining, the width of the lacquering has to be correspondingly made to suit. Spot-welded sheet metal parts can badly corrode in the open air. 30 While pre-lacquered sheet metals may be joined, when the radii are too small, the lacquer can peel off, so that the joining edges may have lacquering defects, that are not corrosion-resistant on the one hand and impair the aesthetic impression on the other.

3 CA 1 195 910 shows a foam-insulated hot water container that can be heated by gas or electricity. Hose-like seals, that can be inflated by compressed air, are used for closing the insulating foam against the combustion chamber during the manufacturing process (i.e. while being filled with foam). A burner unit, that has a 5 circular construction and is provided on the bottom of the equipment, can be separated from the container unit for the purpose of maintenance. In this case, however, hose-like seals that can be inflated by compressed air, have to be provided, that can burst, for example, during a manufacturing step, so that during foaming the foam can expand even in those areas which do not need to be filled 10 with foam. Furthermore, such hose-like inflatable seals are elaborate and expensive. It would be desirable to provide a housing for an electrical building service equipment that makes an efficient heat insulation and sound insulation possible 15 and can be installed in a weather-resistant manner, as well as to provide a heat pump appliance. According to one aspect of the present invention there is provided a housing for an electrical building service equipment with a sheet metal casing that has at 20 least one piece of sheet metal, wherein the ends of the at least one sheet metal piece are joined with one another by plug-in connections, wherein the at least one sheet metal piece has a bevelled construction at its ends, and wherein a U shaped connecting batten is pushed over the bevelled ends of the at least one sheet metal piece. 25 According to another aspect of the present invention, there is provided a method for producing a housing for an electrical building service equipment, including joining the ends of sheet metal pieces of a sheet metal casing by means of plug in connectors, wherein the sheet metal pieces have bevelled ends, over which a 30 U-shaped connecting batten is pushed for the purpose of producing a plug-in connection. According to the above aspects of the present invention a housing of an electrical building service equipment without welding can be provided.

4 In a housing according to the present invention, the connecting batten has bevelled ends and at least one end has a reduction in a leg portion of the bevelled end. 5 The housing according to the present invention can include a first section which serves as an air inlet and a second section which serves as an air outlet and the arrangement is such that the first and second sections are punched out of the housing. 10 The housing according to one aspect of the present invention can include a sheet metal bottom which forms a continuous drip edge within the sheet metal casing. The housing according to the present invention can further include a plurality of 15 height adjustable feet which are partly made from rubber. The present invention also concerns electrical building service equipment, in particular a heat pump appliance with a housing of the above kind, i.e. made from a sheet metal casing, that has at least one sheet metal piece. The ends of the 20 sheet metal pieces are joined with one other by plug-in connections. A functional unit of the electrical building service equipment, that is to be protected by the housing, is positioned within the sheet metal casing and the intermediate space between the functional unit and the sheet metal casing is filled with foam. 25 In an electrical building service equipment according to the invention, a foam filled switching space can be provided to accommodate components of the electrical building service equipment, wherein foam ribs are provided in the region of the switching space. 30 This present invention also concerns a foam adapter to fill with foam an electrical building service equipment. For this purpose the foam adapter has a collar at its top end. The collar has a plurality of first holes for ventilation and a second hole to introduce the foam during the foaming process.

5 In a method according to the present invention, the functional unit of an electrical building service equipment can be positioned within the sheet metal casing and an intermediate space which is formed between the functional unit and the casing is filled with foam by means of a foam adapter. 5 In the following the embodiments and advantages of the invention are explained in detail based on the attached drawings. They show in: Fig.1 - a perspective view of a top half of an electrical building service equipment, 10 Fig.2 - a perspective view of an installation platform, Fig.3 - an illustration of the manufacturing process of a heat pump appliance of Fig.1 according to a second embodiment, 15 Fig.4a - a schematic view of a heat pump appliance according to a third embodiment, Fig.4b - a top view on a sheet metal lid, 20 Fig.4c - a cambered sheet metal lid for the housing of 4a, Fig.5 - a schematic view of a heat pump appliance according to a third embodiment, 25 Fig.6 - a perspective view of the heat pump appliance according to the third embodiment, Figs.7a-7b - perspective views of a foam adapter to produce a heat pump 30 appliance according to the first, second or third embodiments, Figs.8a-8d - a sectioned view during the joining of two sheet metal pieces to form a sheet metal casing according to a fourth embodiment, 6 Fig.9 - a top view on a joining rail according to Fig.8a, Fig.10 - a schematic sectioned view of a housing according to a fifth embodiment, and 5 Fig. 11 - a schematic sectioned view of a bottom region of a heat pump appliance according to a sixth embodiment. Fig.1 shows a perspective view of a top half of an electrical building service 10 equipment, in particular of a heat pump appliance according to an embodiment of the invention. The heat pump appliance has a cylindrical sheet metal casing (not illustrated) and two openings 1, 2. Through the openings in the sheet metal casing, which preferably accommodate ventilation grills 34, the air to be heated is conveyed through the compressor 3 and thus cools the compressor. The 15 evaporator 5 separates the suction side 4 from the pressurised side 5. Furthermore a pipe 7 is provided, that serves the purpose of guiding the condensate, occurring during the cooling of the air, along the pipe downwards and to the underside of the heat pump appliance. On the inside of the sheet metal casing of the heat pump preferably a PU foam is provided or sprayed, that serves 20 both for the heat and sound insulation. Fig.2 shows a perspective view of an installation platform 10, that is placed on the foam-coated hot water container according to Fig.1, and can accommodate, for example, the evaporator and the compressor. 25 By virtue of filling with foam the sheet metal casing is strengthened in such a manner, that with the foam and the sheet metal casing an appropriate mechanical stability of the heat pump can be achieved. 30 Preferably the housing of the heat pump is made from a sheet metal casing. As has already been described above, the sheet metal casing is particularly mechanically stabilised by the foam filling, so that a relatively thin sheet metal of approx. 0.5-1 mm thickness can be used.

7 When the container is filled with foam, preferably two ribs 8, 9 (see Fig. 1), which surround the foamed space at least partially, will be also coated with foam. By virtue of the circular configuration of the ribs 8, 9 an easy-flowing air conveyance between the suction side and the pressurised side is made possible. As an 5 alternative, an angular configuration of the ribs is also feasible. For the manufacture of the housing according to the first embodiment preferably a two-piece sheet metal, not previously rounded, is used. Both sheet metal pieces are joined with one another by two plug-in devices, so that a round sheet 10 metal casing will be produced. This sheet metal casing is inserted through the concentric container into the centre. Afterwards by using a foam adapter, in particular according to Figs.7a and 7b, foam is sprayed from above into this arrangement, i.e. between the container and the sheet metal casing. Preferably a hole, as well as further ventilation holes, are provided in the foam adapter so that 15 the air can escape when the foam is sprayed in and preferably rises. The liquid foam penetrates downwards and collects on the bottom of the sheet metal and commences to foam. Subsequently the foam rises and the foam adapter prevents the foam to escape upwards, so that the housing space and the gap, still free, will be filled with foam. After the hardening of the foam the foam adapter is removed, 20 so that an adhesion between the foam and the sheet metal casing is present. This also results in the required strength of the sheet metal casing with the foam. Thus the mechanical stability of the housing is formed by the joining of the sheet metal casing and the foam between the sheet metal casing and the container. The shape of the filled foam can be varied by the configuration of the foam 25 module. Fig.3 shows an illustration of the manufacturing process of a heat pump appliance of Fig.1 according to a second embodiment. The manufacturing process can be carried out, for example, in ten steps. In step 1 the punched 30 (punching out the ventilation grill L) and bevelled metal sheets M are lacquered, and in step 2 the lacquered sheets M are joined by means of plug-in connectors S. In step 3 the joined sheets are rounded. In step 4 the liquefier 27 is wound around the reservoir 13. In step 5 the base plate 11 of the heat pump is mounted on the foam adapter 12 by means of magnets. In step 6 the foam adapter 12, the 8 sheet metal casing 14 and the container 13 are positioned. In step 7 the foam adapter 12 is inserted and the foam dispensing head 21 is activated. In step 8 the foam adapter 12 is retracted and removed. In step 9 the installation of the refrigeration unit 26 the wiring as well as the function testing is carried out. In step 5 10 the heat pump is packed. The joining of the two halves of the casing M in step 2 is preferably carried out with shaped sheet metal strips. The halves M are joined into a concentric casing 14 (step 3). The joining is carried out with shaped sheet metal strips (detail A, 10 step 3), whereby one contact batten S per side is pushed over the bevelled ends of the casing sheets M. The liquefier 27 is wound as a rolled plate about the circumference of the container and braced (step 4). The base plate 11 is joined with the foam adapter 12 by button magnets (step 5). The container 13 is positioned relative the casing 14 and the foam adapter 12 (step 6). The 15 positioning of the container 13 relative the casing 14 is carried out by means of the cut-outs 15 and 16 in the bottom tool 17, that in turn accommodates the container 13 and the casing 14. The positioning of the foam adapter 12 in the circumferential direction is carried out by means of the foam strips 18 glued in, which simultaneously serve as foam locks. The liquefier pipes 19 and 20 can be 20 provided in cut-outs in the foam adapter 12 and in the base plate 11. Step 7 shows the situation, wherein the foam adapter 12 is inserted into the assembly and the foam dispensing head 21 injects at a first position 22 or at two positions 22 and 23. Preferably two positions are used, because the foam spreads better in the liquid state and afterwards can evenly rise. During rising the foam completely 25 fills the annular gap 24. This gap 24 is ventilated via the holes 25. To improve the uniformity of the foam thickness the configuration and the position of the holes are harmonised. In step 8 the foam adapter 12 is removed from the assembly. In step 9 the assembly of the refrigeration unit 26, the wiring as well as the function testing is carried out. 30 Fig.4a shows a schematic view of a heat pump appliance according to a third embodiment. The housing of the heat pump appliance has a sheet metal casing 14 with an essentially cylindrical construction. A sheet metal cover 31 has a cambered and thin-walled construction, so that the rain can flow off. Preferably 9 the sheet metal cover 31 is fastened on the circumference of the collar 30 of the lid 31 with corrosion-resistant screws. The sheet metal casing or the casing sheet is preferably made from two pieces and is made from a thin sheet metal. 5 Fig.4b shows a top view on the sheet metal lid and Fig.4c shows a cambered sheet metal lid 31 for the housing of Fig.4a. The sheet metal lid with a collar circumference 30 with a height of h is deep-drawn by a press from a circular developed projection. To achieve a uniform collar height of h along the circumference of the lid a circular camber may be chosen. 10 Fig.5 shows a schematic view of a heat pump appliance according to the third embodiment. In this case the configuration of the heat pump appliance according to Fig.5 essentially corresponds the configuration of the heat pump appliance according to Fig.1. In the region of a foam space 36 the sheet metal casing 14 is 15 reinforced by foam ribs 32. An air inlet 32a and an exhaust air outlet 32b are protected by a ventilation grill 34 each, that is preferably stamped out from the sheet metal casing 14 (see step 1 of Fig.3). The sheet metal bottom 38 of the housing will be filled with foam and arranged within the sheet metal casing in such a manner, that a continuous drip edge 33 is formed. Furthermore, the heat 20 pump appliance or the housing of the heat pump appliance has height-adjustable rubber feet 35. In Fig.5 the heat pump appliance is illustrated with the cylindrical sheet metal casing. Fig.6 shows a perspective view of the heat pump appliance according to the third 25 embodiment. In this case the heat pump appliance is shown with the sheet metal bottom 38, the sheet metal cover 31 as well as the sheet metal casing 14. Furthermore, the stamped out ventilation grill 34 is shown in Fig.6. The sheet metal casing has preferably a thickness of << 1 mm. When using such 30 a thin sheet metal, in addition to saving material it can also be achieved, that the sheet metal casing can be formed into a cylinder from two halves using little force. During the foaming process and the accompanying build-up of pressure a stable circular geometry can be retained in the region of the foam space 36 despite the thin wall of the sheet metal casing. The stability of the housing, 10 especially in the region of the foam space 36, is further increased by the two foam ribs 32 and 32c. Both these foam ribs 32 and 32c also serve the purpose of air sound reduction of a heat pump unit provided in the foam space 36. 5 Figs.7a and 7b show perspective views of a foam adapter 12 for the production of a heat pump appliance according to the first, second or third embodiments. The foam adapter 12 represents a tool, that is used to fill the gap between the sheet metal casing 14 and the container 13 with foam and to form the switching space 36. In this connection the foam adapter 12 acts as spacer for the foam-free 10 switching space 36, the air inlet 32a and the air outlet 32b. Furthermore, by virtue of the function of the foam adapter 12 as spacer the foam ribs 32 and 32c are constructed. In the bottom 59 of the adapter openings 57 for tubes are provided. Furthermore, in the bottom 59 of the foam adapter button magnets 60 are provided, which accept a bottom sheet metal, in particular base plate 4, serving 15 as separating sheet metal between the foam and the switching space. Anchor strip 42 may be provided in the sheet metal 41 bottom to increase the adhesion between the foam and the sheet metal bottom 41. At the bottom of the foam adapter 12 connecting pipes 53 are provided to accommodate an empty pipe, the purpose of which is to produce a foam-free zone between the upper side of the 20 appliance and the underside of the appliance. This empty pipe can be further used for the removal of the condensate and, when installed in the open, for draining. In its upper region the adapter has a collar 55 with holes 54. The holes 54 serve for the ventilation of the annular space between the container and the casing during the foaming process, when the foam rises. In this connection the 25 positions of the holes 54 should be so chosen, that a uniform distribution of the foam in the annular gap between the container and the casing can be obtained, thus achieving a desired even density of the foam along the height of the reservoir. The purpose of the hole 56 in the collar 55 is to introduce the foam by means of a mixing head. On the underside 55a of the collar 55 a continuous 30 groove may be provided to accommodate the end of the sheet metal casing. To improve the manufacturing process the walls of the groove can have an oblique construction, so that the end of the sheet metal casing can be better and faster introduced into the groove.

11 The sheet metal casing is preferably made from two sheet metal pieces. Each of Figs.8a -8d show a sectioned view during the joining of two sheet metal pieces to form a sheet metal casing according to a fourth embodiment. In Fig.8a a sectioned view of a joint of two halves 77 and 77a of a casing are shown, the 5 bevelled ends 77-1, 77a-1 of which are held together by means of a connecting batten 78, that has preferably a U-shape with bevelled ends 78a. As merely a slight mechanical contact is present between the bevelled ends 77-1, 77a-1 of the halves 77, 77a of the casing and the connecting batten 78 (or its bevelled ends 78a), the connecting batten can be pushed over the ends of the halves 77, 77a of 10 the casing using only a little force. The bevelled ends 77-1, 77a-1 of the sheet metal pieces face inwards i.e. into the volume enclosed by the sheet metal casing. Consequently the connecting batten 78, pushed on, is situated in the enclosed volume. 15 Fig.8b shows a further sectioned view of the joined position of Fig.8a, preferably in rounded state, i.e. the sheet metal casing has a cylindrical geometry. Fig.8b shows a situation, wherein the two halves 77, 77a of the casing have changed their positions relative to the connecting rail 78, i.e. the halves 77, 77a of the casing are bent, so that their other bevelled ends could also be joined with one 20 another by means of a connecting rail 78 and the geometry of the flat sheet metal casing is converted into a cylindrical one. On this occasion mechanical contacts 79 and 80, in particular, occur between the bevelled halves 77, 77a of the casing and the connecting batten 78. The situation shown in Fig.8b can be retained, for example, when both halves of the casing are formed cylindrical. By virtue of the 25 elastic deformation of the bevelled edges 77-1, 77a-1 of the halves 77, 77a of the casing relative to the connecting rail 78, at the contact positions 79, 80 a frictional locking is produced. This frictional locking will prevent that the connecting position of the connecting rail 78 and of the two halves 77, 77a of the casing would open during the foaming process, particularly due to the increased pressure by the 30 expanding foam. The dimensioning of the halves 77, 77a of the casing and of the material should be such, that the expansion of the material of the sheet metal casing during the foaming is within the elastic range of the material. Due to the exothermic reaction heat of the foam during foaming both halves of the casing are heated by approx. 40-50 K. Thus due to the heating up of the sheet metal 12 casing the circumference of the casing will increase by approx. 2 mm if the diameter of the casing is approx. 660 mm. This increase of the circumference is preferably absorbed by the above mentioned frictional locked joint. The desired concentric shape of the sheet metal casing can be produced due to the 5 expansion of the foam during the foaming and the pressure increase associated with it. The temperature-dependent elastic elongation of the circumference of the casing causes an increase of the volume and consequently a limitation of the pressure increase. 10 Fig.8c shows a schematic sectioned view of a connecting position of the halves 77, 77a of the casing and of the connecting batten 78. On this occasion Fig.8c shows the situation after the foaming with heated halves 77, 77a of the casing. Due to the increase of the circumference of the casing the dimension of the gap S between the halves 77, 77a of the casing will increase. 15 Fig.8d shows a sectional view of a connecting position of the halves 77, 77a of the casing and of the connecting rail 78. This shows the situation wherein the halves 77, 77a of the casing have cooled down again after the expansion of the foam. Because the foam has already expanded during the foaming and shrunk 20 somewhat after cooling off, the halves of the casing now cool off and their circumference shortens the tension within the connecting position is reduced. Due to the reduced frictional locking at the contact position 79, 80 the gap S2 is closed again. 25 Fig.9 shows a top view of a connecting rail 78 or connecting claw according to Fig.8a. The connecting rail 78 has bevelled ends 78a and on each of its faces a reduction 79 of the leg, to enable a fast assembly. Fig.10 shows a schematic sectional view of a housing according to a fifth 30 embodiment. In this case the housing is not cylindrical but angular, while two housing sections 81, 82 are joined with one another by means of a connecting rail 83. In this case the connecting rail or connecting batten 83 can be constructed as the connecting rail according to the second embodiment, so that the connecting batten 83 can be used in a longitudinal direction F of the joint, thus joining the 13 housing sections 81, 82 with one another. Thus a corrosion-resistant connection of various housing sections can be provided. Fig. 11 shows a schematic sectioned view of a bottom region of a heat pump 5 appliance according to a sixth embodiment. In this case a sheet metal bottom 90 has a circular construction and is provided within a circular sheet metal casing 91. The sheet metal bottom 90 is provided displaced relative to the inside, so that a drip edge 101 is provided. To seal the annular gap 92 produced, a flexible gasket cord 93 may be used, that is adhered at the bottom end of the inside of the 10 casing prior to the joining. In the bottom region of the heat pump appliance at least three feet 94 are welded to the container 98, of which at least one, preferably all three, are height adjustable. The other ends of the height-adjustable feet 94 have rubber stops 97 15 to reduce the transfer of the sound of the body. The welded-on feet 94 have holes with internal threads 95 to enable the height-adjustment of the heat pump appliance. At that end 97, where the rubber stops are, threaded bars 96 are provided, firmly joined with the foot 94. The sheet metal bottom 90 has at least three, preferably circular, holes 99, through which the legs 97 of the heat pump 20 appliance can be introduced. The above described housing can be also used for an instantaneous heater or other electrical building service equipment. 25 The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.

Claims

1. A housing for an electrical building service equipment with a sheet metal casing that has at least one piece of sheet metal, wherein the ends of the at 5 least one sheet metal piece are joined with one another by plug-in connections, wherein the at least one sheet metal piece has a bevelled construction at its ends, and wherein a U-shaped connecting batten is pushed over the bevelled ends of the at least one sheet metal piece. 10

2. A housing according to claim 1, wherein the connecting batten has bevelled ends and at least at one end has a reduction in a leg portion of the bevelled ends.

3. A housing according to any one of claims 1 or 2, further including a first 15 section serving as air inlet and a second section serving as air outlet, wherein the first and second sections are punched out.

4. A housing according to any one of claims 1 to 3, further including a sheet metal bottom that is so provided within the sheet metal casing that a 20 continuous drip edge is formed.

5. A housing according to any one of claims 1 to 4, further including a plurality of height-adjustable feet, wherein the feet are partly made from rubber. 25

6. An electrical building service equipment, in particular a heat pump appliance, with a housing according to any one of claims 1 to 5, and a functional unit that is to be protected by the housing, wherein an intermediate space between the functional unit and the sheet metal casing is filled with foam. 30

7. An electrical building service equipment according to claim 6, further including a foam-filled switching space to accommodate components of the electrical building service equipment, wherein foam ribs are provided in the region of the switching space. 15

8. A method for producing a housing for an electrical building service equipment, including joining the ends of sheet metal pieces of a sheet metal casing by means of plug-in connectors, wherein the sheet metal pieces have bevelled ends, over which a U-shaped connecting batten is pushed for the purpose of 5 producing a plug-in connection.

9. A method according to claim 8, wherein a functional unit of an electrical building service equipment is positioned within the sheet metal casing and the intermediate space between the functional unit and the sheet metal casing is 10 filled with foam by means of a foam adapter.

10.A housing for an electrical building service equipment substantially as hereinbefore described with reference to the accompanying drawings. 15

11.An electrical building service equipment substantially as hereinbefore described with reference to the accompanying drawings.

12.A method for producing a housing for an electrical building service equipment substantially as hereinbefore described with reference to the accompanying 20 drawings.