EP3207318A1

EP3207318A1 - Door, in particular for a refrigerator and/or freezer

Info

Publication number: EP3207318A1
Application number: EP15775085.2A
Authority: EP
Inventors: Nils WAGNER; Louise ZHAO; Dragan Griebel; Peter Zielke
Original assignee: Rehau AG and Co
Current assignee: Rehau Automotive SE and Co KG
Priority date: 2014-10-13
Filing date: 2015-10-05
Publication date: 2017-08-23
Also published as: DE202014104855U1; CN106793879B; CN106793879A; WO2016058671A1

Abstract

The invention relates to a door, in particular for a refrigerator and/or freezer, comprising a door frame (1) having a polymeric door frame profile (2), and at least two transparent panes (3, 4, 5) which are arranged spaced apart from each other and in parallel to the plane of the door frame and form together with the door frame profile (2) at least one planar hollow space (7, 8) filled with gas (6), the discs (3, 4, 5) being made of a polymeric material.

Description

Door, in particular for a refrigerator and / or freezer

The invention relates to a door, in particular for a refrigerator and / or freezer, with a door frame, which has a door frame profile and at least two transparent panes, which are spaced from each other parallel to the door frame plane and in this case form at least one flat, gas-filled cavity.

Such doors are used in particular for refrigerators for the food retail trade. On the one hand, they are intended to keep the energy consumption of the refrigerators or freezers low due to good thermal insulation and, on the other hand, allow customers to have a direct view of the contents of the appliance even when the door is closed. Of particular importance in this context is that the transparent panes are not covered with condensation, whereby the visibility of the product and also the overall appearance of the product range is impaired. The risk of condensation forming is especially due to the comparatively cold surface of the outside of the door, at which water vapor contained in the ambient air can be deposited in liquid form. Especially at high temperatures, the ambient air can absorb large amounts of water vapor, so that in particular in warm areas standing outdoors coolers or freezers are affected by the unwanted condensation. Therefore, it is often a mandatory requirement of the equipment manufacturer, even under defined extreme ambient air conditions - ie high outside temperature with high humidity - to keep the door by a corresponding design design free of condensate. Especially at a low internal temperature of the device, a lot of effort is required to meet this requirement. In practice, this frequently leads to the fact that the door is provided with a contra-productive heating with regard to the purpose of the device in order to prevent the formation of condensation, in which case heat outputs in the range of 100 W or even more are the rule. Another disadvantage is that the heater increases the design complexity of the door. From DE 34 19 977 A1 discloses a door for a refrigerator or freezer is known in which three transparent, spaced-apart discs are provided. These discs are bordered by a frame, the distance between the discs is determined by separate spacer strips. These spacers impair the thermal insulation of the door as they lead to undesirable thermal bridging. Such spacer elements are also disclosed in the freezer door described in DE 10 2005 059 145 A1.

It is also known from the prior art to use glass panes spaced apart from one another in the case of corresponding doors, the cavities formed by these panes being filled with dry, ie water vapor-free, argon in order to improve the thermal insulation. Argon has a lower thermal conductivity of λ _ΑΓ = 0.018 W / mK ( _LU ft = 0.026 W / mK) compared to air. However, this cavity filling with pure noble gas is complicated and expensive.

The invention has for its object to provide a door, especially for a refrigerator and / or freezer, which has a low tendency to form condensation, is inexpensive to produce and also ensures low energy consumption of the device.

According to the invention the object is achieved by a door, in particular for a refrigerator and / or freezer, with

a door frame having a polymeric door frame profile, and

- At least two transparent discs, which are spaced from each other parallel to the door frame plane and in this case together with the door frame profile at least form a flat, gas-filled cavity, - wherein the discs are made of a polymeric material.

According to the invention therefore, a polymeric door frame profile is used, which forms significant advantages in terms of thermal insulation due to the low thermal conductivity of polymeric materials over metal solutions, eg aluminum profiles. The polymeric door frame profile creates thermal bridging between the interior of the device and prevents the outside of the door, whereby the risk of condensation on the outside of the door is permanently reduced. Furthermore, the low thermal conductivity of polymeric materials according to the invention is also used to increase the thermal insulation effect of the discs according to the invention. By using a polymeric material for the disks (polymeric materials usually have a thermal conductivity in the range of λ _Κυ * 0.15 * 0.3 W / mK) is the corresponding thermal resistance coefficient ω = 1 / λ compared to glass ( _glass = 0 , 75 W / mK). Transparent in the context of the invention means, in particular, that the individual disks each have a transmittance for visible light of at least 70%, preferably at least 80%, particularly preferably at least 90%.

According to a preferred embodiment of the invention, the gas filling the at least one areal cavity consists of at least 70% by volume of nitrogen. In particular, the cavity may be filled with atmospheric air; a special, expensive argon filling is not required due to the improved thermal insulation properties of the door frame profile and the panes. The air encountered in the earth's atmosphere usually has a nitrogen content of 77-79 vol .-%, an oxygen content of 20 - 22 vol .-% and other gases (water vapor, argon, C0 _2, and other gases in traces). Depending on the condition, the water vapor content in the atmospheric air is usually 1 - 2 Vol .-% In very cold air, this value can also be lower, in very hot air and higher. Therefore, to safely avoid condensation within the cavity, it may be desirable to dry the atmospheric air before it is filled into the cavity. The at least one cavity is expediently sealed after its filling to the outside environment, so that practically no moisture can penetrate into the cavity from the outside when the refrigerator or freezer is in operation.

Conveniently, at least three transparent discs are provided, which accordingly form at least two planar cavities. A three-pane construction is advantageous in terms of thermal insulation. According to a preferred embodiment of the invention, the at least two discs are made of polymethylene methacrylate (PMMA).

PMMA is a well-to-disc processable polymer with particularly good thermal insulation properties. PMMA has a significantly lower thermal conductivity of λρΜΜΑ = 0.19 W / mK compared to glass, so that the thermal resistance coefficient ω of PMMA is approximately four times as high as that of glass. However, it is also within the scope of the invention that as a polycarbonate (PC), a cyclopolyolefin polymer (COC), polystyrene (PS) or polyacrylic ester imide (PMMI). Also, the above-mentioned materials for various slices can be freely combined (eg, inner pane of PMMA, outer pane of PC). All of the abovementioned materials have the advantage that, even with a slice thickness of several millimeters, they ensure high degrees of transmission, in particular> 90%, for visible light.

Another great advantage of the teaching according to the invention is that the discs made of polymer material have a comparatively low weight. This advantage can be used according to a preferred embodiment of the invention to keep the discs without separate spacers at a distance from each other, for which purpose all discs are directly connected to the door frame, preferably glued, are. Thus, a thermal bridge formation due to spacers can be avoided and thus the tendency for condensation on the outside of the door can be further reduced. In particular, it is within the scope of the invention that at least one disc is connected to the door frame via a connecting web arranged on the door frame profile, preferably integrally formed. Preferably, at least one connecting web connects an inner pane, which is surrounded on both sides by further disks, to the door frame.

Expediently, the disks have a thickness 6s of not more than 6 mm, preferably not more than 3 mm. This weight and material-saving design is possible in particular with correspondingly thicker dimensioning of the cavities. The at least one planar cavity preferably has a thickness δ _Η of 10 to 30 mm. In this way, on the one hand, with regard to the cavity, a high specific thermal resistance Wx. = δ _Η / λ _Η guaranteed and on the other hand, the cavity thickness δ _{Η is} still so small dimensioned that the adverse influence of free convection in the cavity is low or negligible. In the context of the invention, it is particularly the case that the ratio of disk thickness 5 _S to thickness δ _{Η of} the areal cavity is at least 5, eg at least 6, for example at least 8. In the context of the invention, it is furthermore particularly the case that all disks have the same thickness ö _s and / or all the two-dimensional cavities have the same thickness δ _Η .

The polymeric door frame profile may be made of polyvinyl chloride (PVC). Alternatively, it is also possible, the door frame profile, for example, polypropylene (PP) or polyamide (PA) manufacture. In the context of the invention, it is further that the door frame profile has at least one hollow chamber. It may be advantageous in this context, if the door frame profile in order to avoid condensation processes in the cavities in the hollow chamber wall openings which connect via the hollow chamber at least two cavities fluidly with each other. This fluidic connection can optionally be supported via arranged in the hollow chamber tubes, which are connected to these openings end. By means of the openings, a small air flow between the two so interconnected cavities are generated, which is suitably passed as close as possible to the surface of the cooling material according to the closest disc and can transport moisture away from this surface during this movement. As a result, although the thermal insulation properties of the door deteriorate slightly; However, this measure can make the door heating described above unnecessary under certain conditions.

Alternatively or additionally, in order to prevent condensation between the panes, a hygroscopically active substance may also be provided in the at least one cavity, eg in the form of dry beads, the substance suitably containing silica gel or consisting of silica gel. Furthermore, this substance can provide indicator properties in terms of their moisture content, for example in the form of a color indicator. The indicator indicates to what extent the absorption capacity of the substance for further moisture has already been exhausted. Such substances are offered for example by the company. BASF as Sorbead ^® Orange CHAMELEON ^®. In this way, the avoidance of condensation in the at least one cavity can be additionally secured. If the substance indicates an increasing depletion of its absorption capacity for further moisture by the color indicator, the gas filling of the at least one cavity, eg with fresh dried air, can be renewed within the scope of a device maintenance. Finally, the disc on the outside of the door may be designed to be light-conducting. If a narrow side of this disc is illuminated with a light source, the entire pane lights up accordingly, whereby the appearance of the door can be further improved. In the context of the invention, it is here in particular that the disc on the outside of the door has a greater thickness (eg, 4 + 6 mm) than the remaining discs, which are for example at most 3 mm thick. This optional measure is based on the fact that the Achieving the desired optical effect with appropriate illumination of the outer pane a certain minimum thickness of the same is required.

The invention further provides a cooling device with a door according to the invention.

In the following the invention will be explained with reference to a drawing showing only one embodiment. Shown schematically: a hinged on a refrigerator or freezer door according to the prior art

Fig. 2a, b a door according to the invention in a front and rear view Fig. 3 shows the section A-A in Fig. 2b in a three-dimensional view.

Fig. 4a, b the section B-B in Fig. 2b in two different embodiments of

Invention Fig. 5a, b Figs. 4a, b corresponding cross-sectional views according to the prior art

Fig. 1 shows in cross section a freezer assembly, as described in the prior art according to DE 10 2005 059 145 A1. The freezer assembly 50 is part of an otherwise not shown freezer. The freezer door assembly 50 has a glass door, generally designated 51. This is in the closed position via a flexible seal 52 on a door jamb 53. The glass door 51 comprises, as a multi-pane insulating glass, a laminated pane 54 having three glass panes spaced apart from one another by means of spacing elements 55, namely an inner pane 3 'facing an interior 56 of the freezer, a center pane 4' and an outer pane 5 '. The middle plate 4 'is located between the inner pane 3' and the outer pane 5 '. The composite pane 54 is at the edge of a vertically oriented door frame profile 2 'added. In the region of this receptacle, the door frame profile 2 'is designed as a substantially U-shaped receiving groove 57 for the disk composite 54. The Abstandssele 55 are connected to the discs 3 ', 4', 5 'via adhesive layers 58. Between a base 59 of the receiving groove 57 and the spacer elements 55 are arranged as secondary sealing gaskets 60 made of polyurethane, which seal the generated by the discs 3 ', 4', and 5 'of the laminated pane 54 cavities 7', 8 'against the environment. To avoid condensation inside the cavities 7 ', 8' is glued between the sealing elements 60 and the door frame profile 2 'on the base 59, a Wärmeleitmetallfolie 61 made of aluminum on a bonding agent. This film 61 extends in the receiving groove 57 between the inner pane 3 'and the outer pane 5'. The door frame profile 2 'is designed as a hollow chamber profile. It has a plastic profile base 62 made of polyvinyl chloride (PVC). The plastic profile base body 62 is at its visible sides, in the figure 1 so at the bottom and on the left side, with a

Decorative layer in the form of a decorative metal foil 63 coated aluminum, which is to prevent condensation in this area. The plastic profile base body 62 is covered at the top by a cover plate 63 a, which in an upper locking receptacle of

Plastic profile base 62 is engaged. Between an inner wall 64 of the cover plate 63a and one of these inner wall 64 facing outer wall 65 of the door jamb 53, the flexible seal 52 is arranged. The seal 52 consists of three elastic sealing walls, namely an inner wall 66 facing the inner space 56, a middle wall 67 and an outer wall 68. The sealing walls 66, 67, 68 of the one-piece seal 52 are made of softer plastic than the material of the door frame profile 2 ' , for example made of soft PVC. The seal 52 has a latching profile section 69 which is latched into a receiving chamber 70 of the cover plate 63a. In the figure 1 above the middle wall 67 and the outer wall 68, the seal 52 has a receiving chamber 71 for a magnet 72. The latter interacts in the closed position of the glass door with a metallic portion 73 of the lower wall 65 of the door jamb 53. As seen from the interior 56, the seal 66 is displaced outward to the extent that adjacent to the seal 66 between the door jamb 53 and the edge of the disk assembly 54, a gap 74 is formed. This is partially filled by a profile element 75. The latter represents a separation between the seal 66 and the interior 56. The profile element 75 is designed as a hollow chamber profile. In the closed position of the glass door 51 remains between the profile element 75 and the door jamb 53 a channel 76 of defined width, so as to ensure that in the closed position, the profile element 75 is not applied to the glass door 51 and the door jamb 53 at the same time and in this way the Closed position undesirable influences. The profile element 75 is formed integrally with the cover plate 63a.

2a, b and 3 show a door according to the invention for a refrigerator or freezer with a door frame 1, which has a polymeric door frame profile 2 with a door handle 100 attached thereto. This door can - eg analogous to Fig. 1 - be posted on a door jamb of the corresponding device. The door frame profile 2 was produced by means of an extrusion process and is - as shown in Fig. 2a showing the door front side and the door rear side representing Fig. 2b seen - assembled from four mitred single profiles frame-shaped. The door in turn has three transparent panes, namely an inner pane 3, a central pane 4, and an outer pane 5, which are spaced from each other parallel to the door frame plane and this together with the door frame profile 2 two-dimensional, filled with gas 6 cavities, namely an inner cavity 7 and an outer cavity 8, form (see Fig. 3). The middle plate 4 is correspondingly arranged between the inner pane 3 facing the interior of the appliance and the outer pane 5 facing the surroundings U. The discs 3, 4, 5 are made of the polymeric material PMMA. The gas 6 filling the two flat cavities 7, 8 consists of atmospheric air, which has been dried by means of a drying process before being introduced into the cavities 7, 8. As can be seen from FIG. 3, the disks 3, 4, 5 are held at a distance from one another without separate spacer elements (see item 55 in FIG. 1) and are all glued directly to the door frame profile 2 by means of adhesive 80. Both the inner disk 3 facing the device and the middle disk 4 of the composite are connected to the door frame 1 for this purpose in each case via a connecting web 9 integrally formed on the door frame profile 2. As can be seen in FIGS. 4a, 4b, the inner disk 3 and the middle disk 4 each have a thickness _S of 2 mm. The outer pane 5, however, is formed with 5 _S A = 5 mm thicker, which will be discussed later. The two-dimensional cavities 7, 8, however, each have a thickness δ _Η of 14 mm (FIG. 4a) or 16 mm (FIG. 4b). In the exemplary embodiment according to FIG. 4 a, the ratio of the cavity thickness to the slice thickness δ _Η / 5 _S = 7 is accordingly, in contrast to 8 in FIG. 4 b.

The door frame profile 2 is made of PVC and has - as shown in FIG. 3 - a hollow chamber 10. Furthermore, if it is expedient in the concrete application case, openings 1 1, 12 are provided in the hollow chamber wall of the door frame profile 2 which connect the two cavities 7, 8 via the hollow chamber 10 in terms of flow. By this fluidic connection, warmer gas 6 is transported to a lesser extent from the outer cavity 8 in the colder inner cavity 7, wherein this small, marked with an arrow 13 gas flow through a corresponding arrangement of the openings 11, 12 directly to the cold outer surface 14 of the inner pane 3 is passed and in this case moisture is transported away from the surface 14, so that condensation on this surface 14 is avoided. Of course, it is also within the scope of the invention, the openings 11, 12 not provide, so that the cavities 7, 8 are each completely sealed. It can also be seen that the outer pane 5 facing the outer environment U of the door is adhesively adhesively bonded to the door frame profile 2 by means of adhesive 80 and is flush with it. As a result, the appearance of the door is further improved. The outer pane 5 is also designed to be light-conducting and can be illuminated via a arranged on a narrow side of the outer pane 5 light source 15, so that the entire outer pane 5 lights up slightly. The light-conducting properties require a certain minimum thickness of the corresponding disc. In order to achieve the described optical effect, the outer pane 5 is therefore thicker than the two other panes 3, 4.

FIGS. 5a, 5b show cross-sections through doors according to the prior art analogous to the illustration in FIG. 4a. b. In these doors, the discs 3 ', 4', 5 'made of glass and the cavities 7', 8 'are filled with argon 6'. The discs 3 ', 4', 5 'are comparatively thick and therefore have a high weight. The poor thermal insulation properties of glass are compensated by the use of argon 6 '.

claims

Claims

claims

Door, in particular for a refrigerator and / or freezer, with

- A door frame (1) having a polymeric door frame profile (2), and

at least two transparent panes (3, 4, 5) which are arranged at a distance from each other parallel to the door frame plane and together with the door frame profile (2) form at least one planar cavity (7, 8) filled with gas (6),

- Wherein the discs (3, 4, 5) consist of a polymeric material.

Door according to claim 1, characterized in that the at least one flat cavity (7, 8) filling gas (6) consists of at least 70 vol .-% of nitrogen.

Door according to claim 1 or 2, characterized in that at least three transparent discs (3, 4, 5,) are provided, which accordingly form at least two cavities (7, 8).

Door according to one of claims 1 to 3, characterized in that the discs (3, 4, 5) of polymethyl methacrylate (PMMA), polycarbonate (PC), a

Cyclopolyolefin polymer (COC), polystyrene (PS) or polyacrylic ester imide (PMMI).

Door according to one of claims 1 to 4, characterized in that the discs (3, 4, 5) without separate spacer elements (55) are kept at a distance from each other and all this directly connected to the door frame profile (2), preferably glued, are.

6. Door according to one of claims 1 to 5, characterized in that at least one disc (3, 4) arranged on a door frame profile (2), preferably integrally formed, connecting web (9) with the door frame (1) is connected.

7. Door according to claim 6, characterized in that the connecting web (9) an inner, on both sides of further discs (3, 5) surrounded disc (4) with the door frame (1) connects. 8. Door according to one of claims 1 to 7, characterized in that the discs (3, 4, 5) have a thickness (5 _S ) of at most 6 mm, preferably at most 3 mm.

9. Door according to one of claims 1 to 8, characterized in that the at least one planar cavity (7, 8) has a thickness (δ _Η ) of 10 to 30 mm.

10. Door according to one of claims 1 to 9, characterized in that the ratio of cavity thickness (δ _Η ) to disc thickness (6 _S ) is at least 5, for example at least 6. 11. Door according to one of claims 1 to 10, characterized in that the door frame profile (2) consists of polyvinyl chloride (PVC).

12. Door according to one of claims 1 to 11, characterized in that the door frame profile (2) has at least one hollow chamber (10).

13. Door according to claim 12, characterized in that the door frame profile (2) in the hollow chamber openings (11, 12) which connect via the hollow chamber (10) at least two flat cavities (7, 8) fluidly with each other. 14. Door according to one of claims 1 to 13, characterized in that seen from the outside of the door first disc (5) is designed to be light-conducting.

15. Device for cooling objects, especially food, with

a housing for receiving the objects,

- One, preferably electrical, cooling unit for cooling the housing interior and

- A serving to close the housing door according to one of claims 1 to 14.