Patent application title: REFRIGERATING DEVICE COMPRISING A PRESSURE COMPENSATION OPENING
Thomas Bischofberger (Kisslegg, DE)
Martin Buchstab (Bopfingen, DE)
Alexander Görz (Aalen, DE)
Alexander Görz (Aalen, DE)
Hans Ihle (Giengen, DE)
Wolfgang Kentner (Röfingen, DE)
Wolfgang Kentner (Röfingen, DE)
Karl-Friedrich Laible (Langenau, DE)
BSH BOSCH UND SIEMENS HAUSGERÄTE GMBH
BSH BOSCH UND SIEMENS HAUSGERTE GMBH
IPC8 Class: AF25D2302FI
Class name: Cooled enclosure movable unit of refrigeration producing assembly unit includes movable wall section, e.g., door
Publication date: 2009-12-31
Patent application number: 20090320515
A refrigerating device having a body and a door that enclose a
refrigerated interior, have frame surfaces oriented toward each other and
delimit a gap filled by a seal, the refrigerating device including at
least one wall in at least one frame surface being forming with a passage
therein, said passage being configured to bridge the seal, thereby
allowing the interior to communicate with the environment.
12. A refrigerating device having a body and a door that enclose a refrigerated interior, have frame surfaces oriented toward each other and delimit a gap filled by a seal, the refrigerating device comprising at least one wall in at least one frame surface being forming with a passage therein, said passage being configured to bridge the seal, thereby allowing the interior to communicate with the environment.
13. The refrigerating device according to claim 12 wherein the passage extends through the frame surface in a non-linear path.
14. The refrigerating device according to claim 12 wherein the passage includes at least one section extending in the longitudinal direction of the seal.
15. The refrigerating device according to claim 12 and further comprising a heater mounted at a front of the body wherein the passage extends through an area of the housing heated by the heater.
16. The refrigerating device according to claim 12 wherein the seal is fixed in a groove formed in a first one of two frame surfaces and the passage is formed on the second one of two frame surface.
17. The refrigerating device according to claim 12 wherein the seal is fixed in a groove of one of the two frame surfaces and the passage is formed on the same frame surface as the groove to extend between the walls of the groove and an anchoring section of the sealing profile engaged in the groove.
18. The refrigerating device according to claim 17 wherein the groove is transversely divided by a rib which engages in a longitudinal channel of the seal, and wherein the rib has a cutout through which the passage extends.
19. The refrigerating device according to claim 12 wherein at least one end of the passage is disposed at a corner of a frame surface.
20. The refrigerating device according to claim 12 and further comprising a frame heater disposed on a frame surface of the body.
21. The refrigerating device according to claim 20 wherein the frame heater is formed using a refrigerant pipe extending annularly in a discontinuous manner on the frame surface of the body thereby defining an interruption of the refrigerant pipe, wherein the passage is formed on the frame surface of the body generally at the level of the interruption.
22. The refrigerating device according to claim 20 and further comprising a pressure compensation valve extending through a wall of at least one of the body and the door thereby proving an inflow of air from the environment into the interior and to thereby block an outflow of air from the interior into the environment.
The present invention relates to a refrigerating device, such as,
say, a refrigerator or freezer, having a pressure compensation opening
which serves to prevent a negative pressure being generated in the
interior of the refrigerating device.
Every time the door of a refrigerating device is opened, warm air enters its interior, cools down therein after the door is closed and generates a negative pressure by means of which the door is sucked against the front of the body. The effect of this negative pressure is that after being closed the door is very difficult to open again until the pressure between the interior and the environment is equalized once more. Although a pressure equalization is in fact always reestablished after a relatively long time on account of the fact that the seal conventionally fitted between the door and the front of the body of the refrigerating device does not close so as to be completely airtight, efforts are generally nonetheless directed at keeping the leakage rate of said seal to a minimum, since air that is exchanged by way of leakages in the seal between the interior and the environment also always leads to an undesirable introduction of heat and humidity into the interior. The higher the precision with which the refrigerating device has been manufactured and consequently the smaller the leakage rate, the longer the negative pressure persists after the door is closed.
This problem makes itself particularly clearly felt in the case of refrigerating devices in which the frame surfaces of body and door that are disposed opposite one another and typically sealing off one another by means of a magnetic seal are embodied as a single piece and as a result form a contact surface that is practically free of irregularities for the magnetic seal and allows a very tight closure.
DE 102 33 216 A1 discloses a refrigerating device having an air passage which allows ambient air to enter the interior when the door is closed. The air passage of said known refrigerating device is provided in order to prevent refrigerated items stored therein, such as, say, the corks of wine bottles, from drying out. A secondary effect which is not considered in DE 102 33 216 A1 is that the passage prevents a negative pressure from being generated in the interior after the door is closed. The air passage of said known refrigerating device is implemented as a bored hole which extends through a wall of the body or of the door. A passage of said kind necessitates considerable manufacturing overhead, since its walls must tightly adjoin an inner and outer skin of the body or door in order to prevent insulating material that is being used to fill out the walls from escaping via the passage. The possibility of accommodating the passage in the magnetic sealing strip is cited as an alternative. However, conventional magnetic sealing strips are not suitable per se for enabling an opening to be formed therein.
An object of the present invention is to provide a refrigerating device having a pressure compensation opening which, with minimal manufacturing overhead, effectively prevents a negative pressure from being generated after the door is closed.
The object is achieved in that in the case of refrigerating device comprising a body and a door which enclose a refrigerated interior and have frame surfaces that are oriented toward each other and delimit a gap that is filled with a seal, a passage bridging the seal is recessed into at least one of the frame surfaces, thereby allowing the interior to communicate with the environment. Thus, instead of creating a passage in the body, in the door or in the seal in the conventional way, by means of the passage according to the invention a connection is created which extends in each case between the seal and the body or between the seal and the door. Since no passage hole is formed, the sealing problem does not arise. The passage can be formed without additional overhead at the same time as the frame surfaces of door or body are molded, in particular by means of a deep-drawing process. The passage can have the shape of a trench, a channel or a plurality of interconnected trench or channel sections.
In order to prevent as far as possible an exchange of air through the passage which goes beyond the unavoidable amount due to the temperature fluctuations of the interior, it is furthermore preferred that the passage bridges the seal by a non-straight path.
A non-straight path of said kind can furthermore be considerably longer than the width of the bridged seal, such that there is available in the passage a large surface on which the moisture from the aspirated air can condense. This reduces the probability that condensed moisture will fill the cross-section of the passage and obstruct the flow of air in the passage.
In order to achieve a passage of great length it can be provided in particular that the passage includes at least one section running in the longitudinal direction of the seal.
If the seal is fixed in a groove in one of the two frame surfaces, it is particularly easy to form the passage on the other frame surface.
The passage can be formed on the same frame surface as the groove in a particularly inconspicuous manner; in this case the groove extends diagonally across the passage, and at most the two ends of the passage are visible on different sides of the seal.
If a rib is formed in the base of the groove so as to engage in a longitudinal channel of the seal, said rib is preferably interrupted locally in order to form the passage.
In addition, at least one end of the passage is preferably disposed at a corner of the frame surface, since the corners are generally the warmest areas of the refrigerating device housing and therefore the tendency to form condensate in the passage is relatively low at these points.
In order to prevent frost from forming in the passage and blocking it in the course of the operation of the refrigerating device, the passage is preferably heatable. Heating can be effected without additional costs by means of a frame heater which is provided in many refrigerating devices in order to prevent dew from forming on outer surfaces of the body or door that are adjacent to the seal.
If the frame heater is formed by means of a refrigerant pipe extending annularly in a discontinuous manner on the frame surface of the body, the passage is advantageously formed on the frame surface of the body at the level of the interruption.
In addition to the passage, a pressure compensation valve extending through a wall of the body or door can also be provided on a refrigerating device of the above-described type, which valve allows an inflow of air from the environment into the interior, but blocks an outflow of air from the interior. Since a valve of said type prevents an uncontrolled exchange of air between interior and environment and consequently an undesirable introduction of heat into the housing, it can have a substantially greater free cross-section than the passage without appreciably increasing the inflow of heat to the interior and consequently allow a faster pressure compensation than said passage after the door is closed. It has been demonstrated that pressure compensation valves of said kind tend to freeze up in continuous operation, and that the presence of the passage removes this tendency to freeze up.
Further features and advantages of the invention may be derived from the following description of exemplary embodiments with reference to the accompanying figures, in which:
FIG. 1 shows a schematic perspective view of a refrigerating device according to a first embodiment of the invention;
FIG. 2 shows a partial section through a wall of the body of the refrigerating device along the plane designated by II in FIG. 1;
FIG. 2a shows a detail view of a corner of the body of the refrigerating device according to a variant of the first embodiment.
FIG. 3 shows a section through a pressure compensation valve;
FIG. 4 shows a bottom corner of the internal wall of a refrigerating device door according to a second embodiment of the invention;
FIG. 5 shows a section through the internal wall and the sealing profile fixed therein along the plane designated by V in FIG. 4;
FIG. 6 shows a section along the plane designated by VI in FIG. 4;
FIG. 7 shows a perspective view of a corner of the internal wall of a refrigerating device door and a sealing profile accommodated therein according to a third embodiment of the invention; and
FIG. 8 shows a section along the plane designated by VIII in FIG. 7.
FIG. 1 is a schematic perspective view of a refrigerating device having a body 1 and a door 2 attached thereto which enclose a refrigerated interior 3. The walls of the body and the door each have, in a manner known per se, a solid outer skin and a solid inner skin which delimit an intermediate space filled with insulating foam material. The inner skin of the walls and a frame surface 5 surrounding the front opening of the body 1 are formed in one piece from a plastic sheet in a deep-drawing process. A magnetic seal 4 is fixed in a manner known per se in a front frame of the door 2 that is located opposite the front frame 5 when the door 2 is in the closed position. A passage in the form of a trench 8 is recessed into the front frame 5 in such a way that when the door 2 is closed, one end of the trench 8 comes to lie on the outside and the other on the inside of the seal 4.
FIG. 2 shows a section along the plane designated by II in FIG. 1 through the trench 8 and its environment. In the sectional view shown in FIG. 2, two sections 15, 15' of a pipe which acts as a frame heater can be seen. The section 15 conducts warm, compressed refrigerant from a compressor (not shown) housed in a rear region of the body 1 and bends adjacent to the trench 8 in order to extend along a bottom horizontal section of the frame surface 5. The pipe runs along the entire frame surface 5 and finally arrives from above, as section 15', at the trench 8 once again, where it bends in the depth direction of the body 1 and runs onward to a condenser mounted externally on the rear wall of the body 1. The frame heater thus extends annularly along the entire frame surface 5, with the exception of a gap between the two segments 15, 15' into which the trench 8 engages. Thus, the trench 8 does not obstruct a routing of the frame heater in direct contact with the frame surface 5.
The trench 8 shown in FIGS. 1 and 2 bridges the magnetic seal 4 in a straight line and at right angles. In order on the one hand to realize a low conductance value of the passage formed through the trench 8 and on the other hand to be able to make the cross-section of the trench 8 large enough so that not just a drop of condensed water will suffice to close the trench 8, it is desirable to increase the length of the trench 8, e.g. by its bridging the seal 4 at an acute angle, or, as shown in the detail view of FIG. 2a, by its comprising a section parallel to the seal 4 which runs inside an area of the frame surface 5 which is covered by the seal 4 when the door 2 is closed and is delimited by dashed lines in FIG. 2b.
The trench 8 can form the only passage between the interior 3 and the environment of the refrigerating device which supports a pressure compensation between the interior 3 and the environment after the door 2 is closed. According to a developed embodiment, a pressure compensation valve is provided in addition for that purpose, for example in an opening 6 formed in the lower area of the door. An example of a possible structure of the pressure compensation valve is shown in FIG. 3, which shows a perspective longitudinal section through the pressure compensation valve 7.
A sleeve 11 secured in a foam-tight manner on the internal wall 10 by means of a bayonet joint extends between an exterior panel 9 of the door 2 and an internal wall 10 deep-drawn from plastic. A membrane 12 held under flexural stress in the interior of the sleeve 11 has edges tightly adjoining the walls of the sleeve 11 and is held in position by means of an intermediate wall 13 extending transversely through the interior of the sleeve 11 and a cap part 14. In the event of a negative pressure in the interior 3, air flows through between the edges of the membrane 12 and the sleeve 11 in order to compensate for the negative pressure; a positive pressure in the interior 3, on the other hand, would press the membrane 12 against the sleeve 11, thus increasing the sealing effect of the valve 7; the pressure is therefore equalized by way of the trench 8.
If the valve 7 were provided as the only pressure compensation means between the interior 3 and the environment, air from outside would slowly flow through the valve 7 when the interior 3 cools down in an operating phase of the compressor. In this case there is a risk that the air will cool down sharply already when passing through the opening 6 and moisture contained therein will condense out at the valve 7 and so lead to the freezing of the valve 7. However, since the trench 8 is provided according to the invention and contains no membrane obstructing the air flow, in such a case the air will flow into the interior 3 exclusively by way of the trench 8. Consequently the valve 7 cannot freeze up, and the trench 8 is protected against freezing up by virtue of its close proximity to the frame heater 41.
FIG. 4 is a perspective view of a bottom corner of the internal wall 10 of the door 2 as well as of the magnetic seal 4 secured to the internal wall 10 according to a second embodiment of the invention. In this second embodiment, the trench 8 on the frame surface 5 of the body 1 is replaced by a corresponding trench 8' formed on the frame surface of the internal wall 10, two ends of which can be seen in FIG. 4.
On a rear face of the magnetic seal 4 facing away from a chamber containing a magnetic strip 16 there are formed two projections 17, 18, of which one, 17, is populated by barbed hooks. The projections 17, 18 engage in a groove 19 of the internal wall 10 which is subdivided into an inner and an outer section 21, 22 by means of a rib 20 running in the longitudinal direction of the groove 19. The barbed hooks of the projection 17 are locked in place on undercuts of the inner section 21. A transverse wall 23 extending in the width direction of the magnetic seal 4 and bulging forward into the section 22 is held by means of the locking mechanism in a flexurally loaded position in which it holds the projection 18 pressed into the outer section 22 of the groove 19. A thin, flexible wall section 24 of the magnetic seal 4 is bent inward by an edge of the outer section 22, such that the wall section 24 rests essentially tightly against this edge. Formed on an opposing edge of the transverse wall 23 is a lip 25 which is pressed tightly against a shoulder 26 of the internal wall 10 adjoining the inner section 21 by means of the locking mechanism of the projection 17. The wall section 24, the lip 25 and the barbed hooks of the projection 17 form a plurality of sealing lines between the internal wall 10 and the magnetic seal 4.
However, said sealing lines do not extend over the entire length of the magnetic seal 4, but are interrupted by the trench 8' at the corner of the door 2 shown. The trench 8' is formed by an indentation in the internal wall 10 being drawn at the point where a horizontal and a vertical section of the groove 19 meet. An outer contour 28 of said indentation can be seen in FIG. 5, which shows a section through the internal wall 10 and the magnetic seal 4 along the plane designated by V in FIG. 4.
FIG. 6 shows a section along the sectional plane inclined at 45° to the horizontal and designated by VI in FIG. 4. The sectional plane runs along the trench 8', and it can be seen that neither the wall section 24 nor the barbed hooks or the lip 25 touch the internal wall 10 along said sectional plane. A passage extending between the magnetic seal 4 and the door 2 is created by means of said trench 8'.
The trench 8' allows a pressure compensation between interior and exterior while bypassing the pressure compensation valve 7, although the course of the trench 8' frequently changing its direction in the manner of a labyrinth seal limits the exchange of air between interior and exterior to the degree necessary for the pressure compensation. Since on the one hand the trench 8' is heated by means of the front 5 and on the other hand air which has passed the trench 8' must still pass a temperature-compensating gap 29 between the internal wall 10 and the frame surface 5 before reaching the interior 3, there is no risk of the trench 8' becoming blocked due to excessive condensation.
A third embodiment of the invention is described with reference to FIGS. 7 and 8. Like FIG. 4, FIG. 7 is a perspective view of a corner of the internal wall 10, wherein the groove 19 of the internal wall 10 is shown fitted with the magnetic seal 4 only on one part of its length in order to be able to show a cutout 30 formed in the rib 20 separating the sections 21, 22 of the groove 19 from each other. The cross-sections of the groove 19 and the magnetic seal 4 are the same as shown in FIG. 5. As can be seen with reference to the section of FIG. 8 analogous to FIG. 6, the passage 8' is interrupted by the rib 20 in the sectional plane of said figure. As can be seen with reference to FIG. 5, however, in both sections 21, 22 of the groove 19 there are in each case longitudinal channels 31, 32 delimited by the walls of the groove 19 on the one hand and by the magnetic seal 4 itself on the other hand, of which one channel 31 communicates with the environment at the level of the corner shown in FIG. 7 via an external section 33 of the passage 8' (see FIG. 8) and the other channel 32 communicates with the interior 3 via an internal section 34 of the passage 8'. The two longitudinal channels 31, 32 are connected to each other via the cutout 30. Since the cutout 30 is disposed at a great distance from the corner in which the two sections 33, 34 are disposed, the length of the entire passage 8' can easily be made greater than the edge length of the door 2. In an extreme case the cutout 30 could even be formed at the corner of the door 2 diametrically opposite the corner shown in FIG. 7. In spite of a possibly large cross-section of the individual sections of the passage, the great length of the passage 8' results in a low conductance value by means of which an exchange of air between the interior 3 and the environment which goes beyond the amount caused by temperature fluctuations of the interior 3 is reliably suppressed.
Patent applications by Alexander Görz, Aalen DE
Patent applications by Alexander Görz, Aalen DE
Patent applications by Hans Ihle, Giengen DE
Patent applications by Karl-Friedrich Laible, Langenau DE
Patent applications by Martin Buchstab, Bopfingen DE
Patent applications by Thomas Bischofberger, Kisslegg DE
Patent applications by Wolfgang Kentner, Röfingen DE
Patent applications by BSH BOSCH UND SIEMENS HAUSGERÄTE GMBH
Patent applications by BSH BOSCH UND SIEMENS HAUSGERTE GMBH
Patent applications in class Unit includes movable wall section, e.g., door
Patent applications in all subclasses Unit includes movable wall section, e.g., door