CLOSURE UNIT OF A VENTILATION DEVICE

Description

TECHNICAL AREA

[0001] The present invention relates to a closure unit of a ventilation device, in particular a ventilation device with heat recovery. STATE OF THE ART

[0002] Buildings are increasingly being equipped with ventilation systems featuring heat recovery. For this purpose, the outside air drawn into the building and the exhaust air extracted from the interior are passed through a common heat exchanger. This transfers heat from one airflow to the other.

[0003] Depending on the season and prevailing temperatures, this heat exchange is either undesirable or not desired to a consistent degree. Therefore, bypass ducts are provided to direct one of the two airflows inwards or outwards without passing through the heat exchanger. The passage through the heat exchanger is closed by a shut-off device, typically a flap or a roller shutter.

[0004] DE 10 2013 216 306 A1 uses a first flap in the bypass duct and a second flap in the supply air duct. The two flaps are operated independently of each other.

[0005] EP 0 044 560 B1 also discloses a ventilation device with a heat exchanger and a bypass, wherein the device has individually actuated flaps.

[0006] EP 1 132 690 B1 shows two heat exchangers connected in series, two bypass channels and several individually operated flaps.

[0007] EP 2 498 014 B1 discloses a heat recovery module with a roller shutter which, when rolled up, blocks the bypass and releases the heat exchanger, and when unwound, releases the bypass but blocks the heat exchanger.

[0008] EP 1 962 031 A2 shows a heat recovery module with a flap and a slide valve forming a single structural unit. Their actuation movements are positively coupled, achieved by connecting the perpendicularly aligned parts. This structural unit adjoins the heat exchanger bypass device directly without any additional pipes or channels.

[0009] Parallel-connected heat exchangers are also known. US 2007 / 0158049 A1, for example, discloses such a ventilation unit with several heat exchangers arranged side by side, connected in parallel and thus with parallel flow through them. A common bypass channel is arranged next to the heat exchangers.

[0010] DE 10 2011 114 885 A1 describes a heat exchanger arrangement with a gaseous and a liquid fluid. The arrangement has two parallel heat exchangers, which are spatially offset from one another. Two bypass channels allow the supply and discharge of air to the heat exchangers. Each bypass channel has its own separately actuated shut-off valve.

[0011] WO 97 / 06390 A1 discloses an air conditioning unit for installation in a house wall, comprising two heat exchangers with cooling units, the two heat exchangers being connected to each other via a compressor. A swivel element is arranged between the two heat exchangers, which can be pivoted about a pivot axis so that different flow paths can be selected.

[0012] The known devices still require a relatively large amount of space. The use of multiple heat exchangers has the disadvantage of requiring more bypass channels and flaps, which increases the space requirement and manufacturing costs, particularly due to the increased number of motors needed to actuate the flaps. PRESENTATION OF THE INVENTION

[0013] It is therefore an object of the invention to design ventilation devices, in particular a building ventilation system, in the most cost-effective and space-saving way possible.

[0014] This problem is solved by a locking unit with the features of claim 1.

[0015] The inventive closure unit of a ventilation device comprises at least two pivotably arranged flaps for closing each ventilation duct. The two flaps are movable by means of a common shaft, which defines a common pivot axis. The two flaps are thus positively coupled and can be actuated simultaneously by means of a single motor.

[0016] This closure unit is suitable for a wide variety of applications in ventilation systems where two ventilation ducts need to be opened or closed simultaneously. Depending on the position of the flaps, one ventilation duct can be opened while the other is closed. Preferably, however, both ventilation ducts are opened or closed at the same time.

[0017] This closure unit serves, for example, as a double bypass valve with a single motor. However, this closure unit is preferably used in a ventilation device that still has a bypass function without a separate bypass duct. This will be explained in more detail later in the text.

[0018] This closure unit is particularly suitable for use in ventilation systems with heat recovery, especially by means of heat exchangers. Preferably, two or more heat exchangers are present, which are preferably operated in parallel. This will be explained in more detail below.

[0019] Preferably, the pivot axis of the locking unit according to the invention runs centrally through the two flaps.

[0020] The shaft can be operated manually. Preferably, however, it is driven by a motor. Preferably, the motor is arranged longitudinally along the shaft, either above or below the two flaps, or centrally between them. Since only a single motor is required, manufacturing costs can be reduced. The arrangement above or below the flaps reduces the space requirement, especially when a low-profile motor is used. This arrangement also allows optimal accessibility to the motor within the ventilation unit, which significantly simplifies maintenance.

[0021] Preferably, the two flaps are arranged at a 90° angle to each other. If the two ventilation ducts run parallel to each other, with this 90° arrangement of the flaps, the first duct is closed by the first flap, while the second duct is opened by the second flap. If the ventilation ducts are arranged at a 90° angle to each other, the ducts are closed or opened simultaneously with a 90° arrangement of the flaps. This 90° arrangement of the flaps thus allows for use in differently arranged ducts. The same applies if the flaps are arranged parallel to each other, although with the opposite effect in their closing behavior.

[0022] In a preferred embodiment, each of the two flaps forms a closing surface, with the two closing surfaces encompassing the pivot axis of the shaft. This arrangement facilitates cost-effective manufacturing and requires relatively little space. Preferably, the two flaps have a rectangular cross-section. Other shapes, particularly round ones, are also possible. The shape of the flap is preferably adapted to the shape of the channels to be closed.

[0023] The locking unit comprises a first frame, in particular a first housing, for pivotally receiving a first flap, and a second frame, in particular a second housing, for pivotally receiving a second flap. The shaft has an upper section that is pivotably mounted in the first frame, in particular in the first housing, and which is connected at one end to the first flap and at one end to the motor. The shaft also has a lower section that is connected at one end to the first flap and at one end to the second flap. The second flap and / or the second end of the lower section of the shaft is pivotally mounted in the second frame, in particular in the second housing.

[0024] This allows the closure unit to be designed as a relatively simple and robust module that can be integrated as a structural unit into a ventilation device and can also be easily replaced during servicing if necessary.

[0025] This closure unit can be used in a wide variety of ventilation applications. However, it is preferably used in the ventilation device described below.

[0026] A ventilation system for a building has the following features: at least one first and one second heat exchanger, which are operated in parallel, an outside air duct for supplying outside air from the outside into the two heat exchangers, a supply air duct for removing the outside air, now called supply air, from the heat exchangers into an interior space of the building, an exhaust air duct for supplying exhaust air from the interior space of the building into the two heat exchangers and an exhaust air duct for removing the exhaust air, now called exhaust air, from the heat exchangers to the outside.

[0027] Furthermore, a locking unit is provided, which can be selected as desired. releases all channels or allows an air volume flow of outside air through one of the two heat exchangers and simultaneously prevents an air volume flow of exhaust air through this one of the two heat exchangers, and simultaneously allows the air volume flow of exhaust air through the other of the two heat exchangers and prevents the air volume flow of outside air through this other of the two heat exchangers.

[0028] This ventilation device can be designed to be extremely compact and flat. Despite this, the ventilation device still allows for a high volume flow.

[0029] It is intended for use in a building ventilation system, in particular in a central building ventilation system, preferably in a residential or office building.

[0030] A particular advantage is that the ventilation system does not require an additional bypass duct. The two heat exchangers themselves form bypass channels, namely when they are only subjected to one of the two airflows, thus preventing heat exchange with the other airflow.

[0031] The closing unit used in the ventilation device can consist of two individually actuated or jointly actuated, in particular positively coupled, closing elements. Preferably, the closing unit according to the invention described above is used.

[0032] In a preferred embodiment of the ventilation device, the closure unit is designed such that it selectively allows or prevents the air volume flows only partially by only partially opening or closing the channels or sub-channels.

[0033] In preferred embodiments, this arrangement thus makes it possible to route the air volume flows through the two heat exchangers in different proportions. For example, the outside air can be routed 2 / 3 through the first heat exchanger and 1 / 3 through the second heat exchanger, while in this case the exhaust air is routed 1 / 3 through the first heat exchanger and 2 / 3 through the second heat exchanger.

[0034] Preferably, the closure unit of the ventilation device has two closure elements that can be actuated together by means of a common motor. The closure elements can be flaps as in the device. They can also be differently arranged flaps or other types of closure elements.

[0035] In a preferred embodiment of the ventilation device, the ducts are divided into sub-ducts. That is, the outside air duct divides into a first outside air sub-duct and a second outside air sub-duct, wherein the first outside air sub-duct leads to the first heat exchanger and the second outside air sub-duct leads to the second heat exchanger. The supply air duct divides into a first supply air sub-duct and a second supply air sub-duct, wherein the first supply air sub-duct leads from the first heat exchanger and the second supply air sub-duct leads from the second heat exchanger. The exhaust air duct divides into a first exhaust air sub-duct and a second exhaust air sub-duct, wherein the first exhaust air sub-duct leads to the first heat exchanger and the second exhaust air sub-duct leads to the second heat exchanger.And the exhaust air duct is divided into a first exhaust air sub-duct and a second exhaust air sub-duct, with the first exhaust air sub-duct leading from the first heat exchanger and the second exhaust air sub-duct leading from the second heat exchanger.

[0036] Preferably, the partial channels that are opened or closed by means of the closure unit are offset from each other at an angle of 90° within the area of ​​the closure unit. Preferably, the flaps are also arranged at an angle of 90° to each other, with one flap being arranged in each partial channel.

[0037] Depending on the embodiment, all the sub-channels have the same cross-sectional area and preferably even the same cross-sectional shape. In preferred embodiments, a first sub-channel has a smaller cross-section than a corresponding second sub-channel, at least in the area of ​​the closure device. Preferably, the sub-channel located upstream of the heat exchanger is larger, so that the sub-channel downstream of the heat exchanger is smaller. This results in optimized flow characteristics. The flow rate is improved, and a more uniform distribution upstream of the heat exchanger and higher efficiency are achieved. In preferred embodiments, the width of the sub-channels is the same, but their heights differ.

[0038] Preferably, at least one fan is present. Preferably, two fans are present; one for outside air or supply air and one for exhaust air or extraction air.

[0039] Depending on the design, the closing unit simultaneously closes or opens the first supply air duct and the second exhaust air duct, or the closing unit simultaneously closes or opens the first outside air duct and the second exhaust air duct.

[0040] In a method for operating the aforementioned ventilation device If at least the first and second heat exchangers are operated in parallel, the outside air duct supplies the outside air to the two heat exchangers, the supply air duct carries the outside air from the heat exchangers into the interior of the building, the exhaust air duct carries the exhaust air from the interior of the building to the two heat exchangers, and the exhaust air duct carries the exhaust air from the heat exchanger to the outside.

[0041] The locking unit optionally all channels are free or allows an air volume flow of outside air through one of the two heat exchangers and simultaneously prevents an air volume flow of exhaust air through this one of the two heat exchangers, while simultaneously allowing the air volume flow of exhaust air through the other of the two heat exchangers and preventing the air volume flow of outside air through this other of the two heat exchangers.

[0042] This eliminates the need for a separate bypass channel. A simple closure unit, for example with two jointly actuated, preferably positively coupled, flaps, is sufficient to prevent heat exchange between the two airflows.

[0043] Further embodiments are specified in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] A preferred embodiment of the invention is described below with reference to the drawings, which serve only for illustration and are not to be interpreted restrictively. The drawings show: Figure 1 is a schematic representation of a ventilation device; Figure 2 is a perspective view of a closure unit according to the invention; Figure 3 is a first view of the closure unit according to the invention. Figure 2 Figure 4 shows a cross-section through a locking unit according to Figure 3 Figure 5 shows a second view of the locking unit according to Figure 2 Figure 6 shows a cross-section through a locking unit according to Figure 5 Figure 7 shows an exploded view of a first flap assembly of the closure unit according to Figure 2 Figure 8 shows a perspective view of the upper part according to Figure 7 Figure 9 shows a longitudinal section through the upper part according to Figure 7 Figure 10 shows an exploded view of a second flap assembly of the closure unit according to Figure 2 Figure 11 shows a perspective view of the lower part according to Figure 10 Figure 12 shows a longitudinal section through the upper part according to Figure 10 Figure 13 shows a first perspective view of part of the ventilation device, and Figure 14 shows a second perspective view of the part according to Figure 13 . DESCRIPTION OF PREFERRED EXECUTION FORMS

[0045] Figure 1shows a schematic view of a ventilation device for use in a building ventilation system, in particular in a central ventilation system.

[0046] The ventilation device has a closed housing 7, which is as flat as possible. Two heat exchangers 60, 61 are arranged in the housing 7. They are preferably arranged side by side and operated in parallel. The heat exchangers 60, 61 are preferably plate heat exchangers of a known type or otherwise designed, preferably flat, heat exchangers of a known type.

[0047] The housing 7 leads into an outside air duct 40 for supplying outside air to the two heat exchangers 60, 61, a supply air duct 41 for discharging the outside air flowing through the heat exchangers 60, 61 into an interior space of the building, an exhaust air duct 50 for introducing exhaust air from the interior space of the building into the two heat exchangers 60, 61 and an exhaust air duct 51 for discharging the exhaust air flowing through the two heat exchangers 60, 61 to the outside.

[0048] The exhaust air discharged to the outside is called exhaust air, while the outside air drawn into the interior is called supply air. If the two air volume flows of outside air and exhaust air pass through both heat exchangers 60, 61 simultaneously, heat transfer takes place in the known manner, serving for heat recovery in winter and, if necessary, also for cooling in summer. Depending on the season or temperature conditions, heat exchange may be undesirable or only desired to a reduced extent.

[0049] Preferably, at least one, and preferably several, fans 80, 81 are provided. In this example, a first fan 80 is located in the supply air duct 41 and a second fan 81 in the exhaust air duct 51. In other embodiments, the first fan 80 is arranged in the exhaust air duct 41 and the second fan 81 in the supply air duct 51. The fans 80, 81 are preferably operated by means of a control system, preferably according to a program.

[0050] To allow airflow through the two heat exchangers 60 and 61 in parallel operation, the aforementioned channels 40, 41, 50, and 51 are divided into corresponding sub-channels. Thus, there are a first and second outside air sub-channel 400 and 401, a first and second supply air sub-channel 410 and 411, a first and second exhaust air sub-channel 500 and 501, and a first and second exhaust air sub-channel 510 and 511. The first sub-channels 400, 410, 500, and 510 are connected to the first heat exchanger 60, and the second sub-channels 401, 411, 501, and 511 are connected to the second heat exchanger 61.

[0051] According to the invention, a closure unit M is provided that closes two of the partial channels simultaneously. The closure unit M has two closure bodies, each of which closes one of the two partial channels. Preferably, the two closure bodies are flaps. Preferably, the closure bodies are motor-driven and can be actuated via a control system.

[0052] In the simplest embodiment, the two locking bodies are arranged spatially separate from each other and are actuated simultaneously or sequentially by means of the control system.

[0053] In preferred embodiments, however, the two closure bodies are arranged adjacent to each other. The two partial channels to be closed run in the area of ​​the closure unit M, also called closure module or module, and thus adjacent to each other in the area of ​​the closure bodies, so that they can be closed and reopened simultaneously. The two partial channels can run parallel to each other. Preferably, however, they intersect, preferably running one above the other. Figure 1This concerns the first supply air duct 410 and the second exhaust air duct 501. If these two ducts are open, both the outside air volume flow and the exhaust air volume flow pass through both heat exchangers 60, 61. The two heat exchangers 60, 61 are thus subjected to parallel flow from both air volume flows.

[0054] If the two sub-channels 410 and 501 are closed, the outside air volume flow can only pass through the second heat exchanger 61 and the exhaust air volume flow only through the first heat exchanger 60. The flows are thus "bypassed," i.e., routed past each other without the need for a separate bypass channel. No heat transfer takes place between the two air volume flows.

[0055] Alternatively, the sealing unit can also be arranged on the other side of the heat exchangers 60, 61. This is shown in the Figure 1The second outdoor air duct 401 and the first exhaust air duct 510 are represented by a dashed rectangle, as they are labeled with the reference symbol M'. In this variant, the second outdoor air duct 401 and the first exhaust air duct 510 are arranged at a 90° angle to each other and one above the other, so that they can be closed together. Therefore, when the closure unit M' is closed, the outdoor air volume flow is directed exclusively through the first heat exchanger 60, and the exhaust air volume flow is directed exclusively through the second heat exchanger 61. In this case as well, no additional bypass duct is necessary.

[0056] The M closure unit can also close other combinations of first and second partial channels, as is easily recognizable to the expert.

[0057] In the Figures 2 to 12A closing unit M according to the invention is shown, which is preferably usable in the described ventilation device. However, this closing unit M can also be used in other ventilation devices in which two channels arranged one above the other or next to each other are to be closed together and simultaneously.

[0058] If the air ducts are arranged one above the other, they intersect at a 90° angle. If they are arranged side by side, they run parallel. In both cases, a pivot axis of the closure unit runs at a 90° angle to the longitudinal directions of the air ducts. For air ducts arranged one above the other, the pivot axis is vertical; for air ducts arranged side by side, it is horizontal.

[0059] As in the Figures 2 to 6As can be clearly seen, the closure unit according to the invention comprises a first motor unit 1, a first flap assembly 2, and a second flap assembly 3. It is preferably designed as a structural unit in the form of a module that can be installed as a whole in the ventilation device. In other embodiments, the parts are installed individually or as sub-modules.

[0060] The motor unit 1 includes a motor 10, which is designed to be as flat as possible. It is fixed to a frame 20, 21 of the first flap assembly 2. A power cable 11 leads to a control unit for the ventilation device (not shown). The motor unit 1 also includes a rotary table 12, which can be pivoted by means of the motor 10. It can also be operated manually. In this example, a component 13 with a magnet is provided for this purpose.

[0061] The device comprises a multi-section shaft 221, 222, 223, which defines a pivot axis S. An upper shaft section 221 is fixed in the rotary table 12 and is pivotable or rotatable with it. The upper shaft section 221 is connected to a pivotable or rotatable first flap 220 of the first flap assembly 2. In this example, it is integrally formed with the first flap 220. A lower shaft section 222 extends downwards from the first flap 220 along the pivot axis S. This section 222 is also preferably integrally formed with the first flap 220. It is connected to a second flap 320 of the second flap assembly 3. Preferably, it is detachably connected to this.

[0062] As in the Figures 2 to 6As can be clearly seen, the pivot axis S runs within the surfaces of the two flaps 220, 320. Preferably, it runs centrally. The two flaps 220, 320 are arranged at an angle of 90° to each other. They are shaped according to the form of the air ducts they accommodate. In this example, the air ducts have a rectangular cross-section, and the flaps 220, 320 are correspondingly rectangular. They can be the same size and have the same shape. Preferably, however, the duct downstream of the heat exchanger, here the upper duct, is narrower for aerodynamic reasons, so that the first flap 220 is narrower and longer than the second flap 320.

[0063] When the flaps 220, 320 are rotated by means of the motor-driven shaft 221, 222, they pivot together, simultaneously opening or closing their respective partial channels. Intermediate positions are also possible, in which case they open or close their partial channels in the same proportion.

[0064] The two flaps 220, 320 are preferably held in frames 20, 21, 30, 31. This allows unit M to be arranged as an intermediate piece between two sections of the air ducts and connected to it. This facilitates the assembly of the ventilation device, especially if the device itself is also designed as a structural unit, i.e., as a module.

[0065] In the Figures 7 to 9 The first flap unit 2 is shown. It comprises three components: a right frame part 20, a left frame part 21 and a first flap element 22 pivotably arranged therein.

[0066] The two frame parts 20, 21 each have an upper surface 200, 210 and upwardly projecting side walls 201, 211 with inwardly directed retaining lugs 202, 212 for receiving and fixing the motor 10.

[0067] The two frame parts 20, 21 each have a semicircular recess 206, 216 at the top and bottom, which form circular openings in the assembled state of the first flap unit 2 and which serve to accommodate the shaft sections 221, 222 and a second end part 322.

[0068] The two frame parts 20, 21 can preferably be joined and fixed together to form a common frame by means of snap connections. For this purpose, for example, snap-in brackets 203, 213 and associated snap-in hooks 204, 214 are provided. The side surfaces 205, 215 preferably have a triangular cross-section, tapering downwards, i.e., away from the motor 10.

[0069] The first flap element 22 is preferably formed in one piece. It has the plate-shaped first flap 220, to which the upper shaft section 221 is integrally formed at the center of the upper end and the lower shaft section 222 is integrally formed at the center of the lower end. The lower shaft section 222 terminates in a first end part 223 formed as a polygon.

[0070] The first flap 220 and / or the first frame 20, 21 are preferably designed to close as tightly as possible. It is held in the frame 20, 21 so as to be rotatable or pivotable.

[0071] As in the Figures 8 and 9 As can be clearly seen, the upper shaft section 221 penetrates the upper area of ​​the frame 20, 21, and the lower shaft section 223 penetrates the lower area. Both protrude from the frame 20, 21 so that they can be connected to the motor 10 or the turntable 12 and to the second flap unit 3.

[0072] The second flap unit 3 also has a right and a left frame part 30, 31 with a second flap element 32 held between them. The two frame parts 30, 31 each have a rectangular frame 300, 310, the walls of which are relatively narrow. These two frames 300, 310 can preferably be connected and fixed by means of snap connections. Corresponding locking levers 303, 313 and locking hooks 304, 314 are provided. The frames 300, 310 have semicircular recesses 306, 316 arranged centrally at the top, which, when the frames 30, 31 are connected, form a common circular through-opening for receiving a shaft bearing 321. The frames 300, 310 also have semicircular recesses 306, 316 arranged centrally at the bottom, which, when the frames 30, 31 are assembled, form a common circular receiving opening for receiving a second end part 322.

[0073] The second flap element 32 is preferably also formed in one piece. It has the plate-shaped second flap 320, on which the shaft bearing 321 is formed centrally at the upper end in the form of an internal polygon. The shaft bearing 321 serves for a rotationally fixed connection with the first end part 223 of the lower shaft section 222. The second end part 322 is integrally formed centrally at the lower end of the second flap 320, as it serves for the rotatable or pivotable mounting of the second flap 320 in the lower receiving opening 316 of the second frame 30, 31.

[0074] The second flap 320 and / or the second frame 30, 31 are also preferably designed to close as tightly as possible. It is rotatably or pivotably held in the second frame 30, 31.

[0075] The individual elements of the locking unit M are preferably made of metal or plastic. They can be manufactured cost-effectively and assembled easily. Furthermore, installation in the ventilation device is simplified thanks to the two frames.

[0076] The Figures 13 and 14 Figure 1 shows a section of a ventilation device with an integrated closure unit according to the invention. The partial channels are provided with the same reference numerals as in the example described above.

[0077] In the examples described in this text, the supply air duct can also be the exhaust air duct, and the outside air duct can also be the exhaust air duct. The text should be understood accordingly. The same applies to the sub-ducts.

[0078] The inventive closure unit, in which two flaps are actuated together, enables the use of two parallel-operated heat exchangers without an additional bypass channel. REFERENCE MARK LIST

[0079] 1 Motor unit 304 Snap-in hook 10 Motor 306 Exclusion 11 Cable 31 left frame part 12 turntable 310 left frame 13 Component with magnet 313 locking lever 314 Snap-in hook 2 first flap mechanism 316 Exclusion 20 right frame part 32 second flap element 200 upper right surface 320 second flap 201 side wall 321 shaft bearings 202 Retaining nose 322 second end part 203 locking lever 204 Snap-in hook 40 outdoor air duct 205 side surface 400 first outdoor air duct 206 Exclusion 401 second outdoor air duct 21 left frame part 41 Air supply duct 210 upper left surface 410 first supply air duct 211 side wall 411 second supply air duct 212 Retaining nose 50 Exhaust duct 213 locking lever 500 first exhaust air duct 214 Snap-in hook 501 second exhaust air duct 215 side surface 51 Exhaust air duct 216 Exclusion 510 first exhaust air duct 22 first flap element 511 second exhaust air duct 220 first take 60 first heat exchanger 221 upper wave section 61 second heat exchanger 222 lower wave section 7 Housing 223 first end part 80 first fan 81 second fan 3 second flap mechanism 30 right frame part M Locking unit 300 right frame M' Locking unit 303 locking lever S Swivel axis

Claims

1. Closure unit for a ventilation apparatus, in particular a ventilation apparatus with heat recovery, wherein the closure unit has at least two pivotably arranged flaps (220, 320) for closing off in each case one ventilation channel, wherein the two flaps are movable by means of a common shaft (221, 222) of the closure unit, wherein the common shaft (221, 222) defines a pivot axis (S), characterized in that the closure unit has a first frame (20, 21) for pivotably receiving a first flap and has a second frame (30, 31) for pivotably receiving a second flap, in that the shaft has an upper portion (221) which is pivotably mounted in the first frame and which is connected at a first end to the first flap and at a second end to the motor, and in that the shaft has a lower portion (222) which is connected at a first end to the first flap and at a second end to the second flap, wherein the second flap and / or the second end of the lower portion of the shaft is pivotably mounted in the second frame.

2. Closure unit as claimed in claim 1, wherein the pivot axis extends centrally through the two flaps.

3. Closure unit as claimed in either of claims 1 and 2, wherein the closure unit comprises a motor (10) which, in the longitudinal direction of the shaft, is arranged above or below the two flaps or centrally between the two flaps, and wherein the common shaft is driven by the motor (10).

4. Closure unit as claimed in one of claims 1 to 3, wherein the two flaps are arranged at an angle of 90° or of 0° to one another.

5. Closure unit as claimed in one of claims 1 to 4, wherein each of the two flaps forms a closure surface, and wherein the two closure surfaces contain the pivot axis of the shaft.

6. Closure unit as claimed in one of claims 1 to 5, wherein the two flaps have a rectangular cross section.

7. Closure unit as claimed in one of claims 1 to 6, wherein said closure unit is a structural unit in the form of a closure module (M).