EP3421892A2 - Ventilation device for an electrical device and electrical device with such a ventilation device - Google Patents

Abstract

An electric appliance as an electric cooking appliance is a hob, oven or microwave. It has a ventilation device with a fan and an elongated air duct in which the fan is arranged. The fan has an oscillating movable arranged flat flap, are arranged on the actuators for an oscillating movement and which is mounted on a front longitudinal edge. The air guide has a flat cross-section, in particular rectangular, and downstream of the ventilation device to be cooled electrical components of the electrical appliance are arranged. By the oscillating moving flap an air flow is generated with strong turbulence, which has a good cooling effect of the components.

Description

Field of application and state of the art

The invention relates to a ventilation device for an electrical appliance, in particular for an electric cooking appliance, as well as an electrical appliance with a ventilation device.

From the WO 2014/076474 A1 For example, a fluid pump is known with a fluid channel in which pumped fluid can be passed. The fluid pump has essentially a flat flap, which is arranged to oscillate movable in the manner of a fan. For this purpose, it is held with its leading edge on a clamping as a holder. By piezo actuators on the top and on the bottom, which are activated alternately, the flat flap is moved in an oscillating manner and fans out so to speak, fluid to generate a fluid flow or a fluid flow in the fluid guide. The advantage of this device lies in the extensive silence. Although a fluid throughput is not as great as in conventional rotating fans or fluid pumps. For this purpose, a particularly turbulent flow is caused by the special type of production, which in turn is very good for a function of the cooling. In addition, it is just quiet or noiseless and requires relatively little energy.

Task and solution

The invention has for its object to provide a ventilation device mentioned above and provided with a ventilation device electrical appliance, with which problems of the prior art can be solved and it is particularly possible to effectively cool a component of an electrical appliance, quiet and energy-saving cause.

This object is achieved by a ventilation device with the features of claim 1 and by an electrical appliance with the features of claim 7. Advantageous and preferred embodiments of the invention are the subject of further claims and are explained in more detail below. Some of the features are described only for the ventilation device or only for the electrical appliance. However, they should be able to apply independently and independently of each other for both the ventilation device and for the electrical appliance. The wording of the claims is incorporated herein by express reference.

It is envisaged that the ventilation device has a fan and an elongated air duct, in which the fan is arranged. The fan has an oscillating movably arranged flat flap on with a longitudinal region, wherein it is stored or supported along this longitudinal region. This longitudinal region is preferably a front edge of the flap in the direction of the air flow, that is to say that edge of the flap onto which the air flow first strikes. This edge or said longitudinal region extend transversely to a longitudinal direction of the air duct and thus also transversely to an air flow taking place therein. This is in principle from the aforementioned WO 2014/076474 A1 known.

The air guide has a flat cross section, preferably wider than high, which is in particular rectangular. A width of the flat flap may amount to at least 60% of the width of the air duct, because the flap so extends with its own width in this direction. Advantageously, the width of the flat flap is about 70% to 85% or even up to 95%. The more width of the air guide the flap covers, the more efficient the ventilation device works in principle. Thus, on the one hand, the largest possible flap can be installed in the air duct, which generates as much air movement or air flow as possible. On the other hand, the efficiency of the fan or the oscillating flap increases, the closer it also approaches the inner side wall areas of the air duct. The holder of the flat flap on a longitudinal side as a longitudinal region can advantageously be designed in the manner of a clamping. At a minimum, this mount should be relatively stable so that it remains as unchanged as possible while the flap is just oscillating. The bracket itself is popular in the oscillating movement of the flap advantageous quiet or is unmoved.

Downstream of the ventilation device to be cooled electrical components of the electrical appliance are arranged. Since the generated air flow is very likely not to be particularly strong, electrical components of the electrical appliance to be cooled should be arranged behind the ventilation device or downstream thereof. They are better cooled by the strongly swirling air flow. Thus, it can be advantageously provided that the fan is arranged with its flap relatively far forward in the ventilation device or in the air duct, so particularly advantageous where a kind of cooling air duct or the like. starts, especially just behind an air intake.

According to the invention, it is provided for the ventilation device that at the holder of the flat flap at least in addition to a lateral side of this flap, advantageously next to both lateral sides, separate and separately operable balancing means are provided by the flap. With these compensating means damping of vibrations in the ventilation device due to the operation with the oscillating moving flat flap can be achieved. Namely, the flap moves by appropriate deflection in one direction, so the aforementioned clamping is slightly twisted by the applied torque or at least a force exercised on it. This means on the one hand a greater mechanical load on the ventilation device, in particular for the arrangement of the flap on its holder or clamping, on the other hand for the holder itself to the ventilation duct or to the air duct. By means of these compensating means, which are advantageously controlled in exactly the opposite direction or in opposite directions to the oscillation of the flap, as a kind of counter-oscillation or compensation, these disadvantages can be reduced or advantageously even completely avoided. A ventilation device designed in this way can then be quieter again in the ventilation mode than the ventilation device mentioned above WO 2014/076474 A1 , quieter than a rotating fan is it anyway. Advantageously, the compensation means are designed and arranged so that they cause a certain reduction in the area of the flap, at least if they are arranged laterally next to them, but this does not turn out to be significant or disturbing overall. Depending on the design of the compensating means, this omission of some area of the flap can be compensated or at least reduced.

In an advantageous embodiment, a compensation means is elongated, particularly advantageous flat and elongated, for example as a strip. It can protrude from the holder of the flat flap in the same direction as the flap or in the direction of the course of the air duct downstream. The compensating means should be arranged torque-resistant on the holder, as is also the case for the flap. In a further embodiment of the invention, the at least one compensating means is flexible or elastic designed to perform an oscillating movement, which is similar to the oscillating movement of the flat flap, just just in opposite directions. So it is not stored by means of a rotary joint. If, for example, the flap moves upwards, the compensating means should move downwards, at least if it is arranged laterally next to it. As a result, as is easily imaginable, the force input into the holder or into the ventilation device can be reduced by the movement of the flat flap, because an opposing and thus neutralizing force input takes place. This reduces mechanical stress and possible resulting noise. Ideally, the at least one compensating means is moved relative to the flap, advantageously in opposite directions, that the holder is largely, advantageously completely, torque-free.

A movement of the compensating means can be caused as for the flap itself, so advantageous via piezo actuators that are particularly advantageous applied to a surface of a strip-shaped compensating means, so preferably opposite on both sides. The compensating means should be moved at the same frequency as the flap, with a magnitude of the deflection, if adjustable, by a controller just the same should be set that no torque or only the lowest possible torque is entered into the holder, and as little as possible vibrations are generated.

A mass of the at least one compensating means is preferably larger than a mass of the entire flat flap or, overall, all the compensating means of a flap have a greater mass than this. This not only compensates for the mass of the moving flap itself, but above all the force which acts as a torque on the holder by the air resistance of the much larger surface of the flap. Thus, in particular, the mass of the compensating means of a flap can be at least twice, preferably at least ten times greater.

A compensation means is advantageously elongate and strip-shaped, wherein a width of a compensating means may amount to 2% to 20% of the width of the flat flap. From 4% to 8% is considered advantageous, so that the essential width of the air guide for the moving flap is provided for generating the air flow for cooling air. If there is sufficient space in the air duct, in particular also seen in the flow direction in front of the flap, the compensating means could also be arranged in front of or protrude from the holder for the flap in the other direction. Then, while their oscillating motion somewhat affects the air flow within the air duct. If, however, then the flap can occupy almost the full width within the air duct, so that the air flow can be effectively effected so that any negative effects of the compensating means are overcompensated in this regard. A length of the compensating means along the flow direction may be similar to that for the flap itself, thereby also facilitating an opposite swing. However, this can also be varied for a desired optimization of the function and above all for the effect of the compensating means.

In an embodiment of the invention, the compensating means may be formed integrally with the holder. For example, the holder can be a more stable flat material compared to the flap, for example plastic or metal. A mold may be an L-shape with the flap attached to the long leg of the L-shape and the short leg of the L-shape forming the leveling means. Alternatively it can be present as an extension of an L-shape, a U-shape, wherein the flat flap is attached to the intermediate leg of the U-shape and the two outer legs form the compensating means. The flap is then arranged between these two elongate compensating means. Since the flap, as explained above, consists of considerably thinner material than the holder, it can be easily attached to the holder and is then stably stored. The bracket itself may be on side heels or the like. be secured within the air duct, advantageously on the inner side walls to which it tapers.

Advantageously, the fan or the flap, possibly with compensation means previously described, operated at a frequency near or exactly at a resonant frequency. Then the cooling capacity is optimal or as large as possible, advantageously also as efficient as possible in terms of the energy applied to the operation of the fan.

In a preferred embodiment of the invention, the air duct of the ventilation device for the electrical appliance on at least one continuous and largely closed channel wall on a ventilation duct. This can be arranged particularly well to be cooled components of the electrical device. Alternatively, the cooling air can be guided as well as possible in a known manner.

An inventive electrical appliance is an electric cooking appliance or used for cooking food preparation, especially as a hob, oven or microwave. To a oven is also a steamer or a so-called steamer counted. Although the ventilation device provided according to the invention for such an electrical device can have the above-described compensating means on the fan, it does not necessarily have to have it. Depending on the configuration of the electrical appliance and the required cooling capacity or strength of the air flow, an operation of such a fan with an oscillating moving flat flap can also be achieved sufficiently quietly or noiselessly without the need for compensating means. In an advantageous embodiment of an electrical appliance according to the invention, however, the compensating means are present in the above-described form.

Components of the electric cooking appliance, which are to be cooled particularly strong, are usually circuit breakers or power semiconductors as a circuit breaker. Likewise, induction coils or induction heating coils are advantageously provided with cooling, which are to be installed in an induction hob. They can become warm on the one hand by self-heating due to the current flow. On the other hand, they can be heated strongly by a cooking vessel set up for heating, wherein this heat flow through a hob plate passes through down and also can be very harmful.

In one embodiment of the invention, it is possible that components of the electric cooking appliance, which are to be cooled, are at least partially disposed within the air duct or within a ventilation duct of the air duct. At least with a cooling surface usually provided for them on one side, with which they also or the like to heat sink. flat adjacent can be attached, they can then be arranged in the air duct and be cooled directly, for example by passing cooling air. You can either be flush with an inner wall of the air duct or an aforementioned channel wall, so as not to brake an air flow too much. For improved cooling, however, they may just be placed slightly overhanging inwards, so as to be even better cooled and to increase turbulence for a better cooling effect.

Furthermore, it is even possible to arrange these components to be cooled largely or completely within the air duct. The more the component protrudes into the air duct or within the ventilation duct, the better it can be cooled by the prevailing air flow.

In an alternative embodiment of the invention, components of the electric cooking appliance to be cooled are arranged at least partially outside the elongate air duct or outside a ventilation duct of the air duct. Advantageously, they are arranged completely outside the air duct, so that in their area the air duct has an aforementioned largely or completely closed duct wall. The components to be cooled can then bear against an outer surface, in particular an aforementioned specific cooling surface, on an outer side of the air duct or the ventilation duct so as to be cooled. Thus, they are not acted upon directly by the cooling air, but at least indirectly through the duct wall through. Advantageously, such a channel wall formed of metal, on the one hand for a higher temperature resistance and on the other to achieve a higher heat conduction and thus cooling effect. In this case, so to speak, the cooling surface for the component to be cooled can be increased by the region of the duct wall around this component, which in turn in all probability improves the cooling effect. In addition, it may still be possible, in a development of the invention on the inside of a channel wall, on whose opposite outer side a component to be cooled is arranged, a surface enlargement for improved cooling by, for example, conventional cooling fins, cooling fins or the like. provided. Thus, the cooling effect for the components can be improved in a known per se by an even larger surface.

If the electric appliance or electric cooking appliance according to the invention is an electric hob, in particular an induction hob, then it may have a flat housing. This may be similar in size to a known flat housing for induction hobs and be covered up by a hob plate. In the housing, the functional units of Induction hob arranged, in particular control and power electronics, possibly also the induction heating coils.

In a first basic embodiment of the invention, the air guide and / or the fan can be arranged below a housing bottom of the flat housing. Then the air duct or cooling air duct is actually arranged outside of the housing. This is especially recommended if there is not enough space for the ventilation device inside the housing. Then it can either be provided that openings are provided for cooling air supply between the air guide and an inner region of the housing in the housing bottom, that is usually upwards. An outlet of the air guide should then be formed into the housing, in particular to be arranged there to be cooled components. Further components to be cooled can then be arranged directly to the aforementioned openings for cooling air supply, so that they are directly charged with cooling air and thus cooled. These components to be cooled are then arranged above the air duct in the housing.

Mainly advantageous then the components to be cooled according to the manner described above with a cooling surface and thus applied flat against the outside of a channel wall of the air duct so as to be indirectly cooled. Under certain circumstances, such a cooling surface of a component to be cooled also lie flat against the housing bottom, against which in turn the channel wall rests flat when it is made of metal. Despite the multiple component transitions or material transitions, a heat flow or a heat conduction is generally still sufficiently good. This can odgl by thermal paste. to be improved. Furthermore, here again the above-described effect of the enlarged surfaces can be used in the manner of a heat sink, so that so to speak, the air flow cools the channel wall, the channel wall cools the housing bottom and this in turn cools the component.

In a fundamentally different embodiment of the invention, the electrical appliance is also an electric hob, in particular an induction hob, and in turn has a flat housing which is covered upwardly by a hob plate. Here, then, the air guide is disposed within the housing, so that, so to speak, the air duct leads the cooling air into the housing. Then several and especially different components in the hob can be cooled well and efficiently. Furthermore, this can also be done a branch of the cooling air supply in the housing. Although a necessary fan for the air duct can still be arranged in front of the housing or outside the housing, it is advantageously arranged therein. This means that the fan with the flap is at least not arranged below the housing bottom, but particularly advantageous above the housing bottom and thus just inside the case. Thus, it is possible that the air duct or the ventilation duct are arranged within the housing. As a result, although additional space is needed in the housing. But this can be compensated if the air duct or the ventilation duct are not formed too large.

In a further embodiment of the invention, it is possible here that adjacent sub-housing areas are provided to the left and right of the air duct, in particular in a plane parallel to the hob plate left and right side next to the air duct, wherein components are arranged in these sub-housing areas. These may be components that do not require particularly strong cooling, but for which a slight supply of cooling air is sufficient. By means of smaller lateral openings in the ventilation duct, some cooling air can be conducted to these components, in particular it is sufficient here if a low air exchange takes place. Input called power switches are particularly advantageously located within the air duct or adjacent the air duct to be cooled by the fan. This can be done according to one of the aforementioned possibilities, so that, for example, a channel wall forms a type of cooling surface or heat sink, against which such a circuit breaker with its own cooling surface is applied for good heat conduction.

Especially if no components are arranged in the ventilation duct, it can serve as a cooling air supply for a plurality of points. Thus, one or more openings can emerge in at least one adjacent region of the housing of the electrical appliance, in which components are arranged to be forwarded to the cooling air from the ventilation duct. Depending on the size and design of the openings, the amount of diverted cooling air can be influenced.

In a further possible embodiment of the invention, components to be cooled, in particular circuit breakers, which have to be cooled particularly strongly, can be arranged inside the air duct and next to one another. In this way, they can be supplied with cooling air in parallel and at the same time, without them heating each other more and more of the cooling air. Advantageously, they are arranged next to one another, particularly advantageously exclusively next to one another and not one behind the other in the direction of the cooling air or in the direction of the air flow. In this area, a ventilation duct may be slightly widened compared to its other course. Alternatively, it can be very wide overall, but relatively flat, so as not to require so much space and yet be able to work well with one or more flat flaps.

A further advantageous embodiment provides that an elongated ventilation duct has a kind of central or central air inlet, possibly also a plurality of central or central air inlets. From this, in each case a part of the air duct, each with a cooling air duct, extends in at least two different directions, in particular in opposite directions. Within the air duct a plurality of fans are arranged in each case near or directly to the central air inlet, wherein each fan has at least one flat flap. Advantageously, at least one planar flap is provided per fan as a total per outgoing direction or per outgoing cooling air duct. These flat flaps are particularly advantageously arranged inside the respective cooling air duct behind the central air inlet, so that incoming air is well and efficiently moved in two different or opposite directions from the fans. The air duct or the cooling air ducts are also advantageously flat and wide.

Furthermore, it is possible for at least two flat flaps to be arranged laterally next to one another per cooling air channel, so that virtually their grips or holders extend along the same straight line. The laterally juxtaposed flat flaps are particularly advantageous arranged on the same holder as clamping. This reduces the manufacturing and assembly costs. Thus, for example, four flaps may be provided in two cooling air ducts, wherein cooling air flows in at least one central air inlet and is transported by corresponding oscillating movements of the flat flaps along the two cooling air ducts for cooling of components. It is also possible that all the flaps are arranged on a single bracket as clamping, then just on opposite sides.

In a method for controlling such a ventilation device, it is advantageously possible to operate obliquely mutually opposite flaps simultaneously and in the same direction. The respective adjacent flat flaps, which in turn are at an angle to each other, are actuated in opposite directions. Thus, for example, two obliquely opposing flaps simultaneously move upwards, while the other two obliquely opposite flaps simultaneously move downwards, each with the same frequency and deflection. As a result, under certain circumstances it is even possible, without the aforementioned compensation means, to operate a suitably designed fan or a ventilation device largely vibration-free and as quietly as possible or even noiselessly.

An aforementioned central air inlet may be provided in the area or in the middle between the flaps. It can be provided on a broad flat side of the air duct. Advantageous It is possible that on both opposite broad flat sides of the air guide corresponding, preferably the same size, air inlets are provided. This allows more air to be sucked in. If such a ventilation device is installed in an electric hob, as has been explained above, in particular with the ventilation device in the housing, it may be advantageous if provided only at a bottom of the air duct or the housing of the electric cooktop a central air inlet down is. If the ventilation device is arranged at the bottom of the housing, openings may also be provided on the lateral sides of the air guide.

If a ventilation device is installed in another electric cooking appliance than the hob described in detail here, largely similar principles apply. In the said ovens or microwaves are generally no flat housing provided as in a hob, so that the air duct is preferably integrated into the housing. But even there, because of the largest possible muffles in the devices, the air duct may be formed relatively flat, which in turn makes the use of a ventilation device according to the invention with at least one oscillating flap moving particularly advantageous. There may then be provided in addition to a cooling of components and a cooling of the muffle after an operation or a Wrasenabzug. This usually has a not particularly strong air flow and runs even after switching off the device. That's why even here as silent as possible ventilation device would be an advantage.

These and other features will become apparent from the claims and from the description and drawings, wherein the individual features in each case alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into individual sections and intermediate headings does not limit the statements made thereunder in their generality.

Brief description of the drawings

Fig. 1

einen Schnitt durch eine erfindungsgemäße Lüftungsvorrichtung in Prinzipdarstellung,

Fig. 2

eine Schrägdarstellung der Lüftungsvorrichtung aus Fig. 1 mit einem Lüfter mit einer Klappe in einer Luftführung als Lüftungskanal,

Fig. 3

eine isolierte Darstellung eines Lüfters der erfindungsgemäßen Lüftungsvorrichtung mit einer breiten flächigen Klappe und an beiden Seiten angeordneten länglichen Ausgleichsmitteln,

Fig. 4

eine teilweise Darstellung eines Einbaus einer Lüftungsvorrichtung ähnlich Fig. 1 in ein Induktionskochfeld mit zu kühlenden Bauteilen, die außen an der Luftführung bzw. an einem Lüftungskanal anliegen,

Fig. 5

eine Abwandlung der Fig. 4 mit den zu kühlenden Bauteilen, die vollständig innerhalb der Luftführung bzw. des Lüftungskanals liegen,

Fig. 6

ein vollständiges Induktionskochfeld gemäß der Erfindung in Schnittdarstellung mit unten an einem Gehäuse angeordneter Lüftungsvorrichtung,

Fig. 7

einen Schnitt durch ein alternatives erfindungsgemäßes Induktionskochfeld mit einer Lüftungsvorrichtung mit Luftführung bzw. Lüftungskanal, der weitgehend in das Gehäuse integriert ist,

Fig. 8

eine Schrägdarstellung eines Induktionskochfelds in auseinandergezogener Darstellung mit einem dreiteiligen Gehäuse ähnlich Fig. 7, wobei die Luftführung vollständig innerhalb des Gehäuses verläuft und links und rechts davon Teilgehäusebereiche frei sind,

Fig. 9

eine Abwandlung des Induktionskochfelds aus Fig. 8 mit Öffnungen für Kühlluft zwischen der mittleren Luftführung und den beiden Teilgehäusebereichen daneben,

Fig. 10

eine abgewandelte Darstellung ähnlich Fig. 2 einer Lüftungsvorrichtung mit sehr breiter flächiger Klappe, hinter der direkt mehrere zu kühlende Leistungsschalter nebeneinander angeordnet sind,

Fig. 11

eine Draufsicht auf eine weitere erfindungsgemäße Ausgestaltung einer Lüftungsvorrichtung mit zentralem Lufteinlass und mehreren flächigen Klappen, die in zwei entgegengesetzten Richtungen Kühlluft in zwei Lüftungskanäle einbringen,

Fig. 12

eine seitliche Schnittdarstellung durch die Lüftungsvorrichtung aus Fig. 11 und

Fig. 13

eine Abwandlung der Darstellung aus Fig. 8 eines Induktionskochfelds mit einer Lüftungsvorrichtung der Fig. 11 und 12.

Embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings show:

Fig. 1

a section through a ventilation device according to the invention in a schematic representation,

Fig. 2

an oblique view of the ventilation device Fig. 1 with a fan with a flap in an air duct as a ventilation duct,

Fig. 3

an isolated view of a fan of the ventilation device according to the invention with a wide flat flap and arranged on both sides elongate compensating means,

Fig. 4

a partial view of an installation of a ventilation device similar Fig. 1 in an induction hob with components to be cooled, which lie on the outside of the air duct or on a ventilation duct,

Fig. 5

a modification of the Fig. 4 with the components to be cooled, which lie completely within the air duct or the ventilation duct,

Fig. 6

a complete induction hob according to the invention in a sectional view with arranged below at a housing ventilation device,

Fig. 7

a section through an alternative inventive induction hob with a ventilation device with air duct or ventilation duct, which is largely integrated into the housing,

Fig. 8

an oblique view of an induction hob in exploded view with a three-piece housing similar Fig. 7 , wherein the air duct extends completely within the housing and left and right thereof partial housing areas are free,

Fig. 9

a modification of the induction cooktop Fig. 8 with openings for cooling air between the middle air duct and the two sub-housing areas next to it,

Fig. 10

a modified representation similar Fig. 2 a ventilation device with a very wide flat flap behind which directly several circuit breakers to be cooled are arranged side by side,

Fig. 11

a top view of a further inventive embodiment of a ventilation device with central air inlet and a plurality of planar flaps, which introduce cooling air into two ventilation channels in two opposite directions,

Fig. 12

a side sectional view through the ventilation device Fig. 11 and

Fig. 13

a modification of the presentation Fig. 8 an induction hob with a ventilation device of FIGS. 11 and 12 ,

Detailed description of the embodiments

In a ventilation device 11 according to the invention according to Fig. 1 and 2 , which is provided for ventilation or cooling of an electrical appliance according to the aforementioned type, a per se conventional ventilation duct 13 is provided, which also serves as an air duct or this forms a large part, advantageously consisting of thin sheet metal. A height of the ventilation duct can be relatively small and preferably 0.5 cm to 2.5 cm, preferably 1.5 cm to 1.8 cm. He can from the oblique representation of Fig. 2 also in detail be seen, in principle, but it can also be relatively arbitrarily formed as a per se possible ventilation duct. Viewed from the side center in the ventilation duct 13 at about half the height, a fan 15 is provided, as he corresponds to the invention. The fan 15 is in principle according to the aforementioned WO 2014/076474 A1 formed with an elongated retaining strip 16, see also the Fig. 2 , The retaining strip 16 as the above-described holder or clamping should be stable in itself and ensure a stable arrangement of the fan 15 within the ventilation device 11. It is advantageously made of metal or plastic. Attached to it, advantageously clamped in the center, is a flat flap 18. It forms the main part of the fan 15. On its upper side, an upper piezoelectric actuator 20 and on its underside a lower piezoelectric actuator 21 are arranged. Of course, other actuators can be used or an oscillating movement of the flat flap 18 up and down with the illustrated amplitude could also be generated differently, see the above WO 2014/076474 A1 , These should generally be referenced in terms of functional details.

A more accurate control of the piezo actuators 20 and 21 for moving the flap 18 is not shown here, but for the skilled person due to the aforementioned disclosure in the WO 2014/076474 A1 easy to realize. A control of the fan 15 by means of the piezo actuators 20 and 21 may be provided separately for the fan, alternatively be provided in a controller or a microcontroller of the respective electrical device.

The ventilation direction of the ventilation device 11 in Fig. 1 is from left to right, see also the three arrows in the Fig. 2 , Downstream of the fan 15 are in Fig. 1 produced air vortex, while each air flow moves to the right, and these air vortices or this turbulent air flow provide for a particularly good cooling, as explained above. According to the Fig. 2 For example, the fan 15 may occupy a large part of the width inside the ventilation duct 13. So it can be as large as possible or the flat flap 18 can be as large as possible for a strong air flow. Furthermore, a strong air flow is achieved as efficiently as possible by taking the wide width.

As is apparent from the individual representation of the fan 15 of the invention Fig. 3 can be seen, here on the support bar 16 left and right next to the flap 18 strip-shaped balance weights provided, namely a left balance weight 23a and a right balance weight 23b. In the Fig. 3 is like in Fig. 2 the flap 18 is swung up and the counterweights 23a and 23b opposite to it down. The balancing weights 23a and 23b are used to reduce vibrations and thus disturbing noises that could arise during operation of the fan 15 with the oscillating up and down flap 18. By their exactly opposite movement described above can cause the balance weights 23a and 23b that the retaining strip 16 is largely, advantageously completely, free of registered torques, in particular due to the movement of the flap 18. Weight, dimensions and rigidity of the balance weights 23a and 23b are on the Flap 18 matched. The actuation of the balance weights 23 should always be in opposite directions to the flap 18. Depending on the dimensioning and design can be achieved that a compensation or compensation of the movement of the flap 18 by means of the balance weights 23a and 23b only at a working frequency and thus at a ventilation strength, alternatively also at different operating frequencies or ventilation levels. This would then be an adjustable ventilation performance of the fan 15 can be achieved.

At the balance weights 23a and 23b, piezo actuators, not shown here, are advantageously provided similar to the piezo actuators 20 and 21 on the flap 18, advantageously again at the bottom and at the top. However, this is easily realizable for the skilled person and therefore not shown in detail here.

The balance weights 23a and 23b are advantageously made of the same material as the flap 18, for example made of plastic and / or metal. Furthermore, the balance weights 23 should be relatively narrow, if possible, so that the flap 18 can be made as wide as possible. By virtue of their strip shape with a certain width, the compensating weights 23 can indeed also contribute to effecting the air flow and at least to achieve additional turbulences. However, it is considered advantageous to make them relatively narrow.

Furthermore, it can be seen from the illustrations that the balancing weights 23a and 23b are arranged so to speak laterally next to the flap 18 and protrude from the retaining strip 16 in the same direction. But they can also protrude in the other opposite direction, whereby it is possible that the flap 18 can actually occupy the largely full width within the ventilation duct 13. Then their movement can be the same with that of the flap 18 to make the retaining strip 16 largely free of vibration. If the balance weights 23 are relatively narrow, they have no great effect on the air flow, so that it does not bother even if they are arranged upstream of the flap 18 in the flow direction.

The balance weights 23 may be attached to the retaining strip 16 as separately manufactured parts, for example, be clamped similar to the flap 18. You can also be attached to the outside, for example, be glued or screwed. In a Further advantageous embodiment of the invention, the balancing weights 23 may even be as described above integral part of the retaining strip 16, so as a kind of leg protrude from this.

In the Fig. 4 a partial section of an induction hob 26 is shown, in which a ventilation device 11 according to the Fig. 1 to 3 is integrated. In this case, a fan 15 with flat flap 18 of the ventilation device 11 may be formed as in the FIGS. 2 and 3 seen in detail, so with balancing weights. The ventilation device 11 may also include a fan 15 without balancing weights according to the aforementioned WO 2014/076474 A1 exhibit. A certain amount of vibration can also be compensated by a mechanically stable design, so that this does not necessarily have to be annoying.

The ventilation duct 13 of the ventilation device 11 extends in the Fig. 4 from left to right and is largely closed along its canal walls. Cooling air can enter the ventilation duct 13 to an air inlet 14 on the left side of the ventilation duct 13 and is moved by the fan 15 to the right, ie downstream, up to an air outlet 24. Induction heating coils 28 are arranged on an upper side of the ventilation duct 13. They lie flat against the top of the ventilation duct 13 and are so well cooled by cooling air within the ventilation duct 13, but so to speak indirectly. Circuit breaker 30, advantageously as an IGBT, are also applied flat on an underside of the ventilation duct 13 and are thus also cooled, and again indirectly, so to speak. The cooling air can flow out to the right to the air outlet 24 from the ventilation duct 13, advantageously from the induction hob 26 back to the outside. Under some circumstances, before that part of the cooling air flowing through can still be branched off in order to cool further components or regions of the induction hob 26.

An alternative embodiment of an induction hob 126 accordingly Fig. 5 has a ventilation device 111, which is similar in principle, with ventilation duct 113, air inlet 114 and fan 115 near the air inlet. Again, the flow direction from left to right hi to an air outlet 124. However, Induktionsheizspulen 128 and circuit breaker 130 are completely within the ventilation duct 113 is provided. Thus, their inwardly facing side of the cooling air, in particular by the vortex, are well cooled. The opposite side of the components to be cooled can also be cooled by their surface contact with the inside of the upper and lower walls of the ventilation duct 113. This is particularly advantageous if a wall of the ventilation duct 113 consists of metal, as has been explained above, but this is only possible because of the induction heating coils below. This metal surface then acts as a kind of heat sink, since it is cooled at its otherwise inward-free areas of the cooling air. possibly In this way, the cooling effect on this side can be even greater, so that a specially provided cooling surface of one of the components can even be directed outwards for direct, heat-transmitting contact with the inside of a channel wall.

Based on Fig. 5 it is also easy to imagine that the induction heating coils 128 and / or the circuit breaker 130 protrude only partially into the ventilation duct 113, then advantageously with its main cooling surface.

In the Fig. 6 a complete inventive induction hob 226 is shown as an inventive electrical appliance. It has a cooktop panel 227 and a housing 232 disposed thereunder, as is known per se from induction cooktops. On the underside of the hob plate 227 is an induction heating coil 228 representative of many more, in order to heat a set up on the hob plate 227 cooking vessel can. The housing 232 may be made of sheet metal, but it is advantageously made of plastic and relatively flat in the manner of a pan. At the bottom in the housing 232, a large-area component carrier 234 is provided, in particular a printed circuit board. On the left, on the upper side of the component carrier 234, a region is provided with control components 236. On the right side, on the underside of the component carrier 234, a region is provided in which the power switches 230 described above are arranged. They are arranged in such a way that their cooling surface points downwards and either abuts on the upper side of an upper duct wall of the ventilation duct 213 of the ventilation device 211. Here, cooling air is sucked in on the left at the air inlet 214, moved from the fan 215 to the right in the flow direction towards the circuit breakers 230. The rightmost cooling air can then emerge again from an air outlet 224. Through breakthroughs in the bottom of the housing 232, the power switch 230 as good as possible thermally conductive be connected to the ventilation device 211 in one of the aforementioned ways, so either by flat concern or, alternatively conceivable by passing through cutouts in the housing bottom and in the upper channel wall directly into the ventilation duct 213 inside.

The embodiment of the induction hob 226 of Fig. 6 Thus, as an example, shows a possibility of arranging a ventilation device according to the invention with a cooling effect upwards on a lower side of a housing of an electrical appliance or an induction hob. The ventilation device 211 is thus arranged outside of the housing 232. Such a ventilation device 211 may advantageously have a relatively low height, so have a relatively flat ventilation channel 213, advantageously for example only 0.3 cm to 2 cm high.

In the Fig. 7 an alternative embodiment of an induction hob 326 is shown, which also has a hob plate 327 and a housing 332 underneath for the functional units of the induction hob. A ventilation device 311 with ventilation duct 313 and fan 315 thereon is, so to speak, partially integrated in this housing 332. The largest part of the ventilation duct 313 runs inside the housing 332, only at the air inlet 314 at the bottom left the ventilation duct protrudes downwards, so to speak, so that the air inlet 314 can suck in air from below, which the fan 315 then transports to the right up to one Air outlet 324.

Circuit breakers 330 are similar here as in Fig. 4 provided, just just on the other side, and applied to the cooling of the manner described above to the top of the ventilation duct 313. They can either be created only outside, alternatively, they can also partially or largely protrude into the ventilation duct 313 so as to be acted upon directly by the turbulent cooling air for cooling. Other control components or the like. of the induction hob 326 are not shown here, but their arrangement is not a problem for those skilled in the art. The cooling air can escape again on the right of the ventilation channel 313, alternatively it can be partially or completely introduced into the housing 332, for example in order to cool the induction coil 328 as well.

In the Fig. 8 FIG. 12 is a plan view of an induction hob 426 similar to FIG Fig. 7 shown. The representation of a hob plate is omitted here, but four induction heating coils 428 are arranged on a conventional support plate 431. Below is a housing 432 for the induction hob 426 is shown, which is divided into three here, so to speak. In a central region of the housing 432, a ventilation device 411 is provided, as in principle in similar form in the Fig. 1 and 2 is shown. Behind an air intake 414, which is similar to the front or the front Fig. 7 may be formed, is equal to a fan 415 according to the invention. Downstream thereof, power switches 430 to be cooled are arranged in the ventilation duct 413. Thereafter, more components to be cooled can come. At the rear end of the ventilation duct 413, the air may escape again, either laterally outward or downwardly at an air outlet 424. In the left sub-housing area 433a, components or functional parts of the induction hob 426 may be disposed which need not be cooled, as well in the right sub-housing area 433b.

In a modification of an induction hob 526 according to FIG Fig. 9 is similar to in Fig. 8 , a support plate 531 provided with four induction heating coils 528, over which still extends a cooking plate not shown here. A housing 532 is in turn divided into three sub-housing areas, wherein a ventilation device 511 is provided in the middle. It has an air inlet 514 as in FIG Fig. 8 , behind which a fan 515 according to the invention is arranged is. Behind it come as in Fig. 8 two circuit breakers 530 to be cooled within the ventilation duct 513.

Deviating from the Fig. 8 Here, at the rear end of the ventilation duct 513, two side openings 538a and 538b are provided in the lateral sides of the ventilation duct 513, through which cooling air can flow outwardly into the left part housing area 533a and the right part housing area 533b. Thus, this cooling air can cool components or functional parts of the induction hob 526 arranged therein. The deflected cooling air then flows forward in the sub-housing portions 533a and 533b, to air outlets 524a and 524b provided at the front left and right of the air inlet 514. Alternatively, the air outlets 524 may also be downwardly provided, similar to what has been previously described for the air intake, see Fig. 7 ,

In this ventilation concept for an induction hob as an inventive electrical appliance cooling air can be distributed throughout the housing, but with focus or focus on a particular area, namely those with the main circuit to be cooled circuit breakers.

In the Fig. 10 is shown as a further detail, as in a ventilation device 611 a very wide, but relatively shallow ventilation duct 613 is provided. A front-side front air inlet 614 is correspondingly narrow. For the fan 615 is very wide or provided with a very wide and thus large-scale flap 618. It could also be shared. Circuit breakers 630 to be cooled are provided laterally next to each other just behind the fan 615 downstream, namely eight circuit breakers 630 side by side. So they can be very well supplied with cooling air. Downstream downstream of the circuit breakers 630, further components or functional parts of an induction hob or of another electrical appliance can come, which must be cooled a little less.

In the FIGS. 11 and 12 is shown in plan view and in side view another ventilation device 711 with a ventilation duct 713, which is designed as a left partial ventilation channel 713a and as a right partial ventilation channel 713b. A central or central air inlet is also split into a partial air inlet 714a at the top and a partial air inlet 714b at the bottom. In this area, an inventive, above-described fan 715 is arranged with a central retaining strip 716, projecting in opposite directions in each case two flaps 718a and 718a 'and 718b and 718b'. They are supported in the manner described above and provided with a corresponding control as actuators, which are not shown here. They take up the extensive width of the ventilation duct 713a and 713b. In the lateral representation of the Fig. 12 It can be seen that they are also centrally located in height.

In the oblique view of Fig. 13 is similar for another induction hob 726 Fig. 8 illustrated how under a support plate 731 with four induction heating coils 728, a corresponding housing 732 is provided with partial housing areas. Between a left part housing portion 733a and a right part housing portion 733b, the ventilation device 711 according to the invention is arranged in a slight modification of the FIGS. 11 and 12 , here only with a central air inlet 714 in the bottom, so below. Otherwise it would not make sense here. There, cooling air is sucked in by the fan 715 and then moved in opposite directions in the two partial ventilation channels 713a to the front and 713b to the rear. Thus, the power switches 730a and 730b disposed respectively downstream of the fan 715 can be cooled. Air outlets 724a and 724b are arranged here on the front side, but may also be provided again downwards. Of course, further components to be cooled can also be arranged on or in the partial ventilation ducts 713a and 713b.

Advantageously, on the one hand, the flaps 718a and 718b 'are moved simultaneously and in the same direction and, on the other hand, the flaps 718a' and 718b. Thus, when the flaps 718a and 718b 'are moved up, the other two flaps 718a' and 718b are simultaneously and similarly downwardly moved. This takes place in each case with the same frequency and the same deflection, so that overall the retaining strip 716 can actually remain largely vibration-free. As a result, a noise can be reduced.

Claims (15)

Ventilation device for an electrical appliance, wherein the ventilation device comprises: - a fan, an elongate air duct in which the fan is arranged, - An oscillating movable arranged flat flap on the fan, Actuators on the flat flap to their oscillating movement, wherein the air guide has a flat cross-section,
wherein the width of the flat flap is at least 60% of the width of the air duct along which it extends,
wherein the planar flap is held on a longitudinal side as a holder which extends transversely to a longitudinal direction of the air duct and transversely to an air flow therein,
wherein downstream of the ventilation device to be cooled electrical components of the electrical appliance are arranged,
characterized in that
on the holder of the flat flap at least on a lateral side of the flat flap outside separate compensation means are arranged for damping vibrations due to the operation of the ventilation device with the oscillating moving flat flap. Ventilation device according to claim 1, characterized in that on both lateral sides of the flat flap externally separate compensation means are arranged, preferably mirror-symmetrically equal and / or arranged compensating means. Ventilation device according to claim 2, characterized in that at least one compensating means is elongate and protrudes from the holder of the flat flap in the direction of the course of the air duct downstream behind the fan, wherein the compensating means is fixed torque on the holder, wherein preferably the at least one compensating means flexible or elastic is contrary to the oscillating movement of the flat flap for an oscillating movement. Ventilation device according to claim 2 or 3, characterized in that a mass of the at least one compensating means is greater than a mass of the entire flat flap, in particular at least twice greater or preferably at least ten times greater. Ventilation device according to one of the preceding claims, characterized in that a compensating means is elongated and strip-shaped, wherein preferably a width of the compensating means is 2% to 20% of the width of the flat flap, in particular 4% to 8%. Ventilation device according to one of the preceding claims, characterized in that active compensating actuators are arranged on the compensating means for their oscillating movement, in particular arranged in the same way as the actuators on the flat flap, wherein preferably these active compensating actuators are formed corresponding to the actuators on the planar Flap. Electric appliance with a ventilation device according to the preamble of claim 1, characterized in that the electrical appliance is an electric cooking appliance as a hob, oven or microwave. Electric appliance according to claim 7, characterized in that to be cooled components of the electric cooking appliance are at least partially disposed within the air duct or within a ventilation duct of the air duct, preferably arranged completely within thereof. Electrical appliance according to claim 7, characterized in that components of the electric cooking appliance to be cooled are arranged at least partially outside the air duct or outside a ventilation duct of the elongate air duct, the components to be cooled having an outer surface, in particular as a cooling surface, on an outer side of the air duct or on an outer side of the ventilation duct abut for cooling. Electrical appliance according to one of claims 7 to 9, characterized in that it is an electric hob, with a flat housing, which is covered by a cooking plate top, wherein the air duct and / or the fan are arranged below a housing bottom, in particular openings for Cooling air duct between the air duct and an inner region of the housing are provided in the housing bottom, wherein preferably an outlet of the air duct is formed in the housing, in particular to be cooled components of the electric cooktop are arranged above the air duct in the housing. Electric appliance according to one of claims 7 to 9, characterized in that it is an electric hob, in particular an induction hob, with a flat housing, which is covered by a cooking plate top, wherein the air duct is disposed within the housing, in particular also the fan itself between a housing bottom and the covering hob plate, wherein preferably the fan is arranged in the front region of the air duct, in particular close to an opening in the housing for the inflow of cooling air. Electrical appliance according to claim 11, characterized in that in a plane parallel to the hob plate left and right next to the air duct adjacent partial housing areas are provided with components arranged therein, preferably within the air duct or the air duct adjacent circuit breaker are arranged for cooling by the fan, said In particular, openings are provided for forwarding the cooling air from the ventilation duct into the at least one adjoining partial housing area, in particular by the air guide in at least one adjoining partial housing area with components arranged therein. Electric appliance according to one of claims 7 to 12, characterized in that components to be cooled, in particular circuit breakers, are arranged inside the air duct and next to one another, preferably exclusively adjacent to one another and not behind one another in the direction of the cooling air. Electric appliance according to one of claims 7 to 13, characterized in that an air duct extends from a central air inlet in at least two different directions, in particular opposing directions, each having a cooling air duct, wherein within the air duct near or directly to the central air inlet more fans are each arranged with at least one flat flap per outgoing direction or per outgoing cooling air duct, wherein preferably the flat flaps are disposed within the cooling air duct behind the central air inlet. Electric appliance according to claim 14, characterized in that the air duct or the cooling air ducts are flat and wide and at least two flat flaps are arranged side by side per cooling air duct, in particular juxtaposed flat flaps are arranged on the same holder as clamping, preferably obliquely opposite flaps at the same time and in the same direction are operable and in opposite directions to each directly adjacent flat flap.

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